Commit | Line | Data |
---|---|---|
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 | 21 | #include <linux/hardirq.h> |
2d8b820b | 22 | #include <linux/kthread.h> |
5072c59f | 23 | #include <linux/uaccess.h> |
2d8b820b | 24 | #include <linux/ftrace.h> |
b0fc494f | 25 | #include <linux/sysctl.h> |
5072c59f | 26 | #include <linux/ctype.h> |
2d8b820b | 27 | #include <linux/hash.h> |
3d083395 SR |
28 | #include <linux/list.h> |
29 | ||
30 | #include "trace.h" | |
16444a8a | 31 | |
4eebcc81 SR |
32 | /* ftrace_enabled is a method to turn ftrace on or off */ |
33 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 34 | static int last_ftrace_enabled; |
b0fc494f | 35 | |
4eebcc81 SR |
36 | /* |
37 | * ftrace_disabled is set when an anomaly is discovered. | |
38 | * ftrace_disabled is much stronger than ftrace_enabled. | |
39 | */ | |
40 | static int ftrace_disabled __read_mostly; | |
41 | ||
3d083395 | 42 | static DEFINE_SPINLOCK(ftrace_lock); |
b0fc494f SR |
43 | static DEFINE_MUTEX(ftrace_sysctl_lock); |
44 | ||
16444a8a ACM |
45 | static struct ftrace_ops ftrace_list_end __read_mostly = |
46 | { | |
47 | .func = ftrace_stub, | |
48 | }; | |
49 | ||
50 | static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; | |
51 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; | |
52 | ||
e309b41d | 53 | void ftrace_list_func(unsigned long ip, unsigned long parent_ip) |
16444a8a ACM |
54 | { |
55 | struct ftrace_ops *op = ftrace_list; | |
56 | ||
57 | /* in case someone actually ports this to alpha! */ | |
58 | read_barrier_depends(); | |
59 | ||
60 | while (op != &ftrace_list_end) { | |
61 | /* silly alpha */ | |
62 | read_barrier_depends(); | |
63 | op->func(ip, parent_ip); | |
64 | op = op->next; | |
65 | }; | |
66 | } | |
67 | ||
68 | /** | |
3d083395 | 69 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 70 | * |
3d083395 SR |
71 | * This NULLs the ftrace function and in essence stops |
72 | * tracing. There may be lag | |
16444a8a | 73 | */ |
3d083395 | 74 | void clear_ftrace_function(void) |
16444a8a | 75 | { |
3d083395 SR |
76 | ftrace_trace_function = ftrace_stub; |
77 | } | |
78 | ||
e309b41d | 79 | static int __register_ftrace_function(struct ftrace_ops *ops) |
3d083395 SR |
80 | { |
81 | /* Should never be called by interrupts */ | |
82 | spin_lock(&ftrace_lock); | |
16444a8a | 83 | |
16444a8a ACM |
84 | ops->next = ftrace_list; |
85 | /* | |
86 | * We are entering ops into the ftrace_list but another | |
87 | * CPU might be walking that list. We need to make sure | |
88 | * the ops->next pointer is valid before another CPU sees | |
89 | * the ops pointer included into the ftrace_list. | |
90 | */ | |
91 | smp_wmb(); | |
92 | ftrace_list = ops; | |
3d083395 | 93 | |
b0fc494f SR |
94 | if (ftrace_enabled) { |
95 | /* | |
96 | * For one func, simply call it directly. | |
97 | * For more than one func, call the chain. | |
98 | */ | |
99 | if (ops->next == &ftrace_list_end) | |
100 | ftrace_trace_function = ops->func; | |
101 | else | |
102 | ftrace_trace_function = ftrace_list_func; | |
103 | } | |
3d083395 SR |
104 | |
105 | spin_unlock(&ftrace_lock); | |
16444a8a ACM |
106 | |
107 | return 0; | |
108 | } | |
109 | ||
e309b41d | 110 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 111 | { |
16444a8a ACM |
112 | struct ftrace_ops **p; |
113 | int ret = 0; | |
114 | ||
3d083395 | 115 | spin_lock(&ftrace_lock); |
16444a8a ACM |
116 | |
117 | /* | |
3d083395 SR |
118 | * If we are removing the last function, then simply point |
119 | * to the ftrace_stub. | |
16444a8a ACM |
120 | */ |
121 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { | |
122 | ftrace_trace_function = ftrace_stub; | |
123 | ftrace_list = &ftrace_list_end; | |
124 | goto out; | |
125 | } | |
126 | ||
127 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) | |
128 | if (*p == ops) | |
129 | break; | |
130 | ||
131 | if (*p != ops) { | |
132 | ret = -1; | |
133 | goto out; | |
134 | } | |
135 | ||
136 | *p = (*p)->next; | |
137 | ||
b0fc494f SR |
138 | if (ftrace_enabled) { |
139 | /* If we only have one func left, then call that directly */ | |
140 | if (ftrace_list == &ftrace_list_end || | |
141 | ftrace_list->next == &ftrace_list_end) | |
142 | ftrace_trace_function = ftrace_list->func; | |
143 | } | |
16444a8a ACM |
144 | |
145 | out: | |
3d083395 SR |
146 | spin_unlock(&ftrace_lock); |
147 | ||
148 | return ret; | |
149 | } | |
150 | ||
151 | #ifdef CONFIG_DYNAMIC_FTRACE | |
152 | ||
e1c08bdd | 153 | static struct task_struct *ftraced_task; |
e1c08bdd | 154 | |
d61f82d0 SR |
155 | enum { |
156 | FTRACE_ENABLE_CALLS = (1 << 0), | |
157 | FTRACE_DISABLE_CALLS = (1 << 1), | |
158 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
159 | FTRACE_ENABLE_MCOUNT = (1 << 3), | |
160 | FTRACE_DISABLE_MCOUNT = (1 << 4), | |
161 | }; | |
162 | ||
5072c59f SR |
163 | static int ftrace_filtered; |
164 | ||
3d083395 SR |
165 | static struct hlist_head ftrace_hash[FTRACE_HASHSIZE]; |
166 | ||
167 | static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu); | |
168 | ||
169 | static DEFINE_SPINLOCK(ftrace_shutdown_lock); | |
170 | static DEFINE_MUTEX(ftraced_lock); | |
41c52c0d | 171 | static DEFINE_MUTEX(ftrace_regex_lock); |
3d083395 | 172 | |
3c1720f0 SR |
173 | struct ftrace_page { |
174 | struct ftrace_page *next; | |
aa5e5cea | 175 | unsigned long index; |
3c1720f0 | 176 | struct dyn_ftrace records[]; |
aa5e5cea | 177 | }; |
3c1720f0 SR |
178 | |
179 | #define ENTRIES_PER_PAGE \ | |
180 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
181 | ||
182 | /* estimate from running different kernels */ | |
183 | #define NR_TO_INIT 10000 | |
184 | ||
185 | static struct ftrace_page *ftrace_pages_start; | |
186 | static struct ftrace_page *ftrace_pages; | |
187 | ||
3d083395 SR |
188 | static int ftraced_trigger; |
189 | static int ftraced_suspend; | |
ad90c0e3 | 190 | static int ftraced_stop; |
3d083395 SR |
191 | |
192 | static int ftrace_record_suspend; | |
193 | ||
37ad5084 SR |
194 | static struct dyn_ftrace *ftrace_free_records; |
195 | ||
e309b41d | 196 | static inline int |
9ff9cdb2 | 197 | ftrace_ip_in_hash(unsigned long ip, unsigned long key) |
3d083395 SR |
198 | { |
199 | struct dyn_ftrace *p; | |
200 | struct hlist_node *t; | |
201 | int found = 0; | |
202 | ||
ffdaa358 | 203 | hlist_for_each_entry_rcu(p, t, &ftrace_hash[key], node) { |
3d083395 SR |
204 | if (p->ip == ip) { |
205 | found = 1; | |
206 | break; | |
207 | } | |
208 | } | |
209 | ||
210 | return found; | |
211 | } | |
212 | ||
e309b41d | 213 | static inline void |
3d083395 SR |
214 | ftrace_add_hash(struct dyn_ftrace *node, unsigned long key) |
215 | { | |
ffdaa358 | 216 | hlist_add_head_rcu(&node->node, &ftrace_hash[key]); |
3d083395 SR |
217 | } |
218 | ||
0eb96701 AS |
219 | /* called from kstop_machine */ |
220 | static inline void ftrace_del_hash(struct dyn_ftrace *node) | |
221 | { | |
222 | hlist_del(&node->node); | |
223 | } | |
224 | ||
e309b41d | 225 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
37ad5084 SR |
226 | { |
227 | /* no locking, only called from kstop_machine */ | |
228 | ||
229 | rec->ip = (unsigned long)ftrace_free_records; | |
230 | ftrace_free_records = rec; | |
231 | rec->flags |= FTRACE_FL_FREE; | |
232 | } | |
233 | ||
e309b41d | 234 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 235 | { |
37ad5084 SR |
236 | struct dyn_ftrace *rec; |
237 | ||
238 | /* First check for freed records */ | |
239 | if (ftrace_free_records) { | |
240 | rec = ftrace_free_records; | |
241 | ||
37ad5084 SR |
242 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
243 | WARN_ON_ONCE(1); | |
244 | ftrace_free_records = NULL; | |
4eebcc81 SR |
245 | ftrace_disabled = 1; |
246 | ftrace_enabled = 0; | |
37ad5084 SR |
247 | return NULL; |
248 | } | |
249 | ||
250 | ftrace_free_records = (void *)rec->ip; | |
251 | memset(rec, 0, sizeof(*rec)); | |
252 | return rec; | |
253 | } | |
254 | ||
3c1720f0 SR |
255 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
256 | if (!ftrace_pages->next) | |
257 | return NULL; | |
258 | ftrace_pages = ftrace_pages->next; | |
259 | } | |
260 | ||
261 | return &ftrace_pages->records[ftrace_pages->index++]; | |
262 | } | |
263 | ||
e309b41d | 264 | static void |
d61f82d0 | 265 | ftrace_record_ip(unsigned long ip) |
3d083395 SR |
266 | { |
267 | struct dyn_ftrace *node; | |
268 | unsigned long flags; | |
269 | unsigned long key; | |
270 | int resched; | |
271 | int atomic; | |
2bb6f8d6 | 272 | int cpu; |
3d083395 | 273 | |
4eebcc81 | 274 | if (!ftrace_enabled || ftrace_disabled) |
d61f82d0 SR |
275 | return; |
276 | ||
3d083395 SR |
277 | resched = need_resched(); |
278 | preempt_disable_notrace(); | |
279 | ||
2bb6f8d6 SR |
280 | /* |
281 | * We simply need to protect against recursion. | |
282 | * Use the the raw version of smp_processor_id and not | |
283 | * __get_cpu_var which can call debug hooks that can | |
284 | * cause a recursive crash here. | |
285 | */ | |
286 | cpu = raw_smp_processor_id(); | |
287 | per_cpu(ftrace_shutdown_disable_cpu, cpu)++; | |
288 | if (per_cpu(ftrace_shutdown_disable_cpu, cpu) != 1) | |
3d083395 SR |
289 | goto out; |
290 | ||
291 | if (unlikely(ftrace_record_suspend)) | |
292 | goto out; | |
293 | ||
294 | key = hash_long(ip, FTRACE_HASHBITS); | |
295 | ||
296 | WARN_ON_ONCE(key >= FTRACE_HASHSIZE); | |
297 | ||
298 | if (ftrace_ip_in_hash(ip, key)) | |
299 | goto out; | |
300 | ||
301 | atomic = irqs_disabled(); | |
302 | ||
303 | spin_lock_irqsave(&ftrace_shutdown_lock, flags); | |
304 | ||
305 | /* This ip may have hit the hash before the lock */ | |
306 | if (ftrace_ip_in_hash(ip, key)) | |
307 | goto out_unlock; | |
308 | ||
d61f82d0 | 309 | node = ftrace_alloc_dyn_node(ip); |
3d083395 SR |
310 | if (!node) |
311 | goto out_unlock; | |
312 | ||
313 | node->ip = ip; | |
314 | ||
315 | ftrace_add_hash(node, key); | |
316 | ||
317 | ftraced_trigger = 1; | |
318 | ||
319 | out_unlock: | |
320 | spin_unlock_irqrestore(&ftrace_shutdown_lock, flags); | |
321 | out: | |
2bb6f8d6 | 322 | per_cpu(ftrace_shutdown_disable_cpu, cpu)--; |
3d083395 SR |
323 | |
324 | /* prevent recursion with scheduler */ | |
325 | if (resched) | |
326 | preempt_enable_no_resched_notrace(); | |
327 | else | |
328 | preempt_enable_notrace(); | |
329 | } | |
330 | ||
caf8cdeb SR |
331 | #define FTRACE_ADDR ((long)(ftrace_caller)) |
332 | #define MCOUNT_ADDR ((long)(mcount)) | |
3c1720f0 | 333 | |
0eb96701 | 334 | static int |
5072c59f SR |
335 | __ftrace_replace_code(struct dyn_ftrace *rec, |
336 | unsigned char *old, unsigned char *new, int enable) | |
337 | { | |
41c52c0d | 338 | unsigned long ip, fl; |
5072c59f SR |
339 | |
340 | ip = rec->ip; | |
341 | ||
342 | if (ftrace_filtered && enable) { | |
5072c59f SR |
343 | /* |
344 | * If filtering is on: | |
345 | * | |
346 | * If this record is set to be filtered and | |
347 | * is enabled then do nothing. | |
348 | * | |
349 | * If this record is set to be filtered and | |
350 | * it is not enabled, enable it. | |
351 | * | |
352 | * If this record is not set to be filtered | |
353 | * and it is not enabled do nothing. | |
354 | * | |
41c52c0d SR |
355 | * If this record is set not to trace then |
356 | * do nothing. | |
357 | * | |
5072c59f SR |
358 | * If this record is not set to be filtered and |
359 | * it is enabled, disable it. | |
360 | */ | |
361 | fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED); | |
362 | ||
363 | if ((fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) || | |
41c52c0d | 364 | (fl == 0) || (rec->flags & FTRACE_FL_NOTRACE)) |
0eb96701 | 365 | return 0; |
5072c59f SR |
366 | |
367 | /* | |
368 | * If it is enabled disable it, | |
369 | * otherwise enable it! | |
370 | */ | |
371 | if (fl == FTRACE_FL_ENABLED) { | |
372 | /* swap new and old */ | |
373 | new = old; | |
374 | old = ftrace_call_replace(ip, FTRACE_ADDR); | |
375 | rec->flags &= ~FTRACE_FL_ENABLED; | |
376 | } else { | |
377 | new = ftrace_call_replace(ip, FTRACE_ADDR); | |
378 | rec->flags |= FTRACE_FL_ENABLED; | |
379 | } | |
380 | } else { | |
381 | ||
41c52c0d SR |
382 | if (enable) { |
383 | /* | |
384 | * If this record is set not to trace and is | |
385 | * not enabled, do nothing. | |
386 | */ | |
387 | fl = rec->flags & (FTRACE_FL_NOTRACE | FTRACE_FL_ENABLED); | |
388 | if (fl == FTRACE_FL_NOTRACE) | |
0eb96701 | 389 | return 0; |
41c52c0d | 390 | |
5072c59f | 391 | new = ftrace_call_replace(ip, FTRACE_ADDR); |
41c52c0d | 392 | } else |
5072c59f SR |
393 | old = ftrace_call_replace(ip, FTRACE_ADDR); |
394 | ||
395 | if (enable) { | |
396 | if (rec->flags & FTRACE_FL_ENABLED) | |
0eb96701 | 397 | return 0; |
5072c59f SR |
398 | rec->flags |= FTRACE_FL_ENABLED; |
399 | } else { | |
400 | if (!(rec->flags & FTRACE_FL_ENABLED)) | |
0eb96701 | 401 | return 0; |
5072c59f SR |
402 | rec->flags &= ~FTRACE_FL_ENABLED; |
403 | } | |
404 | } | |
405 | ||
0eb96701 | 406 | return ftrace_modify_code(ip, old, new); |
5072c59f SR |
407 | } |
408 | ||
e309b41d | 409 | static void ftrace_replace_code(int enable) |
3c1720f0 | 410 | { |
0eb96701 | 411 | int i, failed; |
3c1720f0 SR |
412 | unsigned char *new = NULL, *old = NULL; |
413 | struct dyn_ftrace *rec; | |
414 | struct ftrace_page *pg; | |
3c1720f0 | 415 | |
5072c59f | 416 | if (enable) |
3c1720f0 SR |
417 | old = ftrace_nop_replace(); |
418 | else | |
419 | new = ftrace_nop_replace(); | |
420 | ||
421 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
422 | for (i = 0; i < pg->index; i++) { | |
423 | rec = &pg->records[i]; | |
424 | ||
425 | /* don't modify code that has already faulted */ | |
426 | if (rec->flags & FTRACE_FL_FAILED) | |
427 | continue; | |
428 | ||
0eb96701 AS |
429 | failed = __ftrace_replace_code(rec, old, new, enable); |
430 | if (failed && (rec->flags & FTRACE_FL_CONVERTED)) { | |
431 | rec->flags |= FTRACE_FL_FAILED; | |
432 | if ((system_state == SYSTEM_BOOTING) || | |
433 | !kernel_text_address(rec->ip)) { | |
434 | ftrace_del_hash(rec); | |
435 | ftrace_free_rec(rec); | |
436 | } | |
437 | } | |
3c1720f0 SR |
438 | } |
439 | } | |
440 | } | |
441 | ||
e309b41d | 442 | static void ftrace_shutdown_replenish(void) |
3c1720f0 SR |
443 | { |
444 | if (ftrace_pages->next) | |
445 | return; | |
446 | ||
447 | /* allocate another page */ | |
448 | ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL); | |
449 | } | |
3d083395 | 450 | |
492a7ea5 | 451 | static int |
d61f82d0 | 452 | ftrace_code_disable(struct dyn_ftrace *rec) |
3c1720f0 SR |
453 | { |
454 | unsigned long ip; | |
455 | unsigned char *nop, *call; | |
456 | int failed; | |
457 | ||
458 | ip = rec->ip; | |
459 | ||
460 | nop = ftrace_nop_replace(); | |
d61f82d0 | 461 | call = ftrace_call_replace(ip, MCOUNT_ADDR); |
3c1720f0 SR |
462 | |
463 | failed = ftrace_modify_code(ip, call, nop); | |
37ad5084 | 464 | if (failed) { |
3c1720f0 | 465 | rec->flags |= FTRACE_FL_FAILED; |
492a7ea5 | 466 | return 0; |
37ad5084 | 467 | } |
492a7ea5 | 468 | return 1; |
3c1720f0 SR |
469 | } |
470 | ||
ad90c0e3 SR |
471 | static int __ftrace_update_code(void *ignore); |
472 | ||
e309b41d | 473 | static int __ftrace_modify_code(void *data) |
3d083395 | 474 | { |
d61f82d0 SR |
475 | unsigned long addr; |
476 | int *command = data; | |
477 | ||
ad90c0e3 SR |
478 | if (*command & FTRACE_ENABLE_CALLS) { |
479 | /* | |
480 | * Update any recorded ips now that we have the | |
481 | * machine stopped | |
482 | */ | |
483 | __ftrace_update_code(NULL); | |
d61f82d0 | 484 | ftrace_replace_code(1); |
ad90c0e3 | 485 | } else if (*command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
486 | ftrace_replace_code(0); |
487 | ||
488 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
489 | ftrace_update_ftrace_func(ftrace_trace_function); | |
490 | ||
491 | if (*command & FTRACE_ENABLE_MCOUNT) { | |
492 | addr = (unsigned long)ftrace_record_ip; | |
493 | ftrace_mcount_set(&addr); | |
494 | } else if (*command & FTRACE_DISABLE_MCOUNT) { | |
495 | addr = (unsigned long)ftrace_stub; | |
496 | ftrace_mcount_set(&addr); | |
497 | } | |
498 | ||
499 | return 0; | |
3d083395 SR |
500 | } |
501 | ||
e309b41d | 502 | static void ftrace_run_update_code(int command) |
3d083395 | 503 | { |
d61f82d0 | 504 | stop_machine_run(__ftrace_modify_code, &command, NR_CPUS); |
3d083395 SR |
505 | } |
506 | ||
ad90c0e3 SR |
507 | void ftrace_disable_daemon(void) |
508 | { | |
509 | /* Stop the daemon from calling kstop_machine */ | |
510 | mutex_lock(&ftraced_lock); | |
511 | ftraced_stop = 1; | |
512 | mutex_unlock(&ftraced_lock); | |
513 | ||
514 | ftrace_force_update(); | |
515 | } | |
516 | ||
517 | void ftrace_enable_daemon(void) | |
518 | { | |
519 | mutex_lock(&ftraced_lock); | |
520 | ftraced_stop = 0; | |
521 | mutex_unlock(&ftraced_lock); | |
522 | ||
523 | ftrace_force_update(); | |
524 | } | |
525 | ||
d61f82d0 SR |
526 | static ftrace_func_t saved_ftrace_func; |
527 | ||
e309b41d | 528 | static void ftrace_startup(void) |
3d083395 | 529 | { |
d61f82d0 SR |
530 | int command = 0; |
531 | ||
4eebcc81 SR |
532 | if (unlikely(ftrace_disabled)) |
533 | return; | |
534 | ||
3d083395 SR |
535 | mutex_lock(&ftraced_lock); |
536 | ftraced_suspend++; | |
d61f82d0 SR |
537 | if (ftraced_suspend == 1) |
538 | command |= FTRACE_ENABLE_CALLS; | |
539 | ||
540 | if (saved_ftrace_func != ftrace_trace_function) { | |
541 | saved_ftrace_func = ftrace_trace_function; | |
542 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
543 | } | |
544 | ||
545 | if (!command || !ftrace_enabled) | |
3d083395 | 546 | goto out; |
3d083395 | 547 | |
d61f82d0 | 548 | ftrace_run_update_code(command); |
3d083395 SR |
549 | out: |
550 | mutex_unlock(&ftraced_lock); | |
551 | } | |
552 | ||
e309b41d | 553 | static void ftrace_shutdown(void) |
3d083395 | 554 | { |
d61f82d0 SR |
555 | int command = 0; |
556 | ||
4eebcc81 SR |
557 | if (unlikely(ftrace_disabled)) |
558 | return; | |
559 | ||
3d083395 SR |
560 | mutex_lock(&ftraced_lock); |
561 | ftraced_suspend--; | |
d61f82d0 SR |
562 | if (!ftraced_suspend) |
563 | command |= FTRACE_DISABLE_CALLS; | |
3d083395 | 564 | |
d61f82d0 SR |
565 | if (saved_ftrace_func != ftrace_trace_function) { |
566 | saved_ftrace_func = ftrace_trace_function; | |
567 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
568 | } | |
3d083395 | 569 | |
d61f82d0 SR |
570 | if (!command || !ftrace_enabled) |
571 | goto out; | |
572 | ||
573 | ftrace_run_update_code(command); | |
3d083395 SR |
574 | out: |
575 | mutex_unlock(&ftraced_lock); | |
576 | } | |
577 | ||
e309b41d | 578 | static void ftrace_startup_sysctl(void) |
b0fc494f | 579 | { |
d61f82d0 SR |
580 | int command = FTRACE_ENABLE_MCOUNT; |
581 | ||
4eebcc81 SR |
582 | if (unlikely(ftrace_disabled)) |
583 | return; | |
584 | ||
b0fc494f | 585 | mutex_lock(&ftraced_lock); |
d61f82d0 SR |
586 | /* Force update next time */ |
587 | saved_ftrace_func = NULL; | |
b0fc494f SR |
588 | /* ftraced_suspend is true if we want ftrace running */ |
589 | if (ftraced_suspend) | |
d61f82d0 SR |
590 | command |= FTRACE_ENABLE_CALLS; |
591 | ||
592 | ftrace_run_update_code(command); | |
b0fc494f SR |
593 | mutex_unlock(&ftraced_lock); |
594 | } | |
595 | ||
e309b41d | 596 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 597 | { |
d61f82d0 SR |
598 | int command = FTRACE_DISABLE_MCOUNT; |
599 | ||
4eebcc81 SR |
600 | if (unlikely(ftrace_disabled)) |
601 | return; | |
602 | ||
b0fc494f SR |
603 | mutex_lock(&ftraced_lock); |
604 | /* ftraced_suspend is true if ftrace is running */ | |
605 | if (ftraced_suspend) | |
d61f82d0 SR |
606 | command |= FTRACE_DISABLE_CALLS; |
607 | ||
608 | ftrace_run_update_code(command); | |
b0fc494f SR |
609 | mutex_unlock(&ftraced_lock); |
610 | } | |
611 | ||
3d083395 SR |
612 | static cycle_t ftrace_update_time; |
613 | static unsigned long ftrace_update_cnt; | |
614 | unsigned long ftrace_update_tot_cnt; | |
615 | ||
e309b41d | 616 | static int __ftrace_update_code(void *ignore) |
3d083395 SR |
617 | { |
618 | struct dyn_ftrace *p; | |
0eb96701 | 619 | struct hlist_node *t, *n; |
d61f82d0 | 620 | int save_ftrace_enabled; |
3d083395 SR |
621 | cycle_t start, stop; |
622 | int i; | |
623 | ||
d61f82d0 | 624 | /* Don't be recording funcs now */ |
ad90c0e3 | 625 | ftrace_record_suspend++; |
d61f82d0 SR |
626 | save_ftrace_enabled = ftrace_enabled; |
627 | ftrace_enabled = 0; | |
3d083395 | 628 | |
750ed1a4 | 629 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
630 | ftrace_update_cnt = 0; |
631 | ||
632 | /* No locks needed, the machine is stopped! */ | |
633 | for (i = 0; i < FTRACE_HASHSIZE; i++) { | |
0eb96701 AS |
634 | /* all CPUS are stopped, we are safe to modify code */ |
635 | hlist_for_each_entry_safe(p, t, n, &ftrace_hash[i], node) { | |
636 | /* Skip over failed records which have not been | |
637 | * freed. */ | |
638 | if (p->flags & FTRACE_FL_FAILED) | |
639 | continue; | |
3d083395 | 640 | |
0eb96701 AS |
641 | /* Unconverted records are always at the head of the |
642 | * hash bucket. Once we encounter a converted record, | |
643 | * simply skip over to the next bucket. Saves ftraced | |
644 | * some processor cycles (ftrace does its bid for | |
645 | * global warming :-p ). */ | |
646 | if (p->flags & (FTRACE_FL_CONVERTED)) | |
647 | break; | |
3d083395 | 648 | |
0eb96701 AS |
649 | if (ftrace_code_disable(p)) { |
650 | p->flags |= FTRACE_FL_CONVERTED; | |
492a7ea5 | 651 | ftrace_update_cnt++; |
0eb96701 AS |
652 | } else { |
653 | if ((system_state == SYSTEM_BOOTING) || | |
654 | !kernel_text_address(p->ip)) { | |
655 | ftrace_del_hash(p); | |
656 | ftrace_free_rec(p); | |
657 | ||
658 | } | |
659 | } | |
3d083395 | 660 | } |
3d083395 SR |
661 | } |
662 | ||
750ed1a4 | 663 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
664 | ftrace_update_time = stop - start; |
665 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
ad90c0e3 | 666 | ftraced_trigger = 0; |
3d083395 | 667 | |
d61f82d0 | 668 | ftrace_enabled = save_ftrace_enabled; |
ad90c0e3 | 669 | ftrace_record_suspend--; |
16444a8a ACM |
670 | |
671 | return 0; | |
672 | } | |
673 | ||
ad90c0e3 | 674 | static int ftrace_update_code(void) |
3d083395 | 675 | { |
ad90c0e3 SR |
676 | if (unlikely(ftrace_disabled) || |
677 | !ftrace_enabled || !ftraced_trigger) | |
678 | return 0; | |
4eebcc81 | 679 | |
3d083395 | 680 | stop_machine_run(__ftrace_update_code, NULL, NR_CPUS); |
ad90c0e3 SR |
681 | |
682 | return 1; | |
3d083395 SR |
683 | } |
684 | ||
e309b41d | 685 | static int ftraced(void *ignore) |
3d083395 SR |
686 | { |
687 | unsigned long usecs; | |
688 | ||
3d083395 SR |
689 | while (!kthread_should_stop()) { |
690 | ||
07a267cd SR |
691 | set_current_state(TASK_INTERRUPTIBLE); |
692 | ||
3d083395 SR |
693 | /* check once a second */ |
694 | schedule_timeout(HZ); | |
695 | ||
4eebcc81 SR |
696 | if (unlikely(ftrace_disabled)) |
697 | continue; | |
698 | ||
b0fc494f | 699 | mutex_lock(&ftrace_sysctl_lock); |
3d083395 | 700 | mutex_lock(&ftraced_lock); |
ad90c0e3 SR |
701 | if (!ftraced_suspend && !ftraced_stop && |
702 | ftrace_update_code()) { | |
3d083395 SR |
703 | usecs = nsecs_to_usecs(ftrace_update_time); |
704 | if (ftrace_update_tot_cnt > 100000) { | |
705 | ftrace_update_tot_cnt = 0; | |
706 | pr_info("hm, dftrace overflow: %lu change%s" | |
ad90c0e3 | 707 | " (%lu total) in %lu usec%s\n", |
3d083395 SR |
708 | ftrace_update_cnt, |
709 | ftrace_update_cnt != 1 ? "s" : "", | |
710 | ftrace_update_tot_cnt, | |
711 | usecs, usecs != 1 ? "s" : ""); | |
4eebcc81 | 712 | ftrace_disabled = 1; |
3d083395 SR |
713 | WARN_ON_ONCE(1); |
714 | } | |
3d083395 SR |
715 | } |
716 | mutex_unlock(&ftraced_lock); | |
b0fc494f | 717 | mutex_unlock(&ftrace_sysctl_lock); |
3d083395 SR |
718 | |
719 | ftrace_shutdown_replenish(); | |
3d083395 SR |
720 | } |
721 | __set_current_state(TASK_RUNNING); | |
722 | return 0; | |
723 | } | |
724 | ||
3c1720f0 SR |
725 | static int __init ftrace_dyn_table_alloc(void) |
726 | { | |
727 | struct ftrace_page *pg; | |
728 | int cnt; | |
729 | int i; | |
3c1720f0 SR |
730 | |
731 | /* allocate a few pages */ | |
732 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
733 | if (!ftrace_pages_start) | |
734 | return -1; | |
735 | ||
736 | /* | |
737 | * Allocate a few more pages. | |
738 | * | |
739 | * TODO: have some parser search vmlinux before | |
740 | * final linking to find all calls to ftrace. | |
741 | * Then we can: | |
742 | * a) know how many pages to allocate. | |
743 | * and/or | |
744 | * b) set up the table then. | |
745 | * | |
746 | * The dynamic code is still necessary for | |
747 | * modules. | |
748 | */ | |
749 | ||
750 | pg = ftrace_pages = ftrace_pages_start; | |
751 | ||
752 | cnt = NR_TO_INIT / ENTRIES_PER_PAGE; | |
753 | ||
754 | for (i = 0; i < cnt; i++) { | |
755 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
756 | ||
757 | /* If we fail, we'll try later anyway */ | |
758 | if (!pg->next) | |
759 | break; | |
760 | ||
761 | pg = pg->next; | |
762 | } | |
763 | ||
764 | return 0; | |
765 | } | |
766 | ||
5072c59f SR |
767 | enum { |
768 | FTRACE_ITER_FILTER = (1 << 0), | |
769 | FTRACE_ITER_CONT = (1 << 1), | |
41c52c0d | 770 | FTRACE_ITER_NOTRACE = (1 << 2), |
eb9a7bf0 | 771 | FTRACE_ITER_FAILURES = (1 << 3), |
5072c59f SR |
772 | }; |
773 | ||
774 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
775 | ||
776 | struct ftrace_iterator { | |
777 | loff_t pos; | |
778 | struct ftrace_page *pg; | |
779 | unsigned idx; | |
780 | unsigned flags; | |
781 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
782 | unsigned buffer_idx; | |
783 | unsigned filtered; | |
784 | }; | |
785 | ||
e309b41d | 786 | static void * |
5072c59f SR |
787 | t_next(struct seq_file *m, void *v, loff_t *pos) |
788 | { | |
789 | struct ftrace_iterator *iter = m->private; | |
790 | struct dyn_ftrace *rec = NULL; | |
791 | ||
792 | (*pos)++; | |
793 | ||
794 | retry: | |
795 | if (iter->idx >= iter->pg->index) { | |
796 | if (iter->pg->next) { | |
797 | iter->pg = iter->pg->next; | |
798 | iter->idx = 0; | |
799 | goto retry; | |
800 | } | |
801 | } else { | |
802 | rec = &iter->pg->records[iter->idx++]; | |
eb9a7bf0 AS |
803 | if ((!(iter->flags & FTRACE_ITER_FAILURES) && |
804 | (rec->flags & FTRACE_FL_FAILED)) || | |
805 | ||
806 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
807 | (!(rec->flags & FTRACE_FL_FAILED) || | |
808 | (rec->flags & FTRACE_FL_FREE))) || | |
809 | ||
5072c59f | 810 | ((iter->flags & FTRACE_ITER_FILTER) && |
41c52c0d | 811 | !(rec->flags & FTRACE_FL_FILTER)) || |
eb9a7bf0 | 812 | |
41c52c0d SR |
813 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
814 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
815 | rec = NULL; |
816 | goto retry; | |
817 | } | |
818 | } | |
819 | ||
820 | iter->pos = *pos; | |
821 | ||
822 | return rec; | |
823 | } | |
824 | ||
825 | static void *t_start(struct seq_file *m, loff_t *pos) | |
826 | { | |
827 | struct ftrace_iterator *iter = m->private; | |
828 | void *p = NULL; | |
829 | loff_t l = -1; | |
830 | ||
831 | if (*pos != iter->pos) { | |
832 | for (p = t_next(m, p, &l); p && l < *pos; p = t_next(m, p, &l)) | |
833 | ; | |
834 | } else { | |
835 | l = *pos; | |
836 | p = t_next(m, p, &l); | |
837 | } | |
838 | ||
839 | return p; | |
840 | } | |
841 | ||
842 | static void t_stop(struct seq_file *m, void *p) | |
843 | { | |
844 | } | |
845 | ||
846 | static int t_show(struct seq_file *m, void *v) | |
847 | { | |
848 | struct dyn_ftrace *rec = v; | |
849 | char str[KSYM_SYMBOL_LEN]; | |
850 | ||
851 | if (!rec) | |
852 | return 0; | |
853 | ||
854 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
855 | ||
856 | seq_printf(m, "%s\n", str); | |
857 | ||
858 | return 0; | |
859 | } | |
860 | ||
861 | static struct seq_operations show_ftrace_seq_ops = { | |
862 | .start = t_start, | |
863 | .next = t_next, | |
864 | .stop = t_stop, | |
865 | .show = t_show, | |
866 | }; | |
867 | ||
e309b41d | 868 | static int |
5072c59f SR |
869 | ftrace_avail_open(struct inode *inode, struct file *file) |
870 | { | |
871 | struct ftrace_iterator *iter; | |
872 | int ret; | |
873 | ||
4eebcc81 SR |
874 | if (unlikely(ftrace_disabled)) |
875 | return -ENODEV; | |
876 | ||
5072c59f SR |
877 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
878 | if (!iter) | |
879 | return -ENOMEM; | |
880 | ||
881 | iter->pg = ftrace_pages_start; | |
882 | iter->pos = -1; | |
883 | ||
884 | ret = seq_open(file, &show_ftrace_seq_ops); | |
885 | if (!ret) { | |
886 | struct seq_file *m = file->private_data; | |
4bf39a94 | 887 | |
5072c59f | 888 | m->private = iter; |
4bf39a94 | 889 | } else { |
5072c59f | 890 | kfree(iter); |
4bf39a94 | 891 | } |
5072c59f SR |
892 | |
893 | return ret; | |
894 | } | |
895 | ||
896 | int ftrace_avail_release(struct inode *inode, struct file *file) | |
897 | { | |
898 | struct seq_file *m = (struct seq_file *)file->private_data; | |
899 | struct ftrace_iterator *iter = m->private; | |
900 | ||
901 | seq_release(inode, file); | |
902 | kfree(iter); | |
4bf39a94 | 903 | |
5072c59f SR |
904 | return 0; |
905 | } | |
906 | ||
eb9a7bf0 AS |
907 | static int |
908 | ftrace_failures_open(struct inode *inode, struct file *file) | |
909 | { | |
910 | int ret; | |
911 | struct seq_file *m; | |
912 | struct ftrace_iterator *iter; | |
913 | ||
914 | ret = ftrace_avail_open(inode, file); | |
915 | if (!ret) { | |
916 | m = (struct seq_file *)file->private_data; | |
917 | iter = (struct ftrace_iterator *)m->private; | |
918 | iter->flags = FTRACE_ITER_FAILURES; | |
919 | } | |
920 | ||
921 | return ret; | |
922 | } | |
923 | ||
924 | ||
41c52c0d | 925 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
926 | { |
927 | struct ftrace_page *pg; | |
928 | struct dyn_ftrace *rec; | |
41c52c0d | 929 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f SR |
930 | unsigned i; |
931 | ||
932 | /* keep kstop machine from running */ | |
933 | preempt_disable(); | |
41c52c0d SR |
934 | if (enable) |
935 | ftrace_filtered = 0; | |
5072c59f SR |
936 | pg = ftrace_pages_start; |
937 | while (pg) { | |
938 | for (i = 0; i < pg->index; i++) { | |
939 | rec = &pg->records[i]; | |
940 | if (rec->flags & FTRACE_FL_FAILED) | |
941 | continue; | |
41c52c0d | 942 | rec->flags &= ~type; |
5072c59f SR |
943 | } |
944 | pg = pg->next; | |
945 | } | |
946 | preempt_enable(); | |
947 | } | |
948 | ||
e309b41d | 949 | static int |
41c52c0d | 950 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
951 | { |
952 | struct ftrace_iterator *iter; | |
953 | int ret = 0; | |
954 | ||
4eebcc81 SR |
955 | if (unlikely(ftrace_disabled)) |
956 | return -ENODEV; | |
957 | ||
5072c59f SR |
958 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
959 | if (!iter) | |
960 | return -ENOMEM; | |
961 | ||
41c52c0d | 962 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
963 | if ((file->f_mode & FMODE_WRITE) && |
964 | !(file->f_flags & O_APPEND)) | |
41c52c0d | 965 | ftrace_filter_reset(enable); |
5072c59f SR |
966 | |
967 | if (file->f_mode & FMODE_READ) { | |
968 | iter->pg = ftrace_pages_start; | |
969 | iter->pos = -1; | |
41c52c0d SR |
970 | iter->flags = enable ? FTRACE_ITER_FILTER : |
971 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
972 | |
973 | ret = seq_open(file, &show_ftrace_seq_ops); | |
974 | if (!ret) { | |
975 | struct seq_file *m = file->private_data; | |
976 | m->private = iter; | |
977 | } else | |
978 | kfree(iter); | |
979 | } else | |
980 | file->private_data = iter; | |
41c52c0d | 981 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
982 | |
983 | return ret; | |
984 | } | |
985 | ||
41c52c0d SR |
986 | static int |
987 | ftrace_filter_open(struct inode *inode, struct file *file) | |
988 | { | |
989 | return ftrace_regex_open(inode, file, 1); | |
990 | } | |
991 | ||
992 | static int | |
993 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
994 | { | |
995 | return ftrace_regex_open(inode, file, 0); | |
996 | } | |
997 | ||
e309b41d | 998 | static ssize_t |
41c52c0d | 999 | ftrace_regex_read(struct file *file, char __user *ubuf, |
5072c59f SR |
1000 | size_t cnt, loff_t *ppos) |
1001 | { | |
1002 | if (file->f_mode & FMODE_READ) | |
1003 | return seq_read(file, ubuf, cnt, ppos); | |
1004 | else | |
1005 | return -EPERM; | |
1006 | } | |
1007 | ||
e309b41d | 1008 | static loff_t |
41c52c0d | 1009 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
1010 | { |
1011 | loff_t ret; | |
1012 | ||
1013 | if (file->f_mode & FMODE_READ) | |
1014 | ret = seq_lseek(file, offset, origin); | |
1015 | else | |
1016 | file->f_pos = ret = 1; | |
1017 | ||
1018 | return ret; | |
1019 | } | |
1020 | ||
1021 | enum { | |
1022 | MATCH_FULL, | |
1023 | MATCH_FRONT_ONLY, | |
1024 | MATCH_MIDDLE_ONLY, | |
1025 | MATCH_END_ONLY, | |
1026 | }; | |
1027 | ||
e309b41d | 1028 | static void |
41c52c0d | 1029 | ftrace_match(unsigned char *buff, int len, int enable) |
5072c59f SR |
1030 | { |
1031 | char str[KSYM_SYMBOL_LEN]; | |
1032 | char *search = NULL; | |
1033 | struct ftrace_page *pg; | |
1034 | struct dyn_ftrace *rec; | |
1035 | int type = MATCH_FULL; | |
41c52c0d | 1036 | unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f SR |
1037 | unsigned i, match = 0, search_len = 0; |
1038 | ||
1039 | for (i = 0; i < len; i++) { | |
1040 | if (buff[i] == '*') { | |
1041 | if (!i) { | |
1042 | search = buff + i + 1; | |
1043 | type = MATCH_END_ONLY; | |
1044 | search_len = len - (i + 1); | |
1045 | } else { | |
1046 | if (type == MATCH_END_ONLY) { | |
1047 | type = MATCH_MIDDLE_ONLY; | |
1048 | } else { | |
1049 | match = i; | |
1050 | type = MATCH_FRONT_ONLY; | |
1051 | } | |
1052 | buff[i] = 0; | |
1053 | break; | |
1054 | } | |
1055 | } | |
1056 | } | |
1057 | ||
1058 | /* keep kstop machine from running */ | |
1059 | preempt_disable(); | |
41c52c0d SR |
1060 | if (enable) |
1061 | ftrace_filtered = 1; | |
5072c59f SR |
1062 | pg = ftrace_pages_start; |
1063 | while (pg) { | |
1064 | for (i = 0; i < pg->index; i++) { | |
1065 | int matched = 0; | |
1066 | char *ptr; | |
1067 | ||
1068 | rec = &pg->records[i]; | |
1069 | if (rec->flags & FTRACE_FL_FAILED) | |
1070 | continue; | |
1071 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1072 | switch (type) { | |
1073 | case MATCH_FULL: | |
1074 | if (strcmp(str, buff) == 0) | |
1075 | matched = 1; | |
1076 | break; | |
1077 | case MATCH_FRONT_ONLY: | |
1078 | if (memcmp(str, buff, match) == 0) | |
1079 | matched = 1; | |
1080 | break; | |
1081 | case MATCH_MIDDLE_ONLY: | |
1082 | if (strstr(str, search)) | |
1083 | matched = 1; | |
1084 | break; | |
1085 | case MATCH_END_ONLY: | |
1086 | ptr = strstr(str, search); | |
1087 | if (ptr && (ptr[search_len] == 0)) | |
1088 | matched = 1; | |
1089 | break; | |
1090 | } | |
1091 | if (matched) | |
41c52c0d | 1092 | rec->flags |= flag; |
5072c59f SR |
1093 | } |
1094 | pg = pg->next; | |
1095 | } | |
1096 | preempt_enable(); | |
1097 | } | |
1098 | ||
e309b41d | 1099 | static ssize_t |
41c52c0d SR |
1100 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
1101 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
1102 | { |
1103 | struct ftrace_iterator *iter; | |
1104 | char ch; | |
1105 | size_t read = 0; | |
1106 | ssize_t ret; | |
1107 | ||
1108 | if (!cnt || cnt < 0) | |
1109 | return 0; | |
1110 | ||
41c52c0d | 1111 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1112 | |
1113 | if (file->f_mode & FMODE_READ) { | |
1114 | struct seq_file *m = file->private_data; | |
1115 | iter = m->private; | |
1116 | } else | |
1117 | iter = file->private_data; | |
1118 | ||
1119 | if (!*ppos) { | |
1120 | iter->flags &= ~FTRACE_ITER_CONT; | |
1121 | iter->buffer_idx = 0; | |
1122 | } | |
1123 | ||
1124 | ret = get_user(ch, ubuf++); | |
1125 | if (ret) | |
1126 | goto out; | |
1127 | read++; | |
1128 | cnt--; | |
1129 | ||
1130 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { | |
1131 | /* skip white space */ | |
1132 | while (cnt && isspace(ch)) { | |
1133 | ret = get_user(ch, ubuf++); | |
1134 | if (ret) | |
1135 | goto out; | |
1136 | read++; | |
1137 | cnt--; | |
1138 | } | |
1139 | ||
5072c59f SR |
1140 | if (isspace(ch)) { |
1141 | file->f_pos += read; | |
1142 | ret = read; | |
1143 | goto out; | |
1144 | } | |
1145 | ||
1146 | iter->buffer_idx = 0; | |
1147 | } | |
1148 | ||
1149 | while (cnt && !isspace(ch)) { | |
1150 | if (iter->buffer_idx < FTRACE_BUFF_MAX) | |
1151 | iter->buffer[iter->buffer_idx++] = ch; | |
1152 | else { | |
1153 | ret = -EINVAL; | |
1154 | goto out; | |
1155 | } | |
1156 | ret = get_user(ch, ubuf++); | |
1157 | if (ret) | |
1158 | goto out; | |
1159 | read++; | |
1160 | cnt--; | |
1161 | } | |
1162 | ||
1163 | if (isspace(ch)) { | |
1164 | iter->filtered++; | |
1165 | iter->buffer[iter->buffer_idx] = 0; | |
41c52c0d | 1166 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1167 | iter->buffer_idx = 0; |
1168 | } else | |
1169 | iter->flags |= FTRACE_ITER_CONT; | |
1170 | ||
1171 | ||
1172 | file->f_pos += read; | |
1173 | ||
1174 | ret = read; | |
1175 | out: | |
41c52c0d | 1176 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1177 | |
1178 | return ret; | |
1179 | } | |
1180 | ||
41c52c0d SR |
1181 | static ssize_t |
1182 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
1183 | size_t cnt, loff_t *ppos) | |
1184 | { | |
1185 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
1186 | } | |
1187 | ||
1188 | static ssize_t | |
1189 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
1190 | size_t cnt, loff_t *ppos) | |
1191 | { | |
1192 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
1193 | } | |
1194 | ||
1195 | static void | |
1196 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
1197 | { | |
1198 | if (unlikely(ftrace_disabled)) | |
1199 | return; | |
1200 | ||
1201 | mutex_lock(&ftrace_regex_lock); | |
1202 | if (reset) | |
1203 | ftrace_filter_reset(enable); | |
1204 | if (buf) | |
1205 | ftrace_match(buf, len, enable); | |
1206 | mutex_unlock(&ftrace_regex_lock); | |
1207 | } | |
1208 | ||
77a2b37d SR |
1209 | /** |
1210 | * ftrace_set_filter - set a function to filter on in ftrace | |
1211 | * @buf - the string that holds the function filter text. | |
1212 | * @len - the length of the string. | |
1213 | * @reset - non zero to reset all filters before applying this filter. | |
1214 | * | |
1215 | * Filters denote which functions should be enabled when tracing is enabled. | |
1216 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
1217 | */ | |
e309b41d | 1218 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 1219 | { |
41c52c0d SR |
1220 | ftrace_set_regex(buf, len, reset, 1); |
1221 | } | |
4eebcc81 | 1222 | |
41c52c0d SR |
1223 | /** |
1224 | * ftrace_set_notrace - set a function to not trace in ftrace | |
1225 | * @buf - the string that holds the function notrace text. | |
1226 | * @len - the length of the string. | |
1227 | * @reset - non zero to reset all filters before applying this filter. | |
1228 | * | |
1229 | * Notrace Filters denote which functions should not be enabled when tracing | |
1230 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
1231 | * for tracing. | |
1232 | */ | |
1233 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
1234 | { | |
1235 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
1236 | } |
1237 | ||
e309b41d | 1238 | static int |
41c52c0d | 1239 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1240 | { |
1241 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1242 | struct ftrace_iterator *iter; | |
1243 | ||
41c52c0d | 1244 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1245 | if (file->f_mode & FMODE_READ) { |
1246 | iter = m->private; | |
1247 | ||
1248 | seq_release(inode, file); | |
1249 | } else | |
1250 | iter = file->private_data; | |
1251 | ||
1252 | if (iter->buffer_idx) { | |
1253 | iter->filtered++; | |
1254 | iter->buffer[iter->buffer_idx] = 0; | |
41c52c0d | 1255 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1256 | } |
1257 | ||
1258 | mutex_lock(&ftrace_sysctl_lock); | |
1259 | mutex_lock(&ftraced_lock); | |
1260 | if (iter->filtered && ftraced_suspend && ftrace_enabled) | |
1261 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); | |
1262 | mutex_unlock(&ftraced_lock); | |
1263 | mutex_unlock(&ftrace_sysctl_lock); | |
1264 | ||
1265 | kfree(iter); | |
41c52c0d | 1266 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1267 | return 0; |
1268 | } | |
1269 | ||
41c52c0d SR |
1270 | static int |
1271 | ftrace_filter_release(struct inode *inode, struct file *file) | |
1272 | { | |
1273 | return ftrace_regex_release(inode, file, 1); | |
1274 | } | |
1275 | ||
1276 | static int | |
1277 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
1278 | { | |
1279 | return ftrace_regex_release(inode, file, 0); | |
1280 | } | |
1281 | ||
ad90c0e3 SR |
1282 | static ssize_t |
1283 | ftraced_read(struct file *filp, char __user *ubuf, | |
1284 | size_t cnt, loff_t *ppos) | |
1285 | { | |
1286 | /* don't worry about races */ | |
1287 | char *buf = ftraced_stop ? "disabled\n" : "enabled\n"; | |
1288 | int r = strlen(buf); | |
1289 | ||
1290 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
1291 | } | |
1292 | ||
1293 | static ssize_t | |
1294 | ftraced_write(struct file *filp, const char __user *ubuf, | |
1295 | size_t cnt, loff_t *ppos) | |
1296 | { | |
1297 | char buf[64]; | |
1298 | long val; | |
1299 | int ret; | |
1300 | ||
1301 | if (cnt >= sizeof(buf)) | |
1302 | return -EINVAL; | |
1303 | ||
1304 | if (copy_from_user(&buf, ubuf, cnt)) | |
1305 | return -EFAULT; | |
1306 | ||
1307 | if (strncmp(buf, "enable", 6) == 0) | |
1308 | val = 1; | |
1309 | else if (strncmp(buf, "disable", 7) == 0) | |
1310 | val = 0; | |
1311 | else { | |
1312 | buf[cnt] = 0; | |
1313 | ||
1314 | ret = strict_strtoul(buf, 10, &val); | |
1315 | if (ret < 0) | |
1316 | return ret; | |
1317 | ||
1318 | val = !!val; | |
1319 | } | |
1320 | ||
1321 | if (val) | |
1322 | ftrace_enable_daemon(); | |
1323 | else | |
1324 | ftrace_disable_daemon(); | |
1325 | ||
1326 | filp->f_pos += cnt; | |
1327 | ||
1328 | return cnt; | |
1329 | } | |
1330 | ||
5072c59f SR |
1331 | static struct file_operations ftrace_avail_fops = { |
1332 | .open = ftrace_avail_open, | |
1333 | .read = seq_read, | |
1334 | .llseek = seq_lseek, | |
1335 | .release = ftrace_avail_release, | |
1336 | }; | |
1337 | ||
eb9a7bf0 AS |
1338 | static struct file_operations ftrace_failures_fops = { |
1339 | .open = ftrace_failures_open, | |
1340 | .read = seq_read, | |
1341 | .llseek = seq_lseek, | |
1342 | .release = ftrace_avail_release, | |
1343 | }; | |
1344 | ||
5072c59f SR |
1345 | static struct file_operations ftrace_filter_fops = { |
1346 | .open = ftrace_filter_open, | |
41c52c0d | 1347 | .read = ftrace_regex_read, |
5072c59f | 1348 | .write = ftrace_filter_write, |
41c52c0d | 1349 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
1350 | .release = ftrace_filter_release, |
1351 | }; | |
1352 | ||
41c52c0d SR |
1353 | static struct file_operations ftrace_notrace_fops = { |
1354 | .open = ftrace_notrace_open, | |
1355 | .read = ftrace_regex_read, | |
1356 | .write = ftrace_notrace_write, | |
1357 | .llseek = ftrace_regex_lseek, | |
1358 | .release = ftrace_notrace_release, | |
1359 | }; | |
1360 | ||
ad90c0e3 SR |
1361 | static struct file_operations ftraced_fops = { |
1362 | .open = tracing_open_generic, | |
1363 | .read = ftraced_read, | |
1364 | .write = ftraced_write, | |
1365 | }; | |
1366 | ||
e1c08bdd SR |
1367 | /** |
1368 | * ftrace_force_update - force an update to all recording ftrace functions | |
e1c08bdd SR |
1369 | */ |
1370 | int ftrace_force_update(void) | |
1371 | { | |
e1c08bdd SR |
1372 | int ret = 0; |
1373 | ||
4eebcc81 | 1374 | if (unlikely(ftrace_disabled)) |
e1c08bdd SR |
1375 | return -ENODEV; |
1376 | ||
ad90c0e3 | 1377 | mutex_lock(&ftrace_sysctl_lock); |
e1c08bdd | 1378 | mutex_lock(&ftraced_lock); |
e1c08bdd | 1379 | |
ad90c0e3 SR |
1380 | /* |
1381 | * If ftraced_trigger is not set, then there is nothing | |
1382 | * to update. | |
1383 | */ | |
1384 | if (ftraced_trigger && !ftrace_update_code()) | |
1385 | ret = -EBUSY; | |
e1c08bdd SR |
1386 | |
1387 | mutex_unlock(&ftraced_lock); | |
ad90c0e3 | 1388 | mutex_unlock(&ftrace_sysctl_lock); |
e1c08bdd SR |
1389 | |
1390 | return ret; | |
1391 | } | |
1392 | ||
4eebcc81 SR |
1393 | static void ftrace_force_shutdown(void) |
1394 | { | |
1395 | struct task_struct *task; | |
1396 | int command = FTRACE_DISABLE_CALLS | FTRACE_UPDATE_TRACE_FUNC; | |
1397 | ||
1398 | mutex_lock(&ftraced_lock); | |
1399 | task = ftraced_task; | |
1400 | ftraced_task = NULL; | |
1401 | ftraced_suspend = -1; | |
1402 | ftrace_run_update_code(command); | |
1403 | mutex_unlock(&ftraced_lock); | |
1404 | ||
1405 | if (task) | |
1406 | kthread_stop(task); | |
1407 | } | |
1408 | ||
5072c59f SR |
1409 | static __init int ftrace_init_debugfs(void) |
1410 | { | |
1411 | struct dentry *d_tracer; | |
1412 | struct dentry *entry; | |
1413 | ||
1414 | d_tracer = tracing_init_dentry(); | |
1415 | ||
1416 | entry = debugfs_create_file("available_filter_functions", 0444, | |
1417 | d_tracer, NULL, &ftrace_avail_fops); | |
1418 | if (!entry) | |
1419 | pr_warning("Could not create debugfs " | |
1420 | "'available_filter_functions' entry\n"); | |
1421 | ||
eb9a7bf0 AS |
1422 | entry = debugfs_create_file("failures", 0444, |
1423 | d_tracer, NULL, &ftrace_failures_fops); | |
1424 | if (!entry) | |
1425 | pr_warning("Could not create debugfs 'failures' entry\n"); | |
1426 | ||
5072c59f SR |
1427 | entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer, |
1428 | NULL, &ftrace_filter_fops); | |
1429 | if (!entry) | |
1430 | pr_warning("Could not create debugfs " | |
1431 | "'set_ftrace_filter' entry\n"); | |
41c52c0d SR |
1432 | |
1433 | entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer, | |
1434 | NULL, &ftrace_notrace_fops); | |
1435 | if (!entry) | |
1436 | pr_warning("Could not create debugfs " | |
1437 | "'set_ftrace_notrace' entry\n"); | |
ad90c0e3 SR |
1438 | |
1439 | entry = debugfs_create_file("ftraced_enabled", 0644, d_tracer, | |
1440 | NULL, &ftraced_fops); | |
1441 | if (!entry) | |
1442 | pr_warning("Could not create debugfs " | |
1443 | "'ftraced_enabled' entry\n"); | |
5072c59f SR |
1444 | return 0; |
1445 | } | |
1446 | ||
1447 | fs_initcall(ftrace_init_debugfs); | |
1448 | ||
e309b41d | 1449 | static int __init ftrace_dynamic_init(void) |
3d083395 SR |
1450 | { |
1451 | struct task_struct *p; | |
d61f82d0 | 1452 | unsigned long addr; |
3d083395 SR |
1453 | int ret; |
1454 | ||
d61f82d0 | 1455 | addr = (unsigned long)ftrace_record_ip; |
9ff9cdb2 | 1456 | |
d61f82d0 SR |
1457 | stop_machine_run(ftrace_dyn_arch_init, &addr, NR_CPUS); |
1458 | ||
1459 | /* ftrace_dyn_arch_init places the return code in addr */ | |
4eebcc81 SR |
1460 | if (addr) { |
1461 | ret = (int)addr; | |
1462 | goto failed; | |
1463 | } | |
d61f82d0 | 1464 | |
3c1720f0 | 1465 | ret = ftrace_dyn_table_alloc(); |
3d083395 | 1466 | if (ret) |
4eebcc81 | 1467 | goto failed; |
3d083395 SR |
1468 | |
1469 | p = kthread_run(ftraced, NULL, "ftraced"); | |
4eebcc81 SR |
1470 | if (IS_ERR(p)) { |
1471 | ret = -1; | |
1472 | goto failed; | |
1473 | } | |
3d083395 | 1474 | |
d61f82d0 | 1475 | last_ftrace_enabled = ftrace_enabled = 1; |
e1c08bdd | 1476 | ftraced_task = p; |
3d083395 SR |
1477 | |
1478 | return 0; | |
4eebcc81 SR |
1479 | |
1480 | failed: | |
1481 | ftrace_disabled = 1; | |
1482 | return ret; | |
3d083395 SR |
1483 | } |
1484 | ||
d61f82d0 | 1485 | core_initcall(ftrace_dynamic_init); |
3d083395 | 1486 | #else |
c7aafc54 IM |
1487 | # define ftrace_startup() do { } while (0) |
1488 | # define ftrace_shutdown() do { } while (0) | |
1489 | # define ftrace_startup_sysctl() do { } while (0) | |
1490 | # define ftrace_shutdown_sysctl() do { } while (0) | |
4eebcc81 | 1491 | # define ftrace_force_shutdown() do { } while (0) |
3d083395 SR |
1492 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
1493 | ||
4eebcc81 SR |
1494 | /** |
1495 | * ftrace_kill - totally shutdown ftrace | |
1496 | * | |
1497 | * This is a safety measure. If something was detected that seems | |
1498 | * wrong, calling this function will keep ftrace from doing | |
1499 | * any more modifications, and updates. | |
1500 | * used when something went wrong. | |
1501 | */ | |
1502 | void ftrace_kill(void) | |
1503 | { | |
1504 | mutex_lock(&ftrace_sysctl_lock); | |
1505 | ftrace_disabled = 1; | |
1506 | ftrace_enabled = 0; | |
1507 | ||
1508 | clear_ftrace_function(); | |
1509 | mutex_unlock(&ftrace_sysctl_lock); | |
1510 | ||
1511 | /* Try to totally disable ftrace */ | |
1512 | ftrace_force_shutdown(); | |
1513 | } | |
1514 | ||
16444a8a | 1515 | /** |
3d083395 SR |
1516 | * register_ftrace_function - register a function for profiling |
1517 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 1518 | * |
3d083395 SR |
1519 | * Register a function to be called by all functions in the |
1520 | * kernel. | |
1521 | * | |
1522 | * Note: @ops->func and all the functions it calls must be labeled | |
1523 | * with "notrace", otherwise it will go into a | |
1524 | * recursive loop. | |
16444a8a | 1525 | */ |
3d083395 | 1526 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 1527 | { |
b0fc494f SR |
1528 | int ret; |
1529 | ||
4eebcc81 SR |
1530 | if (unlikely(ftrace_disabled)) |
1531 | return -1; | |
1532 | ||
b0fc494f | 1533 | mutex_lock(&ftrace_sysctl_lock); |
b0fc494f | 1534 | ret = __register_ftrace_function(ops); |
d61f82d0 | 1535 | ftrace_startup(); |
b0fc494f SR |
1536 | mutex_unlock(&ftrace_sysctl_lock); |
1537 | ||
1538 | return ret; | |
3d083395 SR |
1539 | } |
1540 | ||
1541 | /** | |
1542 | * unregister_ftrace_function - unresgister a function for profiling. | |
1543 | * @ops - ops structure that holds the function to unregister | |
1544 | * | |
1545 | * Unregister a function that was added to be called by ftrace profiling. | |
1546 | */ | |
1547 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
1548 | { | |
1549 | int ret; | |
1550 | ||
b0fc494f | 1551 | mutex_lock(&ftrace_sysctl_lock); |
3d083395 | 1552 | ret = __unregister_ftrace_function(ops); |
d61f82d0 | 1553 | ftrace_shutdown(); |
b0fc494f SR |
1554 | mutex_unlock(&ftrace_sysctl_lock); |
1555 | ||
1556 | return ret; | |
1557 | } | |
1558 | ||
e309b41d | 1559 | int |
b0fc494f | 1560 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
5072c59f | 1561 | struct file *file, void __user *buffer, size_t *lenp, |
b0fc494f SR |
1562 | loff_t *ppos) |
1563 | { | |
1564 | int ret; | |
1565 | ||
4eebcc81 SR |
1566 | if (unlikely(ftrace_disabled)) |
1567 | return -ENODEV; | |
1568 | ||
b0fc494f SR |
1569 | mutex_lock(&ftrace_sysctl_lock); |
1570 | ||
5072c59f | 1571 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
b0fc494f SR |
1572 | |
1573 | if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) | |
1574 | goto out; | |
1575 | ||
1576 | last_ftrace_enabled = ftrace_enabled; | |
1577 | ||
1578 | if (ftrace_enabled) { | |
1579 | ||
1580 | ftrace_startup_sysctl(); | |
1581 | ||
1582 | /* we are starting ftrace again */ | |
1583 | if (ftrace_list != &ftrace_list_end) { | |
1584 | if (ftrace_list->next == &ftrace_list_end) | |
1585 | ftrace_trace_function = ftrace_list->func; | |
1586 | else | |
1587 | ftrace_trace_function = ftrace_list_func; | |
1588 | } | |
1589 | ||
1590 | } else { | |
1591 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
1592 | ftrace_trace_function = ftrace_stub; | |
1593 | ||
1594 | ftrace_shutdown_sysctl(); | |
1595 | } | |
1596 | ||
1597 | out: | |
1598 | mutex_unlock(&ftrace_sysctl_lock); | |
3d083395 | 1599 | return ret; |
16444a8a | 1600 | } |