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Commit | Line | Data |
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16444a8a ACM |
1 | /* |
2 | * Infrastructure for profiling code inserted by 'gcc -pg'. | |
3 | * | |
4 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> | |
5 | * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com> | |
6 | * | |
7 | * Originally ported from the -rt patch by: | |
8 | * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com> | |
9 | * | |
10 | * Based on code in the latency_tracer, that is: | |
11 | * | |
12 | * Copyright (C) 2004-2006 Ingo Molnar | |
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> |
f22f9a89 | 24 | #include <linux/kprobes.h> |
2d8b820b | 25 | #include <linux/ftrace.h> |
b0fc494f | 26 | #include <linux/sysctl.h> |
5072c59f | 27 | #include <linux/ctype.h> |
2d8b820b | 28 | #include <linux/hash.h> |
3d083395 SR |
29 | #include <linux/list.h> |
30 | ||
395a59d0 AS |
31 | #include <asm/ftrace.h> |
32 | ||
3d083395 | 33 | #include "trace.h" |
16444a8a | 34 | |
4eebcc81 SR |
35 | /* ftrace_enabled is a method to turn ftrace on or off */ |
36 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 37 | static int last_ftrace_enabled; |
b0fc494f | 38 | |
4eebcc81 SR |
39 | /* |
40 | * ftrace_disabled is set when an anomaly is discovered. | |
41 | * ftrace_disabled is much stronger than ftrace_enabled. | |
42 | */ | |
43 | static int ftrace_disabled __read_mostly; | |
44 | ||
3d083395 | 45 | static DEFINE_SPINLOCK(ftrace_lock); |
b0fc494f SR |
46 | static DEFINE_MUTEX(ftrace_sysctl_lock); |
47 | ||
16444a8a ACM |
48 | static struct ftrace_ops ftrace_list_end __read_mostly = |
49 | { | |
50 | .func = ftrace_stub, | |
51 | }; | |
52 | ||
53 | static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; | |
54 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; | |
55 | ||
f2252935 | 56 | static void ftrace_list_func(unsigned long ip, unsigned long parent_ip) |
16444a8a ACM |
57 | { |
58 | struct ftrace_ops *op = ftrace_list; | |
59 | ||
60 | /* in case someone actually ports this to alpha! */ | |
61 | read_barrier_depends(); | |
62 | ||
63 | while (op != &ftrace_list_end) { | |
64 | /* silly alpha */ | |
65 | read_barrier_depends(); | |
66 | op->func(ip, parent_ip); | |
67 | op = op->next; | |
68 | }; | |
69 | } | |
70 | ||
71 | /** | |
3d083395 | 72 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 73 | * |
3d083395 SR |
74 | * This NULLs the ftrace function and in essence stops |
75 | * tracing. There may be lag | |
16444a8a | 76 | */ |
3d083395 | 77 | void clear_ftrace_function(void) |
16444a8a | 78 | { |
3d083395 SR |
79 | ftrace_trace_function = ftrace_stub; |
80 | } | |
81 | ||
e309b41d | 82 | static int __register_ftrace_function(struct ftrace_ops *ops) |
3d083395 SR |
83 | { |
84 | /* Should never be called by interrupts */ | |
85 | spin_lock(&ftrace_lock); | |
16444a8a | 86 | |
16444a8a ACM |
87 | ops->next = ftrace_list; |
88 | /* | |
89 | * We are entering ops into the ftrace_list but another | |
90 | * CPU might be walking that list. We need to make sure | |
91 | * the ops->next pointer is valid before another CPU sees | |
92 | * the ops pointer included into the ftrace_list. | |
93 | */ | |
94 | smp_wmb(); | |
95 | ftrace_list = ops; | |
3d083395 | 96 | |
b0fc494f SR |
97 | if (ftrace_enabled) { |
98 | /* | |
99 | * For one func, simply call it directly. | |
100 | * For more than one func, call the chain. | |
101 | */ | |
102 | if (ops->next == &ftrace_list_end) | |
103 | ftrace_trace_function = ops->func; | |
104 | else | |
105 | ftrace_trace_function = ftrace_list_func; | |
106 | } | |
3d083395 SR |
107 | |
108 | spin_unlock(&ftrace_lock); | |
16444a8a ACM |
109 | |
110 | return 0; | |
111 | } | |
112 | ||
e309b41d | 113 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 114 | { |
16444a8a ACM |
115 | struct ftrace_ops **p; |
116 | int ret = 0; | |
117 | ||
3d083395 | 118 | spin_lock(&ftrace_lock); |
16444a8a ACM |
119 | |
120 | /* | |
3d083395 SR |
121 | * If we are removing the last function, then simply point |
122 | * to the ftrace_stub. | |
16444a8a ACM |
123 | */ |
124 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { | |
125 | ftrace_trace_function = ftrace_stub; | |
126 | ftrace_list = &ftrace_list_end; | |
127 | goto out; | |
128 | } | |
129 | ||
130 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) | |
131 | if (*p == ops) | |
132 | break; | |
133 | ||
134 | if (*p != ops) { | |
135 | ret = -1; | |
136 | goto out; | |
137 | } | |
138 | ||
139 | *p = (*p)->next; | |
140 | ||
b0fc494f SR |
141 | if (ftrace_enabled) { |
142 | /* If we only have one func left, then call that directly */ | |
143 | if (ftrace_list == &ftrace_list_end || | |
144 | ftrace_list->next == &ftrace_list_end) | |
145 | ftrace_trace_function = ftrace_list->func; | |
146 | } | |
16444a8a ACM |
147 | |
148 | out: | |
3d083395 SR |
149 | spin_unlock(&ftrace_lock); |
150 | ||
151 | return ret; | |
152 | } | |
153 | ||
154 | #ifdef CONFIG_DYNAMIC_FTRACE | |
155 | ||
e1c08bdd | 156 | static struct task_struct *ftraced_task; |
e1c08bdd | 157 | |
d61f82d0 SR |
158 | enum { |
159 | FTRACE_ENABLE_CALLS = (1 << 0), | |
160 | FTRACE_DISABLE_CALLS = (1 << 1), | |
161 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
162 | FTRACE_ENABLE_MCOUNT = (1 << 3), | |
163 | FTRACE_DISABLE_MCOUNT = (1 << 4), | |
164 | }; | |
165 | ||
5072c59f | 166 | static int ftrace_filtered; |
ecea656d AS |
167 | static int tracing_on; |
168 | static int frozen_record_count; | |
5072c59f | 169 | |
3d083395 SR |
170 | static struct hlist_head ftrace_hash[FTRACE_HASHSIZE]; |
171 | ||
172 | static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu); | |
173 | ||
174 | static DEFINE_SPINLOCK(ftrace_shutdown_lock); | |
175 | static DEFINE_MUTEX(ftraced_lock); | |
41c52c0d | 176 | static DEFINE_MUTEX(ftrace_regex_lock); |
3d083395 | 177 | |
3c1720f0 SR |
178 | struct ftrace_page { |
179 | struct ftrace_page *next; | |
aa5e5cea | 180 | unsigned long index; |
3c1720f0 | 181 | struct dyn_ftrace records[]; |
aa5e5cea | 182 | }; |
3c1720f0 SR |
183 | |
184 | #define ENTRIES_PER_PAGE \ | |
185 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
186 | ||
187 | /* estimate from running different kernels */ | |
188 | #define NR_TO_INIT 10000 | |
189 | ||
190 | static struct ftrace_page *ftrace_pages_start; | |
191 | static struct ftrace_page *ftrace_pages; | |
192 | ||
3d083395 SR |
193 | static int ftraced_trigger; |
194 | static int ftraced_suspend; | |
ad90c0e3 | 195 | static int ftraced_stop; |
3d083395 SR |
196 | |
197 | static int ftrace_record_suspend; | |
198 | ||
37ad5084 SR |
199 | static struct dyn_ftrace *ftrace_free_records; |
200 | ||
ecea656d AS |
201 | |
202 | #ifdef CONFIG_KPROBES | |
203 | static inline void freeze_record(struct dyn_ftrace *rec) | |
204 | { | |
205 | if (!(rec->flags & FTRACE_FL_FROZEN)) { | |
206 | rec->flags |= FTRACE_FL_FROZEN; | |
207 | frozen_record_count++; | |
208 | } | |
209 | } | |
210 | ||
211 | static inline void unfreeze_record(struct dyn_ftrace *rec) | |
212 | { | |
213 | if (rec->flags & FTRACE_FL_FROZEN) { | |
214 | rec->flags &= ~FTRACE_FL_FROZEN; | |
215 | frozen_record_count--; | |
216 | } | |
217 | } | |
218 | ||
219 | static inline int record_frozen(struct dyn_ftrace *rec) | |
220 | { | |
221 | return rec->flags & FTRACE_FL_FROZEN; | |
222 | } | |
223 | #else | |
224 | # define freeze_record(rec) ({ 0; }) | |
225 | # define unfreeze_record(rec) ({ 0; }) | |
226 | # define record_frozen(rec) ({ 0; }) | |
227 | #endif /* CONFIG_KPROBES */ | |
228 | ||
229 | int skip_trace(unsigned long ip) | |
230 | { | |
231 | unsigned long fl; | |
232 | struct dyn_ftrace *rec; | |
233 | struct hlist_node *t; | |
234 | struct hlist_head *head; | |
235 | ||
236 | if (frozen_record_count == 0) | |
237 | return 0; | |
238 | ||
239 | head = &ftrace_hash[hash_long(ip, FTRACE_HASHBITS)]; | |
240 | hlist_for_each_entry_rcu(rec, t, head, node) { | |
241 | if (rec->ip == ip) { | |
242 | if (record_frozen(rec)) { | |
243 | if (rec->flags & FTRACE_FL_FAILED) | |
244 | return 1; | |
245 | ||
246 | if (!(rec->flags & FTRACE_FL_CONVERTED)) | |
247 | return 1; | |
248 | ||
249 | if (!tracing_on || !ftrace_enabled) | |
250 | return 1; | |
251 | ||
252 | if (ftrace_filtered) { | |
253 | fl = rec->flags & (FTRACE_FL_FILTER | | |
254 | FTRACE_FL_NOTRACE); | |
255 | if (!fl || (fl & FTRACE_FL_NOTRACE)) | |
256 | return 1; | |
257 | } | |
258 | } | |
259 | break; | |
260 | } | |
261 | } | |
262 | ||
263 | return 0; | |
264 | } | |
265 | ||
e309b41d | 266 | static inline int |
9ff9cdb2 | 267 | ftrace_ip_in_hash(unsigned long ip, unsigned long key) |
3d083395 SR |
268 | { |
269 | struct dyn_ftrace *p; | |
270 | struct hlist_node *t; | |
271 | int found = 0; | |
272 | ||
ffdaa358 | 273 | hlist_for_each_entry_rcu(p, t, &ftrace_hash[key], node) { |
3d083395 SR |
274 | if (p->ip == ip) { |
275 | found = 1; | |
276 | break; | |
277 | } | |
278 | } | |
279 | ||
280 | return found; | |
281 | } | |
282 | ||
e309b41d | 283 | static inline void |
3d083395 SR |
284 | ftrace_add_hash(struct dyn_ftrace *node, unsigned long key) |
285 | { | |
ffdaa358 | 286 | hlist_add_head_rcu(&node->node, &ftrace_hash[key]); |
3d083395 SR |
287 | } |
288 | ||
0eb96701 AS |
289 | /* called from kstop_machine */ |
290 | static inline void ftrace_del_hash(struct dyn_ftrace *node) | |
291 | { | |
292 | hlist_del(&node->node); | |
293 | } | |
294 | ||
e309b41d | 295 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
37ad5084 | 296 | { |
37ad5084 SR |
297 | rec->ip = (unsigned long)ftrace_free_records; |
298 | ftrace_free_records = rec; | |
299 | rec->flags |= FTRACE_FL_FREE; | |
300 | } | |
301 | ||
fed1939c SR |
302 | void ftrace_release(void *start, unsigned long size) |
303 | { | |
304 | struct dyn_ftrace *rec; | |
305 | struct ftrace_page *pg; | |
306 | unsigned long s = (unsigned long)start; | |
307 | unsigned long e = s + size; | |
308 | int i; | |
309 | ||
310 | if (!start) | |
311 | return; | |
312 | ||
313 | /* No interrupt should call this */ | |
314 | spin_lock(&ftrace_lock); | |
315 | ||
316 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
317 | for (i = 0; i < pg->index; i++) { | |
318 | rec = &pg->records[i]; | |
319 | ||
320 | if ((rec->ip >= s) && (rec->ip < e)) | |
321 | ftrace_free_rec(rec); | |
322 | } | |
323 | } | |
324 | spin_unlock(&ftrace_lock); | |
325 | ||
326 | } | |
327 | ||
e309b41d | 328 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 329 | { |
37ad5084 SR |
330 | struct dyn_ftrace *rec; |
331 | ||
332 | /* First check for freed records */ | |
333 | if (ftrace_free_records) { | |
334 | rec = ftrace_free_records; | |
335 | ||
37ad5084 SR |
336 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
337 | WARN_ON_ONCE(1); | |
338 | ftrace_free_records = NULL; | |
4eebcc81 SR |
339 | ftrace_disabled = 1; |
340 | ftrace_enabled = 0; | |
37ad5084 SR |
341 | return NULL; |
342 | } | |
343 | ||
344 | ftrace_free_records = (void *)rec->ip; | |
345 | memset(rec, 0, sizeof(*rec)); | |
346 | return rec; | |
347 | } | |
348 | ||
3c1720f0 SR |
349 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
350 | if (!ftrace_pages->next) | |
351 | return NULL; | |
352 | ftrace_pages = ftrace_pages->next; | |
353 | } | |
354 | ||
355 | return &ftrace_pages->records[ftrace_pages->index++]; | |
356 | } | |
357 | ||
e309b41d | 358 | static void |
d61f82d0 | 359 | ftrace_record_ip(unsigned long ip) |
3d083395 SR |
360 | { |
361 | struct dyn_ftrace *node; | |
362 | unsigned long flags; | |
363 | unsigned long key; | |
364 | int resched; | |
365 | int atomic; | |
2bb6f8d6 | 366 | int cpu; |
3d083395 | 367 | |
4eebcc81 | 368 | if (!ftrace_enabled || ftrace_disabled) |
d61f82d0 SR |
369 | return; |
370 | ||
3d083395 SR |
371 | resched = need_resched(); |
372 | preempt_disable_notrace(); | |
373 | ||
2bb6f8d6 SR |
374 | /* |
375 | * We simply need to protect against recursion. | |
376 | * Use the the raw version of smp_processor_id and not | |
377 | * __get_cpu_var which can call debug hooks that can | |
378 | * cause a recursive crash here. | |
379 | */ | |
380 | cpu = raw_smp_processor_id(); | |
381 | per_cpu(ftrace_shutdown_disable_cpu, cpu)++; | |
382 | if (per_cpu(ftrace_shutdown_disable_cpu, cpu) != 1) | |
3d083395 SR |
383 | goto out; |
384 | ||
385 | if (unlikely(ftrace_record_suspend)) | |
386 | goto out; | |
387 | ||
388 | key = hash_long(ip, FTRACE_HASHBITS); | |
389 | ||
390 | WARN_ON_ONCE(key >= FTRACE_HASHSIZE); | |
391 | ||
392 | if (ftrace_ip_in_hash(ip, key)) | |
393 | goto out; | |
394 | ||
395 | atomic = irqs_disabled(); | |
396 | ||
397 | spin_lock_irqsave(&ftrace_shutdown_lock, flags); | |
398 | ||
399 | /* This ip may have hit the hash before the lock */ | |
400 | if (ftrace_ip_in_hash(ip, key)) | |
401 | goto out_unlock; | |
402 | ||
d61f82d0 | 403 | node = ftrace_alloc_dyn_node(ip); |
3d083395 SR |
404 | if (!node) |
405 | goto out_unlock; | |
406 | ||
407 | node->ip = ip; | |
408 | ||
409 | ftrace_add_hash(node, key); | |
410 | ||
411 | ftraced_trigger = 1; | |
412 | ||
413 | out_unlock: | |
414 | spin_unlock_irqrestore(&ftrace_shutdown_lock, flags); | |
415 | out: | |
2bb6f8d6 | 416 | per_cpu(ftrace_shutdown_disable_cpu, cpu)--; |
3d083395 SR |
417 | |
418 | /* prevent recursion with scheduler */ | |
419 | if (resched) | |
420 | preempt_enable_no_resched_notrace(); | |
421 | else | |
422 | preempt_enable_notrace(); | |
423 | } | |
424 | ||
caf8cdeb | 425 | #define FTRACE_ADDR ((long)(ftrace_caller)) |
3c1720f0 | 426 | |
0eb96701 | 427 | static int |
5072c59f SR |
428 | __ftrace_replace_code(struct dyn_ftrace *rec, |
429 | unsigned char *old, unsigned char *new, int enable) | |
430 | { | |
41c52c0d | 431 | unsigned long ip, fl; |
5072c59f SR |
432 | |
433 | ip = rec->ip; | |
434 | ||
435 | if (ftrace_filtered && enable) { | |
5072c59f SR |
436 | /* |
437 | * If filtering is on: | |
438 | * | |
439 | * If this record is set to be filtered and | |
440 | * is enabled then do nothing. | |
441 | * | |
442 | * If this record is set to be filtered and | |
443 | * it is not enabled, enable it. | |
444 | * | |
445 | * If this record is not set to be filtered | |
446 | * and it is not enabled do nothing. | |
447 | * | |
41c52c0d SR |
448 | * If this record is set not to trace then |
449 | * do nothing. | |
450 | * | |
a4500b84 AS |
451 | * If this record is set not to trace and |
452 | * it is enabled then disable it. | |
453 | * | |
5072c59f SR |
454 | * If this record is not set to be filtered and |
455 | * it is enabled, disable it. | |
456 | */ | |
a4500b84 AS |
457 | |
458 | fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE | | |
459 | FTRACE_FL_ENABLED); | |
5072c59f SR |
460 | |
461 | if ((fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) || | |
a4500b84 AS |
462 | (fl == (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE)) || |
463 | !fl || (fl == FTRACE_FL_NOTRACE)) | |
0eb96701 | 464 | return 0; |
5072c59f SR |
465 | |
466 | /* | |
467 | * If it is enabled disable it, | |
468 | * otherwise enable it! | |
469 | */ | |
a4500b84 | 470 | if (fl & FTRACE_FL_ENABLED) { |
5072c59f SR |
471 | /* swap new and old */ |
472 | new = old; | |
473 | old = ftrace_call_replace(ip, FTRACE_ADDR); | |
474 | rec->flags &= ~FTRACE_FL_ENABLED; | |
475 | } else { | |
476 | new = ftrace_call_replace(ip, FTRACE_ADDR); | |
477 | rec->flags |= FTRACE_FL_ENABLED; | |
478 | } | |
479 | } else { | |
480 | ||
41c52c0d SR |
481 | if (enable) { |
482 | /* | |
483 | * If this record is set not to trace and is | |
484 | * not enabled, do nothing. | |
485 | */ | |
486 | fl = rec->flags & (FTRACE_FL_NOTRACE | FTRACE_FL_ENABLED); | |
487 | if (fl == FTRACE_FL_NOTRACE) | |
0eb96701 | 488 | return 0; |
41c52c0d | 489 | |
5072c59f | 490 | new = ftrace_call_replace(ip, FTRACE_ADDR); |
41c52c0d | 491 | } else |
5072c59f SR |
492 | old = ftrace_call_replace(ip, FTRACE_ADDR); |
493 | ||
494 | if (enable) { | |
495 | if (rec->flags & FTRACE_FL_ENABLED) | |
0eb96701 | 496 | return 0; |
5072c59f SR |
497 | rec->flags |= FTRACE_FL_ENABLED; |
498 | } else { | |
499 | if (!(rec->flags & FTRACE_FL_ENABLED)) | |
0eb96701 | 500 | return 0; |
5072c59f SR |
501 | rec->flags &= ~FTRACE_FL_ENABLED; |
502 | } | |
503 | } | |
504 | ||
0eb96701 | 505 | return ftrace_modify_code(ip, old, new); |
5072c59f SR |
506 | } |
507 | ||
e309b41d | 508 | static void ftrace_replace_code(int enable) |
3c1720f0 | 509 | { |
0eb96701 | 510 | int i, failed; |
3c1720f0 SR |
511 | unsigned char *new = NULL, *old = NULL; |
512 | struct dyn_ftrace *rec; | |
513 | struct ftrace_page *pg; | |
3c1720f0 | 514 | |
5072c59f | 515 | if (enable) |
3c1720f0 SR |
516 | old = ftrace_nop_replace(); |
517 | else | |
518 | new = ftrace_nop_replace(); | |
519 | ||
520 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
521 | for (i = 0; i < pg->index; i++) { | |
522 | rec = &pg->records[i]; | |
523 | ||
524 | /* don't modify code that has already faulted */ | |
525 | if (rec->flags & FTRACE_FL_FAILED) | |
526 | continue; | |
527 | ||
f22f9a89 | 528 | /* ignore updates to this record's mcount site */ |
98a05ed4 AS |
529 | if (get_kprobe((void *)rec->ip)) { |
530 | freeze_record(rec); | |
f22f9a89 | 531 | continue; |
98a05ed4 AS |
532 | } else { |
533 | unfreeze_record(rec); | |
534 | } | |
f22f9a89 | 535 | |
0eb96701 AS |
536 | failed = __ftrace_replace_code(rec, old, new, enable); |
537 | if (failed && (rec->flags & FTRACE_FL_CONVERTED)) { | |
538 | rec->flags |= FTRACE_FL_FAILED; | |
539 | if ((system_state == SYSTEM_BOOTING) || | |
34078a5e | 540 | !core_kernel_text(rec->ip)) { |
0eb96701 AS |
541 | ftrace_del_hash(rec); |
542 | ftrace_free_rec(rec); | |
543 | } | |
544 | } | |
3c1720f0 SR |
545 | } |
546 | } | |
547 | } | |
548 | ||
e309b41d | 549 | static void ftrace_shutdown_replenish(void) |
3c1720f0 SR |
550 | { |
551 | if (ftrace_pages->next) | |
552 | return; | |
553 | ||
554 | /* allocate another page */ | |
555 | ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL); | |
556 | } | |
3d083395 | 557 | |
492a7ea5 | 558 | static int |
d61f82d0 | 559 | ftrace_code_disable(struct dyn_ftrace *rec) |
3c1720f0 SR |
560 | { |
561 | unsigned long ip; | |
562 | unsigned char *nop, *call; | |
563 | int failed; | |
564 | ||
565 | ip = rec->ip; | |
566 | ||
567 | nop = ftrace_nop_replace(); | |
d61f82d0 | 568 | call = ftrace_call_replace(ip, MCOUNT_ADDR); |
3c1720f0 SR |
569 | |
570 | failed = ftrace_modify_code(ip, call, nop); | |
37ad5084 | 571 | if (failed) { |
3c1720f0 | 572 | rec->flags |= FTRACE_FL_FAILED; |
492a7ea5 | 573 | return 0; |
37ad5084 | 574 | } |
492a7ea5 | 575 | return 1; |
3c1720f0 SR |
576 | } |
577 | ||
ad90c0e3 SR |
578 | static int __ftrace_update_code(void *ignore); |
579 | ||
e309b41d | 580 | static int __ftrace_modify_code(void *data) |
3d083395 | 581 | { |
d61f82d0 SR |
582 | unsigned long addr; |
583 | int *command = data; | |
584 | ||
ad90c0e3 SR |
585 | if (*command & FTRACE_ENABLE_CALLS) { |
586 | /* | |
587 | * Update any recorded ips now that we have the | |
588 | * machine stopped | |
589 | */ | |
590 | __ftrace_update_code(NULL); | |
d61f82d0 | 591 | ftrace_replace_code(1); |
ecea656d AS |
592 | tracing_on = 1; |
593 | } else if (*command & FTRACE_DISABLE_CALLS) { | |
d61f82d0 | 594 | ftrace_replace_code(0); |
ecea656d AS |
595 | tracing_on = 0; |
596 | } | |
d61f82d0 SR |
597 | |
598 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
599 | ftrace_update_ftrace_func(ftrace_trace_function); | |
600 | ||
601 | if (*command & FTRACE_ENABLE_MCOUNT) { | |
602 | addr = (unsigned long)ftrace_record_ip; | |
603 | ftrace_mcount_set(&addr); | |
604 | } else if (*command & FTRACE_DISABLE_MCOUNT) { | |
605 | addr = (unsigned long)ftrace_stub; | |
606 | ftrace_mcount_set(&addr); | |
607 | } | |
608 | ||
609 | return 0; | |
3d083395 SR |
610 | } |
611 | ||
e309b41d | 612 | static void ftrace_run_update_code(int command) |
3d083395 | 613 | { |
784e2d76 | 614 | stop_machine(__ftrace_modify_code, &command, NULL); |
3d083395 SR |
615 | } |
616 | ||
ad90c0e3 SR |
617 | void ftrace_disable_daemon(void) |
618 | { | |
619 | /* Stop the daemon from calling kstop_machine */ | |
620 | mutex_lock(&ftraced_lock); | |
621 | ftraced_stop = 1; | |
622 | mutex_unlock(&ftraced_lock); | |
623 | ||
624 | ftrace_force_update(); | |
625 | } | |
626 | ||
627 | void ftrace_enable_daemon(void) | |
628 | { | |
629 | mutex_lock(&ftraced_lock); | |
630 | ftraced_stop = 0; | |
631 | mutex_unlock(&ftraced_lock); | |
632 | ||
633 | ftrace_force_update(); | |
634 | } | |
635 | ||
d61f82d0 SR |
636 | static ftrace_func_t saved_ftrace_func; |
637 | ||
e309b41d | 638 | static void ftrace_startup(void) |
3d083395 | 639 | { |
d61f82d0 SR |
640 | int command = 0; |
641 | ||
4eebcc81 SR |
642 | if (unlikely(ftrace_disabled)) |
643 | return; | |
644 | ||
3d083395 SR |
645 | mutex_lock(&ftraced_lock); |
646 | ftraced_suspend++; | |
d61f82d0 SR |
647 | if (ftraced_suspend == 1) |
648 | command |= FTRACE_ENABLE_CALLS; | |
649 | ||
650 | if (saved_ftrace_func != ftrace_trace_function) { | |
651 | saved_ftrace_func = ftrace_trace_function; | |
652 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
653 | } | |
654 | ||
655 | if (!command || !ftrace_enabled) | |
3d083395 | 656 | goto out; |
3d083395 | 657 | |
d61f82d0 | 658 | ftrace_run_update_code(command); |
3d083395 SR |
659 | out: |
660 | mutex_unlock(&ftraced_lock); | |
661 | } | |
662 | ||
e309b41d | 663 | static void ftrace_shutdown(void) |
3d083395 | 664 | { |
d61f82d0 SR |
665 | int command = 0; |
666 | ||
4eebcc81 SR |
667 | if (unlikely(ftrace_disabled)) |
668 | return; | |
669 | ||
3d083395 SR |
670 | mutex_lock(&ftraced_lock); |
671 | ftraced_suspend--; | |
d61f82d0 SR |
672 | if (!ftraced_suspend) |
673 | command |= FTRACE_DISABLE_CALLS; | |
3d083395 | 674 | |
d61f82d0 SR |
675 | if (saved_ftrace_func != ftrace_trace_function) { |
676 | saved_ftrace_func = ftrace_trace_function; | |
677 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
678 | } | |
3d083395 | 679 | |
d61f82d0 SR |
680 | if (!command || !ftrace_enabled) |
681 | goto out; | |
682 | ||
683 | ftrace_run_update_code(command); | |
3d083395 SR |
684 | out: |
685 | mutex_unlock(&ftraced_lock); | |
686 | } | |
687 | ||
e309b41d | 688 | static void ftrace_startup_sysctl(void) |
b0fc494f | 689 | { |
d61f82d0 SR |
690 | int command = FTRACE_ENABLE_MCOUNT; |
691 | ||
4eebcc81 SR |
692 | if (unlikely(ftrace_disabled)) |
693 | return; | |
694 | ||
b0fc494f | 695 | mutex_lock(&ftraced_lock); |
d61f82d0 SR |
696 | /* Force update next time */ |
697 | saved_ftrace_func = NULL; | |
b0fc494f SR |
698 | /* ftraced_suspend is true if we want ftrace running */ |
699 | if (ftraced_suspend) | |
d61f82d0 SR |
700 | command |= FTRACE_ENABLE_CALLS; |
701 | ||
702 | ftrace_run_update_code(command); | |
b0fc494f SR |
703 | mutex_unlock(&ftraced_lock); |
704 | } | |
705 | ||
e309b41d | 706 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 707 | { |
d61f82d0 SR |
708 | int command = FTRACE_DISABLE_MCOUNT; |
709 | ||
4eebcc81 SR |
710 | if (unlikely(ftrace_disabled)) |
711 | return; | |
712 | ||
b0fc494f SR |
713 | mutex_lock(&ftraced_lock); |
714 | /* ftraced_suspend is true if ftrace is running */ | |
715 | if (ftraced_suspend) | |
d61f82d0 SR |
716 | command |= FTRACE_DISABLE_CALLS; |
717 | ||
718 | ftrace_run_update_code(command); | |
b0fc494f SR |
719 | mutex_unlock(&ftraced_lock); |
720 | } | |
721 | ||
3d083395 SR |
722 | static cycle_t ftrace_update_time; |
723 | static unsigned long ftrace_update_cnt; | |
724 | unsigned long ftrace_update_tot_cnt; | |
725 | ||
e309b41d | 726 | static int __ftrace_update_code(void *ignore) |
3d083395 | 727 | { |
f22f9a89 AS |
728 | int i, save_ftrace_enabled; |
729 | cycle_t start, stop; | |
3d083395 | 730 | struct dyn_ftrace *p; |
0eb96701 | 731 | struct hlist_node *t, *n; |
f22f9a89 | 732 | struct hlist_head *head, temp_list; |
3d083395 | 733 | |
d61f82d0 | 734 | /* Don't be recording funcs now */ |
ad90c0e3 | 735 | ftrace_record_suspend++; |
d61f82d0 SR |
736 | save_ftrace_enabled = ftrace_enabled; |
737 | ftrace_enabled = 0; | |
3d083395 | 738 | |
750ed1a4 | 739 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
740 | ftrace_update_cnt = 0; |
741 | ||
742 | /* No locks needed, the machine is stopped! */ | |
743 | for (i = 0; i < FTRACE_HASHSIZE; i++) { | |
f22f9a89 AS |
744 | INIT_HLIST_HEAD(&temp_list); |
745 | head = &ftrace_hash[i]; | |
746 | ||
0eb96701 | 747 | /* all CPUS are stopped, we are safe to modify code */ |
f22f9a89 | 748 | hlist_for_each_entry_safe(p, t, n, head, node) { |
0eb96701 AS |
749 | /* Skip over failed records which have not been |
750 | * freed. */ | |
751 | if (p->flags & FTRACE_FL_FAILED) | |
752 | continue; | |
3d083395 | 753 | |
0eb96701 AS |
754 | /* Unconverted records are always at the head of the |
755 | * hash bucket. Once we encounter a converted record, | |
756 | * simply skip over to the next bucket. Saves ftraced | |
757 | * some processor cycles (ftrace does its bid for | |
758 | * global warming :-p ). */ | |
759 | if (p->flags & (FTRACE_FL_CONVERTED)) | |
760 | break; | |
3d083395 | 761 | |
f22f9a89 AS |
762 | /* Ignore updates to this record's mcount site. |
763 | * Reintroduce this record at the head of this | |
764 | * bucket to attempt to "convert" it again if | |
765 | * the kprobe on it is unregistered before the | |
766 | * next run. */ | |
767 | if (get_kprobe((void *)p->ip)) { | |
768 | ftrace_del_hash(p); | |
769 | INIT_HLIST_NODE(&p->node); | |
770 | hlist_add_head(&p->node, &temp_list); | |
98a05ed4 | 771 | freeze_record(p); |
f22f9a89 | 772 | continue; |
98a05ed4 AS |
773 | } else { |
774 | unfreeze_record(p); | |
f22f9a89 AS |
775 | } |
776 | ||
777 | /* convert record (i.e, patch mcount-call with NOP) */ | |
0eb96701 AS |
778 | if (ftrace_code_disable(p)) { |
779 | p->flags |= FTRACE_FL_CONVERTED; | |
492a7ea5 | 780 | ftrace_update_cnt++; |
0eb96701 AS |
781 | } else { |
782 | if ((system_state == SYSTEM_BOOTING) || | |
34078a5e | 783 | !core_kernel_text(p->ip)) { |
0eb96701 AS |
784 | ftrace_del_hash(p); |
785 | ftrace_free_rec(p); | |
0eb96701 AS |
786 | } |
787 | } | |
3d083395 | 788 | } |
f22f9a89 AS |
789 | |
790 | hlist_for_each_entry_safe(p, t, n, &temp_list, node) { | |
791 | hlist_del(&p->node); | |
792 | INIT_HLIST_NODE(&p->node); | |
793 | hlist_add_head(&p->node, head); | |
794 | } | |
3d083395 SR |
795 | } |
796 | ||
750ed1a4 | 797 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
798 | ftrace_update_time = stop - start; |
799 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
ad90c0e3 | 800 | ftraced_trigger = 0; |
3d083395 | 801 | |
d61f82d0 | 802 | ftrace_enabled = save_ftrace_enabled; |
ad90c0e3 | 803 | ftrace_record_suspend--; |
16444a8a ACM |
804 | |
805 | return 0; | |
806 | } | |
807 | ||
ad90c0e3 | 808 | static int ftrace_update_code(void) |
3d083395 | 809 | { |
ad90c0e3 SR |
810 | if (unlikely(ftrace_disabled) || |
811 | !ftrace_enabled || !ftraced_trigger) | |
812 | return 0; | |
4eebcc81 | 813 | |
784e2d76 | 814 | stop_machine(__ftrace_update_code, NULL, NULL); |
ad90c0e3 SR |
815 | |
816 | return 1; | |
3d083395 SR |
817 | } |
818 | ||
68bf21aa | 819 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
820 | { |
821 | struct ftrace_page *pg; | |
822 | int cnt; | |
823 | int i; | |
3c1720f0 SR |
824 | |
825 | /* allocate a few pages */ | |
826 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
827 | if (!ftrace_pages_start) | |
828 | return -1; | |
829 | ||
830 | /* | |
831 | * Allocate a few more pages. | |
832 | * | |
833 | * TODO: have some parser search vmlinux before | |
834 | * final linking to find all calls to ftrace. | |
835 | * Then we can: | |
836 | * a) know how many pages to allocate. | |
837 | * and/or | |
838 | * b) set up the table then. | |
839 | * | |
840 | * The dynamic code is still necessary for | |
841 | * modules. | |
842 | */ | |
843 | ||
844 | pg = ftrace_pages = ftrace_pages_start; | |
845 | ||
68bf21aa SR |
846 | cnt = num_to_init / ENTRIES_PER_PAGE; |
847 | pr_info("ftrace: allocating %ld hash entries in %d pages\n", | |
848 | num_to_init, cnt); | |
3c1720f0 SR |
849 | |
850 | for (i = 0; i < cnt; i++) { | |
851 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
852 | ||
853 | /* If we fail, we'll try later anyway */ | |
854 | if (!pg->next) | |
855 | break; | |
856 | ||
857 | pg = pg->next; | |
858 | } | |
859 | ||
860 | return 0; | |
861 | } | |
862 | ||
5072c59f SR |
863 | enum { |
864 | FTRACE_ITER_FILTER = (1 << 0), | |
865 | FTRACE_ITER_CONT = (1 << 1), | |
41c52c0d | 866 | FTRACE_ITER_NOTRACE = (1 << 2), |
eb9a7bf0 | 867 | FTRACE_ITER_FAILURES = (1 << 3), |
5072c59f SR |
868 | }; |
869 | ||
870 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
871 | ||
872 | struct ftrace_iterator { | |
873 | loff_t pos; | |
874 | struct ftrace_page *pg; | |
875 | unsigned idx; | |
876 | unsigned flags; | |
877 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
878 | unsigned buffer_idx; | |
879 | unsigned filtered; | |
880 | }; | |
881 | ||
e309b41d | 882 | static void * |
5072c59f SR |
883 | t_next(struct seq_file *m, void *v, loff_t *pos) |
884 | { | |
885 | struct ftrace_iterator *iter = m->private; | |
886 | struct dyn_ftrace *rec = NULL; | |
887 | ||
888 | (*pos)++; | |
889 | ||
890 | retry: | |
891 | if (iter->idx >= iter->pg->index) { | |
892 | if (iter->pg->next) { | |
893 | iter->pg = iter->pg->next; | |
894 | iter->idx = 0; | |
895 | goto retry; | |
896 | } | |
897 | } else { | |
898 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
899 | if ((rec->flags & FTRACE_FL_FREE) || |
900 | ||
901 | (!(iter->flags & FTRACE_ITER_FAILURES) && | |
eb9a7bf0 AS |
902 | (rec->flags & FTRACE_FL_FAILED)) || |
903 | ||
904 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
a9fdda33 | 905 | !(rec->flags & FTRACE_FL_FAILED)) || |
eb9a7bf0 | 906 | |
41c52c0d SR |
907 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
908 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
909 | rec = NULL; |
910 | goto retry; | |
911 | } | |
912 | } | |
913 | ||
914 | iter->pos = *pos; | |
915 | ||
916 | return rec; | |
917 | } | |
918 | ||
919 | static void *t_start(struct seq_file *m, loff_t *pos) | |
920 | { | |
921 | struct ftrace_iterator *iter = m->private; | |
922 | void *p = NULL; | |
923 | loff_t l = -1; | |
924 | ||
925 | if (*pos != iter->pos) { | |
926 | for (p = t_next(m, p, &l); p && l < *pos; p = t_next(m, p, &l)) | |
927 | ; | |
928 | } else { | |
929 | l = *pos; | |
930 | p = t_next(m, p, &l); | |
931 | } | |
932 | ||
933 | return p; | |
934 | } | |
935 | ||
936 | static void t_stop(struct seq_file *m, void *p) | |
937 | { | |
938 | } | |
939 | ||
940 | static int t_show(struct seq_file *m, void *v) | |
941 | { | |
942 | struct dyn_ftrace *rec = v; | |
943 | char str[KSYM_SYMBOL_LEN]; | |
944 | ||
945 | if (!rec) | |
946 | return 0; | |
947 | ||
948 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
949 | ||
950 | seq_printf(m, "%s\n", str); | |
951 | ||
952 | return 0; | |
953 | } | |
954 | ||
955 | static struct seq_operations show_ftrace_seq_ops = { | |
956 | .start = t_start, | |
957 | .next = t_next, | |
958 | .stop = t_stop, | |
959 | .show = t_show, | |
960 | }; | |
961 | ||
e309b41d | 962 | static int |
5072c59f SR |
963 | ftrace_avail_open(struct inode *inode, struct file *file) |
964 | { | |
965 | struct ftrace_iterator *iter; | |
966 | int ret; | |
967 | ||
4eebcc81 SR |
968 | if (unlikely(ftrace_disabled)) |
969 | return -ENODEV; | |
970 | ||
5072c59f SR |
971 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
972 | if (!iter) | |
973 | return -ENOMEM; | |
974 | ||
975 | iter->pg = ftrace_pages_start; | |
976 | iter->pos = -1; | |
977 | ||
978 | ret = seq_open(file, &show_ftrace_seq_ops); | |
979 | if (!ret) { | |
980 | struct seq_file *m = file->private_data; | |
4bf39a94 | 981 | |
5072c59f | 982 | m->private = iter; |
4bf39a94 | 983 | } else { |
5072c59f | 984 | kfree(iter); |
4bf39a94 | 985 | } |
5072c59f SR |
986 | |
987 | return ret; | |
988 | } | |
989 | ||
990 | int ftrace_avail_release(struct inode *inode, struct file *file) | |
991 | { | |
992 | struct seq_file *m = (struct seq_file *)file->private_data; | |
993 | struct ftrace_iterator *iter = m->private; | |
994 | ||
995 | seq_release(inode, file); | |
996 | kfree(iter); | |
4bf39a94 | 997 | |
5072c59f SR |
998 | return 0; |
999 | } | |
1000 | ||
eb9a7bf0 AS |
1001 | static int |
1002 | ftrace_failures_open(struct inode *inode, struct file *file) | |
1003 | { | |
1004 | int ret; | |
1005 | struct seq_file *m; | |
1006 | struct ftrace_iterator *iter; | |
1007 | ||
1008 | ret = ftrace_avail_open(inode, file); | |
1009 | if (!ret) { | |
1010 | m = (struct seq_file *)file->private_data; | |
1011 | iter = (struct ftrace_iterator *)m->private; | |
1012 | iter->flags = FTRACE_ITER_FAILURES; | |
1013 | } | |
1014 | ||
1015 | return ret; | |
1016 | } | |
1017 | ||
1018 | ||
41c52c0d | 1019 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
1020 | { |
1021 | struct ftrace_page *pg; | |
1022 | struct dyn_ftrace *rec; | |
41c52c0d | 1023 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f SR |
1024 | unsigned i; |
1025 | ||
1026 | /* keep kstop machine from running */ | |
1027 | preempt_disable(); | |
41c52c0d SR |
1028 | if (enable) |
1029 | ftrace_filtered = 0; | |
5072c59f SR |
1030 | pg = ftrace_pages_start; |
1031 | while (pg) { | |
1032 | for (i = 0; i < pg->index; i++) { | |
1033 | rec = &pg->records[i]; | |
1034 | if (rec->flags & FTRACE_FL_FAILED) | |
1035 | continue; | |
41c52c0d | 1036 | rec->flags &= ~type; |
5072c59f SR |
1037 | } |
1038 | pg = pg->next; | |
1039 | } | |
1040 | preempt_enable(); | |
1041 | } | |
1042 | ||
e309b41d | 1043 | static int |
41c52c0d | 1044 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1045 | { |
1046 | struct ftrace_iterator *iter; | |
1047 | int ret = 0; | |
1048 | ||
4eebcc81 SR |
1049 | if (unlikely(ftrace_disabled)) |
1050 | return -ENODEV; | |
1051 | ||
5072c59f SR |
1052 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1053 | if (!iter) | |
1054 | return -ENOMEM; | |
1055 | ||
41c52c0d | 1056 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1057 | if ((file->f_mode & FMODE_WRITE) && |
1058 | !(file->f_flags & O_APPEND)) | |
41c52c0d | 1059 | ftrace_filter_reset(enable); |
5072c59f SR |
1060 | |
1061 | if (file->f_mode & FMODE_READ) { | |
1062 | iter->pg = ftrace_pages_start; | |
1063 | iter->pos = -1; | |
41c52c0d SR |
1064 | iter->flags = enable ? FTRACE_ITER_FILTER : |
1065 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
1066 | |
1067 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1068 | if (!ret) { | |
1069 | struct seq_file *m = file->private_data; | |
1070 | m->private = iter; | |
1071 | } else | |
1072 | kfree(iter); | |
1073 | } else | |
1074 | file->private_data = iter; | |
41c52c0d | 1075 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1076 | |
1077 | return ret; | |
1078 | } | |
1079 | ||
41c52c0d SR |
1080 | static int |
1081 | ftrace_filter_open(struct inode *inode, struct file *file) | |
1082 | { | |
1083 | return ftrace_regex_open(inode, file, 1); | |
1084 | } | |
1085 | ||
1086 | static int | |
1087 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
1088 | { | |
1089 | return ftrace_regex_open(inode, file, 0); | |
1090 | } | |
1091 | ||
e309b41d | 1092 | static ssize_t |
41c52c0d | 1093 | ftrace_regex_read(struct file *file, char __user *ubuf, |
5072c59f SR |
1094 | size_t cnt, loff_t *ppos) |
1095 | { | |
1096 | if (file->f_mode & FMODE_READ) | |
1097 | return seq_read(file, ubuf, cnt, ppos); | |
1098 | else | |
1099 | return -EPERM; | |
1100 | } | |
1101 | ||
e309b41d | 1102 | static loff_t |
41c52c0d | 1103 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
1104 | { |
1105 | loff_t ret; | |
1106 | ||
1107 | if (file->f_mode & FMODE_READ) | |
1108 | ret = seq_lseek(file, offset, origin); | |
1109 | else | |
1110 | file->f_pos = ret = 1; | |
1111 | ||
1112 | return ret; | |
1113 | } | |
1114 | ||
1115 | enum { | |
1116 | MATCH_FULL, | |
1117 | MATCH_FRONT_ONLY, | |
1118 | MATCH_MIDDLE_ONLY, | |
1119 | MATCH_END_ONLY, | |
1120 | }; | |
1121 | ||
e309b41d | 1122 | static void |
41c52c0d | 1123 | ftrace_match(unsigned char *buff, int len, int enable) |
5072c59f SR |
1124 | { |
1125 | char str[KSYM_SYMBOL_LEN]; | |
1126 | char *search = NULL; | |
1127 | struct ftrace_page *pg; | |
1128 | struct dyn_ftrace *rec; | |
1129 | int type = MATCH_FULL; | |
41c52c0d | 1130 | unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f SR |
1131 | unsigned i, match = 0, search_len = 0; |
1132 | ||
1133 | for (i = 0; i < len; i++) { | |
1134 | if (buff[i] == '*') { | |
1135 | if (!i) { | |
1136 | search = buff + i + 1; | |
1137 | type = MATCH_END_ONLY; | |
1138 | search_len = len - (i + 1); | |
1139 | } else { | |
1140 | if (type == MATCH_END_ONLY) { | |
1141 | type = MATCH_MIDDLE_ONLY; | |
1142 | } else { | |
1143 | match = i; | |
1144 | type = MATCH_FRONT_ONLY; | |
1145 | } | |
1146 | buff[i] = 0; | |
1147 | break; | |
1148 | } | |
1149 | } | |
1150 | } | |
1151 | ||
1152 | /* keep kstop machine from running */ | |
1153 | preempt_disable(); | |
41c52c0d SR |
1154 | if (enable) |
1155 | ftrace_filtered = 1; | |
5072c59f SR |
1156 | pg = ftrace_pages_start; |
1157 | while (pg) { | |
1158 | for (i = 0; i < pg->index; i++) { | |
1159 | int matched = 0; | |
1160 | char *ptr; | |
1161 | ||
1162 | rec = &pg->records[i]; | |
1163 | if (rec->flags & FTRACE_FL_FAILED) | |
1164 | continue; | |
1165 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1166 | switch (type) { | |
1167 | case MATCH_FULL: | |
1168 | if (strcmp(str, buff) == 0) | |
1169 | matched = 1; | |
1170 | break; | |
1171 | case MATCH_FRONT_ONLY: | |
1172 | if (memcmp(str, buff, match) == 0) | |
1173 | matched = 1; | |
1174 | break; | |
1175 | case MATCH_MIDDLE_ONLY: | |
1176 | if (strstr(str, search)) | |
1177 | matched = 1; | |
1178 | break; | |
1179 | case MATCH_END_ONLY: | |
1180 | ptr = strstr(str, search); | |
1181 | if (ptr && (ptr[search_len] == 0)) | |
1182 | matched = 1; | |
1183 | break; | |
1184 | } | |
1185 | if (matched) | |
41c52c0d | 1186 | rec->flags |= flag; |
5072c59f SR |
1187 | } |
1188 | pg = pg->next; | |
1189 | } | |
1190 | preempt_enable(); | |
1191 | } | |
1192 | ||
e309b41d | 1193 | static ssize_t |
41c52c0d SR |
1194 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
1195 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
1196 | { |
1197 | struct ftrace_iterator *iter; | |
1198 | char ch; | |
1199 | size_t read = 0; | |
1200 | ssize_t ret; | |
1201 | ||
1202 | if (!cnt || cnt < 0) | |
1203 | return 0; | |
1204 | ||
41c52c0d | 1205 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1206 | |
1207 | if (file->f_mode & FMODE_READ) { | |
1208 | struct seq_file *m = file->private_data; | |
1209 | iter = m->private; | |
1210 | } else | |
1211 | iter = file->private_data; | |
1212 | ||
1213 | if (!*ppos) { | |
1214 | iter->flags &= ~FTRACE_ITER_CONT; | |
1215 | iter->buffer_idx = 0; | |
1216 | } | |
1217 | ||
1218 | ret = get_user(ch, ubuf++); | |
1219 | if (ret) | |
1220 | goto out; | |
1221 | read++; | |
1222 | cnt--; | |
1223 | ||
1224 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { | |
1225 | /* skip white space */ | |
1226 | while (cnt && isspace(ch)) { | |
1227 | ret = get_user(ch, ubuf++); | |
1228 | if (ret) | |
1229 | goto out; | |
1230 | read++; | |
1231 | cnt--; | |
1232 | } | |
1233 | ||
5072c59f SR |
1234 | if (isspace(ch)) { |
1235 | file->f_pos += read; | |
1236 | ret = read; | |
1237 | goto out; | |
1238 | } | |
1239 | ||
1240 | iter->buffer_idx = 0; | |
1241 | } | |
1242 | ||
1243 | while (cnt && !isspace(ch)) { | |
1244 | if (iter->buffer_idx < FTRACE_BUFF_MAX) | |
1245 | iter->buffer[iter->buffer_idx++] = ch; | |
1246 | else { | |
1247 | ret = -EINVAL; | |
1248 | goto out; | |
1249 | } | |
1250 | ret = get_user(ch, ubuf++); | |
1251 | if (ret) | |
1252 | goto out; | |
1253 | read++; | |
1254 | cnt--; | |
1255 | } | |
1256 | ||
1257 | if (isspace(ch)) { | |
1258 | iter->filtered++; | |
1259 | iter->buffer[iter->buffer_idx] = 0; | |
41c52c0d | 1260 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1261 | iter->buffer_idx = 0; |
1262 | } else | |
1263 | iter->flags |= FTRACE_ITER_CONT; | |
1264 | ||
1265 | ||
1266 | file->f_pos += read; | |
1267 | ||
1268 | ret = read; | |
1269 | out: | |
41c52c0d | 1270 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1271 | |
1272 | return ret; | |
1273 | } | |
1274 | ||
41c52c0d SR |
1275 | static ssize_t |
1276 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
1277 | size_t cnt, loff_t *ppos) | |
1278 | { | |
1279 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
1280 | } | |
1281 | ||
1282 | static ssize_t | |
1283 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
1284 | size_t cnt, loff_t *ppos) | |
1285 | { | |
1286 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
1287 | } | |
1288 | ||
1289 | static void | |
1290 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
1291 | { | |
1292 | if (unlikely(ftrace_disabled)) | |
1293 | return; | |
1294 | ||
1295 | mutex_lock(&ftrace_regex_lock); | |
1296 | if (reset) | |
1297 | ftrace_filter_reset(enable); | |
1298 | if (buf) | |
1299 | ftrace_match(buf, len, enable); | |
1300 | mutex_unlock(&ftrace_regex_lock); | |
1301 | } | |
1302 | ||
77a2b37d SR |
1303 | /** |
1304 | * ftrace_set_filter - set a function to filter on in ftrace | |
1305 | * @buf - the string that holds the function filter text. | |
1306 | * @len - the length of the string. | |
1307 | * @reset - non zero to reset all filters before applying this filter. | |
1308 | * | |
1309 | * Filters denote which functions should be enabled when tracing is enabled. | |
1310 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
1311 | */ | |
e309b41d | 1312 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 1313 | { |
41c52c0d SR |
1314 | ftrace_set_regex(buf, len, reset, 1); |
1315 | } | |
4eebcc81 | 1316 | |
41c52c0d SR |
1317 | /** |
1318 | * ftrace_set_notrace - set a function to not trace in ftrace | |
1319 | * @buf - the string that holds the function notrace text. | |
1320 | * @len - the length of the string. | |
1321 | * @reset - non zero to reset all filters before applying this filter. | |
1322 | * | |
1323 | * Notrace Filters denote which functions should not be enabled when tracing | |
1324 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
1325 | * for tracing. | |
1326 | */ | |
1327 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
1328 | { | |
1329 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
1330 | } |
1331 | ||
e309b41d | 1332 | static int |
41c52c0d | 1333 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1334 | { |
1335 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1336 | struct ftrace_iterator *iter; | |
1337 | ||
41c52c0d | 1338 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1339 | if (file->f_mode & FMODE_READ) { |
1340 | iter = m->private; | |
1341 | ||
1342 | seq_release(inode, file); | |
1343 | } else | |
1344 | iter = file->private_data; | |
1345 | ||
1346 | if (iter->buffer_idx) { | |
1347 | iter->filtered++; | |
1348 | iter->buffer[iter->buffer_idx] = 0; | |
41c52c0d | 1349 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1350 | } |
1351 | ||
1352 | mutex_lock(&ftrace_sysctl_lock); | |
1353 | mutex_lock(&ftraced_lock); | |
1354 | if (iter->filtered && ftraced_suspend && ftrace_enabled) | |
1355 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); | |
1356 | mutex_unlock(&ftraced_lock); | |
1357 | mutex_unlock(&ftrace_sysctl_lock); | |
1358 | ||
1359 | kfree(iter); | |
41c52c0d | 1360 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1361 | return 0; |
1362 | } | |
1363 | ||
41c52c0d SR |
1364 | static int |
1365 | ftrace_filter_release(struct inode *inode, struct file *file) | |
1366 | { | |
1367 | return ftrace_regex_release(inode, file, 1); | |
1368 | } | |
1369 | ||
1370 | static int | |
1371 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
1372 | { | |
1373 | return ftrace_regex_release(inode, file, 0); | |
1374 | } | |
1375 | ||
ad90c0e3 SR |
1376 | static ssize_t |
1377 | ftraced_read(struct file *filp, char __user *ubuf, | |
1378 | size_t cnt, loff_t *ppos) | |
1379 | { | |
1380 | /* don't worry about races */ | |
1381 | char *buf = ftraced_stop ? "disabled\n" : "enabled\n"; | |
1382 | int r = strlen(buf); | |
1383 | ||
1384 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
1385 | } | |
1386 | ||
1387 | static ssize_t | |
1388 | ftraced_write(struct file *filp, const char __user *ubuf, | |
1389 | size_t cnt, loff_t *ppos) | |
1390 | { | |
1391 | char buf[64]; | |
1392 | long val; | |
1393 | int ret; | |
1394 | ||
1395 | if (cnt >= sizeof(buf)) | |
1396 | return -EINVAL; | |
1397 | ||
1398 | if (copy_from_user(&buf, ubuf, cnt)) | |
1399 | return -EFAULT; | |
1400 | ||
1401 | if (strncmp(buf, "enable", 6) == 0) | |
1402 | val = 1; | |
1403 | else if (strncmp(buf, "disable", 7) == 0) | |
1404 | val = 0; | |
1405 | else { | |
1406 | buf[cnt] = 0; | |
1407 | ||
1408 | ret = strict_strtoul(buf, 10, &val); | |
1409 | if (ret < 0) | |
1410 | return ret; | |
1411 | ||
1412 | val = !!val; | |
1413 | } | |
1414 | ||
1415 | if (val) | |
1416 | ftrace_enable_daemon(); | |
1417 | else | |
1418 | ftrace_disable_daemon(); | |
1419 | ||
1420 | filp->f_pos += cnt; | |
1421 | ||
1422 | return cnt; | |
1423 | } | |
1424 | ||
5072c59f SR |
1425 | static struct file_operations ftrace_avail_fops = { |
1426 | .open = ftrace_avail_open, | |
1427 | .read = seq_read, | |
1428 | .llseek = seq_lseek, | |
1429 | .release = ftrace_avail_release, | |
1430 | }; | |
1431 | ||
eb9a7bf0 AS |
1432 | static struct file_operations ftrace_failures_fops = { |
1433 | .open = ftrace_failures_open, | |
1434 | .read = seq_read, | |
1435 | .llseek = seq_lseek, | |
1436 | .release = ftrace_avail_release, | |
1437 | }; | |
1438 | ||
5072c59f SR |
1439 | static struct file_operations ftrace_filter_fops = { |
1440 | .open = ftrace_filter_open, | |
41c52c0d | 1441 | .read = ftrace_regex_read, |
5072c59f | 1442 | .write = ftrace_filter_write, |
41c52c0d | 1443 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
1444 | .release = ftrace_filter_release, |
1445 | }; | |
1446 | ||
41c52c0d SR |
1447 | static struct file_operations ftrace_notrace_fops = { |
1448 | .open = ftrace_notrace_open, | |
1449 | .read = ftrace_regex_read, | |
1450 | .write = ftrace_notrace_write, | |
1451 | .llseek = ftrace_regex_lseek, | |
1452 | .release = ftrace_notrace_release, | |
1453 | }; | |
1454 | ||
ad90c0e3 SR |
1455 | static struct file_operations ftraced_fops = { |
1456 | .open = tracing_open_generic, | |
1457 | .read = ftraced_read, | |
1458 | .write = ftraced_write, | |
1459 | }; | |
1460 | ||
e1c08bdd SR |
1461 | /** |
1462 | * ftrace_force_update - force an update to all recording ftrace functions | |
e1c08bdd SR |
1463 | */ |
1464 | int ftrace_force_update(void) | |
1465 | { | |
e1c08bdd SR |
1466 | int ret = 0; |
1467 | ||
4eebcc81 | 1468 | if (unlikely(ftrace_disabled)) |
e1c08bdd SR |
1469 | return -ENODEV; |
1470 | ||
ad90c0e3 | 1471 | mutex_lock(&ftrace_sysctl_lock); |
e1c08bdd | 1472 | mutex_lock(&ftraced_lock); |
e1c08bdd | 1473 | |
ad90c0e3 SR |
1474 | /* |
1475 | * If ftraced_trigger is not set, then there is nothing | |
1476 | * to update. | |
1477 | */ | |
1478 | if (ftraced_trigger && !ftrace_update_code()) | |
1479 | ret = -EBUSY; | |
e1c08bdd SR |
1480 | |
1481 | mutex_unlock(&ftraced_lock); | |
ad90c0e3 | 1482 | mutex_unlock(&ftrace_sysctl_lock); |
e1c08bdd SR |
1483 | |
1484 | return ret; | |
1485 | } | |
1486 | ||
4eebcc81 SR |
1487 | static void ftrace_force_shutdown(void) |
1488 | { | |
1489 | struct task_struct *task; | |
1490 | int command = FTRACE_DISABLE_CALLS | FTRACE_UPDATE_TRACE_FUNC; | |
1491 | ||
1492 | mutex_lock(&ftraced_lock); | |
1493 | task = ftraced_task; | |
1494 | ftraced_task = NULL; | |
1495 | ftraced_suspend = -1; | |
1496 | ftrace_run_update_code(command); | |
1497 | mutex_unlock(&ftraced_lock); | |
1498 | ||
1499 | if (task) | |
1500 | kthread_stop(task); | |
1501 | } | |
1502 | ||
5072c59f SR |
1503 | static __init int ftrace_init_debugfs(void) |
1504 | { | |
1505 | struct dentry *d_tracer; | |
1506 | struct dentry *entry; | |
1507 | ||
1508 | d_tracer = tracing_init_dentry(); | |
1509 | ||
1510 | entry = debugfs_create_file("available_filter_functions", 0444, | |
1511 | d_tracer, NULL, &ftrace_avail_fops); | |
1512 | if (!entry) | |
1513 | pr_warning("Could not create debugfs " | |
1514 | "'available_filter_functions' entry\n"); | |
1515 | ||
eb9a7bf0 AS |
1516 | entry = debugfs_create_file("failures", 0444, |
1517 | d_tracer, NULL, &ftrace_failures_fops); | |
1518 | if (!entry) | |
1519 | pr_warning("Could not create debugfs 'failures' entry\n"); | |
1520 | ||
5072c59f SR |
1521 | entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer, |
1522 | NULL, &ftrace_filter_fops); | |
1523 | if (!entry) | |
1524 | pr_warning("Could not create debugfs " | |
1525 | "'set_ftrace_filter' entry\n"); | |
41c52c0d SR |
1526 | |
1527 | entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer, | |
1528 | NULL, &ftrace_notrace_fops); | |
1529 | if (!entry) | |
1530 | pr_warning("Could not create debugfs " | |
1531 | "'set_ftrace_notrace' entry\n"); | |
ad90c0e3 SR |
1532 | |
1533 | entry = debugfs_create_file("ftraced_enabled", 0644, d_tracer, | |
1534 | NULL, &ftraced_fops); | |
1535 | if (!entry) | |
1536 | pr_warning("Could not create debugfs " | |
1537 | "'ftraced_enabled' entry\n"); | |
5072c59f SR |
1538 | return 0; |
1539 | } | |
1540 | ||
1541 | fs_initcall(ftrace_init_debugfs); | |
1542 | ||
68bf21aa SR |
1543 | #ifdef CONFIG_FTRACE_MCOUNT_RECORD |
1544 | static int ftrace_convert_nops(unsigned long *start, | |
1545 | unsigned long *end) | |
1546 | { | |
1547 | unsigned long *p; | |
1548 | unsigned long addr; | |
1549 | unsigned long flags; | |
1550 | ||
1551 | p = start; | |
1552 | while (p < end) { | |
1553 | addr = ftrace_call_adjust(*p++); | |
fed1939c | 1554 | spin_lock(&ftrace_lock); |
68bf21aa | 1555 | ftrace_record_ip(addr); |
fed1939c | 1556 | spin_unlock(&ftrace_lock); |
68bf21aa SR |
1557 | ftrace_shutdown_replenish(); |
1558 | } | |
1559 | ||
1560 | /* p is ignored */ | |
1561 | local_irq_save(flags); | |
1562 | __ftrace_update_code(p); | |
1563 | local_irq_restore(flags); | |
1564 | ||
1565 | return 0; | |
1566 | } | |
1567 | ||
90d595fe SR |
1568 | void ftrace_init_module(unsigned long *start, unsigned long *end) |
1569 | { | |
fed1939c SR |
1570 | if (start == end) |
1571 | return; | |
90d595fe SR |
1572 | ftrace_convert_nops(start, end); |
1573 | } | |
1574 | ||
68bf21aa SR |
1575 | extern unsigned long __start_mcount_loc[]; |
1576 | extern unsigned long __stop_mcount_loc[]; | |
1577 | ||
1578 | void __init ftrace_init(void) | |
1579 | { | |
1580 | unsigned long count, addr, flags; | |
1581 | int ret; | |
1582 | ||
1583 | /* Keep the ftrace pointer to the stub */ | |
1584 | addr = (unsigned long)ftrace_stub; | |
1585 | ||
1586 | local_irq_save(flags); | |
1587 | ftrace_dyn_arch_init(&addr); | |
1588 | local_irq_restore(flags); | |
1589 | ||
1590 | /* ftrace_dyn_arch_init places the return code in addr */ | |
1591 | if (addr) | |
1592 | goto failed; | |
1593 | ||
1594 | count = __stop_mcount_loc - __start_mcount_loc; | |
1595 | ||
1596 | ret = ftrace_dyn_table_alloc(count); | |
1597 | if (ret) | |
1598 | goto failed; | |
1599 | ||
1600 | last_ftrace_enabled = ftrace_enabled = 1; | |
1601 | ||
1602 | ret = ftrace_convert_nops(__start_mcount_loc, | |
1603 | __stop_mcount_loc); | |
1604 | ||
1605 | return; | |
1606 | failed: | |
1607 | ftrace_disabled = 1; | |
1608 | } | |
1609 | #else /* CONFIG_FTRACE_MCOUNT_RECORD */ | |
1610 | static int ftraced(void *ignore) | |
1611 | { | |
1612 | unsigned long usecs; | |
1613 | ||
1614 | while (!kthread_should_stop()) { | |
1615 | ||
1616 | set_current_state(TASK_INTERRUPTIBLE); | |
1617 | ||
1618 | /* check once a second */ | |
1619 | schedule_timeout(HZ); | |
1620 | ||
1621 | if (unlikely(ftrace_disabled)) | |
1622 | continue; | |
1623 | ||
1624 | mutex_lock(&ftrace_sysctl_lock); | |
1625 | mutex_lock(&ftraced_lock); | |
1626 | if (!ftraced_suspend && !ftraced_stop && | |
1627 | ftrace_update_code()) { | |
1628 | usecs = nsecs_to_usecs(ftrace_update_time); | |
1629 | if (ftrace_update_tot_cnt > 100000) { | |
1630 | ftrace_update_tot_cnt = 0; | |
1631 | pr_info("hm, dftrace overflow: %lu change%s" | |
1632 | " (%lu total) in %lu usec%s\n", | |
1633 | ftrace_update_cnt, | |
1634 | ftrace_update_cnt != 1 ? "s" : "", | |
1635 | ftrace_update_tot_cnt, | |
1636 | usecs, usecs != 1 ? "s" : ""); | |
1637 | ftrace_disabled = 1; | |
1638 | WARN_ON_ONCE(1); | |
1639 | } | |
1640 | } | |
1641 | mutex_unlock(&ftraced_lock); | |
1642 | mutex_unlock(&ftrace_sysctl_lock); | |
1643 | ||
1644 | ftrace_shutdown_replenish(); | |
1645 | } | |
1646 | __set_current_state(TASK_RUNNING); | |
1647 | return 0; | |
1648 | } | |
1649 | ||
e309b41d | 1650 | static int __init ftrace_dynamic_init(void) |
3d083395 SR |
1651 | { |
1652 | struct task_struct *p; | |
d61f82d0 | 1653 | unsigned long addr; |
3d083395 SR |
1654 | int ret; |
1655 | ||
d61f82d0 | 1656 | addr = (unsigned long)ftrace_record_ip; |
9ff9cdb2 | 1657 | |
784e2d76 | 1658 | stop_machine(ftrace_dyn_arch_init, &addr, NULL); |
d61f82d0 SR |
1659 | |
1660 | /* ftrace_dyn_arch_init places the return code in addr */ | |
4eebcc81 SR |
1661 | if (addr) { |
1662 | ret = (int)addr; | |
1663 | goto failed; | |
1664 | } | |
d61f82d0 | 1665 | |
68bf21aa | 1666 | ret = ftrace_dyn_table_alloc(NR_TO_INIT); |
3d083395 | 1667 | if (ret) |
4eebcc81 | 1668 | goto failed; |
3d083395 SR |
1669 | |
1670 | p = kthread_run(ftraced, NULL, "ftraced"); | |
4eebcc81 SR |
1671 | if (IS_ERR(p)) { |
1672 | ret = -1; | |
1673 | goto failed; | |
1674 | } | |
3d083395 | 1675 | |
d61f82d0 | 1676 | last_ftrace_enabled = ftrace_enabled = 1; |
e1c08bdd | 1677 | ftraced_task = p; |
3d083395 SR |
1678 | |
1679 | return 0; | |
4eebcc81 SR |
1680 | |
1681 | failed: | |
1682 | ftrace_disabled = 1; | |
1683 | return ret; | |
3d083395 SR |
1684 | } |
1685 | ||
d61f82d0 | 1686 | core_initcall(ftrace_dynamic_init); |
68bf21aa SR |
1687 | #endif /* CONFIG_FTRACE_MCOUNT_RECORD */ |
1688 | ||
3d083395 | 1689 | #else |
c7aafc54 IM |
1690 | # define ftrace_startup() do { } while (0) |
1691 | # define ftrace_shutdown() do { } while (0) | |
1692 | # define ftrace_startup_sysctl() do { } while (0) | |
1693 | # define ftrace_shutdown_sysctl() do { } while (0) | |
4eebcc81 | 1694 | # define ftrace_force_shutdown() do { } while (0) |
3d083395 SR |
1695 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
1696 | ||
a2bb6a3d SR |
1697 | /** |
1698 | * ftrace_kill_atomic - kill ftrace from critical sections | |
1699 | * | |
1700 | * This function should be used by panic code. It stops ftrace | |
1701 | * but in a not so nice way. If you need to simply kill ftrace | |
1702 | * from a non-atomic section, use ftrace_kill. | |
1703 | */ | |
1704 | void ftrace_kill_atomic(void) | |
1705 | { | |
1706 | ftrace_disabled = 1; | |
1707 | ftrace_enabled = 0; | |
b2613e37 | 1708 | #ifdef CONFIG_DYNAMIC_FTRACE |
a2bb6a3d | 1709 | ftraced_suspend = -1; |
b2613e37 | 1710 | #endif |
a2bb6a3d SR |
1711 | clear_ftrace_function(); |
1712 | } | |
1713 | ||
4eebcc81 SR |
1714 | /** |
1715 | * ftrace_kill - totally shutdown ftrace | |
1716 | * | |
1717 | * This is a safety measure. If something was detected that seems | |
1718 | * wrong, calling this function will keep ftrace from doing | |
1719 | * any more modifications, and updates. | |
1720 | * used when something went wrong. | |
1721 | */ | |
1722 | void ftrace_kill(void) | |
1723 | { | |
1724 | mutex_lock(&ftrace_sysctl_lock); | |
1725 | ftrace_disabled = 1; | |
1726 | ftrace_enabled = 0; | |
1727 | ||
1728 | clear_ftrace_function(); | |
1729 | mutex_unlock(&ftrace_sysctl_lock); | |
1730 | ||
1731 | /* Try to totally disable ftrace */ | |
1732 | ftrace_force_shutdown(); | |
1733 | } | |
1734 | ||
16444a8a | 1735 | /** |
3d083395 SR |
1736 | * register_ftrace_function - register a function for profiling |
1737 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 1738 | * |
3d083395 SR |
1739 | * Register a function to be called by all functions in the |
1740 | * kernel. | |
1741 | * | |
1742 | * Note: @ops->func and all the functions it calls must be labeled | |
1743 | * with "notrace", otherwise it will go into a | |
1744 | * recursive loop. | |
16444a8a | 1745 | */ |
3d083395 | 1746 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 1747 | { |
b0fc494f SR |
1748 | int ret; |
1749 | ||
4eebcc81 SR |
1750 | if (unlikely(ftrace_disabled)) |
1751 | return -1; | |
1752 | ||
b0fc494f | 1753 | mutex_lock(&ftrace_sysctl_lock); |
b0fc494f | 1754 | ret = __register_ftrace_function(ops); |
d61f82d0 | 1755 | ftrace_startup(); |
b0fc494f SR |
1756 | mutex_unlock(&ftrace_sysctl_lock); |
1757 | ||
1758 | return ret; | |
3d083395 SR |
1759 | } |
1760 | ||
1761 | /** | |
1762 | * unregister_ftrace_function - unresgister a function for profiling. | |
1763 | * @ops - ops structure that holds the function to unregister | |
1764 | * | |
1765 | * Unregister a function that was added to be called by ftrace profiling. | |
1766 | */ | |
1767 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
1768 | { | |
1769 | int ret; | |
1770 | ||
b0fc494f | 1771 | mutex_lock(&ftrace_sysctl_lock); |
3d083395 | 1772 | ret = __unregister_ftrace_function(ops); |
d61f82d0 | 1773 | ftrace_shutdown(); |
b0fc494f SR |
1774 | mutex_unlock(&ftrace_sysctl_lock); |
1775 | ||
1776 | return ret; | |
1777 | } | |
1778 | ||
e309b41d | 1779 | int |
b0fc494f | 1780 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
5072c59f | 1781 | struct file *file, void __user *buffer, size_t *lenp, |
b0fc494f SR |
1782 | loff_t *ppos) |
1783 | { | |
1784 | int ret; | |
1785 | ||
4eebcc81 SR |
1786 | if (unlikely(ftrace_disabled)) |
1787 | return -ENODEV; | |
1788 | ||
b0fc494f SR |
1789 | mutex_lock(&ftrace_sysctl_lock); |
1790 | ||
5072c59f | 1791 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
b0fc494f SR |
1792 | |
1793 | if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) | |
1794 | goto out; | |
1795 | ||
1796 | last_ftrace_enabled = ftrace_enabled; | |
1797 | ||
1798 | if (ftrace_enabled) { | |
1799 | ||
1800 | ftrace_startup_sysctl(); | |
1801 | ||
1802 | /* we are starting ftrace again */ | |
1803 | if (ftrace_list != &ftrace_list_end) { | |
1804 | if (ftrace_list->next == &ftrace_list_end) | |
1805 | ftrace_trace_function = ftrace_list->func; | |
1806 | else | |
1807 | ftrace_trace_function = ftrace_list_func; | |
1808 | } | |
1809 | ||
1810 | } else { | |
1811 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
1812 | ftrace_trace_function = ftrace_stub; | |
1813 | ||
1814 | ftrace_shutdown_sysctl(); | |
1815 | } | |
1816 | ||
1817 | out: | |
1818 | mutex_unlock(&ftrace_sysctl_lock); | |
3d083395 | 1819 | return ret; |
16444a8a | 1820 | } |