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> |
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 | 83 | { |
99ecdc43 | 84 | /* should not be called from interrupt context */ |
3d083395 | 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 | ||
99ecdc43 | 118 | /* should not be called from interrupt context */ |
3d083395 | 119 | spin_lock(&ftrace_lock); |
16444a8a ACM |
120 | |
121 | /* | |
3d083395 SR |
122 | * If we are removing the last function, then simply point |
123 | * to the ftrace_stub. | |
16444a8a ACM |
124 | */ |
125 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { | |
126 | ftrace_trace_function = ftrace_stub; | |
127 | ftrace_list = &ftrace_list_end; | |
128 | goto out; | |
129 | } | |
130 | ||
131 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) | |
132 | if (*p == ops) | |
133 | break; | |
134 | ||
135 | if (*p != ops) { | |
136 | ret = -1; | |
137 | goto out; | |
138 | } | |
139 | ||
140 | *p = (*p)->next; | |
141 | ||
b0fc494f SR |
142 | if (ftrace_enabled) { |
143 | /* If we only have one func left, then call that directly */ | |
144 | if (ftrace_list == &ftrace_list_end || | |
145 | ftrace_list->next == &ftrace_list_end) | |
146 | ftrace_trace_function = ftrace_list->func; | |
147 | } | |
16444a8a ACM |
148 | |
149 | out: | |
3d083395 SR |
150 | spin_unlock(&ftrace_lock); |
151 | ||
152 | return ret; | |
153 | } | |
154 | ||
155 | #ifdef CONFIG_DYNAMIC_FTRACE | |
156 | ||
99ecdc43 SR |
157 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
158 | /* | |
159 | * The hash lock is only needed when the recording of the mcount | |
160 | * callers are dynamic. That is, by the caller themselves and | |
161 | * not recorded via the compilation. | |
162 | */ | |
163 | static DEFINE_SPINLOCK(ftrace_hash_lock); | |
2d7da80f | 164 | #define ftrace_hash_lock(flags) spin_lock_irqsave(&ftrace_hash_lock, flags) |
644f991d SR |
165 | #define ftrace_hash_unlock(flags) \ |
166 | spin_unlock_irqrestore(&ftrace_hash_lock, flags) | |
99ecdc43 SR |
167 | #else |
168 | /* This is protected via the ftrace_lock with MCOUNT_RECORD. */ | |
ac8825ec | 169 | #define ftrace_hash_lock(flags) do { (void)(flags); } while (0) |
99ecdc43 SR |
170 | #define ftrace_hash_unlock(flags) do { } while(0) |
171 | #endif | |
172 | ||
71c67d58 SN |
173 | /* |
174 | * Since MCOUNT_ADDR may point to mcount itself, we do not want | |
175 | * to get it confused by reading a reference in the code as we | |
176 | * are parsing on objcopy output of text. Use a variable for | |
177 | * it instead. | |
178 | */ | |
179 | static unsigned long mcount_addr = MCOUNT_ADDR; | |
180 | ||
e1c08bdd | 181 | static struct task_struct *ftraced_task; |
e1c08bdd | 182 | |
d61f82d0 SR |
183 | enum { |
184 | FTRACE_ENABLE_CALLS = (1 << 0), | |
185 | FTRACE_DISABLE_CALLS = (1 << 1), | |
186 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
187 | FTRACE_ENABLE_MCOUNT = (1 << 3), | |
188 | FTRACE_DISABLE_MCOUNT = (1 << 4), | |
189 | }; | |
190 | ||
5072c59f | 191 | static int ftrace_filtered; |
ecea656d AS |
192 | static int tracing_on; |
193 | static int frozen_record_count; | |
5072c59f | 194 | |
3d083395 SR |
195 | static struct hlist_head ftrace_hash[FTRACE_HASHSIZE]; |
196 | ||
197 | static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu); | |
198 | ||
3d083395 | 199 | static DEFINE_MUTEX(ftraced_lock); |
41c52c0d | 200 | static DEFINE_MUTEX(ftrace_regex_lock); |
3d083395 | 201 | |
3c1720f0 SR |
202 | struct ftrace_page { |
203 | struct ftrace_page *next; | |
aa5e5cea | 204 | unsigned long index; |
3c1720f0 | 205 | struct dyn_ftrace records[]; |
aa5e5cea | 206 | }; |
3c1720f0 SR |
207 | |
208 | #define ENTRIES_PER_PAGE \ | |
209 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
210 | ||
211 | /* estimate from running different kernels */ | |
212 | #define NR_TO_INIT 10000 | |
213 | ||
214 | static struct ftrace_page *ftrace_pages_start; | |
215 | static struct ftrace_page *ftrace_pages; | |
216 | ||
3d083395 SR |
217 | static int ftraced_trigger; |
218 | static int ftraced_suspend; | |
ad90c0e3 | 219 | static int ftraced_stop; |
3d083395 SR |
220 | |
221 | static int ftrace_record_suspend; | |
222 | ||
37ad5084 SR |
223 | static struct dyn_ftrace *ftrace_free_records; |
224 | ||
ecea656d AS |
225 | |
226 | #ifdef CONFIG_KPROBES | |
227 | static inline void freeze_record(struct dyn_ftrace *rec) | |
228 | { | |
229 | if (!(rec->flags & FTRACE_FL_FROZEN)) { | |
230 | rec->flags |= FTRACE_FL_FROZEN; | |
231 | frozen_record_count++; | |
232 | } | |
233 | } | |
234 | ||
235 | static inline void unfreeze_record(struct dyn_ftrace *rec) | |
236 | { | |
237 | if (rec->flags & FTRACE_FL_FROZEN) { | |
238 | rec->flags &= ~FTRACE_FL_FROZEN; | |
239 | frozen_record_count--; | |
240 | } | |
241 | } | |
242 | ||
243 | static inline int record_frozen(struct dyn_ftrace *rec) | |
244 | { | |
245 | return rec->flags & FTRACE_FL_FROZEN; | |
246 | } | |
247 | #else | |
248 | # define freeze_record(rec) ({ 0; }) | |
249 | # define unfreeze_record(rec) ({ 0; }) | |
250 | # define record_frozen(rec) ({ 0; }) | |
251 | #endif /* CONFIG_KPROBES */ | |
252 | ||
253 | int skip_trace(unsigned long ip) | |
254 | { | |
255 | unsigned long fl; | |
256 | struct dyn_ftrace *rec; | |
257 | struct hlist_node *t; | |
258 | struct hlist_head *head; | |
259 | ||
260 | if (frozen_record_count == 0) | |
261 | return 0; | |
262 | ||
263 | head = &ftrace_hash[hash_long(ip, FTRACE_HASHBITS)]; | |
264 | hlist_for_each_entry_rcu(rec, t, head, node) { | |
265 | if (rec->ip == ip) { | |
266 | if (record_frozen(rec)) { | |
267 | if (rec->flags & FTRACE_FL_FAILED) | |
268 | return 1; | |
269 | ||
270 | if (!(rec->flags & FTRACE_FL_CONVERTED)) | |
271 | return 1; | |
272 | ||
273 | if (!tracing_on || !ftrace_enabled) | |
274 | return 1; | |
275 | ||
276 | if (ftrace_filtered) { | |
277 | fl = rec->flags & (FTRACE_FL_FILTER | | |
278 | FTRACE_FL_NOTRACE); | |
279 | if (!fl || (fl & FTRACE_FL_NOTRACE)) | |
280 | return 1; | |
281 | } | |
282 | } | |
283 | break; | |
284 | } | |
285 | } | |
286 | ||
287 | return 0; | |
288 | } | |
289 | ||
e309b41d | 290 | static inline int |
9ff9cdb2 | 291 | ftrace_ip_in_hash(unsigned long ip, unsigned long key) |
3d083395 SR |
292 | { |
293 | struct dyn_ftrace *p; | |
294 | struct hlist_node *t; | |
295 | int found = 0; | |
296 | ||
ffdaa358 | 297 | hlist_for_each_entry_rcu(p, t, &ftrace_hash[key], node) { |
3d083395 SR |
298 | if (p->ip == ip) { |
299 | found = 1; | |
300 | break; | |
301 | } | |
302 | } | |
303 | ||
304 | return found; | |
305 | } | |
306 | ||
e309b41d | 307 | static inline void |
3d083395 SR |
308 | ftrace_add_hash(struct dyn_ftrace *node, unsigned long key) |
309 | { | |
ffdaa358 | 310 | hlist_add_head_rcu(&node->node, &ftrace_hash[key]); |
3d083395 SR |
311 | } |
312 | ||
0eb96701 AS |
313 | /* called from kstop_machine */ |
314 | static inline void ftrace_del_hash(struct dyn_ftrace *node) | |
315 | { | |
316 | hlist_del(&node->node); | |
317 | } | |
318 | ||
e309b41d | 319 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
37ad5084 | 320 | { |
37ad5084 SR |
321 | rec->ip = (unsigned long)ftrace_free_records; |
322 | ftrace_free_records = rec; | |
323 | rec->flags |= FTRACE_FL_FREE; | |
324 | } | |
325 | ||
fed1939c SR |
326 | void ftrace_release(void *start, unsigned long size) |
327 | { | |
328 | struct dyn_ftrace *rec; | |
329 | struct ftrace_page *pg; | |
330 | unsigned long s = (unsigned long)start; | |
331 | unsigned long e = s + size; | |
332 | int i; | |
333 | ||
00fd61ae | 334 | if (ftrace_disabled || !start) |
fed1939c SR |
335 | return; |
336 | ||
99ecdc43 | 337 | /* should not be called from interrupt context */ |
fed1939c SR |
338 | spin_lock(&ftrace_lock); |
339 | ||
340 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
341 | for (i = 0; i < pg->index; i++) { | |
342 | rec = &pg->records[i]; | |
343 | ||
344 | if ((rec->ip >= s) && (rec->ip < e)) | |
345 | ftrace_free_rec(rec); | |
346 | } | |
347 | } | |
348 | spin_unlock(&ftrace_lock); | |
349 | ||
350 | } | |
351 | ||
e309b41d | 352 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 353 | { |
37ad5084 SR |
354 | struct dyn_ftrace *rec; |
355 | ||
356 | /* First check for freed records */ | |
357 | if (ftrace_free_records) { | |
358 | rec = ftrace_free_records; | |
359 | ||
37ad5084 SR |
360 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
361 | WARN_ON_ONCE(1); | |
362 | ftrace_free_records = NULL; | |
4eebcc81 SR |
363 | ftrace_disabled = 1; |
364 | ftrace_enabled = 0; | |
37ad5084 SR |
365 | return NULL; |
366 | } | |
367 | ||
368 | ftrace_free_records = (void *)rec->ip; | |
369 | memset(rec, 0, sizeof(*rec)); | |
370 | return rec; | |
371 | } | |
372 | ||
3c1720f0 SR |
373 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
374 | if (!ftrace_pages->next) | |
375 | return NULL; | |
376 | ftrace_pages = ftrace_pages->next; | |
377 | } | |
378 | ||
379 | return &ftrace_pages->records[ftrace_pages->index++]; | |
380 | } | |
381 | ||
e309b41d | 382 | static void |
d61f82d0 | 383 | ftrace_record_ip(unsigned long ip) |
3d083395 SR |
384 | { |
385 | struct dyn_ftrace *node; | |
386 | unsigned long flags; | |
387 | unsigned long key; | |
388 | int resched; | |
2bb6f8d6 | 389 | int cpu; |
3d083395 | 390 | |
4eebcc81 | 391 | if (!ftrace_enabled || ftrace_disabled) |
d61f82d0 SR |
392 | return; |
393 | ||
3d083395 SR |
394 | resched = need_resched(); |
395 | preempt_disable_notrace(); | |
396 | ||
2bb6f8d6 SR |
397 | /* |
398 | * We simply need to protect against recursion. | |
399 | * Use the the raw version of smp_processor_id and not | |
400 | * __get_cpu_var which can call debug hooks that can | |
401 | * cause a recursive crash here. | |
402 | */ | |
403 | cpu = raw_smp_processor_id(); | |
404 | per_cpu(ftrace_shutdown_disable_cpu, cpu)++; | |
405 | if (per_cpu(ftrace_shutdown_disable_cpu, cpu) != 1) | |
3d083395 SR |
406 | goto out; |
407 | ||
408 | if (unlikely(ftrace_record_suspend)) | |
409 | goto out; | |
410 | ||
411 | key = hash_long(ip, FTRACE_HASHBITS); | |
412 | ||
413 | WARN_ON_ONCE(key >= FTRACE_HASHSIZE); | |
414 | ||
415 | if (ftrace_ip_in_hash(ip, key)) | |
416 | goto out; | |
417 | ||
99ecdc43 | 418 | ftrace_hash_lock(flags); |
3d083395 SR |
419 | |
420 | /* This ip may have hit the hash before the lock */ | |
421 | if (ftrace_ip_in_hash(ip, key)) | |
422 | goto out_unlock; | |
423 | ||
d61f82d0 | 424 | node = ftrace_alloc_dyn_node(ip); |
3d083395 SR |
425 | if (!node) |
426 | goto out_unlock; | |
427 | ||
428 | node->ip = ip; | |
429 | ||
430 | ftrace_add_hash(node, key); | |
431 | ||
432 | ftraced_trigger = 1; | |
433 | ||
434 | out_unlock: | |
99ecdc43 | 435 | ftrace_hash_unlock(flags); |
3d083395 | 436 | out: |
2bb6f8d6 | 437 | per_cpu(ftrace_shutdown_disable_cpu, cpu)--; |
3d083395 SR |
438 | |
439 | /* prevent recursion with scheduler */ | |
440 | if (resched) | |
441 | preempt_enable_no_resched_notrace(); | |
442 | else | |
443 | preempt_enable_notrace(); | |
444 | } | |
445 | ||
caf8cdeb | 446 | #define FTRACE_ADDR ((long)(ftrace_caller)) |
3c1720f0 | 447 | |
0eb96701 | 448 | static int |
5072c59f SR |
449 | __ftrace_replace_code(struct dyn_ftrace *rec, |
450 | unsigned char *old, unsigned char *new, int enable) | |
451 | { | |
41c52c0d | 452 | unsigned long ip, fl; |
5072c59f SR |
453 | |
454 | ip = rec->ip; | |
455 | ||
456 | if (ftrace_filtered && enable) { | |
5072c59f SR |
457 | /* |
458 | * If filtering is on: | |
459 | * | |
460 | * If this record is set to be filtered and | |
461 | * is enabled then do nothing. | |
462 | * | |
463 | * If this record is set to be filtered and | |
464 | * it is not enabled, enable it. | |
465 | * | |
466 | * If this record is not set to be filtered | |
467 | * and it is not enabled do nothing. | |
468 | * | |
41c52c0d SR |
469 | * If this record is set not to trace then |
470 | * do nothing. | |
471 | * | |
a4500b84 AS |
472 | * If this record is set not to trace and |
473 | * it is enabled then disable it. | |
474 | * | |
5072c59f SR |
475 | * If this record is not set to be filtered and |
476 | * it is enabled, disable it. | |
477 | */ | |
a4500b84 AS |
478 | |
479 | fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE | | |
480 | FTRACE_FL_ENABLED); | |
5072c59f SR |
481 | |
482 | if ((fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) || | |
a4500b84 AS |
483 | (fl == (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE)) || |
484 | !fl || (fl == FTRACE_FL_NOTRACE)) | |
0eb96701 | 485 | return 0; |
5072c59f SR |
486 | |
487 | /* | |
488 | * If it is enabled disable it, | |
489 | * otherwise enable it! | |
490 | */ | |
a4500b84 | 491 | if (fl & FTRACE_FL_ENABLED) { |
5072c59f SR |
492 | /* swap new and old */ |
493 | new = old; | |
494 | old = ftrace_call_replace(ip, FTRACE_ADDR); | |
495 | rec->flags &= ~FTRACE_FL_ENABLED; | |
496 | } else { | |
497 | new = ftrace_call_replace(ip, FTRACE_ADDR); | |
498 | rec->flags |= FTRACE_FL_ENABLED; | |
499 | } | |
500 | } else { | |
501 | ||
41c52c0d SR |
502 | if (enable) { |
503 | /* | |
504 | * If this record is set not to trace and is | |
505 | * not enabled, do nothing. | |
506 | */ | |
507 | fl = rec->flags & (FTRACE_FL_NOTRACE | FTRACE_FL_ENABLED); | |
508 | if (fl == FTRACE_FL_NOTRACE) | |
0eb96701 | 509 | return 0; |
41c52c0d | 510 | |
5072c59f | 511 | new = ftrace_call_replace(ip, FTRACE_ADDR); |
41c52c0d | 512 | } else |
5072c59f SR |
513 | old = ftrace_call_replace(ip, FTRACE_ADDR); |
514 | ||
515 | if (enable) { | |
516 | if (rec->flags & FTRACE_FL_ENABLED) | |
0eb96701 | 517 | return 0; |
5072c59f SR |
518 | rec->flags |= FTRACE_FL_ENABLED; |
519 | } else { | |
520 | if (!(rec->flags & FTRACE_FL_ENABLED)) | |
0eb96701 | 521 | return 0; |
5072c59f SR |
522 | rec->flags &= ~FTRACE_FL_ENABLED; |
523 | } | |
524 | } | |
525 | ||
0eb96701 | 526 | return ftrace_modify_code(ip, old, new); |
5072c59f SR |
527 | } |
528 | ||
e309b41d | 529 | static void ftrace_replace_code(int enable) |
3c1720f0 | 530 | { |
0eb96701 | 531 | int i, failed; |
3c1720f0 SR |
532 | unsigned char *new = NULL, *old = NULL; |
533 | struct dyn_ftrace *rec; | |
534 | struct ftrace_page *pg; | |
3c1720f0 | 535 | |
5072c59f | 536 | if (enable) |
3c1720f0 SR |
537 | old = ftrace_nop_replace(); |
538 | else | |
539 | new = ftrace_nop_replace(); | |
540 | ||
541 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
542 | for (i = 0; i < pg->index; i++) { | |
543 | rec = &pg->records[i]; | |
544 | ||
545 | /* don't modify code that has already faulted */ | |
546 | if (rec->flags & FTRACE_FL_FAILED) | |
547 | continue; | |
548 | ||
f22f9a89 | 549 | /* ignore updates to this record's mcount site */ |
98a05ed4 AS |
550 | if (get_kprobe((void *)rec->ip)) { |
551 | freeze_record(rec); | |
f22f9a89 | 552 | continue; |
98a05ed4 AS |
553 | } else { |
554 | unfreeze_record(rec); | |
555 | } | |
f22f9a89 | 556 | |
0eb96701 AS |
557 | failed = __ftrace_replace_code(rec, old, new, enable); |
558 | if (failed && (rec->flags & FTRACE_FL_CONVERTED)) { | |
559 | rec->flags |= FTRACE_FL_FAILED; | |
560 | if ((system_state == SYSTEM_BOOTING) || | |
34078a5e | 561 | !core_kernel_text(rec->ip)) { |
0eb96701 AS |
562 | ftrace_del_hash(rec); |
563 | ftrace_free_rec(rec); | |
564 | } | |
565 | } | |
3c1720f0 SR |
566 | } |
567 | } | |
568 | } | |
569 | ||
e309b41d | 570 | static void ftrace_shutdown_replenish(void) |
3c1720f0 SR |
571 | { |
572 | if (ftrace_pages->next) | |
573 | return; | |
574 | ||
575 | /* allocate another page */ | |
576 | ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL); | |
577 | } | |
3d083395 | 578 | |
492a7ea5 | 579 | static int |
d61f82d0 | 580 | ftrace_code_disable(struct dyn_ftrace *rec) |
3c1720f0 SR |
581 | { |
582 | unsigned long ip; | |
583 | unsigned char *nop, *call; | |
584 | int failed; | |
585 | ||
586 | ip = rec->ip; | |
587 | ||
588 | nop = ftrace_nop_replace(); | |
3b47bfc1 | 589 | call = ftrace_call_replace(ip, mcount_addr); |
3c1720f0 SR |
590 | |
591 | failed = ftrace_modify_code(ip, call, nop); | |
37ad5084 | 592 | if (failed) { |
3c1720f0 | 593 | rec->flags |= FTRACE_FL_FAILED; |
492a7ea5 | 594 | return 0; |
37ad5084 | 595 | } |
492a7ea5 | 596 | return 1; |
3c1720f0 SR |
597 | } |
598 | ||
ad90c0e3 SR |
599 | static int __ftrace_update_code(void *ignore); |
600 | ||
e309b41d | 601 | static int __ftrace_modify_code(void *data) |
3d083395 | 602 | { |
d61f82d0 SR |
603 | unsigned long addr; |
604 | int *command = data; | |
605 | ||
ad90c0e3 SR |
606 | if (*command & FTRACE_ENABLE_CALLS) { |
607 | /* | |
608 | * Update any recorded ips now that we have the | |
609 | * machine stopped | |
610 | */ | |
611 | __ftrace_update_code(NULL); | |
d61f82d0 | 612 | ftrace_replace_code(1); |
ecea656d AS |
613 | tracing_on = 1; |
614 | } else if (*command & FTRACE_DISABLE_CALLS) { | |
d61f82d0 | 615 | ftrace_replace_code(0); |
ecea656d AS |
616 | tracing_on = 0; |
617 | } | |
d61f82d0 SR |
618 | |
619 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
620 | ftrace_update_ftrace_func(ftrace_trace_function); | |
621 | ||
622 | if (*command & FTRACE_ENABLE_MCOUNT) { | |
623 | addr = (unsigned long)ftrace_record_ip; | |
624 | ftrace_mcount_set(&addr); | |
625 | } else if (*command & FTRACE_DISABLE_MCOUNT) { | |
626 | addr = (unsigned long)ftrace_stub; | |
627 | ftrace_mcount_set(&addr); | |
628 | } | |
629 | ||
630 | return 0; | |
3d083395 SR |
631 | } |
632 | ||
e309b41d | 633 | static void ftrace_run_update_code(int command) |
3d083395 | 634 | { |
784e2d76 | 635 | stop_machine(__ftrace_modify_code, &command, NULL); |
3d083395 SR |
636 | } |
637 | ||
ad90c0e3 SR |
638 | void ftrace_disable_daemon(void) |
639 | { | |
640 | /* Stop the daemon from calling kstop_machine */ | |
641 | mutex_lock(&ftraced_lock); | |
642 | ftraced_stop = 1; | |
643 | mutex_unlock(&ftraced_lock); | |
644 | ||
645 | ftrace_force_update(); | |
646 | } | |
647 | ||
648 | void ftrace_enable_daemon(void) | |
649 | { | |
650 | mutex_lock(&ftraced_lock); | |
651 | ftraced_stop = 0; | |
652 | mutex_unlock(&ftraced_lock); | |
653 | ||
654 | ftrace_force_update(); | |
655 | } | |
656 | ||
d61f82d0 SR |
657 | static ftrace_func_t saved_ftrace_func; |
658 | ||
e309b41d | 659 | static void ftrace_startup(void) |
3d083395 | 660 | { |
d61f82d0 SR |
661 | int command = 0; |
662 | ||
4eebcc81 SR |
663 | if (unlikely(ftrace_disabled)) |
664 | return; | |
665 | ||
3d083395 SR |
666 | mutex_lock(&ftraced_lock); |
667 | ftraced_suspend++; | |
d61f82d0 SR |
668 | if (ftraced_suspend == 1) |
669 | command |= FTRACE_ENABLE_CALLS; | |
670 | ||
671 | if (saved_ftrace_func != ftrace_trace_function) { | |
672 | saved_ftrace_func = ftrace_trace_function; | |
673 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
674 | } | |
675 | ||
676 | if (!command || !ftrace_enabled) | |
3d083395 | 677 | goto out; |
3d083395 | 678 | |
d61f82d0 | 679 | ftrace_run_update_code(command); |
3d083395 SR |
680 | out: |
681 | mutex_unlock(&ftraced_lock); | |
682 | } | |
683 | ||
e309b41d | 684 | static void ftrace_shutdown(void) |
3d083395 | 685 | { |
d61f82d0 SR |
686 | int command = 0; |
687 | ||
4eebcc81 SR |
688 | if (unlikely(ftrace_disabled)) |
689 | return; | |
690 | ||
3d083395 SR |
691 | mutex_lock(&ftraced_lock); |
692 | ftraced_suspend--; | |
d61f82d0 SR |
693 | if (!ftraced_suspend) |
694 | command |= FTRACE_DISABLE_CALLS; | |
3d083395 | 695 | |
d61f82d0 SR |
696 | if (saved_ftrace_func != ftrace_trace_function) { |
697 | saved_ftrace_func = ftrace_trace_function; | |
698 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
699 | } | |
3d083395 | 700 | |
d61f82d0 SR |
701 | if (!command || !ftrace_enabled) |
702 | goto out; | |
703 | ||
704 | ftrace_run_update_code(command); | |
3d083395 SR |
705 | out: |
706 | mutex_unlock(&ftraced_lock); | |
707 | } | |
708 | ||
e309b41d | 709 | static void ftrace_startup_sysctl(void) |
b0fc494f | 710 | { |
d61f82d0 SR |
711 | int command = FTRACE_ENABLE_MCOUNT; |
712 | ||
4eebcc81 SR |
713 | if (unlikely(ftrace_disabled)) |
714 | return; | |
715 | ||
b0fc494f | 716 | mutex_lock(&ftraced_lock); |
d61f82d0 SR |
717 | /* Force update next time */ |
718 | saved_ftrace_func = NULL; | |
b0fc494f SR |
719 | /* ftraced_suspend is true if we want ftrace running */ |
720 | if (ftraced_suspend) | |
d61f82d0 SR |
721 | command |= FTRACE_ENABLE_CALLS; |
722 | ||
723 | ftrace_run_update_code(command); | |
b0fc494f SR |
724 | mutex_unlock(&ftraced_lock); |
725 | } | |
726 | ||
e309b41d | 727 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 728 | { |
d61f82d0 SR |
729 | int command = FTRACE_DISABLE_MCOUNT; |
730 | ||
4eebcc81 SR |
731 | if (unlikely(ftrace_disabled)) |
732 | return; | |
733 | ||
b0fc494f SR |
734 | mutex_lock(&ftraced_lock); |
735 | /* ftraced_suspend is true if ftrace is running */ | |
736 | if (ftraced_suspend) | |
d61f82d0 SR |
737 | command |= FTRACE_DISABLE_CALLS; |
738 | ||
739 | ftrace_run_update_code(command); | |
b0fc494f SR |
740 | mutex_unlock(&ftraced_lock); |
741 | } | |
742 | ||
3d083395 SR |
743 | static cycle_t ftrace_update_time; |
744 | static unsigned long ftrace_update_cnt; | |
745 | unsigned long ftrace_update_tot_cnt; | |
746 | ||
e309b41d | 747 | static int __ftrace_update_code(void *ignore) |
3d083395 | 748 | { |
f22f9a89 AS |
749 | int i, save_ftrace_enabled; |
750 | cycle_t start, stop; | |
3d083395 | 751 | struct dyn_ftrace *p; |
0eb96701 | 752 | struct hlist_node *t, *n; |
f22f9a89 | 753 | struct hlist_head *head, temp_list; |
3d083395 | 754 | |
d61f82d0 | 755 | /* Don't be recording funcs now */ |
ad90c0e3 | 756 | ftrace_record_suspend++; |
d61f82d0 SR |
757 | save_ftrace_enabled = ftrace_enabled; |
758 | ftrace_enabled = 0; | |
3d083395 | 759 | |
750ed1a4 | 760 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
761 | ftrace_update_cnt = 0; |
762 | ||
763 | /* No locks needed, the machine is stopped! */ | |
764 | for (i = 0; i < FTRACE_HASHSIZE; i++) { | |
f22f9a89 AS |
765 | INIT_HLIST_HEAD(&temp_list); |
766 | head = &ftrace_hash[i]; | |
767 | ||
0eb96701 | 768 | /* all CPUS are stopped, we are safe to modify code */ |
f22f9a89 | 769 | hlist_for_each_entry_safe(p, t, n, head, node) { |
0eb96701 AS |
770 | /* Skip over failed records which have not been |
771 | * freed. */ | |
772 | if (p->flags & FTRACE_FL_FAILED) | |
773 | continue; | |
3d083395 | 774 | |
0eb96701 AS |
775 | /* Unconverted records are always at the head of the |
776 | * hash bucket. Once we encounter a converted record, | |
777 | * simply skip over to the next bucket. Saves ftraced | |
778 | * some processor cycles (ftrace does its bid for | |
779 | * global warming :-p ). */ | |
780 | if (p->flags & (FTRACE_FL_CONVERTED)) | |
781 | break; | |
3d083395 | 782 | |
f22f9a89 AS |
783 | /* Ignore updates to this record's mcount site. |
784 | * Reintroduce this record at the head of this | |
785 | * bucket to attempt to "convert" it again if | |
786 | * the kprobe on it is unregistered before the | |
787 | * next run. */ | |
788 | if (get_kprobe((void *)p->ip)) { | |
789 | ftrace_del_hash(p); | |
790 | INIT_HLIST_NODE(&p->node); | |
791 | hlist_add_head(&p->node, &temp_list); | |
98a05ed4 | 792 | freeze_record(p); |
f22f9a89 | 793 | continue; |
98a05ed4 AS |
794 | } else { |
795 | unfreeze_record(p); | |
f22f9a89 AS |
796 | } |
797 | ||
798 | /* convert record (i.e, patch mcount-call with NOP) */ | |
0eb96701 AS |
799 | if (ftrace_code_disable(p)) { |
800 | p->flags |= FTRACE_FL_CONVERTED; | |
492a7ea5 | 801 | ftrace_update_cnt++; |
0eb96701 AS |
802 | } else { |
803 | if ((system_state == SYSTEM_BOOTING) || | |
34078a5e | 804 | !core_kernel_text(p->ip)) { |
0eb96701 AS |
805 | ftrace_del_hash(p); |
806 | ftrace_free_rec(p); | |
0eb96701 AS |
807 | } |
808 | } | |
3d083395 | 809 | } |
f22f9a89 AS |
810 | |
811 | hlist_for_each_entry_safe(p, t, n, &temp_list, node) { | |
812 | hlist_del(&p->node); | |
813 | INIT_HLIST_NODE(&p->node); | |
814 | hlist_add_head(&p->node, head); | |
815 | } | |
3d083395 SR |
816 | } |
817 | ||
750ed1a4 | 818 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
819 | ftrace_update_time = stop - start; |
820 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
ad90c0e3 | 821 | ftraced_trigger = 0; |
3d083395 | 822 | |
d61f82d0 | 823 | ftrace_enabled = save_ftrace_enabled; |
ad90c0e3 | 824 | ftrace_record_suspend--; |
16444a8a ACM |
825 | |
826 | return 0; | |
827 | } | |
828 | ||
ad90c0e3 | 829 | static int ftrace_update_code(void) |
3d083395 | 830 | { |
ad90c0e3 SR |
831 | if (unlikely(ftrace_disabled) || |
832 | !ftrace_enabled || !ftraced_trigger) | |
833 | return 0; | |
4eebcc81 | 834 | |
784e2d76 | 835 | stop_machine(__ftrace_update_code, NULL, NULL); |
ad90c0e3 SR |
836 | |
837 | return 1; | |
3d083395 SR |
838 | } |
839 | ||
68bf21aa | 840 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
841 | { |
842 | struct ftrace_page *pg; | |
843 | int cnt; | |
844 | int i; | |
3c1720f0 SR |
845 | |
846 | /* allocate a few pages */ | |
847 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
848 | if (!ftrace_pages_start) | |
849 | return -1; | |
850 | ||
851 | /* | |
852 | * Allocate a few more pages. | |
853 | * | |
854 | * TODO: have some parser search vmlinux before | |
855 | * final linking to find all calls to ftrace. | |
856 | * Then we can: | |
857 | * a) know how many pages to allocate. | |
858 | * and/or | |
859 | * b) set up the table then. | |
860 | * | |
861 | * The dynamic code is still necessary for | |
862 | * modules. | |
863 | */ | |
864 | ||
865 | pg = ftrace_pages = ftrace_pages_start; | |
866 | ||
68bf21aa SR |
867 | cnt = num_to_init / ENTRIES_PER_PAGE; |
868 | pr_info("ftrace: allocating %ld hash entries in %d pages\n", | |
869 | num_to_init, cnt); | |
3c1720f0 SR |
870 | |
871 | for (i = 0; i < cnt; i++) { | |
872 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
873 | ||
874 | /* If we fail, we'll try later anyway */ | |
875 | if (!pg->next) | |
876 | break; | |
877 | ||
878 | pg = pg->next; | |
879 | } | |
880 | ||
881 | return 0; | |
882 | } | |
883 | ||
5072c59f SR |
884 | enum { |
885 | FTRACE_ITER_FILTER = (1 << 0), | |
886 | FTRACE_ITER_CONT = (1 << 1), | |
41c52c0d | 887 | FTRACE_ITER_NOTRACE = (1 << 2), |
eb9a7bf0 | 888 | FTRACE_ITER_FAILURES = (1 << 3), |
5072c59f SR |
889 | }; |
890 | ||
891 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
892 | ||
893 | struct ftrace_iterator { | |
894 | loff_t pos; | |
895 | struct ftrace_page *pg; | |
896 | unsigned idx; | |
897 | unsigned flags; | |
898 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
899 | unsigned buffer_idx; | |
900 | unsigned filtered; | |
901 | }; | |
902 | ||
e309b41d | 903 | static void * |
5072c59f SR |
904 | t_next(struct seq_file *m, void *v, loff_t *pos) |
905 | { | |
906 | struct ftrace_iterator *iter = m->private; | |
907 | struct dyn_ftrace *rec = NULL; | |
908 | ||
909 | (*pos)++; | |
910 | ||
99ecdc43 SR |
911 | /* should not be called from interrupt context */ |
912 | spin_lock(&ftrace_lock); | |
5072c59f SR |
913 | retry: |
914 | if (iter->idx >= iter->pg->index) { | |
915 | if (iter->pg->next) { | |
916 | iter->pg = iter->pg->next; | |
917 | iter->idx = 0; | |
918 | goto retry; | |
919 | } | |
920 | } else { | |
921 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
922 | if ((rec->flags & FTRACE_FL_FREE) || |
923 | ||
924 | (!(iter->flags & FTRACE_ITER_FAILURES) && | |
eb9a7bf0 AS |
925 | (rec->flags & FTRACE_FL_FAILED)) || |
926 | ||
927 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
a9fdda33 | 928 | !(rec->flags & FTRACE_FL_FAILED)) || |
eb9a7bf0 | 929 | |
41c52c0d SR |
930 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
931 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
932 | rec = NULL; |
933 | goto retry; | |
934 | } | |
935 | } | |
99ecdc43 | 936 | spin_unlock(&ftrace_lock); |
5072c59f SR |
937 | |
938 | iter->pos = *pos; | |
939 | ||
940 | return rec; | |
941 | } | |
942 | ||
943 | static void *t_start(struct seq_file *m, loff_t *pos) | |
944 | { | |
945 | struct ftrace_iterator *iter = m->private; | |
946 | void *p = NULL; | |
947 | loff_t l = -1; | |
948 | ||
949 | if (*pos != iter->pos) { | |
950 | for (p = t_next(m, p, &l); p && l < *pos; p = t_next(m, p, &l)) | |
951 | ; | |
952 | } else { | |
953 | l = *pos; | |
954 | p = t_next(m, p, &l); | |
955 | } | |
956 | ||
957 | return p; | |
958 | } | |
959 | ||
960 | static void t_stop(struct seq_file *m, void *p) | |
961 | { | |
962 | } | |
963 | ||
964 | static int t_show(struct seq_file *m, void *v) | |
965 | { | |
966 | struct dyn_ftrace *rec = v; | |
967 | char str[KSYM_SYMBOL_LEN]; | |
968 | ||
969 | if (!rec) | |
970 | return 0; | |
971 | ||
972 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
973 | ||
974 | seq_printf(m, "%s\n", str); | |
975 | ||
976 | return 0; | |
977 | } | |
978 | ||
979 | static struct seq_operations show_ftrace_seq_ops = { | |
980 | .start = t_start, | |
981 | .next = t_next, | |
982 | .stop = t_stop, | |
983 | .show = t_show, | |
984 | }; | |
985 | ||
e309b41d | 986 | static int |
5072c59f SR |
987 | ftrace_avail_open(struct inode *inode, struct file *file) |
988 | { | |
989 | struct ftrace_iterator *iter; | |
990 | int ret; | |
991 | ||
4eebcc81 SR |
992 | if (unlikely(ftrace_disabled)) |
993 | return -ENODEV; | |
994 | ||
5072c59f SR |
995 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
996 | if (!iter) | |
997 | return -ENOMEM; | |
998 | ||
999 | iter->pg = ftrace_pages_start; | |
1000 | iter->pos = -1; | |
1001 | ||
1002 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1003 | if (!ret) { | |
1004 | struct seq_file *m = file->private_data; | |
4bf39a94 | 1005 | |
5072c59f | 1006 | m->private = iter; |
4bf39a94 | 1007 | } else { |
5072c59f | 1008 | kfree(iter); |
4bf39a94 | 1009 | } |
5072c59f SR |
1010 | |
1011 | return ret; | |
1012 | } | |
1013 | ||
1014 | int ftrace_avail_release(struct inode *inode, struct file *file) | |
1015 | { | |
1016 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1017 | struct ftrace_iterator *iter = m->private; | |
1018 | ||
1019 | seq_release(inode, file); | |
1020 | kfree(iter); | |
4bf39a94 | 1021 | |
5072c59f SR |
1022 | return 0; |
1023 | } | |
1024 | ||
eb9a7bf0 AS |
1025 | static int |
1026 | ftrace_failures_open(struct inode *inode, struct file *file) | |
1027 | { | |
1028 | int ret; | |
1029 | struct seq_file *m; | |
1030 | struct ftrace_iterator *iter; | |
1031 | ||
1032 | ret = ftrace_avail_open(inode, file); | |
1033 | if (!ret) { | |
1034 | m = (struct seq_file *)file->private_data; | |
1035 | iter = (struct ftrace_iterator *)m->private; | |
1036 | iter->flags = FTRACE_ITER_FAILURES; | |
1037 | } | |
1038 | ||
1039 | return ret; | |
1040 | } | |
1041 | ||
1042 | ||
41c52c0d | 1043 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
1044 | { |
1045 | struct ftrace_page *pg; | |
1046 | struct dyn_ftrace *rec; | |
41c52c0d | 1047 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f SR |
1048 | unsigned i; |
1049 | ||
99ecdc43 SR |
1050 | /* should not be called from interrupt context */ |
1051 | spin_lock(&ftrace_lock); | |
41c52c0d SR |
1052 | if (enable) |
1053 | ftrace_filtered = 0; | |
5072c59f SR |
1054 | pg = ftrace_pages_start; |
1055 | while (pg) { | |
1056 | for (i = 0; i < pg->index; i++) { | |
1057 | rec = &pg->records[i]; | |
1058 | if (rec->flags & FTRACE_FL_FAILED) | |
1059 | continue; | |
41c52c0d | 1060 | rec->flags &= ~type; |
5072c59f SR |
1061 | } |
1062 | pg = pg->next; | |
1063 | } | |
99ecdc43 | 1064 | spin_unlock(&ftrace_lock); |
5072c59f SR |
1065 | } |
1066 | ||
e309b41d | 1067 | static int |
41c52c0d | 1068 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1069 | { |
1070 | struct ftrace_iterator *iter; | |
1071 | int ret = 0; | |
1072 | ||
4eebcc81 SR |
1073 | if (unlikely(ftrace_disabled)) |
1074 | return -ENODEV; | |
1075 | ||
5072c59f SR |
1076 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1077 | if (!iter) | |
1078 | return -ENOMEM; | |
1079 | ||
41c52c0d | 1080 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1081 | if ((file->f_mode & FMODE_WRITE) && |
1082 | !(file->f_flags & O_APPEND)) | |
41c52c0d | 1083 | ftrace_filter_reset(enable); |
5072c59f SR |
1084 | |
1085 | if (file->f_mode & FMODE_READ) { | |
1086 | iter->pg = ftrace_pages_start; | |
1087 | iter->pos = -1; | |
41c52c0d SR |
1088 | iter->flags = enable ? FTRACE_ITER_FILTER : |
1089 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
1090 | |
1091 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1092 | if (!ret) { | |
1093 | struct seq_file *m = file->private_data; | |
1094 | m->private = iter; | |
1095 | } else | |
1096 | kfree(iter); | |
1097 | } else | |
1098 | file->private_data = iter; | |
41c52c0d | 1099 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1100 | |
1101 | return ret; | |
1102 | } | |
1103 | ||
41c52c0d SR |
1104 | static int |
1105 | ftrace_filter_open(struct inode *inode, struct file *file) | |
1106 | { | |
1107 | return ftrace_regex_open(inode, file, 1); | |
1108 | } | |
1109 | ||
1110 | static int | |
1111 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
1112 | { | |
1113 | return ftrace_regex_open(inode, file, 0); | |
1114 | } | |
1115 | ||
e309b41d | 1116 | static ssize_t |
41c52c0d | 1117 | ftrace_regex_read(struct file *file, char __user *ubuf, |
5072c59f SR |
1118 | size_t cnt, loff_t *ppos) |
1119 | { | |
1120 | if (file->f_mode & FMODE_READ) | |
1121 | return seq_read(file, ubuf, cnt, ppos); | |
1122 | else | |
1123 | return -EPERM; | |
1124 | } | |
1125 | ||
e309b41d | 1126 | static loff_t |
41c52c0d | 1127 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
1128 | { |
1129 | loff_t ret; | |
1130 | ||
1131 | if (file->f_mode & FMODE_READ) | |
1132 | ret = seq_lseek(file, offset, origin); | |
1133 | else | |
1134 | file->f_pos = ret = 1; | |
1135 | ||
1136 | return ret; | |
1137 | } | |
1138 | ||
1139 | enum { | |
1140 | MATCH_FULL, | |
1141 | MATCH_FRONT_ONLY, | |
1142 | MATCH_MIDDLE_ONLY, | |
1143 | MATCH_END_ONLY, | |
1144 | }; | |
1145 | ||
e309b41d | 1146 | static void |
41c52c0d | 1147 | ftrace_match(unsigned char *buff, int len, int enable) |
5072c59f SR |
1148 | { |
1149 | char str[KSYM_SYMBOL_LEN]; | |
1150 | char *search = NULL; | |
1151 | struct ftrace_page *pg; | |
1152 | struct dyn_ftrace *rec; | |
1153 | int type = MATCH_FULL; | |
41c52c0d | 1154 | unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f SR |
1155 | unsigned i, match = 0, search_len = 0; |
1156 | ||
1157 | for (i = 0; i < len; i++) { | |
1158 | if (buff[i] == '*') { | |
1159 | if (!i) { | |
1160 | search = buff + i + 1; | |
1161 | type = MATCH_END_ONLY; | |
1162 | search_len = len - (i + 1); | |
1163 | } else { | |
1164 | if (type == MATCH_END_ONLY) { | |
1165 | type = MATCH_MIDDLE_ONLY; | |
1166 | } else { | |
1167 | match = i; | |
1168 | type = MATCH_FRONT_ONLY; | |
1169 | } | |
1170 | buff[i] = 0; | |
1171 | break; | |
1172 | } | |
1173 | } | |
1174 | } | |
1175 | ||
99ecdc43 SR |
1176 | /* should not be called from interrupt context */ |
1177 | spin_lock(&ftrace_lock); | |
41c52c0d SR |
1178 | if (enable) |
1179 | ftrace_filtered = 1; | |
5072c59f SR |
1180 | pg = ftrace_pages_start; |
1181 | while (pg) { | |
1182 | for (i = 0; i < pg->index; i++) { | |
1183 | int matched = 0; | |
1184 | char *ptr; | |
1185 | ||
1186 | rec = &pg->records[i]; | |
1187 | if (rec->flags & FTRACE_FL_FAILED) | |
1188 | continue; | |
1189 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1190 | switch (type) { | |
1191 | case MATCH_FULL: | |
1192 | if (strcmp(str, buff) == 0) | |
1193 | matched = 1; | |
1194 | break; | |
1195 | case MATCH_FRONT_ONLY: | |
1196 | if (memcmp(str, buff, match) == 0) | |
1197 | matched = 1; | |
1198 | break; | |
1199 | case MATCH_MIDDLE_ONLY: | |
1200 | if (strstr(str, search)) | |
1201 | matched = 1; | |
1202 | break; | |
1203 | case MATCH_END_ONLY: | |
1204 | ptr = strstr(str, search); | |
1205 | if (ptr && (ptr[search_len] == 0)) | |
1206 | matched = 1; | |
1207 | break; | |
1208 | } | |
1209 | if (matched) | |
41c52c0d | 1210 | rec->flags |= flag; |
5072c59f SR |
1211 | } |
1212 | pg = pg->next; | |
1213 | } | |
99ecdc43 | 1214 | spin_unlock(&ftrace_lock); |
5072c59f SR |
1215 | } |
1216 | ||
e309b41d | 1217 | static ssize_t |
41c52c0d SR |
1218 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
1219 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
1220 | { |
1221 | struct ftrace_iterator *iter; | |
1222 | char ch; | |
1223 | size_t read = 0; | |
1224 | ssize_t ret; | |
1225 | ||
1226 | if (!cnt || cnt < 0) | |
1227 | return 0; | |
1228 | ||
41c52c0d | 1229 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1230 | |
1231 | if (file->f_mode & FMODE_READ) { | |
1232 | struct seq_file *m = file->private_data; | |
1233 | iter = m->private; | |
1234 | } else | |
1235 | iter = file->private_data; | |
1236 | ||
1237 | if (!*ppos) { | |
1238 | iter->flags &= ~FTRACE_ITER_CONT; | |
1239 | iter->buffer_idx = 0; | |
1240 | } | |
1241 | ||
1242 | ret = get_user(ch, ubuf++); | |
1243 | if (ret) | |
1244 | goto out; | |
1245 | read++; | |
1246 | cnt--; | |
1247 | ||
1248 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { | |
1249 | /* skip white space */ | |
1250 | while (cnt && isspace(ch)) { | |
1251 | ret = get_user(ch, ubuf++); | |
1252 | if (ret) | |
1253 | goto out; | |
1254 | read++; | |
1255 | cnt--; | |
1256 | } | |
1257 | ||
5072c59f SR |
1258 | if (isspace(ch)) { |
1259 | file->f_pos += read; | |
1260 | ret = read; | |
1261 | goto out; | |
1262 | } | |
1263 | ||
1264 | iter->buffer_idx = 0; | |
1265 | } | |
1266 | ||
1267 | while (cnt && !isspace(ch)) { | |
1268 | if (iter->buffer_idx < FTRACE_BUFF_MAX) | |
1269 | iter->buffer[iter->buffer_idx++] = ch; | |
1270 | else { | |
1271 | ret = -EINVAL; | |
1272 | goto out; | |
1273 | } | |
1274 | ret = get_user(ch, ubuf++); | |
1275 | if (ret) | |
1276 | goto out; | |
1277 | read++; | |
1278 | cnt--; | |
1279 | } | |
1280 | ||
1281 | if (isspace(ch)) { | |
1282 | iter->filtered++; | |
1283 | iter->buffer[iter->buffer_idx] = 0; | |
41c52c0d | 1284 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1285 | iter->buffer_idx = 0; |
1286 | } else | |
1287 | iter->flags |= FTRACE_ITER_CONT; | |
1288 | ||
1289 | ||
1290 | file->f_pos += read; | |
1291 | ||
1292 | ret = read; | |
1293 | out: | |
41c52c0d | 1294 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1295 | |
1296 | return ret; | |
1297 | } | |
1298 | ||
41c52c0d SR |
1299 | static ssize_t |
1300 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
1301 | size_t cnt, loff_t *ppos) | |
1302 | { | |
1303 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
1304 | } | |
1305 | ||
1306 | static ssize_t | |
1307 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
1308 | size_t cnt, loff_t *ppos) | |
1309 | { | |
1310 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
1311 | } | |
1312 | ||
1313 | static void | |
1314 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
1315 | { | |
1316 | if (unlikely(ftrace_disabled)) | |
1317 | return; | |
1318 | ||
1319 | mutex_lock(&ftrace_regex_lock); | |
1320 | if (reset) | |
1321 | ftrace_filter_reset(enable); | |
1322 | if (buf) | |
1323 | ftrace_match(buf, len, enable); | |
1324 | mutex_unlock(&ftrace_regex_lock); | |
1325 | } | |
1326 | ||
77a2b37d SR |
1327 | /** |
1328 | * ftrace_set_filter - set a function to filter on in ftrace | |
1329 | * @buf - the string that holds the function filter text. | |
1330 | * @len - the length of the string. | |
1331 | * @reset - non zero to reset all filters before applying this filter. | |
1332 | * | |
1333 | * Filters denote which functions should be enabled when tracing is enabled. | |
1334 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
1335 | */ | |
e309b41d | 1336 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 1337 | { |
41c52c0d SR |
1338 | ftrace_set_regex(buf, len, reset, 1); |
1339 | } | |
4eebcc81 | 1340 | |
41c52c0d SR |
1341 | /** |
1342 | * ftrace_set_notrace - set a function to not trace in ftrace | |
1343 | * @buf - the string that holds the function notrace text. | |
1344 | * @len - the length of the string. | |
1345 | * @reset - non zero to reset all filters before applying this filter. | |
1346 | * | |
1347 | * Notrace Filters denote which functions should not be enabled when tracing | |
1348 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
1349 | * for tracing. | |
1350 | */ | |
1351 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
1352 | { | |
1353 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
1354 | } |
1355 | ||
e309b41d | 1356 | static int |
41c52c0d | 1357 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1358 | { |
1359 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1360 | struct ftrace_iterator *iter; | |
1361 | ||
41c52c0d | 1362 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1363 | if (file->f_mode & FMODE_READ) { |
1364 | iter = m->private; | |
1365 | ||
1366 | seq_release(inode, file); | |
1367 | } else | |
1368 | iter = file->private_data; | |
1369 | ||
1370 | if (iter->buffer_idx) { | |
1371 | iter->filtered++; | |
1372 | iter->buffer[iter->buffer_idx] = 0; | |
41c52c0d | 1373 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1374 | } |
1375 | ||
1376 | mutex_lock(&ftrace_sysctl_lock); | |
1377 | mutex_lock(&ftraced_lock); | |
1378 | if (iter->filtered && ftraced_suspend && ftrace_enabled) | |
1379 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); | |
1380 | mutex_unlock(&ftraced_lock); | |
1381 | mutex_unlock(&ftrace_sysctl_lock); | |
1382 | ||
1383 | kfree(iter); | |
41c52c0d | 1384 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1385 | return 0; |
1386 | } | |
1387 | ||
41c52c0d SR |
1388 | static int |
1389 | ftrace_filter_release(struct inode *inode, struct file *file) | |
1390 | { | |
1391 | return ftrace_regex_release(inode, file, 1); | |
1392 | } | |
1393 | ||
1394 | static int | |
1395 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
1396 | { | |
1397 | return ftrace_regex_release(inode, file, 0); | |
1398 | } | |
1399 | ||
ad90c0e3 SR |
1400 | static ssize_t |
1401 | ftraced_read(struct file *filp, char __user *ubuf, | |
1402 | size_t cnt, loff_t *ppos) | |
1403 | { | |
1404 | /* don't worry about races */ | |
1405 | char *buf = ftraced_stop ? "disabled\n" : "enabled\n"; | |
1406 | int r = strlen(buf); | |
1407 | ||
1408 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
1409 | } | |
1410 | ||
1411 | static ssize_t | |
1412 | ftraced_write(struct file *filp, const char __user *ubuf, | |
1413 | size_t cnt, loff_t *ppos) | |
1414 | { | |
1415 | char buf[64]; | |
1416 | long val; | |
1417 | int ret; | |
1418 | ||
1419 | if (cnt >= sizeof(buf)) | |
1420 | return -EINVAL; | |
1421 | ||
1422 | if (copy_from_user(&buf, ubuf, cnt)) | |
1423 | return -EFAULT; | |
1424 | ||
1425 | if (strncmp(buf, "enable", 6) == 0) | |
1426 | val = 1; | |
1427 | else if (strncmp(buf, "disable", 7) == 0) | |
1428 | val = 0; | |
1429 | else { | |
1430 | buf[cnt] = 0; | |
1431 | ||
1432 | ret = strict_strtoul(buf, 10, &val); | |
1433 | if (ret < 0) | |
1434 | return ret; | |
1435 | ||
1436 | val = !!val; | |
1437 | } | |
1438 | ||
1439 | if (val) | |
1440 | ftrace_enable_daemon(); | |
1441 | else | |
1442 | ftrace_disable_daemon(); | |
1443 | ||
1444 | filp->f_pos += cnt; | |
1445 | ||
1446 | return cnt; | |
1447 | } | |
1448 | ||
5072c59f SR |
1449 | static struct file_operations ftrace_avail_fops = { |
1450 | .open = ftrace_avail_open, | |
1451 | .read = seq_read, | |
1452 | .llseek = seq_lseek, | |
1453 | .release = ftrace_avail_release, | |
1454 | }; | |
1455 | ||
eb9a7bf0 AS |
1456 | static struct file_operations ftrace_failures_fops = { |
1457 | .open = ftrace_failures_open, | |
1458 | .read = seq_read, | |
1459 | .llseek = seq_lseek, | |
1460 | .release = ftrace_avail_release, | |
1461 | }; | |
1462 | ||
5072c59f SR |
1463 | static struct file_operations ftrace_filter_fops = { |
1464 | .open = ftrace_filter_open, | |
41c52c0d | 1465 | .read = ftrace_regex_read, |
5072c59f | 1466 | .write = ftrace_filter_write, |
41c52c0d | 1467 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
1468 | .release = ftrace_filter_release, |
1469 | }; | |
1470 | ||
41c52c0d SR |
1471 | static struct file_operations ftrace_notrace_fops = { |
1472 | .open = ftrace_notrace_open, | |
1473 | .read = ftrace_regex_read, | |
1474 | .write = ftrace_notrace_write, | |
1475 | .llseek = ftrace_regex_lseek, | |
1476 | .release = ftrace_notrace_release, | |
1477 | }; | |
1478 | ||
ad90c0e3 SR |
1479 | static struct file_operations ftraced_fops = { |
1480 | .open = tracing_open_generic, | |
1481 | .read = ftraced_read, | |
1482 | .write = ftraced_write, | |
1483 | }; | |
1484 | ||
e1c08bdd SR |
1485 | /** |
1486 | * ftrace_force_update - force an update to all recording ftrace functions | |
e1c08bdd SR |
1487 | */ |
1488 | int ftrace_force_update(void) | |
1489 | { | |
e1c08bdd SR |
1490 | int ret = 0; |
1491 | ||
4eebcc81 | 1492 | if (unlikely(ftrace_disabled)) |
e1c08bdd SR |
1493 | return -ENODEV; |
1494 | ||
ad90c0e3 | 1495 | mutex_lock(&ftrace_sysctl_lock); |
e1c08bdd | 1496 | mutex_lock(&ftraced_lock); |
e1c08bdd | 1497 | |
ad90c0e3 SR |
1498 | /* |
1499 | * If ftraced_trigger is not set, then there is nothing | |
1500 | * to update. | |
1501 | */ | |
1502 | if (ftraced_trigger && !ftrace_update_code()) | |
1503 | ret = -EBUSY; | |
e1c08bdd SR |
1504 | |
1505 | mutex_unlock(&ftraced_lock); | |
ad90c0e3 | 1506 | mutex_unlock(&ftrace_sysctl_lock); |
e1c08bdd SR |
1507 | |
1508 | return ret; | |
1509 | } | |
1510 | ||
4eebcc81 SR |
1511 | static void ftrace_force_shutdown(void) |
1512 | { | |
1513 | struct task_struct *task; | |
1514 | int command = FTRACE_DISABLE_CALLS | FTRACE_UPDATE_TRACE_FUNC; | |
1515 | ||
1516 | mutex_lock(&ftraced_lock); | |
1517 | task = ftraced_task; | |
1518 | ftraced_task = NULL; | |
1519 | ftraced_suspend = -1; | |
1520 | ftrace_run_update_code(command); | |
1521 | mutex_unlock(&ftraced_lock); | |
1522 | ||
1523 | if (task) | |
1524 | kthread_stop(task); | |
1525 | } | |
1526 | ||
5072c59f SR |
1527 | static __init int ftrace_init_debugfs(void) |
1528 | { | |
1529 | struct dentry *d_tracer; | |
1530 | struct dentry *entry; | |
1531 | ||
1532 | d_tracer = tracing_init_dentry(); | |
1533 | ||
1534 | entry = debugfs_create_file("available_filter_functions", 0444, | |
1535 | d_tracer, NULL, &ftrace_avail_fops); | |
1536 | if (!entry) | |
1537 | pr_warning("Could not create debugfs " | |
1538 | "'available_filter_functions' entry\n"); | |
1539 | ||
eb9a7bf0 AS |
1540 | entry = debugfs_create_file("failures", 0444, |
1541 | d_tracer, NULL, &ftrace_failures_fops); | |
1542 | if (!entry) | |
1543 | pr_warning("Could not create debugfs 'failures' entry\n"); | |
1544 | ||
5072c59f SR |
1545 | entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer, |
1546 | NULL, &ftrace_filter_fops); | |
1547 | if (!entry) | |
1548 | pr_warning("Could not create debugfs " | |
1549 | "'set_ftrace_filter' entry\n"); | |
41c52c0d SR |
1550 | |
1551 | entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer, | |
1552 | NULL, &ftrace_notrace_fops); | |
1553 | if (!entry) | |
1554 | pr_warning("Could not create debugfs " | |
1555 | "'set_ftrace_notrace' entry\n"); | |
ad90c0e3 SR |
1556 | |
1557 | entry = debugfs_create_file("ftraced_enabled", 0644, d_tracer, | |
1558 | NULL, &ftraced_fops); | |
1559 | if (!entry) | |
1560 | pr_warning("Could not create debugfs " | |
1561 | "'ftraced_enabled' entry\n"); | |
5072c59f SR |
1562 | return 0; |
1563 | } | |
1564 | ||
1565 | fs_initcall(ftrace_init_debugfs); | |
1566 | ||
68bf21aa SR |
1567 | #ifdef CONFIG_FTRACE_MCOUNT_RECORD |
1568 | static int ftrace_convert_nops(unsigned long *start, | |
1569 | unsigned long *end) | |
1570 | { | |
1571 | unsigned long *p; | |
1572 | unsigned long addr; | |
1573 | unsigned long flags; | |
1574 | ||
1575 | p = start; | |
1576 | while (p < end) { | |
1577 | addr = ftrace_call_adjust(*p++); | |
99ecdc43 | 1578 | /* should not be called from interrupt context */ |
fed1939c | 1579 | spin_lock(&ftrace_lock); |
68bf21aa | 1580 | ftrace_record_ip(addr); |
fed1939c | 1581 | spin_unlock(&ftrace_lock); |
68bf21aa SR |
1582 | ftrace_shutdown_replenish(); |
1583 | } | |
1584 | ||
1585 | /* p is ignored */ | |
1586 | local_irq_save(flags); | |
1587 | __ftrace_update_code(p); | |
1588 | local_irq_restore(flags); | |
1589 | ||
1590 | return 0; | |
1591 | } | |
1592 | ||
90d595fe SR |
1593 | void ftrace_init_module(unsigned long *start, unsigned long *end) |
1594 | { | |
00fd61ae | 1595 | if (ftrace_disabled || start == end) |
fed1939c | 1596 | return; |
90d595fe SR |
1597 | ftrace_convert_nops(start, end); |
1598 | } | |
1599 | ||
68bf21aa SR |
1600 | extern unsigned long __start_mcount_loc[]; |
1601 | extern unsigned long __stop_mcount_loc[]; | |
1602 | ||
1603 | void __init ftrace_init(void) | |
1604 | { | |
1605 | unsigned long count, addr, flags; | |
1606 | int ret; | |
1607 | ||
1608 | /* Keep the ftrace pointer to the stub */ | |
1609 | addr = (unsigned long)ftrace_stub; | |
1610 | ||
1611 | local_irq_save(flags); | |
1612 | ftrace_dyn_arch_init(&addr); | |
1613 | local_irq_restore(flags); | |
1614 | ||
1615 | /* ftrace_dyn_arch_init places the return code in addr */ | |
1616 | if (addr) | |
1617 | goto failed; | |
1618 | ||
1619 | count = __stop_mcount_loc - __start_mcount_loc; | |
1620 | ||
1621 | ret = ftrace_dyn_table_alloc(count); | |
1622 | if (ret) | |
1623 | goto failed; | |
1624 | ||
1625 | last_ftrace_enabled = ftrace_enabled = 1; | |
1626 | ||
1627 | ret = ftrace_convert_nops(__start_mcount_loc, | |
1628 | __stop_mcount_loc); | |
1629 | ||
1630 | return; | |
1631 | failed: | |
1632 | ftrace_disabled = 1; | |
1633 | } | |
1634 | #else /* CONFIG_FTRACE_MCOUNT_RECORD */ | |
1635 | static int ftraced(void *ignore) | |
1636 | { | |
1637 | unsigned long usecs; | |
1638 | ||
1639 | while (!kthread_should_stop()) { | |
1640 | ||
1641 | set_current_state(TASK_INTERRUPTIBLE); | |
1642 | ||
1643 | /* check once a second */ | |
1644 | schedule_timeout(HZ); | |
1645 | ||
1646 | if (unlikely(ftrace_disabled)) | |
1647 | continue; | |
1648 | ||
1649 | mutex_lock(&ftrace_sysctl_lock); | |
1650 | mutex_lock(&ftraced_lock); | |
1651 | if (!ftraced_suspend && !ftraced_stop && | |
1652 | ftrace_update_code()) { | |
1653 | usecs = nsecs_to_usecs(ftrace_update_time); | |
1654 | if (ftrace_update_tot_cnt > 100000) { | |
1655 | ftrace_update_tot_cnt = 0; | |
1656 | pr_info("hm, dftrace overflow: %lu change%s" | |
1657 | " (%lu total) in %lu usec%s\n", | |
1658 | ftrace_update_cnt, | |
1659 | ftrace_update_cnt != 1 ? "s" : "", | |
1660 | ftrace_update_tot_cnt, | |
1661 | usecs, usecs != 1 ? "s" : ""); | |
1662 | ftrace_disabled = 1; | |
1663 | WARN_ON_ONCE(1); | |
1664 | } | |
1665 | } | |
1666 | mutex_unlock(&ftraced_lock); | |
1667 | mutex_unlock(&ftrace_sysctl_lock); | |
1668 | ||
1669 | ftrace_shutdown_replenish(); | |
1670 | } | |
1671 | __set_current_state(TASK_RUNNING); | |
1672 | return 0; | |
1673 | } | |
1674 | ||
e309b41d | 1675 | static int __init ftrace_dynamic_init(void) |
3d083395 SR |
1676 | { |
1677 | struct task_struct *p; | |
d61f82d0 | 1678 | unsigned long addr; |
3d083395 SR |
1679 | int ret; |
1680 | ||
d61f82d0 | 1681 | addr = (unsigned long)ftrace_record_ip; |
9ff9cdb2 | 1682 | |
784e2d76 | 1683 | stop_machine(ftrace_dyn_arch_init, &addr, NULL); |
d61f82d0 SR |
1684 | |
1685 | /* ftrace_dyn_arch_init places the return code in addr */ | |
4eebcc81 SR |
1686 | if (addr) { |
1687 | ret = (int)addr; | |
1688 | goto failed; | |
1689 | } | |
d61f82d0 | 1690 | |
68bf21aa | 1691 | ret = ftrace_dyn_table_alloc(NR_TO_INIT); |
3d083395 | 1692 | if (ret) |
4eebcc81 | 1693 | goto failed; |
3d083395 SR |
1694 | |
1695 | p = kthread_run(ftraced, NULL, "ftraced"); | |
4eebcc81 SR |
1696 | if (IS_ERR(p)) { |
1697 | ret = -1; | |
1698 | goto failed; | |
1699 | } | |
3d083395 | 1700 | |
d61f82d0 | 1701 | last_ftrace_enabled = ftrace_enabled = 1; |
e1c08bdd | 1702 | ftraced_task = p; |
3d083395 SR |
1703 | |
1704 | return 0; | |
4eebcc81 SR |
1705 | |
1706 | failed: | |
1707 | ftrace_disabled = 1; | |
1708 | return ret; | |
3d083395 SR |
1709 | } |
1710 | ||
d61f82d0 | 1711 | core_initcall(ftrace_dynamic_init); |
68bf21aa SR |
1712 | #endif /* CONFIG_FTRACE_MCOUNT_RECORD */ |
1713 | ||
3d083395 | 1714 | #else |
c7aafc54 IM |
1715 | # define ftrace_startup() do { } while (0) |
1716 | # define ftrace_shutdown() do { } while (0) | |
1717 | # define ftrace_startup_sysctl() do { } while (0) | |
1718 | # define ftrace_shutdown_sysctl() do { } while (0) | |
4eebcc81 | 1719 | # define ftrace_force_shutdown() do { } while (0) |
3d083395 SR |
1720 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
1721 | ||
a2bb6a3d SR |
1722 | /** |
1723 | * ftrace_kill_atomic - kill ftrace from critical sections | |
1724 | * | |
1725 | * This function should be used by panic code. It stops ftrace | |
1726 | * but in a not so nice way. If you need to simply kill ftrace | |
1727 | * from a non-atomic section, use ftrace_kill. | |
1728 | */ | |
1729 | void ftrace_kill_atomic(void) | |
1730 | { | |
1731 | ftrace_disabled = 1; | |
1732 | ftrace_enabled = 0; | |
b2613e37 | 1733 | #ifdef CONFIG_DYNAMIC_FTRACE |
a2bb6a3d | 1734 | ftraced_suspend = -1; |
b2613e37 | 1735 | #endif |
a2bb6a3d SR |
1736 | clear_ftrace_function(); |
1737 | } | |
1738 | ||
4eebcc81 SR |
1739 | /** |
1740 | * ftrace_kill - totally shutdown ftrace | |
1741 | * | |
1742 | * This is a safety measure. If something was detected that seems | |
1743 | * wrong, calling this function will keep ftrace from doing | |
1744 | * any more modifications, and updates. | |
1745 | * used when something went wrong. | |
1746 | */ | |
1747 | void ftrace_kill(void) | |
1748 | { | |
1749 | mutex_lock(&ftrace_sysctl_lock); | |
1750 | ftrace_disabled = 1; | |
1751 | ftrace_enabled = 0; | |
1752 | ||
1753 | clear_ftrace_function(); | |
1754 | mutex_unlock(&ftrace_sysctl_lock); | |
1755 | ||
1756 | /* Try to totally disable ftrace */ | |
1757 | ftrace_force_shutdown(); | |
1758 | } | |
1759 | ||
16444a8a | 1760 | /** |
3d083395 SR |
1761 | * register_ftrace_function - register a function for profiling |
1762 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 1763 | * |
3d083395 SR |
1764 | * Register a function to be called by all functions in the |
1765 | * kernel. | |
1766 | * | |
1767 | * Note: @ops->func and all the functions it calls must be labeled | |
1768 | * with "notrace", otherwise it will go into a | |
1769 | * recursive loop. | |
16444a8a | 1770 | */ |
3d083395 | 1771 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 1772 | { |
b0fc494f SR |
1773 | int ret; |
1774 | ||
4eebcc81 SR |
1775 | if (unlikely(ftrace_disabled)) |
1776 | return -1; | |
1777 | ||
b0fc494f | 1778 | mutex_lock(&ftrace_sysctl_lock); |
b0fc494f | 1779 | ret = __register_ftrace_function(ops); |
d61f82d0 | 1780 | ftrace_startup(); |
b0fc494f SR |
1781 | mutex_unlock(&ftrace_sysctl_lock); |
1782 | ||
1783 | return ret; | |
3d083395 SR |
1784 | } |
1785 | ||
1786 | /** | |
1787 | * unregister_ftrace_function - unresgister a function for profiling. | |
1788 | * @ops - ops structure that holds the function to unregister | |
1789 | * | |
1790 | * Unregister a function that was added to be called by ftrace profiling. | |
1791 | */ | |
1792 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
1793 | { | |
1794 | int ret; | |
1795 | ||
b0fc494f | 1796 | mutex_lock(&ftrace_sysctl_lock); |
3d083395 | 1797 | ret = __unregister_ftrace_function(ops); |
d61f82d0 | 1798 | ftrace_shutdown(); |
b0fc494f SR |
1799 | mutex_unlock(&ftrace_sysctl_lock); |
1800 | ||
1801 | return ret; | |
1802 | } | |
1803 | ||
e309b41d | 1804 | int |
b0fc494f | 1805 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
5072c59f | 1806 | struct file *file, void __user *buffer, size_t *lenp, |
b0fc494f SR |
1807 | loff_t *ppos) |
1808 | { | |
1809 | int ret; | |
1810 | ||
4eebcc81 SR |
1811 | if (unlikely(ftrace_disabled)) |
1812 | return -ENODEV; | |
1813 | ||
b0fc494f SR |
1814 | mutex_lock(&ftrace_sysctl_lock); |
1815 | ||
5072c59f | 1816 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
b0fc494f SR |
1817 | |
1818 | if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) | |
1819 | goto out; | |
1820 | ||
1821 | last_ftrace_enabled = ftrace_enabled; | |
1822 | ||
1823 | if (ftrace_enabled) { | |
1824 | ||
1825 | ftrace_startup_sysctl(); | |
1826 | ||
1827 | /* we are starting ftrace again */ | |
1828 | if (ftrace_list != &ftrace_list_end) { | |
1829 | if (ftrace_list->next == &ftrace_list_end) | |
1830 | ftrace_trace_function = ftrace_list->func; | |
1831 | else | |
1832 | ftrace_trace_function = ftrace_list_func; | |
1833 | } | |
1834 | ||
1835 | } else { | |
1836 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
1837 | ftrace_trace_function = ftrace_stub; | |
1838 | ||
1839 | ftrace_shutdown_sysctl(); | |
1840 | } | |
1841 | ||
1842 | out: | |
1843 | mutex_unlock(&ftrace_sysctl_lock); | |
3d083395 | 1844 | return ret; |
16444a8a | 1845 | } |