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 | |
13 | * Copyright (C) 2004 William Lee Irwin III | |
14 | */ | |
15 | ||
3d083395 SR |
16 | #include <linux/stop_machine.h> |
17 | #include <linux/clocksource.h> | |
18 | #include <linux/kallsyms.h> | |
5072c59f SR |
19 | #include <linux/seq_file.h> |
20 | #include <linux/debugfs.h> | |
3d083395 SR |
21 | #include <linux/kthread.h> |
22 | #include <linux/hardirq.h> | |
16444a8a | 23 | #include <linux/ftrace.h> |
5072c59f | 24 | #include <linux/uaccess.h> |
b0fc494f | 25 | #include <linux/sysctl.h> |
3d083395 | 26 | #include <linux/hash.h> |
5072c59f | 27 | #include <linux/ctype.h> |
3d083395 SR |
28 | #include <linux/list.h> |
29 | ||
30 | #include "trace.h" | |
16444a8a | 31 | |
d61f82d0 SR |
32 | int ftrace_enabled; |
33 | static int last_ftrace_enabled; | |
b0fc494f | 34 | |
3d083395 | 35 | static DEFINE_SPINLOCK(ftrace_lock); |
b0fc494f SR |
36 | static DEFINE_MUTEX(ftrace_sysctl_lock); |
37 | ||
16444a8a ACM |
38 | static struct ftrace_ops ftrace_list_end __read_mostly = |
39 | { | |
40 | .func = ftrace_stub, | |
41 | }; | |
42 | ||
43 | static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; | |
44 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; | |
45 | ||
46 | /* mcount is defined per arch in assembly */ | |
47 | EXPORT_SYMBOL(mcount); | |
48 | ||
49 | notrace void ftrace_list_func(unsigned long ip, unsigned long parent_ip) | |
50 | { | |
51 | struct ftrace_ops *op = ftrace_list; | |
52 | ||
53 | /* in case someone actually ports this to alpha! */ | |
54 | read_barrier_depends(); | |
55 | ||
56 | while (op != &ftrace_list_end) { | |
57 | /* silly alpha */ | |
58 | read_barrier_depends(); | |
59 | op->func(ip, parent_ip); | |
60 | op = op->next; | |
61 | }; | |
62 | } | |
63 | ||
64 | /** | |
3d083395 | 65 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 66 | * |
3d083395 SR |
67 | * This NULLs the ftrace function and in essence stops |
68 | * tracing. There may be lag | |
16444a8a | 69 | */ |
3d083395 | 70 | void clear_ftrace_function(void) |
16444a8a | 71 | { |
3d083395 SR |
72 | ftrace_trace_function = ftrace_stub; |
73 | } | |
74 | ||
75 | static int notrace __register_ftrace_function(struct ftrace_ops *ops) | |
76 | { | |
77 | /* Should never be called by interrupts */ | |
78 | spin_lock(&ftrace_lock); | |
16444a8a | 79 | |
16444a8a ACM |
80 | ops->next = ftrace_list; |
81 | /* | |
82 | * We are entering ops into the ftrace_list but another | |
83 | * CPU might be walking that list. We need to make sure | |
84 | * the ops->next pointer is valid before another CPU sees | |
85 | * the ops pointer included into the ftrace_list. | |
86 | */ | |
87 | smp_wmb(); | |
88 | ftrace_list = ops; | |
3d083395 | 89 | |
b0fc494f SR |
90 | if (ftrace_enabled) { |
91 | /* | |
92 | * For one func, simply call it directly. | |
93 | * For more than one func, call the chain. | |
94 | */ | |
95 | if (ops->next == &ftrace_list_end) | |
96 | ftrace_trace_function = ops->func; | |
97 | else | |
98 | ftrace_trace_function = ftrace_list_func; | |
99 | } | |
3d083395 SR |
100 | |
101 | spin_unlock(&ftrace_lock); | |
16444a8a ACM |
102 | |
103 | return 0; | |
104 | } | |
105 | ||
3d083395 | 106 | static int notrace __unregister_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 107 | { |
16444a8a ACM |
108 | struct ftrace_ops **p; |
109 | int ret = 0; | |
110 | ||
3d083395 | 111 | spin_lock(&ftrace_lock); |
16444a8a ACM |
112 | |
113 | /* | |
3d083395 SR |
114 | * If we are removing the last function, then simply point |
115 | * to the ftrace_stub. | |
16444a8a ACM |
116 | */ |
117 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { | |
118 | ftrace_trace_function = ftrace_stub; | |
119 | ftrace_list = &ftrace_list_end; | |
120 | goto out; | |
121 | } | |
122 | ||
123 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) | |
124 | if (*p == ops) | |
125 | break; | |
126 | ||
127 | if (*p != ops) { | |
128 | ret = -1; | |
129 | goto out; | |
130 | } | |
131 | ||
132 | *p = (*p)->next; | |
133 | ||
b0fc494f SR |
134 | if (ftrace_enabled) { |
135 | /* If we only have one func left, then call that directly */ | |
136 | if (ftrace_list == &ftrace_list_end || | |
137 | ftrace_list->next == &ftrace_list_end) | |
138 | ftrace_trace_function = ftrace_list->func; | |
139 | } | |
16444a8a ACM |
140 | |
141 | out: | |
3d083395 SR |
142 | spin_unlock(&ftrace_lock); |
143 | ||
144 | return ret; | |
145 | } | |
146 | ||
147 | #ifdef CONFIG_DYNAMIC_FTRACE | |
148 | ||
e1c08bdd SR |
149 | static struct task_struct *ftraced_task; |
150 | static DECLARE_WAIT_QUEUE_HEAD(ftraced_waiters); | |
151 | static unsigned long ftraced_iteration_counter; | |
152 | ||
d61f82d0 SR |
153 | enum { |
154 | FTRACE_ENABLE_CALLS = (1 << 0), | |
155 | FTRACE_DISABLE_CALLS = (1 << 1), | |
156 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
157 | FTRACE_ENABLE_MCOUNT = (1 << 3), | |
158 | FTRACE_DISABLE_MCOUNT = (1 << 4), | |
159 | }; | |
160 | ||
5072c59f SR |
161 | static int ftrace_filtered; |
162 | ||
3d083395 SR |
163 | static struct hlist_head ftrace_hash[FTRACE_HASHSIZE]; |
164 | ||
165 | static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu); | |
166 | ||
167 | static DEFINE_SPINLOCK(ftrace_shutdown_lock); | |
168 | static DEFINE_MUTEX(ftraced_lock); | |
5072c59f | 169 | static DEFINE_MUTEX(ftrace_filter_lock); |
3d083395 | 170 | |
3c1720f0 SR |
171 | struct ftrace_page { |
172 | struct ftrace_page *next; | |
173 | int index; | |
174 | struct dyn_ftrace records[]; | |
175 | } __attribute__((packed)); | |
176 | ||
177 | #define ENTRIES_PER_PAGE \ | |
178 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
179 | ||
180 | /* estimate from running different kernels */ | |
181 | #define NR_TO_INIT 10000 | |
182 | ||
183 | static struct ftrace_page *ftrace_pages_start; | |
184 | static struct ftrace_page *ftrace_pages; | |
185 | ||
3d083395 SR |
186 | static int ftraced_trigger; |
187 | static int ftraced_suspend; | |
188 | ||
189 | static int ftrace_record_suspend; | |
190 | ||
37ad5084 SR |
191 | static struct dyn_ftrace *ftrace_free_records; |
192 | ||
3d083395 SR |
193 | static inline int |
194 | notrace ftrace_ip_in_hash(unsigned long ip, unsigned long key) | |
195 | { | |
196 | struct dyn_ftrace *p; | |
197 | struct hlist_node *t; | |
198 | int found = 0; | |
199 | ||
200 | hlist_for_each_entry(p, t, &ftrace_hash[key], node) { | |
201 | if (p->ip == ip) { | |
202 | found = 1; | |
203 | break; | |
204 | } | |
205 | } | |
206 | ||
207 | return found; | |
208 | } | |
209 | ||
210 | static inline void notrace | |
211 | ftrace_add_hash(struct dyn_ftrace *node, unsigned long key) | |
212 | { | |
213 | hlist_add_head(&node->node, &ftrace_hash[key]); | |
214 | } | |
215 | ||
37ad5084 SR |
216 | static notrace void ftrace_free_rec(struct dyn_ftrace *rec) |
217 | { | |
218 | /* no locking, only called from kstop_machine */ | |
219 | ||
220 | rec->ip = (unsigned long)ftrace_free_records; | |
221 | ftrace_free_records = rec; | |
222 | rec->flags |= FTRACE_FL_FREE; | |
223 | } | |
224 | ||
d61f82d0 | 225 | static notrace struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 226 | { |
37ad5084 SR |
227 | struct dyn_ftrace *rec; |
228 | ||
229 | /* First check for freed records */ | |
230 | if (ftrace_free_records) { | |
231 | rec = ftrace_free_records; | |
232 | ||
233 | /* todo, disable tracing altogether on this warning */ | |
234 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { | |
235 | WARN_ON_ONCE(1); | |
236 | ftrace_free_records = NULL; | |
237 | return NULL; | |
238 | } | |
239 | ||
240 | ftrace_free_records = (void *)rec->ip; | |
241 | memset(rec, 0, sizeof(*rec)); | |
242 | return rec; | |
243 | } | |
244 | ||
3c1720f0 SR |
245 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
246 | if (!ftrace_pages->next) | |
247 | return NULL; | |
248 | ftrace_pages = ftrace_pages->next; | |
249 | } | |
250 | ||
251 | return &ftrace_pages->records[ftrace_pages->index++]; | |
252 | } | |
253 | ||
3d083395 | 254 | static void notrace |
d61f82d0 | 255 | ftrace_record_ip(unsigned long ip) |
3d083395 SR |
256 | { |
257 | struct dyn_ftrace *node; | |
258 | unsigned long flags; | |
259 | unsigned long key; | |
260 | int resched; | |
261 | int atomic; | |
262 | ||
d61f82d0 SR |
263 | if (!ftrace_enabled) |
264 | return; | |
265 | ||
3d083395 SR |
266 | resched = need_resched(); |
267 | preempt_disable_notrace(); | |
268 | ||
269 | /* We simply need to protect against recursion */ | |
270 | __get_cpu_var(ftrace_shutdown_disable_cpu)++; | |
271 | if (__get_cpu_var(ftrace_shutdown_disable_cpu) != 1) | |
272 | goto out; | |
273 | ||
274 | if (unlikely(ftrace_record_suspend)) | |
275 | goto out; | |
276 | ||
277 | key = hash_long(ip, FTRACE_HASHBITS); | |
278 | ||
279 | WARN_ON_ONCE(key >= FTRACE_HASHSIZE); | |
280 | ||
281 | if (ftrace_ip_in_hash(ip, key)) | |
282 | goto out; | |
283 | ||
284 | atomic = irqs_disabled(); | |
285 | ||
286 | spin_lock_irqsave(&ftrace_shutdown_lock, flags); | |
287 | ||
288 | /* This ip may have hit the hash before the lock */ | |
289 | if (ftrace_ip_in_hash(ip, key)) | |
290 | goto out_unlock; | |
291 | ||
292 | /* | |
293 | * There's a slight race that the ftraced will update the | |
d61f82d0 | 294 | * hash and reset here. If it is already converted, skip it. |
3d083395 | 295 | */ |
d61f82d0 SR |
296 | if (ftrace_ip_converted(ip)) |
297 | goto out_unlock; | |
298 | ||
299 | node = ftrace_alloc_dyn_node(ip); | |
3d083395 SR |
300 | if (!node) |
301 | goto out_unlock; | |
302 | ||
303 | node->ip = ip; | |
304 | ||
305 | ftrace_add_hash(node, key); | |
306 | ||
307 | ftraced_trigger = 1; | |
308 | ||
309 | out_unlock: | |
310 | spin_unlock_irqrestore(&ftrace_shutdown_lock, flags); | |
311 | out: | |
312 | __get_cpu_var(ftrace_shutdown_disable_cpu)--; | |
313 | ||
314 | /* prevent recursion with scheduler */ | |
315 | if (resched) | |
316 | preempt_enable_no_resched_notrace(); | |
317 | else | |
318 | preempt_enable_notrace(); | |
319 | } | |
320 | ||
d61f82d0 | 321 | #define FTRACE_ADDR ((long)(&ftrace_caller)) |
3c1720f0 SR |
322 | #define MCOUNT_ADDR ((long)(&mcount)) |
323 | ||
5072c59f SR |
324 | static void notrace |
325 | __ftrace_replace_code(struct dyn_ftrace *rec, | |
326 | unsigned char *old, unsigned char *new, int enable) | |
327 | { | |
328 | unsigned long ip; | |
329 | int failed; | |
330 | ||
331 | ip = rec->ip; | |
332 | ||
333 | if (ftrace_filtered && enable) { | |
334 | unsigned long fl; | |
335 | /* | |
336 | * If filtering is on: | |
337 | * | |
338 | * If this record is set to be filtered and | |
339 | * is enabled then do nothing. | |
340 | * | |
341 | * If this record is set to be filtered and | |
342 | * it is not enabled, enable it. | |
343 | * | |
344 | * If this record is not set to be filtered | |
345 | * and it is not enabled do nothing. | |
346 | * | |
347 | * If this record is not set to be filtered and | |
348 | * it is enabled, disable it. | |
349 | */ | |
350 | fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED); | |
351 | ||
352 | if ((fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) || | |
353 | (fl == 0)) | |
354 | return; | |
355 | ||
356 | /* | |
357 | * If it is enabled disable it, | |
358 | * otherwise enable it! | |
359 | */ | |
360 | if (fl == FTRACE_FL_ENABLED) { | |
361 | /* swap new and old */ | |
362 | new = old; | |
363 | old = ftrace_call_replace(ip, FTRACE_ADDR); | |
364 | rec->flags &= ~FTRACE_FL_ENABLED; | |
365 | } else { | |
366 | new = ftrace_call_replace(ip, FTRACE_ADDR); | |
367 | rec->flags |= FTRACE_FL_ENABLED; | |
368 | } | |
369 | } else { | |
370 | ||
371 | if (enable) | |
372 | new = ftrace_call_replace(ip, FTRACE_ADDR); | |
373 | else | |
374 | old = ftrace_call_replace(ip, FTRACE_ADDR); | |
375 | ||
376 | if (enable) { | |
377 | if (rec->flags & FTRACE_FL_ENABLED) | |
378 | return; | |
379 | rec->flags |= FTRACE_FL_ENABLED; | |
380 | } else { | |
381 | if (!(rec->flags & FTRACE_FL_ENABLED)) | |
382 | return; | |
383 | rec->flags &= ~FTRACE_FL_ENABLED; | |
384 | } | |
385 | } | |
386 | ||
387 | failed = ftrace_modify_code(ip, old, new); | |
37ad5084 SR |
388 | if (failed) { |
389 | unsigned long key; | |
390 | /* It is possible that the function hasn't been converted yet */ | |
391 | key = hash_long(ip, FTRACE_HASHBITS); | |
392 | if (!ftrace_ip_in_hash(ip, key)) { | |
393 | rec->flags |= FTRACE_FL_FAILED; | |
394 | ftrace_free_rec(rec); | |
395 | } | |
396 | ||
397 | } | |
5072c59f SR |
398 | } |
399 | ||
400 | static void notrace ftrace_replace_code(int enable) | |
3c1720f0 SR |
401 | { |
402 | unsigned char *new = NULL, *old = NULL; | |
403 | struct dyn_ftrace *rec; | |
404 | struct ftrace_page *pg; | |
3c1720f0 SR |
405 | int i; |
406 | ||
5072c59f | 407 | if (enable) |
3c1720f0 SR |
408 | old = ftrace_nop_replace(); |
409 | else | |
410 | new = ftrace_nop_replace(); | |
411 | ||
412 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
413 | for (i = 0; i < pg->index; i++) { | |
414 | rec = &pg->records[i]; | |
415 | ||
416 | /* don't modify code that has already faulted */ | |
417 | if (rec->flags & FTRACE_FL_FAILED) | |
418 | continue; | |
419 | ||
5072c59f | 420 | __ftrace_replace_code(rec, old, new, enable); |
3c1720f0 SR |
421 | } |
422 | } | |
423 | } | |
424 | ||
3c1720f0 SR |
425 | static notrace void ftrace_shutdown_replenish(void) |
426 | { | |
427 | if (ftrace_pages->next) | |
428 | return; | |
429 | ||
430 | /* allocate another page */ | |
431 | ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL); | |
432 | } | |
3d083395 | 433 | |
3c1720f0 | 434 | static notrace void |
d61f82d0 | 435 | ftrace_code_disable(struct dyn_ftrace *rec) |
3c1720f0 SR |
436 | { |
437 | unsigned long ip; | |
438 | unsigned char *nop, *call; | |
439 | int failed; | |
440 | ||
441 | ip = rec->ip; | |
442 | ||
443 | nop = ftrace_nop_replace(); | |
d61f82d0 | 444 | call = ftrace_call_replace(ip, MCOUNT_ADDR); |
3c1720f0 SR |
445 | |
446 | failed = ftrace_modify_code(ip, call, nop); | |
37ad5084 | 447 | if (failed) { |
3c1720f0 | 448 | rec->flags |= FTRACE_FL_FAILED; |
37ad5084 SR |
449 | ftrace_free_rec(rec); |
450 | } | |
3c1720f0 SR |
451 | } |
452 | ||
d61f82d0 | 453 | static int notrace __ftrace_modify_code(void *data) |
3d083395 | 454 | { |
d61f82d0 SR |
455 | unsigned long addr; |
456 | int *command = data; | |
457 | ||
458 | if (*command & FTRACE_ENABLE_CALLS) | |
459 | ftrace_replace_code(1); | |
460 | else if (*command & FTRACE_DISABLE_CALLS) | |
461 | ftrace_replace_code(0); | |
462 | ||
463 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
464 | ftrace_update_ftrace_func(ftrace_trace_function); | |
465 | ||
466 | if (*command & FTRACE_ENABLE_MCOUNT) { | |
467 | addr = (unsigned long)ftrace_record_ip; | |
468 | ftrace_mcount_set(&addr); | |
469 | } else if (*command & FTRACE_DISABLE_MCOUNT) { | |
470 | addr = (unsigned long)ftrace_stub; | |
471 | ftrace_mcount_set(&addr); | |
472 | } | |
473 | ||
474 | return 0; | |
3d083395 SR |
475 | } |
476 | ||
d61f82d0 | 477 | static void notrace ftrace_run_update_code(int command) |
3d083395 | 478 | { |
d61f82d0 | 479 | stop_machine_run(__ftrace_modify_code, &command, NR_CPUS); |
3d083395 SR |
480 | } |
481 | ||
d61f82d0 SR |
482 | static ftrace_func_t saved_ftrace_func; |
483 | ||
3d083395 SR |
484 | static void notrace ftrace_startup(void) |
485 | { | |
d61f82d0 SR |
486 | int command = 0; |
487 | ||
3d083395 SR |
488 | mutex_lock(&ftraced_lock); |
489 | ftraced_suspend++; | |
d61f82d0 SR |
490 | if (ftraced_suspend == 1) |
491 | command |= FTRACE_ENABLE_CALLS; | |
492 | ||
493 | if (saved_ftrace_func != ftrace_trace_function) { | |
494 | saved_ftrace_func = ftrace_trace_function; | |
495 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
496 | } | |
497 | ||
498 | if (!command || !ftrace_enabled) | |
3d083395 | 499 | goto out; |
3d083395 | 500 | |
d61f82d0 | 501 | ftrace_run_update_code(command); |
3d083395 SR |
502 | out: |
503 | mutex_unlock(&ftraced_lock); | |
504 | } | |
505 | ||
506 | static void notrace ftrace_shutdown(void) | |
507 | { | |
d61f82d0 SR |
508 | int command = 0; |
509 | ||
3d083395 SR |
510 | mutex_lock(&ftraced_lock); |
511 | ftraced_suspend--; | |
d61f82d0 SR |
512 | if (!ftraced_suspend) |
513 | command |= FTRACE_DISABLE_CALLS; | |
3d083395 | 514 | |
d61f82d0 SR |
515 | if (saved_ftrace_func != ftrace_trace_function) { |
516 | saved_ftrace_func = ftrace_trace_function; | |
517 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
518 | } | |
3d083395 | 519 | |
d61f82d0 SR |
520 | if (!command || !ftrace_enabled) |
521 | goto out; | |
522 | ||
523 | ftrace_run_update_code(command); | |
3d083395 SR |
524 | out: |
525 | mutex_unlock(&ftraced_lock); | |
526 | } | |
527 | ||
b0fc494f SR |
528 | static void notrace ftrace_startup_sysctl(void) |
529 | { | |
d61f82d0 SR |
530 | int command = FTRACE_ENABLE_MCOUNT; |
531 | ||
b0fc494f | 532 | mutex_lock(&ftraced_lock); |
d61f82d0 SR |
533 | /* Force update next time */ |
534 | saved_ftrace_func = NULL; | |
b0fc494f SR |
535 | /* ftraced_suspend is true if we want ftrace running */ |
536 | if (ftraced_suspend) | |
d61f82d0 SR |
537 | command |= FTRACE_ENABLE_CALLS; |
538 | ||
539 | ftrace_run_update_code(command); | |
b0fc494f SR |
540 | mutex_unlock(&ftraced_lock); |
541 | } | |
542 | ||
543 | static void notrace ftrace_shutdown_sysctl(void) | |
544 | { | |
d61f82d0 SR |
545 | int command = FTRACE_DISABLE_MCOUNT; |
546 | ||
b0fc494f SR |
547 | mutex_lock(&ftraced_lock); |
548 | /* ftraced_suspend is true if ftrace is running */ | |
549 | if (ftraced_suspend) | |
d61f82d0 SR |
550 | command |= FTRACE_DISABLE_CALLS; |
551 | ||
552 | ftrace_run_update_code(command); | |
b0fc494f SR |
553 | mutex_unlock(&ftraced_lock); |
554 | } | |
555 | ||
3d083395 SR |
556 | static cycle_t ftrace_update_time; |
557 | static unsigned long ftrace_update_cnt; | |
558 | unsigned long ftrace_update_tot_cnt; | |
559 | ||
560 | static int notrace __ftrace_update_code(void *ignore) | |
561 | { | |
562 | struct dyn_ftrace *p; | |
563 | struct hlist_head head; | |
564 | struct hlist_node *t; | |
d61f82d0 | 565 | int save_ftrace_enabled; |
3d083395 SR |
566 | cycle_t start, stop; |
567 | int i; | |
568 | ||
d61f82d0 SR |
569 | /* Don't be recording funcs now */ |
570 | save_ftrace_enabled = ftrace_enabled; | |
571 | ftrace_enabled = 0; | |
3d083395 | 572 | |
750ed1a4 | 573 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
574 | ftrace_update_cnt = 0; |
575 | ||
576 | /* No locks needed, the machine is stopped! */ | |
577 | for (i = 0; i < FTRACE_HASHSIZE; i++) { | |
578 | if (hlist_empty(&ftrace_hash[i])) | |
579 | continue; | |
580 | ||
581 | head = ftrace_hash[i]; | |
582 | INIT_HLIST_HEAD(&ftrace_hash[i]); | |
583 | ||
584 | /* all CPUS are stopped, we are safe to modify code */ | |
585 | hlist_for_each_entry(p, t, &head, node) { | |
d61f82d0 | 586 | ftrace_code_disable(p); |
3d083395 SR |
587 | ftrace_update_cnt++; |
588 | } | |
589 | ||
590 | } | |
591 | ||
750ed1a4 | 592 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
593 | ftrace_update_time = stop - start; |
594 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
595 | ||
d61f82d0 | 596 | ftrace_enabled = save_ftrace_enabled; |
16444a8a ACM |
597 | |
598 | return 0; | |
599 | } | |
600 | ||
3d083395 SR |
601 | static void notrace ftrace_update_code(void) |
602 | { | |
603 | stop_machine_run(__ftrace_update_code, NULL, NR_CPUS); | |
604 | } | |
605 | ||
606 | static int notrace ftraced(void *ignore) | |
607 | { | |
608 | unsigned long usecs; | |
609 | ||
610 | set_current_state(TASK_INTERRUPTIBLE); | |
611 | ||
612 | while (!kthread_should_stop()) { | |
613 | ||
614 | /* check once a second */ | |
615 | schedule_timeout(HZ); | |
616 | ||
b0fc494f | 617 | mutex_lock(&ftrace_sysctl_lock); |
3d083395 | 618 | mutex_lock(&ftraced_lock); |
b0fc494f | 619 | if (ftrace_enabled && ftraced_trigger && !ftraced_suspend) { |
3d083395 SR |
620 | ftrace_record_suspend++; |
621 | ftrace_update_code(); | |
622 | usecs = nsecs_to_usecs(ftrace_update_time); | |
623 | if (ftrace_update_tot_cnt > 100000) { | |
624 | ftrace_update_tot_cnt = 0; | |
625 | pr_info("hm, dftrace overflow: %lu change%s" | |
626 | " (%lu total) in %lu usec%s\n", | |
627 | ftrace_update_cnt, | |
628 | ftrace_update_cnt != 1 ? "s" : "", | |
629 | ftrace_update_tot_cnt, | |
630 | usecs, usecs != 1 ? "s" : ""); | |
631 | WARN_ON_ONCE(1); | |
632 | } | |
633 | ftraced_trigger = 0; | |
634 | ftrace_record_suspend--; | |
635 | } | |
e1c08bdd | 636 | ftraced_iteration_counter++; |
3d083395 | 637 | mutex_unlock(&ftraced_lock); |
b0fc494f | 638 | mutex_unlock(&ftrace_sysctl_lock); |
3d083395 | 639 | |
e1c08bdd SR |
640 | wake_up_interruptible(&ftraced_waiters); |
641 | ||
3d083395 SR |
642 | ftrace_shutdown_replenish(); |
643 | ||
644 | set_current_state(TASK_INTERRUPTIBLE); | |
645 | } | |
646 | __set_current_state(TASK_RUNNING); | |
647 | return 0; | |
648 | } | |
649 | ||
3c1720f0 SR |
650 | static int __init ftrace_dyn_table_alloc(void) |
651 | { | |
652 | struct ftrace_page *pg; | |
653 | int cnt; | |
654 | int i; | |
3c1720f0 SR |
655 | |
656 | /* allocate a few pages */ | |
657 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
658 | if (!ftrace_pages_start) | |
659 | return -1; | |
660 | ||
661 | /* | |
662 | * Allocate a few more pages. | |
663 | * | |
664 | * TODO: have some parser search vmlinux before | |
665 | * final linking to find all calls to ftrace. | |
666 | * Then we can: | |
667 | * a) know how many pages to allocate. | |
668 | * and/or | |
669 | * b) set up the table then. | |
670 | * | |
671 | * The dynamic code is still necessary for | |
672 | * modules. | |
673 | */ | |
674 | ||
675 | pg = ftrace_pages = ftrace_pages_start; | |
676 | ||
677 | cnt = NR_TO_INIT / ENTRIES_PER_PAGE; | |
678 | ||
679 | for (i = 0; i < cnt; i++) { | |
680 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
681 | ||
682 | /* If we fail, we'll try later anyway */ | |
683 | if (!pg->next) | |
684 | break; | |
685 | ||
686 | pg = pg->next; | |
687 | } | |
688 | ||
689 | return 0; | |
690 | } | |
691 | ||
5072c59f SR |
692 | enum { |
693 | FTRACE_ITER_FILTER = (1 << 0), | |
694 | FTRACE_ITER_CONT = (1 << 1), | |
695 | }; | |
696 | ||
697 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
698 | ||
699 | struct ftrace_iterator { | |
700 | loff_t pos; | |
701 | struct ftrace_page *pg; | |
702 | unsigned idx; | |
703 | unsigned flags; | |
704 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
705 | unsigned buffer_idx; | |
706 | unsigned filtered; | |
707 | }; | |
708 | ||
709 | static void notrace * | |
710 | t_next(struct seq_file *m, void *v, loff_t *pos) | |
711 | { | |
712 | struct ftrace_iterator *iter = m->private; | |
713 | struct dyn_ftrace *rec = NULL; | |
714 | ||
715 | (*pos)++; | |
716 | ||
717 | retry: | |
718 | if (iter->idx >= iter->pg->index) { | |
719 | if (iter->pg->next) { | |
720 | iter->pg = iter->pg->next; | |
721 | iter->idx = 0; | |
722 | goto retry; | |
723 | } | |
724 | } else { | |
725 | rec = &iter->pg->records[iter->idx++]; | |
726 | if ((rec->flags & FTRACE_FL_FAILED) || | |
727 | ((iter->flags & FTRACE_ITER_FILTER) && | |
728 | !(rec->flags & FTRACE_FL_FILTER))) { | |
729 | rec = NULL; | |
730 | goto retry; | |
731 | } | |
732 | } | |
733 | ||
734 | iter->pos = *pos; | |
735 | ||
736 | return rec; | |
737 | } | |
738 | ||
739 | static void *t_start(struct seq_file *m, loff_t *pos) | |
740 | { | |
741 | struct ftrace_iterator *iter = m->private; | |
742 | void *p = NULL; | |
743 | loff_t l = -1; | |
744 | ||
745 | if (*pos != iter->pos) { | |
746 | for (p = t_next(m, p, &l); p && l < *pos; p = t_next(m, p, &l)) | |
747 | ; | |
748 | } else { | |
749 | l = *pos; | |
750 | p = t_next(m, p, &l); | |
751 | } | |
752 | ||
753 | return p; | |
754 | } | |
755 | ||
756 | static void t_stop(struct seq_file *m, void *p) | |
757 | { | |
758 | } | |
759 | ||
760 | static int t_show(struct seq_file *m, void *v) | |
761 | { | |
762 | struct dyn_ftrace *rec = v; | |
763 | char str[KSYM_SYMBOL_LEN]; | |
764 | ||
765 | if (!rec) | |
766 | return 0; | |
767 | ||
768 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
769 | ||
770 | seq_printf(m, "%s\n", str); | |
771 | ||
772 | return 0; | |
773 | } | |
774 | ||
775 | static struct seq_operations show_ftrace_seq_ops = { | |
776 | .start = t_start, | |
777 | .next = t_next, | |
778 | .stop = t_stop, | |
779 | .show = t_show, | |
780 | }; | |
781 | ||
782 | static int notrace | |
783 | ftrace_avail_open(struct inode *inode, struct file *file) | |
784 | { | |
785 | struct ftrace_iterator *iter; | |
786 | int ret; | |
787 | ||
788 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); | |
789 | if (!iter) | |
790 | return -ENOMEM; | |
791 | ||
792 | iter->pg = ftrace_pages_start; | |
793 | iter->pos = -1; | |
794 | ||
795 | ret = seq_open(file, &show_ftrace_seq_ops); | |
796 | if (!ret) { | |
797 | struct seq_file *m = file->private_data; | |
4bf39a94 | 798 | |
5072c59f | 799 | m->private = iter; |
4bf39a94 | 800 | } else { |
5072c59f | 801 | kfree(iter); |
4bf39a94 | 802 | } |
5072c59f SR |
803 | |
804 | return ret; | |
805 | } | |
806 | ||
807 | int ftrace_avail_release(struct inode *inode, struct file *file) | |
808 | { | |
809 | struct seq_file *m = (struct seq_file *)file->private_data; | |
810 | struct ftrace_iterator *iter = m->private; | |
811 | ||
812 | seq_release(inode, file); | |
813 | kfree(iter); | |
4bf39a94 | 814 | |
5072c59f SR |
815 | return 0; |
816 | } | |
817 | ||
818 | static void notrace ftrace_filter_reset(void) | |
819 | { | |
820 | struct ftrace_page *pg; | |
821 | struct dyn_ftrace *rec; | |
822 | unsigned i; | |
823 | ||
824 | /* keep kstop machine from running */ | |
825 | preempt_disable(); | |
826 | ftrace_filtered = 0; | |
827 | pg = ftrace_pages_start; | |
828 | while (pg) { | |
829 | for (i = 0; i < pg->index; i++) { | |
830 | rec = &pg->records[i]; | |
831 | if (rec->flags & FTRACE_FL_FAILED) | |
832 | continue; | |
833 | rec->flags &= ~FTRACE_FL_FILTER; | |
834 | } | |
835 | pg = pg->next; | |
836 | } | |
837 | preempt_enable(); | |
838 | } | |
839 | ||
840 | static int notrace | |
841 | ftrace_filter_open(struct inode *inode, struct file *file) | |
842 | { | |
843 | struct ftrace_iterator *iter; | |
844 | int ret = 0; | |
845 | ||
846 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); | |
847 | if (!iter) | |
848 | return -ENOMEM; | |
849 | ||
850 | mutex_lock(&ftrace_filter_lock); | |
851 | if ((file->f_mode & FMODE_WRITE) && | |
852 | !(file->f_flags & O_APPEND)) | |
853 | ftrace_filter_reset(); | |
854 | ||
855 | if (file->f_mode & FMODE_READ) { | |
856 | iter->pg = ftrace_pages_start; | |
857 | iter->pos = -1; | |
858 | iter->flags = FTRACE_ITER_FILTER; | |
859 | ||
860 | ret = seq_open(file, &show_ftrace_seq_ops); | |
861 | if (!ret) { | |
862 | struct seq_file *m = file->private_data; | |
863 | m->private = iter; | |
864 | } else | |
865 | kfree(iter); | |
866 | } else | |
867 | file->private_data = iter; | |
868 | mutex_unlock(&ftrace_filter_lock); | |
869 | ||
870 | return ret; | |
871 | } | |
872 | ||
873 | static ssize_t notrace | |
874 | ftrace_filter_read(struct file *file, char __user *ubuf, | |
875 | size_t cnt, loff_t *ppos) | |
876 | { | |
877 | if (file->f_mode & FMODE_READ) | |
878 | return seq_read(file, ubuf, cnt, ppos); | |
879 | else | |
880 | return -EPERM; | |
881 | } | |
882 | ||
883 | static loff_t notrace | |
884 | ftrace_filter_lseek(struct file *file, loff_t offset, int origin) | |
885 | { | |
886 | loff_t ret; | |
887 | ||
888 | if (file->f_mode & FMODE_READ) | |
889 | ret = seq_lseek(file, offset, origin); | |
890 | else | |
891 | file->f_pos = ret = 1; | |
892 | ||
893 | return ret; | |
894 | } | |
895 | ||
896 | enum { | |
897 | MATCH_FULL, | |
898 | MATCH_FRONT_ONLY, | |
899 | MATCH_MIDDLE_ONLY, | |
900 | MATCH_END_ONLY, | |
901 | }; | |
902 | ||
903 | static void notrace | |
904 | ftrace_match(unsigned char *buff, int len) | |
905 | { | |
906 | char str[KSYM_SYMBOL_LEN]; | |
907 | char *search = NULL; | |
908 | struct ftrace_page *pg; | |
909 | struct dyn_ftrace *rec; | |
910 | int type = MATCH_FULL; | |
911 | unsigned i, match = 0, search_len = 0; | |
912 | ||
913 | for (i = 0; i < len; i++) { | |
914 | if (buff[i] == '*') { | |
915 | if (!i) { | |
916 | search = buff + i + 1; | |
917 | type = MATCH_END_ONLY; | |
918 | search_len = len - (i + 1); | |
919 | } else { | |
920 | if (type == MATCH_END_ONLY) { | |
921 | type = MATCH_MIDDLE_ONLY; | |
922 | } else { | |
923 | match = i; | |
924 | type = MATCH_FRONT_ONLY; | |
925 | } | |
926 | buff[i] = 0; | |
927 | break; | |
928 | } | |
929 | } | |
930 | } | |
931 | ||
932 | /* keep kstop machine from running */ | |
933 | preempt_disable(); | |
934 | ftrace_filtered = 1; | |
935 | pg = ftrace_pages_start; | |
936 | while (pg) { | |
937 | for (i = 0; i < pg->index; i++) { | |
938 | int matched = 0; | |
939 | char *ptr; | |
940 | ||
941 | rec = &pg->records[i]; | |
942 | if (rec->flags & FTRACE_FL_FAILED) | |
943 | continue; | |
944 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
945 | switch (type) { | |
946 | case MATCH_FULL: | |
947 | if (strcmp(str, buff) == 0) | |
948 | matched = 1; | |
949 | break; | |
950 | case MATCH_FRONT_ONLY: | |
951 | if (memcmp(str, buff, match) == 0) | |
952 | matched = 1; | |
953 | break; | |
954 | case MATCH_MIDDLE_ONLY: | |
955 | if (strstr(str, search)) | |
956 | matched = 1; | |
957 | break; | |
958 | case MATCH_END_ONLY: | |
959 | ptr = strstr(str, search); | |
960 | if (ptr && (ptr[search_len] == 0)) | |
961 | matched = 1; | |
962 | break; | |
963 | } | |
964 | if (matched) | |
965 | rec->flags |= FTRACE_FL_FILTER; | |
966 | } | |
967 | pg = pg->next; | |
968 | } | |
969 | preempt_enable(); | |
970 | } | |
971 | ||
972 | static ssize_t notrace | |
973 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
974 | size_t cnt, loff_t *ppos) | |
975 | { | |
976 | struct ftrace_iterator *iter; | |
977 | char ch; | |
978 | size_t read = 0; | |
979 | ssize_t ret; | |
980 | ||
981 | if (!cnt || cnt < 0) | |
982 | return 0; | |
983 | ||
984 | mutex_lock(&ftrace_filter_lock); | |
985 | ||
986 | if (file->f_mode & FMODE_READ) { | |
987 | struct seq_file *m = file->private_data; | |
988 | iter = m->private; | |
989 | } else | |
990 | iter = file->private_data; | |
991 | ||
992 | if (!*ppos) { | |
993 | iter->flags &= ~FTRACE_ITER_CONT; | |
994 | iter->buffer_idx = 0; | |
995 | } | |
996 | ||
997 | ret = get_user(ch, ubuf++); | |
998 | if (ret) | |
999 | goto out; | |
1000 | read++; | |
1001 | cnt--; | |
1002 | ||
1003 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { | |
1004 | /* skip white space */ | |
1005 | while (cnt && isspace(ch)) { | |
1006 | ret = get_user(ch, ubuf++); | |
1007 | if (ret) | |
1008 | goto out; | |
1009 | read++; | |
1010 | cnt--; | |
1011 | } | |
1012 | ||
1013 | ||
1014 | if (isspace(ch)) { | |
1015 | file->f_pos += read; | |
1016 | ret = read; | |
1017 | goto out; | |
1018 | } | |
1019 | ||
1020 | iter->buffer_idx = 0; | |
1021 | } | |
1022 | ||
1023 | while (cnt && !isspace(ch)) { | |
1024 | if (iter->buffer_idx < FTRACE_BUFF_MAX) | |
1025 | iter->buffer[iter->buffer_idx++] = ch; | |
1026 | else { | |
1027 | ret = -EINVAL; | |
1028 | goto out; | |
1029 | } | |
1030 | ret = get_user(ch, ubuf++); | |
1031 | if (ret) | |
1032 | goto out; | |
1033 | read++; | |
1034 | cnt--; | |
1035 | } | |
1036 | ||
1037 | if (isspace(ch)) { | |
1038 | iter->filtered++; | |
1039 | iter->buffer[iter->buffer_idx] = 0; | |
1040 | ftrace_match(iter->buffer, iter->buffer_idx); | |
1041 | iter->buffer_idx = 0; | |
1042 | } else | |
1043 | iter->flags |= FTRACE_ITER_CONT; | |
1044 | ||
1045 | ||
1046 | file->f_pos += read; | |
1047 | ||
1048 | ret = read; | |
1049 | out: | |
1050 | mutex_unlock(&ftrace_filter_lock); | |
1051 | ||
1052 | return ret; | |
1053 | } | |
1054 | ||
77a2b37d SR |
1055 | /** |
1056 | * ftrace_set_filter - set a function to filter on in ftrace | |
1057 | * @buf - the string that holds the function filter text. | |
1058 | * @len - the length of the string. | |
1059 | * @reset - non zero to reset all filters before applying this filter. | |
1060 | * | |
1061 | * Filters denote which functions should be enabled when tracing is enabled. | |
1062 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
1063 | */ | |
1064 | notrace void ftrace_set_filter(unsigned char *buf, int len, int reset) | |
1065 | { | |
1066 | mutex_lock(&ftrace_filter_lock); | |
1067 | if (reset) | |
1068 | ftrace_filter_reset(); | |
1069 | if (buf) | |
1070 | ftrace_match(buf, len); | |
1071 | mutex_unlock(&ftrace_filter_lock); | |
1072 | } | |
1073 | ||
5072c59f SR |
1074 | static int notrace |
1075 | ftrace_filter_release(struct inode *inode, struct file *file) | |
1076 | { | |
1077 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1078 | struct ftrace_iterator *iter; | |
1079 | ||
1080 | mutex_lock(&ftrace_filter_lock); | |
1081 | if (file->f_mode & FMODE_READ) { | |
1082 | iter = m->private; | |
1083 | ||
1084 | seq_release(inode, file); | |
1085 | } else | |
1086 | iter = file->private_data; | |
1087 | ||
1088 | if (iter->buffer_idx) { | |
1089 | iter->filtered++; | |
1090 | iter->buffer[iter->buffer_idx] = 0; | |
1091 | ftrace_match(iter->buffer, iter->buffer_idx); | |
1092 | } | |
1093 | ||
1094 | mutex_lock(&ftrace_sysctl_lock); | |
1095 | mutex_lock(&ftraced_lock); | |
1096 | if (iter->filtered && ftraced_suspend && ftrace_enabled) | |
1097 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); | |
1098 | mutex_unlock(&ftraced_lock); | |
1099 | mutex_unlock(&ftrace_sysctl_lock); | |
1100 | ||
1101 | kfree(iter); | |
1102 | mutex_unlock(&ftrace_filter_lock); | |
1103 | return 0; | |
1104 | } | |
1105 | ||
1106 | static struct file_operations ftrace_avail_fops = { | |
1107 | .open = ftrace_avail_open, | |
1108 | .read = seq_read, | |
1109 | .llseek = seq_lseek, | |
1110 | .release = ftrace_avail_release, | |
1111 | }; | |
1112 | ||
1113 | static struct file_operations ftrace_filter_fops = { | |
1114 | .open = ftrace_filter_open, | |
1115 | .read = ftrace_filter_read, | |
1116 | .write = ftrace_filter_write, | |
1117 | .llseek = ftrace_filter_lseek, | |
1118 | .release = ftrace_filter_release, | |
1119 | }; | |
1120 | ||
e1c08bdd SR |
1121 | /** |
1122 | * ftrace_force_update - force an update to all recording ftrace functions | |
1123 | * | |
1124 | * The ftrace dynamic update daemon only wakes up once a second. | |
1125 | * There may be cases where an update needs to be done immediately | |
1126 | * for tests or internal kernel tracing to begin. This function | |
1127 | * wakes the daemon to do an update and will not return until the | |
1128 | * update is complete. | |
1129 | */ | |
1130 | int ftrace_force_update(void) | |
1131 | { | |
1132 | unsigned long last_counter; | |
1133 | DECLARE_WAITQUEUE(wait, current); | |
1134 | int ret = 0; | |
1135 | ||
1136 | if (!ftraced_task) | |
1137 | return -ENODEV; | |
1138 | ||
1139 | mutex_lock(&ftraced_lock); | |
1140 | last_counter = ftraced_iteration_counter; | |
1141 | ||
1142 | set_current_state(TASK_INTERRUPTIBLE); | |
1143 | add_wait_queue(&ftraced_waiters, &wait); | |
1144 | ||
1145 | do { | |
1146 | mutex_unlock(&ftraced_lock); | |
1147 | wake_up_process(ftraced_task); | |
1148 | schedule(); | |
1149 | mutex_lock(&ftraced_lock); | |
1150 | if (signal_pending(current)) { | |
1151 | ret = -EINTR; | |
1152 | break; | |
1153 | } | |
1154 | set_current_state(TASK_INTERRUPTIBLE); | |
1155 | } while (last_counter == ftraced_iteration_counter); | |
1156 | ||
1157 | mutex_unlock(&ftraced_lock); | |
1158 | remove_wait_queue(&ftraced_waiters, &wait); | |
1159 | set_current_state(TASK_RUNNING); | |
1160 | ||
1161 | return ret; | |
1162 | } | |
1163 | ||
5072c59f SR |
1164 | static __init int ftrace_init_debugfs(void) |
1165 | { | |
1166 | struct dentry *d_tracer; | |
1167 | struct dentry *entry; | |
1168 | ||
1169 | d_tracer = tracing_init_dentry(); | |
1170 | ||
1171 | entry = debugfs_create_file("available_filter_functions", 0444, | |
1172 | d_tracer, NULL, &ftrace_avail_fops); | |
1173 | if (!entry) | |
1174 | pr_warning("Could not create debugfs " | |
1175 | "'available_filter_functions' entry\n"); | |
1176 | ||
1177 | entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer, | |
1178 | NULL, &ftrace_filter_fops); | |
1179 | if (!entry) | |
1180 | pr_warning("Could not create debugfs " | |
1181 | "'set_ftrace_filter' entry\n"); | |
1182 | return 0; | |
1183 | } | |
1184 | ||
1185 | fs_initcall(ftrace_init_debugfs); | |
1186 | ||
d61f82d0 | 1187 | static int __init notrace ftrace_dynamic_init(void) |
3d083395 SR |
1188 | { |
1189 | struct task_struct *p; | |
d61f82d0 | 1190 | unsigned long addr; |
3d083395 SR |
1191 | int ret; |
1192 | ||
d61f82d0 SR |
1193 | addr = (unsigned long)ftrace_record_ip; |
1194 | stop_machine_run(ftrace_dyn_arch_init, &addr, NR_CPUS); | |
1195 | ||
1196 | /* ftrace_dyn_arch_init places the return code in addr */ | |
1197 | if (addr) | |
1198 | return addr; | |
1199 | ||
3c1720f0 | 1200 | ret = ftrace_dyn_table_alloc(); |
3d083395 SR |
1201 | if (ret) |
1202 | return ret; | |
1203 | ||
1204 | p = kthread_run(ftraced, NULL, "ftraced"); | |
1205 | if (IS_ERR(p)) | |
1206 | return -1; | |
1207 | ||
d61f82d0 | 1208 | last_ftrace_enabled = ftrace_enabled = 1; |
e1c08bdd | 1209 | ftraced_task = p; |
3d083395 SR |
1210 | |
1211 | return 0; | |
1212 | } | |
1213 | ||
d61f82d0 | 1214 | core_initcall(ftrace_dynamic_init); |
3d083395 | 1215 | #else |
c7aafc54 IM |
1216 | # define ftrace_startup() do { } while (0) |
1217 | # define ftrace_shutdown() do { } while (0) | |
1218 | # define ftrace_startup_sysctl() do { } while (0) | |
1219 | # define ftrace_shutdown_sysctl() do { } while (0) | |
3d083395 SR |
1220 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
1221 | ||
16444a8a | 1222 | /** |
3d083395 SR |
1223 | * register_ftrace_function - register a function for profiling |
1224 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 1225 | * |
3d083395 SR |
1226 | * Register a function to be called by all functions in the |
1227 | * kernel. | |
1228 | * | |
1229 | * Note: @ops->func and all the functions it calls must be labeled | |
1230 | * with "notrace", otherwise it will go into a | |
1231 | * recursive loop. | |
16444a8a | 1232 | */ |
3d083395 | 1233 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 1234 | { |
b0fc494f SR |
1235 | int ret; |
1236 | ||
1237 | mutex_lock(&ftrace_sysctl_lock); | |
b0fc494f | 1238 | ret = __register_ftrace_function(ops); |
d61f82d0 | 1239 | ftrace_startup(); |
b0fc494f SR |
1240 | mutex_unlock(&ftrace_sysctl_lock); |
1241 | ||
1242 | return ret; | |
3d083395 SR |
1243 | } |
1244 | ||
1245 | /** | |
1246 | * unregister_ftrace_function - unresgister a function for profiling. | |
1247 | * @ops - ops structure that holds the function to unregister | |
1248 | * | |
1249 | * Unregister a function that was added to be called by ftrace profiling. | |
1250 | */ | |
1251 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
1252 | { | |
1253 | int ret; | |
1254 | ||
b0fc494f | 1255 | mutex_lock(&ftrace_sysctl_lock); |
3d083395 | 1256 | ret = __unregister_ftrace_function(ops); |
d61f82d0 | 1257 | ftrace_shutdown(); |
b0fc494f SR |
1258 | mutex_unlock(&ftrace_sysctl_lock); |
1259 | ||
1260 | return ret; | |
1261 | } | |
1262 | ||
1263 | notrace int | |
1264 | ftrace_enable_sysctl(struct ctl_table *table, int write, | |
5072c59f | 1265 | struct file *file, void __user *buffer, size_t *lenp, |
b0fc494f SR |
1266 | loff_t *ppos) |
1267 | { | |
1268 | int ret; | |
1269 | ||
1270 | mutex_lock(&ftrace_sysctl_lock); | |
1271 | ||
5072c59f | 1272 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
b0fc494f SR |
1273 | |
1274 | if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) | |
1275 | goto out; | |
1276 | ||
1277 | last_ftrace_enabled = ftrace_enabled; | |
1278 | ||
1279 | if (ftrace_enabled) { | |
1280 | ||
1281 | ftrace_startup_sysctl(); | |
1282 | ||
1283 | /* we are starting ftrace again */ | |
1284 | if (ftrace_list != &ftrace_list_end) { | |
1285 | if (ftrace_list->next == &ftrace_list_end) | |
1286 | ftrace_trace_function = ftrace_list->func; | |
1287 | else | |
1288 | ftrace_trace_function = ftrace_list_func; | |
1289 | } | |
1290 | ||
1291 | } else { | |
1292 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
1293 | ftrace_trace_function = ftrace_stub; | |
1294 | ||
1295 | ftrace_shutdown_sysctl(); | |
1296 | } | |
1297 | ||
1298 | out: | |
1299 | mutex_unlock(&ftrace_sysctl_lock); | |
3d083395 | 1300 | return ret; |
16444a8a | 1301 | } |