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 | |
6912896e SR |
35 | #define FTRACE_WARN_ON(cond) \ |
36 | do { \ | |
37 | if (WARN_ON(cond)) \ | |
38 | ftrace_kill(); \ | |
39 | } while (0) | |
40 | ||
41 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
42 | do { \ | |
43 | if (WARN_ON_ONCE(cond)) \ | |
44 | ftrace_kill(); \ | |
45 | } while (0) | |
46 | ||
4eebcc81 SR |
47 | /* ftrace_enabled is a method to turn ftrace on or off */ |
48 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 49 | static int last_ftrace_enabled; |
b0fc494f | 50 | |
4eebcc81 SR |
51 | /* |
52 | * ftrace_disabled is set when an anomaly is discovered. | |
53 | * ftrace_disabled is much stronger than ftrace_enabled. | |
54 | */ | |
55 | static int ftrace_disabled __read_mostly; | |
56 | ||
3d083395 | 57 | static DEFINE_SPINLOCK(ftrace_lock); |
b0fc494f SR |
58 | static DEFINE_MUTEX(ftrace_sysctl_lock); |
59 | ||
16444a8a ACM |
60 | static struct ftrace_ops ftrace_list_end __read_mostly = |
61 | { | |
62 | .func = ftrace_stub, | |
63 | }; | |
64 | ||
65 | static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; | |
66 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; | |
67 | ||
f2252935 | 68 | static void ftrace_list_func(unsigned long ip, unsigned long parent_ip) |
16444a8a ACM |
69 | { |
70 | struct ftrace_ops *op = ftrace_list; | |
71 | ||
72 | /* in case someone actually ports this to alpha! */ | |
73 | read_barrier_depends(); | |
74 | ||
75 | while (op != &ftrace_list_end) { | |
76 | /* silly alpha */ | |
77 | read_barrier_depends(); | |
78 | op->func(ip, parent_ip); | |
79 | op = op->next; | |
80 | }; | |
81 | } | |
82 | ||
83 | /** | |
3d083395 | 84 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 85 | * |
3d083395 SR |
86 | * This NULLs the ftrace function and in essence stops |
87 | * tracing. There may be lag | |
16444a8a | 88 | */ |
3d083395 | 89 | void clear_ftrace_function(void) |
16444a8a | 90 | { |
3d083395 SR |
91 | ftrace_trace_function = ftrace_stub; |
92 | } | |
93 | ||
e309b41d | 94 | static int __register_ftrace_function(struct ftrace_ops *ops) |
3d083395 | 95 | { |
99ecdc43 | 96 | /* should not be called from interrupt context */ |
3d083395 | 97 | spin_lock(&ftrace_lock); |
16444a8a | 98 | |
16444a8a ACM |
99 | ops->next = ftrace_list; |
100 | /* | |
101 | * We are entering ops into the ftrace_list but another | |
102 | * CPU might be walking that list. We need to make sure | |
103 | * the ops->next pointer is valid before another CPU sees | |
104 | * the ops pointer included into the ftrace_list. | |
105 | */ | |
106 | smp_wmb(); | |
107 | ftrace_list = ops; | |
3d083395 | 108 | |
b0fc494f SR |
109 | if (ftrace_enabled) { |
110 | /* | |
111 | * For one func, simply call it directly. | |
112 | * For more than one func, call the chain. | |
113 | */ | |
114 | if (ops->next == &ftrace_list_end) | |
115 | ftrace_trace_function = ops->func; | |
116 | else | |
117 | ftrace_trace_function = ftrace_list_func; | |
118 | } | |
3d083395 SR |
119 | |
120 | spin_unlock(&ftrace_lock); | |
16444a8a ACM |
121 | |
122 | return 0; | |
123 | } | |
124 | ||
e309b41d | 125 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 126 | { |
16444a8a ACM |
127 | struct ftrace_ops **p; |
128 | int ret = 0; | |
129 | ||
99ecdc43 | 130 | /* should not be called from interrupt context */ |
3d083395 | 131 | spin_lock(&ftrace_lock); |
16444a8a ACM |
132 | |
133 | /* | |
3d083395 SR |
134 | * If we are removing the last function, then simply point |
135 | * to the ftrace_stub. | |
16444a8a ACM |
136 | */ |
137 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { | |
138 | ftrace_trace_function = ftrace_stub; | |
139 | ftrace_list = &ftrace_list_end; | |
140 | goto out; | |
141 | } | |
142 | ||
143 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) | |
144 | if (*p == ops) | |
145 | break; | |
146 | ||
147 | if (*p != ops) { | |
148 | ret = -1; | |
149 | goto out; | |
150 | } | |
151 | ||
152 | *p = (*p)->next; | |
153 | ||
b0fc494f SR |
154 | if (ftrace_enabled) { |
155 | /* If we only have one func left, then call that directly */ | |
156 | if (ftrace_list == &ftrace_list_end || | |
157 | ftrace_list->next == &ftrace_list_end) | |
158 | ftrace_trace_function = ftrace_list->func; | |
159 | } | |
16444a8a ACM |
160 | |
161 | out: | |
3d083395 SR |
162 | spin_unlock(&ftrace_lock); |
163 | ||
164 | return ret; | |
165 | } | |
166 | ||
167 | #ifdef CONFIG_DYNAMIC_FTRACE | |
168 | ||
99ecdc43 SR |
169 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
170 | /* | |
171 | * The hash lock is only needed when the recording of the mcount | |
172 | * callers are dynamic. That is, by the caller themselves and | |
173 | * not recorded via the compilation. | |
174 | */ | |
175 | static DEFINE_SPINLOCK(ftrace_hash_lock); | |
2d7da80f | 176 | #define ftrace_hash_lock(flags) spin_lock_irqsave(&ftrace_hash_lock, flags) |
644f991d SR |
177 | #define ftrace_hash_unlock(flags) \ |
178 | spin_unlock_irqrestore(&ftrace_hash_lock, flags) | |
bd95b88d | 179 | static void ftrace_release_hash(unsigned long start, unsigned long end); |
99ecdc43 SR |
180 | #else |
181 | /* This is protected via the ftrace_lock with MCOUNT_RECORD. */ | |
ac8825ec | 182 | #define ftrace_hash_lock(flags) do { (void)(flags); } while (0) |
99ecdc43 | 183 | #define ftrace_hash_unlock(flags) do { } while(0) |
bd95b88d SR |
184 | static inline void ftrace_release_hash(unsigned long start, unsigned long end) |
185 | { | |
186 | } | |
99ecdc43 SR |
187 | #endif |
188 | ||
71c67d58 SN |
189 | /* |
190 | * Since MCOUNT_ADDR may point to mcount itself, we do not want | |
191 | * to get it confused by reading a reference in the code as we | |
192 | * are parsing on objcopy output of text. Use a variable for | |
193 | * it instead. | |
194 | */ | |
195 | static unsigned long mcount_addr = MCOUNT_ADDR; | |
196 | ||
e1c08bdd | 197 | static struct task_struct *ftraced_task; |
e1c08bdd | 198 | |
d61f82d0 SR |
199 | enum { |
200 | FTRACE_ENABLE_CALLS = (1 << 0), | |
201 | FTRACE_DISABLE_CALLS = (1 << 1), | |
202 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
203 | FTRACE_ENABLE_MCOUNT = (1 << 3), | |
204 | FTRACE_DISABLE_MCOUNT = (1 << 4), | |
205 | }; | |
206 | ||
5072c59f | 207 | static int ftrace_filtered; |
ecea656d AS |
208 | static int tracing_on; |
209 | static int frozen_record_count; | |
5072c59f | 210 | |
3d083395 SR |
211 | static struct hlist_head ftrace_hash[FTRACE_HASHSIZE]; |
212 | ||
213 | static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu); | |
214 | ||
3d083395 | 215 | static DEFINE_MUTEX(ftraced_lock); |
41c52c0d | 216 | static DEFINE_MUTEX(ftrace_regex_lock); |
3d083395 | 217 | |
3c1720f0 SR |
218 | struct ftrace_page { |
219 | struct ftrace_page *next; | |
aa5e5cea | 220 | unsigned long index; |
3c1720f0 | 221 | struct dyn_ftrace records[]; |
aa5e5cea | 222 | }; |
3c1720f0 SR |
223 | |
224 | #define ENTRIES_PER_PAGE \ | |
225 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
226 | ||
227 | /* estimate from running different kernels */ | |
228 | #define NR_TO_INIT 10000 | |
229 | ||
230 | static struct ftrace_page *ftrace_pages_start; | |
231 | static struct ftrace_page *ftrace_pages; | |
232 | ||
3d083395 SR |
233 | static int ftraced_trigger; |
234 | static int ftraced_suspend; | |
ad90c0e3 | 235 | static int ftraced_stop; |
3d083395 SR |
236 | |
237 | static int ftrace_record_suspend; | |
238 | ||
37ad5084 SR |
239 | static struct dyn_ftrace *ftrace_free_records; |
240 | ||
ecea656d AS |
241 | |
242 | #ifdef CONFIG_KPROBES | |
243 | static inline void freeze_record(struct dyn_ftrace *rec) | |
244 | { | |
245 | if (!(rec->flags & FTRACE_FL_FROZEN)) { | |
246 | rec->flags |= FTRACE_FL_FROZEN; | |
247 | frozen_record_count++; | |
248 | } | |
249 | } | |
250 | ||
251 | static inline void unfreeze_record(struct dyn_ftrace *rec) | |
252 | { | |
253 | if (rec->flags & FTRACE_FL_FROZEN) { | |
254 | rec->flags &= ~FTRACE_FL_FROZEN; | |
255 | frozen_record_count--; | |
256 | } | |
257 | } | |
258 | ||
259 | static inline int record_frozen(struct dyn_ftrace *rec) | |
260 | { | |
261 | return rec->flags & FTRACE_FL_FROZEN; | |
262 | } | |
263 | #else | |
264 | # define freeze_record(rec) ({ 0; }) | |
265 | # define unfreeze_record(rec) ({ 0; }) | |
266 | # define record_frozen(rec) ({ 0; }) | |
267 | #endif /* CONFIG_KPROBES */ | |
268 | ||
269 | int skip_trace(unsigned long ip) | |
270 | { | |
271 | unsigned long fl; | |
272 | struct dyn_ftrace *rec; | |
273 | struct hlist_node *t; | |
274 | struct hlist_head *head; | |
275 | ||
276 | if (frozen_record_count == 0) | |
277 | return 0; | |
278 | ||
279 | head = &ftrace_hash[hash_long(ip, FTRACE_HASHBITS)]; | |
280 | hlist_for_each_entry_rcu(rec, t, head, node) { | |
281 | if (rec->ip == ip) { | |
282 | if (record_frozen(rec)) { | |
283 | if (rec->flags & FTRACE_FL_FAILED) | |
284 | return 1; | |
285 | ||
286 | if (!(rec->flags & FTRACE_FL_CONVERTED)) | |
287 | return 1; | |
288 | ||
289 | if (!tracing_on || !ftrace_enabled) | |
290 | return 1; | |
291 | ||
292 | if (ftrace_filtered) { | |
293 | fl = rec->flags & (FTRACE_FL_FILTER | | |
294 | FTRACE_FL_NOTRACE); | |
295 | if (!fl || (fl & FTRACE_FL_NOTRACE)) | |
296 | return 1; | |
297 | } | |
298 | } | |
299 | break; | |
300 | } | |
301 | } | |
302 | ||
303 | return 0; | |
304 | } | |
305 | ||
e309b41d | 306 | static inline int |
9ff9cdb2 | 307 | ftrace_ip_in_hash(unsigned long ip, unsigned long key) |
3d083395 SR |
308 | { |
309 | struct dyn_ftrace *p; | |
310 | struct hlist_node *t; | |
311 | int found = 0; | |
312 | ||
ffdaa358 | 313 | hlist_for_each_entry_rcu(p, t, &ftrace_hash[key], node) { |
3d083395 SR |
314 | if (p->ip == ip) { |
315 | found = 1; | |
316 | break; | |
317 | } | |
318 | } | |
319 | ||
320 | return found; | |
321 | } | |
322 | ||
e309b41d | 323 | static inline void |
3d083395 SR |
324 | ftrace_add_hash(struct dyn_ftrace *node, unsigned long key) |
325 | { | |
ffdaa358 | 326 | hlist_add_head_rcu(&node->node, &ftrace_hash[key]); |
3d083395 SR |
327 | } |
328 | ||
0eb96701 AS |
329 | /* called from kstop_machine */ |
330 | static inline void ftrace_del_hash(struct dyn_ftrace *node) | |
331 | { | |
332 | hlist_del(&node->node); | |
333 | } | |
334 | ||
e309b41d | 335 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
37ad5084 | 336 | { |
37ad5084 SR |
337 | rec->ip = (unsigned long)ftrace_free_records; |
338 | ftrace_free_records = rec; | |
339 | rec->flags |= FTRACE_FL_FREE; | |
340 | } | |
341 | ||
fed1939c SR |
342 | void ftrace_release(void *start, unsigned long size) |
343 | { | |
344 | struct dyn_ftrace *rec; | |
345 | struct ftrace_page *pg; | |
346 | unsigned long s = (unsigned long)start; | |
347 | unsigned long e = s + size; | |
348 | int i; | |
349 | ||
00fd61ae | 350 | if (ftrace_disabled || !start) |
fed1939c SR |
351 | return; |
352 | ||
99ecdc43 | 353 | /* should not be called from interrupt context */ |
fed1939c SR |
354 | spin_lock(&ftrace_lock); |
355 | ||
356 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
357 | for (i = 0; i < pg->index; i++) { | |
358 | rec = &pg->records[i]; | |
359 | ||
360 | if ((rec->ip >= s) && (rec->ip < e)) | |
361 | ftrace_free_rec(rec); | |
362 | } | |
363 | } | |
364 | spin_unlock(&ftrace_lock); | |
365 | ||
bd95b88d | 366 | ftrace_release_hash(s, e); |
fed1939c SR |
367 | } |
368 | ||
e309b41d | 369 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 370 | { |
37ad5084 SR |
371 | struct dyn_ftrace *rec; |
372 | ||
373 | /* First check for freed records */ | |
374 | if (ftrace_free_records) { | |
375 | rec = ftrace_free_records; | |
376 | ||
37ad5084 | 377 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
6912896e | 378 | FTRACE_WARN_ON_ONCE(1); |
37ad5084 SR |
379 | ftrace_free_records = NULL; |
380 | return NULL; | |
381 | } | |
382 | ||
383 | ftrace_free_records = (void *)rec->ip; | |
384 | memset(rec, 0, sizeof(*rec)); | |
385 | return rec; | |
386 | } | |
387 | ||
3c1720f0 SR |
388 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
389 | if (!ftrace_pages->next) | |
390 | return NULL; | |
391 | ftrace_pages = ftrace_pages->next; | |
392 | } | |
393 | ||
394 | return &ftrace_pages->records[ftrace_pages->index++]; | |
395 | } | |
396 | ||
e309b41d | 397 | static void |
d61f82d0 | 398 | ftrace_record_ip(unsigned long ip) |
3d083395 SR |
399 | { |
400 | struct dyn_ftrace *node; | |
401 | unsigned long flags; | |
402 | unsigned long key; | |
403 | int resched; | |
2bb6f8d6 | 404 | int cpu; |
3d083395 | 405 | |
4eebcc81 | 406 | if (!ftrace_enabled || ftrace_disabled) |
d61f82d0 SR |
407 | return; |
408 | ||
3d083395 SR |
409 | resched = need_resched(); |
410 | preempt_disable_notrace(); | |
411 | ||
2bb6f8d6 SR |
412 | /* |
413 | * We simply need to protect against recursion. | |
414 | * Use the the raw version of smp_processor_id and not | |
415 | * __get_cpu_var which can call debug hooks that can | |
416 | * cause a recursive crash here. | |
417 | */ | |
418 | cpu = raw_smp_processor_id(); | |
419 | per_cpu(ftrace_shutdown_disable_cpu, cpu)++; | |
420 | if (per_cpu(ftrace_shutdown_disable_cpu, cpu) != 1) | |
3d083395 SR |
421 | goto out; |
422 | ||
423 | if (unlikely(ftrace_record_suspend)) | |
424 | goto out; | |
425 | ||
426 | key = hash_long(ip, FTRACE_HASHBITS); | |
427 | ||
6912896e | 428 | FTRACE_WARN_ON_ONCE(key >= FTRACE_HASHSIZE); |
3d083395 SR |
429 | |
430 | if (ftrace_ip_in_hash(ip, key)) | |
431 | goto out; | |
432 | ||
99ecdc43 | 433 | ftrace_hash_lock(flags); |
3d083395 SR |
434 | |
435 | /* This ip may have hit the hash before the lock */ | |
436 | if (ftrace_ip_in_hash(ip, key)) | |
437 | goto out_unlock; | |
438 | ||
d61f82d0 | 439 | node = ftrace_alloc_dyn_node(ip); |
3d083395 SR |
440 | if (!node) |
441 | goto out_unlock; | |
442 | ||
443 | node->ip = ip; | |
444 | ||
445 | ftrace_add_hash(node, key); | |
446 | ||
447 | ftraced_trigger = 1; | |
448 | ||
449 | out_unlock: | |
99ecdc43 | 450 | ftrace_hash_unlock(flags); |
3d083395 | 451 | out: |
2bb6f8d6 | 452 | per_cpu(ftrace_shutdown_disable_cpu, cpu)--; |
3d083395 SR |
453 | |
454 | /* prevent recursion with scheduler */ | |
455 | if (resched) | |
456 | preempt_enable_no_resched_notrace(); | |
457 | else | |
458 | preempt_enable_notrace(); | |
459 | } | |
460 | ||
caf8cdeb | 461 | #define FTRACE_ADDR ((long)(ftrace_caller)) |
3c1720f0 | 462 | |
0eb96701 | 463 | static int |
5072c59f SR |
464 | __ftrace_replace_code(struct dyn_ftrace *rec, |
465 | unsigned char *old, unsigned char *new, int enable) | |
466 | { | |
41c52c0d | 467 | unsigned long ip, fl; |
5072c59f SR |
468 | |
469 | ip = rec->ip; | |
470 | ||
471 | if (ftrace_filtered && enable) { | |
5072c59f SR |
472 | /* |
473 | * If filtering is on: | |
474 | * | |
475 | * If this record is set to be filtered and | |
476 | * is enabled then do nothing. | |
477 | * | |
478 | * If this record is set to be filtered and | |
479 | * it is not enabled, enable it. | |
480 | * | |
481 | * If this record is not set to be filtered | |
482 | * and it is not enabled do nothing. | |
483 | * | |
41c52c0d SR |
484 | * If this record is set not to trace then |
485 | * do nothing. | |
486 | * | |
a4500b84 AS |
487 | * If this record is set not to trace and |
488 | * it is enabled then disable it. | |
489 | * | |
5072c59f SR |
490 | * If this record is not set to be filtered and |
491 | * it is enabled, disable it. | |
492 | */ | |
a4500b84 AS |
493 | |
494 | fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE | | |
495 | FTRACE_FL_ENABLED); | |
5072c59f SR |
496 | |
497 | if ((fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) || | |
a4500b84 AS |
498 | (fl == (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE)) || |
499 | !fl || (fl == FTRACE_FL_NOTRACE)) | |
0eb96701 | 500 | return 0; |
5072c59f SR |
501 | |
502 | /* | |
503 | * If it is enabled disable it, | |
504 | * otherwise enable it! | |
505 | */ | |
a4500b84 | 506 | if (fl & FTRACE_FL_ENABLED) { |
5072c59f SR |
507 | /* swap new and old */ |
508 | new = old; | |
509 | old = ftrace_call_replace(ip, FTRACE_ADDR); | |
510 | rec->flags &= ~FTRACE_FL_ENABLED; | |
511 | } else { | |
512 | new = ftrace_call_replace(ip, FTRACE_ADDR); | |
513 | rec->flags |= FTRACE_FL_ENABLED; | |
514 | } | |
515 | } else { | |
516 | ||
41c52c0d SR |
517 | if (enable) { |
518 | /* | |
519 | * If this record is set not to trace and is | |
520 | * not enabled, do nothing. | |
521 | */ | |
522 | fl = rec->flags & (FTRACE_FL_NOTRACE | FTRACE_FL_ENABLED); | |
523 | if (fl == FTRACE_FL_NOTRACE) | |
0eb96701 | 524 | return 0; |
41c52c0d | 525 | |
5072c59f | 526 | new = ftrace_call_replace(ip, FTRACE_ADDR); |
41c52c0d | 527 | } else |
5072c59f SR |
528 | old = ftrace_call_replace(ip, FTRACE_ADDR); |
529 | ||
530 | if (enable) { | |
531 | if (rec->flags & FTRACE_FL_ENABLED) | |
0eb96701 | 532 | return 0; |
5072c59f SR |
533 | rec->flags |= FTRACE_FL_ENABLED; |
534 | } else { | |
535 | if (!(rec->flags & FTRACE_FL_ENABLED)) | |
0eb96701 | 536 | return 0; |
5072c59f SR |
537 | rec->flags &= ~FTRACE_FL_ENABLED; |
538 | } | |
539 | } | |
540 | ||
0eb96701 | 541 | return ftrace_modify_code(ip, old, new); |
5072c59f SR |
542 | } |
543 | ||
e309b41d | 544 | static void ftrace_replace_code(int enable) |
3c1720f0 | 545 | { |
0eb96701 | 546 | int i, failed; |
3c1720f0 SR |
547 | unsigned char *new = NULL, *old = NULL; |
548 | struct dyn_ftrace *rec; | |
549 | struct ftrace_page *pg; | |
3c1720f0 | 550 | |
5072c59f | 551 | if (enable) |
3c1720f0 SR |
552 | old = ftrace_nop_replace(); |
553 | else | |
554 | new = ftrace_nop_replace(); | |
555 | ||
556 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
557 | for (i = 0; i < pg->index; i++) { | |
558 | rec = &pg->records[i]; | |
559 | ||
560 | /* don't modify code that has already faulted */ | |
561 | if (rec->flags & FTRACE_FL_FAILED) | |
562 | continue; | |
563 | ||
f22f9a89 | 564 | /* ignore updates to this record's mcount site */ |
98a05ed4 AS |
565 | if (get_kprobe((void *)rec->ip)) { |
566 | freeze_record(rec); | |
f22f9a89 | 567 | continue; |
98a05ed4 AS |
568 | } else { |
569 | unfreeze_record(rec); | |
570 | } | |
f22f9a89 | 571 | |
0eb96701 AS |
572 | failed = __ftrace_replace_code(rec, old, new, enable); |
573 | if (failed && (rec->flags & FTRACE_FL_CONVERTED)) { | |
574 | rec->flags |= FTRACE_FL_FAILED; | |
575 | if ((system_state == SYSTEM_BOOTING) || | |
34078a5e | 576 | !core_kernel_text(rec->ip)) { |
0eb96701 AS |
577 | ftrace_del_hash(rec); |
578 | ftrace_free_rec(rec); | |
579 | } | |
580 | } | |
3c1720f0 SR |
581 | } |
582 | } | |
583 | } | |
584 | ||
e309b41d | 585 | static void ftrace_shutdown_replenish(void) |
3c1720f0 SR |
586 | { |
587 | if (ftrace_pages->next) | |
588 | return; | |
589 | ||
590 | /* allocate another page */ | |
591 | ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL); | |
592 | } | |
3d083395 | 593 | |
05736a42 SR |
594 | static void print_ip_ins(const char *fmt, unsigned char *p) |
595 | { | |
596 | int i; | |
597 | ||
598 | printk(KERN_CONT "%s", fmt); | |
599 | ||
600 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
601 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
602 | } | |
603 | ||
492a7ea5 | 604 | static int |
d61f82d0 | 605 | ftrace_code_disable(struct dyn_ftrace *rec) |
3c1720f0 SR |
606 | { |
607 | unsigned long ip; | |
608 | unsigned char *nop, *call; | |
593eb8a2 | 609 | int ret; |
3c1720f0 SR |
610 | |
611 | ip = rec->ip; | |
612 | ||
613 | nop = ftrace_nop_replace(); | |
3b47bfc1 | 614 | call = ftrace_call_replace(ip, mcount_addr); |
3c1720f0 | 615 | |
593eb8a2 SR |
616 | ret = ftrace_modify_code(ip, call, nop); |
617 | if (ret) { | |
618 | switch (ret) { | |
619 | case -EFAULT: | |
6912896e | 620 | FTRACE_WARN_ON_ONCE(1); |
05736a42 SR |
621 | pr_info("ftrace faulted on modifying "); |
622 | print_ip_sym(ip); | |
623 | break; | |
593eb8a2 | 624 | case -EINVAL: |
6912896e | 625 | FTRACE_WARN_ON_ONCE(1); |
05736a42 SR |
626 | pr_info("ftrace failed to modify "); |
627 | print_ip_sym(ip); | |
628 | print_ip_ins(" expected: ", call); | |
629 | print_ip_ins(" actual: ", (unsigned char *)ip); | |
630 | print_ip_ins(" replace: ", nop); | |
631 | printk(KERN_CONT "\n"); | |
632 | break; | |
593eb8a2 | 633 | case -EPERM: |
6912896e | 634 | FTRACE_WARN_ON_ONCE(1); |
593eb8a2 SR |
635 | pr_info("ftrace faulted on writing "); |
636 | print_ip_sym(ip); | |
637 | break; | |
638 | default: | |
6912896e | 639 | FTRACE_WARN_ON_ONCE(1); |
593eb8a2 SR |
640 | pr_info("ftrace faulted on unknown error "); |
641 | print_ip_sym(ip); | |
05736a42 SR |
642 | } |
643 | ||
3c1720f0 | 644 | rec->flags |= FTRACE_FL_FAILED; |
492a7ea5 | 645 | return 0; |
37ad5084 | 646 | } |
492a7ea5 | 647 | return 1; |
3c1720f0 SR |
648 | } |
649 | ||
ad90c0e3 SR |
650 | static int __ftrace_update_code(void *ignore); |
651 | ||
e309b41d | 652 | static int __ftrace_modify_code(void *data) |
3d083395 | 653 | { |
d61f82d0 SR |
654 | unsigned long addr; |
655 | int *command = data; | |
656 | ||
ad90c0e3 SR |
657 | if (*command & FTRACE_ENABLE_CALLS) { |
658 | /* | |
659 | * Update any recorded ips now that we have the | |
660 | * machine stopped | |
661 | */ | |
662 | __ftrace_update_code(NULL); | |
d61f82d0 | 663 | ftrace_replace_code(1); |
ecea656d AS |
664 | tracing_on = 1; |
665 | } else if (*command & FTRACE_DISABLE_CALLS) { | |
d61f82d0 | 666 | ftrace_replace_code(0); |
ecea656d AS |
667 | tracing_on = 0; |
668 | } | |
d61f82d0 SR |
669 | |
670 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
671 | ftrace_update_ftrace_func(ftrace_trace_function); | |
672 | ||
673 | if (*command & FTRACE_ENABLE_MCOUNT) { | |
674 | addr = (unsigned long)ftrace_record_ip; | |
675 | ftrace_mcount_set(&addr); | |
676 | } else if (*command & FTRACE_DISABLE_MCOUNT) { | |
677 | addr = (unsigned long)ftrace_stub; | |
678 | ftrace_mcount_set(&addr); | |
679 | } | |
680 | ||
681 | return 0; | |
3d083395 SR |
682 | } |
683 | ||
e309b41d | 684 | static void ftrace_run_update_code(int command) |
3d083395 | 685 | { |
784e2d76 | 686 | stop_machine(__ftrace_modify_code, &command, NULL); |
3d083395 SR |
687 | } |
688 | ||
ad90c0e3 SR |
689 | void ftrace_disable_daemon(void) |
690 | { | |
691 | /* Stop the daemon from calling kstop_machine */ | |
692 | mutex_lock(&ftraced_lock); | |
693 | ftraced_stop = 1; | |
694 | mutex_unlock(&ftraced_lock); | |
695 | ||
696 | ftrace_force_update(); | |
697 | } | |
698 | ||
699 | void ftrace_enable_daemon(void) | |
700 | { | |
701 | mutex_lock(&ftraced_lock); | |
702 | ftraced_stop = 0; | |
703 | mutex_unlock(&ftraced_lock); | |
704 | ||
705 | ftrace_force_update(); | |
706 | } | |
707 | ||
d61f82d0 SR |
708 | static ftrace_func_t saved_ftrace_func; |
709 | ||
e309b41d | 710 | static void ftrace_startup(void) |
3d083395 | 711 | { |
d61f82d0 SR |
712 | int command = 0; |
713 | ||
4eebcc81 SR |
714 | if (unlikely(ftrace_disabled)) |
715 | return; | |
716 | ||
3d083395 SR |
717 | mutex_lock(&ftraced_lock); |
718 | ftraced_suspend++; | |
d61f82d0 SR |
719 | if (ftraced_suspend == 1) |
720 | command |= FTRACE_ENABLE_CALLS; | |
721 | ||
722 | if (saved_ftrace_func != ftrace_trace_function) { | |
723 | saved_ftrace_func = ftrace_trace_function; | |
724 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
725 | } | |
726 | ||
727 | if (!command || !ftrace_enabled) | |
3d083395 | 728 | goto out; |
3d083395 | 729 | |
d61f82d0 | 730 | ftrace_run_update_code(command); |
3d083395 SR |
731 | out: |
732 | mutex_unlock(&ftraced_lock); | |
733 | } | |
734 | ||
e309b41d | 735 | static void ftrace_shutdown(void) |
3d083395 | 736 | { |
d61f82d0 SR |
737 | int command = 0; |
738 | ||
4eebcc81 SR |
739 | if (unlikely(ftrace_disabled)) |
740 | return; | |
741 | ||
3d083395 SR |
742 | mutex_lock(&ftraced_lock); |
743 | ftraced_suspend--; | |
d61f82d0 SR |
744 | if (!ftraced_suspend) |
745 | command |= FTRACE_DISABLE_CALLS; | |
3d083395 | 746 | |
d61f82d0 SR |
747 | if (saved_ftrace_func != ftrace_trace_function) { |
748 | saved_ftrace_func = ftrace_trace_function; | |
749 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
750 | } | |
3d083395 | 751 | |
d61f82d0 SR |
752 | if (!command || !ftrace_enabled) |
753 | goto out; | |
754 | ||
755 | ftrace_run_update_code(command); | |
3d083395 SR |
756 | out: |
757 | mutex_unlock(&ftraced_lock); | |
758 | } | |
759 | ||
e309b41d | 760 | static void ftrace_startup_sysctl(void) |
b0fc494f | 761 | { |
d61f82d0 SR |
762 | int command = FTRACE_ENABLE_MCOUNT; |
763 | ||
4eebcc81 SR |
764 | if (unlikely(ftrace_disabled)) |
765 | return; | |
766 | ||
b0fc494f | 767 | mutex_lock(&ftraced_lock); |
d61f82d0 SR |
768 | /* Force update next time */ |
769 | saved_ftrace_func = NULL; | |
b0fc494f SR |
770 | /* ftraced_suspend is true if we want ftrace running */ |
771 | if (ftraced_suspend) | |
d61f82d0 SR |
772 | command |= FTRACE_ENABLE_CALLS; |
773 | ||
774 | ftrace_run_update_code(command); | |
b0fc494f SR |
775 | mutex_unlock(&ftraced_lock); |
776 | } | |
777 | ||
e309b41d | 778 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 779 | { |
d61f82d0 SR |
780 | int command = FTRACE_DISABLE_MCOUNT; |
781 | ||
4eebcc81 SR |
782 | if (unlikely(ftrace_disabled)) |
783 | return; | |
784 | ||
b0fc494f SR |
785 | mutex_lock(&ftraced_lock); |
786 | /* ftraced_suspend is true if ftrace is running */ | |
787 | if (ftraced_suspend) | |
d61f82d0 SR |
788 | command |= FTRACE_DISABLE_CALLS; |
789 | ||
790 | ftrace_run_update_code(command); | |
b0fc494f SR |
791 | mutex_unlock(&ftraced_lock); |
792 | } | |
793 | ||
3d083395 SR |
794 | static cycle_t ftrace_update_time; |
795 | static unsigned long ftrace_update_cnt; | |
796 | unsigned long ftrace_update_tot_cnt; | |
797 | ||
e309b41d | 798 | static int __ftrace_update_code(void *ignore) |
3d083395 | 799 | { |
f22f9a89 AS |
800 | int i, save_ftrace_enabled; |
801 | cycle_t start, stop; | |
3d083395 | 802 | struct dyn_ftrace *p; |
0eb96701 | 803 | struct hlist_node *t, *n; |
f22f9a89 | 804 | struct hlist_head *head, temp_list; |
3d083395 | 805 | |
d61f82d0 | 806 | /* Don't be recording funcs now */ |
ad90c0e3 | 807 | ftrace_record_suspend++; |
d61f82d0 SR |
808 | save_ftrace_enabled = ftrace_enabled; |
809 | ftrace_enabled = 0; | |
3d083395 | 810 | |
750ed1a4 | 811 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
812 | ftrace_update_cnt = 0; |
813 | ||
814 | /* No locks needed, the machine is stopped! */ | |
815 | for (i = 0; i < FTRACE_HASHSIZE; i++) { | |
f22f9a89 AS |
816 | INIT_HLIST_HEAD(&temp_list); |
817 | head = &ftrace_hash[i]; | |
818 | ||
0eb96701 | 819 | /* all CPUS are stopped, we are safe to modify code */ |
f22f9a89 | 820 | hlist_for_each_entry_safe(p, t, n, head, node) { |
0eb96701 AS |
821 | /* Skip over failed records which have not been |
822 | * freed. */ | |
823 | if (p->flags & FTRACE_FL_FAILED) | |
824 | continue; | |
3d083395 | 825 | |
0eb96701 AS |
826 | /* Unconverted records are always at the head of the |
827 | * hash bucket. Once we encounter a converted record, | |
828 | * simply skip over to the next bucket. Saves ftraced | |
829 | * some processor cycles (ftrace does its bid for | |
830 | * global warming :-p ). */ | |
831 | if (p->flags & (FTRACE_FL_CONVERTED)) | |
832 | break; | |
3d083395 | 833 | |
f22f9a89 AS |
834 | /* Ignore updates to this record's mcount site. |
835 | * Reintroduce this record at the head of this | |
836 | * bucket to attempt to "convert" it again if | |
837 | * the kprobe on it is unregistered before the | |
838 | * next run. */ | |
839 | if (get_kprobe((void *)p->ip)) { | |
840 | ftrace_del_hash(p); | |
841 | INIT_HLIST_NODE(&p->node); | |
842 | hlist_add_head(&p->node, &temp_list); | |
98a05ed4 | 843 | freeze_record(p); |
f22f9a89 | 844 | continue; |
98a05ed4 AS |
845 | } else { |
846 | unfreeze_record(p); | |
f22f9a89 AS |
847 | } |
848 | ||
849 | /* convert record (i.e, patch mcount-call with NOP) */ | |
0eb96701 AS |
850 | if (ftrace_code_disable(p)) { |
851 | p->flags |= FTRACE_FL_CONVERTED; | |
492a7ea5 | 852 | ftrace_update_cnt++; |
0eb96701 AS |
853 | } else { |
854 | if ((system_state == SYSTEM_BOOTING) || | |
34078a5e | 855 | !core_kernel_text(p->ip)) { |
0eb96701 AS |
856 | ftrace_del_hash(p); |
857 | ftrace_free_rec(p); | |
0eb96701 AS |
858 | } |
859 | } | |
3d083395 | 860 | } |
f22f9a89 AS |
861 | |
862 | hlist_for_each_entry_safe(p, t, n, &temp_list, node) { | |
863 | hlist_del(&p->node); | |
864 | INIT_HLIST_NODE(&p->node); | |
865 | hlist_add_head(&p->node, head); | |
866 | } | |
3d083395 SR |
867 | } |
868 | ||
750ed1a4 | 869 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
870 | ftrace_update_time = stop - start; |
871 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
ad90c0e3 | 872 | ftraced_trigger = 0; |
3d083395 | 873 | |
d61f82d0 | 874 | ftrace_enabled = save_ftrace_enabled; |
ad90c0e3 | 875 | ftrace_record_suspend--; |
16444a8a ACM |
876 | |
877 | return 0; | |
878 | } | |
879 | ||
ad90c0e3 | 880 | static int ftrace_update_code(void) |
3d083395 | 881 | { |
ad90c0e3 SR |
882 | if (unlikely(ftrace_disabled) || |
883 | !ftrace_enabled || !ftraced_trigger) | |
884 | return 0; | |
4eebcc81 | 885 | |
784e2d76 | 886 | stop_machine(__ftrace_update_code, NULL, NULL); |
ad90c0e3 SR |
887 | |
888 | return 1; | |
3d083395 SR |
889 | } |
890 | ||
68bf21aa | 891 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
892 | { |
893 | struct ftrace_page *pg; | |
894 | int cnt; | |
895 | int i; | |
3c1720f0 SR |
896 | |
897 | /* allocate a few pages */ | |
898 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
899 | if (!ftrace_pages_start) | |
900 | return -1; | |
901 | ||
902 | /* | |
903 | * Allocate a few more pages. | |
904 | * | |
905 | * TODO: have some parser search vmlinux before | |
906 | * final linking to find all calls to ftrace. | |
907 | * Then we can: | |
908 | * a) know how many pages to allocate. | |
909 | * and/or | |
910 | * b) set up the table then. | |
911 | * | |
912 | * The dynamic code is still necessary for | |
913 | * modules. | |
914 | */ | |
915 | ||
916 | pg = ftrace_pages = ftrace_pages_start; | |
917 | ||
68bf21aa SR |
918 | cnt = num_to_init / ENTRIES_PER_PAGE; |
919 | pr_info("ftrace: allocating %ld hash entries in %d pages\n", | |
920 | num_to_init, cnt); | |
3c1720f0 SR |
921 | |
922 | for (i = 0; i < cnt; i++) { | |
923 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
924 | ||
925 | /* If we fail, we'll try later anyway */ | |
926 | if (!pg->next) | |
927 | break; | |
928 | ||
929 | pg = pg->next; | |
930 | } | |
931 | ||
932 | return 0; | |
933 | } | |
934 | ||
5072c59f SR |
935 | enum { |
936 | FTRACE_ITER_FILTER = (1 << 0), | |
937 | FTRACE_ITER_CONT = (1 << 1), | |
41c52c0d | 938 | FTRACE_ITER_NOTRACE = (1 << 2), |
eb9a7bf0 | 939 | FTRACE_ITER_FAILURES = (1 << 3), |
5072c59f SR |
940 | }; |
941 | ||
942 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
943 | ||
944 | struct ftrace_iterator { | |
945 | loff_t pos; | |
946 | struct ftrace_page *pg; | |
947 | unsigned idx; | |
948 | unsigned flags; | |
949 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
950 | unsigned buffer_idx; | |
951 | unsigned filtered; | |
952 | }; | |
953 | ||
e309b41d | 954 | static void * |
5072c59f SR |
955 | t_next(struct seq_file *m, void *v, loff_t *pos) |
956 | { | |
957 | struct ftrace_iterator *iter = m->private; | |
958 | struct dyn_ftrace *rec = NULL; | |
959 | ||
960 | (*pos)++; | |
961 | ||
99ecdc43 SR |
962 | /* should not be called from interrupt context */ |
963 | spin_lock(&ftrace_lock); | |
5072c59f SR |
964 | retry: |
965 | if (iter->idx >= iter->pg->index) { | |
966 | if (iter->pg->next) { | |
967 | iter->pg = iter->pg->next; | |
968 | iter->idx = 0; | |
969 | goto retry; | |
970 | } | |
971 | } else { | |
972 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
973 | if ((rec->flags & FTRACE_FL_FREE) || |
974 | ||
975 | (!(iter->flags & FTRACE_ITER_FAILURES) && | |
eb9a7bf0 AS |
976 | (rec->flags & FTRACE_FL_FAILED)) || |
977 | ||
978 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
a9fdda33 | 979 | !(rec->flags & FTRACE_FL_FAILED)) || |
eb9a7bf0 | 980 | |
41c52c0d SR |
981 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
982 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
983 | rec = NULL; |
984 | goto retry; | |
985 | } | |
986 | } | |
99ecdc43 | 987 | spin_unlock(&ftrace_lock); |
5072c59f SR |
988 | |
989 | iter->pos = *pos; | |
990 | ||
991 | return rec; | |
992 | } | |
993 | ||
994 | static void *t_start(struct seq_file *m, loff_t *pos) | |
995 | { | |
996 | struct ftrace_iterator *iter = m->private; | |
997 | void *p = NULL; | |
998 | loff_t l = -1; | |
999 | ||
1000 | if (*pos != iter->pos) { | |
1001 | for (p = t_next(m, p, &l); p && l < *pos; p = t_next(m, p, &l)) | |
1002 | ; | |
1003 | } else { | |
1004 | l = *pos; | |
1005 | p = t_next(m, p, &l); | |
1006 | } | |
1007 | ||
1008 | return p; | |
1009 | } | |
1010 | ||
1011 | static void t_stop(struct seq_file *m, void *p) | |
1012 | { | |
1013 | } | |
1014 | ||
1015 | static int t_show(struct seq_file *m, void *v) | |
1016 | { | |
1017 | struct dyn_ftrace *rec = v; | |
1018 | char str[KSYM_SYMBOL_LEN]; | |
1019 | ||
1020 | if (!rec) | |
1021 | return 0; | |
1022 | ||
1023 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1024 | ||
1025 | seq_printf(m, "%s\n", str); | |
1026 | ||
1027 | return 0; | |
1028 | } | |
1029 | ||
1030 | static struct seq_operations show_ftrace_seq_ops = { | |
1031 | .start = t_start, | |
1032 | .next = t_next, | |
1033 | .stop = t_stop, | |
1034 | .show = t_show, | |
1035 | }; | |
1036 | ||
e309b41d | 1037 | static int |
5072c59f SR |
1038 | ftrace_avail_open(struct inode *inode, struct file *file) |
1039 | { | |
1040 | struct ftrace_iterator *iter; | |
1041 | int ret; | |
1042 | ||
4eebcc81 SR |
1043 | if (unlikely(ftrace_disabled)) |
1044 | return -ENODEV; | |
1045 | ||
5072c59f SR |
1046 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1047 | if (!iter) | |
1048 | return -ENOMEM; | |
1049 | ||
1050 | iter->pg = ftrace_pages_start; | |
1051 | iter->pos = -1; | |
1052 | ||
1053 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1054 | if (!ret) { | |
1055 | struct seq_file *m = file->private_data; | |
4bf39a94 | 1056 | |
5072c59f | 1057 | m->private = iter; |
4bf39a94 | 1058 | } else { |
5072c59f | 1059 | kfree(iter); |
4bf39a94 | 1060 | } |
5072c59f SR |
1061 | |
1062 | return ret; | |
1063 | } | |
1064 | ||
1065 | int ftrace_avail_release(struct inode *inode, struct file *file) | |
1066 | { | |
1067 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1068 | struct ftrace_iterator *iter = m->private; | |
1069 | ||
1070 | seq_release(inode, file); | |
1071 | kfree(iter); | |
4bf39a94 | 1072 | |
5072c59f SR |
1073 | return 0; |
1074 | } | |
1075 | ||
eb9a7bf0 AS |
1076 | static int |
1077 | ftrace_failures_open(struct inode *inode, struct file *file) | |
1078 | { | |
1079 | int ret; | |
1080 | struct seq_file *m; | |
1081 | struct ftrace_iterator *iter; | |
1082 | ||
1083 | ret = ftrace_avail_open(inode, file); | |
1084 | if (!ret) { | |
1085 | m = (struct seq_file *)file->private_data; | |
1086 | iter = (struct ftrace_iterator *)m->private; | |
1087 | iter->flags = FTRACE_ITER_FAILURES; | |
1088 | } | |
1089 | ||
1090 | return ret; | |
1091 | } | |
1092 | ||
1093 | ||
41c52c0d | 1094 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
1095 | { |
1096 | struct ftrace_page *pg; | |
1097 | struct dyn_ftrace *rec; | |
41c52c0d | 1098 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f SR |
1099 | unsigned i; |
1100 | ||
99ecdc43 SR |
1101 | /* should not be called from interrupt context */ |
1102 | spin_lock(&ftrace_lock); | |
41c52c0d SR |
1103 | if (enable) |
1104 | ftrace_filtered = 0; | |
5072c59f SR |
1105 | pg = ftrace_pages_start; |
1106 | while (pg) { | |
1107 | for (i = 0; i < pg->index; i++) { | |
1108 | rec = &pg->records[i]; | |
1109 | if (rec->flags & FTRACE_FL_FAILED) | |
1110 | continue; | |
41c52c0d | 1111 | rec->flags &= ~type; |
5072c59f SR |
1112 | } |
1113 | pg = pg->next; | |
1114 | } | |
99ecdc43 | 1115 | spin_unlock(&ftrace_lock); |
5072c59f SR |
1116 | } |
1117 | ||
e309b41d | 1118 | static int |
41c52c0d | 1119 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1120 | { |
1121 | struct ftrace_iterator *iter; | |
1122 | int ret = 0; | |
1123 | ||
4eebcc81 SR |
1124 | if (unlikely(ftrace_disabled)) |
1125 | return -ENODEV; | |
1126 | ||
5072c59f SR |
1127 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1128 | if (!iter) | |
1129 | return -ENOMEM; | |
1130 | ||
41c52c0d | 1131 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1132 | if ((file->f_mode & FMODE_WRITE) && |
1133 | !(file->f_flags & O_APPEND)) | |
41c52c0d | 1134 | ftrace_filter_reset(enable); |
5072c59f SR |
1135 | |
1136 | if (file->f_mode & FMODE_READ) { | |
1137 | iter->pg = ftrace_pages_start; | |
1138 | iter->pos = -1; | |
41c52c0d SR |
1139 | iter->flags = enable ? FTRACE_ITER_FILTER : |
1140 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
1141 | |
1142 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1143 | if (!ret) { | |
1144 | struct seq_file *m = file->private_data; | |
1145 | m->private = iter; | |
1146 | } else | |
1147 | kfree(iter); | |
1148 | } else | |
1149 | file->private_data = iter; | |
41c52c0d | 1150 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1151 | |
1152 | return ret; | |
1153 | } | |
1154 | ||
41c52c0d SR |
1155 | static int |
1156 | ftrace_filter_open(struct inode *inode, struct file *file) | |
1157 | { | |
1158 | return ftrace_regex_open(inode, file, 1); | |
1159 | } | |
1160 | ||
1161 | static int | |
1162 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
1163 | { | |
1164 | return ftrace_regex_open(inode, file, 0); | |
1165 | } | |
1166 | ||
e309b41d | 1167 | static ssize_t |
41c52c0d | 1168 | ftrace_regex_read(struct file *file, char __user *ubuf, |
5072c59f SR |
1169 | size_t cnt, loff_t *ppos) |
1170 | { | |
1171 | if (file->f_mode & FMODE_READ) | |
1172 | return seq_read(file, ubuf, cnt, ppos); | |
1173 | else | |
1174 | return -EPERM; | |
1175 | } | |
1176 | ||
e309b41d | 1177 | static loff_t |
41c52c0d | 1178 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
1179 | { |
1180 | loff_t ret; | |
1181 | ||
1182 | if (file->f_mode & FMODE_READ) | |
1183 | ret = seq_lseek(file, offset, origin); | |
1184 | else | |
1185 | file->f_pos = ret = 1; | |
1186 | ||
1187 | return ret; | |
1188 | } | |
1189 | ||
1190 | enum { | |
1191 | MATCH_FULL, | |
1192 | MATCH_FRONT_ONLY, | |
1193 | MATCH_MIDDLE_ONLY, | |
1194 | MATCH_END_ONLY, | |
1195 | }; | |
1196 | ||
e309b41d | 1197 | static void |
41c52c0d | 1198 | ftrace_match(unsigned char *buff, int len, int enable) |
5072c59f SR |
1199 | { |
1200 | char str[KSYM_SYMBOL_LEN]; | |
1201 | char *search = NULL; | |
1202 | struct ftrace_page *pg; | |
1203 | struct dyn_ftrace *rec; | |
1204 | int type = MATCH_FULL; | |
41c52c0d | 1205 | unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f SR |
1206 | unsigned i, match = 0, search_len = 0; |
1207 | ||
1208 | for (i = 0; i < len; i++) { | |
1209 | if (buff[i] == '*') { | |
1210 | if (!i) { | |
1211 | search = buff + i + 1; | |
1212 | type = MATCH_END_ONLY; | |
1213 | search_len = len - (i + 1); | |
1214 | } else { | |
1215 | if (type == MATCH_END_ONLY) { | |
1216 | type = MATCH_MIDDLE_ONLY; | |
1217 | } else { | |
1218 | match = i; | |
1219 | type = MATCH_FRONT_ONLY; | |
1220 | } | |
1221 | buff[i] = 0; | |
1222 | break; | |
1223 | } | |
1224 | } | |
1225 | } | |
1226 | ||
99ecdc43 SR |
1227 | /* should not be called from interrupt context */ |
1228 | spin_lock(&ftrace_lock); | |
41c52c0d SR |
1229 | if (enable) |
1230 | ftrace_filtered = 1; | |
5072c59f SR |
1231 | pg = ftrace_pages_start; |
1232 | while (pg) { | |
1233 | for (i = 0; i < pg->index; i++) { | |
1234 | int matched = 0; | |
1235 | char *ptr; | |
1236 | ||
1237 | rec = &pg->records[i]; | |
1238 | if (rec->flags & FTRACE_FL_FAILED) | |
1239 | continue; | |
1240 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1241 | switch (type) { | |
1242 | case MATCH_FULL: | |
1243 | if (strcmp(str, buff) == 0) | |
1244 | matched = 1; | |
1245 | break; | |
1246 | case MATCH_FRONT_ONLY: | |
1247 | if (memcmp(str, buff, match) == 0) | |
1248 | matched = 1; | |
1249 | break; | |
1250 | case MATCH_MIDDLE_ONLY: | |
1251 | if (strstr(str, search)) | |
1252 | matched = 1; | |
1253 | break; | |
1254 | case MATCH_END_ONLY: | |
1255 | ptr = strstr(str, search); | |
1256 | if (ptr && (ptr[search_len] == 0)) | |
1257 | matched = 1; | |
1258 | break; | |
1259 | } | |
1260 | if (matched) | |
41c52c0d | 1261 | rec->flags |= flag; |
5072c59f SR |
1262 | } |
1263 | pg = pg->next; | |
1264 | } | |
99ecdc43 | 1265 | spin_unlock(&ftrace_lock); |
5072c59f SR |
1266 | } |
1267 | ||
e309b41d | 1268 | static ssize_t |
41c52c0d SR |
1269 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
1270 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
1271 | { |
1272 | struct ftrace_iterator *iter; | |
1273 | char ch; | |
1274 | size_t read = 0; | |
1275 | ssize_t ret; | |
1276 | ||
1277 | if (!cnt || cnt < 0) | |
1278 | return 0; | |
1279 | ||
41c52c0d | 1280 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1281 | |
1282 | if (file->f_mode & FMODE_READ) { | |
1283 | struct seq_file *m = file->private_data; | |
1284 | iter = m->private; | |
1285 | } else | |
1286 | iter = file->private_data; | |
1287 | ||
1288 | if (!*ppos) { | |
1289 | iter->flags &= ~FTRACE_ITER_CONT; | |
1290 | iter->buffer_idx = 0; | |
1291 | } | |
1292 | ||
1293 | ret = get_user(ch, ubuf++); | |
1294 | if (ret) | |
1295 | goto out; | |
1296 | read++; | |
1297 | cnt--; | |
1298 | ||
1299 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { | |
1300 | /* skip white space */ | |
1301 | while (cnt && isspace(ch)) { | |
1302 | ret = get_user(ch, ubuf++); | |
1303 | if (ret) | |
1304 | goto out; | |
1305 | read++; | |
1306 | cnt--; | |
1307 | } | |
1308 | ||
5072c59f SR |
1309 | if (isspace(ch)) { |
1310 | file->f_pos += read; | |
1311 | ret = read; | |
1312 | goto out; | |
1313 | } | |
1314 | ||
1315 | iter->buffer_idx = 0; | |
1316 | } | |
1317 | ||
1318 | while (cnt && !isspace(ch)) { | |
1319 | if (iter->buffer_idx < FTRACE_BUFF_MAX) | |
1320 | iter->buffer[iter->buffer_idx++] = ch; | |
1321 | else { | |
1322 | ret = -EINVAL; | |
1323 | goto out; | |
1324 | } | |
1325 | ret = get_user(ch, ubuf++); | |
1326 | if (ret) | |
1327 | goto out; | |
1328 | read++; | |
1329 | cnt--; | |
1330 | } | |
1331 | ||
1332 | if (isspace(ch)) { | |
1333 | iter->filtered++; | |
1334 | iter->buffer[iter->buffer_idx] = 0; | |
41c52c0d | 1335 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1336 | iter->buffer_idx = 0; |
1337 | } else | |
1338 | iter->flags |= FTRACE_ITER_CONT; | |
1339 | ||
1340 | ||
1341 | file->f_pos += read; | |
1342 | ||
1343 | ret = read; | |
1344 | out: | |
41c52c0d | 1345 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1346 | |
1347 | return ret; | |
1348 | } | |
1349 | ||
41c52c0d SR |
1350 | static ssize_t |
1351 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
1352 | size_t cnt, loff_t *ppos) | |
1353 | { | |
1354 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
1355 | } | |
1356 | ||
1357 | static ssize_t | |
1358 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
1359 | size_t cnt, loff_t *ppos) | |
1360 | { | |
1361 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
1362 | } | |
1363 | ||
1364 | static void | |
1365 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
1366 | { | |
1367 | if (unlikely(ftrace_disabled)) | |
1368 | return; | |
1369 | ||
1370 | mutex_lock(&ftrace_regex_lock); | |
1371 | if (reset) | |
1372 | ftrace_filter_reset(enable); | |
1373 | if (buf) | |
1374 | ftrace_match(buf, len, enable); | |
1375 | mutex_unlock(&ftrace_regex_lock); | |
1376 | } | |
1377 | ||
77a2b37d SR |
1378 | /** |
1379 | * ftrace_set_filter - set a function to filter on in ftrace | |
1380 | * @buf - the string that holds the function filter text. | |
1381 | * @len - the length of the string. | |
1382 | * @reset - non zero to reset all filters before applying this filter. | |
1383 | * | |
1384 | * Filters denote which functions should be enabled when tracing is enabled. | |
1385 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
1386 | */ | |
e309b41d | 1387 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 1388 | { |
41c52c0d SR |
1389 | ftrace_set_regex(buf, len, reset, 1); |
1390 | } | |
4eebcc81 | 1391 | |
41c52c0d SR |
1392 | /** |
1393 | * ftrace_set_notrace - set a function to not trace in ftrace | |
1394 | * @buf - the string that holds the function notrace text. | |
1395 | * @len - the length of the string. | |
1396 | * @reset - non zero to reset all filters before applying this filter. | |
1397 | * | |
1398 | * Notrace Filters denote which functions should not be enabled when tracing | |
1399 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
1400 | * for tracing. | |
1401 | */ | |
1402 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
1403 | { | |
1404 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
1405 | } |
1406 | ||
e309b41d | 1407 | static int |
41c52c0d | 1408 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1409 | { |
1410 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1411 | struct ftrace_iterator *iter; | |
1412 | ||
41c52c0d | 1413 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1414 | if (file->f_mode & FMODE_READ) { |
1415 | iter = m->private; | |
1416 | ||
1417 | seq_release(inode, file); | |
1418 | } else | |
1419 | iter = file->private_data; | |
1420 | ||
1421 | if (iter->buffer_idx) { | |
1422 | iter->filtered++; | |
1423 | iter->buffer[iter->buffer_idx] = 0; | |
41c52c0d | 1424 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1425 | } |
1426 | ||
1427 | mutex_lock(&ftrace_sysctl_lock); | |
1428 | mutex_lock(&ftraced_lock); | |
1429 | if (iter->filtered && ftraced_suspend && ftrace_enabled) | |
1430 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); | |
1431 | mutex_unlock(&ftraced_lock); | |
1432 | mutex_unlock(&ftrace_sysctl_lock); | |
1433 | ||
1434 | kfree(iter); | |
41c52c0d | 1435 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1436 | return 0; |
1437 | } | |
1438 | ||
41c52c0d SR |
1439 | static int |
1440 | ftrace_filter_release(struct inode *inode, struct file *file) | |
1441 | { | |
1442 | return ftrace_regex_release(inode, file, 1); | |
1443 | } | |
1444 | ||
1445 | static int | |
1446 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
1447 | { | |
1448 | return ftrace_regex_release(inode, file, 0); | |
1449 | } | |
1450 | ||
ad90c0e3 SR |
1451 | static ssize_t |
1452 | ftraced_read(struct file *filp, char __user *ubuf, | |
1453 | size_t cnt, loff_t *ppos) | |
1454 | { | |
1455 | /* don't worry about races */ | |
1456 | char *buf = ftraced_stop ? "disabled\n" : "enabled\n"; | |
1457 | int r = strlen(buf); | |
1458 | ||
1459 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
1460 | } | |
1461 | ||
1462 | static ssize_t | |
1463 | ftraced_write(struct file *filp, const char __user *ubuf, | |
1464 | size_t cnt, loff_t *ppos) | |
1465 | { | |
1466 | char buf[64]; | |
1467 | long val; | |
1468 | int ret; | |
1469 | ||
1470 | if (cnt >= sizeof(buf)) | |
1471 | return -EINVAL; | |
1472 | ||
1473 | if (copy_from_user(&buf, ubuf, cnt)) | |
1474 | return -EFAULT; | |
1475 | ||
1476 | if (strncmp(buf, "enable", 6) == 0) | |
1477 | val = 1; | |
1478 | else if (strncmp(buf, "disable", 7) == 0) | |
1479 | val = 0; | |
1480 | else { | |
1481 | buf[cnt] = 0; | |
1482 | ||
1483 | ret = strict_strtoul(buf, 10, &val); | |
1484 | if (ret < 0) | |
1485 | return ret; | |
1486 | ||
1487 | val = !!val; | |
1488 | } | |
1489 | ||
1490 | if (val) | |
1491 | ftrace_enable_daemon(); | |
1492 | else | |
1493 | ftrace_disable_daemon(); | |
1494 | ||
1495 | filp->f_pos += cnt; | |
1496 | ||
1497 | return cnt; | |
1498 | } | |
1499 | ||
5072c59f SR |
1500 | static struct file_operations ftrace_avail_fops = { |
1501 | .open = ftrace_avail_open, | |
1502 | .read = seq_read, | |
1503 | .llseek = seq_lseek, | |
1504 | .release = ftrace_avail_release, | |
1505 | }; | |
1506 | ||
eb9a7bf0 AS |
1507 | static struct file_operations ftrace_failures_fops = { |
1508 | .open = ftrace_failures_open, | |
1509 | .read = seq_read, | |
1510 | .llseek = seq_lseek, | |
1511 | .release = ftrace_avail_release, | |
1512 | }; | |
1513 | ||
5072c59f SR |
1514 | static struct file_operations ftrace_filter_fops = { |
1515 | .open = ftrace_filter_open, | |
41c52c0d | 1516 | .read = ftrace_regex_read, |
5072c59f | 1517 | .write = ftrace_filter_write, |
41c52c0d | 1518 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
1519 | .release = ftrace_filter_release, |
1520 | }; | |
1521 | ||
41c52c0d SR |
1522 | static struct file_operations ftrace_notrace_fops = { |
1523 | .open = ftrace_notrace_open, | |
1524 | .read = ftrace_regex_read, | |
1525 | .write = ftrace_notrace_write, | |
1526 | .llseek = ftrace_regex_lseek, | |
1527 | .release = ftrace_notrace_release, | |
1528 | }; | |
1529 | ||
ad90c0e3 SR |
1530 | static struct file_operations ftraced_fops = { |
1531 | .open = tracing_open_generic, | |
1532 | .read = ftraced_read, | |
1533 | .write = ftraced_write, | |
1534 | }; | |
1535 | ||
e1c08bdd SR |
1536 | /** |
1537 | * ftrace_force_update - force an update to all recording ftrace functions | |
e1c08bdd SR |
1538 | */ |
1539 | int ftrace_force_update(void) | |
1540 | { | |
e1c08bdd SR |
1541 | int ret = 0; |
1542 | ||
4eebcc81 | 1543 | if (unlikely(ftrace_disabled)) |
e1c08bdd SR |
1544 | return -ENODEV; |
1545 | ||
ad90c0e3 | 1546 | mutex_lock(&ftrace_sysctl_lock); |
e1c08bdd | 1547 | mutex_lock(&ftraced_lock); |
e1c08bdd | 1548 | |
ad90c0e3 SR |
1549 | /* |
1550 | * If ftraced_trigger is not set, then there is nothing | |
1551 | * to update. | |
1552 | */ | |
1553 | if (ftraced_trigger && !ftrace_update_code()) | |
1554 | ret = -EBUSY; | |
e1c08bdd SR |
1555 | |
1556 | mutex_unlock(&ftraced_lock); | |
ad90c0e3 | 1557 | mutex_unlock(&ftrace_sysctl_lock); |
e1c08bdd SR |
1558 | |
1559 | return ret; | |
1560 | } | |
1561 | ||
5072c59f SR |
1562 | static __init int ftrace_init_debugfs(void) |
1563 | { | |
1564 | struct dentry *d_tracer; | |
1565 | struct dentry *entry; | |
1566 | ||
1567 | d_tracer = tracing_init_dentry(); | |
1568 | ||
1569 | entry = debugfs_create_file("available_filter_functions", 0444, | |
1570 | d_tracer, NULL, &ftrace_avail_fops); | |
1571 | if (!entry) | |
1572 | pr_warning("Could not create debugfs " | |
1573 | "'available_filter_functions' entry\n"); | |
1574 | ||
eb9a7bf0 AS |
1575 | entry = debugfs_create_file("failures", 0444, |
1576 | d_tracer, NULL, &ftrace_failures_fops); | |
1577 | if (!entry) | |
1578 | pr_warning("Could not create debugfs 'failures' entry\n"); | |
1579 | ||
5072c59f SR |
1580 | entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer, |
1581 | NULL, &ftrace_filter_fops); | |
1582 | if (!entry) | |
1583 | pr_warning("Could not create debugfs " | |
1584 | "'set_ftrace_filter' entry\n"); | |
41c52c0d SR |
1585 | |
1586 | entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer, | |
1587 | NULL, &ftrace_notrace_fops); | |
1588 | if (!entry) | |
1589 | pr_warning("Could not create debugfs " | |
1590 | "'set_ftrace_notrace' entry\n"); | |
ad90c0e3 SR |
1591 | |
1592 | entry = debugfs_create_file("ftraced_enabled", 0644, d_tracer, | |
1593 | NULL, &ftraced_fops); | |
1594 | if (!entry) | |
1595 | pr_warning("Could not create debugfs " | |
1596 | "'ftraced_enabled' entry\n"); | |
5072c59f SR |
1597 | return 0; |
1598 | } | |
1599 | ||
1600 | fs_initcall(ftrace_init_debugfs); | |
1601 | ||
68bf21aa SR |
1602 | #ifdef CONFIG_FTRACE_MCOUNT_RECORD |
1603 | static int ftrace_convert_nops(unsigned long *start, | |
1604 | unsigned long *end) | |
1605 | { | |
1606 | unsigned long *p; | |
1607 | unsigned long addr; | |
1608 | unsigned long flags; | |
1609 | ||
1610 | p = start; | |
1611 | while (p < end) { | |
1612 | addr = ftrace_call_adjust(*p++); | |
99ecdc43 | 1613 | /* should not be called from interrupt context */ |
fed1939c | 1614 | spin_lock(&ftrace_lock); |
68bf21aa | 1615 | ftrace_record_ip(addr); |
fed1939c | 1616 | spin_unlock(&ftrace_lock); |
68bf21aa SR |
1617 | ftrace_shutdown_replenish(); |
1618 | } | |
1619 | ||
1620 | /* p is ignored */ | |
1621 | local_irq_save(flags); | |
1622 | __ftrace_update_code(p); | |
1623 | local_irq_restore(flags); | |
1624 | ||
1625 | return 0; | |
1626 | } | |
1627 | ||
90d595fe SR |
1628 | void ftrace_init_module(unsigned long *start, unsigned long *end) |
1629 | { | |
00fd61ae | 1630 | if (ftrace_disabled || start == end) |
fed1939c | 1631 | return; |
90d595fe SR |
1632 | ftrace_convert_nops(start, end); |
1633 | } | |
1634 | ||
68bf21aa SR |
1635 | extern unsigned long __start_mcount_loc[]; |
1636 | extern unsigned long __stop_mcount_loc[]; | |
1637 | ||
1638 | void __init ftrace_init(void) | |
1639 | { | |
1640 | unsigned long count, addr, flags; | |
1641 | int ret; | |
1642 | ||
1643 | /* Keep the ftrace pointer to the stub */ | |
1644 | addr = (unsigned long)ftrace_stub; | |
1645 | ||
1646 | local_irq_save(flags); | |
1647 | ftrace_dyn_arch_init(&addr); | |
1648 | local_irq_restore(flags); | |
1649 | ||
1650 | /* ftrace_dyn_arch_init places the return code in addr */ | |
1651 | if (addr) | |
1652 | goto failed; | |
1653 | ||
1654 | count = __stop_mcount_loc - __start_mcount_loc; | |
1655 | ||
1656 | ret = ftrace_dyn_table_alloc(count); | |
1657 | if (ret) | |
1658 | goto failed; | |
1659 | ||
1660 | last_ftrace_enabled = ftrace_enabled = 1; | |
1661 | ||
1662 | ret = ftrace_convert_nops(__start_mcount_loc, | |
1663 | __stop_mcount_loc); | |
1664 | ||
1665 | return; | |
1666 | failed: | |
1667 | ftrace_disabled = 1; | |
1668 | } | |
1669 | #else /* CONFIG_FTRACE_MCOUNT_RECORD */ | |
bd95b88d SR |
1670 | |
1671 | static void ftrace_release_hash(unsigned long start, unsigned long end) | |
1672 | { | |
1673 | struct dyn_ftrace *rec; | |
1674 | struct hlist_node *t, *n; | |
1675 | struct hlist_head *head, temp_list; | |
1676 | unsigned long flags; | |
1677 | int i, cpu; | |
1678 | ||
1679 | preempt_disable_notrace(); | |
1680 | ||
1681 | /* disable incase we call something that calls mcount */ | |
1682 | cpu = raw_smp_processor_id(); | |
1683 | per_cpu(ftrace_shutdown_disable_cpu, cpu)++; | |
1684 | ||
1685 | ftrace_hash_lock(flags); | |
1686 | ||
1687 | for (i = 0; i < FTRACE_HASHSIZE; i++) { | |
1688 | INIT_HLIST_HEAD(&temp_list); | |
1689 | head = &ftrace_hash[i]; | |
1690 | ||
1691 | /* all CPUS are stopped, we are safe to modify code */ | |
1692 | hlist_for_each_entry_safe(rec, t, n, head, node) { | |
1693 | if (rec->flags & FTRACE_FL_FREE) | |
1694 | continue; | |
1695 | ||
1696 | if ((rec->ip >= start) && (rec->ip < end)) | |
1697 | ftrace_free_rec(rec); | |
1698 | } | |
1699 | } | |
1700 | ||
1701 | ftrace_hash_unlock(flags); | |
1702 | ||
1703 | per_cpu(ftrace_shutdown_disable_cpu, cpu)--; | |
1704 | preempt_enable_notrace(); | |
1705 | ||
1706 | } | |
1707 | ||
68bf21aa SR |
1708 | static int ftraced(void *ignore) |
1709 | { | |
1710 | unsigned long usecs; | |
1711 | ||
1712 | while (!kthread_should_stop()) { | |
1713 | ||
1714 | set_current_state(TASK_INTERRUPTIBLE); | |
1715 | ||
1716 | /* check once a second */ | |
1717 | schedule_timeout(HZ); | |
1718 | ||
1719 | if (unlikely(ftrace_disabled)) | |
1720 | continue; | |
1721 | ||
1722 | mutex_lock(&ftrace_sysctl_lock); | |
1723 | mutex_lock(&ftraced_lock); | |
1724 | if (!ftraced_suspend && !ftraced_stop && | |
1725 | ftrace_update_code()) { | |
1726 | usecs = nsecs_to_usecs(ftrace_update_time); | |
1727 | if (ftrace_update_tot_cnt > 100000) { | |
1728 | ftrace_update_tot_cnt = 0; | |
1729 | pr_info("hm, dftrace overflow: %lu change%s" | |
1730 | " (%lu total) in %lu usec%s\n", | |
1731 | ftrace_update_cnt, | |
1732 | ftrace_update_cnt != 1 ? "s" : "", | |
1733 | ftrace_update_tot_cnt, | |
1734 | usecs, usecs != 1 ? "s" : ""); | |
6912896e | 1735 | FTRACE_WARN_ON_ONCE(1); |
68bf21aa SR |
1736 | } |
1737 | } | |
1738 | mutex_unlock(&ftraced_lock); | |
1739 | mutex_unlock(&ftrace_sysctl_lock); | |
1740 | ||
1741 | ftrace_shutdown_replenish(); | |
1742 | } | |
1743 | __set_current_state(TASK_RUNNING); | |
1744 | return 0; | |
1745 | } | |
1746 | ||
e309b41d | 1747 | static int __init ftrace_dynamic_init(void) |
3d083395 SR |
1748 | { |
1749 | struct task_struct *p; | |
d61f82d0 | 1750 | unsigned long addr; |
3d083395 SR |
1751 | int ret; |
1752 | ||
d61f82d0 | 1753 | addr = (unsigned long)ftrace_record_ip; |
9ff9cdb2 | 1754 | |
784e2d76 | 1755 | stop_machine(ftrace_dyn_arch_init, &addr, NULL); |
d61f82d0 SR |
1756 | |
1757 | /* ftrace_dyn_arch_init places the return code in addr */ | |
4eebcc81 SR |
1758 | if (addr) { |
1759 | ret = (int)addr; | |
1760 | goto failed; | |
1761 | } | |
d61f82d0 | 1762 | |
68bf21aa | 1763 | ret = ftrace_dyn_table_alloc(NR_TO_INIT); |
3d083395 | 1764 | if (ret) |
4eebcc81 | 1765 | goto failed; |
3d083395 SR |
1766 | |
1767 | p = kthread_run(ftraced, NULL, "ftraced"); | |
4eebcc81 SR |
1768 | if (IS_ERR(p)) { |
1769 | ret = -1; | |
1770 | goto failed; | |
1771 | } | |
3d083395 | 1772 | |
d61f82d0 | 1773 | last_ftrace_enabled = ftrace_enabled = 1; |
e1c08bdd | 1774 | ftraced_task = p; |
3d083395 SR |
1775 | |
1776 | return 0; | |
4eebcc81 SR |
1777 | |
1778 | failed: | |
1779 | ftrace_disabled = 1; | |
1780 | return ret; | |
3d083395 SR |
1781 | } |
1782 | ||
d61f82d0 | 1783 | core_initcall(ftrace_dynamic_init); |
68bf21aa SR |
1784 | #endif /* CONFIG_FTRACE_MCOUNT_RECORD */ |
1785 | ||
3d083395 | 1786 | #else |
c7aafc54 IM |
1787 | # define ftrace_startup() do { } while (0) |
1788 | # define ftrace_shutdown() do { } while (0) | |
1789 | # define ftrace_startup_sysctl() do { } while (0) | |
1790 | # define ftrace_shutdown_sysctl() do { } while (0) | |
3d083395 SR |
1791 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
1792 | ||
a2bb6a3d | 1793 | /** |
81adbdc0 | 1794 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
1795 | * |
1796 | * This function should be used by panic code. It stops ftrace | |
1797 | * but in a not so nice way. If you need to simply kill ftrace | |
1798 | * from a non-atomic section, use ftrace_kill. | |
1799 | */ | |
81adbdc0 | 1800 | void ftrace_kill(void) |
a2bb6a3d SR |
1801 | { |
1802 | ftrace_disabled = 1; | |
1803 | ftrace_enabled = 0; | |
b2613e37 | 1804 | #ifdef CONFIG_DYNAMIC_FTRACE |
a2bb6a3d | 1805 | ftraced_suspend = -1; |
b2613e37 | 1806 | #endif |
a2bb6a3d SR |
1807 | clear_ftrace_function(); |
1808 | } | |
1809 | ||
16444a8a | 1810 | /** |
3d083395 SR |
1811 | * register_ftrace_function - register a function for profiling |
1812 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 1813 | * |
3d083395 SR |
1814 | * Register a function to be called by all functions in the |
1815 | * kernel. | |
1816 | * | |
1817 | * Note: @ops->func and all the functions it calls must be labeled | |
1818 | * with "notrace", otherwise it will go into a | |
1819 | * recursive loop. | |
16444a8a | 1820 | */ |
3d083395 | 1821 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 1822 | { |
b0fc494f SR |
1823 | int ret; |
1824 | ||
4eebcc81 SR |
1825 | if (unlikely(ftrace_disabled)) |
1826 | return -1; | |
1827 | ||
b0fc494f | 1828 | mutex_lock(&ftrace_sysctl_lock); |
b0fc494f | 1829 | ret = __register_ftrace_function(ops); |
d61f82d0 | 1830 | ftrace_startup(); |
b0fc494f SR |
1831 | mutex_unlock(&ftrace_sysctl_lock); |
1832 | ||
1833 | return ret; | |
3d083395 SR |
1834 | } |
1835 | ||
1836 | /** | |
1837 | * unregister_ftrace_function - unresgister a function for profiling. | |
1838 | * @ops - ops structure that holds the function to unregister | |
1839 | * | |
1840 | * Unregister a function that was added to be called by ftrace profiling. | |
1841 | */ | |
1842 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
1843 | { | |
1844 | int ret; | |
1845 | ||
b0fc494f | 1846 | mutex_lock(&ftrace_sysctl_lock); |
3d083395 | 1847 | ret = __unregister_ftrace_function(ops); |
d61f82d0 | 1848 | ftrace_shutdown(); |
b0fc494f SR |
1849 | mutex_unlock(&ftrace_sysctl_lock); |
1850 | ||
1851 | return ret; | |
1852 | } | |
1853 | ||
e309b41d | 1854 | int |
b0fc494f | 1855 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
5072c59f | 1856 | struct file *file, void __user *buffer, size_t *lenp, |
b0fc494f SR |
1857 | loff_t *ppos) |
1858 | { | |
1859 | int ret; | |
1860 | ||
4eebcc81 SR |
1861 | if (unlikely(ftrace_disabled)) |
1862 | return -ENODEV; | |
1863 | ||
b0fc494f SR |
1864 | mutex_lock(&ftrace_sysctl_lock); |
1865 | ||
5072c59f | 1866 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
b0fc494f SR |
1867 | |
1868 | if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) | |
1869 | goto out; | |
1870 | ||
1871 | last_ftrace_enabled = ftrace_enabled; | |
1872 | ||
1873 | if (ftrace_enabled) { | |
1874 | ||
1875 | ftrace_startup_sysctl(); | |
1876 | ||
1877 | /* we are starting ftrace again */ | |
1878 | if (ftrace_list != &ftrace_list_end) { | |
1879 | if (ftrace_list->next == &ftrace_list_end) | |
1880 | ftrace_trace_function = ftrace_list->func; | |
1881 | else | |
1882 | ftrace_trace_function = ftrace_list_func; | |
1883 | } | |
1884 | ||
1885 | } else { | |
1886 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
1887 | ftrace_trace_function = ftrace_stub; | |
1888 | ||
1889 | ftrace_shutdown_sysctl(); | |
1890 | } | |
1891 | ||
1892 | out: | |
1893 | mutex_unlock(&ftrace_sysctl_lock); | |
3d083395 | 1894 | return ret; |
16444a8a | 1895 | } |