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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, |
395b97a3 | 83 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | 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, | |
a1e2e31d | 124 | struct ftrace_ops *op, struct pt_regs *regs); |
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 | ||
717e3f5e SRV |
142 | #define FTRACE_PID_IGNORE -1 |
143 | #define FTRACE_PID_TRACE -2 | |
144 | ||
2f5f6ad9 | 145 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 146 | struct ftrace_ops *op, struct pt_regs *regs) |
df4fc315 | 147 | { |
345ddcc8 | 148 | struct trace_array *tr = op->private; |
717e3f5e | 149 | int pid; |
345ddcc8 | 150 | |
717e3f5e SRV |
151 | if (tr) { |
152 | pid = this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid); | |
153 | if (pid == FTRACE_PID_IGNORE) | |
154 | return; | |
155 | if (pid != FTRACE_PID_TRACE && | |
156 | pid != current->pid) | |
157 | return; | |
158 | } | |
df4fc315 | 159 | |
e3eea140 | 160 | op->saved_func(ip, parent_ip, op, regs); |
df4fc315 SR |
161 | } |
162 | ||
405e1d83 SRRH |
163 | static void ftrace_sync(struct work_struct *work) |
164 | { | |
165 | /* | |
166 | * This function is just a stub to implement a hard force | |
74401729 | 167 | * of synchronize_rcu(). This requires synchronizing |
405e1d83 SRRH |
168 | * tasks even in userspace and idle. |
169 | * | |
170 | * Yes, function tracing is rude. | |
171 | */ | |
172 | } | |
173 | ||
174 | static void ftrace_sync_ipi(void *data) | |
175 | { | |
176 | /* Probably not needed, but do it anyway */ | |
177 | smp_rmb(); | |
178 | } | |
179 | ||
00ccbf2f SRRH |
180 | static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops) |
181 | { | |
182 | /* | |
ba27f2bc | 183 | * If this is a dynamic, RCU, or per CPU ops, or we force list func, |
00ccbf2f SRRH |
184 | * then it needs to call the list anyway. |
185 | */ | |
b3a88803 PZ |
186 | if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_RCU) || |
187 | FTRACE_FORCE_LIST_FUNC) | |
00ccbf2f SRRH |
188 | return ftrace_ops_list_func; |
189 | ||
190 | return ftrace_ops_get_func(ops); | |
191 | } | |
192 | ||
2b499381 SR |
193 | static void update_ftrace_function(void) |
194 | { | |
195 | ftrace_func_t func; | |
196 | ||
f7aad4e1 SRRH |
197 | /* |
198 | * Prepare the ftrace_ops that the arch callback will use. | |
199 | * If there's only one ftrace_ops registered, the ftrace_ops_list | |
200 | * will point to the ops we want. | |
201 | */ | |
f86f4180 CZ |
202 | set_function_trace_op = rcu_dereference_protected(ftrace_ops_list, |
203 | lockdep_is_held(&ftrace_lock)); | |
f7aad4e1 SRRH |
204 | |
205 | /* If there's no ftrace_ops registered, just call the stub function */ | |
f86f4180 | 206 | if (set_function_trace_op == &ftrace_list_end) { |
f7aad4e1 SRRH |
207 | func = ftrace_stub; |
208 | ||
cdbe61bf SR |
209 | /* |
210 | * If we are at the end of the list and this ops is | |
4740974a SR |
211 | * recursion safe and not dynamic and the arch supports passing ops, |
212 | * then have the mcount trampoline call the function directly. | |
cdbe61bf | 213 | */ |
f86f4180 CZ |
214 | } else if (rcu_dereference_protected(ftrace_ops_list->next, |
215 | lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { | |
00ccbf2f | 216 | func = ftrace_ops_get_list_func(ftrace_ops_list); |
f7aad4e1 | 217 | |
2f5f6ad9 SR |
218 | } else { |
219 | /* Just use the default ftrace_ops */ | |
405e1d83 | 220 | set_function_trace_op = &ftrace_list_end; |
b848914c | 221 | func = ftrace_ops_list_func; |
2f5f6ad9 | 222 | } |
2b499381 | 223 | |
5f8bf2d2 SRRH |
224 | update_function_graph_func(); |
225 | ||
405e1d83 SRRH |
226 | /* If there's no change, then do nothing more here */ |
227 | if (ftrace_trace_function == func) | |
228 | return; | |
229 | ||
230 | /* | |
231 | * If we are using the list function, it doesn't care | |
232 | * about the function_trace_ops. | |
233 | */ | |
234 | if (func == ftrace_ops_list_func) { | |
235 | ftrace_trace_function = func; | |
236 | /* | |
237 | * Don't even bother setting function_trace_ops, | |
238 | * it would be racy to do so anyway. | |
239 | */ | |
240 | return; | |
241 | } | |
242 | ||
243 | #ifndef CONFIG_DYNAMIC_FTRACE | |
244 | /* | |
245 | * For static tracing, we need to be a bit more careful. | |
246 | * The function change takes affect immediately. Thus, | |
247 | * we need to coorditate the setting of the function_trace_ops | |
248 | * with the setting of the ftrace_trace_function. | |
249 | * | |
250 | * Set the function to the list ops, which will call the | |
251 | * function we want, albeit indirectly, but it handles the | |
252 | * ftrace_ops and doesn't depend on function_trace_op. | |
253 | */ | |
254 | ftrace_trace_function = ftrace_ops_list_func; | |
255 | /* | |
256 | * Make sure all CPUs see this. Yes this is slow, but static | |
257 | * tracing is slow and nasty to have enabled. | |
258 | */ | |
259 | schedule_on_each_cpu(ftrace_sync); | |
260 | /* Now all cpus are using the list ops. */ | |
261 | function_trace_op = set_function_trace_op; | |
262 | /* Make sure the function_trace_op is visible on all CPUs */ | |
263 | smp_wmb(); | |
264 | /* Nasty way to force a rmb on all cpus */ | |
265 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
266 | /* OK, we are all set to update the ftrace_trace_function now! */ | |
267 | #endif /* !CONFIG_DYNAMIC_FTRACE */ | |
268 | ||
491d0dcf | 269 | ftrace_trace_function = func; |
491d0dcf SR |
270 | } |
271 | ||
f86f4180 CZ |
272 | static void add_ftrace_ops(struct ftrace_ops __rcu **list, |
273 | struct ftrace_ops *ops) | |
3d083395 | 274 | { |
f86f4180 CZ |
275 | rcu_assign_pointer(ops->next, *list); |
276 | ||
16444a8a | 277 | /* |
b848914c | 278 | * We are entering ops into the list but another |
16444a8a ACM |
279 | * CPU might be walking that list. We need to make sure |
280 | * the ops->next pointer is valid before another CPU sees | |
b848914c | 281 | * the ops pointer included into the list. |
16444a8a | 282 | */ |
2b499381 | 283 | rcu_assign_pointer(*list, ops); |
16444a8a ACM |
284 | } |
285 | ||
f86f4180 CZ |
286 | static int remove_ftrace_ops(struct ftrace_ops __rcu **list, |
287 | struct ftrace_ops *ops) | |
16444a8a | 288 | { |
16444a8a | 289 | struct ftrace_ops **p; |
16444a8a ACM |
290 | |
291 | /* | |
3d083395 SR |
292 | * If we are removing the last function, then simply point |
293 | * to the ftrace_stub. | |
16444a8a | 294 | */ |
f86f4180 CZ |
295 | if (rcu_dereference_protected(*list, |
296 | lockdep_is_held(&ftrace_lock)) == ops && | |
297 | rcu_dereference_protected(ops->next, | |
298 | lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { | |
2b499381 | 299 | *list = &ftrace_list_end; |
e6ea44e9 | 300 | return 0; |
16444a8a ACM |
301 | } |
302 | ||
2b499381 | 303 | for (p = list; *p != &ftrace_list_end; p = &(*p)->next) |
16444a8a ACM |
304 | if (*p == ops) |
305 | break; | |
306 | ||
e6ea44e9 SR |
307 | if (*p != ops) |
308 | return -1; | |
16444a8a ACM |
309 | |
310 | *p = (*p)->next; | |
2b499381 SR |
311 | return 0; |
312 | } | |
16444a8a | 313 | |
f3bea491 SRRH |
314 | static void ftrace_update_trampoline(struct ftrace_ops *ops); |
315 | ||
3306fc4a | 316 | int __register_ftrace_function(struct ftrace_ops *ops) |
2b499381 | 317 | { |
591dffda SRRH |
318 | if (ops->flags & FTRACE_OPS_FL_DELETED) |
319 | return -EINVAL; | |
320 | ||
b848914c SR |
321 | if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) |
322 | return -EBUSY; | |
323 | ||
06aeaaea | 324 | #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
08f6fba5 SR |
325 | /* |
326 | * If the ftrace_ops specifies SAVE_REGS, then it only can be used | |
327 | * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set. | |
328 | * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant. | |
329 | */ | |
330 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS && | |
331 | !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)) | |
332 | return -EINVAL; | |
333 | ||
334 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED) | |
335 | ops->flags |= FTRACE_OPS_FL_SAVE_REGS; | |
336 | #endif | |
7162431d MB |
337 | if (!ftrace_enabled && (ops->flags & FTRACE_OPS_FL_PERMANENT)) |
338 | return -EBUSY; | |
08f6fba5 | 339 | |
cdbe61bf SR |
340 | if (!core_kernel_data((unsigned long)ops)) |
341 | ops->flags |= FTRACE_OPS_FL_DYNAMIC; | |
342 | ||
ba27f2bc | 343 | add_ftrace_ops(&ftrace_ops_list, ops); |
b848914c | 344 | |
e3eea140 SRRH |
345 | /* Always save the function, and reset at unregistering */ |
346 | ops->saved_func = ops->func; | |
347 | ||
345ddcc8 | 348 | if (ftrace_pids_enabled(ops)) |
e3eea140 SRRH |
349 | ops->func = ftrace_pid_func; |
350 | ||
f3bea491 SRRH |
351 | ftrace_update_trampoline(ops); |
352 | ||
2b499381 SR |
353 | if (ftrace_enabled) |
354 | update_ftrace_function(); | |
355 | ||
356 | return 0; | |
357 | } | |
358 | ||
3306fc4a | 359 | int __unregister_ftrace_function(struct ftrace_ops *ops) |
2b499381 SR |
360 | { |
361 | int ret; | |
362 | ||
b848914c SR |
363 | if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) |
364 | return -EBUSY; | |
365 | ||
ba27f2bc | 366 | ret = remove_ftrace_ops(&ftrace_ops_list, ops); |
b848914c | 367 | |
2b499381 SR |
368 | if (ret < 0) |
369 | return ret; | |
b848914c | 370 | |
491d0dcf SR |
371 | if (ftrace_enabled) |
372 | update_ftrace_function(); | |
16444a8a | 373 | |
e3eea140 SRRH |
374 | ops->func = ops->saved_func; |
375 | ||
e6ea44e9 | 376 | return 0; |
3d083395 SR |
377 | } |
378 | ||
df4fc315 SR |
379 | static void ftrace_update_pid_func(void) |
380 | { | |
e3eea140 SRRH |
381 | struct ftrace_ops *op; |
382 | ||
491d0dcf | 383 | /* Only do something if we are tracing something */ |
df4fc315 | 384 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 385 | return; |
df4fc315 | 386 | |
e3eea140 SRRH |
387 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
388 | if (op->flags & FTRACE_OPS_FL_PID) { | |
345ddcc8 SRRH |
389 | op->func = ftrace_pids_enabled(op) ? |
390 | ftrace_pid_func : op->saved_func; | |
e3eea140 SRRH |
391 | ftrace_update_trampoline(op); |
392 | } | |
393 | } while_for_each_ftrace_op(op); | |
394 | ||
491d0dcf | 395 | update_ftrace_function(); |
df4fc315 SR |
396 | } |
397 | ||
493762fc SR |
398 | #ifdef CONFIG_FUNCTION_PROFILER |
399 | struct ftrace_profile { | |
400 | struct hlist_node node; | |
401 | unsigned long ip; | |
402 | unsigned long counter; | |
0706f1c4 SR |
403 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
404 | unsigned long long time; | |
e330b3bc | 405 | unsigned long long time_squared; |
0706f1c4 | 406 | #endif |
8fc0c701 SR |
407 | }; |
408 | ||
493762fc SR |
409 | struct ftrace_profile_page { |
410 | struct ftrace_profile_page *next; | |
411 | unsigned long index; | |
412 | struct ftrace_profile records[]; | |
d61f82d0 SR |
413 | }; |
414 | ||
cafb168a SR |
415 | struct ftrace_profile_stat { |
416 | atomic_t disabled; | |
417 | struct hlist_head *hash; | |
418 | struct ftrace_profile_page *pages; | |
419 | struct ftrace_profile_page *start; | |
420 | struct tracer_stat stat; | |
421 | }; | |
422 | ||
493762fc SR |
423 | #define PROFILE_RECORDS_SIZE \ |
424 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 425 | |
493762fc SR |
426 | #define PROFILES_PER_PAGE \ |
427 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 428 | |
fb9fb015 SR |
429 | static int ftrace_profile_enabled __read_mostly; |
430 | ||
431 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
432 | static DEFINE_MUTEX(ftrace_profile_lock); |
433 | ||
cafb168a | 434 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc | 435 | |
20079ebe NK |
436 | #define FTRACE_PROFILE_HASH_BITS 10 |
437 | #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS) | |
493762fc | 438 | |
bac429f0 SR |
439 | static void * |
440 | function_stat_next(void *v, int idx) | |
441 | { | |
493762fc SR |
442 | struct ftrace_profile *rec = v; |
443 | struct ftrace_profile_page *pg; | |
bac429f0 | 444 | |
493762fc | 445 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
446 | |
447 | again: | |
0296e425 LZ |
448 | if (idx != 0) |
449 | rec++; | |
450 | ||
bac429f0 SR |
451 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
452 | pg = pg->next; | |
453 | if (!pg) | |
454 | return NULL; | |
455 | rec = &pg->records[0]; | |
493762fc SR |
456 | if (!rec->counter) |
457 | goto again; | |
bac429f0 SR |
458 | } |
459 | ||
bac429f0 SR |
460 | return rec; |
461 | } | |
462 | ||
463 | static void *function_stat_start(struct tracer_stat *trace) | |
464 | { | |
cafb168a SR |
465 | struct ftrace_profile_stat *stat = |
466 | container_of(trace, struct ftrace_profile_stat, stat); | |
467 | ||
468 | if (!stat || !stat->start) | |
469 | return NULL; | |
470 | ||
471 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
472 | } |
473 | ||
0706f1c4 SR |
474 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
475 | /* function graph compares on total time */ | |
80042c8f | 476 | static int function_stat_cmp(const void *p1, const void *p2) |
0706f1c4 | 477 | { |
80042c8f AS |
478 | const struct ftrace_profile *a = p1; |
479 | const struct ftrace_profile *b = p2; | |
0706f1c4 SR |
480 | |
481 | if (a->time < b->time) | |
482 | return -1; | |
483 | if (a->time > b->time) | |
484 | return 1; | |
485 | else | |
486 | return 0; | |
487 | } | |
488 | #else | |
489 | /* not function graph compares against hits */ | |
80042c8f | 490 | static int function_stat_cmp(const void *p1, const void *p2) |
bac429f0 | 491 | { |
80042c8f AS |
492 | const struct ftrace_profile *a = p1; |
493 | const struct ftrace_profile *b = p2; | |
bac429f0 SR |
494 | |
495 | if (a->counter < b->counter) | |
496 | return -1; | |
497 | if (a->counter > b->counter) | |
498 | return 1; | |
499 | else | |
500 | return 0; | |
501 | } | |
0706f1c4 | 502 | #endif |
bac429f0 SR |
503 | |
504 | static int function_stat_headers(struct seq_file *m) | |
505 | { | |
0706f1c4 | 506 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
fa6f0cc7 RV |
507 | seq_puts(m, " Function " |
508 | "Hit Time Avg s^2\n" | |
509 | " -------- " | |
510 | "--- ---- --- ---\n"); | |
0706f1c4 | 511 | #else |
fa6f0cc7 RV |
512 | seq_puts(m, " Function Hit\n" |
513 | " -------- ---\n"); | |
0706f1c4 | 514 | #endif |
bac429f0 SR |
515 | return 0; |
516 | } | |
517 | ||
518 | static int function_stat_show(struct seq_file *m, void *v) | |
519 | { | |
493762fc | 520 | struct ftrace_profile *rec = v; |
bac429f0 | 521 | char str[KSYM_SYMBOL_LEN]; |
3aaba20f | 522 | int ret = 0; |
0706f1c4 | 523 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
524 | static struct trace_seq s; |
525 | unsigned long long avg; | |
e330b3bc | 526 | unsigned long long stddev; |
0706f1c4 | 527 | #endif |
3aaba20f LZ |
528 | mutex_lock(&ftrace_profile_lock); |
529 | ||
530 | /* we raced with function_profile_reset() */ | |
531 | if (unlikely(rec->counter == 0)) { | |
532 | ret = -EBUSY; | |
533 | goto out; | |
534 | } | |
bac429f0 | 535 | |
8e436ca0 | 536 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e31f7939 | 537 | avg = div64_ul(rec->time, rec->counter); |
8e436ca0 UT |
538 | if (tracing_thresh && (avg < tracing_thresh)) |
539 | goto out; | |
540 | #endif | |
541 | ||
bac429f0 | 542 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
0706f1c4 SR |
543 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
544 | ||
545 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
fa6f0cc7 | 546 | seq_puts(m, " "); |
34886c8b | 547 | |
e330b3bc CD |
548 | /* Sample standard deviation (s^2) */ |
549 | if (rec->counter <= 1) | |
550 | stddev = 0; | |
551 | else { | |
52d85d76 JL |
552 | /* |
553 | * Apply Welford's method: | |
554 | * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2) | |
555 | */ | |
556 | stddev = rec->counter * rec->time_squared - | |
557 | rec->time * rec->time; | |
558 | ||
e330b3bc CD |
559 | /* |
560 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
561 | * trace_print_graph_duration will divide 1000 again. | |
562 | */ | |
e31f7939 WY |
563 | stddev = div64_ul(stddev, |
564 | rec->counter * (rec->counter - 1) * 1000); | |
e330b3bc CD |
565 | } |
566 | ||
34886c8b SR |
567 | trace_seq_init(&s); |
568 | trace_print_graph_duration(rec->time, &s); | |
569 | trace_seq_puts(&s, " "); | |
570 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
571 | trace_seq_puts(&s, " "); |
572 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 | 573 | trace_print_seq(m, &s); |
0706f1c4 SR |
574 | #endif |
575 | seq_putc(m, '\n'); | |
3aaba20f LZ |
576 | out: |
577 | mutex_unlock(&ftrace_profile_lock); | |
bac429f0 | 578 | |
3aaba20f | 579 | return ret; |
bac429f0 SR |
580 | } |
581 | ||
cafb168a | 582 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 583 | { |
493762fc | 584 | struct ftrace_profile_page *pg; |
bac429f0 | 585 | |
cafb168a | 586 | pg = stat->pages = stat->start; |
bac429f0 | 587 | |
493762fc SR |
588 | while (pg) { |
589 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
590 | pg->index = 0; | |
591 | pg = pg->next; | |
bac429f0 SR |
592 | } |
593 | ||
cafb168a | 594 | memset(stat->hash, 0, |
493762fc SR |
595 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
596 | } | |
bac429f0 | 597 | |
cafb168a | 598 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
599 | { |
600 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
601 | int functions; |
602 | int pages; | |
493762fc | 603 | int i; |
bac429f0 | 604 | |
493762fc | 605 | /* If we already allocated, do nothing */ |
cafb168a | 606 | if (stat->pages) |
493762fc | 607 | return 0; |
bac429f0 | 608 | |
cafb168a SR |
609 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
610 | if (!stat->pages) | |
493762fc | 611 | return -ENOMEM; |
bac429f0 | 612 | |
318e0a73 SR |
613 | #ifdef CONFIG_DYNAMIC_FTRACE |
614 | functions = ftrace_update_tot_cnt; | |
615 | #else | |
616 | /* | |
617 | * We do not know the number of functions that exist because | |
618 | * dynamic tracing is what counts them. With past experience | |
619 | * we have around 20K functions. That should be more than enough. | |
620 | * It is highly unlikely we will execute every function in | |
621 | * the kernel. | |
622 | */ | |
623 | functions = 20000; | |
624 | #endif | |
625 | ||
cafb168a | 626 | pg = stat->start = stat->pages; |
bac429f0 | 627 | |
318e0a73 SR |
628 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
629 | ||
39e30cd1 | 630 | for (i = 1; i < pages; i++) { |
493762fc | 631 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 632 | if (!pg->next) |
318e0a73 | 633 | goto out_free; |
493762fc SR |
634 | pg = pg->next; |
635 | } | |
636 | ||
637 | return 0; | |
318e0a73 SR |
638 | |
639 | out_free: | |
640 | pg = stat->start; | |
641 | while (pg) { | |
642 | unsigned long tmp = (unsigned long)pg; | |
643 | ||
644 | pg = pg->next; | |
645 | free_page(tmp); | |
646 | } | |
647 | ||
318e0a73 SR |
648 | stat->pages = NULL; |
649 | stat->start = NULL; | |
650 | ||
651 | return -ENOMEM; | |
bac429f0 SR |
652 | } |
653 | ||
cafb168a | 654 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 655 | { |
cafb168a | 656 | struct ftrace_profile_stat *stat; |
493762fc | 657 | int size; |
bac429f0 | 658 | |
cafb168a SR |
659 | stat = &per_cpu(ftrace_profile_stats, cpu); |
660 | ||
661 | if (stat->hash) { | |
493762fc | 662 | /* If the profile is already created, simply reset it */ |
cafb168a | 663 | ftrace_profile_reset(stat); |
493762fc SR |
664 | return 0; |
665 | } | |
bac429f0 | 666 | |
493762fc SR |
667 | /* |
668 | * We are profiling all functions, but usually only a few thousand | |
669 | * functions are hit. We'll make a hash of 1024 items. | |
670 | */ | |
671 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 672 | |
6396bb22 | 673 | stat->hash = kcalloc(size, sizeof(struct hlist_head), GFP_KERNEL); |
493762fc | 674 | |
cafb168a | 675 | if (!stat->hash) |
493762fc SR |
676 | return -ENOMEM; |
677 | ||
318e0a73 | 678 | /* Preallocate the function profiling pages */ |
cafb168a SR |
679 | if (ftrace_profile_pages_init(stat) < 0) { |
680 | kfree(stat->hash); | |
681 | stat->hash = NULL; | |
493762fc SR |
682 | return -ENOMEM; |
683 | } | |
684 | ||
685 | return 0; | |
bac429f0 SR |
686 | } |
687 | ||
cafb168a SR |
688 | static int ftrace_profile_init(void) |
689 | { | |
690 | int cpu; | |
691 | int ret = 0; | |
692 | ||
c4602c1c | 693 | for_each_possible_cpu(cpu) { |
cafb168a SR |
694 | ret = ftrace_profile_init_cpu(cpu); |
695 | if (ret) | |
696 | break; | |
697 | } | |
698 | ||
699 | return ret; | |
700 | } | |
701 | ||
493762fc | 702 | /* interrupts must be disabled */ |
cafb168a SR |
703 | static struct ftrace_profile * |
704 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 705 | { |
493762fc | 706 | struct ftrace_profile *rec; |
bac429f0 | 707 | struct hlist_head *hhd; |
bac429f0 SR |
708 | unsigned long key; |
709 | ||
20079ebe | 710 | key = hash_long(ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 711 | hhd = &stat->hash[key]; |
bac429f0 SR |
712 | |
713 | if (hlist_empty(hhd)) | |
714 | return NULL; | |
715 | ||
1bb539ca | 716 | hlist_for_each_entry_rcu_notrace(rec, hhd, node) { |
bac429f0 | 717 | if (rec->ip == ip) |
493762fc SR |
718 | return rec; |
719 | } | |
720 | ||
721 | return NULL; | |
722 | } | |
723 | ||
cafb168a SR |
724 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
725 | struct ftrace_profile *rec) | |
493762fc SR |
726 | { |
727 | unsigned long key; | |
728 | ||
20079ebe | 729 | key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 730 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
731 | } |
732 | ||
318e0a73 SR |
733 | /* |
734 | * The memory is already allocated, this simply finds a new record to use. | |
735 | */ | |
493762fc | 736 | static struct ftrace_profile * |
318e0a73 | 737 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
738 | { |
739 | struct ftrace_profile *rec = NULL; | |
740 | ||
318e0a73 | 741 | /* prevent recursion (from NMIs) */ |
cafb168a | 742 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
743 | goto out; |
744 | ||
493762fc | 745 | /* |
318e0a73 SR |
746 | * Try to find the function again since an NMI |
747 | * could have added it | |
493762fc | 748 | */ |
cafb168a | 749 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 750 | if (rec) |
cafb168a | 751 | goto out; |
493762fc | 752 | |
cafb168a SR |
753 | if (stat->pages->index == PROFILES_PER_PAGE) { |
754 | if (!stat->pages->next) | |
755 | goto out; | |
756 | stat->pages = stat->pages->next; | |
bac429f0 | 757 | } |
493762fc | 758 | |
cafb168a | 759 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 760 | rec->ip = ip; |
cafb168a | 761 | ftrace_add_profile(stat, rec); |
493762fc | 762 | |
bac429f0 | 763 | out: |
cafb168a | 764 | atomic_dec(&stat->disabled); |
bac429f0 SR |
765 | |
766 | return rec; | |
767 | } | |
768 | ||
769 | static void | |
2f5f6ad9 | 770 | function_profile_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 771 | struct ftrace_ops *ops, struct pt_regs *regs) |
bac429f0 | 772 | { |
cafb168a | 773 | struct ftrace_profile_stat *stat; |
493762fc | 774 | struct ftrace_profile *rec; |
bac429f0 SR |
775 | unsigned long flags; |
776 | ||
777 | if (!ftrace_profile_enabled) | |
778 | return; | |
779 | ||
780 | local_irq_save(flags); | |
cafb168a | 781 | |
bdffd893 | 782 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 783 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
784 | goto out; |
785 | ||
786 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 787 | if (!rec) { |
318e0a73 | 788 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
789 | if (!rec) |
790 | goto out; | |
791 | } | |
bac429f0 SR |
792 | |
793 | rec->counter++; | |
794 | out: | |
795 | local_irq_restore(flags); | |
796 | } | |
797 | ||
0706f1c4 | 798 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e73e679f SRV |
799 | static bool fgraph_graph_time = true; |
800 | ||
801 | void ftrace_graph_graph_time_control(bool enable) | |
802 | { | |
803 | fgraph_graph_time = enable; | |
804 | } | |
805 | ||
0706f1c4 SR |
806 | static int profile_graph_entry(struct ftrace_graph_ent *trace) |
807 | { | |
b0e21a61 | 808 | struct ftrace_ret_stack *ret_stack; |
8861dd30 | 809 | |
a1e2e31d | 810 | function_profile_call(trace->func, 0, NULL, NULL); |
8861dd30 | 811 | |
a8f0f9e4 SRV |
812 | /* If function graph is shutting down, ret_stack can be NULL */ |
813 | if (!current->ret_stack) | |
814 | return 0; | |
815 | ||
b0e21a61 SRV |
816 | ret_stack = ftrace_graph_get_ret_stack(current, 0); |
817 | if (ret_stack) | |
818 | ret_stack->subtime = 0; | |
8861dd30 | 819 | |
0706f1c4 SR |
820 | return 1; |
821 | } | |
822 | ||
823 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
824 | { | |
b0e21a61 | 825 | struct ftrace_ret_stack *ret_stack; |
cafb168a | 826 | struct ftrace_profile_stat *stat; |
a2a16d6a | 827 | unsigned long long calltime; |
0706f1c4 | 828 | struct ftrace_profile *rec; |
cafb168a | 829 | unsigned long flags; |
0706f1c4 SR |
830 | |
831 | local_irq_save(flags); | |
bdffd893 | 832 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 833 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
834 | goto out; |
835 | ||
37e44bc5 SR |
836 | /* If the calltime was zero'd ignore it */ |
837 | if (!trace->calltime) | |
838 | goto out; | |
839 | ||
a2a16d6a SR |
840 | calltime = trace->rettime - trace->calltime; |
841 | ||
55577204 | 842 | if (!fgraph_graph_time) { |
a2a16d6a SR |
843 | |
844 | /* Append this call time to the parent time to subtract */ | |
b0e21a61 SRV |
845 | ret_stack = ftrace_graph_get_ret_stack(current, 1); |
846 | if (ret_stack) | |
847 | ret_stack->subtime += calltime; | |
a2a16d6a | 848 | |
b0e21a61 SRV |
849 | ret_stack = ftrace_graph_get_ret_stack(current, 0); |
850 | if (ret_stack && ret_stack->subtime < calltime) | |
851 | calltime -= ret_stack->subtime; | |
a2a16d6a SR |
852 | else |
853 | calltime = 0; | |
854 | } | |
855 | ||
cafb168a | 856 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 857 | if (rec) { |
a2a16d6a | 858 | rec->time += calltime; |
e330b3bc CD |
859 | rec->time_squared += calltime * calltime; |
860 | } | |
a2a16d6a | 861 | |
cafb168a | 862 | out: |
0706f1c4 SR |
863 | local_irq_restore(flags); |
864 | } | |
865 | ||
688f7089 SRV |
866 | static struct fgraph_ops fprofiler_ops = { |
867 | .entryfunc = &profile_graph_entry, | |
868 | .retfunc = &profile_graph_return, | |
869 | }; | |
870 | ||
0706f1c4 SR |
871 | static int register_ftrace_profiler(void) |
872 | { | |
688f7089 | 873 | return register_ftrace_graph(&fprofiler_ops); |
0706f1c4 SR |
874 | } |
875 | ||
876 | static void unregister_ftrace_profiler(void) | |
877 | { | |
688f7089 | 878 | unregister_ftrace_graph(&fprofiler_ops); |
0706f1c4 SR |
879 | } |
880 | #else | |
bd38c0e6 | 881 | static struct ftrace_ops ftrace_profile_ops __read_mostly = { |
fb9fb015 | 882 | .func = function_profile_call, |
f04f24fb | 883 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, |
33b7f99c | 884 | INIT_OPS_HASH(ftrace_profile_ops) |
bac429f0 SR |
885 | }; |
886 | ||
0706f1c4 SR |
887 | static int register_ftrace_profiler(void) |
888 | { | |
889 | return register_ftrace_function(&ftrace_profile_ops); | |
890 | } | |
891 | ||
892 | static void unregister_ftrace_profiler(void) | |
893 | { | |
894 | unregister_ftrace_function(&ftrace_profile_ops); | |
895 | } | |
896 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
897 | ||
bac429f0 SR |
898 | static ssize_t |
899 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
900 | size_t cnt, loff_t *ppos) | |
901 | { | |
902 | unsigned long val; | |
bac429f0 SR |
903 | int ret; |
904 | ||
22fe9b54 PH |
905 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
906 | if (ret) | |
bac429f0 SR |
907 | return ret; |
908 | ||
909 | val = !!val; | |
910 | ||
911 | mutex_lock(&ftrace_profile_lock); | |
912 | if (ftrace_profile_enabled ^ val) { | |
913 | if (val) { | |
493762fc SR |
914 | ret = ftrace_profile_init(); |
915 | if (ret < 0) { | |
916 | cnt = ret; | |
917 | goto out; | |
918 | } | |
919 | ||
0706f1c4 SR |
920 | ret = register_ftrace_profiler(); |
921 | if (ret < 0) { | |
922 | cnt = ret; | |
923 | goto out; | |
924 | } | |
bac429f0 SR |
925 | ftrace_profile_enabled = 1; |
926 | } else { | |
927 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
928 | /* |
929 | * unregister_ftrace_profiler calls stop_machine | |
74401729 | 930 | * so this acts like an synchronize_rcu. |
0f6ce3de | 931 | */ |
0706f1c4 | 932 | unregister_ftrace_profiler(); |
bac429f0 SR |
933 | } |
934 | } | |
493762fc | 935 | out: |
bac429f0 SR |
936 | mutex_unlock(&ftrace_profile_lock); |
937 | ||
cf8517cf | 938 | *ppos += cnt; |
bac429f0 SR |
939 | |
940 | return cnt; | |
941 | } | |
942 | ||
493762fc SR |
943 | static ssize_t |
944 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
945 | size_t cnt, loff_t *ppos) | |
946 | { | |
fb9fb015 | 947 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
948 | int r; |
949 | ||
950 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
951 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
952 | } | |
953 | ||
bac429f0 SR |
954 | static const struct file_operations ftrace_profile_fops = { |
955 | .open = tracing_open_generic, | |
956 | .read = ftrace_profile_read, | |
957 | .write = ftrace_profile_write, | |
6038f373 | 958 | .llseek = default_llseek, |
bac429f0 SR |
959 | }; |
960 | ||
cafb168a SR |
961 | /* used to initialize the real stat files */ |
962 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
963 | .name = "functions", |
964 | .stat_start = function_stat_start, | |
965 | .stat_next = function_stat_next, | |
966 | .stat_cmp = function_stat_cmp, | |
967 | .stat_headers = function_stat_headers, | |
968 | .stat_show = function_stat_show | |
cafb168a SR |
969 | }; |
970 | ||
8434dc93 | 971 | static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
bac429f0 | 972 | { |
cafb168a | 973 | struct ftrace_profile_stat *stat; |
bac429f0 | 974 | struct dentry *entry; |
cafb168a | 975 | char *name; |
bac429f0 | 976 | int ret; |
cafb168a SR |
977 | int cpu; |
978 | ||
979 | for_each_possible_cpu(cpu) { | |
980 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
981 | ||
6363c6b5 | 982 | name = kasprintf(GFP_KERNEL, "function%d", cpu); |
cafb168a SR |
983 | if (!name) { |
984 | /* | |
985 | * The files created are permanent, if something happens | |
986 | * we still do not free memory. | |
987 | */ | |
cafb168a SR |
988 | WARN(1, |
989 | "Could not allocate stat file for cpu %d\n", | |
990 | cpu); | |
991 | return; | |
992 | } | |
993 | stat->stat = function_stats; | |
cafb168a SR |
994 | stat->stat.name = name; |
995 | ret = register_stat_tracer(&stat->stat); | |
996 | if (ret) { | |
997 | WARN(1, | |
998 | "Could not register function stat for cpu %d\n", | |
999 | cpu); | |
1000 | kfree(name); | |
1001 | return; | |
1002 | } | |
bac429f0 SR |
1003 | } |
1004 | ||
8434dc93 | 1005 | entry = tracefs_create_file("function_profile_enabled", 0644, |
bac429f0 SR |
1006 | d_tracer, NULL, &ftrace_profile_fops); |
1007 | if (!entry) | |
a395d6a7 | 1008 | pr_warn("Could not create tracefs 'function_profile_enabled' entry\n"); |
bac429f0 SR |
1009 | } |
1010 | ||
bac429f0 | 1011 | #else /* CONFIG_FUNCTION_PROFILER */ |
8434dc93 | 1012 | static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
bac429f0 SR |
1013 | { |
1014 | } | |
bac429f0 SR |
1015 | #endif /* CONFIG_FUNCTION_PROFILER */ |
1016 | ||
493762fc SR |
1017 | #ifdef CONFIG_DYNAMIC_FTRACE |
1018 | ||
79922b80 SRRH |
1019 | static struct ftrace_ops *removed_ops; |
1020 | ||
e1effa01 SRRH |
1021 | /* |
1022 | * Set when doing a global update, like enabling all recs or disabling them. | |
1023 | * It is not set when just updating a single ftrace_ops. | |
1024 | */ | |
1025 | static bool update_all_ops; | |
1026 | ||
493762fc SR |
1027 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
1028 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
1029 | #endif | |
1030 | ||
7b60f3d8 SRV |
1031 | struct ftrace_func_probe { |
1032 | struct ftrace_probe_ops *probe_ops; | |
1033 | struct ftrace_ops ops; | |
1034 | struct trace_array *tr; | |
1035 | struct list_head list; | |
6e444319 | 1036 | void *data; |
7b60f3d8 SRV |
1037 | int ref; |
1038 | }; | |
1039 | ||
33dc9b12 SR |
1040 | /* |
1041 | * We make these constant because no one should touch them, | |
1042 | * but they are used as the default "empty hash", to avoid allocating | |
1043 | * it all the time. These are in a read only section such that if | |
1044 | * anyone does try to modify it, it will cause an exception. | |
1045 | */ | |
1046 | static const struct hlist_head empty_buckets[1]; | |
1047 | static const struct ftrace_hash empty_hash = { | |
1048 | .buckets = (struct hlist_head *)empty_buckets, | |
1cf41dd7 | 1049 | }; |
33dc9b12 | 1050 | #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) |
493762fc | 1051 | |
3306fc4a | 1052 | struct ftrace_ops global_ops = { |
33b7f99c SRRH |
1053 | .func = ftrace_stub, |
1054 | .local_hash.notrace_hash = EMPTY_HASH, | |
1055 | .local_hash.filter_hash = EMPTY_HASH, | |
1056 | INIT_OPS_HASH(global_ops) | |
1057 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | | |
e3eea140 SRRH |
1058 | FTRACE_OPS_FL_INITIALIZED | |
1059 | FTRACE_OPS_FL_PID, | |
f45948e8 SR |
1060 | }; |
1061 | ||
aec0be2d | 1062 | /* |
6be7fa3c | 1063 | * Used by the stack undwinder to know about dynamic ftrace trampolines. |
aec0be2d | 1064 | */ |
6be7fa3c | 1065 | struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr) |
aec0be2d | 1066 | { |
6be7fa3c | 1067 | struct ftrace_ops *op = NULL; |
aec0be2d SRRH |
1068 | |
1069 | /* | |
1070 | * Some of the ops may be dynamically allocated, | |
74401729 | 1071 | * they are freed after a synchronize_rcu(). |
aec0be2d SRRH |
1072 | */ |
1073 | preempt_disable_notrace(); | |
1074 | ||
1075 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1076 | /* | |
1077 | * This is to check for dynamically allocated trampolines. | |
1078 | * Trampolines that are in kernel text will have | |
1079 | * core_kernel_text() return true. | |
1080 | */ | |
1081 | if (op->trampoline && op->trampoline_size) | |
1082 | if (addr >= op->trampoline && | |
1083 | addr < op->trampoline + op->trampoline_size) { | |
6be7fa3c SRV |
1084 | preempt_enable_notrace(); |
1085 | return op; | |
aec0be2d SRRH |
1086 | } |
1087 | } while_for_each_ftrace_op(op); | |
aec0be2d SRRH |
1088 | preempt_enable_notrace(); |
1089 | ||
6be7fa3c SRV |
1090 | return NULL; |
1091 | } | |
1092 | ||
1093 | /* | |
1094 | * This is used by __kernel_text_address() to return true if the | |
1095 | * address is on a dynamically allocated trampoline that would | |
1096 | * not return true for either core_kernel_text() or | |
1097 | * is_module_text_address(). | |
1098 | */ | |
1099 | bool is_ftrace_trampoline(unsigned long addr) | |
1100 | { | |
1101 | return ftrace_ops_trampoline(addr) != NULL; | |
aec0be2d SRRH |
1102 | } |
1103 | ||
493762fc SR |
1104 | struct ftrace_page { |
1105 | struct ftrace_page *next; | |
a7900875 | 1106 | struct dyn_ftrace *records; |
493762fc | 1107 | int index; |
a7900875 | 1108 | int size; |
493762fc SR |
1109 | }; |
1110 | ||
a7900875 SR |
1111 | #define ENTRY_SIZE sizeof(struct dyn_ftrace) |
1112 | #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE) | |
493762fc | 1113 | |
493762fc SR |
1114 | static struct ftrace_page *ftrace_pages_start; |
1115 | static struct ftrace_page *ftrace_pages; | |
1116 | ||
2b0cce0e SRV |
1117 | static __always_inline unsigned long |
1118 | ftrace_hash_key(struct ftrace_hash *hash, unsigned long ip) | |
1119 | { | |
1120 | if (hash->size_bits > 0) | |
1121 | return hash_long(ip, hash->size_bits); | |
1122 | ||
1123 | return 0; | |
1124 | } | |
1125 | ||
2b2c279c SRV |
1126 | /* Only use this function if ftrace_hash_empty() has already been tested */ |
1127 | static __always_inline struct ftrace_func_entry * | |
1128 | __ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
b448c4e3 SR |
1129 | { |
1130 | unsigned long key; | |
1131 | struct ftrace_func_entry *entry; | |
1132 | struct hlist_head *hhd; | |
b448c4e3 | 1133 | |
2b0cce0e | 1134 | key = ftrace_hash_key(hash, ip); |
b448c4e3 SR |
1135 | hhd = &hash->buckets[key]; |
1136 | ||
1bb539ca | 1137 | hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) { |
b448c4e3 SR |
1138 | if (entry->ip == ip) |
1139 | return entry; | |
1140 | } | |
1141 | return NULL; | |
1142 | } | |
1143 | ||
2b2c279c SRV |
1144 | /** |
1145 | * ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash | |
1146 | * @hash: The hash to look at | |
1147 | * @ip: The instruction pointer to test | |
1148 | * | |
1149 | * Search a given @hash to see if a given instruction pointer (@ip) | |
1150 | * exists in it. | |
1151 | * | |
1152 | * Returns the entry that holds the @ip if found. NULL otherwise. | |
1153 | */ | |
1154 | struct ftrace_func_entry * | |
1155 | ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
1156 | { | |
1157 | if (ftrace_hash_empty(hash)) | |
1158 | return NULL; | |
1159 | ||
1160 | return __ftrace_lookup_ip(hash, ip); | |
1161 | } | |
1162 | ||
33dc9b12 SR |
1163 | static void __add_hash_entry(struct ftrace_hash *hash, |
1164 | struct ftrace_func_entry *entry) | |
b448c4e3 | 1165 | { |
b448c4e3 SR |
1166 | struct hlist_head *hhd; |
1167 | unsigned long key; | |
1168 | ||
2b0cce0e | 1169 | key = ftrace_hash_key(hash, entry->ip); |
b448c4e3 SR |
1170 | hhd = &hash->buckets[key]; |
1171 | hlist_add_head(&entry->hlist, hhd); | |
1172 | hash->count++; | |
33dc9b12 SR |
1173 | } |
1174 | ||
1175 | static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip) | |
1176 | { | |
1177 | struct ftrace_func_entry *entry; | |
1178 | ||
1179 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1180 | if (!entry) | |
1181 | return -ENOMEM; | |
1182 | ||
1183 | entry->ip = ip; | |
1184 | __add_hash_entry(hash, entry); | |
b448c4e3 SR |
1185 | |
1186 | return 0; | |
1187 | } | |
1188 | ||
1189 | static void | |
33dc9b12 | 1190 | free_hash_entry(struct ftrace_hash *hash, |
b448c4e3 SR |
1191 | struct ftrace_func_entry *entry) |
1192 | { | |
1193 | hlist_del(&entry->hlist); | |
1194 | kfree(entry); | |
1195 | hash->count--; | |
1196 | } | |
1197 | ||
33dc9b12 SR |
1198 | static void |
1199 | remove_hash_entry(struct ftrace_hash *hash, | |
1200 | struct ftrace_func_entry *entry) | |
1201 | { | |
eee8ded1 | 1202 | hlist_del_rcu(&entry->hlist); |
33dc9b12 SR |
1203 | hash->count--; |
1204 | } | |
1205 | ||
b448c4e3 SR |
1206 | static void ftrace_hash_clear(struct ftrace_hash *hash) |
1207 | { | |
1208 | struct hlist_head *hhd; | |
b67bfe0d | 1209 | struct hlist_node *tn; |
b448c4e3 SR |
1210 | struct ftrace_func_entry *entry; |
1211 | int size = 1 << hash->size_bits; | |
1212 | int i; | |
1213 | ||
33dc9b12 SR |
1214 | if (!hash->count) |
1215 | return; | |
1216 | ||
b448c4e3 SR |
1217 | for (i = 0; i < size; i++) { |
1218 | hhd = &hash->buckets[i]; | |
b67bfe0d | 1219 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) |
33dc9b12 | 1220 | free_hash_entry(hash, entry); |
b448c4e3 SR |
1221 | } |
1222 | FTRACE_WARN_ON(hash->count); | |
1223 | } | |
1224 | ||
673feb9d SRV |
1225 | static void free_ftrace_mod(struct ftrace_mod_load *ftrace_mod) |
1226 | { | |
1227 | list_del(&ftrace_mod->list); | |
1228 | kfree(ftrace_mod->module); | |
1229 | kfree(ftrace_mod->func); | |
1230 | kfree(ftrace_mod); | |
1231 | } | |
1232 | ||
1233 | static void clear_ftrace_mod_list(struct list_head *head) | |
1234 | { | |
1235 | struct ftrace_mod_load *p, *n; | |
1236 | ||
1237 | /* stack tracer isn't supported yet */ | |
1238 | if (!head) | |
1239 | return; | |
1240 | ||
1241 | mutex_lock(&ftrace_lock); | |
1242 | list_for_each_entry_safe(p, n, head, list) | |
1243 | free_ftrace_mod(p); | |
1244 | mutex_unlock(&ftrace_lock); | |
1245 | } | |
1246 | ||
33dc9b12 SR |
1247 | static void free_ftrace_hash(struct ftrace_hash *hash) |
1248 | { | |
1249 | if (!hash || hash == EMPTY_HASH) | |
1250 | return; | |
1251 | ftrace_hash_clear(hash); | |
1252 | kfree(hash->buckets); | |
1253 | kfree(hash); | |
1254 | } | |
1255 | ||
07fd5515 SR |
1256 | static void __free_ftrace_hash_rcu(struct rcu_head *rcu) |
1257 | { | |
1258 | struct ftrace_hash *hash; | |
1259 | ||
1260 | hash = container_of(rcu, struct ftrace_hash, rcu); | |
1261 | free_ftrace_hash(hash); | |
1262 | } | |
1263 | ||
1264 | static void free_ftrace_hash_rcu(struct ftrace_hash *hash) | |
1265 | { | |
1266 | if (!hash || hash == EMPTY_HASH) | |
1267 | return; | |
74401729 | 1268 | call_rcu(&hash->rcu, __free_ftrace_hash_rcu); |
07fd5515 SR |
1269 | } |
1270 | ||
5500fa51 JO |
1271 | void ftrace_free_filter(struct ftrace_ops *ops) |
1272 | { | |
f04f24fb | 1273 | ftrace_ops_init(ops); |
33b7f99c SRRH |
1274 | free_ftrace_hash(ops->func_hash->filter_hash); |
1275 | free_ftrace_hash(ops->func_hash->notrace_hash); | |
5500fa51 JO |
1276 | } |
1277 | ||
33dc9b12 SR |
1278 | static struct ftrace_hash *alloc_ftrace_hash(int size_bits) |
1279 | { | |
1280 | struct ftrace_hash *hash; | |
1281 | int size; | |
1282 | ||
1283 | hash = kzalloc(sizeof(*hash), GFP_KERNEL); | |
1284 | if (!hash) | |
1285 | return NULL; | |
1286 | ||
1287 | size = 1 << size_bits; | |
47b0edcb | 1288 | hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL); |
33dc9b12 SR |
1289 | |
1290 | if (!hash->buckets) { | |
1291 | kfree(hash); | |
1292 | return NULL; | |
1293 | } | |
1294 | ||
1295 | hash->size_bits = size_bits; | |
1296 | ||
1297 | return hash; | |
1298 | } | |
1299 | ||
673feb9d SRV |
1300 | |
1301 | static int ftrace_add_mod(struct trace_array *tr, | |
1302 | const char *func, const char *module, | |
1303 | int enable) | |
1304 | { | |
1305 | struct ftrace_mod_load *ftrace_mod; | |
1306 | struct list_head *mod_head = enable ? &tr->mod_trace : &tr->mod_notrace; | |
1307 | ||
1308 | ftrace_mod = kzalloc(sizeof(*ftrace_mod), GFP_KERNEL); | |
1309 | if (!ftrace_mod) | |
1310 | return -ENOMEM; | |
1311 | ||
1312 | ftrace_mod->func = kstrdup(func, GFP_KERNEL); | |
1313 | ftrace_mod->module = kstrdup(module, GFP_KERNEL); | |
1314 | ftrace_mod->enable = enable; | |
1315 | ||
1316 | if (!ftrace_mod->func || !ftrace_mod->module) | |
1317 | goto out_free; | |
1318 | ||
1319 | list_add(&ftrace_mod->list, mod_head); | |
1320 | ||
1321 | return 0; | |
1322 | ||
1323 | out_free: | |
1324 | free_ftrace_mod(ftrace_mod); | |
1325 | ||
1326 | return -ENOMEM; | |
1327 | } | |
1328 | ||
33dc9b12 SR |
1329 | static struct ftrace_hash * |
1330 | alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) | |
1331 | { | |
1332 | struct ftrace_func_entry *entry; | |
1333 | struct ftrace_hash *new_hash; | |
33dc9b12 SR |
1334 | int size; |
1335 | int ret; | |
1336 | int i; | |
1337 | ||
1338 | new_hash = alloc_ftrace_hash(size_bits); | |
1339 | if (!new_hash) | |
1340 | return NULL; | |
1341 | ||
8c08f0d5 SRV |
1342 | if (hash) |
1343 | new_hash->flags = hash->flags; | |
1344 | ||
33dc9b12 | 1345 | /* Empty hash? */ |
06a51d93 | 1346 | if (ftrace_hash_empty(hash)) |
33dc9b12 SR |
1347 | return new_hash; |
1348 | ||
1349 | size = 1 << hash->size_bits; | |
1350 | for (i = 0; i < size; i++) { | |
b67bfe0d | 1351 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { |
33dc9b12 SR |
1352 | ret = add_hash_entry(new_hash, entry->ip); |
1353 | if (ret < 0) | |
1354 | goto free_hash; | |
1355 | } | |
1356 | } | |
1357 | ||
1358 | FTRACE_WARN_ON(new_hash->count != hash->count); | |
1359 | ||
1360 | return new_hash; | |
1361 | ||
1362 | free_hash: | |
1363 | free_ftrace_hash(new_hash); | |
1364 | return NULL; | |
1365 | } | |
1366 | ||
41fb61c2 | 1367 | static void |
84261912 | 1368 | ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash); |
41fb61c2 | 1369 | static void |
84261912 | 1370 | ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash); |
41fb61c2 | 1371 | |
f8b8be8a MH |
1372 | static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, |
1373 | struct ftrace_hash *new_hash); | |
1374 | ||
714641c3 | 1375 | static struct ftrace_hash *dup_hash(struct ftrace_hash *src, int size) |
33dc9b12 SR |
1376 | { |
1377 | struct ftrace_func_entry *entry; | |
07fd5515 | 1378 | struct ftrace_hash *new_hash; |
714641c3 SRV |
1379 | struct hlist_head *hhd; |
1380 | struct hlist_node *tn; | |
33dc9b12 SR |
1381 | int bits = 0; |
1382 | int i; | |
1383 | ||
33dc9b12 SR |
1384 | /* |
1385 | * Make the hash size about 1/2 the # found | |
1386 | */ | |
1387 | for (size /= 2; size; size >>= 1) | |
1388 | bits++; | |
1389 | ||
1390 | /* Don't allocate too much */ | |
1391 | if (bits > FTRACE_HASH_MAX_BITS) | |
1392 | bits = FTRACE_HASH_MAX_BITS; | |
1393 | ||
07fd5515 SR |
1394 | new_hash = alloc_ftrace_hash(bits); |
1395 | if (!new_hash) | |
3e278c0d | 1396 | return NULL; |
33dc9b12 | 1397 | |
8c08f0d5 SRV |
1398 | new_hash->flags = src->flags; |
1399 | ||
33dc9b12 SR |
1400 | size = 1 << src->size_bits; |
1401 | for (i = 0; i < size; i++) { | |
1402 | hhd = &src->buckets[i]; | |
b67bfe0d | 1403 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) { |
33dc9b12 | 1404 | remove_hash_entry(src, entry); |
07fd5515 | 1405 | __add_hash_entry(new_hash, entry); |
33dc9b12 SR |
1406 | } |
1407 | } | |
3e278c0d NK |
1408 | return new_hash; |
1409 | } | |
1410 | ||
714641c3 SRV |
1411 | static struct ftrace_hash * |
1412 | __ftrace_hash_move(struct ftrace_hash *src) | |
1413 | { | |
1414 | int size = src->count; | |
1415 | ||
1416 | /* | |
1417 | * If the new source is empty, just return the empty_hash. | |
1418 | */ | |
1419 | if (ftrace_hash_empty(src)) | |
1420 | return EMPTY_HASH; | |
1421 | ||
1422 | return dup_hash(src, size); | |
1423 | } | |
1424 | ||
3e278c0d NK |
1425 | static int |
1426 | ftrace_hash_move(struct ftrace_ops *ops, int enable, | |
1427 | struct ftrace_hash **dst, struct ftrace_hash *src) | |
1428 | { | |
1429 | struct ftrace_hash *new_hash; | |
1430 | int ret; | |
1431 | ||
1432 | /* Reject setting notrace hash on IPMODIFY ftrace_ops */ | |
1433 | if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable) | |
1434 | return -EINVAL; | |
1435 | ||
1436 | new_hash = __ftrace_hash_move(src); | |
1437 | if (!new_hash) | |
1438 | return -ENOMEM; | |
1439 | ||
f8b8be8a MH |
1440 | /* Make sure this can be applied if it is IPMODIFY ftrace_ops */ |
1441 | if (enable) { | |
1442 | /* IPMODIFY should be updated only when filter_hash updating */ | |
1443 | ret = ftrace_hash_ipmodify_update(ops, new_hash); | |
1444 | if (ret < 0) { | |
1445 | free_ftrace_hash(new_hash); | |
1446 | return ret; | |
1447 | } | |
1448 | } | |
1449 | ||
5c27c775 MH |
1450 | /* |
1451 | * Remove the current set, update the hash and add | |
1452 | * them back. | |
1453 | */ | |
84261912 | 1454 | ftrace_hash_rec_disable_modify(ops, enable); |
5c27c775 | 1455 | |
07fd5515 | 1456 | rcu_assign_pointer(*dst, new_hash); |
07fd5515 | 1457 | |
84261912 | 1458 | ftrace_hash_rec_enable_modify(ops, enable); |
41fb61c2 | 1459 | |
5c27c775 | 1460 | return 0; |
33dc9b12 SR |
1461 | } |
1462 | ||
fef5aeee SRRH |
1463 | static bool hash_contains_ip(unsigned long ip, |
1464 | struct ftrace_ops_hash *hash) | |
1465 | { | |
1466 | /* | |
1467 | * The function record is a match if it exists in the filter | |
1468 | * hash and not in the notrace hash. Note, an emty hash is | |
1469 | * considered a match for the filter hash, but an empty | |
1470 | * notrace hash is considered not in the notrace hash. | |
1471 | */ | |
1472 | return (ftrace_hash_empty(hash->filter_hash) || | |
2b2c279c | 1473 | __ftrace_lookup_ip(hash->filter_hash, ip)) && |
fef5aeee | 1474 | (ftrace_hash_empty(hash->notrace_hash) || |
2b2c279c | 1475 | !__ftrace_lookup_ip(hash->notrace_hash, ip)); |
fef5aeee SRRH |
1476 | } |
1477 | ||
b848914c SR |
1478 | /* |
1479 | * Test the hashes for this ops to see if we want to call | |
1480 | * the ops->func or not. | |
1481 | * | |
1482 | * It's a match if the ip is in the ops->filter_hash or | |
1483 | * the filter_hash does not exist or is empty, | |
1484 | * AND | |
1485 | * the ip is not in the ops->notrace_hash. | |
cdbe61bf SR |
1486 | * |
1487 | * This needs to be called with preemption disabled as | |
74401729 | 1488 | * the hashes are freed with call_rcu(). |
b848914c | 1489 | */ |
3306fc4a | 1490 | int |
195a8afc | 1491 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
b848914c | 1492 | { |
fef5aeee | 1493 | struct ftrace_ops_hash hash; |
b848914c SR |
1494 | int ret; |
1495 | ||
195a8afc SRRH |
1496 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
1497 | /* | |
1498 | * There's a small race when adding ops that the ftrace handler | |
1499 | * that wants regs, may be called without them. We can not | |
1500 | * allow that handler to be called if regs is NULL. | |
1501 | */ | |
1502 | if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS)) | |
1503 | return 0; | |
1504 | #endif | |
1505 | ||
f86f4180 CZ |
1506 | rcu_assign_pointer(hash.filter_hash, ops->func_hash->filter_hash); |
1507 | rcu_assign_pointer(hash.notrace_hash, ops->func_hash->notrace_hash); | |
b848914c | 1508 | |
fef5aeee | 1509 | if (hash_contains_ip(ip, &hash)) |
b848914c SR |
1510 | ret = 1; |
1511 | else | |
1512 | ret = 0; | |
b848914c SR |
1513 | |
1514 | return ret; | |
1515 | } | |
1516 | ||
493762fc SR |
1517 | /* |
1518 | * This is a double for. Do not use 'break' to break out of the loop, | |
1519 | * you must use a goto. | |
1520 | */ | |
1521 | #define do_for_each_ftrace_rec(pg, rec) \ | |
1522 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
1523 | int _____i; \ | |
1524 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
1525 | rec = &pg->records[_____i]; | |
1526 | ||
1527 | #define while_for_each_ftrace_rec() \ | |
1528 | } \ | |
1529 | } | |
1530 | ||
5855fead SR |
1531 | |
1532 | static int ftrace_cmp_recs(const void *a, const void *b) | |
1533 | { | |
a650e02a SR |
1534 | const struct dyn_ftrace *key = a; |
1535 | const struct dyn_ftrace *rec = b; | |
5855fead | 1536 | |
a650e02a | 1537 | if (key->flags < rec->ip) |
5855fead | 1538 | return -1; |
a650e02a SR |
1539 | if (key->ip >= rec->ip + MCOUNT_INSN_SIZE) |
1540 | return 1; | |
5855fead SR |
1541 | return 0; |
1542 | } | |
1543 | ||
7e16f581 SRV |
1544 | static struct dyn_ftrace *lookup_rec(unsigned long start, unsigned long end) |
1545 | { | |
1546 | struct ftrace_page *pg; | |
1547 | struct dyn_ftrace *rec = NULL; | |
1548 | struct dyn_ftrace key; | |
1549 | ||
1550 | key.ip = start; | |
1551 | key.flags = end; /* overload flags, as it is unsigned long */ | |
1552 | ||
1553 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
1554 | if (end < pg->records[0].ip || | |
1555 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) | |
1556 | continue; | |
1557 | rec = bsearch(&key, pg->records, pg->index, | |
1558 | sizeof(struct dyn_ftrace), | |
1559 | ftrace_cmp_recs); | |
1560 | } | |
1561 | return rec; | |
1562 | } | |
1563 | ||
04cf31a7 ME |
1564 | /** |
1565 | * ftrace_location_range - return the first address of a traced location | |
1566 | * if it touches the given ip range | |
1567 | * @start: start of range to search. | |
1568 | * @end: end of range to search (inclusive). @end points to the last byte | |
1569 | * to check. | |
1570 | * | |
1571 | * Returns rec->ip if the related ftrace location is a least partly within | |
1572 | * the given address range. That is, the first address of the instruction | |
1573 | * that is either a NOP or call to the function tracer. It checks the ftrace | |
1574 | * internal tables to determine if the address belongs or not. | |
1575 | */ | |
1576 | unsigned long ftrace_location_range(unsigned long start, unsigned long end) | |
c88fd863 | 1577 | { |
c88fd863 | 1578 | struct dyn_ftrace *rec; |
5855fead | 1579 | |
7e16f581 SRV |
1580 | rec = lookup_rec(start, end); |
1581 | if (rec) | |
1582 | return rec->ip; | |
c88fd863 SR |
1583 | |
1584 | return 0; | |
1585 | } | |
1586 | ||
a650e02a SR |
1587 | /** |
1588 | * ftrace_location - return true if the ip giving is a traced location | |
1589 | * @ip: the instruction pointer to check | |
1590 | * | |
f0cf973a | 1591 | * Returns rec->ip if @ip given is a pointer to a ftrace location. |
a650e02a SR |
1592 | * That is, the instruction that is either a NOP or call to |
1593 | * the function tracer. It checks the ftrace internal tables to | |
1594 | * determine if the address belongs or not. | |
1595 | */ | |
f0cf973a | 1596 | unsigned long ftrace_location(unsigned long ip) |
a650e02a SR |
1597 | { |
1598 | return ftrace_location_range(ip, ip); | |
1599 | } | |
1600 | ||
1601 | /** | |
1602 | * ftrace_text_reserved - return true if range contains an ftrace location | |
1603 | * @start: start of range to search | |
1604 | * @end: end of range to search (inclusive). @end points to the last byte to check. | |
1605 | * | |
1606 | * Returns 1 if @start and @end contains a ftrace location. | |
1607 | * That is, the instruction that is either a NOP or call to | |
1608 | * the function tracer. It checks the ftrace internal tables to | |
1609 | * determine if the address belongs or not. | |
1610 | */ | |
d88471cb | 1611 | int ftrace_text_reserved(const void *start, const void *end) |
a650e02a | 1612 | { |
f0cf973a SR |
1613 | unsigned long ret; |
1614 | ||
1615 | ret = ftrace_location_range((unsigned long)start, | |
1616 | (unsigned long)end); | |
1617 | ||
1618 | return (int)!!ret; | |
a650e02a SR |
1619 | } |
1620 | ||
4fbb48cb SRRH |
1621 | /* Test if ops registered to this rec needs regs */ |
1622 | static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec) | |
1623 | { | |
1624 | struct ftrace_ops *ops; | |
1625 | bool keep_regs = false; | |
1626 | ||
1627 | for (ops = ftrace_ops_list; | |
1628 | ops != &ftrace_list_end; ops = ops->next) { | |
1629 | /* pass rec in as regs to have non-NULL val */ | |
1630 | if (ftrace_ops_test(ops, rec->ip, rec)) { | |
1631 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1632 | keep_regs = true; | |
1633 | break; | |
1634 | } | |
1635 | } | |
1636 | } | |
1637 | ||
1638 | return keep_regs; | |
1639 | } | |
1640 | ||
a124692b CJ |
1641 | static struct ftrace_ops * |
1642 | ftrace_find_tramp_ops_any(struct dyn_ftrace *rec); | |
1643 | static struct ftrace_ops * | |
1644 | ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops); | |
1645 | ||
84b6d3e6 | 1646 | static bool __ftrace_hash_rec_update(struct ftrace_ops *ops, |
ed926f9b SR |
1647 | int filter_hash, |
1648 | bool inc) | |
1649 | { | |
1650 | struct ftrace_hash *hash; | |
1651 | struct ftrace_hash *other_hash; | |
1652 | struct ftrace_page *pg; | |
1653 | struct dyn_ftrace *rec; | |
84b6d3e6 | 1654 | bool update = false; |
ed926f9b | 1655 | int count = 0; |
8c08f0d5 | 1656 | int all = false; |
ed926f9b SR |
1657 | |
1658 | /* Only update if the ops has been registered */ | |
1659 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
84b6d3e6 | 1660 | return false; |
ed926f9b SR |
1661 | |
1662 | /* | |
1663 | * In the filter_hash case: | |
1664 | * If the count is zero, we update all records. | |
1665 | * Otherwise we just update the items in the hash. | |
1666 | * | |
1667 | * In the notrace_hash case: | |
1668 | * We enable the update in the hash. | |
1669 | * As disabling notrace means enabling the tracing, | |
1670 | * and enabling notrace means disabling, the inc variable | |
1671 | * gets inversed. | |
1672 | */ | |
1673 | if (filter_hash) { | |
33b7f99c SRRH |
1674 | hash = ops->func_hash->filter_hash; |
1675 | other_hash = ops->func_hash->notrace_hash; | |
06a51d93 | 1676 | if (ftrace_hash_empty(hash)) |
8c08f0d5 | 1677 | all = true; |
ed926f9b SR |
1678 | } else { |
1679 | inc = !inc; | |
33b7f99c SRRH |
1680 | hash = ops->func_hash->notrace_hash; |
1681 | other_hash = ops->func_hash->filter_hash; | |
ed926f9b SR |
1682 | /* |
1683 | * If the notrace hash has no items, | |
1684 | * then there's nothing to do. | |
1685 | */ | |
06a51d93 | 1686 | if (ftrace_hash_empty(hash)) |
84b6d3e6 | 1687 | return false; |
ed926f9b SR |
1688 | } |
1689 | ||
1690 | do_for_each_ftrace_rec(pg, rec) { | |
1691 | int in_other_hash = 0; | |
1692 | int in_hash = 0; | |
1693 | int match = 0; | |
1694 | ||
b7ffffbb SRRH |
1695 | if (rec->flags & FTRACE_FL_DISABLED) |
1696 | continue; | |
1697 | ||
ed926f9b SR |
1698 | if (all) { |
1699 | /* | |
1700 | * Only the filter_hash affects all records. | |
1701 | * Update if the record is not in the notrace hash. | |
1702 | */ | |
b848914c | 1703 | if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) |
ed926f9b SR |
1704 | match = 1; |
1705 | } else { | |
06a51d93 SR |
1706 | in_hash = !!ftrace_lookup_ip(hash, rec->ip); |
1707 | in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip); | |
ed926f9b SR |
1708 | |
1709 | /* | |
19eab4a4 SRRH |
1710 | * If filter_hash is set, we want to match all functions |
1711 | * that are in the hash but not in the other hash. | |
ed926f9b | 1712 | * |
19eab4a4 SRRH |
1713 | * If filter_hash is not set, then we are decrementing. |
1714 | * That means we match anything that is in the hash | |
1715 | * and also in the other_hash. That is, we need to turn | |
1716 | * off functions in the other hash because they are disabled | |
1717 | * by this hash. | |
ed926f9b SR |
1718 | */ |
1719 | if (filter_hash && in_hash && !in_other_hash) | |
1720 | match = 1; | |
1721 | else if (!filter_hash && in_hash && | |
06a51d93 | 1722 | (in_other_hash || ftrace_hash_empty(other_hash))) |
ed926f9b SR |
1723 | match = 1; |
1724 | } | |
1725 | if (!match) | |
1726 | continue; | |
1727 | ||
1728 | if (inc) { | |
1729 | rec->flags++; | |
0376bde1 | 1730 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX)) |
84b6d3e6 | 1731 | return false; |
79922b80 | 1732 | |
763e34e7 SRV |
1733 | if (ops->flags & FTRACE_OPS_FL_DIRECT) |
1734 | rec->flags |= FTRACE_FL_DIRECT; | |
1735 | ||
79922b80 SRRH |
1736 | /* |
1737 | * If there's only a single callback registered to a | |
1738 | * function, and the ops has a trampoline registered | |
1739 | * for it, then we can call it directly. | |
1740 | */ | |
fef5aeee | 1741 | if (ftrace_rec_count(rec) == 1 && ops->trampoline) |
79922b80 | 1742 | rec->flags |= FTRACE_FL_TRAMP; |
fef5aeee | 1743 | else |
79922b80 SRRH |
1744 | /* |
1745 | * If we are adding another function callback | |
1746 | * to this function, and the previous had a | |
bce0b6c5 SRRH |
1747 | * custom trampoline in use, then we need to go |
1748 | * back to the default trampoline. | |
79922b80 | 1749 | */ |
fef5aeee | 1750 | rec->flags &= ~FTRACE_FL_TRAMP; |
79922b80 | 1751 | |
08f6fba5 SR |
1752 | /* |
1753 | * If any ops wants regs saved for this function | |
1754 | * then all ops will get saved regs. | |
1755 | */ | |
1756 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) | |
1757 | rec->flags |= FTRACE_FL_REGS; | |
ed926f9b | 1758 | } else { |
0376bde1 | 1759 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0)) |
84b6d3e6 | 1760 | return false; |
ed926f9b | 1761 | rec->flags--; |
79922b80 | 1762 | |
763e34e7 SRV |
1763 | /* |
1764 | * Only the internal direct_ops should have the | |
1765 | * DIRECT flag set. Thus, if it is removing a | |
1766 | * function, then that function should no longer | |
1767 | * be direct. | |
1768 | */ | |
1769 | if (ops->flags & FTRACE_OPS_FL_DIRECT) | |
1770 | rec->flags &= ~FTRACE_FL_DIRECT; | |
1771 | ||
4fbb48cb SRRH |
1772 | /* |
1773 | * If the rec had REGS enabled and the ops that is | |
1774 | * being removed had REGS set, then see if there is | |
1775 | * still any ops for this record that wants regs. | |
1776 | * If not, we can stop recording them. | |
1777 | */ | |
0376bde1 | 1778 | if (ftrace_rec_count(rec) > 0 && |
4fbb48cb SRRH |
1779 | rec->flags & FTRACE_FL_REGS && |
1780 | ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1781 | if (!test_rec_ops_needs_regs(rec)) | |
1782 | rec->flags &= ~FTRACE_FL_REGS; | |
1783 | } | |
79922b80 | 1784 | |
fef5aeee | 1785 | /* |
a124692b CJ |
1786 | * The TRAMP needs to be set only if rec count |
1787 | * is decremented to one, and the ops that is | |
1788 | * left has a trampoline. As TRAMP can only be | |
1789 | * enabled if there is only a single ops attached | |
1790 | * to it. | |
fef5aeee | 1791 | */ |
a124692b CJ |
1792 | if (ftrace_rec_count(rec) == 1 && |
1793 | ftrace_find_tramp_ops_any(rec)) | |
1794 | rec->flags |= FTRACE_FL_TRAMP; | |
1795 | else | |
1796 | rec->flags &= ~FTRACE_FL_TRAMP; | |
fef5aeee | 1797 | |
79922b80 SRRH |
1798 | /* |
1799 | * flags will be cleared in ftrace_check_record() | |
1800 | * if rec count is zero. | |
1801 | */ | |
ed926f9b SR |
1802 | } |
1803 | count++; | |
84b6d3e6 JO |
1804 | |
1805 | /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */ | |
7375dca1 | 1806 | update |= ftrace_test_record(rec, true) != FTRACE_UPDATE_IGNORE; |
84b6d3e6 | 1807 | |
ed926f9b SR |
1808 | /* Shortcut, if we handled all records, we are done. */ |
1809 | if (!all && count == hash->count) | |
84b6d3e6 | 1810 | return update; |
ed926f9b | 1811 | } while_for_each_ftrace_rec(); |
84b6d3e6 JO |
1812 | |
1813 | return update; | |
ed926f9b SR |
1814 | } |
1815 | ||
84b6d3e6 | 1816 | static bool ftrace_hash_rec_disable(struct ftrace_ops *ops, |
ed926f9b SR |
1817 | int filter_hash) |
1818 | { | |
84b6d3e6 | 1819 | return __ftrace_hash_rec_update(ops, filter_hash, 0); |
ed926f9b SR |
1820 | } |
1821 | ||
84b6d3e6 | 1822 | static bool ftrace_hash_rec_enable(struct ftrace_ops *ops, |
ed926f9b SR |
1823 | int filter_hash) |
1824 | { | |
84b6d3e6 | 1825 | return __ftrace_hash_rec_update(ops, filter_hash, 1); |
ed926f9b SR |
1826 | } |
1827 | ||
84261912 SRRH |
1828 | static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops, |
1829 | int filter_hash, int inc) | |
1830 | { | |
1831 | struct ftrace_ops *op; | |
1832 | ||
1833 | __ftrace_hash_rec_update(ops, filter_hash, inc); | |
1834 | ||
1835 | if (ops->func_hash != &global_ops.local_hash) | |
1836 | return; | |
1837 | ||
1838 | /* | |
1839 | * If the ops shares the global_ops hash, then we need to update | |
1840 | * all ops that are enabled and use this hash. | |
1841 | */ | |
1842 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1843 | /* Already done */ | |
1844 | if (op == ops) | |
1845 | continue; | |
1846 | if (op->func_hash == &global_ops.local_hash) | |
1847 | __ftrace_hash_rec_update(op, filter_hash, inc); | |
1848 | } while_for_each_ftrace_op(op); | |
1849 | } | |
1850 | ||
1851 | static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, | |
1852 | int filter_hash) | |
1853 | { | |
1854 | ftrace_hash_rec_update_modify(ops, filter_hash, 0); | |
1855 | } | |
1856 | ||
1857 | static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, | |
1858 | int filter_hash) | |
1859 | { | |
1860 | ftrace_hash_rec_update_modify(ops, filter_hash, 1); | |
1861 | } | |
1862 | ||
f8b8be8a MH |
1863 | /* |
1864 | * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK | |
1865 | * or no-needed to update, -EBUSY if it detects a conflict of the flag | |
1866 | * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs. | |
1867 | * Note that old_hash and new_hash has below meanings | |
1868 | * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected) | |
1869 | * - If the hash is EMPTY_HASH, it hits nothing | |
1870 | * - Anything else hits the recs which match the hash entries. | |
1871 | */ | |
1872 | static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops, | |
1873 | struct ftrace_hash *old_hash, | |
1874 | struct ftrace_hash *new_hash) | |
1875 | { | |
1876 | struct ftrace_page *pg; | |
1877 | struct dyn_ftrace *rec, *end = NULL; | |
1878 | int in_old, in_new; | |
1879 | ||
1880 | /* Only update if the ops has been registered */ | |
1881 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
1882 | return 0; | |
1883 | ||
1884 | if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY)) | |
1885 | return 0; | |
1886 | ||
1887 | /* | |
1888 | * Since the IPMODIFY is a very address sensitive action, we do not | |
1889 | * allow ftrace_ops to set all functions to new hash. | |
1890 | */ | |
1891 | if (!new_hash || !old_hash) | |
1892 | return -EINVAL; | |
1893 | ||
1894 | /* Update rec->flags */ | |
1895 | do_for_each_ftrace_rec(pg, rec) { | |
546fece4 SRRH |
1896 | |
1897 | if (rec->flags & FTRACE_FL_DISABLED) | |
1898 | continue; | |
1899 | ||
f8b8be8a MH |
1900 | /* We need to update only differences of filter_hash */ |
1901 | in_old = !!ftrace_lookup_ip(old_hash, rec->ip); | |
1902 | in_new = !!ftrace_lookup_ip(new_hash, rec->ip); | |
1903 | if (in_old == in_new) | |
1904 | continue; | |
1905 | ||
1906 | if (in_new) { | |
1907 | /* New entries must ensure no others are using it */ | |
1908 | if (rec->flags & FTRACE_FL_IPMODIFY) | |
1909 | goto rollback; | |
1910 | rec->flags |= FTRACE_FL_IPMODIFY; | |
1911 | } else /* Removed entry */ | |
1912 | rec->flags &= ~FTRACE_FL_IPMODIFY; | |
1913 | } while_for_each_ftrace_rec(); | |
1914 | ||
1915 | return 0; | |
1916 | ||
1917 | rollback: | |
1918 | end = rec; | |
1919 | ||
1920 | /* Roll back what we did above */ | |
1921 | do_for_each_ftrace_rec(pg, rec) { | |
546fece4 SRRH |
1922 | |
1923 | if (rec->flags & FTRACE_FL_DISABLED) | |
1924 | continue; | |
1925 | ||
f8b8be8a MH |
1926 | if (rec == end) |
1927 | goto err_out; | |
1928 | ||
1929 | in_old = !!ftrace_lookup_ip(old_hash, rec->ip); | |
1930 | in_new = !!ftrace_lookup_ip(new_hash, rec->ip); | |
1931 | if (in_old == in_new) | |
1932 | continue; | |
1933 | ||
1934 | if (in_new) | |
1935 | rec->flags &= ~FTRACE_FL_IPMODIFY; | |
1936 | else | |
1937 | rec->flags |= FTRACE_FL_IPMODIFY; | |
1938 | } while_for_each_ftrace_rec(); | |
1939 | ||
1940 | err_out: | |
1941 | return -EBUSY; | |
1942 | } | |
1943 | ||
1944 | static int ftrace_hash_ipmodify_enable(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 | return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash); | |
1952 | } | |
1953 | ||
1954 | /* Disabling always succeeds */ | |
1955 | static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops) | |
1956 | { | |
1957 | struct ftrace_hash *hash = ops->func_hash->filter_hash; | |
1958 | ||
1959 | if (ftrace_hash_empty(hash)) | |
1960 | hash = NULL; | |
1961 | ||
1962 | __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH); | |
1963 | } | |
1964 | ||
1965 | static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, | |
1966 | struct ftrace_hash *new_hash) | |
1967 | { | |
1968 | struct ftrace_hash *old_hash = ops->func_hash->filter_hash; | |
1969 | ||
1970 | if (ftrace_hash_empty(old_hash)) | |
1971 | old_hash = NULL; | |
1972 | ||
1973 | if (ftrace_hash_empty(new_hash)) | |
1974 | new_hash = NULL; | |
1975 | ||
1976 | return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash); | |
1977 | } | |
1978 | ||
b05086c7 | 1979 | static void print_ip_ins(const char *fmt, const unsigned char *p) |
b17e8a37 SR |
1980 | { |
1981 | int i; | |
1982 | ||
1983 | printk(KERN_CONT "%s", fmt); | |
1984 | ||
1985 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
1986 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
1987 | } | |
1988 | ||
02a392a0 | 1989 | enum ftrace_bug_type ftrace_bug_type; |
b05086c7 | 1990 | const void *ftrace_expected; |
02a392a0 SRRH |
1991 | |
1992 | static void print_bug_type(void) | |
1993 | { | |
1994 | switch (ftrace_bug_type) { | |
1995 | case FTRACE_BUG_UNKNOWN: | |
1996 | break; | |
1997 | case FTRACE_BUG_INIT: | |
1998 | pr_info("Initializing ftrace call sites\n"); | |
1999 | break; | |
2000 | case FTRACE_BUG_NOP: | |
2001 | pr_info("Setting ftrace call site to NOP\n"); | |
2002 | break; | |
2003 | case FTRACE_BUG_CALL: | |
2004 | pr_info("Setting ftrace call site to call ftrace function\n"); | |
2005 | break; | |
2006 | case FTRACE_BUG_UPDATE: | |
2007 | pr_info("Updating ftrace call site to call a different ftrace function\n"); | |
2008 | break; | |
2009 | } | |
2010 | } | |
2011 | ||
c88fd863 SR |
2012 | /** |
2013 | * ftrace_bug - report and shutdown function tracer | |
2014 | * @failed: The failed type (EFAULT, EINVAL, EPERM) | |
4fd3279b | 2015 | * @rec: The record that failed |
c88fd863 SR |
2016 | * |
2017 | * The arch code that enables or disables the function tracing | |
2018 | * can call ftrace_bug() when it has detected a problem in | |
2019 | * modifying the code. @failed should be one of either: | |
2020 | * EFAULT - if the problem happens on reading the @ip address | |
2021 | * EINVAL - if what is read at @ip is not what was expected | |
9efb85c5 | 2022 | * EPERM - if the problem happens on writing to the @ip address |
c88fd863 | 2023 | */ |
4fd3279b | 2024 | void ftrace_bug(int failed, struct dyn_ftrace *rec) |
b17e8a37 | 2025 | { |
4fd3279b SRRH |
2026 | unsigned long ip = rec ? rec->ip : 0; |
2027 | ||
b17e8a37 SR |
2028 | switch (failed) { |
2029 | case -EFAULT: | |
2030 | FTRACE_WARN_ON_ONCE(1); | |
2031 | pr_info("ftrace faulted on modifying "); | |
2032 | print_ip_sym(ip); | |
2033 | break; | |
2034 | case -EINVAL: | |
2035 | FTRACE_WARN_ON_ONCE(1); | |
2036 | pr_info("ftrace failed to modify "); | |
2037 | print_ip_sym(ip); | |
b05086c7 | 2038 | print_ip_ins(" actual: ", (unsigned char *)ip); |
4fd3279b | 2039 | pr_cont("\n"); |
b05086c7 SRRH |
2040 | if (ftrace_expected) { |
2041 | print_ip_ins(" expected: ", ftrace_expected); | |
2042 | pr_cont("\n"); | |
2043 | } | |
b17e8a37 SR |
2044 | break; |
2045 | case -EPERM: | |
2046 | FTRACE_WARN_ON_ONCE(1); | |
2047 | pr_info("ftrace faulted on writing "); | |
2048 | print_ip_sym(ip); | |
2049 | break; | |
2050 | default: | |
2051 | FTRACE_WARN_ON_ONCE(1); | |
2052 | pr_info("ftrace faulted on unknown error "); | |
2053 | print_ip_sym(ip); | |
2054 | } | |
02a392a0 | 2055 | print_bug_type(); |
4fd3279b SRRH |
2056 | if (rec) { |
2057 | struct ftrace_ops *ops = NULL; | |
2058 | ||
2059 | pr_info("ftrace record flags: %lx\n", rec->flags); | |
2060 | pr_cont(" (%ld)%s", ftrace_rec_count(rec), | |
2061 | rec->flags & FTRACE_FL_REGS ? " R" : " "); | |
2062 | if (rec->flags & FTRACE_FL_TRAMP_EN) { | |
2063 | ops = ftrace_find_tramp_ops_any(rec); | |
39daa7b9 SRRH |
2064 | if (ops) { |
2065 | do { | |
2066 | pr_cont("\ttramp: %pS (%pS)", | |
2067 | (void *)ops->trampoline, | |
2068 | (void *)ops->func); | |
2069 | ops = ftrace_find_tramp_ops_next(rec, ops); | |
2070 | } while (ops); | |
2071 | } else | |
4fd3279b SRRH |
2072 | pr_cont("\ttramp: ERROR!"); |
2073 | ||
2074 | } | |
2075 | ip = ftrace_get_addr_curr(rec); | |
39daa7b9 | 2076 | pr_cont("\n expected tramp: %lx\n", ip); |
4fd3279b | 2077 | } |
b17e8a37 SR |
2078 | } |
2079 | ||
7375dca1 | 2080 | static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update) |
5072c59f | 2081 | { |
64fbcd16 | 2082 | unsigned long flag = 0UL; |
e7d3737e | 2083 | |
02a392a0 SRRH |
2084 | ftrace_bug_type = FTRACE_BUG_UNKNOWN; |
2085 | ||
b7ffffbb SRRH |
2086 | if (rec->flags & FTRACE_FL_DISABLED) |
2087 | return FTRACE_UPDATE_IGNORE; | |
2088 | ||
982c350b | 2089 | /* |
30fb6aa7 | 2090 | * If we are updating calls: |
982c350b | 2091 | * |
ed926f9b SR |
2092 | * If the record has a ref count, then we need to enable it |
2093 | * because someone is using it. | |
982c350b | 2094 | * |
ed926f9b SR |
2095 | * Otherwise we make sure its disabled. |
2096 | * | |
30fb6aa7 | 2097 | * If we are disabling calls, then disable all records that |
ed926f9b | 2098 | * are enabled. |
982c350b | 2099 | */ |
0376bde1 | 2100 | if (enable && ftrace_rec_count(rec)) |
ed926f9b | 2101 | flag = FTRACE_FL_ENABLED; |
982c350b | 2102 | |
08f6fba5 | 2103 | /* |
79922b80 SRRH |
2104 | * If enabling and the REGS flag does not match the REGS_EN, or |
2105 | * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore | |
2106 | * this record. Set flags to fail the compare against ENABLED. | |
763e34e7 | 2107 | * Same for direct calls. |
08f6fba5 | 2108 | */ |
79922b80 | 2109 | if (flag) { |
763e34e7 | 2110 | if (!(rec->flags & FTRACE_FL_REGS) != |
79922b80 SRRH |
2111 | !(rec->flags & FTRACE_FL_REGS_EN)) |
2112 | flag |= FTRACE_FL_REGS; | |
2113 | ||
763e34e7 | 2114 | if (!(rec->flags & FTRACE_FL_TRAMP) != |
79922b80 SRRH |
2115 | !(rec->flags & FTRACE_FL_TRAMP_EN)) |
2116 | flag |= FTRACE_FL_TRAMP; | |
763e34e7 SRV |
2117 | |
2118 | /* | |
2119 | * Direct calls are special, as count matters. | |
2120 | * We must test the record for direct, if the | |
2121 | * DIRECT and DIRECT_EN do not match, but only | |
2122 | * if the count is 1. That's because, if the | |
2123 | * count is something other than one, we do not | |
2124 | * want the direct enabled (it will be done via the | |
2125 | * direct helper). But if DIRECT_EN is set, and | |
2126 | * the count is not one, we need to clear it. | |
2127 | */ | |
2128 | if (ftrace_rec_count(rec) == 1) { | |
2129 | if (!(rec->flags & FTRACE_FL_DIRECT) != | |
2130 | !(rec->flags & FTRACE_FL_DIRECT_EN)) | |
2131 | flag |= FTRACE_FL_DIRECT; | |
2132 | } else if (rec->flags & FTRACE_FL_DIRECT_EN) { | |
2133 | flag |= FTRACE_FL_DIRECT; | |
2134 | } | |
79922b80 | 2135 | } |
08f6fba5 | 2136 | |
64fbcd16 XG |
2137 | /* If the state of this record hasn't changed, then do nothing */ |
2138 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
c88fd863 | 2139 | return FTRACE_UPDATE_IGNORE; |
982c350b | 2140 | |
64fbcd16 | 2141 | if (flag) { |
08f6fba5 SR |
2142 | /* Save off if rec is being enabled (for return value) */ |
2143 | flag ^= rec->flags & FTRACE_FL_ENABLED; | |
2144 | ||
2145 | if (update) { | |
c88fd863 | 2146 | rec->flags |= FTRACE_FL_ENABLED; |
08f6fba5 SR |
2147 | if (flag & FTRACE_FL_REGS) { |
2148 | if (rec->flags & FTRACE_FL_REGS) | |
2149 | rec->flags |= FTRACE_FL_REGS_EN; | |
2150 | else | |
2151 | rec->flags &= ~FTRACE_FL_REGS_EN; | |
2152 | } | |
79922b80 SRRH |
2153 | if (flag & FTRACE_FL_TRAMP) { |
2154 | if (rec->flags & FTRACE_FL_TRAMP) | |
2155 | rec->flags |= FTRACE_FL_TRAMP_EN; | |
2156 | else | |
2157 | rec->flags &= ~FTRACE_FL_TRAMP_EN; | |
2158 | } | |
763e34e7 SRV |
2159 | if (flag & FTRACE_FL_DIRECT) { |
2160 | /* | |
2161 | * If there's only one user (direct_ops helper) | |
2162 | * then we can call the direct function | |
2163 | * directly (no ftrace trampoline). | |
2164 | */ | |
2165 | if (ftrace_rec_count(rec) == 1) { | |
2166 | if (rec->flags & FTRACE_FL_DIRECT) | |
2167 | rec->flags |= FTRACE_FL_DIRECT_EN; | |
2168 | else | |
2169 | rec->flags &= ~FTRACE_FL_DIRECT_EN; | |
2170 | } else { | |
2171 | /* | |
2172 | * Can only call directly if there's | |
2173 | * only one callback to the function. | |
2174 | */ | |
2175 | rec->flags &= ~FTRACE_FL_DIRECT_EN; | |
2176 | } | |
2177 | } | |
08f6fba5 SR |
2178 | } |
2179 | ||
2180 | /* | |
2181 | * If this record is being updated from a nop, then | |
2182 | * return UPDATE_MAKE_CALL. | |
08f6fba5 SR |
2183 | * Otherwise, |
2184 | * return UPDATE_MODIFY_CALL to tell the caller to convert | |
f1b2f2bd | 2185 | * from the save regs, to a non-save regs function or |
79922b80 | 2186 | * vice versa, or from a trampoline call. |
08f6fba5 | 2187 | */ |
02a392a0 SRRH |
2188 | if (flag & FTRACE_FL_ENABLED) { |
2189 | ftrace_bug_type = FTRACE_BUG_CALL; | |
08f6fba5 | 2190 | return FTRACE_UPDATE_MAKE_CALL; |
02a392a0 | 2191 | } |
f1b2f2bd | 2192 | |
02a392a0 | 2193 | ftrace_bug_type = FTRACE_BUG_UPDATE; |
f1b2f2bd | 2194 | return FTRACE_UPDATE_MODIFY_CALL; |
c88fd863 SR |
2195 | } |
2196 | ||
08f6fba5 SR |
2197 | if (update) { |
2198 | /* If there's no more users, clear all flags */ | |
0376bde1 | 2199 | if (!ftrace_rec_count(rec)) |
08f6fba5 SR |
2200 | rec->flags = 0; |
2201 | else | |
b24d443b SRRH |
2202 | /* |
2203 | * Just disable the record, but keep the ops TRAMP | |
2204 | * and REGS states. The _EN flags must be disabled though. | |
2205 | */ | |
2206 | rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN | | |
763e34e7 | 2207 | FTRACE_FL_REGS_EN | FTRACE_FL_DIRECT_EN); |
08f6fba5 | 2208 | } |
c88fd863 | 2209 | |
02a392a0 | 2210 | ftrace_bug_type = FTRACE_BUG_NOP; |
c88fd863 SR |
2211 | return FTRACE_UPDATE_MAKE_NOP; |
2212 | } | |
2213 | ||
2214 | /** | |
2215 | * ftrace_update_record, set a record that now is tracing or not | |
2216 | * @rec: the record to update | |
7375dca1 | 2217 | * @enable: set to true if the record is tracing, false to force disable |
c88fd863 SR |
2218 | * |
2219 | * The records that represent all functions that can be traced need | |
2220 | * to be updated when tracing has been enabled. | |
2221 | */ | |
7375dca1 | 2222 | int ftrace_update_record(struct dyn_ftrace *rec, bool enable) |
c88fd863 | 2223 | { |
7375dca1 | 2224 | return ftrace_check_record(rec, enable, true); |
c88fd863 SR |
2225 | } |
2226 | ||
2227 | /** | |
2228 | * ftrace_test_record, check if the record has been enabled or not | |
2229 | * @rec: the record to test | |
7375dca1 | 2230 | * @enable: set to true to check if enabled, false if it is disabled |
c88fd863 SR |
2231 | * |
2232 | * The arch code may need to test if a record is already set to | |
2233 | * tracing to determine how to modify the function code that it | |
2234 | * represents. | |
2235 | */ | |
7375dca1 | 2236 | int ftrace_test_record(struct dyn_ftrace *rec, bool enable) |
c88fd863 | 2237 | { |
7375dca1 | 2238 | return ftrace_check_record(rec, enable, false); |
c88fd863 SR |
2239 | } |
2240 | ||
5fecaa04 SRRH |
2241 | static struct ftrace_ops * |
2242 | ftrace_find_tramp_ops_any(struct dyn_ftrace *rec) | |
2243 | { | |
2244 | struct ftrace_ops *op; | |
fef5aeee | 2245 | unsigned long ip = rec->ip; |
5fecaa04 SRRH |
2246 | |
2247 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2248 | ||
2249 | if (!op->trampoline) | |
2250 | continue; | |
2251 | ||
fef5aeee | 2252 | if (hash_contains_ip(ip, op->func_hash)) |
5fecaa04 SRRH |
2253 | return op; |
2254 | } while_for_each_ftrace_op(op); | |
2255 | ||
2256 | return NULL; | |
2257 | } | |
2258 | ||
39daa7b9 SRRH |
2259 | static struct ftrace_ops * |
2260 | ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, | |
2261 | struct ftrace_ops *op) | |
2262 | { | |
2263 | unsigned long ip = rec->ip; | |
2264 | ||
2265 | while_for_each_ftrace_op(op) { | |
2266 | ||
2267 | if (!op->trampoline) | |
2268 | continue; | |
2269 | ||
2270 | if (hash_contains_ip(ip, op->func_hash)) | |
2271 | return op; | |
2272 | } | |
2273 | ||
2274 | return NULL; | |
2275 | } | |
2276 | ||
79922b80 SRRH |
2277 | static struct ftrace_ops * |
2278 | ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec) | |
2279 | { | |
2280 | struct ftrace_ops *op; | |
fef5aeee | 2281 | unsigned long ip = rec->ip; |
79922b80 | 2282 | |
fef5aeee SRRH |
2283 | /* |
2284 | * Need to check removed ops first. | |
2285 | * If they are being removed, and this rec has a tramp, | |
2286 | * and this rec is in the ops list, then it would be the | |
2287 | * one with the tramp. | |
2288 | */ | |
2289 | if (removed_ops) { | |
2290 | if (hash_contains_ip(ip, &removed_ops->old_hash)) | |
79922b80 SRRH |
2291 | return removed_ops; |
2292 | } | |
2293 | ||
fef5aeee SRRH |
2294 | /* |
2295 | * Need to find the current trampoline for a rec. | |
2296 | * Now, a trampoline is only attached to a rec if there | |
2297 | * was a single 'ops' attached to it. But this can be called | |
2298 | * when we are adding another op to the rec or removing the | |
2299 | * current one. Thus, if the op is being added, we can | |
2300 | * ignore it because it hasn't attached itself to the rec | |
4fc40904 SRRH |
2301 | * yet. |
2302 | * | |
2303 | * If an ops is being modified (hooking to different functions) | |
2304 | * then we don't care about the new functions that are being | |
2305 | * added, just the old ones (that are probably being removed). | |
2306 | * | |
2307 | * If we are adding an ops to a function that already is using | |
2308 | * a trampoline, it needs to be removed (trampolines are only | |
2309 | * for single ops connected), then an ops that is not being | |
2310 | * modified also needs to be checked. | |
fef5aeee | 2311 | */ |
79922b80 | 2312 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
fef5aeee SRRH |
2313 | |
2314 | if (!op->trampoline) | |
2315 | continue; | |
2316 | ||
2317 | /* | |
2318 | * If the ops is being added, it hasn't gotten to | |
2319 | * the point to be removed from this tree yet. | |
2320 | */ | |
2321 | if (op->flags & FTRACE_OPS_FL_ADDING) | |
79922b80 SRRH |
2322 | continue; |
2323 | ||
4fc40904 | 2324 | |
fef5aeee | 2325 | /* |
4fc40904 SRRH |
2326 | * If the ops is being modified and is in the old |
2327 | * hash, then it is probably being removed from this | |
2328 | * function. | |
fef5aeee | 2329 | */ |
fef5aeee SRRH |
2330 | if ((op->flags & FTRACE_OPS_FL_MODIFYING) && |
2331 | hash_contains_ip(ip, &op->old_hash)) | |
79922b80 | 2332 | return op; |
4fc40904 SRRH |
2333 | /* |
2334 | * If the ops is not being added or modified, and it's | |
2335 | * in its normal filter hash, then this must be the one | |
2336 | * we want! | |
2337 | */ | |
2338 | if (!(op->flags & FTRACE_OPS_FL_MODIFYING) && | |
2339 | hash_contains_ip(ip, op->func_hash)) | |
2340 | return op; | |
79922b80 SRRH |
2341 | |
2342 | } while_for_each_ftrace_op(op); | |
2343 | ||
2344 | return NULL; | |
2345 | } | |
2346 | ||
2347 | static struct ftrace_ops * | |
2348 | ftrace_find_tramp_ops_new(struct dyn_ftrace *rec) | |
2349 | { | |
2350 | struct ftrace_ops *op; | |
fef5aeee | 2351 | unsigned long ip = rec->ip; |
79922b80 SRRH |
2352 | |
2353 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2354 | /* pass rec in as regs to have non-NULL val */ | |
fef5aeee | 2355 | if (hash_contains_ip(ip, op->func_hash)) |
79922b80 SRRH |
2356 | return op; |
2357 | } while_for_each_ftrace_op(op); | |
2358 | ||
2359 | return NULL; | |
2360 | } | |
2361 | ||
763e34e7 SRV |
2362 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
2363 | /* Protected by rcu_tasks for reading, and direct_mutex for writing */ | |
2364 | static struct ftrace_hash *direct_functions = EMPTY_HASH; | |
2365 | static DEFINE_MUTEX(direct_mutex); | |
a3ad1a7e | 2366 | int ftrace_direct_func_count; |
763e34e7 SRV |
2367 | |
2368 | /* | |
2369 | * Search the direct_functions hash to see if the given instruction pointer | |
2370 | * has a direct caller attached to it. | |
2371 | */ | |
ff205766 | 2372 | unsigned long ftrace_find_rec_direct(unsigned long ip) |
763e34e7 SRV |
2373 | { |
2374 | struct ftrace_func_entry *entry; | |
2375 | ||
2376 | entry = __ftrace_lookup_ip(direct_functions, ip); | |
2377 | if (!entry) | |
2378 | return 0; | |
2379 | ||
2380 | return entry->direct; | |
2381 | } | |
2382 | ||
2383 | static void call_direct_funcs(unsigned long ip, unsigned long pip, | |
2384 | struct ftrace_ops *ops, struct pt_regs *regs) | |
2385 | { | |
2386 | unsigned long addr; | |
2387 | ||
ff205766 | 2388 | addr = ftrace_find_rec_direct(ip); |
763e34e7 SRV |
2389 | if (!addr) |
2390 | return; | |
2391 | ||
2392 | arch_ftrace_set_direct_caller(regs, addr); | |
2393 | } | |
2394 | ||
2395 | struct ftrace_ops direct_ops = { | |
2396 | .func = call_direct_funcs, | |
2397 | .flags = FTRACE_OPS_FL_IPMODIFY | FTRACE_OPS_FL_RECURSION_SAFE | |
2398 | | FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_REGS | |
2399 | | FTRACE_OPS_FL_PERMANENT, | |
2400 | }; | |
763e34e7 SRV |
2401 | #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ |
2402 | ||
7413af1f SRRH |
2403 | /** |
2404 | * ftrace_get_addr_new - Get the call address to set to | |
2405 | * @rec: The ftrace record descriptor | |
2406 | * | |
2407 | * If the record has the FTRACE_FL_REGS set, that means that it | |
2408 | * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS | |
2409 | * is not not set, then it wants to convert to the normal callback. | |
2410 | * | |
2411 | * Returns the address of the trampoline to set to | |
2412 | */ | |
2413 | unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec) | |
2414 | { | |
79922b80 | 2415 | struct ftrace_ops *ops; |
763e34e7 SRV |
2416 | unsigned long addr; |
2417 | ||
2418 | if ((rec->flags & FTRACE_FL_DIRECT) && | |
2419 | (ftrace_rec_count(rec) == 1)) { | |
ff205766 | 2420 | addr = ftrace_find_rec_direct(rec->ip); |
763e34e7 SRV |
2421 | if (addr) |
2422 | return addr; | |
2423 | WARN_ON_ONCE(1); | |
2424 | } | |
79922b80 SRRH |
2425 | |
2426 | /* Trampolines take precedence over regs */ | |
2427 | if (rec->flags & FTRACE_FL_TRAMP) { | |
2428 | ops = ftrace_find_tramp_ops_new(rec); | |
2429 | if (FTRACE_WARN_ON(!ops || !ops->trampoline)) { | |
bce0b6c5 SRRH |
2430 | pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n", |
2431 | (void *)rec->ip, (void *)rec->ip, rec->flags); | |
79922b80 SRRH |
2432 | /* Ftrace is shutting down, return anything */ |
2433 | return (unsigned long)FTRACE_ADDR; | |
2434 | } | |
2435 | return ops->trampoline; | |
2436 | } | |
2437 | ||
7413af1f SRRH |
2438 | if (rec->flags & FTRACE_FL_REGS) |
2439 | return (unsigned long)FTRACE_REGS_ADDR; | |
2440 | else | |
2441 | return (unsigned long)FTRACE_ADDR; | |
2442 | } | |
2443 | ||
2444 | /** | |
2445 | * ftrace_get_addr_curr - Get the call address that is already there | |
2446 | * @rec: The ftrace record descriptor | |
2447 | * | |
2448 | * The FTRACE_FL_REGS_EN is set when the record already points to | |
2449 | * a function that saves all the regs. Basically the '_EN' version | |
2450 | * represents the current state of the function. | |
2451 | * | |
2452 | * Returns the address of the trampoline that is currently being called | |
2453 | */ | |
2454 | unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec) | |
2455 | { | |
79922b80 | 2456 | struct ftrace_ops *ops; |
763e34e7 SRV |
2457 | unsigned long addr; |
2458 | ||
2459 | /* Direct calls take precedence over trampolines */ | |
2460 | if (rec->flags & FTRACE_FL_DIRECT_EN) { | |
ff205766 | 2461 | addr = ftrace_find_rec_direct(rec->ip); |
763e34e7 SRV |
2462 | if (addr) |
2463 | return addr; | |
2464 | WARN_ON_ONCE(1); | |
2465 | } | |
79922b80 SRRH |
2466 | |
2467 | /* Trampolines take precedence over regs */ | |
2468 | if (rec->flags & FTRACE_FL_TRAMP_EN) { | |
2469 | ops = ftrace_find_tramp_ops_curr(rec); | |
2470 | if (FTRACE_WARN_ON(!ops)) { | |
a395d6a7 JP |
2471 | pr_warn("Bad trampoline accounting at: %p (%pS)\n", |
2472 | (void *)rec->ip, (void *)rec->ip); | |
79922b80 SRRH |
2473 | /* Ftrace is shutting down, return anything */ |
2474 | return (unsigned long)FTRACE_ADDR; | |
2475 | } | |
2476 | return ops->trampoline; | |
2477 | } | |
2478 | ||
7413af1f SRRH |
2479 | if (rec->flags & FTRACE_FL_REGS_EN) |
2480 | return (unsigned long)FTRACE_REGS_ADDR; | |
2481 | else | |
2482 | return (unsigned long)FTRACE_ADDR; | |
2483 | } | |
2484 | ||
c88fd863 | 2485 | static int |
7375dca1 | 2486 | __ftrace_replace_code(struct dyn_ftrace *rec, bool enable) |
c88fd863 | 2487 | { |
08f6fba5 | 2488 | unsigned long ftrace_old_addr; |
c88fd863 SR |
2489 | unsigned long ftrace_addr; |
2490 | int ret; | |
2491 | ||
7c0868e0 | 2492 | ftrace_addr = ftrace_get_addr_new(rec); |
c88fd863 | 2493 | |
7c0868e0 SRRH |
2494 | /* This needs to be done before we call ftrace_update_record */ |
2495 | ftrace_old_addr = ftrace_get_addr_curr(rec); | |
2496 | ||
2497 | ret = ftrace_update_record(rec, enable); | |
08f6fba5 | 2498 | |
02a392a0 SRRH |
2499 | ftrace_bug_type = FTRACE_BUG_UNKNOWN; |
2500 | ||
c88fd863 SR |
2501 | switch (ret) { |
2502 | case FTRACE_UPDATE_IGNORE: | |
2503 | return 0; | |
2504 | ||
2505 | case FTRACE_UPDATE_MAKE_CALL: | |
02a392a0 | 2506 | ftrace_bug_type = FTRACE_BUG_CALL; |
64fbcd16 | 2507 | return ftrace_make_call(rec, ftrace_addr); |
c88fd863 SR |
2508 | |
2509 | case FTRACE_UPDATE_MAKE_NOP: | |
02a392a0 | 2510 | ftrace_bug_type = FTRACE_BUG_NOP; |
39b5552c | 2511 | return ftrace_make_nop(NULL, rec, ftrace_old_addr); |
08f6fba5 | 2512 | |
08f6fba5 | 2513 | case FTRACE_UPDATE_MODIFY_CALL: |
02a392a0 | 2514 | ftrace_bug_type = FTRACE_BUG_UPDATE; |
08f6fba5 | 2515 | return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr); |
5072c59f SR |
2516 | } |
2517 | ||
9efb85c5 | 2518 | return -1; /* unknown ftrace bug */ |
5072c59f SR |
2519 | } |
2520 | ||
a0572f68 | 2521 | void __weak ftrace_replace_code(int mod_flags) |
3c1720f0 | 2522 | { |
3c1720f0 SR |
2523 | struct dyn_ftrace *rec; |
2524 | struct ftrace_page *pg; | |
7375dca1 | 2525 | bool enable = mod_flags & FTRACE_MODIFY_ENABLE_FL; |
a0572f68 | 2526 | int schedulable = mod_flags & FTRACE_MODIFY_MAY_SLEEP_FL; |
6a24a244 | 2527 | int failed; |
3c1720f0 | 2528 | |
45a4a237 SR |
2529 | if (unlikely(ftrace_disabled)) |
2530 | return; | |
2531 | ||
265c831c | 2532 | do_for_each_ftrace_rec(pg, rec) { |
546fece4 SRRH |
2533 | |
2534 | if (rec->flags & FTRACE_FL_DISABLED) | |
2535 | continue; | |
2536 | ||
e4f5d544 | 2537 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 2538 | if (failed) { |
4fd3279b | 2539 | ftrace_bug(failed, rec); |
3279ba37 SR |
2540 | /* Stop processing */ |
2541 | return; | |
3c1720f0 | 2542 | } |
a0572f68 SRV |
2543 | if (schedulable) |
2544 | cond_resched(); | |
265c831c | 2545 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
2546 | } |
2547 | ||
c88fd863 SR |
2548 | struct ftrace_rec_iter { |
2549 | struct ftrace_page *pg; | |
2550 | int index; | |
2551 | }; | |
2552 | ||
2553 | /** | |
2554 | * ftrace_rec_iter_start, start up iterating over traced functions | |
2555 | * | |
2556 | * Returns an iterator handle that is used to iterate over all | |
2557 | * the records that represent address locations where functions | |
2558 | * are traced. | |
2559 | * | |
2560 | * May return NULL if no records are available. | |
2561 | */ | |
2562 | struct ftrace_rec_iter *ftrace_rec_iter_start(void) | |
2563 | { | |
2564 | /* | |
2565 | * We only use a single iterator. | |
2566 | * Protected by the ftrace_lock mutex. | |
2567 | */ | |
2568 | static struct ftrace_rec_iter ftrace_rec_iter; | |
2569 | struct ftrace_rec_iter *iter = &ftrace_rec_iter; | |
2570 | ||
2571 | iter->pg = ftrace_pages_start; | |
2572 | iter->index = 0; | |
2573 | ||
2574 | /* Could have empty pages */ | |
2575 | while (iter->pg && !iter->pg->index) | |
2576 | iter->pg = iter->pg->next; | |
2577 | ||
2578 | if (!iter->pg) | |
2579 | return NULL; | |
2580 | ||
2581 | return iter; | |
2582 | } | |
2583 | ||
2584 | /** | |
2585 | * ftrace_rec_iter_next, get the next record to process. | |
2586 | * @iter: The handle to the iterator. | |
2587 | * | |
2588 | * Returns the next iterator after the given iterator @iter. | |
2589 | */ | |
2590 | struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) | |
2591 | { | |
2592 | iter->index++; | |
2593 | ||
2594 | if (iter->index >= iter->pg->index) { | |
2595 | iter->pg = iter->pg->next; | |
2596 | iter->index = 0; | |
2597 | ||
2598 | /* Could have empty pages */ | |
2599 | while (iter->pg && !iter->pg->index) | |
2600 | iter->pg = iter->pg->next; | |
2601 | } | |
2602 | ||
2603 | if (!iter->pg) | |
2604 | return NULL; | |
2605 | ||
2606 | return iter; | |
2607 | } | |
2608 | ||
2609 | /** | |
2610 | * ftrace_rec_iter_record, get the record at the iterator location | |
2611 | * @iter: The current iterator location | |
2612 | * | |
2613 | * Returns the record that the current @iter is at. | |
2614 | */ | |
2615 | struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) | |
2616 | { | |
2617 | return &iter->pg->records[iter->index]; | |
2618 | } | |
2619 | ||
492a7ea5 | 2620 | static int |
fbf6c73c | 2621 | ftrace_nop_initialize(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 | 2622 | { |
593eb8a2 | 2623 | int ret; |
3c1720f0 | 2624 | |
45a4a237 SR |
2625 | if (unlikely(ftrace_disabled)) |
2626 | return 0; | |
2627 | ||
fbf6c73c | 2628 | ret = ftrace_init_nop(mod, rec); |
593eb8a2 | 2629 | if (ret) { |
02a392a0 | 2630 | ftrace_bug_type = FTRACE_BUG_INIT; |
4fd3279b | 2631 | ftrace_bug(ret, rec); |
492a7ea5 | 2632 | return 0; |
37ad5084 | 2633 | } |
492a7ea5 | 2634 | return 1; |
3c1720f0 SR |
2635 | } |
2636 | ||
000ab691 SR |
2637 | /* |
2638 | * archs can override this function if they must do something | |
2639 | * before the modifying code is performed. | |
2640 | */ | |
2641 | int __weak ftrace_arch_code_modify_prepare(void) | |
2642 | { | |
2643 | return 0; | |
2644 | } | |
2645 | ||
2646 | /* | |
2647 | * archs can override this function if they must do something | |
2648 | * after the modifying code is performed. | |
2649 | */ | |
2650 | int __weak ftrace_arch_code_modify_post_process(void) | |
2651 | { | |
2652 | return 0; | |
2653 | } | |
2654 | ||
8ed3e2cf | 2655 | void ftrace_modify_all_code(int command) |
3d083395 | 2656 | { |
59338f75 | 2657 | int update = command & FTRACE_UPDATE_TRACE_FUNC; |
a0572f68 | 2658 | int mod_flags = 0; |
cd21067f | 2659 | int err = 0; |
59338f75 | 2660 | |
a0572f68 SRV |
2661 | if (command & FTRACE_MAY_SLEEP) |
2662 | mod_flags = FTRACE_MODIFY_MAY_SLEEP_FL; | |
2663 | ||
59338f75 SRRH |
2664 | /* |
2665 | * If the ftrace_caller calls a ftrace_ops func directly, | |
2666 | * we need to make sure that it only traces functions it | |
2667 | * expects to trace. When doing the switch of functions, | |
2668 | * we need to update to the ftrace_ops_list_func first | |
2669 | * before the transition between old and new calls are set, | |
2670 | * as the ftrace_ops_list_func will check the ops hashes | |
2671 | * to make sure the ops are having the right functions | |
2672 | * traced. | |
2673 | */ | |
cd21067f PM |
2674 | if (update) { |
2675 | err = ftrace_update_ftrace_func(ftrace_ops_list_func); | |
2676 | if (FTRACE_WARN_ON(err)) | |
2677 | return; | |
2678 | } | |
59338f75 | 2679 | |
8ed3e2cf | 2680 | if (command & FTRACE_UPDATE_CALLS) |
a0572f68 | 2681 | ftrace_replace_code(mod_flags | FTRACE_MODIFY_ENABLE_FL); |
8ed3e2cf | 2682 | else if (command & FTRACE_DISABLE_CALLS) |
a0572f68 | 2683 | ftrace_replace_code(mod_flags); |
d61f82d0 | 2684 | |
405e1d83 SRRH |
2685 | if (update && ftrace_trace_function != ftrace_ops_list_func) { |
2686 | function_trace_op = set_function_trace_op; | |
2687 | smp_wmb(); | |
2688 | /* If irqs are disabled, we are in stop machine */ | |
2689 | if (!irqs_disabled()) | |
2690 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
cd21067f PM |
2691 | err = ftrace_update_ftrace_func(ftrace_trace_function); |
2692 | if (FTRACE_WARN_ON(err)) | |
2693 | return; | |
405e1d83 | 2694 | } |
d61f82d0 | 2695 | |
8ed3e2cf | 2696 | if (command & FTRACE_START_FUNC_RET) |
cd21067f | 2697 | err = ftrace_enable_ftrace_graph_caller(); |
8ed3e2cf | 2698 | else if (command & FTRACE_STOP_FUNC_RET) |
cd21067f PM |
2699 | err = ftrace_disable_ftrace_graph_caller(); |
2700 | FTRACE_WARN_ON(err); | |
8ed3e2cf SR |
2701 | } |
2702 | ||
2703 | static int __ftrace_modify_code(void *data) | |
2704 | { | |
2705 | int *command = data; | |
2706 | ||
2707 | ftrace_modify_all_code(*command); | |
5a45cfe1 | 2708 | |
d61f82d0 | 2709 | return 0; |
3d083395 SR |
2710 | } |
2711 | ||
c88fd863 SR |
2712 | /** |
2713 | * ftrace_run_stop_machine, go back to the stop machine method | |
2714 | * @command: The command to tell ftrace what to do | |
2715 | * | |
2716 | * If an arch needs to fall back to the stop machine method, the | |
2717 | * it can call this function. | |
2718 | */ | |
2719 | void ftrace_run_stop_machine(int command) | |
2720 | { | |
2721 | stop_machine(__ftrace_modify_code, &command, NULL); | |
2722 | } | |
2723 | ||
2724 | /** | |
2725 | * arch_ftrace_update_code, modify the code to trace or not trace | |
2726 | * @command: The command that needs to be done | |
2727 | * | |
2728 | * Archs can override this function if it does not need to | |
2729 | * run stop_machine() to modify code. | |
2730 | */ | |
2731 | void __weak arch_ftrace_update_code(int command) | |
2732 | { | |
2733 | ftrace_run_stop_machine(command); | |
2734 | } | |
2735 | ||
e309b41d | 2736 | static void ftrace_run_update_code(int command) |
3d083395 | 2737 | { |
000ab691 SR |
2738 | int ret; |
2739 | ||
2740 | ret = ftrace_arch_code_modify_prepare(); | |
2741 | FTRACE_WARN_ON(ret); | |
2742 | if (ret) | |
d5b844a2 | 2743 | return; |
000ab691 | 2744 | |
c88fd863 SR |
2745 | /* |
2746 | * By default we use stop_machine() to modify the code. | |
2747 | * But archs can do what ever they want as long as it | |
2748 | * is safe. The stop_machine() is the safest, but also | |
2749 | * produces the most overhead. | |
2750 | */ | |
2751 | arch_ftrace_update_code(command); | |
2752 | ||
000ab691 SR |
2753 | ret = ftrace_arch_code_modify_post_process(); |
2754 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
2755 | } |
2756 | ||
8252ecf3 | 2757 | static void ftrace_run_modify_code(struct ftrace_ops *ops, int command, |
7485058e | 2758 | struct ftrace_ops_hash *old_hash) |
e1effa01 SRRH |
2759 | { |
2760 | ops->flags |= FTRACE_OPS_FL_MODIFYING; | |
7485058e SRRH |
2761 | ops->old_hash.filter_hash = old_hash->filter_hash; |
2762 | ops->old_hash.notrace_hash = old_hash->notrace_hash; | |
e1effa01 | 2763 | ftrace_run_update_code(command); |
8252ecf3 | 2764 | ops->old_hash.filter_hash = NULL; |
7485058e | 2765 | ops->old_hash.notrace_hash = NULL; |
e1effa01 SRRH |
2766 | ops->flags &= ~FTRACE_OPS_FL_MODIFYING; |
2767 | } | |
2768 | ||
d61f82d0 | 2769 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 2770 | static int ftrace_start_up; |
df4fc315 | 2771 | |
12cce594 SRRH |
2772 | void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops) |
2773 | { | |
2774 | } | |
2775 | ||
df4fc315 SR |
2776 | static void ftrace_startup_enable(int command) |
2777 | { | |
2778 | if (saved_ftrace_func != ftrace_trace_function) { | |
2779 | saved_ftrace_func = ftrace_trace_function; | |
2780 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2781 | } | |
2782 | ||
2783 | if (!command || !ftrace_enabled) | |
2784 | return; | |
2785 | ||
2786 | ftrace_run_update_code(command); | |
2787 | } | |
d61f82d0 | 2788 | |
e1effa01 SRRH |
2789 | static void ftrace_startup_all(int command) |
2790 | { | |
2791 | update_all_ops = true; | |
2792 | ftrace_startup_enable(command); | |
2793 | update_all_ops = false; | |
2794 | } | |
2795 | ||
3306fc4a | 2796 | int ftrace_startup(struct ftrace_ops *ops, int command) |
3d083395 | 2797 | { |
8a56d776 | 2798 | int ret; |
b848914c | 2799 | |
4eebcc81 | 2800 | if (unlikely(ftrace_disabled)) |
a1cd6173 | 2801 | return -ENODEV; |
4eebcc81 | 2802 | |
8a56d776 SRRH |
2803 | ret = __register_ftrace_function(ops); |
2804 | if (ret) | |
2805 | return ret; | |
2806 | ||
60a7ecf4 | 2807 | ftrace_start_up++; |
d61f82d0 | 2808 | |
e1effa01 SRRH |
2809 | /* |
2810 | * Note that ftrace probes uses this to start up | |
2811 | * and modify functions it will probe. But we still | |
2812 | * set the ADDING flag for modification, as probes | |
2813 | * do not have trampolines. If they add them in the | |
2814 | * future, then the probes will need to distinguish | |
2815 | * between adding and updating probes. | |
2816 | */ | |
2817 | ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING; | |
66209a5b | 2818 | |
f8b8be8a MH |
2819 | ret = ftrace_hash_ipmodify_enable(ops); |
2820 | if (ret < 0) { | |
2821 | /* Rollback registration process */ | |
2822 | __unregister_ftrace_function(ops); | |
2823 | ftrace_start_up--; | |
2824 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; | |
2825 | return ret; | |
2826 | } | |
2827 | ||
7f50d06b JO |
2828 | if (ftrace_hash_rec_enable(ops, 1)) |
2829 | command |= FTRACE_UPDATE_CALLS; | |
ed926f9b | 2830 | |
df4fc315 | 2831 | ftrace_startup_enable(command); |
a1cd6173 | 2832 | |
e1effa01 SRRH |
2833 | ops->flags &= ~FTRACE_OPS_FL_ADDING; |
2834 | ||
a1cd6173 | 2835 | return 0; |
3d083395 SR |
2836 | } |
2837 | ||
3306fc4a | 2838 | int ftrace_shutdown(struct ftrace_ops *ops, int command) |
3d083395 | 2839 | { |
8a56d776 | 2840 | int ret; |
b848914c | 2841 | |
4eebcc81 | 2842 | if (unlikely(ftrace_disabled)) |
8a56d776 SRRH |
2843 | return -ENODEV; |
2844 | ||
2845 | ret = __unregister_ftrace_function(ops); | |
2846 | if (ret) | |
2847 | return ret; | |
4eebcc81 | 2848 | |
60a7ecf4 | 2849 | ftrace_start_up--; |
9ea1a153 FW |
2850 | /* |
2851 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
2852 | * critical but the ftrace_call callers may be never nopped again after | |
2853 | * further ftrace uses. | |
2854 | */ | |
2855 | WARN_ON_ONCE(ftrace_start_up < 0); | |
2856 | ||
f8b8be8a MH |
2857 | /* Disabling ipmodify never fails */ |
2858 | ftrace_hash_ipmodify_disable(ops); | |
ed926f9b | 2859 | |
7f50d06b JO |
2860 | if (ftrace_hash_rec_disable(ops, 1)) |
2861 | command |= FTRACE_UPDATE_CALLS; | |
b848914c | 2862 | |
7f50d06b | 2863 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
3d083395 | 2864 | |
d61f82d0 SR |
2865 | if (saved_ftrace_func != ftrace_trace_function) { |
2866 | saved_ftrace_func = ftrace_trace_function; | |
2867 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2868 | } | |
3d083395 | 2869 | |
a4c35ed2 SRRH |
2870 | if (!command || !ftrace_enabled) { |
2871 | /* | |
edb096e0 SRV |
2872 | * If these are dynamic or per_cpu ops, they still |
2873 | * need their data freed. Since, function tracing is | |
a4c35ed2 SRRH |
2874 | * not currently active, we can just free them |
2875 | * without synchronizing all CPUs. | |
2876 | */ | |
b3a88803 | 2877 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) |
edb096e0 SRV |
2878 | goto free_ops; |
2879 | ||
8a56d776 | 2880 | return 0; |
a4c35ed2 | 2881 | } |
d61f82d0 | 2882 | |
79922b80 SRRH |
2883 | /* |
2884 | * If the ops uses a trampoline, then it needs to be | |
2885 | * tested first on update. | |
2886 | */ | |
e1effa01 | 2887 | ops->flags |= FTRACE_OPS_FL_REMOVING; |
79922b80 SRRH |
2888 | removed_ops = ops; |
2889 | ||
fef5aeee SRRH |
2890 | /* The trampoline logic checks the old hashes */ |
2891 | ops->old_hash.filter_hash = ops->func_hash->filter_hash; | |
2892 | ops->old_hash.notrace_hash = ops->func_hash->notrace_hash; | |
2893 | ||
d61f82d0 | 2894 | ftrace_run_update_code(command); |
a4c35ed2 | 2895 | |
84bde62c SRRH |
2896 | /* |
2897 | * If there's no more ops registered with ftrace, run a | |
2898 | * sanity check to make sure all rec flags are cleared. | |
2899 | */ | |
f86f4180 CZ |
2900 | if (rcu_dereference_protected(ftrace_ops_list, |
2901 | lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { | |
84bde62c SRRH |
2902 | struct ftrace_page *pg; |
2903 | struct dyn_ftrace *rec; | |
2904 | ||
2905 | do_for_each_ftrace_rec(pg, rec) { | |
977c1f9c | 2906 | if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_FL_DISABLED)) |
84bde62c SRRH |
2907 | pr_warn(" %pS flags:%lx\n", |
2908 | (void *)rec->ip, rec->flags); | |
2909 | } while_for_each_ftrace_rec(); | |
2910 | } | |
2911 | ||
fef5aeee SRRH |
2912 | ops->old_hash.filter_hash = NULL; |
2913 | ops->old_hash.notrace_hash = NULL; | |
2914 | ||
2915 | removed_ops = NULL; | |
e1effa01 | 2916 | ops->flags &= ~FTRACE_OPS_FL_REMOVING; |
79922b80 | 2917 | |
a4c35ed2 SRRH |
2918 | /* |
2919 | * Dynamic ops may be freed, we must make sure that all | |
2920 | * callers are done before leaving this function. | |
ba27f2bc | 2921 | * The same goes for freeing the per_cpu data of the per_cpu |
a4c35ed2 | 2922 | * ops. |
a4c35ed2 | 2923 | */ |
b3a88803 | 2924 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) { |
0598e4f0 SRV |
2925 | /* |
2926 | * We need to do a hard force of sched synchronization. | |
2927 | * This is because we use preempt_disable() to do RCU, but | |
2928 | * the function tracers can be called where RCU is not watching | |
2929 | * (like before user_exit()). We can not rely on the RCU | |
2930 | * infrastructure to do the synchronization, thus we must do it | |
2931 | * ourselves. | |
2932 | */ | |
a4c35ed2 SRRH |
2933 | schedule_on_each_cpu(ftrace_sync); |
2934 | ||
0598e4f0 SRV |
2935 | /* |
2936 | * When the kernel is preeptive, tasks can be preempted | |
2937 | * while on a ftrace trampoline. Just scheduling a task on | |
2938 | * a CPU is not good enough to flush them. Calling | |
2939 | * synchornize_rcu_tasks() will wait for those tasks to | |
2940 | * execute and either schedule voluntarily or enter user space. | |
2941 | */ | |
30c93704 | 2942 | if (IS_ENABLED(CONFIG_PREEMPTION)) |
0598e4f0 SRV |
2943 | synchronize_rcu_tasks(); |
2944 | ||
edb096e0 | 2945 | free_ops: |
12cce594 | 2946 | arch_ftrace_trampoline_free(ops); |
a4c35ed2 SRRH |
2947 | } |
2948 | ||
8a56d776 | 2949 | return 0; |
3d083395 SR |
2950 | } |
2951 | ||
e309b41d | 2952 | static void ftrace_startup_sysctl(void) |
b0fc494f | 2953 | { |
1619dc3f PA |
2954 | int command; |
2955 | ||
4eebcc81 SR |
2956 | if (unlikely(ftrace_disabled)) |
2957 | return; | |
2958 | ||
d61f82d0 SR |
2959 | /* Force update next time */ |
2960 | saved_ftrace_func = NULL; | |
60a7ecf4 | 2961 | /* ftrace_start_up is true if we want ftrace running */ |
1619dc3f PA |
2962 | if (ftrace_start_up) { |
2963 | command = FTRACE_UPDATE_CALLS; | |
2964 | if (ftrace_graph_active) | |
2965 | command |= FTRACE_START_FUNC_RET; | |
524a3868 | 2966 | ftrace_startup_enable(command); |
1619dc3f | 2967 | } |
b0fc494f SR |
2968 | } |
2969 | ||
e309b41d | 2970 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 2971 | { |
1619dc3f PA |
2972 | int command; |
2973 | ||
4eebcc81 SR |
2974 | if (unlikely(ftrace_disabled)) |
2975 | return; | |
2976 | ||
60a7ecf4 | 2977 | /* ftrace_start_up is true if ftrace is running */ |
1619dc3f PA |
2978 | if (ftrace_start_up) { |
2979 | command = FTRACE_DISABLE_CALLS; | |
2980 | if (ftrace_graph_active) | |
2981 | command |= FTRACE_STOP_FUNC_RET; | |
2982 | ftrace_run_update_code(command); | |
2983 | } | |
b0fc494f SR |
2984 | } |
2985 | ||
a5a1d1c2 | 2986 | static u64 ftrace_update_time; |
3d083395 | 2987 | unsigned long ftrace_update_tot_cnt; |
da537f0a SRV |
2988 | unsigned long ftrace_number_of_pages; |
2989 | unsigned long ftrace_number_of_groups; | |
3d083395 | 2990 | |
8c4f3c3f | 2991 | static inline int ops_traces_mod(struct ftrace_ops *ops) |
f7bc8b61 | 2992 | { |
8c4f3c3f SRRH |
2993 | /* |
2994 | * Filter_hash being empty will default to trace module. | |
2995 | * But notrace hash requires a test of individual module functions. | |
2996 | */ | |
33b7f99c SRRH |
2997 | return ftrace_hash_empty(ops->func_hash->filter_hash) && |
2998 | ftrace_hash_empty(ops->func_hash->notrace_hash); | |
8c4f3c3f SRRH |
2999 | } |
3000 | ||
3001 | /* | |
3002 | * Check if the current ops references the record. | |
3003 | * | |
3004 | * If the ops traces all functions, then it was already accounted for. | |
3005 | * If the ops does not trace the current record function, skip it. | |
3006 | * If the ops ignores the function via notrace filter, skip it. | |
3007 | */ | |
3008 | static inline bool | |
3009 | ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec) | |
3010 | { | |
3011 | /* If ops isn't enabled, ignore it */ | |
3012 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
44ec3ec0 | 3013 | return false; |
8c4f3c3f | 3014 | |
b7ffffbb | 3015 | /* If ops traces all then it includes this function */ |
8c4f3c3f | 3016 | if (ops_traces_mod(ops)) |
44ec3ec0 | 3017 | return true; |
8c4f3c3f SRRH |
3018 | |
3019 | /* The function must be in the filter */ | |
33b7f99c | 3020 | if (!ftrace_hash_empty(ops->func_hash->filter_hash) && |
2b2c279c | 3021 | !__ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip)) |
44ec3ec0 | 3022 | return false; |
f7bc8b61 | 3023 | |
8c4f3c3f | 3024 | /* If in notrace hash, we ignore it too */ |
33b7f99c | 3025 | if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip)) |
44ec3ec0 | 3026 | return false; |
8c4f3c3f | 3027 | |
44ec3ec0 | 3028 | return true; |
8c4f3c3f SRRH |
3029 | } |
3030 | ||
1dc43cf0 | 3031 | static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs) |
3d083395 | 3032 | { |
85ae32ae | 3033 | struct ftrace_page *pg; |
e94142a6 | 3034 | struct dyn_ftrace *p; |
a5a1d1c2 | 3035 | u64 start, stop; |
1dc43cf0 | 3036 | unsigned long update_cnt = 0; |
b7ffffbb | 3037 | unsigned long rec_flags = 0; |
85ae32ae | 3038 | int i; |
f7bc8b61 | 3039 | |
b7ffffbb SRRH |
3040 | start = ftrace_now(raw_smp_processor_id()); |
3041 | ||
f7bc8b61 | 3042 | /* |
b7ffffbb SRRH |
3043 | * When a module is loaded, this function is called to convert |
3044 | * the calls to mcount in its text to nops, and also to create | |
3045 | * an entry in the ftrace data. Now, if ftrace is activated | |
3046 | * after this call, but before the module sets its text to | |
3047 | * read-only, the modification of enabling ftrace can fail if | |
3048 | * the read-only is done while ftrace is converting the calls. | |
3049 | * To prevent this, the module's records are set as disabled | |
3050 | * and will be enabled after the call to set the module's text | |
3051 | * to read-only. | |
f7bc8b61 | 3052 | */ |
b7ffffbb SRRH |
3053 | if (mod) |
3054 | rec_flags |= FTRACE_FL_DISABLED; | |
3d083395 | 3055 | |
1dc43cf0 | 3056 | for (pg = new_pgs; pg; pg = pg->next) { |
3d083395 | 3057 | |
85ae32ae | 3058 | for (i = 0; i < pg->index; i++) { |
8c4f3c3f | 3059 | |
85ae32ae SR |
3060 | /* If something went wrong, bail without enabling anything */ |
3061 | if (unlikely(ftrace_disabled)) | |
3062 | return -1; | |
f22f9a89 | 3063 | |
85ae32ae | 3064 | p = &pg->records[i]; |
b7ffffbb | 3065 | p->flags = rec_flags; |
f22f9a89 | 3066 | |
85ae32ae SR |
3067 | /* |
3068 | * Do the initial record conversion from mcount jump | |
3069 | * to the NOP instructions. | |
3070 | */ | |
cbdaeaf0 | 3071 | if (!__is_defined(CC_USING_NOP_MCOUNT) && |
fbf6c73c | 3072 | !ftrace_nop_initialize(mod, p)) |
85ae32ae | 3073 | break; |
5cb084bb | 3074 | |
1dc43cf0 | 3075 | update_cnt++; |
5cb084bb | 3076 | } |
3d083395 SR |
3077 | } |
3078 | ||
750ed1a4 | 3079 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 | 3080 | ftrace_update_time = stop - start; |
1dc43cf0 | 3081 | ftrace_update_tot_cnt += update_cnt; |
3d083395 | 3082 | |
16444a8a ACM |
3083 | return 0; |
3084 | } | |
3085 | ||
a7900875 | 3086 | static int ftrace_allocate_records(struct ftrace_page *pg, int count) |
3c1720f0 | 3087 | { |
a7900875 | 3088 | int order; |
3c1720f0 | 3089 | int cnt; |
3c1720f0 | 3090 | |
a7900875 SR |
3091 | if (WARN_ON(!count)) |
3092 | return -EINVAL; | |
3093 | ||
3094 | order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE)); | |
3c1720f0 SR |
3095 | |
3096 | /* | |
a7900875 SR |
3097 | * We want to fill as much as possible. No more than a page |
3098 | * may be empty. | |
3c1720f0 | 3099 | */ |
a7900875 SR |
3100 | while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE) |
3101 | order--; | |
3c1720f0 | 3102 | |
a7900875 SR |
3103 | again: |
3104 | pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); | |
3c1720f0 | 3105 | |
a7900875 SR |
3106 | if (!pg->records) { |
3107 | /* if we can't allocate this size, try something smaller */ | |
3108 | if (!order) | |
3109 | return -ENOMEM; | |
3110 | order >>= 1; | |
3111 | goto again; | |
3112 | } | |
3c1720f0 | 3113 | |
da537f0a SRV |
3114 | ftrace_number_of_pages += 1 << order; |
3115 | ftrace_number_of_groups++; | |
3116 | ||
a7900875 SR |
3117 | cnt = (PAGE_SIZE << order) / ENTRY_SIZE; |
3118 | pg->size = cnt; | |
3c1720f0 | 3119 | |
a7900875 SR |
3120 | if (cnt > count) |
3121 | cnt = count; | |
3122 | ||
3123 | return cnt; | |
3124 | } | |
3125 | ||
3126 | static struct ftrace_page * | |
3127 | ftrace_allocate_pages(unsigned long num_to_init) | |
3128 | { | |
3129 | struct ftrace_page *start_pg; | |
3130 | struct ftrace_page *pg; | |
3131 | int order; | |
3132 | int cnt; | |
3133 | ||
3134 | if (!num_to_init) | |
9efb85c5 | 3135 | return NULL; |
a7900875 SR |
3136 | |
3137 | start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL); | |
3138 | if (!pg) | |
3139 | return NULL; | |
3140 | ||
3141 | /* | |
3142 | * Try to allocate as much as possible in one continues | |
3143 | * location that fills in all of the space. We want to | |
3144 | * waste as little space as possible. | |
3145 | */ | |
3146 | for (;;) { | |
3147 | cnt = ftrace_allocate_records(pg, num_to_init); | |
3148 | if (cnt < 0) | |
3149 | goto free_pages; | |
3150 | ||
3151 | num_to_init -= cnt; | |
3152 | if (!num_to_init) | |
3c1720f0 SR |
3153 | break; |
3154 | ||
a7900875 SR |
3155 | pg->next = kzalloc(sizeof(*pg), GFP_KERNEL); |
3156 | if (!pg->next) | |
3157 | goto free_pages; | |
3158 | ||
3c1720f0 SR |
3159 | pg = pg->next; |
3160 | } | |
3161 | ||
a7900875 SR |
3162 | return start_pg; |
3163 | ||
3164 | free_pages: | |
1f61be00 NK |
3165 | pg = start_pg; |
3166 | while (pg) { | |
a7900875 SR |
3167 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
3168 | free_pages((unsigned long)pg->records, order); | |
3169 | start_pg = pg->next; | |
3170 | kfree(pg); | |
3171 | pg = start_pg; | |
da537f0a SRV |
3172 | ftrace_number_of_pages -= 1 << order; |
3173 | ftrace_number_of_groups--; | |
a7900875 SR |
3174 | } |
3175 | pr_info("ftrace: FAILED to allocate memory for functions\n"); | |
3176 | return NULL; | |
3177 | } | |
3178 | ||
5072c59f SR |
3179 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
3180 | ||
3181 | struct ftrace_iterator { | |
98c4fd04 | 3182 | loff_t pos; |
4aeb6967 | 3183 | loff_t func_pos; |
5985ea8b | 3184 | loff_t mod_pos; |
4aeb6967 SR |
3185 | struct ftrace_page *pg; |
3186 | struct dyn_ftrace *func; | |
3187 | struct ftrace_func_probe *probe; | |
eee8ded1 | 3188 | struct ftrace_func_entry *probe_entry; |
4aeb6967 | 3189 | struct trace_parser parser; |
1cf41dd7 | 3190 | struct ftrace_hash *hash; |
33dc9b12 | 3191 | struct ftrace_ops *ops; |
5985ea8b SRV |
3192 | struct trace_array *tr; |
3193 | struct list_head *mod_list; | |
eee8ded1 | 3194 | int pidx; |
4aeb6967 SR |
3195 | int idx; |
3196 | unsigned flags; | |
5072c59f SR |
3197 | }; |
3198 | ||
8fc0c701 | 3199 | static void * |
eee8ded1 | 3200 | t_probe_next(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
3201 | { |
3202 | struct ftrace_iterator *iter = m->private; | |
d2afd57a | 3203 | struct trace_array *tr = iter->ops->private; |
04ec7bb6 | 3204 | struct list_head *func_probes; |
eee8ded1 SRV |
3205 | struct ftrace_hash *hash; |
3206 | struct list_head *next; | |
4aeb6967 | 3207 | struct hlist_node *hnd = NULL; |
8fc0c701 | 3208 | struct hlist_head *hhd; |
eee8ded1 | 3209 | int size; |
8fc0c701 | 3210 | |
8fc0c701 | 3211 | (*pos)++; |
98c4fd04 | 3212 | iter->pos = *pos; |
8fc0c701 | 3213 | |
04ec7bb6 | 3214 | if (!tr) |
8fc0c701 SR |
3215 | return NULL; |
3216 | ||
04ec7bb6 SRV |
3217 | func_probes = &tr->func_probes; |
3218 | if (list_empty(func_probes)) | |
8fc0c701 SR |
3219 | return NULL; |
3220 | ||
eee8ded1 | 3221 | if (!iter->probe) { |
04ec7bb6 | 3222 | next = func_probes->next; |
7b60f3d8 | 3223 | iter->probe = list_entry(next, struct ftrace_func_probe, list); |
eee8ded1 SRV |
3224 | } |
3225 | ||
3226 | if (iter->probe_entry) | |
3227 | hnd = &iter->probe_entry->hlist; | |
3228 | ||
3229 | hash = iter->probe->ops.func_hash->filter_hash; | |
7bd46644 | 3230 | |
372e0d01 SRV |
3231 | /* |
3232 | * A probe being registered may temporarily have an empty hash | |
3233 | * and it's at the end of the func_probes list. | |
3234 | */ | |
3235 | if (!hash || hash == EMPTY_HASH) | |
7bd46644 NR |
3236 | return NULL; |
3237 | ||
eee8ded1 SRV |
3238 | size = 1 << hash->size_bits; |
3239 | ||
3240 | retry: | |
3241 | if (iter->pidx >= size) { | |
04ec7bb6 | 3242 | if (iter->probe->list.next == func_probes) |
eee8ded1 SRV |
3243 | return NULL; |
3244 | next = iter->probe->list.next; | |
7b60f3d8 | 3245 | iter->probe = list_entry(next, struct ftrace_func_probe, list); |
eee8ded1 SRV |
3246 | hash = iter->probe->ops.func_hash->filter_hash; |
3247 | size = 1 << hash->size_bits; | |
3248 | iter->pidx = 0; | |
3249 | } | |
3250 | ||
3251 | hhd = &hash->buckets[iter->pidx]; | |
8fc0c701 SR |
3252 | |
3253 | if (hlist_empty(hhd)) { | |
eee8ded1 | 3254 | iter->pidx++; |
8fc0c701 SR |
3255 | hnd = NULL; |
3256 | goto retry; | |
3257 | } | |
3258 | ||
3259 | if (!hnd) | |
3260 | hnd = hhd->first; | |
3261 | else { | |
3262 | hnd = hnd->next; | |
3263 | if (!hnd) { | |
eee8ded1 | 3264 | iter->pidx++; |
8fc0c701 SR |
3265 | goto retry; |
3266 | } | |
3267 | } | |
3268 | ||
4aeb6967 SR |
3269 | if (WARN_ON_ONCE(!hnd)) |
3270 | return NULL; | |
3271 | ||
eee8ded1 | 3272 | iter->probe_entry = hlist_entry(hnd, struct ftrace_func_entry, hlist); |
4aeb6967 SR |
3273 | |
3274 | return iter; | |
8fc0c701 SR |
3275 | } |
3276 | ||
eee8ded1 | 3277 | static void *t_probe_start(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
3278 | { |
3279 | struct ftrace_iterator *iter = m->private; | |
3280 | void *p = NULL; | |
d82d6244 LZ |
3281 | loff_t l; |
3282 | ||
eee8ded1 | 3283 | if (!(iter->flags & FTRACE_ITER_DO_PROBES)) |
69a3083c SR |
3284 | return NULL; |
3285 | ||
5985ea8b | 3286 | if (iter->mod_pos > *pos) |
2bccfffd | 3287 | return NULL; |
8fc0c701 | 3288 | |
eee8ded1 SRV |
3289 | iter->probe = NULL; |
3290 | iter->probe_entry = NULL; | |
3291 | iter->pidx = 0; | |
5985ea8b | 3292 | for (l = 0; l <= (*pos - iter->mod_pos); ) { |
eee8ded1 | 3293 | p = t_probe_next(m, &l); |
d82d6244 LZ |
3294 | if (!p) |
3295 | break; | |
3296 | } | |
4aeb6967 SR |
3297 | if (!p) |
3298 | return NULL; | |
3299 | ||
98c4fd04 | 3300 | /* Only set this if we have an item */ |
eee8ded1 | 3301 | iter->flags |= FTRACE_ITER_PROBE; |
98c4fd04 | 3302 | |
4aeb6967 | 3303 | return iter; |
8fc0c701 SR |
3304 | } |
3305 | ||
4aeb6967 | 3306 | static int |
eee8ded1 | 3307 | t_probe_show(struct seq_file *m, struct ftrace_iterator *iter) |
8fc0c701 | 3308 | { |
eee8ded1 | 3309 | struct ftrace_func_entry *probe_entry; |
7b60f3d8 SRV |
3310 | struct ftrace_probe_ops *probe_ops; |
3311 | struct ftrace_func_probe *probe; | |
8fc0c701 | 3312 | |
eee8ded1 SRV |
3313 | probe = iter->probe; |
3314 | probe_entry = iter->probe_entry; | |
8fc0c701 | 3315 | |
eee8ded1 | 3316 | if (WARN_ON_ONCE(!probe || !probe_entry)) |
4aeb6967 | 3317 | return -EIO; |
8fc0c701 | 3318 | |
7b60f3d8 | 3319 | probe_ops = probe->probe_ops; |
809dcf29 | 3320 | |
7b60f3d8 | 3321 | if (probe_ops->print) |
6e444319 | 3322 | return probe_ops->print(m, probe_entry->ip, probe_ops, probe->data); |
8fc0c701 | 3323 | |
7b60f3d8 SRV |
3324 | seq_printf(m, "%ps:%ps\n", (void *)probe_entry->ip, |
3325 | (void *)probe_ops->func); | |
8fc0c701 SR |
3326 | |
3327 | return 0; | |
3328 | } | |
3329 | ||
5985ea8b SRV |
3330 | static void * |
3331 | t_mod_next(struct seq_file *m, loff_t *pos) | |
3332 | { | |
3333 | struct ftrace_iterator *iter = m->private; | |
3334 | struct trace_array *tr = iter->tr; | |
3335 | ||
3336 | (*pos)++; | |
3337 | iter->pos = *pos; | |
3338 | ||
3339 | iter->mod_list = iter->mod_list->next; | |
3340 | ||
3341 | if (iter->mod_list == &tr->mod_trace || | |
3342 | iter->mod_list == &tr->mod_notrace) { | |
3343 | iter->flags &= ~FTRACE_ITER_MOD; | |
3344 | return NULL; | |
3345 | } | |
3346 | ||
3347 | iter->mod_pos = *pos; | |
3348 | ||
3349 | return iter; | |
3350 | } | |
3351 | ||
3352 | static void *t_mod_start(struct seq_file *m, loff_t *pos) | |
3353 | { | |
3354 | struct ftrace_iterator *iter = m->private; | |
3355 | void *p = NULL; | |
3356 | loff_t l; | |
3357 | ||
3358 | if (iter->func_pos > *pos) | |
3359 | return NULL; | |
3360 | ||
3361 | iter->mod_pos = iter->func_pos; | |
3362 | ||
3363 | /* probes are only available if tr is set */ | |
3364 | if (!iter->tr) | |
3365 | return NULL; | |
3366 | ||
3367 | for (l = 0; l <= (*pos - iter->func_pos); ) { | |
3368 | p = t_mod_next(m, &l); | |
3369 | if (!p) | |
3370 | break; | |
3371 | } | |
3372 | if (!p) { | |
3373 | iter->flags &= ~FTRACE_ITER_MOD; | |
3374 | return t_probe_start(m, pos); | |
3375 | } | |
3376 | ||
3377 | /* Only set this if we have an item */ | |
3378 | iter->flags |= FTRACE_ITER_MOD; | |
3379 | ||
3380 | return iter; | |
3381 | } | |
3382 | ||
3383 | static int | |
3384 | t_mod_show(struct seq_file *m, struct ftrace_iterator *iter) | |
3385 | { | |
3386 | struct ftrace_mod_load *ftrace_mod; | |
3387 | struct trace_array *tr = iter->tr; | |
3388 | ||
3389 | if (WARN_ON_ONCE(!iter->mod_list) || | |
3390 | iter->mod_list == &tr->mod_trace || | |
3391 | iter->mod_list == &tr->mod_notrace) | |
3392 | return -EIO; | |
3393 | ||
3394 | ftrace_mod = list_entry(iter->mod_list, struct ftrace_mod_load, list); | |
3395 | ||
3396 | if (ftrace_mod->func) | |
3397 | seq_printf(m, "%s", ftrace_mod->func); | |
3398 | else | |
3399 | seq_putc(m, '*'); | |
3400 | ||
3401 | seq_printf(m, ":mod:%s\n", ftrace_mod->module); | |
3402 | ||
3403 | return 0; | |
3404 | } | |
3405 | ||
e309b41d | 3406 | static void * |
5bd84629 | 3407 | t_func_next(struct seq_file *m, loff_t *pos) |
5072c59f SR |
3408 | { |
3409 | struct ftrace_iterator *iter = m->private; | |
3410 | struct dyn_ftrace *rec = NULL; | |
3411 | ||
3412 | (*pos)++; | |
0c75a3ed | 3413 | |
5072c59f SR |
3414 | retry: |
3415 | if (iter->idx >= iter->pg->index) { | |
3416 | if (iter->pg->next) { | |
3417 | iter->pg = iter->pg->next; | |
3418 | iter->idx = 0; | |
3419 | goto retry; | |
3420 | } | |
3421 | } else { | |
3422 | rec = &iter->pg->records[iter->idx++]; | |
c20489da SRV |
3423 | if (((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) && |
3424 | !ftrace_lookup_ip(iter->hash, rec->ip)) || | |
647bcd03 SR |
3425 | |
3426 | ((iter->flags & FTRACE_ITER_ENABLED) && | |
23ea9c4d | 3427 | !(rec->flags & FTRACE_FL_ENABLED))) { |
647bcd03 | 3428 | |
5072c59f SR |
3429 | rec = NULL; |
3430 | goto retry; | |
3431 | } | |
3432 | } | |
3433 | ||
4aeb6967 | 3434 | if (!rec) |
5bd84629 | 3435 | return NULL; |
4aeb6967 | 3436 | |
5bd84629 | 3437 | iter->pos = iter->func_pos = *pos; |
4aeb6967 SR |
3438 | iter->func = rec; |
3439 | ||
3440 | return iter; | |
5072c59f SR |
3441 | } |
3442 | ||
5bd84629 SRV |
3443 | static void * |
3444 | t_next(struct seq_file *m, void *v, loff_t *pos) | |
3445 | { | |
3446 | struct ftrace_iterator *iter = m->private; | |
5985ea8b | 3447 | loff_t l = *pos; /* t_probe_start() must use original pos */ |
5bd84629 SRV |
3448 | void *ret; |
3449 | ||
3450 | if (unlikely(ftrace_disabled)) | |
3451 | return NULL; | |
3452 | ||
eee8ded1 SRV |
3453 | if (iter->flags & FTRACE_ITER_PROBE) |
3454 | return t_probe_next(m, pos); | |
5bd84629 | 3455 | |
5985ea8b SRV |
3456 | if (iter->flags & FTRACE_ITER_MOD) |
3457 | return t_mod_next(m, pos); | |
3458 | ||
5bd84629 | 3459 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
eee8ded1 | 3460 | /* next must increment pos, and t_probe_start does not */ |
5bd84629 | 3461 | (*pos)++; |
5985ea8b | 3462 | return t_mod_start(m, &l); |
5bd84629 SRV |
3463 | } |
3464 | ||
3465 | ret = t_func_next(m, pos); | |
3466 | ||
3467 | if (!ret) | |
5985ea8b | 3468 | return t_mod_start(m, &l); |
5bd84629 SRV |
3469 | |
3470 | return ret; | |
3471 | } | |
3472 | ||
98c4fd04 SR |
3473 | static void reset_iter_read(struct ftrace_iterator *iter) |
3474 | { | |
3475 | iter->pos = 0; | |
3476 | iter->func_pos = 0; | |
5985ea8b | 3477 | iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_PROBE | FTRACE_ITER_MOD); |
5072c59f SR |
3478 | } |
3479 | ||
3480 | static void *t_start(struct seq_file *m, loff_t *pos) | |
3481 | { | |
3482 | struct ftrace_iterator *iter = m->private; | |
3483 | void *p = NULL; | |
694ce0a5 | 3484 | loff_t l; |
5072c59f | 3485 | |
8fc0c701 | 3486 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
3487 | |
3488 | if (unlikely(ftrace_disabled)) | |
3489 | return NULL; | |
3490 | ||
98c4fd04 SR |
3491 | /* |
3492 | * If an lseek was done, then reset and start from beginning. | |
3493 | */ | |
3494 | if (*pos < iter->pos) | |
3495 | reset_iter_read(iter); | |
3496 | ||
0c75a3ed SR |
3497 | /* |
3498 | * For set_ftrace_filter reading, if we have the filter | |
3499 | * off, we can short cut and just print out that all | |
3500 | * functions are enabled. | |
3501 | */ | |
c20489da SRV |
3502 | if ((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) && |
3503 | ftrace_hash_empty(iter->hash)) { | |
43ff926a | 3504 | iter->func_pos = 1; /* Account for the message */ |
0c75a3ed | 3505 | if (*pos > 0) |
5985ea8b | 3506 | return t_mod_start(m, pos); |
0c75a3ed | 3507 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 | 3508 | /* reset in case of seek/pread */ |
eee8ded1 | 3509 | iter->flags &= ~FTRACE_ITER_PROBE; |
0c75a3ed SR |
3510 | return iter; |
3511 | } | |
3512 | ||
5985ea8b SRV |
3513 | if (iter->flags & FTRACE_ITER_MOD) |
3514 | return t_mod_start(m, pos); | |
8fc0c701 | 3515 | |
98c4fd04 SR |
3516 | /* |
3517 | * Unfortunately, we need to restart at ftrace_pages_start | |
3518 | * every time we let go of the ftrace_mutex. This is because | |
3519 | * those pointers can change without the lock. | |
3520 | */ | |
694ce0a5 LZ |
3521 | iter->pg = ftrace_pages_start; |
3522 | iter->idx = 0; | |
3523 | for (l = 0; l <= *pos; ) { | |
5bd84629 | 3524 | p = t_func_next(m, &l); |
694ce0a5 LZ |
3525 | if (!p) |
3526 | break; | |
50cdaf08 | 3527 | } |
5821e1b7 | 3528 | |
69a3083c | 3529 | if (!p) |
5985ea8b | 3530 | return t_mod_start(m, pos); |
4aeb6967 SR |
3531 | |
3532 | return iter; | |
5072c59f SR |
3533 | } |
3534 | ||
3535 | static void t_stop(struct seq_file *m, void *p) | |
3536 | { | |
8fc0c701 | 3537 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
3538 | } |
3539 | ||
15d5b02c SRRH |
3540 | void * __weak |
3541 | arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec) | |
3542 | { | |
3543 | return NULL; | |
3544 | } | |
3545 | ||
3546 | static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops, | |
3547 | struct dyn_ftrace *rec) | |
3548 | { | |
3549 | void *ptr; | |
3550 | ||
3551 | ptr = arch_ftrace_trampoline_func(ops, rec); | |
3552 | if (ptr) | |
3553 | seq_printf(m, " ->%pS", ptr); | |
3554 | } | |
3555 | ||
5072c59f SR |
3556 | static int t_show(struct seq_file *m, void *v) |
3557 | { | |
0c75a3ed | 3558 | struct ftrace_iterator *iter = m->private; |
4aeb6967 | 3559 | struct dyn_ftrace *rec; |
5072c59f | 3560 | |
eee8ded1 SRV |
3561 | if (iter->flags & FTRACE_ITER_PROBE) |
3562 | return t_probe_show(m, iter); | |
8fc0c701 | 3563 | |
5985ea8b SRV |
3564 | if (iter->flags & FTRACE_ITER_MOD) |
3565 | return t_mod_show(m, iter); | |
3566 | ||
0c75a3ed | 3567 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
8c006cf7 | 3568 | if (iter->flags & FTRACE_ITER_NOTRACE) |
fa6f0cc7 | 3569 | seq_puts(m, "#### no functions disabled ####\n"); |
8c006cf7 | 3570 | else |
fa6f0cc7 | 3571 | seq_puts(m, "#### all functions enabled ####\n"); |
0c75a3ed SR |
3572 | return 0; |
3573 | } | |
3574 | ||
4aeb6967 SR |
3575 | rec = iter->func; |
3576 | ||
5072c59f SR |
3577 | if (!rec) |
3578 | return 0; | |
3579 | ||
647bcd03 | 3580 | seq_printf(m, "%ps", (void *)rec->ip); |
9674b2fa | 3581 | if (iter->flags & FTRACE_ITER_ENABLED) { |
030f4e1c | 3582 | struct ftrace_ops *ops; |
15d5b02c | 3583 | |
763e34e7 | 3584 | seq_printf(m, " (%ld)%s%s%s", |
0376bde1 | 3585 | ftrace_rec_count(rec), |
f8b8be8a | 3586 | rec->flags & FTRACE_FL_REGS ? " R" : " ", |
763e34e7 SRV |
3587 | rec->flags & FTRACE_FL_IPMODIFY ? " I" : " ", |
3588 | rec->flags & FTRACE_FL_DIRECT ? " D" : " "); | |
9674b2fa | 3589 | if (rec->flags & FTRACE_FL_TRAMP_EN) { |
5fecaa04 | 3590 | ops = ftrace_find_tramp_ops_any(rec); |
39daa7b9 SRRH |
3591 | if (ops) { |
3592 | do { | |
3593 | seq_printf(m, "\ttramp: %pS (%pS)", | |
3594 | (void *)ops->trampoline, | |
3595 | (void *)ops->func); | |
030f4e1c | 3596 | add_trampoline_func(m, ops, rec); |
39daa7b9 SRRH |
3597 | ops = ftrace_find_tramp_ops_next(rec, ops); |
3598 | } while (ops); | |
3599 | } else | |
fa6f0cc7 | 3600 | seq_puts(m, "\ttramp: ERROR!"); |
030f4e1c SRRH |
3601 | } else { |
3602 | add_trampoline_func(m, NULL, rec); | |
9674b2fa | 3603 | } |
763e34e7 SRV |
3604 | if (rec->flags & FTRACE_FL_DIRECT) { |
3605 | unsigned long direct; | |
3606 | ||
ff205766 | 3607 | direct = ftrace_find_rec_direct(rec->ip); |
763e34e7 SRV |
3608 | if (direct) |
3609 | seq_printf(m, "\n\tdirect-->%pS", (void *)direct); | |
3610 | } | |
9674b2fa SRRH |
3611 | } |
3612 | ||
fa6f0cc7 | 3613 | seq_putc(m, '\n'); |
5072c59f SR |
3614 | |
3615 | return 0; | |
3616 | } | |
3617 | ||
88e9d34c | 3618 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
3619 | .start = t_start, |
3620 | .next = t_next, | |
3621 | .stop = t_stop, | |
3622 | .show = t_show, | |
3623 | }; | |
3624 | ||
e309b41d | 3625 | static int |
5072c59f SR |
3626 | ftrace_avail_open(struct inode *inode, struct file *file) |
3627 | { | |
3628 | struct ftrace_iterator *iter; | |
17911ff3 SRV |
3629 | int ret; |
3630 | ||
3631 | ret = security_locked_down(LOCKDOWN_TRACEFS); | |
3632 | if (ret) | |
3633 | return ret; | |
5072c59f | 3634 | |
4eebcc81 SR |
3635 | if (unlikely(ftrace_disabled)) |
3636 | return -ENODEV; | |
3637 | ||
50e18b94 | 3638 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
c1bc5919 SRV |
3639 | if (!iter) |
3640 | return -ENOMEM; | |
5072c59f | 3641 | |
c1bc5919 SRV |
3642 | iter->pg = ftrace_pages_start; |
3643 | iter->ops = &global_ops; | |
3644 | ||
3645 | return 0; | |
5072c59f SR |
3646 | } |
3647 | ||
647bcd03 SR |
3648 | static int |
3649 | ftrace_enabled_open(struct inode *inode, struct file *file) | |
3650 | { | |
3651 | struct ftrace_iterator *iter; | |
647bcd03 | 3652 | |
17911ff3 SRV |
3653 | /* |
3654 | * This shows us what functions are currently being | |
3655 | * traced and by what. Not sure if we want lockdown | |
3656 | * to hide such critical information for an admin. | |
3657 | * Although, perhaps it can show information we don't | |
3658 | * want people to see, but if something is tracing | |
3659 | * something, we probably want to know about it. | |
3660 | */ | |
3661 | ||
50e18b94 | 3662 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
c1bc5919 SRV |
3663 | if (!iter) |
3664 | return -ENOMEM; | |
647bcd03 | 3665 | |
c1bc5919 SRV |
3666 | iter->pg = ftrace_pages_start; |
3667 | iter->flags = FTRACE_ITER_ENABLED; | |
3668 | iter->ops = &global_ops; | |
3669 | ||
3670 | return 0; | |
647bcd03 SR |
3671 | } |
3672 | ||
fc13cb0c SR |
3673 | /** |
3674 | * ftrace_regex_open - initialize function tracer filter files | |
3675 | * @ops: The ftrace_ops that hold the hash filters | |
3676 | * @flag: The type of filter to process | |
3677 | * @inode: The inode, usually passed in to your open routine | |
3678 | * @file: The file, usually passed in to your open routine | |
3679 | * | |
3680 | * ftrace_regex_open() initializes the filter files for the | |
3681 | * @ops. Depending on @flag it may process the filter hash or | |
3682 | * the notrace hash of @ops. With this called from the open | |
3683 | * routine, you can use ftrace_filter_write() for the write | |
3684 | * routine if @flag has FTRACE_ITER_FILTER set, or | |
3685 | * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set. | |
098c879e | 3686 | * tracing_lseek() should be used as the lseek routine, and |
fc13cb0c SR |
3687 | * release must call ftrace_regex_release(). |
3688 | */ | |
3689 | int | |
f45948e8 | 3690 | ftrace_regex_open(struct ftrace_ops *ops, int flag, |
1cf41dd7 | 3691 | struct inode *inode, struct file *file) |
5072c59f SR |
3692 | { |
3693 | struct ftrace_iterator *iter; | |
f45948e8 | 3694 | struct ftrace_hash *hash; |
673feb9d SRV |
3695 | struct list_head *mod_head; |
3696 | struct trace_array *tr = ops->private; | |
9ef16693 | 3697 | int ret = -ENOMEM; |
5072c59f | 3698 | |
f04f24fb MH |
3699 | ftrace_ops_init(ops); |
3700 | ||
4eebcc81 SR |
3701 | if (unlikely(ftrace_disabled)) |
3702 | return -ENODEV; | |
3703 | ||
8530dec6 | 3704 | if (tracing_check_open_get_tr(tr)) |
9ef16693 SRV |
3705 | return -ENODEV; |
3706 | ||
5072c59f SR |
3707 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
3708 | if (!iter) | |
9ef16693 | 3709 | goto out; |
5072c59f | 3710 | |
9ef16693 SRV |
3711 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) |
3712 | goto out; | |
689fd8b6 | 3713 | |
3f2367ba MH |
3714 | iter->ops = ops; |
3715 | iter->flags = flag; | |
5985ea8b | 3716 | iter->tr = tr; |
3f2367ba | 3717 | |
33b7f99c | 3718 | mutex_lock(&ops->func_hash->regex_lock); |
3f2367ba | 3719 | |
673feb9d | 3720 | if (flag & FTRACE_ITER_NOTRACE) { |
33b7f99c | 3721 | hash = ops->func_hash->notrace_hash; |
5985ea8b | 3722 | mod_head = tr ? &tr->mod_notrace : NULL; |
673feb9d | 3723 | } else { |
33b7f99c | 3724 | hash = ops->func_hash->filter_hash; |
5985ea8b | 3725 | mod_head = tr ? &tr->mod_trace : NULL; |
673feb9d | 3726 | } |
f45948e8 | 3727 | |
5985ea8b SRV |
3728 | iter->mod_list = mod_head; |
3729 | ||
33dc9b12 | 3730 | if (file->f_mode & FMODE_WRITE) { |
ef2fbe16 NK |
3731 | const int size_bits = FTRACE_HASH_DEFAULT_BITS; |
3732 | ||
673feb9d | 3733 | if (file->f_flags & O_TRUNC) { |
ef2fbe16 | 3734 | iter->hash = alloc_ftrace_hash(size_bits); |
673feb9d SRV |
3735 | clear_ftrace_mod_list(mod_head); |
3736 | } else { | |
ef2fbe16 | 3737 | iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash); |
673feb9d | 3738 | } |
ef2fbe16 | 3739 | |
33dc9b12 SR |
3740 | if (!iter->hash) { |
3741 | trace_parser_put(&iter->parser); | |
3f2367ba | 3742 | goto out_unlock; |
33dc9b12 | 3743 | } |
c20489da SRV |
3744 | } else |
3745 | iter->hash = hash; | |
1cf41dd7 | 3746 | |
9ef16693 SRV |
3747 | ret = 0; |
3748 | ||
5072c59f SR |
3749 | if (file->f_mode & FMODE_READ) { |
3750 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
3751 | |
3752 | ret = seq_open(file, &show_ftrace_seq_ops); | |
3753 | if (!ret) { | |
3754 | struct seq_file *m = file->private_data; | |
3755 | m->private = iter; | |
79fe249c | 3756 | } else { |
33dc9b12 SR |
3757 | /* Failed */ |
3758 | free_ftrace_hash(iter->hash); | |
79fe249c | 3759 | trace_parser_put(&iter->parser); |
79fe249c | 3760 | } |
5072c59f SR |
3761 | } else |
3762 | file->private_data = iter; | |
3f2367ba MH |
3763 | |
3764 | out_unlock: | |
33b7f99c | 3765 | mutex_unlock(&ops->func_hash->regex_lock); |
5072c59f | 3766 | |
9ef16693 SRV |
3767 | out: |
3768 | if (ret) { | |
3769 | kfree(iter); | |
3770 | if (tr) | |
3771 | trace_array_put(tr); | |
3772 | } | |
3773 | ||
5072c59f SR |
3774 | return ret; |
3775 | } | |
3776 | ||
41c52c0d SR |
3777 | static int |
3778 | ftrace_filter_open(struct inode *inode, struct file *file) | |
3779 | { | |
e3b3e2e8 SRRH |
3780 | struct ftrace_ops *ops = inode->i_private; |
3781 | ||
17911ff3 | 3782 | /* Checks for tracefs lockdown */ |
e3b3e2e8 | 3783 | return ftrace_regex_open(ops, |
eee8ded1 | 3784 | FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES, |
69a3083c | 3785 | inode, file); |
41c52c0d SR |
3786 | } |
3787 | ||
3788 | static int | |
3789 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
3790 | { | |
e3b3e2e8 SRRH |
3791 | struct ftrace_ops *ops = inode->i_private; |
3792 | ||
17911ff3 | 3793 | /* Checks for tracefs lockdown */ |
e3b3e2e8 | 3794 | return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE, |
1cf41dd7 | 3795 | inode, file); |
41c52c0d SR |
3796 | } |
3797 | ||
3ba00929 DS |
3798 | /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */ |
3799 | struct ftrace_glob { | |
3800 | char *search; | |
3801 | unsigned len; | |
3802 | int type; | |
3803 | }; | |
3804 | ||
7132e2d6 TJB |
3805 | /* |
3806 | * If symbols in an architecture don't correspond exactly to the user-visible | |
3807 | * name of what they represent, it is possible to define this function to | |
3808 | * perform the necessary adjustments. | |
3809 | */ | |
3810 | char * __weak arch_ftrace_match_adjust(char *str, const char *search) | |
3811 | { | |
3812 | return str; | |
3813 | } | |
3814 | ||
3ba00929 | 3815 | static int ftrace_match(char *str, struct ftrace_glob *g) |
9f4801e3 | 3816 | { |
9f4801e3 | 3817 | int matched = 0; |
751e9983 | 3818 | int slen; |
9f4801e3 | 3819 | |
7132e2d6 TJB |
3820 | str = arch_ftrace_match_adjust(str, g->search); |
3821 | ||
3ba00929 | 3822 | switch (g->type) { |
9f4801e3 | 3823 | case MATCH_FULL: |
3ba00929 | 3824 | if (strcmp(str, g->search) == 0) |
9f4801e3 SR |
3825 | matched = 1; |
3826 | break; | |
3827 | case MATCH_FRONT_ONLY: | |
3ba00929 | 3828 | if (strncmp(str, g->search, g->len) == 0) |
9f4801e3 SR |
3829 | matched = 1; |
3830 | break; | |
3831 | case MATCH_MIDDLE_ONLY: | |
3ba00929 | 3832 | if (strstr(str, g->search)) |
9f4801e3 SR |
3833 | matched = 1; |
3834 | break; | |
3835 | case MATCH_END_ONLY: | |
751e9983 | 3836 | slen = strlen(str); |
3ba00929 DS |
3837 | if (slen >= g->len && |
3838 | memcmp(str + slen - g->len, g->search, g->len) == 0) | |
9f4801e3 SR |
3839 | matched = 1; |
3840 | break; | |
60f1d5e3 MH |
3841 | case MATCH_GLOB: |
3842 | if (glob_match(g->search, str)) | |
3843 | matched = 1; | |
3844 | break; | |
9f4801e3 SR |
3845 | } |
3846 | ||
3847 | return matched; | |
3848 | } | |
3849 | ||
b448c4e3 | 3850 | static int |
f0a3b154 | 3851 | enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter) |
996e87be | 3852 | { |
b448c4e3 | 3853 | struct ftrace_func_entry *entry; |
b448c4e3 SR |
3854 | int ret = 0; |
3855 | ||
1cf41dd7 | 3856 | entry = ftrace_lookup_ip(hash, rec->ip); |
f0a3b154 | 3857 | if (clear_filter) { |
1cf41dd7 SR |
3858 | /* Do nothing if it doesn't exist */ |
3859 | if (!entry) | |
3860 | return 0; | |
b448c4e3 | 3861 | |
33dc9b12 | 3862 | free_hash_entry(hash, entry); |
1cf41dd7 SR |
3863 | } else { |
3864 | /* Do nothing if it exists */ | |
3865 | if (entry) | |
3866 | return 0; | |
b448c4e3 | 3867 | |
1cf41dd7 | 3868 | ret = add_hash_entry(hash, rec->ip); |
b448c4e3 SR |
3869 | } |
3870 | return ret; | |
996e87be SR |
3871 | } |
3872 | ||
f79b3f33 SRV |
3873 | static int |
3874 | add_rec_by_index(struct ftrace_hash *hash, struct ftrace_glob *func_g, | |
3875 | int clear_filter) | |
3876 | { | |
3877 | long index = simple_strtoul(func_g->search, NULL, 0); | |
3878 | struct ftrace_page *pg; | |
3879 | struct dyn_ftrace *rec; | |
3880 | ||
3881 | /* The index starts at 1 */ | |
3882 | if (--index < 0) | |
3883 | return 0; | |
3884 | ||
3885 | do_for_each_ftrace_rec(pg, rec) { | |
3886 | if (pg->index <= index) { | |
3887 | index -= pg->index; | |
3888 | /* this is a double loop, break goes to the next page */ | |
3889 | break; | |
3890 | } | |
3891 | rec = &pg->records[index]; | |
3892 | enter_record(hash, rec, clear_filter); | |
3893 | return 1; | |
3894 | } while_for_each_ftrace_rec(); | |
3895 | return 0; | |
3896 | } | |
3897 | ||
64e7c440 | 3898 | static int |
0b507e1e DS |
3899 | ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g, |
3900 | struct ftrace_glob *mod_g, int exclude_mod) | |
64e7c440 SR |
3901 | { |
3902 | char str[KSYM_SYMBOL_LEN]; | |
b9df92d2 SR |
3903 | char *modname; |
3904 | ||
3905 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
3906 | ||
0b507e1e DS |
3907 | if (mod_g) { |
3908 | int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0; | |
3909 | ||
3910 | /* blank module name to match all modules */ | |
3911 | if (!mod_g->len) { | |
3912 | /* blank module globbing: modname xor exclude_mod */ | |
77c0edde | 3913 | if (!exclude_mod != !modname) |
0b507e1e DS |
3914 | goto func_match; |
3915 | return 0; | |
3916 | } | |
3917 | ||
77c0edde SRV |
3918 | /* |
3919 | * exclude_mod is set to trace everything but the given | |
3920 | * module. If it is set and the module matches, then | |
3921 | * return 0. If it is not set, and the module doesn't match | |
3922 | * also return 0. Otherwise, check the function to see if | |
3923 | * that matches. | |
3924 | */ | |
3925 | if (!mod_matches == !exclude_mod) | |
b9df92d2 | 3926 | return 0; |
0b507e1e | 3927 | func_match: |
b9df92d2 | 3928 | /* blank search means to match all funcs in the mod */ |
3ba00929 | 3929 | if (!func_g->len) |
b9df92d2 SR |
3930 | return 1; |
3931 | } | |
64e7c440 | 3932 | |
3ba00929 | 3933 | return ftrace_match(str, func_g); |
64e7c440 SR |
3934 | } |
3935 | ||
1cf41dd7 | 3936 | static int |
3ba00929 | 3937 | match_records(struct ftrace_hash *hash, char *func, int len, char *mod) |
9f4801e3 | 3938 | { |
9f4801e3 SR |
3939 | struct ftrace_page *pg; |
3940 | struct dyn_ftrace *rec; | |
3ba00929 | 3941 | struct ftrace_glob func_g = { .type = MATCH_FULL }; |
0b507e1e DS |
3942 | struct ftrace_glob mod_g = { .type = MATCH_FULL }; |
3943 | struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL; | |
3944 | int exclude_mod = 0; | |
311d16da | 3945 | int found = 0; |
b448c4e3 | 3946 | int ret; |
2e028c4f | 3947 | int clear_filter = 0; |
9f4801e3 | 3948 | |
0b507e1e | 3949 | if (func) { |
3ba00929 DS |
3950 | func_g.type = filter_parse_regex(func, len, &func_g.search, |
3951 | &clear_filter); | |
3952 | func_g.len = strlen(func_g.search); | |
b9df92d2 | 3953 | } |
9f4801e3 | 3954 | |
0b507e1e DS |
3955 | if (mod) { |
3956 | mod_g.type = filter_parse_regex(mod, strlen(mod), | |
3957 | &mod_g.search, &exclude_mod); | |
3958 | mod_g.len = strlen(mod_g.search); | |
b9df92d2 | 3959 | } |
9f4801e3 | 3960 | |
52baf119 | 3961 | mutex_lock(&ftrace_lock); |
265c831c | 3962 | |
b9df92d2 SR |
3963 | if (unlikely(ftrace_disabled)) |
3964 | goto out_unlock; | |
9f4801e3 | 3965 | |
f79b3f33 SRV |
3966 | if (func_g.type == MATCH_INDEX) { |
3967 | found = add_rec_by_index(hash, &func_g, clear_filter); | |
3968 | goto out_unlock; | |
3969 | } | |
3970 | ||
265c831c | 3971 | do_for_each_ftrace_rec(pg, rec) { |
546fece4 SRRH |
3972 | |
3973 | if (rec->flags & FTRACE_FL_DISABLED) | |
3974 | continue; | |
3975 | ||
0b507e1e | 3976 | if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) { |
f0a3b154 | 3977 | ret = enter_record(hash, rec, clear_filter); |
b448c4e3 SR |
3978 | if (ret < 0) { |
3979 | found = ret; | |
3980 | goto out_unlock; | |
3981 | } | |
311d16da | 3982 | found = 1; |
265c831c SR |
3983 | } |
3984 | } while_for_each_ftrace_rec(); | |
b9df92d2 | 3985 | out_unlock: |
52baf119 | 3986 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
3987 | |
3988 | return found; | |
5072c59f SR |
3989 | } |
3990 | ||
64e7c440 | 3991 | static int |
1cf41dd7 | 3992 | ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) |
64e7c440 | 3993 | { |
f0a3b154 | 3994 | return match_records(hash, buff, len, NULL); |
64e7c440 SR |
3995 | } |
3996 | ||
e16b35dd SRV |
3997 | static void ftrace_ops_update_code(struct ftrace_ops *ops, |
3998 | struct ftrace_ops_hash *old_hash) | |
3999 | { | |
4000 | struct ftrace_ops *op; | |
4001 | ||
4002 | if (!ftrace_enabled) | |
4003 | return; | |
4004 | ||
4005 | if (ops->flags & FTRACE_OPS_FL_ENABLED) { | |
4006 | ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash); | |
4007 | return; | |
4008 | } | |
4009 | ||
4010 | /* | |
4011 | * If this is the shared global_ops filter, then we need to | |
4012 | * check if there is another ops that shares it, is enabled. | |
4013 | * If so, we still need to run the modify code. | |
4014 | */ | |
4015 | if (ops->func_hash != &global_ops.local_hash) | |
4016 | return; | |
4017 | ||
4018 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
4019 | if (op->func_hash == &global_ops.local_hash && | |
4020 | op->flags & FTRACE_OPS_FL_ENABLED) { | |
4021 | ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash); | |
4022 | /* Only need to do this once */ | |
4023 | return; | |
4024 | } | |
4025 | } while_for_each_ftrace_op(op); | |
4026 | } | |
4027 | ||
4028 | static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops, | |
4029 | struct ftrace_hash **orig_hash, | |
4030 | struct ftrace_hash *hash, | |
4031 | int enable) | |
4032 | { | |
4033 | struct ftrace_ops_hash old_hash_ops; | |
4034 | struct ftrace_hash *old_hash; | |
4035 | int ret; | |
4036 | ||
4037 | old_hash = *orig_hash; | |
4038 | old_hash_ops.filter_hash = ops->func_hash->filter_hash; | |
4039 | old_hash_ops.notrace_hash = ops->func_hash->notrace_hash; | |
4040 | ret = ftrace_hash_move(ops, enable, orig_hash, hash); | |
4041 | if (!ret) { | |
4042 | ftrace_ops_update_code(ops, &old_hash_ops); | |
4043 | free_ftrace_hash_rcu(old_hash); | |
4044 | } | |
4045 | return ret; | |
4046 | } | |
64e7c440 | 4047 | |
673feb9d SRV |
4048 | static bool module_exists(const char *module) |
4049 | { | |
4050 | /* All modules have the symbol __this_module */ | |
0f5e5a3a | 4051 | static const char this_mod[] = "__this_module"; |
419e9fe5 | 4052 | char modname[MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 2]; |
673feb9d SRV |
4053 | unsigned long val; |
4054 | int n; | |
4055 | ||
419e9fe5 | 4056 | n = snprintf(modname, sizeof(modname), "%s:%s", module, this_mod); |
673feb9d | 4057 | |
419e9fe5 | 4058 | if (n > sizeof(modname) - 1) |
673feb9d SRV |
4059 | return false; |
4060 | ||
4061 | val = module_kallsyms_lookup_name(modname); | |
4062 | return val != 0; | |
4063 | } | |
4064 | ||
4065 | static int cache_mod(struct trace_array *tr, | |
4066 | const char *func, char *module, int enable) | |
4067 | { | |
4068 | struct ftrace_mod_load *ftrace_mod, *n; | |
4069 | struct list_head *head = enable ? &tr->mod_trace : &tr->mod_notrace; | |
4070 | int ret; | |
4071 | ||
4072 | mutex_lock(&ftrace_lock); | |
4073 | ||
4074 | /* We do not cache inverse filters */ | |
4075 | if (func[0] == '!') { | |
4076 | func++; | |
4077 | ret = -EINVAL; | |
4078 | ||
4079 | /* Look to remove this hash */ | |
4080 | list_for_each_entry_safe(ftrace_mod, n, head, list) { | |
4081 | if (strcmp(ftrace_mod->module, module) != 0) | |
4082 | continue; | |
4083 | ||
4084 | /* no func matches all */ | |
44925dff | 4085 | if (strcmp(func, "*") == 0 || |
673feb9d SRV |
4086 | (ftrace_mod->func && |
4087 | strcmp(ftrace_mod->func, func) == 0)) { | |
4088 | ret = 0; | |
4089 | free_ftrace_mod(ftrace_mod); | |
4090 | continue; | |
4091 | } | |
4092 | } | |
4093 | goto out; | |
4094 | } | |
4095 | ||
4096 | ret = -EINVAL; | |
4097 | /* We only care about modules that have not been loaded yet */ | |
4098 | if (module_exists(module)) | |
4099 | goto out; | |
4100 | ||
4101 | /* Save this string off, and execute it when the module is loaded */ | |
4102 | ret = ftrace_add_mod(tr, func, module, enable); | |
4103 | out: | |
4104 | mutex_unlock(&ftrace_lock); | |
4105 | ||
4106 | return ret; | |
4107 | } | |
4108 | ||
d7fbf8df SRV |
4109 | static int |
4110 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, | |
4111 | int reset, int enable); | |
4112 | ||
69449bbd | 4113 | #ifdef CONFIG_MODULES |
d7fbf8df SRV |
4114 | static void process_mod_list(struct list_head *head, struct ftrace_ops *ops, |
4115 | char *mod, bool enable) | |
4116 | { | |
4117 | struct ftrace_mod_load *ftrace_mod, *n; | |
4118 | struct ftrace_hash **orig_hash, *new_hash; | |
4119 | LIST_HEAD(process_mods); | |
4120 | char *func; | |
4121 | int ret; | |
4122 | ||
4123 | mutex_lock(&ops->func_hash->regex_lock); | |
4124 | ||
4125 | if (enable) | |
4126 | orig_hash = &ops->func_hash->filter_hash; | |
4127 | else | |
4128 | orig_hash = &ops->func_hash->notrace_hash; | |
4129 | ||
4130 | new_hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, | |
4131 | *orig_hash); | |
4132 | if (!new_hash) | |
3b58a3c7 | 4133 | goto out; /* warn? */ |
d7fbf8df SRV |
4134 | |
4135 | mutex_lock(&ftrace_lock); | |
4136 | ||
4137 | list_for_each_entry_safe(ftrace_mod, n, head, list) { | |
4138 | ||
4139 | if (strcmp(ftrace_mod->module, mod) != 0) | |
4140 | continue; | |
4141 | ||
4142 | if (ftrace_mod->func) | |
4143 | func = kstrdup(ftrace_mod->func, GFP_KERNEL); | |
4144 | else | |
4145 | func = kstrdup("*", GFP_KERNEL); | |
4146 | ||
4147 | if (!func) /* warn? */ | |
4148 | continue; | |
4149 | ||
4150 | list_del(&ftrace_mod->list); | |
4151 | list_add(&ftrace_mod->list, &process_mods); | |
4152 | ||
4153 | /* Use the newly allocated func, as it may be "*" */ | |
4154 | kfree(ftrace_mod->func); | |
4155 | ftrace_mod->func = func; | |
4156 | } | |
4157 | ||
4158 | mutex_unlock(&ftrace_lock); | |
4159 | ||
4160 | list_for_each_entry_safe(ftrace_mod, n, &process_mods, list) { | |
4161 | ||
4162 | func = ftrace_mod->func; | |
4163 | ||
4164 | /* Grabs ftrace_lock, which is why we have this extra step */ | |
4165 | match_records(new_hash, func, strlen(func), mod); | |
4166 | free_ftrace_mod(ftrace_mod); | |
4167 | } | |
4168 | ||
8c08f0d5 SRV |
4169 | if (enable && list_empty(head)) |
4170 | new_hash->flags &= ~FTRACE_HASH_FL_MOD; | |
4171 | ||
d7fbf8df SRV |
4172 | mutex_lock(&ftrace_lock); |
4173 | ||
4174 | ret = ftrace_hash_move_and_update_ops(ops, orig_hash, | |
4175 | new_hash, enable); | |
4176 | mutex_unlock(&ftrace_lock); | |
4177 | ||
3b58a3c7 | 4178 | out: |
d7fbf8df SRV |
4179 | mutex_unlock(&ops->func_hash->regex_lock); |
4180 | ||
4181 | free_ftrace_hash(new_hash); | |
4182 | } | |
4183 | ||
4184 | static void process_cached_mods(const char *mod_name) | |
4185 | { | |
4186 | struct trace_array *tr; | |
4187 | char *mod; | |
4188 | ||
4189 | mod = kstrdup(mod_name, GFP_KERNEL); | |
4190 | if (!mod) | |
4191 | return; | |
4192 | ||
4193 | mutex_lock(&trace_types_lock); | |
4194 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
4195 | if (!list_empty(&tr->mod_trace)) | |
4196 | process_mod_list(&tr->mod_trace, tr->ops, mod, true); | |
4197 | if (!list_empty(&tr->mod_notrace)) | |
4198 | process_mod_list(&tr->mod_notrace, tr->ops, mod, false); | |
4199 | } | |
4200 | mutex_unlock(&trace_types_lock); | |
4201 | ||
4202 | kfree(mod); | |
4203 | } | |
69449bbd | 4204 | #endif |
d7fbf8df | 4205 | |
f6180773 SR |
4206 | /* |
4207 | * We register the module command as a template to show others how | |
4208 | * to register the a command as well. | |
4209 | */ | |
4210 | ||
4211 | static int | |
04ec7bb6 | 4212 | ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash, |
673feb9d | 4213 | char *func_orig, char *cmd, char *module, int enable) |
f6180773 | 4214 | { |
673feb9d | 4215 | char *func; |
5e3949f0 | 4216 | int ret; |
f6180773 | 4217 | |
673feb9d SRV |
4218 | /* match_records() modifies func, and we need the original */ |
4219 | func = kstrdup(func_orig, GFP_KERNEL); | |
4220 | if (!func) | |
4221 | return -ENOMEM; | |
4222 | ||
f6180773 SR |
4223 | /* |
4224 | * cmd == 'mod' because we only registered this func | |
4225 | * for the 'mod' ftrace_func_command. | |
4226 | * But if you register one func with multiple commands, | |
4227 | * you can tell which command was used by the cmd | |
4228 | * parameter. | |
4229 | */ | |
f0a3b154 | 4230 | ret = match_records(hash, func, strlen(func), module); |
673feb9d SRV |
4231 | kfree(func); |
4232 | ||
b448c4e3 | 4233 | if (!ret) |
673feb9d | 4234 | return cache_mod(tr, func_orig, module, enable); |
b448c4e3 SR |
4235 | if (ret < 0) |
4236 | return ret; | |
b448c4e3 | 4237 | return 0; |
f6180773 SR |
4238 | } |
4239 | ||
4240 | static struct ftrace_func_command ftrace_mod_cmd = { | |
4241 | .name = "mod", | |
4242 | .func = ftrace_mod_callback, | |
4243 | }; | |
4244 | ||
4245 | static int __init ftrace_mod_cmd_init(void) | |
4246 | { | |
4247 | return register_ftrace_command(&ftrace_mod_cmd); | |
4248 | } | |
6f415672 | 4249 | core_initcall(ftrace_mod_cmd_init); |
f6180773 | 4250 | |
2f5f6ad9 | 4251 | static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 4252 | struct ftrace_ops *op, struct pt_regs *pt_regs) |
59df055f | 4253 | { |
eee8ded1 | 4254 | struct ftrace_probe_ops *probe_ops; |
7b60f3d8 | 4255 | struct ftrace_func_probe *probe; |
59df055f | 4256 | |
7b60f3d8 SRV |
4257 | probe = container_of(op, struct ftrace_func_probe, ops); |
4258 | probe_ops = probe->probe_ops; | |
59df055f SR |
4259 | |
4260 | /* | |
4261 | * Disable preemption for these calls to prevent a RCU grace | |
4262 | * period. This syncs the hash iteration and freeing of items | |
4263 | * on the hash. rcu_read_lock is too dangerous here. | |
4264 | */ | |
5168ae50 | 4265 | preempt_disable_notrace(); |
6e444319 | 4266 | probe_ops->func(ip, parent_ip, probe->tr, probe_ops, probe->data); |
5168ae50 | 4267 | preempt_enable_notrace(); |
59df055f SR |
4268 | } |
4269 | ||
41794f19 SRV |
4270 | struct ftrace_func_map { |
4271 | struct ftrace_func_entry entry; | |
4272 | void *data; | |
59df055f SR |
4273 | }; |
4274 | ||
41794f19 SRV |
4275 | struct ftrace_func_mapper { |
4276 | struct ftrace_hash hash; | |
4277 | }; | |
59df055f | 4278 | |
41794f19 SRV |
4279 | /** |
4280 | * allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper | |
4281 | * | |
4282 | * Returns a ftrace_func_mapper descriptor that can be used to map ips to data. | |
4283 | */ | |
4284 | struct ftrace_func_mapper *allocate_ftrace_func_mapper(void) | |
59df055f | 4285 | { |
41794f19 | 4286 | struct ftrace_hash *hash; |
59df055f | 4287 | |
41794f19 SRV |
4288 | /* |
4289 | * The mapper is simply a ftrace_hash, but since the entries | |
4290 | * in the hash are not ftrace_func_entry type, we define it | |
4291 | * as a separate structure. | |
4292 | */ | |
4293 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); | |
4294 | return (struct ftrace_func_mapper *)hash; | |
4295 | } | |
59df055f | 4296 | |
41794f19 SRV |
4297 | /** |
4298 | * ftrace_func_mapper_find_ip - Find some data mapped to an ip | |
4299 | * @mapper: The mapper that has the ip maps | |
4300 | * @ip: the instruction pointer to find the data for | |
4301 | * | |
4302 | * Returns the data mapped to @ip if found otherwise NULL. The return | |
4303 | * is actually the address of the mapper data pointer. The address is | |
4304 | * returned for use cases where the data is no bigger than a long, and | |
4305 | * the user can use the data pointer as its data instead of having to | |
4306 | * allocate more memory for the reference. | |
4307 | */ | |
4308 | void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper, | |
4309 | unsigned long ip) | |
4310 | { | |
4311 | struct ftrace_func_entry *entry; | |
4312 | struct ftrace_func_map *map; | |
59df055f | 4313 | |
41794f19 SRV |
4314 | entry = ftrace_lookup_ip(&mapper->hash, ip); |
4315 | if (!entry) | |
4316 | return NULL; | |
b848914c | 4317 | |
41794f19 SRV |
4318 | map = (struct ftrace_func_map *)entry; |
4319 | return &map->data; | |
59df055f SR |
4320 | } |
4321 | ||
41794f19 SRV |
4322 | /** |
4323 | * ftrace_func_mapper_add_ip - Map some data to an ip | |
4324 | * @mapper: The mapper that has the ip maps | |
4325 | * @ip: The instruction pointer address to map @data to | |
4326 | * @data: The data to map to @ip | |
4327 | * | |
4328 | * Returns 0 on succes otherwise an error. | |
4329 | */ | |
4330 | int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper, | |
4331 | unsigned long ip, void *data) | |
59df055f | 4332 | { |
41794f19 SRV |
4333 | struct ftrace_func_entry *entry; |
4334 | struct ftrace_func_map *map; | |
59df055f | 4335 | |
41794f19 SRV |
4336 | entry = ftrace_lookup_ip(&mapper->hash, ip); |
4337 | if (entry) | |
4338 | return -EBUSY; | |
59df055f | 4339 | |
41794f19 SRV |
4340 | map = kmalloc(sizeof(*map), GFP_KERNEL); |
4341 | if (!map) | |
4342 | return -ENOMEM; | |
59df055f | 4343 | |
41794f19 SRV |
4344 | map->entry.ip = ip; |
4345 | map->data = data; | |
b848914c | 4346 | |
41794f19 | 4347 | __add_hash_entry(&mapper->hash, &map->entry); |
59df055f | 4348 | |
41794f19 SRV |
4349 | return 0; |
4350 | } | |
59df055f | 4351 | |
41794f19 SRV |
4352 | /** |
4353 | * ftrace_func_mapper_remove_ip - Remove an ip from the mapping | |
4354 | * @mapper: The mapper that has the ip maps | |
4355 | * @ip: The instruction pointer address to remove the data from | |
4356 | * | |
4357 | * Returns the data if it is found, otherwise NULL. | |
4358 | * Note, if the data pointer is used as the data itself, (see | |
4359 | * ftrace_func_mapper_find_ip(), then the return value may be meaningless, | |
4360 | * if the data pointer was set to zero. | |
4361 | */ | |
4362 | void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper, | |
4363 | unsigned long ip) | |
59df055f | 4364 | { |
41794f19 SRV |
4365 | struct ftrace_func_entry *entry; |
4366 | struct ftrace_func_map *map; | |
4367 | void *data; | |
4368 | ||
4369 | entry = ftrace_lookup_ip(&mapper->hash, ip); | |
4370 | if (!entry) | |
4371 | return NULL; | |
4372 | ||
4373 | map = (struct ftrace_func_map *)entry; | |
4374 | data = map->data; | |
4375 | ||
4376 | remove_hash_entry(&mapper->hash, entry); | |
59df055f | 4377 | kfree(entry); |
41794f19 SRV |
4378 | |
4379 | return data; | |
4380 | } | |
4381 | ||
4382 | /** | |
4383 | * free_ftrace_func_mapper - free a mapping of ips and data | |
4384 | * @mapper: The mapper that has the ip maps | |
4385 | * @free_func: A function to be called on each data item. | |
4386 | * | |
4387 | * This is used to free the function mapper. The @free_func is optional | |
4388 | * and can be used if the data needs to be freed as well. | |
4389 | */ | |
4390 | void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper, | |
4391 | ftrace_mapper_func free_func) | |
4392 | { | |
4393 | struct ftrace_func_entry *entry; | |
4394 | struct ftrace_func_map *map; | |
4395 | struct hlist_head *hhd; | |
04e03d9a WL |
4396 | int size, i; |
4397 | ||
4398 | if (!mapper) | |
4399 | return; | |
41794f19 SRV |
4400 | |
4401 | if (free_func && mapper->hash.count) { | |
04e03d9a | 4402 | size = 1 << mapper->hash.size_bits; |
41794f19 SRV |
4403 | for (i = 0; i < size; i++) { |
4404 | hhd = &mapper->hash.buckets[i]; | |
4405 | hlist_for_each_entry(entry, hhd, hlist) { | |
4406 | map = (struct ftrace_func_map *)entry; | |
4407 | free_func(map); | |
4408 | } | |
4409 | } | |
4410 | } | |
4411 | free_ftrace_hash(&mapper->hash); | |
4412 | } | |
4413 | ||
7b60f3d8 SRV |
4414 | static void release_probe(struct ftrace_func_probe *probe) |
4415 | { | |
4416 | struct ftrace_probe_ops *probe_ops; | |
4417 | ||
4418 | mutex_lock(&ftrace_lock); | |
4419 | ||
4420 | WARN_ON(probe->ref <= 0); | |
4421 | ||
4422 | /* Subtract the ref that was used to protect this instance */ | |
4423 | probe->ref--; | |
4424 | ||
4425 | if (!probe->ref) { | |
4426 | probe_ops = probe->probe_ops; | |
6e444319 SRV |
4427 | /* |
4428 | * Sending zero as ip tells probe_ops to free | |
4429 | * the probe->data itself | |
4430 | */ | |
4431 | if (probe_ops->free) | |
4432 | probe_ops->free(probe_ops, probe->tr, 0, probe->data); | |
7b60f3d8 SRV |
4433 | list_del(&probe->list); |
4434 | kfree(probe); | |
4435 | } | |
4436 | mutex_unlock(&ftrace_lock); | |
4437 | } | |
4438 | ||
4439 | static void acquire_probe_locked(struct ftrace_func_probe *probe) | |
4440 | { | |
4441 | /* | |
4442 | * Add one ref to keep it from being freed when releasing the | |
4443 | * ftrace_lock mutex. | |
4444 | */ | |
4445 | probe->ref++; | |
59df055f SR |
4446 | } |
4447 | ||
59df055f | 4448 | int |
04ec7bb6 | 4449 | register_ftrace_function_probe(char *glob, struct trace_array *tr, |
7b60f3d8 SRV |
4450 | struct ftrace_probe_ops *probe_ops, |
4451 | void *data) | |
59df055f | 4452 | { |
1ec3a81a | 4453 | struct ftrace_func_entry *entry; |
7b60f3d8 | 4454 | struct ftrace_func_probe *probe; |
1ec3a81a SRV |
4455 | struct ftrace_hash **orig_hash; |
4456 | struct ftrace_hash *old_hash; | |
e1df4cb6 | 4457 | struct ftrace_hash *hash; |
59df055f | 4458 | int count = 0; |
1ec3a81a | 4459 | int size; |
e1df4cb6 | 4460 | int ret; |
1ec3a81a | 4461 | int i; |
59df055f | 4462 | |
04ec7bb6 | 4463 | if (WARN_ON(!tr)) |
59df055f SR |
4464 | return -EINVAL; |
4465 | ||
1ec3a81a SRV |
4466 | /* We do not support '!' for function probes */ |
4467 | if (WARN_ON(glob[0] == '!')) | |
59df055f | 4468 | return -EINVAL; |
59df055f | 4469 | |
7485058e | 4470 | |
7b60f3d8 SRV |
4471 | mutex_lock(&ftrace_lock); |
4472 | /* Check if the probe_ops is already registered */ | |
4473 | list_for_each_entry(probe, &tr->func_probes, list) { | |
4474 | if (probe->probe_ops == probe_ops) | |
4475 | break; | |
e1df4cb6 | 4476 | } |
7b60f3d8 SRV |
4477 | if (&probe->list == &tr->func_probes) { |
4478 | probe = kzalloc(sizeof(*probe), GFP_KERNEL); | |
4479 | if (!probe) { | |
4480 | mutex_unlock(&ftrace_lock); | |
4481 | return -ENOMEM; | |
4482 | } | |
4483 | probe->probe_ops = probe_ops; | |
4484 | probe->ops.func = function_trace_probe_call; | |
4485 | probe->tr = tr; | |
4486 | ftrace_ops_init(&probe->ops); | |
4487 | list_add(&probe->list, &tr->func_probes); | |
e1df4cb6 | 4488 | } |
59df055f | 4489 | |
7b60f3d8 | 4490 | acquire_probe_locked(probe); |
5ae0bf59 | 4491 | |
7b60f3d8 | 4492 | mutex_unlock(&ftrace_lock); |
59df055f | 4493 | |
372e0d01 SRV |
4494 | /* |
4495 | * Note, there's a small window here that the func_hash->filter_hash | |
4496 | * may be NULL or empty. Need to be carefule when reading the loop. | |
4497 | */ | |
7b60f3d8 | 4498 | mutex_lock(&probe->ops.func_hash->regex_lock); |
546fece4 | 4499 | |
7b60f3d8 | 4500 | orig_hash = &probe->ops.func_hash->filter_hash; |
1ec3a81a SRV |
4501 | old_hash = *orig_hash; |
4502 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); | |
59df055f | 4503 | |
5b0022dd NR |
4504 | if (!hash) { |
4505 | ret = -ENOMEM; | |
4506 | goto out; | |
4507 | } | |
4508 | ||
1ec3a81a | 4509 | ret = ftrace_match_records(hash, glob, strlen(glob)); |
59df055f | 4510 | |
1ec3a81a SRV |
4511 | /* Nothing found? */ |
4512 | if (!ret) | |
4513 | ret = -EINVAL; | |
59df055f | 4514 | |
1ec3a81a SRV |
4515 | if (ret < 0) |
4516 | goto out; | |
59df055f | 4517 | |
1ec3a81a SRV |
4518 | size = 1 << hash->size_bits; |
4519 | for (i = 0; i < size; i++) { | |
4520 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
4521 | if (ftrace_lookup_ip(old_hash, entry->ip)) | |
59df055f | 4522 | continue; |
1ec3a81a SRV |
4523 | /* |
4524 | * The caller might want to do something special | |
4525 | * for each function we find. We call the callback | |
4526 | * to give the caller an opportunity to do so. | |
4527 | */ | |
7b60f3d8 SRV |
4528 | if (probe_ops->init) { |
4529 | ret = probe_ops->init(probe_ops, tr, | |
6e444319 SRV |
4530 | entry->ip, data, |
4531 | &probe->data); | |
4532 | if (ret < 0) { | |
4533 | if (probe_ops->free && count) | |
4534 | probe_ops->free(probe_ops, tr, | |
4535 | 0, probe->data); | |
4536 | probe->data = NULL; | |
eee8ded1 | 4537 | goto out; |
6e444319 | 4538 | } |
59df055f | 4539 | } |
1ec3a81a | 4540 | count++; |
59df055f | 4541 | } |
1ec3a81a | 4542 | } |
59df055f | 4543 | |
1ec3a81a | 4544 | mutex_lock(&ftrace_lock); |
59df055f | 4545 | |
7b60f3d8 SRV |
4546 | if (!count) { |
4547 | /* Nothing was added? */ | |
4548 | ret = -EINVAL; | |
4549 | goto out_unlock; | |
4550 | } | |
e1df4cb6 | 4551 | |
7b60f3d8 SRV |
4552 | ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash, |
4553 | hash, 1); | |
1ec3a81a | 4554 | if (ret < 0) |
8d70725e | 4555 | goto err_unlock; |
8252ecf3 | 4556 | |
7b60f3d8 SRV |
4557 | /* One ref for each new function traced */ |
4558 | probe->ref += count; | |
8252ecf3 | 4559 | |
7b60f3d8 SRV |
4560 | if (!(probe->ops.flags & FTRACE_OPS_FL_ENABLED)) |
4561 | ret = ftrace_startup(&probe->ops, 0); | |
e1df4cb6 | 4562 | |
59df055f | 4563 | out_unlock: |
5ae0bf59 | 4564 | mutex_unlock(&ftrace_lock); |
8252ecf3 | 4565 | |
3296fc4e | 4566 | if (!ret) |
1ec3a81a | 4567 | ret = count; |
5ae0bf59 | 4568 | out: |
7b60f3d8 | 4569 | mutex_unlock(&probe->ops.func_hash->regex_lock); |
e1df4cb6 | 4570 | free_ftrace_hash(hash); |
59df055f | 4571 | |
7b60f3d8 | 4572 | release_probe(probe); |
59df055f | 4573 | |
1ec3a81a | 4574 | return ret; |
59df055f | 4575 | |
8d70725e | 4576 | err_unlock: |
7b60f3d8 | 4577 | if (!probe_ops->free || !count) |
8d70725e SRV |
4578 | goto out_unlock; |
4579 | ||
4580 | /* Failed to do the move, need to call the free functions */ | |
4581 | for (i = 0; i < size; i++) { | |
4582 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
4583 | if (ftrace_lookup_ip(old_hash, entry->ip)) | |
4584 | continue; | |
6e444319 | 4585 | probe_ops->free(probe_ops, tr, entry->ip, probe->data); |
8d70725e SRV |
4586 | } |
4587 | } | |
4588 | goto out_unlock; | |
59df055f SR |
4589 | } |
4590 | ||
d3d532d7 | 4591 | int |
7b60f3d8 SRV |
4592 | unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr, |
4593 | struct ftrace_probe_ops *probe_ops) | |
59df055f | 4594 | { |
82cc4fc2 | 4595 | struct ftrace_ops_hash old_hash_ops; |
eee8ded1 | 4596 | struct ftrace_func_entry *entry; |
7b60f3d8 | 4597 | struct ftrace_func_probe *probe; |
3ba00929 | 4598 | struct ftrace_glob func_g; |
1ec3a81a SRV |
4599 | struct ftrace_hash **orig_hash; |
4600 | struct ftrace_hash *old_hash; | |
1ec3a81a | 4601 | struct ftrace_hash *hash = NULL; |
b67bfe0d | 4602 | struct hlist_node *tmp; |
eee8ded1 | 4603 | struct hlist_head hhd; |
59df055f | 4604 | char str[KSYM_SYMBOL_LEN]; |
7b60f3d8 SRV |
4605 | int count = 0; |
4606 | int i, ret = -ENODEV; | |
eee8ded1 | 4607 | int size; |
59df055f | 4608 | |
cbab567c | 4609 | if (!glob || !strlen(glob) || !strcmp(glob, "*")) |
3ba00929 | 4610 | func_g.search = NULL; |
cbab567c | 4611 | else { |
59df055f SR |
4612 | int not; |
4613 | ||
3ba00929 DS |
4614 | func_g.type = filter_parse_regex(glob, strlen(glob), |
4615 | &func_g.search, ¬); | |
4616 | func_g.len = strlen(func_g.search); | |
59df055f | 4617 | |
b6887d79 | 4618 | /* we do not support '!' for function probes */ |
59df055f | 4619 | if (WARN_ON(not)) |
d3d532d7 | 4620 | return -EINVAL; |
59df055f SR |
4621 | } |
4622 | ||
7b60f3d8 SRV |
4623 | mutex_lock(&ftrace_lock); |
4624 | /* Check if the probe_ops is already registered */ | |
4625 | list_for_each_entry(probe, &tr->func_probes, list) { | |
4626 | if (probe->probe_ops == probe_ops) | |
4627 | break; | |
59df055f | 4628 | } |
7b60f3d8 SRV |
4629 | if (&probe->list == &tr->func_probes) |
4630 | goto err_unlock_ftrace; | |
4631 | ||
4632 | ret = -EINVAL; | |
4633 | if (!(probe->ops.flags & FTRACE_OPS_FL_INITIALIZED)) | |
4634 | goto err_unlock_ftrace; | |
4635 | ||
4636 | acquire_probe_locked(probe); | |
4637 | ||
4638 | mutex_unlock(&ftrace_lock); | |
59df055f | 4639 | |
7b60f3d8 | 4640 | mutex_lock(&probe->ops.func_hash->regex_lock); |
1ec3a81a | 4641 | |
7b60f3d8 | 4642 | orig_hash = &probe->ops.func_hash->filter_hash; |
1ec3a81a SRV |
4643 | old_hash = *orig_hash; |
4644 | ||
1ec3a81a SRV |
4645 | if (ftrace_hash_empty(old_hash)) |
4646 | goto out_unlock; | |
e1df4cb6 | 4647 | |
82cc4fc2 SRV |
4648 | old_hash_ops.filter_hash = old_hash; |
4649 | /* Probes only have filters */ | |
4650 | old_hash_ops.notrace_hash = NULL; | |
4651 | ||
d3d532d7 | 4652 | ret = -ENOMEM; |
1ec3a81a | 4653 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); |
e1df4cb6 | 4654 | if (!hash) |
e1df4cb6 SRRH |
4655 | goto out_unlock; |
4656 | ||
eee8ded1 | 4657 | INIT_HLIST_HEAD(&hhd); |
59df055f | 4658 | |
eee8ded1 SRV |
4659 | size = 1 << hash->size_bits; |
4660 | for (i = 0; i < size; i++) { | |
4661 | hlist_for_each_entry_safe(entry, tmp, &hash->buckets[i], hlist) { | |
59df055f | 4662 | |
3ba00929 | 4663 | if (func_g.search) { |
59df055f SR |
4664 | kallsyms_lookup(entry->ip, NULL, NULL, |
4665 | NULL, str); | |
3ba00929 | 4666 | if (!ftrace_match(str, &func_g)) |
59df055f SR |
4667 | continue; |
4668 | } | |
7b60f3d8 | 4669 | count++; |
eee8ded1 SRV |
4670 | remove_hash_entry(hash, entry); |
4671 | hlist_add_head(&entry->hlist, &hhd); | |
59df055f SR |
4672 | } |
4673 | } | |
d3d532d7 SRV |
4674 | |
4675 | /* Nothing found? */ | |
7b60f3d8 | 4676 | if (!count) { |
d3d532d7 SRV |
4677 | ret = -EINVAL; |
4678 | goto out_unlock; | |
4679 | } | |
4680 | ||
3f2367ba | 4681 | mutex_lock(&ftrace_lock); |
1ec3a81a | 4682 | |
7b60f3d8 | 4683 | WARN_ON(probe->ref < count); |
eee8ded1 | 4684 | |
7b60f3d8 | 4685 | probe->ref -= count; |
1ec3a81a | 4686 | |
7b60f3d8 SRV |
4687 | if (ftrace_hash_empty(hash)) |
4688 | ftrace_shutdown(&probe->ops, 0); | |
4689 | ||
4690 | ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash, | |
1ec3a81a | 4691 | hash, 1); |
82cc4fc2 SRV |
4692 | |
4693 | /* still need to update the function call sites */ | |
1ec3a81a | 4694 | if (ftrace_enabled && !ftrace_hash_empty(hash)) |
7b60f3d8 | 4695 | ftrace_run_modify_code(&probe->ops, FTRACE_UPDATE_CALLS, |
82cc4fc2 | 4696 | &old_hash_ops); |
74401729 | 4697 | synchronize_rcu(); |
3296fc4e | 4698 | |
eee8ded1 SRV |
4699 | hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) { |
4700 | hlist_del(&entry->hlist); | |
7b60f3d8 | 4701 | if (probe_ops->free) |
6e444319 | 4702 | probe_ops->free(probe_ops, tr, entry->ip, probe->data); |
eee8ded1 | 4703 | kfree(entry); |
7818b388 | 4704 | } |
3f2367ba | 4705 | mutex_unlock(&ftrace_lock); |
3ba00929 | 4706 | |
e1df4cb6 | 4707 | out_unlock: |
7b60f3d8 | 4708 | mutex_unlock(&probe->ops.func_hash->regex_lock); |
e1df4cb6 | 4709 | free_ftrace_hash(hash); |
59df055f | 4710 | |
7b60f3d8 | 4711 | release_probe(probe); |
59df055f | 4712 | |
7b60f3d8 | 4713 | return ret; |
59df055f | 4714 | |
7b60f3d8 SRV |
4715 | err_unlock_ftrace: |
4716 | mutex_unlock(&ftrace_lock); | |
d3d532d7 | 4717 | return ret; |
59df055f SR |
4718 | } |
4719 | ||
a0e6369e NR |
4720 | void clear_ftrace_function_probes(struct trace_array *tr) |
4721 | { | |
4722 | struct ftrace_func_probe *probe, *n; | |
4723 | ||
4724 | list_for_each_entry_safe(probe, n, &tr->func_probes, list) | |
4725 | unregister_ftrace_function_probe_func(NULL, tr, probe->probe_ops); | |
4726 | } | |
4727 | ||
f6180773 SR |
4728 | static LIST_HEAD(ftrace_commands); |
4729 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
4730 | ||
38de93ab TZ |
4731 | /* |
4732 | * Currently we only register ftrace commands from __init, so mark this | |
4733 | * __init too. | |
4734 | */ | |
4735 | __init int register_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
4736 | { |
4737 | struct ftrace_func_command *p; | |
4738 | int ret = 0; | |
4739 | ||
4740 | mutex_lock(&ftrace_cmd_mutex); | |
4741 | list_for_each_entry(p, &ftrace_commands, list) { | |
4742 | if (strcmp(cmd->name, p->name) == 0) { | |
4743 | ret = -EBUSY; | |
4744 | goto out_unlock; | |
4745 | } | |
4746 | } | |
4747 | list_add(&cmd->list, &ftrace_commands); | |
4748 | out_unlock: | |
4749 | mutex_unlock(&ftrace_cmd_mutex); | |
4750 | ||
4751 | return ret; | |
4752 | } | |
4753 | ||
38de93ab TZ |
4754 | /* |
4755 | * Currently we only unregister ftrace commands from __init, so mark | |
4756 | * this __init too. | |
4757 | */ | |
4758 | __init int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
4759 | { |
4760 | struct ftrace_func_command *p, *n; | |
4761 | int ret = -ENODEV; | |
4762 | ||
4763 | mutex_lock(&ftrace_cmd_mutex); | |
4764 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
4765 | if (strcmp(cmd->name, p->name) == 0) { | |
4766 | ret = 0; | |
4767 | list_del_init(&p->list); | |
4768 | goto out_unlock; | |
4769 | } | |
4770 | } | |
4771 | out_unlock: | |
4772 | mutex_unlock(&ftrace_cmd_mutex); | |
4773 | ||
4774 | return ret; | |
4775 | } | |
4776 | ||
04ec7bb6 | 4777 | static int ftrace_process_regex(struct ftrace_iterator *iter, |
33dc9b12 | 4778 | char *buff, int len, int enable) |
64e7c440 | 4779 | { |
04ec7bb6 | 4780 | struct ftrace_hash *hash = iter->hash; |
d2afd57a | 4781 | struct trace_array *tr = iter->ops->private; |
f6180773 | 4782 | char *func, *command, *next = buff; |
6a24a244 | 4783 | struct ftrace_func_command *p; |
0aff1c0c | 4784 | int ret = -EINVAL; |
64e7c440 SR |
4785 | |
4786 | func = strsep(&next, ":"); | |
4787 | ||
4788 | if (!next) { | |
1cf41dd7 | 4789 | ret = ftrace_match_records(hash, func, len); |
b448c4e3 SR |
4790 | if (!ret) |
4791 | ret = -EINVAL; | |
4792 | if (ret < 0) | |
4793 | return ret; | |
4794 | return 0; | |
64e7c440 SR |
4795 | } |
4796 | ||
f6180773 | 4797 | /* command found */ |
64e7c440 SR |
4798 | |
4799 | command = strsep(&next, ":"); | |
4800 | ||
f6180773 SR |
4801 | mutex_lock(&ftrace_cmd_mutex); |
4802 | list_for_each_entry(p, &ftrace_commands, list) { | |
4803 | if (strcmp(p->name, command) == 0) { | |
04ec7bb6 | 4804 | ret = p->func(tr, hash, func, command, next, enable); |
f6180773 SR |
4805 | goto out_unlock; |
4806 | } | |
64e7c440 | 4807 | } |
f6180773 SR |
4808 | out_unlock: |
4809 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 4810 | |
f6180773 | 4811 | return ret; |
64e7c440 SR |
4812 | } |
4813 | ||
e309b41d | 4814 | static ssize_t |
41c52c0d SR |
4815 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
4816 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
4817 | { |
4818 | struct ftrace_iterator *iter; | |
689fd8b6 | 4819 | struct trace_parser *parser; |
4820 | ssize_t ret, read; | |
5072c59f | 4821 | |
4ba7978e | 4822 | if (!cnt) |
5072c59f SR |
4823 | return 0; |
4824 | ||
5072c59f SR |
4825 | if (file->f_mode & FMODE_READ) { |
4826 | struct seq_file *m = file->private_data; | |
4827 | iter = m->private; | |
4828 | } else | |
4829 | iter = file->private_data; | |
4830 | ||
f04f24fb | 4831 | if (unlikely(ftrace_disabled)) |
3f2367ba MH |
4832 | return -ENODEV; |
4833 | ||
4834 | /* iter->hash is a local copy, so we don't need regex_lock */ | |
f04f24fb | 4835 | |
689fd8b6 | 4836 | parser = &iter->parser; |
4837 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 4838 | |
4ba7978e | 4839 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 4840 | !trace_parser_cont(parser)) { |
04ec7bb6 | 4841 | ret = ftrace_process_regex(iter, parser->buffer, |
689fd8b6 | 4842 | parser->idx, enable); |
313254a9 | 4843 | trace_parser_clear(parser); |
7c088b51 | 4844 | if (ret < 0) |
3f2367ba | 4845 | goto out; |
eda1e328 | 4846 | } |
5072c59f | 4847 | |
5072c59f | 4848 | ret = read; |
3f2367ba | 4849 | out: |
5072c59f SR |
4850 | return ret; |
4851 | } | |
4852 | ||
fc13cb0c | 4853 | ssize_t |
41c52c0d SR |
4854 | ftrace_filter_write(struct file *file, const char __user *ubuf, |
4855 | size_t cnt, loff_t *ppos) | |
4856 | { | |
4857 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
4858 | } | |
4859 | ||
fc13cb0c | 4860 | ssize_t |
41c52c0d SR |
4861 | ftrace_notrace_write(struct file *file, const char __user *ubuf, |
4862 | size_t cnt, loff_t *ppos) | |
4863 | { | |
4864 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
4865 | } | |
4866 | ||
33dc9b12 | 4867 | static int |
647664ea MH |
4868 | ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) |
4869 | { | |
4870 | struct ftrace_func_entry *entry; | |
4871 | ||
4872 | if (!ftrace_location(ip)) | |
4873 | return -EINVAL; | |
4874 | ||
4875 | if (remove) { | |
4876 | entry = ftrace_lookup_ip(hash, ip); | |
4877 | if (!entry) | |
4878 | return -ENOENT; | |
4879 | free_hash_entry(hash, entry); | |
4880 | return 0; | |
4881 | } | |
4882 | ||
4883 | return add_hash_entry(hash, ip); | |
4884 | } | |
4885 | ||
4886 | static int | |
4887 | ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, | |
4888 | unsigned long ip, int remove, int reset, int enable) | |
41c52c0d | 4889 | { |
33dc9b12 | 4890 | struct ftrace_hash **orig_hash; |
f45948e8 | 4891 | struct ftrace_hash *hash; |
33dc9b12 | 4892 | int ret; |
f45948e8 | 4893 | |
41c52c0d | 4894 | if (unlikely(ftrace_disabled)) |
33dc9b12 | 4895 | return -ENODEV; |
41c52c0d | 4896 | |
33b7f99c | 4897 | mutex_lock(&ops->func_hash->regex_lock); |
3f2367ba | 4898 | |
f45948e8 | 4899 | if (enable) |
33b7f99c | 4900 | orig_hash = &ops->func_hash->filter_hash; |
f45948e8 | 4901 | else |
33b7f99c | 4902 | orig_hash = &ops->func_hash->notrace_hash; |
33dc9b12 | 4903 | |
b972cc58 WN |
4904 | if (reset) |
4905 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); | |
4906 | else | |
4907 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
4908 | ||
3f2367ba MH |
4909 | if (!hash) { |
4910 | ret = -ENOMEM; | |
4911 | goto out_regex_unlock; | |
4912 | } | |
f45948e8 | 4913 | |
ac483c44 JO |
4914 | if (buf && !ftrace_match_records(hash, buf, len)) { |
4915 | ret = -EINVAL; | |
4916 | goto out_regex_unlock; | |
4917 | } | |
647664ea MH |
4918 | if (ip) { |
4919 | ret = ftrace_match_addr(hash, ip, remove); | |
4920 | if (ret < 0) | |
4921 | goto out_regex_unlock; | |
4922 | } | |
33dc9b12 SR |
4923 | |
4924 | mutex_lock(&ftrace_lock); | |
e16b35dd | 4925 | ret = ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable); |
33dc9b12 SR |
4926 | mutex_unlock(&ftrace_lock); |
4927 | ||
ac483c44 | 4928 | out_regex_unlock: |
33b7f99c | 4929 | mutex_unlock(&ops->func_hash->regex_lock); |
33dc9b12 SR |
4930 | |
4931 | free_ftrace_hash(hash); | |
4932 | return ret; | |
41c52c0d SR |
4933 | } |
4934 | ||
647664ea MH |
4935 | static int |
4936 | ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove, | |
4937 | int reset, int enable) | |
4938 | { | |
9efb85c5 | 4939 | return ftrace_set_hash(ops, NULL, 0, ip, remove, reset, enable); |
647664ea MH |
4940 | } |
4941 | ||
763e34e7 | 4942 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
013bf0da SRV |
4943 | |
4944 | struct ftrace_direct_func { | |
4945 | struct list_head next; | |
4946 | unsigned long addr; | |
4947 | int count; | |
4948 | }; | |
4949 | ||
4950 | static LIST_HEAD(ftrace_direct_funcs); | |
4951 | ||
4952 | /** | |
4953 | * ftrace_find_direct_func - test an address if it is a registered direct caller | |
4954 | * @addr: The address of a registered direct caller | |
4955 | * | |
4956 | * This searches to see if a ftrace direct caller has been registered | |
4957 | * at a specific address, and if so, it returns a descriptor for it. | |
4958 | * | |
4959 | * This can be used by architecture code to see if an address is | |
4960 | * a direct caller (trampoline) attached to a fentry/mcount location. | |
4961 | * This is useful for the function_graph tracer, as it may need to | |
4962 | * do adjustments if it traced a location that also has a direct | |
4963 | * trampoline attached to it. | |
4964 | */ | |
4965 | struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr) | |
4966 | { | |
4967 | struct ftrace_direct_func *entry; | |
4968 | bool found = false; | |
4969 | ||
4970 | /* May be called by fgraph trampoline (protected by rcu tasks) */ | |
4971 | list_for_each_entry_rcu(entry, &ftrace_direct_funcs, next) { | |
4972 | if (entry->addr == addr) { | |
4973 | found = true; | |
4974 | break; | |
4975 | } | |
4976 | } | |
4977 | if (found) | |
4978 | return entry; | |
4979 | ||
4980 | return NULL; | |
4981 | } | |
4982 | ||
763e34e7 SRV |
4983 | /** |
4984 | * register_ftrace_direct - Call a custom trampoline directly | |
4985 | * @ip: The address of the nop at the beginning of a function | |
4986 | * @addr: The address of the trampoline to call at @ip | |
4987 | * | |
4988 | * This is used to connect a direct call from the nop location (@ip) | |
4989 | * at the start of ftrace traced functions. The location that it calls | |
4990 | * (@addr) must be able to handle a direct call, and save the parameters | |
4991 | * of the function being traced, and restore them (or inject new ones | |
4992 | * if needed), before returning. | |
4993 | * | |
4994 | * Returns: | |
4995 | * 0 on success | |
4996 | * -EBUSY - Another direct function is already attached (there can be only one) | |
4997 | * -ENODEV - @ip does not point to a ftrace nop location (or not supported) | |
4998 | * -ENOMEM - There was an allocation failure. | |
4999 | */ | |
5000 | int register_ftrace_direct(unsigned long ip, unsigned long addr) | |
5001 | { | |
013bf0da | 5002 | struct ftrace_direct_func *direct; |
763e34e7 SRV |
5003 | struct ftrace_func_entry *entry; |
5004 | struct ftrace_hash *free_hash = NULL; | |
5005 | struct dyn_ftrace *rec; | |
5006 | int ret = -EBUSY; | |
5007 | ||
5008 | mutex_lock(&direct_mutex); | |
5009 | ||
5010 | /* See if there's a direct function at @ip already */ | |
ff205766 | 5011 | if (ftrace_find_rec_direct(ip)) |
763e34e7 SRV |
5012 | goto out_unlock; |
5013 | ||
5014 | ret = -ENODEV; | |
5015 | rec = lookup_rec(ip, ip); | |
5016 | if (!rec) | |
5017 | goto out_unlock; | |
5018 | ||
5019 | /* | |
5020 | * Check if the rec says it has a direct call but we didn't | |
5021 | * find one earlier? | |
5022 | */ | |
5023 | if (WARN_ON(rec->flags & FTRACE_FL_DIRECT)) | |
5024 | goto out_unlock; | |
5025 | ||
5026 | /* Make sure the ip points to the exact record */ | |
406acdd3 SRV |
5027 | if (ip != rec->ip) { |
5028 | ip = rec->ip; | |
5029 | /* Need to check this ip for a direct. */ | |
ff205766 | 5030 | if (ftrace_find_rec_direct(ip)) |
406acdd3 SRV |
5031 | goto out_unlock; |
5032 | } | |
763e34e7 SRV |
5033 | |
5034 | ret = -ENOMEM; | |
5035 | if (ftrace_hash_empty(direct_functions) || | |
5036 | direct_functions->count > 2 * (1 << direct_functions->size_bits)) { | |
5037 | struct ftrace_hash *new_hash; | |
5038 | int size = ftrace_hash_empty(direct_functions) ? 0 : | |
5039 | direct_functions->count + 1; | |
5040 | ||
5041 | if (size < 32) | |
5042 | size = 32; | |
5043 | ||
5044 | new_hash = dup_hash(direct_functions, size); | |
5045 | if (!new_hash) | |
5046 | goto out_unlock; | |
5047 | ||
5048 | free_hash = direct_functions; | |
5049 | direct_functions = new_hash; | |
5050 | } | |
5051 | ||
5052 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
5053 | if (!entry) | |
5054 | goto out_unlock; | |
5055 | ||
013bf0da SRV |
5056 | direct = ftrace_find_direct_func(addr); |
5057 | if (!direct) { | |
5058 | direct = kmalloc(sizeof(*direct), GFP_KERNEL); | |
5059 | if (!direct) { | |
5060 | kfree(entry); | |
5061 | goto out_unlock; | |
5062 | } | |
5063 | direct->addr = addr; | |
5064 | direct->count = 0; | |
5065 | list_add_rcu(&direct->next, &ftrace_direct_funcs); | |
a3ad1a7e | 5066 | ftrace_direct_func_count++; |
013bf0da SRV |
5067 | } |
5068 | ||
763e34e7 SRV |
5069 | entry->ip = ip; |
5070 | entry->direct = addr; | |
5071 | __add_hash_entry(direct_functions, entry); | |
5072 | ||
5073 | ret = ftrace_set_filter_ip(&direct_ops, ip, 0, 0); | |
5074 | if (ret) | |
5075 | remove_hash_entry(direct_functions, entry); | |
5076 | ||
5077 | if (!ret && !(direct_ops.flags & FTRACE_OPS_FL_ENABLED)) { | |
5078 | ret = register_ftrace_function(&direct_ops); | |
5079 | if (ret) | |
5080 | ftrace_set_filter_ip(&direct_ops, ip, 1, 0); | |
5081 | } | |
5082 | ||
013bf0da | 5083 | if (ret) { |
763e34e7 | 5084 | kfree(entry); |
013bf0da SRV |
5085 | if (!direct->count) { |
5086 | list_del_rcu(&direct->next); | |
5087 | synchronize_rcu_tasks(); | |
5088 | kfree(direct); | |
5089 | if (free_hash) | |
5090 | free_ftrace_hash(free_hash); | |
5091 | free_hash = NULL; | |
a3ad1a7e | 5092 | ftrace_direct_func_count--; |
013bf0da SRV |
5093 | } |
5094 | } else { | |
1c7f9b67 | 5095 | direct->count++; |
013bf0da | 5096 | } |
763e34e7 SRV |
5097 | out_unlock: |
5098 | mutex_unlock(&direct_mutex); | |
5099 | ||
5100 | if (free_hash) { | |
5101 | synchronize_rcu_tasks(); | |
5102 | free_ftrace_hash(free_hash); | |
5103 | } | |
5104 | ||
5105 | return ret; | |
5106 | } | |
5107 | EXPORT_SYMBOL_GPL(register_ftrace_direct); | |
5108 | ||
ea806eb3 SRV |
5109 | static struct ftrace_func_entry *find_direct_entry(unsigned long *ip, |
5110 | struct dyn_ftrace **recp) | |
763e34e7 SRV |
5111 | { |
5112 | struct ftrace_func_entry *entry; | |
5113 | struct dyn_ftrace *rec; | |
763e34e7 | 5114 | |
128161f4 SRV |
5115 | rec = lookup_rec(*ip, *ip); |
5116 | if (!rec) | |
5117 | return NULL; | |
763e34e7 | 5118 | |
128161f4 | 5119 | entry = __ftrace_lookup_ip(direct_functions, rec->ip); |
763e34e7 | 5120 | if (!entry) { |
128161f4 SRV |
5121 | WARN_ON(rec->flags & FTRACE_FL_DIRECT); |
5122 | return NULL; | |
5123 | } | |
763e34e7 | 5124 | |
128161f4 | 5125 | WARN_ON(!(rec->flags & FTRACE_FL_DIRECT)); |
763e34e7 | 5126 | |
128161f4 SRV |
5127 | /* Passed in ip just needs to be on the call site */ |
5128 | *ip = rec->ip; | |
5129 | ||
ea806eb3 SRV |
5130 | if (recp) |
5131 | *recp = rec; | |
5132 | ||
128161f4 SRV |
5133 | return entry; |
5134 | } | |
5135 | ||
5136 | int unregister_ftrace_direct(unsigned long ip, unsigned long addr) | |
5137 | { | |
5138 | struct ftrace_direct_func *direct; | |
5139 | struct ftrace_func_entry *entry; | |
5140 | int ret = -ENODEV; | |
5141 | ||
5142 | mutex_lock(&direct_mutex); | |
5143 | ||
ea806eb3 | 5144 | entry = find_direct_entry(&ip, NULL); |
128161f4 SRV |
5145 | if (!entry) |
5146 | goto out_unlock; | |
763e34e7 SRV |
5147 | |
5148 | if (direct_functions->count == 1) | |
5149 | unregister_ftrace_function(&direct_ops); | |
5150 | ||
5151 | ret = ftrace_set_filter_ip(&direct_ops, ip, 1, 0); | |
5152 | ||
5153 | WARN_ON(ret); | |
5154 | ||
5155 | remove_hash_entry(direct_functions, entry); | |
5156 | ||
013bf0da SRV |
5157 | direct = ftrace_find_direct_func(addr); |
5158 | if (!WARN_ON(!direct)) { | |
5159 | /* This is the good path (see the ! before WARN) */ | |
5160 | direct->count--; | |
5161 | WARN_ON(direct->count < 0); | |
5162 | if (!direct->count) { | |
5163 | list_del_rcu(&direct->next); | |
5164 | synchronize_rcu_tasks(); | |
5165 | kfree(direct); | |
a3ad1a7e | 5166 | ftrace_direct_func_count--; |
013bf0da SRV |
5167 | } |
5168 | } | |
763e34e7 SRV |
5169 | out_unlock: |
5170 | mutex_unlock(&direct_mutex); | |
5171 | ||
5172 | return ret; | |
5173 | } | |
5174 | EXPORT_SYMBOL_GPL(unregister_ftrace_direct); | |
0567d680 SRV |
5175 | |
5176 | static struct ftrace_ops stub_ops = { | |
5177 | .func = ftrace_stub, | |
5178 | }; | |
5179 | ||
ea806eb3 SRV |
5180 | /** |
5181 | * ftrace_modify_direct_caller - modify ftrace nop directly | |
5182 | * @entry: The ftrace hash entry of the direct helper for @rec | |
5183 | * @rec: The record representing the function site to patch | |
5184 | * @old_addr: The location that the site at @rec->ip currently calls | |
5185 | * @new_addr: The location that the site at @rec->ip should call | |
5186 | * | |
5187 | * An architecture may overwrite this function to optimize the | |
5188 | * changing of the direct callback on an ftrace nop location. | |
5189 | * This is called with the ftrace_lock mutex held, and no other | |
5190 | * ftrace callbacks are on the associated record (@rec). Thus, | |
5191 | * it is safe to modify the ftrace record, where it should be | |
5192 | * currently calling @old_addr directly, to call @new_addr. | |
5193 | * | |
5194 | * Safety checks should be made to make sure that the code at | |
5195 | * @rec->ip is currently calling @old_addr. And this must | |
5196 | * also update entry->direct to @new_addr. | |
5197 | */ | |
5198 | int __weak ftrace_modify_direct_caller(struct ftrace_func_entry *entry, | |
5199 | struct dyn_ftrace *rec, | |
5200 | unsigned long old_addr, | |
5201 | unsigned long new_addr) | |
5202 | { | |
5203 | unsigned long ip = rec->ip; | |
5204 | int ret; | |
5205 | ||
5206 | /* | |
5207 | * The ftrace_lock was used to determine if the record | |
5208 | * had more than one registered user to it. If it did, | |
5209 | * we needed to prevent that from changing to do the quick | |
5210 | * switch. But if it did not (only a direct caller was attached) | |
5211 | * then this function is called. But this function can deal | |
5212 | * with attached callers to the rec that we care about, and | |
5213 | * since this function uses standard ftrace calls that take | |
5214 | * the ftrace_lock mutex, we need to release it. | |
5215 | */ | |
5216 | mutex_unlock(&ftrace_lock); | |
5217 | ||
5218 | /* | |
5219 | * By setting a stub function at the same address, we force | |
5220 | * the code to call the iterator and the direct_ops helper. | |
5221 | * This means that @ip does not call the direct call, and | |
5222 | * we can simply modify it. | |
5223 | */ | |
5224 | ret = ftrace_set_filter_ip(&stub_ops, ip, 0, 0); | |
5225 | if (ret) | |
5226 | goto out_lock; | |
5227 | ||
5228 | ret = register_ftrace_function(&stub_ops); | |
5229 | if (ret) { | |
5230 | ftrace_set_filter_ip(&stub_ops, ip, 1, 0); | |
5231 | goto out_lock; | |
5232 | } | |
5233 | ||
5234 | entry->direct = new_addr; | |
5235 | ||
5236 | /* | |
5237 | * By removing the stub, we put back the direct call, calling | |
5238 | * the @new_addr. | |
5239 | */ | |
5240 | unregister_ftrace_function(&stub_ops); | |
5241 | ftrace_set_filter_ip(&stub_ops, ip, 1, 0); | |
5242 | ||
5243 | out_lock: | |
5244 | mutex_lock(&ftrace_lock); | |
5245 | ||
5246 | return ret; | |
5247 | } | |
5248 | ||
0567d680 SRV |
5249 | /** |
5250 | * modify_ftrace_direct - Modify an existing direct call to call something else | |
5251 | * @ip: The instruction pointer to modify | |
5252 | * @old_addr: The address that the current @ip calls directly | |
5253 | * @new_addr: The address that the @ip should call | |
5254 | * | |
5255 | * This modifies a ftrace direct caller at an instruction pointer without | |
5256 | * having to disable it first. The direct call will switch over to the | |
5257 | * @new_addr without missing anything. | |
5258 | * | |
5259 | * Returns: zero on success. Non zero on error, which includes: | |
5260 | * -ENODEV : the @ip given has no direct caller attached | |
5261 | * -EINVAL : the @old_addr does not match the current direct caller | |
5262 | */ | |
5263 | int modify_ftrace_direct(unsigned long ip, | |
5264 | unsigned long old_addr, unsigned long new_addr) | |
5265 | { | |
5266 | struct ftrace_func_entry *entry; | |
ea806eb3 | 5267 | struct dyn_ftrace *rec; |
0567d680 SRV |
5268 | int ret = -ENODEV; |
5269 | ||
5270 | mutex_lock(&direct_mutex); | |
0567d680 | 5271 | |
ea806eb3 SRV |
5272 | mutex_lock(&ftrace_lock); |
5273 | entry = find_direct_entry(&ip, &rec); | |
128161f4 SRV |
5274 | if (!entry) |
5275 | goto out_unlock; | |
0567d680 SRV |
5276 | |
5277 | ret = -EINVAL; | |
5278 | if (entry->direct != old_addr) | |
5279 | goto out_unlock; | |
5280 | ||
5281 | /* | |
ea806eb3 SRV |
5282 | * If there's no other ftrace callback on the rec->ip location, |
5283 | * then it can be changed directly by the architecture. | |
5284 | * If there is another caller, then we just need to change the | |
5285 | * direct caller helper to point to @new_addr. | |
0567d680 | 5286 | */ |
ea806eb3 SRV |
5287 | if (ftrace_rec_count(rec) == 1) { |
5288 | ret = ftrace_modify_direct_caller(entry, rec, old_addr, new_addr); | |
5289 | } else { | |
5290 | entry->direct = new_addr; | |
5291 | ret = 0; | |
0567d680 SRV |
5292 | } |
5293 | ||
0567d680 | 5294 | out_unlock: |
ea806eb3 | 5295 | mutex_unlock(&ftrace_lock); |
0567d680 SRV |
5296 | mutex_unlock(&direct_mutex); |
5297 | return ret; | |
5298 | } | |
5299 | EXPORT_SYMBOL_GPL(modify_ftrace_direct); | |
763e34e7 SRV |
5300 | #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ |
5301 | ||
647664ea MH |
5302 | /** |
5303 | * ftrace_set_filter_ip - set a function to filter on in ftrace by address | |
5304 | * @ops - the ops to set the filter with | |
5305 | * @ip - the address to add to or remove from the filter. | |
5306 | * @remove - non zero to remove the ip from the filter | |
5307 | * @reset - non zero to reset all filters before applying this filter. | |
5308 | * | |
5309 | * Filters denote which functions should be enabled when tracing is enabled | |
5310 | * If @ip is NULL, it failes to update filter. | |
5311 | */ | |
5312 | int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, | |
5313 | int remove, int reset) | |
5314 | { | |
f04f24fb | 5315 | ftrace_ops_init(ops); |
647664ea MH |
5316 | return ftrace_set_addr(ops, ip, remove, reset, 1); |
5317 | } | |
5318 | EXPORT_SYMBOL_GPL(ftrace_set_filter_ip); | |
5319 | ||
d032ae89 JF |
5320 | /** |
5321 | * ftrace_ops_set_global_filter - setup ops to use global filters | |
5322 | * @ops - the ops which will use the global filters | |
5323 | * | |
5324 | * ftrace users who need global function trace filtering should call this. | |
5325 | * It can set the global filter only if ops were not initialized before. | |
5326 | */ | |
5327 | void ftrace_ops_set_global_filter(struct ftrace_ops *ops) | |
5328 | { | |
5329 | if (ops->flags & FTRACE_OPS_FL_INITIALIZED) | |
5330 | return; | |
5331 | ||
5332 | ftrace_ops_init(ops); | |
5333 | ops->func_hash = &global_ops.local_hash; | |
5334 | } | |
5335 | EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter); | |
5336 | ||
647664ea MH |
5337 | static int |
5338 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, | |
5339 | int reset, int enable) | |
5340 | { | |
5341 | return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable); | |
5342 | } | |
5343 | ||
77a2b37d SR |
5344 | /** |
5345 | * ftrace_set_filter - set a function to filter on in ftrace | |
936e074b SR |
5346 | * @ops - the ops to set the filter with |
5347 | * @buf - the string that holds the function filter text. | |
5348 | * @len - the length of the string. | |
5349 | * @reset - non zero to reset all filters before applying this filter. | |
5350 | * | |
5351 | * Filters denote which functions should be enabled when tracing is enabled. | |
5352 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
5353 | */ | |
ac483c44 | 5354 | int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
5355 | int len, int reset) |
5356 | { | |
f04f24fb | 5357 | ftrace_ops_init(ops); |
ac483c44 | 5358 | return ftrace_set_regex(ops, buf, len, reset, 1); |
936e074b SR |
5359 | } |
5360 | EXPORT_SYMBOL_GPL(ftrace_set_filter); | |
5361 | ||
5362 | /** | |
5363 | * ftrace_set_notrace - set a function to not trace in ftrace | |
5364 | * @ops - the ops to set the notrace filter with | |
5365 | * @buf - the string that holds the function notrace text. | |
5366 | * @len - the length of the string. | |
5367 | * @reset - non zero to reset all filters before applying this filter. | |
5368 | * | |
5369 | * Notrace Filters denote which functions should not be enabled when tracing | |
5370 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
5371 | * for tracing. | |
5372 | */ | |
ac483c44 | 5373 | int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
5374 | int len, int reset) |
5375 | { | |
f04f24fb | 5376 | ftrace_ops_init(ops); |
ac483c44 | 5377 | return ftrace_set_regex(ops, buf, len, reset, 0); |
936e074b SR |
5378 | } |
5379 | EXPORT_SYMBOL_GPL(ftrace_set_notrace); | |
5380 | /** | |
8d1b065d | 5381 | * ftrace_set_global_filter - set a function to filter on with global tracers |
77a2b37d SR |
5382 | * @buf - the string that holds the function filter text. |
5383 | * @len - the length of the string. | |
5384 | * @reset - non zero to reset all filters before applying this filter. | |
5385 | * | |
5386 | * Filters denote which functions should be enabled when tracing is enabled. | |
5387 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
5388 | */ | |
936e074b | 5389 | void ftrace_set_global_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 5390 | { |
f45948e8 | 5391 | ftrace_set_regex(&global_ops, buf, len, reset, 1); |
41c52c0d | 5392 | } |
936e074b | 5393 | EXPORT_SYMBOL_GPL(ftrace_set_global_filter); |
4eebcc81 | 5394 | |
41c52c0d | 5395 | /** |
8d1b065d | 5396 | * ftrace_set_global_notrace - set a function to not trace with global tracers |
41c52c0d SR |
5397 | * @buf - the string that holds the function notrace text. |
5398 | * @len - the length of the string. | |
5399 | * @reset - non zero to reset all filters before applying this filter. | |
5400 | * | |
5401 | * Notrace Filters denote which functions should not be enabled when tracing | |
5402 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
5403 | * for tracing. | |
5404 | */ | |
936e074b | 5405 | void ftrace_set_global_notrace(unsigned char *buf, int len, int reset) |
41c52c0d | 5406 | { |
f45948e8 | 5407 | ftrace_set_regex(&global_ops, buf, len, reset, 0); |
77a2b37d | 5408 | } |
936e074b | 5409 | EXPORT_SYMBOL_GPL(ftrace_set_global_notrace); |
77a2b37d | 5410 | |
2af15d6a SR |
5411 | /* |
5412 | * command line interface to allow users to set filters on boot up. | |
5413 | */ | |
5414 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
5415 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
5416 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
5417 | ||
f1ed7c74 SRRH |
5418 | /* Used by function selftest to not test if filter is set */ |
5419 | bool ftrace_filter_param __initdata; | |
5420 | ||
2af15d6a SR |
5421 | static int __init set_ftrace_notrace(char *str) |
5422 | { | |
f1ed7c74 | 5423 | ftrace_filter_param = true; |
75761cc1 | 5424 | strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
5425 | return 1; |
5426 | } | |
5427 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
5428 | ||
5429 | static int __init set_ftrace_filter(char *str) | |
5430 | { | |
f1ed7c74 | 5431 | ftrace_filter_param = true; |
75761cc1 | 5432 | strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
5433 | return 1; |
5434 | } | |
5435 | __setup("ftrace_filter=", set_ftrace_filter); | |
5436 | ||
369bc18f | 5437 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 5438 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
0d7d9a16 | 5439 | static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata; |
b9b0c831 | 5440 | static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer); |
801c29fd | 5441 | |
369bc18f SA |
5442 | static int __init set_graph_function(char *str) |
5443 | { | |
06f43d66 | 5444 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
5445 | return 1; |
5446 | } | |
5447 | __setup("ftrace_graph_filter=", set_graph_function); | |
5448 | ||
0d7d9a16 NK |
5449 | static int __init set_graph_notrace_function(char *str) |
5450 | { | |
5451 | strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE); | |
5452 | return 1; | |
5453 | } | |
5454 | __setup("ftrace_graph_notrace=", set_graph_notrace_function); | |
5455 | ||
65a50c65 TB |
5456 | static int __init set_graph_max_depth_function(char *str) |
5457 | { | |
5458 | if (!str) | |
5459 | return 0; | |
5460 | fgraph_max_depth = simple_strtoul(str, NULL, 0); | |
5461 | return 1; | |
5462 | } | |
5463 | __setup("ftrace_graph_max_depth=", set_graph_max_depth_function); | |
0d7d9a16 NK |
5464 | |
5465 | static void __init set_ftrace_early_graph(char *buf, int enable) | |
369bc18f SA |
5466 | { |
5467 | int ret; | |
5468 | char *func; | |
b9b0c831 | 5469 | struct ftrace_hash *hash; |
0d7d9a16 | 5470 | |
92ad18ec | 5471 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); |
24589e3a | 5472 | if (MEM_FAIL(!hash, "Failed to allocate hash\n")) |
92ad18ec | 5473 | return; |
369bc18f SA |
5474 | |
5475 | while (buf) { | |
5476 | func = strsep(&buf, ","); | |
5477 | /* we allow only one expression at a time */ | |
b9b0c831 | 5478 | ret = ftrace_graph_set_hash(hash, func); |
369bc18f SA |
5479 | if (ret) |
5480 | printk(KERN_DEBUG "ftrace: function %s not " | |
5481 | "traceable\n", func); | |
5482 | } | |
92ad18ec SRV |
5483 | |
5484 | if (enable) | |
5485 | ftrace_graph_hash = hash; | |
5486 | else | |
5487 | ftrace_graph_notrace_hash = hash; | |
369bc18f SA |
5488 | } |
5489 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
5490 | ||
2a85a37f SR |
5491 | void __init |
5492 | ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable) | |
2af15d6a SR |
5493 | { |
5494 | char *func; | |
5495 | ||
f04f24fb MH |
5496 | ftrace_ops_init(ops); |
5497 | ||
2af15d6a SR |
5498 | while (buf) { |
5499 | func = strsep(&buf, ","); | |
f45948e8 | 5500 | ftrace_set_regex(ops, func, strlen(func), 0, enable); |
2af15d6a SR |
5501 | } |
5502 | } | |
5503 | ||
5504 | static void __init set_ftrace_early_filters(void) | |
5505 | { | |
5506 | if (ftrace_filter_buf[0]) | |
2a85a37f | 5507 | ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1); |
2af15d6a | 5508 | if (ftrace_notrace_buf[0]) |
2a85a37f | 5509 | ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0); |
369bc18f SA |
5510 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5511 | if (ftrace_graph_buf[0]) | |
0d7d9a16 NK |
5512 | set_ftrace_early_graph(ftrace_graph_buf, 1); |
5513 | if (ftrace_graph_notrace_buf[0]) | |
5514 | set_ftrace_early_graph(ftrace_graph_notrace_buf, 0); | |
369bc18f | 5515 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
2af15d6a SR |
5516 | } |
5517 | ||
fc13cb0c | 5518 | int ftrace_regex_release(struct inode *inode, struct file *file) |
5072c59f SR |
5519 | { |
5520 | struct seq_file *m = (struct seq_file *)file->private_data; | |
5521 | struct ftrace_iterator *iter; | |
33dc9b12 | 5522 | struct ftrace_hash **orig_hash; |
689fd8b6 | 5523 | struct trace_parser *parser; |
ed926f9b | 5524 | int filter_hash; |
33dc9b12 | 5525 | int ret; |
5072c59f | 5526 | |
5072c59f SR |
5527 | if (file->f_mode & FMODE_READ) { |
5528 | iter = m->private; | |
5072c59f SR |
5529 | seq_release(inode, file); |
5530 | } else | |
5531 | iter = file->private_data; | |
5532 | ||
689fd8b6 | 5533 | parser = &iter->parser; |
5534 | if (trace_parser_loaded(parser)) { | |
1cf41dd7 | 5535 | ftrace_match_records(iter->hash, parser->buffer, parser->idx); |
5072c59f SR |
5536 | } |
5537 | ||
689fd8b6 | 5538 | trace_parser_put(parser); |
689fd8b6 | 5539 | |
33b7f99c | 5540 | mutex_lock(&iter->ops->func_hash->regex_lock); |
3f2367ba | 5541 | |
058e297d | 5542 | if (file->f_mode & FMODE_WRITE) { |
ed926f9b SR |
5543 | filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); |
5544 | ||
8c08f0d5 | 5545 | if (filter_hash) { |
33b7f99c | 5546 | orig_hash = &iter->ops->func_hash->filter_hash; |
69d71879 | 5547 | if (iter->tr && !list_empty(&iter->tr->mod_trace)) |
8c08f0d5 SRV |
5548 | iter->hash->flags |= FTRACE_HASH_FL_MOD; |
5549 | } else | |
33b7f99c | 5550 | orig_hash = &iter->ops->func_hash->notrace_hash; |
33dc9b12 | 5551 | |
058e297d | 5552 | mutex_lock(&ftrace_lock); |
e16b35dd SRV |
5553 | ret = ftrace_hash_move_and_update_ops(iter->ops, orig_hash, |
5554 | iter->hash, filter_hash); | |
058e297d | 5555 | mutex_unlock(&ftrace_lock); |
c20489da SRV |
5556 | } else { |
5557 | /* For read only, the hash is the ops hash */ | |
5558 | iter->hash = NULL; | |
058e297d | 5559 | } |
3f2367ba | 5560 | |
33b7f99c | 5561 | mutex_unlock(&iter->ops->func_hash->regex_lock); |
33dc9b12 | 5562 | free_ftrace_hash(iter->hash); |
9ef16693 SRV |
5563 | if (iter->tr) |
5564 | trace_array_put(iter->tr); | |
33dc9b12 | 5565 | kfree(iter); |
058e297d | 5566 | |
5072c59f SR |
5567 | return 0; |
5568 | } | |
5569 | ||
5e2336a0 | 5570 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
5571 | .open = ftrace_avail_open, |
5572 | .read = seq_read, | |
5573 | .llseek = seq_lseek, | |
3be04b47 | 5574 | .release = seq_release_private, |
5072c59f SR |
5575 | }; |
5576 | ||
647bcd03 SR |
5577 | static const struct file_operations ftrace_enabled_fops = { |
5578 | .open = ftrace_enabled_open, | |
5579 | .read = seq_read, | |
5580 | .llseek = seq_lseek, | |
5581 | .release = seq_release_private, | |
5582 | }; | |
5583 | ||
5e2336a0 | 5584 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 5585 | .open = ftrace_filter_open, |
850a80cf | 5586 | .read = seq_read, |
5072c59f | 5587 | .write = ftrace_filter_write, |
098c879e | 5588 | .llseek = tracing_lseek, |
1cf41dd7 | 5589 | .release = ftrace_regex_release, |
5072c59f SR |
5590 | }; |
5591 | ||
5e2336a0 | 5592 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 5593 | .open = ftrace_notrace_open, |
850a80cf | 5594 | .read = seq_read, |
41c52c0d | 5595 | .write = ftrace_notrace_write, |
098c879e | 5596 | .llseek = tracing_lseek, |
1cf41dd7 | 5597 | .release = ftrace_regex_release, |
41c52c0d SR |
5598 | }; |
5599 | ||
ea4e2bc4 SR |
5600 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5601 | ||
5602 | static DEFINE_MUTEX(graph_lock); | |
5603 | ||
24a9729f | 5604 | struct ftrace_hash __rcu *ftrace_graph_hash = EMPTY_HASH; |
fd0e6852 | 5605 | struct ftrace_hash __rcu *ftrace_graph_notrace_hash = EMPTY_HASH; |
b9b0c831 NK |
5606 | |
5607 | enum graph_filter_type { | |
5608 | GRAPH_FILTER_NOTRACE = 0, | |
5609 | GRAPH_FILTER_FUNCTION, | |
5610 | }; | |
ea4e2bc4 | 5611 | |
555fc781 SRV |
5612 | #define FTRACE_GRAPH_EMPTY ((void *)1) |
5613 | ||
faf982a6 | 5614 | struct ftrace_graph_data { |
e704eff3 SRV |
5615 | struct ftrace_hash *hash; |
5616 | struct ftrace_func_entry *entry; | |
5617 | int idx; /* for hash table iteration */ | |
5618 | enum graph_filter_type type; | |
5619 | struct ftrace_hash *new_hash; | |
5620 | const struct seq_operations *seq_ops; | |
5621 | struct trace_parser parser; | |
faf982a6 NK |
5622 | }; |
5623 | ||
ea4e2bc4 | 5624 | static void * |
85951842 | 5625 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 5626 | { |
faf982a6 | 5627 | struct ftrace_graph_data *fgd = m->private; |
b9b0c831 NK |
5628 | struct ftrace_func_entry *entry = fgd->entry; |
5629 | struct hlist_head *head; | |
5630 | int i, idx = fgd->idx; | |
faf982a6 | 5631 | |
b9b0c831 | 5632 | if (*pos >= fgd->hash->count) |
ea4e2bc4 | 5633 | return NULL; |
b9b0c831 NK |
5634 | |
5635 | if (entry) { | |
5636 | hlist_for_each_entry_continue(entry, hlist) { | |
5637 | fgd->entry = entry; | |
5638 | return entry; | |
5639 | } | |
5640 | ||
5641 | idx++; | |
5642 | } | |
5643 | ||
5644 | for (i = idx; i < 1 << fgd->hash->size_bits; i++) { | |
5645 | head = &fgd->hash->buckets[i]; | |
5646 | hlist_for_each_entry(entry, head, hlist) { | |
5647 | fgd->entry = entry; | |
5648 | fgd->idx = i; | |
5649 | return entry; | |
5650 | } | |
5651 | } | |
5652 | return NULL; | |
85951842 | 5653 | } |
ea4e2bc4 | 5654 | |
85951842 LZ |
5655 | static void * |
5656 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
5657 | { | |
5658 | (*pos)++; | |
5659 | return __g_next(m, pos); | |
ea4e2bc4 SR |
5660 | } |
5661 | ||
5662 | static void *g_start(struct seq_file *m, loff_t *pos) | |
5663 | { | |
faf982a6 NK |
5664 | struct ftrace_graph_data *fgd = m->private; |
5665 | ||
ea4e2bc4 SR |
5666 | mutex_lock(&graph_lock); |
5667 | ||
649b988b SRV |
5668 | if (fgd->type == GRAPH_FILTER_FUNCTION) |
5669 | fgd->hash = rcu_dereference_protected(ftrace_graph_hash, | |
5670 | lockdep_is_held(&graph_lock)); | |
5671 | else | |
5672 | fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash, | |
5673 | lockdep_is_held(&graph_lock)); | |
5674 | ||
f9349a8f | 5675 | /* Nothing, tell g_show to print all functions are enabled */ |
b9b0c831 | 5676 | if (ftrace_hash_empty(fgd->hash) && !*pos) |
555fc781 | 5677 | return FTRACE_GRAPH_EMPTY; |
f9349a8f | 5678 | |
b9b0c831 NK |
5679 | fgd->idx = 0; |
5680 | fgd->entry = NULL; | |
85951842 | 5681 | return __g_next(m, pos); |
ea4e2bc4 SR |
5682 | } |
5683 | ||
5684 | static void g_stop(struct seq_file *m, void *p) | |
5685 | { | |
5686 | mutex_unlock(&graph_lock); | |
5687 | } | |
5688 | ||
5689 | static int g_show(struct seq_file *m, void *v) | |
5690 | { | |
b9b0c831 | 5691 | struct ftrace_func_entry *entry = v; |
ea4e2bc4 | 5692 | |
b9b0c831 | 5693 | if (!entry) |
ea4e2bc4 SR |
5694 | return 0; |
5695 | ||
555fc781 | 5696 | if (entry == FTRACE_GRAPH_EMPTY) { |
280d1429 NK |
5697 | struct ftrace_graph_data *fgd = m->private; |
5698 | ||
b9b0c831 | 5699 | if (fgd->type == GRAPH_FILTER_FUNCTION) |
fa6f0cc7 | 5700 | seq_puts(m, "#### all functions enabled ####\n"); |
280d1429 | 5701 | else |
fa6f0cc7 | 5702 | seq_puts(m, "#### no functions disabled ####\n"); |
f9349a8f FW |
5703 | return 0; |
5704 | } | |
5705 | ||
b9b0c831 | 5706 | seq_printf(m, "%ps\n", (void *)entry->ip); |
ea4e2bc4 SR |
5707 | |
5708 | return 0; | |
5709 | } | |
5710 | ||
88e9d34c | 5711 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
5712 | .start = g_start, |
5713 | .next = g_next, | |
5714 | .stop = g_stop, | |
5715 | .show = g_show, | |
5716 | }; | |
5717 | ||
5718 | static int | |
faf982a6 NK |
5719 | __ftrace_graph_open(struct inode *inode, struct file *file, |
5720 | struct ftrace_graph_data *fgd) | |
ea4e2bc4 | 5721 | { |
17911ff3 | 5722 | int ret; |
b9b0c831 | 5723 | struct ftrace_hash *new_hash = NULL; |
ea4e2bc4 | 5724 | |
17911ff3 SRV |
5725 | ret = security_locked_down(LOCKDOWN_TRACEFS); |
5726 | if (ret) | |
5727 | return ret; | |
5728 | ||
b9b0c831 NK |
5729 | if (file->f_mode & FMODE_WRITE) { |
5730 | const int size_bits = FTRACE_HASH_DEFAULT_BITS; | |
5731 | ||
e704eff3 SRV |
5732 | if (trace_parser_get_init(&fgd->parser, FTRACE_BUFF_MAX)) |
5733 | return -ENOMEM; | |
5734 | ||
b9b0c831 NK |
5735 | if (file->f_flags & O_TRUNC) |
5736 | new_hash = alloc_ftrace_hash(size_bits); | |
5737 | else | |
5738 | new_hash = alloc_and_copy_ftrace_hash(size_bits, | |
5739 | fgd->hash); | |
5740 | if (!new_hash) { | |
5741 | ret = -ENOMEM; | |
5742 | goto out; | |
5743 | } | |
ea4e2bc4 SR |
5744 | } |
5745 | ||
faf982a6 | 5746 | if (file->f_mode & FMODE_READ) { |
b9b0c831 | 5747 | ret = seq_open(file, &ftrace_graph_seq_ops); |
faf982a6 NK |
5748 | if (!ret) { |
5749 | struct seq_file *m = file->private_data; | |
5750 | m->private = fgd; | |
b9b0c831 NK |
5751 | } else { |
5752 | /* Failed */ | |
5753 | free_ftrace_hash(new_hash); | |
5754 | new_hash = NULL; | |
faf982a6 NK |
5755 | } |
5756 | } else | |
5757 | file->private_data = fgd; | |
ea4e2bc4 | 5758 | |
b9b0c831 | 5759 | out: |
e704eff3 SRV |
5760 | if (ret < 0 && file->f_mode & FMODE_WRITE) |
5761 | trace_parser_put(&fgd->parser); | |
5762 | ||
b9b0c831 | 5763 | fgd->new_hash = new_hash; |
649b988b SRV |
5764 | |
5765 | /* | |
5766 | * All uses of fgd->hash must be taken with the graph_lock | |
5767 | * held. The graph_lock is going to be released, so force | |
5768 | * fgd->hash to be reinitialized when it is taken again. | |
5769 | */ | |
5770 | fgd->hash = NULL; | |
5771 | ||
ea4e2bc4 SR |
5772 | return ret; |
5773 | } | |
5774 | ||
faf982a6 NK |
5775 | static int |
5776 | ftrace_graph_open(struct inode *inode, struct file *file) | |
5777 | { | |
5778 | struct ftrace_graph_data *fgd; | |
b9b0c831 | 5779 | int ret; |
faf982a6 NK |
5780 | |
5781 | if (unlikely(ftrace_disabled)) | |
5782 | return -ENODEV; | |
5783 | ||
5784 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
5785 | if (fgd == NULL) | |
5786 | return -ENOMEM; | |
5787 | ||
b9b0c831 NK |
5788 | mutex_lock(&graph_lock); |
5789 | ||
649b988b SRV |
5790 | fgd->hash = rcu_dereference_protected(ftrace_graph_hash, |
5791 | lockdep_is_held(&graph_lock)); | |
b9b0c831 | 5792 | fgd->type = GRAPH_FILTER_FUNCTION; |
faf982a6 NK |
5793 | fgd->seq_ops = &ftrace_graph_seq_ops; |
5794 | ||
b9b0c831 NK |
5795 | ret = __ftrace_graph_open(inode, file, fgd); |
5796 | if (ret < 0) | |
5797 | kfree(fgd); | |
5798 | ||
5799 | mutex_unlock(&graph_lock); | |
5800 | return ret; | |
faf982a6 NK |
5801 | } |
5802 | ||
29ad23b0 NK |
5803 | static int |
5804 | ftrace_graph_notrace_open(struct inode *inode, struct file *file) | |
5805 | { | |
5806 | struct ftrace_graph_data *fgd; | |
b9b0c831 | 5807 | int ret; |
29ad23b0 NK |
5808 | |
5809 | if (unlikely(ftrace_disabled)) | |
5810 | return -ENODEV; | |
5811 | ||
5812 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
5813 | if (fgd == NULL) | |
5814 | return -ENOMEM; | |
5815 | ||
b9b0c831 NK |
5816 | mutex_lock(&graph_lock); |
5817 | ||
649b988b SRV |
5818 | fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash, |
5819 | lockdep_is_held(&graph_lock)); | |
b9b0c831 | 5820 | fgd->type = GRAPH_FILTER_NOTRACE; |
29ad23b0 NK |
5821 | fgd->seq_ops = &ftrace_graph_seq_ops; |
5822 | ||
b9b0c831 NK |
5823 | ret = __ftrace_graph_open(inode, file, fgd); |
5824 | if (ret < 0) | |
5825 | kfree(fgd); | |
5826 | ||
5827 | mutex_unlock(&graph_lock); | |
5828 | return ret; | |
29ad23b0 NK |
5829 | } |
5830 | ||
87827111 LZ |
5831 | static int |
5832 | ftrace_graph_release(struct inode *inode, struct file *file) | |
5833 | { | |
b9b0c831 | 5834 | struct ftrace_graph_data *fgd; |
e704eff3 SRV |
5835 | struct ftrace_hash *old_hash, *new_hash; |
5836 | struct trace_parser *parser; | |
5837 | int ret = 0; | |
b9b0c831 | 5838 | |
faf982a6 NK |
5839 | if (file->f_mode & FMODE_READ) { |
5840 | struct seq_file *m = file->private_data; | |
5841 | ||
b9b0c831 | 5842 | fgd = m->private; |
87827111 | 5843 | seq_release(inode, file); |
faf982a6 | 5844 | } else { |
b9b0c831 | 5845 | fgd = file->private_data; |
faf982a6 NK |
5846 | } |
5847 | ||
e704eff3 SRV |
5848 | |
5849 | if (file->f_mode & FMODE_WRITE) { | |
5850 | ||
5851 | parser = &fgd->parser; | |
5852 | ||
5853 | if (trace_parser_loaded((parser))) { | |
e704eff3 SRV |
5854 | ret = ftrace_graph_set_hash(fgd->new_hash, |
5855 | parser->buffer); | |
5856 | } | |
5857 | ||
5858 | trace_parser_put(parser); | |
5859 | ||
5860 | new_hash = __ftrace_hash_move(fgd->new_hash); | |
5861 | if (!new_hash) { | |
5862 | ret = -ENOMEM; | |
5863 | goto out; | |
5864 | } | |
5865 | ||
5866 | mutex_lock(&graph_lock); | |
5867 | ||
5868 | if (fgd->type == GRAPH_FILTER_FUNCTION) { | |
5869 | old_hash = rcu_dereference_protected(ftrace_graph_hash, | |
5870 | lockdep_is_held(&graph_lock)); | |
5871 | rcu_assign_pointer(ftrace_graph_hash, new_hash); | |
5872 | } else { | |
5873 | old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash, | |
5874 | lockdep_is_held(&graph_lock)); | |
5875 | rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash); | |
5876 | } | |
5877 | ||
5878 | mutex_unlock(&graph_lock); | |
5879 | ||
54a16ff6 SRV |
5880 | /* |
5881 | * We need to do a hard force of sched synchronization. | |
5882 | * This is because we use preempt_disable() to do RCU, but | |
5883 | * the function tracers can be called where RCU is not watching | |
5884 | * (like before user_exit()). We can not rely on the RCU | |
5885 | * infrastructure to do the synchronization, thus we must do it | |
5886 | * ourselves. | |
5887 | */ | |
5888 | schedule_on_each_cpu(ftrace_sync); | |
e704eff3 SRV |
5889 | |
5890 | free_ftrace_hash(old_hash); | |
5891 | } | |
5892 | ||
5893 | out: | |
f9797c2f | 5894 | free_ftrace_hash(fgd->new_hash); |
b9b0c831 NK |
5895 | kfree(fgd); |
5896 | ||
e704eff3 | 5897 | return ret; |
87827111 LZ |
5898 | } |
5899 | ||
ea4e2bc4 | 5900 | static int |
b9b0c831 | 5901 | ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer) |
ea4e2bc4 | 5902 | { |
3ba00929 | 5903 | struct ftrace_glob func_g; |
ea4e2bc4 SR |
5904 | struct dyn_ftrace *rec; |
5905 | struct ftrace_page *pg; | |
b9b0c831 | 5906 | struct ftrace_func_entry *entry; |
c7c6b1fe | 5907 | int fail = 1; |
3ba00929 | 5908 | int not; |
ea4e2bc4 | 5909 | |
f9349a8f | 5910 | /* decode regex */ |
3ba00929 DS |
5911 | func_g.type = filter_parse_regex(buffer, strlen(buffer), |
5912 | &func_g.search, ¬); | |
f9349a8f | 5913 | |
3ba00929 | 5914 | func_g.len = strlen(func_g.search); |
f9349a8f | 5915 | |
52baf119 | 5916 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
5917 | |
5918 | if (unlikely(ftrace_disabled)) { | |
5919 | mutex_unlock(&ftrace_lock); | |
5920 | return -ENODEV; | |
5921 | } | |
5922 | ||
265c831c SR |
5923 | do_for_each_ftrace_rec(pg, rec) { |
5924 | ||
546fece4 SRRH |
5925 | if (rec->flags & FTRACE_FL_DISABLED) |
5926 | continue; | |
5927 | ||
0b507e1e | 5928 | if (ftrace_match_record(rec, &func_g, NULL, 0)) { |
b9b0c831 | 5929 | entry = ftrace_lookup_ip(hash, rec->ip); |
c7c6b1fe LZ |
5930 | |
5931 | if (!not) { | |
5932 | fail = 0; | |
b9b0c831 NK |
5933 | |
5934 | if (entry) | |
5935 | continue; | |
5936 | if (add_hash_entry(hash, rec->ip) < 0) | |
5937 | goto out; | |
c7c6b1fe | 5938 | } else { |
b9b0c831 NK |
5939 | if (entry) { |
5940 | free_hash_entry(hash, entry); | |
c7c6b1fe LZ |
5941 | fail = 0; |
5942 | } | |
5943 | } | |
ea4e2bc4 | 5944 | } |
265c831c | 5945 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 5946 | out: |
52baf119 | 5947 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 5948 | |
c7c6b1fe LZ |
5949 | if (fail) |
5950 | return -EINVAL; | |
5951 | ||
c7c6b1fe | 5952 | return 0; |
ea4e2bc4 SR |
5953 | } |
5954 | ||
5955 | static ssize_t | |
5956 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
5957 | size_t cnt, loff_t *ppos) | |
5958 | { | |
6a10108b | 5959 | ssize_t read, ret = 0; |
faf982a6 | 5960 | struct ftrace_graph_data *fgd = file->private_data; |
e704eff3 | 5961 | struct trace_parser *parser; |
ea4e2bc4 | 5962 | |
c7c6b1fe | 5963 | if (!cnt) |
ea4e2bc4 SR |
5964 | return 0; |
5965 | ||
ae98d27a SRV |
5966 | /* Read mode uses seq functions */ |
5967 | if (file->f_mode & FMODE_READ) { | |
5968 | struct seq_file *m = file->private_data; | |
5969 | fgd = m->private; | |
5970 | } | |
5971 | ||
e704eff3 | 5972 | parser = &fgd->parser; |
ea4e2bc4 | 5973 | |
e704eff3 | 5974 | read = trace_get_user(parser, ubuf, cnt, ppos); |
689fd8b6 | 5975 | |
e704eff3 SRV |
5976 | if (read >= 0 && trace_parser_loaded(parser) && |
5977 | !trace_parser_cont(parser)) { | |
6a10108b | 5978 | |
b9b0c831 | 5979 | ret = ftrace_graph_set_hash(fgd->new_hash, |
e704eff3 SRV |
5980 | parser->buffer); |
5981 | trace_parser_clear(parser); | |
ea4e2bc4 | 5982 | } |
ea4e2bc4 | 5983 | |
6a10108b NK |
5984 | if (!ret) |
5985 | ret = read; | |
1eb90f13 | 5986 | |
ea4e2bc4 SR |
5987 | return ret; |
5988 | } | |
5989 | ||
5990 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
5991 | .open = ftrace_graph_open, |
5992 | .read = seq_read, | |
5993 | .write = ftrace_graph_write, | |
098c879e | 5994 | .llseek = tracing_lseek, |
87827111 | 5995 | .release = ftrace_graph_release, |
ea4e2bc4 | 5996 | }; |
29ad23b0 NK |
5997 | |
5998 | static const struct file_operations ftrace_graph_notrace_fops = { | |
5999 | .open = ftrace_graph_notrace_open, | |
6000 | .read = seq_read, | |
6001 | .write = ftrace_graph_write, | |
098c879e | 6002 | .llseek = tracing_lseek, |
29ad23b0 NK |
6003 | .release = ftrace_graph_release, |
6004 | }; | |
ea4e2bc4 SR |
6005 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
6006 | ||
591dffda SRRH |
6007 | void ftrace_create_filter_files(struct ftrace_ops *ops, |
6008 | struct dentry *parent) | |
6009 | { | |
6010 | ||
6011 | trace_create_file("set_ftrace_filter", 0644, parent, | |
6012 | ops, &ftrace_filter_fops); | |
6013 | ||
6014 | trace_create_file("set_ftrace_notrace", 0644, parent, | |
6015 | ops, &ftrace_notrace_fops); | |
6016 | } | |
6017 | ||
6018 | /* | |
6019 | * The name "destroy_filter_files" is really a misnomer. Although | |
9efb85c5 | 6020 | * in the future, it may actually delete the files, but this is |
591dffda SRRH |
6021 | * really intended to make sure the ops passed in are disabled |
6022 | * and that when this function returns, the caller is free to | |
6023 | * free the ops. | |
6024 | * | |
6025 | * The "destroy" name is only to match the "create" name that this | |
6026 | * should be paired with. | |
6027 | */ | |
6028 | void ftrace_destroy_filter_files(struct ftrace_ops *ops) | |
6029 | { | |
6030 | mutex_lock(&ftrace_lock); | |
6031 | if (ops->flags & FTRACE_OPS_FL_ENABLED) | |
6032 | ftrace_shutdown(ops, 0); | |
6033 | ops->flags |= FTRACE_OPS_FL_DELETED; | |
2840f84f | 6034 | ftrace_free_filter(ops); |
591dffda SRRH |
6035 | mutex_unlock(&ftrace_lock); |
6036 | } | |
6037 | ||
8434dc93 | 6038 | static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer) |
5072c59f | 6039 | { |
5072c59f | 6040 | |
5452af66 FW |
6041 | trace_create_file("available_filter_functions", 0444, |
6042 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 6043 | |
647bcd03 SR |
6044 | trace_create_file("enabled_functions", 0444, |
6045 | d_tracer, NULL, &ftrace_enabled_fops); | |
6046 | ||
591dffda | 6047 | ftrace_create_filter_files(&global_ops, d_tracer); |
ad90c0e3 | 6048 | |
ea4e2bc4 | 6049 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
1ce0500d | 6050 | trace_create_file("set_graph_function", 0644, d_tracer, |
ea4e2bc4 SR |
6051 | NULL, |
6052 | &ftrace_graph_fops); | |
1ce0500d | 6053 | trace_create_file("set_graph_notrace", 0644, d_tracer, |
29ad23b0 NK |
6054 | NULL, |
6055 | &ftrace_graph_notrace_fops); | |
ea4e2bc4 SR |
6056 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
6057 | ||
5072c59f SR |
6058 | return 0; |
6059 | } | |
6060 | ||
9fd49328 | 6061 | static int ftrace_cmp_ips(const void *a, const void *b) |
68950619 | 6062 | { |
9fd49328 SR |
6063 | const unsigned long *ipa = a; |
6064 | const unsigned long *ipb = b; | |
68950619 | 6065 | |
9fd49328 SR |
6066 | if (*ipa > *ipb) |
6067 | return 1; | |
6068 | if (*ipa < *ipb) | |
6069 | return -1; | |
6070 | return 0; | |
6071 | } | |
6072 | ||
5cb084bb | 6073 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 6074 | unsigned long *start, |
68bf21aa SR |
6075 | unsigned long *end) |
6076 | { | |
706c81f8 | 6077 | struct ftrace_page *start_pg; |
a7900875 | 6078 | struct ftrace_page *pg; |
706c81f8 | 6079 | struct dyn_ftrace *rec; |
a7900875 | 6080 | unsigned long count; |
68bf21aa SR |
6081 | unsigned long *p; |
6082 | unsigned long addr; | |
4376cac6 | 6083 | unsigned long flags = 0; /* Shut up gcc */ |
a7900875 SR |
6084 | int ret = -ENOMEM; |
6085 | ||
6086 | count = end - start; | |
6087 | ||
6088 | if (!count) | |
6089 | return 0; | |
6090 | ||
9fd49328 | 6091 | sort(start, count, sizeof(*start), |
6db02903 | 6092 | ftrace_cmp_ips, NULL); |
9fd49328 | 6093 | |
706c81f8 SR |
6094 | start_pg = ftrace_allocate_pages(count); |
6095 | if (!start_pg) | |
a7900875 | 6096 | return -ENOMEM; |
68bf21aa | 6097 | |
e6ea44e9 | 6098 | mutex_lock(&ftrace_lock); |
a7900875 | 6099 | |
32082309 SR |
6100 | /* |
6101 | * Core and each module needs their own pages, as | |
6102 | * modules will free them when they are removed. | |
6103 | * Force a new page to be allocated for modules. | |
6104 | */ | |
a7900875 SR |
6105 | if (!mod) { |
6106 | WARN_ON(ftrace_pages || ftrace_pages_start); | |
6107 | /* First initialization */ | |
706c81f8 | 6108 | ftrace_pages = ftrace_pages_start = start_pg; |
a7900875 | 6109 | } else { |
32082309 | 6110 | if (!ftrace_pages) |
a7900875 | 6111 | goto out; |
32082309 | 6112 | |
a7900875 SR |
6113 | if (WARN_ON(ftrace_pages->next)) { |
6114 | /* Hmm, we have free pages? */ | |
6115 | while (ftrace_pages->next) | |
6116 | ftrace_pages = ftrace_pages->next; | |
32082309 | 6117 | } |
a7900875 | 6118 | |
706c81f8 | 6119 | ftrace_pages->next = start_pg; |
32082309 SR |
6120 | } |
6121 | ||
68bf21aa | 6122 | p = start; |
706c81f8 | 6123 | pg = start_pg; |
68bf21aa SR |
6124 | while (p < end) { |
6125 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
6126 | /* |
6127 | * Some architecture linkers will pad between | |
6128 | * the different mcount_loc sections of different | |
6129 | * object files to satisfy alignments. | |
6130 | * Skip any NULL pointers. | |
6131 | */ | |
6132 | if (!addr) | |
6133 | continue; | |
706c81f8 SR |
6134 | |
6135 | if (pg->index == pg->size) { | |
6136 | /* We should have allocated enough */ | |
6137 | if (WARN_ON(!pg->next)) | |
6138 | break; | |
6139 | pg = pg->next; | |
6140 | } | |
6141 | ||
6142 | rec = &pg->records[pg->index++]; | |
6143 | rec->ip = addr; | |
68bf21aa SR |
6144 | } |
6145 | ||
706c81f8 SR |
6146 | /* We should have used all pages */ |
6147 | WARN_ON(pg->next); | |
6148 | ||
6149 | /* Assign the last page to ftrace_pages */ | |
6150 | ftrace_pages = pg; | |
6151 | ||
a4f18ed1 | 6152 | /* |
4376cac6 SR |
6153 | * We only need to disable interrupts on start up |
6154 | * because we are modifying code that an interrupt | |
6155 | * may execute, and the modification is not atomic. | |
6156 | * But for modules, nothing runs the code we modify | |
6157 | * until we are finished with it, and there's no | |
6158 | * reason to cause large interrupt latencies while we do it. | |
a4f18ed1 | 6159 | */ |
4376cac6 SR |
6160 | if (!mod) |
6161 | local_irq_save(flags); | |
1dc43cf0 | 6162 | ftrace_update_code(mod, start_pg); |
4376cac6 SR |
6163 | if (!mod) |
6164 | local_irq_restore(flags); | |
a7900875 SR |
6165 | ret = 0; |
6166 | out: | |
e6ea44e9 | 6167 | mutex_unlock(&ftrace_lock); |
68bf21aa | 6168 | |
a7900875 | 6169 | return ret; |
68bf21aa SR |
6170 | } |
6171 | ||
aba4b5c2 SRV |
6172 | struct ftrace_mod_func { |
6173 | struct list_head list; | |
6174 | char *name; | |
6175 | unsigned long ip; | |
6176 | unsigned int size; | |
6177 | }; | |
6178 | ||
6179 | struct ftrace_mod_map { | |
6aa69784 | 6180 | struct rcu_head rcu; |
aba4b5c2 SRV |
6181 | struct list_head list; |
6182 | struct module *mod; | |
6183 | unsigned long start_addr; | |
6184 | unsigned long end_addr; | |
6185 | struct list_head funcs; | |
6171a031 | 6186 | unsigned int num_funcs; |
aba4b5c2 SRV |
6187 | }; |
6188 | ||
93eb677d | 6189 | #ifdef CONFIG_MODULES |
32082309 SR |
6190 | |
6191 | #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next) | |
6192 | ||
6aa69784 SRV |
6193 | static LIST_HEAD(ftrace_mod_maps); |
6194 | ||
b7ffffbb SRRH |
6195 | static int referenced_filters(struct dyn_ftrace *rec) |
6196 | { | |
6197 | struct ftrace_ops *ops; | |
6198 | int cnt = 0; | |
6199 | ||
6200 | for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) { | |
6201 | if (ops_references_rec(ops, rec)) | |
6202 | cnt++; | |
6203 | } | |
6204 | ||
6205 | return cnt; | |
6206 | } | |
6207 | ||
2a5bfe47 SRV |
6208 | static void |
6209 | clear_mod_from_hash(struct ftrace_page *pg, struct ftrace_hash *hash) | |
6210 | { | |
6211 | struct ftrace_func_entry *entry; | |
6212 | struct dyn_ftrace *rec; | |
6213 | int i; | |
6214 | ||
6215 | if (ftrace_hash_empty(hash)) | |
6216 | return; | |
6217 | ||
6218 | for (i = 0; i < pg->index; i++) { | |
6219 | rec = &pg->records[i]; | |
6220 | entry = __ftrace_lookup_ip(hash, rec->ip); | |
6221 | /* | |
6222 | * Do not allow this rec to match again. | |
6223 | * Yeah, it may waste some memory, but will be removed | |
6224 | * if/when the hash is modified again. | |
6225 | */ | |
6226 | if (entry) | |
6227 | entry->ip = 0; | |
6228 | } | |
6229 | } | |
6230 | ||
6231 | /* Clear any records from hashs */ | |
6232 | static void clear_mod_from_hashes(struct ftrace_page *pg) | |
6233 | { | |
6234 | struct trace_array *tr; | |
6235 | ||
6236 | mutex_lock(&trace_types_lock); | |
6237 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
6238 | if (!tr->ops || !tr->ops->func_hash) | |
6239 | continue; | |
6240 | mutex_lock(&tr->ops->func_hash->regex_lock); | |
6241 | clear_mod_from_hash(pg, tr->ops->func_hash->filter_hash); | |
6242 | clear_mod_from_hash(pg, tr->ops->func_hash->notrace_hash); | |
6243 | mutex_unlock(&tr->ops->func_hash->regex_lock); | |
6244 | } | |
6245 | mutex_unlock(&trace_types_lock); | |
6246 | } | |
6247 | ||
6aa69784 SRV |
6248 | static void ftrace_free_mod_map(struct rcu_head *rcu) |
6249 | { | |
6250 | struct ftrace_mod_map *mod_map = container_of(rcu, struct ftrace_mod_map, rcu); | |
6251 | struct ftrace_mod_func *mod_func; | |
6252 | struct ftrace_mod_func *n; | |
6253 | ||
6254 | /* All the contents of mod_map are now not visible to readers */ | |
6255 | list_for_each_entry_safe(mod_func, n, &mod_map->funcs, list) { | |
6256 | kfree(mod_func->name); | |
6257 | list_del(&mod_func->list); | |
6258 | kfree(mod_func); | |
6259 | } | |
6260 | ||
6261 | kfree(mod_map); | |
6262 | } | |
6263 | ||
e7247a15 | 6264 | void ftrace_release_mod(struct module *mod) |
93eb677d | 6265 | { |
6aa69784 SRV |
6266 | struct ftrace_mod_map *mod_map; |
6267 | struct ftrace_mod_map *n; | |
93eb677d | 6268 | struct dyn_ftrace *rec; |
32082309 | 6269 | struct ftrace_page **last_pg; |
2a5bfe47 | 6270 | struct ftrace_page *tmp_page = NULL; |
93eb677d | 6271 | struct ftrace_page *pg; |
a7900875 | 6272 | int order; |
93eb677d | 6273 | |
45a4a237 SR |
6274 | mutex_lock(&ftrace_lock); |
6275 | ||
e7247a15 | 6276 | if (ftrace_disabled) |
45a4a237 | 6277 | goto out_unlock; |
93eb677d | 6278 | |
6aa69784 SRV |
6279 | list_for_each_entry_safe(mod_map, n, &ftrace_mod_maps, list) { |
6280 | if (mod_map->mod == mod) { | |
6281 | list_del_rcu(&mod_map->list); | |
74401729 | 6282 | call_rcu(&mod_map->rcu, ftrace_free_mod_map); |
6aa69784 SRV |
6283 | break; |
6284 | } | |
6285 | } | |
6286 | ||
32082309 SR |
6287 | /* |
6288 | * Each module has its own ftrace_pages, remove | |
6289 | * them from the list. | |
6290 | */ | |
6291 | last_pg = &ftrace_pages_start; | |
6292 | for (pg = ftrace_pages_start; pg; pg = *last_pg) { | |
6293 | rec = &pg->records[0]; | |
3e234289 SRV |
6294 | if (within_module_core(rec->ip, mod) || |
6295 | within_module_init(rec->ip, mod)) { | |
93eb677d | 6296 | /* |
32082309 SR |
6297 | * As core pages are first, the first |
6298 | * page should never be a module page. | |
93eb677d | 6299 | */ |
32082309 SR |
6300 | if (WARN_ON(pg == ftrace_pages_start)) |
6301 | goto out_unlock; | |
6302 | ||
6303 | /* Check if we are deleting the last page */ | |
6304 | if (pg == ftrace_pages) | |
6305 | ftrace_pages = next_to_ftrace_page(last_pg); | |
6306 | ||
83dd1493 | 6307 | ftrace_update_tot_cnt -= pg->index; |
32082309 | 6308 | *last_pg = pg->next; |
2a5bfe47 SRV |
6309 | |
6310 | pg->next = tmp_page; | |
6311 | tmp_page = pg; | |
32082309 SR |
6312 | } else |
6313 | last_pg = &pg->next; | |
6314 | } | |
45a4a237 | 6315 | out_unlock: |
93eb677d | 6316 | mutex_unlock(&ftrace_lock); |
2a5bfe47 SRV |
6317 | |
6318 | for (pg = tmp_page; pg; pg = tmp_page) { | |
6319 | ||
6320 | /* Needs to be called outside of ftrace_lock */ | |
6321 | clear_mod_from_hashes(pg); | |
6322 | ||
6323 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); | |
6324 | free_pages((unsigned long)pg->records, order); | |
6325 | tmp_page = pg->next; | |
6326 | kfree(pg); | |
da537f0a SRV |
6327 | ftrace_number_of_pages -= 1 << order; |
6328 | ftrace_number_of_groups--; | |
2a5bfe47 | 6329 | } |
93eb677d SR |
6330 | } |
6331 | ||
7dcd182b | 6332 | void ftrace_module_enable(struct module *mod) |
b7ffffbb SRRH |
6333 | { |
6334 | struct dyn_ftrace *rec; | |
6335 | struct ftrace_page *pg; | |
6336 | ||
6337 | mutex_lock(&ftrace_lock); | |
6338 | ||
6339 | if (ftrace_disabled) | |
6340 | goto out_unlock; | |
6341 | ||
6342 | /* | |
6343 | * If the tracing is enabled, go ahead and enable the record. | |
6344 | * | |
9efb85c5 | 6345 | * The reason not to enable the record immediately is the |
b7ffffbb SRRH |
6346 | * inherent check of ftrace_make_nop/ftrace_make_call for |
6347 | * correct previous instructions. Making first the NOP | |
6348 | * conversion puts the module to the correct state, thus | |
6349 | * passing the ftrace_make_call check. | |
6350 | * | |
6351 | * We also delay this to after the module code already set the | |
6352 | * text to read-only, as we now need to set it back to read-write | |
6353 | * so that we can modify the text. | |
6354 | */ | |
6355 | if (ftrace_start_up) | |
6356 | ftrace_arch_code_modify_prepare(); | |
6357 | ||
6358 | do_for_each_ftrace_rec(pg, rec) { | |
6359 | int cnt; | |
6360 | /* | |
6361 | * do_for_each_ftrace_rec() is a double loop. | |
6362 | * module text shares the pg. If a record is | |
6363 | * not part of this module, then skip this pg, | |
6364 | * which the "break" will do. | |
6365 | */ | |
3e234289 SRV |
6366 | if (!within_module_core(rec->ip, mod) && |
6367 | !within_module_init(rec->ip, mod)) | |
b7ffffbb SRRH |
6368 | break; |
6369 | ||
6370 | cnt = 0; | |
6371 | ||
6372 | /* | |
6373 | * When adding a module, we need to check if tracers are | |
6374 | * currently enabled and if they are, and can trace this record, | |
6375 | * we need to enable the module functions as well as update the | |
6376 | * reference counts for those function records. | |
6377 | */ | |
6378 | if (ftrace_start_up) | |
6379 | cnt += referenced_filters(rec); | |
6380 | ||
6381 | /* This clears FTRACE_FL_DISABLED */ | |
6382 | rec->flags = cnt; | |
6383 | ||
6384 | if (ftrace_start_up && cnt) { | |
6385 | int failed = __ftrace_replace_code(rec, 1); | |
6386 | if (failed) { | |
6387 | ftrace_bug(failed, rec); | |
6388 | goto out_loop; | |
6389 | } | |
6390 | } | |
6391 | ||
6392 | } while_for_each_ftrace_rec(); | |
6393 | ||
6394 | out_loop: | |
6395 | if (ftrace_start_up) | |
6396 | ftrace_arch_code_modify_post_process(); | |
6397 | ||
6398 | out_unlock: | |
6399 | mutex_unlock(&ftrace_lock); | |
d7fbf8df SRV |
6400 | |
6401 | process_cached_mods(mod->name); | |
b7ffffbb SRRH |
6402 | } |
6403 | ||
b6b71f66 | 6404 | void ftrace_module_init(struct module *mod) |
90d595fe | 6405 | { |
97e9b4fc | 6406 | if (ftrace_disabled || !mod->num_ftrace_callsites) |
fed1939c | 6407 | return; |
90d595fe | 6408 | |
97e9b4fc SRRH |
6409 | ftrace_process_locs(mod, mod->ftrace_callsites, |
6410 | mod->ftrace_callsites + mod->num_ftrace_callsites); | |
8c189ea6 | 6411 | } |
aba4b5c2 SRV |
6412 | |
6413 | static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map, | |
6414 | struct dyn_ftrace *rec) | |
6415 | { | |
6416 | struct ftrace_mod_func *mod_func; | |
6417 | unsigned long symsize; | |
6418 | unsigned long offset; | |
6419 | char str[KSYM_SYMBOL_LEN]; | |
6420 | char *modname; | |
6421 | const char *ret; | |
6422 | ||
6423 | ret = kallsyms_lookup(rec->ip, &symsize, &offset, &modname, str); | |
6424 | if (!ret) | |
6425 | return; | |
6426 | ||
6427 | mod_func = kmalloc(sizeof(*mod_func), GFP_KERNEL); | |
6428 | if (!mod_func) | |
6429 | return; | |
6430 | ||
6431 | mod_func->name = kstrdup(str, GFP_KERNEL); | |
6432 | if (!mod_func->name) { | |
6433 | kfree(mod_func); | |
6434 | return; | |
6435 | } | |
6436 | ||
6437 | mod_func->ip = rec->ip - offset; | |
6438 | mod_func->size = symsize; | |
6439 | ||
6171a031 SRV |
6440 | mod_map->num_funcs++; |
6441 | ||
aba4b5c2 SRV |
6442 | list_add_rcu(&mod_func->list, &mod_map->funcs); |
6443 | } | |
6444 | ||
aba4b5c2 SRV |
6445 | static struct ftrace_mod_map * |
6446 | allocate_ftrace_mod_map(struct module *mod, | |
6447 | unsigned long start, unsigned long end) | |
6448 | { | |
6449 | struct ftrace_mod_map *mod_map; | |
6450 | ||
6451 | mod_map = kmalloc(sizeof(*mod_map), GFP_KERNEL); | |
6452 | if (!mod_map) | |
6453 | return NULL; | |
6454 | ||
6455 | mod_map->mod = mod; | |
6456 | mod_map->start_addr = start; | |
6457 | mod_map->end_addr = end; | |
6171a031 | 6458 | mod_map->num_funcs = 0; |
aba4b5c2 SRV |
6459 | |
6460 | INIT_LIST_HEAD_RCU(&mod_map->funcs); | |
6461 | ||
6462 | list_add_rcu(&mod_map->list, &ftrace_mod_maps); | |
6463 | ||
6464 | return mod_map; | |
6465 | } | |
6466 | ||
6467 | static const char * | |
6468 | ftrace_func_address_lookup(struct ftrace_mod_map *mod_map, | |
6469 | unsigned long addr, unsigned long *size, | |
6470 | unsigned long *off, char *sym) | |
6471 | { | |
6472 | struct ftrace_mod_func *found_func = NULL; | |
6473 | struct ftrace_mod_func *mod_func; | |
6474 | ||
6475 | list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) { | |
6476 | if (addr >= mod_func->ip && | |
6477 | addr < mod_func->ip + mod_func->size) { | |
6478 | found_func = mod_func; | |
6479 | break; | |
6480 | } | |
6481 | } | |
6482 | ||
6483 | if (found_func) { | |
6484 | if (size) | |
6485 | *size = found_func->size; | |
6486 | if (off) | |
6487 | *off = addr - found_func->ip; | |
6488 | if (sym) | |
6489 | strlcpy(sym, found_func->name, KSYM_NAME_LEN); | |
6490 | ||
6491 | return found_func->name; | |
6492 | } | |
6493 | ||
6494 | return NULL; | |
6495 | } | |
6496 | ||
6497 | const char * | |
6498 | ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, | |
6499 | unsigned long *off, char **modname, char *sym) | |
6500 | { | |
6501 | struct ftrace_mod_map *mod_map; | |
6502 | const char *ret = NULL; | |
6503 | ||
74401729 | 6504 | /* mod_map is freed via call_rcu() */ |
aba4b5c2 SRV |
6505 | preempt_disable(); |
6506 | list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) { | |
6507 | ret = ftrace_func_address_lookup(mod_map, addr, size, off, sym); | |
6508 | if (ret) { | |
6509 | if (modname) | |
6510 | *modname = mod_map->mod->name; | |
6511 | break; | |
6512 | } | |
6513 | } | |
6514 | preempt_enable(); | |
6515 | ||
6516 | return ret; | |
6517 | } | |
6518 | ||
6171a031 SRV |
6519 | int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, |
6520 | char *type, char *name, | |
6521 | char *module_name, int *exported) | |
6522 | { | |
6523 | struct ftrace_mod_map *mod_map; | |
6524 | struct ftrace_mod_func *mod_func; | |
6525 | ||
6526 | preempt_disable(); | |
6527 | list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) { | |
6528 | ||
6529 | if (symnum >= mod_map->num_funcs) { | |
6530 | symnum -= mod_map->num_funcs; | |
6531 | continue; | |
6532 | } | |
6533 | ||
6534 | list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) { | |
6535 | if (symnum > 1) { | |
6536 | symnum--; | |
6537 | continue; | |
6538 | } | |
6539 | ||
6540 | *value = mod_func->ip; | |
6541 | *type = 'T'; | |
6542 | strlcpy(name, mod_func->name, KSYM_NAME_LEN); | |
6543 | strlcpy(module_name, mod_map->mod->name, MODULE_NAME_LEN); | |
6544 | *exported = 1; | |
6545 | preempt_enable(); | |
6546 | return 0; | |
6547 | } | |
6548 | WARN_ON(1); | |
6549 | break; | |
6550 | } | |
6551 | preempt_enable(); | |
6552 | return -ERANGE; | |
6553 | } | |
6554 | ||
aba4b5c2 SRV |
6555 | #else |
6556 | static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map, | |
6557 | struct dyn_ftrace *rec) { } | |
6558 | static inline struct ftrace_mod_map * | |
6559 | allocate_ftrace_mod_map(struct module *mod, | |
6560 | unsigned long start, unsigned long end) | |
6561 | { | |
6562 | return NULL; | |
6563 | } | |
93eb677d SR |
6564 | #endif /* CONFIG_MODULES */ |
6565 | ||
8715b108 JF |
6566 | struct ftrace_init_func { |
6567 | struct list_head list; | |
6568 | unsigned long ip; | |
6569 | }; | |
6570 | ||
6571 | /* Clear any init ips from hashes */ | |
6572 | static void | |
6573 | clear_func_from_hash(struct ftrace_init_func *func, struct ftrace_hash *hash) | |
42c269c8 | 6574 | { |
8715b108 JF |
6575 | struct ftrace_func_entry *entry; |
6576 | ||
08468754 | 6577 | entry = ftrace_lookup_ip(hash, func->ip); |
8715b108 JF |
6578 | /* |
6579 | * Do not allow this rec to match again. | |
6580 | * Yeah, it may waste some memory, but will be removed | |
6581 | * if/when the hash is modified again. | |
6582 | */ | |
6583 | if (entry) | |
6584 | entry->ip = 0; | |
6585 | } | |
6586 | ||
6587 | static void | |
6588 | clear_func_from_hashes(struct ftrace_init_func *func) | |
6589 | { | |
6590 | struct trace_array *tr; | |
6591 | ||
6592 | mutex_lock(&trace_types_lock); | |
6593 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
6594 | if (!tr->ops || !tr->ops->func_hash) | |
6595 | continue; | |
6596 | mutex_lock(&tr->ops->func_hash->regex_lock); | |
6597 | clear_func_from_hash(func, tr->ops->func_hash->filter_hash); | |
6598 | clear_func_from_hash(func, tr->ops->func_hash->notrace_hash); | |
6599 | mutex_unlock(&tr->ops->func_hash->regex_lock); | |
6600 | } | |
6601 | mutex_unlock(&trace_types_lock); | |
6602 | } | |
6603 | ||
6604 | static void add_to_clear_hash_list(struct list_head *clear_list, | |
6605 | struct dyn_ftrace *rec) | |
6606 | { | |
6607 | struct ftrace_init_func *func; | |
6608 | ||
6609 | func = kmalloc(sizeof(*func), GFP_KERNEL); | |
6610 | if (!func) { | |
24589e3a | 6611 | MEM_FAIL(1, "alloc failure, ftrace filter could be stale\n"); |
8715b108 JF |
6612 | return; |
6613 | } | |
6614 | ||
6615 | func->ip = rec->ip; | |
6616 | list_add(&func->list, clear_list); | |
6617 | } | |
6618 | ||
aba4b5c2 | 6619 | void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr) |
42c269c8 | 6620 | { |
6cafbe15 SRV |
6621 | unsigned long start = (unsigned long)(start_ptr); |
6622 | unsigned long end = (unsigned long)(end_ptr); | |
42c269c8 SRV |
6623 | struct ftrace_page **last_pg = &ftrace_pages_start; |
6624 | struct ftrace_page *pg; | |
6625 | struct dyn_ftrace *rec; | |
6626 | struct dyn_ftrace key; | |
aba4b5c2 | 6627 | struct ftrace_mod_map *mod_map = NULL; |
8715b108 JF |
6628 | struct ftrace_init_func *func, *func_next; |
6629 | struct list_head clear_hash; | |
42c269c8 SRV |
6630 | int order; |
6631 | ||
8715b108 JF |
6632 | INIT_LIST_HEAD(&clear_hash); |
6633 | ||
42c269c8 SRV |
6634 | key.ip = start; |
6635 | key.flags = end; /* overload flags, as it is unsigned long */ | |
6636 | ||
6637 | mutex_lock(&ftrace_lock); | |
6638 | ||
aba4b5c2 SRV |
6639 | /* |
6640 | * If we are freeing module init memory, then check if | |
6641 | * any tracer is active. If so, we need to save a mapping of | |
6642 | * the module functions being freed with the address. | |
6643 | */ | |
6644 | if (mod && ftrace_ops_list != &ftrace_list_end) | |
6645 | mod_map = allocate_ftrace_mod_map(mod, start, end); | |
6646 | ||
42c269c8 SRV |
6647 | for (pg = ftrace_pages_start; pg; last_pg = &pg->next, pg = *last_pg) { |
6648 | if (end < pg->records[0].ip || | |
6649 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) | |
6650 | continue; | |
6651 | again: | |
6652 | rec = bsearch(&key, pg->records, pg->index, | |
6653 | sizeof(struct dyn_ftrace), | |
6654 | ftrace_cmp_recs); | |
6655 | if (!rec) | |
6656 | continue; | |
aba4b5c2 | 6657 | |
8715b108 JF |
6658 | /* rec will be cleared from hashes after ftrace_lock unlock */ |
6659 | add_to_clear_hash_list(&clear_hash, rec); | |
6660 | ||
aba4b5c2 SRV |
6661 | if (mod_map) |
6662 | save_ftrace_mod_rec(mod_map, rec); | |
6663 | ||
42c269c8 | 6664 | pg->index--; |
4ec78467 | 6665 | ftrace_update_tot_cnt--; |
42c269c8 SRV |
6666 | if (!pg->index) { |
6667 | *last_pg = pg->next; | |
6668 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); | |
6669 | free_pages((unsigned long)pg->records, order); | |
da537f0a SRV |
6670 | ftrace_number_of_pages -= 1 << order; |
6671 | ftrace_number_of_groups--; | |
42c269c8 SRV |
6672 | kfree(pg); |
6673 | pg = container_of(last_pg, struct ftrace_page, next); | |
6674 | if (!(*last_pg)) | |
6675 | ftrace_pages = pg; | |
6676 | continue; | |
6677 | } | |
6678 | memmove(rec, rec + 1, | |
6679 | (pg->index - (rec - pg->records)) * sizeof(*rec)); | |
6680 | /* More than one function may be in this block */ | |
6681 | goto again; | |
6682 | } | |
6683 | mutex_unlock(&ftrace_lock); | |
8715b108 JF |
6684 | |
6685 | list_for_each_entry_safe(func, func_next, &clear_hash, list) { | |
6686 | clear_func_from_hashes(func); | |
6687 | kfree(func); | |
6688 | } | |
42c269c8 SRV |
6689 | } |
6690 | ||
6cafbe15 SRV |
6691 | void __init ftrace_free_init_mem(void) |
6692 | { | |
6693 | void *start = (void *)(&__init_begin); | |
6694 | void *end = (void *)(&__init_end); | |
6695 | ||
aba4b5c2 | 6696 | ftrace_free_mem(NULL, start, end); |
42c269c8 SRV |
6697 | } |
6698 | ||
68bf21aa SR |
6699 | void __init ftrace_init(void) |
6700 | { | |
1dc43cf0 JS |
6701 | extern unsigned long __start_mcount_loc[]; |
6702 | extern unsigned long __stop_mcount_loc[]; | |
3a36cb11 | 6703 | unsigned long count, flags; |
68bf21aa SR |
6704 | int ret; |
6705 | ||
68bf21aa | 6706 | local_irq_save(flags); |
3a36cb11 | 6707 | ret = ftrace_dyn_arch_init(); |
68bf21aa | 6708 | local_irq_restore(flags); |
af64a7cb | 6709 | if (ret) |
68bf21aa SR |
6710 | goto failed; |
6711 | ||
6712 | count = __stop_mcount_loc - __start_mcount_loc; | |
c867ccd8 JS |
6713 | if (!count) { |
6714 | pr_info("ftrace: No functions to be traced?\n"); | |
68bf21aa | 6715 | goto failed; |
c867ccd8 JS |
6716 | } |
6717 | ||
6718 | pr_info("ftrace: allocating %ld entries in %ld pages\n", | |
6719 | count, count / ENTRIES_PER_PAGE + 1); | |
68bf21aa SR |
6720 | |
6721 | last_ftrace_enabled = ftrace_enabled = 1; | |
6722 | ||
5cb084bb | 6723 | ret = ftrace_process_locs(NULL, |
31e88909 | 6724 | __start_mcount_loc, |
68bf21aa SR |
6725 | __stop_mcount_loc); |
6726 | ||
da537f0a SRV |
6727 | pr_info("ftrace: allocated %ld pages with %ld groups\n", |
6728 | ftrace_number_of_pages, ftrace_number_of_groups); | |
6729 | ||
2af15d6a SR |
6730 | set_ftrace_early_filters(); |
6731 | ||
68bf21aa SR |
6732 | return; |
6733 | failed: | |
6734 | ftrace_disabled = 1; | |
6735 | } | |
68bf21aa | 6736 | |
f3bea491 SRRH |
6737 | /* Do nothing if arch does not support this */ |
6738 | void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops) | |
6739 | { | |
6740 | } | |
6741 | ||
6742 | static void ftrace_update_trampoline(struct ftrace_ops *ops) | |
6743 | { | |
f3bea491 SRRH |
6744 | arch_ftrace_update_trampoline(ops); |
6745 | } | |
6746 | ||
04ec7bb6 SRV |
6747 | void ftrace_init_trace_array(struct trace_array *tr) |
6748 | { | |
6749 | INIT_LIST_HEAD(&tr->func_probes); | |
673feb9d SRV |
6750 | INIT_LIST_HEAD(&tr->mod_trace); |
6751 | INIT_LIST_HEAD(&tr->mod_notrace); | |
04ec7bb6 | 6752 | } |
3d083395 | 6753 | #else |
0b6e4d56 | 6754 | |
3306fc4a | 6755 | struct ftrace_ops global_ops = { |
bd69c30b | 6756 | .func = ftrace_stub, |
e3eea140 SRRH |
6757 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | |
6758 | FTRACE_OPS_FL_INITIALIZED | | |
6759 | FTRACE_OPS_FL_PID, | |
bd69c30b SR |
6760 | }; |
6761 | ||
0b6e4d56 FW |
6762 | static int __init ftrace_nodyn_init(void) |
6763 | { | |
6764 | ftrace_enabled = 1; | |
6765 | return 0; | |
6766 | } | |
6f415672 | 6767 | core_initcall(ftrace_nodyn_init); |
0b6e4d56 | 6768 | |
8434dc93 | 6769 | static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; } |
df4fc315 | 6770 | static inline void ftrace_startup_enable(int command) { } |
e1effa01 | 6771 | static inline void ftrace_startup_all(int command) { } |
8a56d776 | 6772 | |
c7aafc54 IM |
6773 | # define ftrace_startup_sysctl() do { } while (0) |
6774 | # define ftrace_shutdown_sysctl() do { } while (0) | |
b848914c | 6775 | |
f3bea491 SRRH |
6776 | static void ftrace_update_trampoline(struct ftrace_ops *ops) |
6777 | { | |
6778 | } | |
6779 | ||
3d083395 SR |
6780 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
6781 | ||
4104d326 SRRH |
6782 | __init void ftrace_init_global_array_ops(struct trace_array *tr) |
6783 | { | |
6784 | tr->ops = &global_ops; | |
6785 | tr->ops->private = tr; | |
04ec7bb6 | 6786 | ftrace_init_trace_array(tr); |
4104d326 SRRH |
6787 | } |
6788 | ||
6789 | void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func) | |
6790 | { | |
6791 | /* If we filter on pids, update to use the pid function */ | |
6792 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) { | |
6793 | if (WARN_ON(tr->ops->func != ftrace_stub)) | |
6794 | printk("ftrace ops had %pS for function\n", | |
6795 | tr->ops->func); | |
4104d326 SRRH |
6796 | } |
6797 | tr->ops->func = func; | |
6798 | tr->ops->private = tr; | |
6799 | } | |
6800 | ||
6801 | void ftrace_reset_array_ops(struct trace_array *tr) | |
6802 | { | |
6803 | tr->ops->func = ftrace_stub; | |
6804 | } | |
6805 | ||
fabe38ab | 6806 | static nokprobe_inline void |
2f5f6ad9 | 6807 | __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 6808 | struct ftrace_ops *ignored, struct pt_regs *regs) |
b848914c | 6809 | { |
cdbe61bf | 6810 | struct ftrace_ops *op; |
edc15caf | 6811 | int bit; |
b848914c | 6812 | |
edc15caf SR |
6813 | bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); |
6814 | if (bit < 0) | |
6815 | return; | |
b1cff0ad | 6816 | |
cdbe61bf SR |
6817 | /* |
6818 | * Some of the ops may be dynamically allocated, | |
74401729 | 6819 | * they must be freed after a synchronize_rcu(). |
cdbe61bf SR |
6820 | */ |
6821 | preempt_disable_notrace(); | |
ba27f2bc | 6822 | |
0a016409 | 6823 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
2fa717a0 SRV |
6824 | /* Stub functions don't need to be called nor tested */ |
6825 | if (op->flags & FTRACE_OPS_FL_STUB) | |
6826 | continue; | |
ba27f2bc SRRH |
6827 | /* |
6828 | * Check the following for each ops before calling their func: | |
6829 | * if RCU flag is set, then rcu_is_watching() must be true | |
6830 | * if PER_CPU is set, then ftrace_function_local_disable() | |
6831 | * must be false | |
6832 | * Otherwise test if the ip matches the ops filter | |
6833 | * | |
6834 | * If any of the above fails then the op->func() is not executed. | |
6835 | */ | |
6836 | if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) && | |
ba27f2bc | 6837 | ftrace_ops_test(op, ip, regs)) { |
1d48d596 SRRH |
6838 | if (FTRACE_WARN_ON(!op->func)) { |
6839 | pr_warn("op=%p %pS\n", op, op); | |
4104d326 SRRH |
6840 | goto out; |
6841 | } | |
a1e2e31d | 6842 | op->func(ip, parent_ip, op, regs); |
4104d326 | 6843 | } |
0a016409 | 6844 | } while_for_each_ftrace_op(op); |
4104d326 | 6845 | out: |
cdbe61bf | 6846 | preempt_enable_notrace(); |
edc15caf | 6847 | trace_clear_recursion(bit); |
b848914c SR |
6848 | } |
6849 | ||
2f5f6ad9 SR |
6850 | /* |
6851 | * Some archs only support passing ip and parent_ip. Even though | |
6852 | * the list function ignores the op parameter, we do not want any | |
6853 | * C side effects, where a function is called without the caller | |
6854 | * sending a third parameter. | |
a1e2e31d SR |
6855 | * Archs are to support both the regs and ftrace_ops at the same time. |
6856 | * If they support ftrace_ops, it is assumed they support regs. | |
6857 | * If call backs want to use regs, they must either check for regs | |
06aeaaea MH |
6858 | * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS. |
6859 | * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved. | |
a1e2e31d | 6860 | * An architecture can pass partial regs with ftrace_ops and still |
b8ec330a | 6861 | * set the ARCH_SUPPORTS_FTRACE_OPS. |
2f5f6ad9 SR |
6862 | */ |
6863 | #if ARCH_SUPPORTS_FTRACE_OPS | |
6864 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 6865 | struct ftrace_ops *op, struct pt_regs *regs) |
2f5f6ad9 | 6866 | { |
a1e2e31d | 6867 | __ftrace_ops_list_func(ip, parent_ip, NULL, regs); |
2f5f6ad9 | 6868 | } |
fabe38ab | 6869 | NOKPROBE_SYMBOL(ftrace_ops_list_func); |
2f5f6ad9 SR |
6870 | #else |
6871 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip) | |
6872 | { | |
a1e2e31d | 6873 | __ftrace_ops_list_func(ip, parent_ip, NULL, NULL); |
2f5f6ad9 | 6874 | } |
fabe38ab | 6875 | NOKPROBE_SYMBOL(ftrace_ops_no_ops); |
2f5f6ad9 SR |
6876 | #endif |
6877 | ||
f1ff6348 SRRH |
6878 | /* |
6879 | * If there's only one function registered but it does not support | |
c68c0fa2 SRRH |
6880 | * recursion, needs RCU protection and/or requires per cpu handling, then |
6881 | * this function will be called by the mcount trampoline. | |
f1ff6348 | 6882 | */ |
c68c0fa2 | 6883 | static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip, |
f1ff6348 SRRH |
6884 | struct ftrace_ops *op, struct pt_regs *regs) |
6885 | { | |
6886 | int bit; | |
6887 | ||
c68c0fa2 SRRH |
6888 | if ((op->flags & FTRACE_OPS_FL_RCU) && !rcu_is_watching()) |
6889 | return; | |
6890 | ||
f1ff6348 SRRH |
6891 | bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); |
6892 | if (bit < 0) | |
6893 | return; | |
6894 | ||
c68c0fa2 | 6895 | preempt_disable_notrace(); |
f1ff6348 | 6896 | |
b3a88803 | 6897 | op->func(ip, parent_ip, op, regs); |
c68c0fa2 SRRH |
6898 | |
6899 | preempt_enable_notrace(); | |
f1ff6348 SRRH |
6900 | trace_clear_recursion(bit); |
6901 | } | |
fabe38ab | 6902 | NOKPROBE_SYMBOL(ftrace_ops_assist_func); |
f1ff6348 | 6903 | |
87354059 SRRH |
6904 | /** |
6905 | * ftrace_ops_get_func - get the function a trampoline should call | |
6906 | * @ops: the ops to get the function for | |
6907 | * | |
6908 | * Normally the mcount trampoline will call the ops->func, but there | |
6909 | * are times that it should not. For example, if the ops does not | |
6910 | * have its own recursion protection, then it should call the | |
3a150df9 | 6911 | * ftrace_ops_assist_func() instead. |
87354059 SRRH |
6912 | * |
6913 | * Returns the function that the trampoline should call for @ops. | |
6914 | */ | |
6915 | ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops) | |
6916 | { | |
87354059 | 6917 | /* |
c68c0fa2 SRRH |
6918 | * If the function does not handle recursion, needs to be RCU safe, |
6919 | * or does per cpu logic, then we need to call the assist handler. | |
87354059 | 6920 | */ |
c68c0fa2 | 6921 | if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE) || |
b3a88803 | 6922 | ops->flags & FTRACE_OPS_FL_RCU) |
c68c0fa2 | 6923 | return ftrace_ops_assist_func; |
87354059 SRRH |
6924 | |
6925 | return ops->func; | |
6926 | } | |
6927 | ||
345ddcc8 SRRH |
6928 | static void |
6929 | ftrace_filter_pid_sched_switch_probe(void *data, bool preempt, | |
6930 | struct task_struct *prev, struct task_struct *next) | |
978f3a45 | 6931 | { |
345ddcc8 SRRH |
6932 | struct trace_array *tr = data; |
6933 | struct trace_pid_list *pid_list; | |
b3b1e6ed | 6934 | struct trace_pid_list *no_pid_list; |
978f3a45 | 6935 | |
345ddcc8 | 6936 | pid_list = rcu_dereference_sched(tr->function_pids); |
b3b1e6ed | 6937 | no_pid_list = rcu_dereference_sched(tr->function_no_pids); |
e32d8956 | 6938 | |
b3b1e6ed | 6939 | if (trace_ignore_this_task(pid_list, no_pid_list, next)) |
717e3f5e SRV |
6940 | this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, |
6941 | FTRACE_PID_IGNORE); | |
6942 | else | |
6943 | this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, | |
6944 | next->pid); | |
978f3a45 SR |
6945 | } |
6946 | ||
1e10486f NK |
6947 | static void |
6948 | ftrace_pid_follow_sched_process_fork(void *data, | |
6949 | struct task_struct *self, | |
6950 | struct task_struct *task) | |
6951 | { | |
6952 | struct trace_pid_list *pid_list; | |
6953 | struct trace_array *tr = data; | |
6954 | ||
6955 | pid_list = rcu_dereference_sched(tr->function_pids); | |
6956 | trace_filter_add_remove_task(pid_list, self, task); | |
b3b1e6ed SRV |
6957 | |
6958 | pid_list = rcu_dereference_sched(tr->function_no_pids); | |
6959 | trace_filter_add_remove_task(pid_list, self, task); | |
1e10486f NK |
6960 | } |
6961 | ||
6962 | static void | |
6963 | ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task) | |
6964 | { | |
6965 | struct trace_pid_list *pid_list; | |
6966 | struct trace_array *tr = data; | |
6967 | ||
6968 | pid_list = rcu_dereference_sched(tr->function_pids); | |
6969 | trace_filter_add_remove_task(pid_list, NULL, task); | |
b3b1e6ed SRV |
6970 | |
6971 | pid_list = rcu_dereference_sched(tr->function_no_pids); | |
6972 | trace_filter_add_remove_task(pid_list, NULL, task); | |
1e10486f NK |
6973 | } |
6974 | ||
6975 | void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) | |
6976 | { | |
6977 | if (enable) { | |
6978 | register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, | |
6979 | tr); | |
6980 | register_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit, | |
6981 | tr); | |
6982 | } else { | |
6983 | unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, | |
6984 | tr); | |
6985 | unregister_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit, | |
6986 | tr); | |
6987 | } | |
6988 | } | |
6989 | ||
b3b1e6ed SRV |
6990 | enum { |
6991 | TRACE_PIDS = BIT(0), | |
6992 | TRACE_NO_PIDS = BIT(1), | |
6993 | }; | |
6994 | ||
6995 | static void clear_ftrace_pids(struct trace_array *tr, int type) | |
e32d8956 | 6996 | { |
345ddcc8 | 6997 | struct trace_pid_list *pid_list; |
b3b1e6ed | 6998 | struct trace_pid_list *no_pid_list; |
345ddcc8 | 6999 | int cpu; |
e32d8956 | 7000 | |
345ddcc8 SRRH |
7001 | pid_list = rcu_dereference_protected(tr->function_pids, |
7002 | lockdep_is_held(&ftrace_lock)); | |
b3b1e6ed SRV |
7003 | no_pid_list = rcu_dereference_protected(tr->function_no_pids, |
7004 | lockdep_is_held(&ftrace_lock)); | |
7005 | ||
7006 | /* Make sure there's something to do */ | |
7007 | if (!(((type & TRACE_PIDS) && pid_list) || | |
7008 | ((type & TRACE_NO_PIDS) && no_pid_list))) | |
345ddcc8 | 7009 | return; |
229c4ef8 | 7010 | |
b3b1e6ed SRV |
7011 | /* See if the pids still need to be checked after this */ |
7012 | if (!((!(type & TRACE_PIDS) && pid_list) || | |
7013 | (!(type & TRACE_NO_PIDS) && no_pid_list))) { | |
7014 | unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr); | |
7015 | for_each_possible_cpu(cpu) | |
7016 | per_cpu_ptr(tr->array_buffer.data, cpu)->ftrace_ignore_pid = FTRACE_PID_TRACE; | |
7017 | } | |
e32d8956 | 7018 | |
b3b1e6ed SRV |
7019 | if (type & TRACE_PIDS) |
7020 | rcu_assign_pointer(tr->function_pids, NULL); | |
978f3a45 | 7021 | |
b3b1e6ed SRV |
7022 | if (type & TRACE_NO_PIDS) |
7023 | rcu_assign_pointer(tr->function_no_pids, NULL); | |
978f3a45 | 7024 | |
345ddcc8 | 7025 | /* Wait till all users are no longer using pid filtering */ |
74401729 | 7026 | synchronize_rcu(); |
e32d8956 | 7027 | |
b3b1e6ed SRV |
7028 | if ((type & TRACE_PIDS) && pid_list) |
7029 | trace_free_pid_list(pid_list); | |
7030 | ||
7031 | if ((type & TRACE_NO_PIDS) && no_pid_list) | |
7032 | trace_free_pid_list(no_pid_list); | |
e32d8956 SR |
7033 | } |
7034 | ||
d879d0b8 NK |
7035 | void ftrace_clear_pids(struct trace_array *tr) |
7036 | { | |
7037 | mutex_lock(&ftrace_lock); | |
7038 | ||
b3b1e6ed | 7039 | clear_ftrace_pids(tr, TRACE_PIDS | TRACE_NO_PIDS); |
d879d0b8 NK |
7040 | |
7041 | mutex_unlock(&ftrace_lock); | |
7042 | } | |
7043 | ||
b3b1e6ed | 7044 | static void ftrace_pid_reset(struct trace_array *tr, int type) |
df4fc315 | 7045 | { |
756d17ee | 7046 | mutex_lock(&ftrace_lock); |
b3b1e6ed | 7047 | clear_ftrace_pids(tr, type); |
978f3a45 | 7048 | |
756d17ee | 7049 | ftrace_update_pid_func(); |
e1effa01 | 7050 | ftrace_startup_all(0); |
756d17ee | 7051 | |
7052 | mutex_unlock(&ftrace_lock); | |
756d17ee | 7053 | } |
7054 | ||
345ddcc8 SRRH |
7055 | /* Greater than any max PID */ |
7056 | #define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1) | |
df4fc315 | 7057 | |
756d17ee | 7058 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
345ddcc8 | 7059 | __acquires(RCU) |
756d17ee | 7060 | { |
345ddcc8 SRRH |
7061 | struct trace_pid_list *pid_list; |
7062 | struct trace_array *tr = m->private; | |
7063 | ||
756d17ee | 7064 | mutex_lock(&ftrace_lock); |
345ddcc8 SRRH |
7065 | rcu_read_lock_sched(); |
7066 | ||
7067 | pid_list = rcu_dereference_sched(tr->function_pids); | |
756d17ee | 7068 | |
345ddcc8 SRRH |
7069 | if (!pid_list) |
7070 | return !(*pos) ? FTRACE_NO_PIDS : NULL; | |
756d17ee | 7071 | |
345ddcc8 | 7072 | return trace_pid_start(pid_list, pos); |
756d17ee | 7073 | } |
7074 | ||
7075 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
7076 | { | |
345ddcc8 SRRH |
7077 | struct trace_array *tr = m->private; |
7078 | struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids); | |
7079 | ||
e4075e8b VA |
7080 | if (v == FTRACE_NO_PIDS) { |
7081 | (*pos)++; | |
756d17ee | 7082 | return NULL; |
e4075e8b | 7083 | } |
345ddcc8 | 7084 | return trace_pid_next(pid_list, v, pos); |
756d17ee | 7085 | } |
7086 | ||
7087 | static void fpid_stop(struct seq_file *m, void *p) | |
345ddcc8 | 7088 | __releases(RCU) |
756d17ee | 7089 | { |
345ddcc8 | 7090 | rcu_read_unlock_sched(); |
756d17ee | 7091 | mutex_unlock(&ftrace_lock); |
7092 | } | |
7093 | ||
7094 | static int fpid_show(struct seq_file *m, void *v) | |
7095 | { | |
345ddcc8 | 7096 | if (v == FTRACE_NO_PIDS) { |
fa6f0cc7 | 7097 | seq_puts(m, "no pid\n"); |
756d17ee | 7098 | return 0; |
7099 | } | |
7100 | ||
345ddcc8 | 7101 | return trace_pid_show(m, v); |
756d17ee | 7102 | } |
7103 | ||
7104 | static const struct seq_operations ftrace_pid_sops = { | |
7105 | .start = fpid_start, | |
7106 | .next = fpid_next, | |
7107 | .stop = fpid_stop, | |
7108 | .show = fpid_show, | |
7109 | }; | |
7110 | ||
b3b1e6ed SRV |
7111 | static void *fnpid_start(struct seq_file *m, loff_t *pos) |
7112 | __acquires(RCU) | |
7113 | { | |
7114 | struct trace_pid_list *pid_list; | |
7115 | struct trace_array *tr = m->private; | |
7116 | ||
7117 | mutex_lock(&ftrace_lock); | |
7118 | rcu_read_lock_sched(); | |
7119 | ||
7120 | pid_list = rcu_dereference_sched(tr->function_no_pids); | |
7121 | ||
7122 | if (!pid_list) | |
7123 | return !(*pos) ? FTRACE_NO_PIDS : NULL; | |
7124 | ||
7125 | return trace_pid_start(pid_list, pos); | |
7126 | } | |
7127 | ||
7128 | static void *fnpid_next(struct seq_file *m, void *v, loff_t *pos) | |
756d17ee | 7129 | { |
b3b1e6ed SRV |
7130 | struct trace_array *tr = m->private; |
7131 | struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_no_pids); | |
7132 | ||
7133 | if (v == FTRACE_NO_PIDS) { | |
7134 | (*pos)++; | |
7135 | return NULL; | |
7136 | } | |
7137 | return trace_pid_next(pid_list, v, pos); | |
7138 | } | |
7139 | ||
7140 | static const struct seq_operations ftrace_no_pid_sops = { | |
7141 | .start = fnpid_start, | |
7142 | .next = fnpid_next, | |
7143 | .stop = fpid_stop, | |
7144 | .show = fpid_show, | |
7145 | }; | |
7146 | ||
7147 | static int pid_open(struct inode *inode, struct file *file, int type) | |
7148 | { | |
7149 | const struct seq_operations *seq_ops; | |
345ddcc8 SRRH |
7150 | struct trace_array *tr = inode->i_private; |
7151 | struct seq_file *m; | |
756d17ee | 7152 | int ret = 0; |
7153 | ||
8530dec6 SRV |
7154 | ret = tracing_check_open_get_tr(tr); |
7155 | if (ret) | |
7156 | return ret; | |
345ddcc8 | 7157 | |
756d17ee | 7158 | if ((file->f_mode & FMODE_WRITE) && |
7159 | (file->f_flags & O_TRUNC)) | |
b3b1e6ed SRV |
7160 | ftrace_pid_reset(tr, type); |
7161 | ||
7162 | switch (type) { | |
7163 | case TRACE_PIDS: | |
7164 | seq_ops = &ftrace_pid_sops; | |
7165 | break; | |
7166 | case TRACE_NO_PIDS: | |
7167 | seq_ops = &ftrace_no_pid_sops; | |
7168 | break; | |
7169 | } | |
756d17ee | 7170 | |
b3b1e6ed | 7171 | ret = seq_open(file, seq_ops); |
345ddcc8 SRRH |
7172 | if (ret < 0) { |
7173 | trace_array_put(tr); | |
7174 | } else { | |
7175 | m = file->private_data; | |
7176 | /* copy tr over to seq ops */ | |
7177 | m->private = tr; | |
7178 | } | |
756d17ee | 7179 | |
7180 | return ret; | |
7181 | } | |
7182 | ||
b3b1e6ed SRV |
7183 | static int |
7184 | ftrace_pid_open(struct inode *inode, struct file *file) | |
7185 | { | |
7186 | return pid_open(inode, file, TRACE_PIDS); | |
7187 | } | |
7188 | ||
7189 | static int | |
7190 | ftrace_no_pid_open(struct inode *inode, struct file *file) | |
7191 | { | |
7192 | return pid_open(inode, file, TRACE_NO_PIDS); | |
7193 | } | |
7194 | ||
345ddcc8 SRRH |
7195 | static void ignore_task_cpu(void *data) |
7196 | { | |
7197 | struct trace_array *tr = data; | |
7198 | struct trace_pid_list *pid_list; | |
b3b1e6ed | 7199 | struct trace_pid_list *no_pid_list; |
345ddcc8 SRRH |
7200 | |
7201 | /* | |
7202 | * This function is called by on_each_cpu() while the | |
7203 | * event_mutex is held. | |
7204 | */ | |
7205 | pid_list = rcu_dereference_protected(tr->function_pids, | |
7206 | mutex_is_locked(&ftrace_lock)); | |
b3b1e6ed SRV |
7207 | no_pid_list = rcu_dereference_protected(tr->function_no_pids, |
7208 | mutex_is_locked(&ftrace_lock)); | |
345ddcc8 | 7209 | |
b3b1e6ed | 7210 | if (trace_ignore_this_task(pid_list, no_pid_list, current)) |
717e3f5e SRV |
7211 | this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, |
7212 | FTRACE_PID_IGNORE); | |
7213 | else | |
7214 | this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, | |
7215 | current->pid); | |
345ddcc8 SRRH |
7216 | } |
7217 | ||
df4fc315 | 7218 | static ssize_t |
b3b1e6ed SRV |
7219 | pid_write(struct file *filp, const char __user *ubuf, |
7220 | size_t cnt, loff_t *ppos, int type) | |
df4fc315 | 7221 | { |
345ddcc8 SRRH |
7222 | struct seq_file *m = filp->private_data; |
7223 | struct trace_array *tr = m->private; | |
b3b1e6ed SRV |
7224 | struct trace_pid_list *filtered_pids; |
7225 | struct trace_pid_list *other_pids; | |
345ddcc8 SRRH |
7226 | struct trace_pid_list *pid_list; |
7227 | ssize_t ret; | |
df4fc315 | 7228 | |
345ddcc8 SRRH |
7229 | if (!cnt) |
7230 | return 0; | |
7231 | ||
7232 | mutex_lock(&ftrace_lock); | |
7233 | ||
b3b1e6ed SRV |
7234 | switch (type) { |
7235 | case TRACE_PIDS: | |
7236 | filtered_pids = rcu_dereference_protected(tr->function_pids, | |
345ddcc8 | 7237 | lockdep_is_held(&ftrace_lock)); |
b3b1e6ed SRV |
7238 | other_pids = rcu_dereference_protected(tr->function_no_pids, |
7239 | lockdep_is_held(&ftrace_lock)); | |
7240 | break; | |
7241 | case TRACE_NO_PIDS: | |
7242 | filtered_pids = rcu_dereference_protected(tr->function_no_pids, | |
7243 | lockdep_is_held(&ftrace_lock)); | |
7244 | other_pids = rcu_dereference_protected(tr->function_pids, | |
7245 | lockdep_is_held(&ftrace_lock)); | |
7246 | break; | |
7247 | } | |
345ddcc8 SRRH |
7248 | |
7249 | ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt); | |
7250 | if (ret < 0) | |
7251 | goto out; | |
df4fc315 | 7252 | |
b3b1e6ed SRV |
7253 | switch (type) { |
7254 | case TRACE_PIDS: | |
7255 | rcu_assign_pointer(tr->function_pids, pid_list); | |
7256 | break; | |
7257 | case TRACE_NO_PIDS: | |
7258 | rcu_assign_pointer(tr->function_no_pids, pid_list); | |
7259 | break; | |
7260 | } | |
7261 | ||
df4fc315 | 7262 | |
345ddcc8 | 7263 | if (filtered_pids) { |
74401729 | 7264 | synchronize_rcu(); |
345ddcc8 | 7265 | trace_free_pid_list(filtered_pids); |
b3b1e6ed | 7266 | } else if (pid_list && !other_pids) { |
345ddcc8 SRRH |
7267 | /* Register a probe to set whether to ignore the tracing of a task */ |
7268 | register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr); | |
7269 | } | |
df4fc315 | 7270 | |
756d17ee | 7271 | /* |
345ddcc8 SRRH |
7272 | * Ignoring of pids is done at task switch. But we have to |
7273 | * check for those tasks that are currently running. | |
7274 | * Always do this in case a pid was appended or removed. | |
756d17ee | 7275 | */ |
345ddcc8 | 7276 | on_each_cpu(ignore_task_cpu, tr, 1); |
756d17ee | 7277 | |
345ddcc8 SRRH |
7278 | ftrace_update_pid_func(); |
7279 | ftrace_startup_all(0); | |
7280 | out: | |
7281 | mutex_unlock(&ftrace_lock); | |
df4fc315 | 7282 | |
345ddcc8 SRRH |
7283 | if (ret > 0) |
7284 | *ppos += ret; | |
df4fc315 | 7285 | |
345ddcc8 | 7286 | return ret; |
756d17ee | 7287 | } |
df4fc315 | 7288 | |
b3b1e6ed SRV |
7289 | static ssize_t |
7290 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
7291 | size_t cnt, loff_t *ppos) | |
7292 | { | |
7293 | return pid_write(filp, ubuf, cnt, ppos, TRACE_PIDS); | |
7294 | } | |
7295 | ||
7296 | static ssize_t | |
7297 | ftrace_no_pid_write(struct file *filp, const char __user *ubuf, | |
7298 | size_t cnt, loff_t *ppos) | |
7299 | { | |
7300 | return pid_write(filp, ubuf, cnt, ppos, TRACE_NO_PIDS); | |
7301 | } | |
7302 | ||
756d17ee | 7303 | static int |
7304 | ftrace_pid_release(struct inode *inode, struct file *file) | |
7305 | { | |
345ddcc8 | 7306 | struct trace_array *tr = inode->i_private; |
df4fc315 | 7307 | |
345ddcc8 SRRH |
7308 | trace_array_put(tr); |
7309 | ||
7310 | return seq_release(inode, file); | |
df4fc315 SR |
7311 | } |
7312 | ||
5e2336a0 | 7313 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 7314 | .open = ftrace_pid_open, |
7315 | .write = ftrace_pid_write, | |
7316 | .read = seq_read, | |
098c879e | 7317 | .llseek = tracing_lseek, |
756d17ee | 7318 | .release = ftrace_pid_release, |
df4fc315 SR |
7319 | }; |
7320 | ||
b3b1e6ed SRV |
7321 | static const struct file_operations ftrace_no_pid_fops = { |
7322 | .open = ftrace_no_pid_open, | |
7323 | .write = ftrace_no_pid_write, | |
7324 | .read = seq_read, | |
7325 | .llseek = tracing_lseek, | |
7326 | .release = ftrace_pid_release, | |
7327 | }; | |
7328 | ||
345ddcc8 | 7329 | void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer) |
df4fc315 | 7330 | { |
5452af66 | 7331 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
345ddcc8 | 7332 | tr, &ftrace_pid_fops); |
b3b1e6ed SRV |
7333 | trace_create_file("set_ftrace_notrace_pid", 0644, d_tracer, |
7334 | tr, &ftrace_no_pid_fops); | |
df4fc315 | 7335 | } |
df4fc315 | 7336 | |
501c2375 SRRH |
7337 | void __init ftrace_init_tracefs_toplevel(struct trace_array *tr, |
7338 | struct dentry *d_tracer) | |
7339 | { | |
7340 | /* Only the top level directory has the dyn_tracefs and profile */ | |
7341 | WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL)); | |
7342 | ||
7343 | ftrace_init_dyn_tracefs(d_tracer); | |
7344 | ftrace_profile_tracefs(d_tracer); | |
7345 | } | |
7346 | ||
a2bb6a3d | 7347 | /** |
81adbdc0 | 7348 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
7349 | * |
7350 | * This function should be used by panic code. It stops ftrace | |
7351 | * but in a not so nice way. If you need to simply kill ftrace | |
7352 | * from a non-atomic section, use ftrace_kill. | |
7353 | */ | |
81adbdc0 | 7354 | void ftrace_kill(void) |
a2bb6a3d SR |
7355 | { |
7356 | ftrace_disabled = 1; | |
7357 | ftrace_enabled = 0; | |
5ccba64a | 7358 | ftrace_trace_function = ftrace_stub; |
a2bb6a3d SR |
7359 | } |
7360 | ||
e0a413f6 SR |
7361 | /** |
7362 | * Test if ftrace is dead or not. | |
7363 | */ | |
7364 | int ftrace_is_dead(void) | |
7365 | { | |
7366 | return ftrace_disabled; | |
7367 | } | |
7368 | ||
16444a8a | 7369 | /** |
3d083395 SR |
7370 | * register_ftrace_function - register a function for profiling |
7371 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 7372 | * |
3d083395 SR |
7373 | * Register a function to be called by all functions in the |
7374 | * kernel. | |
7375 | * | |
7376 | * Note: @ops->func and all the functions it calls must be labeled | |
7377 | * with "notrace", otherwise it will go into a | |
7378 | * recursive loop. | |
16444a8a | 7379 | */ |
3d083395 | 7380 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 7381 | { |
45a4a237 | 7382 | int ret = -1; |
4eebcc81 | 7383 | |
f04f24fb MH |
7384 | ftrace_ops_init(ops); |
7385 | ||
e6ea44e9 | 7386 | mutex_lock(&ftrace_lock); |
e7d3737e | 7387 | |
8a56d776 | 7388 | ret = ftrace_startup(ops, 0); |
b848914c | 7389 | |
e6ea44e9 | 7390 | mutex_unlock(&ftrace_lock); |
8d240dd8 | 7391 | |
b0fc494f | 7392 | return ret; |
3d083395 | 7393 | } |
cdbe61bf | 7394 | EXPORT_SYMBOL_GPL(register_ftrace_function); |
3d083395 SR |
7395 | |
7396 | /** | |
32632920 | 7397 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
7398 | * @ops - ops structure that holds the function to unregister |
7399 | * | |
7400 | * Unregister a function that was added to be called by ftrace profiling. | |
7401 | */ | |
7402 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
7403 | { | |
7404 | int ret; | |
7405 | ||
e6ea44e9 | 7406 | mutex_lock(&ftrace_lock); |
8a56d776 | 7407 | ret = ftrace_shutdown(ops, 0); |
e6ea44e9 | 7408 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
7409 | |
7410 | return ret; | |
7411 | } | |
cdbe61bf | 7412 | EXPORT_SYMBOL_GPL(unregister_ftrace_function); |
b0fc494f | 7413 | |
7162431d MB |
7414 | static bool is_permanent_ops_registered(void) |
7415 | { | |
7416 | struct ftrace_ops *op; | |
7417 | ||
7418 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
7419 | if (op->flags & FTRACE_OPS_FL_PERMANENT) | |
7420 | return true; | |
7421 | } while_for_each_ftrace_op(op); | |
7422 | ||
7423 | return false; | |
7424 | } | |
7425 | ||
e309b41d | 7426 | int |
b0fc494f | 7427 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
8d65af78 | 7428 | void __user *buffer, size_t *lenp, |
b0fc494f SR |
7429 | loff_t *ppos) |
7430 | { | |
45a4a237 | 7431 | int ret = -ENODEV; |
4eebcc81 | 7432 | |
e6ea44e9 | 7433 | mutex_lock(&ftrace_lock); |
b0fc494f | 7434 | |
45a4a237 SR |
7435 | if (unlikely(ftrace_disabled)) |
7436 | goto out; | |
7437 | ||
7438 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
b0fc494f | 7439 | |
a32c7765 | 7440 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
7441 | goto out; |
7442 | ||
b0fc494f SR |
7443 | if (ftrace_enabled) { |
7444 | ||
b0fc494f | 7445 | /* we are starting ftrace again */ |
f86f4180 CZ |
7446 | if (rcu_dereference_protected(ftrace_ops_list, |
7447 | lockdep_is_held(&ftrace_lock)) != &ftrace_list_end) | |
5000c418 | 7448 | update_ftrace_function(); |
b0fc494f | 7449 | |
524a3868 SRRH |
7450 | ftrace_startup_sysctl(); |
7451 | ||
b0fc494f | 7452 | } else { |
7162431d MB |
7453 | if (is_permanent_ops_registered()) { |
7454 | ftrace_enabled = true; | |
7455 | ret = -EBUSY; | |
7456 | goto out; | |
7457 | } | |
7458 | ||
b0fc494f SR |
7459 | /* stopping ftrace calls (just send to ftrace_stub) */ |
7460 | ftrace_trace_function = ftrace_stub; | |
7461 | ||
7462 | ftrace_shutdown_sysctl(); | |
7463 | } | |
7464 | ||
7162431d | 7465 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f | 7466 | out: |
e6ea44e9 | 7467 | mutex_unlock(&ftrace_lock); |
3d083395 | 7468 | return ret; |
16444a8a | 7469 | } |