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bcea3f96 | 1 | // SPDX-License-Identifier: GPL-2.0 |
16444a8a ACM |
2 | /* |
3 | * Infrastructure for profiling code inserted by 'gcc -pg'. | |
4 | * | |
5 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> | |
6 | * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com> | |
7 | * | |
8 | * Originally ported from the -rt patch by: | |
9 | * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com> | |
10 | * | |
11 | * Based on code in the latency_tracer, that is: | |
12 | * | |
13 | * Copyright (C) 2004-2006 Ingo Molnar | |
6d49e352 | 14 | * Copyright (C) 2004 Nadia Yvette Chambers |
16444a8a ACM |
15 | */ |
16 | ||
3d083395 SR |
17 | #include <linux/stop_machine.h> |
18 | #include <linux/clocksource.h> | |
29930025 | 19 | #include <linux/sched/task.h> |
3d083395 | 20 | #include <linux/kallsyms.h> |
17911ff3 | 21 | #include <linux/security.h> |
5072c59f | 22 | #include <linux/seq_file.h> |
8434dc93 | 23 | #include <linux/tracefs.h> |
3d083395 | 24 | #include <linux/hardirq.h> |
2d8b820b | 25 | #include <linux/kthread.h> |
5072c59f | 26 | #include <linux/uaccess.h> |
5855fead | 27 | #include <linux/bsearch.h> |
56d82e00 | 28 | #include <linux/module.h> |
2d8b820b | 29 | #include <linux/ftrace.h> |
b0fc494f | 30 | #include <linux/sysctl.h> |
5a0e3ad6 | 31 | #include <linux/slab.h> |
5072c59f | 32 | #include <linux/ctype.h> |
68950619 | 33 | #include <linux/sort.h> |
3d083395 | 34 | #include <linux/list.h> |
59df055f | 35 | #include <linux/hash.h> |
3f379b03 | 36 | #include <linux/rcupdate.h> |
fabe38ab | 37 | #include <linux/kprobes.h> |
3d083395 | 38 | |
ad8d75ff | 39 | #include <trace/events/sched.h> |
8aef2d28 | 40 | |
b80f0f6c | 41 | #include <asm/sections.h> |
2af15d6a | 42 | #include <asm/setup.h> |
395a59d0 | 43 | |
3306fc4a | 44 | #include "ftrace_internal.h" |
0706f1c4 | 45 | #include "trace_output.h" |
bac429f0 | 46 | #include "trace_stat.h" |
16444a8a | 47 | |
6912896e | 48 | #define FTRACE_WARN_ON(cond) \ |
0778d9ad SR |
49 | ({ \ |
50 | int ___r = cond; \ | |
51 | if (WARN_ON(___r)) \ | |
6912896e | 52 | ftrace_kill(); \ |
0778d9ad SR |
53 | ___r; \ |
54 | }) | |
6912896e SR |
55 | |
56 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
0778d9ad SR |
57 | ({ \ |
58 | int ___r = cond; \ | |
59 | if (WARN_ON_ONCE(___r)) \ | |
6912896e | 60 | ftrace_kill(); \ |
0778d9ad SR |
61 | ___r; \ |
62 | }) | |
6912896e | 63 | |
8fc0c701 | 64 | /* hash bits for specific function selection */ |
33dc9b12 SR |
65 | #define FTRACE_HASH_DEFAULT_BITS 10 |
66 | #define FTRACE_HASH_MAX_BITS 12 | |
8fc0c701 | 67 | |
f04f24fb | 68 | #ifdef CONFIG_DYNAMIC_FTRACE |
33b7f99c SRRH |
69 | #define INIT_OPS_HASH(opsname) \ |
70 | .func_hash = &opsname.local_hash, \ | |
71 | .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock), | |
f04f24fb | 72 | #else |
33b7f99c | 73 | #define INIT_OPS_HASH(opsname) |
f04f24fb MH |
74 | #endif |
75 | ||
a0572f68 SRV |
76 | enum { |
77 | FTRACE_MODIFY_ENABLE_FL = (1 << 0), | |
78 | FTRACE_MODIFY_MAY_SLEEP_FL = (1 << 1), | |
79 | }; | |
80 | ||
3306fc4a | 81 | struct ftrace_ops ftrace_list_end __read_mostly = { |
2f5f6ad9 | 82 | .func = ftrace_stub, |
a25d036d | 83 | .flags = FTRACE_OPS_FL_STUB, |
33b7f99c | 84 | INIT_OPS_HASH(ftrace_list_end) |
2f5f6ad9 SR |
85 | }; |
86 | ||
4eebcc81 SR |
87 | /* ftrace_enabled is a method to turn ftrace on or off */ |
88 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 89 | static int last_ftrace_enabled; |
b0fc494f | 90 | |
2f5f6ad9 SR |
91 | /* Current function tracing op */ |
92 | struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end; | |
405e1d83 SRRH |
93 | /* What to set function_trace_op to */ |
94 | static struct ftrace_ops *set_function_trace_op; | |
60a7ecf4 | 95 | |
345ddcc8 | 96 | static bool ftrace_pids_enabled(struct ftrace_ops *ops) |
e3eea140 | 97 | { |
345ddcc8 SRRH |
98 | struct trace_array *tr; |
99 | ||
100 | if (!(ops->flags & FTRACE_OPS_FL_PID) || !ops->private) | |
101 | return false; | |
102 | ||
103 | tr = ops->private; | |
104 | ||
b3b1e6ed | 105 | return tr->function_pids != NULL || tr->function_no_pids != NULL; |
e3eea140 SRRH |
106 | } |
107 | ||
108 | static void ftrace_update_trampoline(struct ftrace_ops *ops); | |
109 | ||
4eebcc81 SR |
110 | /* |
111 | * ftrace_disabled is set when an anomaly is discovered. | |
112 | * ftrace_disabled is much stronger than ftrace_enabled. | |
113 | */ | |
114 | static int ftrace_disabled __read_mostly; | |
115 | ||
3306fc4a | 116 | DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 117 | |
3306fc4a | 118 | struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = &ftrace_list_end; |
16444a8a | 119 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
3306fc4a | 120 | struct ftrace_ops global_ops; |
16444a8a | 121 | |
2f5f6ad9 SR |
122 | #if ARCH_SUPPORTS_FTRACE_OPS |
123 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
d19ad077 | 124 | struct ftrace_ops *op, struct ftrace_regs *fregs); |
2f5f6ad9 SR |
125 | #else |
126 | /* See comment below, where ftrace_ops_list_func is defined */ | |
127 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip); | |
128 | #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops) | |
129 | #endif | |
b848914c | 130 | |
f04f24fb MH |
131 | static inline void ftrace_ops_init(struct ftrace_ops *ops) |
132 | { | |
133 | #ifdef CONFIG_DYNAMIC_FTRACE | |
134 | if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) { | |
33b7f99c SRRH |
135 | mutex_init(&ops->local_hash.regex_lock); |
136 | ops->func_hash = &ops->local_hash; | |
f04f24fb MH |
137 | ops->flags |= FTRACE_OPS_FL_INITIALIZED; |
138 | } | |
139 | #endif | |
140 | } | |
141 | ||
2f5f6ad9 | 142 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, |
d19ad077 | 143 | struct ftrace_ops *op, struct ftrace_regs *fregs) |
df4fc315 | 144 | { |
345ddcc8 | 145 | struct trace_array *tr = op->private; |
717e3f5e | 146 | int pid; |
345ddcc8 | 147 | |
717e3f5e SRV |
148 | if (tr) { |
149 | pid = this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid); | |
150 | if (pid == FTRACE_PID_IGNORE) | |
151 | return; | |
152 | if (pid != FTRACE_PID_TRACE && | |
153 | pid != current->pid) | |
154 | return; | |
155 | } | |
df4fc315 | 156 | |
d19ad077 | 157 | op->saved_func(ip, parent_ip, op, fregs); |
df4fc315 SR |
158 | } |
159 | ||
405e1d83 SRRH |
160 | static void ftrace_sync_ipi(void *data) |
161 | { | |
162 | /* Probably not needed, but do it anyway */ | |
163 | smp_rmb(); | |
164 | } | |
165 | ||
00ccbf2f SRRH |
166 | static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops) |
167 | { | |
168 | /* | |
ba27f2bc | 169 | * If this is a dynamic, RCU, or per CPU ops, or we force list func, |
00ccbf2f SRRH |
170 | * then it needs to call the list anyway. |
171 | */ | |
b3a88803 PZ |
172 | if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_RCU) || |
173 | FTRACE_FORCE_LIST_FUNC) | |
00ccbf2f SRRH |
174 | return ftrace_ops_list_func; |
175 | ||
176 | return ftrace_ops_get_func(ops); | |
177 | } | |
178 | ||
2b499381 SR |
179 | static void update_ftrace_function(void) |
180 | { | |
181 | ftrace_func_t func; | |
182 | ||
f7aad4e1 SRRH |
183 | /* |
184 | * Prepare the ftrace_ops that the arch callback will use. | |
185 | * If there's only one ftrace_ops registered, the ftrace_ops_list | |
186 | * will point to the ops we want. | |
187 | */ | |
f86f4180 CZ |
188 | set_function_trace_op = rcu_dereference_protected(ftrace_ops_list, |
189 | lockdep_is_held(&ftrace_lock)); | |
f7aad4e1 SRRH |
190 | |
191 | /* If there's no ftrace_ops registered, just call the stub function */ | |
f86f4180 | 192 | if (set_function_trace_op == &ftrace_list_end) { |
f7aad4e1 SRRH |
193 | func = ftrace_stub; |
194 | ||
cdbe61bf SR |
195 | /* |
196 | * If we are at the end of the list and this ops is | |
4740974a SR |
197 | * recursion safe and not dynamic and the arch supports passing ops, |
198 | * then have the mcount trampoline call the function directly. | |
cdbe61bf | 199 | */ |
f86f4180 CZ |
200 | } else if (rcu_dereference_protected(ftrace_ops_list->next, |
201 | lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { | |
00ccbf2f | 202 | func = ftrace_ops_get_list_func(ftrace_ops_list); |
f7aad4e1 | 203 | |
2f5f6ad9 SR |
204 | } else { |
205 | /* Just use the default ftrace_ops */ | |
405e1d83 | 206 | set_function_trace_op = &ftrace_list_end; |
b848914c | 207 | func = ftrace_ops_list_func; |
2f5f6ad9 | 208 | } |
2b499381 | 209 | |
5f8bf2d2 SRRH |
210 | update_function_graph_func(); |
211 | ||
405e1d83 SRRH |
212 | /* If there's no change, then do nothing more here */ |
213 | if (ftrace_trace_function == func) | |
214 | return; | |
215 | ||
216 | /* | |
217 | * If we are using the list function, it doesn't care | |
218 | * about the function_trace_ops. | |
219 | */ | |
220 | if (func == ftrace_ops_list_func) { | |
221 | ftrace_trace_function = func; | |
222 | /* | |
223 | * Don't even bother setting function_trace_ops, | |
224 | * it would be racy to do so anyway. | |
225 | */ | |
226 | return; | |
227 | } | |
228 | ||
229 | #ifndef CONFIG_DYNAMIC_FTRACE | |
230 | /* | |
231 | * For static tracing, we need to be a bit more careful. | |
232 | * The function change takes affect immediately. Thus, | |
fdda88d3 | 233 | * we need to coordinate the setting of the function_trace_ops |
405e1d83 SRRH |
234 | * with the setting of the ftrace_trace_function. |
235 | * | |
236 | * Set the function to the list ops, which will call the | |
237 | * function we want, albeit indirectly, but it handles the | |
238 | * ftrace_ops and doesn't depend on function_trace_op. | |
239 | */ | |
240 | ftrace_trace_function = ftrace_ops_list_func; | |
241 | /* | |
242 | * Make sure all CPUs see this. Yes this is slow, but static | |
243 | * tracing is slow and nasty to have enabled. | |
244 | */ | |
e5a971d7 | 245 | synchronize_rcu_tasks_rude(); |
405e1d83 SRRH |
246 | /* Now all cpus are using the list ops. */ |
247 | function_trace_op = set_function_trace_op; | |
248 | /* Make sure the function_trace_op is visible on all CPUs */ | |
249 | smp_wmb(); | |
250 | /* Nasty way to force a rmb on all cpus */ | |
251 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
252 | /* OK, we are all set to update the ftrace_trace_function now! */ | |
253 | #endif /* !CONFIG_DYNAMIC_FTRACE */ | |
254 | ||
491d0dcf | 255 | ftrace_trace_function = func; |
491d0dcf SR |
256 | } |
257 | ||
f86f4180 CZ |
258 | static void add_ftrace_ops(struct ftrace_ops __rcu **list, |
259 | struct ftrace_ops *ops) | |
3d083395 | 260 | { |
f86f4180 CZ |
261 | rcu_assign_pointer(ops->next, *list); |
262 | ||
16444a8a | 263 | /* |
b848914c | 264 | * We are entering ops into the list but another |
16444a8a ACM |
265 | * CPU might be walking that list. We need to make sure |
266 | * the ops->next pointer is valid before another CPU sees | |
b848914c | 267 | * the ops pointer included into the list. |
16444a8a | 268 | */ |
2b499381 | 269 | rcu_assign_pointer(*list, ops); |
16444a8a ACM |
270 | } |
271 | ||
f86f4180 CZ |
272 | static int remove_ftrace_ops(struct ftrace_ops __rcu **list, |
273 | struct ftrace_ops *ops) | |
16444a8a | 274 | { |
16444a8a | 275 | struct ftrace_ops **p; |
16444a8a ACM |
276 | |
277 | /* | |
3d083395 SR |
278 | * If we are removing the last function, then simply point |
279 | * to the ftrace_stub. | |
16444a8a | 280 | */ |
f86f4180 CZ |
281 | if (rcu_dereference_protected(*list, |
282 | lockdep_is_held(&ftrace_lock)) == ops && | |
283 | rcu_dereference_protected(ops->next, | |
284 | lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { | |
2b499381 | 285 | *list = &ftrace_list_end; |
e6ea44e9 | 286 | return 0; |
16444a8a ACM |
287 | } |
288 | ||
2b499381 | 289 | for (p = list; *p != &ftrace_list_end; p = &(*p)->next) |
16444a8a ACM |
290 | if (*p == ops) |
291 | break; | |
292 | ||
e6ea44e9 SR |
293 | if (*p != ops) |
294 | return -1; | |
16444a8a ACM |
295 | |
296 | *p = (*p)->next; | |
2b499381 SR |
297 | return 0; |
298 | } | |
16444a8a | 299 | |
f3bea491 SRRH |
300 | static void ftrace_update_trampoline(struct ftrace_ops *ops); |
301 | ||
3306fc4a | 302 | int __register_ftrace_function(struct ftrace_ops *ops) |
2b499381 | 303 | { |
591dffda SRRH |
304 | if (ops->flags & FTRACE_OPS_FL_DELETED) |
305 | return -EINVAL; | |
306 | ||
b848914c SR |
307 | if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) |
308 | return -EBUSY; | |
309 | ||
06aeaaea | 310 | #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
08f6fba5 SR |
311 | /* |
312 | * If the ftrace_ops specifies SAVE_REGS, then it only can be used | |
313 | * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set. | |
314 | * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant. | |
315 | */ | |
316 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS && | |
317 | !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)) | |
318 | return -EINVAL; | |
319 | ||
320 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED) | |
321 | ops->flags |= FTRACE_OPS_FL_SAVE_REGS; | |
322 | #endif | |
7162431d MB |
323 | if (!ftrace_enabled && (ops->flags & FTRACE_OPS_FL_PERMANENT)) |
324 | return -EBUSY; | |
08f6fba5 | 325 | |
cdbe61bf SR |
326 | if (!core_kernel_data((unsigned long)ops)) |
327 | ops->flags |= FTRACE_OPS_FL_DYNAMIC; | |
328 | ||
ba27f2bc | 329 | add_ftrace_ops(&ftrace_ops_list, ops); |
b848914c | 330 | |
e3eea140 SRRH |
331 | /* Always save the function, and reset at unregistering */ |
332 | ops->saved_func = ops->func; | |
333 | ||
345ddcc8 | 334 | if (ftrace_pids_enabled(ops)) |
e3eea140 SRRH |
335 | ops->func = ftrace_pid_func; |
336 | ||
f3bea491 SRRH |
337 | ftrace_update_trampoline(ops); |
338 | ||
2b499381 SR |
339 | if (ftrace_enabled) |
340 | update_ftrace_function(); | |
341 | ||
342 | return 0; | |
343 | } | |
344 | ||
3306fc4a | 345 | int __unregister_ftrace_function(struct ftrace_ops *ops) |
2b499381 SR |
346 | { |
347 | int ret; | |
348 | ||
b848914c SR |
349 | if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) |
350 | return -EBUSY; | |
351 | ||
ba27f2bc | 352 | ret = remove_ftrace_ops(&ftrace_ops_list, ops); |
b848914c | 353 | |
2b499381 SR |
354 | if (ret < 0) |
355 | return ret; | |
b848914c | 356 | |
491d0dcf SR |
357 | if (ftrace_enabled) |
358 | update_ftrace_function(); | |
16444a8a | 359 | |
e3eea140 SRRH |
360 | ops->func = ops->saved_func; |
361 | ||
e6ea44e9 | 362 | return 0; |
3d083395 SR |
363 | } |
364 | ||
df4fc315 SR |
365 | static void ftrace_update_pid_func(void) |
366 | { | |
e3eea140 SRRH |
367 | struct ftrace_ops *op; |
368 | ||
491d0dcf | 369 | /* Only do something if we are tracing something */ |
df4fc315 | 370 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 371 | return; |
df4fc315 | 372 | |
e3eea140 SRRH |
373 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
374 | if (op->flags & FTRACE_OPS_FL_PID) { | |
345ddcc8 SRRH |
375 | op->func = ftrace_pids_enabled(op) ? |
376 | ftrace_pid_func : op->saved_func; | |
e3eea140 SRRH |
377 | ftrace_update_trampoline(op); |
378 | } | |
379 | } while_for_each_ftrace_op(op); | |
380 | ||
491d0dcf | 381 | update_ftrace_function(); |
df4fc315 SR |
382 | } |
383 | ||
493762fc SR |
384 | #ifdef CONFIG_FUNCTION_PROFILER |
385 | struct ftrace_profile { | |
386 | struct hlist_node node; | |
387 | unsigned long ip; | |
388 | unsigned long counter; | |
0706f1c4 SR |
389 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
390 | unsigned long long time; | |
e330b3bc | 391 | unsigned long long time_squared; |
0706f1c4 | 392 | #endif |
8fc0c701 SR |
393 | }; |
394 | ||
493762fc SR |
395 | struct ftrace_profile_page { |
396 | struct ftrace_profile_page *next; | |
397 | unsigned long index; | |
398 | struct ftrace_profile records[]; | |
d61f82d0 SR |
399 | }; |
400 | ||
cafb168a SR |
401 | struct ftrace_profile_stat { |
402 | atomic_t disabled; | |
403 | struct hlist_head *hash; | |
404 | struct ftrace_profile_page *pages; | |
405 | struct ftrace_profile_page *start; | |
406 | struct tracer_stat stat; | |
407 | }; | |
408 | ||
493762fc SR |
409 | #define PROFILE_RECORDS_SIZE \ |
410 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 411 | |
493762fc SR |
412 | #define PROFILES_PER_PAGE \ |
413 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 414 | |
fb9fb015 SR |
415 | static int ftrace_profile_enabled __read_mostly; |
416 | ||
417 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
418 | static DEFINE_MUTEX(ftrace_profile_lock); |
419 | ||
cafb168a | 420 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc | 421 | |
20079ebe NK |
422 | #define FTRACE_PROFILE_HASH_BITS 10 |
423 | #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS) | |
493762fc | 424 | |
bac429f0 SR |
425 | static void * |
426 | function_stat_next(void *v, int idx) | |
427 | { | |
493762fc SR |
428 | struct ftrace_profile *rec = v; |
429 | struct ftrace_profile_page *pg; | |
bac429f0 | 430 | |
493762fc | 431 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
432 | |
433 | again: | |
0296e425 LZ |
434 | if (idx != 0) |
435 | rec++; | |
436 | ||
bac429f0 SR |
437 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
438 | pg = pg->next; | |
439 | if (!pg) | |
440 | return NULL; | |
441 | rec = &pg->records[0]; | |
493762fc SR |
442 | if (!rec->counter) |
443 | goto again; | |
bac429f0 SR |
444 | } |
445 | ||
bac429f0 SR |
446 | return rec; |
447 | } | |
448 | ||
449 | static void *function_stat_start(struct tracer_stat *trace) | |
450 | { | |
cafb168a SR |
451 | struct ftrace_profile_stat *stat = |
452 | container_of(trace, struct ftrace_profile_stat, stat); | |
453 | ||
454 | if (!stat || !stat->start) | |
455 | return NULL; | |
456 | ||
457 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
458 | } |
459 | ||
0706f1c4 SR |
460 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
461 | /* function graph compares on total time */ | |
80042c8f | 462 | static int function_stat_cmp(const void *p1, const void *p2) |
0706f1c4 | 463 | { |
80042c8f AS |
464 | const struct ftrace_profile *a = p1; |
465 | const struct ftrace_profile *b = p2; | |
0706f1c4 SR |
466 | |
467 | if (a->time < b->time) | |
468 | return -1; | |
469 | if (a->time > b->time) | |
470 | return 1; | |
471 | else | |
472 | return 0; | |
473 | } | |
474 | #else | |
475 | /* not function graph compares against hits */ | |
80042c8f | 476 | static int function_stat_cmp(const void *p1, const void *p2) |
bac429f0 | 477 | { |
80042c8f AS |
478 | const struct ftrace_profile *a = p1; |
479 | const struct ftrace_profile *b = p2; | |
bac429f0 SR |
480 | |
481 | if (a->counter < b->counter) | |
482 | return -1; | |
483 | if (a->counter > b->counter) | |
484 | return 1; | |
485 | else | |
486 | return 0; | |
487 | } | |
0706f1c4 | 488 | #endif |
bac429f0 SR |
489 | |
490 | static int function_stat_headers(struct seq_file *m) | |
491 | { | |
0706f1c4 | 492 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
fa6f0cc7 RV |
493 | seq_puts(m, " Function " |
494 | "Hit Time Avg s^2\n" | |
495 | " -------- " | |
496 | "--- ---- --- ---\n"); | |
0706f1c4 | 497 | #else |
fa6f0cc7 RV |
498 | seq_puts(m, " Function Hit\n" |
499 | " -------- ---\n"); | |
0706f1c4 | 500 | #endif |
bac429f0 SR |
501 | return 0; |
502 | } | |
503 | ||
504 | static int function_stat_show(struct seq_file *m, void *v) | |
505 | { | |
493762fc | 506 | struct ftrace_profile *rec = v; |
bac429f0 | 507 | char str[KSYM_SYMBOL_LEN]; |
3aaba20f | 508 | int ret = 0; |
0706f1c4 | 509 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
510 | static struct trace_seq s; |
511 | unsigned long long avg; | |
e330b3bc | 512 | unsigned long long stddev; |
0706f1c4 | 513 | #endif |
3aaba20f LZ |
514 | mutex_lock(&ftrace_profile_lock); |
515 | ||
516 | /* we raced with function_profile_reset() */ | |
517 | if (unlikely(rec->counter == 0)) { | |
518 | ret = -EBUSY; | |
519 | goto out; | |
520 | } | |
bac429f0 | 521 | |
8e436ca0 | 522 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e31f7939 | 523 | avg = div64_ul(rec->time, rec->counter); |
8e436ca0 UT |
524 | if (tracing_thresh && (avg < tracing_thresh)) |
525 | goto out; | |
526 | #endif | |
527 | ||
bac429f0 | 528 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
0706f1c4 SR |
529 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
530 | ||
531 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
fa6f0cc7 | 532 | seq_puts(m, " "); |
34886c8b | 533 | |
e330b3bc CD |
534 | /* Sample standard deviation (s^2) */ |
535 | if (rec->counter <= 1) | |
536 | stddev = 0; | |
537 | else { | |
52d85d76 JL |
538 | /* |
539 | * Apply Welford's method: | |
540 | * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2) | |
541 | */ | |
542 | stddev = rec->counter * rec->time_squared - | |
543 | rec->time * rec->time; | |
544 | ||
e330b3bc CD |
545 | /* |
546 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
547 | * trace_print_graph_duration will divide 1000 again. | |
548 | */ | |
e31f7939 WY |
549 | stddev = div64_ul(stddev, |
550 | rec->counter * (rec->counter - 1) * 1000); | |
e330b3bc CD |
551 | } |
552 | ||
34886c8b SR |
553 | trace_seq_init(&s); |
554 | trace_print_graph_duration(rec->time, &s); | |
555 | trace_seq_puts(&s, " "); | |
556 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
557 | trace_seq_puts(&s, " "); |
558 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 | 559 | trace_print_seq(m, &s); |
0706f1c4 SR |
560 | #endif |
561 | seq_putc(m, '\n'); | |
3aaba20f LZ |
562 | out: |
563 | mutex_unlock(&ftrace_profile_lock); | |
bac429f0 | 564 | |
3aaba20f | 565 | return ret; |
bac429f0 SR |
566 | } |
567 | ||
cafb168a | 568 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 569 | { |
493762fc | 570 | struct ftrace_profile_page *pg; |
bac429f0 | 571 | |
cafb168a | 572 | pg = stat->pages = stat->start; |
bac429f0 | 573 | |
493762fc SR |
574 | while (pg) { |
575 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
576 | pg->index = 0; | |
577 | pg = pg->next; | |
bac429f0 SR |
578 | } |
579 | ||
cafb168a | 580 | memset(stat->hash, 0, |
493762fc SR |
581 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
582 | } | |
bac429f0 | 583 | |
cafb168a | 584 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
585 | { |
586 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
587 | int functions; |
588 | int pages; | |
493762fc | 589 | int i; |
bac429f0 | 590 | |
493762fc | 591 | /* If we already allocated, do nothing */ |
cafb168a | 592 | if (stat->pages) |
493762fc | 593 | return 0; |
bac429f0 | 594 | |
cafb168a SR |
595 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
596 | if (!stat->pages) | |
493762fc | 597 | return -ENOMEM; |
bac429f0 | 598 | |
318e0a73 SR |
599 | #ifdef CONFIG_DYNAMIC_FTRACE |
600 | functions = ftrace_update_tot_cnt; | |
601 | #else | |
602 | /* | |
603 | * We do not know the number of functions that exist because | |
604 | * dynamic tracing is what counts them. With past experience | |
605 | * we have around 20K functions. That should be more than enough. | |
606 | * It is highly unlikely we will execute every function in | |
607 | * the kernel. | |
608 | */ | |
609 | functions = 20000; | |
610 | #endif | |
611 | ||
cafb168a | 612 | pg = stat->start = stat->pages; |
bac429f0 | 613 | |
318e0a73 SR |
614 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
615 | ||
39e30cd1 | 616 | for (i = 1; i < pages; i++) { |
493762fc | 617 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 618 | if (!pg->next) |
318e0a73 | 619 | goto out_free; |
493762fc SR |
620 | pg = pg->next; |
621 | } | |
622 | ||
623 | return 0; | |
318e0a73 SR |
624 | |
625 | out_free: | |
626 | pg = stat->start; | |
627 | while (pg) { | |
628 | unsigned long tmp = (unsigned long)pg; | |
629 | ||
630 | pg = pg->next; | |
631 | free_page(tmp); | |
632 | } | |
633 | ||
318e0a73 SR |
634 | stat->pages = NULL; |
635 | stat->start = NULL; | |
636 | ||
637 | return -ENOMEM; | |
bac429f0 SR |
638 | } |
639 | ||
cafb168a | 640 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 641 | { |
cafb168a | 642 | struct ftrace_profile_stat *stat; |
493762fc | 643 | int size; |
bac429f0 | 644 | |
cafb168a SR |
645 | stat = &per_cpu(ftrace_profile_stats, cpu); |
646 | ||
647 | if (stat->hash) { | |
493762fc | 648 | /* If the profile is already created, simply reset it */ |
cafb168a | 649 | ftrace_profile_reset(stat); |
493762fc SR |
650 | return 0; |
651 | } | |
bac429f0 | 652 | |
493762fc SR |
653 | /* |
654 | * We are profiling all functions, but usually only a few thousand | |
655 | * functions are hit. We'll make a hash of 1024 items. | |
656 | */ | |
657 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 658 | |
6396bb22 | 659 | stat->hash = kcalloc(size, sizeof(struct hlist_head), GFP_KERNEL); |
493762fc | 660 | |
cafb168a | 661 | if (!stat->hash) |
493762fc SR |
662 | return -ENOMEM; |
663 | ||
318e0a73 | 664 | /* Preallocate the function profiling pages */ |
cafb168a SR |
665 | if (ftrace_profile_pages_init(stat) < 0) { |
666 | kfree(stat->hash); | |
667 | stat->hash = NULL; | |
493762fc SR |
668 | return -ENOMEM; |
669 | } | |
670 | ||
671 | return 0; | |
bac429f0 SR |
672 | } |
673 | ||
cafb168a SR |
674 | static int ftrace_profile_init(void) |
675 | { | |
676 | int cpu; | |
677 | int ret = 0; | |
678 | ||
c4602c1c | 679 | for_each_possible_cpu(cpu) { |
cafb168a SR |
680 | ret = ftrace_profile_init_cpu(cpu); |
681 | if (ret) | |
682 | break; | |
683 | } | |
684 | ||
685 | return ret; | |
686 | } | |
687 | ||
493762fc | 688 | /* interrupts must be disabled */ |
cafb168a SR |
689 | static struct ftrace_profile * |
690 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 691 | { |
493762fc | 692 | struct ftrace_profile *rec; |
bac429f0 | 693 | struct hlist_head *hhd; |
bac429f0 SR |
694 | unsigned long key; |
695 | ||
20079ebe | 696 | key = hash_long(ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 697 | hhd = &stat->hash[key]; |
bac429f0 SR |
698 | |
699 | if (hlist_empty(hhd)) | |
700 | return NULL; | |
701 | ||
1bb539ca | 702 | hlist_for_each_entry_rcu_notrace(rec, hhd, node) { |
bac429f0 | 703 | if (rec->ip == ip) |
493762fc SR |
704 | return rec; |
705 | } | |
706 | ||
707 | return NULL; | |
708 | } | |
709 | ||
cafb168a SR |
710 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
711 | struct ftrace_profile *rec) | |
493762fc SR |
712 | { |
713 | unsigned long key; | |
714 | ||
20079ebe | 715 | key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 716 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
717 | } |
718 | ||
318e0a73 SR |
719 | /* |
720 | * The memory is already allocated, this simply finds a new record to use. | |
721 | */ | |
493762fc | 722 | static struct ftrace_profile * |
318e0a73 | 723 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
724 | { |
725 | struct ftrace_profile *rec = NULL; | |
726 | ||
318e0a73 | 727 | /* prevent recursion (from NMIs) */ |
cafb168a | 728 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
729 | goto out; |
730 | ||
493762fc | 731 | /* |
318e0a73 SR |
732 | * Try to find the function again since an NMI |
733 | * could have added it | |
493762fc | 734 | */ |
cafb168a | 735 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 736 | if (rec) |
cafb168a | 737 | goto out; |
493762fc | 738 | |
cafb168a SR |
739 | if (stat->pages->index == PROFILES_PER_PAGE) { |
740 | if (!stat->pages->next) | |
741 | goto out; | |
742 | stat->pages = stat->pages->next; | |
bac429f0 | 743 | } |
493762fc | 744 | |
cafb168a | 745 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 746 | rec->ip = ip; |
cafb168a | 747 | ftrace_add_profile(stat, rec); |
493762fc | 748 | |
bac429f0 | 749 | out: |
cafb168a | 750 | atomic_dec(&stat->disabled); |
bac429f0 SR |
751 | |
752 | return rec; | |
753 | } | |
754 | ||
755 | static void | |
2f5f6ad9 | 756 | function_profile_call(unsigned long ip, unsigned long parent_ip, |
d19ad077 | 757 | struct ftrace_ops *ops, struct ftrace_regs *fregs) |
bac429f0 | 758 | { |
cafb168a | 759 | struct ftrace_profile_stat *stat; |
493762fc | 760 | struct ftrace_profile *rec; |
bac429f0 SR |
761 | unsigned long flags; |
762 | ||
763 | if (!ftrace_profile_enabled) | |
764 | return; | |
765 | ||
766 | local_irq_save(flags); | |
cafb168a | 767 | |
bdffd893 | 768 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 769 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
770 | goto out; |
771 | ||
772 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 773 | if (!rec) { |
318e0a73 | 774 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
775 | if (!rec) |
776 | goto out; | |
777 | } | |
bac429f0 SR |
778 | |
779 | rec->counter++; | |
780 | out: | |
781 | local_irq_restore(flags); | |
782 | } | |
783 | ||
0706f1c4 | 784 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e73e679f SRV |
785 | static bool fgraph_graph_time = true; |
786 | ||
787 | void ftrace_graph_graph_time_control(bool enable) | |
788 | { | |
789 | fgraph_graph_time = enable; | |
790 | } | |
791 | ||
0706f1c4 SR |
792 | static int profile_graph_entry(struct ftrace_graph_ent *trace) |
793 | { | |
b0e21a61 | 794 | struct ftrace_ret_stack *ret_stack; |
8861dd30 | 795 | |
a1e2e31d | 796 | function_profile_call(trace->func, 0, NULL, NULL); |
8861dd30 | 797 | |
a8f0f9e4 SRV |
798 | /* If function graph is shutting down, ret_stack can be NULL */ |
799 | if (!current->ret_stack) | |
800 | return 0; | |
801 | ||
b0e21a61 SRV |
802 | ret_stack = ftrace_graph_get_ret_stack(current, 0); |
803 | if (ret_stack) | |
804 | ret_stack->subtime = 0; | |
8861dd30 | 805 | |
0706f1c4 SR |
806 | return 1; |
807 | } | |
808 | ||
809 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
810 | { | |
b0e21a61 | 811 | struct ftrace_ret_stack *ret_stack; |
cafb168a | 812 | struct ftrace_profile_stat *stat; |
a2a16d6a | 813 | unsigned long long calltime; |
0706f1c4 | 814 | struct ftrace_profile *rec; |
cafb168a | 815 | unsigned long flags; |
0706f1c4 SR |
816 | |
817 | local_irq_save(flags); | |
bdffd893 | 818 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 819 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
820 | goto out; |
821 | ||
37e44bc5 SR |
822 | /* If the calltime was zero'd ignore it */ |
823 | if (!trace->calltime) | |
824 | goto out; | |
825 | ||
a2a16d6a SR |
826 | calltime = trace->rettime - trace->calltime; |
827 | ||
55577204 | 828 | if (!fgraph_graph_time) { |
a2a16d6a SR |
829 | |
830 | /* Append this call time to the parent time to subtract */ | |
b0e21a61 SRV |
831 | ret_stack = ftrace_graph_get_ret_stack(current, 1); |
832 | if (ret_stack) | |
833 | ret_stack->subtime += calltime; | |
a2a16d6a | 834 | |
b0e21a61 SRV |
835 | ret_stack = ftrace_graph_get_ret_stack(current, 0); |
836 | if (ret_stack && ret_stack->subtime < calltime) | |
837 | calltime -= ret_stack->subtime; | |
a2a16d6a SR |
838 | else |
839 | calltime = 0; | |
840 | } | |
841 | ||
cafb168a | 842 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 843 | if (rec) { |
a2a16d6a | 844 | rec->time += calltime; |
e330b3bc CD |
845 | rec->time_squared += calltime * calltime; |
846 | } | |
a2a16d6a | 847 | |
cafb168a | 848 | out: |
0706f1c4 SR |
849 | local_irq_restore(flags); |
850 | } | |
851 | ||
688f7089 SRV |
852 | static struct fgraph_ops fprofiler_ops = { |
853 | .entryfunc = &profile_graph_entry, | |
854 | .retfunc = &profile_graph_return, | |
855 | }; | |
856 | ||
0706f1c4 SR |
857 | static int register_ftrace_profiler(void) |
858 | { | |
688f7089 | 859 | return register_ftrace_graph(&fprofiler_ops); |
0706f1c4 SR |
860 | } |
861 | ||
862 | static void unregister_ftrace_profiler(void) | |
863 | { | |
688f7089 | 864 | unregister_ftrace_graph(&fprofiler_ops); |
0706f1c4 SR |
865 | } |
866 | #else | |
bd38c0e6 | 867 | static struct ftrace_ops ftrace_profile_ops __read_mostly = { |
fb9fb015 | 868 | .func = function_profile_call, |
a25d036d | 869 | .flags = FTRACE_OPS_FL_INITIALIZED, |
33b7f99c | 870 | INIT_OPS_HASH(ftrace_profile_ops) |
bac429f0 SR |
871 | }; |
872 | ||
0706f1c4 SR |
873 | static int register_ftrace_profiler(void) |
874 | { | |
875 | return register_ftrace_function(&ftrace_profile_ops); | |
876 | } | |
877 | ||
878 | static void unregister_ftrace_profiler(void) | |
879 | { | |
880 | unregister_ftrace_function(&ftrace_profile_ops); | |
881 | } | |
882 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
883 | ||
bac429f0 SR |
884 | static ssize_t |
885 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
886 | size_t cnt, loff_t *ppos) | |
887 | { | |
888 | unsigned long val; | |
bac429f0 SR |
889 | int ret; |
890 | ||
22fe9b54 PH |
891 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
892 | if (ret) | |
bac429f0 SR |
893 | return ret; |
894 | ||
895 | val = !!val; | |
896 | ||
897 | mutex_lock(&ftrace_profile_lock); | |
898 | if (ftrace_profile_enabled ^ val) { | |
899 | if (val) { | |
493762fc SR |
900 | ret = ftrace_profile_init(); |
901 | if (ret < 0) { | |
902 | cnt = ret; | |
903 | goto out; | |
904 | } | |
905 | ||
0706f1c4 SR |
906 | ret = register_ftrace_profiler(); |
907 | if (ret < 0) { | |
908 | cnt = ret; | |
909 | goto out; | |
910 | } | |
bac429f0 SR |
911 | ftrace_profile_enabled = 1; |
912 | } else { | |
913 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
914 | /* |
915 | * unregister_ftrace_profiler calls stop_machine | |
74401729 | 916 | * so this acts like an synchronize_rcu. |
0f6ce3de | 917 | */ |
0706f1c4 | 918 | unregister_ftrace_profiler(); |
bac429f0 SR |
919 | } |
920 | } | |
493762fc | 921 | out: |
bac429f0 SR |
922 | mutex_unlock(&ftrace_profile_lock); |
923 | ||
cf8517cf | 924 | *ppos += cnt; |
bac429f0 SR |
925 | |
926 | return cnt; | |
927 | } | |
928 | ||
493762fc SR |
929 | static ssize_t |
930 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
931 | size_t cnt, loff_t *ppos) | |
932 | { | |
fb9fb015 | 933 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
934 | int r; |
935 | ||
936 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
937 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
938 | } | |
939 | ||
bac429f0 SR |
940 | static const struct file_operations ftrace_profile_fops = { |
941 | .open = tracing_open_generic, | |
942 | .read = ftrace_profile_read, | |
943 | .write = ftrace_profile_write, | |
6038f373 | 944 | .llseek = default_llseek, |
bac429f0 SR |
945 | }; |
946 | ||
cafb168a SR |
947 | /* used to initialize the real stat files */ |
948 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
949 | .name = "functions", |
950 | .stat_start = function_stat_start, | |
951 | .stat_next = function_stat_next, | |
952 | .stat_cmp = function_stat_cmp, | |
953 | .stat_headers = function_stat_headers, | |
954 | .stat_show = function_stat_show | |
cafb168a SR |
955 | }; |
956 | ||
8434dc93 | 957 | static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
bac429f0 | 958 | { |
cafb168a | 959 | struct ftrace_profile_stat *stat; |
bac429f0 | 960 | struct dentry *entry; |
cafb168a | 961 | char *name; |
bac429f0 | 962 | int ret; |
cafb168a SR |
963 | int cpu; |
964 | ||
965 | for_each_possible_cpu(cpu) { | |
966 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
967 | ||
6363c6b5 | 968 | name = kasprintf(GFP_KERNEL, "function%d", cpu); |
cafb168a SR |
969 | if (!name) { |
970 | /* | |
971 | * The files created are permanent, if something happens | |
972 | * we still do not free memory. | |
973 | */ | |
cafb168a SR |
974 | WARN(1, |
975 | "Could not allocate stat file for cpu %d\n", | |
976 | cpu); | |
977 | return; | |
978 | } | |
979 | stat->stat = function_stats; | |
cafb168a SR |
980 | stat->stat.name = name; |
981 | ret = register_stat_tracer(&stat->stat); | |
982 | if (ret) { | |
983 | WARN(1, | |
984 | "Could not register function stat for cpu %d\n", | |
985 | cpu); | |
986 | kfree(name); | |
987 | return; | |
988 | } | |
bac429f0 SR |
989 | } |
990 | ||
8434dc93 | 991 | entry = tracefs_create_file("function_profile_enabled", 0644, |
bac429f0 SR |
992 | d_tracer, NULL, &ftrace_profile_fops); |
993 | if (!entry) | |
a395d6a7 | 994 | pr_warn("Could not create tracefs 'function_profile_enabled' entry\n"); |
bac429f0 SR |
995 | } |
996 | ||
bac429f0 | 997 | #else /* CONFIG_FUNCTION_PROFILER */ |
8434dc93 | 998 | static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
bac429f0 SR |
999 | { |
1000 | } | |
bac429f0 SR |
1001 | #endif /* CONFIG_FUNCTION_PROFILER */ |
1002 | ||
493762fc SR |
1003 | #ifdef CONFIG_DYNAMIC_FTRACE |
1004 | ||
79922b80 SRRH |
1005 | static struct ftrace_ops *removed_ops; |
1006 | ||
e1effa01 SRRH |
1007 | /* |
1008 | * Set when doing a global update, like enabling all recs or disabling them. | |
1009 | * It is not set when just updating a single ftrace_ops. | |
1010 | */ | |
1011 | static bool update_all_ops; | |
1012 | ||
493762fc SR |
1013 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
1014 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
1015 | #endif | |
1016 | ||
7b60f3d8 SRV |
1017 | struct ftrace_func_probe { |
1018 | struct ftrace_probe_ops *probe_ops; | |
1019 | struct ftrace_ops ops; | |
1020 | struct trace_array *tr; | |
1021 | struct list_head list; | |
6e444319 | 1022 | void *data; |
7b60f3d8 SRV |
1023 | int ref; |
1024 | }; | |
1025 | ||
33dc9b12 SR |
1026 | /* |
1027 | * We make these constant because no one should touch them, | |
1028 | * but they are used as the default "empty hash", to avoid allocating | |
1029 | * it all the time. These are in a read only section such that if | |
1030 | * anyone does try to modify it, it will cause an exception. | |
1031 | */ | |
1032 | static const struct hlist_head empty_buckets[1]; | |
1033 | static const struct ftrace_hash empty_hash = { | |
1034 | .buckets = (struct hlist_head *)empty_buckets, | |
1cf41dd7 | 1035 | }; |
33dc9b12 | 1036 | #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) |
493762fc | 1037 | |
3306fc4a | 1038 | struct ftrace_ops global_ops = { |
33b7f99c SRRH |
1039 | .func = ftrace_stub, |
1040 | .local_hash.notrace_hash = EMPTY_HASH, | |
1041 | .local_hash.filter_hash = EMPTY_HASH, | |
1042 | INIT_OPS_HASH(global_ops) | |
a25d036d | 1043 | .flags = FTRACE_OPS_FL_INITIALIZED | |
e3eea140 | 1044 | FTRACE_OPS_FL_PID, |
f45948e8 SR |
1045 | }; |
1046 | ||
aec0be2d | 1047 | /* |
6be7fa3c | 1048 | * Used by the stack undwinder to know about dynamic ftrace trampolines. |
aec0be2d | 1049 | */ |
6be7fa3c | 1050 | struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr) |
aec0be2d | 1051 | { |
6be7fa3c | 1052 | struct ftrace_ops *op = NULL; |
aec0be2d SRRH |
1053 | |
1054 | /* | |
1055 | * Some of the ops may be dynamically allocated, | |
74401729 | 1056 | * they are freed after a synchronize_rcu(). |
aec0be2d SRRH |
1057 | */ |
1058 | preempt_disable_notrace(); | |
1059 | ||
1060 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1061 | /* | |
1062 | * This is to check for dynamically allocated trampolines. | |
1063 | * Trampolines that are in kernel text will have | |
1064 | * core_kernel_text() return true. | |
1065 | */ | |
1066 | if (op->trampoline && op->trampoline_size) | |
1067 | if (addr >= op->trampoline && | |
1068 | addr < op->trampoline + op->trampoline_size) { | |
6be7fa3c SRV |
1069 | preempt_enable_notrace(); |
1070 | return op; | |
aec0be2d SRRH |
1071 | } |
1072 | } while_for_each_ftrace_op(op); | |
aec0be2d SRRH |
1073 | preempt_enable_notrace(); |
1074 | ||
6be7fa3c SRV |
1075 | return NULL; |
1076 | } | |
1077 | ||
1078 | /* | |
1079 | * This is used by __kernel_text_address() to return true if the | |
1080 | * address is on a dynamically allocated trampoline that would | |
1081 | * not return true for either core_kernel_text() or | |
1082 | * is_module_text_address(). | |
1083 | */ | |
1084 | bool is_ftrace_trampoline(unsigned long addr) | |
1085 | { | |
1086 | return ftrace_ops_trampoline(addr) != NULL; | |
aec0be2d SRRH |
1087 | } |
1088 | ||
493762fc SR |
1089 | struct ftrace_page { |
1090 | struct ftrace_page *next; | |
a7900875 | 1091 | struct dyn_ftrace *records; |
493762fc | 1092 | int index; |
a7900875 | 1093 | int size; |
493762fc SR |
1094 | }; |
1095 | ||
a7900875 SR |
1096 | #define ENTRY_SIZE sizeof(struct dyn_ftrace) |
1097 | #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE) | |
493762fc | 1098 | |
493762fc SR |
1099 | static struct ftrace_page *ftrace_pages_start; |
1100 | static struct ftrace_page *ftrace_pages; | |
1101 | ||
2b0cce0e SRV |
1102 | static __always_inline unsigned long |
1103 | ftrace_hash_key(struct ftrace_hash *hash, unsigned long ip) | |
1104 | { | |
1105 | if (hash->size_bits > 0) | |
1106 | return hash_long(ip, hash->size_bits); | |
1107 | ||
1108 | return 0; | |
1109 | } | |
1110 | ||
2b2c279c SRV |
1111 | /* Only use this function if ftrace_hash_empty() has already been tested */ |
1112 | static __always_inline struct ftrace_func_entry * | |
1113 | __ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
b448c4e3 SR |
1114 | { |
1115 | unsigned long key; | |
1116 | struct ftrace_func_entry *entry; | |
1117 | struct hlist_head *hhd; | |
b448c4e3 | 1118 | |
2b0cce0e | 1119 | key = ftrace_hash_key(hash, ip); |
b448c4e3 SR |
1120 | hhd = &hash->buckets[key]; |
1121 | ||
1bb539ca | 1122 | hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) { |
b448c4e3 SR |
1123 | if (entry->ip == ip) |
1124 | return entry; | |
1125 | } | |
1126 | return NULL; | |
1127 | } | |
1128 | ||
2b2c279c SRV |
1129 | /** |
1130 | * ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash | |
1131 | * @hash: The hash to look at | |
1132 | * @ip: The instruction pointer to test | |
1133 | * | |
1134 | * Search a given @hash to see if a given instruction pointer (@ip) | |
1135 | * exists in it. | |
1136 | * | |
1137 | * Returns the entry that holds the @ip if found. NULL otherwise. | |
1138 | */ | |
1139 | struct ftrace_func_entry * | |
1140 | ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
1141 | { | |
1142 | if (ftrace_hash_empty(hash)) | |
1143 | return NULL; | |
1144 | ||
1145 | return __ftrace_lookup_ip(hash, ip); | |
1146 | } | |
1147 | ||
33dc9b12 SR |
1148 | static void __add_hash_entry(struct ftrace_hash *hash, |
1149 | struct ftrace_func_entry *entry) | |
b448c4e3 | 1150 | { |
b448c4e3 SR |
1151 | struct hlist_head *hhd; |
1152 | unsigned long key; | |
1153 | ||
2b0cce0e | 1154 | key = ftrace_hash_key(hash, entry->ip); |
b448c4e3 SR |
1155 | hhd = &hash->buckets[key]; |
1156 | hlist_add_head(&entry->hlist, hhd); | |
1157 | hash->count++; | |
33dc9b12 SR |
1158 | } |
1159 | ||
1160 | static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip) | |
1161 | { | |
1162 | struct ftrace_func_entry *entry; | |
1163 | ||
1164 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1165 | if (!entry) | |
1166 | return -ENOMEM; | |
1167 | ||
1168 | entry->ip = ip; | |
1169 | __add_hash_entry(hash, entry); | |
b448c4e3 SR |
1170 | |
1171 | return 0; | |
1172 | } | |
1173 | ||
1174 | static void | |
33dc9b12 | 1175 | free_hash_entry(struct ftrace_hash *hash, |
b448c4e3 SR |
1176 | struct ftrace_func_entry *entry) |
1177 | { | |
1178 | hlist_del(&entry->hlist); | |
1179 | kfree(entry); | |
1180 | hash->count--; | |
1181 | } | |
1182 | ||
33dc9b12 SR |
1183 | static void |
1184 | remove_hash_entry(struct ftrace_hash *hash, | |
1185 | struct ftrace_func_entry *entry) | |
1186 | { | |
eee8ded1 | 1187 | hlist_del_rcu(&entry->hlist); |
33dc9b12 SR |
1188 | hash->count--; |
1189 | } | |
1190 | ||
b448c4e3 SR |
1191 | static void ftrace_hash_clear(struct ftrace_hash *hash) |
1192 | { | |
1193 | struct hlist_head *hhd; | |
b67bfe0d | 1194 | struct hlist_node *tn; |
b448c4e3 SR |
1195 | struct ftrace_func_entry *entry; |
1196 | int size = 1 << hash->size_bits; | |
1197 | int i; | |
1198 | ||
33dc9b12 SR |
1199 | if (!hash->count) |
1200 | return; | |
1201 | ||
b448c4e3 SR |
1202 | for (i = 0; i < size; i++) { |
1203 | hhd = &hash->buckets[i]; | |
b67bfe0d | 1204 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) |
33dc9b12 | 1205 | free_hash_entry(hash, entry); |
b448c4e3 SR |
1206 | } |
1207 | FTRACE_WARN_ON(hash->count); | |
1208 | } | |
1209 | ||
673feb9d SRV |
1210 | static void free_ftrace_mod(struct ftrace_mod_load *ftrace_mod) |
1211 | { | |
1212 | list_del(&ftrace_mod->list); | |
1213 | kfree(ftrace_mod->module); | |
1214 | kfree(ftrace_mod->func); | |
1215 | kfree(ftrace_mod); | |
1216 | } | |
1217 | ||
1218 | static void clear_ftrace_mod_list(struct list_head *head) | |
1219 | { | |
1220 | struct ftrace_mod_load *p, *n; | |
1221 | ||
1222 | /* stack tracer isn't supported yet */ | |
1223 | if (!head) | |
1224 | return; | |
1225 | ||
1226 | mutex_lock(&ftrace_lock); | |
1227 | list_for_each_entry_safe(p, n, head, list) | |
1228 | free_ftrace_mod(p); | |
1229 | mutex_unlock(&ftrace_lock); | |
1230 | } | |
1231 | ||
33dc9b12 SR |
1232 | static void free_ftrace_hash(struct ftrace_hash *hash) |
1233 | { | |
1234 | if (!hash || hash == EMPTY_HASH) | |
1235 | return; | |
1236 | ftrace_hash_clear(hash); | |
1237 | kfree(hash->buckets); | |
1238 | kfree(hash); | |
1239 | } | |
1240 | ||
07fd5515 SR |
1241 | static void __free_ftrace_hash_rcu(struct rcu_head *rcu) |
1242 | { | |
1243 | struct ftrace_hash *hash; | |
1244 | ||
1245 | hash = container_of(rcu, struct ftrace_hash, rcu); | |
1246 | free_ftrace_hash(hash); | |
1247 | } | |
1248 | ||
1249 | static void free_ftrace_hash_rcu(struct ftrace_hash *hash) | |
1250 | { | |
1251 | if (!hash || hash == EMPTY_HASH) | |
1252 | return; | |
74401729 | 1253 | call_rcu(&hash->rcu, __free_ftrace_hash_rcu); |
07fd5515 SR |
1254 | } |
1255 | ||
5500fa51 JO |
1256 | void ftrace_free_filter(struct ftrace_ops *ops) |
1257 | { | |
f04f24fb | 1258 | ftrace_ops_init(ops); |
33b7f99c SRRH |
1259 | free_ftrace_hash(ops->func_hash->filter_hash); |
1260 | free_ftrace_hash(ops->func_hash->notrace_hash); | |
5500fa51 JO |
1261 | } |
1262 | ||
33dc9b12 SR |
1263 | static struct ftrace_hash *alloc_ftrace_hash(int size_bits) |
1264 | { | |
1265 | struct ftrace_hash *hash; | |
1266 | int size; | |
1267 | ||
1268 | hash = kzalloc(sizeof(*hash), GFP_KERNEL); | |
1269 | if (!hash) | |
1270 | return NULL; | |
1271 | ||
1272 | size = 1 << size_bits; | |
47b0edcb | 1273 | hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL); |
33dc9b12 SR |
1274 | |
1275 | if (!hash->buckets) { | |
1276 | kfree(hash); | |
1277 | return NULL; | |
1278 | } | |
1279 | ||
1280 | hash->size_bits = size_bits; | |
1281 | ||
1282 | return hash; | |
1283 | } | |
1284 | ||
673feb9d SRV |
1285 | |
1286 | static int ftrace_add_mod(struct trace_array *tr, | |
1287 | const char *func, const char *module, | |
1288 | int enable) | |
1289 | { | |
1290 | struct ftrace_mod_load *ftrace_mod; | |
1291 | struct list_head *mod_head = enable ? &tr->mod_trace : &tr->mod_notrace; | |
1292 | ||
1293 | ftrace_mod = kzalloc(sizeof(*ftrace_mod), GFP_KERNEL); | |
1294 | if (!ftrace_mod) | |
1295 | return -ENOMEM; | |
1296 | ||
1297 | ftrace_mod->func = kstrdup(func, GFP_KERNEL); | |
1298 | ftrace_mod->module = kstrdup(module, GFP_KERNEL); | |
1299 | ftrace_mod->enable = enable; | |
1300 | ||
1301 | if (!ftrace_mod->func || !ftrace_mod->module) | |
1302 | goto out_free; | |
1303 | ||
1304 | list_add(&ftrace_mod->list, mod_head); | |
1305 | ||
1306 | return 0; | |
1307 | ||
1308 | out_free: | |
1309 | free_ftrace_mod(ftrace_mod); | |
1310 | ||
1311 | return -ENOMEM; | |
1312 | } | |
1313 | ||
33dc9b12 SR |
1314 | static struct ftrace_hash * |
1315 | alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) | |
1316 | { | |
1317 | struct ftrace_func_entry *entry; | |
1318 | struct ftrace_hash *new_hash; | |
33dc9b12 SR |
1319 | int size; |
1320 | int ret; | |
1321 | int i; | |
1322 | ||
1323 | new_hash = alloc_ftrace_hash(size_bits); | |
1324 | if (!new_hash) | |
1325 | return NULL; | |
1326 | ||
8c08f0d5 SRV |
1327 | if (hash) |
1328 | new_hash->flags = hash->flags; | |
1329 | ||
33dc9b12 | 1330 | /* Empty hash? */ |
06a51d93 | 1331 | if (ftrace_hash_empty(hash)) |
33dc9b12 SR |
1332 | return new_hash; |
1333 | ||
1334 | size = 1 << hash->size_bits; | |
1335 | for (i = 0; i < size; i++) { | |
b67bfe0d | 1336 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { |
33dc9b12 SR |
1337 | ret = add_hash_entry(new_hash, entry->ip); |
1338 | if (ret < 0) | |
1339 | goto free_hash; | |
1340 | } | |
1341 | } | |
1342 | ||
1343 | FTRACE_WARN_ON(new_hash->count != hash->count); | |
1344 | ||
1345 | return new_hash; | |
1346 | ||
1347 | free_hash: | |
1348 | free_ftrace_hash(new_hash); | |
1349 | return NULL; | |
1350 | } | |
1351 | ||
41fb61c2 | 1352 | static void |
84261912 | 1353 | ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash); |
41fb61c2 | 1354 | static void |
84261912 | 1355 | ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash); |
41fb61c2 | 1356 | |
f8b8be8a MH |
1357 | static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, |
1358 | struct ftrace_hash *new_hash); | |
1359 | ||
714641c3 | 1360 | static struct ftrace_hash *dup_hash(struct ftrace_hash *src, int size) |
33dc9b12 SR |
1361 | { |
1362 | struct ftrace_func_entry *entry; | |
07fd5515 | 1363 | struct ftrace_hash *new_hash; |
714641c3 SRV |
1364 | struct hlist_head *hhd; |
1365 | struct hlist_node *tn; | |
33dc9b12 SR |
1366 | int bits = 0; |
1367 | int i; | |
1368 | ||
33dc9b12 | 1369 | /* |
be493132 SRV |
1370 | * Use around half the size (max bit of it), but |
1371 | * a minimum of 2 is fine (as size of 0 or 1 both give 1 for bits). | |
33dc9b12 | 1372 | */ |
be493132 | 1373 | bits = fls(size / 2); |
33dc9b12 SR |
1374 | |
1375 | /* Don't allocate too much */ | |
1376 | if (bits > FTRACE_HASH_MAX_BITS) | |
1377 | bits = FTRACE_HASH_MAX_BITS; | |
1378 | ||
07fd5515 SR |
1379 | new_hash = alloc_ftrace_hash(bits); |
1380 | if (!new_hash) | |
3e278c0d | 1381 | return NULL; |
33dc9b12 | 1382 | |
8c08f0d5 SRV |
1383 | new_hash->flags = src->flags; |
1384 | ||
33dc9b12 SR |
1385 | size = 1 << src->size_bits; |
1386 | for (i = 0; i < size; i++) { | |
1387 | hhd = &src->buckets[i]; | |
b67bfe0d | 1388 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) { |
33dc9b12 | 1389 | remove_hash_entry(src, entry); |
07fd5515 | 1390 | __add_hash_entry(new_hash, entry); |
33dc9b12 SR |
1391 | } |
1392 | } | |
3e278c0d NK |
1393 | return new_hash; |
1394 | } | |
1395 | ||
714641c3 SRV |
1396 | static struct ftrace_hash * |
1397 | __ftrace_hash_move(struct ftrace_hash *src) | |
1398 | { | |
1399 | int size = src->count; | |
1400 | ||
1401 | /* | |
1402 | * If the new source is empty, just return the empty_hash. | |
1403 | */ | |
1404 | if (ftrace_hash_empty(src)) | |
1405 | return EMPTY_HASH; | |
1406 | ||
1407 | return dup_hash(src, size); | |
1408 | } | |
1409 | ||
3e278c0d NK |
1410 | static int |
1411 | ftrace_hash_move(struct ftrace_ops *ops, int enable, | |
1412 | struct ftrace_hash **dst, struct ftrace_hash *src) | |
1413 | { | |
1414 | struct ftrace_hash *new_hash; | |
1415 | int ret; | |
1416 | ||
1417 | /* Reject setting notrace hash on IPMODIFY ftrace_ops */ | |
1418 | if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable) | |
1419 | return -EINVAL; | |
1420 | ||
1421 | new_hash = __ftrace_hash_move(src); | |
1422 | if (!new_hash) | |
1423 | return -ENOMEM; | |
1424 | ||
f8b8be8a MH |
1425 | /* Make sure this can be applied if it is IPMODIFY ftrace_ops */ |
1426 | if (enable) { | |
1427 | /* IPMODIFY should be updated only when filter_hash updating */ | |
1428 | ret = ftrace_hash_ipmodify_update(ops, new_hash); | |
1429 | if (ret < 0) { | |
1430 | free_ftrace_hash(new_hash); | |
1431 | return ret; | |
1432 | } | |
1433 | } | |
1434 | ||
5c27c775 MH |
1435 | /* |
1436 | * Remove the current set, update the hash and add | |
1437 | * them back. | |
1438 | */ | |
84261912 | 1439 | ftrace_hash_rec_disable_modify(ops, enable); |
5c27c775 | 1440 | |
07fd5515 | 1441 | rcu_assign_pointer(*dst, new_hash); |
07fd5515 | 1442 | |
84261912 | 1443 | ftrace_hash_rec_enable_modify(ops, enable); |
41fb61c2 | 1444 | |
5c27c775 | 1445 | return 0; |
33dc9b12 SR |
1446 | } |
1447 | ||
fef5aeee SRRH |
1448 | static bool hash_contains_ip(unsigned long ip, |
1449 | struct ftrace_ops_hash *hash) | |
1450 | { | |
1451 | /* | |
1452 | * The function record is a match if it exists in the filter | |
fdda88d3 | 1453 | * hash and not in the notrace hash. Note, an empty hash is |
fef5aeee SRRH |
1454 | * considered a match for the filter hash, but an empty |
1455 | * notrace hash is considered not in the notrace hash. | |
1456 | */ | |
1457 | return (ftrace_hash_empty(hash->filter_hash) || | |
2b2c279c | 1458 | __ftrace_lookup_ip(hash->filter_hash, ip)) && |
fef5aeee | 1459 | (ftrace_hash_empty(hash->notrace_hash) || |
2b2c279c | 1460 | !__ftrace_lookup_ip(hash->notrace_hash, ip)); |
fef5aeee SRRH |
1461 | } |
1462 | ||
b848914c SR |
1463 | /* |
1464 | * Test the hashes for this ops to see if we want to call | |
1465 | * the ops->func or not. | |
1466 | * | |
1467 | * It's a match if the ip is in the ops->filter_hash or | |
1468 | * the filter_hash does not exist or is empty, | |
1469 | * AND | |
1470 | * the ip is not in the ops->notrace_hash. | |
cdbe61bf SR |
1471 | * |
1472 | * This needs to be called with preemption disabled as | |
74401729 | 1473 | * the hashes are freed with call_rcu(). |
b848914c | 1474 | */ |
3306fc4a | 1475 | int |
195a8afc | 1476 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
b848914c | 1477 | { |
fef5aeee | 1478 | struct ftrace_ops_hash hash; |
b848914c SR |
1479 | int ret; |
1480 | ||
195a8afc SRRH |
1481 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
1482 | /* | |
1483 | * There's a small race when adding ops that the ftrace handler | |
1484 | * that wants regs, may be called without them. We can not | |
1485 | * allow that handler to be called if regs is NULL. | |
1486 | */ | |
1487 | if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS)) | |
1488 | return 0; | |
1489 | #endif | |
1490 | ||
f86f4180 CZ |
1491 | rcu_assign_pointer(hash.filter_hash, ops->func_hash->filter_hash); |
1492 | rcu_assign_pointer(hash.notrace_hash, ops->func_hash->notrace_hash); | |
b848914c | 1493 | |
fef5aeee | 1494 | if (hash_contains_ip(ip, &hash)) |
b848914c SR |
1495 | ret = 1; |
1496 | else | |
1497 | ret = 0; | |
b848914c SR |
1498 | |
1499 | return ret; | |
1500 | } | |
1501 | ||
493762fc SR |
1502 | /* |
1503 | * This is a double for. Do not use 'break' to break out of the loop, | |
1504 | * you must use a goto. | |
1505 | */ | |
1506 | #define do_for_each_ftrace_rec(pg, rec) \ | |
1507 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
1508 | int _____i; \ | |
1509 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
1510 | rec = &pg->records[_____i]; | |
1511 | ||
1512 | #define while_for_each_ftrace_rec() \ | |
1513 | } \ | |
1514 | } | |
1515 | ||
5855fead SR |
1516 | |
1517 | static int ftrace_cmp_recs(const void *a, const void *b) | |
1518 | { | |
a650e02a SR |
1519 | const struct dyn_ftrace *key = a; |
1520 | const struct dyn_ftrace *rec = b; | |
5855fead | 1521 | |
a650e02a | 1522 | if (key->flags < rec->ip) |
5855fead | 1523 | return -1; |
a650e02a SR |
1524 | if (key->ip >= rec->ip + MCOUNT_INSN_SIZE) |
1525 | return 1; | |
5855fead SR |
1526 | return 0; |
1527 | } | |
1528 | ||
7e16f581 SRV |
1529 | static struct dyn_ftrace *lookup_rec(unsigned long start, unsigned long end) |
1530 | { | |
1531 | struct ftrace_page *pg; | |
1532 | struct dyn_ftrace *rec = NULL; | |
1533 | struct dyn_ftrace key; | |
1534 | ||
1535 | key.ip = start; | |
1536 | key.flags = end; /* overload flags, as it is unsigned long */ | |
1537 | ||
1538 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
1539 | if (end < pg->records[0].ip || | |
1540 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) | |
1541 | continue; | |
1542 | rec = bsearch(&key, pg->records, pg->index, | |
1543 | sizeof(struct dyn_ftrace), | |
1544 | ftrace_cmp_recs); | |
d9815bff AS |
1545 | if (rec) |
1546 | break; | |
7e16f581 SRV |
1547 | } |
1548 | return rec; | |
1549 | } | |
1550 | ||
04cf31a7 ME |
1551 | /** |
1552 | * ftrace_location_range - return the first address of a traced location | |
1553 | * if it touches the given ip range | |
1554 | * @start: start of range to search. | |
1555 | * @end: end of range to search (inclusive). @end points to the last byte | |
1556 | * to check. | |
1557 | * | |
1558 | * Returns rec->ip if the related ftrace location is a least partly within | |
1559 | * the given address range. That is, the first address of the instruction | |
1560 | * that is either a NOP or call to the function tracer. It checks the ftrace | |
1561 | * internal tables to determine if the address belongs or not. | |
1562 | */ | |
1563 | unsigned long ftrace_location_range(unsigned long start, unsigned long end) | |
c88fd863 | 1564 | { |
c88fd863 | 1565 | struct dyn_ftrace *rec; |
5855fead | 1566 | |
7e16f581 SRV |
1567 | rec = lookup_rec(start, end); |
1568 | if (rec) | |
1569 | return rec->ip; | |
c88fd863 SR |
1570 | |
1571 | return 0; | |
1572 | } | |
1573 | ||
a650e02a SR |
1574 | /** |
1575 | * ftrace_location - return true if the ip giving is a traced location | |
1576 | * @ip: the instruction pointer to check | |
1577 | * | |
f0cf973a | 1578 | * Returns rec->ip if @ip given is a pointer to a ftrace location. |
a650e02a SR |
1579 | * That is, the instruction that is either a NOP or call to |
1580 | * the function tracer. It checks the ftrace internal tables to | |
1581 | * determine if the address belongs or not. | |
1582 | */ | |
f0cf973a | 1583 | unsigned long ftrace_location(unsigned long ip) |
a650e02a SR |
1584 | { |
1585 | return ftrace_location_range(ip, ip); | |
1586 | } | |
1587 | ||
1588 | /** | |
1589 | * ftrace_text_reserved - return true if range contains an ftrace location | |
1590 | * @start: start of range to search | |
1591 | * @end: end of range to search (inclusive). @end points to the last byte to check. | |
1592 | * | |
1593 | * Returns 1 if @start and @end contains a ftrace location. | |
1594 | * That is, the instruction that is either a NOP or call to | |
1595 | * the function tracer. It checks the ftrace internal tables to | |
1596 | * determine if the address belongs or not. | |
1597 | */ | |
d88471cb | 1598 | int ftrace_text_reserved(const void *start, const void *end) |
a650e02a | 1599 | { |
f0cf973a SR |
1600 | unsigned long ret; |
1601 | ||
1602 | ret = ftrace_location_range((unsigned long)start, | |
1603 | (unsigned long)end); | |
1604 | ||
1605 | return (int)!!ret; | |
a650e02a SR |
1606 | } |
1607 | ||
4fbb48cb SRRH |
1608 | /* Test if ops registered to this rec needs regs */ |
1609 | static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec) | |
1610 | { | |
1611 | struct ftrace_ops *ops; | |
1612 | bool keep_regs = false; | |
1613 | ||
1614 | for (ops = ftrace_ops_list; | |
1615 | ops != &ftrace_list_end; ops = ops->next) { | |
1616 | /* pass rec in as regs to have non-NULL val */ | |
1617 | if (ftrace_ops_test(ops, rec->ip, rec)) { | |
1618 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1619 | keep_regs = true; | |
1620 | break; | |
1621 | } | |
1622 | } | |
1623 | } | |
1624 | ||
1625 | return keep_regs; | |
1626 | } | |
1627 | ||
a124692b CJ |
1628 | static struct ftrace_ops * |
1629 | ftrace_find_tramp_ops_any(struct dyn_ftrace *rec); | |
1630 | static struct ftrace_ops * | |
4c75b0ff NR |
1631 | ftrace_find_tramp_ops_any_other(struct dyn_ftrace *rec, struct ftrace_ops *op_exclude); |
1632 | static struct ftrace_ops * | |
a124692b CJ |
1633 | ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops); |
1634 | ||
84b6d3e6 | 1635 | static bool __ftrace_hash_rec_update(struct ftrace_ops *ops, |
ed926f9b SR |
1636 | int filter_hash, |
1637 | bool inc) | |
1638 | { | |
1639 | struct ftrace_hash *hash; | |
1640 | struct ftrace_hash *other_hash; | |
1641 | struct ftrace_page *pg; | |
1642 | struct dyn_ftrace *rec; | |
84b6d3e6 | 1643 | bool update = false; |
ed926f9b | 1644 | int count = 0; |
8c08f0d5 | 1645 | int all = false; |
ed926f9b SR |
1646 | |
1647 | /* Only update if the ops has been registered */ | |
1648 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
84b6d3e6 | 1649 | return false; |
ed926f9b SR |
1650 | |
1651 | /* | |
1652 | * In the filter_hash case: | |
1653 | * If the count is zero, we update all records. | |
1654 | * Otherwise we just update the items in the hash. | |
1655 | * | |
1656 | * In the notrace_hash case: | |
1657 | * We enable the update in the hash. | |
1658 | * As disabling notrace means enabling the tracing, | |
1659 | * and enabling notrace means disabling, the inc variable | |
1660 | * gets inversed. | |
1661 | */ | |
1662 | if (filter_hash) { | |
33b7f99c SRRH |
1663 | hash = ops->func_hash->filter_hash; |
1664 | other_hash = ops->func_hash->notrace_hash; | |
06a51d93 | 1665 | if (ftrace_hash_empty(hash)) |
8c08f0d5 | 1666 | all = true; |
ed926f9b SR |
1667 | } else { |
1668 | inc = !inc; | |
33b7f99c SRRH |
1669 | hash = ops->func_hash->notrace_hash; |
1670 | other_hash = ops->func_hash->filter_hash; | |
ed926f9b SR |
1671 | /* |
1672 | * If the notrace hash has no items, | |
1673 | * then there's nothing to do. | |
1674 | */ | |
06a51d93 | 1675 | if (ftrace_hash_empty(hash)) |
84b6d3e6 | 1676 | return false; |
ed926f9b SR |
1677 | } |
1678 | ||
1679 | do_for_each_ftrace_rec(pg, rec) { | |
1680 | int in_other_hash = 0; | |
1681 | int in_hash = 0; | |
1682 | int match = 0; | |
1683 | ||
b7ffffbb SRRH |
1684 | if (rec->flags & FTRACE_FL_DISABLED) |
1685 | continue; | |
1686 | ||
ed926f9b SR |
1687 | if (all) { |
1688 | /* | |
1689 | * Only the filter_hash affects all records. | |
1690 | * Update if the record is not in the notrace hash. | |
1691 | */ | |
b848914c | 1692 | if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) |
ed926f9b SR |
1693 | match = 1; |
1694 | } else { | |
06a51d93 SR |
1695 | in_hash = !!ftrace_lookup_ip(hash, rec->ip); |
1696 | in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip); | |
ed926f9b SR |
1697 | |
1698 | /* | |
19eab4a4 SRRH |
1699 | * If filter_hash is set, we want to match all functions |
1700 | * that are in the hash but not in the other hash. | |
ed926f9b | 1701 | * |
19eab4a4 SRRH |
1702 | * If filter_hash is not set, then we are decrementing. |
1703 | * That means we match anything that is in the hash | |
1704 | * and also in the other_hash. That is, we need to turn | |
1705 | * off functions in the other hash because they are disabled | |
1706 | * by this hash. | |
ed926f9b SR |
1707 | */ |
1708 | if (filter_hash && in_hash && !in_other_hash) | |
1709 | match = 1; | |
1710 | else if (!filter_hash && in_hash && | |
06a51d93 | 1711 | (in_other_hash || ftrace_hash_empty(other_hash))) |
ed926f9b SR |
1712 | match = 1; |
1713 | } | |
1714 | if (!match) | |
1715 | continue; | |
1716 | ||
1717 | if (inc) { | |
1718 | rec->flags++; | |
0376bde1 | 1719 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX)) |
84b6d3e6 | 1720 | return false; |
79922b80 | 1721 | |
763e34e7 SRV |
1722 | if (ops->flags & FTRACE_OPS_FL_DIRECT) |
1723 | rec->flags |= FTRACE_FL_DIRECT; | |
1724 | ||
79922b80 SRRH |
1725 | /* |
1726 | * If there's only a single callback registered to a | |
1727 | * function, and the ops has a trampoline registered | |
1728 | * for it, then we can call it directly. | |
1729 | */ | |
fef5aeee | 1730 | if (ftrace_rec_count(rec) == 1 && ops->trampoline) |
79922b80 | 1731 | rec->flags |= FTRACE_FL_TRAMP; |
fef5aeee | 1732 | else |
79922b80 SRRH |
1733 | /* |
1734 | * If we are adding another function callback | |
1735 | * to this function, and the previous had a | |
bce0b6c5 SRRH |
1736 | * custom trampoline in use, then we need to go |
1737 | * back to the default trampoline. | |
79922b80 | 1738 | */ |
fef5aeee | 1739 | rec->flags &= ~FTRACE_FL_TRAMP; |
79922b80 | 1740 | |
08f6fba5 SR |
1741 | /* |
1742 | * If any ops wants regs saved for this function | |
1743 | * then all ops will get saved regs. | |
1744 | */ | |
1745 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) | |
1746 | rec->flags |= FTRACE_FL_REGS; | |
ed926f9b | 1747 | } else { |
0376bde1 | 1748 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0)) |
84b6d3e6 | 1749 | return false; |
ed926f9b | 1750 | rec->flags--; |
79922b80 | 1751 | |
763e34e7 SRV |
1752 | /* |
1753 | * Only the internal direct_ops should have the | |
1754 | * DIRECT flag set. Thus, if it is removing a | |
1755 | * function, then that function should no longer | |
1756 | * be direct. | |
1757 | */ | |
1758 | if (ops->flags & FTRACE_OPS_FL_DIRECT) | |
1759 | rec->flags &= ~FTRACE_FL_DIRECT; | |
1760 | ||
4fbb48cb SRRH |
1761 | /* |
1762 | * If the rec had REGS enabled and the ops that is | |
1763 | * being removed had REGS set, then see if there is | |
1764 | * still any ops for this record that wants regs. | |
1765 | * If not, we can stop recording them. | |
1766 | */ | |
0376bde1 | 1767 | if (ftrace_rec_count(rec) > 0 && |
4fbb48cb SRRH |
1768 | rec->flags & FTRACE_FL_REGS && |
1769 | ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1770 | if (!test_rec_ops_needs_regs(rec)) | |
1771 | rec->flags &= ~FTRACE_FL_REGS; | |
1772 | } | |
79922b80 | 1773 | |
fef5aeee | 1774 | /* |
a124692b CJ |
1775 | * The TRAMP needs to be set only if rec count |
1776 | * is decremented to one, and the ops that is | |
1777 | * left has a trampoline. As TRAMP can only be | |
1778 | * enabled if there is only a single ops attached | |
1779 | * to it. | |
fef5aeee | 1780 | */ |
a124692b | 1781 | if (ftrace_rec_count(rec) == 1 && |
4c75b0ff | 1782 | ftrace_find_tramp_ops_any_other(rec, ops)) |
a124692b CJ |
1783 | rec->flags |= FTRACE_FL_TRAMP; |
1784 | else | |
1785 | rec->flags &= ~FTRACE_FL_TRAMP; | |
fef5aeee | 1786 | |
79922b80 SRRH |
1787 | /* |
1788 | * flags will be cleared in ftrace_check_record() | |
1789 | * if rec count is zero. | |
1790 | */ | |
ed926f9b SR |
1791 | } |
1792 | count++; | |
84b6d3e6 JO |
1793 | |
1794 | /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */ | |
7375dca1 | 1795 | update |= ftrace_test_record(rec, true) != FTRACE_UPDATE_IGNORE; |
84b6d3e6 | 1796 | |
ed926f9b SR |
1797 | /* Shortcut, if we handled all records, we are done. */ |
1798 | if (!all && count == hash->count) | |
84b6d3e6 | 1799 | return update; |
ed926f9b | 1800 | } while_for_each_ftrace_rec(); |
84b6d3e6 JO |
1801 | |
1802 | return update; | |
ed926f9b SR |
1803 | } |
1804 | ||
84b6d3e6 | 1805 | static bool ftrace_hash_rec_disable(struct ftrace_ops *ops, |
ed926f9b SR |
1806 | int filter_hash) |
1807 | { | |
84b6d3e6 | 1808 | return __ftrace_hash_rec_update(ops, filter_hash, 0); |
ed926f9b SR |
1809 | } |
1810 | ||
84b6d3e6 | 1811 | static bool ftrace_hash_rec_enable(struct ftrace_ops *ops, |
ed926f9b SR |
1812 | int filter_hash) |
1813 | { | |
84b6d3e6 | 1814 | return __ftrace_hash_rec_update(ops, filter_hash, 1); |
ed926f9b SR |
1815 | } |
1816 | ||
84261912 SRRH |
1817 | static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops, |
1818 | int filter_hash, int inc) | |
1819 | { | |
1820 | struct ftrace_ops *op; | |
1821 | ||
1822 | __ftrace_hash_rec_update(ops, filter_hash, inc); | |
1823 | ||
1824 | if (ops->func_hash != &global_ops.local_hash) | |
1825 | return; | |
1826 | ||
1827 | /* | |
1828 | * If the ops shares the global_ops hash, then we need to update | |
1829 | * all ops that are enabled and use this hash. | |
1830 | */ | |
1831 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1832 | /* Already done */ | |
1833 | if (op == ops) | |
1834 | continue; | |
1835 | if (op->func_hash == &global_ops.local_hash) | |
1836 | __ftrace_hash_rec_update(op, filter_hash, inc); | |
1837 | } while_for_each_ftrace_op(op); | |
1838 | } | |
1839 | ||
1840 | static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, | |
1841 | int filter_hash) | |
1842 | { | |
1843 | ftrace_hash_rec_update_modify(ops, filter_hash, 0); | |
1844 | } | |
1845 | ||
1846 | static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, | |
1847 | int filter_hash) | |
1848 | { | |
1849 | ftrace_hash_rec_update_modify(ops, filter_hash, 1); | |
1850 | } | |
1851 | ||
f8b8be8a MH |
1852 | /* |
1853 | * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK | |
1854 | * or no-needed to update, -EBUSY if it detects a conflict of the flag | |
1855 | * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs. | |
1856 | * Note that old_hash and new_hash has below meanings | |
1857 | * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected) | |
1858 | * - If the hash is EMPTY_HASH, it hits nothing | |
1859 | * - Anything else hits the recs which match the hash entries. | |
1860 | */ | |
1861 | static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops, | |
1862 | struct ftrace_hash *old_hash, | |
1863 | struct ftrace_hash *new_hash) | |
1864 | { | |
1865 | struct ftrace_page *pg; | |
1866 | struct dyn_ftrace *rec, *end = NULL; | |
1867 | int in_old, in_new; | |
1868 | ||
1869 | /* Only update if the ops has been registered */ | |
1870 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
1871 | return 0; | |
1872 | ||
1873 | if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY)) | |
1874 | return 0; | |
1875 | ||
1876 | /* | |
1877 | * Since the IPMODIFY is a very address sensitive action, we do not | |
1878 | * allow ftrace_ops to set all functions to new hash. | |
1879 | */ | |
1880 | if (!new_hash || !old_hash) | |
1881 | return -EINVAL; | |
1882 | ||
1883 | /* Update rec->flags */ | |
1884 | do_for_each_ftrace_rec(pg, rec) { | |
546fece4 SRRH |
1885 | |
1886 | if (rec->flags & FTRACE_FL_DISABLED) | |
1887 | continue; | |
1888 | ||
f8b8be8a MH |
1889 | /* We need to update only differences of filter_hash */ |
1890 | in_old = !!ftrace_lookup_ip(old_hash, rec->ip); | |
1891 | in_new = !!ftrace_lookup_ip(new_hash, rec->ip); | |
1892 | if (in_old == in_new) | |
1893 | continue; | |
1894 | ||
1895 | if (in_new) { | |
1896 | /* New entries must ensure no others are using it */ | |
1897 | if (rec->flags & FTRACE_FL_IPMODIFY) | |
1898 | goto rollback; | |
1899 | rec->flags |= FTRACE_FL_IPMODIFY; | |
1900 | } else /* Removed entry */ | |
1901 | rec->flags &= ~FTRACE_FL_IPMODIFY; | |
1902 | } while_for_each_ftrace_rec(); | |
1903 | ||
1904 | return 0; | |
1905 | ||
1906 | rollback: | |
1907 | end = rec; | |
1908 | ||
1909 | /* Roll back what we did above */ | |
1910 | do_for_each_ftrace_rec(pg, rec) { | |
546fece4 SRRH |
1911 | |
1912 | if (rec->flags & FTRACE_FL_DISABLED) | |
1913 | continue; | |
1914 | ||
f8b8be8a MH |
1915 | if (rec == end) |
1916 | goto err_out; | |
1917 | ||
1918 | in_old = !!ftrace_lookup_ip(old_hash, rec->ip); | |
1919 | in_new = !!ftrace_lookup_ip(new_hash, rec->ip); | |
1920 | if (in_old == in_new) | |
1921 | continue; | |
1922 | ||
1923 | if (in_new) | |
1924 | rec->flags &= ~FTRACE_FL_IPMODIFY; | |
1925 | else | |
1926 | rec->flags |= FTRACE_FL_IPMODIFY; | |
1927 | } while_for_each_ftrace_rec(); | |
1928 | ||
1929 | err_out: | |
1930 | return -EBUSY; | |
1931 | } | |
1932 | ||
1933 | static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops) | |
1934 | { | |
1935 | struct ftrace_hash *hash = ops->func_hash->filter_hash; | |
1936 | ||
1937 | if (ftrace_hash_empty(hash)) | |
1938 | hash = NULL; | |
1939 | ||
1940 | return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash); | |
1941 | } | |
1942 | ||
1943 | /* Disabling always succeeds */ | |
1944 | static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops) | |
1945 | { | |
1946 | struct ftrace_hash *hash = ops->func_hash->filter_hash; | |
1947 | ||
1948 | if (ftrace_hash_empty(hash)) | |
1949 | hash = NULL; | |
1950 | ||
1951 | __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH); | |
1952 | } | |
1953 | ||
1954 | static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, | |
1955 | struct ftrace_hash *new_hash) | |
1956 | { | |
1957 | struct ftrace_hash *old_hash = ops->func_hash->filter_hash; | |
1958 | ||
1959 | if (ftrace_hash_empty(old_hash)) | |
1960 | old_hash = NULL; | |
1961 | ||
1962 | if (ftrace_hash_empty(new_hash)) | |
1963 | new_hash = NULL; | |
1964 | ||
1965 | return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash); | |
1966 | } | |
1967 | ||
b05086c7 | 1968 | static void print_ip_ins(const char *fmt, const unsigned char *p) |
b17e8a37 SR |
1969 | { |
1970 | int i; | |
1971 | ||
1972 | printk(KERN_CONT "%s", fmt); | |
1973 | ||
1974 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
1975 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
1976 | } | |
1977 | ||
02a392a0 | 1978 | enum ftrace_bug_type ftrace_bug_type; |
b05086c7 | 1979 | const void *ftrace_expected; |
02a392a0 SRRH |
1980 | |
1981 | static void print_bug_type(void) | |
1982 | { | |
1983 | switch (ftrace_bug_type) { | |
1984 | case FTRACE_BUG_UNKNOWN: | |
1985 | break; | |
1986 | case FTRACE_BUG_INIT: | |
1987 | pr_info("Initializing ftrace call sites\n"); | |
1988 | break; | |
1989 | case FTRACE_BUG_NOP: | |
1990 | pr_info("Setting ftrace call site to NOP\n"); | |
1991 | break; | |
1992 | case FTRACE_BUG_CALL: | |
1993 | pr_info("Setting ftrace call site to call ftrace function\n"); | |
1994 | break; | |
1995 | case FTRACE_BUG_UPDATE: | |
1996 | pr_info("Updating ftrace call site to call a different ftrace function\n"); | |
1997 | break; | |
1998 | } | |
1999 | } | |
2000 | ||
c88fd863 SR |
2001 | /** |
2002 | * ftrace_bug - report and shutdown function tracer | |
2003 | * @failed: The failed type (EFAULT, EINVAL, EPERM) | |
4fd3279b | 2004 | * @rec: The record that failed |
c88fd863 SR |
2005 | * |
2006 | * The arch code that enables or disables the function tracing | |
2007 | * can call ftrace_bug() when it has detected a problem in | |
2008 | * modifying the code. @failed should be one of either: | |
2009 | * EFAULT - if the problem happens on reading the @ip address | |
2010 | * EINVAL - if what is read at @ip is not what was expected | |
9efb85c5 | 2011 | * EPERM - if the problem happens on writing to the @ip address |
c88fd863 | 2012 | */ |
4fd3279b | 2013 | void ftrace_bug(int failed, struct dyn_ftrace *rec) |
b17e8a37 | 2014 | { |
4fd3279b SRRH |
2015 | unsigned long ip = rec ? rec->ip : 0; |
2016 | ||
c143b775 CJ |
2017 | pr_info("------------[ ftrace bug ]------------\n"); |
2018 | ||
b17e8a37 SR |
2019 | switch (failed) { |
2020 | case -EFAULT: | |
b17e8a37 | 2021 | pr_info("ftrace faulted on modifying "); |
2062a4e8 | 2022 | print_ip_sym(KERN_INFO, ip); |
b17e8a37 SR |
2023 | break; |
2024 | case -EINVAL: | |
b17e8a37 | 2025 | pr_info("ftrace failed to modify "); |
2062a4e8 | 2026 | print_ip_sym(KERN_INFO, ip); |
b05086c7 | 2027 | print_ip_ins(" actual: ", (unsigned char *)ip); |
4fd3279b | 2028 | pr_cont("\n"); |
b05086c7 SRRH |
2029 | if (ftrace_expected) { |
2030 | print_ip_ins(" expected: ", ftrace_expected); | |
2031 | pr_cont("\n"); | |
2032 | } | |
b17e8a37 SR |
2033 | break; |
2034 | case -EPERM: | |
b17e8a37 | 2035 | pr_info("ftrace faulted on writing "); |
2062a4e8 | 2036 | print_ip_sym(KERN_INFO, ip); |
b17e8a37 SR |
2037 | break; |
2038 | default: | |
b17e8a37 | 2039 | pr_info("ftrace faulted on unknown error "); |
2062a4e8 | 2040 | print_ip_sym(KERN_INFO, ip); |
b17e8a37 | 2041 | } |
02a392a0 | 2042 | print_bug_type(); |
4fd3279b SRRH |
2043 | if (rec) { |
2044 | struct ftrace_ops *ops = NULL; | |
2045 | ||
2046 | pr_info("ftrace record flags: %lx\n", rec->flags); | |
2047 | pr_cont(" (%ld)%s", ftrace_rec_count(rec), | |
2048 | rec->flags & FTRACE_FL_REGS ? " R" : " "); | |
2049 | if (rec->flags & FTRACE_FL_TRAMP_EN) { | |
2050 | ops = ftrace_find_tramp_ops_any(rec); | |
39daa7b9 SRRH |
2051 | if (ops) { |
2052 | do { | |
2053 | pr_cont("\ttramp: %pS (%pS)", | |
2054 | (void *)ops->trampoline, | |
2055 | (void *)ops->func); | |
2056 | ops = ftrace_find_tramp_ops_next(rec, ops); | |
2057 | } while (ops); | |
2058 | } else | |
4fd3279b SRRH |
2059 | pr_cont("\ttramp: ERROR!"); |
2060 | ||
2061 | } | |
2062 | ip = ftrace_get_addr_curr(rec); | |
39daa7b9 | 2063 | pr_cont("\n expected tramp: %lx\n", ip); |
4fd3279b | 2064 | } |
c143b775 CJ |
2065 | |
2066 | FTRACE_WARN_ON_ONCE(1); | |
b17e8a37 SR |
2067 | } |
2068 | ||
7375dca1 | 2069 | static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update) |
5072c59f | 2070 | { |
64fbcd16 | 2071 | unsigned long flag = 0UL; |
e7d3737e | 2072 | |
02a392a0 SRRH |
2073 | ftrace_bug_type = FTRACE_BUG_UNKNOWN; |
2074 | ||
b7ffffbb SRRH |
2075 | if (rec->flags & FTRACE_FL_DISABLED) |
2076 | return FTRACE_UPDATE_IGNORE; | |
2077 | ||
982c350b | 2078 | /* |
30fb6aa7 | 2079 | * If we are updating calls: |
982c350b | 2080 | * |
ed926f9b SR |
2081 | * If the record has a ref count, then we need to enable it |
2082 | * because someone is using it. | |
982c350b | 2083 | * |
ed926f9b SR |
2084 | * Otherwise we make sure its disabled. |
2085 | * | |
30fb6aa7 | 2086 | * If we are disabling calls, then disable all records that |
ed926f9b | 2087 | * are enabled. |
982c350b | 2088 | */ |
0376bde1 | 2089 | if (enable && ftrace_rec_count(rec)) |
ed926f9b | 2090 | flag = FTRACE_FL_ENABLED; |
982c350b | 2091 | |
08f6fba5 | 2092 | /* |
79922b80 SRRH |
2093 | * If enabling and the REGS flag does not match the REGS_EN, or |
2094 | * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore | |
2095 | * this record. Set flags to fail the compare against ENABLED. | |
763e34e7 | 2096 | * Same for direct calls. |
08f6fba5 | 2097 | */ |
79922b80 | 2098 | if (flag) { |
763e34e7 | 2099 | if (!(rec->flags & FTRACE_FL_REGS) != |
79922b80 SRRH |
2100 | !(rec->flags & FTRACE_FL_REGS_EN)) |
2101 | flag |= FTRACE_FL_REGS; | |
2102 | ||
763e34e7 | 2103 | if (!(rec->flags & FTRACE_FL_TRAMP) != |
79922b80 SRRH |
2104 | !(rec->flags & FTRACE_FL_TRAMP_EN)) |
2105 | flag |= FTRACE_FL_TRAMP; | |
763e34e7 SRV |
2106 | |
2107 | /* | |
2108 | * Direct calls are special, as count matters. | |
2109 | * We must test the record for direct, if the | |
2110 | * DIRECT and DIRECT_EN do not match, but only | |
2111 | * if the count is 1. That's because, if the | |
2112 | * count is something other than one, we do not | |
2113 | * want the direct enabled (it will be done via the | |
2114 | * direct helper). But if DIRECT_EN is set, and | |
2115 | * the count is not one, we need to clear it. | |
2116 | */ | |
2117 | if (ftrace_rec_count(rec) == 1) { | |
2118 | if (!(rec->flags & FTRACE_FL_DIRECT) != | |
2119 | !(rec->flags & FTRACE_FL_DIRECT_EN)) | |
2120 | flag |= FTRACE_FL_DIRECT; | |
2121 | } else if (rec->flags & FTRACE_FL_DIRECT_EN) { | |
2122 | flag |= FTRACE_FL_DIRECT; | |
2123 | } | |
79922b80 | 2124 | } |
08f6fba5 | 2125 | |
64fbcd16 XG |
2126 | /* If the state of this record hasn't changed, then do nothing */ |
2127 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
c88fd863 | 2128 | return FTRACE_UPDATE_IGNORE; |
982c350b | 2129 | |
64fbcd16 | 2130 | if (flag) { |
08f6fba5 SR |
2131 | /* Save off if rec is being enabled (for return value) */ |
2132 | flag ^= rec->flags & FTRACE_FL_ENABLED; | |
2133 | ||
2134 | if (update) { | |
c88fd863 | 2135 | rec->flags |= FTRACE_FL_ENABLED; |
08f6fba5 SR |
2136 | if (flag & FTRACE_FL_REGS) { |
2137 | if (rec->flags & FTRACE_FL_REGS) | |
2138 | rec->flags |= FTRACE_FL_REGS_EN; | |
2139 | else | |
2140 | rec->flags &= ~FTRACE_FL_REGS_EN; | |
2141 | } | |
79922b80 SRRH |
2142 | if (flag & FTRACE_FL_TRAMP) { |
2143 | if (rec->flags & FTRACE_FL_TRAMP) | |
2144 | rec->flags |= FTRACE_FL_TRAMP_EN; | |
2145 | else | |
2146 | rec->flags &= ~FTRACE_FL_TRAMP_EN; | |
2147 | } | |
d19ad077 | 2148 | |
763e34e7 SRV |
2149 | if (flag & FTRACE_FL_DIRECT) { |
2150 | /* | |
2151 | * If there's only one user (direct_ops helper) | |
2152 | * then we can call the direct function | |
2153 | * directly (no ftrace trampoline). | |
2154 | */ | |
2155 | if (ftrace_rec_count(rec) == 1) { | |
2156 | if (rec->flags & FTRACE_FL_DIRECT) | |
2157 | rec->flags |= FTRACE_FL_DIRECT_EN; | |
2158 | else | |
2159 | rec->flags &= ~FTRACE_FL_DIRECT_EN; | |
2160 | } else { | |
2161 | /* | |
2162 | * Can only call directly if there's | |
2163 | * only one callback to the function. | |
2164 | */ | |
2165 | rec->flags &= ~FTRACE_FL_DIRECT_EN; | |
2166 | } | |
2167 | } | |
08f6fba5 SR |
2168 | } |
2169 | ||
2170 | /* | |
2171 | * If this record is being updated from a nop, then | |
2172 | * return UPDATE_MAKE_CALL. | |
08f6fba5 SR |
2173 | * Otherwise, |
2174 | * return UPDATE_MODIFY_CALL to tell the caller to convert | |
f1b2f2bd | 2175 | * from the save regs, to a non-save regs function or |
79922b80 | 2176 | * vice versa, or from a trampoline call. |
08f6fba5 | 2177 | */ |
02a392a0 SRRH |
2178 | if (flag & FTRACE_FL_ENABLED) { |
2179 | ftrace_bug_type = FTRACE_BUG_CALL; | |
08f6fba5 | 2180 | return FTRACE_UPDATE_MAKE_CALL; |
02a392a0 | 2181 | } |
f1b2f2bd | 2182 | |
02a392a0 | 2183 | ftrace_bug_type = FTRACE_BUG_UPDATE; |
f1b2f2bd | 2184 | return FTRACE_UPDATE_MODIFY_CALL; |
c88fd863 SR |
2185 | } |
2186 | ||
08f6fba5 SR |
2187 | if (update) { |
2188 | /* If there's no more users, clear all flags */ | |
0376bde1 | 2189 | if (!ftrace_rec_count(rec)) |
08f6fba5 SR |
2190 | rec->flags = 0; |
2191 | else | |
b24d443b SRRH |
2192 | /* |
2193 | * Just disable the record, but keep the ops TRAMP | |
2194 | * and REGS states. The _EN flags must be disabled though. | |
2195 | */ | |
2196 | rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN | | |
763e34e7 | 2197 | FTRACE_FL_REGS_EN | FTRACE_FL_DIRECT_EN); |
08f6fba5 | 2198 | } |
c88fd863 | 2199 | |
02a392a0 | 2200 | ftrace_bug_type = FTRACE_BUG_NOP; |
c88fd863 SR |
2201 | return FTRACE_UPDATE_MAKE_NOP; |
2202 | } | |
2203 | ||
2204 | /** | |
2205 | * ftrace_update_record, set a record that now is tracing or not | |
2206 | * @rec: the record to update | |
7375dca1 | 2207 | * @enable: set to true if the record is tracing, false to force disable |
c88fd863 SR |
2208 | * |
2209 | * The records that represent all functions that can be traced need | |
2210 | * to be updated when tracing has been enabled. | |
2211 | */ | |
7375dca1 | 2212 | int ftrace_update_record(struct dyn_ftrace *rec, bool enable) |
c88fd863 | 2213 | { |
7375dca1 | 2214 | return ftrace_check_record(rec, enable, true); |
c88fd863 SR |
2215 | } |
2216 | ||
2217 | /** | |
2218 | * ftrace_test_record, check if the record has been enabled or not | |
2219 | * @rec: the record to test | |
7375dca1 | 2220 | * @enable: set to true to check if enabled, false if it is disabled |
c88fd863 SR |
2221 | * |
2222 | * The arch code may need to test if a record is already set to | |
2223 | * tracing to determine how to modify the function code that it | |
2224 | * represents. | |
2225 | */ | |
7375dca1 | 2226 | int ftrace_test_record(struct dyn_ftrace *rec, bool enable) |
c88fd863 | 2227 | { |
7375dca1 | 2228 | return ftrace_check_record(rec, enable, false); |
c88fd863 SR |
2229 | } |
2230 | ||
5fecaa04 SRRH |
2231 | static struct ftrace_ops * |
2232 | ftrace_find_tramp_ops_any(struct dyn_ftrace *rec) | |
2233 | { | |
2234 | struct ftrace_ops *op; | |
fef5aeee | 2235 | unsigned long ip = rec->ip; |
5fecaa04 SRRH |
2236 | |
2237 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2238 | ||
2239 | if (!op->trampoline) | |
2240 | continue; | |
2241 | ||
fef5aeee | 2242 | if (hash_contains_ip(ip, op->func_hash)) |
5fecaa04 SRRH |
2243 | return op; |
2244 | } while_for_each_ftrace_op(op); | |
2245 | ||
2246 | return NULL; | |
2247 | } | |
2248 | ||
4c75b0ff NR |
2249 | static struct ftrace_ops * |
2250 | ftrace_find_tramp_ops_any_other(struct dyn_ftrace *rec, struct ftrace_ops *op_exclude) | |
2251 | { | |
2252 | struct ftrace_ops *op; | |
2253 | unsigned long ip = rec->ip; | |
2254 | ||
2255 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2256 | ||
2257 | if (op == op_exclude || !op->trampoline) | |
2258 | continue; | |
2259 | ||
2260 | if (hash_contains_ip(ip, op->func_hash)) | |
2261 | return op; | |
2262 | } while_for_each_ftrace_op(op); | |
2263 | ||
2264 | return NULL; | |
2265 | } | |
2266 | ||
39daa7b9 SRRH |
2267 | static struct ftrace_ops * |
2268 | ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, | |
2269 | struct ftrace_ops *op) | |
2270 | { | |
2271 | unsigned long ip = rec->ip; | |
2272 | ||
2273 | while_for_each_ftrace_op(op) { | |
2274 | ||
2275 | if (!op->trampoline) | |
2276 | continue; | |
2277 | ||
2278 | if (hash_contains_ip(ip, op->func_hash)) | |
2279 | return op; | |
026bb845 | 2280 | } |
39daa7b9 SRRH |
2281 | |
2282 | return NULL; | |
2283 | } | |
2284 | ||
79922b80 SRRH |
2285 | static struct ftrace_ops * |
2286 | ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec) | |
2287 | { | |
2288 | struct ftrace_ops *op; | |
fef5aeee | 2289 | unsigned long ip = rec->ip; |
79922b80 | 2290 | |
fef5aeee SRRH |
2291 | /* |
2292 | * Need to check removed ops first. | |
2293 | * If they are being removed, and this rec has a tramp, | |
2294 | * and this rec is in the ops list, then it would be the | |
2295 | * one with the tramp. | |
2296 | */ | |
2297 | if (removed_ops) { | |
2298 | if (hash_contains_ip(ip, &removed_ops->old_hash)) | |
79922b80 SRRH |
2299 | return removed_ops; |
2300 | } | |
2301 | ||
fef5aeee SRRH |
2302 | /* |
2303 | * Need to find the current trampoline for a rec. | |
2304 | * Now, a trampoline is only attached to a rec if there | |
2305 | * was a single 'ops' attached to it. But this can be called | |
2306 | * when we are adding another op to the rec or removing the | |
2307 | * current one. Thus, if the op is being added, we can | |
2308 | * ignore it because it hasn't attached itself to the rec | |
4fc40904 SRRH |
2309 | * yet. |
2310 | * | |
2311 | * If an ops is being modified (hooking to different functions) | |
2312 | * then we don't care about the new functions that are being | |
2313 | * added, just the old ones (that are probably being removed). | |
2314 | * | |
2315 | * If we are adding an ops to a function that already is using | |
2316 | * a trampoline, it needs to be removed (trampolines are only | |
2317 | * for single ops connected), then an ops that is not being | |
2318 | * modified also needs to be checked. | |
fef5aeee | 2319 | */ |
79922b80 | 2320 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
fef5aeee SRRH |
2321 | |
2322 | if (!op->trampoline) | |
2323 | continue; | |
2324 | ||
2325 | /* | |
2326 | * If the ops is being added, it hasn't gotten to | |
2327 | * the point to be removed from this tree yet. | |
2328 | */ | |
2329 | if (op->flags & FTRACE_OPS_FL_ADDING) | |
79922b80 SRRH |
2330 | continue; |
2331 | ||
4fc40904 | 2332 | |
fef5aeee | 2333 | /* |
4fc40904 SRRH |
2334 | * If the ops is being modified and is in the old |
2335 | * hash, then it is probably being removed from this | |
2336 | * function. | |
fef5aeee | 2337 | */ |
fef5aeee SRRH |
2338 | if ((op->flags & FTRACE_OPS_FL_MODIFYING) && |
2339 | hash_contains_ip(ip, &op->old_hash)) | |
79922b80 | 2340 | return op; |
4fc40904 SRRH |
2341 | /* |
2342 | * If the ops is not being added or modified, and it's | |
2343 | * in its normal filter hash, then this must be the one | |
2344 | * we want! | |
2345 | */ | |
2346 | if (!(op->flags & FTRACE_OPS_FL_MODIFYING) && | |
2347 | hash_contains_ip(ip, op->func_hash)) | |
2348 | return op; | |
79922b80 SRRH |
2349 | |
2350 | } while_for_each_ftrace_op(op); | |
2351 | ||
2352 | return NULL; | |
2353 | } | |
2354 | ||
2355 | static struct ftrace_ops * | |
2356 | ftrace_find_tramp_ops_new(struct dyn_ftrace *rec) | |
2357 | { | |
2358 | struct ftrace_ops *op; | |
fef5aeee | 2359 | unsigned long ip = rec->ip; |
79922b80 SRRH |
2360 | |
2361 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2362 | /* pass rec in as regs to have non-NULL val */ | |
fef5aeee | 2363 | if (hash_contains_ip(ip, op->func_hash)) |
79922b80 SRRH |
2364 | return op; |
2365 | } while_for_each_ftrace_op(op); | |
2366 | ||
2367 | return NULL; | |
2368 | } | |
2369 | ||
763e34e7 SRV |
2370 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
2371 | /* Protected by rcu_tasks for reading, and direct_mutex for writing */ | |
2372 | static struct ftrace_hash *direct_functions = EMPTY_HASH; | |
2373 | static DEFINE_MUTEX(direct_mutex); | |
a3ad1a7e | 2374 | int ftrace_direct_func_count; |
763e34e7 SRV |
2375 | |
2376 | /* | |
2377 | * Search the direct_functions hash to see if the given instruction pointer | |
2378 | * has a direct caller attached to it. | |
2379 | */ | |
ff205766 | 2380 | unsigned long ftrace_find_rec_direct(unsigned long ip) |
763e34e7 SRV |
2381 | { |
2382 | struct ftrace_func_entry *entry; | |
2383 | ||
2384 | entry = __ftrace_lookup_ip(direct_functions, ip); | |
2385 | if (!entry) | |
2386 | return 0; | |
2387 | ||
2388 | return entry->direct; | |
2389 | } | |
2390 | ||
2391 | static void call_direct_funcs(unsigned long ip, unsigned long pip, | |
d19ad077 | 2392 | struct ftrace_ops *ops, struct ftrace_regs *fregs) |
763e34e7 | 2393 | { |
d19ad077 | 2394 | struct pt_regs *regs = ftrace_get_regs(fregs); |
763e34e7 SRV |
2395 | unsigned long addr; |
2396 | ||
ff205766 | 2397 | addr = ftrace_find_rec_direct(ip); |
763e34e7 SRV |
2398 | if (!addr) |
2399 | return; | |
2400 | ||
2401 | arch_ftrace_set_direct_caller(regs, addr); | |
2402 | } | |
2403 | ||
2404 | struct ftrace_ops direct_ops = { | |
2405 | .func = call_direct_funcs, | |
a25d036d | 2406 | .flags = FTRACE_OPS_FL_IPMODIFY |
763e34e7 SRV |
2407 | | FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_REGS |
2408 | | FTRACE_OPS_FL_PERMANENT, | |
5da7cd11 SRV |
2409 | /* |
2410 | * By declaring the main trampoline as this trampoline | |
2411 | * it will never have one allocated for it. Allocated | |
2412 | * trampolines should not call direct functions. | |
2413 | * The direct_ops should only be called by the builtin | |
2414 | * ftrace_regs_caller trampoline. | |
2415 | */ | |
2416 | .trampoline = FTRACE_REGS_ADDR, | |
763e34e7 | 2417 | }; |
763e34e7 SRV |
2418 | #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ |
2419 | ||
7413af1f SRRH |
2420 | /** |
2421 | * ftrace_get_addr_new - Get the call address to set to | |
2422 | * @rec: The ftrace record descriptor | |
2423 | * | |
2424 | * If the record has the FTRACE_FL_REGS set, that means that it | |
2425 | * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS | |
5c8c206e | 2426 | * is not set, then it wants to convert to the normal callback. |
7413af1f SRRH |
2427 | * |
2428 | * Returns the address of the trampoline to set to | |
2429 | */ | |
2430 | unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec) | |
2431 | { | |
79922b80 | 2432 | struct ftrace_ops *ops; |
763e34e7 SRV |
2433 | unsigned long addr; |
2434 | ||
2435 | if ((rec->flags & FTRACE_FL_DIRECT) && | |
2436 | (ftrace_rec_count(rec) == 1)) { | |
ff205766 | 2437 | addr = ftrace_find_rec_direct(rec->ip); |
763e34e7 SRV |
2438 | if (addr) |
2439 | return addr; | |
2440 | WARN_ON_ONCE(1); | |
2441 | } | |
79922b80 SRRH |
2442 | |
2443 | /* Trampolines take precedence over regs */ | |
2444 | if (rec->flags & FTRACE_FL_TRAMP) { | |
2445 | ops = ftrace_find_tramp_ops_new(rec); | |
2446 | if (FTRACE_WARN_ON(!ops || !ops->trampoline)) { | |
bce0b6c5 SRRH |
2447 | pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n", |
2448 | (void *)rec->ip, (void *)rec->ip, rec->flags); | |
79922b80 SRRH |
2449 | /* Ftrace is shutting down, return anything */ |
2450 | return (unsigned long)FTRACE_ADDR; | |
2451 | } | |
2452 | return ops->trampoline; | |
2453 | } | |
2454 | ||
7413af1f SRRH |
2455 | if (rec->flags & FTRACE_FL_REGS) |
2456 | return (unsigned long)FTRACE_REGS_ADDR; | |
2457 | else | |
2458 | return (unsigned long)FTRACE_ADDR; | |
2459 | } | |
2460 | ||
2461 | /** | |
2462 | * ftrace_get_addr_curr - Get the call address that is already there | |
2463 | * @rec: The ftrace record descriptor | |
2464 | * | |
2465 | * The FTRACE_FL_REGS_EN is set when the record already points to | |
2466 | * a function that saves all the regs. Basically the '_EN' version | |
2467 | * represents the current state of the function. | |
2468 | * | |
2469 | * Returns the address of the trampoline that is currently being called | |
2470 | */ | |
2471 | unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec) | |
2472 | { | |
79922b80 | 2473 | struct ftrace_ops *ops; |
763e34e7 SRV |
2474 | unsigned long addr; |
2475 | ||
2476 | /* Direct calls take precedence over trampolines */ | |
2477 | if (rec->flags & FTRACE_FL_DIRECT_EN) { | |
ff205766 | 2478 | addr = ftrace_find_rec_direct(rec->ip); |
763e34e7 SRV |
2479 | if (addr) |
2480 | return addr; | |
2481 | WARN_ON_ONCE(1); | |
2482 | } | |
79922b80 SRRH |
2483 | |
2484 | /* Trampolines take precedence over regs */ | |
2485 | if (rec->flags & FTRACE_FL_TRAMP_EN) { | |
2486 | ops = ftrace_find_tramp_ops_curr(rec); | |
2487 | if (FTRACE_WARN_ON(!ops)) { | |
a395d6a7 JP |
2488 | pr_warn("Bad trampoline accounting at: %p (%pS)\n", |
2489 | (void *)rec->ip, (void *)rec->ip); | |
79922b80 SRRH |
2490 | /* Ftrace is shutting down, return anything */ |
2491 | return (unsigned long)FTRACE_ADDR; | |
2492 | } | |
2493 | return ops->trampoline; | |
2494 | } | |
2495 | ||
7413af1f SRRH |
2496 | if (rec->flags & FTRACE_FL_REGS_EN) |
2497 | return (unsigned long)FTRACE_REGS_ADDR; | |
2498 | else | |
2499 | return (unsigned long)FTRACE_ADDR; | |
2500 | } | |
2501 | ||
c88fd863 | 2502 | static int |
7375dca1 | 2503 | __ftrace_replace_code(struct dyn_ftrace *rec, bool enable) |
c88fd863 | 2504 | { |
08f6fba5 | 2505 | unsigned long ftrace_old_addr; |
c88fd863 SR |
2506 | unsigned long ftrace_addr; |
2507 | int ret; | |
2508 | ||
7c0868e0 | 2509 | ftrace_addr = ftrace_get_addr_new(rec); |
c88fd863 | 2510 | |
7c0868e0 SRRH |
2511 | /* This needs to be done before we call ftrace_update_record */ |
2512 | ftrace_old_addr = ftrace_get_addr_curr(rec); | |
2513 | ||
2514 | ret = ftrace_update_record(rec, enable); | |
08f6fba5 | 2515 | |
02a392a0 SRRH |
2516 | ftrace_bug_type = FTRACE_BUG_UNKNOWN; |
2517 | ||
c88fd863 SR |
2518 | switch (ret) { |
2519 | case FTRACE_UPDATE_IGNORE: | |
2520 | return 0; | |
2521 | ||
2522 | case FTRACE_UPDATE_MAKE_CALL: | |
02a392a0 | 2523 | ftrace_bug_type = FTRACE_BUG_CALL; |
64fbcd16 | 2524 | return ftrace_make_call(rec, ftrace_addr); |
c88fd863 SR |
2525 | |
2526 | case FTRACE_UPDATE_MAKE_NOP: | |
02a392a0 | 2527 | ftrace_bug_type = FTRACE_BUG_NOP; |
39b5552c | 2528 | return ftrace_make_nop(NULL, rec, ftrace_old_addr); |
08f6fba5 | 2529 | |
08f6fba5 | 2530 | case FTRACE_UPDATE_MODIFY_CALL: |
02a392a0 | 2531 | ftrace_bug_type = FTRACE_BUG_UPDATE; |
08f6fba5 | 2532 | return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr); |
5072c59f SR |
2533 | } |
2534 | ||
9efb85c5 | 2535 | return -1; /* unknown ftrace bug */ |
5072c59f SR |
2536 | } |
2537 | ||
a0572f68 | 2538 | void __weak ftrace_replace_code(int mod_flags) |
3c1720f0 | 2539 | { |
3c1720f0 SR |
2540 | struct dyn_ftrace *rec; |
2541 | struct ftrace_page *pg; | |
7375dca1 | 2542 | bool enable = mod_flags & FTRACE_MODIFY_ENABLE_FL; |
a0572f68 | 2543 | int schedulable = mod_flags & FTRACE_MODIFY_MAY_SLEEP_FL; |
6a24a244 | 2544 | int failed; |
3c1720f0 | 2545 | |
45a4a237 SR |
2546 | if (unlikely(ftrace_disabled)) |
2547 | return; | |
2548 | ||
265c831c | 2549 | do_for_each_ftrace_rec(pg, rec) { |
546fece4 SRRH |
2550 | |
2551 | if (rec->flags & FTRACE_FL_DISABLED) | |
2552 | continue; | |
2553 | ||
e4f5d544 | 2554 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 2555 | if (failed) { |
4fd3279b | 2556 | ftrace_bug(failed, rec); |
3279ba37 SR |
2557 | /* Stop processing */ |
2558 | return; | |
3c1720f0 | 2559 | } |
a0572f68 SRV |
2560 | if (schedulable) |
2561 | cond_resched(); | |
265c831c | 2562 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
2563 | } |
2564 | ||
c88fd863 SR |
2565 | struct ftrace_rec_iter { |
2566 | struct ftrace_page *pg; | |
2567 | int index; | |
2568 | }; | |
2569 | ||
2570 | /** | |
2571 | * ftrace_rec_iter_start, start up iterating over traced functions | |
2572 | * | |
2573 | * Returns an iterator handle that is used to iterate over all | |
2574 | * the records that represent address locations where functions | |
2575 | * are traced. | |
2576 | * | |
2577 | * May return NULL if no records are available. | |
2578 | */ | |
2579 | struct ftrace_rec_iter *ftrace_rec_iter_start(void) | |
2580 | { | |
2581 | /* | |
2582 | * We only use a single iterator. | |
2583 | * Protected by the ftrace_lock mutex. | |
2584 | */ | |
2585 | static struct ftrace_rec_iter ftrace_rec_iter; | |
2586 | struct ftrace_rec_iter *iter = &ftrace_rec_iter; | |
2587 | ||
2588 | iter->pg = ftrace_pages_start; | |
2589 | iter->index = 0; | |
2590 | ||
2591 | /* Could have empty pages */ | |
2592 | while (iter->pg && !iter->pg->index) | |
2593 | iter->pg = iter->pg->next; | |
2594 | ||
2595 | if (!iter->pg) | |
2596 | return NULL; | |
2597 | ||
2598 | return iter; | |
2599 | } | |
2600 | ||
2601 | /** | |
2602 | * ftrace_rec_iter_next, get the next record to process. | |
2603 | * @iter: The handle to the iterator. | |
2604 | * | |
2605 | * Returns the next iterator after the given iterator @iter. | |
2606 | */ | |
2607 | struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) | |
2608 | { | |
2609 | iter->index++; | |
2610 | ||
2611 | if (iter->index >= iter->pg->index) { | |
2612 | iter->pg = iter->pg->next; | |
2613 | iter->index = 0; | |
2614 | ||
2615 | /* Could have empty pages */ | |
2616 | while (iter->pg && !iter->pg->index) | |
2617 | iter->pg = iter->pg->next; | |
2618 | } | |
2619 | ||
2620 | if (!iter->pg) | |
2621 | return NULL; | |
2622 | ||
2623 | return iter; | |
2624 | } | |
2625 | ||
2626 | /** | |
2627 | * ftrace_rec_iter_record, get the record at the iterator location | |
2628 | * @iter: The current iterator location | |
2629 | * | |
2630 | * Returns the record that the current @iter is at. | |
2631 | */ | |
2632 | struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) | |
2633 | { | |
2634 | return &iter->pg->records[iter->index]; | |
2635 | } | |
2636 | ||
492a7ea5 | 2637 | static int |
fbf6c73c | 2638 | ftrace_nop_initialize(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 | 2639 | { |
593eb8a2 | 2640 | int ret; |
3c1720f0 | 2641 | |
45a4a237 SR |
2642 | if (unlikely(ftrace_disabled)) |
2643 | return 0; | |
2644 | ||
fbf6c73c | 2645 | ret = ftrace_init_nop(mod, rec); |
593eb8a2 | 2646 | if (ret) { |
02a392a0 | 2647 | ftrace_bug_type = FTRACE_BUG_INIT; |
4fd3279b | 2648 | ftrace_bug(ret, rec); |
492a7ea5 | 2649 | return 0; |
37ad5084 | 2650 | } |
492a7ea5 | 2651 | return 1; |
3c1720f0 SR |
2652 | } |
2653 | ||
000ab691 SR |
2654 | /* |
2655 | * archs can override this function if they must do something | |
2656 | * before the modifying code is performed. | |
2657 | */ | |
2658 | int __weak ftrace_arch_code_modify_prepare(void) | |
2659 | { | |
2660 | return 0; | |
2661 | } | |
2662 | ||
2663 | /* | |
2664 | * archs can override this function if they must do something | |
2665 | * after the modifying code is performed. | |
2666 | */ | |
2667 | int __weak ftrace_arch_code_modify_post_process(void) | |
2668 | { | |
2669 | return 0; | |
2670 | } | |
2671 | ||
8ed3e2cf | 2672 | void ftrace_modify_all_code(int command) |
3d083395 | 2673 | { |
59338f75 | 2674 | int update = command & FTRACE_UPDATE_TRACE_FUNC; |
a0572f68 | 2675 | int mod_flags = 0; |
cd21067f | 2676 | int err = 0; |
59338f75 | 2677 | |
a0572f68 SRV |
2678 | if (command & FTRACE_MAY_SLEEP) |
2679 | mod_flags = FTRACE_MODIFY_MAY_SLEEP_FL; | |
2680 | ||
59338f75 SRRH |
2681 | /* |
2682 | * If the ftrace_caller calls a ftrace_ops func directly, | |
2683 | * we need to make sure that it only traces functions it | |
2684 | * expects to trace. When doing the switch of functions, | |
2685 | * we need to update to the ftrace_ops_list_func first | |
2686 | * before the transition between old and new calls are set, | |
2687 | * as the ftrace_ops_list_func will check the ops hashes | |
2688 | * to make sure the ops are having the right functions | |
2689 | * traced. | |
2690 | */ | |
cd21067f PM |
2691 | if (update) { |
2692 | err = ftrace_update_ftrace_func(ftrace_ops_list_func); | |
2693 | if (FTRACE_WARN_ON(err)) | |
2694 | return; | |
2695 | } | |
59338f75 | 2696 | |
8ed3e2cf | 2697 | if (command & FTRACE_UPDATE_CALLS) |
a0572f68 | 2698 | ftrace_replace_code(mod_flags | FTRACE_MODIFY_ENABLE_FL); |
8ed3e2cf | 2699 | else if (command & FTRACE_DISABLE_CALLS) |
a0572f68 | 2700 | ftrace_replace_code(mod_flags); |
d61f82d0 | 2701 | |
405e1d83 SRRH |
2702 | if (update && ftrace_trace_function != ftrace_ops_list_func) { |
2703 | function_trace_op = set_function_trace_op; | |
2704 | smp_wmb(); | |
2705 | /* If irqs are disabled, we are in stop machine */ | |
2706 | if (!irqs_disabled()) | |
2707 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
cd21067f PM |
2708 | err = ftrace_update_ftrace_func(ftrace_trace_function); |
2709 | if (FTRACE_WARN_ON(err)) | |
2710 | return; | |
405e1d83 | 2711 | } |
d61f82d0 | 2712 | |
8ed3e2cf | 2713 | if (command & FTRACE_START_FUNC_RET) |
cd21067f | 2714 | err = ftrace_enable_ftrace_graph_caller(); |
8ed3e2cf | 2715 | else if (command & FTRACE_STOP_FUNC_RET) |
cd21067f PM |
2716 | err = ftrace_disable_ftrace_graph_caller(); |
2717 | FTRACE_WARN_ON(err); | |
8ed3e2cf SR |
2718 | } |
2719 | ||
2720 | static int __ftrace_modify_code(void *data) | |
2721 | { | |
2722 | int *command = data; | |
2723 | ||
2724 | ftrace_modify_all_code(*command); | |
5a45cfe1 | 2725 | |
d61f82d0 | 2726 | return 0; |
3d083395 SR |
2727 | } |
2728 | ||
c88fd863 SR |
2729 | /** |
2730 | * ftrace_run_stop_machine, go back to the stop machine method | |
2731 | * @command: The command to tell ftrace what to do | |
2732 | * | |
2733 | * If an arch needs to fall back to the stop machine method, the | |
2734 | * it can call this function. | |
2735 | */ | |
2736 | void ftrace_run_stop_machine(int command) | |
2737 | { | |
2738 | stop_machine(__ftrace_modify_code, &command, NULL); | |
2739 | } | |
2740 | ||
2741 | /** | |
2742 | * arch_ftrace_update_code, modify the code to trace or not trace | |
2743 | * @command: The command that needs to be done | |
2744 | * | |
2745 | * Archs can override this function if it does not need to | |
2746 | * run stop_machine() to modify code. | |
2747 | */ | |
2748 | void __weak arch_ftrace_update_code(int command) | |
2749 | { | |
2750 | ftrace_run_stop_machine(command); | |
2751 | } | |
2752 | ||
e309b41d | 2753 | static void ftrace_run_update_code(int command) |
3d083395 | 2754 | { |
000ab691 SR |
2755 | int ret; |
2756 | ||
2757 | ret = ftrace_arch_code_modify_prepare(); | |
2758 | FTRACE_WARN_ON(ret); | |
2759 | if (ret) | |
d5b844a2 | 2760 | return; |
000ab691 | 2761 | |
c88fd863 SR |
2762 | /* |
2763 | * By default we use stop_machine() to modify the code. | |
2764 | * But archs can do what ever they want as long as it | |
2765 | * is safe. The stop_machine() is the safest, but also | |
2766 | * produces the most overhead. | |
2767 | */ | |
2768 | arch_ftrace_update_code(command); | |
2769 | ||
000ab691 SR |
2770 | ret = ftrace_arch_code_modify_post_process(); |
2771 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
2772 | } |
2773 | ||
8252ecf3 | 2774 | static void ftrace_run_modify_code(struct ftrace_ops *ops, int command, |
7485058e | 2775 | struct ftrace_ops_hash *old_hash) |
e1effa01 SRRH |
2776 | { |
2777 | ops->flags |= FTRACE_OPS_FL_MODIFYING; | |
7485058e SRRH |
2778 | ops->old_hash.filter_hash = old_hash->filter_hash; |
2779 | ops->old_hash.notrace_hash = old_hash->notrace_hash; | |
e1effa01 | 2780 | ftrace_run_update_code(command); |
8252ecf3 | 2781 | ops->old_hash.filter_hash = NULL; |
7485058e | 2782 | ops->old_hash.notrace_hash = NULL; |
e1effa01 SRRH |
2783 | ops->flags &= ~FTRACE_OPS_FL_MODIFYING; |
2784 | } | |
2785 | ||
d61f82d0 | 2786 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 2787 | static int ftrace_start_up; |
df4fc315 | 2788 | |
12cce594 SRRH |
2789 | void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops) |
2790 | { | |
2791 | } | |
2792 | ||
fc0ea795 AH |
2793 | /* List of trace_ops that have allocated trampolines */ |
2794 | static LIST_HEAD(ftrace_ops_trampoline_list); | |
2795 | ||
2796 | static void ftrace_add_trampoline_to_kallsyms(struct ftrace_ops *ops) | |
2797 | { | |
2798 | lockdep_assert_held(&ftrace_lock); | |
2799 | list_add_rcu(&ops->list, &ftrace_ops_trampoline_list); | |
2800 | } | |
2801 | ||
2802 | static void ftrace_remove_trampoline_from_kallsyms(struct ftrace_ops *ops) | |
2803 | { | |
2804 | lockdep_assert_held(&ftrace_lock); | |
2805 | list_del_rcu(&ops->list); | |
478ece95 | 2806 | synchronize_rcu(); |
fc0ea795 AH |
2807 | } |
2808 | ||
2809 | /* | |
2810 | * "__builtin__ftrace" is used as a module name in /proc/kallsyms for symbols | |
2811 | * for pages allocated for ftrace purposes, even though "__builtin__ftrace" is | |
2812 | * not a module. | |
2813 | */ | |
2814 | #define FTRACE_TRAMPOLINE_MOD "__builtin__ftrace" | |
2815 | #define FTRACE_TRAMPOLINE_SYM "ftrace_trampoline" | |
2816 | ||
2817 | static void ftrace_trampoline_free(struct ftrace_ops *ops) | |
2818 | { | |
2819 | if (ops && (ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP) && | |
dd9ddf46 | 2820 | ops->trampoline) { |
548e1f6c AH |
2821 | /* |
2822 | * Record the text poke event before the ksymbol unregister | |
2823 | * event. | |
2824 | */ | |
2825 | perf_event_text_poke((void *)ops->trampoline, | |
2826 | (void *)ops->trampoline, | |
2827 | ops->trampoline_size, NULL, 0); | |
dd9ddf46 AH |
2828 | perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL, |
2829 | ops->trampoline, ops->trampoline_size, | |
2830 | true, FTRACE_TRAMPOLINE_SYM); | |
2831 | /* Remove from kallsyms after the perf events */ | |
fc0ea795 | 2832 | ftrace_remove_trampoline_from_kallsyms(ops); |
dd9ddf46 | 2833 | } |
fc0ea795 AH |
2834 | |
2835 | arch_ftrace_trampoline_free(ops); | |
2836 | } | |
2837 | ||
df4fc315 SR |
2838 | static void ftrace_startup_enable(int command) |
2839 | { | |
2840 | if (saved_ftrace_func != ftrace_trace_function) { | |
2841 | saved_ftrace_func = ftrace_trace_function; | |
2842 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2843 | } | |
2844 | ||
2845 | if (!command || !ftrace_enabled) | |
2846 | return; | |
2847 | ||
2848 | ftrace_run_update_code(command); | |
2849 | } | |
d61f82d0 | 2850 | |
e1effa01 SRRH |
2851 | static void ftrace_startup_all(int command) |
2852 | { | |
2853 | update_all_ops = true; | |
2854 | ftrace_startup_enable(command); | |
2855 | update_all_ops = false; | |
2856 | } | |
2857 | ||
3306fc4a | 2858 | int ftrace_startup(struct ftrace_ops *ops, int command) |
3d083395 | 2859 | { |
8a56d776 | 2860 | int ret; |
b848914c | 2861 | |
4eebcc81 | 2862 | if (unlikely(ftrace_disabled)) |
a1cd6173 | 2863 | return -ENODEV; |
4eebcc81 | 2864 | |
8a56d776 SRRH |
2865 | ret = __register_ftrace_function(ops); |
2866 | if (ret) | |
2867 | return ret; | |
2868 | ||
60a7ecf4 | 2869 | ftrace_start_up++; |
d61f82d0 | 2870 | |
e1effa01 SRRH |
2871 | /* |
2872 | * Note that ftrace probes uses this to start up | |
2873 | * and modify functions it will probe. But we still | |
2874 | * set the ADDING flag for modification, as probes | |
2875 | * do not have trampolines. If they add them in the | |
2876 | * future, then the probes will need to distinguish | |
2877 | * between adding and updating probes. | |
2878 | */ | |
2879 | ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING; | |
66209a5b | 2880 | |
f8b8be8a MH |
2881 | ret = ftrace_hash_ipmodify_enable(ops); |
2882 | if (ret < 0) { | |
2883 | /* Rollback registration process */ | |
2884 | __unregister_ftrace_function(ops); | |
2885 | ftrace_start_up--; | |
2886 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; | |
d5e47505 MB |
2887 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) |
2888 | ftrace_trampoline_free(ops); | |
f8b8be8a MH |
2889 | return ret; |
2890 | } | |
2891 | ||
7f50d06b JO |
2892 | if (ftrace_hash_rec_enable(ops, 1)) |
2893 | command |= FTRACE_UPDATE_CALLS; | |
ed926f9b | 2894 | |
df4fc315 | 2895 | ftrace_startup_enable(command); |
a1cd6173 | 2896 | |
e1effa01 SRRH |
2897 | ops->flags &= ~FTRACE_OPS_FL_ADDING; |
2898 | ||
a1cd6173 | 2899 | return 0; |
3d083395 SR |
2900 | } |
2901 | ||
3306fc4a | 2902 | int ftrace_shutdown(struct ftrace_ops *ops, int command) |
3d083395 | 2903 | { |
8a56d776 | 2904 | int ret; |
b848914c | 2905 | |
4eebcc81 | 2906 | if (unlikely(ftrace_disabled)) |
8a56d776 SRRH |
2907 | return -ENODEV; |
2908 | ||
2909 | ret = __unregister_ftrace_function(ops); | |
2910 | if (ret) | |
2911 | return ret; | |
4eebcc81 | 2912 | |
60a7ecf4 | 2913 | ftrace_start_up--; |
9ea1a153 FW |
2914 | /* |
2915 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
2916 | * critical but the ftrace_call callers may be never nopped again after | |
2917 | * further ftrace uses. | |
2918 | */ | |
2919 | WARN_ON_ONCE(ftrace_start_up < 0); | |
2920 | ||
f8b8be8a MH |
2921 | /* Disabling ipmodify never fails */ |
2922 | ftrace_hash_ipmodify_disable(ops); | |
ed926f9b | 2923 | |
7f50d06b JO |
2924 | if (ftrace_hash_rec_disable(ops, 1)) |
2925 | command |= FTRACE_UPDATE_CALLS; | |
b848914c | 2926 | |
7f50d06b | 2927 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
3d083395 | 2928 | |
d61f82d0 SR |
2929 | if (saved_ftrace_func != ftrace_trace_function) { |
2930 | saved_ftrace_func = ftrace_trace_function; | |
2931 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2932 | } | |
3d083395 | 2933 | |
a4c35ed2 SRRH |
2934 | if (!command || !ftrace_enabled) { |
2935 | /* | |
edb096e0 SRV |
2936 | * If these are dynamic or per_cpu ops, they still |
2937 | * need their data freed. Since, function tracing is | |
a4c35ed2 SRRH |
2938 | * not currently active, we can just free them |
2939 | * without synchronizing all CPUs. | |
2940 | */ | |
b3a88803 | 2941 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) |
edb096e0 SRV |
2942 | goto free_ops; |
2943 | ||
8a56d776 | 2944 | return 0; |
a4c35ed2 | 2945 | } |
d61f82d0 | 2946 | |
79922b80 SRRH |
2947 | /* |
2948 | * If the ops uses a trampoline, then it needs to be | |
2949 | * tested first on update. | |
2950 | */ | |
e1effa01 | 2951 | ops->flags |= FTRACE_OPS_FL_REMOVING; |
79922b80 SRRH |
2952 | removed_ops = ops; |
2953 | ||
fef5aeee SRRH |
2954 | /* The trampoline logic checks the old hashes */ |
2955 | ops->old_hash.filter_hash = ops->func_hash->filter_hash; | |
2956 | ops->old_hash.notrace_hash = ops->func_hash->notrace_hash; | |
2957 | ||
d61f82d0 | 2958 | ftrace_run_update_code(command); |
a4c35ed2 | 2959 | |
84bde62c SRRH |
2960 | /* |
2961 | * If there's no more ops registered with ftrace, run a | |
2962 | * sanity check to make sure all rec flags are cleared. | |
2963 | */ | |
f86f4180 CZ |
2964 | if (rcu_dereference_protected(ftrace_ops_list, |
2965 | lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { | |
84bde62c SRRH |
2966 | struct ftrace_page *pg; |
2967 | struct dyn_ftrace *rec; | |
2968 | ||
2969 | do_for_each_ftrace_rec(pg, rec) { | |
977c1f9c | 2970 | if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_FL_DISABLED)) |
84bde62c SRRH |
2971 | pr_warn(" %pS flags:%lx\n", |
2972 | (void *)rec->ip, rec->flags); | |
2973 | } while_for_each_ftrace_rec(); | |
2974 | } | |
2975 | ||
fef5aeee SRRH |
2976 | ops->old_hash.filter_hash = NULL; |
2977 | ops->old_hash.notrace_hash = NULL; | |
2978 | ||
2979 | removed_ops = NULL; | |
e1effa01 | 2980 | ops->flags &= ~FTRACE_OPS_FL_REMOVING; |
79922b80 | 2981 | |
a4c35ed2 SRRH |
2982 | /* |
2983 | * Dynamic ops may be freed, we must make sure that all | |
2984 | * callers are done before leaving this function. | |
ba27f2bc | 2985 | * The same goes for freeing the per_cpu data of the per_cpu |
a4c35ed2 | 2986 | * ops. |
a4c35ed2 | 2987 | */ |
b3a88803 | 2988 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) { |
0598e4f0 SRV |
2989 | /* |
2990 | * We need to do a hard force of sched synchronization. | |
2991 | * This is because we use preempt_disable() to do RCU, but | |
2992 | * the function tracers can be called where RCU is not watching | |
2993 | * (like before user_exit()). We can not rely on the RCU | |
2994 | * infrastructure to do the synchronization, thus we must do it | |
2995 | * ourselves. | |
2996 | */ | |
e5a971d7 | 2997 | synchronize_rcu_tasks_rude(); |
a4c35ed2 | 2998 | |
0598e4f0 | 2999 | /* |
fdda88d3 | 3000 | * When the kernel is preemptive, tasks can be preempted |
0598e4f0 SRV |
3001 | * while on a ftrace trampoline. Just scheduling a task on |
3002 | * a CPU is not good enough to flush them. Calling | |
3003 | * synchornize_rcu_tasks() will wait for those tasks to | |
3004 | * execute and either schedule voluntarily or enter user space. | |
3005 | */ | |
30c93704 | 3006 | if (IS_ENABLED(CONFIG_PREEMPTION)) |
0598e4f0 SRV |
3007 | synchronize_rcu_tasks(); |
3008 | ||
edb096e0 | 3009 | free_ops: |
fc0ea795 | 3010 | ftrace_trampoline_free(ops); |
a4c35ed2 SRRH |
3011 | } |
3012 | ||
8a56d776 | 3013 | return 0; |
3d083395 SR |
3014 | } |
3015 | ||
e309b41d | 3016 | static void ftrace_startup_sysctl(void) |
b0fc494f | 3017 | { |
1619dc3f PA |
3018 | int command; |
3019 | ||
4eebcc81 SR |
3020 | if (unlikely(ftrace_disabled)) |
3021 | return; | |
3022 | ||
d61f82d0 SR |
3023 | /* Force update next time */ |
3024 | saved_ftrace_func = NULL; | |
60a7ecf4 | 3025 | /* ftrace_start_up is true if we want ftrace running */ |
1619dc3f PA |
3026 | if (ftrace_start_up) { |
3027 | command = FTRACE_UPDATE_CALLS; | |
3028 | if (ftrace_graph_active) | |
3029 | command |= FTRACE_START_FUNC_RET; | |
524a3868 | 3030 | ftrace_startup_enable(command); |
1619dc3f | 3031 | } |
b0fc494f SR |
3032 | } |
3033 | ||
e309b41d | 3034 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 3035 | { |
1619dc3f PA |
3036 | int command; |
3037 | ||
4eebcc81 SR |
3038 | if (unlikely(ftrace_disabled)) |
3039 | return; | |
3040 | ||
60a7ecf4 | 3041 | /* ftrace_start_up is true if ftrace is running */ |
1619dc3f PA |
3042 | if (ftrace_start_up) { |
3043 | command = FTRACE_DISABLE_CALLS; | |
3044 | if (ftrace_graph_active) | |
3045 | command |= FTRACE_STOP_FUNC_RET; | |
3046 | ftrace_run_update_code(command); | |
3047 | } | |
b0fc494f SR |
3048 | } |
3049 | ||
a5a1d1c2 | 3050 | static u64 ftrace_update_time; |
3d083395 | 3051 | unsigned long ftrace_update_tot_cnt; |
da537f0a SRV |
3052 | unsigned long ftrace_number_of_pages; |
3053 | unsigned long ftrace_number_of_groups; | |
3d083395 | 3054 | |
8c4f3c3f | 3055 | static inline int ops_traces_mod(struct ftrace_ops *ops) |
f7bc8b61 | 3056 | { |
8c4f3c3f SRRH |
3057 | /* |
3058 | * Filter_hash being empty will default to trace module. | |
3059 | * But notrace hash requires a test of individual module functions. | |
3060 | */ | |
33b7f99c SRRH |
3061 | return ftrace_hash_empty(ops->func_hash->filter_hash) && |
3062 | ftrace_hash_empty(ops->func_hash->notrace_hash); | |
8c4f3c3f SRRH |
3063 | } |
3064 | ||
3065 | /* | |
3066 | * Check if the current ops references the record. | |
3067 | * | |
3068 | * If the ops traces all functions, then it was already accounted for. | |
3069 | * If the ops does not trace the current record function, skip it. | |
3070 | * If the ops ignores the function via notrace filter, skip it. | |
3071 | */ | |
3072 | static inline bool | |
3073 | ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec) | |
3074 | { | |
3075 | /* If ops isn't enabled, ignore it */ | |
3076 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
44ec3ec0 | 3077 | return false; |
8c4f3c3f | 3078 | |
b7ffffbb | 3079 | /* If ops traces all then it includes this function */ |
8c4f3c3f | 3080 | if (ops_traces_mod(ops)) |
44ec3ec0 | 3081 | return true; |
8c4f3c3f SRRH |
3082 | |
3083 | /* The function must be in the filter */ | |
33b7f99c | 3084 | if (!ftrace_hash_empty(ops->func_hash->filter_hash) && |
2b2c279c | 3085 | !__ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip)) |
44ec3ec0 | 3086 | return false; |
f7bc8b61 | 3087 | |
8c4f3c3f | 3088 | /* If in notrace hash, we ignore it too */ |
33b7f99c | 3089 | if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip)) |
44ec3ec0 | 3090 | return false; |
8c4f3c3f | 3091 | |
44ec3ec0 | 3092 | return true; |
8c4f3c3f SRRH |
3093 | } |
3094 | ||
1dc43cf0 | 3095 | static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs) |
3d083395 | 3096 | { |
85ae32ae | 3097 | struct ftrace_page *pg; |
e94142a6 | 3098 | struct dyn_ftrace *p; |
a5a1d1c2 | 3099 | u64 start, stop; |
1dc43cf0 | 3100 | unsigned long update_cnt = 0; |
b7ffffbb | 3101 | unsigned long rec_flags = 0; |
85ae32ae | 3102 | int i; |
f7bc8b61 | 3103 | |
b7ffffbb SRRH |
3104 | start = ftrace_now(raw_smp_processor_id()); |
3105 | ||
f7bc8b61 | 3106 | /* |
b7ffffbb SRRH |
3107 | * When a module is loaded, this function is called to convert |
3108 | * the calls to mcount in its text to nops, and also to create | |
3109 | * an entry in the ftrace data. Now, if ftrace is activated | |
3110 | * after this call, but before the module sets its text to | |
3111 | * read-only, the modification of enabling ftrace can fail if | |
3112 | * the read-only is done while ftrace is converting the calls. | |
3113 | * To prevent this, the module's records are set as disabled | |
3114 | * and will be enabled after the call to set the module's text | |
3115 | * to read-only. | |
f7bc8b61 | 3116 | */ |
b7ffffbb SRRH |
3117 | if (mod) |
3118 | rec_flags |= FTRACE_FL_DISABLED; | |
3d083395 | 3119 | |
1dc43cf0 | 3120 | for (pg = new_pgs; pg; pg = pg->next) { |
3d083395 | 3121 | |
85ae32ae | 3122 | for (i = 0; i < pg->index; i++) { |
8c4f3c3f | 3123 | |
85ae32ae SR |
3124 | /* If something went wrong, bail without enabling anything */ |
3125 | if (unlikely(ftrace_disabled)) | |
3126 | return -1; | |
f22f9a89 | 3127 | |
85ae32ae | 3128 | p = &pg->records[i]; |
b7ffffbb | 3129 | p->flags = rec_flags; |
f22f9a89 | 3130 | |
85ae32ae SR |
3131 | /* |
3132 | * Do the initial record conversion from mcount jump | |
3133 | * to the NOP instructions. | |
3134 | */ | |
cbdaeaf0 | 3135 | if (!__is_defined(CC_USING_NOP_MCOUNT) && |
fbf6c73c | 3136 | !ftrace_nop_initialize(mod, p)) |
85ae32ae | 3137 | break; |
5cb084bb | 3138 | |
1dc43cf0 | 3139 | update_cnt++; |
5cb084bb | 3140 | } |
3d083395 SR |
3141 | } |
3142 | ||
750ed1a4 | 3143 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 | 3144 | ftrace_update_time = stop - start; |
1dc43cf0 | 3145 | ftrace_update_tot_cnt += update_cnt; |
3d083395 | 3146 | |
16444a8a ACM |
3147 | return 0; |
3148 | } | |
3149 | ||
a7900875 | 3150 | static int ftrace_allocate_records(struct ftrace_page *pg, int count) |
3c1720f0 | 3151 | { |
a7900875 | 3152 | int order; |
7ba031e8 | 3153 | int pages; |
3c1720f0 | 3154 | int cnt; |
3c1720f0 | 3155 | |
a7900875 SR |
3156 | if (WARN_ON(!count)) |
3157 | return -EINVAL; | |
3158 | ||
b40c6eab WY |
3159 | pages = DIV_ROUND_UP(count, ENTRIES_PER_PAGE); |
3160 | order = get_count_order(pages); | |
3c1720f0 SR |
3161 | |
3162 | /* | |
a7900875 SR |
3163 | * We want to fill as much as possible. No more than a page |
3164 | * may be empty. | |
3c1720f0 | 3165 | */ |
b40c6eab | 3166 | if (!is_power_of_2(pages)) |
a7900875 | 3167 | order--; |
3c1720f0 | 3168 | |
a7900875 SR |
3169 | again: |
3170 | pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); | |
3c1720f0 | 3171 | |
a7900875 SR |
3172 | if (!pg->records) { |
3173 | /* if we can't allocate this size, try something smaller */ | |
3174 | if (!order) | |
3175 | return -ENOMEM; | |
3176 | order >>= 1; | |
3177 | goto again; | |
3178 | } | |
3c1720f0 | 3179 | |
da537f0a SRV |
3180 | ftrace_number_of_pages += 1 << order; |
3181 | ftrace_number_of_groups++; | |
3182 | ||
a7900875 SR |
3183 | cnt = (PAGE_SIZE << order) / ENTRY_SIZE; |
3184 | pg->size = cnt; | |
3c1720f0 | 3185 | |
a7900875 SR |
3186 | if (cnt > count) |
3187 | cnt = count; | |
3188 | ||
3189 | return cnt; | |
3190 | } | |
3191 | ||
3192 | static struct ftrace_page * | |
3193 | ftrace_allocate_pages(unsigned long num_to_init) | |
3194 | { | |
3195 | struct ftrace_page *start_pg; | |
3196 | struct ftrace_page *pg; | |
3197 | int order; | |
3198 | int cnt; | |
3199 | ||
3200 | if (!num_to_init) | |
9efb85c5 | 3201 | return NULL; |
a7900875 SR |
3202 | |
3203 | start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL); | |
3204 | if (!pg) | |
3205 | return NULL; | |
3206 | ||
3207 | /* | |
3208 | * Try to allocate as much as possible in one continues | |
3209 | * location that fills in all of the space. We want to | |
3210 | * waste as little space as possible. | |
3211 | */ | |
3212 | for (;;) { | |
3213 | cnt = ftrace_allocate_records(pg, num_to_init); | |
3214 | if (cnt < 0) | |
3215 | goto free_pages; | |
3216 | ||
3217 | num_to_init -= cnt; | |
3218 | if (!num_to_init) | |
3c1720f0 SR |
3219 | break; |
3220 | ||
a7900875 SR |
3221 | pg->next = kzalloc(sizeof(*pg), GFP_KERNEL); |
3222 | if (!pg->next) | |
3223 | goto free_pages; | |
3224 | ||
3c1720f0 SR |
3225 | pg = pg->next; |
3226 | } | |
3227 | ||
a7900875 SR |
3228 | return start_pg; |
3229 | ||
3230 | free_pages: | |
1f61be00 NK |
3231 | pg = start_pg; |
3232 | while (pg) { | |
a7900875 SR |
3233 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
3234 | free_pages((unsigned long)pg->records, order); | |
3235 | start_pg = pg->next; | |
3236 | kfree(pg); | |
3237 | pg = start_pg; | |
da537f0a SRV |
3238 | ftrace_number_of_pages -= 1 << order; |
3239 | ftrace_number_of_groups--; | |
a7900875 SR |
3240 | } |
3241 | pr_info("ftrace: FAILED to allocate memory for functions\n"); | |
3242 | return NULL; | |
3243 | } | |
3244 | ||
5072c59f SR |
3245 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
3246 | ||
3247 | struct ftrace_iterator { | |
98c4fd04 | 3248 | loff_t pos; |
4aeb6967 | 3249 | loff_t func_pos; |
5985ea8b | 3250 | loff_t mod_pos; |
4aeb6967 SR |
3251 | struct ftrace_page *pg; |
3252 | struct dyn_ftrace *func; | |
3253 | struct ftrace_func_probe *probe; | |
eee8ded1 | 3254 | struct ftrace_func_entry *probe_entry; |
4aeb6967 | 3255 | struct trace_parser parser; |
1cf41dd7 | 3256 | struct ftrace_hash *hash; |
33dc9b12 | 3257 | struct ftrace_ops *ops; |
5985ea8b SRV |
3258 | struct trace_array *tr; |
3259 | struct list_head *mod_list; | |
eee8ded1 | 3260 | int pidx; |
4aeb6967 SR |
3261 | int idx; |
3262 | unsigned flags; | |
5072c59f SR |
3263 | }; |
3264 | ||
8fc0c701 | 3265 | static void * |
eee8ded1 | 3266 | t_probe_next(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
3267 | { |
3268 | struct ftrace_iterator *iter = m->private; | |
d2afd57a | 3269 | struct trace_array *tr = iter->ops->private; |
04ec7bb6 | 3270 | struct list_head *func_probes; |
eee8ded1 SRV |
3271 | struct ftrace_hash *hash; |
3272 | struct list_head *next; | |
4aeb6967 | 3273 | struct hlist_node *hnd = NULL; |
8fc0c701 | 3274 | struct hlist_head *hhd; |
eee8ded1 | 3275 | int size; |
8fc0c701 | 3276 | |
8fc0c701 | 3277 | (*pos)++; |
98c4fd04 | 3278 | iter->pos = *pos; |
8fc0c701 | 3279 | |
04ec7bb6 | 3280 | if (!tr) |
8fc0c701 SR |
3281 | return NULL; |
3282 | ||
04ec7bb6 SRV |
3283 | func_probes = &tr->func_probes; |
3284 | if (list_empty(func_probes)) | |
8fc0c701 SR |
3285 | return NULL; |
3286 | ||
eee8ded1 | 3287 | if (!iter->probe) { |
04ec7bb6 | 3288 | next = func_probes->next; |
7b60f3d8 | 3289 | iter->probe = list_entry(next, struct ftrace_func_probe, list); |
eee8ded1 SRV |
3290 | } |
3291 | ||
3292 | if (iter->probe_entry) | |
3293 | hnd = &iter->probe_entry->hlist; | |
3294 | ||
3295 | hash = iter->probe->ops.func_hash->filter_hash; | |
7bd46644 | 3296 | |
372e0d01 SRV |
3297 | /* |
3298 | * A probe being registered may temporarily have an empty hash | |
3299 | * and it's at the end of the func_probes list. | |
3300 | */ | |
3301 | if (!hash || hash == EMPTY_HASH) | |
7bd46644 NR |
3302 | return NULL; |
3303 | ||
eee8ded1 SRV |
3304 | size = 1 << hash->size_bits; |
3305 | ||
3306 | retry: | |
3307 | if (iter->pidx >= size) { | |
04ec7bb6 | 3308 | if (iter->probe->list.next == func_probes) |
eee8ded1 SRV |
3309 | return NULL; |
3310 | next = iter->probe->list.next; | |
7b60f3d8 | 3311 | iter->probe = list_entry(next, struct ftrace_func_probe, list); |
eee8ded1 SRV |
3312 | hash = iter->probe->ops.func_hash->filter_hash; |
3313 | size = 1 << hash->size_bits; | |
3314 | iter->pidx = 0; | |
3315 | } | |
3316 | ||
3317 | hhd = &hash->buckets[iter->pidx]; | |
8fc0c701 SR |
3318 | |
3319 | if (hlist_empty(hhd)) { | |
eee8ded1 | 3320 | iter->pidx++; |
8fc0c701 SR |
3321 | hnd = NULL; |
3322 | goto retry; | |
3323 | } | |
3324 | ||
3325 | if (!hnd) | |
3326 | hnd = hhd->first; | |
3327 | else { | |
3328 | hnd = hnd->next; | |
3329 | if (!hnd) { | |
eee8ded1 | 3330 | iter->pidx++; |
8fc0c701 SR |
3331 | goto retry; |
3332 | } | |
3333 | } | |
3334 | ||
4aeb6967 SR |
3335 | if (WARN_ON_ONCE(!hnd)) |
3336 | return NULL; | |
3337 | ||
eee8ded1 | 3338 | iter->probe_entry = hlist_entry(hnd, struct ftrace_func_entry, hlist); |
4aeb6967 SR |
3339 | |
3340 | return iter; | |
8fc0c701 SR |
3341 | } |
3342 | ||
eee8ded1 | 3343 | static void *t_probe_start(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
3344 | { |
3345 | struct ftrace_iterator *iter = m->private; | |
3346 | void *p = NULL; | |
d82d6244 LZ |
3347 | loff_t l; |
3348 | ||
eee8ded1 | 3349 | if (!(iter->flags & FTRACE_ITER_DO_PROBES)) |
69a3083c SR |
3350 | return NULL; |
3351 | ||
5985ea8b | 3352 | if (iter->mod_pos > *pos) |
2bccfffd | 3353 | return NULL; |
8fc0c701 | 3354 | |
eee8ded1 SRV |
3355 | iter->probe = NULL; |
3356 | iter->probe_entry = NULL; | |
3357 | iter->pidx = 0; | |
5985ea8b | 3358 | for (l = 0; l <= (*pos - iter->mod_pos); ) { |
eee8ded1 | 3359 | p = t_probe_next(m, &l); |
d82d6244 LZ |
3360 | if (!p) |
3361 | break; | |
3362 | } | |
4aeb6967 SR |
3363 | if (!p) |
3364 | return NULL; | |
3365 | ||
98c4fd04 | 3366 | /* Only set this if we have an item */ |
eee8ded1 | 3367 | iter->flags |= FTRACE_ITER_PROBE; |
98c4fd04 | 3368 | |
4aeb6967 | 3369 | return iter; |
8fc0c701 SR |
3370 | } |
3371 | ||
4aeb6967 | 3372 | static int |
eee8ded1 | 3373 | t_probe_show(struct seq_file *m, struct ftrace_iterator *iter) |
8fc0c701 | 3374 | { |
eee8ded1 | 3375 | struct ftrace_func_entry *probe_entry; |
7b60f3d8 SRV |
3376 | struct ftrace_probe_ops *probe_ops; |
3377 | struct ftrace_func_probe *probe; | |
8fc0c701 | 3378 | |
eee8ded1 SRV |
3379 | probe = iter->probe; |
3380 | probe_entry = iter->probe_entry; | |
8fc0c701 | 3381 | |
eee8ded1 | 3382 | if (WARN_ON_ONCE(!probe || !probe_entry)) |
4aeb6967 | 3383 | return -EIO; |
8fc0c701 | 3384 | |
7b60f3d8 | 3385 | probe_ops = probe->probe_ops; |
809dcf29 | 3386 | |
7b60f3d8 | 3387 | if (probe_ops->print) |
6e444319 | 3388 | return probe_ops->print(m, probe_entry->ip, probe_ops, probe->data); |
8fc0c701 | 3389 | |
7b60f3d8 SRV |
3390 | seq_printf(m, "%ps:%ps\n", (void *)probe_entry->ip, |
3391 | (void *)probe_ops->func); | |
8fc0c701 SR |
3392 | |
3393 | return 0; | |
3394 | } | |
3395 | ||
5985ea8b SRV |
3396 | static void * |
3397 | t_mod_next(struct seq_file *m, loff_t *pos) | |
3398 | { | |
3399 | struct ftrace_iterator *iter = m->private; | |
3400 | struct trace_array *tr = iter->tr; | |
3401 | ||
3402 | (*pos)++; | |
3403 | iter->pos = *pos; | |
3404 | ||
3405 | iter->mod_list = iter->mod_list->next; | |
3406 | ||
3407 | if (iter->mod_list == &tr->mod_trace || | |
3408 | iter->mod_list == &tr->mod_notrace) { | |
3409 | iter->flags &= ~FTRACE_ITER_MOD; | |
3410 | return NULL; | |
3411 | } | |
3412 | ||
3413 | iter->mod_pos = *pos; | |
3414 | ||
3415 | return iter; | |
3416 | } | |
3417 | ||
3418 | static void *t_mod_start(struct seq_file *m, loff_t *pos) | |
3419 | { | |
3420 | struct ftrace_iterator *iter = m->private; | |
3421 | void *p = NULL; | |
3422 | loff_t l; | |
3423 | ||
3424 | if (iter->func_pos > *pos) | |
3425 | return NULL; | |
3426 | ||
3427 | iter->mod_pos = iter->func_pos; | |
3428 | ||
3429 | /* probes are only available if tr is set */ | |
3430 | if (!iter->tr) | |
3431 | return NULL; | |
3432 | ||
3433 | for (l = 0; l <= (*pos - iter->func_pos); ) { | |
3434 | p = t_mod_next(m, &l); | |
3435 | if (!p) | |
3436 | break; | |
3437 | } | |
3438 | if (!p) { | |
3439 | iter->flags &= ~FTRACE_ITER_MOD; | |
3440 | return t_probe_start(m, pos); | |
3441 | } | |
3442 | ||
3443 | /* Only set this if we have an item */ | |
3444 | iter->flags |= FTRACE_ITER_MOD; | |
3445 | ||
3446 | return iter; | |
3447 | } | |
3448 | ||
3449 | static int | |
3450 | t_mod_show(struct seq_file *m, struct ftrace_iterator *iter) | |
3451 | { | |
3452 | struct ftrace_mod_load *ftrace_mod; | |
3453 | struct trace_array *tr = iter->tr; | |
3454 | ||
3455 | if (WARN_ON_ONCE(!iter->mod_list) || | |
3456 | iter->mod_list == &tr->mod_trace || | |
3457 | iter->mod_list == &tr->mod_notrace) | |
3458 | return -EIO; | |
3459 | ||
3460 | ftrace_mod = list_entry(iter->mod_list, struct ftrace_mod_load, list); | |
3461 | ||
3462 | if (ftrace_mod->func) | |
3463 | seq_printf(m, "%s", ftrace_mod->func); | |
3464 | else | |
3465 | seq_putc(m, '*'); | |
3466 | ||
3467 | seq_printf(m, ":mod:%s\n", ftrace_mod->module); | |
3468 | ||
3469 | return 0; | |
3470 | } | |
3471 | ||
e309b41d | 3472 | static void * |
5bd84629 | 3473 | t_func_next(struct seq_file *m, loff_t *pos) |
5072c59f SR |
3474 | { |
3475 | struct ftrace_iterator *iter = m->private; | |
3476 | struct dyn_ftrace *rec = NULL; | |
3477 | ||
3478 | (*pos)++; | |
0c75a3ed | 3479 | |
5072c59f SR |
3480 | retry: |
3481 | if (iter->idx >= iter->pg->index) { | |
3482 | if (iter->pg->next) { | |
3483 | iter->pg = iter->pg->next; | |
3484 | iter->idx = 0; | |
3485 | goto retry; | |
3486 | } | |
3487 | } else { | |
3488 | rec = &iter->pg->records[iter->idx++]; | |
c20489da SRV |
3489 | if (((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) && |
3490 | !ftrace_lookup_ip(iter->hash, rec->ip)) || | |
647bcd03 SR |
3491 | |
3492 | ((iter->flags & FTRACE_ITER_ENABLED) && | |
23ea9c4d | 3493 | !(rec->flags & FTRACE_FL_ENABLED))) { |
647bcd03 | 3494 | |
5072c59f SR |
3495 | rec = NULL; |
3496 | goto retry; | |
3497 | } | |
3498 | } | |
3499 | ||
4aeb6967 | 3500 | if (!rec) |
5bd84629 | 3501 | return NULL; |
4aeb6967 | 3502 | |
5bd84629 | 3503 | iter->pos = iter->func_pos = *pos; |
4aeb6967 SR |
3504 | iter->func = rec; |
3505 | ||
3506 | return iter; | |
5072c59f SR |
3507 | } |
3508 | ||
5bd84629 SRV |
3509 | static void * |
3510 | t_next(struct seq_file *m, void *v, loff_t *pos) | |
3511 | { | |
3512 | struct ftrace_iterator *iter = m->private; | |
5985ea8b | 3513 | loff_t l = *pos; /* t_probe_start() must use original pos */ |
5bd84629 SRV |
3514 | void *ret; |
3515 | ||
3516 | if (unlikely(ftrace_disabled)) | |
3517 | return NULL; | |
3518 | ||
eee8ded1 SRV |
3519 | if (iter->flags & FTRACE_ITER_PROBE) |
3520 | return t_probe_next(m, pos); | |
5bd84629 | 3521 | |
5985ea8b SRV |
3522 | if (iter->flags & FTRACE_ITER_MOD) |
3523 | return t_mod_next(m, pos); | |
3524 | ||
5bd84629 | 3525 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
eee8ded1 | 3526 | /* next must increment pos, and t_probe_start does not */ |
5bd84629 | 3527 | (*pos)++; |
5985ea8b | 3528 | return t_mod_start(m, &l); |
5bd84629 SRV |
3529 | } |
3530 | ||
3531 | ret = t_func_next(m, pos); | |
3532 | ||
3533 | if (!ret) | |
5985ea8b | 3534 | return t_mod_start(m, &l); |
5bd84629 SRV |
3535 | |
3536 | return ret; | |
3537 | } | |
3538 | ||
98c4fd04 SR |
3539 | static void reset_iter_read(struct ftrace_iterator *iter) |
3540 | { | |
3541 | iter->pos = 0; | |
3542 | iter->func_pos = 0; | |
5985ea8b | 3543 | iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_PROBE | FTRACE_ITER_MOD); |
5072c59f SR |
3544 | } |
3545 | ||
3546 | static void *t_start(struct seq_file *m, loff_t *pos) | |
3547 | { | |
3548 | struct ftrace_iterator *iter = m->private; | |
3549 | void *p = NULL; | |
694ce0a5 | 3550 | loff_t l; |
5072c59f | 3551 | |
8fc0c701 | 3552 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
3553 | |
3554 | if (unlikely(ftrace_disabled)) | |
3555 | return NULL; | |
3556 | ||
98c4fd04 SR |
3557 | /* |
3558 | * If an lseek was done, then reset and start from beginning. | |
3559 | */ | |
3560 | if (*pos < iter->pos) | |
3561 | reset_iter_read(iter); | |
3562 | ||
0c75a3ed SR |
3563 | /* |
3564 | * For set_ftrace_filter reading, if we have the filter | |
3565 | * off, we can short cut and just print out that all | |
3566 | * functions are enabled. | |
3567 | */ | |
c20489da SRV |
3568 | if ((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) && |
3569 | ftrace_hash_empty(iter->hash)) { | |
43ff926a | 3570 | iter->func_pos = 1; /* Account for the message */ |
0c75a3ed | 3571 | if (*pos > 0) |
5985ea8b | 3572 | return t_mod_start(m, pos); |
0c75a3ed | 3573 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 | 3574 | /* reset in case of seek/pread */ |
eee8ded1 | 3575 | iter->flags &= ~FTRACE_ITER_PROBE; |
0c75a3ed SR |
3576 | return iter; |
3577 | } | |
3578 | ||
5985ea8b SRV |
3579 | if (iter->flags & FTRACE_ITER_MOD) |
3580 | return t_mod_start(m, pos); | |
8fc0c701 | 3581 | |
98c4fd04 SR |
3582 | /* |
3583 | * Unfortunately, we need to restart at ftrace_pages_start | |
3584 | * every time we let go of the ftrace_mutex. This is because | |
3585 | * those pointers can change without the lock. | |
3586 | */ | |
694ce0a5 LZ |
3587 | iter->pg = ftrace_pages_start; |
3588 | iter->idx = 0; | |
3589 | for (l = 0; l <= *pos; ) { | |
5bd84629 | 3590 | p = t_func_next(m, &l); |
694ce0a5 LZ |
3591 | if (!p) |
3592 | break; | |
50cdaf08 | 3593 | } |
5821e1b7 | 3594 | |
69a3083c | 3595 | if (!p) |
5985ea8b | 3596 | return t_mod_start(m, pos); |
4aeb6967 SR |
3597 | |
3598 | return iter; | |
5072c59f SR |
3599 | } |
3600 | ||
3601 | static void t_stop(struct seq_file *m, void *p) | |
3602 | { | |
8fc0c701 | 3603 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
3604 | } |
3605 | ||
15d5b02c SRRH |
3606 | void * __weak |
3607 | arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec) | |
3608 | { | |
3609 | return NULL; | |
3610 | } | |
3611 | ||
3612 | static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops, | |
3613 | struct dyn_ftrace *rec) | |
3614 | { | |
3615 | void *ptr; | |
3616 | ||
3617 | ptr = arch_ftrace_trampoline_func(ops, rec); | |
3618 | if (ptr) | |
3619 | seq_printf(m, " ->%pS", ptr); | |
3620 | } | |
3621 | ||
5072c59f SR |
3622 | static int t_show(struct seq_file *m, void *v) |
3623 | { | |
0c75a3ed | 3624 | struct ftrace_iterator *iter = m->private; |
4aeb6967 | 3625 | struct dyn_ftrace *rec; |
5072c59f | 3626 | |
eee8ded1 SRV |
3627 | if (iter->flags & FTRACE_ITER_PROBE) |
3628 | return t_probe_show(m, iter); | |
8fc0c701 | 3629 | |
5985ea8b SRV |
3630 | if (iter->flags & FTRACE_ITER_MOD) |
3631 | return t_mod_show(m, iter); | |
3632 | ||
0c75a3ed | 3633 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
8c006cf7 | 3634 | if (iter->flags & FTRACE_ITER_NOTRACE) |
fa6f0cc7 | 3635 | seq_puts(m, "#### no functions disabled ####\n"); |
8c006cf7 | 3636 | else |
fa6f0cc7 | 3637 | seq_puts(m, "#### all functions enabled ####\n"); |
0c75a3ed SR |
3638 | return 0; |
3639 | } | |
3640 | ||
4aeb6967 SR |
3641 | rec = iter->func; |
3642 | ||
5072c59f SR |
3643 | if (!rec) |
3644 | return 0; | |
3645 | ||
647bcd03 | 3646 | seq_printf(m, "%ps", (void *)rec->ip); |
9674b2fa | 3647 | if (iter->flags & FTRACE_ITER_ENABLED) { |
030f4e1c | 3648 | struct ftrace_ops *ops; |
15d5b02c | 3649 | |
763e34e7 | 3650 | seq_printf(m, " (%ld)%s%s%s", |
0376bde1 | 3651 | ftrace_rec_count(rec), |
f8b8be8a | 3652 | rec->flags & FTRACE_FL_REGS ? " R" : " ", |
763e34e7 SRV |
3653 | rec->flags & FTRACE_FL_IPMODIFY ? " I" : " ", |
3654 | rec->flags & FTRACE_FL_DIRECT ? " D" : " "); | |
9674b2fa | 3655 | if (rec->flags & FTRACE_FL_TRAMP_EN) { |
5fecaa04 | 3656 | ops = ftrace_find_tramp_ops_any(rec); |
39daa7b9 SRRH |
3657 | if (ops) { |
3658 | do { | |
3659 | seq_printf(m, "\ttramp: %pS (%pS)", | |
3660 | (void *)ops->trampoline, | |
3661 | (void *)ops->func); | |
030f4e1c | 3662 | add_trampoline_func(m, ops, rec); |
39daa7b9 SRRH |
3663 | ops = ftrace_find_tramp_ops_next(rec, ops); |
3664 | } while (ops); | |
3665 | } else | |
fa6f0cc7 | 3666 | seq_puts(m, "\ttramp: ERROR!"); |
030f4e1c SRRH |
3667 | } else { |
3668 | add_trampoline_func(m, NULL, rec); | |
9674b2fa | 3669 | } |
763e34e7 SRV |
3670 | if (rec->flags & FTRACE_FL_DIRECT) { |
3671 | unsigned long direct; | |
3672 | ||
ff205766 | 3673 | direct = ftrace_find_rec_direct(rec->ip); |
763e34e7 SRV |
3674 | if (direct) |
3675 | seq_printf(m, "\n\tdirect-->%pS", (void *)direct); | |
3676 | } | |
026bb845 | 3677 | } |
9674b2fa | 3678 | |
fa6f0cc7 | 3679 | seq_putc(m, '\n'); |
5072c59f SR |
3680 | |
3681 | return 0; | |
3682 | } | |
3683 | ||
88e9d34c | 3684 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
3685 | .start = t_start, |
3686 | .next = t_next, | |
3687 | .stop = t_stop, | |
3688 | .show = t_show, | |
3689 | }; | |
3690 | ||
e309b41d | 3691 | static int |
5072c59f SR |
3692 | ftrace_avail_open(struct inode *inode, struct file *file) |
3693 | { | |
3694 | struct ftrace_iterator *iter; | |
17911ff3 SRV |
3695 | int ret; |
3696 | ||
3697 | ret = security_locked_down(LOCKDOWN_TRACEFS); | |
3698 | if (ret) | |
3699 | return ret; | |
5072c59f | 3700 | |
4eebcc81 SR |
3701 | if (unlikely(ftrace_disabled)) |
3702 | return -ENODEV; | |
3703 | ||
50e18b94 | 3704 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
c1bc5919 SRV |
3705 | if (!iter) |
3706 | return -ENOMEM; | |
5072c59f | 3707 | |
c1bc5919 SRV |
3708 | iter->pg = ftrace_pages_start; |
3709 | iter->ops = &global_ops; | |
3710 | ||
3711 | return 0; | |
5072c59f SR |
3712 | } |
3713 | ||
647bcd03 SR |
3714 | static int |
3715 | ftrace_enabled_open(struct inode *inode, struct file *file) | |
3716 | { | |
3717 | struct ftrace_iterator *iter; | |
647bcd03 | 3718 | |
17911ff3 SRV |
3719 | /* |
3720 | * This shows us what functions are currently being | |
3721 | * traced and by what. Not sure if we want lockdown | |
3722 | * to hide such critical information for an admin. | |
3723 | * Although, perhaps it can show information we don't | |
3724 | * want people to see, but if something is tracing | |
3725 | * something, we probably want to know about it. | |
3726 | */ | |
3727 | ||
50e18b94 | 3728 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
c1bc5919 SRV |
3729 | if (!iter) |
3730 | return -ENOMEM; | |
647bcd03 | 3731 | |
c1bc5919 SRV |
3732 | iter->pg = ftrace_pages_start; |
3733 | iter->flags = FTRACE_ITER_ENABLED; | |
3734 | iter->ops = &global_ops; | |
3735 | ||
3736 | return 0; | |
647bcd03 SR |
3737 | } |
3738 | ||
fc13cb0c SR |
3739 | /** |
3740 | * ftrace_regex_open - initialize function tracer filter files | |
3741 | * @ops: The ftrace_ops that hold the hash filters | |
3742 | * @flag: The type of filter to process | |
3743 | * @inode: The inode, usually passed in to your open routine | |
3744 | * @file: The file, usually passed in to your open routine | |
3745 | * | |
3746 | * ftrace_regex_open() initializes the filter files for the | |
3747 | * @ops. Depending on @flag it may process the filter hash or | |
3748 | * the notrace hash of @ops. With this called from the open | |
3749 | * routine, you can use ftrace_filter_write() for the write | |
3750 | * routine if @flag has FTRACE_ITER_FILTER set, or | |
3751 | * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set. | |
098c879e | 3752 | * tracing_lseek() should be used as the lseek routine, and |
fc13cb0c SR |
3753 | * release must call ftrace_regex_release(). |
3754 | */ | |
3755 | int | |
f45948e8 | 3756 | ftrace_regex_open(struct ftrace_ops *ops, int flag, |
1cf41dd7 | 3757 | struct inode *inode, struct file *file) |
5072c59f SR |
3758 | { |
3759 | struct ftrace_iterator *iter; | |
f45948e8 | 3760 | struct ftrace_hash *hash; |
673feb9d SRV |
3761 | struct list_head *mod_head; |
3762 | struct trace_array *tr = ops->private; | |
9ef16693 | 3763 | int ret = -ENOMEM; |
5072c59f | 3764 | |
f04f24fb MH |
3765 | ftrace_ops_init(ops); |
3766 | ||
4eebcc81 SR |
3767 | if (unlikely(ftrace_disabled)) |
3768 | return -ENODEV; | |
3769 | ||
8530dec6 | 3770 | if (tracing_check_open_get_tr(tr)) |
9ef16693 SRV |
3771 | return -ENODEV; |
3772 | ||
5072c59f SR |
3773 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
3774 | if (!iter) | |
9ef16693 | 3775 | goto out; |
5072c59f | 3776 | |
9ef16693 SRV |
3777 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) |
3778 | goto out; | |
689fd8b6 | 3779 | |
3f2367ba MH |
3780 | iter->ops = ops; |
3781 | iter->flags = flag; | |
5985ea8b | 3782 | iter->tr = tr; |
3f2367ba | 3783 | |
33b7f99c | 3784 | mutex_lock(&ops->func_hash->regex_lock); |
3f2367ba | 3785 | |
673feb9d | 3786 | if (flag & FTRACE_ITER_NOTRACE) { |
33b7f99c | 3787 | hash = ops->func_hash->notrace_hash; |
5985ea8b | 3788 | mod_head = tr ? &tr->mod_notrace : NULL; |
673feb9d | 3789 | } else { |
33b7f99c | 3790 | hash = ops->func_hash->filter_hash; |
5985ea8b | 3791 | mod_head = tr ? &tr->mod_trace : NULL; |
673feb9d | 3792 | } |
f45948e8 | 3793 | |
5985ea8b SRV |
3794 | iter->mod_list = mod_head; |
3795 | ||
33dc9b12 | 3796 | if (file->f_mode & FMODE_WRITE) { |
ef2fbe16 NK |
3797 | const int size_bits = FTRACE_HASH_DEFAULT_BITS; |
3798 | ||
673feb9d | 3799 | if (file->f_flags & O_TRUNC) { |
ef2fbe16 | 3800 | iter->hash = alloc_ftrace_hash(size_bits); |
673feb9d SRV |
3801 | clear_ftrace_mod_list(mod_head); |
3802 | } else { | |
ef2fbe16 | 3803 | iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash); |
673feb9d | 3804 | } |
ef2fbe16 | 3805 | |
33dc9b12 SR |
3806 | if (!iter->hash) { |
3807 | trace_parser_put(&iter->parser); | |
3f2367ba | 3808 | goto out_unlock; |
33dc9b12 | 3809 | } |
c20489da SRV |
3810 | } else |
3811 | iter->hash = hash; | |
1cf41dd7 | 3812 | |
9ef16693 SRV |
3813 | ret = 0; |
3814 | ||
5072c59f SR |
3815 | if (file->f_mode & FMODE_READ) { |
3816 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
3817 | |
3818 | ret = seq_open(file, &show_ftrace_seq_ops); | |
3819 | if (!ret) { | |
3820 | struct seq_file *m = file->private_data; | |
3821 | m->private = iter; | |
79fe249c | 3822 | } else { |
33dc9b12 SR |
3823 | /* Failed */ |
3824 | free_ftrace_hash(iter->hash); | |
79fe249c | 3825 | trace_parser_put(&iter->parser); |
79fe249c | 3826 | } |
5072c59f SR |
3827 | } else |
3828 | file->private_data = iter; | |
3f2367ba MH |
3829 | |
3830 | out_unlock: | |
33b7f99c | 3831 | mutex_unlock(&ops->func_hash->regex_lock); |
5072c59f | 3832 | |
9ef16693 SRV |
3833 | out: |
3834 | if (ret) { | |
3835 | kfree(iter); | |
3836 | if (tr) | |
3837 | trace_array_put(tr); | |
3838 | } | |
3839 | ||
5072c59f SR |
3840 | return ret; |
3841 | } | |
3842 | ||
41c52c0d SR |
3843 | static int |
3844 | ftrace_filter_open(struct inode *inode, struct file *file) | |
3845 | { | |
e3b3e2e8 SRRH |
3846 | struct ftrace_ops *ops = inode->i_private; |
3847 | ||
17911ff3 | 3848 | /* Checks for tracefs lockdown */ |
e3b3e2e8 | 3849 | return ftrace_regex_open(ops, |
eee8ded1 | 3850 | FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES, |
69a3083c | 3851 | inode, file); |
41c52c0d SR |
3852 | } |
3853 | ||
3854 | static int | |
3855 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
3856 | { | |
e3b3e2e8 SRRH |
3857 | struct ftrace_ops *ops = inode->i_private; |
3858 | ||
17911ff3 | 3859 | /* Checks for tracefs lockdown */ |
e3b3e2e8 | 3860 | return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE, |
1cf41dd7 | 3861 | inode, file); |
41c52c0d SR |
3862 | } |
3863 | ||
3ba00929 DS |
3864 | /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */ |
3865 | struct ftrace_glob { | |
3866 | char *search; | |
3867 | unsigned len; | |
3868 | int type; | |
3869 | }; | |
3870 | ||
7132e2d6 TJB |
3871 | /* |
3872 | * If symbols in an architecture don't correspond exactly to the user-visible | |
3873 | * name of what they represent, it is possible to define this function to | |
3874 | * perform the necessary adjustments. | |
3875 | */ | |
3876 | char * __weak arch_ftrace_match_adjust(char *str, const char *search) | |
3877 | { | |
3878 | return str; | |
3879 | } | |
3880 | ||
3ba00929 | 3881 | static int ftrace_match(char *str, struct ftrace_glob *g) |
9f4801e3 | 3882 | { |
9f4801e3 | 3883 | int matched = 0; |
751e9983 | 3884 | int slen; |
9f4801e3 | 3885 | |
7132e2d6 TJB |
3886 | str = arch_ftrace_match_adjust(str, g->search); |
3887 | ||
3ba00929 | 3888 | switch (g->type) { |
9f4801e3 | 3889 | case MATCH_FULL: |
3ba00929 | 3890 | if (strcmp(str, g->search) == 0) |
9f4801e3 SR |
3891 | matched = 1; |
3892 | break; | |
3893 | case MATCH_FRONT_ONLY: | |
3ba00929 | 3894 | if (strncmp(str, g->search, g->len) == 0) |
9f4801e3 SR |
3895 | matched = 1; |
3896 | break; | |
3897 | case MATCH_MIDDLE_ONLY: | |
3ba00929 | 3898 | if (strstr(str, g->search)) |
9f4801e3 SR |
3899 | matched = 1; |
3900 | break; | |
3901 | case MATCH_END_ONLY: | |
751e9983 | 3902 | slen = strlen(str); |
3ba00929 DS |
3903 | if (slen >= g->len && |
3904 | memcmp(str + slen - g->len, g->search, g->len) == 0) | |
9f4801e3 SR |
3905 | matched = 1; |
3906 | break; | |
60f1d5e3 MH |
3907 | case MATCH_GLOB: |
3908 | if (glob_match(g->search, str)) | |
3909 | matched = 1; | |
3910 | break; | |
9f4801e3 SR |
3911 | } |
3912 | ||
3913 | return matched; | |
3914 | } | |
3915 | ||
b448c4e3 | 3916 | static int |
f0a3b154 | 3917 | enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter) |
996e87be | 3918 | { |
b448c4e3 | 3919 | struct ftrace_func_entry *entry; |
b448c4e3 SR |
3920 | int ret = 0; |
3921 | ||
1cf41dd7 | 3922 | entry = ftrace_lookup_ip(hash, rec->ip); |
f0a3b154 | 3923 | if (clear_filter) { |
1cf41dd7 SR |
3924 | /* Do nothing if it doesn't exist */ |
3925 | if (!entry) | |
3926 | return 0; | |
b448c4e3 | 3927 | |
33dc9b12 | 3928 | free_hash_entry(hash, entry); |
1cf41dd7 SR |
3929 | } else { |
3930 | /* Do nothing if it exists */ | |
3931 | if (entry) | |
3932 | return 0; | |
b448c4e3 | 3933 | |
1cf41dd7 | 3934 | ret = add_hash_entry(hash, rec->ip); |
b448c4e3 SR |
3935 | } |
3936 | return ret; | |
996e87be SR |
3937 | } |
3938 | ||
f79b3f33 SRV |
3939 | static int |
3940 | add_rec_by_index(struct ftrace_hash *hash, struct ftrace_glob *func_g, | |
3941 | int clear_filter) | |
3942 | { | |
3943 | long index = simple_strtoul(func_g->search, NULL, 0); | |
3944 | struct ftrace_page *pg; | |
3945 | struct dyn_ftrace *rec; | |
3946 | ||
3947 | /* The index starts at 1 */ | |
3948 | if (--index < 0) | |
3949 | return 0; | |
3950 | ||
3951 | do_for_each_ftrace_rec(pg, rec) { | |
3952 | if (pg->index <= index) { | |
3953 | index -= pg->index; | |
3954 | /* this is a double loop, break goes to the next page */ | |
3955 | break; | |
3956 | } | |
3957 | rec = &pg->records[index]; | |
3958 | enter_record(hash, rec, clear_filter); | |
3959 | return 1; | |
3960 | } while_for_each_ftrace_rec(); | |
3961 | return 0; | |
3962 | } | |
3963 | ||
64e7c440 | 3964 | static int |
0b507e1e DS |
3965 | ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g, |
3966 | struct ftrace_glob *mod_g, int exclude_mod) | |
64e7c440 SR |
3967 | { |
3968 | char str[KSYM_SYMBOL_LEN]; | |
b9df92d2 SR |
3969 | char *modname; |
3970 | ||
3971 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
3972 | ||
0b507e1e DS |
3973 | if (mod_g) { |
3974 | int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0; | |
3975 | ||
3976 | /* blank module name to match all modules */ | |
3977 | if (!mod_g->len) { | |
3978 | /* blank module globbing: modname xor exclude_mod */ | |
77c0edde | 3979 | if (!exclude_mod != !modname) |
0b507e1e DS |
3980 | goto func_match; |
3981 | return 0; | |
3982 | } | |
3983 | ||
77c0edde SRV |
3984 | /* |
3985 | * exclude_mod is set to trace everything but the given | |
3986 | * module. If it is set and the module matches, then | |
3987 | * return 0. If it is not set, and the module doesn't match | |
3988 | * also return 0. Otherwise, check the function to see if | |
3989 | * that matches. | |
3990 | */ | |
3991 | if (!mod_matches == !exclude_mod) | |
b9df92d2 | 3992 | return 0; |
0b507e1e | 3993 | func_match: |
b9df92d2 | 3994 | /* blank search means to match all funcs in the mod */ |
3ba00929 | 3995 | if (!func_g->len) |
b9df92d2 SR |
3996 | return 1; |
3997 | } | |
64e7c440 | 3998 | |
3ba00929 | 3999 | return ftrace_match(str, func_g); |
64e7c440 SR |
4000 | } |
4001 | ||
1cf41dd7 | 4002 | static int |
3ba00929 | 4003 | match_records(struct ftrace_hash *hash, char *func, int len, char *mod) |
9f4801e3 | 4004 | { |
9f4801e3 SR |
4005 | struct ftrace_page *pg; |
4006 | struct dyn_ftrace *rec; | |
3ba00929 | 4007 | struct ftrace_glob func_g = { .type = MATCH_FULL }; |
0b507e1e DS |
4008 | struct ftrace_glob mod_g = { .type = MATCH_FULL }; |
4009 | struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL; | |
4010 | int exclude_mod = 0; | |
311d16da | 4011 | int found = 0; |
b448c4e3 | 4012 | int ret; |
2e028c4f | 4013 | int clear_filter = 0; |
9f4801e3 | 4014 | |
0b507e1e | 4015 | if (func) { |
3ba00929 DS |
4016 | func_g.type = filter_parse_regex(func, len, &func_g.search, |
4017 | &clear_filter); | |
4018 | func_g.len = strlen(func_g.search); | |
b9df92d2 | 4019 | } |
9f4801e3 | 4020 | |
0b507e1e DS |
4021 | if (mod) { |
4022 | mod_g.type = filter_parse_regex(mod, strlen(mod), | |
4023 | &mod_g.search, &exclude_mod); | |
4024 | mod_g.len = strlen(mod_g.search); | |
b9df92d2 | 4025 | } |
9f4801e3 | 4026 | |
52baf119 | 4027 | mutex_lock(&ftrace_lock); |
265c831c | 4028 | |
b9df92d2 SR |
4029 | if (unlikely(ftrace_disabled)) |
4030 | goto out_unlock; | |
9f4801e3 | 4031 | |
f79b3f33 SRV |
4032 | if (func_g.type == MATCH_INDEX) { |
4033 | found = add_rec_by_index(hash, &func_g, clear_filter); | |
4034 | goto out_unlock; | |
4035 | } | |
4036 | ||
265c831c | 4037 | do_for_each_ftrace_rec(pg, rec) { |
546fece4 SRRH |
4038 | |
4039 | if (rec->flags & FTRACE_FL_DISABLED) | |
4040 | continue; | |
4041 | ||
0b507e1e | 4042 | if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) { |
f0a3b154 | 4043 | ret = enter_record(hash, rec, clear_filter); |
b448c4e3 SR |
4044 | if (ret < 0) { |
4045 | found = ret; | |
4046 | goto out_unlock; | |
4047 | } | |
311d16da | 4048 | found = 1; |
265c831c SR |
4049 | } |
4050 | } while_for_each_ftrace_rec(); | |
b9df92d2 | 4051 | out_unlock: |
52baf119 | 4052 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
4053 | |
4054 | return found; | |
5072c59f SR |
4055 | } |
4056 | ||
64e7c440 | 4057 | static int |
1cf41dd7 | 4058 | ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) |
64e7c440 | 4059 | { |
f0a3b154 | 4060 | return match_records(hash, buff, len, NULL); |
64e7c440 SR |
4061 | } |
4062 | ||
e16b35dd SRV |
4063 | static void ftrace_ops_update_code(struct ftrace_ops *ops, |
4064 | struct ftrace_ops_hash *old_hash) | |
4065 | { | |
4066 | struct ftrace_ops *op; | |
4067 | ||
4068 | if (!ftrace_enabled) | |
4069 | return; | |
4070 | ||
4071 | if (ops->flags & FTRACE_OPS_FL_ENABLED) { | |
4072 | ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash); | |
4073 | return; | |
4074 | } | |
4075 | ||
4076 | /* | |
4077 | * If this is the shared global_ops filter, then we need to | |
4078 | * check if there is another ops that shares it, is enabled. | |
4079 | * If so, we still need to run the modify code. | |
4080 | */ | |
4081 | if (ops->func_hash != &global_ops.local_hash) | |
4082 | return; | |
4083 | ||
4084 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
4085 | if (op->func_hash == &global_ops.local_hash && | |
4086 | op->flags & FTRACE_OPS_FL_ENABLED) { | |
4087 | ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash); | |
4088 | /* Only need to do this once */ | |
4089 | return; | |
4090 | } | |
4091 | } while_for_each_ftrace_op(op); | |
4092 | } | |
4093 | ||
4094 | static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops, | |
4095 | struct ftrace_hash **orig_hash, | |
4096 | struct ftrace_hash *hash, | |
4097 | int enable) | |
4098 | { | |
4099 | struct ftrace_ops_hash old_hash_ops; | |
4100 | struct ftrace_hash *old_hash; | |
4101 | int ret; | |
4102 | ||
4103 | old_hash = *orig_hash; | |
4104 | old_hash_ops.filter_hash = ops->func_hash->filter_hash; | |
4105 | old_hash_ops.notrace_hash = ops->func_hash->notrace_hash; | |
4106 | ret = ftrace_hash_move(ops, enable, orig_hash, hash); | |
4107 | if (!ret) { | |
4108 | ftrace_ops_update_code(ops, &old_hash_ops); | |
4109 | free_ftrace_hash_rcu(old_hash); | |
4110 | } | |
4111 | return ret; | |
4112 | } | |
64e7c440 | 4113 | |
673feb9d SRV |
4114 | static bool module_exists(const char *module) |
4115 | { | |
4116 | /* All modules have the symbol __this_module */ | |
0f5e5a3a | 4117 | static const char this_mod[] = "__this_module"; |
419e9fe5 | 4118 | char modname[MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 2]; |
673feb9d SRV |
4119 | unsigned long val; |
4120 | int n; | |
4121 | ||
419e9fe5 | 4122 | n = snprintf(modname, sizeof(modname), "%s:%s", module, this_mod); |
673feb9d | 4123 | |
419e9fe5 | 4124 | if (n > sizeof(modname) - 1) |
673feb9d SRV |
4125 | return false; |
4126 | ||
4127 | val = module_kallsyms_lookup_name(modname); | |
4128 | return val != 0; | |
4129 | } | |
4130 | ||
4131 | static int cache_mod(struct trace_array *tr, | |
4132 | const char *func, char *module, int enable) | |
4133 | { | |
4134 | struct ftrace_mod_load *ftrace_mod, *n; | |
4135 | struct list_head *head = enable ? &tr->mod_trace : &tr->mod_notrace; | |
4136 | int ret; | |
4137 | ||
4138 | mutex_lock(&ftrace_lock); | |
4139 | ||
4140 | /* We do not cache inverse filters */ | |
4141 | if (func[0] == '!') { | |
4142 | func++; | |
4143 | ret = -EINVAL; | |
4144 | ||
4145 | /* Look to remove this hash */ | |
4146 | list_for_each_entry_safe(ftrace_mod, n, head, list) { | |
4147 | if (strcmp(ftrace_mod->module, module) != 0) | |
4148 | continue; | |
4149 | ||
4150 | /* no func matches all */ | |
44925dff | 4151 | if (strcmp(func, "*") == 0 || |
673feb9d SRV |
4152 | (ftrace_mod->func && |
4153 | strcmp(ftrace_mod->func, func) == 0)) { | |
4154 | ret = 0; | |
4155 | free_ftrace_mod(ftrace_mod); | |
4156 | continue; | |
4157 | } | |
4158 | } | |
4159 | goto out; | |
4160 | } | |
4161 | ||
4162 | ret = -EINVAL; | |
4163 | /* We only care about modules that have not been loaded yet */ | |
4164 | if (module_exists(module)) | |
4165 | goto out; | |
4166 | ||
4167 | /* Save this string off, and execute it when the module is loaded */ | |
4168 | ret = ftrace_add_mod(tr, func, module, enable); | |
4169 | out: | |
4170 | mutex_unlock(&ftrace_lock); | |
4171 | ||
4172 | return ret; | |
4173 | } | |
4174 | ||
d7fbf8df SRV |
4175 | static int |
4176 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, | |
4177 | int reset, int enable); | |
4178 | ||
69449bbd | 4179 | #ifdef CONFIG_MODULES |
d7fbf8df SRV |
4180 | static void process_mod_list(struct list_head *head, struct ftrace_ops *ops, |
4181 | char *mod, bool enable) | |
4182 | { | |
4183 | struct ftrace_mod_load *ftrace_mod, *n; | |
4184 | struct ftrace_hash **orig_hash, *new_hash; | |
4185 | LIST_HEAD(process_mods); | |
4186 | char *func; | |
d7fbf8df SRV |
4187 | |
4188 | mutex_lock(&ops->func_hash->regex_lock); | |
4189 | ||
4190 | if (enable) | |
4191 | orig_hash = &ops->func_hash->filter_hash; | |
4192 | else | |
4193 | orig_hash = &ops->func_hash->notrace_hash; | |
4194 | ||
4195 | new_hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, | |
4196 | *orig_hash); | |
4197 | if (!new_hash) | |
3b58a3c7 | 4198 | goto out; /* warn? */ |
d7fbf8df SRV |
4199 | |
4200 | mutex_lock(&ftrace_lock); | |
4201 | ||
4202 | list_for_each_entry_safe(ftrace_mod, n, head, list) { | |
4203 | ||
4204 | if (strcmp(ftrace_mod->module, mod) != 0) | |
4205 | continue; | |
4206 | ||
4207 | if (ftrace_mod->func) | |
4208 | func = kstrdup(ftrace_mod->func, GFP_KERNEL); | |
4209 | else | |
4210 | func = kstrdup("*", GFP_KERNEL); | |
4211 | ||
4212 | if (!func) /* warn? */ | |
4213 | continue; | |
4214 | ||
4215 | list_del(&ftrace_mod->list); | |
4216 | list_add(&ftrace_mod->list, &process_mods); | |
4217 | ||
4218 | /* Use the newly allocated func, as it may be "*" */ | |
4219 | kfree(ftrace_mod->func); | |
4220 | ftrace_mod->func = func; | |
4221 | } | |
4222 | ||
4223 | mutex_unlock(&ftrace_lock); | |
4224 | ||
4225 | list_for_each_entry_safe(ftrace_mod, n, &process_mods, list) { | |
4226 | ||
4227 | func = ftrace_mod->func; | |
4228 | ||
4229 | /* Grabs ftrace_lock, which is why we have this extra step */ | |
4230 | match_records(new_hash, func, strlen(func), mod); | |
4231 | free_ftrace_mod(ftrace_mod); | |
4232 | } | |
4233 | ||
8c08f0d5 SRV |
4234 | if (enable && list_empty(head)) |
4235 | new_hash->flags &= ~FTRACE_HASH_FL_MOD; | |
4236 | ||
d7fbf8df SRV |
4237 | mutex_lock(&ftrace_lock); |
4238 | ||
045e269c | 4239 | ftrace_hash_move_and_update_ops(ops, orig_hash, |
d7fbf8df SRV |
4240 | new_hash, enable); |
4241 | mutex_unlock(&ftrace_lock); | |
4242 | ||
3b58a3c7 | 4243 | out: |
d7fbf8df SRV |
4244 | mutex_unlock(&ops->func_hash->regex_lock); |
4245 | ||
4246 | free_ftrace_hash(new_hash); | |
4247 | } | |
4248 | ||
4249 | static void process_cached_mods(const char *mod_name) | |
4250 | { | |
4251 | struct trace_array *tr; | |
4252 | char *mod; | |
4253 | ||
4254 | mod = kstrdup(mod_name, GFP_KERNEL); | |
4255 | if (!mod) | |
4256 | return; | |
4257 | ||
4258 | mutex_lock(&trace_types_lock); | |
4259 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
4260 | if (!list_empty(&tr->mod_trace)) | |
4261 | process_mod_list(&tr->mod_trace, tr->ops, mod, true); | |
4262 | if (!list_empty(&tr->mod_notrace)) | |
4263 | process_mod_list(&tr->mod_notrace, tr->ops, mod, false); | |
4264 | } | |
4265 | mutex_unlock(&trace_types_lock); | |
4266 | ||
4267 | kfree(mod); | |
4268 | } | |
69449bbd | 4269 | #endif |
d7fbf8df | 4270 | |
f6180773 SR |
4271 | /* |
4272 | * We register the module command as a template to show others how | |
4273 | * to register the a command as well. | |
4274 | */ | |
4275 | ||
4276 | static int | |
04ec7bb6 | 4277 | ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash, |
673feb9d | 4278 | char *func_orig, char *cmd, char *module, int enable) |
f6180773 | 4279 | { |
673feb9d | 4280 | char *func; |
5e3949f0 | 4281 | int ret; |
f6180773 | 4282 | |
673feb9d SRV |
4283 | /* match_records() modifies func, and we need the original */ |
4284 | func = kstrdup(func_orig, GFP_KERNEL); | |
4285 | if (!func) | |
4286 | return -ENOMEM; | |
4287 | ||
f6180773 SR |
4288 | /* |
4289 | * cmd == 'mod' because we only registered this func | |
4290 | * for the 'mod' ftrace_func_command. | |
4291 | * But if you register one func with multiple commands, | |
4292 | * you can tell which command was used by the cmd | |
4293 | * parameter. | |
4294 | */ | |
f0a3b154 | 4295 | ret = match_records(hash, func, strlen(func), module); |
673feb9d SRV |
4296 | kfree(func); |
4297 | ||
b448c4e3 | 4298 | if (!ret) |
673feb9d | 4299 | return cache_mod(tr, func_orig, module, enable); |
b448c4e3 SR |
4300 | if (ret < 0) |
4301 | return ret; | |
b448c4e3 | 4302 | return 0; |
f6180773 SR |
4303 | } |
4304 | ||
4305 | static struct ftrace_func_command ftrace_mod_cmd = { | |
4306 | .name = "mod", | |
4307 | .func = ftrace_mod_callback, | |
4308 | }; | |
4309 | ||
4310 | static int __init ftrace_mod_cmd_init(void) | |
4311 | { | |
4312 | return register_ftrace_command(&ftrace_mod_cmd); | |
4313 | } | |
6f415672 | 4314 | core_initcall(ftrace_mod_cmd_init); |
f6180773 | 4315 | |
2f5f6ad9 | 4316 | static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, |
d19ad077 | 4317 | struct ftrace_ops *op, struct ftrace_regs *fregs) |
59df055f | 4318 | { |
eee8ded1 | 4319 | struct ftrace_probe_ops *probe_ops; |
7b60f3d8 | 4320 | struct ftrace_func_probe *probe; |
59df055f | 4321 | |
7b60f3d8 SRV |
4322 | probe = container_of(op, struct ftrace_func_probe, ops); |
4323 | probe_ops = probe->probe_ops; | |
59df055f SR |
4324 | |
4325 | /* | |
4326 | * Disable preemption for these calls to prevent a RCU grace | |
4327 | * period. This syncs the hash iteration and freeing of items | |
4328 | * on the hash. rcu_read_lock is too dangerous here. | |
4329 | */ | |
5168ae50 | 4330 | preempt_disable_notrace(); |
6e444319 | 4331 | probe_ops->func(ip, parent_ip, probe->tr, probe_ops, probe->data); |
5168ae50 | 4332 | preempt_enable_notrace(); |
59df055f SR |
4333 | } |
4334 | ||
41794f19 SRV |
4335 | struct ftrace_func_map { |
4336 | struct ftrace_func_entry entry; | |
4337 | void *data; | |
59df055f SR |
4338 | }; |
4339 | ||
41794f19 SRV |
4340 | struct ftrace_func_mapper { |
4341 | struct ftrace_hash hash; | |
4342 | }; | |
59df055f | 4343 | |
41794f19 SRV |
4344 | /** |
4345 | * allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper | |
4346 | * | |
4347 | * Returns a ftrace_func_mapper descriptor that can be used to map ips to data. | |
4348 | */ | |
4349 | struct ftrace_func_mapper *allocate_ftrace_func_mapper(void) | |
59df055f | 4350 | { |
41794f19 | 4351 | struct ftrace_hash *hash; |
59df055f | 4352 | |
41794f19 SRV |
4353 | /* |
4354 | * The mapper is simply a ftrace_hash, but since the entries | |
4355 | * in the hash are not ftrace_func_entry type, we define it | |
4356 | * as a separate structure. | |
4357 | */ | |
4358 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); | |
4359 | return (struct ftrace_func_mapper *)hash; | |
4360 | } | |
59df055f | 4361 | |
41794f19 SRV |
4362 | /** |
4363 | * ftrace_func_mapper_find_ip - Find some data mapped to an ip | |
4364 | * @mapper: The mapper that has the ip maps | |
4365 | * @ip: the instruction pointer to find the data for | |
4366 | * | |
4367 | * Returns the data mapped to @ip if found otherwise NULL. The return | |
4368 | * is actually the address of the mapper data pointer. The address is | |
4369 | * returned for use cases where the data is no bigger than a long, and | |
4370 | * the user can use the data pointer as its data instead of having to | |
4371 | * allocate more memory for the reference. | |
4372 | */ | |
4373 | void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper, | |
4374 | unsigned long ip) | |
4375 | { | |
4376 | struct ftrace_func_entry *entry; | |
4377 | struct ftrace_func_map *map; | |
59df055f | 4378 | |
41794f19 SRV |
4379 | entry = ftrace_lookup_ip(&mapper->hash, ip); |
4380 | if (!entry) | |
4381 | return NULL; | |
b848914c | 4382 | |
41794f19 SRV |
4383 | map = (struct ftrace_func_map *)entry; |
4384 | return &map->data; | |
59df055f SR |
4385 | } |
4386 | ||
41794f19 SRV |
4387 | /** |
4388 | * ftrace_func_mapper_add_ip - Map some data to an ip | |
4389 | * @mapper: The mapper that has the ip maps | |
4390 | * @ip: The instruction pointer address to map @data to | |
4391 | * @data: The data to map to @ip | |
4392 | * | |
fdda88d3 | 4393 | * Returns 0 on success otherwise an error. |
41794f19 SRV |
4394 | */ |
4395 | int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper, | |
4396 | unsigned long ip, void *data) | |
59df055f | 4397 | { |
41794f19 SRV |
4398 | struct ftrace_func_entry *entry; |
4399 | struct ftrace_func_map *map; | |
59df055f | 4400 | |
41794f19 SRV |
4401 | entry = ftrace_lookup_ip(&mapper->hash, ip); |
4402 | if (entry) | |
4403 | return -EBUSY; | |
59df055f | 4404 | |
41794f19 SRV |
4405 | map = kmalloc(sizeof(*map), GFP_KERNEL); |
4406 | if (!map) | |
4407 | return -ENOMEM; | |
59df055f | 4408 | |
41794f19 SRV |
4409 | map->entry.ip = ip; |
4410 | map->data = data; | |
b848914c | 4411 | |
41794f19 | 4412 | __add_hash_entry(&mapper->hash, &map->entry); |
59df055f | 4413 | |
41794f19 SRV |
4414 | return 0; |
4415 | } | |
59df055f | 4416 | |
41794f19 SRV |
4417 | /** |
4418 | * ftrace_func_mapper_remove_ip - Remove an ip from the mapping | |
4419 | * @mapper: The mapper that has the ip maps | |
4420 | * @ip: The instruction pointer address to remove the data from | |
4421 | * | |
4422 | * Returns the data if it is found, otherwise NULL. | |
4423 | * Note, if the data pointer is used as the data itself, (see | |
4424 | * ftrace_func_mapper_find_ip(), then the return value may be meaningless, | |
4425 | * if the data pointer was set to zero. | |
4426 | */ | |
4427 | void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper, | |
4428 | unsigned long ip) | |
59df055f | 4429 | { |
41794f19 SRV |
4430 | struct ftrace_func_entry *entry; |
4431 | struct ftrace_func_map *map; | |
4432 | void *data; | |
4433 | ||
4434 | entry = ftrace_lookup_ip(&mapper->hash, ip); | |
4435 | if (!entry) | |
4436 | return NULL; | |
4437 | ||
4438 | map = (struct ftrace_func_map *)entry; | |
4439 | data = map->data; | |
4440 | ||
4441 | remove_hash_entry(&mapper->hash, entry); | |
59df055f | 4442 | kfree(entry); |
41794f19 SRV |
4443 | |
4444 | return data; | |
4445 | } | |
4446 | ||
4447 | /** | |
4448 | * free_ftrace_func_mapper - free a mapping of ips and data | |
4449 | * @mapper: The mapper that has the ip maps | |
4450 | * @free_func: A function to be called on each data item. | |
4451 | * | |
4452 | * This is used to free the function mapper. The @free_func is optional | |
4453 | * and can be used if the data needs to be freed as well. | |
4454 | */ | |
4455 | void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper, | |
4456 | ftrace_mapper_func free_func) | |
4457 | { | |
4458 | struct ftrace_func_entry *entry; | |
4459 | struct ftrace_func_map *map; | |
4460 | struct hlist_head *hhd; | |
04e03d9a WL |
4461 | int size, i; |
4462 | ||
4463 | if (!mapper) | |
4464 | return; | |
41794f19 SRV |
4465 | |
4466 | if (free_func && mapper->hash.count) { | |
04e03d9a | 4467 | size = 1 << mapper->hash.size_bits; |
41794f19 SRV |
4468 | for (i = 0; i < size; i++) { |
4469 | hhd = &mapper->hash.buckets[i]; | |
4470 | hlist_for_each_entry(entry, hhd, hlist) { | |
4471 | map = (struct ftrace_func_map *)entry; | |
4472 | free_func(map); | |
4473 | } | |
4474 | } | |
4475 | } | |
4476 | free_ftrace_hash(&mapper->hash); | |
4477 | } | |
4478 | ||
7b60f3d8 SRV |
4479 | static void release_probe(struct ftrace_func_probe *probe) |
4480 | { | |
4481 | struct ftrace_probe_ops *probe_ops; | |
4482 | ||
4483 | mutex_lock(&ftrace_lock); | |
4484 | ||
4485 | WARN_ON(probe->ref <= 0); | |
4486 | ||
4487 | /* Subtract the ref that was used to protect this instance */ | |
4488 | probe->ref--; | |
4489 | ||
4490 | if (!probe->ref) { | |
4491 | probe_ops = probe->probe_ops; | |
6e444319 SRV |
4492 | /* |
4493 | * Sending zero as ip tells probe_ops to free | |
4494 | * the probe->data itself | |
4495 | */ | |
4496 | if (probe_ops->free) | |
4497 | probe_ops->free(probe_ops, probe->tr, 0, probe->data); | |
7b60f3d8 SRV |
4498 | list_del(&probe->list); |
4499 | kfree(probe); | |
4500 | } | |
4501 | mutex_unlock(&ftrace_lock); | |
4502 | } | |
4503 | ||
4504 | static void acquire_probe_locked(struct ftrace_func_probe *probe) | |
4505 | { | |
4506 | /* | |
4507 | * Add one ref to keep it from being freed when releasing the | |
4508 | * ftrace_lock mutex. | |
4509 | */ | |
4510 | probe->ref++; | |
59df055f SR |
4511 | } |
4512 | ||
59df055f | 4513 | int |
04ec7bb6 | 4514 | register_ftrace_function_probe(char *glob, struct trace_array *tr, |
7b60f3d8 SRV |
4515 | struct ftrace_probe_ops *probe_ops, |
4516 | void *data) | |
59df055f | 4517 | { |
1ec3a81a | 4518 | struct ftrace_func_entry *entry; |
7b60f3d8 | 4519 | struct ftrace_func_probe *probe; |
1ec3a81a SRV |
4520 | struct ftrace_hash **orig_hash; |
4521 | struct ftrace_hash *old_hash; | |
e1df4cb6 | 4522 | struct ftrace_hash *hash; |
59df055f | 4523 | int count = 0; |
1ec3a81a | 4524 | int size; |
e1df4cb6 | 4525 | int ret; |
1ec3a81a | 4526 | int i; |
59df055f | 4527 | |
04ec7bb6 | 4528 | if (WARN_ON(!tr)) |
59df055f SR |
4529 | return -EINVAL; |
4530 | ||
1ec3a81a SRV |
4531 | /* We do not support '!' for function probes */ |
4532 | if (WARN_ON(glob[0] == '!')) | |
59df055f | 4533 | return -EINVAL; |
59df055f | 4534 | |
7485058e | 4535 | |
7b60f3d8 SRV |
4536 | mutex_lock(&ftrace_lock); |
4537 | /* Check if the probe_ops is already registered */ | |
4538 | list_for_each_entry(probe, &tr->func_probes, list) { | |
4539 | if (probe->probe_ops == probe_ops) | |
4540 | break; | |
e1df4cb6 | 4541 | } |
7b60f3d8 SRV |
4542 | if (&probe->list == &tr->func_probes) { |
4543 | probe = kzalloc(sizeof(*probe), GFP_KERNEL); | |
4544 | if (!probe) { | |
4545 | mutex_unlock(&ftrace_lock); | |
4546 | return -ENOMEM; | |
4547 | } | |
4548 | probe->probe_ops = probe_ops; | |
4549 | probe->ops.func = function_trace_probe_call; | |
4550 | probe->tr = tr; | |
4551 | ftrace_ops_init(&probe->ops); | |
4552 | list_add(&probe->list, &tr->func_probes); | |
e1df4cb6 | 4553 | } |
59df055f | 4554 | |
7b60f3d8 | 4555 | acquire_probe_locked(probe); |
5ae0bf59 | 4556 | |
7b60f3d8 | 4557 | mutex_unlock(&ftrace_lock); |
59df055f | 4558 | |
372e0d01 SRV |
4559 | /* |
4560 | * Note, there's a small window here that the func_hash->filter_hash | |
fdda88d3 | 4561 | * may be NULL or empty. Need to be careful when reading the loop. |
372e0d01 | 4562 | */ |
7b60f3d8 | 4563 | mutex_lock(&probe->ops.func_hash->regex_lock); |
546fece4 | 4564 | |
7b60f3d8 | 4565 | orig_hash = &probe->ops.func_hash->filter_hash; |
1ec3a81a SRV |
4566 | old_hash = *orig_hash; |
4567 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); | |
59df055f | 4568 | |
5b0022dd NR |
4569 | if (!hash) { |
4570 | ret = -ENOMEM; | |
4571 | goto out; | |
4572 | } | |
4573 | ||
1ec3a81a | 4574 | ret = ftrace_match_records(hash, glob, strlen(glob)); |
59df055f | 4575 | |
1ec3a81a SRV |
4576 | /* Nothing found? */ |
4577 | if (!ret) | |
4578 | ret = -EINVAL; | |
59df055f | 4579 | |
1ec3a81a SRV |
4580 | if (ret < 0) |
4581 | goto out; | |
59df055f | 4582 | |
1ec3a81a SRV |
4583 | size = 1 << hash->size_bits; |
4584 | for (i = 0; i < size; i++) { | |
4585 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
4586 | if (ftrace_lookup_ip(old_hash, entry->ip)) | |
59df055f | 4587 | continue; |
1ec3a81a SRV |
4588 | /* |
4589 | * The caller might want to do something special | |
4590 | * for each function we find. We call the callback | |
4591 | * to give the caller an opportunity to do so. | |
4592 | */ | |
7b60f3d8 SRV |
4593 | if (probe_ops->init) { |
4594 | ret = probe_ops->init(probe_ops, tr, | |
6e444319 SRV |
4595 | entry->ip, data, |
4596 | &probe->data); | |
4597 | if (ret < 0) { | |
4598 | if (probe_ops->free && count) | |
4599 | probe_ops->free(probe_ops, tr, | |
4600 | 0, probe->data); | |
4601 | probe->data = NULL; | |
eee8ded1 | 4602 | goto out; |
6e444319 | 4603 | } |
59df055f | 4604 | } |
1ec3a81a | 4605 | count++; |
59df055f | 4606 | } |
1ec3a81a | 4607 | } |
59df055f | 4608 | |
1ec3a81a | 4609 | mutex_lock(&ftrace_lock); |
59df055f | 4610 | |
7b60f3d8 SRV |
4611 | if (!count) { |
4612 | /* Nothing was added? */ | |
4613 | ret = -EINVAL; | |
4614 | goto out_unlock; | |
4615 | } | |
e1df4cb6 | 4616 | |
7b60f3d8 SRV |
4617 | ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash, |
4618 | hash, 1); | |
1ec3a81a | 4619 | if (ret < 0) |
8d70725e | 4620 | goto err_unlock; |
8252ecf3 | 4621 | |
7b60f3d8 SRV |
4622 | /* One ref for each new function traced */ |
4623 | probe->ref += count; | |
8252ecf3 | 4624 | |
7b60f3d8 SRV |
4625 | if (!(probe->ops.flags & FTRACE_OPS_FL_ENABLED)) |
4626 | ret = ftrace_startup(&probe->ops, 0); | |
e1df4cb6 | 4627 | |
59df055f | 4628 | out_unlock: |
5ae0bf59 | 4629 | mutex_unlock(&ftrace_lock); |
8252ecf3 | 4630 | |
3296fc4e | 4631 | if (!ret) |
1ec3a81a | 4632 | ret = count; |
5ae0bf59 | 4633 | out: |
7b60f3d8 | 4634 | mutex_unlock(&probe->ops.func_hash->regex_lock); |
e1df4cb6 | 4635 | free_ftrace_hash(hash); |
59df055f | 4636 | |
7b60f3d8 | 4637 | release_probe(probe); |
59df055f | 4638 | |
1ec3a81a | 4639 | return ret; |
59df055f | 4640 | |
8d70725e | 4641 | err_unlock: |
7b60f3d8 | 4642 | if (!probe_ops->free || !count) |
8d70725e SRV |
4643 | goto out_unlock; |
4644 | ||
4645 | /* Failed to do the move, need to call the free functions */ | |
4646 | for (i = 0; i < size; i++) { | |
4647 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
4648 | if (ftrace_lookup_ip(old_hash, entry->ip)) | |
4649 | continue; | |
6e444319 | 4650 | probe_ops->free(probe_ops, tr, entry->ip, probe->data); |
8d70725e SRV |
4651 | } |
4652 | } | |
4653 | goto out_unlock; | |
59df055f SR |
4654 | } |
4655 | ||
d3d532d7 | 4656 | int |
7b60f3d8 SRV |
4657 | unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr, |
4658 | struct ftrace_probe_ops *probe_ops) | |
59df055f | 4659 | { |
82cc4fc2 | 4660 | struct ftrace_ops_hash old_hash_ops; |
eee8ded1 | 4661 | struct ftrace_func_entry *entry; |
7b60f3d8 | 4662 | struct ftrace_func_probe *probe; |
3ba00929 | 4663 | struct ftrace_glob func_g; |
1ec3a81a SRV |
4664 | struct ftrace_hash **orig_hash; |
4665 | struct ftrace_hash *old_hash; | |
1ec3a81a | 4666 | struct ftrace_hash *hash = NULL; |
b67bfe0d | 4667 | struct hlist_node *tmp; |
eee8ded1 | 4668 | struct hlist_head hhd; |
59df055f | 4669 | char str[KSYM_SYMBOL_LEN]; |
7b60f3d8 SRV |
4670 | int count = 0; |
4671 | int i, ret = -ENODEV; | |
eee8ded1 | 4672 | int size; |
59df055f | 4673 | |
cbab567c | 4674 | if (!glob || !strlen(glob) || !strcmp(glob, "*")) |
3ba00929 | 4675 | func_g.search = NULL; |
cbab567c | 4676 | else { |
59df055f SR |
4677 | int not; |
4678 | ||
3ba00929 DS |
4679 | func_g.type = filter_parse_regex(glob, strlen(glob), |
4680 | &func_g.search, ¬); | |
4681 | func_g.len = strlen(func_g.search); | |
59df055f | 4682 | |
b6887d79 | 4683 | /* we do not support '!' for function probes */ |
59df055f | 4684 | if (WARN_ON(not)) |
d3d532d7 | 4685 | return -EINVAL; |
59df055f SR |
4686 | } |
4687 | ||
7b60f3d8 SRV |
4688 | mutex_lock(&ftrace_lock); |
4689 | /* Check if the probe_ops is already registered */ | |
4690 | list_for_each_entry(probe, &tr->func_probes, list) { | |
4691 | if (probe->probe_ops == probe_ops) | |
4692 | break; | |
59df055f | 4693 | } |
7b60f3d8 SRV |
4694 | if (&probe->list == &tr->func_probes) |
4695 | goto err_unlock_ftrace; | |
4696 | ||
4697 | ret = -EINVAL; | |
4698 | if (!(probe->ops.flags & FTRACE_OPS_FL_INITIALIZED)) | |
4699 | goto err_unlock_ftrace; | |
4700 | ||
4701 | acquire_probe_locked(probe); | |
4702 | ||
4703 | mutex_unlock(&ftrace_lock); | |
59df055f | 4704 | |
7b60f3d8 | 4705 | mutex_lock(&probe->ops.func_hash->regex_lock); |
1ec3a81a | 4706 | |
7b60f3d8 | 4707 | orig_hash = &probe->ops.func_hash->filter_hash; |
1ec3a81a SRV |
4708 | old_hash = *orig_hash; |
4709 | ||
1ec3a81a SRV |
4710 | if (ftrace_hash_empty(old_hash)) |
4711 | goto out_unlock; | |
e1df4cb6 | 4712 | |
82cc4fc2 SRV |
4713 | old_hash_ops.filter_hash = old_hash; |
4714 | /* Probes only have filters */ | |
4715 | old_hash_ops.notrace_hash = NULL; | |
4716 | ||
d3d532d7 | 4717 | ret = -ENOMEM; |
1ec3a81a | 4718 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); |
e1df4cb6 | 4719 | if (!hash) |
e1df4cb6 SRRH |
4720 | goto out_unlock; |
4721 | ||
eee8ded1 | 4722 | INIT_HLIST_HEAD(&hhd); |
59df055f | 4723 | |
eee8ded1 SRV |
4724 | size = 1 << hash->size_bits; |
4725 | for (i = 0; i < size; i++) { | |
4726 | hlist_for_each_entry_safe(entry, tmp, &hash->buckets[i], hlist) { | |
59df055f | 4727 | |
3ba00929 | 4728 | if (func_g.search) { |
59df055f SR |
4729 | kallsyms_lookup(entry->ip, NULL, NULL, |
4730 | NULL, str); | |
3ba00929 | 4731 | if (!ftrace_match(str, &func_g)) |
59df055f SR |
4732 | continue; |
4733 | } | |
7b60f3d8 | 4734 | count++; |
eee8ded1 SRV |
4735 | remove_hash_entry(hash, entry); |
4736 | hlist_add_head(&entry->hlist, &hhd); | |
59df055f SR |
4737 | } |
4738 | } | |
d3d532d7 SRV |
4739 | |
4740 | /* Nothing found? */ | |
7b60f3d8 | 4741 | if (!count) { |
d3d532d7 SRV |
4742 | ret = -EINVAL; |
4743 | goto out_unlock; | |
4744 | } | |
4745 | ||
3f2367ba | 4746 | mutex_lock(&ftrace_lock); |
1ec3a81a | 4747 | |
7b60f3d8 | 4748 | WARN_ON(probe->ref < count); |
eee8ded1 | 4749 | |
7b60f3d8 | 4750 | probe->ref -= count; |
1ec3a81a | 4751 | |
7b60f3d8 SRV |
4752 | if (ftrace_hash_empty(hash)) |
4753 | ftrace_shutdown(&probe->ops, 0); | |
4754 | ||
4755 | ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash, | |
1ec3a81a | 4756 | hash, 1); |
82cc4fc2 SRV |
4757 | |
4758 | /* still need to update the function call sites */ | |
1ec3a81a | 4759 | if (ftrace_enabled && !ftrace_hash_empty(hash)) |
7b60f3d8 | 4760 | ftrace_run_modify_code(&probe->ops, FTRACE_UPDATE_CALLS, |
82cc4fc2 | 4761 | &old_hash_ops); |
74401729 | 4762 | synchronize_rcu(); |
3296fc4e | 4763 | |
eee8ded1 SRV |
4764 | hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) { |
4765 | hlist_del(&entry->hlist); | |
7b60f3d8 | 4766 | if (probe_ops->free) |
6e444319 | 4767 | probe_ops->free(probe_ops, tr, entry->ip, probe->data); |
eee8ded1 | 4768 | kfree(entry); |
7818b388 | 4769 | } |
3f2367ba | 4770 | mutex_unlock(&ftrace_lock); |
3ba00929 | 4771 | |
e1df4cb6 | 4772 | out_unlock: |
7b60f3d8 | 4773 | mutex_unlock(&probe->ops.func_hash->regex_lock); |
e1df4cb6 | 4774 | free_ftrace_hash(hash); |
59df055f | 4775 | |
7b60f3d8 | 4776 | release_probe(probe); |
59df055f | 4777 | |
7b60f3d8 | 4778 | return ret; |
59df055f | 4779 | |
7b60f3d8 SRV |
4780 | err_unlock_ftrace: |
4781 | mutex_unlock(&ftrace_lock); | |
d3d532d7 | 4782 | return ret; |
59df055f SR |
4783 | } |
4784 | ||
a0e6369e NR |
4785 | void clear_ftrace_function_probes(struct trace_array *tr) |
4786 | { | |
4787 | struct ftrace_func_probe *probe, *n; | |
4788 | ||
4789 | list_for_each_entry_safe(probe, n, &tr->func_probes, list) | |
4790 | unregister_ftrace_function_probe_func(NULL, tr, probe->probe_ops); | |
4791 | } | |
4792 | ||
f6180773 SR |
4793 | static LIST_HEAD(ftrace_commands); |
4794 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
4795 | ||
38de93ab TZ |
4796 | /* |
4797 | * Currently we only register ftrace commands from __init, so mark this | |
4798 | * __init too. | |
4799 | */ | |
4800 | __init int register_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
4801 | { |
4802 | struct ftrace_func_command *p; | |
4803 | int ret = 0; | |
4804 | ||
4805 | mutex_lock(&ftrace_cmd_mutex); | |
4806 | list_for_each_entry(p, &ftrace_commands, list) { | |
4807 | if (strcmp(cmd->name, p->name) == 0) { | |
4808 | ret = -EBUSY; | |
4809 | goto out_unlock; | |
4810 | } | |
4811 | } | |
4812 | list_add(&cmd->list, &ftrace_commands); | |
4813 | out_unlock: | |
4814 | mutex_unlock(&ftrace_cmd_mutex); | |
4815 | ||
4816 | return ret; | |
4817 | } | |
4818 | ||
38de93ab TZ |
4819 | /* |
4820 | * Currently we only unregister ftrace commands from __init, so mark | |
4821 | * this __init too. | |
4822 | */ | |
4823 | __init int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
4824 | { |
4825 | struct ftrace_func_command *p, *n; | |
4826 | int ret = -ENODEV; | |
4827 | ||
4828 | mutex_lock(&ftrace_cmd_mutex); | |
4829 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
4830 | if (strcmp(cmd->name, p->name) == 0) { | |
4831 | ret = 0; | |
4832 | list_del_init(&p->list); | |
4833 | goto out_unlock; | |
4834 | } | |
4835 | } | |
4836 | out_unlock: | |
4837 | mutex_unlock(&ftrace_cmd_mutex); | |
4838 | ||
4839 | return ret; | |
4840 | } | |
4841 | ||
04ec7bb6 | 4842 | static int ftrace_process_regex(struct ftrace_iterator *iter, |
33dc9b12 | 4843 | char *buff, int len, int enable) |
64e7c440 | 4844 | { |
04ec7bb6 | 4845 | struct ftrace_hash *hash = iter->hash; |
d2afd57a | 4846 | struct trace_array *tr = iter->ops->private; |
f6180773 | 4847 | char *func, *command, *next = buff; |
6a24a244 | 4848 | struct ftrace_func_command *p; |
0aff1c0c | 4849 | int ret = -EINVAL; |
64e7c440 SR |
4850 | |
4851 | func = strsep(&next, ":"); | |
4852 | ||
4853 | if (!next) { | |
1cf41dd7 | 4854 | ret = ftrace_match_records(hash, func, len); |
b448c4e3 SR |
4855 | if (!ret) |
4856 | ret = -EINVAL; | |
4857 | if (ret < 0) | |
4858 | return ret; | |
4859 | return 0; | |
64e7c440 SR |
4860 | } |
4861 | ||
f6180773 | 4862 | /* command found */ |
64e7c440 SR |
4863 | |
4864 | command = strsep(&next, ":"); | |
4865 | ||
f6180773 SR |
4866 | mutex_lock(&ftrace_cmd_mutex); |
4867 | list_for_each_entry(p, &ftrace_commands, list) { | |
4868 | if (strcmp(p->name, command) == 0) { | |
04ec7bb6 | 4869 | ret = p->func(tr, hash, func, command, next, enable); |
f6180773 SR |
4870 | goto out_unlock; |
4871 | } | |
64e7c440 | 4872 | } |
f6180773 SR |
4873 | out_unlock: |
4874 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 4875 | |
f6180773 | 4876 | return ret; |
64e7c440 SR |
4877 | } |
4878 | ||
e309b41d | 4879 | static ssize_t |
41c52c0d SR |
4880 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
4881 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
4882 | { |
4883 | struct ftrace_iterator *iter; | |
689fd8b6 | 4884 | struct trace_parser *parser; |
4885 | ssize_t ret, read; | |
5072c59f | 4886 | |
4ba7978e | 4887 | if (!cnt) |
5072c59f SR |
4888 | return 0; |
4889 | ||
5072c59f SR |
4890 | if (file->f_mode & FMODE_READ) { |
4891 | struct seq_file *m = file->private_data; | |
4892 | iter = m->private; | |
4893 | } else | |
4894 | iter = file->private_data; | |
4895 | ||
f04f24fb | 4896 | if (unlikely(ftrace_disabled)) |
3f2367ba MH |
4897 | return -ENODEV; |
4898 | ||
4899 | /* iter->hash is a local copy, so we don't need regex_lock */ | |
f04f24fb | 4900 | |
689fd8b6 | 4901 | parser = &iter->parser; |
4902 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 4903 | |
4ba7978e | 4904 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 4905 | !trace_parser_cont(parser)) { |
04ec7bb6 | 4906 | ret = ftrace_process_regex(iter, parser->buffer, |
689fd8b6 | 4907 | parser->idx, enable); |
313254a9 | 4908 | trace_parser_clear(parser); |
7c088b51 | 4909 | if (ret < 0) |
3f2367ba | 4910 | goto out; |
eda1e328 | 4911 | } |
5072c59f | 4912 | |
5072c59f | 4913 | ret = read; |
3f2367ba | 4914 | out: |
5072c59f SR |
4915 | return ret; |
4916 | } | |
4917 | ||
fc13cb0c | 4918 | ssize_t |
41c52c0d SR |
4919 | ftrace_filter_write(struct file *file, const char __user *ubuf, |
4920 | size_t cnt, loff_t *ppos) | |
4921 | { | |
4922 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
4923 | } | |
4924 | ||
fc13cb0c | 4925 | ssize_t |
41c52c0d SR |
4926 | ftrace_notrace_write(struct file *file, const char __user *ubuf, |
4927 | size_t cnt, loff_t *ppos) | |
4928 | { | |
4929 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
4930 | } | |
4931 | ||
33dc9b12 | 4932 | static int |
647664ea MH |
4933 | ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) |
4934 | { | |
4935 | struct ftrace_func_entry *entry; | |
4936 | ||
4937 | if (!ftrace_location(ip)) | |
4938 | return -EINVAL; | |
4939 | ||
4940 | if (remove) { | |
4941 | entry = ftrace_lookup_ip(hash, ip); | |
4942 | if (!entry) | |
4943 | return -ENOENT; | |
4944 | free_hash_entry(hash, entry); | |
4945 | return 0; | |
4946 | } | |
4947 | ||
4948 | return add_hash_entry(hash, ip); | |
4949 | } | |
4950 | ||
4951 | static int | |
4952 | ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, | |
4953 | unsigned long ip, int remove, int reset, int enable) | |
41c52c0d | 4954 | { |
33dc9b12 | 4955 | struct ftrace_hash **orig_hash; |
f45948e8 | 4956 | struct ftrace_hash *hash; |
33dc9b12 | 4957 | int ret; |
f45948e8 | 4958 | |
41c52c0d | 4959 | if (unlikely(ftrace_disabled)) |
33dc9b12 | 4960 | return -ENODEV; |
41c52c0d | 4961 | |
33b7f99c | 4962 | mutex_lock(&ops->func_hash->regex_lock); |
3f2367ba | 4963 | |
f45948e8 | 4964 | if (enable) |
33b7f99c | 4965 | orig_hash = &ops->func_hash->filter_hash; |
f45948e8 | 4966 | else |
33b7f99c | 4967 | orig_hash = &ops->func_hash->notrace_hash; |
33dc9b12 | 4968 | |
b972cc58 WN |
4969 | if (reset) |
4970 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); | |
4971 | else | |
4972 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
4973 | ||
3f2367ba MH |
4974 | if (!hash) { |
4975 | ret = -ENOMEM; | |
4976 | goto out_regex_unlock; | |
4977 | } | |
f45948e8 | 4978 | |
ac483c44 JO |
4979 | if (buf && !ftrace_match_records(hash, buf, len)) { |
4980 | ret = -EINVAL; | |
4981 | goto out_regex_unlock; | |
4982 | } | |
647664ea MH |
4983 | if (ip) { |
4984 | ret = ftrace_match_addr(hash, ip, remove); | |
4985 | if (ret < 0) | |
4986 | goto out_regex_unlock; | |
4987 | } | |
33dc9b12 SR |
4988 | |
4989 | mutex_lock(&ftrace_lock); | |
e16b35dd | 4990 | ret = ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable); |
33dc9b12 SR |
4991 | mutex_unlock(&ftrace_lock); |
4992 | ||
ac483c44 | 4993 | out_regex_unlock: |
33b7f99c | 4994 | mutex_unlock(&ops->func_hash->regex_lock); |
33dc9b12 SR |
4995 | |
4996 | free_ftrace_hash(hash); | |
4997 | return ret; | |
41c52c0d SR |
4998 | } |
4999 | ||
647664ea MH |
5000 | static int |
5001 | ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove, | |
5002 | int reset, int enable) | |
5003 | { | |
9efb85c5 | 5004 | return ftrace_set_hash(ops, NULL, 0, ip, remove, reset, enable); |
647664ea MH |
5005 | } |
5006 | ||
763e34e7 | 5007 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
013bf0da SRV |
5008 | |
5009 | struct ftrace_direct_func { | |
5010 | struct list_head next; | |
5011 | unsigned long addr; | |
5012 | int count; | |
5013 | }; | |
5014 | ||
5015 | static LIST_HEAD(ftrace_direct_funcs); | |
5016 | ||
5017 | /** | |
5018 | * ftrace_find_direct_func - test an address if it is a registered direct caller | |
5019 | * @addr: The address of a registered direct caller | |
5020 | * | |
5021 | * This searches to see if a ftrace direct caller has been registered | |
5022 | * at a specific address, and if so, it returns a descriptor for it. | |
5023 | * | |
5024 | * This can be used by architecture code to see if an address is | |
5025 | * a direct caller (trampoline) attached to a fentry/mcount location. | |
5026 | * This is useful for the function_graph tracer, as it may need to | |
5027 | * do adjustments if it traced a location that also has a direct | |
5028 | * trampoline attached to it. | |
5029 | */ | |
5030 | struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr) | |
5031 | { | |
5032 | struct ftrace_direct_func *entry; | |
5033 | bool found = false; | |
5034 | ||
5035 | /* May be called by fgraph trampoline (protected by rcu tasks) */ | |
5036 | list_for_each_entry_rcu(entry, &ftrace_direct_funcs, next) { | |
5037 | if (entry->addr == addr) { | |
5038 | found = true; | |
5039 | break; | |
5040 | } | |
5041 | } | |
5042 | if (found) | |
5043 | return entry; | |
5044 | ||
5045 | return NULL; | |
5046 | } | |
5047 | ||
8a141dd7 AS |
5048 | static struct ftrace_direct_func *ftrace_alloc_direct_func(unsigned long addr) |
5049 | { | |
5050 | struct ftrace_direct_func *direct; | |
5051 | ||
5052 | direct = kmalloc(sizeof(*direct), GFP_KERNEL); | |
5053 | if (!direct) | |
5054 | return NULL; | |
5055 | direct->addr = addr; | |
5056 | direct->count = 0; | |
5057 | list_add_rcu(&direct->next, &ftrace_direct_funcs); | |
5058 | ftrace_direct_func_count++; | |
5059 | return direct; | |
5060 | } | |
5061 | ||
763e34e7 SRV |
5062 | /** |
5063 | * register_ftrace_direct - Call a custom trampoline directly | |
5064 | * @ip: The address of the nop at the beginning of a function | |
5065 | * @addr: The address of the trampoline to call at @ip | |
5066 | * | |
5067 | * This is used to connect a direct call from the nop location (@ip) | |
5068 | * at the start of ftrace traced functions. The location that it calls | |
5069 | * (@addr) must be able to handle a direct call, and save the parameters | |
5070 | * of the function being traced, and restore them (or inject new ones | |
5071 | * if needed), before returning. | |
5072 | * | |
5073 | * Returns: | |
5074 | * 0 on success | |
5075 | * -EBUSY - Another direct function is already attached (there can be only one) | |
5076 | * -ENODEV - @ip does not point to a ftrace nop location (or not supported) | |
5077 | * -ENOMEM - There was an allocation failure. | |
5078 | */ | |
5079 | int register_ftrace_direct(unsigned long ip, unsigned long addr) | |
5080 | { | |
013bf0da | 5081 | struct ftrace_direct_func *direct; |
763e34e7 SRV |
5082 | struct ftrace_func_entry *entry; |
5083 | struct ftrace_hash *free_hash = NULL; | |
5084 | struct dyn_ftrace *rec; | |
5085 | int ret = -EBUSY; | |
5086 | ||
5087 | mutex_lock(&direct_mutex); | |
5088 | ||
5089 | /* See if there's a direct function at @ip already */ | |
ff205766 | 5090 | if (ftrace_find_rec_direct(ip)) |
763e34e7 SRV |
5091 | goto out_unlock; |
5092 | ||
5093 | ret = -ENODEV; | |
5094 | rec = lookup_rec(ip, ip); | |
5095 | if (!rec) | |
5096 | goto out_unlock; | |
5097 | ||
5098 | /* | |
5099 | * Check if the rec says it has a direct call but we didn't | |
5100 | * find one earlier? | |
5101 | */ | |
5102 | if (WARN_ON(rec->flags & FTRACE_FL_DIRECT)) | |
5103 | goto out_unlock; | |
5104 | ||
5105 | /* Make sure the ip points to the exact record */ | |
406acdd3 SRV |
5106 | if (ip != rec->ip) { |
5107 | ip = rec->ip; | |
5108 | /* Need to check this ip for a direct. */ | |
ff205766 | 5109 | if (ftrace_find_rec_direct(ip)) |
406acdd3 SRV |
5110 | goto out_unlock; |
5111 | } | |
763e34e7 SRV |
5112 | |
5113 | ret = -ENOMEM; | |
5114 | if (ftrace_hash_empty(direct_functions) || | |
5115 | direct_functions->count > 2 * (1 << direct_functions->size_bits)) { | |
5116 | struct ftrace_hash *new_hash; | |
5117 | int size = ftrace_hash_empty(direct_functions) ? 0 : | |
5118 | direct_functions->count + 1; | |
5119 | ||
5120 | if (size < 32) | |
5121 | size = 32; | |
5122 | ||
5123 | new_hash = dup_hash(direct_functions, size); | |
5124 | if (!new_hash) | |
5125 | goto out_unlock; | |
5126 | ||
5127 | free_hash = direct_functions; | |
5128 | direct_functions = new_hash; | |
5129 | } | |
5130 | ||
5131 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
5132 | if (!entry) | |
5133 | goto out_unlock; | |
5134 | ||
013bf0da SRV |
5135 | direct = ftrace_find_direct_func(addr); |
5136 | if (!direct) { | |
8a141dd7 | 5137 | direct = ftrace_alloc_direct_func(addr); |
013bf0da SRV |
5138 | if (!direct) { |
5139 | kfree(entry); | |
5140 | goto out_unlock; | |
5141 | } | |
013bf0da SRV |
5142 | } |
5143 | ||
763e34e7 SRV |
5144 | entry->ip = ip; |
5145 | entry->direct = addr; | |
5146 | __add_hash_entry(direct_functions, entry); | |
5147 | ||
5148 | ret = ftrace_set_filter_ip(&direct_ops, ip, 0, 0); | |
5149 | if (ret) | |
5150 | remove_hash_entry(direct_functions, entry); | |
5151 | ||
5152 | if (!ret && !(direct_ops.flags & FTRACE_OPS_FL_ENABLED)) { | |
5153 | ret = register_ftrace_function(&direct_ops); | |
5154 | if (ret) | |
5155 | ftrace_set_filter_ip(&direct_ops, ip, 1, 0); | |
5156 | } | |
5157 | ||
013bf0da | 5158 | if (ret) { |
763e34e7 | 5159 | kfree(entry); |
013bf0da SRV |
5160 | if (!direct->count) { |
5161 | list_del_rcu(&direct->next); | |
5162 | synchronize_rcu_tasks(); | |
5163 | kfree(direct); | |
5164 | if (free_hash) | |
5165 | free_ftrace_hash(free_hash); | |
5166 | free_hash = NULL; | |
a3ad1a7e | 5167 | ftrace_direct_func_count--; |
013bf0da SRV |
5168 | } |
5169 | } else { | |
1c7f9b67 | 5170 | direct->count++; |
013bf0da | 5171 | } |
763e34e7 SRV |
5172 | out_unlock: |
5173 | mutex_unlock(&direct_mutex); | |
5174 | ||
5175 | if (free_hash) { | |
5176 | synchronize_rcu_tasks(); | |
5177 | free_ftrace_hash(free_hash); | |
5178 | } | |
5179 | ||
5180 | return ret; | |
5181 | } | |
5182 | EXPORT_SYMBOL_GPL(register_ftrace_direct); | |
5183 | ||
ea806eb3 SRV |
5184 | static struct ftrace_func_entry *find_direct_entry(unsigned long *ip, |
5185 | struct dyn_ftrace **recp) | |
763e34e7 SRV |
5186 | { |
5187 | struct ftrace_func_entry *entry; | |
5188 | struct dyn_ftrace *rec; | |
763e34e7 | 5189 | |
128161f4 SRV |
5190 | rec = lookup_rec(*ip, *ip); |
5191 | if (!rec) | |
5192 | return NULL; | |
763e34e7 | 5193 | |
128161f4 | 5194 | entry = __ftrace_lookup_ip(direct_functions, rec->ip); |
763e34e7 | 5195 | if (!entry) { |
128161f4 SRV |
5196 | WARN_ON(rec->flags & FTRACE_FL_DIRECT); |
5197 | return NULL; | |
5198 | } | |
763e34e7 | 5199 | |
128161f4 | 5200 | WARN_ON(!(rec->flags & FTRACE_FL_DIRECT)); |
763e34e7 | 5201 | |
128161f4 SRV |
5202 | /* Passed in ip just needs to be on the call site */ |
5203 | *ip = rec->ip; | |
5204 | ||
ea806eb3 SRV |
5205 | if (recp) |
5206 | *recp = rec; | |
5207 | ||
128161f4 SRV |
5208 | return entry; |
5209 | } | |
5210 | ||
5211 | int unregister_ftrace_direct(unsigned long ip, unsigned long addr) | |
5212 | { | |
5213 | struct ftrace_direct_func *direct; | |
5214 | struct ftrace_func_entry *entry; | |
5215 | int ret = -ENODEV; | |
5216 | ||
5217 | mutex_lock(&direct_mutex); | |
5218 | ||
ea806eb3 | 5219 | entry = find_direct_entry(&ip, NULL); |
128161f4 SRV |
5220 | if (!entry) |
5221 | goto out_unlock; | |
763e34e7 SRV |
5222 | |
5223 | if (direct_functions->count == 1) | |
5224 | unregister_ftrace_function(&direct_ops); | |
5225 | ||
5226 | ret = ftrace_set_filter_ip(&direct_ops, ip, 1, 0); | |
5227 | ||
5228 | WARN_ON(ret); | |
5229 | ||
5230 | remove_hash_entry(direct_functions, entry); | |
5231 | ||
013bf0da SRV |
5232 | direct = ftrace_find_direct_func(addr); |
5233 | if (!WARN_ON(!direct)) { | |
5234 | /* This is the good path (see the ! before WARN) */ | |
5235 | direct->count--; | |
5236 | WARN_ON(direct->count < 0); | |
5237 | if (!direct->count) { | |
5238 | list_del_rcu(&direct->next); | |
5239 | synchronize_rcu_tasks(); | |
5240 | kfree(direct); | |
353da879 | 5241 | kfree(entry); |
a3ad1a7e | 5242 | ftrace_direct_func_count--; |
013bf0da SRV |
5243 | } |
5244 | } | |
763e34e7 SRV |
5245 | out_unlock: |
5246 | mutex_unlock(&direct_mutex); | |
5247 | ||
5248 | return ret; | |
5249 | } | |
5250 | EXPORT_SYMBOL_GPL(unregister_ftrace_direct); | |
0567d680 SRV |
5251 | |
5252 | static struct ftrace_ops stub_ops = { | |
5253 | .func = ftrace_stub, | |
5254 | }; | |
5255 | ||
ea806eb3 SRV |
5256 | /** |
5257 | * ftrace_modify_direct_caller - modify ftrace nop directly | |
5258 | * @entry: The ftrace hash entry of the direct helper for @rec | |
5259 | * @rec: The record representing the function site to patch | |
5260 | * @old_addr: The location that the site at @rec->ip currently calls | |
5261 | * @new_addr: The location that the site at @rec->ip should call | |
5262 | * | |
5263 | * An architecture may overwrite this function to optimize the | |
5264 | * changing of the direct callback on an ftrace nop location. | |
5265 | * This is called with the ftrace_lock mutex held, and no other | |
5266 | * ftrace callbacks are on the associated record (@rec). Thus, | |
5267 | * it is safe to modify the ftrace record, where it should be | |
5268 | * currently calling @old_addr directly, to call @new_addr. | |
5269 | * | |
5270 | * Safety checks should be made to make sure that the code at | |
5271 | * @rec->ip is currently calling @old_addr. And this must | |
5272 | * also update entry->direct to @new_addr. | |
5273 | */ | |
5274 | int __weak ftrace_modify_direct_caller(struct ftrace_func_entry *entry, | |
5275 | struct dyn_ftrace *rec, | |
5276 | unsigned long old_addr, | |
5277 | unsigned long new_addr) | |
5278 | { | |
5279 | unsigned long ip = rec->ip; | |
5280 | int ret; | |
5281 | ||
5282 | /* | |
5283 | * The ftrace_lock was used to determine if the record | |
5284 | * had more than one registered user to it. If it did, | |
5285 | * we needed to prevent that from changing to do the quick | |
5286 | * switch. But if it did not (only a direct caller was attached) | |
5287 | * then this function is called. But this function can deal | |
5288 | * with attached callers to the rec that we care about, and | |
5289 | * since this function uses standard ftrace calls that take | |
5290 | * the ftrace_lock mutex, we need to release it. | |
5291 | */ | |
5292 | mutex_unlock(&ftrace_lock); | |
5293 | ||
5294 | /* | |
5295 | * By setting a stub function at the same address, we force | |
5296 | * the code to call the iterator and the direct_ops helper. | |
5297 | * This means that @ip does not call the direct call, and | |
5298 | * we can simply modify it. | |
5299 | */ | |
5300 | ret = ftrace_set_filter_ip(&stub_ops, ip, 0, 0); | |
5301 | if (ret) | |
5302 | goto out_lock; | |
5303 | ||
5304 | ret = register_ftrace_function(&stub_ops); | |
5305 | if (ret) { | |
5306 | ftrace_set_filter_ip(&stub_ops, ip, 1, 0); | |
5307 | goto out_lock; | |
5308 | } | |
5309 | ||
5310 | entry->direct = new_addr; | |
5311 | ||
5312 | /* | |
5313 | * By removing the stub, we put back the direct call, calling | |
5314 | * the @new_addr. | |
5315 | */ | |
5316 | unregister_ftrace_function(&stub_ops); | |
5317 | ftrace_set_filter_ip(&stub_ops, ip, 1, 0); | |
5318 | ||
5319 | out_lock: | |
5320 | mutex_lock(&ftrace_lock); | |
5321 | ||
5322 | return ret; | |
5323 | } | |
5324 | ||
0567d680 SRV |
5325 | /** |
5326 | * modify_ftrace_direct - Modify an existing direct call to call something else | |
5327 | * @ip: The instruction pointer to modify | |
5328 | * @old_addr: The address that the current @ip calls directly | |
5329 | * @new_addr: The address that the @ip should call | |
5330 | * | |
5331 | * This modifies a ftrace direct caller at an instruction pointer without | |
5332 | * having to disable it first. The direct call will switch over to the | |
5333 | * @new_addr without missing anything. | |
5334 | * | |
5335 | * Returns: zero on success. Non zero on error, which includes: | |
5336 | * -ENODEV : the @ip given has no direct caller attached | |
5337 | * -EINVAL : the @old_addr does not match the current direct caller | |
5338 | */ | |
5339 | int modify_ftrace_direct(unsigned long ip, | |
5340 | unsigned long old_addr, unsigned long new_addr) | |
5341 | { | |
8a141dd7 | 5342 | struct ftrace_direct_func *direct, *new_direct = NULL; |
0567d680 | 5343 | struct ftrace_func_entry *entry; |
ea806eb3 | 5344 | struct dyn_ftrace *rec; |
0567d680 SRV |
5345 | int ret = -ENODEV; |
5346 | ||
5347 | mutex_lock(&direct_mutex); | |
0567d680 | 5348 | |
ea806eb3 SRV |
5349 | mutex_lock(&ftrace_lock); |
5350 | entry = find_direct_entry(&ip, &rec); | |
128161f4 SRV |
5351 | if (!entry) |
5352 | goto out_unlock; | |
0567d680 SRV |
5353 | |
5354 | ret = -EINVAL; | |
5355 | if (entry->direct != old_addr) | |
5356 | goto out_unlock; | |
5357 | ||
8a141dd7 AS |
5358 | direct = ftrace_find_direct_func(old_addr); |
5359 | if (WARN_ON(!direct)) | |
5360 | goto out_unlock; | |
5361 | if (direct->count > 1) { | |
5362 | ret = -ENOMEM; | |
5363 | new_direct = ftrace_alloc_direct_func(new_addr); | |
5364 | if (!new_direct) | |
5365 | goto out_unlock; | |
5366 | direct->count--; | |
5367 | new_direct->count++; | |
5368 | } else { | |
5369 | direct->addr = new_addr; | |
5370 | } | |
5371 | ||
0567d680 | 5372 | /* |
ea806eb3 SRV |
5373 | * If there's no other ftrace callback on the rec->ip location, |
5374 | * then it can be changed directly by the architecture. | |
5375 | * If there is another caller, then we just need to change the | |
5376 | * direct caller helper to point to @new_addr. | |
0567d680 | 5377 | */ |
ea806eb3 SRV |
5378 | if (ftrace_rec_count(rec) == 1) { |
5379 | ret = ftrace_modify_direct_caller(entry, rec, old_addr, new_addr); | |
5380 | } else { | |
5381 | entry->direct = new_addr; | |
5382 | ret = 0; | |
0567d680 SRV |
5383 | } |
5384 | ||
8a141dd7 AS |
5385 | if (unlikely(ret && new_direct)) { |
5386 | direct->count++; | |
5387 | list_del_rcu(&new_direct->next); | |
5388 | synchronize_rcu_tasks(); | |
5389 | kfree(new_direct); | |
5390 | ftrace_direct_func_count--; | |
5391 | } | |
5392 | ||
0567d680 | 5393 | out_unlock: |
ea806eb3 | 5394 | mutex_unlock(&ftrace_lock); |
0567d680 SRV |
5395 | mutex_unlock(&direct_mutex); |
5396 | return ret; | |
5397 | } | |
5398 | EXPORT_SYMBOL_GPL(modify_ftrace_direct); | |
763e34e7 SRV |
5399 | #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ |
5400 | ||
647664ea MH |
5401 | /** |
5402 | * ftrace_set_filter_ip - set a function to filter on in ftrace by address | |
5403 | * @ops - the ops to set the filter with | |
5404 | * @ip - the address to add to or remove from the filter. | |
5405 | * @remove - non zero to remove the ip from the filter | |
5406 | * @reset - non zero to reset all filters before applying this filter. | |
5407 | * | |
5408 | * Filters denote which functions should be enabled when tracing is enabled | |
5409 | * If @ip is NULL, it failes to update filter. | |
5410 | */ | |
5411 | int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, | |
5412 | int remove, int reset) | |
5413 | { | |
f04f24fb | 5414 | ftrace_ops_init(ops); |
647664ea MH |
5415 | return ftrace_set_addr(ops, ip, remove, reset, 1); |
5416 | } | |
5417 | EXPORT_SYMBOL_GPL(ftrace_set_filter_ip); | |
5418 | ||
d032ae89 JF |
5419 | /** |
5420 | * ftrace_ops_set_global_filter - setup ops to use global filters | |
5421 | * @ops - the ops which will use the global filters | |
5422 | * | |
5423 | * ftrace users who need global function trace filtering should call this. | |
5424 | * It can set the global filter only if ops were not initialized before. | |
5425 | */ | |
5426 | void ftrace_ops_set_global_filter(struct ftrace_ops *ops) | |
5427 | { | |
5428 | if (ops->flags & FTRACE_OPS_FL_INITIALIZED) | |
5429 | return; | |
5430 | ||
5431 | ftrace_ops_init(ops); | |
5432 | ops->func_hash = &global_ops.local_hash; | |
5433 | } | |
5434 | EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter); | |
5435 | ||
647664ea MH |
5436 | static int |
5437 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, | |
5438 | int reset, int enable) | |
5439 | { | |
5440 | return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable); | |
5441 | } | |
5442 | ||
77a2b37d SR |
5443 | /** |
5444 | * ftrace_set_filter - set a function to filter on in ftrace | |
936e074b SR |
5445 | * @ops - the ops to set the filter with |
5446 | * @buf - the string that holds the function filter text. | |
5447 | * @len - the length of the string. | |
5448 | * @reset - non zero to reset all filters before applying this filter. | |
5449 | * | |
5450 | * Filters denote which functions should be enabled when tracing is enabled. | |
5451 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
5452 | */ | |
ac483c44 | 5453 | int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
5454 | int len, int reset) |
5455 | { | |
f04f24fb | 5456 | ftrace_ops_init(ops); |
ac483c44 | 5457 | return ftrace_set_regex(ops, buf, len, reset, 1); |
936e074b SR |
5458 | } |
5459 | EXPORT_SYMBOL_GPL(ftrace_set_filter); | |
5460 | ||
5461 | /** | |
5462 | * ftrace_set_notrace - set a function to not trace in ftrace | |
5463 | * @ops - the ops to set the notrace filter with | |
5464 | * @buf - the string that holds the function notrace text. | |
5465 | * @len - the length of the string. | |
5466 | * @reset - non zero to reset all filters before applying this filter. | |
5467 | * | |
5468 | * Notrace Filters denote which functions should not be enabled when tracing | |
5469 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
5470 | * for tracing. | |
5471 | */ | |
ac483c44 | 5472 | int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
5473 | int len, int reset) |
5474 | { | |
f04f24fb | 5475 | ftrace_ops_init(ops); |
ac483c44 | 5476 | return ftrace_set_regex(ops, buf, len, reset, 0); |
936e074b SR |
5477 | } |
5478 | EXPORT_SYMBOL_GPL(ftrace_set_notrace); | |
5479 | /** | |
8d1b065d | 5480 | * ftrace_set_global_filter - set a function to filter on with global tracers |
77a2b37d SR |
5481 | * @buf - the string that holds the function filter text. |
5482 | * @len - the length of the string. | |
5483 | * @reset - non zero to reset all filters before applying this filter. | |
5484 | * | |
5485 | * Filters denote which functions should be enabled when tracing is enabled. | |
5486 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
5487 | */ | |
936e074b | 5488 | void ftrace_set_global_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 5489 | { |
f45948e8 | 5490 | ftrace_set_regex(&global_ops, buf, len, reset, 1); |
41c52c0d | 5491 | } |
936e074b | 5492 | EXPORT_SYMBOL_GPL(ftrace_set_global_filter); |
4eebcc81 | 5493 | |
41c52c0d | 5494 | /** |
8d1b065d | 5495 | * ftrace_set_global_notrace - set a function to not trace with global tracers |
41c52c0d SR |
5496 | * @buf - the string that holds the function notrace text. |
5497 | * @len - the length of the string. | |
5498 | * @reset - non zero to reset all filters before applying this filter. | |
5499 | * | |
5500 | * Notrace Filters denote which functions should not be enabled when tracing | |
5501 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
5502 | * for tracing. | |
5503 | */ | |
936e074b | 5504 | void ftrace_set_global_notrace(unsigned char *buf, int len, int reset) |
41c52c0d | 5505 | { |
f45948e8 | 5506 | ftrace_set_regex(&global_ops, buf, len, reset, 0); |
77a2b37d | 5507 | } |
936e074b | 5508 | EXPORT_SYMBOL_GPL(ftrace_set_global_notrace); |
77a2b37d | 5509 | |
2af15d6a SR |
5510 | /* |
5511 | * command line interface to allow users to set filters on boot up. | |
5512 | */ | |
5513 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
5514 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
5515 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
5516 | ||
f1ed7c74 SRRH |
5517 | /* Used by function selftest to not test if filter is set */ |
5518 | bool ftrace_filter_param __initdata; | |
5519 | ||
2af15d6a SR |
5520 | static int __init set_ftrace_notrace(char *str) |
5521 | { | |
f1ed7c74 | 5522 | ftrace_filter_param = true; |
75761cc1 | 5523 | strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
5524 | return 1; |
5525 | } | |
5526 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
5527 | ||
5528 | static int __init set_ftrace_filter(char *str) | |
5529 | { | |
f1ed7c74 | 5530 | ftrace_filter_param = true; |
75761cc1 | 5531 | strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
5532 | return 1; |
5533 | } | |
5534 | __setup("ftrace_filter=", set_ftrace_filter); | |
5535 | ||
369bc18f | 5536 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 5537 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
0d7d9a16 | 5538 | static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata; |
b9b0c831 | 5539 | static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer); |
801c29fd | 5540 | |
369bc18f SA |
5541 | static int __init set_graph_function(char *str) |
5542 | { | |
06f43d66 | 5543 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
5544 | return 1; |
5545 | } | |
5546 | __setup("ftrace_graph_filter=", set_graph_function); | |
5547 | ||
0d7d9a16 NK |
5548 | static int __init set_graph_notrace_function(char *str) |
5549 | { | |
5550 | strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE); | |
5551 | return 1; | |
5552 | } | |
5553 | __setup("ftrace_graph_notrace=", set_graph_notrace_function); | |
5554 | ||
65a50c65 TB |
5555 | static int __init set_graph_max_depth_function(char *str) |
5556 | { | |
5557 | if (!str) | |
5558 | return 0; | |
5559 | fgraph_max_depth = simple_strtoul(str, NULL, 0); | |
5560 | return 1; | |
5561 | } | |
5562 | __setup("ftrace_graph_max_depth=", set_graph_max_depth_function); | |
0d7d9a16 NK |
5563 | |
5564 | static void __init set_ftrace_early_graph(char *buf, int enable) | |
369bc18f SA |
5565 | { |
5566 | int ret; | |
5567 | char *func; | |
b9b0c831 | 5568 | struct ftrace_hash *hash; |
0d7d9a16 | 5569 | |
92ad18ec | 5570 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); |
24589e3a | 5571 | if (MEM_FAIL(!hash, "Failed to allocate hash\n")) |
92ad18ec | 5572 | return; |
369bc18f SA |
5573 | |
5574 | while (buf) { | |
5575 | func = strsep(&buf, ","); | |
5576 | /* we allow only one expression at a time */ | |
b9b0c831 | 5577 | ret = ftrace_graph_set_hash(hash, func); |
369bc18f SA |
5578 | if (ret) |
5579 | printk(KERN_DEBUG "ftrace: function %s not " | |
5580 | "traceable\n", func); | |
5581 | } | |
92ad18ec SRV |
5582 | |
5583 | if (enable) | |
5584 | ftrace_graph_hash = hash; | |
5585 | else | |
5586 | ftrace_graph_notrace_hash = hash; | |
369bc18f SA |
5587 | } |
5588 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
5589 | ||
2a85a37f SR |
5590 | void __init |
5591 | ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable) | |
2af15d6a SR |
5592 | { |
5593 | char *func; | |
5594 | ||
f04f24fb MH |
5595 | ftrace_ops_init(ops); |
5596 | ||
2af15d6a SR |
5597 | while (buf) { |
5598 | func = strsep(&buf, ","); | |
f45948e8 | 5599 | ftrace_set_regex(ops, func, strlen(func), 0, enable); |
2af15d6a SR |
5600 | } |
5601 | } | |
5602 | ||
5603 | static void __init set_ftrace_early_filters(void) | |
5604 | { | |
5605 | if (ftrace_filter_buf[0]) | |
2a85a37f | 5606 | ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1); |
2af15d6a | 5607 | if (ftrace_notrace_buf[0]) |
2a85a37f | 5608 | ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0); |
369bc18f SA |
5609 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5610 | if (ftrace_graph_buf[0]) | |
0d7d9a16 NK |
5611 | set_ftrace_early_graph(ftrace_graph_buf, 1); |
5612 | if (ftrace_graph_notrace_buf[0]) | |
5613 | set_ftrace_early_graph(ftrace_graph_notrace_buf, 0); | |
369bc18f | 5614 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
2af15d6a SR |
5615 | } |
5616 | ||
fc13cb0c | 5617 | int ftrace_regex_release(struct inode *inode, struct file *file) |
5072c59f SR |
5618 | { |
5619 | struct seq_file *m = (struct seq_file *)file->private_data; | |
5620 | struct ftrace_iterator *iter; | |
33dc9b12 | 5621 | struct ftrace_hash **orig_hash; |
689fd8b6 | 5622 | struct trace_parser *parser; |
ed926f9b | 5623 | int filter_hash; |
5072c59f | 5624 | |
5072c59f SR |
5625 | if (file->f_mode & FMODE_READ) { |
5626 | iter = m->private; | |
5072c59f SR |
5627 | seq_release(inode, file); |
5628 | } else | |
5629 | iter = file->private_data; | |
5630 | ||
689fd8b6 | 5631 | parser = &iter->parser; |
5632 | if (trace_parser_loaded(parser)) { | |
1cf41dd7 | 5633 | ftrace_match_records(iter->hash, parser->buffer, parser->idx); |
5072c59f SR |
5634 | } |
5635 | ||
689fd8b6 | 5636 | trace_parser_put(parser); |
689fd8b6 | 5637 | |
33b7f99c | 5638 | mutex_lock(&iter->ops->func_hash->regex_lock); |
3f2367ba | 5639 | |
058e297d | 5640 | if (file->f_mode & FMODE_WRITE) { |
ed926f9b SR |
5641 | filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); |
5642 | ||
8c08f0d5 | 5643 | if (filter_hash) { |
33b7f99c | 5644 | orig_hash = &iter->ops->func_hash->filter_hash; |
69d71879 | 5645 | if (iter->tr && !list_empty(&iter->tr->mod_trace)) |
8c08f0d5 SRV |
5646 | iter->hash->flags |= FTRACE_HASH_FL_MOD; |
5647 | } else | |
33b7f99c | 5648 | orig_hash = &iter->ops->func_hash->notrace_hash; |
33dc9b12 | 5649 | |
058e297d | 5650 | mutex_lock(&ftrace_lock); |
045e269c | 5651 | ftrace_hash_move_and_update_ops(iter->ops, orig_hash, |
e16b35dd | 5652 | iter->hash, filter_hash); |
058e297d | 5653 | mutex_unlock(&ftrace_lock); |
c20489da SRV |
5654 | } else { |
5655 | /* For read only, the hash is the ops hash */ | |
5656 | iter->hash = NULL; | |
058e297d | 5657 | } |
3f2367ba | 5658 | |
33b7f99c | 5659 | mutex_unlock(&iter->ops->func_hash->regex_lock); |
33dc9b12 | 5660 | free_ftrace_hash(iter->hash); |
9ef16693 SRV |
5661 | if (iter->tr) |
5662 | trace_array_put(iter->tr); | |
33dc9b12 | 5663 | kfree(iter); |
058e297d | 5664 | |
5072c59f SR |
5665 | return 0; |
5666 | } | |
5667 | ||
5e2336a0 | 5668 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
5669 | .open = ftrace_avail_open, |
5670 | .read = seq_read, | |
5671 | .llseek = seq_lseek, | |
3be04b47 | 5672 | .release = seq_release_private, |
5072c59f SR |
5673 | }; |
5674 | ||
647bcd03 SR |
5675 | static const struct file_operations ftrace_enabled_fops = { |
5676 | .open = ftrace_enabled_open, | |
5677 | .read = seq_read, | |
5678 | .llseek = seq_lseek, | |
5679 | .release = seq_release_private, | |
5680 | }; | |
5681 | ||
5e2336a0 | 5682 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 5683 | .open = ftrace_filter_open, |
850a80cf | 5684 | .read = seq_read, |
5072c59f | 5685 | .write = ftrace_filter_write, |
098c879e | 5686 | .llseek = tracing_lseek, |
1cf41dd7 | 5687 | .release = ftrace_regex_release, |
5072c59f SR |
5688 | }; |
5689 | ||
5e2336a0 | 5690 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 5691 | .open = ftrace_notrace_open, |
850a80cf | 5692 | .read = seq_read, |
41c52c0d | 5693 | .write = ftrace_notrace_write, |
098c879e | 5694 | .llseek = tracing_lseek, |
1cf41dd7 | 5695 | .release = ftrace_regex_release, |
41c52c0d SR |
5696 | }; |
5697 | ||
ea4e2bc4 SR |
5698 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5699 | ||
5700 | static DEFINE_MUTEX(graph_lock); | |
5701 | ||
24a9729f | 5702 | struct ftrace_hash __rcu *ftrace_graph_hash = EMPTY_HASH; |
fd0e6852 | 5703 | struct ftrace_hash __rcu *ftrace_graph_notrace_hash = EMPTY_HASH; |
b9b0c831 NK |
5704 | |
5705 | enum graph_filter_type { | |
5706 | GRAPH_FILTER_NOTRACE = 0, | |
5707 | GRAPH_FILTER_FUNCTION, | |
5708 | }; | |
ea4e2bc4 | 5709 | |
555fc781 SRV |
5710 | #define FTRACE_GRAPH_EMPTY ((void *)1) |
5711 | ||
faf982a6 | 5712 | struct ftrace_graph_data { |
e704eff3 SRV |
5713 | struct ftrace_hash *hash; |
5714 | struct ftrace_func_entry *entry; | |
5715 | int idx; /* for hash table iteration */ | |
5716 | enum graph_filter_type type; | |
5717 | struct ftrace_hash *new_hash; | |
5718 | const struct seq_operations *seq_ops; | |
5719 | struct trace_parser parser; | |
faf982a6 NK |
5720 | }; |
5721 | ||
ea4e2bc4 | 5722 | static void * |
85951842 | 5723 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 5724 | { |
faf982a6 | 5725 | struct ftrace_graph_data *fgd = m->private; |
b9b0c831 NK |
5726 | struct ftrace_func_entry *entry = fgd->entry; |
5727 | struct hlist_head *head; | |
5728 | int i, idx = fgd->idx; | |
faf982a6 | 5729 | |
b9b0c831 | 5730 | if (*pos >= fgd->hash->count) |
ea4e2bc4 | 5731 | return NULL; |
b9b0c831 NK |
5732 | |
5733 | if (entry) { | |
5734 | hlist_for_each_entry_continue(entry, hlist) { | |
5735 | fgd->entry = entry; | |
5736 | return entry; | |
5737 | } | |
5738 | ||
5739 | idx++; | |
5740 | } | |
5741 | ||
5742 | for (i = idx; i < 1 << fgd->hash->size_bits; i++) { | |
5743 | head = &fgd->hash->buckets[i]; | |
5744 | hlist_for_each_entry(entry, head, hlist) { | |
5745 | fgd->entry = entry; | |
5746 | fgd->idx = i; | |
5747 | return entry; | |
5748 | } | |
5749 | } | |
5750 | return NULL; | |
85951842 | 5751 | } |
ea4e2bc4 | 5752 | |
85951842 LZ |
5753 | static void * |
5754 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
5755 | { | |
5756 | (*pos)++; | |
5757 | return __g_next(m, pos); | |
ea4e2bc4 SR |
5758 | } |
5759 | ||
5760 | static void *g_start(struct seq_file *m, loff_t *pos) | |
5761 | { | |
faf982a6 NK |
5762 | struct ftrace_graph_data *fgd = m->private; |
5763 | ||
ea4e2bc4 SR |
5764 | mutex_lock(&graph_lock); |
5765 | ||
649b988b SRV |
5766 | if (fgd->type == GRAPH_FILTER_FUNCTION) |
5767 | fgd->hash = rcu_dereference_protected(ftrace_graph_hash, | |
5768 | lockdep_is_held(&graph_lock)); | |
5769 | else | |
5770 | fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash, | |
5771 | lockdep_is_held(&graph_lock)); | |
5772 | ||
f9349a8f | 5773 | /* Nothing, tell g_show to print all functions are enabled */ |
b9b0c831 | 5774 | if (ftrace_hash_empty(fgd->hash) && !*pos) |
555fc781 | 5775 | return FTRACE_GRAPH_EMPTY; |
f9349a8f | 5776 | |
b9b0c831 NK |
5777 | fgd->idx = 0; |
5778 | fgd->entry = NULL; | |
85951842 | 5779 | return __g_next(m, pos); |
ea4e2bc4 SR |
5780 | } |
5781 | ||
5782 | static void g_stop(struct seq_file *m, void *p) | |
5783 | { | |
5784 | mutex_unlock(&graph_lock); | |
5785 | } | |
5786 | ||
5787 | static int g_show(struct seq_file *m, void *v) | |
5788 | { | |
b9b0c831 | 5789 | struct ftrace_func_entry *entry = v; |
ea4e2bc4 | 5790 | |
b9b0c831 | 5791 | if (!entry) |
ea4e2bc4 SR |
5792 | return 0; |
5793 | ||
555fc781 | 5794 | if (entry == FTRACE_GRAPH_EMPTY) { |
280d1429 NK |
5795 | struct ftrace_graph_data *fgd = m->private; |
5796 | ||
b9b0c831 | 5797 | if (fgd->type == GRAPH_FILTER_FUNCTION) |
fa6f0cc7 | 5798 | seq_puts(m, "#### all functions enabled ####\n"); |
280d1429 | 5799 | else |
fa6f0cc7 | 5800 | seq_puts(m, "#### no functions disabled ####\n"); |
f9349a8f FW |
5801 | return 0; |
5802 | } | |
5803 | ||
b9b0c831 | 5804 | seq_printf(m, "%ps\n", (void *)entry->ip); |
ea4e2bc4 SR |
5805 | |
5806 | return 0; | |
5807 | } | |
5808 | ||
88e9d34c | 5809 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
5810 | .start = g_start, |
5811 | .next = g_next, | |
5812 | .stop = g_stop, | |
5813 | .show = g_show, | |
5814 | }; | |
5815 | ||
5816 | static int | |
faf982a6 NK |
5817 | __ftrace_graph_open(struct inode *inode, struct file *file, |
5818 | struct ftrace_graph_data *fgd) | |
ea4e2bc4 | 5819 | { |
17911ff3 | 5820 | int ret; |
b9b0c831 | 5821 | struct ftrace_hash *new_hash = NULL; |
ea4e2bc4 | 5822 | |
17911ff3 SRV |
5823 | ret = security_locked_down(LOCKDOWN_TRACEFS); |
5824 | if (ret) | |
5825 | return ret; | |
5826 | ||
b9b0c831 NK |
5827 | if (file->f_mode & FMODE_WRITE) { |
5828 | const int size_bits = FTRACE_HASH_DEFAULT_BITS; | |
5829 | ||
e704eff3 SRV |
5830 | if (trace_parser_get_init(&fgd->parser, FTRACE_BUFF_MAX)) |
5831 | return -ENOMEM; | |
5832 | ||
b9b0c831 NK |
5833 | if (file->f_flags & O_TRUNC) |
5834 | new_hash = alloc_ftrace_hash(size_bits); | |
5835 | else | |
5836 | new_hash = alloc_and_copy_ftrace_hash(size_bits, | |
5837 | fgd->hash); | |
5838 | if (!new_hash) { | |
5839 | ret = -ENOMEM; | |
5840 | goto out; | |
5841 | } | |
ea4e2bc4 SR |
5842 | } |
5843 | ||
faf982a6 | 5844 | if (file->f_mode & FMODE_READ) { |
b9b0c831 | 5845 | ret = seq_open(file, &ftrace_graph_seq_ops); |
faf982a6 NK |
5846 | if (!ret) { |
5847 | struct seq_file *m = file->private_data; | |
5848 | m->private = fgd; | |
b9b0c831 NK |
5849 | } else { |
5850 | /* Failed */ | |
5851 | free_ftrace_hash(new_hash); | |
5852 | new_hash = NULL; | |
faf982a6 NK |
5853 | } |
5854 | } else | |
5855 | file->private_data = fgd; | |
ea4e2bc4 | 5856 | |
b9b0c831 | 5857 | out: |
e704eff3 SRV |
5858 | if (ret < 0 && file->f_mode & FMODE_WRITE) |
5859 | trace_parser_put(&fgd->parser); | |
5860 | ||
b9b0c831 | 5861 | fgd->new_hash = new_hash; |
649b988b SRV |
5862 | |
5863 | /* | |
5864 | * All uses of fgd->hash must be taken with the graph_lock | |
5865 | * held. The graph_lock is going to be released, so force | |
5866 | * fgd->hash to be reinitialized when it is taken again. | |
5867 | */ | |
5868 | fgd->hash = NULL; | |
5869 | ||
ea4e2bc4 SR |
5870 | return ret; |
5871 | } | |
5872 | ||
faf982a6 NK |
5873 | static int |
5874 | ftrace_graph_open(struct inode *inode, struct file *file) | |
5875 | { | |
5876 | struct ftrace_graph_data *fgd; | |
b9b0c831 | 5877 | int ret; |
faf982a6 NK |
5878 | |
5879 | if (unlikely(ftrace_disabled)) | |
5880 | return -ENODEV; | |
5881 | ||
5882 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
5883 | if (fgd == NULL) | |
5884 | return -ENOMEM; | |
5885 | ||
b9b0c831 NK |
5886 | mutex_lock(&graph_lock); |
5887 | ||
649b988b SRV |
5888 | fgd->hash = rcu_dereference_protected(ftrace_graph_hash, |
5889 | lockdep_is_held(&graph_lock)); | |
b9b0c831 | 5890 | fgd->type = GRAPH_FILTER_FUNCTION; |
faf982a6 NK |
5891 | fgd->seq_ops = &ftrace_graph_seq_ops; |
5892 | ||
b9b0c831 NK |
5893 | ret = __ftrace_graph_open(inode, file, fgd); |
5894 | if (ret < 0) | |
5895 | kfree(fgd); | |
5896 | ||
5897 | mutex_unlock(&graph_lock); | |
5898 | return ret; | |
faf982a6 NK |
5899 | } |
5900 | ||
29ad23b0 NK |
5901 | static int |
5902 | ftrace_graph_notrace_open(struct inode *inode, struct file *file) | |
5903 | { | |
5904 | struct ftrace_graph_data *fgd; | |
b9b0c831 | 5905 | int ret; |
29ad23b0 NK |
5906 | |
5907 | if (unlikely(ftrace_disabled)) | |
5908 | return -ENODEV; | |
5909 | ||
5910 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
5911 | if (fgd == NULL) | |
5912 | return -ENOMEM; | |
5913 | ||
b9b0c831 NK |
5914 | mutex_lock(&graph_lock); |
5915 | ||
649b988b SRV |
5916 | fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash, |
5917 | lockdep_is_held(&graph_lock)); | |
b9b0c831 | 5918 | fgd->type = GRAPH_FILTER_NOTRACE; |
29ad23b0 NK |
5919 | fgd->seq_ops = &ftrace_graph_seq_ops; |
5920 | ||
b9b0c831 NK |
5921 | ret = __ftrace_graph_open(inode, file, fgd); |
5922 | if (ret < 0) | |
5923 | kfree(fgd); | |
5924 | ||
5925 | mutex_unlock(&graph_lock); | |
5926 | return ret; | |
29ad23b0 NK |
5927 | } |
5928 | ||
87827111 LZ |
5929 | static int |
5930 | ftrace_graph_release(struct inode *inode, struct file *file) | |
5931 | { | |
b9b0c831 | 5932 | struct ftrace_graph_data *fgd; |
e704eff3 SRV |
5933 | struct ftrace_hash *old_hash, *new_hash; |
5934 | struct trace_parser *parser; | |
5935 | int ret = 0; | |
b9b0c831 | 5936 | |
faf982a6 NK |
5937 | if (file->f_mode & FMODE_READ) { |
5938 | struct seq_file *m = file->private_data; | |
5939 | ||
b9b0c831 | 5940 | fgd = m->private; |
87827111 | 5941 | seq_release(inode, file); |
faf982a6 | 5942 | } else { |
b9b0c831 | 5943 | fgd = file->private_data; |
faf982a6 NK |
5944 | } |
5945 | ||
e704eff3 SRV |
5946 | |
5947 | if (file->f_mode & FMODE_WRITE) { | |
5948 | ||
5949 | parser = &fgd->parser; | |
5950 | ||
5951 | if (trace_parser_loaded((parser))) { | |
e704eff3 SRV |
5952 | ret = ftrace_graph_set_hash(fgd->new_hash, |
5953 | parser->buffer); | |
5954 | } | |
5955 | ||
5956 | trace_parser_put(parser); | |
5957 | ||
5958 | new_hash = __ftrace_hash_move(fgd->new_hash); | |
5959 | if (!new_hash) { | |
5960 | ret = -ENOMEM; | |
5961 | goto out; | |
5962 | } | |
5963 | ||
5964 | mutex_lock(&graph_lock); | |
5965 | ||
5966 | if (fgd->type == GRAPH_FILTER_FUNCTION) { | |
5967 | old_hash = rcu_dereference_protected(ftrace_graph_hash, | |
5968 | lockdep_is_held(&graph_lock)); | |
5969 | rcu_assign_pointer(ftrace_graph_hash, new_hash); | |
5970 | } else { | |
5971 | old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash, | |
5972 | lockdep_is_held(&graph_lock)); | |
5973 | rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash); | |
5974 | } | |
5975 | ||
5976 | mutex_unlock(&graph_lock); | |
5977 | ||
54a16ff6 SRV |
5978 | /* |
5979 | * We need to do a hard force of sched synchronization. | |
5980 | * This is because we use preempt_disable() to do RCU, but | |
5981 | * the function tracers can be called where RCU is not watching | |
5982 | * (like before user_exit()). We can not rely on the RCU | |
5983 | * infrastructure to do the synchronization, thus we must do it | |
5984 | * ourselves. | |
5985 | */ | |
e5a971d7 | 5986 | synchronize_rcu_tasks_rude(); |
e704eff3 SRV |
5987 | |
5988 | free_ftrace_hash(old_hash); | |
5989 | } | |
5990 | ||
5991 | out: | |
f9797c2f | 5992 | free_ftrace_hash(fgd->new_hash); |
b9b0c831 NK |
5993 | kfree(fgd); |
5994 | ||
e704eff3 | 5995 | return ret; |
87827111 LZ |
5996 | } |
5997 | ||
ea4e2bc4 | 5998 | static int |
b9b0c831 | 5999 | ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer) |
ea4e2bc4 | 6000 | { |
3ba00929 | 6001 | struct ftrace_glob func_g; |
ea4e2bc4 SR |
6002 | struct dyn_ftrace *rec; |
6003 | struct ftrace_page *pg; | |
b9b0c831 | 6004 | struct ftrace_func_entry *entry; |
c7c6b1fe | 6005 | int fail = 1; |
3ba00929 | 6006 | int not; |
ea4e2bc4 | 6007 | |
f9349a8f | 6008 | /* decode regex */ |
3ba00929 DS |
6009 | func_g.type = filter_parse_regex(buffer, strlen(buffer), |
6010 | &func_g.search, ¬); | |
f9349a8f | 6011 | |
3ba00929 | 6012 | func_g.len = strlen(func_g.search); |
f9349a8f | 6013 | |
52baf119 | 6014 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
6015 | |
6016 | if (unlikely(ftrace_disabled)) { | |
6017 | mutex_unlock(&ftrace_lock); | |
6018 | return -ENODEV; | |
6019 | } | |
6020 | ||
265c831c SR |
6021 | do_for_each_ftrace_rec(pg, rec) { |
6022 | ||
546fece4 SRRH |
6023 | if (rec->flags & FTRACE_FL_DISABLED) |
6024 | continue; | |
6025 | ||
0b507e1e | 6026 | if (ftrace_match_record(rec, &func_g, NULL, 0)) { |
b9b0c831 | 6027 | entry = ftrace_lookup_ip(hash, rec->ip); |
c7c6b1fe LZ |
6028 | |
6029 | if (!not) { | |
6030 | fail = 0; | |
b9b0c831 NK |
6031 | |
6032 | if (entry) | |
6033 | continue; | |
6034 | if (add_hash_entry(hash, rec->ip) < 0) | |
6035 | goto out; | |
c7c6b1fe | 6036 | } else { |
b9b0c831 NK |
6037 | if (entry) { |
6038 | free_hash_entry(hash, entry); | |
c7c6b1fe LZ |
6039 | fail = 0; |
6040 | } | |
6041 | } | |
ea4e2bc4 | 6042 | } |
265c831c | 6043 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 6044 | out: |
52baf119 | 6045 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 6046 | |
c7c6b1fe LZ |
6047 | if (fail) |
6048 | return -EINVAL; | |
6049 | ||
c7c6b1fe | 6050 | return 0; |
ea4e2bc4 SR |
6051 | } |
6052 | ||
6053 | static ssize_t | |
6054 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
6055 | size_t cnt, loff_t *ppos) | |
6056 | { | |
6a10108b | 6057 | ssize_t read, ret = 0; |
faf982a6 | 6058 | struct ftrace_graph_data *fgd = file->private_data; |
e704eff3 | 6059 | struct trace_parser *parser; |
ea4e2bc4 | 6060 | |
c7c6b1fe | 6061 | if (!cnt) |
ea4e2bc4 SR |
6062 | return 0; |
6063 | ||
ae98d27a SRV |
6064 | /* Read mode uses seq functions */ |
6065 | if (file->f_mode & FMODE_READ) { | |
6066 | struct seq_file *m = file->private_data; | |
6067 | fgd = m->private; | |
6068 | } | |
6069 | ||
e704eff3 | 6070 | parser = &fgd->parser; |
ea4e2bc4 | 6071 | |
e704eff3 | 6072 | read = trace_get_user(parser, ubuf, cnt, ppos); |
689fd8b6 | 6073 | |
e704eff3 SRV |
6074 | if (read >= 0 && trace_parser_loaded(parser) && |
6075 | !trace_parser_cont(parser)) { | |
6a10108b | 6076 | |
b9b0c831 | 6077 | ret = ftrace_graph_set_hash(fgd->new_hash, |
e704eff3 SRV |
6078 | parser->buffer); |
6079 | trace_parser_clear(parser); | |
ea4e2bc4 | 6080 | } |
ea4e2bc4 | 6081 | |
6a10108b NK |
6082 | if (!ret) |
6083 | ret = read; | |
1eb90f13 | 6084 | |
ea4e2bc4 SR |
6085 | return ret; |
6086 | } | |
6087 | ||
6088 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
6089 | .open = ftrace_graph_open, |
6090 | .read = seq_read, | |
6091 | .write = ftrace_graph_write, | |
098c879e | 6092 | .llseek = tracing_lseek, |
87827111 | 6093 | .release = ftrace_graph_release, |
ea4e2bc4 | 6094 | }; |
29ad23b0 NK |
6095 | |
6096 | static const struct file_operations ftrace_graph_notrace_fops = { | |
6097 | .open = ftrace_graph_notrace_open, | |
6098 | .read = seq_read, | |
6099 | .write = ftrace_graph_write, | |
098c879e | 6100 | .llseek = tracing_lseek, |
29ad23b0 NK |
6101 | .release = ftrace_graph_release, |
6102 | }; | |
ea4e2bc4 SR |
6103 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
6104 | ||
591dffda SRRH |
6105 | void ftrace_create_filter_files(struct ftrace_ops *ops, |
6106 | struct dentry *parent) | |
6107 | { | |
6108 | ||
6109 | trace_create_file("set_ftrace_filter", 0644, parent, | |
6110 | ops, &ftrace_filter_fops); | |
6111 | ||
6112 | trace_create_file("set_ftrace_notrace", 0644, parent, | |
6113 | ops, &ftrace_notrace_fops); | |
6114 | } | |
6115 | ||
6116 | /* | |
6117 | * The name "destroy_filter_files" is really a misnomer. Although | |
9efb85c5 | 6118 | * in the future, it may actually delete the files, but this is |
591dffda SRRH |
6119 | * really intended to make sure the ops passed in are disabled |
6120 | * and that when this function returns, the caller is free to | |
6121 | * free the ops. | |
6122 | * | |
6123 | * The "destroy" name is only to match the "create" name that this | |
6124 | * should be paired with. | |
6125 | */ | |
6126 | void ftrace_destroy_filter_files(struct ftrace_ops *ops) | |
6127 | { | |
6128 | mutex_lock(&ftrace_lock); | |
6129 | if (ops->flags & FTRACE_OPS_FL_ENABLED) | |
6130 | ftrace_shutdown(ops, 0); | |
6131 | ops->flags |= FTRACE_OPS_FL_DELETED; | |
2840f84f | 6132 | ftrace_free_filter(ops); |
591dffda SRRH |
6133 | mutex_unlock(&ftrace_lock); |
6134 | } | |
6135 | ||
8434dc93 | 6136 | static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer) |
5072c59f | 6137 | { |
5072c59f | 6138 | |
5452af66 FW |
6139 | trace_create_file("available_filter_functions", 0444, |
6140 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 6141 | |
647bcd03 SR |
6142 | trace_create_file("enabled_functions", 0444, |
6143 | d_tracer, NULL, &ftrace_enabled_fops); | |
6144 | ||
591dffda | 6145 | ftrace_create_filter_files(&global_ops, d_tracer); |
ad90c0e3 | 6146 | |
ea4e2bc4 | 6147 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
1ce0500d | 6148 | trace_create_file("set_graph_function", 0644, d_tracer, |
ea4e2bc4 SR |
6149 | NULL, |
6150 | &ftrace_graph_fops); | |
1ce0500d | 6151 | trace_create_file("set_graph_notrace", 0644, d_tracer, |
29ad23b0 NK |
6152 | NULL, |
6153 | &ftrace_graph_notrace_fops); | |
ea4e2bc4 SR |
6154 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
6155 | ||
5072c59f SR |
6156 | return 0; |
6157 | } | |
6158 | ||
9fd49328 | 6159 | static int ftrace_cmp_ips(const void *a, const void *b) |
68950619 | 6160 | { |
9fd49328 SR |
6161 | const unsigned long *ipa = a; |
6162 | const unsigned long *ipb = b; | |
68950619 | 6163 | |
9fd49328 SR |
6164 | if (*ipa > *ipb) |
6165 | return 1; | |
6166 | if (*ipa < *ipb) | |
6167 | return -1; | |
6168 | return 0; | |
6169 | } | |
6170 | ||
5cb084bb | 6171 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 6172 | unsigned long *start, |
68bf21aa SR |
6173 | unsigned long *end) |
6174 | { | |
706c81f8 | 6175 | struct ftrace_page *start_pg; |
a7900875 | 6176 | struct ftrace_page *pg; |
706c81f8 | 6177 | struct dyn_ftrace *rec; |
a7900875 | 6178 | unsigned long count; |
68bf21aa SR |
6179 | unsigned long *p; |
6180 | unsigned long addr; | |
4376cac6 | 6181 | unsigned long flags = 0; /* Shut up gcc */ |
a7900875 SR |
6182 | int ret = -ENOMEM; |
6183 | ||
6184 | count = end - start; | |
6185 | ||
6186 | if (!count) | |
6187 | return 0; | |
6188 | ||
9fd49328 | 6189 | sort(start, count, sizeof(*start), |
6db02903 | 6190 | ftrace_cmp_ips, NULL); |
9fd49328 | 6191 | |
706c81f8 SR |
6192 | start_pg = ftrace_allocate_pages(count); |
6193 | if (!start_pg) | |
a7900875 | 6194 | return -ENOMEM; |
68bf21aa | 6195 | |
e6ea44e9 | 6196 | mutex_lock(&ftrace_lock); |
a7900875 | 6197 | |
32082309 SR |
6198 | /* |
6199 | * Core and each module needs their own pages, as | |
6200 | * modules will free them when they are removed. | |
6201 | * Force a new page to be allocated for modules. | |
6202 | */ | |
a7900875 SR |
6203 | if (!mod) { |
6204 | WARN_ON(ftrace_pages || ftrace_pages_start); | |
6205 | /* First initialization */ | |
706c81f8 | 6206 | ftrace_pages = ftrace_pages_start = start_pg; |
a7900875 | 6207 | } else { |
32082309 | 6208 | if (!ftrace_pages) |
a7900875 | 6209 | goto out; |
32082309 | 6210 | |
a7900875 SR |
6211 | if (WARN_ON(ftrace_pages->next)) { |
6212 | /* Hmm, we have free pages? */ | |
6213 | while (ftrace_pages->next) | |
6214 | ftrace_pages = ftrace_pages->next; | |
32082309 | 6215 | } |
a7900875 | 6216 | |
706c81f8 | 6217 | ftrace_pages->next = start_pg; |
32082309 SR |
6218 | } |
6219 | ||
68bf21aa | 6220 | p = start; |
706c81f8 | 6221 | pg = start_pg; |
68bf21aa SR |
6222 | while (p < end) { |
6223 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
6224 | /* |
6225 | * Some architecture linkers will pad between | |
6226 | * the different mcount_loc sections of different | |
6227 | * object files to satisfy alignments. | |
6228 | * Skip any NULL pointers. | |
6229 | */ | |
6230 | if (!addr) | |
6231 | continue; | |
706c81f8 SR |
6232 | |
6233 | if (pg->index == pg->size) { | |
6234 | /* We should have allocated enough */ | |
6235 | if (WARN_ON(!pg->next)) | |
6236 | break; | |
6237 | pg = pg->next; | |
6238 | } | |
6239 | ||
6240 | rec = &pg->records[pg->index++]; | |
6241 | rec->ip = addr; | |
68bf21aa SR |
6242 | } |
6243 | ||
706c81f8 SR |
6244 | /* We should have used all pages */ |
6245 | WARN_ON(pg->next); | |
6246 | ||
6247 | /* Assign the last page to ftrace_pages */ | |
6248 | ftrace_pages = pg; | |
6249 | ||
a4f18ed1 | 6250 | /* |
4376cac6 SR |
6251 | * We only need to disable interrupts on start up |
6252 | * because we are modifying code that an interrupt | |
6253 | * may execute, and the modification is not atomic. | |
6254 | * But for modules, nothing runs the code we modify | |
6255 | * until we are finished with it, and there's no | |
6256 | * reason to cause large interrupt latencies while we do it. | |
a4f18ed1 | 6257 | */ |
4376cac6 SR |
6258 | if (!mod) |
6259 | local_irq_save(flags); | |
1dc43cf0 | 6260 | ftrace_update_code(mod, start_pg); |
4376cac6 SR |
6261 | if (!mod) |
6262 | local_irq_restore(flags); | |
a7900875 SR |
6263 | ret = 0; |
6264 | out: | |
e6ea44e9 | 6265 | mutex_unlock(&ftrace_lock); |
68bf21aa | 6266 | |
a7900875 | 6267 | return ret; |
68bf21aa SR |
6268 | } |
6269 | ||
aba4b5c2 SRV |
6270 | struct ftrace_mod_func { |
6271 | struct list_head list; | |
6272 | char *name; | |
6273 | unsigned long ip; | |
6274 | unsigned int size; | |
6275 | }; | |
6276 | ||
6277 | struct ftrace_mod_map { | |
6aa69784 | 6278 | struct rcu_head rcu; |
aba4b5c2 SRV |
6279 | struct list_head list; |
6280 | struct module *mod; | |
6281 | unsigned long start_addr; | |
6282 | unsigned long end_addr; | |
6283 | struct list_head funcs; | |
6171a031 | 6284 | unsigned int num_funcs; |
aba4b5c2 SRV |
6285 | }; |
6286 | ||
fc0ea795 AH |
6287 | static int ftrace_get_trampoline_kallsym(unsigned int symnum, |
6288 | unsigned long *value, char *type, | |
6289 | char *name, char *module_name, | |
6290 | int *exported) | |
6291 | { | |
6292 | struct ftrace_ops *op; | |
6293 | ||
6294 | list_for_each_entry_rcu(op, &ftrace_ops_trampoline_list, list) { | |
6295 | if (!op->trampoline || symnum--) | |
6296 | continue; | |
6297 | *value = op->trampoline; | |
6298 | *type = 't'; | |
6299 | strlcpy(name, FTRACE_TRAMPOLINE_SYM, KSYM_NAME_LEN); | |
6300 | strlcpy(module_name, FTRACE_TRAMPOLINE_MOD, MODULE_NAME_LEN); | |
6301 | *exported = 0; | |
6302 | return 0; | |
6303 | } | |
6304 | ||
6305 | return -ERANGE; | |
6306 | } | |
6307 | ||
93eb677d | 6308 | #ifdef CONFIG_MODULES |
32082309 SR |
6309 | |
6310 | #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next) | |
6311 | ||
6aa69784 SRV |
6312 | static LIST_HEAD(ftrace_mod_maps); |
6313 | ||
b7ffffbb SRRH |
6314 | static int referenced_filters(struct dyn_ftrace *rec) |
6315 | { | |
6316 | struct ftrace_ops *ops; | |
6317 | int cnt = 0; | |
6318 | ||
6319 | for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) { | |
8a224ffb | 6320 | if (ops_references_rec(ops, rec)) { |
c5f51572 CZ |
6321 | if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_DIRECT)) |
6322 | continue; | |
6323 | if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_IPMODIFY)) | |
6324 | continue; | |
8a224ffb CZ |
6325 | cnt++; |
6326 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) | |
6327 | rec->flags |= FTRACE_FL_REGS; | |
c5f51572 CZ |
6328 | if (cnt == 1 && ops->trampoline) |
6329 | rec->flags |= FTRACE_FL_TRAMP; | |
6330 | else | |
6331 | rec->flags &= ~FTRACE_FL_TRAMP; | |
8a224ffb | 6332 | } |
b7ffffbb SRRH |
6333 | } |
6334 | ||
6335 | return cnt; | |
6336 | } | |
6337 | ||
2a5bfe47 SRV |
6338 | static void |
6339 | clear_mod_from_hash(struct ftrace_page *pg, struct ftrace_hash *hash) | |
6340 | { | |
6341 | struct ftrace_func_entry *entry; | |
6342 | struct dyn_ftrace *rec; | |
6343 | int i; | |
6344 | ||
6345 | if (ftrace_hash_empty(hash)) | |
6346 | return; | |
6347 | ||
6348 | for (i = 0; i < pg->index; i++) { | |
6349 | rec = &pg->records[i]; | |
6350 | entry = __ftrace_lookup_ip(hash, rec->ip); | |
6351 | /* | |
6352 | * Do not allow this rec to match again. | |
6353 | * Yeah, it may waste some memory, but will be removed | |
6354 | * if/when the hash is modified again. | |
6355 | */ | |
6356 | if (entry) | |
6357 | entry->ip = 0; | |
6358 | } | |
6359 | } | |
6360 | ||
6361 | /* Clear any records from hashs */ | |
6362 | static void clear_mod_from_hashes(struct ftrace_page *pg) | |
6363 | { | |
6364 | struct trace_array *tr; | |
6365 | ||
6366 | mutex_lock(&trace_types_lock); | |
6367 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
6368 | if (!tr->ops || !tr->ops->func_hash) | |
6369 | continue; | |
6370 | mutex_lock(&tr->ops->func_hash->regex_lock); | |
6371 | clear_mod_from_hash(pg, tr->ops->func_hash->filter_hash); | |
6372 | clear_mod_from_hash(pg, tr->ops->func_hash->notrace_hash); | |
6373 | mutex_unlock(&tr->ops->func_hash->regex_lock); | |
6374 | } | |
6375 | mutex_unlock(&trace_types_lock); | |
6376 | } | |
6377 | ||
6aa69784 SRV |
6378 | static void ftrace_free_mod_map(struct rcu_head *rcu) |
6379 | { | |
6380 | struct ftrace_mod_map *mod_map = container_of(rcu, struct ftrace_mod_map, rcu); | |
6381 | struct ftrace_mod_func *mod_func; | |
6382 | struct ftrace_mod_func *n; | |
6383 | ||
6384 | /* All the contents of mod_map are now not visible to readers */ | |
6385 | list_for_each_entry_safe(mod_func, n, &mod_map->funcs, list) { | |
6386 | kfree(mod_func->name); | |
6387 | list_del(&mod_func->list); | |
6388 | kfree(mod_func); | |
6389 | } | |
6390 | ||
6391 | kfree(mod_map); | |
6392 | } | |
6393 | ||
e7247a15 | 6394 | void ftrace_release_mod(struct module *mod) |
93eb677d | 6395 | { |
6aa69784 SRV |
6396 | struct ftrace_mod_map *mod_map; |
6397 | struct ftrace_mod_map *n; | |
93eb677d | 6398 | struct dyn_ftrace *rec; |
32082309 | 6399 | struct ftrace_page **last_pg; |
2a5bfe47 | 6400 | struct ftrace_page *tmp_page = NULL; |
93eb677d | 6401 | struct ftrace_page *pg; |
a7900875 | 6402 | int order; |
93eb677d | 6403 | |
45a4a237 SR |
6404 | mutex_lock(&ftrace_lock); |
6405 | ||
e7247a15 | 6406 | if (ftrace_disabled) |
45a4a237 | 6407 | goto out_unlock; |
93eb677d | 6408 | |
6aa69784 SRV |
6409 | list_for_each_entry_safe(mod_map, n, &ftrace_mod_maps, list) { |
6410 | if (mod_map->mod == mod) { | |
6411 | list_del_rcu(&mod_map->list); | |
74401729 | 6412 | call_rcu(&mod_map->rcu, ftrace_free_mod_map); |
6aa69784 SRV |
6413 | break; |
6414 | } | |
6415 | } | |
6416 | ||
32082309 SR |
6417 | /* |
6418 | * Each module has its own ftrace_pages, remove | |
6419 | * them from the list. | |
6420 | */ | |
6421 | last_pg = &ftrace_pages_start; | |
6422 | for (pg = ftrace_pages_start; pg; pg = *last_pg) { | |
6423 | rec = &pg->records[0]; | |
3e234289 SRV |
6424 | if (within_module_core(rec->ip, mod) || |
6425 | within_module_init(rec->ip, mod)) { | |
93eb677d | 6426 | /* |
32082309 SR |
6427 | * As core pages are first, the first |
6428 | * page should never be a module page. | |
93eb677d | 6429 | */ |
32082309 SR |
6430 | if (WARN_ON(pg == ftrace_pages_start)) |
6431 | goto out_unlock; | |
6432 | ||
6433 | /* Check if we are deleting the last page */ | |
6434 | if (pg == ftrace_pages) | |
6435 | ftrace_pages = next_to_ftrace_page(last_pg); | |
6436 | ||
83dd1493 | 6437 | ftrace_update_tot_cnt -= pg->index; |
32082309 | 6438 | *last_pg = pg->next; |
2a5bfe47 SRV |
6439 | |
6440 | pg->next = tmp_page; | |
6441 | tmp_page = pg; | |
32082309 SR |
6442 | } else |
6443 | last_pg = &pg->next; | |
6444 | } | |
45a4a237 | 6445 | out_unlock: |
93eb677d | 6446 | mutex_unlock(&ftrace_lock); |
2a5bfe47 SRV |
6447 | |
6448 | for (pg = tmp_page; pg; pg = tmp_page) { | |
6449 | ||
6450 | /* Needs to be called outside of ftrace_lock */ | |
6451 | clear_mod_from_hashes(pg); | |
6452 | ||
6453 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); | |
6454 | free_pages((unsigned long)pg->records, order); | |
6455 | tmp_page = pg->next; | |
6456 | kfree(pg); | |
da537f0a SRV |
6457 | ftrace_number_of_pages -= 1 << order; |
6458 | ftrace_number_of_groups--; | |
2a5bfe47 | 6459 | } |
93eb677d SR |
6460 | } |
6461 | ||
7dcd182b | 6462 | void ftrace_module_enable(struct module *mod) |
b7ffffbb SRRH |
6463 | { |
6464 | struct dyn_ftrace *rec; | |
6465 | struct ftrace_page *pg; | |
6466 | ||
6467 | mutex_lock(&ftrace_lock); | |
6468 | ||
6469 | if (ftrace_disabled) | |
6470 | goto out_unlock; | |
6471 | ||
6472 | /* | |
6473 | * If the tracing is enabled, go ahead and enable the record. | |
6474 | * | |
9efb85c5 | 6475 | * The reason not to enable the record immediately is the |
b7ffffbb SRRH |
6476 | * inherent check of ftrace_make_nop/ftrace_make_call for |
6477 | * correct previous instructions. Making first the NOP | |
6478 | * conversion puts the module to the correct state, thus | |
6479 | * passing the ftrace_make_call check. | |
6480 | * | |
6481 | * We also delay this to after the module code already set the | |
6482 | * text to read-only, as we now need to set it back to read-write | |
6483 | * so that we can modify the text. | |
6484 | */ | |
6485 | if (ftrace_start_up) | |
6486 | ftrace_arch_code_modify_prepare(); | |
6487 | ||
6488 | do_for_each_ftrace_rec(pg, rec) { | |
6489 | int cnt; | |
6490 | /* | |
6491 | * do_for_each_ftrace_rec() is a double loop. | |
6492 | * module text shares the pg. If a record is | |
6493 | * not part of this module, then skip this pg, | |
6494 | * which the "break" will do. | |
6495 | */ | |
3e234289 SRV |
6496 | if (!within_module_core(rec->ip, mod) && |
6497 | !within_module_init(rec->ip, mod)) | |
b7ffffbb SRRH |
6498 | break; |
6499 | ||
6500 | cnt = 0; | |
6501 | ||
6502 | /* | |
6503 | * When adding a module, we need to check if tracers are | |
6504 | * currently enabled and if they are, and can trace this record, | |
6505 | * we need to enable the module functions as well as update the | |
6506 | * reference counts for those function records. | |
6507 | */ | |
6508 | if (ftrace_start_up) | |
6509 | cnt += referenced_filters(rec); | |
6510 | ||
8a224ffb CZ |
6511 | rec->flags &= ~FTRACE_FL_DISABLED; |
6512 | rec->flags += cnt; | |
b7ffffbb SRRH |
6513 | |
6514 | if (ftrace_start_up && cnt) { | |
6515 | int failed = __ftrace_replace_code(rec, 1); | |
6516 | if (failed) { | |
6517 | ftrace_bug(failed, rec); | |
6518 | goto out_loop; | |
6519 | } | |
6520 | } | |
6521 | ||
6522 | } while_for_each_ftrace_rec(); | |
6523 | ||
6524 | out_loop: | |
6525 | if (ftrace_start_up) | |
6526 | ftrace_arch_code_modify_post_process(); | |
6527 | ||
6528 | out_unlock: | |
6529 | mutex_unlock(&ftrace_lock); | |
d7fbf8df SRV |
6530 | |
6531 | process_cached_mods(mod->name); | |
b7ffffbb SRRH |
6532 | } |
6533 | ||
b6b71f66 | 6534 | void ftrace_module_init(struct module *mod) |
90d595fe | 6535 | { |
97e9b4fc | 6536 | if (ftrace_disabled || !mod->num_ftrace_callsites) |
fed1939c | 6537 | return; |
90d595fe | 6538 | |
97e9b4fc SRRH |
6539 | ftrace_process_locs(mod, mod->ftrace_callsites, |
6540 | mod->ftrace_callsites + mod->num_ftrace_callsites); | |
8c189ea6 | 6541 | } |
aba4b5c2 SRV |
6542 | |
6543 | static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map, | |
6544 | struct dyn_ftrace *rec) | |
6545 | { | |
6546 | struct ftrace_mod_func *mod_func; | |
6547 | unsigned long symsize; | |
6548 | unsigned long offset; | |
6549 | char str[KSYM_SYMBOL_LEN]; | |
6550 | char *modname; | |
6551 | const char *ret; | |
6552 | ||
6553 | ret = kallsyms_lookup(rec->ip, &symsize, &offset, &modname, str); | |
6554 | if (!ret) | |
6555 | return; | |
6556 | ||
6557 | mod_func = kmalloc(sizeof(*mod_func), GFP_KERNEL); | |
6558 | if (!mod_func) | |
6559 | return; | |
6560 | ||
6561 | mod_func->name = kstrdup(str, GFP_KERNEL); | |
6562 | if (!mod_func->name) { | |
6563 | kfree(mod_func); | |
6564 | return; | |
6565 | } | |
6566 | ||
6567 | mod_func->ip = rec->ip - offset; | |
6568 | mod_func->size = symsize; | |
6569 | ||
6171a031 SRV |
6570 | mod_map->num_funcs++; |
6571 | ||
aba4b5c2 SRV |
6572 | list_add_rcu(&mod_func->list, &mod_map->funcs); |
6573 | } | |
6574 | ||
aba4b5c2 SRV |
6575 | static struct ftrace_mod_map * |
6576 | allocate_ftrace_mod_map(struct module *mod, | |
6577 | unsigned long start, unsigned long end) | |
6578 | { | |
6579 | struct ftrace_mod_map *mod_map; | |
6580 | ||
6581 | mod_map = kmalloc(sizeof(*mod_map), GFP_KERNEL); | |
6582 | if (!mod_map) | |
6583 | return NULL; | |
6584 | ||
6585 | mod_map->mod = mod; | |
6586 | mod_map->start_addr = start; | |
6587 | mod_map->end_addr = end; | |
6171a031 | 6588 | mod_map->num_funcs = 0; |
aba4b5c2 SRV |
6589 | |
6590 | INIT_LIST_HEAD_RCU(&mod_map->funcs); | |
6591 | ||
6592 | list_add_rcu(&mod_map->list, &ftrace_mod_maps); | |
6593 | ||
6594 | return mod_map; | |
6595 | } | |
6596 | ||
6597 | static const char * | |
6598 | ftrace_func_address_lookup(struct ftrace_mod_map *mod_map, | |
6599 | unsigned long addr, unsigned long *size, | |
6600 | unsigned long *off, char *sym) | |
6601 | { | |
6602 | struct ftrace_mod_func *found_func = NULL; | |
6603 | struct ftrace_mod_func *mod_func; | |
6604 | ||
6605 | list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) { | |
6606 | if (addr >= mod_func->ip && | |
6607 | addr < mod_func->ip + mod_func->size) { | |
6608 | found_func = mod_func; | |
6609 | break; | |
6610 | } | |
6611 | } | |
6612 | ||
6613 | if (found_func) { | |
6614 | if (size) | |
6615 | *size = found_func->size; | |
6616 | if (off) | |
6617 | *off = addr - found_func->ip; | |
6618 | if (sym) | |
6619 | strlcpy(sym, found_func->name, KSYM_NAME_LEN); | |
6620 | ||
6621 | return found_func->name; | |
6622 | } | |
6623 | ||
6624 | return NULL; | |
6625 | } | |
6626 | ||
6627 | const char * | |
6628 | ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, | |
6629 | unsigned long *off, char **modname, char *sym) | |
6630 | { | |
6631 | struct ftrace_mod_map *mod_map; | |
6632 | const char *ret = NULL; | |
6633 | ||
74401729 | 6634 | /* mod_map is freed via call_rcu() */ |
aba4b5c2 SRV |
6635 | preempt_disable(); |
6636 | list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) { | |
6637 | ret = ftrace_func_address_lookup(mod_map, addr, size, off, sym); | |
6638 | if (ret) { | |
6639 | if (modname) | |
6640 | *modname = mod_map->mod->name; | |
6641 | break; | |
6642 | } | |
6643 | } | |
6644 | preempt_enable(); | |
6645 | ||
6646 | return ret; | |
6647 | } | |
6648 | ||
6171a031 SRV |
6649 | int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, |
6650 | char *type, char *name, | |
6651 | char *module_name, int *exported) | |
6652 | { | |
6653 | struct ftrace_mod_map *mod_map; | |
6654 | struct ftrace_mod_func *mod_func; | |
fc0ea795 | 6655 | int ret; |
6171a031 SRV |
6656 | |
6657 | preempt_disable(); | |
6658 | list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) { | |
6659 | ||
6660 | if (symnum >= mod_map->num_funcs) { | |
6661 | symnum -= mod_map->num_funcs; | |
6662 | continue; | |
6663 | } | |
6664 | ||
6665 | list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) { | |
6666 | if (symnum > 1) { | |
6667 | symnum--; | |
6668 | continue; | |
6669 | } | |
6670 | ||
6671 | *value = mod_func->ip; | |
6672 | *type = 'T'; | |
6673 | strlcpy(name, mod_func->name, KSYM_NAME_LEN); | |
6674 | strlcpy(module_name, mod_map->mod->name, MODULE_NAME_LEN); | |
6675 | *exported = 1; | |
6676 | preempt_enable(); | |
6677 | return 0; | |
6678 | } | |
6679 | WARN_ON(1); | |
6680 | break; | |
6681 | } | |
fc0ea795 AH |
6682 | ret = ftrace_get_trampoline_kallsym(symnum, value, type, name, |
6683 | module_name, exported); | |
6171a031 | 6684 | preempt_enable(); |
fc0ea795 | 6685 | return ret; |
6171a031 SRV |
6686 | } |
6687 | ||
aba4b5c2 SRV |
6688 | #else |
6689 | static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map, | |
6690 | struct dyn_ftrace *rec) { } | |
6691 | static inline struct ftrace_mod_map * | |
6692 | allocate_ftrace_mod_map(struct module *mod, | |
6693 | unsigned long start, unsigned long end) | |
6694 | { | |
6695 | return NULL; | |
6696 | } | |
fc0ea795 AH |
6697 | int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, |
6698 | char *type, char *name, char *module_name, | |
6699 | int *exported) | |
6700 | { | |
6701 | int ret; | |
6702 | ||
6703 | preempt_disable(); | |
6704 | ret = ftrace_get_trampoline_kallsym(symnum, value, type, name, | |
6705 | module_name, exported); | |
6706 | preempt_enable(); | |
6707 | return ret; | |
6708 | } | |
93eb677d SR |
6709 | #endif /* CONFIG_MODULES */ |
6710 | ||
8715b108 JF |
6711 | struct ftrace_init_func { |
6712 | struct list_head list; | |
6713 | unsigned long ip; | |
6714 | }; | |
6715 | ||
6716 | /* Clear any init ips from hashes */ | |
6717 | static void | |
6718 | clear_func_from_hash(struct ftrace_init_func *func, struct ftrace_hash *hash) | |
42c269c8 | 6719 | { |
8715b108 JF |
6720 | struct ftrace_func_entry *entry; |
6721 | ||
08468754 | 6722 | entry = ftrace_lookup_ip(hash, func->ip); |
8715b108 JF |
6723 | /* |
6724 | * Do not allow this rec to match again. | |
6725 | * Yeah, it may waste some memory, but will be removed | |
6726 | * if/when the hash is modified again. | |
6727 | */ | |
6728 | if (entry) | |
6729 | entry->ip = 0; | |
6730 | } | |
6731 | ||
6732 | static void | |
6733 | clear_func_from_hashes(struct ftrace_init_func *func) | |
6734 | { | |
6735 | struct trace_array *tr; | |
6736 | ||
6737 | mutex_lock(&trace_types_lock); | |
6738 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
6739 | if (!tr->ops || !tr->ops->func_hash) | |
6740 | continue; | |
6741 | mutex_lock(&tr->ops->func_hash->regex_lock); | |
6742 | clear_func_from_hash(func, tr->ops->func_hash->filter_hash); | |
6743 | clear_func_from_hash(func, tr->ops->func_hash->notrace_hash); | |
6744 | mutex_unlock(&tr->ops->func_hash->regex_lock); | |
6745 | } | |
6746 | mutex_unlock(&trace_types_lock); | |
6747 | } | |
6748 | ||
6749 | static void add_to_clear_hash_list(struct list_head *clear_list, | |
6750 | struct dyn_ftrace *rec) | |
6751 | { | |
6752 | struct ftrace_init_func *func; | |
6753 | ||
6754 | func = kmalloc(sizeof(*func), GFP_KERNEL); | |
6755 | if (!func) { | |
24589e3a | 6756 | MEM_FAIL(1, "alloc failure, ftrace filter could be stale\n"); |
8715b108 JF |
6757 | return; |
6758 | } | |
6759 | ||
6760 | func->ip = rec->ip; | |
6761 | list_add(&func->list, clear_list); | |
6762 | } | |
6763 | ||
aba4b5c2 | 6764 | void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr) |
42c269c8 | 6765 | { |
6cafbe15 SRV |
6766 | unsigned long start = (unsigned long)(start_ptr); |
6767 | unsigned long end = (unsigned long)(end_ptr); | |
42c269c8 SRV |
6768 | struct ftrace_page **last_pg = &ftrace_pages_start; |
6769 | struct ftrace_page *pg; | |
6770 | struct dyn_ftrace *rec; | |
6771 | struct dyn_ftrace key; | |
aba4b5c2 | 6772 | struct ftrace_mod_map *mod_map = NULL; |
8715b108 JF |
6773 | struct ftrace_init_func *func, *func_next; |
6774 | struct list_head clear_hash; | |
42c269c8 SRV |
6775 | int order; |
6776 | ||
8715b108 JF |
6777 | INIT_LIST_HEAD(&clear_hash); |
6778 | ||
42c269c8 SRV |
6779 | key.ip = start; |
6780 | key.flags = end; /* overload flags, as it is unsigned long */ | |
6781 | ||
6782 | mutex_lock(&ftrace_lock); | |
6783 | ||
aba4b5c2 SRV |
6784 | /* |
6785 | * If we are freeing module init memory, then check if | |
6786 | * any tracer is active. If so, we need to save a mapping of | |
6787 | * the module functions being freed with the address. | |
6788 | */ | |
6789 | if (mod && ftrace_ops_list != &ftrace_list_end) | |
6790 | mod_map = allocate_ftrace_mod_map(mod, start, end); | |
6791 | ||
42c269c8 SRV |
6792 | for (pg = ftrace_pages_start; pg; last_pg = &pg->next, pg = *last_pg) { |
6793 | if (end < pg->records[0].ip || | |
6794 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) | |
6795 | continue; | |
6796 | again: | |
6797 | rec = bsearch(&key, pg->records, pg->index, | |
6798 | sizeof(struct dyn_ftrace), | |
6799 | ftrace_cmp_recs); | |
6800 | if (!rec) | |
6801 | continue; | |
aba4b5c2 | 6802 | |
8715b108 JF |
6803 | /* rec will be cleared from hashes after ftrace_lock unlock */ |
6804 | add_to_clear_hash_list(&clear_hash, rec); | |
6805 | ||
aba4b5c2 SRV |
6806 | if (mod_map) |
6807 | save_ftrace_mod_rec(mod_map, rec); | |
6808 | ||
42c269c8 | 6809 | pg->index--; |
4ec78467 | 6810 | ftrace_update_tot_cnt--; |
42c269c8 SRV |
6811 | if (!pg->index) { |
6812 | *last_pg = pg->next; | |
6813 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); | |
6814 | free_pages((unsigned long)pg->records, order); | |
da537f0a SRV |
6815 | ftrace_number_of_pages -= 1 << order; |
6816 | ftrace_number_of_groups--; | |
42c269c8 SRV |
6817 | kfree(pg); |
6818 | pg = container_of(last_pg, struct ftrace_page, next); | |
6819 | if (!(*last_pg)) | |
6820 | ftrace_pages = pg; | |
6821 | continue; | |
6822 | } | |
6823 | memmove(rec, rec + 1, | |
6824 | (pg->index - (rec - pg->records)) * sizeof(*rec)); | |
6825 | /* More than one function may be in this block */ | |
6826 | goto again; | |
6827 | } | |
6828 | mutex_unlock(&ftrace_lock); | |
8715b108 JF |
6829 | |
6830 | list_for_each_entry_safe(func, func_next, &clear_hash, list) { | |
6831 | clear_func_from_hashes(func); | |
6832 | kfree(func); | |
6833 | } | |
42c269c8 SRV |
6834 | } |
6835 | ||
6cafbe15 SRV |
6836 | void __init ftrace_free_init_mem(void) |
6837 | { | |
6838 | void *start = (void *)(&__init_begin); | |
6839 | void *end = (void *)(&__init_end); | |
6840 | ||
aba4b5c2 | 6841 | ftrace_free_mem(NULL, start, end); |
42c269c8 SRV |
6842 | } |
6843 | ||
68bf21aa SR |
6844 | void __init ftrace_init(void) |
6845 | { | |
1dc43cf0 JS |
6846 | extern unsigned long __start_mcount_loc[]; |
6847 | extern unsigned long __stop_mcount_loc[]; | |
3a36cb11 | 6848 | unsigned long count, flags; |
68bf21aa SR |
6849 | int ret; |
6850 | ||
68bf21aa | 6851 | local_irq_save(flags); |
3a36cb11 | 6852 | ret = ftrace_dyn_arch_init(); |
68bf21aa | 6853 | local_irq_restore(flags); |
af64a7cb | 6854 | if (ret) |
68bf21aa SR |
6855 | goto failed; |
6856 | ||
6857 | count = __stop_mcount_loc - __start_mcount_loc; | |
c867ccd8 JS |
6858 | if (!count) { |
6859 | pr_info("ftrace: No functions to be traced?\n"); | |
68bf21aa | 6860 | goto failed; |
c867ccd8 JS |
6861 | } |
6862 | ||
6863 | pr_info("ftrace: allocating %ld entries in %ld pages\n", | |
6864 | count, count / ENTRIES_PER_PAGE + 1); | |
68bf21aa SR |
6865 | |
6866 | last_ftrace_enabled = ftrace_enabled = 1; | |
6867 | ||
5cb084bb | 6868 | ret = ftrace_process_locs(NULL, |
31e88909 | 6869 | __start_mcount_loc, |
68bf21aa SR |
6870 | __stop_mcount_loc); |
6871 | ||
da537f0a SRV |
6872 | pr_info("ftrace: allocated %ld pages with %ld groups\n", |
6873 | ftrace_number_of_pages, ftrace_number_of_groups); | |
6874 | ||
2af15d6a SR |
6875 | set_ftrace_early_filters(); |
6876 | ||
68bf21aa SR |
6877 | return; |
6878 | failed: | |
6879 | ftrace_disabled = 1; | |
6880 | } | |
68bf21aa | 6881 | |
f3bea491 SRRH |
6882 | /* Do nothing if arch does not support this */ |
6883 | void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops) | |
6884 | { | |
6885 | } | |
6886 | ||
6887 | static void ftrace_update_trampoline(struct ftrace_ops *ops) | |
6888 | { | |
fc0ea795 AH |
6889 | unsigned long trampoline = ops->trampoline; |
6890 | ||
f3bea491 | 6891 | arch_ftrace_update_trampoline(ops); |
fc0ea795 | 6892 | if (ops->trampoline && ops->trampoline != trampoline && |
dd9ddf46 AH |
6893 | (ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP)) { |
6894 | /* Add to kallsyms before the perf events */ | |
fc0ea795 | 6895 | ftrace_add_trampoline_to_kallsyms(ops); |
dd9ddf46 AH |
6896 | perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL, |
6897 | ops->trampoline, ops->trampoline_size, false, | |
6898 | FTRACE_TRAMPOLINE_SYM); | |
548e1f6c AH |
6899 | /* |
6900 | * Record the perf text poke event after the ksymbol register | |
6901 | * event. | |
6902 | */ | |
6903 | perf_event_text_poke((void *)ops->trampoline, NULL, 0, | |
6904 | (void *)ops->trampoline, | |
6905 | ops->trampoline_size); | |
dd9ddf46 | 6906 | } |
f3bea491 SRRH |
6907 | } |
6908 | ||
04ec7bb6 SRV |
6909 | void ftrace_init_trace_array(struct trace_array *tr) |
6910 | { | |
6911 | INIT_LIST_HEAD(&tr->func_probes); | |
673feb9d SRV |
6912 | INIT_LIST_HEAD(&tr->mod_trace); |
6913 | INIT_LIST_HEAD(&tr->mod_notrace); | |
04ec7bb6 | 6914 | } |
3d083395 | 6915 | #else |
0b6e4d56 | 6916 | |
3306fc4a | 6917 | struct ftrace_ops global_ops = { |
bd69c30b | 6918 | .func = ftrace_stub, |
a25d036d | 6919 | .flags = FTRACE_OPS_FL_INITIALIZED | |
e3eea140 | 6920 | FTRACE_OPS_FL_PID, |
bd69c30b SR |
6921 | }; |
6922 | ||
0b6e4d56 FW |
6923 | static int __init ftrace_nodyn_init(void) |
6924 | { | |
6925 | ftrace_enabled = 1; | |
6926 | return 0; | |
6927 | } | |
6f415672 | 6928 | core_initcall(ftrace_nodyn_init); |
0b6e4d56 | 6929 | |
8434dc93 | 6930 | static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; } |
df4fc315 | 6931 | static inline void ftrace_startup_enable(int command) { } |
e1effa01 | 6932 | static inline void ftrace_startup_all(int command) { } |
8a56d776 | 6933 | |
c7aafc54 IM |
6934 | # define ftrace_startup_sysctl() do { } while (0) |
6935 | # define ftrace_shutdown_sysctl() do { } while (0) | |
b848914c | 6936 | |
f3bea491 SRRH |
6937 | static void ftrace_update_trampoline(struct ftrace_ops *ops) |
6938 | { | |
6939 | } | |
6940 | ||
3d083395 SR |
6941 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
6942 | ||
4104d326 SRRH |
6943 | __init void ftrace_init_global_array_ops(struct trace_array *tr) |
6944 | { | |
6945 | tr->ops = &global_ops; | |
6946 | tr->ops->private = tr; | |
04ec7bb6 | 6947 | ftrace_init_trace_array(tr); |
4104d326 SRRH |
6948 | } |
6949 | ||
6950 | void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func) | |
6951 | { | |
6952 | /* If we filter on pids, update to use the pid function */ | |
6953 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) { | |
6954 | if (WARN_ON(tr->ops->func != ftrace_stub)) | |
6955 | printk("ftrace ops had %pS for function\n", | |
6956 | tr->ops->func); | |
4104d326 SRRH |
6957 | } |
6958 | tr->ops->func = func; | |
6959 | tr->ops->private = tr; | |
6960 | } | |
6961 | ||
6962 | void ftrace_reset_array_ops(struct trace_array *tr) | |
6963 | { | |
6964 | tr->ops->func = ftrace_stub; | |
6965 | } | |
6966 | ||
fabe38ab | 6967 | static nokprobe_inline void |
2f5f6ad9 | 6968 | __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, |
d19ad077 | 6969 | struct ftrace_ops *ignored, struct ftrace_regs *fregs) |
b848914c | 6970 | { |
d19ad077 | 6971 | struct pt_regs *regs = ftrace_get_regs(fregs); |
cdbe61bf | 6972 | struct ftrace_ops *op; |
edc15caf | 6973 | int bit; |
b848914c | 6974 | |
773c1670 | 6975 | bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START, TRACE_LIST_MAX); |
edc15caf SR |
6976 | if (bit < 0) |
6977 | return; | |
b1cff0ad | 6978 | |
cdbe61bf SR |
6979 | /* |
6980 | * Some of the ops may be dynamically allocated, | |
74401729 | 6981 | * they must be freed after a synchronize_rcu(). |
cdbe61bf SR |
6982 | */ |
6983 | preempt_disable_notrace(); | |
ba27f2bc | 6984 | |
0a016409 | 6985 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
2fa717a0 SRV |
6986 | /* Stub functions don't need to be called nor tested */ |
6987 | if (op->flags & FTRACE_OPS_FL_STUB) | |
6988 | continue; | |
ba27f2bc SRRH |
6989 | /* |
6990 | * Check the following for each ops before calling their func: | |
6991 | * if RCU flag is set, then rcu_is_watching() must be true | |
6992 | * if PER_CPU is set, then ftrace_function_local_disable() | |
6993 | * must be false | |
6994 | * Otherwise test if the ip matches the ops filter | |
6995 | * | |
6996 | * If any of the above fails then the op->func() is not executed. | |
6997 | */ | |
6998 | if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) && | |
ba27f2bc | 6999 | ftrace_ops_test(op, ip, regs)) { |
1d48d596 SRRH |
7000 | if (FTRACE_WARN_ON(!op->func)) { |
7001 | pr_warn("op=%p %pS\n", op, op); | |
4104d326 SRRH |
7002 | goto out; |
7003 | } | |
d19ad077 | 7004 | op->func(ip, parent_ip, op, fregs); |
4104d326 | 7005 | } |
0a016409 | 7006 | } while_for_each_ftrace_op(op); |
4104d326 | 7007 | out: |
cdbe61bf | 7008 | preempt_enable_notrace(); |
edc15caf | 7009 | trace_clear_recursion(bit); |
b848914c SR |
7010 | } |
7011 | ||
2f5f6ad9 SR |
7012 | /* |
7013 | * Some archs only support passing ip and parent_ip. Even though | |
7014 | * the list function ignores the op parameter, we do not want any | |
7015 | * C side effects, where a function is called without the caller | |
7016 | * sending a third parameter. | |
a1e2e31d SR |
7017 | * Archs are to support both the regs and ftrace_ops at the same time. |
7018 | * If they support ftrace_ops, it is assumed they support regs. | |
7019 | * If call backs want to use regs, they must either check for regs | |
06aeaaea MH |
7020 | * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS. |
7021 | * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved. | |
a1e2e31d | 7022 | * An architecture can pass partial regs with ftrace_ops and still |
b8ec330a | 7023 | * set the ARCH_SUPPORTS_FTRACE_OPS. |
2f5f6ad9 SR |
7024 | */ |
7025 | #if ARCH_SUPPORTS_FTRACE_OPS | |
7026 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
d19ad077 | 7027 | struct ftrace_ops *op, struct ftrace_regs *fregs) |
2f5f6ad9 | 7028 | { |
d19ad077 | 7029 | __ftrace_ops_list_func(ip, parent_ip, NULL, fregs); |
2f5f6ad9 | 7030 | } |
fabe38ab | 7031 | NOKPROBE_SYMBOL(ftrace_ops_list_func); |
2f5f6ad9 SR |
7032 | #else |
7033 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip) | |
7034 | { | |
a1e2e31d | 7035 | __ftrace_ops_list_func(ip, parent_ip, NULL, NULL); |
2f5f6ad9 | 7036 | } |
fabe38ab | 7037 | NOKPROBE_SYMBOL(ftrace_ops_no_ops); |
2f5f6ad9 SR |
7038 | #endif |
7039 | ||
f1ff6348 SRRH |
7040 | /* |
7041 | * If there's only one function registered but it does not support | |
c68c0fa2 SRRH |
7042 | * recursion, needs RCU protection and/or requires per cpu handling, then |
7043 | * this function will be called by the mcount trampoline. | |
f1ff6348 | 7044 | */ |
c68c0fa2 | 7045 | static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip, |
d19ad077 | 7046 | struct ftrace_ops *op, struct ftrace_regs *fregs) |
f1ff6348 SRRH |
7047 | { |
7048 | int bit; | |
7049 | ||
773c1670 | 7050 | bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START, TRACE_LIST_MAX); |
f1ff6348 SRRH |
7051 | if (bit < 0) |
7052 | return; | |
7053 | ||
c68c0fa2 | 7054 | preempt_disable_notrace(); |
f1ff6348 | 7055 | |
b40341fa | 7056 | if (!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) |
d19ad077 | 7057 | op->func(ip, parent_ip, op, fregs); |
c68c0fa2 SRRH |
7058 | |
7059 | preempt_enable_notrace(); | |
f1ff6348 SRRH |
7060 | trace_clear_recursion(bit); |
7061 | } | |
fabe38ab | 7062 | NOKPROBE_SYMBOL(ftrace_ops_assist_func); |
f1ff6348 | 7063 | |
87354059 SRRH |
7064 | /** |
7065 | * ftrace_ops_get_func - get the function a trampoline should call | |
7066 | * @ops: the ops to get the function for | |
7067 | * | |
7068 | * Normally the mcount trampoline will call the ops->func, but there | |
7069 | * are times that it should not. For example, if the ops does not | |
7070 | * have its own recursion protection, then it should call the | |
3a150df9 | 7071 | * ftrace_ops_assist_func() instead. |
87354059 SRRH |
7072 | * |
7073 | * Returns the function that the trampoline should call for @ops. | |
7074 | */ | |
7075 | ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops) | |
7076 | { | |
87354059 | 7077 | /* |
a25d036d SRV |
7078 | * If the function does not handle recursion or needs to be RCU safe, |
7079 | * then we need to call the assist handler. | |
87354059 | 7080 | */ |
a25d036d SRV |
7081 | if (ops->flags & (FTRACE_OPS_FL_RECURSION | |
7082 | FTRACE_OPS_FL_RCU)) | |
c68c0fa2 | 7083 | return ftrace_ops_assist_func; |
87354059 SRRH |
7084 | |
7085 | return ops->func; | |
7086 | } | |
7087 | ||
345ddcc8 SRRH |
7088 | static void |
7089 | ftrace_filter_pid_sched_switch_probe(void *data, bool preempt, | |
7090 | struct task_struct *prev, struct task_struct *next) | |
978f3a45 | 7091 | { |
345ddcc8 SRRH |
7092 | struct trace_array *tr = data; |
7093 | struct trace_pid_list *pid_list; | |
b3b1e6ed | 7094 | struct trace_pid_list *no_pid_list; |
978f3a45 | 7095 | |
345ddcc8 | 7096 | pid_list = rcu_dereference_sched(tr->function_pids); |
b3b1e6ed | 7097 | no_pid_list = rcu_dereference_sched(tr->function_no_pids); |
e32d8956 | 7098 | |
b3b1e6ed | 7099 | if (trace_ignore_this_task(pid_list, no_pid_list, next)) |
717e3f5e SRV |
7100 | this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, |
7101 | FTRACE_PID_IGNORE); | |
7102 | else | |
7103 | this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, | |
7104 | next->pid); | |
978f3a45 SR |
7105 | } |
7106 | ||
1e10486f NK |
7107 | static void |
7108 | ftrace_pid_follow_sched_process_fork(void *data, | |
7109 | struct task_struct *self, | |
7110 | struct task_struct *task) | |
7111 | { | |
7112 | struct trace_pid_list *pid_list; | |
7113 | struct trace_array *tr = data; | |
7114 | ||
7115 | pid_list = rcu_dereference_sched(tr->function_pids); | |
7116 | trace_filter_add_remove_task(pid_list, self, task); | |
b3b1e6ed SRV |
7117 | |
7118 | pid_list = rcu_dereference_sched(tr->function_no_pids); | |
7119 | trace_filter_add_remove_task(pid_list, self, task); | |
1e10486f NK |
7120 | } |
7121 | ||
7122 | static void | |
7123 | ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task) | |
7124 | { | |
7125 | struct trace_pid_list *pid_list; | |
7126 | struct trace_array *tr = data; | |
7127 | ||
7128 | pid_list = rcu_dereference_sched(tr->function_pids); | |
7129 | trace_filter_add_remove_task(pid_list, NULL, task); | |
b3b1e6ed SRV |
7130 | |
7131 | pid_list = rcu_dereference_sched(tr->function_no_pids); | |
7132 | trace_filter_add_remove_task(pid_list, NULL, task); | |
1e10486f NK |
7133 | } |
7134 | ||
7135 | void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) | |
7136 | { | |
7137 | if (enable) { | |
7138 | register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, | |
7139 | tr); | |
afcab636 | 7140 | register_trace_sched_process_free(ftrace_pid_follow_sched_process_exit, |
1e10486f NK |
7141 | tr); |
7142 | } else { | |
7143 | unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, | |
7144 | tr); | |
afcab636 | 7145 | unregister_trace_sched_process_free(ftrace_pid_follow_sched_process_exit, |
1e10486f NK |
7146 | tr); |
7147 | } | |
7148 | } | |
7149 | ||
b3b1e6ed | 7150 | static void clear_ftrace_pids(struct trace_array *tr, int type) |
e32d8956 | 7151 | { |
345ddcc8 | 7152 | struct trace_pid_list *pid_list; |
b3b1e6ed | 7153 | struct trace_pid_list *no_pid_list; |
345ddcc8 | 7154 | int cpu; |
e32d8956 | 7155 | |
345ddcc8 SRRH |
7156 | pid_list = rcu_dereference_protected(tr->function_pids, |
7157 | lockdep_is_held(&ftrace_lock)); | |
b3b1e6ed SRV |
7158 | no_pid_list = rcu_dereference_protected(tr->function_no_pids, |
7159 | lockdep_is_held(&ftrace_lock)); | |
7160 | ||
7161 | /* Make sure there's something to do */ | |
27683626 | 7162 | if (!pid_type_enabled(type, pid_list, no_pid_list)) |
345ddcc8 | 7163 | return; |
229c4ef8 | 7164 | |
b3b1e6ed | 7165 | /* See if the pids still need to be checked after this */ |
27683626 | 7166 | if (!still_need_pid_events(type, pid_list, no_pid_list)) { |
b3b1e6ed SRV |
7167 | unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr); |
7168 | for_each_possible_cpu(cpu) | |
7169 | per_cpu_ptr(tr->array_buffer.data, cpu)->ftrace_ignore_pid = FTRACE_PID_TRACE; | |
7170 | } | |
e32d8956 | 7171 | |
b3b1e6ed SRV |
7172 | if (type & TRACE_PIDS) |
7173 | rcu_assign_pointer(tr->function_pids, NULL); | |
978f3a45 | 7174 | |
b3b1e6ed SRV |
7175 | if (type & TRACE_NO_PIDS) |
7176 | rcu_assign_pointer(tr->function_no_pids, NULL); | |
978f3a45 | 7177 | |
345ddcc8 | 7178 | /* Wait till all users are no longer using pid filtering */ |
74401729 | 7179 | synchronize_rcu(); |
e32d8956 | 7180 | |
b3b1e6ed SRV |
7181 | if ((type & TRACE_PIDS) && pid_list) |
7182 | trace_free_pid_list(pid_list); | |
7183 | ||
7184 | if ((type & TRACE_NO_PIDS) && no_pid_list) | |
7185 | trace_free_pid_list(no_pid_list); | |
e32d8956 SR |
7186 | } |
7187 | ||
d879d0b8 NK |
7188 | void ftrace_clear_pids(struct trace_array *tr) |
7189 | { | |
7190 | mutex_lock(&ftrace_lock); | |
7191 | ||
b3b1e6ed | 7192 | clear_ftrace_pids(tr, TRACE_PIDS | TRACE_NO_PIDS); |
d879d0b8 NK |
7193 | |
7194 | mutex_unlock(&ftrace_lock); | |
7195 | } | |
7196 | ||
b3b1e6ed | 7197 | static void ftrace_pid_reset(struct trace_array *tr, int type) |
df4fc315 | 7198 | { |
756d17ee | 7199 | mutex_lock(&ftrace_lock); |
b3b1e6ed | 7200 | clear_ftrace_pids(tr, type); |
978f3a45 | 7201 | |
756d17ee | 7202 | ftrace_update_pid_func(); |
e1effa01 | 7203 | ftrace_startup_all(0); |
756d17ee | 7204 | |
7205 | mutex_unlock(&ftrace_lock); | |
756d17ee | 7206 | } |
7207 | ||
345ddcc8 SRRH |
7208 | /* Greater than any max PID */ |
7209 | #define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1) | |
df4fc315 | 7210 | |
756d17ee | 7211 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
345ddcc8 | 7212 | __acquires(RCU) |
756d17ee | 7213 | { |
345ddcc8 SRRH |
7214 | struct trace_pid_list *pid_list; |
7215 | struct trace_array *tr = m->private; | |
7216 | ||
756d17ee | 7217 | mutex_lock(&ftrace_lock); |
345ddcc8 SRRH |
7218 | rcu_read_lock_sched(); |
7219 | ||
7220 | pid_list = rcu_dereference_sched(tr->function_pids); | |
756d17ee | 7221 | |
345ddcc8 SRRH |
7222 | if (!pid_list) |
7223 | return !(*pos) ? FTRACE_NO_PIDS : NULL; | |
756d17ee | 7224 | |
345ddcc8 | 7225 | return trace_pid_start(pid_list, pos); |
756d17ee | 7226 | } |
7227 | ||
7228 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
7229 | { | |
345ddcc8 SRRH |
7230 | struct trace_array *tr = m->private; |
7231 | struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids); | |
7232 | ||
e4075e8b VA |
7233 | if (v == FTRACE_NO_PIDS) { |
7234 | (*pos)++; | |
756d17ee | 7235 | return NULL; |
e4075e8b | 7236 | } |
345ddcc8 | 7237 | return trace_pid_next(pid_list, v, pos); |
756d17ee | 7238 | } |
7239 | ||
7240 | static void fpid_stop(struct seq_file *m, void *p) | |
345ddcc8 | 7241 | __releases(RCU) |
756d17ee | 7242 | { |
345ddcc8 | 7243 | rcu_read_unlock_sched(); |
756d17ee | 7244 | mutex_unlock(&ftrace_lock); |
7245 | } | |
7246 | ||
7247 | static int fpid_show(struct seq_file *m, void *v) | |
7248 | { | |
345ddcc8 | 7249 | if (v == FTRACE_NO_PIDS) { |
fa6f0cc7 | 7250 | seq_puts(m, "no pid\n"); |
756d17ee | 7251 | return 0; |
7252 | } | |
7253 | ||
345ddcc8 | 7254 | return trace_pid_show(m, v); |
756d17ee | 7255 | } |
7256 | ||
7257 | static const struct seq_operations ftrace_pid_sops = { | |
7258 | .start = fpid_start, | |
7259 | .next = fpid_next, | |
7260 | .stop = fpid_stop, | |
7261 | .show = fpid_show, | |
7262 | }; | |
7263 | ||
b3b1e6ed SRV |
7264 | static void *fnpid_start(struct seq_file *m, loff_t *pos) |
7265 | __acquires(RCU) | |
7266 | { | |
7267 | struct trace_pid_list *pid_list; | |
7268 | struct trace_array *tr = m->private; | |
7269 | ||
7270 | mutex_lock(&ftrace_lock); | |
7271 | rcu_read_lock_sched(); | |
7272 | ||
7273 | pid_list = rcu_dereference_sched(tr->function_no_pids); | |
7274 | ||
7275 | if (!pid_list) | |
7276 | return !(*pos) ? FTRACE_NO_PIDS : NULL; | |
7277 | ||
7278 | return trace_pid_start(pid_list, pos); | |
7279 | } | |
7280 | ||
7281 | static void *fnpid_next(struct seq_file *m, void *v, loff_t *pos) | |
756d17ee | 7282 | { |
b3b1e6ed SRV |
7283 | struct trace_array *tr = m->private; |
7284 | struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_no_pids); | |
7285 | ||
7286 | if (v == FTRACE_NO_PIDS) { | |
7287 | (*pos)++; | |
7288 | return NULL; | |
7289 | } | |
7290 | return trace_pid_next(pid_list, v, pos); | |
7291 | } | |
7292 | ||
7293 | static const struct seq_operations ftrace_no_pid_sops = { | |
7294 | .start = fnpid_start, | |
7295 | .next = fnpid_next, | |
7296 | .stop = fpid_stop, | |
7297 | .show = fpid_show, | |
7298 | }; | |
7299 | ||
7300 | static int pid_open(struct inode *inode, struct file *file, int type) | |
7301 | { | |
7302 | const struct seq_operations *seq_ops; | |
345ddcc8 SRRH |
7303 | struct trace_array *tr = inode->i_private; |
7304 | struct seq_file *m; | |
756d17ee | 7305 | int ret = 0; |
7306 | ||
8530dec6 SRV |
7307 | ret = tracing_check_open_get_tr(tr); |
7308 | if (ret) | |
7309 | return ret; | |
345ddcc8 | 7310 | |
756d17ee | 7311 | if ((file->f_mode & FMODE_WRITE) && |
7312 | (file->f_flags & O_TRUNC)) | |
b3b1e6ed SRV |
7313 | ftrace_pid_reset(tr, type); |
7314 | ||
7315 | switch (type) { | |
7316 | case TRACE_PIDS: | |
7317 | seq_ops = &ftrace_pid_sops; | |
7318 | break; | |
7319 | case TRACE_NO_PIDS: | |
7320 | seq_ops = &ftrace_no_pid_sops; | |
7321 | break; | |
026bb845 KC |
7322 | default: |
7323 | trace_array_put(tr); | |
7324 | WARN_ON_ONCE(1); | |
7325 | return -EINVAL; | |
b3b1e6ed | 7326 | } |
756d17ee | 7327 | |
b3b1e6ed | 7328 | ret = seq_open(file, seq_ops); |
345ddcc8 SRRH |
7329 | if (ret < 0) { |
7330 | trace_array_put(tr); | |
7331 | } else { | |
7332 | m = file->private_data; | |
7333 | /* copy tr over to seq ops */ | |
7334 | m->private = tr; | |
7335 | } | |
756d17ee | 7336 | |
7337 | return ret; | |
7338 | } | |
7339 | ||
b3b1e6ed SRV |
7340 | static int |
7341 | ftrace_pid_open(struct inode *inode, struct file *file) | |
7342 | { | |
7343 | return pid_open(inode, file, TRACE_PIDS); | |
7344 | } | |
7345 | ||
7346 | static int | |
7347 | ftrace_no_pid_open(struct inode *inode, struct file *file) | |
7348 | { | |
7349 | return pid_open(inode, file, TRACE_NO_PIDS); | |
7350 | } | |
7351 | ||
345ddcc8 SRRH |
7352 | static void ignore_task_cpu(void *data) |
7353 | { | |
7354 | struct trace_array *tr = data; | |
7355 | struct trace_pid_list *pid_list; | |
b3b1e6ed | 7356 | struct trace_pid_list *no_pid_list; |
345ddcc8 SRRH |
7357 | |
7358 | /* | |
7359 | * This function is called by on_each_cpu() while the | |
7360 | * event_mutex is held. | |
7361 | */ | |
7362 | pid_list = rcu_dereference_protected(tr->function_pids, | |
7363 | mutex_is_locked(&ftrace_lock)); | |
b3b1e6ed SRV |
7364 | no_pid_list = rcu_dereference_protected(tr->function_no_pids, |
7365 | mutex_is_locked(&ftrace_lock)); | |
345ddcc8 | 7366 | |
b3b1e6ed | 7367 | if (trace_ignore_this_task(pid_list, no_pid_list, current)) |
717e3f5e SRV |
7368 | this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, |
7369 | FTRACE_PID_IGNORE); | |
7370 | else | |
7371 | this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, | |
7372 | current->pid); | |
345ddcc8 SRRH |
7373 | } |
7374 | ||
df4fc315 | 7375 | static ssize_t |
b3b1e6ed SRV |
7376 | pid_write(struct file *filp, const char __user *ubuf, |
7377 | size_t cnt, loff_t *ppos, int type) | |
df4fc315 | 7378 | { |
345ddcc8 SRRH |
7379 | struct seq_file *m = filp->private_data; |
7380 | struct trace_array *tr = m->private; | |
b3b1e6ed SRV |
7381 | struct trace_pid_list *filtered_pids; |
7382 | struct trace_pid_list *other_pids; | |
345ddcc8 SRRH |
7383 | struct trace_pid_list *pid_list; |
7384 | ssize_t ret; | |
df4fc315 | 7385 | |
345ddcc8 SRRH |
7386 | if (!cnt) |
7387 | return 0; | |
7388 | ||
7389 | mutex_lock(&ftrace_lock); | |
7390 | ||
b3b1e6ed SRV |
7391 | switch (type) { |
7392 | case TRACE_PIDS: | |
7393 | filtered_pids = rcu_dereference_protected(tr->function_pids, | |
345ddcc8 | 7394 | lockdep_is_held(&ftrace_lock)); |
b3b1e6ed SRV |
7395 | other_pids = rcu_dereference_protected(tr->function_no_pids, |
7396 | lockdep_is_held(&ftrace_lock)); | |
7397 | break; | |
7398 | case TRACE_NO_PIDS: | |
7399 | filtered_pids = rcu_dereference_protected(tr->function_no_pids, | |
7400 | lockdep_is_held(&ftrace_lock)); | |
7401 | other_pids = rcu_dereference_protected(tr->function_pids, | |
345ddcc8 | 7402 | lockdep_is_held(&ftrace_lock)); |
b3b1e6ed | 7403 | break; |
026bb845 KC |
7404 | default: |
7405 | ret = -EINVAL; | |
7406 | WARN_ON_ONCE(1); | |
7407 | goto out; | |
b3b1e6ed | 7408 | } |
345ddcc8 SRRH |
7409 | |
7410 | ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt); | |
7411 | if (ret < 0) | |
7412 | goto out; | |
df4fc315 | 7413 | |
b3b1e6ed SRV |
7414 | switch (type) { |
7415 | case TRACE_PIDS: | |
7416 | rcu_assign_pointer(tr->function_pids, pid_list); | |
7417 | break; | |
7418 | case TRACE_NO_PIDS: | |
7419 | rcu_assign_pointer(tr->function_no_pids, pid_list); | |
7420 | break; | |
7421 | } | |
7422 | ||
df4fc315 | 7423 | |
345ddcc8 | 7424 | if (filtered_pids) { |
74401729 | 7425 | synchronize_rcu(); |
345ddcc8 | 7426 | trace_free_pid_list(filtered_pids); |
b3b1e6ed | 7427 | } else if (pid_list && !other_pids) { |
345ddcc8 SRRH |
7428 | /* Register a probe to set whether to ignore the tracing of a task */ |
7429 | register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr); | |
7430 | } | |
df4fc315 | 7431 | |
756d17ee | 7432 | /* |
345ddcc8 SRRH |
7433 | * Ignoring of pids is done at task switch. But we have to |
7434 | * check for those tasks that are currently running. | |
7435 | * Always do this in case a pid was appended or removed. | |
756d17ee | 7436 | */ |
345ddcc8 | 7437 | on_each_cpu(ignore_task_cpu, tr, 1); |
756d17ee | 7438 | |
345ddcc8 SRRH |
7439 | ftrace_update_pid_func(); |
7440 | ftrace_startup_all(0); | |
7441 | out: | |
7442 | mutex_unlock(&ftrace_lock); | |
df4fc315 | 7443 | |
345ddcc8 SRRH |
7444 | if (ret > 0) |
7445 | *ppos += ret; | |
df4fc315 | 7446 | |
345ddcc8 | 7447 | return ret; |
756d17ee | 7448 | } |
df4fc315 | 7449 | |
b3b1e6ed SRV |
7450 | static ssize_t |
7451 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
7452 | size_t cnt, loff_t *ppos) | |
7453 | { | |
7454 | return pid_write(filp, ubuf, cnt, ppos, TRACE_PIDS); | |
7455 | } | |
7456 | ||
7457 | static ssize_t | |
7458 | ftrace_no_pid_write(struct file *filp, const char __user *ubuf, | |
7459 | size_t cnt, loff_t *ppos) | |
7460 | { | |
7461 | return pid_write(filp, ubuf, cnt, ppos, TRACE_NO_PIDS); | |
7462 | } | |
7463 | ||
756d17ee | 7464 | static int |
7465 | ftrace_pid_release(struct inode *inode, struct file *file) | |
7466 | { | |
345ddcc8 | 7467 | struct trace_array *tr = inode->i_private; |
df4fc315 | 7468 | |
345ddcc8 SRRH |
7469 | trace_array_put(tr); |
7470 | ||
7471 | return seq_release(inode, file); | |
df4fc315 SR |
7472 | } |
7473 | ||
5e2336a0 | 7474 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 7475 | .open = ftrace_pid_open, |
7476 | .write = ftrace_pid_write, | |
7477 | .read = seq_read, | |
098c879e | 7478 | .llseek = tracing_lseek, |
756d17ee | 7479 | .release = ftrace_pid_release, |
df4fc315 SR |
7480 | }; |
7481 | ||
b3b1e6ed SRV |
7482 | static const struct file_operations ftrace_no_pid_fops = { |
7483 | .open = ftrace_no_pid_open, | |
7484 | .write = ftrace_no_pid_write, | |
7485 | .read = seq_read, | |
7486 | .llseek = tracing_lseek, | |
7487 | .release = ftrace_pid_release, | |
7488 | }; | |
7489 | ||
345ddcc8 | 7490 | void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer) |
df4fc315 | 7491 | { |
5452af66 | 7492 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
345ddcc8 | 7493 | tr, &ftrace_pid_fops); |
b3b1e6ed SRV |
7494 | trace_create_file("set_ftrace_notrace_pid", 0644, d_tracer, |
7495 | tr, &ftrace_no_pid_fops); | |
df4fc315 | 7496 | } |
df4fc315 | 7497 | |
501c2375 SRRH |
7498 | void __init ftrace_init_tracefs_toplevel(struct trace_array *tr, |
7499 | struct dentry *d_tracer) | |
7500 | { | |
7501 | /* Only the top level directory has the dyn_tracefs and profile */ | |
7502 | WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL)); | |
7503 | ||
7504 | ftrace_init_dyn_tracefs(d_tracer); | |
7505 | ftrace_profile_tracefs(d_tracer); | |
7506 | } | |
7507 | ||
a2bb6a3d | 7508 | /** |
81adbdc0 | 7509 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
7510 | * |
7511 | * This function should be used by panic code. It stops ftrace | |
7512 | * but in a not so nice way. If you need to simply kill ftrace | |
7513 | * from a non-atomic section, use ftrace_kill. | |
7514 | */ | |
81adbdc0 | 7515 | void ftrace_kill(void) |
a2bb6a3d SR |
7516 | { |
7517 | ftrace_disabled = 1; | |
7518 | ftrace_enabled = 0; | |
5ccba64a | 7519 | ftrace_trace_function = ftrace_stub; |
a2bb6a3d SR |
7520 | } |
7521 | ||
e0a413f6 SR |
7522 | /** |
7523 | * Test if ftrace is dead or not. | |
7524 | */ | |
7525 | int ftrace_is_dead(void) | |
7526 | { | |
7527 | return ftrace_disabled; | |
7528 | } | |
7529 | ||
16444a8a | 7530 | /** |
3d083395 SR |
7531 | * register_ftrace_function - register a function for profiling |
7532 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 7533 | * |
3d083395 SR |
7534 | * Register a function to be called by all functions in the |
7535 | * kernel. | |
7536 | * | |
7537 | * Note: @ops->func and all the functions it calls must be labeled | |
7538 | * with "notrace", otherwise it will go into a | |
7539 | * recursive loop. | |
16444a8a | 7540 | */ |
3d083395 | 7541 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 7542 | { |
45a4a237 | 7543 | int ret = -1; |
4eebcc81 | 7544 | |
f04f24fb MH |
7545 | ftrace_ops_init(ops); |
7546 | ||
e6ea44e9 | 7547 | mutex_lock(&ftrace_lock); |
e7d3737e | 7548 | |
8a56d776 | 7549 | ret = ftrace_startup(ops, 0); |
b848914c | 7550 | |
e6ea44e9 | 7551 | mutex_unlock(&ftrace_lock); |
8d240dd8 | 7552 | |
b0fc494f | 7553 | return ret; |
3d083395 | 7554 | } |
cdbe61bf | 7555 | EXPORT_SYMBOL_GPL(register_ftrace_function); |
3d083395 SR |
7556 | |
7557 | /** | |
32632920 | 7558 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
7559 | * @ops - ops structure that holds the function to unregister |
7560 | * | |
7561 | * Unregister a function that was added to be called by ftrace profiling. | |
7562 | */ | |
7563 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
7564 | { | |
7565 | int ret; | |
7566 | ||
e6ea44e9 | 7567 | mutex_lock(&ftrace_lock); |
8a56d776 | 7568 | ret = ftrace_shutdown(ops, 0); |
e6ea44e9 | 7569 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
7570 | |
7571 | return ret; | |
7572 | } | |
cdbe61bf | 7573 | EXPORT_SYMBOL_GPL(unregister_ftrace_function); |
b0fc494f | 7574 | |
7162431d MB |
7575 | static bool is_permanent_ops_registered(void) |
7576 | { | |
7577 | struct ftrace_ops *op; | |
7578 | ||
7579 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
7580 | if (op->flags & FTRACE_OPS_FL_PERMANENT) | |
7581 | return true; | |
7582 | } while_for_each_ftrace_op(op); | |
7583 | ||
7584 | return false; | |
7585 | } | |
7586 | ||
e309b41d | 7587 | int |
b0fc494f | 7588 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
54fa9ba5 | 7589 | void *buffer, size_t *lenp, loff_t *ppos) |
b0fc494f | 7590 | { |
45a4a237 | 7591 | int ret = -ENODEV; |
4eebcc81 | 7592 | |
e6ea44e9 | 7593 | mutex_lock(&ftrace_lock); |
b0fc494f | 7594 | |
45a4a237 SR |
7595 | if (unlikely(ftrace_disabled)) |
7596 | goto out; | |
7597 | ||
7598 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
b0fc494f | 7599 | |
a32c7765 | 7600 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
7601 | goto out; |
7602 | ||
b0fc494f SR |
7603 | if (ftrace_enabled) { |
7604 | ||
b0fc494f | 7605 | /* we are starting ftrace again */ |
f86f4180 CZ |
7606 | if (rcu_dereference_protected(ftrace_ops_list, |
7607 | lockdep_is_held(&ftrace_lock)) != &ftrace_list_end) | |
5000c418 | 7608 | update_ftrace_function(); |
b0fc494f | 7609 | |
524a3868 SRRH |
7610 | ftrace_startup_sysctl(); |
7611 | ||
b0fc494f | 7612 | } else { |
7162431d MB |
7613 | if (is_permanent_ops_registered()) { |
7614 | ftrace_enabled = true; | |
7615 | ret = -EBUSY; | |
7616 | goto out; | |
7617 | } | |
7618 | ||
b0fc494f SR |
7619 | /* stopping ftrace calls (just send to ftrace_stub) */ |
7620 | ftrace_trace_function = ftrace_stub; | |
7621 | ||
7622 | ftrace_shutdown_sysctl(); | |
7623 | } | |
7624 | ||
7162431d | 7625 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f | 7626 | out: |
e6ea44e9 | 7627 | mutex_unlock(&ftrace_lock); |
3d083395 | 7628 | return ret; |
16444a8a | 7629 | } |