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Commit | Line | Data |
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16444a8a ACM |
1 | /* |
2 | * Infrastructure for profiling code inserted by 'gcc -pg'. | |
3 | * | |
4 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> | |
5 | * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com> | |
6 | * | |
7 | * Originally ported from the -rt patch by: | |
8 | * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com> | |
9 | * | |
10 | * Based on code in the latency_tracer, that is: | |
11 | * | |
12 | * Copyright (C) 2004-2006 Ingo Molnar | |
6d49e352 | 13 | * Copyright (C) 2004 Nadia Yvette Chambers |
16444a8a ACM |
14 | */ |
15 | ||
3d083395 SR |
16 | #include <linux/stop_machine.h> |
17 | #include <linux/clocksource.h> | |
29930025 | 18 | #include <linux/sched/task.h> |
3d083395 | 19 | #include <linux/kallsyms.h> |
5072c59f | 20 | #include <linux/seq_file.h> |
4a2b8dda | 21 | #include <linux/suspend.h> |
8434dc93 | 22 | #include <linux/tracefs.h> |
3d083395 | 23 | #include <linux/hardirq.h> |
2d8b820b | 24 | #include <linux/kthread.h> |
5072c59f | 25 | #include <linux/uaccess.h> |
5855fead | 26 | #include <linux/bsearch.h> |
56d82e00 | 27 | #include <linux/module.h> |
2d8b820b | 28 | #include <linux/ftrace.h> |
b0fc494f | 29 | #include <linux/sysctl.h> |
5a0e3ad6 | 30 | #include <linux/slab.h> |
5072c59f | 31 | #include <linux/ctype.h> |
68950619 | 32 | #include <linux/sort.h> |
3d083395 | 33 | #include <linux/list.h> |
59df055f | 34 | #include <linux/hash.h> |
3f379b03 | 35 | #include <linux/rcupdate.h> |
3d083395 | 36 | |
ad8d75ff | 37 | #include <trace/events/sched.h> |
8aef2d28 | 38 | |
b80f0f6c | 39 | #include <asm/sections.h> |
2af15d6a | 40 | #include <asm/setup.h> |
395a59d0 | 41 | |
0706f1c4 | 42 | #include "trace_output.h" |
bac429f0 | 43 | #include "trace_stat.h" |
16444a8a | 44 | |
6912896e | 45 | #define FTRACE_WARN_ON(cond) \ |
0778d9ad SR |
46 | ({ \ |
47 | int ___r = cond; \ | |
48 | if (WARN_ON(___r)) \ | |
6912896e | 49 | ftrace_kill(); \ |
0778d9ad SR |
50 | ___r; \ |
51 | }) | |
6912896e SR |
52 | |
53 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
0778d9ad SR |
54 | ({ \ |
55 | int ___r = cond; \ | |
56 | if (WARN_ON_ONCE(___r)) \ | |
6912896e | 57 | ftrace_kill(); \ |
0778d9ad SR |
58 | ___r; \ |
59 | }) | |
6912896e | 60 | |
8fc0c701 SR |
61 | /* hash bits for specific function selection */ |
62 | #define FTRACE_HASH_BITS 7 | |
63 | #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS) | |
33dc9b12 SR |
64 | #define FTRACE_HASH_DEFAULT_BITS 10 |
65 | #define FTRACE_HASH_MAX_BITS 12 | |
8fc0c701 | 66 | |
f04f24fb | 67 | #ifdef CONFIG_DYNAMIC_FTRACE |
33b7f99c SRRH |
68 | #define INIT_OPS_HASH(opsname) \ |
69 | .func_hash = &opsname.local_hash, \ | |
70 | .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock), | |
5f151b24 SRRH |
71 | #define ASSIGN_OPS_HASH(opsname, val) \ |
72 | .func_hash = val, \ | |
73 | .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock), | |
f04f24fb | 74 | #else |
33b7f99c | 75 | #define INIT_OPS_HASH(opsname) |
5f151b24 | 76 | #define ASSIGN_OPS_HASH(opsname, val) |
f04f24fb MH |
77 | #endif |
78 | ||
2f5f6ad9 SR |
79 | static struct ftrace_ops ftrace_list_end __read_mostly = { |
80 | .func = ftrace_stub, | |
395b97a3 | 81 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB, |
33b7f99c | 82 | INIT_OPS_HASH(ftrace_list_end) |
2f5f6ad9 SR |
83 | }; |
84 | ||
4eebcc81 SR |
85 | /* ftrace_enabled is a method to turn ftrace on or off */ |
86 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 87 | static int last_ftrace_enabled; |
b0fc494f | 88 | |
2f5f6ad9 SR |
89 | /* Current function tracing op */ |
90 | struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end; | |
405e1d83 SRRH |
91 | /* What to set function_trace_op to */ |
92 | static struct ftrace_ops *set_function_trace_op; | |
60a7ecf4 | 93 | |
345ddcc8 | 94 | static bool ftrace_pids_enabled(struct ftrace_ops *ops) |
e3eea140 | 95 | { |
345ddcc8 SRRH |
96 | struct trace_array *tr; |
97 | ||
98 | if (!(ops->flags & FTRACE_OPS_FL_PID) || !ops->private) | |
99 | return false; | |
100 | ||
101 | tr = ops->private; | |
102 | ||
103 | return tr->function_pids != NULL; | |
e3eea140 SRRH |
104 | } |
105 | ||
106 | static void ftrace_update_trampoline(struct ftrace_ops *ops); | |
107 | ||
4eebcc81 SR |
108 | /* |
109 | * ftrace_disabled is set when an anomaly is discovered. | |
110 | * ftrace_disabled is much stronger than ftrace_enabled. | |
111 | */ | |
112 | static int ftrace_disabled __read_mostly; | |
113 | ||
52baf119 | 114 | static DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 115 | |
f86f4180 | 116 | static struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = &ftrace_list_end; |
16444a8a | 117 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
2b499381 | 118 | static struct ftrace_ops global_ops; |
16444a8a | 119 | |
2f5f6ad9 SR |
120 | #if ARCH_SUPPORTS_FTRACE_OPS |
121 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 122 | struct ftrace_ops *op, struct pt_regs *regs); |
2f5f6ad9 SR |
123 | #else |
124 | /* See comment below, where ftrace_ops_list_func is defined */ | |
125 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip); | |
126 | #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops) | |
127 | #endif | |
b848914c | 128 | |
0a016409 SR |
129 | /* |
130 | * Traverse the ftrace_global_list, invoking all entries. The reason that we | |
1bb539ca | 131 | * can use rcu_dereference_raw_notrace() is that elements removed from this list |
0a016409 | 132 | * are simply leaked, so there is no need to interact with a grace-period |
1bb539ca | 133 | * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle |
0a016409 SR |
134 | * concurrent insertions into the ftrace_global_list. |
135 | * | |
136 | * Silly Alpha and silly pointer-speculation compiler optimizations! | |
137 | */ | |
138 | #define do_for_each_ftrace_op(op, list) \ | |
1bb539ca | 139 | op = rcu_dereference_raw_notrace(list); \ |
0a016409 SR |
140 | do |
141 | ||
142 | /* | |
143 | * Optimized for just a single item in the list (as that is the normal case). | |
144 | */ | |
145 | #define while_for_each_ftrace_op(op) \ | |
1bb539ca | 146 | while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \ |
0a016409 SR |
147 | unlikely((op) != &ftrace_list_end)) |
148 | ||
f04f24fb MH |
149 | static inline void ftrace_ops_init(struct ftrace_ops *ops) |
150 | { | |
151 | #ifdef CONFIG_DYNAMIC_FTRACE | |
152 | if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) { | |
33b7f99c SRRH |
153 | mutex_init(&ops->local_hash.regex_lock); |
154 | ops->func_hash = &ops->local_hash; | |
f04f24fb MH |
155 | ops->flags |= FTRACE_OPS_FL_INITIALIZED; |
156 | } | |
157 | #endif | |
158 | } | |
159 | ||
ea701f11 SR |
160 | /** |
161 | * ftrace_nr_registered_ops - return number of ops registered | |
162 | * | |
163 | * Returns the number of ftrace_ops registered and tracing functions | |
164 | */ | |
165 | int ftrace_nr_registered_ops(void) | |
166 | { | |
167 | struct ftrace_ops *ops; | |
168 | int cnt = 0; | |
169 | ||
170 | mutex_lock(&ftrace_lock); | |
171 | ||
f86f4180 CZ |
172 | for (ops = rcu_dereference_protected(ftrace_ops_list, |
173 | lockdep_is_held(&ftrace_lock)); | |
174 | ops != &ftrace_list_end; | |
175 | ops = rcu_dereference_protected(ops->next, | |
176 | lockdep_is_held(&ftrace_lock))) | |
ea701f11 SR |
177 | cnt++; |
178 | ||
179 | mutex_unlock(&ftrace_lock); | |
180 | ||
181 | return cnt; | |
182 | } | |
183 | ||
2f5f6ad9 | 184 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 185 | struct ftrace_ops *op, struct pt_regs *regs) |
df4fc315 | 186 | { |
345ddcc8 SRRH |
187 | struct trace_array *tr = op->private; |
188 | ||
189 | if (tr && this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid)) | |
df4fc315 SR |
190 | return; |
191 | ||
e3eea140 | 192 | op->saved_func(ip, parent_ip, op, regs); |
df4fc315 SR |
193 | } |
194 | ||
16444a8a | 195 | /** |
3d083395 | 196 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 197 | * |
3d083395 SR |
198 | * This NULLs the ftrace function and in essence stops |
199 | * tracing. There may be lag | |
16444a8a | 200 | */ |
3d083395 | 201 | void clear_ftrace_function(void) |
16444a8a | 202 | { |
3d083395 SR |
203 | ftrace_trace_function = ftrace_stub; |
204 | } | |
205 | ||
405e1d83 SRRH |
206 | static void ftrace_sync(struct work_struct *work) |
207 | { | |
208 | /* | |
209 | * This function is just a stub to implement a hard force | |
210 | * of synchronize_sched(). This requires synchronizing | |
211 | * tasks even in userspace and idle. | |
212 | * | |
213 | * Yes, function tracing is rude. | |
214 | */ | |
215 | } | |
216 | ||
217 | static void ftrace_sync_ipi(void *data) | |
218 | { | |
219 | /* Probably not needed, but do it anyway */ | |
220 | smp_rmb(); | |
221 | } | |
222 | ||
23a8e844 SRRH |
223 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
224 | static void update_function_graph_func(void); | |
55577204 SRRH |
225 | |
226 | /* Both enabled by default (can be cleared by function_graph tracer flags */ | |
227 | static bool fgraph_sleep_time = true; | |
228 | static bool fgraph_graph_time = true; | |
229 | ||
23a8e844 SRRH |
230 | #else |
231 | static inline void update_function_graph_func(void) { } | |
232 | #endif | |
233 | ||
00ccbf2f SRRH |
234 | |
235 | static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops) | |
236 | { | |
237 | /* | |
ba27f2bc | 238 | * If this is a dynamic, RCU, or per CPU ops, or we force list func, |
00ccbf2f SRRH |
239 | * then it needs to call the list anyway. |
240 | */ | |
b3a88803 PZ |
241 | if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_RCU) || |
242 | FTRACE_FORCE_LIST_FUNC) | |
00ccbf2f SRRH |
243 | return ftrace_ops_list_func; |
244 | ||
245 | return ftrace_ops_get_func(ops); | |
246 | } | |
247 | ||
2b499381 SR |
248 | static void update_ftrace_function(void) |
249 | { | |
250 | ftrace_func_t func; | |
251 | ||
f7aad4e1 SRRH |
252 | /* |
253 | * Prepare the ftrace_ops that the arch callback will use. | |
254 | * If there's only one ftrace_ops registered, the ftrace_ops_list | |
255 | * will point to the ops we want. | |
256 | */ | |
f86f4180 CZ |
257 | set_function_trace_op = rcu_dereference_protected(ftrace_ops_list, |
258 | lockdep_is_held(&ftrace_lock)); | |
f7aad4e1 SRRH |
259 | |
260 | /* If there's no ftrace_ops registered, just call the stub function */ | |
f86f4180 | 261 | if (set_function_trace_op == &ftrace_list_end) { |
f7aad4e1 SRRH |
262 | func = ftrace_stub; |
263 | ||
cdbe61bf SR |
264 | /* |
265 | * If we are at the end of the list and this ops is | |
4740974a SR |
266 | * recursion safe and not dynamic and the arch supports passing ops, |
267 | * then have the mcount trampoline call the function directly. | |
cdbe61bf | 268 | */ |
f86f4180 CZ |
269 | } else if (rcu_dereference_protected(ftrace_ops_list->next, |
270 | lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { | |
00ccbf2f | 271 | func = ftrace_ops_get_list_func(ftrace_ops_list); |
f7aad4e1 | 272 | |
2f5f6ad9 SR |
273 | } else { |
274 | /* Just use the default ftrace_ops */ | |
405e1d83 | 275 | set_function_trace_op = &ftrace_list_end; |
b848914c | 276 | func = ftrace_ops_list_func; |
2f5f6ad9 | 277 | } |
2b499381 | 278 | |
5f8bf2d2 SRRH |
279 | update_function_graph_func(); |
280 | ||
405e1d83 SRRH |
281 | /* If there's no change, then do nothing more here */ |
282 | if (ftrace_trace_function == func) | |
283 | return; | |
284 | ||
285 | /* | |
286 | * If we are using the list function, it doesn't care | |
287 | * about the function_trace_ops. | |
288 | */ | |
289 | if (func == ftrace_ops_list_func) { | |
290 | ftrace_trace_function = func; | |
291 | /* | |
292 | * Don't even bother setting function_trace_ops, | |
293 | * it would be racy to do so anyway. | |
294 | */ | |
295 | return; | |
296 | } | |
297 | ||
298 | #ifndef CONFIG_DYNAMIC_FTRACE | |
299 | /* | |
300 | * For static tracing, we need to be a bit more careful. | |
301 | * The function change takes affect immediately. Thus, | |
302 | * we need to coorditate the setting of the function_trace_ops | |
303 | * with the setting of the ftrace_trace_function. | |
304 | * | |
305 | * Set the function to the list ops, which will call the | |
306 | * function we want, albeit indirectly, but it handles the | |
307 | * ftrace_ops and doesn't depend on function_trace_op. | |
308 | */ | |
309 | ftrace_trace_function = ftrace_ops_list_func; | |
310 | /* | |
311 | * Make sure all CPUs see this. Yes this is slow, but static | |
312 | * tracing is slow and nasty to have enabled. | |
313 | */ | |
314 | schedule_on_each_cpu(ftrace_sync); | |
315 | /* Now all cpus are using the list ops. */ | |
316 | function_trace_op = set_function_trace_op; | |
317 | /* Make sure the function_trace_op is visible on all CPUs */ | |
318 | smp_wmb(); | |
319 | /* Nasty way to force a rmb on all cpus */ | |
320 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
321 | /* OK, we are all set to update the ftrace_trace_function now! */ | |
322 | #endif /* !CONFIG_DYNAMIC_FTRACE */ | |
323 | ||
491d0dcf | 324 | ftrace_trace_function = func; |
491d0dcf SR |
325 | } |
326 | ||
7eea4fce JW |
327 | int using_ftrace_ops_list_func(void) |
328 | { | |
329 | return ftrace_trace_function == ftrace_ops_list_func; | |
330 | } | |
331 | ||
f86f4180 CZ |
332 | static void add_ftrace_ops(struct ftrace_ops __rcu **list, |
333 | struct ftrace_ops *ops) | |
3d083395 | 334 | { |
f86f4180 CZ |
335 | rcu_assign_pointer(ops->next, *list); |
336 | ||
16444a8a | 337 | /* |
b848914c | 338 | * We are entering ops into the list but another |
16444a8a ACM |
339 | * CPU might be walking that list. We need to make sure |
340 | * the ops->next pointer is valid before another CPU sees | |
b848914c | 341 | * the ops pointer included into the list. |
16444a8a | 342 | */ |
2b499381 | 343 | rcu_assign_pointer(*list, ops); |
16444a8a ACM |
344 | } |
345 | ||
f86f4180 CZ |
346 | static int remove_ftrace_ops(struct ftrace_ops __rcu **list, |
347 | struct ftrace_ops *ops) | |
16444a8a | 348 | { |
16444a8a | 349 | struct ftrace_ops **p; |
16444a8a ACM |
350 | |
351 | /* | |
3d083395 SR |
352 | * If we are removing the last function, then simply point |
353 | * to the ftrace_stub. | |
16444a8a | 354 | */ |
f86f4180 CZ |
355 | if (rcu_dereference_protected(*list, |
356 | lockdep_is_held(&ftrace_lock)) == ops && | |
357 | rcu_dereference_protected(ops->next, | |
358 | lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { | |
2b499381 | 359 | *list = &ftrace_list_end; |
e6ea44e9 | 360 | return 0; |
16444a8a ACM |
361 | } |
362 | ||
2b499381 | 363 | for (p = list; *p != &ftrace_list_end; p = &(*p)->next) |
16444a8a ACM |
364 | if (*p == ops) |
365 | break; | |
366 | ||
e6ea44e9 SR |
367 | if (*p != ops) |
368 | return -1; | |
16444a8a ACM |
369 | |
370 | *p = (*p)->next; | |
2b499381 SR |
371 | return 0; |
372 | } | |
16444a8a | 373 | |
f3bea491 SRRH |
374 | static void ftrace_update_trampoline(struct ftrace_ops *ops); |
375 | ||
2b499381 SR |
376 | static int __register_ftrace_function(struct ftrace_ops *ops) |
377 | { | |
591dffda SRRH |
378 | if (ops->flags & FTRACE_OPS_FL_DELETED) |
379 | return -EINVAL; | |
380 | ||
b848914c SR |
381 | if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) |
382 | return -EBUSY; | |
383 | ||
06aeaaea | 384 | #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
08f6fba5 SR |
385 | /* |
386 | * If the ftrace_ops specifies SAVE_REGS, then it only can be used | |
387 | * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set. | |
388 | * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant. | |
389 | */ | |
390 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS && | |
391 | !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)) | |
392 | return -EINVAL; | |
393 | ||
394 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED) | |
395 | ops->flags |= FTRACE_OPS_FL_SAVE_REGS; | |
396 | #endif | |
397 | ||
cdbe61bf SR |
398 | if (!core_kernel_data((unsigned long)ops)) |
399 | ops->flags |= FTRACE_OPS_FL_DYNAMIC; | |
400 | ||
ba27f2bc | 401 | add_ftrace_ops(&ftrace_ops_list, ops); |
b848914c | 402 | |
e3eea140 SRRH |
403 | /* Always save the function, and reset at unregistering */ |
404 | ops->saved_func = ops->func; | |
405 | ||
345ddcc8 | 406 | if (ftrace_pids_enabled(ops)) |
e3eea140 SRRH |
407 | ops->func = ftrace_pid_func; |
408 | ||
f3bea491 SRRH |
409 | ftrace_update_trampoline(ops); |
410 | ||
2b499381 SR |
411 | if (ftrace_enabled) |
412 | update_ftrace_function(); | |
413 | ||
414 | return 0; | |
415 | } | |
416 | ||
417 | static int __unregister_ftrace_function(struct ftrace_ops *ops) | |
418 | { | |
419 | int ret; | |
420 | ||
b848914c SR |
421 | if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) |
422 | return -EBUSY; | |
423 | ||
ba27f2bc | 424 | ret = remove_ftrace_ops(&ftrace_ops_list, ops); |
b848914c | 425 | |
2b499381 SR |
426 | if (ret < 0) |
427 | return ret; | |
b848914c | 428 | |
491d0dcf SR |
429 | if (ftrace_enabled) |
430 | update_ftrace_function(); | |
16444a8a | 431 | |
e3eea140 SRRH |
432 | ops->func = ops->saved_func; |
433 | ||
e6ea44e9 | 434 | return 0; |
3d083395 SR |
435 | } |
436 | ||
df4fc315 SR |
437 | static void ftrace_update_pid_func(void) |
438 | { | |
e3eea140 SRRH |
439 | struct ftrace_ops *op; |
440 | ||
491d0dcf | 441 | /* Only do something if we are tracing something */ |
df4fc315 | 442 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 443 | return; |
df4fc315 | 444 | |
e3eea140 SRRH |
445 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
446 | if (op->flags & FTRACE_OPS_FL_PID) { | |
345ddcc8 SRRH |
447 | op->func = ftrace_pids_enabled(op) ? |
448 | ftrace_pid_func : op->saved_func; | |
e3eea140 SRRH |
449 | ftrace_update_trampoline(op); |
450 | } | |
451 | } while_for_each_ftrace_op(op); | |
452 | ||
491d0dcf | 453 | update_ftrace_function(); |
df4fc315 SR |
454 | } |
455 | ||
493762fc SR |
456 | #ifdef CONFIG_FUNCTION_PROFILER |
457 | struct ftrace_profile { | |
458 | struct hlist_node node; | |
459 | unsigned long ip; | |
460 | unsigned long counter; | |
0706f1c4 SR |
461 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
462 | unsigned long long time; | |
e330b3bc | 463 | unsigned long long time_squared; |
0706f1c4 | 464 | #endif |
8fc0c701 SR |
465 | }; |
466 | ||
493762fc SR |
467 | struct ftrace_profile_page { |
468 | struct ftrace_profile_page *next; | |
469 | unsigned long index; | |
470 | struct ftrace_profile records[]; | |
d61f82d0 SR |
471 | }; |
472 | ||
cafb168a SR |
473 | struct ftrace_profile_stat { |
474 | atomic_t disabled; | |
475 | struct hlist_head *hash; | |
476 | struct ftrace_profile_page *pages; | |
477 | struct ftrace_profile_page *start; | |
478 | struct tracer_stat stat; | |
479 | }; | |
480 | ||
493762fc SR |
481 | #define PROFILE_RECORDS_SIZE \ |
482 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 483 | |
493762fc SR |
484 | #define PROFILES_PER_PAGE \ |
485 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 486 | |
fb9fb015 SR |
487 | static int ftrace_profile_enabled __read_mostly; |
488 | ||
489 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
490 | static DEFINE_MUTEX(ftrace_profile_lock); |
491 | ||
cafb168a | 492 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc | 493 | |
20079ebe NK |
494 | #define FTRACE_PROFILE_HASH_BITS 10 |
495 | #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS) | |
493762fc | 496 | |
bac429f0 SR |
497 | static void * |
498 | function_stat_next(void *v, int idx) | |
499 | { | |
493762fc SR |
500 | struct ftrace_profile *rec = v; |
501 | struct ftrace_profile_page *pg; | |
bac429f0 | 502 | |
493762fc | 503 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
504 | |
505 | again: | |
0296e425 LZ |
506 | if (idx != 0) |
507 | rec++; | |
508 | ||
bac429f0 SR |
509 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
510 | pg = pg->next; | |
511 | if (!pg) | |
512 | return NULL; | |
513 | rec = &pg->records[0]; | |
493762fc SR |
514 | if (!rec->counter) |
515 | goto again; | |
bac429f0 SR |
516 | } |
517 | ||
bac429f0 SR |
518 | return rec; |
519 | } | |
520 | ||
521 | static void *function_stat_start(struct tracer_stat *trace) | |
522 | { | |
cafb168a SR |
523 | struct ftrace_profile_stat *stat = |
524 | container_of(trace, struct ftrace_profile_stat, stat); | |
525 | ||
526 | if (!stat || !stat->start) | |
527 | return NULL; | |
528 | ||
529 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
530 | } |
531 | ||
0706f1c4 SR |
532 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
533 | /* function graph compares on total time */ | |
534 | static int function_stat_cmp(void *p1, void *p2) | |
535 | { | |
536 | struct ftrace_profile *a = p1; | |
537 | struct ftrace_profile *b = p2; | |
538 | ||
539 | if (a->time < b->time) | |
540 | return -1; | |
541 | if (a->time > b->time) | |
542 | return 1; | |
543 | else | |
544 | return 0; | |
545 | } | |
546 | #else | |
547 | /* not function graph compares against hits */ | |
bac429f0 SR |
548 | static int function_stat_cmp(void *p1, void *p2) |
549 | { | |
493762fc SR |
550 | struct ftrace_profile *a = p1; |
551 | struct ftrace_profile *b = p2; | |
bac429f0 SR |
552 | |
553 | if (a->counter < b->counter) | |
554 | return -1; | |
555 | if (a->counter > b->counter) | |
556 | return 1; | |
557 | else | |
558 | return 0; | |
559 | } | |
0706f1c4 | 560 | #endif |
bac429f0 SR |
561 | |
562 | static int function_stat_headers(struct seq_file *m) | |
563 | { | |
0706f1c4 | 564 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
fa6f0cc7 RV |
565 | seq_puts(m, " Function " |
566 | "Hit Time Avg s^2\n" | |
567 | " -------- " | |
568 | "--- ---- --- ---\n"); | |
0706f1c4 | 569 | #else |
fa6f0cc7 RV |
570 | seq_puts(m, " Function Hit\n" |
571 | " -------- ---\n"); | |
0706f1c4 | 572 | #endif |
bac429f0 SR |
573 | return 0; |
574 | } | |
575 | ||
576 | static int function_stat_show(struct seq_file *m, void *v) | |
577 | { | |
493762fc | 578 | struct ftrace_profile *rec = v; |
bac429f0 | 579 | char str[KSYM_SYMBOL_LEN]; |
3aaba20f | 580 | int ret = 0; |
0706f1c4 | 581 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
582 | static struct trace_seq s; |
583 | unsigned long long avg; | |
e330b3bc | 584 | unsigned long long stddev; |
0706f1c4 | 585 | #endif |
3aaba20f LZ |
586 | mutex_lock(&ftrace_profile_lock); |
587 | ||
588 | /* we raced with function_profile_reset() */ | |
589 | if (unlikely(rec->counter == 0)) { | |
590 | ret = -EBUSY; | |
591 | goto out; | |
592 | } | |
bac429f0 | 593 | |
8e436ca0 UT |
594 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
595 | avg = rec->time; | |
596 | do_div(avg, rec->counter); | |
597 | if (tracing_thresh && (avg < tracing_thresh)) | |
598 | goto out; | |
599 | #endif | |
600 | ||
bac429f0 | 601 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
0706f1c4 SR |
602 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
603 | ||
604 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
fa6f0cc7 | 605 | seq_puts(m, " "); |
34886c8b | 606 | |
e330b3bc CD |
607 | /* Sample standard deviation (s^2) */ |
608 | if (rec->counter <= 1) | |
609 | stddev = 0; | |
610 | else { | |
52d85d76 JL |
611 | /* |
612 | * Apply Welford's method: | |
613 | * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2) | |
614 | */ | |
615 | stddev = rec->counter * rec->time_squared - | |
616 | rec->time * rec->time; | |
617 | ||
e330b3bc CD |
618 | /* |
619 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
620 | * trace_print_graph_duration will divide 1000 again. | |
621 | */ | |
52d85d76 | 622 | do_div(stddev, rec->counter * (rec->counter - 1) * 1000); |
e330b3bc CD |
623 | } |
624 | ||
34886c8b SR |
625 | trace_seq_init(&s); |
626 | trace_print_graph_duration(rec->time, &s); | |
627 | trace_seq_puts(&s, " "); | |
628 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
629 | trace_seq_puts(&s, " "); |
630 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 | 631 | trace_print_seq(m, &s); |
0706f1c4 SR |
632 | #endif |
633 | seq_putc(m, '\n'); | |
3aaba20f LZ |
634 | out: |
635 | mutex_unlock(&ftrace_profile_lock); | |
bac429f0 | 636 | |
3aaba20f | 637 | return ret; |
bac429f0 SR |
638 | } |
639 | ||
cafb168a | 640 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 641 | { |
493762fc | 642 | struct ftrace_profile_page *pg; |
bac429f0 | 643 | |
cafb168a | 644 | pg = stat->pages = stat->start; |
bac429f0 | 645 | |
493762fc SR |
646 | while (pg) { |
647 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
648 | pg->index = 0; | |
649 | pg = pg->next; | |
bac429f0 SR |
650 | } |
651 | ||
cafb168a | 652 | memset(stat->hash, 0, |
493762fc SR |
653 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
654 | } | |
bac429f0 | 655 | |
cafb168a | 656 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
657 | { |
658 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
659 | int functions; |
660 | int pages; | |
493762fc | 661 | int i; |
bac429f0 | 662 | |
493762fc | 663 | /* If we already allocated, do nothing */ |
cafb168a | 664 | if (stat->pages) |
493762fc | 665 | return 0; |
bac429f0 | 666 | |
cafb168a SR |
667 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
668 | if (!stat->pages) | |
493762fc | 669 | return -ENOMEM; |
bac429f0 | 670 | |
318e0a73 SR |
671 | #ifdef CONFIG_DYNAMIC_FTRACE |
672 | functions = ftrace_update_tot_cnt; | |
673 | #else | |
674 | /* | |
675 | * We do not know the number of functions that exist because | |
676 | * dynamic tracing is what counts them. With past experience | |
677 | * we have around 20K functions. That should be more than enough. | |
678 | * It is highly unlikely we will execute every function in | |
679 | * the kernel. | |
680 | */ | |
681 | functions = 20000; | |
682 | #endif | |
683 | ||
cafb168a | 684 | pg = stat->start = stat->pages; |
bac429f0 | 685 | |
318e0a73 SR |
686 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
687 | ||
39e30cd1 | 688 | for (i = 1; i < pages; i++) { |
493762fc | 689 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 690 | if (!pg->next) |
318e0a73 | 691 | goto out_free; |
493762fc SR |
692 | pg = pg->next; |
693 | } | |
694 | ||
695 | return 0; | |
318e0a73 SR |
696 | |
697 | out_free: | |
698 | pg = stat->start; | |
699 | while (pg) { | |
700 | unsigned long tmp = (unsigned long)pg; | |
701 | ||
702 | pg = pg->next; | |
703 | free_page(tmp); | |
704 | } | |
705 | ||
318e0a73 SR |
706 | stat->pages = NULL; |
707 | stat->start = NULL; | |
708 | ||
709 | return -ENOMEM; | |
bac429f0 SR |
710 | } |
711 | ||
cafb168a | 712 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 713 | { |
cafb168a | 714 | struct ftrace_profile_stat *stat; |
493762fc | 715 | int size; |
bac429f0 | 716 | |
cafb168a SR |
717 | stat = &per_cpu(ftrace_profile_stats, cpu); |
718 | ||
719 | if (stat->hash) { | |
493762fc | 720 | /* If the profile is already created, simply reset it */ |
cafb168a | 721 | ftrace_profile_reset(stat); |
493762fc SR |
722 | return 0; |
723 | } | |
bac429f0 | 724 | |
493762fc SR |
725 | /* |
726 | * We are profiling all functions, but usually only a few thousand | |
727 | * functions are hit. We'll make a hash of 1024 items. | |
728 | */ | |
729 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 730 | |
cafb168a | 731 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
493762fc | 732 | |
cafb168a | 733 | if (!stat->hash) |
493762fc SR |
734 | return -ENOMEM; |
735 | ||
318e0a73 | 736 | /* Preallocate the function profiling pages */ |
cafb168a SR |
737 | if (ftrace_profile_pages_init(stat) < 0) { |
738 | kfree(stat->hash); | |
739 | stat->hash = NULL; | |
493762fc SR |
740 | return -ENOMEM; |
741 | } | |
742 | ||
743 | return 0; | |
bac429f0 SR |
744 | } |
745 | ||
cafb168a SR |
746 | static int ftrace_profile_init(void) |
747 | { | |
748 | int cpu; | |
749 | int ret = 0; | |
750 | ||
c4602c1c | 751 | for_each_possible_cpu(cpu) { |
cafb168a SR |
752 | ret = ftrace_profile_init_cpu(cpu); |
753 | if (ret) | |
754 | break; | |
755 | } | |
756 | ||
757 | return ret; | |
758 | } | |
759 | ||
493762fc | 760 | /* interrupts must be disabled */ |
cafb168a SR |
761 | static struct ftrace_profile * |
762 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 763 | { |
493762fc | 764 | struct ftrace_profile *rec; |
bac429f0 | 765 | struct hlist_head *hhd; |
bac429f0 SR |
766 | unsigned long key; |
767 | ||
20079ebe | 768 | key = hash_long(ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 769 | hhd = &stat->hash[key]; |
bac429f0 SR |
770 | |
771 | if (hlist_empty(hhd)) | |
772 | return NULL; | |
773 | ||
1bb539ca | 774 | hlist_for_each_entry_rcu_notrace(rec, hhd, node) { |
bac429f0 | 775 | if (rec->ip == ip) |
493762fc SR |
776 | return rec; |
777 | } | |
778 | ||
779 | return NULL; | |
780 | } | |
781 | ||
cafb168a SR |
782 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
783 | struct ftrace_profile *rec) | |
493762fc SR |
784 | { |
785 | unsigned long key; | |
786 | ||
20079ebe | 787 | key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 788 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
789 | } |
790 | ||
318e0a73 SR |
791 | /* |
792 | * The memory is already allocated, this simply finds a new record to use. | |
793 | */ | |
493762fc | 794 | static struct ftrace_profile * |
318e0a73 | 795 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
796 | { |
797 | struct ftrace_profile *rec = NULL; | |
798 | ||
318e0a73 | 799 | /* prevent recursion (from NMIs) */ |
cafb168a | 800 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
801 | goto out; |
802 | ||
493762fc | 803 | /* |
318e0a73 SR |
804 | * Try to find the function again since an NMI |
805 | * could have added it | |
493762fc | 806 | */ |
cafb168a | 807 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 808 | if (rec) |
cafb168a | 809 | goto out; |
493762fc | 810 | |
cafb168a SR |
811 | if (stat->pages->index == PROFILES_PER_PAGE) { |
812 | if (!stat->pages->next) | |
813 | goto out; | |
814 | stat->pages = stat->pages->next; | |
bac429f0 | 815 | } |
493762fc | 816 | |
cafb168a | 817 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 818 | rec->ip = ip; |
cafb168a | 819 | ftrace_add_profile(stat, rec); |
493762fc | 820 | |
bac429f0 | 821 | out: |
cafb168a | 822 | atomic_dec(&stat->disabled); |
bac429f0 SR |
823 | |
824 | return rec; | |
825 | } | |
826 | ||
827 | static void | |
2f5f6ad9 | 828 | function_profile_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 829 | struct ftrace_ops *ops, struct pt_regs *regs) |
bac429f0 | 830 | { |
cafb168a | 831 | struct ftrace_profile_stat *stat; |
493762fc | 832 | struct ftrace_profile *rec; |
bac429f0 SR |
833 | unsigned long flags; |
834 | ||
835 | if (!ftrace_profile_enabled) | |
836 | return; | |
837 | ||
838 | local_irq_save(flags); | |
cafb168a | 839 | |
bdffd893 | 840 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 841 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
842 | goto out; |
843 | ||
844 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 845 | if (!rec) { |
318e0a73 | 846 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
847 | if (!rec) |
848 | goto out; | |
849 | } | |
bac429f0 SR |
850 | |
851 | rec->counter++; | |
852 | out: | |
853 | local_irq_restore(flags); | |
854 | } | |
855 | ||
0706f1c4 SR |
856 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
857 | static int profile_graph_entry(struct ftrace_graph_ent *trace) | |
858 | { | |
8861dd30 NK |
859 | int index = trace->depth; |
860 | ||
a1e2e31d | 861 | function_profile_call(trace->func, 0, NULL, NULL); |
8861dd30 | 862 | |
a8f0f9e4 SRV |
863 | /* If function graph is shutting down, ret_stack can be NULL */ |
864 | if (!current->ret_stack) | |
865 | return 0; | |
866 | ||
8861dd30 NK |
867 | if (index >= 0 && index < FTRACE_RETFUNC_DEPTH) |
868 | current->ret_stack[index].subtime = 0; | |
869 | ||
0706f1c4 SR |
870 | return 1; |
871 | } | |
872 | ||
873 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
874 | { | |
cafb168a | 875 | struct ftrace_profile_stat *stat; |
a2a16d6a | 876 | unsigned long long calltime; |
0706f1c4 | 877 | struct ftrace_profile *rec; |
cafb168a | 878 | unsigned long flags; |
0706f1c4 SR |
879 | |
880 | local_irq_save(flags); | |
bdffd893 | 881 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 882 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
883 | goto out; |
884 | ||
37e44bc5 SR |
885 | /* If the calltime was zero'd ignore it */ |
886 | if (!trace->calltime) | |
887 | goto out; | |
888 | ||
a2a16d6a SR |
889 | calltime = trace->rettime - trace->calltime; |
890 | ||
55577204 | 891 | if (!fgraph_graph_time) { |
a2a16d6a SR |
892 | int index; |
893 | ||
894 | index = trace->depth; | |
895 | ||
896 | /* Append this call time to the parent time to subtract */ | |
897 | if (index) | |
898 | current->ret_stack[index - 1].subtime += calltime; | |
899 | ||
900 | if (current->ret_stack[index].subtime < calltime) | |
901 | calltime -= current->ret_stack[index].subtime; | |
902 | else | |
903 | calltime = 0; | |
904 | } | |
905 | ||
cafb168a | 906 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 907 | if (rec) { |
a2a16d6a | 908 | rec->time += calltime; |
e330b3bc CD |
909 | rec->time_squared += calltime * calltime; |
910 | } | |
a2a16d6a | 911 | |
cafb168a | 912 | out: |
0706f1c4 SR |
913 | local_irq_restore(flags); |
914 | } | |
915 | ||
916 | static int register_ftrace_profiler(void) | |
917 | { | |
918 | return register_ftrace_graph(&profile_graph_return, | |
919 | &profile_graph_entry); | |
920 | } | |
921 | ||
922 | static void unregister_ftrace_profiler(void) | |
923 | { | |
924 | unregister_ftrace_graph(); | |
925 | } | |
926 | #else | |
bd38c0e6 | 927 | static struct ftrace_ops ftrace_profile_ops __read_mostly = { |
fb9fb015 | 928 | .func = function_profile_call, |
f04f24fb | 929 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, |
33b7f99c | 930 | INIT_OPS_HASH(ftrace_profile_ops) |
bac429f0 SR |
931 | }; |
932 | ||
0706f1c4 SR |
933 | static int register_ftrace_profiler(void) |
934 | { | |
935 | return register_ftrace_function(&ftrace_profile_ops); | |
936 | } | |
937 | ||
938 | static void unregister_ftrace_profiler(void) | |
939 | { | |
940 | unregister_ftrace_function(&ftrace_profile_ops); | |
941 | } | |
942 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
943 | ||
bac429f0 SR |
944 | static ssize_t |
945 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
946 | size_t cnt, loff_t *ppos) | |
947 | { | |
948 | unsigned long val; | |
bac429f0 SR |
949 | int ret; |
950 | ||
22fe9b54 PH |
951 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
952 | if (ret) | |
bac429f0 SR |
953 | return ret; |
954 | ||
955 | val = !!val; | |
956 | ||
957 | mutex_lock(&ftrace_profile_lock); | |
958 | if (ftrace_profile_enabled ^ val) { | |
959 | if (val) { | |
493762fc SR |
960 | ret = ftrace_profile_init(); |
961 | if (ret < 0) { | |
962 | cnt = ret; | |
963 | goto out; | |
964 | } | |
965 | ||
0706f1c4 SR |
966 | ret = register_ftrace_profiler(); |
967 | if (ret < 0) { | |
968 | cnt = ret; | |
969 | goto out; | |
970 | } | |
bac429f0 SR |
971 | ftrace_profile_enabled = 1; |
972 | } else { | |
973 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
974 | /* |
975 | * unregister_ftrace_profiler calls stop_machine | |
976 | * so this acts like an synchronize_sched. | |
977 | */ | |
0706f1c4 | 978 | unregister_ftrace_profiler(); |
bac429f0 SR |
979 | } |
980 | } | |
493762fc | 981 | out: |
bac429f0 SR |
982 | mutex_unlock(&ftrace_profile_lock); |
983 | ||
cf8517cf | 984 | *ppos += cnt; |
bac429f0 SR |
985 | |
986 | return cnt; | |
987 | } | |
988 | ||
493762fc SR |
989 | static ssize_t |
990 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
991 | size_t cnt, loff_t *ppos) | |
992 | { | |
fb9fb015 | 993 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
994 | int r; |
995 | ||
996 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
997 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
998 | } | |
999 | ||
bac429f0 SR |
1000 | static const struct file_operations ftrace_profile_fops = { |
1001 | .open = tracing_open_generic, | |
1002 | .read = ftrace_profile_read, | |
1003 | .write = ftrace_profile_write, | |
6038f373 | 1004 | .llseek = default_llseek, |
bac429f0 SR |
1005 | }; |
1006 | ||
cafb168a SR |
1007 | /* used to initialize the real stat files */ |
1008 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
1009 | .name = "functions", |
1010 | .stat_start = function_stat_start, | |
1011 | .stat_next = function_stat_next, | |
1012 | .stat_cmp = function_stat_cmp, | |
1013 | .stat_headers = function_stat_headers, | |
1014 | .stat_show = function_stat_show | |
cafb168a SR |
1015 | }; |
1016 | ||
8434dc93 | 1017 | static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
bac429f0 | 1018 | { |
cafb168a | 1019 | struct ftrace_profile_stat *stat; |
bac429f0 | 1020 | struct dentry *entry; |
cafb168a | 1021 | char *name; |
bac429f0 | 1022 | int ret; |
cafb168a SR |
1023 | int cpu; |
1024 | ||
1025 | for_each_possible_cpu(cpu) { | |
1026 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
1027 | ||
6363c6b5 | 1028 | name = kasprintf(GFP_KERNEL, "function%d", cpu); |
cafb168a SR |
1029 | if (!name) { |
1030 | /* | |
1031 | * The files created are permanent, if something happens | |
1032 | * we still do not free memory. | |
1033 | */ | |
cafb168a SR |
1034 | WARN(1, |
1035 | "Could not allocate stat file for cpu %d\n", | |
1036 | cpu); | |
1037 | return; | |
1038 | } | |
1039 | stat->stat = function_stats; | |
cafb168a SR |
1040 | stat->stat.name = name; |
1041 | ret = register_stat_tracer(&stat->stat); | |
1042 | if (ret) { | |
1043 | WARN(1, | |
1044 | "Could not register function stat for cpu %d\n", | |
1045 | cpu); | |
1046 | kfree(name); | |
1047 | return; | |
1048 | } | |
bac429f0 SR |
1049 | } |
1050 | ||
8434dc93 | 1051 | entry = tracefs_create_file("function_profile_enabled", 0644, |
bac429f0 SR |
1052 | d_tracer, NULL, &ftrace_profile_fops); |
1053 | if (!entry) | |
a395d6a7 | 1054 | pr_warn("Could not create tracefs 'function_profile_enabled' entry\n"); |
bac429f0 SR |
1055 | } |
1056 | ||
bac429f0 | 1057 | #else /* CONFIG_FUNCTION_PROFILER */ |
8434dc93 | 1058 | static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
bac429f0 SR |
1059 | { |
1060 | } | |
bac429f0 SR |
1061 | #endif /* CONFIG_FUNCTION_PROFILER */ |
1062 | ||
493762fc SR |
1063 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; |
1064 | ||
1619dc3f PA |
1065 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
1066 | static int ftrace_graph_active; | |
1067 | #else | |
1068 | # define ftrace_graph_active 0 | |
1069 | #endif | |
1070 | ||
493762fc SR |
1071 | #ifdef CONFIG_DYNAMIC_FTRACE |
1072 | ||
79922b80 SRRH |
1073 | static struct ftrace_ops *removed_ops; |
1074 | ||
e1effa01 SRRH |
1075 | /* |
1076 | * Set when doing a global update, like enabling all recs or disabling them. | |
1077 | * It is not set when just updating a single ftrace_ops. | |
1078 | */ | |
1079 | static bool update_all_ops; | |
1080 | ||
493762fc SR |
1081 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
1082 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
1083 | #endif | |
1084 | ||
b448c4e3 SR |
1085 | struct ftrace_func_entry { |
1086 | struct hlist_node hlist; | |
1087 | unsigned long ip; | |
1088 | }; | |
1089 | ||
7b60f3d8 SRV |
1090 | struct ftrace_func_probe { |
1091 | struct ftrace_probe_ops *probe_ops; | |
1092 | struct ftrace_ops ops; | |
1093 | struct trace_array *tr; | |
1094 | struct list_head list; | |
6e444319 | 1095 | void *data; |
7b60f3d8 SRV |
1096 | int ref; |
1097 | }; | |
1098 | ||
33dc9b12 SR |
1099 | /* |
1100 | * We make these constant because no one should touch them, | |
1101 | * but they are used as the default "empty hash", to avoid allocating | |
1102 | * it all the time. These are in a read only section such that if | |
1103 | * anyone does try to modify it, it will cause an exception. | |
1104 | */ | |
1105 | static const struct hlist_head empty_buckets[1]; | |
1106 | static const struct ftrace_hash empty_hash = { | |
1107 | .buckets = (struct hlist_head *)empty_buckets, | |
1cf41dd7 | 1108 | }; |
33dc9b12 | 1109 | #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) |
493762fc | 1110 | |
2b499381 | 1111 | static struct ftrace_ops global_ops = { |
33b7f99c SRRH |
1112 | .func = ftrace_stub, |
1113 | .local_hash.notrace_hash = EMPTY_HASH, | |
1114 | .local_hash.filter_hash = EMPTY_HASH, | |
1115 | INIT_OPS_HASH(global_ops) | |
1116 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | | |
e3eea140 SRRH |
1117 | FTRACE_OPS_FL_INITIALIZED | |
1118 | FTRACE_OPS_FL_PID, | |
f45948e8 SR |
1119 | }; |
1120 | ||
aec0be2d | 1121 | /* |
6be7fa3c | 1122 | * Used by the stack undwinder to know about dynamic ftrace trampolines. |
aec0be2d | 1123 | */ |
6be7fa3c | 1124 | struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr) |
aec0be2d | 1125 | { |
6be7fa3c | 1126 | struct ftrace_ops *op = NULL; |
aec0be2d SRRH |
1127 | |
1128 | /* | |
1129 | * Some of the ops may be dynamically allocated, | |
1130 | * they are freed after a synchronize_sched(). | |
1131 | */ | |
1132 | preempt_disable_notrace(); | |
1133 | ||
1134 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1135 | /* | |
1136 | * This is to check for dynamically allocated trampolines. | |
1137 | * Trampolines that are in kernel text will have | |
1138 | * core_kernel_text() return true. | |
1139 | */ | |
1140 | if (op->trampoline && op->trampoline_size) | |
1141 | if (addr >= op->trampoline && | |
1142 | addr < op->trampoline + op->trampoline_size) { | |
6be7fa3c SRV |
1143 | preempt_enable_notrace(); |
1144 | return op; | |
aec0be2d SRRH |
1145 | } |
1146 | } while_for_each_ftrace_op(op); | |
aec0be2d SRRH |
1147 | preempt_enable_notrace(); |
1148 | ||
6be7fa3c SRV |
1149 | return NULL; |
1150 | } | |
1151 | ||
1152 | /* | |
1153 | * This is used by __kernel_text_address() to return true if the | |
1154 | * address is on a dynamically allocated trampoline that would | |
1155 | * not return true for either core_kernel_text() or | |
1156 | * is_module_text_address(). | |
1157 | */ | |
1158 | bool is_ftrace_trampoline(unsigned long addr) | |
1159 | { | |
1160 | return ftrace_ops_trampoline(addr) != NULL; | |
aec0be2d SRRH |
1161 | } |
1162 | ||
493762fc SR |
1163 | struct ftrace_page { |
1164 | struct ftrace_page *next; | |
a7900875 | 1165 | struct dyn_ftrace *records; |
493762fc | 1166 | int index; |
a7900875 | 1167 | int size; |
493762fc SR |
1168 | }; |
1169 | ||
a7900875 SR |
1170 | #define ENTRY_SIZE sizeof(struct dyn_ftrace) |
1171 | #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE) | |
493762fc SR |
1172 | |
1173 | /* estimate from running different kernels */ | |
1174 | #define NR_TO_INIT 10000 | |
1175 | ||
1176 | static struct ftrace_page *ftrace_pages_start; | |
1177 | static struct ftrace_page *ftrace_pages; | |
1178 | ||
2b0cce0e SRV |
1179 | static __always_inline unsigned long |
1180 | ftrace_hash_key(struct ftrace_hash *hash, unsigned long ip) | |
1181 | { | |
1182 | if (hash->size_bits > 0) | |
1183 | return hash_long(ip, hash->size_bits); | |
1184 | ||
1185 | return 0; | |
1186 | } | |
1187 | ||
2b2c279c SRV |
1188 | /* Only use this function if ftrace_hash_empty() has already been tested */ |
1189 | static __always_inline struct ftrace_func_entry * | |
1190 | __ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
b448c4e3 SR |
1191 | { |
1192 | unsigned long key; | |
1193 | struct ftrace_func_entry *entry; | |
1194 | struct hlist_head *hhd; | |
b448c4e3 | 1195 | |
2b0cce0e | 1196 | key = ftrace_hash_key(hash, ip); |
b448c4e3 SR |
1197 | hhd = &hash->buckets[key]; |
1198 | ||
1bb539ca | 1199 | hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) { |
b448c4e3 SR |
1200 | if (entry->ip == ip) |
1201 | return entry; | |
1202 | } | |
1203 | return NULL; | |
1204 | } | |
1205 | ||
2b2c279c SRV |
1206 | /** |
1207 | * ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash | |
1208 | * @hash: The hash to look at | |
1209 | * @ip: The instruction pointer to test | |
1210 | * | |
1211 | * Search a given @hash to see if a given instruction pointer (@ip) | |
1212 | * exists in it. | |
1213 | * | |
1214 | * Returns the entry that holds the @ip if found. NULL otherwise. | |
1215 | */ | |
1216 | struct ftrace_func_entry * | |
1217 | ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
1218 | { | |
1219 | if (ftrace_hash_empty(hash)) | |
1220 | return NULL; | |
1221 | ||
1222 | return __ftrace_lookup_ip(hash, ip); | |
1223 | } | |
1224 | ||
33dc9b12 SR |
1225 | static void __add_hash_entry(struct ftrace_hash *hash, |
1226 | struct ftrace_func_entry *entry) | |
b448c4e3 | 1227 | { |
b448c4e3 SR |
1228 | struct hlist_head *hhd; |
1229 | unsigned long key; | |
1230 | ||
2b0cce0e | 1231 | key = ftrace_hash_key(hash, entry->ip); |
b448c4e3 SR |
1232 | hhd = &hash->buckets[key]; |
1233 | hlist_add_head(&entry->hlist, hhd); | |
1234 | hash->count++; | |
33dc9b12 SR |
1235 | } |
1236 | ||
1237 | static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip) | |
1238 | { | |
1239 | struct ftrace_func_entry *entry; | |
1240 | ||
1241 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1242 | if (!entry) | |
1243 | return -ENOMEM; | |
1244 | ||
1245 | entry->ip = ip; | |
1246 | __add_hash_entry(hash, entry); | |
b448c4e3 SR |
1247 | |
1248 | return 0; | |
1249 | } | |
1250 | ||
1251 | static void | |
33dc9b12 | 1252 | free_hash_entry(struct ftrace_hash *hash, |
b448c4e3 SR |
1253 | struct ftrace_func_entry *entry) |
1254 | { | |
1255 | hlist_del(&entry->hlist); | |
1256 | kfree(entry); | |
1257 | hash->count--; | |
1258 | } | |
1259 | ||
33dc9b12 SR |
1260 | static void |
1261 | remove_hash_entry(struct ftrace_hash *hash, | |
1262 | struct ftrace_func_entry *entry) | |
1263 | { | |
eee8ded1 | 1264 | hlist_del_rcu(&entry->hlist); |
33dc9b12 SR |
1265 | hash->count--; |
1266 | } | |
1267 | ||
b448c4e3 SR |
1268 | static void ftrace_hash_clear(struct ftrace_hash *hash) |
1269 | { | |
1270 | struct hlist_head *hhd; | |
b67bfe0d | 1271 | struct hlist_node *tn; |
b448c4e3 SR |
1272 | struct ftrace_func_entry *entry; |
1273 | int size = 1 << hash->size_bits; | |
1274 | int i; | |
1275 | ||
33dc9b12 SR |
1276 | if (!hash->count) |
1277 | return; | |
1278 | ||
b448c4e3 SR |
1279 | for (i = 0; i < size; i++) { |
1280 | hhd = &hash->buckets[i]; | |
b67bfe0d | 1281 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) |
33dc9b12 | 1282 | free_hash_entry(hash, entry); |
b448c4e3 SR |
1283 | } |
1284 | FTRACE_WARN_ON(hash->count); | |
1285 | } | |
1286 | ||
673feb9d SRV |
1287 | static void free_ftrace_mod(struct ftrace_mod_load *ftrace_mod) |
1288 | { | |
1289 | list_del(&ftrace_mod->list); | |
1290 | kfree(ftrace_mod->module); | |
1291 | kfree(ftrace_mod->func); | |
1292 | kfree(ftrace_mod); | |
1293 | } | |
1294 | ||
1295 | static void clear_ftrace_mod_list(struct list_head *head) | |
1296 | { | |
1297 | struct ftrace_mod_load *p, *n; | |
1298 | ||
1299 | /* stack tracer isn't supported yet */ | |
1300 | if (!head) | |
1301 | return; | |
1302 | ||
1303 | mutex_lock(&ftrace_lock); | |
1304 | list_for_each_entry_safe(p, n, head, list) | |
1305 | free_ftrace_mod(p); | |
1306 | mutex_unlock(&ftrace_lock); | |
1307 | } | |
1308 | ||
33dc9b12 SR |
1309 | static void free_ftrace_hash(struct ftrace_hash *hash) |
1310 | { | |
1311 | if (!hash || hash == EMPTY_HASH) | |
1312 | return; | |
1313 | ftrace_hash_clear(hash); | |
1314 | kfree(hash->buckets); | |
1315 | kfree(hash); | |
1316 | } | |
1317 | ||
07fd5515 SR |
1318 | static void __free_ftrace_hash_rcu(struct rcu_head *rcu) |
1319 | { | |
1320 | struct ftrace_hash *hash; | |
1321 | ||
1322 | hash = container_of(rcu, struct ftrace_hash, rcu); | |
1323 | free_ftrace_hash(hash); | |
1324 | } | |
1325 | ||
1326 | static void free_ftrace_hash_rcu(struct ftrace_hash *hash) | |
1327 | { | |
1328 | if (!hash || hash == EMPTY_HASH) | |
1329 | return; | |
1330 | call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu); | |
1331 | } | |
1332 | ||
5500fa51 JO |
1333 | void ftrace_free_filter(struct ftrace_ops *ops) |
1334 | { | |
f04f24fb | 1335 | ftrace_ops_init(ops); |
33b7f99c SRRH |
1336 | free_ftrace_hash(ops->func_hash->filter_hash); |
1337 | free_ftrace_hash(ops->func_hash->notrace_hash); | |
5500fa51 JO |
1338 | } |
1339 | ||
33dc9b12 SR |
1340 | static struct ftrace_hash *alloc_ftrace_hash(int size_bits) |
1341 | { | |
1342 | struct ftrace_hash *hash; | |
1343 | int size; | |
1344 | ||
1345 | hash = kzalloc(sizeof(*hash), GFP_KERNEL); | |
1346 | if (!hash) | |
1347 | return NULL; | |
1348 | ||
1349 | size = 1 << size_bits; | |
47b0edcb | 1350 | hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL); |
33dc9b12 SR |
1351 | |
1352 | if (!hash->buckets) { | |
1353 | kfree(hash); | |
1354 | return NULL; | |
1355 | } | |
1356 | ||
1357 | hash->size_bits = size_bits; | |
1358 | ||
1359 | return hash; | |
1360 | } | |
1361 | ||
673feb9d SRV |
1362 | |
1363 | static int ftrace_add_mod(struct trace_array *tr, | |
1364 | const char *func, const char *module, | |
1365 | int enable) | |
1366 | { | |
1367 | struct ftrace_mod_load *ftrace_mod; | |
1368 | struct list_head *mod_head = enable ? &tr->mod_trace : &tr->mod_notrace; | |
1369 | ||
1370 | ftrace_mod = kzalloc(sizeof(*ftrace_mod), GFP_KERNEL); | |
1371 | if (!ftrace_mod) | |
1372 | return -ENOMEM; | |
1373 | ||
1374 | ftrace_mod->func = kstrdup(func, GFP_KERNEL); | |
1375 | ftrace_mod->module = kstrdup(module, GFP_KERNEL); | |
1376 | ftrace_mod->enable = enable; | |
1377 | ||
1378 | if (!ftrace_mod->func || !ftrace_mod->module) | |
1379 | goto out_free; | |
1380 | ||
1381 | list_add(&ftrace_mod->list, mod_head); | |
1382 | ||
1383 | return 0; | |
1384 | ||
1385 | out_free: | |
1386 | free_ftrace_mod(ftrace_mod); | |
1387 | ||
1388 | return -ENOMEM; | |
1389 | } | |
1390 | ||
33dc9b12 SR |
1391 | static struct ftrace_hash * |
1392 | alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) | |
1393 | { | |
1394 | struct ftrace_func_entry *entry; | |
1395 | struct ftrace_hash *new_hash; | |
33dc9b12 SR |
1396 | int size; |
1397 | int ret; | |
1398 | int i; | |
1399 | ||
1400 | new_hash = alloc_ftrace_hash(size_bits); | |
1401 | if (!new_hash) | |
1402 | return NULL; | |
1403 | ||
8c08f0d5 SRV |
1404 | if (hash) |
1405 | new_hash->flags = hash->flags; | |
1406 | ||
33dc9b12 | 1407 | /* Empty hash? */ |
06a51d93 | 1408 | if (ftrace_hash_empty(hash)) |
33dc9b12 SR |
1409 | return new_hash; |
1410 | ||
1411 | size = 1 << hash->size_bits; | |
1412 | for (i = 0; i < size; i++) { | |
b67bfe0d | 1413 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { |
33dc9b12 SR |
1414 | ret = add_hash_entry(new_hash, entry->ip); |
1415 | if (ret < 0) | |
1416 | goto free_hash; | |
1417 | } | |
1418 | } | |
1419 | ||
1420 | FTRACE_WARN_ON(new_hash->count != hash->count); | |
1421 | ||
1422 | return new_hash; | |
1423 | ||
1424 | free_hash: | |
1425 | free_ftrace_hash(new_hash); | |
1426 | return NULL; | |
1427 | } | |
1428 | ||
41fb61c2 | 1429 | static void |
84261912 | 1430 | ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash); |
41fb61c2 | 1431 | static void |
84261912 | 1432 | ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash); |
41fb61c2 | 1433 | |
f8b8be8a MH |
1434 | static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, |
1435 | struct ftrace_hash *new_hash); | |
1436 | ||
3e278c0d NK |
1437 | static struct ftrace_hash * |
1438 | __ftrace_hash_move(struct ftrace_hash *src) | |
33dc9b12 SR |
1439 | { |
1440 | struct ftrace_func_entry *entry; | |
b67bfe0d | 1441 | struct hlist_node *tn; |
33dc9b12 | 1442 | struct hlist_head *hhd; |
07fd5515 | 1443 | struct ftrace_hash *new_hash; |
33dc9b12 SR |
1444 | int size = src->count; |
1445 | int bits = 0; | |
1446 | int i; | |
1447 | ||
1448 | /* | |
3e278c0d | 1449 | * If the new source is empty, just return the empty_hash. |
33dc9b12 | 1450 | */ |
8c08f0d5 | 1451 | if (ftrace_hash_empty(src)) |
3e278c0d | 1452 | return EMPTY_HASH; |
33dc9b12 | 1453 | |
33dc9b12 SR |
1454 | /* |
1455 | * Make the hash size about 1/2 the # found | |
1456 | */ | |
1457 | for (size /= 2; size; size >>= 1) | |
1458 | bits++; | |
1459 | ||
1460 | /* Don't allocate too much */ | |
1461 | if (bits > FTRACE_HASH_MAX_BITS) | |
1462 | bits = FTRACE_HASH_MAX_BITS; | |
1463 | ||
07fd5515 SR |
1464 | new_hash = alloc_ftrace_hash(bits); |
1465 | if (!new_hash) | |
3e278c0d | 1466 | return NULL; |
33dc9b12 | 1467 | |
8c08f0d5 SRV |
1468 | new_hash->flags = src->flags; |
1469 | ||
33dc9b12 SR |
1470 | size = 1 << src->size_bits; |
1471 | for (i = 0; i < size; i++) { | |
1472 | hhd = &src->buckets[i]; | |
b67bfe0d | 1473 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) { |
33dc9b12 | 1474 | remove_hash_entry(src, entry); |
07fd5515 | 1475 | __add_hash_entry(new_hash, entry); |
33dc9b12 SR |
1476 | } |
1477 | } | |
1478 | ||
3e278c0d NK |
1479 | return new_hash; |
1480 | } | |
1481 | ||
1482 | static int | |
1483 | ftrace_hash_move(struct ftrace_ops *ops, int enable, | |
1484 | struct ftrace_hash **dst, struct ftrace_hash *src) | |
1485 | { | |
1486 | struct ftrace_hash *new_hash; | |
1487 | int ret; | |
1488 | ||
1489 | /* Reject setting notrace hash on IPMODIFY ftrace_ops */ | |
1490 | if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable) | |
1491 | return -EINVAL; | |
1492 | ||
1493 | new_hash = __ftrace_hash_move(src); | |
1494 | if (!new_hash) | |
1495 | return -ENOMEM; | |
1496 | ||
f8b8be8a MH |
1497 | /* Make sure this can be applied if it is IPMODIFY ftrace_ops */ |
1498 | if (enable) { | |
1499 | /* IPMODIFY should be updated only when filter_hash updating */ | |
1500 | ret = ftrace_hash_ipmodify_update(ops, new_hash); | |
1501 | if (ret < 0) { | |
1502 | free_ftrace_hash(new_hash); | |
1503 | return ret; | |
1504 | } | |
1505 | } | |
1506 | ||
5c27c775 MH |
1507 | /* |
1508 | * Remove the current set, update the hash and add | |
1509 | * them back. | |
1510 | */ | |
84261912 | 1511 | ftrace_hash_rec_disable_modify(ops, enable); |
5c27c775 | 1512 | |
07fd5515 | 1513 | rcu_assign_pointer(*dst, new_hash); |
07fd5515 | 1514 | |
84261912 | 1515 | ftrace_hash_rec_enable_modify(ops, enable); |
41fb61c2 | 1516 | |
5c27c775 | 1517 | return 0; |
33dc9b12 SR |
1518 | } |
1519 | ||
fef5aeee SRRH |
1520 | static bool hash_contains_ip(unsigned long ip, |
1521 | struct ftrace_ops_hash *hash) | |
1522 | { | |
1523 | /* | |
1524 | * The function record is a match if it exists in the filter | |
1525 | * hash and not in the notrace hash. Note, an emty hash is | |
1526 | * considered a match for the filter hash, but an empty | |
1527 | * notrace hash is considered not in the notrace hash. | |
1528 | */ | |
1529 | return (ftrace_hash_empty(hash->filter_hash) || | |
2b2c279c | 1530 | __ftrace_lookup_ip(hash->filter_hash, ip)) && |
fef5aeee | 1531 | (ftrace_hash_empty(hash->notrace_hash) || |
2b2c279c | 1532 | !__ftrace_lookup_ip(hash->notrace_hash, ip)); |
fef5aeee SRRH |
1533 | } |
1534 | ||
b848914c SR |
1535 | /* |
1536 | * Test the hashes for this ops to see if we want to call | |
1537 | * the ops->func or not. | |
1538 | * | |
1539 | * It's a match if the ip is in the ops->filter_hash or | |
1540 | * the filter_hash does not exist or is empty, | |
1541 | * AND | |
1542 | * the ip is not in the ops->notrace_hash. | |
cdbe61bf SR |
1543 | * |
1544 | * This needs to be called with preemption disabled as | |
1545 | * the hashes are freed with call_rcu_sched(). | |
b848914c SR |
1546 | */ |
1547 | static int | |
195a8afc | 1548 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
b848914c | 1549 | { |
fef5aeee | 1550 | struct ftrace_ops_hash hash; |
b848914c SR |
1551 | int ret; |
1552 | ||
195a8afc SRRH |
1553 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
1554 | /* | |
1555 | * There's a small race when adding ops that the ftrace handler | |
1556 | * that wants regs, may be called without them. We can not | |
1557 | * allow that handler to be called if regs is NULL. | |
1558 | */ | |
1559 | if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS)) | |
1560 | return 0; | |
1561 | #endif | |
1562 | ||
f86f4180 CZ |
1563 | rcu_assign_pointer(hash.filter_hash, ops->func_hash->filter_hash); |
1564 | rcu_assign_pointer(hash.notrace_hash, ops->func_hash->notrace_hash); | |
b848914c | 1565 | |
fef5aeee | 1566 | if (hash_contains_ip(ip, &hash)) |
b848914c SR |
1567 | ret = 1; |
1568 | else | |
1569 | ret = 0; | |
b848914c SR |
1570 | |
1571 | return ret; | |
1572 | } | |
1573 | ||
493762fc SR |
1574 | /* |
1575 | * This is a double for. Do not use 'break' to break out of the loop, | |
1576 | * you must use a goto. | |
1577 | */ | |
1578 | #define do_for_each_ftrace_rec(pg, rec) \ | |
1579 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
1580 | int _____i; \ | |
1581 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
1582 | rec = &pg->records[_____i]; | |
1583 | ||
1584 | #define while_for_each_ftrace_rec() \ | |
1585 | } \ | |
1586 | } | |
1587 | ||
5855fead SR |
1588 | |
1589 | static int ftrace_cmp_recs(const void *a, const void *b) | |
1590 | { | |
a650e02a SR |
1591 | const struct dyn_ftrace *key = a; |
1592 | const struct dyn_ftrace *rec = b; | |
5855fead | 1593 | |
a650e02a | 1594 | if (key->flags < rec->ip) |
5855fead | 1595 | return -1; |
a650e02a SR |
1596 | if (key->ip >= rec->ip + MCOUNT_INSN_SIZE) |
1597 | return 1; | |
5855fead SR |
1598 | return 0; |
1599 | } | |
1600 | ||
04cf31a7 ME |
1601 | /** |
1602 | * ftrace_location_range - return the first address of a traced location | |
1603 | * if it touches the given ip range | |
1604 | * @start: start of range to search. | |
1605 | * @end: end of range to search (inclusive). @end points to the last byte | |
1606 | * to check. | |
1607 | * | |
1608 | * Returns rec->ip if the related ftrace location is a least partly within | |
1609 | * the given address range. That is, the first address of the instruction | |
1610 | * that is either a NOP or call to the function tracer. It checks the ftrace | |
1611 | * internal tables to determine if the address belongs or not. | |
1612 | */ | |
1613 | unsigned long ftrace_location_range(unsigned long start, unsigned long end) | |
c88fd863 SR |
1614 | { |
1615 | struct ftrace_page *pg; | |
1616 | struct dyn_ftrace *rec; | |
5855fead | 1617 | struct dyn_ftrace key; |
c88fd863 | 1618 | |
a650e02a SR |
1619 | key.ip = start; |
1620 | key.flags = end; /* overload flags, as it is unsigned long */ | |
5855fead SR |
1621 | |
1622 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
a650e02a SR |
1623 | if (end < pg->records[0].ip || |
1624 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) | |
9644302e | 1625 | continue; |
5855fead SR |
1626 | rec = bsearch(&key, pg->records, pg->index, |
1627 | sizeof(struct dyn_ftrace), | |
1628 | ftrace_cmp_recs); | |
1629 | if (rec) | |
f0cf973a | 1630 | return rec->ip; |
5855fead | 1631 | } |
c88fd863 SR |
1632 | |
1633 | return 0; | |
1634 | } | |
1635 | ||
a650e02a SR |
1636 | /** |
1637 | * ftrace_location - return true if the ip giving is a traced location | |
1638 | * @ip: the instruction pointer to check | |
1639 | * | |
f0cf973a | 1640 | * Returns rec->ip if @ip given is a pointer to a ftrace location. |
a650e02a SR |
1641 | * That is, the instruction that is either a NOP or call to |
1642 | * the function tracer. It checks the ftrace internal tables to | |
1643 | * determine if the address belongs or not. | |
1644 | */ | |
f0cf973a | 1645 | unsigned long ftrace_location(unsigned long ip) |
a650e02a SR |
1646 | { |
1647 | return ftrace_location_range(ip, ip); | |
1648 | } | |
1649 | ||
1650 | /** | |
1651 | * ftrace_text_reserved - return true if range contains an ftrace location | |
1652 | * @start: start of range to search | |
1653 | * @end: end of range to search (inclusive). @end points to the last byte to check. | |
1654 | * | |
1655 | * Returns 1 if @start and @end contains a ftrace location. | |
1656 | * That is, the instruction that is either a NOP or call to | |
1657 | * the function tracer. It checks the ftrace internal tables to | |
1658 | * determine if the address belongs or not. | |
1659 | */ | |
d88471cb | 1660 | int ftrace_text_reserved(const void *start, const void *end) |
a650e02a | 1661 | { |
f0cf973a SR |
1662 | unsigned long ret; |
1663 | ||
1664 | ret = ftrace_location_range((unsigned long)start, | |
1665 | (unsigned long)end); | |
1666 | ||
1667 | return (int)!!ret; | |
a650e02a SR |
1668 | } |
1669 | ||
4fbb48cb SRRH |
1670 | /* Test if ops registered to this rec needs regs */ |
1671 | static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec) | |
1672 | { | |
1673 | struct ftrace_ops *ops; | |
1674 | bool keep_regs = false; | |
1675 | ||
1676 | for (ops = ftrace_ops_list; | |
1677 | ops != &ftrace_list_end; ops = ops->next) { | |
1678 | /* pass rec in as regs to have non-NULL val */ | |
1679 | if (ftrace_ops_test(ops, rec->ip, rec)) { | |
1680 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1681 | keep_regs = true; | |
1682 | break; | |
1683 | } | |
1684 | } | |
1685 | } | |
1686 | ||
1687 | return keep_regs; | |
1688 | } | |
1689 | ||
84b6d3e6 | 1690 | static bool __ftrace_hash_rec_update(struct ftrace_ops *ops, |
ed926f9b SR |
1691 | int filter_hash, |
1692 | bool inc) | |
1693 | { | |
1694 | struct ftrace_hash *hash; | |
1695 | struct ftrace_hash *other_hash; | |
1696 | struct ftrace_page *pg; | |
1697 | struct dyn_ftrace *rec; | |
84b6d3e6 | 1698 | bool update = false; |
ed926f9b | 1699 | int count = 0; |
8c08f0d5 | 1700 | int all = false; |
ed926f9b SR |
1701 | |
1702 | /* Only update if the ops has been registered */ | |
1703 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
84b6d3e6 | 1704 | return false; |
ed926f9b SR |
1705 | |
1706 | /* | |
1707 | * In the filter_hash case: | |
1708 | * If the count is zero, we update all records. | |
1709 | * Otherwise we just update the items in the hash. | |
1710 | * | |
1711 | * In the notrace_hash case: | |
1712 | * We enable the update in the hash. | |
1713 | * As disabling notrace means enabling the tracing, | |
1714 | * and enabling notrace means disabling, the inc variable | |
1715 | * gets inversed. | |
1716 | */ | |
1717 | if (filter_hash) { | |
33b7f99c SRRH |
1718 | hash = ops->func_hash->filter_hash; |
1719 | other_hash = ops->func_hash->notrace_hash; | |
06a51d93 | 1720 | if (ftrace_hash_empty(hash)) |
8c08f0d5 | 1721 | all = true; |
ed926f9b SR |
1722 | } else { |
1723 | inc = !inc; | |
33b7f99c SRRH |
1724 | hash = ops->func_hash->notrace_hash; |
1725 | other_hash = ops->func_hash->filter_hash; | |
ed926f9b SR |
1726 | /* |
1727 | * If the notrace hash has no items, | |
1728 | * then there's nothing to do. | |
1729 | */ | |
06a51d93 | 1730 | if (ftrace_hash_empty(hash)) |
84b6d3e6 | 1731 | return false; |
ed926f9b SR |
1732 | } |
1733 | ||
1734 | do_for_each_ftrace_rec(pg, rec) { | |
1735 | int in_other_hash = 0; | |
1736 | int in_hash = 0; | |
1737 | int match = 0; | |
1738 | ||
b7ffffbb SRRH |
1739 | if (rec->flags & FTRACE_FL_DISABLED) |
1740 | continue; | |
1741 | ||
ed926f9b SR |
1742 | if (all) { |
1743 | /* | |
1744 | * Only the filter_hash affects all records. | |
1745 | * Update if the record is not in the notrace hash. | |
1746 | */ | |
b848914c | 1747 | if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) |
ed926f9b SR |
1748 | match = 1; |
1749 | } else { | |
06a51d93 SR |
1750 | in_hash = !!ftrace_lookup_ip(hash, rec->ip); |
1751 | in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip); | |
ed926f9b SR |
1752 | |
1753 | /* | |
19eab4a4 SRRH |
1754 | * If filter_hash is set, we want to match all functions |
1755 | * that are in the hash but not in the other hash. | |
ed926f9b | 1756 | * |
19eab4a4 SRRH |
1757 | * If filter_hash is not set, then we are decrementing. |
1758 | * That means we match anything that is in the hash | |
1759 | * and also in the other_hash. That is, we need to turn | |
1760 | * off functions in the other hash because they are disabled | |
1761 | * by this hash. | |
ed926f9b SR |
1762 | */ |
1763 | if (filter_hash && in_hash && !in_other_hash) | |
1764 | match = 1; | |
1765 | else if (!filter_hash && in_hash && | |
06a51d93 | 1766 | (in_other_hash || ftrace_hash_empty(other_hash))) |
ed926f9b SR |
1767 | match = 1; |
1768 | } | |
1769 | if (!match) | |
1770 | continue; | |
1771 | ||
1772 | if (inc) { | |
1773 | rec->flags++; | |
0376bde1 | 1774 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX)) |
84b6d3e6 | 1775 | return false; |
79922b80 SRRH |
1776 | |
1777 | /* | |
1778 | * If there's only a single callback registered to a | |
1779 | * function, and the ops has a trampoline registered | |
1780 | * for it, then we can call it directly. | |
1781 | */ | |
fef5aeee | 1782 | if (ftrace_rec_count(rec) == 1 && ops->trampoline) |
79922b80 | 1783 | rec->flags |= FTRACE_FL_TRAMP; |
fef5aeee | 1784 | else |
79922b80 SRRH |
1785 | /* |
1786 | * If we are adding another function callback | |
1787 | * to this function, and the previous had a | |
bce0b6c5 SRRH |
1788 | * custom trampoline in use, then we need to go |
1789 | * back to the default trampoline. | |
79922b80 | 1790 | */ |
fef5aeee | 1791 | rec->flags &= ~FTRACE_FL_TRAMP; |
79922b80 | 1792 | |
08f6fba5 SR |
1793 | /* |
1794 | * If any ops wants regs saved for this function | |
1795 | * then all ops will get saved regs. | |
1796 | */ | |
1797 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) | |
1798 | rec->flags |= FTRACE_FL_REGS; | |
ed926f9b | 1799 | } else { |
0376bde1 | 1800 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0)) |
84b6d3e6 | 1801 | return false; |
ed926f9b | 1802 | rec->flags--; |
79922b80 | 1803 | |
4fbb48cb SRRH |
1804 | /* |
1805 | * If the rec had REGS enabled and the ops that is | |
1806 | * being removed had REGS set, then see if there is | |
1807 | * still any ops for this record that wants regs. | |
1808 | * If not, we can stop recording them. | |
1809 | */ | |
0376bde1 | 1810 | if (ftrace_rec_count(rec) > 0 && |
4fbb48cb SRRH |
1811 | rec->flags & FTRACE_FL_REGS && |
1812 | ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1813 | if (!test_rec_ops_needs_regs(rec)) | |
1814 | rec->flags &= ~FTRACE_FL_REGS; | |
1815 | } | |
79922b80 | 1816 | |
fef5aeee SRRH |
1817 | /* |
1818 | * If the rec had TRAMP enabled, then it needs to | |
1819 | * be cleared. As TRAMP can only be enabled iff | |
1820 | * there is only a single ops attached to it. | |
1821 | * In otherwords, always disable it on decrementing. | |
1822 | * In the future, we may set it if rec count is | |
1823 | * decremented to one, and the ops that is left | |
1824 | * has a trampoline. | |
1825 | */ | |
1826 | rec->flags &= ~FTRACE_FL_TRAMP; | |
1827 | ||
79922b80 SRRH |
1828 | /* |
1829 | * flags will be cleared in ftrace_check_record() | |
1830 | * if rec count is zero. | |
1831 | */ | |
ed926f9b SR |
1832 | } |
1833 | count++; | |
84b6d3e6 JO |
1834 | |
1835 | /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */ | |
1836 | update |= ftrace_test_record(rec, 1) != FTRACE_UPDATE_IGNORE; | |
1837 | ||
ed926f9b SR |
1838 | /* Shortcut, if we handled all records, we are done. */ |
1839 | if (!all && count == hash->count) | |
84b6d3e6 | 1840 | return update; |
ed926f9b | 1841 | } while_for_each_ftrace_rec(); |
84b6d3e6 JO |
1842 | |
1843 | return update; | |
ed926f9b SR |
1844 | } |
1845 | ||
84b6d3e6 | 1846 | static bool ftrace_hash_rec_disable(struct ftrace_ops *ops, |
ed926f9b SR |
1847 | int filter_hash) |
1848 | { | |
84b6d3e6 | 1849 | return __ftrace_hash_rec_update(ops, filter_hash, 0); |
ed926f9b SR |
1850 | } |
1851 | ||
84b6d3e6 | 1852 | static bool ftrace_hash_rec_enable(struct ftrace_ops *ops, |
ed926f9b SR |
1853 | int filter_hash) |
1854 | { | |
84b6d3e6 | 1855 | return __ftrace_hash_rec_update(ops, filter_hash, 1); |
ed926f9b SR |
1856 | } |
1857 | ||
84261912 SRRH |
1858 | static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops, |
1859 | int filter_hash, int inc) | |
1860 | { | |
1861 | struct ftrace_ops *op; | |
1862 | ||
1863 | __ftrace_hash_rec_update(ops, filter_hash, inc); | |
1864 | ||
1865 | if (ops->func_hash != &global_ops.local_hash) | |
1866 | return; | |
1867 | ||
1868 | /* | |
1869 | * If the ops shares the global_ops hash, then we need to update | |
1870 | * all ops that are enabled and use this hash. | |
1871 | */ | |
1872 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1873 | /* Already done */ | |
1874 | if (op == ops) | |
1875 | continue; | |
1876 | if (op->func_hash == &global_ops.local_hash) | |
1877 | __ftrace_hash_rec_update(op, filter_hash, inc); | |
1878 | } while_for_each_ftrace_op(op); | |
1879 | } | |
1880 | ||
1881 | static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, | |
1882 | int filter_hash) | |
1883 | { | |
1884 | ftrace_hash_rec_update_modify(ops, filter_hash, 0); | |
1885 | } | |
1886 | ||
1887 | static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, | |
1888 | int filter_hash) | |
1889 | { | |
1890 | ftrace_hash_rec_update_modify(ops, filter_hash, 1); | |
1891 | } | |
1892 | ||
f8b8be8a MH |
1893 | /* |
1894 | * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK | |
1895 | * or no-needed to update, -EBUSY if it detects a conflict of the flag | |
1896 | * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs. | |
1897 | * Note that old_hash and new_hash has below meanings | |
1898 | * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected) | |
1899 | * - If the hash is EMPTY_HASH, it hits nothing | |
1900 | * - Anything else hits the recs which match the hash entries. | |
1901 | */ | |
1902 | static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops, | |
1903 | struct ftrace_hash *old_hash, | |
1904 | struct ftrace_hash *new_hash) | |
1905 | { | |
1906 | struct ftrace_page *pg; | |
1907 | struct dyn_ftrace *rec, *end = NULL; | |
1908 | int in_old, in_new; | |
1909 | ||
1910 | /* Only update if the ops has been registered */ | |
1911 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
1912 | return 0; | |
1913 | ||
1914 | if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY)) | |
1915 | return 0; | |
1916 | ||
1917 | /* | |
1918 | * Since the IPMODIFY is a very address sensitive action, we do not | |
1919 | * allow ftrace_ops to set all functions to new hash. | |
1920 | */ | |
1921 | if (!new_hash || !old_hash) | |
1922 | return -EINVAL; | |
1923 | ||
1924 | /* Update rec->flags */ | |
1925 | do_for_each_ftrace_rec(pg, rec) { | |
546fece4 SRRH |
1926 | |
1927 | if (rec->flags & FTRACE_FL_DISABLED) | |
1928 | continue; | |
1929 | ||
f8b8be8a MH |
1930 | /* We need to update only differences of filter_hash */ |
1931 | in_old = !!ftrace_lookup_ip(old_hash, rec->ip); | |
1932 | in_new = !!ftrace_lookup_ip(new_hash, rec->ip); | |
1933 | if (in_old == in_new) | |
1934 | continue; | |
1935 | ||
1936 | if (in_new) { | |
1937 | /* New entries must ensure no others are using it */ | |
1938 | if (rec->flags & FTRACE_FL_IPMODIFY) | |
1939 | goto rollback; | |
1940 | rec->flags |= FTRACE_FL_IPMODIFY; | |
1941 | } else /* Removed entry */ | |
1942 | rec->flags &= ~FTRACE_FL_IPMODIFY; | |
1943 | } while_for_each_ftrace_rec(); | |
1944 | ||
1945 | return 0; | |
1946 | ||
1947 | rollback: | |
1948 | end = rec; | |
1949 | ||
1950 | /* Roll back what we did above */ | |
1951 | do_for_each_ftrace_rec(pg, rec) { | |
546fece4 SRRH |
1952 | |
1953 | if (rec->flags & FTRACE_FL_DISABLED) | |
1954 | continue; | |
1955 | ||
f8b8be8a MH |
1956 | if (rec == end) |
1957 | goto err_out; | |
1958 | ||
1959 | in_old = !!ftrace_lookup_ip(old_hash, rec->ip); | |
1960 | in_new = !!ftrace_lookup_ip(new_hash, rec->ip); | |
1961 | if (in_old == in_new) | |
1962 | continue; | |
1963 | ||
1964 | if (in_new) | |
1965 | rec->flags &= ~FTRACE_FL_IPMODIFY; | |
1966 | else | |
1967 | rec->flags |= FTRACE_FL_IPMODIFY; | |
1968 | } while_for_each_ftrace_rec(); | |
1969 | ||
1970 | err_out: | |
1971 | return -EBUSY; | |
1972 | } | |
1973 | ||
1974 | static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops) | |
1975 | { | |
1976 | struct ftrace_hash *hash = ops->func_hash->filter_hash; | |
1977 | ||
1978 | if (ftrace_hash_empty(hash)) | |
1979 | hash = NULL; | |
1980 | ||
1981 | return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash); | |
1982 | } | |
1983 | ||
1984 | /* Disabling always succeeds */ | |
1985 | static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops) | |
1986 | { | |
1987 | struct ftrace_hash *hash = ops->func_hash->filter_hash; | |
1988 | ||
1989 | if (ftrace_hash_empty(hash)) | |
1990 | hash = NULL; | |
1991 | ||
1992 | __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH); | |
1993 | } | |
1994 | ||
1995 | static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, | |
1996 | struct ftrace_hash *new_hash) | |
1997 | { | |
1998 | struct ftrace_hash *old_hash = ops->func_hash->filter_hash; | |
1999 | ||
2000 | if (ftrace_hash_empty(old_hash)) | |
2001 | old_hash = NULL; | |
2002 | ||
2003 | if (ftrace_hash_empty(new_hash)) | |
2004 | new_hash = NULL; | |
2005 | ||
2006 | return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash); | |
2007 | } | |
2008 | ||
b05086c7 | 2009 | static void print_ip_ins(const char *fmt, const unsigned char *p) |
b17e8a37 SR |
2010 | { |
2011 | int i; | |
2012 | ||
2013 | printk(KERN_CONT "%s", fmt); | |
2014 | ||
2015 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
2016 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
2017 | } | |
2018 | ||
4fd3279b SRRH |
2019 | static struct ftrace_ops * |
2020 | ftrace_find_tramp_ops_any(struct dyn_ftrace *rec); | |
39daa7b9 SRRH |
2021 | static struct ftrace_ops * |
2022 | ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops); | |
4fd3279b | 2023 | |
02a392a0 | 2024 | enum ftrace_bug_type ftrace_bug_type; |
b05086c7 | 2025 | const void *ftrace_expected; |
02a392a0 SRRH |
2026 | |
2027 | static void print_bug_type(void) | |
2028 | { | |
2029 | switch (ftrace_bug_type) { | |
2030 | case FTRACE_BUG_UNKNOWN: | |
2031 | break; | |
2032 | case FTRACE_BUG_INIT: | |
2033 | pr_info("Initializing ftrace call sites\n"); | |
2034 | break; | |
2035 | case FTRACE_BUG_NOP: | |
2036 | pr_info("Setting ftrace call site to NOP\n"); | |
2037 | break; | |
2038 | case FTRACE_BUG_CALL: | |
2039 | pr_info("Setting ftrace call site to call ftrace function\n"); | |
2040 | break; | |
2041 | case FTRACE_BUG_UPDATE: | |
2042 | pr_info("Updating ftrace call site to call a different ftrace function\n"); | |
2043 | break; | |
2044 | } | |
2045 | } | |
2046 | ||
c88fd863 SR |
2047 | /** |
2048 | * ftrace_bug - report and shutdown function tracer | |
2049 | * @failed: The failed type (EFAULT, EINVAL, EPERM) | |
4fd3279b | 2050 | * @rec: The record that failed |
c88fd863 SR |
2051 | * |
2052 | * The arch code that enables or disables the function tracing | |
2053 | * can call ftrace_bug() when it has detected a problem in | |
2054 | * modifying the code. @failed should be one of either: | |
2055 | * EFAULT - if the problem happens on reading the @ip address | |
2056 | * EINVAL - if what is read at @ip is not what was expected | |
2057 | * EPERM - if the problem happens on writting to the @ip address | |
2058 | */ | |
4fd3279b | 2059 | void ftrace_bug(int failed, struct dyn_ftrace *rec) |
b17e8a37 | 2060 | { |
4fd3279b SRRH |
2061 | unsigned long ip = rec ? rec->ip : 0; |
2062 | ||
b17e8a37 SR |
2063 | switch (failed) { |
2064 | case -EFAULT: | |
2065 | FTRACE_WARN_ON_ONCE(1); | |
2066 | pr_info("ftrace faulted on modifying "); | |
2067 | print_ip_sym(ip); | |
2068 | break; | |
2069 | case -EINVAL: | |
2070 | FTRACE_WARN_ON_ONCE(1); | |
2071 | pr_info("ftrace failed to modify "); | |
2072 | print_ip_sym(ip); | |
b05086c7 | 2073 | print_ip_ins(" actual: ", (unsigned char *)ip); |
4fd3279b | 2074 | pr_cont("\n"); |
b05086c7 SRRH |
2075 | if (ftrace_expected) { |
2076 | print_ip_ins(" expected: ", ftrace_expected); | |
2077 | pr_cont("\n"); | |
2078 | } | |
b17e8a37 SR |
2079 | break; |
2080 | case -EPERM: | |
2081 | FTRACE_WARN_ON_ONCE(1); | |
2082 | pr_info("ftrace faulted on writing "); | |
2083 | print_ip_sym(ip); | |
2084 | break; | |
2085 | default: | |
2086 | FTRACE_WARN_ON_ONCE(1); | |
2087 | pr_info("ftrace faulted on unknown error "); | |
2088 | print_ip_sym(ip); | |
2089 | } | |
02a392a0 | 2090 | print_bug_type(); |
4fd3279b SRRH |
2091 | if (rec) { |
2092 | struct ftrace_ops *ops = NULL; | |
2093 | ||
2094 | pr_info("ftrace record flags: %lx\n", rec->flags); | |
2095 | pr_cont(" (%ld)%s", ftrace_rec_count(rec), | |
2096 | rec->flags & FTRACE_FL_REGS ? " R" : " "); | |
2097 | if (rec->flags & FTRACE_FL_TRAMP_EN) { | |
2098 | ops = ftrace_find_tramp_ops_any(rec); | |
39daa7b9 SRRH |
2099 | if (ops) { |
2100 | do { | |
2101 | pr_cont("\ttramp: %pS (%pS)", | |
2102 | (void *)ops->trampoline, | |
2103 | (void *)ops->func); | |
2104 | ops = ftrace_find_tramp_ops_next(rec, ops); | |
2105 | } while (ops); | |
2106 | } else | |
4fd3279b SRRH |
2107 | pr_cont("\ttramp: ERROR!"); |
2108 | ||
2109 | } | |
2110 | ip = ftrace_get_addr_curr(rec); | |
39daa7b9 | 2111 | pr_cont("\n expected tramp: %lx\n", ip); |
4fd3279b | 2112 | } |
b17e8a37 SR |
2113 | } |
2114 | ||
c88fd863 | 2115 | static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update) |
5072c59f | 2116 | { |
64fbcd16 | 2117 | unsigned long flag = 0UL; |
e7d3737e | 2118 | |
02a392a0 SRRH |
2119 | ftrace_bug_type = FTRACE_BUG_UNKNOWN; |
2120 | ||
b7ffffbb SRRH |
2121 | if (rec->flags & FTRACE_FL_DISABLED) |
2122 | return FTRACE_UPDATE_IGNORE; | |
2123 | ||
982c350b | 2124 | /* |
30fb6aa7 | 2125 | * If we are updating calls: |
982c350b | 2126 | * |
ed926f9b SR |
2127 | * If the record has a ref count, then we need to enable it |
2128 | * because someone is using it. | |
982c350b | 2129 | * |
ed926f9b SR |
2130 | * Otherwise we make sure its disabled. |
2131 | * | |
30fb6aa7 | 2132 | * If we are disabling calls, then disable all records that |
ed926f9b | 2133 | * are enabled. |
982c350b | 2134 | */ |
0376bde1 | 2135 | if (enable && ftrace_rec_count(rec)) |
ed926f9b | 2136 | flag = FTRACE_FL_ENABLED; |
982c350b | 2137 | |
08f6fba5 | 2138 | /* |
79922b80 SRRH |
2139 | * If enabling and the REGS flag does not match the REGS_EN, or |
2140 | * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore | |
2141 | * this record. Set flags to fail the compare against ENABLED. | |
08f6fba5 | 2142 | */ |
79922b80 SRRH |
2143 | if (flag) { |
2144 | if (!(rec->flags & FTRACE_FL_REGS) != | |
2145 | !(rec->flags & FTRACE_FL_REGS_EN)) | |
2146 | flag |= FTRACE_FL_REGS; | |
2147 | ||
2148 | if (!(rec->flags & FTRACE_FL_TRAMP) != | |
2149 | !(rec->flags & FTRACE_FL_TRAMP_EN)) | |
2150 | flag |= FTRACE_FL_TRAMP; | |
2151 | } | |
08f6fba5 | 2152 | |
64fbcd16 XG |
2153 | /* If the state of this record hasn't changed, then do nothing */ |
2154 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
c88fd863 | 2155 | return FTRACE_UPDATE_IGNORE; |
982c350b | 2156 | |
64fbcd16 | 2157 | if (flag) { |
08f6fba5 SR |
2158 | /* Save off if rec is being enabled (for return value) */ |
2159 | flag ^= rec->flags & FTRACE_FL_ENABLED; | |
2160 | ||
2161 | if (update) { | |
c88fd863 | 2162 | rec->flags |= FTRACE_FL_ENABLED; |
08f6fba5 SR |
2163 | if (flag & FTRACE_FL_REGS) { |
2164 | if (rec->flags & FTRACE_FL_REGS) | |
2165 | rec->flags |= FTRACE_FL_REGS_EN; | |
2166 | else | |
2167 | rec->flags &= ~FTRACE_FL_REGS_EN; | |
2168 | } | |
79922b80 SRRH |
2169 | if (flag & FTRACE_FL_TRAMP) { |
2170 | if (rec->flags & FTRACE_FL_TRAMP) | |
2171 | rec->flags |= FTRACE_FL_TRAMP_EN; | |
2172 | else | |
2173 | rec->flags &= ~FTRACE_FL_TRAMP_EN; | |
2174 | } | |
08f6fba5 SR |
2175 | } |
2176 | ||
2177 | /* | |
2178 | * If this record is being updated from a nop, then | |
2179 | * return UPDATE_MAKE_CALL. | |
08f6fba5 SR |
2180 | * Otherwise, |
2181 | * return UPDATE_MODIFY_CALL to tell the caller to convert | |
f1b2f2bd | 2182 | * from the save regs, to a non-save regs function or |
79922b80 | 2183 | * vice versa, or from a trampoline call. |
08f6fba5 | 2184 | */ |
02a392a0 SRRH |
2185 | if (flag & FTRACE_FL_ENABLED) { |
2186 | ftrace_bug_type = FTRACE_BUG_CALL; | |
08f6fba5 | 2187 | return FTRACE_UPDATE_MAKE_CALL; |
02a392a0 | 2188 | } |
f1b2f2bd | 2189 | |
02a392a0 | 2190 | ftrace_bug_type = FTRACE_BUG_UPDATE; |
f1b2f2bd | 2191 | return FTRACE_UPDATE_MODIFY_CALL; |
c88fd863 SR |
2192 | } |
2193 | ||
08f6fba5 SR |
2194 | if (update) { |
2195 | /* If there's no more users, clear all flags */ | |
0376bde1 | 2196 | if (!ftrace_rec_count(rec)) |
08f6fba5 SR |
2197 | rec->flags = 0; |
2198 | else | |
b24d443b SRRH |
2199 | /* |
2200 | * Just disable the record, but keep the ops TRAMP | |
2201 | * and REGS states. The _EN flags must be disabled though. | |
2202 | */ | |
2203 | rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN | | |
2204 | FTRACE_FL_REGS_EN); | |
08f6fba5 | 2205 | } |
c88fd863 | 2206 | |
02a392a0 | 2207 | ftrace_bug_type = FTRACE_BUG_NOP; |
c88fd863 SR |
2208 | return FTRACE_UPDATE_MAKE_NOP; |
2209 | } | |
2210 | ||
2211 | /** | |
2212 | * ftrace_update_record, set a record that now is tracing or not | |
2213 | * @rec: the record to update | |
2214 | * @enable: set to 1 if the record is tracing, zero to force disable | |
2215 | * | |
2216 | * The records that represent all functions that can be traced need | |
2217 | * to be updated when tracing has been enabled. | |
2218 | */ | |
2219 | int ftrace_update_record(struct dyn_ftrace *rec, int enable) | |
2220 | { | |
2221 | return ftrace_check_record(rec, enable, 1); | |
2222 | } | |
2223 | ||
2224 | /** | |
2225 | * ftrace_test_record, check if the record has been enabled or not | |
2226 | * @rec: the record to test | |
2227 | * @enable: set to 1 to check if enabled, 0 if it is disabled | |
2228 | * | |
2229 | * The arch code may need to test if a record is already set to | |
2230 | * tracing to determine how to modify the function code that it | |
2231 | * represents. | |
2232 | */ | |
2233 | int ftrace_test_record(struct dyn_ftrace *rec, int enable) | |
2234 | { | |
2235 | return ftrace_check_record(rec, enable, 0); | |
2236 | } | |
2237 | ||
5fecaa04 SRRH |
2238 | static struct ftrace_ops * |
2239 | ftrace_find_tramp_ops_any(struct dyn_ftrace *rec) | |
2240 | { | |
2241 | struct ftrace_ops *op; | |
fef5aeee | 2242 | unsigned long ip = rec->ip; |
5fecaa04 SRRH |
2243 | |
2244 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2245 | ||
2246 | if (!op->trampoline) | |
2247 | continue; | |
2248 | ||
fef5aeee | 2249 | if (hash_contains_ip(ip, op->func_hash)) |
5fecaa04 SRRH |
2250 | return op; |
2251 | } while_for_each_ftrace_op(op); | |
2252 | ||
2253 | return NULL; | |
2254 | } | |
2255 | ||
39daa7b9 SRRH |
2256 | static struct ftrace_ops * |
2257 | ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, | |
2258 | struct ftrace_ops *op) | |
2259 | { | |
2260 | unsigned long ip = rec->ip; | |
2261 | ||
2262 | while_for_each_ftrace_op(op) { | |
2263 | ||
2264 | if (!op->trampoline) | |
2265 | continue; | |
2266 | ||
2267 | if (hash_contains_ip(ip, op->func_hash)) | |
2268 | return op; | |
2269 | } | |
2270 | ||
2271 | return NULL; | |
2272 | } | |
2273 | ||
79922b80 SRRH |
2274 | static struct ftrace_ops * |
2275 | ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec) | |
2276 | { | |
2277 | struct ftrace_ops *op; | |
fef5aeee | 2278 | unsigned long ip = rec->ip; |
79922b80 | 2279 | |
fef5aeee SRRH |
2280 | /* |
2281 | * Need to check removed ops first. | |
2282 | * If they are being removed, and this rec has a tramp, | |
2283 | * and this rec is in the ops list, then it would be the | |
2284 | * one with the tramp. | |
2285 | */ | |
2286 | if (removed_ops) { | |
2287 | if (hash_contains_ip(ip, &removed_ops->old_hash)) | |
79922b80 SRRH |
2288 | return removed_ops; |
2289 | } | |
2290 | ||
fef5aeee SRRH |
2291 | /* |
2292 | * Need to find the current trampoline for a rec. | |
2293 | * Now, a trampoline is only attached to a rec if there | |
2294 | * was a single 'ops' attached to it. But this can be called | |
2295 | * when we are adding another op to the rec or removing the | |
2296 | * current one. Thus, if the op is being added, we can | |
2297 | * ignore it because it hasn't attached itself to the rec | |
4fc40904 SRRH |
2298 | * yet. |
2299 | * | |
2300 | * If an ops is being modified (hooking to different functions) | |
2301 | * then we don't care about the new functions that are being | |
2302 | * added, just the old ones (that are probably being removed). | |
2303 | * | |
2304 | * If we are adding an ops to a function that already is using | |
2305 | * a trampoline, it needs to be removed (trampolines are only | |
2306 | * for single ops connected), then an ops that is not being | |
2307 | * modified also needs to be checked. | |
fef5aeee | 2308 | */ |
79922b80 | 2309 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
fef5aeee SRRH |
2310 | |
2311 | if (!op->trampoline) | |
2312 | continue; | |
2313 | ||
2314 | /* | |
2315 | * If the ops is being added, it hasn't gotten to | |
2316 | * the point to be removed from this tree yet. | |
2317 | */ | |
2318 | if (op->flags & FTRACE_OPS_FL_ADDING) | |
79922b80 SRRH |
2319 | continue; |
2320 | ||
4fc40904 | 2321 | |
fef5aeee | 2322 | /* |
4fc40904 SRRH |
2323 | * If the ops is being modified and is in the old |
2324 | * hash, then it is probably being removed from this | |
2325 | * function. | |
fef5aeee | 2326 | */ |
fef5aeee SRRH |
2327 | if ((op->flags & FTRACE_OPS_FL_MODIFYING) && |
2328 | hash_contains_ip(ip, &op->old_hash)) | |
79922b80 | 2329 | return op; |
4fc40904 SRRH |
2330 | /* |
2331 | * If the ops is not being added or modified, and it's | |
2332 | * in its normal filter hash, then this must be the one | |
2333 | * we want! | |
2334 | */ | |
2335 | if (!(op->flags & FTRACE_OPS_FL_MODIFYING) && | |
2336 | hash_contains_ip(ip, op->func_hash)) | |
2337 | return op; | |
79922b80 SRRH |
2338 | |
2339 | } while_for_each_ftrace_op(op); | |
2340 | ||
2341 | return NULL; | |
2342 | } | |
2343 | ||
2344 | static struct ftrace_ops * | |
2345 | ftrace_find_tramp_ops_new(struct dyn_ftrace *rec) | |
2346 | { | |
2347 | struct ftrace_ops *op; | |
fef5aeee | 2348 | unsigned long ip = rec->ip; |
79922b80 SRRH |
2349 | |
2350 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2351 | /* pass rec in as regs to have non-NULL val */ | |
fef5aeee | 2352 | if (hash_contains_ip(ip, op->func_hash)) |
79922b80 SRRH |
2353 | return op; |
2354 | } while_for_each_ftrace_op(op); | |
2355 | ||
2356 | return NULL; | |
2357 | } | |
2358 | ||
7413af1f SRRH |
2359 | /** |
2360 | * ftrace_get_addr_new - Get the call address to set to | |
2361 | * @rec: The ftrace record descriptor | |
2362 | * | |
2363 | * If the record has the FTRACE_FL_REGS set, that means that it | |
2364 | * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS | |
2365 | * is not not set, then it wants to convert to the normal callback. | |
2366 | * | |
2367 | * Returns the address of the trampoline to set to | |
2368 | */ | |
2369 | unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec) | |
2370 | { | |
79922b80 SRRH |
2371 | struct ftrace_ops *ops; |
2372 | ||
2373 | /* Trampolines take precedence over regs */ | |
2374 | if (rec->flags & FTRACE_FL_TRAMP) { | |
2375 | ops = ftrace_find_tramp_ops_new(rec); | |
2376 | if (FTRACE_WARN_ON(!ops || !ops->trampoline)) { | |
bce0b6c5 SRRH |
2377 | pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n", |
2378 | (void *)rec->ip, (void *)rec->ip, rec->flags); | |
79922b80 SRRH |
2379 | /* Ftrace is shutting down, return anything */ |
2380 | return (unsigned long)FTRACE_ADDR; | |
2381 | } | |
2382 | return ops->trampoline; | |
2383 | } | |
2384 | ||
7413af1f SRRH |
2385 | if (rec->flags & FTRACE_FL_REGS) |
2386 | return (unsigned long)FTRACE_REGS_ADDR; | |
2387 | else | |
2388 | return (unsigned long)FTRACE_ADDR; | |
2389 | } | |
2390 | ||
2391 | /** | |
2392 | * ftrace_get_addr_curr - Get the call address that is already there | |
2393 | * @rec: The ftrace record descriptor | |
2394 | * | |
2395 | * The FTRACE_FL_REGS_EN is set when the record already points to | |
2396 | * a function that saves all the regs. Basically the '_EN' version | |
2397 | * represents the current state of the function. | |
2398 | * | |
2399 | * Returns the address of the trampoline that is currently being called | |
2400 | */ | |
2401 | unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec) | |
2402 | { | |
79922b80 SRRH |
2403 | struct ftrace_ops *ops; |
2404 | ||
2405 | /* Trampolines take precedence over regs */ | |
2406 | if (rec->flags & FTRACE_FL_TRAMP_EN) { | |
2407 | ops = ftrace_find_tramp_ops_curr(rec); | |
2408 | if (FTRACE_WARN_ON(!ops)) { | |
a395d6a7 JP |
2409 | pr_warn("Bad trampoline accounting at: %p (%pS)\n", |
2410 | (void *)rec->ip, (void *)rec->ip); | |
79922b80 SRRH |
2411 | /* Ftrace is shutting down, return anything */ |
2412 | return (unsigned long)FTRACE_ADDR; | |
2413 | } | |
2414 | return ops->trampoline; | |
2415 | } | |
2416 | ||
7413af1f SRRH |
2417 | if (rec->flags & FTRACE_FL_REGS_EN) |
2418 | return (unsigned long)FTRACE_REGS_ADDR; | |
2419 | else | |
2420 | return (unsigned long)FTRACE_ADDR; | |
2421 | } | |
2422 | ||
c88fd863 SR |
2423 | static int |
2424 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) | |
2425 | { | |
08f6fba5 | 2426 | unsigned long ftrace_old_addr; |
c88fd863 SR |
2427 | unsigned long ftrace_addr; |
2428 | int ret; | |
2429 | ||
7c0868e0 | 2430 | ftrace_addr = ftrace_get_addr_new(rec); |
c88fd863 | 2431 | |
7c0868e0 SRRH |
2432 | /* This needs to be done before we call ftrace_update_record */ |
2433 | ftrace_old_addr = ftrace_get_addr_curr(rec); | |
2434 | ||
2435 | ret = ftrace_update_record(rec, enable); | |
08f6fba5 | 2436 | |
02a392a0 SRRH |
2437 | ftrace_bug_type = FTRACE_BUG_UNKNOWN; |
2438 | ||
c88fd863 SR |
2439 | switch (ret) { |
2440 | case FTRACE_UPDATE_IGNORE: | |
2441 | return 0; | |
2442 | ||
2443 | case FTRACE_UPDATE_MAKE_CALL: | |
02a392a0 | 2444 | ftrace_bug_type = FTRACE_BUG_CALL; |
64fbcd16 | 2445 | return ftrace_make_call(rec, ftrace_addr); |
c88fd863 SR |
2446 | |
2447 | case FTRACE_UPDATE_MAKE_NOP: | |
02a392a0 | 2448 | ftrace_bug_type = FTRACE_BUG_NOP; |
39b5552c | 2449 | return ftrace_make_nop(NULL, rec, ftrace_old_addr); |
08f6fba5 | 2450 | |
08f6fba5 | 2451 | case FTRACE_UPDATE_MODIFY_CALL: |
02a392a0 | 2452 | ftrace_bug_type = FTRACE_BUG_UPDATE; |
08f6fba5 | 2453 | return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr); |
5072c59f SR |
2454 | } |
2455 | ||
c88fd863 | 2456 | return -1; /* unknow ftrace bug */ |
5072c59f SR |
2457 | } |
2458 | ||
e4f5d544 | 2459 | void __weak ftrace_replace_code(int enable) |
3c1720f0 | 2460 | { |
3c1720f0 SR |
2461 | struct dyn_ftrace *rec; |
2462 | struct ftrace_page *pg; | |
6a24a244 | 2463 | int failed; |
3c1720f0 | 2464 | |
45a4a237 SR |
2465 | if (unlikely(ftrace_disabled)) |
2466 | return; | |
2467 | ||
265c831c | 2468 | do_for_each_ftrace_rec(pg, rec) { |
546fece4 SRRH |
2469 | |
2470 | if (rec->flags & FTRACE_FL_DISABLED) | |
2471 | continue; | |
2472 | ||
e4f5d544 | 2473 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 2474 | if (failed) { |
4fd3279b | 2475 | ftrace_bug(failed, rec); |
3279ba37 SR |
2476 | /* Stop processing */ |
2477 | return; | |
3c1720f0 | 2478 | } |
265c831c | 2479 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
2480 | } |
2481 | ||
c88fd863 SR |
2482 | struct ftrace_rec_iter { |
2483 | struct ftrace_page *pg; | |
2484 | int index; | |
2485 | }; | |
2486 | ||
2487 | /** | |
2488 | * ftrace_rec_iter_start, start up iterating over traced functions | |
2489 | * | |
2490 | * Returns an iterator handle that is used to iterate over all | |
2491 | * the records that represent address locations where functions | |
2492 | * are traced. | |
2493 | * | |
2494 | * May return NULL if no records are available. | |
2495 | */ | |
2496 | struct ftrace_rec_iter *ftrace_rec_iter_start(void) | |
2497 | { | |
2498 | /* | |
2499 | * We only use a single iterator. | |
2500 | * Protected by the ftrace_lock mutex. | |
2501 | */ | |
2502 | static struct ftrace_rec_iter ftrace_rec_iter; | |
2503 | struct ftrace_rec_iter *iter = &ftrace_rec_iter; | |
2504 | ||
2505 | iter->pg = ftrace_pages_start; | |
2506 | iter->index = 0; | |
2507 | ||
2508 | /* Could have empty pages */ | |
2509 | while (iter->pg && !iter->pg->index) | |
2510 | iter->pg = iter->pg->next; | |
2511 | ||
2512 | if (!iter->pg) | |
2513 | return NULL; | |
2514 | ||
2515 | return iter; | |
2516 | } | |
2517 | ||
2518 | /** | |
2519 | * ftrace_rec_iter_next, get the next record to process. | |
2520 | * @iter: The handle to the iterator. | |
2521 | * | |
2522 | * Returns the next iterator after the given iterator @iter. | |
2523 | */ | |
2524 | struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) | |
2525 | { | |
2526 | iter->index++; | |
2527 | ||
2528 | if (iter->index >= iter->pg->index) { | |
2529 | iter->pg = iter->pg->next; | |
2530 | iter->index = 0; | |
2531 | ||
2532 | /* Could have empty pages */ | |
2533 | while (iter->pg && !iter->pg->index) | |
2534 | iter->pg = iter->pg->next; | |
2535 | } | |
2536 | ||
2537 | if (!iter->pg) | |
2538 | return NULL; | |
2539 | ||
2540 | return iter; | |
2541 | } | |
2542 | ||
2543 | /** | |
2544 | * ftrace_rec_iter_record, get the record at the iterator location | |
2545 | * @iter: The current iterator location | |
2546 | * | |
2547 | * Returns the record that the current @iter is at. | |
2548 | */ | |
2549 | struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) | |
2550 | { | |
2551 | return &iter->pg->records[iter->index]; | |
2552 | } | |
2553 | ||
492a7ea5 | 2554 | static int |
31e88909 | 2555 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 | 2556 | { |
593eb8a2 | 2557 | int ret; |
3c1720f0 | 2558 | |
45a4a237 SR |
2559 | if (unlikely(ftrace_disabled)) |
2560 | return 0; | |
2561 | ||
25aac9dc | 2562 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 2563 | if (ret) { |
02a392a0 | 2564 | ftrace_bug_type = FTRACE_BUG_INIT; |
4fd3279b | 2565 | ftrace_bug(ret, rec); |
492a7ea5 | 2566 | return 0; |
37ad5084 | 2567 | } |
492a7ea5 | 2568 | return 1; |
3c1720f0 SR |
2569 | } |
2570 | ||
000ab691 SR |
2571 | /* |
2572 | * archs can override this function if they must do something | |
2573 | * before the modifying code is performed. | |
2574 | */ | |
2575 | int __weak ftrace_arch_code_modify_prepare(void) | |
2576 | { | |
2577 | return 0; | |
2578 | } | |
2579 | ||
2580 | /* | |
2581 | * archs can override this function if they must do something | |
2582 | * after the modifying code is performed. | |
2583 | */ | |
2584 | int __weak ftrace_arch_code_modify_post_process(void) | |
2585 | { | |
2586 | return 0; | |
2587 | } | |
2588 | ||
8ed3e2cf | 2589 | void ftrace_modify_all_code(int command) |
3d083395 | 2590 | { |
59338f75 | 2591 | int update = command & FTRACE_UPDATE_TRACE_FUNC; |
cd21067f | 2592 | int err = 0; |
59338f75 SRRH |
2593 | |
2594 | /* | |
2595 | * If the ftrace_caller calls a ftrace_ops func directly, | |
2596 | * we need to make sure that it only traces functions it | |
2597 | * expects to trace. When doing the switch of functions, | |
2598 | * we need to update to the ftrace_ops_list_func first | |
2599 | * before the transition between old and new calls are set, | |
2600 | * as the ftrace_ops_list_func will check the ops hashes | |
2601 | * to make sure the ops are having the right functions | |
2602 | * traced. | |
2603 | */ | |
cd21067f PM |
2604 | if (update) { |
2605 | err = ftrace_update_ftrace_func(ftrace_ops_list_func); | |
2606 | if (FTRACE_WARN_ON(err)) | |
2607 | return; | |
2608 | } | |
59338f75 | 2609 | |
8ed3e2cf | 2610 | if (command & FTRACE_UPDATE_CALLS) |
d61f82d0 | 2611 | ftrace_replace_code(1); |
8ed3e2cf | 2612 | else if (command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
2613 | ftrace_replace_code(0); |
2614 | ||
405e1d83 SRRH |
2615 | if (update && ftrace_trace_function != ftrace_ops_list_func) { |
2616 | function_trace_op = set_function_trace_op; | |
2617 | smp_wmb(); | |
2618 | /* If irqs are disabled, we are in stop machine */ | |
2619 | if (!irqs_disabled()) | |
2620 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
cd21067f PM |
2621 | err = ftrace_update_ftrace_func(ftrace_trace_function); |
2622 | if (FTRACE_WARN_ON(err)) | |
2623 | return; | |
405e1d83 | 2624 | } |
d61f82d0 | 2625 | |
8ed3e2cf | 2626 | if (command & FTRACE_START_FUNC_RET) |
cd21067f | 2627 | err = ftrace_enable_ftrace_graph_caller(); |
8ed3e2cf | 2628 | else if (command & FTRACE_STOP_FUNC_RET) |
cd21067f PM |
2629 | err = ftrace_disable_ftrace_graph_caller(); |
2630 | FTRACE_WARN_ON(err); | |
8ed3e2cf SR |
2631 | } |
2632 | ||
2633 | static int __ftrace_modify_code(void *data) | |
2634 | { | |
2635 | int *command = data; | |
2636 | ||
2637 | ftrace_modify_all_code(*command); | |
5a45cfe1 | 2638 | |
d61f82d0 | 2639 | return 0; |
3d083395 SR |
2640 | } |
2641 | ||
c88fd863 SR |
2642 | /** |
2643 | * ftrace_run_stop_machine, go back to the stop machine method | |
2644 | * @command: The command to tell ftrace what to do | |
2645 | * | |
2646 | * If an arch needs to fall back to the stop machine method, the | |
2647 | * it can call this function. | |
2648 | */ | |
2649 | void ftrace_run_stop_machine(int command) | |
2650 | { | |
2651 | stop_machine(__ftrace_modify_code, &command, NULL); | |
2652 | } | |
2653 | ||
2654 | /** | |
2655 | * arch_ftrace_update_code, modify the code to trace or not trace | |
2656 | * @command: The command that needs to be done | |
2657 | * | |
2658 | * Archs can override this function if it does not need to | |
2659 | * run stop_machine() to modify code. | |
2660 | */ | |
2661 | void __weak arch_ftrace_update_code(int command) | |
2662 | { | |
2663 | ftrace_run_stop_machine(command); | |
2664 | } | |
2665 | ||
e309b41d | 2666 | static void ftrace_run_update_code(int command) |
3d083395 | 2667 | { |
000ab691 SR |
2668 | int ret; |
2669 | ||
2670 | ret = ftrace_arch_code_modify_prepare(); | |
2671 | FTRACE_WARN_ON(ret); | |
2672 | if (ret) | |
2673 | return; | |
2674 | ||
c88fd863 SR |
2675 | /* |
2676 | * By default we use stop_machine() to modify the code. | |
2677 | * But archs can do what ever they want as long as it | |
2678 | * is safe. The stop_machine() is the safest, but also | |
2679 | * produces the most overhead. | |
2680 | */ | |
2681 | arch_ftrace_update_code(command); | |
2682 | ||
000ab691 SR |
2683 | ret = ftrace_arch_code_modify_post_process(); |
2684 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
2685 | } |
2686 | ||
8252ecf3 | 2687 | static void ftrace_run_modify_code(struct ftrace_ops *ops, int command, |
7485058e | 2688 | struct ftrace_ops_hash *old_hash) |
e1effa01 SRRH |
2689 | { |
2690 | ops->flags |= FTRACE_OPS_FL_MODIFYING; | |
7485058e SRRH |
2691 | ops->old_hash.filter_hash = old_hash->filter_hash; |
2692 | ops->old_hash.notrace_hash = old_hash->notrace_hash; | |
e1effa01 | 2693 | ftrace_run_update_code(command); |
8252ecf3 | 2694 | ops->old_hash.filter_hash = NULL; |
7485058e | 2695 | ops->old_hash.notrace_hash = NULL; |
e1effa01 SRRH |
2696 | ops->flags &= ~FTRACE_OPS_FL_MODIFYING; |
2697 | } | |
2698 | ||
d61f82d0 | 2699 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 2700 | static int ftrace_start_up; |
df4fc315 | 2701 | |
12cce594 SRRH |
2702 | void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops) |
2703 | { | |
2704 | } | |
2705 | ||
df4fc315 SR |
2706 | static void ftrace_startup_enable(int command) |
2707 | { | |
2708 | if (saved_ftrace_func != ftrace_trace_function) { | |
2709 | saved_ftrace_func = ftrace_trace_function; | |
2710 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2711 | } | |
2712 | ||
2713 | if (!command || !ftrace_enabled) | |
2714 | return; | |
2715 | ||
2716 | ftrace_run_update_code(command); | |
2717 | } | |
d61f82d0 | 2718 | |
e1effa01 SRRH |
2719 | static void ftrace_startup_all(int command) |
2720 | { | |
2721 | update_all_ops = true; | |
2722 | ftrace_startup_enable(command); | |
2723 | update_all_ops = false; | |
2724 | } | |
2725 | ||
a1cd6173 | 2726 | static int ftrace_startup(struct ftrace_ops *ops, int command) |
3d083395 | 2727 | { |
8a56d776 | 2728 | int ret; |
b848914c | 2729 | |
4eebcc81 | 2730 | if (unlikely(ftrace_disabled)) |
a1cd6173 | 2731 | return -ENODEV; |
4eebcc81 | 2732 | |
8a56d776 SRRH |
2733 | ret = __register_ftrace_function(ops); |
2734 | if (ret) | |
2735 | return ret; | |
2736 | ||
60a7ecf4 | 2737 | ftrace_start_up++; |
d61f82d0 | 2738 | |
e1effa01 SRRH |
2739 | /* |
2740 | * Note that ftrace probes uses this to start up | |
2741 | * and modify functions it will probe. But we still | |
2742 | * set the ADDING flag for modification, as probes | |
2743 | * do not have trampolines. If they add them in the | |
2744 | * future, then the probes will need to distinguish | |
2745 | * between adding and updating probes. | |
2746 | */ | |
2747 | ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING; | |
66209a5b | 2748 | |
f8b8be8a MH |
2749 | ret = ftrace_hash_ipmodify_enable(ops); |
2750 | if (ret < 0) { | |
2751 | /* Rollback registration process */ | |
2752 | __unregister_ftrace_function(ops); | |
2753 | ftrace_start_up--; | |
2754 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; | |
2755 | return ret; | |
2756 | } | |
2757 | ||
7f50d06b JO |
2758 | if (ftrace_hash_rec_enable(ops, 1)) |
2759 | command |= FTRACE_UPDATE_CALLS; | |
ed926f9b | 2760 | |
df4fc315 | 2761 | ftrace_startup_enable(command); |
a1cd6173 | 2762 | |
e1effa01 SRRH |
2763 | ops->flags &= ~FTRACE_OPS_FL_ADDING; |
2764 | ||
a1cd6173 | 2765 | return 0; |
3d083395 SR |
2766 | } |
2767 | ||
8a56d776 | 2768 | static int ftrace_shutdown(struct ftrace_ops *ops, int command) |
3d083395 | 2769 | { |
8a56d776 | 2770 | int ret; |
b848914c | 2771 | |
4eebcc81 | 2772 | if (unlikely(ftrace_disabled)) |
8a56d776 SRRH |
2773 | return -ENODEV; |
2774 | ||
2775 | ret = __unregister_ftrace_function(ops); | |
2776 | if (ret) | |
2777 | return ret; | |
4eebcc81 | 2778 | |
60a7ecf4 | 2779 | ftrace_start_up--; |
9ea1a153 FW |
2780 | /* |
2781 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
2782 | * critical but the ftrace_call callers may be never nopped again after | |
2783 | * further ftrace uses. | |
2784 | */ | |
2785 | WARN_ON_ONCE(ftrace_start_up < 0); | |
2786 | ||
f8b8be8a MH |
2787 | /* Disabling ipmodify never fails */ |
2788 | ftrace_hash_ipmodify_disable(ops); | |
ed926f9b | 2789 | |
7f50d06b JO |
2790 | if (ftrace_hash_rec_disable(ops, 1)) |
2791 | command |= FTRACE_UPDATE_CALLS; | |
b848914c | 2792 | |
7f50d06b | 2793 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
3d083395 | 2794 | |
d61f82d0 SR |
2795 | if (saved_ftrace_func != ftrace_trace_function) { |
2796 | saved_ftrace_func = ftrace_trace_function; | |
2797 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2798 | } | |
3d083395 | 2799 | |
a4c35ed2 SRRH |
2800 | if (!command || !ftrace_enabled) { |
2801 | /* | |
edb096e0 SRV |
2802 | * If these are dynamic or per_cpu ops, they still |
2803 | * need their data freed. Since, function tracing is | |
a4c35ed2 SRRH |
2804 | * not currently active, we can just free them |
2805 | * without synchronizing all CPUs. | |
2806 | */ | |
b3a88803 | 2807 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) |
edb096e0 SRV |
2808 | goto free_ops; |
2809 | ||
8a56d776 | 2810 | return 0; |
a4c35ed2 | 2811 | } |
d61f82d0 | 2812 | |
79922b80 SRRH |
2813 | /* |
2814 | * If the ops uses a trampoline, then it needs to be | |
2815 | * tested first on update. | |
2816 | */ | |
e1effa01 | 2817 | ops->flags |= FTRACE_OPS_FL_REMOVING; |
79922b80 SRRH |
2818 | removed_ops = ops; |
2819 | ||
fef5aeee SRRH |
2820 | /* The trampoline logic checks the old hashes */ |
2821 | ops->old_hash.filter_hash = ops->func_hash->filter_hash; | |
2822 | ops->old_hash.notrace_hash = ops->func_hash->notrace_hash; | |
2823 | ||
d61f82d0 | 2824 | ftrace_run_update_code(command); |
a4c35ed2 | 2825 | |
84bde62c SRRH |
2826 | /* |
2827 | * If there's no more ops registered with ftrace, run a | |
2828 | * sanity check to make sure all rec flags are cleared. | |
2829 | */ | |
f86f4180 CZ |
2830 | if (rcu_dereference_protected(ftrace_ops_list, |
2831 | lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { | |
84bde62c SRRH |
2832 | struct ftrace_page *pg; |
2833 | struct dyn_ftrace *rec; | |
2834 | ||
2835 | do_for_each_ftrace_rec(pg, rec) { | |
977c1f9c | 2836 | if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_FL_DISABLED)) |
84bde62c SRRH |
2837 | pr_warn(" %pS flags:%lx\n", |
2838 | (void *)rec->ip, rec->flags); | |
2839 | } while_for_each_ftrace_rec(); | |
2840 | } | |
2841 | ||
fef5aeee SRRH |
2842 | ops->old_hash.filter_hash = NULL; |
2843 | ops->old_hash.notrace_hash = NULL; | |
2844 | ||
2845 | removed_ops = NULL; | |
e1effa01 | 2846 | ops->flags &= ~FTRACE_OPS_FL_REMOVING; |
79922b80 | 2847 | |
a4c35ed2 SRRH |
2848 | /* |
2849 | * Dynamic ops may be freed, we must make sure that all | |
2850 | * callers are done before leaving this function. | |
ba27f2bc | 2851 | * The same goes for freeing the per_cpu data of the per_cpu |
a4c35ed2 | 2852 | * ops. |
a4c35ed2 | 2853 | */ |
b3a88803 | 2854 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) { |
0598e4f0 SRV |
2855 | /* |
2856 | * We need to do a hard force of sched synchronization. | |
2857 | * This is because we use preempt_disable() to do RCU, but | |
2858 | * the function tracers can be called where RCU is not watching | |
2859 | * (like before user_exit()). We can not rely on the RCU | |
2860 | * infrastructure to do the synchronization, thus we must do it | |
2861 | * ourselves. | |
2862 | */ | |
a4c35ed2 SRRH |
2863 | schedule_on_each_cpu(ftrace_sync); |
2864 | ||
0598e4f0 SRV |
2865 | /* |
2866 | * When the kernel is preeptive, tasks can be preempted | |
2867 | * while on a ftrace trampoline. Just scheduling a task on | |
2868 | * a CPU is not good enough to flush them. Calling | |
2869 | * synchornize_rcu_tasks() will wait for those tasks to | |
2870 | * execute and either schedule voluntarily or enter user space. | |
2871 | */ | |
2872 | if (IS_ENABLED(CONFIG_PREEMPT)) | |
2873 | synchronize_rcu_tasks(); | |
2874 | ||
edb096e0 | 2875 | free_ops: |
12cce594 | 2876 | arch_ftrace_trampoline_free(ops); |
a4c35ed2 SRRH |
2877 | } |
2878 | ||
8a56d776 | 2879 | return 0; |
3d083395 SR |
2880 | } |
2881 | ||
e309b41d | 2882 | static void ftrace_startup_sysctl(void) |
b0fc494f | 2883 | { |
1619dc3f PA |
2884 | int command; |
2885 | ||
4eebcc81 SR |
2886 | if (unlikely(ftrace_disabled)) |
2887 | return; | |
2888 | ||
d61f82d0 SR |
2889 | /* Force update next time */ |
2890 | saved_ftrace_func = NULL; | |
60a7ecf4 | 2891 | /* ftrace_start_up is true if we want ftrace running */ |
1619dc3f PA |
2892 | if (ftrace_start_up) { |
2893 | command = FTRACE_UPDATE_CALLS; | |
2894 | if (ftrace_graph_active) | |
2895 | command |= FTRACE_START_FUNC_RET; | |
524a3868 | 2896 | ftrace_startup_enable(command); |
1619dc3f | 2897 | } |
b0fc494f SR |
2898 | } |
2899 | ||
e309b41d | 2900 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 2901 | { |
1619dc3f PA |
2902 | int command; |
2903 | ||
4eebcc81 SR |
2904 | if (unlikely(ftrace_disabled)) |
2905 | return; | |
2906 | ||
60a7ecf4 | 2907 | /* ftrace_start_up is true if ftrace is running */ |
1619dc3f PA |
2908 | if (ftrace_start_up) { |
2909 | command = FTRACE_DISABLE_CALLS; | |
2910 | if (ftrace_graph_active) | |
2911 | command |= FTRACE_STOP_FUNC_RET; | |
2912 | ftrace_run_update_code(command); | |
2913 | } | |
b0fc494f SR |
2914 | } |
2915 | ||
a5a1d1c2 | 2916 | static u64 ftrace_update_time; |
3d083395 SR |
2917 | unsigned long ftrace_update_tot_cnt; |
2918 | ||
8c4f3c3f | 2919 | static inline int ops_traces_mod(struct ftrace_ops *ops) |
f7bc8b61 | 2920 | { |
8c4f3c3f SRRH |
2921 | /* |
2922 | * Filter_hash being empty will default to trace module. | |
2923 | * But notrace hash requires a test of individual module functions. | |
2924 | */ | |
33b7f99c SRRH |
2925 | return ftrace_hash_empty(ops->func_hash->filter_hash) && |
2926 | ftrace_hash_empty(ops->func_hash->notrace_hash); | |
8c4f3c3f SRRH |
2927 | } |
2928 | ||
2929 | /* | |
2930 | * Check if the current ops references the record. | |
2931 | * | |
2932 | * If the ops traces all functions, then it was already accounted for. | |
2933 | * If the ops does not trace the current record function, skip it. | |
2934 | * If the ops ignores the function via notrace filter, skip it. | |
2935 | */ | |
2936 | static inline bool | |
2937 | ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec) | |
2938 | { | |
2939 | /* If ops isn't enabled, ignore it */ | |
2940 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
2941 | return 0; | |
2942 | ||
b7ffffbb | 2943 | /* If ops traces all then it includes this function */ |
8c4f3c3f | 2944 | if (ops_traces_mod(ops)) |
b7ffffbb | 2945 | return 1; |
8c4f3c3f SRRH |
2946 | |
2947 | /* The function must be in the filter */ | |
33b7f99c | 2948 | if (!ftrace_hash_empty(ops->func_hash->filter_hash) && |
2b2c279c | 2949 | !__ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip)) |
8c4f3c3f | 2950 | return 0; |
f7bc8b61 | 2951 | |
8c4f3c3f | 2952 | /* If in notrace hash, we ignore it too */ |
33b7f99c | 2953 | if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip)) |
8c4f3c3f SRRH |
2954 | return 0; |
2955 | ||
2956 | return 1; | |
2957 | } | |
2958 | ||
1dc43cf0 | 2959 | static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs) |
3d083395 | 2960 | { |
85ae32ae | 2961 | struct ftrace_page *pg; |
e94142a6 | 2962 | struct dyn_ftrace *p; |
a5a1d1c2 | 2963 | u64 start, stop; |
1dc43cf0 | 2964 | unsigned long update_cnt = 0; |
b7ffffbb | 2965 | unsigned long rec_flags = 0; |
85ae32ae | 2966 | int i; |
f7bc8b61 | 2967 | |
b7ffffbb SRRH |
2968 | start = ftrace_now(raw_smp_processor_id()); |
2969 | ||
f7bc8b61 | 2970 | /* |
b7ffffbb SRRH |
2971 | * When a module is loaded, this function is called to convert |
2972 | * the calls to mcount in its text to nops, and also to create | |
2973 | * an entry in the ftrace data. Now, if ftrace is activated | |
2974 | * after this call, but before the module sets its text to | |
2975 | * read-only, the modification of enabling ftrace can fail if | |
2976 | * the read-only is done while ftrace is converting the calls. | |
2977 | * To prevent this, the module's records are set as disabled | |
2978 | * and will be enabled after the call to set the module's text | |
2979 | * to read-only. | |
f7bc8b61 | 2980 | */ |
b7ffffbb SRRH |
2981 | if (mod) |
2982 | rec_flags |= FTRACE_FL_DISABLED; | |
3d083395 | 2983 | |
1dc43cf0 | 2984 | for (pg = new_pgs; pg; pg = pg->next) { |
3d083395 | 2985 | |
85ae32ae | 2986 | for (i = 0; i < pg->index; i++) { |
8c4f3c3f | 2987 | |
85ae32ae SR |
2988 | /* If something went wrong, bail without enabling anything */ |
2989 | if (unlikely(ftrace_disabled)) | |
2990 | return -1; | |
f22f9a89 | 2991 | |
85ae32ae | 2992 | p = &pg->records[i]; |
b7ffffbb | 2993 | p->flags = rec_flags; |
f22f9a89 | 2994 | |
85ae32ae SR |
2995 | /* |
2996 | * Do the initial record conversion from mcount jump | |
2997 | * to the NOP instructions. | |
2998 | */ | |
2999 | if (!ftrace_code_disable(mod, p)) | |
3000 | break; | |
5cb084bb | 3001 | |
1dc43cf0 | 3002 | update_cnt++; |
5cb084bb | 3003 | } |
3d083395 SR |
3004 | } |
3005 | ||
750ed1a4 | 3006 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 | 3007 | ftrace_update_time = stop - start; |
1dc43cf0 | 3008 | ftrace_update_tot_cnt += update_cnt; |
3d083395 | 3009 | |
16444a8a ACM |
3010 | return 0; |
3011 | } | |
3012 | ||
a7900875 | 3013 | static int ftrace_allocate_records(struct ftrace_page *pg, int count) |
3c1720f0 | 3014 | { |
a7900875 | 3015 | int order; |
3c1720f0 | 3016 | int cnt; |
3c1720f0 | 3017 | |
a7900875 SR |
3018 | if (WARN_ON(!count)) |
3019 | return -EINVAL; | |
3020 | ||
3021 | order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE)); | |
3c1720f0 SR |
3022 | |
3023 | /* | |
a7900875 SR |
3024 | * We want to fill as much as possible. No more than a page |
3025 | * may be empty. | |
3c1720f0 | 3026 | */ |
a7900875 SR |
3027 | while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE) |
3028 | order--; | |
3c1720f0 | 3029 | |
a7900875 SR |
3030 | again: |
3031 | pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); | |
3c1720f0 | 3032 | |
a7900875 SR |
3033 | if (!pg->records) { |
3034 | /* if we can't allocate this size, try something smaller */ | |
3035 | if (!order) | |
3036 | return -ENOMEM; | |
3037 | order >>= 1; | |
3038 | goto again; | |
3039 | } | |
3c1720f0 | 3040 | |
a7900875 SR |
3041 | cnt = (PAGE_SIZE << order) / ENTRY_SIZE; |
3042 | pg->size = cnt; | |
3c1720f0 | 3043 | |
a7900875 SR |
3044 | if (cnt > count) |
3045 | cnt = count; | |
3046 | ||
3047 | return cnt; | |
3048 | } | |
3049 | ||
3050 | static struct ftrace_page * | |
3051 | ftrace_allocate_pages(unsigned long num_to_init) | |
3052 | { | |
3053 | struct ftrace_page *start_pg; | |
3054 | struct ftrace_page *pg; | |
3055 | int order; | |
3056 | int cnt; | |
3057 | ||
3058 | if (!num_to_init) | |
3059 | return 0; | |
3060 | ||
3061 | start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL); | |
3062 | if (!pg) | |
3063 | return NULL; | |
3064 | ||
3065 | /* | |
3066 | * Try to allocate as much as possible in one continues | |
3067 | * location that fills in all of the space. We want to | |
3068 | * waste as little space as possible. | |
3069 | */ | |
3070 | for (;;) { | |
3071 | cnt = ftrace_allocate_records(pg, num_to_init); | |
3072 | if (cnt < 0) | |
3073 | goto free_pages; | |
3074 | ||
3075 | num_to_init -= cnt; | |
3076 | if (!num_to_init) | |
3c1720f0 SR |
3077 | break; |
3078 | ||
a7900875 SR |
3079 | pg->next = kzalloc(sizeof(*pg), GFP_KERNEL); |
3080 | if (!pg->next) | |
3081 | goto free_pages; | |
3082 | ||
3c1720f0 SR |
3083 | pg = pg->next; |
3084 | } | |
3085 | ||
a7900875 SR |
3086 | return start_pg; |
3087 | ||
3088 | free_pages: | |
1f61be00 NK |
3089 | pg = start_pg; |
3090 | while (pg) { | |
a7900875 SR |
3091 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
3092 | free_pages((unsigned long)pg->records, order); | |
3093 | start_pg = pg->next; | |
3094 | kfree(pg); | |
3095 | pg = start_pg; | |
3096 | } | |
3097 | pr_info("ftrace: FAILED to allocate memory for functions\n"); | |
3098 | return NULL; | |
3099 | } | |
3100 | ||
5072c59f SR |
3101 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
3102 | ||
3103 | struct ftrace_iterator { | |
98c4fd04 | 3104 | loff_t pos; |
4aeb6967 | 3105 | loff_t func_pos; |
5985ea8b | 3106 | loff_t mod_pos; |
4aeb6967 SR |
3107 | struct ftrace_page *pg; |
3108 | struct dyn_ftrace *func; | |
3109 | struct ftrace_func_probe *probe; | |
eee8ded1 | 3110 | struct ftrace_func_entry *probe_entry; |
4aeb6967 | 3111 | struct trace_parser parser; |
1cf41dd7 | 3112 | struct ftrace_hash *hash; |
33dc9b12 | 3113 | struct ftrace_ops *ops; |
5985ea8b SRV |
3114 | struct trace_array *tr; |
3115 | struct list_head *mod_list; | |
eee8ded1 | 3116 | int pidx; |
4aeb6967 SR |
3117 | int idx; |
3118 | unsigned flags; | |
5072c59f SR |
3119 | }; |
3120 | ||
8fc0c701 | 3121 | static void * |
eee8ded1 | 3122 | t_probe_next(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
3123 | { |
3124 | struct ftrace_iterator *iter = m->private; | |
d2afd57a | 3125 | struct trace_array *tr = iter->ops->private; |
04ec7bb6 | 3126 | struct list_head *func_probes; |
eee8ded1 SRV |
3127 | struct ftrace_hash *hash; |
3128 | struct list_head *next; | |
4aeb6967 | 3129 | struct hlist_node *hnd = NULL; |
8fc0c701 | 3130 | struct hlist_head *hhd; |
eee8ded1 | 3131 | int size; |
8fc0c701 | 3132 | |
8fc0c701 | 3133 | (*pos)++; |
98c4fd04 | 3134 | iter->pos = *pos; |
8fc0c701 | 3135 | |
04ec7bb6 | 3136 | if (!tr) |
8fc0c701 SR |
3137 | return NULL; |
3138 | ||
04ec7bb6 SRV |
3139 | func_probes = &tr->func_probes; |
3140 | if (list_empty(func_probes)) | |
8fc0c701 SR |
3141 | return NULL; |
3142 | ||
eee8ded1 | 3143 | if (!iter->probe) { |
04ec7bb6 | 3144 | next = func_probes->next; |
7b60f3d8 | 3145 | iter->probe = list_entry(next, struct ftrace_func_probe, list); |
eee8ded1 SRV |
3146 | } |
3147 | ||
3148 | if (iter->probe_entry) | |
3149 | hnd = &iter->probe_entry->hlist; | |
3150 | ||
3151 | hash = iter->probe->ops.func_hash->filter_hash; | |
3152 | size = 1 << hash->size_bits; | |
3153 | ||
3154 | retry: | |
3155 | if (iter->pidx >= size) { | |
04ec7bb6 | 3156 | if (iter->probe->list.next == func_probes) |
eee8ded1 SRV |
3157 | return NULL; |
3158 | next = iter->probe->list.next; | |
7b60f3d8 | 3159 | iter->probe = list_entry(next, struct ftrace_func_probe, list); |
eee8ded1 SRV |
3160 | hash = iter->probe->ops.func_hash->filter_hash; |
3161 | size = 1 << hash->size_bits; | |
3162 | iter->pidx = 0; | |
3163 | } | |
3164 | ||
3165 | hhd = &hash->buckets[iter->pidx]; | |
8fc0c701 SR |
3166 | |
3167 | if (hlist_empty(hhd)) { | |
eee8ded1 | 3168 | iter->pidx++; |
8fc0c701 SR |
3169 | hnd = NULL; |
3170 | goto retry; | |
3171 | } | |
3172 | ||
3173 | if (!hnd) | |
3174 | hnd = hhd->first; | |
3175 | else { | |
3176 | hnd = hnd->next; | |
3177 | if (!hnd) { | |
eee8ded1 | 3178 | iter->pidx++; |
8fc0c701 SR |
3179 | goto retry; |
3180 | } | |
3181 | } | |
3182 | ||
4aeb6967 SR |
3183 | if (WARN_ON_ONCE(!hnd)) |
3184 | return NULL; | |
3185 | ||
eee8ded1 | 3186 | iter->probe_entry = hlist_entry(hnd, struct ftrace_func_entry, hlist); |
4aeb6967 SR |
3187 | |
3188 | return iter; | |
8fc0c701 SR |
3189 | } |
3190 | ||
eee8ded1 | 3191 | static void *t_probe_start(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
3192 | { |
3193 | struct ftrace_iterator *iter = m->private; | |
3194 | void *p = NULL; | |
d82d6244 LZ |
3195 | loff_t l; |
3196 | ||
eee8ded1 | 3197 | if (!(iter->flags & FTRACE_ITER_DO_PROBES)) |
69a3083c SR |
3198 | return NULL; |
3199 | ||
5985ea8b | 3200 | if (iter->mod_pos > *pos) |
2bccfffd | 3201 | return NULL; |
8fc0c701 | 3202 | |
eee8ded1 SRV |
3203 | iter->probe = NULL; |
3204 | iter->probe_entry = NULL; | |
3205 | iter->pidx = 0; | |
5985ea8b | 3206 | for (l = 0; l <= (*pos - iter->mod_pos); ) { |
eee8ded1 | 3207 | p = t_probe_next(m, &l); |
d82d6244 LZ |
3208 | if (!p) |
3209 | break; | |
3210 | } | |
4aeb6967 SR |
3211 | if (!p) |
3212 | return NULL; | |
3213 | ||
98c4fd04 | 3214 | /* Only set this if we have an item */ |
eee8ded1 | 3215 | iter->flags |= FTRACE_ITER_PROBE; |
98c4fd04 | 3216 | |
4aeb6967 | 3217 | return iter; |
8fc0c701 SR |
3218 | } |
3219 | ||
4aeb6967 | 3220 | static int |
eee8ded1 | 3221 | t_probe_show(struct seq_file *m, struct ftrace_iterator *iter) |
8fc0c701 | 3222 | { |
eee8ded1 | 3223 | struct ftrace_func_entry *probe_entry; |
7b60f3d8 SRV |
3224 | struct ftrace_probe_ops *probe_ops; |
3225 | struct ftrace_func_probe *probe; | |
8fc0c701 | 3226 | |
eee8ded1 SRV |
3227 | probe = iter->probe; |
3228 | probe_entry = iter->probe_entry; | |
8fc0c701 | 3229 | |
eee8ded1 | 3230 | if (WARN_ON_ONCE(!probe || !probe_entry)) |
4aeb6967 | 3231 | return -EIO; |
8fc0c701 | 3232 | |
7b60f3d8 | 3233 | probe_ops = probe->probe_ops; |
809dcf29 | 3234 | |
7b60f3d8 | 3235 | if (probe_ops->print) |
6e444319 | 3236 | return probe_ops->print(m, probe_entry->ip, probe_ops, probe->data); |
8fc0c701 | 3237 | |
7b60f3d8 SRV |
3238 | seq_printf(m, "%ps:%ps\n", (void *)probe_entry->ip, |
3239 | (void *)probe_ops->func); | |
8fc0c701 SR |
3240 | |
3241 | return 0; | |
3242 | } | |
3243 | ||
5985ea8b SRV |
3244 | static void * |
3245 | t_mod_next(struct seq_file *m, loff_t *pos) | |
3246 | { | |
3247 | struct ftrace_iterator *iter = m->private; | |
3248 | struct trace_array *tr = iter->tr; | |
3249 | ||
3250 | (*pos)++; | |
3251 | iter->pos = *pos; | |
3252 | ||
3253 | iter->mod_list = iter->mod_list->next; | |
3254 | ||
3255 | if (iter->mod_list == &tr->mod_trace || | |
3256 | iter->mod_list == &tr->mod_notrace) { | |
3257 | iter->flags &= ~FTRACE_ITER_MOD; | |
3258 | return NULL; | |
3259 | } | |
3260 | ||
3261 | iter->mod_pos = *pos; | |
3262 | ||
3263 | return iter; | |
3264 | } | |
3265 | ||
3266 | static void *t_mod_start(struct seq_file *m, loff_t *pos) | |
3267 | { | |
3268 | struct ftrace_iterator *iter = m->private; | |
3269 | void *p = NULL; | |
3270 | loff_t l; | |
3271 | ||
3272 | if (iter->func_pos > *pos) | |
3273 | return NULL; | |
3274 | ||
3275 | iter->mod_pos = iter->func_pos; | |
3276 | ||
3277 | /* probes are only available if tr is set */ | |
3278 | if (!iter->tr) | |
3279 | return NULL; | |
3280 | ||
3281 | for (l = 0; l <= (*pos - iter->func_pos); ) { | |
3282 | p = t_mod_next(m, &l); | |
3283 | if (!p) | |
3284 | break; | |
3285 | } | |
3286 | if (!p) { | |
3287 | iter->flags &= ~FTRACE_ITER_MOD; | |
3288 | return t_probe_start(m, pos); | |
3289 | } | |
3290 | ||
3291 | /* Only set this if we have an item */ | |
3292 | iter->flags |= FTRACE_ITER_MOD; | |
3293 | ||
3294 | return iter; | |
3295 | } | |
3296 | ||
3297 | static int | |
3298 | t_mod_show(struct seq_file *m, struct ftrace_iterator *iter) | |
3299 | { | |
3300 | struct ftrace_mod_load *ftrace_mod; | |
3301 | struct trace_array *tr = iter->tr; | |
3302 | ||
3303 | if (WARN_ON_ONCE(!iter->mod_list) || | |
3304 | iter->mod_list == &tr->mod_trace || | |
3305 | iter->mod_list == &tr->mod_notrace) | |
3306 | return -EIO; | |
3307 | ||
3308 | ftrace_mod = list_entry(iter->mod_list, struct ftrace_mod_load, list); | |
3309 | ||
3310 | if (ftrace_mod->func) | |
3311 | seq_printf(m, "%s", ftrace_mod->func); | |
3312 | else | |
3313 | seq_putc(m, '*'); | |
3314 | ||
3315 | seq_printf(m, ":mod:%s\n", ftrace_mod->module); | |
3316 | ||
3317 | return 0; | |
3318 | } | |
3319 | ||
e309b41d | 3320 | static void * |
5bd84629 | 3321 | t_func_next(struct seq_file *m, loff_t *pos) |
5072c59f SR |
3322 | { |
3323 | struct ftrace_iterator *iter = m->private; | |
3324 | struct dyn_ftrace *rec = NULL; | |
3325 | ||
3326 | (*pos)++; | |
0c75a3ed | 3327 | |
5072c59f SR |
3328 | retry: |
3329 | if (iter->idx >= iter->pg->index) { | |
3330 | if (iter->pg->next) { | |
3331 | iter->pg = iter->pg->next; | |
3332 | iter->idx = 0; | |
3333 | goto retry; | |
3334 | } | |
3335 | } else { | |
3336 | rec = &iter->pg->records[iter->idx++]; | |
c20489da SRV |
3337 | if (((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) && |
3338 | !ftrace_lookup_ip(iter->hash, rec->ip)) || | |
647bcd03 SR |
3339 | |
3340 | ((iter->flags & FTRACE_ITER_ENABLED) && | |
23ea9c4d | 3341 | !(rec->flags & FTRACE_FL_ENABLED))) { |
647bcd03 | 3342 | |
5072c59f SR |
3343 | rec = NULL; |
3344 | goto retry; | |
3345 | } | |
3346 | } | |
3347 | ||
4aeb6967 | 3348 | if (!rec) |
5bd84629 | 3349 | return NULL; |
4aeb6967 | 3350 | |
5bd84629 | 3351 | iter->pos = iter->func_pos = *pos; |
4aeb6967 SR |
3352 | iter->func = rec; |
3353 | ||
3354 | return iter; | |
5072c59f SR |
3355 | } |
3356 | ||
5bd84629 SRV |
3357 | static void * |
3358 | t_next(struct seq_file *m, void *v, loff_t *pos) | |
3359 | { | |
3360 | struct ftrace_iterator *iter = m->private; | |
5985ea8b | 3361 | loff_t l = *pos; /* t_probe_start() must use original pos */ |
5bd84629 SRV |
3362 | void *ret; |
3363 | ||
3364 | if (unlikely(ftrace_disabled)) | |
3365 | return NULL; | |
3366 | ||
eee8ded1 SRV |
3367 | if (iter->flags & FTRACE_ITER_PROBE) |
3368 | return t_probe_next(m, pos); | |
5bd84629 | 3369 | |
5985ea8b SRV |
3370 | if (iter->flags & FTRACE_ITER_MOD) |
3371 | return t_mod_next(m, pos); | |
3372 | ||
5bd84629 | 3373 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
eee8ded1 | 3374 | /* next must increment pos, and t_probe_start does not */ |
5bd84629 | 3375 | (*pos)++; |
5985ea8b | 3376 | return t_mod_start(m, &l); |
5bd84629 SRV |
3377 | } |
3378 | ||
3379 | ret = t_func_next(m, pos); | |
3380 | ||
3381 | if (!ret) | |
5985ea8b | 3382 | return t_mod_start(m, &l); |
5bd84629 SRV |
3383 | |
3384 | return ret; | |
3385 | } | |
3386 | ||
98c4fd04 SR |
3387 | static void reset_iter_read(struct ftrace_iterator *iter) |
3388 | { | |
3389 | iter->pos = 0; | |
3390 | iter->func_pos = 0; | |
5985ea8b | 3391 | iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_PROBE | FTRACE_ITER_MOD); |
5072c59f SR |
3392 | } |
3393 | ||
3394 | static void *t_start(struct seq_file *m, loff_t *pos) | |
3395 | { | |
3396 | struct ftrace_iterator *iter = m->private; | |
3397 | void *p = NULL; | |
694ce0a5 | 3398 | loff_t l; |
5072c59f | 3399 | |
8fc0c701 | 3400 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
3401 | |
3402 | if (unlikely(ftrace_disabled)) | |
3403 | return NULL; | |
3404 | ||
98c4fd04 SR |
3405 | /* |
3406 | * If an lseek was done, then reset and start from beginning. | |
3407 | */ | |
3408 | if (*pos < iter->pos) | |
3409 | reset_iter_read(iter); | |
3410 | ||
0c75a3ed SR |
3411 | /* |
3412 | * For set_ftrace_filter reading, if we have the filter | |
3413 | * off, we can short cut and just print out that all | |
3414 | * functions are enabled. | |
3415 | */ | |
c20489da SRV |
3416 | if ((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) && |
3417 | ftrace_hash_empty(iter->hash)) { | |
43ff926a | 3418 | iter->func_pos = 1; /* Account for the message */ |
0c75a3ed | 3419 | if (*pos > 0) |
5985ea8b | 3420 | return t_mod_start(m, pos); |
0c75a3ed | 3421 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 | 3422 | /* reset in case of seek/pread */ |
eee8ded1 | 3423 | iter->flags &= ~FTRACE_ITER_PROBE; |
0c75a3ed SR |
3424 | return iter; |
3425 | } | |
3426 | ||
5985ea8b SRV |
3427 | if (iter->flags & FTRACE_ITER_MOD) |
3428 | return t_mod_start(m, pos); | |
8fc0c701 | 3429 | |
98c4fd04 SR |
3430 | /* |
3431 | * Unfortunately, we need to restart at ftrace_pages_start | |
3432 | * every time we let go of the ftrace_mutex. This is because | |
3433 | * those pointers can change without the lock. | |
3434 | */ | |
694ce0a5 LZ |
3435 | iter->pg = ftrace_pages_start; |
3436 | iter->idx = 0; | |
3437 | for (l = 0; l <= *pos; ) { | |
5bd84629 | 3438 | p = t_func_next(m, &l); |
694ce0a5 LZ |
3439 | if (!p) |
3440 | break; | |
50cdaf08 | 3441 | } |
5821e1b7 | 3442 | |
69a3083c | 3443 | if (!p) |
5985ea8b | 3444 | return t_mod_start(m, pos); |
4aeb6967 SR |
3445 | |
3446 | return iter; | |
5072c59f SR |
3447 | } |
3448 | ||
3449 | static void t_stop(struct seq_file *m, void *p) | |
3450 | { | |
8fc0c701 | 3451 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
3452 | } |
3453 | ||
15d5b02c SRRH |
3454 | void * __weak |
3455 | arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec) | |
3456 | { | |
3457 | return NULL; | |
3458 | } | |
3459 | ||
3460 | static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops, | |
3461 | struct dyn_ftrace *rec) | |
3462 | { | |
3463 | void *ptr; | |
3464 | ||
3465 | ptr = arch_ftrace_trampoline_func(ops, rec); | |
3466 | if (ptr) | |
3467 | seq_printf(m, " ->%pS", ptr); | |
3468 | } | |
3469 | ||
5072c59f SR |
3470 | static int t_show(struct seq_file *m, void *v) |
3471 | { | |
0c75a3ed | 3472 | struct ftrace_iterator *iter = m->private; |
4aeb6967 | 3473 | struct dyn_ftrace *rec; |
5072c59f | 3474 | |
eee8ded1 SRV |
3475 | if (iter->flags & FTRACE_ITER_PROBE) |
3476 | return t_probe_show(m, iter); | |
8fc0c701 | 3477 | |
5985ea8b SRV |
3478 | if (iter->flags & FTRACE_ITER_MOD) |
3479 | return t_mod_show(m, iter); | |
3480 | ||
0c75a3ed | 3481 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
8c006cf7 | 3482 | if (iter->flags & FTRACE_ITER_NOTRACE) |
fa6f0cc7 | 3483 | seq_puts(m, "#### no functions disabled ####\n"); |
8c006cf7 | 3484 | else |
fa6f0cc7 | 3485 | seq_puts(m, "#### all functions enabled ####\n"); |
0c75a3ed SR |
3486 | return 0; |
3487 | } | |
3488 | ||
4aeb6967 SR |
3489 | rec = iter->func; |
3490 | ||
5072c59f SR |
3491 | if (!rec) |
3492 | return 0; | |
3493 | ||
647bcd03 | 3494 | seq_printf(m, "%ps", (void *)rec->ip); |
9674b2fa | 3495 | if (iter->flags & FTRACE_ITER_ENABLED) { |
030f4e1c | 3496 | struct ftrace_ops *ops; |
15d5b02c | 3497 | |
f8b8be8a | 3498 | seq_printf(m, " (%ld)%s%s", |
0376bde1 | 3499 | ftrace_rec_count(rec), |
f8b8be8a MH |
3500 | rec->flags & FTRACE_FL_REGS ? " R" : " ", |
3501 | rec->flags & FTRACE_FL_IPMODIFY ? " I" : " "); | |
9674b2fa | 3502 | if (rec->flags & FTRACE_FL_TRAMP_EN) { |
5fecaa04 | 3503 | ops = ftrace_find_tramp_ops_any(rec); |
39daa7b9 SRRH |
3504 | if (ops) { |
3505 | do { | |
3506 | seq_printf(m, "\ttramp: %pS (%pS)", | |
3507 | (void *)ops->trampoline, | |
3508 | (void *)ops->func); | |
030f4e1c | 3509 | add_trampoline_func(m, ops, rec); |
39daa7b9 SRRH |
3510 | ops = ftrace_find_tramp_ops_next(rec, ops); |
3511 | } while (ops); | |
3512 | } else | |
fa6f0cc7 | 3513 | seq_puts(m, "\ttramp: ERROR!"); |
030f4e1c SRRH |
3514 | } else { |
3515 | add_trampoline_func(m, NULL, rec); | |
9674b2fa SRRH |
3516 | } |
3517 | } | |
3518 | ||
fa6f0cc7 | 3519 | seq_putc(m, '\n'); |
5072c59f SR |
3520 | |
3521 | return 0; | |
3522 | } | |
3523 | ||
88e9d34c | 3524 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
3525 | .start = t_start, |
3526 | .next = t_next, | |
3527 | .stop = t_stop, | |
3528 | .show = t_show, | |
3529 | }; | |
3530 | ||
e309b41d | 3531 | static int |
5072c59f SR |
3532 | ftrace_avail_open(struct inode *inode, struct file *file) |
3533 | { | |
3534 | struct ftrace_iterator *iter; | |
5072c59f | 3535 | |
4eebcc81 SR |
3536 | if (unlikely(ftrace_disabled)) |
3537 | return -ENODEV; | |
3538 | ||
50e18b94 | 3539 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
c1bc5919 SRV |
3540 | if (!iter) |
3541 | return -ENOMEM; | |
5072c59f | 3542 | |
c1bc5919 SRV |
3543 | iter->pg = ftrace_pages_start; |
3544 | iter->ops = &global_ops; | |
3545 | ||
3546 | return 0; | |
5072c59f SR |
3547 | } |
3548 | ||
647bcd03 SR |
3549 | static int |
3550 | ftrace_enabled_open(struct inode *inode, struct file *file) | |
3551 | { | |
3552 | struct ftrace_iterator *iter; | |
647bcd03 | 3553 | |
50e18b94 | 3554 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
c1bc5919 SRV |
3555 | if (!iter) |
3556 | return -ENOMEM; | |
647bcd03 | 3557 | |
c1bc5919 SRV |
3558 | iter->pg = ftrace_pages_start; |
3559 | iter->flags = FTRACE_ITER_ENABLED; | |
3560 | iter->ops = &global_ops; | |
3561 | ||
3562 | return 0; | |
647bcd03 SR |
3563 | } |
3564 | ||
fc13cb0c SR |
3565 | /** |
3566 | * ftrace_regex_open - initialize function tracer filter files | |
3567 | * @ops: The ftrace_ops that hold the hash filters | |
3568 | * @flag: The type of filter to process | |
3569 | * @inode: The inode, usually passed in to your open routine | |
3570 | * @file: The file, usually passed in to your open routine | |
3571 | * | |
3572 | * ftrace_regex_open() initializes the filter files for the | |
3573 | * @ops. Depending on @flag it may process the filter hash or | |
3574 | * the notrace hash of @ops. With this called from the open | |
3575 | * routine, you can use ftrace_filter_write() for the write | |
3576 | * routine if @flag has FTRACE_ITER_FILTER set, or | |
3577 | * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set. | |
098c879e | 3578 | * tracing_lseek() should be used as the lseek routine, and |
fc13cb0c SR |
3579 | * release must call ftrace_regex_release(). |
3580 | */ | |
3581 | int | |
f45948e8 | 3582 | ftrace_regex_open(struct ftrace_ops *ops, int flag, |
1cf41dd7 | 3583 | struct inode *inode, struct file *file) |
5072c59f SR |
3584 | { |
3585 | struct ftrace_iterator *iter; | |
f45948e8 | 3586 | struct ftrace_hash *hash; |
673feb9d SRV |
3587 | struct list_head *mod_head; |
3588 | struct trace_array *tr = ops->private; | |
5072c59f SR |
3589 | int ret = 0; |
3590 | ||
f04f24fb MH |
3591 | ftrace_ops_init(ops); |
3592 | ||
4eebcc81 SR |
3593 | if (unlikely(ftrace_disabled)) |
3594 | return -ENODEV; | |
3595 | ||
5072c59f SR |
3596 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
3597 | if (!iter) | |
3598 | return -ENOMEM; | |
3599 | ||
689fd8b6 | 3600 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { |
3601 | kfree(iter); | |
3602 | return -ENOMEM; | |
3603 | } | |
3604 | ||
3f2367ba MH |
3605 | iter->ops = ops; |
3606 | iter->flags = flag; | |
5985ea8b | 3607 | iter->tr = tr; |
3f2367ba | 3608 | |
33b7f99c | 3609 | mutex_lock(&ops->func_hash->regex_lock); |
3f2367ba | 3610 | |
673feb9d | 3611 | if (flag & FTRACE_ITER_NOTRACE) { |
33b7f99c | 3612 | hash = ops->func_hash->notrace_hash; |
5985ea8b | 3613 | mod_head = tr ? &tr->mod_notrace : NULL; |
673feb9d | 3614 | } else { |
33b7f99c | 3615 | hash = ops->func_hash->filter_hash; |
5985ea8b | 3616 | mod_head = tr ? &tr->mod_trace : NULL; |
673feb9d | 3617 | } |
f45948e8 | 3618 | |
5985ea8b SRV |
3619 | iter->mod_list = mod_head; |
3620 | ||
33dc9b12 | 3621 | if (file->f_mode & FMODE_WRITE) { |
ef2fbe16 NK |
3622 | const int size_bits = FTRACE_HASH_DEFAULT_BITS; |
3623 | ||
673feb9d | 3624 | if (file->f_flags & O_TRUNC) { |
ef2fbe16 | 3625 | iter->hash = alloc_ftrace_hash(size_bits); |
673feb9d SRV |
3626 | clear_ftrace_mod_list(mod_head); |
3627 | } else { | |
ef2fbe16 | 3628 | iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash); |
673feb9d | 3629 | } |
ef2fbe16 | 3630 | |
33dc9b12 SR |
3631 | if (!iter->hash) { |
3632 | trace_parser_put(&iter->parser); | |
3633 | kfree(iter); | |
3f2367ba MH |
3634 | ret = -ENOMEM; |
3635 | goto out_unlock; | |
33dc9b12 | 3636 | } |
c20489da SRV |
3637 | } else |
3638 | iter->hash = hash; | |
1cf41dd7 | 3639 | |
5072c59f SR |
3640 | if (file->f_mode & FMODE_READ) { |
3641 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
3642 | |
3643 | ret = seq_open(file, &show_ftrace_seq_ops); | |
3644 | if (!ret) { | |
3645 | struct seq_file *m = file->private_data; | |
3646 | m->private = iter; | |
79fe249c | 3647 | } else { |
33dc9b12 SR |
3648 | /* Failed */ |
3649 | free_ftrace_hash(iter->hash); | |
79fe249c | 3650 | trace_parser_put(&iter->parser); |
5072c59f | 3651 | kfree(iter); |
79fe249c | 3652 | } |
5072c59f SR |
3653 | } else |
3654 | file->private_data = iter; | |
3f2367ba MH |
3655 | |
3656 | out_unlock: | |
33b7f99c | 3657 | mutex_unlock(&ops->func_hash->regex_lock); |
5072c59f SR |
3658 | |
3659 | return ret; | |
3660 | } | |
3661 | ||
41c52c0d SR |
3662 | static int |
3663 | ftrace_filter_open(struct inode *inode, struct file *file) | |
3664 | { | |
e3b3e2e8 SRRH |
3665 | struct ftrace_ops *ops = inode->i_private; |
3666 | ||
3667 | return ftrace_regex_open(ops, | |
eee8ded1 | 3668 | FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES, |
69a3083c | 3669 | inode, file); |
41c52c0d SR |
3670 | } |
3671 | ||
3672 | static int | |
3673 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
3674 | { | |
e3b3e2e8 SRRH |
3675 | struct ftrace_ops *ops = inode->i_private; |
3676 | ||
3677 | return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE, | |
1cf41dd7 | 3678 | inode, file); |
41c52c0d SR |
3679 | } |
3680 | ||
3ba00929 DS |
3681 | /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */ |
3682 | struct ftrace_glob { | |
3683 | char *search; | |
3684 | unsigned len; | |
3685 | int type; | |
3686 | }; | |
3687 | ||
7132e2d6 TJB |
3688 | /* |
3689 | * If symbols in an architecture don't correspond exactly to the user-visible | |
3690 | * name of what they represent, it is possible to define this function to | |
3691 | * perform the necessary adjustments. | |
3692 | */ | |
3693 | char * __weak arch_ftrace_match_adjust(char *str, const char *search) | |
3694 | { | |
3695 | return str; | |
3696 | } | |
3697 | ||
3ba00929 | 3698 | static int ftrace_match(char *str, struct ftrace_glob *g) |
9f4801e3 | 3699 | { |
9f4801e3 | 3700 | int matched = 0; |
751e9983 | 3701 | int slen; |
9f4801e3 | 3702 | |
7132e2d6 TJB |
3703 | str = arch_ftrace_match_adjust(str, g->search); |
3704 | ||
3ba00929 | 3705 | switch (g->type) { |
9f4801e3 | 3706 | case MATCH_FULL: |
3ba00929 | 3707 | if (strcmp(str, g->search) == 0) |
9f4801e3 SR |
3708 | matched = 1; |
3709 | break; | |
3710 | case MATCH_FRONT_ONLY: | |
3ba00929 | 3711 | if (strncmp(str, g->search, g->len) == 0) |
9f4801e3 SR |
3712 | matched = 1; |
3713 | break; | |
3714 | case MATCH_MIDDLE_ONLY: | |
3ba00929 | 3715 | if (strstr(str, g->search)) |
9f4801e3 SR |
3716 | matched = 1; |
3717 | break; | |
3718 | case MATCH_END_ONLY: | |
751e9983 | 3719 | slen = strlen(str); |
3ba00929 DS |
3720 | if (slen >= g->len && |
3721 | memcmp(str + slen - g->len, g->search, g->len) == 0) | |
9f4801e3 SR |
3722 | matched = 1; |
3723 | break; | |
60f1d5e3 MH |
3724 | case MATCH_GLOB: |
3725 | if (glob_match(g->search, str)) | |
3726 | matched = 1; | |
3727 | break; | |
9f4801e3 SR |
3728 | } |
3729 | ||
3730 | return matched; | |
3731 | } | |
3732 | ||
b448c4e3 | 3733 | static int |
f0a3b154 | 3734 | enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter) |
996e87be | 3735 | { |
b448c4e3 | 3736 | struct ftrace_func_entry *entry; |
b448c4e3 SR |
3737 | int ret = 0; |
3738 | ||
1cf41dd7 | 3739 | entry = ftrace_lookup_ip(hash, rec->ip); |
f0a3b154 | 3740 | if (clear_filter) { |
1cf41dd7 SR |
3741 | /* Do nothing if it doesn't exist */ |
3742 | if (!entry) | |
3743 | return 0; | |
b448c4e3 | 3744 | |
33dc9b12 | 3745 | free_hash_entry(hash, entry); |
1cf41dd7 SR |
3746 | } else { |
3747 | /* Do nothing if it exists */ | |
3748 | if (entry) | |
3749 | return 0; | |
b448c4e3 | 3750 | |
1cf41dd7 | 3751 | ret = add_hash_entry(hash, rec->ip); |
b448c4e3 SR |
3752 | } |
3753 | return ret; | |
996e87be SR |
3754 | } |
3755 | ||
64e7c440 | 3756 | static int |
0b507e1e DS |
3757 | ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g, |
3758 | struct ftrace_glob *mod_g, int exclude_mod) | |
64e7c440 SR |
3759 | { |
3760 | char str[KSYM_SYMBOL_LEN]; | |
b9df92d2 SR |
3761 | char *modname; |
3762 | ||
3763 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
3764 | ||
0b507e1e DS |
3765 | if (mod_g) { |
3766 | int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0; | |
3767 | ||
3768 | /* blank module name to match all modules */ | |
3769 | if (!mod_g->len) { | |
3770 | /* blank module globbing: modname xor exclude_mod */ | |
77c0edde | 3771 | if (!exclude_mod != !modname) |
0b507e1e DS |
3772 | goto func_match; |
3773 | return 0; | |
3774 | } | |
3775 | ||
77c0edde SRV |
3776 | /* |
3777 | * exclude_mod is set to trace everything but the given | |
3778 | * module. If it is set and the module matches, then | |
3779 | * return 0. If it is not set, and the module doesn't match | |
3780 | * also return 0. Otherwise, check the function to see if | |
3781 | * that matches. | |
3782 | */ | |
3783 | if (!mod_matches == !exclude_mod) | |
b9df92d2 | 3784 | return 0; |
0b507e1e | 3785 | func_match: |
b9df92d2 | 3786 | /* blank search means to match all funcs in the mod */ |
3ba00929 | 3787 | if (!func_g->len) |
b9df92d2 SR |
3788 | return 1; |
3789 | } | |
64e7c440 | 3790 | |
3ba00929 | 3791 | return ftrace_match(str, func_g); |
64e7c440 SR |
3792 | } |
3793 | ||
1cf41dd7 | 3794 | static int |
3ba00929 | 3795 | match_records(struct ftrace_hash *hash, char *func, int len, char *mod) |
9f4801e3 | 3796 | { |
9f4801e3 SR |
3797 | struct ftrace_page *pg; |
3798 | struct dyn_ftrace *rec; | |
3ba00929 | 3799 | struct ftrace_glob func_g = { .type = MATCH_FULL }; |
0b507e1e DS |
3800 | struct ftrace_glob mod_g = { .type = MATCH_FULL }; |
3801 | struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL; | |
3802 | int exclude_mod = 0; | |
311d16da | 3803 | int found = 0; |
b448c4e3 | 3804 | int ret; |
2e028c4f | 3805 | int clear_filter = 0; |
9f4801e3 | 3806 | |
0b507e1e | 3807 | if (func) { |
3ba00929 DS |
3808 | func_g.type = filter_parse_regex(func, len, &func_g.search, |
3809 | &clear_filter); | |
3810 | func_g.len = strlen(func_g.search); | |
b9df92d2 | 3811 | } |
9f4801e3 | 3812 | |
0b507e1e DS |
3813 | if (mod) { |
3814 | mod_g.type = filter_parse_regex(mod, strlen(mod), | |
3815 | &mod_g.search, &exclude_mod); | |
3816 | mod_g.len = strlen(mod_g.search); | |
b9df92d2 | 3817 | } |
9f4801e3 | 3818 | |
52baf119 | 3819 | mutex_lock(&ftrace_lock); |
265c831c | 3820 | |
b9df92d2 SR |
3821 | if (unlikely(ftrace_disabled)) |
3822 | goto out_unlock; | |
9f4801e3 | 3823 | |
265c831c | 3824 | do_for_each_ftrace_rec(pg, rec) { |
546fece4 SRRH |
3825 | |
3826 | if (rec->flags & FTRACE_FL_DISABLED) | |
3827 | continue; | |
3828 | ||
0b507e1e | 3829 | if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) { |
f0a3b154 | 3830 | ret = enter_record(hash, rec, clear_filter); |
b448c4e3 SR |
3831 | if (ret < 0) { |
3832 | found = ret; | |
3833 | goto out_unlock; | |
3834 | } | |
311d16da | 3835 | found = 1; |
265c831c SR |
3836 | } |
3837 | } while_for_each_ftrace_rec(); | |
b9df92d2 | 3838 | out_unlock: |
52baf119 | 3839 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
3840 | |
3841 | return found; | |
5072c59f SR |
3842 | } |
3843 | ||
64e7c440 | 3844 | static int |
1cf41dd7 | 3845 | ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) |
64e7c440 | 3846 | { |
f0a3b154 | 3847 | return match_records(hash, buff, len, NULL); |
64e7c440 SR |
3848 | } |
3849 | ||
e16b35dd SRV |
3850 | static void ftrace_ops_update_code(struct ftrace_ops *ops, |
3851 | struct ftrace_ops_hash *old_hash) | |
3852 | { | |
3853 | struct ftrace_ops *op; | |
3854 | ||
3855 | if (!ftrace_enabled) | |
3856 | return; | |
3857 | ||
3858 | if (ops->flags & FTRACE_OPS_FL_ENABLED) { | |
3859 | ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash); | |
3860 | return; | |
3861 | } | |
3862 | ||
3863 | /* | |
3864 | * If this is the shared global_ops filter, then we need to | |
3865 | * check if there is another ops that shares it, is enabled. | |
3866 | * If so, we still need to run the modify code. | |
3867 | */ | |
3868 | if (ops->func_hash != &global_ops.local_hash) | |
3869 | return; | |
3870 | ||
3871 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
3872 | if (op->func_hash == &global_ops.local_hash && | |
3873 | op->flags & FTRACE_OPS_FL_ENABLED) { | |
3874 | ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash); | |
3875 | /* Only need to do this once */ | |
3876 | return; | |
3877 | } | |
3878 | } while_for_each_ftrace_op(op); | |
3879 | } | |
3880 | ||
3881 | static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops, | |
3882 | struct ftrace_hash **orig_hash, | |
3883 | struct ftrace_hash *hash, | |
3884 | int enable) | |
3885 | { | |
3886 | struct ftrace_ops_hash old_hash_ops; | |
3887 | struct ftrace_hash *old_hash; | |
3888 | int ret; | |
3889 | ||
3890 | old_hash = *orig_hash; | |
3891 | old_hash_ops.filter_hash = ops->func_hash->filter_hash; | |
3892 | old_hash_ops.notrace_hash = ops->func_hash->notrace_hash; | |
3893 | ret = ftrace_hash_move(ops, enable, orig_hash, hash); | |
3894 | if (!ret) { | |
3895 | ftrace_ops_update_code(ops, &old_hash_ops); | |
3896 | free_ftrace_hash_rcu(old_hash); | |
3897 | } | |
3898 | return ret; | |
3899 | } | |
64e7c440 | 3900 | |
673feb9d SRV |
3901 | static bool module_exists(const char *module) |
3902 | { | |
3903 | /* All modules have the symbol __this_module */ | |
3904 | const char this_mod[] = "__this_module"; | |
3905 | const int modname_size = MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 1; | |
3906 | char modname[modname_size + 1]; | |
3907 | unsigned long val; | |
3908 | int n; | |
3909 | ||
3910 | n = snprintf(modname, modname_size + 1, "%s:%s", module, this_mod); | |
3911 | ||
3912 | if (n > modname_size) | |
3913 | return false; | |
3914 | ||
3915 | val = module_kallsyms_lookup_name(modname); | |
3916 | return val != 0; | |
3917 | } | |
3918 | ||
3919 | static int cache_mod(struct trace_array *tr, | |
3920 | const char *func, char *module, int enable) | |
3921 | { | |
3922 | struct ftrace_mod_load *ftrace_mod, *n; | |
3923 | struct list_head *head = enable ? &tr->mod_trace : &tr->mod_notrace; | |
3924 | int ret; | |
3925 | ||
3926 | mutex_lock(&ftrace_lock); | |
3927 | ||
3928 | /* We do not cache inverse filters */ | |
3929 | if (func[0] == '!') { | |
3930 | func++; | |
3931 | ret = -EINVAL; | |
3932 | ||
3933 | /* Look to remove this hash */ | |
3934 | list_for_each_entry_safe(ftrace_mod, n, head, list) { | |
3935 | if (strcmp(ftrace_mod->module, module) != 0) | |
3936 | continue; | |
3937 | ||
3938 | /* no func matches all */ | |
44925dff | 3939 | if (strcmp(func, "*") == 0 || |
673feb9d SRV |
3940 | (ftrace_mod->func && |
3941 | strcmp(ftrace_mod->func, func) == 0)) { | |
3942 | ret = 0; | |
3943 | free_ftrace_mod(ftrace_mod); | |
3944 | continue; | |
3945 | } | |
3946 | } | |
3947 | goto out; | |
3948 | } | |
3949 | ||
3950 | ret = -EINVAL; | |
3951 | /* We only care about modules that have not been loaded yet */ | |
3952 | if (module_exists(module)) | |
3953 | goto out; | |
3954 | ||
3955 | /* Save this string off, and execute it when the module is loaded */ | |
3956 | ret = ftrace_add_mod(tr, func, module, enable); | |
3957 | out: | |
3958 | mutex_unlock(&ftrace_lock); | |
3959 | ||
3960 | return ret; | |
3961 | } | |
3962 | ||
d7fbf8df SRV |
3963 | static int |
3964 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, | |
3965 | int reset, int enable); | |
3966 | ||
69449bbd | 3967 | #ifdef CONFIG_MODULES |
d7fbf8df SRV |
3968 | static void process_mod_list(struct list_head *head, struct ftrace_ops *ops, |
3969 | char *mod, bool enable) | |
3970 | { | |
3971 | struct ftrace_mod_load *ftrace_mod, *n; | |
3972 | struct ftrace_hash **orig_hash, *new_hash; | |
3973 | LIST_HEAD(process_mods); | |
3974 | char *func; | |
3975 | int ret; | |
3976 | ||
3977 | mutex_lock(&ops->func_hash->regex_lock); | |
3978 | ||
3979 | if (enable) | |
3980 | orig_hash = &ops->func_hash->filter_hash; | |
3981 | else | |
3982 | orig_hash = &ops->func_hash->notrace_hash; | |
3983 | ||
3984 | new_hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, | |
3985 | *orig_hash); | |
3986 | if (!new_hash) | |
3b58a3c7 | 3987 | goto out; /* warn? */ |
d7fbf8df SRV |
3988 | |
3989 | mutex_lock(&ftrace_lock); | |
3990 | ||
3991 | list_for_each_entry_safe(ftrace_mod, n, head, list) { | |
3992 | ||
3993 | if (strcmp(ftrace_mod->module, mod) != 0) | |
3994 | continue; | |
3995 | ||
3996 | if (ftrace_mod->func) | |
3997 | func = kstrdup(ftrace_mod->func, GFP_KERNEL); | |
3998 | else | |
3999 | func = kstrdup("*", GFP_KERNEL); | |
4000 | ||
4001 | if (!func) /* warn? */ | |
4002 | continue; | |
4003 | ||
4004 | list_del(&ftrace_mod->list); | |
4005 | list_add(&ftrace_mod->list, &process_mods); | |
4006 | ||
4007 | /* Use the newly allocated func, as it may be "*" */ | |
4008 | kfree(ftrace_mod->func); | |
4009 | ftrace_mod->func = func; | |
4010 | } | |
4011 | ||
4012 | mutex_unlock(&ftrace_lock); | |
4013 | ||
4014 | list_for_each_entry_safe(ftrace_mod, n, &process_mods, list) { | |
4015 | ||
4016 | func = ftrace_mod->func; | |
4017 | ||
4018 | /* Grabs ftrace_lock, which is why we have this extra step */ | |
4019 | match_records(new_hash, func, strlen(func), mod); | |
4020 | free_ftrace_mod(ftrace_mod); | |
4021 | } | |
4022 | ||
8c08f0d5 SRV |
4023 | if (enable && list_empty(head)) |
4024 | new_hash->flags &= ~FTRACE_HASH_FL_MOD; | |
4025 | ||
d7fbf8df SRV |
4026 | mutex_lock(&ftrace_lock); |
4027 | ||
4028 | ret = ftrace_hash_move_and_update_ops(ops, orig_hash, | |
4029 | new_hash, enable); | |
4030 | mutex_unlock(&ftrace_lock); | |
4031 | ||
3b58a3c7 | 4032 | out: |
d7fbf8df SRV |
4033 | mutex_unlock(&ops->func_hash->regex_lock); |
4034 | ||
4035 | free_ftrace_hash(new_hash); | |
4036 | } | |
4037 | ||
4038 | static void process_cached_mods(const char *mod_name) | |
4039 | { | |
4040 | struct trace_array *tr; | |
4041 | char *mod; | |
4042 | ||
4043 | mod = kstrdup(mod_name, GFP_KERNEL); | |
4044 | if (!mod) | |
4045 | return; | |
4046 | ||
4047 | mutex_lock(&trace_types_lock); | |
4048 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
4049 | if (!list_empty(&tr->mod_trace)) | |
4050 | process_mod_list(&tr->mod_trace, tr->ops, mod, true); | |
4051 | if (!list_empty(&tr->mod_notrace)) | |
4052 | process_mod_list(&tr->mod_notrace, tr->ops, mod, false); | |
4053 | } | |
4054 | mutex_unlock(&trace_types_lock); | |
4055 | ||
4056 | kfree(mod); | |
4057 | } | |
69449bbd | 4058 | #endif |
d7fbf8df | 4059 | |
f6180773 SR |
4060 | /* |
4061 | * We register the module command as a template to show others how | |
4062 | * to register the a command as well. | |
4063 | */ | |
4064 | ||
4065 | static int | |
04ec7bb6 | 4066 | ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash, |
673feb9d | 4067 | char *func_orig, char *cmd, char *module, int enable) |
f6180773 | 4068 | { |
673feb9d | 4069 | char *func; |
5e3949f0 | 4070 | int ret; |
f6180773 | 4071 | |
673feb9d SRV |
4072 | /* match_records() modifies func, and we need the original */ |
4073 | func = kstrdup(func_orig, GFP_KERNEL); | |
4074 | if (!func) | |
4075 | return -ENOMEM; | |
4076 | ||
f6180773 SR |
4077 | /* |
4078 | * cmd == 'mod' because we only registered this func | |
4079 | * for the 'mod' ftrace_func_command. | |
4080 | * But if you register one func with multiple commands, | |
4081 | * you can tell which command was used by the cmd | |
4082 | * parameter. | |
4083 | */ | |
f0a3b154 | 4084 | ret = match_records(hash, func, strlen(func), module); |
673feb9d SRV |
4085 | kfree(func); |
4086 | ||
b448c4e3 | 4087 | if (!ret) |
673feb9d | 4088 | return cache_mod(tr, func_orig, module, enable); |
b448c4e3 SR |
4089 | if (ret < 0) |
4090 | return ret; | |
b448c4e3 | 4091 | return 0; |
f6180773 SR |
4092 | } |
4093 | ||
4094 | static struct ftrace_func_command ftrace_mod_cmd = { | |
4095 | .name = "mod", | |
4096 | .func = ftrace_mod_callback, | |
4097 | }; | |
4098 | ||
4099 | static int __init ftrace_mod_cmd_init(void) | |
4100 | { | |
4101 | return register_ftrace_command(&ftrace_mod_cmd); | |
4102 | } | |
6f415672 | 4103 | core_initcall(ftrace_mod_cmd_init); |
f6180773 | 4104 | |
2f5f6ad9 | 4105 | static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 4106 | struct ftrace_ops *op, struct pt_regs *pt_regs) |
59df055f | 4107 | { |
eee8ded1 | 4108 | struct ftrace_probe_ops *probe_ops; |
7b60f3d8 | 4109 | struct ftrace_func_probe *probe; |
59df055f | 4110 | |
7b60f3d8 SRV |
4111 | probe = container_of(op, struct ftrace_func_probe, ops); |
4112 | probe_ops = probe->probe_ops; | |
59df055f SR |
4113 | |
4114 | /* | |
4115 | * Disable preemption for these calls to prevent a RCU grace | |
4116 | * period. This syncs the hash iteration and freeing of items | |
4117 | * on the hash. rcu_read_lock is too dangerous here. | |
4118 | */ | |
5168ae50 | 4119 | preempt_disable_notrace(); |
6e444319 | 4120 | probe_ops->func(ip, parent_ip, probe->tr, probe_ops, probe->data); |
5168ae50 | 4121 | preempt_enable_notrace(); |
59df055f SR |
4122 | } |
4123 | ||
41794f19 SRV |
4124 | struct ftrace_func_map { |
4125 | struct ftrace_func_entry entry; | |
4126 | void *data; | |
59df055f SR |
4127 | }; |
4128 | ||
41794f19 SRV |
4129 | struct ftrace_func_mapper { |
4130 | struct ftrace_hash hash; | |
4131 | }; | |
59df055f | 4132 | |
41794f19 SRV |
4133 | /** |
4134 | * allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper | |
4135 | * | |
4136 | * Returns a ftrace_func_mapper descriptor that can be used to map ips to data. | |
4137 | */ | |
4138 | struct ftrace_func_mapper *allocate_ftrace_func_mapper(void) | |
59df055f | 4139 | { |
41794f19 | 4140 | struct ftrace_hash *hash; |
59df055f | 4141 | |
41794f19 SRV |
4142 | /* |
4143 | * The mapper is simply a ftrace_hash, but since the entries | |
4144 | * in the hash are not ftrace_func_entry type, we define it | |
4145 | * as a separate structure. | |
4146 | */ | |
4147 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); | |
4148 | return (struct ftrace_func_mapper *)hash; | |
4149 | } | |
59df055f | 4150 | |
41794f19 SRV |
4151 | /** |
4152 | * ftrace_func_mapper_find_ip - Find some data mapped to an ip | |
4153 | * @mapper: The mapper that has the ip maps | |
4154 | * @ip: the instruction pointer to find the data for | |
4155 | * | |
4156 | * Returns the data mapped to @ip if found otherwise NULL. The return | |
4157 | * is actually the address of the mapper data pointer. The address is | |
4158 | * returned for use cases where the data is no bigger than a long, and | |
4159 | * the user can use the data pointer as its data instead of having to | |
4160 | * allocate more memory for the reference. | |
4161 | */ | |
4162 | void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper, | |
4163 | unsigned long ip) | |
4164 | { | |
4165 | struct ftrace_func_entry *entry; | |
4166 | struct ftrace_func_map *map; | |
59df055f | 4167 | |
41794f19 SRV |
4168 | entry = ftrace_lookup_ip(&mapper->hash, ip); |
4169 | if (!entry) | |
4170 | return NULL; | |
b848914c | 4171 | |
41794f19 SRV |
4172 | map = (struct ftrace_func_map *)entry; |
4173 | return &map->data; | |
59df055f SR |
4174 | } |
4175 | ||
41794f19 SRV |
4176 | /** |
4177 | * ftrace_func_mapper_add_ip - Map some data to an ip | |
4178 | * @mapper: The mapper that has the ip maps | |
4179 | * @ip: The instruction pointer address to map @data to | |
4180 | * @data: The data to map to @ip | |
4181 | * | |
4182 | * Returns 0 on succes otherwise an error. | |
4183 | */ | |
4184 | int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper, | |
4185 | unsigned long ip, void *data) | |
59df055f | 4186 | { |
41794f19 SRV |
4187 | struct ftrace_func_entry *entry; |
4188 | struct ftrace_func_map *map; | |
59df055f | 4189 | |
41794f19 SRV |
4190 | entry = ftrace_lookup_ip(&mapper->hash, ip); |
4191 | if (entry) | |
4192 | return -EBUSY; | |
59df055f | 4193 | |
41794f19 SRV |
4194 | map = kmalloc(sizeof(*map), GFP_KERNEL); |
4195 | if (!map) | |
4196 | return -ENOMEM; | |
59df055f | 4197 | |
41794f19 SRV |
4198 | map->entry.ip = ip; |
4199 | map->data = data; | |
b848914c | 4200 | |
41794f19 | 4201 | __add_hash_entry(&mapper->hash, &map->entry); |
59df055f | 4202 | |
41794f19 SRV |
4203 | return 0; |
4204 | } | |
59df055f | 4205 | |
41794f19 SRV |
4206 | /** |
4207 | * ftrace_func_mapper_remove_ip - Remove an ip from the mapping | |
4208 | * @mapper: The mapper that has the ip maps | |
4209 | * @ip: The instruction pointer address to remove the data from | |
4210 | * | |
4211 | * Returns the data if it is found, otherwise NULL. | |
4212 | * Note, if the data pointer is used as the data itself, (see | |
4213 | * ftrace_func_mapper_find_ip(), then the return value may be meaningless, | |
4214 | * if the data pointer was set to zero. | |
4215 | */ | |
4216 | void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper, | |
4217 | unsigned long ip) | |
59df055f | 4218 | { |
41794f19 SRV |
4219 | struct ftrace_func_entry *entry; |
4220 | struct ftrace_func_map *map; | |
4221 | void *data; | |
4222 | ||
4223 | entry = ftrace_lookup_ip(&mapper->hash, ip); | |
4224 | if (!entry) | |
4225 | return NULL; | |
4226 | ||
4227 | map = (struct ftrace_func_map *)entry; | |
4228 | data = map->data; | |
4229 | ||
4230 | remove_hash_entry(&mapper->hash, entry); | |
59df055f | 4231 | kfree(entry); |
41794f19 SRV |
4232 | |
4233 | return data; | |
4234 | } | |
4235 | ||
4236 | /** | |
4237 | * free_ftrace_func_mapper - free a mapping of ips and data | |
4238 | * @mapper: The mapper that has the ip maps | |
4239 | * @free_func: A function to be called on each data item. | |
4240 | * | |
4241 | * This is used to free the function mapper. The @free_func is optional | |
4242 | * and can be used if the data needs to be freed as well. | |
4243 | */ | |
4244 | void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper, | |
4245 | ftrace_mapper_func free_func) | |
4246 | { | |
4247 | struct ftrace_func_entry *entry; | |
4248 | struct ftrace_func_map *map; | |
4249 | struct hlist_head *hhd; | |
4250 | int size = 1 << mapper->hash.size_bits; | |
4251 | int i; | |
4252 | ||
4253 | if (free_func && mapper->hash.count) { | |
4254 | for (i = 0; i < size; i++) { | |
4255 | hhd = &mapper->hash.buckets[i]; | |
4256 | hlist_for_each_entry(entry, hhd, hlist) { | |
4257 | map = (struct ftrace_func_map *)entry; | |
4258 | free_func(map); | |
4259 | } | |
4260 | } | |
4261 | } | |
4262 | free_ftrace_hash(&mapper->hash); | |
4263 | } | |
4264 | ||
7b60f3d8 SRV |
4265 | static void release_probe(struct ftrace_func_probe *probe) |
4266 | { | |
4267 | struct ftrace_probe_ops *probe_ops; | |
4268 | ||
4269 | mutex_lock(&ftrace_lock); | |
4270 | ||
4271 | WARN_ON(probe->ref <= 0); | |
4272 | ||
4273 | /* Subtract the ref that was used to protect this instance */ | |
4274 | probe->ref--; | |
4275 | ||
4276 | if (!probe->ref) { | |
4277 | probe_ops = probe->probe_ops; | |
6e444319 SRV |
4278 | /* |
4279 | * Sending zero as ip tells probe_ops to free | |
4280 | * the probe->data itself | |
4281 | */ | |
4282 | if (probe_ops->free) | |
4283 | probe_ops->free(probe_ops, probe->tr, 0, probe->data); | |
7b60f3d8 SRV |
4284 | list_del(&probe->list); |
4285 | kfree(probe); | |
4286 | } | |
4287 | mutex_unlock(&ftrace_lock); | |
4288 | } | |
4289 | ||
4290 | static void acquire_probe_locked(struct ftrace_func_probe *probe) | |
4291 | { | |
4292 | /* | |
4293 | * Add one ref to keep it from being freed when releasing the | |
4294 | * ftrace_lock mutex. | |
4295 | */ | |
4296 | probe->ref++; | |
59df055f SR |
4297 | } |
4298 | ||
59df055f | 4299 | int |
04ec7bb6 | 4300 | register_ftrace_function_probe(char *glob, struct trace_array *tr, |
7b60f3d8 SRV |
4301 | struct ftrace_probe_ops *probe_ops, |
4302 | void *data) | |
59df055f | 4303 | { |
1ec3a81a | 4304 | struct ftrace_func_entry *entry; |
7b60f3d8 | 4305 | struct ftrace_func_probe *probe; |
1ec3a81a SRV |
4306 | struct ftrace_hash **orig_hash; |
4307 | struct ftrace_hash *old_hash; | |
e1df4cb6 | 4308 | struct ftrace_hash *hash; |
59df055f | 4309 | int count = 0; |
1ec3a81a | 4310 | int size; |
e1df4cb6 | 4311 | int ret; |
1ec3a81a | 4312 | int i; |
59df055f | 4313 | |
04ec7bb6 | 4314 | if (WARN_ON(!tr)) |
59df055f SR |
4315 | return -EINVAL; |
4316 | ||
1ec3a81a SRV |
4317 | /* We do not support '!' for function probes */ |
4318 | if (WARN_ON(glob[0] == '!')) | |
59df055f | 4319 | return -EINVAL; |
59df055f | 4320 | |
7485058e | 4321 | |
7b60f3d8 SRV |
4322 | mutex_lock(&ftrace_lock); |
4323 | /* Check if the probe_ops is already registered */ | |
4324 | list_for_each_entry(probe, &tr->func_probes, list) { | |
4325 | if (probe->probe_ops == probe_ops) | |
4326 | break; | |
e1df4cb6 | 4327 | } |
7b60f3d8 SRV |
4328 | if (&probe->list == &tr->func_probes) { |
4329 | probe = kzalloc(sizeof(*probe), GFP_KERNEL); | |
4330 | if (!probe) { | |
4331 | mutex_unlock(&ftrace_lock); | |
4332 | return -ENOMEM; | |
4333 | } | |
4334 | probe->probe_ops = probe_ops; | |
4335 | probe->ops.func = function_trace_probe_call; | |
4336 | probe->tr = tr; | |
4337 | ftrace_ops_init(&probe->ops); | |
4338 | list_add(&probe->list, &tr->func_probes); | |
e1df4cb6 | 4339 | } |
59df055f | 4340 | |
7b60f3d8 | 4341 | acquire_probe_locked(probe); |
5ae0bf59 | 4342 | |
7b60f3d8 | 4343 | mutex_unlock(&ftrace_lock); |
59df055f | 4344 | |
7b60f3d8 | 4345 | mutex_lock(&probe->ops.func_hash->regex_lock); |
546fece4 | 4346 | |
7b60f3d8 | 4347 | orig_hash = &probe->ops.func_hash->filter_hash; |
1ec3a81a SRV |
4348 | old_hash = *orig_hash; |
4349 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); | |
59df055f | 4350 | |
1ec3a81a | 4351 | ret = ftrace_match_records(hash, glob, strlen(glob)); |
59df055f | 4352 | |
1ec3a81a SRV |
4353 | /* Nothing found? */ |
4354 | if (!ret) | |
4355 | ret = -EINVAL; | |
59df055f | 4356 | |
1ec3a81a SRV |
4357 | if (ret < 0) |
4358 | goto out; | |
59df055f | 4359 | |
1ec3a81a SRV |
4360 | size = 1 << hash->size_bits; |
4361 | for (i = 0; i < size; i++) { | |
4362 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
4363 | if (ftrace_lookup_ip(old_hash, entry->ip)) | |
59df055f | 4364 | continue; |
1ec3a81a SRV |
4365 | /* |
4366 | * The caller might want to do something special | |
4367 | * for each function we find. We call the callback | |
4368 | * to give the caller an opportunity to do so. | |
4369 | */ | |
7b60f3d8 SRV |
4370 | if (probe_ops->init) { |
4371 | ret = probe_ops->init(probe_ops, tr, | |
6e444319 SRV |
4372 | entry->ip, data, |
4373 | &probe->data); | |
4374 | if (ret < 0) { | |
4375 | if (probe_ops->free && count) | |
4376 | probe_ops->free(probe_ops, tr, | |
4377 | 0, probe->data); | |
4378 | probe->data = NULL; | |
eee8ded1 | 4379 | goto out; |
6e444319 | 4380 | } |
59df055f | 4381 | } |
1ec3a81a | 4382 | count++; |
59df055f | 4383 | } |
1ec3a81a | 4384 | } |
59df055f | 4385 | |
1ec3a81a | 4386 | mutex_lock(&ftrace_lock); |
59df055f | 4387 | |
7b60f3d8 SRV |
4388 | if (!count) { |
4389 | /* Nothing was added? */ | |
4390 | ret = -EINVAL; | |
4391 | goto out_unlock; | |
4392 | } | |
e1df4cb6 | 4393 | |
7b60f3d8 SRV |
4394 | ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash, |
4395 | hash, 1); | |
1ec3a81a | 4396 | if (ret < 0) |
8d70725e | 4397 | goto err_unlock; |
8252ecf3 | 4398 | |
7b60f3d8 SRV |
4399 | /* One ref for each new function traced */ |
4400 | probe->ref += count; | |
8252ecf3 | 4401 | |
7b60f3d8 SRV |
4402 | if (!(probe->ops.flags & FTRACE_OPS_FL_ENABLED)) |
4403 | ret = ftrace_startup(&probe->ops, 0); | |
e1df4cb6 | 4404 | |
59df055f | 4405 | out_unlock: |
5ae0bf59 | 4406 | mutex_unlock(&ftrace_lock); |
8252ecf3 | 4407 | |
3296fc4e | 4408 | if (!ret) |
1ec3a81a | 4409 | ret = count; |
5ae0bf59 | 4410 | out: |
7b60f3d8 | 4411 | mutex_unlock(&probe->ops.func_hash->regex_lock); |
e1df4cb6 | 4412 | free_ftrace_hash(hash); |
59df055f | 4413 | |
7b60f3d8 | 4414 | release_probe(probe); |
59df055f | 4415 | |
1ec3a81a | 4416 | return ret; |
59df055f | 4417 | |
8d70725e | 4418 | err_unlock: |
7b60f3d8 | 4419 | if (!probe_ops->free || !count) |
8d70725e SRV |
4420 | goto out_unlock; |
4421 | ||
4422 | /* Failed to do the move, need to call the free functions */ | |
4423 | for (i = 0; i < size; i++) { | |
4424 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
4425 | if (ftrace_lookup_ip(old_hash, entry->ip)) | |
4426 | continue; | |
6e444319 | 4427 | probe_ops->free(probe_ops, tr, entry->ip, probe->data); |
8d70725e SRV |
4428 | } |
4429 | } | |
4430 | goto out_unlock; | |
59df055f SR |
4431 | } |
4432 | ||
d3d532d7 | 4433 | int |
7b60f3d8 SRV |
4434 | unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr, |
4435 | struct ftrace_probe_ops *probe_ops) | |
59df055f | 4436 | { |
82cc4fc2 | 4437 | struct ftrace_ops_hash old_hash_ops; |
eee8ded1 | 4438 | struct ftrace_func_entry *entry; |
7b60f3d8 | 4439 | struct ftrace_func_probe *probe; |
3ba00929 | 4440 | struct ftrace_glob func_g; |
1ec3a81a SRV |
4441 | struct ftrace_hash **orig_hash; |
4442 | struct ftrace_hash *old_hash; | |
1ec3a81a | 4443 | struct ftrace_hash *hash = NULL; |
b67bfe0d | 4444 | struct hlist_node *tmp; |
eee8ded1 | 4445 | struct hlist_head hhd; |
59df055f | 4446 | char str[KSYM_SYMBOL_LEN]; |
7b60f3d8 SRV |
4447 | int count = 0; |
4448 | int i, ret = -ENODEV; | |
eee8ded1 | 4449 | int size; |
59df055f | 4450 | |
cbab567c | 4451 | if (!glob || !strlen(glob) || !strcmp(glob, "*")) |
3ba00929 | 4452 | func_g.search = NULL; |
cbab567c | 4453 | else { |
59df055f SR |
4454 | int not; |
4455 | ||
3ba00929 DS |
4456 | func_g.type = filter_parse_regex(glob, strlen(glob), |
4457 | &func_g.search, ¬); | |
4458 | func_g.len = strlen(func_g.search); | |
4459 | func_g.search = glob; | |
59df055f | 4460 | |
b6887d79 | 4461 | /* we do not support '!' for function probes */ |
59df055f | 4462 | if (WARN_ON(not)) |
d3d532d7 | 4463 | return -EINVAL; |
59df055f SR |
4464 | } |
4465 | ||
7b60f3d8 SRV |
4466 | mutex_lock(&ftrace_lock); |
4467 | /* Check if the probe_ops is already registered */ | |
4468 | list_for_each_entry(probe, &tr->func_probes, list) { | |
4469 | if (probe->probe_ops == probe_ops) | |
4470 | break; | |
59df055f | 4471 | } |
7b60f3d8 SRV |
4472 | if (&probe->list == &tr->func_probes) |
4473 | goto err_unlock_ftrace; | |
4474 | ||
4475 | ret = -EINVAL; | |
4476 | if (!(probe->ops.flags & FTRACE_OPS_FL_INITIALIZED)) | |
4477 | goto err_unlock_ftrace; | |
4478 | ||
4479 | acquire_probe_locked(probe); | |
4480 | ||
4481 | mutex_unlock(&ftrace_lock); | |
59df055f | 4482 | |
7b60f3d8 | 4483 | mutex_lock(&probe->ops.func_hash->regex_lock); |
1ec3a81a | 4484 | |
7b60f3d8 | 4485 | orig_hash = &probe->ops.func_hash->filter_hash; |
1ec3a81a SRV |
4486 | old_hash = *orig_hash; |
4487 | ||
1ec3a81a SRV |
4488 | if (ftrace_hash_empty(old_hash)) |
4489 | goto out_unlock; | |
e1df4cb6 | 4490 | |
82cc4fc2 SRV |
4491 | old_hash_ops.filter_hash = old_hash; |
4492 | /* Probes only have filters */ | |
4493 | old_hash_ops.notrace_hash = NULL; | |
4494 | ||
d3d532d7 | 4495 | ret = -ENOMEM; |
1ec3a81a | 4496 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); |
e1df4cb6 | 4497 | if (!hash) |
e1df4cb6 SRRH |
4498 | goto out_unlock; |
4499 | ||
eee8ded1 | 4500 | INIT_HLIST_HEAD(&hhd); |
59df055f | 4501 | |
eee8ded1 SRV |
4502 | size = 1 << hash->size_bits; |
4503 | for (i = 0; i < size; i++) { | |
4504 | hlist_for_each_entry_safe(entry, tmp, &hash->buckets[i], hlist) { | |
59df055f | 4505 | |
3ba00929 | 4506 | if (func_g.search) { |
59df055f SR |
4507 | kallsyms_lookup(entry->ip, NULL, NULL, |
4508 | NULL, str); | |
3ba00929 | 4509 | if (!ftrace_match(str, &func_g)) |
59df055f SR |
4510 | continue; |
4511 | } | |
7b60f3d8 | 4512 | count++; |
eee8ded1 SRV |
4513 | remove_hash_entry(hash, entry); |
4514 | hlist_add_head(&entry->hlist, &hhd); | |
59df055f SR |
4515 | } |
4516 | } | |
d3d532d7 SRV |
4517 | |
4518 | /* Nothing found? */ | |
7b60f3d8 | 4519 | if (!count) { |
d3d532d7 SRV |
4520 | ret = -EINVAL; |
4521 | goto out_unlock; | |
4522 | } | |
4523 | ||
3f2367ba | 4524 | mutex_lock(&ftrace_lock); |
1ec3a81a | 4525 | |
7b60f3d8 | 4526 | WARN_ON(probe->ref < count); |
eee8ded1 | 4527 | |
7b60f3d8 | 4528 | probe->ref -= count; |
1ec3a81a | 4529 | |
7b60f3d8 SRV |
4530 | if (ftrace_hash_empty(hash)) |
4531 | ftrace_shutdown(&probe->ops, 0); | |
4532 | ||
4533 | ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash, | |
1ec3a81a | 4534 | hash, 1); |
82cc4fc2 SRV |
4535 | |
4536 | /* still need to update the function call sites */ | |
1ec3a81a | 4537 | if (ftrace_enabled && !ftrace_hash_empty(hash)) |
7b60f3d8 | 4538 | ftrace_run_modify_code(&probe->ops, FTRACE_UPDATE_CALLS, |
82cc4fc2 | 4539 | &old_hash_ops); |
7818b388 | 4540 | synchronize_sched(); |
3296fc4e | 4541 | |
eee8ded1 SRV |
4542 | hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) { |
4543 | hlist_del(&entry->hlist); | |
7b60f3d8 | 4544 | if (probe_ops->free) |
6e444319 | 4545 | probe_ops->free(probe_ops, tr, entry->ip, probe->data); |
eee8ded1 | 4546 | kfree(entry); |
7818b388 | 4547 | } |
3f2367ba | 4548 | mutex_unlock(&ftrace_lock); |
3ba00929 | 4549 | |
e1df4cb6 | 4550 | out_unlock: |
7b60f3d8 | 4551 | mutex_unlock(&probe->ops.func_hash->regex_lock); |
e1df4cb6 | 4552 | free_ftrace_hash(hash); |
59df055f | 4553 | |
7b60f3d8 | 4554 | release_probe(probe); |
59df055f | 4555 | |
7b60f3d8 | 4556 | return ret; |
59df055f | 4557 | |
7b60f3d8 SRV |
4558 | err_unlock_ftrace: |
4559 | mutex_unlock(&ftrace_lock); | |
d3d532d7 | 4560 | return ret; |
59df055f SR |
4561 | } |
4562 | ||
a0e6369e NR |
4563 | void clear_ftrace_function_probes(struct trace_array *tr) |
4564 | { | |
4565 | struct ftrace_func_probe *probe, *n; | |
4566 | ||
4567 | list_for_each_entry_safe(probe, n, &tr->func_probes, list) | |
4568 | unregister_ftrace_function_probe_func(NULL, tr, probe->probe_ops); | |
4569 | } | |
4570 | ||
f6180773 SR |
4571 | static LIST_HEAD(ftrace_commands); |
4572 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
4573 | ||
38de93ab TZ |
4574 | /* |
4575 | * Currently we only register ftrace commands from __init, so mark this | |
4576 | * __init too. | |
4577 | */ | |
4578 | __init int register_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
4579 | { |
4580 | struct ftrace_func_command *p; | |
4581 | int ret = 0; | |
4582 | ||
4583 | mutex_lock(&ftrace_cmd_mutex); | |
4584 | list_for_each_entry(p, &ftrace_commands, list) { | |
4585 | if (strcmp(cmd->name, p->name) == 0) { | |
4586 | ret = -EBUSY; | |
4587 | goto out_unlock; | |
4588 | } | |
4589 | } | |
4590 | list_add(&cmd->list, &ftrace_commands); | |
4591 | out_unlock: | |
4592 | mutex_unlock(&ftrace_cmd_mutex); | |
4593 | ||
4594 | return ret; | |
4595 | } | |
4596 | ||
38de93ab TZ |
4597 | /* |
4598 | * Currently we only unregister ftrace commands from __init, so mark | |
4599 | * this __init too. | |
4600 | */ | |
4601 | __init int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
4602 | { |
4603 | struct ftrace_func_command *p, *n; | |
4604 | int ret = -ENODEV; | |
4605 | ||
4606 | mutex_lock(&ftrace_cmd_mutex); | |
4607 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
4608 | if (strcmp(cmd->name, p->name) == 0) { | |
4609 | ret = 0; | |
4610 | list_del_init(&p->list); | |
4611 | goto out_unlock; | |
4612 | } | |
4613 | } | |
4614 | out_unlock: | |
4615 | mutex_unlock(&ftrace_cmd_mutex); | |
4616 | ||
4617 | return ret; | |
4618 | } | |
4619 | ||
04ec7bb6 | 4620 | static int ftrace_process_regex(struct ftrace_iterator *iter, |
33dc9b12 | 4621 | char *buff, int len, int enable) |
64e7c440 | 4622 | { |
04ec7bb6 | 4623 | struct ftrace_hash *hash = iter->hash; |
d2afd57a | 4624 | struct trace_array *tr = iter->ops->private; |
f6180773 | 4625 | char *func, *command, *next = buff; |
6a24a244 | 4626 | struct ftrace_func_command *p; |
0aff1c0c | 4627 | int ret = -EINVAL; |
64e7c440 SR |
4628 | |
4629 | func = strsep(&next, ":"); | |
4630 | ||
4631 | if (!next) { | |
1cf41dd7 | 4632 | ret = ftrace_match_records(hash, func, len); |
b448c4e3 SR |
4633 | if (!ret) |
4634 | ret = -EINVAL; | |
4635 | if (ret < 0) | |
4636 | return ret; | |
4637 | return 0; | |
64e7c440 SR |
4638 | } |
4639 | ||
f6180773 | 4640 | /* command found */ |
64e7c440 SR |
4641 | |
4642 | command = strsep(&next, ":"); | |
4643 | ||
f6180773 SR |
4644 | mutex_lock(&ftrace_cmd_mutex); |
4645 | list_for_each_entry(p, &ftrace_commands, list) { | |
4646 | if (strcmp(p->name, command) == 0) { | |
04ec7bb6 | 4647 | ret = p->func(tr, hash, func, command, next, enable); |
f6180773 SR |
4648 | goto out_unlock; |
4649 | } | |
64e7c440 | 4650 | } |
f6180773 SR |
4651 | out_unlock: |
4652 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 4653 | |
f6180773 | 4654 | return ret; |
64e7c440 SR |
4655 | } |
4656 | ||
e309b41d | 4657 | static ssize_t |
41c52c0d SR |
4658 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
4659 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
4660 | { |
4661 | struct ftrace_iterator *iter; | |
689fd8b6 | 4662 | struct trace_parser *parser; |
4663 | ssize_t ret, read; | |
5072c59f | 4664 | |
4ba7978e | 4665 | if (!cnt) |
5072c59f SR |
4666 | return 0; |
4667 | ||
5072c59f SR |
4668 | if (file->f_mode & FMODE_READ) { |
4669 | struct seq_file *m = file->private_data; | |
4670 | iter = m->private; | |
4671 | } else | |
4672 | iter = file->private_data; | |
4673 | ||
f04f24fb | 4674 | if (unlikely(ftrace_disabled)) |
3f2367ba MH |
4675 | return -ENODEV; |
4676 | ||
4677 | /* iter->hash is a local copy, so we don't need regex_lock */ | |
f04f24fb | 4678 | |
689fd8b6 | 4679 | parser = &iter->parser; |
4680 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 4681 | |
4ba7978e | 4682 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 4683 | !trace_parser_cont(parser)) { |
04ec7bb6 | 4684 | ret = ftrace_process_regex(iter, parser->buffer, |
689fd8b6 | 4685 | parser->idx, enable); |
313254a9 | 4686 | trace_parser_clear(parser); |
7c088b51 | 4687 | if (ret < 0) |
3f2367ba | 4688 | goto out; |
eda1e328 | 4689 | } |
5072c59f | 4690 | |
5072c59f | 4691 | ret = read; |
3f2367ba | 4692 | out: |
5072c59f SR |
4693 | return ret; |
4694 | } | |
4695 | ||
fc13cb0c | 4696 | ssize_t |
41c52c0d SR |
4697 | ftrace_filter_write(struct file *file, const char __user *ubuf, |
4698 | size_t cnt, loff_t *ppos) | |
4699 | { | |
4700 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
4701 | } | |
4702 | ||
fc13cb0c | 4703 | ssize_t |
41c52c0d SR |
4704 | ftrace_notrace_write(struct file *file, const char __user *ubuf, |
4705 | size_t cnt, loff_t *ppos) | |
4706 | { | |
4707 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
4708 | } | |
4709 | ||
33dc9b12 | 4710 | static int |
647664ea MH |
4711 | ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) |
4712 | { | |
4713 | struct ftrace_func_entry *entry; | |
4714 | ||
4715 | if (!ftrace_location(ip)) | |
4716 | return -EINVAL; | |
4717 | ||
4718 | if (remove) { | |
4719 | entry = ftrace_lookup_ip(hash, ip); | |
4720 | if (!entry) | |
4721 | return -ENOENT; | |
4722 | free_hash_entry(hash, entry); | |
4723 | return 0; | |
4724 | } | |
4725 | ||
4726 | return add_hash_entry(hash, ip); | |
4727 | } | |
4728 | ||
4729 | static int | |
4730 | ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, | |
4731 | unsigned long ip, int remove, int reset, int enable) | |
41c52c0d | 4732 | { |
33dc9b12 | 4733 | struct ftrace_hash **orig_hash; |
f45948e8 | 4734 | struct ftrace_hash *hash; |
33dc9b12 | 4735 | int ret; |
f45948e8 | 4736 | |
41c52c0d | 4737 | if (unlikely(ftrace_disabled)) |
33dc9b12 | 4738 | return -ENODEV; |
41c52c0d | 4739 | |
33b7f99c | 4740 | mutex_lock(&ops->func_hash->regex_lock); |
3f2367ba | 4741 | |
f45948e8 | 4742 | if (enable) |
33b7f99c | 4743 | orig_hash = &ops->func_hash->filter_hash; |
f45948e8 | 4744 | else |
33b7f99c | 4745 | orig_hash = &ops->func_hash->notrace_hash; |
33dc9b12 | 4746 | |
b972cc58 WN |
4747 | if (reset) |
4748 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); | |
4749 | else | |
4750 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
4751 | ||
3f2367ba MH |
4752 | if (!hash) { |
4753 | ret = -ENOMEM; | |
4754 | goto out_regex_unlock; | |
4755 | } | |
f45948e8 | 4756 | |
ac483c44 JO |
4757 | if (buf && !ftrace_match_records(hash, buf, len)) { |
4758 | ret = -EINVAL; | |
4759 | goto out_regex_unlock; | |
4760 | } | |
647664ea MH |
4761 | if (ip) { |
4762 | ret = ftrace_match_addr(hash, ip, remove); | |
4763 | if (ret < 0) | |
4764 | goto out_regex_unlock; | |
4765 | } | |
33dc9b12 SR |
4766 | |
4767 | mutex_lock(&ftrace_lock); | |
e16b35dd | 4768 | ret = ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable); |
33dc9b12 SR |
4769 | mutex_unlock(&ftrace_lock); |
4770 | ||
ac483c44 | 4771 | out_regex_unlock: |
33b7f99c | 4772 | mutex_unlock(&ops->func_hash->regex_lock); |
33dc9b12 SR |
4773 | |
4774 | free_ftrace_hash(hash); | |
4775 | return ret; | |
41c52c0d SR |
4776 | } |
4777 | ||
647664ea MH |
4778 | static int |
4779 | ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove, | |
4780 | int reset, int enable) | |
4781 | { | |
4782 | return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable); | |
4783 | } | |
4784 | ||
4785 | /** | |
4786 | * ftrace_set_filter_ip - set a function to filter on in ftrace by address | |
4787 | * @ops - the ops to set the filter with | |
4788 | * @ip - the address to add to or remove from the filter. | |
4789 | * @remove - non zero to remove the ip from the filter | |
4790 | * @reset - non zero to reset all filters before applying this filter. | |
4791 | * | |
4792 | * Filters denote which functions should be enabled when tracing is enabled | |
4793 | * If @ip is NULL, it failes to update filter. | |
4794 | */ | |
4795 | int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, | |
4796 | int remove, int reset) | |
4797 | { | |
f04f24fb | 4798 | ftrace_ops_init(ops); |
647664ea MH |
4799 | return ftrace_set_addr(ops, ip, remove, reset, 1); |
4800 | } | |
4801 | EXPORT_SYMBOL_GPL(ftrace_set_filter_ip); | |
4802 | ||
d032ae89 JF |
4803 | /** |
4804 | * ftrace_ops_set_global_filter - setup ops to use global filters | |
4805 | * @ops - the ops which will use the global filters | |
4806 | * | |
4807 | * ftrace users who need global function trace filtering should call this. | |
4808 | * It can set the global filter only if ops were not initialized before. | |
4809 | */ | |
4810 | void ftrace_ops_set_global_filter(struct ftrace_ops *ops) | |
4811 | { | |
4812 | if (ops->flags & FTRACE_OPS_FL_INITIALIZED) | |
4813 | return; | |
4814 | ||
4815 | ftrace_ops_init(ops); | |
4816 | ops->func_hash = &global_ops.local_hash; | |
4817 | } | |
4818 | EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter); | |
4819 | ||
647664ea MH |
4820 | static int |
4821 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, | |
4822 | int reset, int enable) | |
4823 | { | |
4824 | return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable); | |
4825 | } | |
4826 | ||
77a2b37d SR |
4827 | /** |
4828 | * ftrace_set_filter - set a function to filter on in ftrace | |
936e074b SR |
4829 | * @ops - the ops to set the filter with |
4830 | * @buf - the string that holds the function filter text. | |
4831 | * @len - the length of the string. | |
4832 | * @reset - non zero to reset all filters before applying this filter. | |
4833 | * | |
4834 | * Filters denote which functions should be enabled when tracing is enabled. | |
4835 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
4836 | */ | |
ac483c44 | 4837 | int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
4838 | int len, int reset) |
4839 | { | |
f04f24fb | 4840 | ftrace_ops_init(ops); |
ac483c44 | 4841 | return ftrace_set_regex(ops, buf, len, reset, 1); |
936e074b SR |
4842 | } |
4843 | EXPORT_SYMBOL_GPL(ftrace_set_filter); | |
4844 | ||
4845 | /** | |
4846 | * ftrace_set_notrace - set a function to not trace in ftrace | |
4847 | * @ops - the ops to set the notrace filter with | |
4848 | * @buf - the string that holds the function notrace text. | |
4849 | * @len - the length of the string. | |
4850 | * @reset - non zero to reset all filters before applying this filter. | |
4851 | * | |
4852 | * Notrace Filters denote which functions should not be enabled when tracing | |
4853 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
4854 | * for tracing. | |
4855 | */ | |
ac483c44 | 4856 | int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
4857 | int len, int reset) |
4858 | { | |
f04f24fb | 4859 | ftrace_ops_init(ops); |
ac483c44 | 4860 | return ftrace_set_regex(ops, buf, len, reset, 0); |
936e074b SR |
4861 | } |
4862 | EXPORT_SYMBOL_GPL(ftrace_set_notrace); | |
4863 | /** | |
8d1b065d | 4864 | * ftrace_set_global_filter - set a function to filter on with global tracers |
77a2b37d SR |
4865 | * @buf - the string that holds the function filter text. |
4866 | * @len - the length of the string. | |
4867 | * @reset - non zero to reset all filters before applying this filter. | |
4868 | * | |
4869 | * Filters denote which functions should be enabled when tracing is enabled. | |
4870 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
4871 | */ | |
936e074b | 4872 | void ftrace_set_global_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 4873 | { |
f45948e8 | 4874 | ftrace_set_regex(&global_ops, buf, len, reset, 1); |
41c52c0d | 4875 | } |
936e074b | 4876 | EXPORT_SYMBOL_GPL(ftrace_set_global_filter); |
4eebcc81 | 4877 | |
41c52c0d | 4878 | /** |
8d1b065d | 4879 | * ftrace_set_global_notrace - set a function to not trace with global tracers |
41c52c0d SR |
4880 | * @buf - the string that holds the function notrace text. |
4881 | * @len - the length of the string. | |
4882 | * @reset - non zero to reset all filters before applying this filter. | |
4883 | * | |
4884 | * Notrace Filters denote which functions should not be enabled when tracing | |
4885 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
4886 | * for tracing. | |
4887 | */ | |
936e074b | 4888 | void ftrace_set_global_notrace(unsigned char *buf, int len, int reset) |
41c52c0d | 4889 | { |
f45948e8 | 4890 | ftrace_set_regex(&global_ops, buf, len, reset, 0); |
77a2b37d | 4891 | } |
936e074b | 4892 | EXPORT_SYMBOL_GPL(ftrace_set_global_notrace); |
77a2b37d | 4893 | |
2af15d6a SR |
4894 | /* |
4895 | * command line interface to allow users to set filters on boot up. | |
4896 | */ | |
4897 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
4898 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
4899 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
4900 | ||
f1ed7c74 SRRH |
4901 | /* Used by function selftest to not test if filter is set */ |
4902 | bool ftrace_filter_param __initdata; | |
4903 | ||
2af15d6a SR |
4904 | static int __init set_ftrace_notrace(char *str) |
4905 | { | |
f1ed7c74 | 4906 | ftrace_filter_param = true; |
75761cc1 | 4907 | strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
4908 | return 1; |
4909 | } | |
4910 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
4911 | ||
4912 | static int __init set_ftrace_filter(char *str) | |
4913 | { | |
f1ed7c74 | 4914 | ftrace_filter_param = true; |
75761cc1 | 4915 | strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
4916 | return 1; |
4917 | } | |
4918 | __setup("ftrace_filter=", set_ftrace_filter); | |
4919 | ||
369bc18f | 4920 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 4921 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
0d7d9a16 | 4922 | static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata; |
b9b0c831 | 4923 | static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer); |
801c29fd | 4924 | |
369bc18f SA |
4925 | static int __init set_graph_function(char *str) |
4926 | { | |
06f43d66 | 4927 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
4928 | return 1; |
4929 | } | |
4930 | __setup("ftrace_graph_filter=", set_graph_function); | |
4931 | ||
0d7d9a16 NK |
4932 | static int __init set_graph_notrace_function(char *str) |
4933 | { | |
4934 | strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE); | |
4935 | return 1; | |
4936 | } | |
4937 | __setup("ftrace_graph_notrace=", set_graph_notrace_function); | |
4938 | ||
65a50c65 TB |
4939 | static int __init set_graph_max_depth_function(char *str) |
4940 | { | |
4941 | if (!str) | |
4942 | return 0; | |
4943 | fgraph_max_depth = simple_strtoul(str, NULL, 0); | |
4944 | return 1; | |
4945 | } | |
4946 | __setup("ftrace_graph_max_depth=", set_graph_max_depth_function); | |
0d7d9a16 NK |
4947 | |
4948 | static void __init set_ftrace_early_graph(char *buf, int enable) | |
369bc18f SA |
4949 | { |
4950 | int ret; | |
4951 | char *func; | |
b9b0c831 | 4952 | struct ftrace_hash *hash; |
0d7d9a16 | 4953 | |
92ad18ec SRV |
4954 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); |
4955 | if (WARN_ON(!hash)) | |
4956 | return; | |
369bc18f SA |
4957 | |
4958 | while (buf) { | |
4959 | func = strsep(&buf, ","); | |
4960 | /* we allow only one expression at a time */ | |
b9b0c831 | 4961 | ret = ftrace_graph_set_hash(hash, func); |
369bc18f SA |
4962 | if (ret) |
4963 | printk(KERN_DEBUG "ftrace: function %s not " | |
4964 | "traceable\n", func); | |
4965 | } | |
92ad18ec SRV |
4966 | |
4967 | if (enable) | |
4968 | ftrace_graph_hash = hash; | |
4969 | else | |
4970 | ftrace_graph_notrace_hash = hash; | |
369bc18f SA |
4971 | } |
4972 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
4973 | ||
2a85a37f SR |
4974 | void __init |
4975 | ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable) | |
2af15d6a SR |
4976 | { |
4977 | char *func; | |
4978 | ||
f04f24fb MH |
4979 | ftrace_ops_init(ops); |
4980 | ||
2af15d6a SR |
4981 | while (buf) { |
4982 | func = strsep(&buf, ","); | |
f45948e8 | 4983 | ftrace_set_regex(ops, func, strlen(func), 0, enable); |
2af15d6a SR |
4984 | } |
4985 | } | |
4986 | ||
4987 | static void __init set_ftrace_early_filters(void) | |
4988 | { | |
4989 | if (ftrace_filter_buf[0]) | |
2a85a37f | 4990 | ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1); |
2af15d6a | 4991 | if (ftrace_notrace_buf[0]) |
2a85a37f | 4992 | ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0); |
369bc18f SA |
4993 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
4994 | if (ftrace_graph_buf[0]) | |
0d7d9a16 NK |
4995 | set_ftrace_early_graph(ftrace_graph_buf, 1); |
4996 | if (ftrace_graph_notrace_buf[0]) | |
4997 | set_ftrace_early_graph(ftrace_graph_notrace_buf, 0); | |
369bc18f | 4998 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
2af15d6a SR |
4999 | } |
5000 | ||
fc13cb0c | 5001 | int ftrace_regex_release(struct inode *inode, struct file *file) |
5072c59f SR |
5002 | { |
5003 | struct seq_file *m = (struct seq_file *)file->private_data; | |
5004 | struct ftrace_iterator *iter; | |
33dc9b12 | 5005 | struct ftrace_hash **orig_hash; |
689fd8b6 | 5006 | struct trace_parser *parser; |
ed926f9b | 5007 | int filter_hash; |
33dc9b12 | 5008 | int ret; |
5072c59f | 5009 | |
5072c59f SR |
5010 | if (file->f_mode & FMODE_READ) { |
5011 | iter = m->private; | |
5072c59f SR |
5012 | seq_release(inode, file); |
5013 | } else | |
5014 | iter = file->private_data; | |
5015 | ||
689fd8b6 | 5016 | parser = &iter->parser; |
5017 | if (trace_parser_loaded(parser)) { | |
5018 | parser->buffer[parser->idx] = 0; | |
1cf41dd7 | 5019 | ftrace_match_records(iter->hash, parser->buffer, parser->idx); |
5072c59f SR |
5020 | } |
5021 | ||
689fd8b6 | 5022 | trace_parser_put(parser); |
689fd8b6 | 5023 | |
33b7f99c | 5024 | mutex_lock(&iter->ops->func_hash->regex_lock); |
3f2367ba | 5025 | |
058e297d | 5026 | if (file->f_mode & FMODE_WRITE) { |
ed926f9b SR |
5027 | filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); |
5028 | ||
8c08f0d5 | 5029 | if (filter_hash) { |
33b7f99c | 5030 | orig_hash = &iter->ops->func_hash->filter_hash; |
69d71879 | 5031 | if (iter->tr && !list_empty(&iter->tr->mod_trace)) |
8c08f0d5 SRV |
5032 | iter->hash->flags |= FTRACE_HASH_FL_MOD; |
5033 | } else | |
33b7f99c | 5034 | orig_hash = &iter->ops->func_hash->notrace_hash; |
33dc9b12 | 5035 | |
058e297d | 5036 | mutex_lock(&ftrace_lock); |
e16b35dd SRV |
5037 | ret = ftrace_hash_move_and_update_ops(iter->ops, orig_hash, |
5038 | iter->hash, filter_hash); | |
058e297d | 5039 | mutex_unlock(&ftrace_lock); |
c20489da SRV |
5040 | } else { |
5041 | /* For read only, the hash is the ops hash */ | |
5042 | iter->hash = NULL; | |
058e297d | 5043 | } |
3f2367ba | 5044 | |
33b7f99c | 5045 | mutex_unlock(&iter->ops->func_hash->regex_lock); |
33dc9b12 SR |
5046 | free_ftrace_hash(iter->hash); |
5047 | kfree(iter); | |
058e297d | 5048 | |
5072c59f SR |
5049 | return 0; |
5050 | } | |
5051 | ||
5e2336a0 | 5052 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
5053 | .open = ftrace_avail_open, |
5054 | .read = seq_read, | |
5055 | .llseek = seq_lseek, | |
3be04b47 | 5056 | .release = seq_release_private, |
5072c59f SR |
5057 | }; |
5058 | ||
647bcd03 SR |
5059 | static const struct file_operations ftrace_enabled_fops = { |
5060 | .open = ftrace_enabled_open, | |
5061 | .read = seq_read, | |
5062 | .llseek = seq_lseek, | |
5063 | .release = seq_release_private, | |
5064 | }; | |
5065 | ||
5e2336a0 | 5066 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 5067 | .open = ftrace_filter_open, |
850a80cf | 5068 | .read = seq_read, |
5072c59f | 5069 | .write = ftrace_filter_write, |
098c879e | 5070 | .llseek = tracing_lseek, |
1cf41dd7 | 5071 | .release = ftrace_regex_release, |
5072c59f SR |
5072 | }; |
5073 | ||
5e2336a0 | 5074 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 5075 | .open = ftrace_notrace_open, |
850a80cf | 5076 | .read = seq_read, |
41c52c0d | 5077 | .write = ftrace_notrace_write, |
098c879e | 5078 | .llseek = tracing_lseek, |
1cf41dd7 | 5079 | .release = ftrace_regex_release, |
41c52c0d SR |
5080 | }; |
5081 | ||
ea4e2bc4 SR |
5082 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5083 | ||
5084 | static DEFINE_MUTEX(graph_lock); | |
5085 | ||
b9b0c831 NK |
5086 | struct ftrace_hash *ftrace_graph_hash = EMPTY_HASH; |
5087 | struct ftrace_hash *ftrace_graph_notrace_hash = EMPTY_HASH; | |
5088 | ||
5089 | enum graph_filter_type { | |
5090 | GRAPH_FILTER_NOTRACE = 0, | |
5091 | GRAPH_FILTER_FUNCTION, | |
5092 | }; | |
ea4e2bc4 | 5093 | |
555fc781 SRV |
5094 | #define FTRACE_GRAPH_EMPTY ((void *)1) |
5095 | ||
faf982a6 | 5096 | struct ftrace_graph_data { |
e704eff3 SRV |
5097 | struct ftrace_hash *hash; |
5098 | struct ftrace_func_entry *entry; | |
5099 | int idx; /* for hash table iteration */ | |
5100 | enum graph_filter_type type; | |
5101 | struct ftrace_hash *new_hash; | |
5102 | const struct seq_operations *seq_ops; | |
5103 | struct trace_parser parser; | |
faf982a6 NK |
5104 | }; |
5105 | ||
ea4e2bc4 | 5106 | static void * |
85951842 | 5107 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 5108 | { |
faf982a6 | 5109 | struct ftrace_graph_data *fgd = m->private; |
b9b0c831 NK |
5110 | struct ftrace_func_entry *entry = fgd->entry; |
5111 | struct hlist_head *head; | |
5112 | int i, idx = fgd->idx; | |
faf982a6 | 5113 | |
b9b0c831 | 5114 | if (*pos >= fgd->hash->count) |
ea4e2bc4 | 5115 | return NULL; |
b9b0c831 NK |
5116 | |
5117 | if (entry) { | |
5118 | hlist_for_each_entry_continue(entry, hlist) { | |
5119 | fgd->entry = entry; | |
5120 | return entry; | |
5121 | } | |
5122 | ||
5123 | idx++; | |
5124 | } | |
5125 | ||
5126 | for (i = idx; i < 1 << fgd->hash->size_bits; i++) { | |
5127 | head = &fgd->hash->buckets[i]; | |
5128 | hlist_for_each_entry(entry, head, hlist) { | |
5129 | fgd->entry = entry; | |
5130 | fgd->idx = i; | |
5131 | return entry; | |
5132 | } | |
5133 | } | |
5134 | return NULL; | |
85951842 | 5135 | } |
ea4e2bc4 | 5136 | |
85951842 LZ |
5137 | static void * |
5138 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
5139 | { | |
5140 | (*pos)++; | |
5141 | return __g_next(m, pos); | |
ea4e2bc4 SR |
5142 | } |
5143 | ||
5144 | static void *g_start(struct seq_file *m, loff_t *pos) | |
5145 | { | |
faf982a6 NK |
5146 | struct ftrace_graph_data *fgd = m->private; |
5147 | ||
ea4e2bc4 SR |
5148 | mutex_lock(&graph_lock); |
5149 | ||
649b988b SRV |
5150 | if (fgd->type == GRAPH_FILTER_FUNCTION) |
5151 | fgd->hash = rcu_dereference_protected(ftrace_graph_hash, | |
5152 | lockdep_is_held(&graph_lock)); | |
5153 | else | |
5154 | fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash, | |
5155 | lockdep_is_held(&graph_lock)); | |
5156 | ||
f9349a8f | 5157 | /* Nothing, tell g_show to print all functions are enabled */ |
b9b0c831 | 5158 | if (ftrace_hash_empty(fgd->hash) && !*pos) |
555fc781 | 5159 | return FTRACE_GRAPH_EMPTY; |
f9349a8f | 5160 | |
b9b0c831 NK |
5161 | fgd->idx = 0; |
5162 | fgd->entry = NULL; | |
85951842 | 5163 | return __g_next(m, pos); |
ea4e2bc4 SR |
5164 | } |
5165 | ||
5166 | static void g_stop(struct seq_file *m, void *p) | |
5167 | { | |
5168 | mutex_unlock(&graph_lock); | |
5169 | } | |
5170 | ||
5171 | static int g_show(struct seq_file *m, void *v) | |
5172 | { | |
b9b0c831 | 5173 | struct ftrace_func_entry *entry = v; |
ea4e2bc4 | 5174 | |
b9b0c831 | 5175 | if (!entry) |
ea4e2bc4 SR |
5176 | return 0; |
5177 | ||
555fc781 | 5178 | if (entry == FTRACE_GRAPH_EMPTY) { |
280d1429 NK |
5179 | struct ftrace_graph_data *fgd = m->private; |
5180 | ||
b9b0c831 | 5181 | if (fgd->type == GRAPH_FILTER_FUNCTION) |
fa6f0cc7 | 5182 | seq_puts(m, "#### all functions enabled ####\n"); |
280d1429 | 5183 | else |
fa6f0cc7 | 5184 | seq_puts(m, "#### no functions disabled ####\n"); |
f9349a8f FW |
5185 | return 0; |
5186 | } | |
5187 | ||
b9b0c831 | 5188 | seq_printf(m, "%ps\n", (void *)entry->ip); |
ea4e2bc4 SR |
5189 | |
5190 | return 0; | |
5191 | } | |
5192 | ||
88e9d34c | 5193 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
5194 | .start = g_start, |
5195 | .next = g_next, | |
5196 | .stop = g_stop, | |
5197 | .show = g_show, | |
5198 | }; | |
5199 | ||
5200 | static int | |
faf982a6 NK |
5201 | __ftrace_graph_open(struct inode *inode, struct file *file, |
5202 | struct ftrace_graph_data *fgd) | |
ea4e2bc4 SR |
5203 | { |
5204 | int ret = 0; | |
b9b0c831 | 5205 | struct ftrace_hash *new_hash = NULL; |
ea4e2bc4 | 5206 | |
b9b0c831 NK |
5207 | if (file->f_mode & FMODE_WRITE) { |
5208 | const int size_bits = FTRACE_HASH_DEFAULT_BITS; | |
5209 | ||
e704eff3 SRV |
5210 | if (trace_parser_get_init(&fgd->parser, FTRACE_BUFF_MAX)) |
5211 | return -ENOMEM; | |
5212 | ||
b9b0c831 NK |
5213 | if (file->f_flags & O_TRUNC) |
5214 | new_hash = alloc_ftrace_hash(size_bits); | |
5215 | else | |
5216 | new_hash = alloc_and_copy_ftrace_hash(size_bits, | |
5217 | fgd->hash); | |
5218 | if (!new_hash) { | |
5219 | ret = -ENOMEM; | |
5220 | goto out; | |
5221 | } | |
ea4e2bc4 SR |
5222 | } |
5223 | ||
faf982a6 | 5224 | if (file->f_mode & FMODE_READ) { |
b9b0c831 | 5225 | ret = seq_open(file, &ftrace_graph_seq_ops); |
faf982a6 NK |
5226 | if (!ret) { |
5227 | struct seq_file *m = file->private_data; | |
5228 | m->private = fgd; | |
b9b0c831 NK |
5229 | } else { |
5230 | /* Failed */ | |
5231 | free_ftrace_hash(new_hash); | |
5232 | new_hash = NULL; | |
faf982a6 NK |
5233 | } |
5234 | } else | |
5235 | file->private_data = fgd; | |
ea4e2bc4 | 5236 | |
b9b0c831 | 5237 | out: |
e704eff3 SRV |
5238 | if (ret < 0 && file->f_mode & FMODE_WRITE) |
5239 | trace_parser_put(&fgd->parser); | |
5240 | ||
b9b0c831 | 5241 | fgd->new_hash = new_hash; |
649b988b SRV |
5242 | |
5243 | /* | |
5244 | * All uses of fgd->hash must be taken with the graph_lock | |
5245 | * held. The graph_lock is going to be released, so force | |
5246 | * fgd->hash to be reinitialized when it is taken again. | |
5247 | */ | |
5248 | fgd->hash = NULL; | |
5249 | ||
ea4e2bc4 SR |
5250 | return ret; |
5251 | } | |
5252 | ||
faf982a6 NK |
5253 | static int |
5254 | ftrace_graph_open(struct inode *inode, struct file *file) | |
5255 | { | |
5256 | struct ftrace_graph_data *fgd; | |
b9b0c831 | 5257 | int ret; |
faf982a6 NK |
5258 | |
5259 | if (unlikely(ftrace_disabled)) | |
5260 | return -ENODEV; | |
5261 | ||
5262 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
5263 | if (fgd == NULL) | |
5264 | return -ENOMEM; | |
5265 | ||
b9b0c831 NK |
5266 | mutex_lock(&graph_lock); |
5267 | ||
649b988b SRV |
5268 | fgd->hash = rcu_dereference_protected(ftrace_graph_hash, |
5269 | lockdep_is_held(&graph_lock)); | |
b9b0c831 | 5270 | fgd->type = GRAPH_FILTER_FUNCTION; |
faf982a6 NK |
5271 | fgd->seq_ops = &ftrace_graph_seq_ops; |
5272 | ||
b9b0c831 NK |
5273 | ret = __ftrace_graph_open(inode, file, fgd); |
5274 | if (ret < 0) | |
5275 | kfree(fgd); | |
5276 | ||
5277 | mutex_unlock(&graph_lock); | |
5278 | return ret; | |
faf982a6 NK |
5279 | } |
5280 | ||
29ad23b0 NK |
5281 | static int |
5282 | ftrace_graph_notrace_open(struct inode *inode, struct file *file) | |
5283 | { | |
5284 | struct ftrace_graph_data *fgd; | |
b9b0c831 | 5285 | int ret; |
29ad23b0 NK |
5286 | |
5287 | if (unlikely(ftrace_disabled)) | |
5288 | return -ENODEV; | |
5289 | ||
5290 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
5291 | if (fgd == NULL) | |
5292 | return -ENOMEM; | |
5293 | ||
b9b0c831 NK |
5294 | mutex_lock(&graph_lock); |
5295 | ||
649b988b SRV |
5296 | fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash, |
5297 | lockdep_is_held(&graph_lock)); | |
b9b0c831 | 5298 | fgd->type = GRAPH_FILTER_NOTRACE; |
29ad23b0 NK |
5299 | fgd->seq_ops = &ftrace_graph_seq_ops; |
5300 | ||
b9b0c831 NK |
5301 | ret = __ftrace_graph_open(inode, file, fgd); |
5302 | if (ret < 0) | |
5303 | kfree(fgd); | |
5304 | ||
5305 | mutex_unlock(&graph_lock); | |
5306 | return ret; | |
29ad23b0 NK |
5307 | } |
5308 | ||
87827111 LZ |
5309 | static int |
5310 | ftrace_graph_release(struct inode *inode, struct file *file) | |
5311 | { | |
b9b0c831 | 5312 | struct ftrace_graph_data *fgd; |
e704eff3 SRV |
5313 | struct ftrace_hash *old_hash, *new_hash; |
5314 | struct trace_parser *parser; | |
5315 | int ret = 0; | |
b9b0c831 | 5316 | |
faf982a6 NK |
5317 | if (file->f_mode & FMODE_READ) { |
5318 | struct seq_file *m = file->private_data; | |
5319 | ||
b9b0c831 | 5320 | fgd = m->private; |
87827111 | 5321 | seq_release(inode, file); |
faf982a6 | 5322 | } else { |
b9b0c831 | 5323 | fgd = file->private_data; |
faf982a6 NK |
5324 | } |
5325 | ||
e704eff3 SRV |
5326 | |
5327 | if (file->f_mode & FMODE_WRITE) { | |
5328 | ||
5329 | parser = &fgd->parser; | |
5330 | ||
5331 | if (trace_parser_loaded((parser))) { | |
5332 | parser->buffer[parser->idx] = 0; | |
5333 | ret = ftrace_graph_set_hash(fgd->new_hash, | |
5334 | parser->buffer); | |
5335 | } | |
5336 | ||
5337 | trace_parser_put(parser); | |
5338 | ||
5339 | new_hash = __ftrace_hash_move(fgd->new_hash); | |
5340 | if (!new_hash) { | |
5341 | ret = -ENOMEM; | |
5342 | goto out; | |
5343 | } | |
5344 | ||
5345 | mutex_lock(&graph_lock); | |
5346 | ||
5347 | if (fgd->type == GRAPH_FILTER_FUNCTION) { | |
5348 | old_hash = rcu_dereference_protected(ftrace_graph_hash, | |
5349 | lockdep_is_held(&graph_lock)); | |
5350 | rcu_assign_pointer(ftrace_graph_hash, new_hash); | |
5351 | } else { | |
5352 | old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash, | |
5353 | lockdep_is_held(&graph_lock)); | |
5354 | rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash); | |
5355 | } | |
5356 | ||
5357 | mutex_unlock(&graph_lock); | |
5358 | ||
5359 | /* Wait till all users are no longer using the old hash */ | |
5360 | synchronize_sched(); | |
5361 | ||
5362 | free_ftrace_hash(old_hash); | |
5363 | } | |
5364 | ||
5365 | out: | |
f9797c2f | 5366 | free_ftrace_hash(fgd->new_hash); |
b9b0c831 NK |
5367 | kfree(fgd); |
5368 | ||
e704eff3 | 5369 | return ret; |
87827111 LZ |
5370 | } |
5371 | ||
ea4e2bc4 | 5372 | static int |
b9b0c831 | 5373 | ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer) |
ea4e2bc4 | 5374 | { |
3ba00929 | 5375 | struct ftrace_glob func_g; |
ea4e2bc4 SR |
5376 | struct dyn_ftrace *rec; |
5377 | struct ftrace_page *pg; | |
b9b0c831 | 5378 | struct ftrace_func_entry *entry; |
c7c6b1fe | 5379 | int fail = 1; |
3ba00929 | 5380 | int not; |
ea4e2bc4 | 5381 | |
f9349a8f | 5382 | /* decode regex */ |
3ba00929 DS |
5383 | func_g.type = filter_parse_regex(buffer, strlen(buffer), |
5384 | &func_g.search, ¬); | |
f9349a8f | 5385 | |
3ba00929 | 5386 | func_g.len = strlen(func_g.search); |
f9349a8f | 5387 | |
52baf119 | 5388 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
5389 | |
5390 | if (unlikely(ftrace_disabled)) { | |
5391 | mutex_unlock(&ftrace_lock); | |
5392 | return -ENODEV; | |
5393 | } | |
5394 | ||
265c831c SR |
5395 | do_for_each_ftrace_rec(pg, rec) { |
5396 | ||
546fece4 SRRH |
5397 | if (rec->flags & FTRACE_FL_DISABLED) |
5398 | continue; | |
5399 | ||
0b507e1e | 5400 | if (ftrace_match_record(rec, &func_g, NULL, 0)) { |
b9b0c831 | 5401 | entry = ftrace_lookup_ip(hash, rec->ip); |
c7c6b1fe LZ |
5402 | |
5403 | if (!not) { | |
5404 | fail = 0; | |
b9b0c831 NK |
5405 | |
5406 | if (entry) | |
5407 | continue; | |
5408 | if (add_hash_entry(hash, rec->ip) < 0) | |
5409 | goto out; | |
c7c6b1fe | 5410 | } else { |
b9b0c831 NK |
5411 | if (entry) { |
5412 | free_hash_entry(hash, entry); | |
c7c6b1fe LZ |
5413 | fail = 0; |
5414 | } | |
5415 | } | |
ea4e2bc4 | 5416 | } |
265c831c | 5417 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 5418 | out: |
52baf119 | 5419 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 5420 | |
c7c6b1fe LZ |
5421 | if (fail) |
5422 | return -EINVAL; | |
5423 | ||
c7c6b1fe | 5424 | return 0; |
ea4e2bc4 SR |
5425 | } |
5426 | ||
5427 | static ssize_t | |
5428 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
5429 | size_t cnt, loff_t *ppos) | |
5430 | { | |
6a10108b | 5431 | ssize_t read, ret = 0; |
faf982a6 | 5432 | struct ftrace_graph_data *fgd = file->private_data; |
e704eff3 | 5433 | struct trace_parser *parser; |
ea4e2bc4 | 5434 | |
c7c6b1fe | 5435 | if (!cnt) |
ea4e2bc4 SR |
5436 | return 0; |
5437 | ||
ae98d27a SRV |
5438 | /* Read mode uses seq functions */ |
5439 | if (file->f_mode & FMODE_READ) { | |
5440 | struct seq_file *m = file->private_data; | |
5441 | fgd = m->private; | |
5442 | } | |
5443 | ||
e704eff3 | 5444 | parser = &fgd->parser; |
ea4e2bc4 | 5445 | |
e704eff3 | 5446 | read = trace_get_user(parser, ubuf, cnt, ppos); |
689fd8b6 | 5447 | |
e704eff3 SRV |
5448 | if (read >= 0 && trace_parser_loaded(parser) && |
5449 | !trace_parser_cont(parser)) { | |
6a10108b | 5450 | |
b9b0c831 | 5451 | ret = ftrace_graph_set_hash(fgd->new_hash, |
e704eff3 SRV |
5452 | parser->buffer); |
5453 | trace_parser_clear(parser); | |
ea4e2bc4 | 5454 | } |
ea4e2bc4 | 5455 | |
6a10108b NK |
5456 | if (!ret) |
5457 | ret = read; | |
1eb90f13 | 5458 | |
ea4e2bc4 SR |
5459 | return ret; |
5460 | } | |
5461 | ||
5462 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
5463 | .open = ftrace_graph_open, |
5464 | .read = seq_read, | |
5465 | .write = ftrace_graph_write, | |
098c879e | 5466 | .llseek = tracing_lseek, |
87827111 | 5467 | .release = ftrace_graph_release, |
ea4e2bc4 | 5468 | }; |
29ad23b0 NK |
5469 | |
5470 | static const struct file_operations ftrace_graph_notrace_fops = { | |
5471 | .open = ftrace_graph_notrace_open, | |
5472 | .read = seq_read, | |
5473 | .write = ftrace_graph_write, | |
098c879e | 5474 | .llseek = tracing_lseek, |
29ad23b0 NK |
5475 | .release = ftrace_graph_release, |
5476 | }; | |
ea4e2bc4 SR |
5477 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
5478 | ||
591dffda SRRH |
5479 | void ftrace_create_filter_files(struct ftrace_ops *ops, |
5480 | struct dentry *parent) | |
5481 | { | |
5482 | ||
5483 | trace_create_file("set_ftrace_filter", 0644, parent, | |
5484 | ops, &ftrace_filter_fops); | |
5485 | ||
5486 | trace_create_file("set_ftrace_notrace", 0644, parent, | |
5487 | ops, &ftrace_notrace_fops); | |
5488 | } | |
5489 | ||
5490 | /* | |
5491 | * The name "destroy_filter_files" is really a misnomer. Although | |
5492 | * in the future, it may actualy delete the files, but this is | |
5493 | * really intended to make sure the ops passed in are disabled | |
5494 | * and that when this function returns, the caller is free to | |
5495 | * free the ops. | |
5496 | * | |
5497 | * The "destroy" name is only to match the "create" name that this | |
5498 | * should be paired with. | |
5499 | */ | |
5500 | void ftrace_destroy_filter_files(struct ftrace_ops *ops) | |
5501 | { | |
5502 | mutex_lock(&ftrace_lock); | |
5503 | if (ops->flags & FTRACE_OPS_FL_ENABLED) | |
5504 | ftrace_shutdown(ops, 0); | |
5505 | ops->flags |= FTRACE_OPS_FL_DELETED; | |
5506 | mutex_unlock(&ftrace_lock); | |
5507 | } | |
5508 | ||
8434dc93 | 5509 | static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer) |
5072c59f | 5510 | { |
5072c59f | 5511 | |
5452af66 FW |
5512 | trace_create_file("available_filter_functions", 0444, |
5513 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 5514 | |
647bcd03 SR |
5515 | trace_create_file("enabled_functions", 0444, |
5516 | d_tracer, NULL, &ftrace_enabled_fops); | |
5517 | ||
591dffda | 5518 | ftrace_create_filter_files(&global_ops, d_tracer); |
ad90c0e3 | 5519 | |
ea4e2bc4 | 5520 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 5521 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
5522 | NULL, |
5523 | &ftrace_graph_fops); | |
29ad23b0 NK |
5524 | trace_create_file("set_graph_notrace", 0444, d_tracer, |
5525 | NULL, | |
5526 | &ftrace_graph_notrace_fops); | |
ea4e2bc4 SR |
5527 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
5528 | ||
5072c59f SR |
5529 | return 0; |
5530 | } | |
5531 | ||
9fd49328 | 5532 | static int ftrace_cmp_ips(const void *a, const void *b) |
68950619 | 5533 | { |
9fd49328 SR |
5534 | const unsigned long *ipa = a; |
5535 | const unsigned long *ipb = b; | |
68950619 | 5536 | |
9fd49328 SR |
5537 | if (*ipa > *ipb) |
5538 | return 1; | |
5539 | if (*ipa < *ipb) | |
5540 | return -1; | |
5541 | return 0; | |
5542 | } | |
5543 | ||
5cb084bb | 5544 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 5545 | unsigned long *start, |
68bf21aa SR |
5546 | unsigned long *end) |
5547 | { | |
706c81f8 | 5548 | struct ftrace_page *start_pg; |
a7900875 | 5549 | struct ftrace_page *pg; |
706c81f8 | 5550 | struct dyn_ftrace *rec; |
a7900875 | 5551 | unsigned long count; |
68bf21aa SR |
5552 | unsigned long *p; |
5553 | unsigned long addr; | |
4376cac6 | 5554 | unsigned long flags = 0; /* Shut up gcc */ |
a7900875 SR |
5555 | int ret = -ENOMEM; |
5556 | ||
5557 | count = end - start; | |
5558 | ||
5559 | if (!count) | |
5560 | return 0; | |
5561 | ||
9fd49328 | 5562 | sort(start, count, sizeof(*start), |
6db02903 | 5563 | ftrace_cmp_ips, NULL); |
9fd49328 | 5564 | |
706c81f8 SR |
5565 | start_pg = ftrace_allocate_pages(count); |
5566 | if (!start_pg) | |
a7900875 | 5567 | return -ENOMEM; |
68bf21aa | 5568 | |
e6ea44e9 | 5569 | mutex_lock(&ftrace_lock); |
a7900875 | 5570 | |
32082309 SR |
5571 | /* |
5572 | * Core and each module needs their own pages, as | |
5573 | * modules will free them when they are removed. | |
5574 | * Force a new page to be allocated for modules. | |
5575 | */ | |
a7900875 SR |
5576 | if (!mod) { |
5577 | WARN_ON(ftrace_pages || ftrace_pages_start); | |
5578 | /* First initialization */ | |
706c81f8 | 5579 | ftrace_pages = ftrace_pages_start = start_pg; |
a7900875 | 5580 | } else { |
32082309 | 5581 | if (!ftrace_pages) |
a7900875 | 5582 | goto out; |
32082309 | 5583 | |
a7900875 SR |
5584 | if (WARN_ON(ftrace_pages->next)) { |
5585 | /* Hmm, we have free pages? */ | |
5586 | while (ftrace_pages->next) | |
5587 | ftrace_pages = ftrace_pages->next; | |
32082309 | 5588 | } |
a7900875 | 5589 | |
706c81f8 | 5590 | ftrace_pages->next = start_pg; |
32082309 SR |
5591 | } |
5592 | ||
68bf21aa | 5593 | p = start; |
706c81f8 | 5594 | pg = start_pg; |
68bf21aa SR |
5595 | while (p < end) { |
5596 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
5597 | /* |
5598 | * Some architecture linkers will pad between | |
5599 | * the different mcount_loc sections of different | |
5600 | * object files to satisfy alignments. | |
5601 | * Skip any NULL pointers. | |
5602 | */ | |
5603 | if (!addr) | |
5604 | continue; | |
706c81f8 SR |
5605 | |
5606 | if (pg->index == pg->size) { | |
5607 | /* We should have allocated enough */ | |
5608 | if (WARN_ON(!pg->next)) | |
5609 | break; | |
5610 | pg = pg->next; | |
5611 | } | |
5612 | ||
5613 | rec = &pg->records[pg->index++]; | |
5614 | rec->ip = addr; | |
68bf21aa SR |
5615 | } |
5616 | ||
706c81f8 SR |
5617 | /* We should have used all pages */ |
5618 | WARN_ON(pg->next); | |
5619 | ||
5620 | /* Assign the last page to ftrace_pages */ | |
5621 | ftrace_pages = pg; | |
5622 | ||
a4f18ed1 | 5623 | /* |
4376cac6 SR |
5624 | * We only need to disable interrupts on start up |
5625 | * because we are modifying code that an interrupt | |
5626 | * may execute, and the modification is not atomic. | |
5627 | * But for modules, nothing runs the code we modify | |
5628 | * until we are finished with it, and there's no | |
5629 | * reason to cause large interrupt latencies while we do it. | |
a4f18ed1 | 5630 | */ |
4376cac6 SR |
5631 | if (!mod) |
5632 | local_irq_save(flags); | |
1dc43cf0 | 5633 | ftrace_update_code(mod, start_pg); |
4376cac6 SR |
5634 | if (!mod) |
5635 | local_irq_restore(flags); | |
a7900875 SR |
5636 | ret = 0; |
5637 | out: | |
e6ea44e9 | 5638 | mutex_unlock(&ftrace_lock); |
68bf21aa | 5639 | |
a7900875 | 5640 | return ret; |
68bf21aa SR |
5641 | } |
5642 | ||
aba4b5c2 SRV |
5643 | struct ftrace_mod_func { |
5644 | struct list_head list; | |
5645 | char *name; | |
5646 | unsigned long ip; | |
5647 | unsigned int size; | |
5648 | }; | |
5649 | ||
5650 | struct ftrace_mod_map { | |
6aa69784 | 5651 | struct rcu_head rcu; |
aba4b5c2 SRV |
5652 | struct list_head list; |
5653 | struct module *mod; | |
5654 | unsigned long start_addr; | |
5655 | unsigned long end_addr; | |
5656 | struct list_head funcs; | |
6171a031 | 5657 | unsigned int num_funcs; |
aba4b5c2 SRV |
5658 | }; |
5659 | ||
93eb677d | 5660 | #ifdef CONFIG_MODULES |
32082309 SR |
5661 | |
5662 | #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next) | |
5663 | ||
6aa69784 SRV |
5664 | static LIST_HEAD(ftrace_mod_maps); |
5665 | ||
b7ffffbb SRRH |
5666 | static int referenced_filters(struct dyn_ftrace *rec) |
5667 | { | |
5668 | struct ftrace_ops *ops; | |
5669 | int cnt = 0; | |
5670 | ||
5671 | for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) { | |
5672 | if (ops_references_rec(ops, rec)) | |
5673 | cnt++; | |
5674 | } | |
5675 | ||
5676 | return cnt; | |
5677 | } | |
5678 | ||
2a5bfe47 SRV |
5679 | static void |
5680 | clear_mod_from_hash(struct ftrace_page *pg, struct ftrace_hash *hash) | |
5681 | { | |
5682 | struct ftrace_func_entry *entry; | |
5683 | struct dyn_ftrace *rec; | |
5684 | int i; | |
5685 | ||
5686 | if (ftrace_hash_empty(hash)) | |
5687 | return; | |
5688 | ||
5689 | for (i = 0; i < pg->index; i++) { | |
5690 | rec = &pg->records[i]; | |
5691 | entry = __ftrace_lookup_ip(hash, rec->ip); | |
5692 | /* | |
5693 | * Do not allow this rec to match again. | |
5694 | * Yeah, it may waste some memory, but will be removed | |
5695 | * if/when the hash is modified again. | |
5696 | */ | |
5697 | if (entry) | |
5698 | entry->ip = 0; | |
5699 | } | |
5700 | } | |
5701 | ||
5702 | /* Clear any records from hashs */ | |
5703 | static void clear_mod_from_hashes(struct ftrace_page *pg) | |
5704 | { | |
5705 | struct trace_array *tr; | |
5706 | ||
5707 | mutex_lock(&trace_types_lock); | |
5708 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
5709 | if (!tr->ops || !tr->ops->func_hash) | |
5710 | continue; | |
5711 | mutex_lock(&tr->ops->func_hash->regex_lock); | |
5712 | clear_mod_from_hash(pg, tr->ops->func_hash->filter_hash); | |
5713 | clear_mod_from_hash(pg, tr->ops->func_hash->notrace_hash); | |
5714 | mutex_unlock(&tr->ops->func_hash->regex_lock); | |
5715 | } | |
5716 | mutex_unlock(&trace_types_lock); | |
5717 | } | |
5718 | ||
6aa69784 SRV |
5719 | static void ftrace_free_mod_map(struct rcu_head *rcu) |
5720 | { | |
5721 | struct ftrace_mod_map *mod_map = container_of(rcu, struct ftrace_mod_map, rcu); | |
5722 | struct ftrace_mod_func *mod_func; | |
5723 | struct ftrace_mod_func *n; | |
5724 | ||
5725 | /* All the contents of mod_map are now not visible to readers */ | |
5726 | list_for_each_entry_safe(mod_func, n, &mod_map->funcs, list) { | |
5727 | kfree(mod_func->name); | |
5728 | list_del(&mod_func->list); | |
5729 | kfree(mod_func); | |
5730 | } | |
5731 | ||
5732 | kfree(mod_map); | |
5733 | } | |
5734 | ||
e7247a15 | 5735 | void ftrace_release_mod(struct module *mod) |
93eb677d | 5736 | { |
6aa69784 SRV |
5737 | struct ftrace_mod_map *mod_map; |
5738 | struct ftrace_mod_map *n; | |
93eb677d | 5739 | struct dyn_ftrace *rec; |
32082309 | 5740 | struct ftrace_page **last_pg; |
2a5bfe47 | 5741 | struct ftrace_page *tmp_page = NULL; |
93eb677d | 5742 | struct ftrace_page *pg; |
a7900875 | 5743 | int order; |
93eb677d | 5744 | |
45a4a237 SR |
5745 | mutex_lock(&ftrace_lock); |
5746 | ||
e7247a15 | 5747 | if (ftrace_disabled) |
45a4a237 | 5748 | goto out_unlock; |
93eb677d | 5749 | |
6aa69784 SRV |
5750 | list_for_each_entry_safe(mod_map, n, &ftrace_mod_maps, list) { |
5751 | if (mod_map->mod == mod) { | |
5752 | list_del_rcu(&mod_map->list); | |
5753 | call_rcu_sched(&mod_map->rcu, ftrace_free_mod_map); | |
5754 | break; | |
5755 | } | |
5756 | } | |
5757 | ||
32082309 SR |
5758 | /* |
5759 | * Each module has its own ftrace_pages, remove | |
5760 | * them from the list. | |
5761 | */ | |
5762 | last_pg = &ftrace_pages_start; | |
5763 | for (pg = ftrace_pages_start; pg; pg = *last_pg) { | |
5764 | rec = &pg->records[0]; | |
3e234289 SRV |
5765 | if (within_module_core(rec->ip, mod) || |
5766 | within_module_init(rec->ip, mod)) { | |
93eb677d | 5767 | /* |
32082309 SR |
5768 | * As core pages are first, the first |
5769 | * page should never be a module page. | |
93eb677d | 5770 | */ |
32082309 SR |
5771 | if (WARN_ON(pg == ftrace_pages_start)) |
5772 | goto out_unlock; | |
5773 | ||
5774 | /* Check if we are deleting the last page */ | |
5775 | if (pg == ftrace_pages) | |
5776 | ftrace_pages = next_to_ftrace_page(last_pg); | |
5777 | ||
83dd1493 | 5778 | ftrace_update_tot_cnt -= pg->index; |
32082309 | 5779 | *last_pg = pg->next; |
2a5bfe47 SRV |
5780 | |
5781 | pg->next = tmp_page; | |
5782 | tmp_page = pg; | |
32082309 SR |
5783 | } else |
5784 | last_pg = &pg->next; | |
5785 | } | |
45a4a237 | 5786 | out_unlock: |
93eb677d | 5787 | mutex_unlock(&ftrace_lock); |
2a5bfe47 SRV |
5788 | |
5789 | for (pg = tmp_page; pg; pg = tmp_page) { | |
5790 | ||
5791 | /* Needs to be called outside of ftrace_lock */ | |
5792 | clear_mod_from_hashes(pg); | |
5793 | ||
5794 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); | |
5795 | free_pages((unsigned long)pg->records, order); | |
5796 | tmp_page = pg->next; | |
5797 | kfree(pg); | |
5798 | } | |
93eb677d SR |
5799 | } |
5800 | ||
7dcd182b | 5801 | void ftrace_module_enable(struct module *mod) |
b7ffffbb SRRH |
5802 | { |
5803 | struct dyn_ftrace *rec; | |
5804 | struct ftrace_page *pg; | |
5805 | ||
5806 | mutex_lock(&ftrace_lock); | |
5807 | ||
5808 | if (ftrace_disabled) | |
5809 | goto out_unlock; | |
5810 | ||
5811 | /* | |
5812 | * If the tracing is enabled, go ahead and enable the record. | |
5813 | * | |
5814 | * The reason not to enable the record immediatelly is the | |
5815 | * inherent check of ftrace_make_nop/ftrace_make_call for | |
5816 | * correct previous instructions. Making first the NOP | |
5817 | * conversion puts the module to the correct state, thus | |
5818 | * passing the ftrace_make_call check. | |
5819 | * | |
5820 | * We also delay this to after the module code already set the | |
5821 | * text to read-only, as we now need to set it back to read-write | |
5822 | * so that we can modify the text. | |
5823 | */ | |
5824 | if (ftrace_start_up) | |
5825 | ftrace_arch_code_modify_prepare(); | |
5826 | ||
5827 | do_for_each_ftrace_rec(pg, rec) { | |
5828 | int cnt; | |
5829 | /* | |
5830 | * do_for_each_ftrace_rec() is a double loop. | |
5831 | * module text shares the pg. If a record is | |
5832 | * not part of this module, then skip this pg, | |
5833 | * which the "break" will do. | |
5834 | */ | |
3e234289 SRV |
5835 | if (!within_module_core(rec->ip, mod) && |
5836 | !within_module_init(rec->ip, mod)) | |
b7ffffbb SRRH |
5837 | break; |
5838 | ||
5839 | cnt = 0; | |
5840 | ||
5841 | /* | |
5842 | * When adding a module, we need to check if tracers are | |
5843 | * currently enabled and if they are, and can trace this record, | |
5844 | * we need to enable the module functions as well as update the | |
5845 | * reference counts for those function records. | |
5846 | */ | |
5847 | if (ftrace_start_up) | |
5848 | cnt += referenced_filters(rec); | |
5849 | ||
5850 | /* This clears FTRACE_FL_DISABLED */ | |
5851 | rec->flags = cnt; | |
5852 | ||
5853 | if (ftrace_start_up && cnt) { | |
5854 | int failed = __ftrace_replace_code(rec, 1); | |
5855 | if (failed) { | |
5856 | ftrace_bug(failed, rec); | |
5857 | goto out_loop; | |
5858 | } | |
5859 | } | |
5860 | ||
5861 | } while_for_each_ftrace_rec(); | |
5862 | ||
5863 | out_loop: | |
5864 | if (ftrace_start_up) | |
5865 | ftrace_arch_code_modify_post_process(); | |
5866 | ||
5867 | out_unlock: | |
5868 | mutex_unlock(&ftrace_lock); | |
d7fbf8df SRV |
5869 | |
5870 | process_cached_mods(mod->name); | |
b7ffffbb SRRH |
5871 | } |
5872 | ||
b6b71f66 | 5873 | void ftrace_module_init(struct module *mod) |
90d595fe | 5874 | { |
97e9b4fc | 5875 | if (ftrace_disabled || !mod->num_ftrace_callsites) |
fed1939c | 5876 | return; |
90d595fe | 5877 | |
97e9b4fc SRRH |
5878 | ftrace_process_locs(mod, mod->ftrace_callsites, |
5879 | mod->ftrace_callsites + mod->num_ftrace_callsites); | |
8c189ea6 | 5880 | } |
aba4b5c2 SRV |
5881 | |
5882 | static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map, | |
5883 | struct dyn_ftrace *rec) | |
5884 | { | |
5885 | struct ftrace_mod_func *mod_func; | |
5886 | unsigned long symsize; | |
5887 | unsigned long offset; | |
5888 | char str[KSYM_SYMBOL_LEN]; | |
5889 | char *modname; | |
5890 | const char *ret; | |
5891 | ||
5892 | ret = kallsyms_lookup(rec->ip, &symsize, &offset, &modname, str); | |
5893 | if (!ret) | |
5894 | return; | |
5895 | ||
5896 | mod_func = kmalloc(sizeof(*mod_func), GFP_KERNEL); | |
5897 | if (!mod_func) | |
5898 | return; | |
5899 | ||
5900 | mod_func->name = kstrdup(str, GFP_KERNEL); | |
5901 | if (!mod_func->name) { | |
5902 | kfree(mod_func); | |
5903 | return; | |
5904 | } | |
5905 | ||
5906 | mod_func->ip = rec->ip - offset; | |
5907 | mod_func->size = symsize; | |
5908 | ||
6171a031 SRV |
5909 | mod_map->num_funcs++; |
5910 | ||
aba4b5c2 SRV |
5911 | list_add_rcu(&mod_func->list, &mod_map->funcs); |
5912 | } | |
5913 | ||
aba4b5c2 SRV |
5914 | static struct ftrace_mod_map * |
5915 | allocate_ftrace_mod_map(struct module *mod, | |
5916 | unsigned long start, unsigned long end) | |
5917 | { | |
5918 | struct ftrace_mod_map *mod_map; | |
5919 | ||
5920 | mod_map = kmalloc(sizeof(*mod_map), GFP_KERNEL); | |
5921 | if (!mod_map) | |
5922 | return NULL; | |
5923 | ||
5924 | mod_map->mod = mod; | |
5925 | mod_map->start_addr = start; | |
5926 | mod_map->end_addr = end; | |
6171a031 | 5927 | mod_map->num_funcs = 0; |
aba4b5c2 SRV |
5928 | |
5929 | INIT_LIST_HEAD_RCU(&mod_map->funcs); | |
5930 | ||
5931 | list_add_rcu(&mod_map->list, &ftrace_mod_maps); | |
5932 | ||
5933 | return mod_map; | |
5934 | } | |
5935 | ||
5936 | static const char * | |
5937 | ftrace_func_address_lookup(struct ftrace_mod_map *mod_map, | |
5938 | unsigned long addr, unsigned long *size, | |
5939 | unsigned long *off, char *sym) | |
5940 | { | |
5941 | struct ftrace_mod_func *found_func = NULL; | |
5942 | struct ftrace_mod_func *mod_func; | |
5943 | ||
5944 | list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) { | |
5945 | if (addr >= mod_func->ip && | |
5946 | addr < mod_func->ip + mod_func->size) { | |
5947 | found_func = mod_func; | |
5948 | break; | |
5949 | } | |
5950 | } | |
5951 | ||
5952 | if (found_func) { | |
5953 | if (size) | |
5954 | *size = found_func->size; | |
5955 | if (off) | |
5956 | *off = addr - found_func->ip; | |
5957 | if (sym) | |
5958 | strlcpy(sym, found_func->name, KSYM_NAME_LEN); | |
5959 | ||
5960 | return found_func->name; | |
5961 | } | |
5962 | ||
5963 | return NULL; | |
5964 | } | |
5965 | ||
5966 | const char * | |
5967 | ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, | |
5968 | unsigned long *off, char **modname, char *sym) | |
5969 | { | |
5970 | struct ftrace_mod_map *mod_map; | |
5971 | const char *ret = NULL; | |
5972 | ||
6aa69784 | 5973 | /* mod_map is freed via call_rcu_sched() */ |
aba4b5c2 SRV |
5974 | preempt_disable(); |
5975 | list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) { | |
5976 | ret = ftrace_func_address_lookup(mod_map, addr, size, off, sym); | |
5977 | if (ret) { | |
5978 | if (modname) | |
5979 | *modname = mod_map->mod->name; | |
5980 | break; | |
5981 | } | |
5982 | } | |
5983 | preempt_enable(); | |
5984 | ||
5985 | return ret; | |
5986 | } | |
5987 | ||
6171a031 SRV |
5988 | int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, |
5989 | char *type, char *name, | |
5990 | char *module_name, int *exported) | |
5991 | { | |
5992 | struct ftrace_mod_map *mod_map; | |
5993 | struct ftrace_mod_func *mod_func; | |
5994 | ||
5995 | preempt_disable(); | |
5996 | list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) { | |
5997 | ||
5998 | if (symnum >= mod_map->num_funcs) { | |
5999 | symnum -= mod_map->num_funcs; | |
6000 | continue; | |
6001 | } | |
6002 | ||
6003 | list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) { | |
6004 | if (symnum > 1) { | |
6005 | symnum--; | |
6006 | continue; | |
6007 | } | |
6008 | ||
6009 | *value = mod_func->ip; | |
6010 | *type = 'T'; | |
6011 | strlcpy(name, mod_func->name, KSYM_NAME_LEN); | |
6012 | strlcpy(module_name, mod_map->mod->name, MODULE_NAME_LEN); | |
6013 | *exported = 1; | |
6014 | preempt_enable(); | |
6015 | return 0; | |
6016 | } | |
6017 | WARN_ON(1); | |
6018 | break; | |
6019 | } | |
6020 | preempt_enable(); | |
6021 | return -ERANGE; | |
6022 | } | |
6023 | ||
aba4b5c2 SRV |
6024 | #else |
6025 | static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map, | |
6026 | struct dyn_ftrace *rec) { } | |
6027 | static inline struct ftrace_mod_map * | |
6028 | allocate_ftrace_mod_map(struct module *mod, | |
6029 | unsigned long start, unsigned long end) | |
6030 | { | |
6031 | return NULL; | |
6032 | } | |
93eb677d SR |
6033 | #endif /* CONFIG_MODULES */ |
6034 | ||
8715b108 JF |
6035 | struct ftrace_init_func { |
6036 | struct list_head list; | |
6037 | unsigned long ip; | |
6038 | }; | |
6039 | ||
6040 | /* Clear any init ips from hashes */ | |
6041 | static void | |
6042 | clear_func_from_hash(struct ftrace_init_func *func, struct ftrace_hash *hash) | |
42c269c8 | 6043 | { |
8715b108 JF |
6044 | struct ftrace_func_entry *entry; |
6045 | ||
6046 | if (ftrace_hash_empty(hash)) | |
6047 | return; | |
6048 | ||
6049 | entry = __ftrace_lookup_ip(hash, func->ip); | |
6050 | ||
6051 | /* | |
6052 | * Do not allow this rec to match again. | |
6053 | * Yeah, it may waste some memory, but will be removed | |
6054 | * if/when the hash is modified again. | |
6055 | */ | |
6056 | if (entry) | |
6057 | entry->ip = 0; | |
6058 | } | |
6059 | ||
6060 | static void | |
6061 | clear_func_from_hashes(struct ftrace_init_func *func) | |
6062 | { | |
6063 | struct trace_array *tr; | |
6064 | ||
6065 | mutex_lock(&trace_types_lock); | |
6066 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
6067 | if (!tr->ops || !tr->ops->func_hash) | |
6068 | continue; | |
6069 | mutex_lock(&tr->ops->func_hash->regex_lock); | |
6070 | clear_func_from_hash(func, tr->ops->func_hash->filter_hash); | |
6071 | clear_func_from_hash(func, tr->ops->func_hash->notrace_hash); | |
6072 | mutex_unlock(&tr->ops->func_hash->regex_lock); | |
6073 | } | |
6074 | mutex_unlock(&trace_types_lock); | |
6075 | } | |
6076 | ||
6077 | static void add_to_clear_hash_list(struct list_head *clear_list, | |
6078 | struct dyn_ftrace *rec) | |
6079 | { | |
6080 | struct ftrace_init_func *func; | |
6081 | ||
6082 | func = kmalloc(sizeof(*func), GFP_KERNEL); | |
6083 | if (!func) { | |
6084 | WARN_ONCE(1, "alloc failure, ftrace filter could be stale\n"); | |
6085 | return; | |
6086 | } | |
6087 | ||
6088 | func->ip = rec->ip; | |
6089 | list_add(&func->list, clear_list); | |
6090 | } | |
6091 | ||
aba4b5c2 | 6092 | void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr) |
42c269c8 | 6093 | { |
6cafbe15 SRV |
6094 | unsigned long start = (unsigned long)(start_ptr); |
6095 | unsigned long end = (unsigned long)(end_ptr); | |
42c269c8 SRV |
6096 | struct ftrace_page **last_pg = &ftrace_pages_start; |
6097 | struct ftrace_page *pg; | |
6098 | struct dyn_ftrace *rec; | |
6099 | struct dyn_ftrace key; | |
aba4b5c2 | 6100 | struct ftrace_mod_map *mod_map = NULL; |
8715b108 JF |
6101 | struct ftrace_init_func *func, *func_next; |
6102 | struct list_head clear_hash; | |
42c269c8 SRV |
6103 | int order; |
6104 | ||
8715b108 JF |
6105 | INIT_LIST_HEAD(&clear_hash); |
6106 | ||
42c269c8 SRV |
6107 | key.ip = start; |
6108 | key.flags = end; /* overload flags, as it is unsigned long */ | |
6109 | ||
6110 | mutex_lock(&ftrace_lock); | |
6111 | ||
aba4b5c2 SRV |
6112 | /* |
6113 | * If we are freeing module init memory, then check if | |
6114 | * any tracer is active. If so, we need to save a mapping of | |
6115 | * the module functions being freed with the address. | |
6116 | */ | |
6117 | if (mod && ftrace_ops_list != &ftrace_list_end) | |
6118 | mod_map = allocate_ftrace_mod_map(mod, start, end); | |
6119 | ||
42c269c8 SRV |
6120 | for (pg = ftrace_pages_start; pg; last_pg = &pg->next, pg = *last_pg) { |
6121 | if (end < pg->records[0].ip || | |
6122 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) | |
6123 | continue; | |
6124 | again: | |
6125 | rec = bsearch(&key, pg->records, pg->index, | |
6126 | sizeof(struct dyn_ftrace), | |
6127 | ftrace_cmp_recs); | |
6128 | if (!rec) | |
6129 | continue; | |
aba4b5c2 | 6130 | |
8715b108 JF |
6131 | /* rec will be cleared from hashes after ftrace_lock unlock */ |
6132 | add_to_clear_hash_list(&clear_hash, rec); | |
6133 | ||
aba4b5c2 SRV |
6134 | if (mod_map) |
6135 | save_ftrace_mod_rec(mod_map, rec); | |
6136 | ||
42c269c8 | 6137 | pg->index--; |
4ec78467 | 6138 | ftrace_update_tot_cnt--; |
42c269c8 SRV |
6139 | if (!pg->index) { |
6140 | *last_pg = pg->next; | |
6141 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); | |
6142 | free_pages((unsigned long)pg->records, order); | |
6143 | kfree(pg); | |
6144 | pg = container_of(last_pg, struct ftrace_page, next); | |
6145 | if (!(*last_pg)) | |
6146 | ftrace_pages = pg; | |
6147 | continue; | |
6148 | } | |
6149 | memmove(rec, rec + 1, | |
6150 | (pg->index - (rec - pg->records)) * sizeof(*rec)); | |
6151 | /* More than one function may be in this block */ | |
6152 | goto again; | |
6153 | } | |
6154 | mutex_unlock(&ftrace_lock); | |
8715b108 JF |
6155 | |
6156 | list_for_each_entry_safe(func, func_next, &clear_hash, list) { | |
6157 | clear_func_from_hashes(func); | |
6158 | kfree(func); | |
6159 | } | |
42c269c8 SRV |
6160 | } |
6161 | ||
6cafbe15 SRV |
6162 | void __init ftrace_free_init_mem(void) |
6163 | { | |
6164 | void *start = (void *)(&__init_begin); | |
6165 | void *end = (void *)(&__init_end); | |
6166 | ||
aba4b5c2 | 6167 | ftrace_free_mem(NULL, start, end); |
42c269c8 SRV |
6168 | } |
6169 | ||
68bf21aa SR |
6170 | void __init ftrace_init(void) |
6171 | { | |
1dc43cf0 JS |
6172 | extern unsigned long __start_mcount_loc[]; |
6173 | extern unsigned long __stop_mcount_loc[]; | |
3a36cb11 | 6174 | unsigned long count, flags; |
68bf21aa SR |
6175 | int ret; |
6176 | ||
68bf21aa | 6177 | local_irq_save(flags); |
3a36cb11 | 6178 | ret = ftrace_dyn_arch_init(); |
68bf21aa | 6179 | local_irq_restore(flags); |
af64a7cb | 6180 | if (ret) |
68bf21aa SR |
6181 | goto failed; |
6182 | ||
6183 | count = __stop_mcount_loc - __start_mcount_loc; | |
c867ccd8 JS |
6184 | if (!count) { |
6185 | pr_info("ftrace: No functions to be traced?\n"); | |
68bf21aa | 6186 | goto failed; |
c867ccd8 JS |
6187 | } |
6188 | ||
6189 | pr_info("ftrace: allocating %ld entries in %ld pages\n", | |
6190 | count, count / ENTRIES_PER_PAGE + 1); | |
68bf21aa SR |
6191 | |
6192 | last_ftrace_enabled = ftrace_enabled = 1; | |
6193 | ||
5cb084bb | 6194 | ret = ftrace_process_locs(NULL, |
31e88909 | 6195 | __start_mcount_loc, |
68bf21aa SR |
6196 | __stop_mcount_loc); |
6197 | ||
2af15d6a SR |
6198 | set_ftrace_early_filters(); |
6199 | ||
68bf21aa SR |
6200 | return; |
6201 | failed: | |
6202 | ftrace_disabled = 1; | |
6203 | } | |
68bf21aa | 6204 | |
f3bea491 SRRH |
6205 | /* Do nothing if arch does not support this */ |
6206 | void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops) | |
6207 | { | |
6208 | } | |
6209 | ||
6210 | static void ftrace_update_trampoline(struct ftrace_ops *ops) | |
6211 | { | |
f3bea491 SRRH |
6212 | arch_ftrace_update_trampoline(ops); |
6213 | } | |
6214 | ||
04ec7bb6 SRV |
6215 | void ftrace_init_trace_array(struct trace_array *tr) |
6216 | { | |
6217 | INIT_LIST_HEAD(&tr->func_probes); | |
673feb9d SRV |
6218 | INIT_LIST_HEAD(&tr->mod_trace); |
6219 | INIT_LIST_HEAD(&tr->mod_notrace); | |
04ec7bb6 | 6220 | } |
3d083395 | 6221 | #else |
0b6e4d56 | 6222 | |
2b499381 | 6223 | static struct ftrace_ops global_ops = { |
bd69c30b | 6224 | .func = ftrace_stub, |
e3eea140 SRRH |
6225 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | |
6226 | FTRACE_OPS_FL_INITIALIZED | | |
6227 | FTRACE_OPS_FL_PID, | |
bd69c30b SR |
6228 | }; |
6229 | ||
0b6e4d56 FW |
6230 | static int __init ftrace_nodyn_init(void) |
6231 | { | |
6232 | ftrace_enabled = 1; | |
6233 | return 0; | |
6234 | } | |
6f415672 | 6235 | core_initcall(ftrace_nodyn_init); |
0b6e4d56 | 6236 | |
8434dc93 | 6237 | static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; } |
df4fc315 | 6238 | static inline void ftrace_startup_enable(int command) { } |
e1effa01 | 6239 | static inline void ftrace_startup_all(int command) { } |
5a45cfe1 | 6240 | /* Keep as macros so we do not need to define the commands */ |
8a56d776 SRRH |
6241 | # define ftrace_startup(ops, command) \ |
6242 | ({ \ | |
6243 | int ___ret = __register_ftrace_function(ops); \ | |
6244 | if (!___ret) \ | |
6245 | (ops)->flags |= FTRACE_OPS_FL_ENABLED; \ | |
6246 | ___ret; \ | |
3b6cfdb1 | 6247 | }) |
1fcc1553 SRRH |
6248 | # define ftrace_shutdown(ops, command) \ |
6249 | ({ \ | |
6250 | int ___ret = __unregister_ftrace_function(ops); \ | |
6251 | if (!___ret) \ | |
6252 | (ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \ | |
6253 | ___ret; \ | |
6254 | }) | |
8a56d776 | 6255 | |
c7aafc54 IM |
6256 | # define ftrace_startup_sysctl() do { } while (0) |
6257 | # define ftrace_shutdown_sysctl() do { } while (0) | |
b848914c SR |
6258 | |
6259 | static inline int | |
195a8afc | 6260 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
b848914c SR |
6261 | { |
6262 | return 1; | |
6263 | } | |
6264 | ||
f3bea491 SRRH |
6265 | static void ftrace_update_trampoline(struct ftrace_ops *ops) |
6266 | { | |
6267 | } | |
6268 | ||
3d083395 SR |
6269 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
6270 | ||
4104d326 SRRH |
6271 | __init void ftrace_init_global_array_ops(struct trace_array *tr) |
6272 | { | |
6273 | tr->ops = &global_ops; | |
6274 | tr->ops->private = tr; | |
04ec7bb6 | 6275 | ftrace_init_trace_array(tr); |
4104d326 SRRH |
6276 | } |
6277 | ||
6278 | void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func) | |
6279 | { | |
6280 | /* If we filter on pids, update to use the pid function */ | |
6281 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) { | |
6282 | if (WARN_ON(tr->ops->func != ftrace_stub)) | |
6283 | printk("ftrace ops had %pS for function\n", | |
6284 | tr->ops->func); | |
4104d326 SRRH |
6285 | } |
6286 | tr->ops->func = func; | |
6287 | tr->ops->private = tr; | |
6288 | } | |
6289 | ||
6290 | void ftrace_reset_array_ops(struct trace_array *tr) | |
6291 | { | |
6292 | tr->ops->func = ftrace_stub; | |
6293 | } | |
6294 | ||
2f5f6ad9 SR |
6295 | static inline void |
6296 | __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 6297 | struct ftrace_ops *ignored, struct pt_regs *regs) |
b848914c | 6298 | { |
cdbe61bf | 6299 | struct ftrace_ops *op; |
edc15caf | 6300 | int bit; |
b848914c | 6301 | |
edc15caf SR |
6302 | bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); |
6303 | if (bit < 0) | |
6304 | return; | |
b1cff0ad | 6305 | |
cdbe61bf SR |
6306 | /* |
6307 | * Some of the ops may be dynamically allocated, | |
6308 | * they must be freed after a synchronize_sched(). | |
6309 | */ | |
6310 | preempt_disable_notrace(); | |
ba27f2bc | 6311 | |
0a016409 | 6312 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
ba27f2bc SRRH |
6313 | /* |
6314 | * Check the following for each ops before calling their func: | |
6315 | * if RCU flag is set, then rcu_is_watching() must be true | |
6316 | * if PER_CPU is set, then ftrace_function_local_disable() | |
6317 | * must be false | |
6318 | * Otherwise test if the ip matches the ops filter | |
6319 | * | |
6320 | * If any of the above fails then the op->func() is not executed. | |
6321 | */ | |
6322 | if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) && | |
ba27f2bc | 6323 | ftrace_ops_test(op, ip, regs)) { |
1d48d596 SRRH |
6324 | if (FTRACE_WARN_ON(!op->func)) { |
6325 | pr_warn("op=%p %pS\n", op, op); | |
4104d326 SRRH |
6326 | goto out; |
6327 | } | |
a1e2e31d | 6328 | op->func(ip, parent_ip, op, regs); |
4104d326 | 6329 | } |
0a016409 | 6330 | } while_for_each_ftrace_op(op); |
4104d326 | 6331 | out: |
cdbe61bf | 6332 | preempt_enable_notrace(); |
edc15caf | 6333 | trace_clear_recursion(bit); |
b848914c SR |
6334 | } |
6335 | ||
2f5f6ad9 SR |
6336 | /* |
6337 | * Some archs only support passing ip and parent_ip. Even though | |
6338 | * the list function ignores the op parameter, we do not want any | |
6339 | * C side effects, where a function is called without the caller | |
6340 | * sending a third parameter. | |
a1e2e31d SR |
6341 | * Archs are to support both the regs and ftrace_ops at the same time. |
6342 | * If they support ftrace_ops, it is assumed they support regs. | |
6343 | * If call backs want to use regs, they must either check for regs | |
06aeaaea MH |
6344 | * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS. |
6345 | * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved. | |
a1e2e31d | 6346 | * An architecture can pass partial regs with ftrace_ops and still |
b8ec330a | 6347 | * set the ARCH_SUPPORTS_FTRACE_OPS. |
2f5f6ad9 SR |
6348 | */ |
6349 | #if ARCH_SUPPORTS_FTRACE_OPS | |
6350 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 6351 | struct ftrace_ops *op, struct pt_regs *regs) |
2f5f6ad9 | 6352 | { |
a1e2e31d | 6353 | __ftrace_ops_list_func(ip, parent_ip, NULL, regs); |
2f5f6ad9 SR |
6354 | } |
6355 | #else | |
6356 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip) | |
6357 | { | |
a1e2e31d | 6358 | __ftrace_ops_list_func(ip, parent_ip, NULL, NULL); |
2f5f6ad9 SR |
6359 | } |
6360 | #endif | |
6361 | ||
f1ff6348 SRRH |
6362 | /* |
6363 | * If there's only one function registered but it does not support | |
c68c0fa2 SRRH |
6364 | * recursion, needs RCU protection and/or requires per cpu handling, then |
6365 | * this function will be called by the mcount trampoline. | |
f1ff6348 | 6366 | */ |
c68c0fa2 | 6367 | static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip, |
f1ff6348 SRRH |
6368 | struct ftrace_ops *op, struct pt_regs *regs) |
6369 | { | |
6370 | int bit; | |
6371 | ||
c68c0fa2 SRRH |
6372 | if ((op->flags & FTRACE_OPS_FL_RCU) && !rcu_is_watching()) |
6373 | return; | |
6374 | ||
f1ff6348 SRRH |
6375 | bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); |
6376 | if (bit < 0) | |
6377 | return; | |
6378 | ||
c68c0fa2 | 6379 | preempt_disable_notrace(); |
f1ff6348 | 6380 | |
b3a88803 | 6381 | op->func(ip, parent_ip, op, regs); |
c68c0fa2 SRRH |
6382 | |
6383 | preempt_enable_notrace(); | |
f1ff6348 SRRH |
6384 | trace_clear_recursion(bit); |
6385 | } | |
6386 | ||
87354059 SRRH |
6387 | /** |
6388 | * ftrace_ops_get_func - get the function a trampoline should call | |
6389 | * @ops: the ops to get the function for | |
6390 | * | |
6391 | * Normally the mcount trampoline will call the ops->func, but there | |
6392 | * are times that it should not. For example, if the ops does not | |
6393 | * have its own recursion protection, then it should call the | |
3a150df9 | 6394 | * ftrace_ops_assist_func() instead. |
87354059 SRRH |
6395 | * |
6396 | * Returns the function that the trampoline should call for @ops. | |
6397 | */ | |
6398 | ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops) | |
6399 | { | |
87354059 | 6400 | /* |
c68c0fa2 SRRH |
6401 | * If the function does not handle recursion, needs to be RCU safe, |
6402 | * or does per cpu logic, then we need to call the assist handler. | |
87354059 | 6403 | */ |
c68c0fa2 | 6404 | if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE) || |
b3a88803 | 6405 | ops->flags & FTRACE_OPS_FL_RCU) |
c68c0fa2 | 6406 | return ftrace_ops_assist_func; |
87354059 SRRH |
6407 | |
6408 | return ops->func; | |
6409 | } | |
6410 | ||
345ddcc8 SRRH |
6411 | static void |
6412 | ftrace_filter_pid_sched_switch_probe(void *data, bool preempt, | |
6413 | struct task_struct *prev, struct task_struct *next) | |
978f3a45 | 6414 | { |
345ddcc8 SRRH |
6415 | struct trace_array *tr = data; |
6416 | struct trace_pid_list *pid_list; | |
978f3a45 | 6417 | |
345ddcc8 | 6418 | pid_list = rcu_dereference_sched(tr->function_pids); |
e32d8956 | 6419 | |
345ddcc8 SRRH |
6420 | this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid, |
6421 | trace_ignore_this_task(pid_list, next)); | |
978f3a45 SR |
6422 | } |
6423 | ||
1e10486f NK |
6424 | static void |
6425 | ftrace_pid_follow_sched_process_fork(void *data, | |
6426 | struct task_struct *self, | |
6427 | struct task_struct *task) | |
6428 | { | |
6429 | struct trace_pid_list *pid_list; | |
6430 | struct trace_array *tr = data; | |
6431 | ||
6432 | pid_list = rcu_dereference_sched(tr->function_pids); | |
6433 | trace_filter_add_remove_task(pid_list, self, task); | |
6434 | } | |
6435 | ||
6436 | static void | |
6437 | ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task) | |
6438 | { | |
6439 | struct trace_pid_list *pid_list; | |
6440 | struct trace_array *tr = data; | |
6441 | ||
6442 | pid_list = rcu_dereference_sched(tr->function_pids); | |
6443 | trace_filter_add_remove_task(pid_list, NULL, task); | |
6444 | } | |
6445 | ||
6446 | void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) | |
6447 | { | |
6448 | if (enable) { | |
6449 | register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, | |
6450 | tr); | |
6451 | register_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit, | |
6452 | tr); | |
6453 | } else { | |
6454 | unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, | |
6455 | tr); | |
6456 | unregister_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit, | |
6457 | tr); | |
6458 | } | |
6459 | } | |
6460 | ||
345ddcc8 | 6461 | static void clear_ftrace_pids(struct trace_array *tr) |
e32d8956 | 6462 | { |
345ddcc8 SRRH |
6463 | struct trace_pid_list *pid_list; |
6464 | int cpu; | |
e32d8956 | 6465 | |
345ddcc8 SRRH |
6466 | pid_list = rcu_dereference_protected(tr->function_pids, |
6467 | lockdep_is_held(&ftrace_lock)); | |
6468 | if (!pid_list) | |
6469 | return; | |
229c4ef8 | 6470 | |
345ddcc8 | 6471 | unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr); |
e32d8956 | 6472 | |
345ddcc8 SRRH |
6473 | for_each_possible_cpu(cpu) |
6474 | per_cpu_ptr(tr->trace_buffer.data, cpu)->ftrace_ignore_pid = false; | |
978f3a45 | 6475 | |
345ddcc8 | 6476 | rcu_assign_pointer(tr->function_pids, NULL); |
978f3a45 | 6477 | |
345ddcc8 SRRH |
6478 | /* Wait till all users are no longer using pid filtering */ |
6479 | synchronize_sched(); | |
e32d8956 | 6480 | |
345ddcc8 | 6481 | trace_free_pid_list(pid_list); |
e32d8956 SR |
6482 | } |
6483 | ||
d879d0b8 NK |
6484 | void ftrace_clear_pids(struct trace_array *tr) |
6485 | { | |
6486 | mutex_lock(&ftrace_lock); | |
6487 | ||
6488 | clear_ftrace_pids(tr); | |
6489 | ||
6490 | mutex_unlock(&ftrace_lock); | |
6491 | } | |
6492 | ||
345ddcc8 | 6493 | static void ftrace_pid_reset(struct trace_array *tr) |
df4fc315 | 6494 | { |
756d17ee | 6495 | mutex_lock(&ftrace_lock); |
345ddcc8 | 6496 | clear_ftrace_pids(tr); |
978f3a45 | 6497 | |
756d17ee | 6498 | ftrace_update_pid_func(); |
e1effa01 | 6499 | ftrace_startup_all(0); |
756d17ee | 6500 | |
6501 | mutex_unlock(&ftrace_lock); | |
756d17ee | 6502 | } |
6503 | ||
345ddcc8 SRRH |
6504 | /* Greater than any max PID */ |
6505 | #define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1) | |
df4fc315 | 6506 | |
756d17ee | 6507 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
345ddcc8 | 6508 | __acquires(RCU) |
756d17ee | 6509 | { |
345ddcc8 SRRH |
6510 | struct trace_pid_list *pid_list; |
6511 | struct trace_array *tr = m->private; | |
6512 | ||
756d17ee | 6513 | mutex_lock(&ftrace_lock); |
345ddcc8 SRRH |
6514 | rcu_read_lock_sched(); |
6515 | ||
6516 | pid_list = rcu_dereference_sched(tr->function_pids); | |
756d17ee | 6517 | |
345ddcc8 SRRH |
6518 | if (!pid_list) |
6519 | return !(*pos) ? FTRACE_NO_PIDS : NULL; | |
756d17ee | 6520 | |
345ddcc8 | 6521 | return trace_pid_start(pid_list, pos); |
756d17ee | 6522 | } |
6523 | ||
6524 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
6525 | { | |
345ddcc8 SRRH |
6526 | struct trace_array *tr = m->private; |
6527 | struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids); | |
6528 | ||
6529 | if (v == FTRACE_NO_PIDS) | |
756d17ee | 6530 | return NULL; |
6531 | ||
345ddcc8 | 6532 | return trace_pid_next(pid_list, v, pos); |
756d17ee | 6533 | } |
6534 | ||
6535 | static void fpid_stop(struct seq_file *m, void *p) | |
345ddcc8 | 6536 | __releases(RCU) |
756d17ee | 6537 | { |
345ddcc8 | 6538 | rcu_read_unlock_sched(); |
756d17ee | 6539 | mutex_unlock(&ftrace_lock); |
6540 | } | |
6541 | ||
6542 | static int fpid_show(struct seq_file *m, void *v) | |
6543 | { | |
345ddcc8 | 6544 | if (v == FTRACE_NO_PIDS) { |
fa6f0cc7 | 6545 | seq_puts(m, "no pid\n"); |
756d17ee | 6546 | return 0; |
6547 | } | |
6548 | ||
345ddcc8 | 6549 | return trace_pid_show(m, v); |
756d17ee | 6550 | } |
6551 | ||
6552 | static const struct seq_operations ftrace_pid_sops = { | |
6553 | .start = fpid_start, | |
6554 | .next = fpid_next, | |
6555 | .stop = fpid_stop, | |
6556 | .show = fpid_show, | |
6557 | }; | |
6558 | ||
6559 | static int | |
6560 | ftrace_pid_open(struct inode *inode, struct file *file) | |
6561 | { | |
345ddcc8 SRRH |
6562 | struct trace_array *tr = inode->i_private; |
6563 | struct seq_file *m; | |
756d17ee | 6564 | int ret = 0; |
6565 | ||
345ddcc8 SRRH |
6566 | if (trace_array_get(tr) < 0) |
6567 | return -ENODEV; | |
6568 | ||
756d17ee | 6569 | if ((file->f_mode & FMODE_WRITE) && |
6570 | (file->f_flags & O_TRUNC)) | |
345ddcc8 | 6571 | ftrace_pid_reset(tr); |
756d17ee | 6572 | |
345ddcc8 SRRH |
6573 | ret = seq_open(file, &ftrace_pid_sops); |
6574 | if (ret < 0) { | |
6575 | trace_array_put(tr); | |
6576 | } else { | |
6577 | m = file->private_data; | |
6578 | /* copy tr over to seq ops */ | |
6579 | m->private = tr; | |
6580 | } | |
756d17ee | 6581 | |
6582 | return ret; | |
6583 | } | |
6584 | ||
345ddcc8 SRRH |
6585 | static void ignore_task_cpu(void *data) |
6586 | { | |
6587 | struct trace_array *tr = data; | |
6588 | struct trace_pid_list *pid_list; | |
6589 | ||
6590 | /* | |
6591 | * This function is called by on_each_cpu() while the | |
6592 | * event_mutex is held. | |
6593 | */ | |
6594 | pid_list = rcu_dereference_protected(tr->function_pids, | |
6595 | mutex_is_locked(&ftrace_lock)); | |
6596 | ||
6597 | this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid, | |
6598 | trace_ignore_this_task(pid_list, current)); | |
6599 | } | |
6600 | ||
df4fc315 SR |
6601 | static ssize_t |
6602 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
6603 | size_t cnt, loff_t *ppos) | |
6604 | { | |
345ddcc8 SRRH |
6605 | struct seq_file *m = filp->private_data; |
6606 | struct trace_array *tr = m->private; | |
6607 | struct trace_pid_list *filtered_pids = NULL; | |
6608 | struct trace_pid_list *pid_list; | |
6609 | ssize_t ret; | |
df4fc315 | 6610 | |
345ddcc8 SRRH |
6611 | if (!cnt) |
6612 | return 0; | |
6613 | ||
6614 | mutex_lock(&ftrace_lock); | |
6615 | ||
6616 | filtered_pids = rcu_dereference_protected(tr->function_pids, | |
6617 | lockdep_is_held(&ftrace_lock)); | |
6618 | ||
6619 | ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt); | |
6620 | if (ret < 0) | |
6621 | goto out; | |
df4fc315 | 6622 | |
345ddcc8 | 6623 | rcu_assign_pointer(tr->function_pids, pid_list); |
df4fc315 | 6624 | |
345ddcc8 SRRH |
6625 | if (filtered_pids) { |
6626 | synchronize_sched(); | |
6627 | trace_free_pid_list(filtered_pids); | |
6628 | } else if (pid_list) { | |
6629 | /* Register a probe to set whether to ignore the tracing of a task */ | |
6630 | register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr); | |
6631 | } | |
df4fc315 | 6632 | |
756d17ee | 6633 | /* |
345ddcc8 SRRH |
6634 | * Ignoring of pids is done at task switch. But we have to |
6635 | * check for those tasks that are currently running. | |
6636 | * Always do this in case a pid was appended or removed. | |
756d17ee | 6637 | */ |
345ddcc8 | 6638 | on_each_cpu(ignore_task_cpu, tr, 1); |
756d17ee | 6639 | |
345ddcc8 SRRH |
6640 | ftrace_update_pid_func(); |
6641 | ftrace_startup_all(0); | |
6642 | out: | |
6643 | mutex_unlock(&ftrace_lock); | |
df4fc315 | 6644 | |
345ddcc8 SRRH |
6645 | if (ret > 0) |
6646 | *ppos += ret; | |
df4fc315 | 6647 | |
345ddcc8 | 6648 | return ret; |
756d17ee | 6649 | } |
df4fc315 | 6650 | |
756d17ee | 6651 | static int |
6652 | ftrace_pid_release(struct inode *inode, struct file *file) | |
6653 | { | |
345ddcc8 | 6654 | struct trace_array *tr = inode->i_private; |
df4fc315 | 6655 | |
345ddcc8 SRRH |
6656 | trace_array_put(tr); |
6657 | ||
6658 | return seq_release(inode, file); | |
df4fc315 SR |
6659 | } |
6660 | ||
5e2336a0 | 6661 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 6662 | .open = ftrace_pid_open, |
6663 | .write = ftrace_pid_write, | |
6664 | .read = seq_read, | |
098c879e | 6665 | .llseek = tracing_lseek, |
756d17ee | 6666 | .release = ftrace_pid_release, |
df4fc315 SR |
6667 | }; |
6668 | ||
345ddcc8 | 6669 | void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer) |
df4fc315 | 6670 | { |
5452af66 | 6671 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
345ddcc8 | 6672 | tr, &ftrace_pid_fops); |
df4fc315 | 6673 | } |
df4fc315 | 6674 | |
501c2375 SRRH |
6675 | void __init ftrace_init_tracefs_toplevel(struct trace_array *tr, |
6676 | struct dentry *d_tracer) | |
6677 | { | |
6678 | /* Only the top level directory has the dyn_tracefs and profile */ | |
6679 | WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL)); | |
6680 | ||
6681 | ftrace_init_dyn_tracefs(d_tracer); | |
6682 | ftrace_profile_tracefs(d_tracer); | |
6683 | } | |
6684 | ||
a2bb6a3d | 6685 | /** |
81adbdc0 | 6686 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
6687 | * |
6688 | * This function should be used by panic code. It stops ftrace | |
6689 | * but in a not so nice way. If you need to simply kill ftrace | |
6690 | * from a non-atomic section, use ftrace_kill. | |
6691 | */ | |
81adbdc0 | 6692 | void ftrace_kill(void) |
a2bb6a3d SR |
6693 | { |
6694 | ftrace_disabled = 1; | |
6695 | ftrace_enabled = 0; | |
a2bb6a3d SR |
6696 | clear_ftrace_function(); |
6697 | } | |
6698 | ||
e0a413f6 SR |
6699 | /** |
6700 | * Test if ftrace is dead or not. | |
6701 | */ | |
6702 | int ftrace_is_dead(void) | |
6703 | { | |
6704 | return ftrace_disabled; | |
6705 | } | |
6706 | ||
16444a8a | 6707 | /** |
3d083395 SR |
6708 | * register_ftrace_function - register a function for profiling |
6709 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 6710 | * |
3d083395 SR |
6711 | * Register a function to be called by all functions in the |
6712 | * kernel. | |
6713 | * | |
6714 | * Note: @ops->func and all the functions it calls must be labeled | |
6715 | * with "notrace", otherwise it will go into a | |
6716 | * recursive loop. | |
16444a8a | 6717 | */ |
3d083395 | 6718 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 6719 | { |
45a4a237 | 6720 | int ret = -1; |
4eebcc81 | 6721 | |
f04f24fb MH |
6722 | ftrace_ops_init(ops); |
6723 | ||
e6ea44e9 | 6724 | mutex_lock(&ftrace_lock); |
e7d3737e | 6725 | |
8a56d776 | 6726 | ret = ftrace_startup(ops, 0); |
b848914c | 6727 | |
e6ea44e9 | 6728 | mutex_unlock(&ftrace_lock); |
8d240dd8 | 6729 | |
b0fc494f | 6730 | return ret; |
3d083395 | 6731 | } |
cdbe61bf | 6732 | EXPORT_SYMBOL_GPL(register_ftrace_function); |
3d083395 SR |
6733 | |
6734 | /** | |
32632920 | 6735 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
6736 | * @ops - ops structure that holds the function to unregister |
6737 | * | |
6738 | * Unregister a function that was added to be called by ftrace profiling. | |
6739 | */ | |
6740 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
6741 | { | |
6742 | int ret; | |
6743 | ||
e6ea44e9 | 6744 | mutex_lock(&ftrace_lock); |
8a56d776 | 6745 | ret = ftrace_shutdown(ops, 0); |
e6ea44e9 | 6746 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
6747 | |
6748 | return ret; | |
6749 | } | |
cdbe61bf | 6750 | EXPORT_SYMBOL_GPL(unregister_ftrace_function); |
b0fc494f | 6751 | |
e309b41d | 6752 | int |
b0fc494f | 6753 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
8d65af78 | 6754 | void __user *buffer, size_t *lenp, |
b0fc494f SR |
6755 | loff_t *ppos) |
6756 | { | |
45a4a237 | 6757 | int ret = -ENODEV; |
4eebcc81 | 6758 | |
e6ea44e9 | 6759 | mutex_lock(&ftrace_lock); |
b0fc494f | 6760 | |
45a4a237 SR |
6761 | if (unlikely(ftrace_disabled)) |
6762 | goto out; | |
6763 | ||
6764 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
b0fc494f | 6765 | |
a32c7765 | 6766 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
6767 | goto out; |
6768 | ||
a32c7765 | 6769 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f SR |
6770 | |
6771 | if (ftrace_enabled) { | |
6772 | ||
b0fc494f | 6773 | /* we are starting ftrace again */ |
f86f4180 CZ |
6774 | if (rcu_dereference_protected(ftrace_ops_list, |
6775 | lockdep_is_held(&ftrace_lock)) != &ftrace_list_end) | |
5000c418 | 6776 | update_ftrace_function(); |
b0fc494f | 6777 | |
524a3868 SRRH |
6778 | ftrace_startup_sysctl(); |
6779 | ||
b0fc494f SR |
6780 | } else { |
6781 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
6782 | ftrace_trace_function = ftrace_stub; | |
6783 | ||
6784 | ftrace_shutdown_sysctl(); | |
6785 | } | |
6786 | ||
6787 | out: | |
e6ea44e9 | 6788 | mutex_unlock(&ftrace_lock); |
3d083395 | 6789 | return ret; |
16444a8a | 6790 | } |
f17845e5 | 6791 | |
fb52607a | 6792 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 6793 | |
5f151b24 SRRH |
6794 | static struct ftrace_ops graph_ops = { |
6795 | .func = ftrace_stub, | |
6796 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | | |
6797 | FTRACE_OPS_FL_INITIALIZED | | |
e3eea140 | 6798 | FTRACE_OPS_FL_PID | |
5f151b24 SRRH |
6799 | FTRACE_OPS_FL_STUB, |
6800 | #ifdef FTRACE_GRAPH_TRAMP_ADDR | |
6801 | .trampoline = FTRACE_GRAPH_TRAMP_ADDR, | |
aec0be2d | 6802 | /* trampoline_size is only needed for dynamically allocated tramps */ |
5f151b24 SRRH |
6803 | #endif |
6804 | ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash) | |
6805 | }; | |
6806 | ||
55577204 SRRH |
6807 | void ftrace_graph_sleep_time_control(bool enable) |
6808 | { | |
6809 | fgraph_sleep_time = enable; | |
6810 | } | |
6811 | ||
6812 | void ftrace_graph_graph_time_control(bool enable) | |
6813 | { | |
6814 | fgraph_graph_time = enable; | |
6815 | } | |
6816 | ||
e49dc19c SR |
6817 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
6818 | { | |
6819 | return 0; | |
6820 | } | |
6821 | ||
287b6e68 FW |
6822 | /* The callbacks that hook a function */ |
6823 | trace_func_graph_ret_t ftrace_graph_return = | |
6824 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 6825 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
23a8e844 | 6826 | static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
6827 | |
6828 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
6829 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
6830 | { | |
6831 | int i; | |
6832 | int ret = 0; | |
f201ae23 FW |
6833 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; |
6834 | struct task_struct *g, *t; | |
6835 | ||
6836 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
6837 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
6838 | * sizeof(struct ftrace_ret_stack), | |
6839 | GFP_KERNEL); | |
6840 | if (!ret_stack_list[i]) { | |
6841 | start = 0; | |
6842 | end = i; | |
6843 | ret = -ENOMEM; | |
6844 | goto free; | |
6845 | } | |
6846 | } | |
6847 | ||
6112a300 | 6848 | read_lock(&tasklist_lock); |
f201ae23 FW |
6849 | do_each_thread(g, t) { |
6850 | if (start == end) { | |
6851 | ret = -EAGAIN; | |
6852 | goto unlock; | |
6853 | } | |
6854 | ||
6855 | if (t->ret_stack == NULL) { | |
380c4b14 | 6856 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 6857 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
6858 | t->curr_ret_stack = -1; |
6859 | /* Make sure the tasks see the -1 first: */ | |
6860 | smp_wmb(); | |
6861 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
6862 | } |
6863 | } while_each_thread(g, t); | |
6864 | ||
6865 | unlock: | |
6112a300 | 6866 | read_unlock(&tasklist_lock); |
f201ae23 FW |
6867 | free: |
6868 | for (i = start; i < end; i++) | |
6869 | kfree(ret_stack_list[i]); | |
6870 | return ret; | |
6871 | } | |
6872 | ||
8aef2d28 | 6873 | static void |
c73464b1 | 6874 | ftrace_graph_probe_sched_switch(void *ignore, bool preempt, |
38516ab5 | 6875 | struct task_struct *prev, struct task_struct *next) |
8aef2d28 SR |
6876 | { |
6877 | unsigned long long timestamp; | |
6878 | int index; | |
6879 | ||
be6f164a SR |
6880 | /* |
6881 | * Does the user want to count the time a function was asleep. | |
6882 | * If so, do not update the time stamps. | |
6883 | */ | |
55577204 | 6884 | if (fgraph_sleep_time) |
be6f164a SR |
6885 | return; |
6886 | ||
8aef2d28 SR |
6887 | timestamp = trace_clock_local(); |
6888 | ||
6889 | prev->ftrace_timestamp = timestamp; | |
6890 | ||
6891 | /* only process tasks that we timestamped */ | |
6892 | if (!next->ftrace_timestamp) | |
6893 | return; | |
6894 | ||
6895 | /* | |
6896 | * Update all the counters in next to make up for the | |
6897 | * time next was sleeping. | |
6898 | */ | |
6899 | timestamp -= next->ftrace_timestamp; | |
6900 | ||
6901 | for (index = next->curr_ret_stack; index >= 0; index--) | |
6902 | next->ret_stack[index].calltime += timestamp; | |
6903 | } | |
6904 | ||
f201ae23 | 6905 | /* Allocate a return stack for each task */ |
fb52607a | 6906 | static int start_graph_tracing(void) |
f201ae23 FW |
6907 | { |
6908 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 6909 | int ret, cpu; |
f201ae23 FW |
6910 | |
6911 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
6912 | sizeof(struct ftrace_ret_stack *), | |
6913 | GFP_KERNEL); | |
6914 | ||
6915 | if (!ret_stack_list) | |
6916 | return -ENOMEM; | |
6917 | ||
5b058bcd | 6918 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
6919 | for_each_online_cpu(cpu) { |
6920 | if (!idle_task(cpu)->ret_stack) | |
868baf07 | 6921 | ftrace_graph_init_idle_task(idle_task(cpu), cpu); |
179c498a | 6922 | } |
5b058bcd | 6923 | |
f201ae23 FW |
6924 | do { |
6925 | ret = alloc_retstack_tasklist(ret_stack_list); | |
6926 | } while (ret == -EAGAIN); | |
6927 | ||
8aef2d28 | 6928 | if (!ret) { |
38516ab5 | 6929 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
8aef2d28 SR |
6930 | if (ret) |
6931 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
6932 | " probe to kernel_sched_switch\n"); | |
6933 | } | |
6934 | ||
f201ae23 FW |
6935 | kfree(ret_stack_list); |
6936 | return ret; | |
6937 | } | |
6938 | ||
4a2b8dda FW |
6939 | /* |
6940 | * Hibernation protection. | |
6941 | * The state of the current task is too much unstable during | |
6942 | * suspend/restore to disk. We want to protect against that. | |
6943 | */ | |
6944 | static int | |
6945 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
6946 | void *unused) | |
6947 | { | |
6948 | switch (state) { | |
6949 | case PM_HIBERNATION_PREPARE: | |
6950 | pause_graph_tracing(); | |
6951 | break; | |
6952 | ||
6953 | case PM_POST_HIBERNATION: | |
6954 | unpause_graph_tracing(); | |
6955 | break; | |
6956 | } | |
6957 | return NOTIFY_DONE; | |
6958 | } | |
6959 | ||
23a8e844 SRRH |
6960 | static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace) |
6961 | { | |
6962 | if (!ftrace_ops_test(&global_ops, trace->func, NULL)) | |
6963 | return 0; | |
6964 | return __ftrace_graph_entry(trace); | |
6965 | } | |
6966 | ||
6967 | /* | |
6968 | * The function graph tracer should only trace the functions defined | |
6969 | * by set_ftrace_filter and set_ftrace_notrace. If another function | |
6970 | * tracer ops is registered, the graph tracer requires testing the | |
6971 | * function against the global ops, and not just trace any function | |
6972 | * that any ftrace_ops registered. | |
6973 | */ | |
6974 | static void update_function_graph_func(void) | |
6975 | { | |
5f151b24 SRRH |
6976 | struct ftrace_ops *op; |
6977 | bool do_test = false; | |
6978 | ||
6979 | /* | |
6980 | * The graph and global ops share the same set of functions | |
6981 | * to test. If any other ops is on the list, then | |
6982 | * the graph tracing needs to test if its the function | |
6983 | * it should call. | |
6984 | */ | |
6985 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
6986 | if (op != &global_ops && op != &graph_ops && | |
6987 | op != &ftrace_list_end) { | |
6988 | do_test = true; | |
6989 | /* in double loop, break out with goto */ | |
6990 | goto out; | |
6991 | } | |
6992 | } while_for_each_ftrace_op(op); | |
6993 | out: | |
6994 | if (do_test) | |
23a8e844 | 6995 | ftrace_graph_entry = ftrace_graph_entry_test; |
5f151b24 SRRH |
6996 | else |
6997 | ftrace_graph_entry = __ftrace_graph_entry; | |
23a8e844 SRRH |
6998 | } |
6999 | ||
8275f69f MK |
7000 | static struct notifier_block ftrace_suspend_notifier = { |
7001 | .notifier_call = ftrace_suspend_notifier_call, | |
7002 | }; | |
7003 | ||
287b6e68 FW |
7004 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
7005 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 7006 | { |
e7d3737e FW |
7007 | int ret = 0; |
7008 | ||
e6ea44e9 | 7009 | mutex_lock(&ftrace_lock); |
e7d3737e | 7010 | |
05ce5818 | 7011 | /* we currently allow only one tracer registered at a time */ |
597af815 | 7012 | if (ftrace_graph_active) { |
05ce5818 SR |
7013 | ret = -EBUSY; |
7014 | goto out; | |
7015 | } | |
7016 | ||
4a2b8dda FW |
7017 | register_pm_notifier(&ftrace_suspend_notifier); |
7018 | ||
597af815 | 7019 | ftrace_graph_active++; |
fb52607a | 7020 | ret = start_graph_tracing(); |
f201ae23 | 7021 | if (ret) { |
597af815 | 7022 | ftrace_graph_active--; |
f201ae23 FW |
7023 | goto out; |
7024 | } | |
e53a6319 | 7025 | |
287b6e68 | 7026 | ftrace_graph_return = retfunc; |
23a8e844 SRRH |
7027 | |
7028 | /* | |
7029 | * Update the indirect function to the entryfunc, and the | |
7030 | * function that gets called to the entry_test first. Then | |
7031 | * call the update fgraph entry function to determine if | |
7032 | * the entryfunc should be called directly or not. | |
7033 | */ | |
7034 | __ftrace_graph_entry = entryfunc; | |
7035 | ftrace_graph_entry = ftrace_graph_entry_test; | |
7036 | update_function_graph_func(); | |
e53a6319 | 7037 | |
5f151b24 | 7038 | ret = ftrace_startup(&graph_ops, FTRACE_START_FUNC_RET); |
e7d3737e | 7039 | out: |
e6ea44e9 | 7040 | mutex_unlock(&ftrace_lock); |
e7d3737e | 7041 | return ret; |
15e6cb36 FW |
7042 | } |
7043 | ||
fb52607a | 7044 | void unregister_ftrace_graph(void) |
15e6cb36 | 7045 | { |
e6ea44e9 | 7046 | mutex_lock(&ftrace_lock); |
e7d3737e | 7047 | |
597af815 | 7048 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
7049 | goto out; |
7050 | ||
597af815 | 7051 | ftrace_graph_active--; |
287b6e68 | 7052 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 7053 | ftrace_graph_entry = ftrace_graph_entry_stub; |
23a8e844 | 7054 | __ftrace_graph_entry = ftrace_graph_entry_stub; |
5f151b24 | 7055 | ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET); |
4a2b8dda | 7056 | unregister_pm_notifier(&ftrace_suspend_notifier); |
38516ab5 | 7057 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
e7d3737e | 7058 | |
2aad1b76 | 7059 | out: |
e6ea44e9 | 7060 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 7061 | } |
f201ae23 | 7062 | |
868baf07 SR |
7063 | static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack); |
7064 | ||
7065 | static void | |
7066 | graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack) | |
7067 | { | |
7068 | atomic_set(&t->tracing_graph_pause, 0); | |
7069 | atomic_set(&t->trace_overrun, 0); | |
7070 | t->ftrace_timestamp = 0; | |
25985edc | 7071 | /* make curr_ret_stack visible before we add the ret_stack */ |
868baf07 SR |
7072 | smp_wmb(); |
7073 | t->ret_stack = ret_stack; | |
7074 | } | |
7075 | ||
7076 | /* | |
7077 | * Allocate a return stack for the idle task. May be the first | |
7078 | * time through, or it may be done by CPU hotplug online. | |
7079 | */ | |
7080 | void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) | |
7081 | { | |
7082 | t->curr_ret_stack = -1; | |
7083 | /* | |
7084 | * The idle task has no parent, it either has its own | |
7085 | * stack or no stack at all. | |
7086 | */ | |
7087 | if (t->ret_stack) | |
7088 | WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu)); | |
7089 | ||
7090 | if (ftrace_graph_active) { | |
7091 | struct ftrace_ret_stack *ret_stack; | |
7092 | ||
7093 | ret_stack = per_cpu(idle_ret_stack, cpu); | |
7094 | if (!ret_stack) { | |
7095 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
7096 | * sizeof(struct ftrace_ret_stack), | |
7097 | GFP_KERNEL); | |
7098 | if (!ret_stack) | |
7099 | return; | |
7100 | per_cpu(idle_ret_stack, cpu) = ret_stack; | |
7101 | } | |
7102 | graph_init_task(t, ret_stack); | |
7103 | } | |
7104 | } | |
7105 | ||
f201ae23 | 7106 | /* Allocate a return stack for newly created task */ |
fb52607a | 7107 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 7108 | { |
84047e36 SR |
7109 | /* Make sure we do not use the parent ret_stack */ |
7110 | t->ret_stack = NULL; | |
ea14eb71 | 7111 | t->curr_ret_stack = -1; |
84047e36 | 7112 | |
597af815 | 7113 | if (ftrace_graph_active) { |
82310a32 SR |
7114 | struct ftrace_ret_stack *ret_stack; |
7115 | ||
7116 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
7117 | * sizeof(struct ftrace_ret_stack), |
7118 | GFP_KERNEL); | |
82310a32 | 7119 | if (!ret_stack) |
f201ae23 | 7120 | return; |
868baf07 | 7121 | graph_init_task(t, ret_stack); |
84047e36 | 7122 | } |
f201ae23 FW |
7123 | } |
7124 | ||
fb52607a | 7125 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 7126 | { |
eae849ca FW |
7127 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
7128 | ||
f201ae23 | 7129 | t->ret_stack = NULL; |
eae849ca FW |
7130 | /* NULL must become visible to IRQs before we free it: */ |
7131 | barrier(); | |
7132 | ||
7133 | kfree(ret_stack); | |
f201ae23 | 7134 | } |
15e6cb36 | 7135 | #endif |