]>
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) | |
bd95b88d | 167 | static void ftrace_release_hash(unsigned long start, unsigned long end); |
99ecdc43 SR |
168 | #else |
169 | /* This is protected via the ftrace_lock with MCOUNT_RECORD. */ | |
ac8825ec | 170 | #define ftrace_hash_lock(flags) do { (void)(flags); } while (0) |
99ecdc43 | 171 | #define ftrace_hash_unlock(flags) do { } while(0) |
bd95b88d SR |
172 | static inline void ftrace_release_hash(unsigned long start, unsigned long end) |
173 | { | |
174 | } | |
99ecdc43 SR |
175 | #endif |
176 | ||
71c67d58 SN |
177 | /* |
178 | * Since MCOUNT_ADDR may point to mcount itself, we do not want | |
179 | * to get it confused by reading a reference in the code as we | |
180 | * are parsing on objcopy output of text. Use a variable for | |
181 | * it instead. | |
182 | */ | |
183 | static unsigned long mcount_addr = MCOUNT_ADDR; | |
184 | ||
e1c08bdd | 185 | static struct task_struct *ftraced_task; |
e1c08bdd | 186 | |
d61f82d0 SR |
187 | enum { |
188 | FTRACE_ENABLE_CALLS = (1 << 0), | |
189 | FTRACE_DISABLE_CALLS = (1 << 1), | |
190 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
191 | FTRACE_ENABLE_MCOUNT = (1 << 3), | |
192 | FTRACE_DISABLE_MCOUNT = (1 << 4), | |
193 | }; | |
194 | ||
5072c59f | 195 | static int ftrace_filtered; |
ecea656d AS |
196 | static int tracing_on; |
197 | static int frozen_record_count; | |
5072c59f | 198 | |
3d083395 SR |
199 | static struct hlist_head ftrace_hash[FTRACE_HASHSIZE]; |
200 | ||
201 | static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu); | |
202 | ||
3d083395 | 203 | static DEFINE_MUTEX(ftraced_lock); |
41c52c0d | 204 | static DEFINE_MUTEX(ftrace_regex_lock); |
3d083395 | 205 | |
3c1720f0 SR |
206 | struct ftrace_page { |
207 | struct ftrace_page *next; | |
aa5e5cea | 208 | unsigned long index; |
3c1720f0 | 209 | struct dyn_ftrace records[]; |
aa5e5cea | 210 | }; |
3c1720f0 SR |
211 | |
212 | #define ENTRIES_PER_PAGE \ | |
213 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
214 | ||
215 | /* estimate from running different kernels */ | |
216 | #define NR_TO_INIT 10000 | |
217 | ||
218 | static struct ftrace_page *ftrace_pages_start; | |
219 | static struct ftrace_page *ftrace_pages; | |
220 | ||
3d083395 SR |
221 | static int ftraced_trigger; |
222 | static int ftraced_suspend; | |
ad90c0e3 | 223 | static int ftraced_stop; |
3d083395 SR |
224 | |
225 | static int ftrace_record_suspend; | |
226 | ||
37ad5084 SR |
227 | static struct dyn_ftrace *ftrace_free_records; |
228 | ||
ecea656d AS |
229 | |
230 | #ifdef CONFIG_KPROBES | |
231 | static inline void freeze_record(struct dyn_ftrace *rec) | |
232 | { | |
233 | if (!(rec->flags & FTRACE_FL_FROZEN)) { | |
234 | rec->flags |= FTRACE_FL_FROZEN; | |
235 | frozen_record_count++; | |
236 | } | |
237 | } | |
238 | ||
239 | static inline void unfreeze_record(struct dyn_ftrace *rec) | |
240 | { | |
241 | if (rec->flags & FTRACE_FL_FROZEN) { | |
242 | rec->flags &= ~FTRACE_FL_FROZEN; | |
243 | frozen_record_count--; | |
244 | } | |
245 | } | |
246 | ||
247 | static inline int record_frozen(struct dyn_ftrace *rec) | |
248 | { | |
249 | return rec->flags & FTRACE_FL_FROZEN; | |
250 | } | |
251 | #else | |
252 | # define freeze_record(rec) ({ 0; }) | |
253 | # define unfreeze_record(rec) ({ 0; }) | |
254 | # define record_frozen(rec) ({ 0; }) | |
255 | #endif /* CONFIG_KPROBES */ | |
256 | ||
257 | int skip_trace(unsigned long ip) | |
258 | { | |
259 | unsigned long fl; | |
260 | struct dyn_ftrace *rec; | |
261 | struct hlist_node *t; | |
262 | struct hlist_head *head; | |
263 | ||
264 | if (frozen_record_count == 0) | |
265 | return 0; | |
266 | ||
267 | head = &ftrace_hash[hash_long(ip, FTRACE_HASHBITS)]; | |
268 | hlist_for_each_entry_rcu(rec, t, head, node) { | |
269 | if (rec->ip == ip) { | |
270 | if (record_frozen(rec)) { | |
271 | if (rec->flags & FTRACE_FL_FAILED) | |
272 | return 1; | |
273 | ||
274 | if (!(rec->flags & FTRACE_FL_CONVERTED)) | |
275 | return 1; | |
276 | ||
277 | if (!tracing_on || !ftrace_enabled) | |
278 | return 1; | |
279 | ||
280 | if (ftrace_filtered) { | |
281 | fl = rec->flags & (FTRACE_FL_FILTER | | |
282 | FTRACE_FL_NOTRACE); | |
283 | if (!fl || (fl & FTRACE_FL_NOTRACE)) | |
284 | return 1; | |
285 | } | |
286 | } | |
287 | break; | |
288 | } | |
289 | } | |
290 | ||
291 | return 0; | |
292 | } | |
293 | ||
e309b41d | 294 | static inline int |
9ff9cdb2 | 295 | ftrace_ip_in_hash(unsigned long ip, unsigned long key) |
3d083395 SR |
296 | { |
297 | struct dyn_ftrace *p; | |
298 | struct hlist_node *t; | |
299 | int found = 0; | |
300 | ||
ffdaa358 | 301 | hlist_for_each_entry_rcu(p, t, &ftrace_hash[key], node) { |
3d083395 SR |
302 | if (p->ip == ip) { |
303 | found = 1; | |
304 | break; | |
305 | } | |
306 | } | |
307 | ||
308 | return found; | |
309 | } | |
310 | ||
e309b41d | 311 | static inline void |
3d083395 SR |
312 | ftrace_add_hash(struct dyn_ftrace *node, unsigned long key) |
313 | { | |
ffdaa358 | 314 | hlist_add_head_rcu(&node->node, &ftrace_hash[key]); |
3d083395 SR |
315 | } |
316 | ||
0eb96701 AS |
317 | /* called from kstop_machine */ |
318 | static inline void ftrace_del_hash(struct dyn_ftrace *node) | |
319 | { | |
320 | hlist_del(&node->node); | |
321 | } | |
322 | ||
e309b41d | 323 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
37ad5084 | 324 | { |
37ad5084 SR |
325 | rec->ip = (unsigned long)ftrace_free_records; |
326 | ftrace_free_records = rec; | |
327 | rec->flags |= FTRACE_FL_FREE; | |
328 | } | |
329 | ||
fed1939c SR |
330 | void ftrace_release(void *start, unsigned long size) |
331 | { | |
332 | struct dyn_ftrace *rec; | |
333 | struct ftrace_page *pg; | |
334 | unsigned long s = (unsigned long)start; | |
335 | unsigned long e = s + size; | |
336 | int i; | |
337 | ||
00fd61ae | 338 | if (ftrace_disabled || !start) |
fed1939c SR |
339 | return; |
340 | ||
99ecdc43 | 341 | /* should not be called from interrupt context */ |
fed1939c SR |
342 | spin_lock(&ftrace_lock); |
343 | ||
344 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
345 | for (i = 0; i < pg->index; i++) { | |
346 | rec = &pg->records[i]; | |
347 | ||
348 | if ((rec->ip >= s) && (rec->ip < e)) | |
349 | ftrace_free_rec(rec); | |
350 | } | |
351 | } | |
352 | spin_unlock(&ftrace_lock); | |
353 | ||
bd95b88d | 354 | ftrace_release_hash(s, e); |
fed1939c SR |
355 | } |
356 | ||
e309b41d | 357 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 358 | { |
37ad5084 SR |
359 | struct dyn_ftrace *rec; |
360 | ||
361 | /* First check for freed records */ | |
362 | if (ftrace_free_records) { | |
363 | rec = ftrace_free_records; | |
364 | ||
37ad5084 SR |
365 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
366 | WARN_ON_ONCE(1); | |
367 | ftrace_free_records = NULL; | |
4eebcc81 SR |
368 | ftrace_disabled = 1; |
369 | ftrace_enabled = 0; | |
37ad5084 SR |
370 | return NULL; |
371 | } | |
372 | ||
373 | ftrace_free_records = (void *)rec->ip; | |
374 | memset(rec, 0, sizeof(*rec)); | |
375 | return rec; | |
376 | } | |
377 | ||
3c1720f0 SR |
378 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
379 | if (!ftrace_pages->next) | |
380 | return NULL; | |
381 | ftrace_pages = ftrace_pages->next; | |
382 | } | |
383 | ||
384 | return &ftrace_pages->records[ftrace_pages->index++]; | |
385 | } | |
386 | ||
e309b41d | 387 | static void |
d61f82d0 | 388 | ftrace_record_ip(unsigned long ip) |
3d083395 SR |
389 | { |
390 | struct dyn_ftrace *node; | |
391 | unsigned long flags; | |
392 | unsigned long key; | |
393 | int resched; | |
2bb6f8d6 | 394 | int cpu; |
3d083395 | 395 | |
4eebcc81 | 396 | if (!ftrace_enabled || ftrace_disabled) |
d61f82d0 SR |
397 | return; |
398 | ||
3d083395 SR |
399 | resched = need_resched(); |
400 | preempt_disable_notrace(); | |
401 | ||
2bb6f8d6 SR |
402 | /* |
403 | * We simply need to protect against recursion. | |
404 | * Use the the raw version of smp_processor_id and not | |
405 | * __get_cpu_var which can call debug hooks that can | |
406 | * cause a recursive crash here. | |
407 | */ | |
408 | cpu = raw_smp_processor_id(); | |
409 | per_cpu(ftrace_shutdown_disable_cpu, cpu)++; | |
410 | if (per_cpu(ftrace_shutdown_disable_cpu, cpu) != 1) | |
3d083395 SR |
411 | goto out; |
412 | ||
413 | if (unlikely(ftrace_record_suspend)) | |
414 | goto out; | |
415 | ||
416 | key = hash_long(ip, FTRACE_HASHBITS); | |
417 | ||
418 | WARN_ON_ONCE(key >= FTRACE_HASHSIZE); | |
419 | ||
420 | if (ftrace_ip_in_hash(ip, key)) | |
421 | goto out; | |
422 | ||
99ecdc43 | 423 | ftrace_hash_lock(flags); |
3d083395 SR |
424 | |
425 | /* This ip may have hit the hash before the lock */ | |
426 | if (ftrace_ip_in_hash(ip, key)) | |
427 | goto out_unlock; | |
428 | ||
d61f82d0 | 429 | node = ftrace_alloc_dyn_node(ip); |
3d083395 SR |
430 | if (!node) |
431 | goto out_unlock; | |
432 | ||
433 | node->ip = ip; | |
434 | ||
435 | ftrace_add_hash(node, key); | |
436 | ||
437 | ftraced_trigger = 1; | |
438 | ||
439 | out_unlock: | |
99ecdc43 | 440 | ftrace_hash_unlock(flags); |
3d083395 | 441 | out: |
2bb6f8d6 | 442 | per_cpu(ftrace_shutdown_disable_cpu, cpu)--; |
3d083395 SR |
443 | |
444 | /* prevent recursion with scheduler */ | |
445 | if (resched) | |
446 | preempt_enable_no_resched_notrace(); | |
447 | else | |
448 | preempt_enable_notrace(); | |
449 | } | |
450 | ||
caf8cdeb | 451 | #define FTRACE_ADDR ((long)(ftrace_caller)) |
3c1720f0 | 452 | |
0eb96701 | 453 | static int |
5072c59f SR |
454 | __ftrace_replace_code(struct dyn_ftrace *rec, |
455 | unsigned char *old, unsigned char *new, int enable) | |
456 | { | |
41c52c0d | 457 | unsigned long ip, fl; |
5072c59f SR |
458 | |
459 | ip = rec->ip; | |
460 | ||
461 | if (ftrace_filtered && enable) { | |
5072c59f SR |
462 | /* |
463 | * If filtering is on: | |
464 | * | |
465 | * If this record is set to be filtered and | |
466 | * is enabled then do nothing. | |
467 | * | |
468 | * If this record is set to be filtered and | |
469 | * it is not enabled, enable it. | |
470 | * | |
471 | * If this record is not set to be filtered | |
472 | * and it is not enabled do nothing. | |
473 | * | |
41c52c0d SR |
474 | * If this record is set not to trace then |
475 | * do nothing. | |
476 | * | |
a4500b84 AS |
477 | * If this record is set not to trace and |
478 | * it is enabled then disable it. | |
479 | * | |
5072c59f SR |
480 | * If this record is not set to be filtered and |
481 | * it is enabled, disable it. | |
482 | */ | |
a4500b84 AS |
483 | |
484 | fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE | | |
485 | FTRACE_FL_ENABLED); | |
5072c59f SR |
486 | |
487 | if ((fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) || | |
a4500b84 AS |
488 | (fl == (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE)) || |
489 | !fl || (fl == FTRACE_FL_NOTRACE)) | |
0eb96701 | 490 | return 0; |
5072c59f SR |
491 | |
492 | /* | |
493 | * If it is enabled disable it, | |
494 | * otherwise enable it! | |
495 | */ | |
a4500b84 | 496 | if (fl & FTRACE_FL_ENABLED) { |
5072c59f SR |
497 | /* swap new and old */ |
498 | new = old; | |
499 | old = ftrace_call_replace(ip, FTRACE_ADDR); | |
500 | rec->flags &= ~FTRACE_FL_ENABLED; | |
501 | } else { | |
502 | new = ftrace_call_replace(ip, FTRACE_ADDR); | |
503 | rec->flags |= FTRACE_FL_ENABLED; | |
504 | } | |
505 | } else { | |
506 | ||
41c52c0d SR |
507 | if (enable) { |
508 | /* | |
509 | * If this record is set not to trace and is | |
510 | * not enabled, do nothing. | |
511 | */ | |
512 | fl = rec->flags & (FTRACE_FL_NOTRACE | FTRACE_FL_ENABLED); | |
513 | if (fl == FTRACE_FL_NOTRACE) | |
0eb96701 | 514 | return 0; |
41c52c0d | 515 | |
5072c59f | 516 | new = ftrace_call_replace(ip, FTRACE_ADDR); |
41c52c0d | 517 | } else |
5072c59f SR |
518 | old = ftrace_call_replace(ip, FTRACE_ADDR); |
519 | ||
520 | if (enable) { | |
521 | if (rec->flags & FTRACE_FL_ENABLED) | |
0eb96701 | 522 | return 0; |
5072c59f SR |
523 | rec->flags |= FTRACE_FL_ENABLED; |
524 | } else { | |
525 | if (!(rec->flags & FTRACE_FL_ENABLED)) | |
0eb96701 | 526 | return 0; |
5072c59f SR |
527 | rec->flags &= ~FTRACE_FL_ENABLED; |
528 | } | |
529 | } | |
530 | ||
0eb96701 | 531 | return ftrace_modify_code(ip, old, new); |
5072c59f SR |
532 | } |
533 | ||
e309b41d | 534 | static void ftrace_replace_code(int enable) |
3c1720f0 | 535 | { |
0eb96701 | 536 | int i, failed; |
3c1720f0 SR |
537 | unsigned char *new = NULL, *old = NULL; |
538 | struct dyn_ftrace *rec; | |
539 | struct ftrace_page *pg; | |
3c1720f0 | 540 | |
5072c59f | 541 | if (enable) |
3c1720f0 SR |
542 | old = ftrace_nop_replace(); |
543 | else | |
544 | new = ftrace_nop_replace(); | |
545 | ||
546 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
547 | for (i = 0; i < pg->index; i++) { | |
548 | rec = &pg->records[i]; | |
549 | ||
550 | /* don't modify code that has already faulted */ | |
551 | if (rec->flags & FTRACE_FL_FAILED) | |
552 | continue; | |
553 | ||
f22f9a89 | 554 | /* ignore updates to this record's mcount site */ |
98a05ed4 AS |
555 | if (get_kprobe((void *)rec->ip)) { |
556 | freeze_record(rec); | |
f22f9a89 | 557 | continue; |
98a05ed4 AS |
558 | } else { |
559 | unfreeze_record(rec); | |
560 | } | |
f22f9a89 | 561 | |
0eb96701 AS |
562 | failed = __ftrace_replace_code(rec, old, new, enable); |
563 | if (failed && (rec->flags & FTRACE_FL_CONVERTED)) { | |
564 | rec->flags |= FTRACE_FL_FAILED; | |
565 | if ((system_state == SYSTEM_BOOTING) || | |
34078a5e | 566 | !core_kernel_text(rec->ip)) { |
0eb96701 AS |
567 | ftrace_del_hash(rec); |
568 | ftrace_free_rec(rec); | |
569 | } | |
570 | } | |
3c1720f0 SR |
571 | } |
572 | } | |
573 | } | |
574 | ||
e309b41d | 575 | static void ftrace_shutdown_replenish(void) |
3c1720f0 SR |
576 | { |
577 | if (ftrace_pages->next) | |
578 | return; | |
579 | ||
580 | /* allocate another page */ | |
581 | ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL); | |
582 | } | |
3d083395 | 583 | |
05736a42 SR |
584 | static void print_ip_ins(const char *fmt, unsigned char *p) |
585 | { | |
586 | int i; | |
587 | ||
588 | printk(KERN_CONT "%s", fmt); | |
589 | ||
590 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
591 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
592 | } | |
593 | ||
492a7ea5 | 594 | static int |
d61f82d0 | 595 | ftrace_code_disable(struct dyn_ftrace *rec) |
3c1720f0 SR |
596 | { |
597 | unsigned long ip; | |
598 | unsigned char *nop, *call; | |
599 | int failed; | |
600 | ||
601 | ip = rec->ip; | |
602 | ||
603 | nop = ftrace_nop_replace(); | |
3b47bfc1 | 604 | call = ftrace_call_replace(ip, mcount_addr); |
3c1720f0 SR |
605 | |
606 | failed = ftrace_modify_code(ip, call, nop); | |
37ad5084 | 607 | if (failed) { |
05736a42 SR |
608 | switch (failed) { |
609 | case 1: | |
610 | WARN_ON_ONCE(1); | |
611 | pr_info("ftrace faulted on modifying "); | |
612 | print_ip_sym(ip); | |
613 | break; | |
614 | case 2: | |
615 | WARN_ON_ONCE(1); | |
616 | pr_info("ftrace failed to modify "); | |
617 | print_ip_sym(ip); | |
618 | print_ip_ins(" expected: ", call); | |
619 | print_ip_ins(" actual: ", (unsigned char *)ip); | |
620 | print_ip_ins(" replace: ", nop); | |
621 | printk(KERN_CONT "\n"); | |
622 | break; | |
623 | } | |
624 | ||
3c1720f0 | 625 | rec->flags |= FTRACE_FL_FAILED; |
492a7ea5 | 626 | return 0; |
37ad5084 | 627 | } |
492a7ea5 | 628 | return 1; |
3c1720f0 SR |
629 | } |
630 | ||
ad90c0e3 SR |
631 | static int __ftrace_update_code(void *ignore); |
632 | ||
e309b41d | 633 | static int __ftrace_modify_code(void *data) |
3d083395 | 634 | { |
d61f82d0 SR |
635 | unsigned long addr; |
636 | int *command = data; | |
637 | ||
ad90c0e3 SR |
638 | if (*command & FTRACE_ENABLE_CALLS) { |
639 | /* | |
640 | * Update any recorded ips now that we have the | |
641 | * machine stopped | |
642 | */ | |
643 | __ftrace_update_code(NULL); | |
d61f82d0 | 644 | ftrace_replace_code(1); |
ecea656d AS |
645 | tracing_on = 1; |
646 | } else if (*command & FTRACE_DISABLE_CALLS) { | |
d61f82d0 | 647 | ftrace_replace_code(0); |
ecea656d AS |
648 | tracing_on = 0; |
649 | } | |
d61f82d0 SR |
650 | |
651 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
652 | ftrace_update_ftrace_func(ftrace_trace_function); | |
653 | ||
654 | if (*command & FTRACE_ENABLE_MCOUNT) { | |
655 | addr = (unsigned long)ftrace_record_ip; | |
656 | ftrace_mcount_set(&addr); | |
657 | } else if (*command & FTRACE_DISABLE_MCOUNT) { | |
658 | addr = (unsigned long)ftrace_stub; | |
659 | ftrace_mcount_set(&addr); | |
660 | } | |
661 | ||
662 | return 0; | |
3d083395 SR |
663 | } |
664 | ||
e309b41d | 665 | static void ftrace_run_update_code(int command) |
3d083395 | 666 | { |
784e2d76 | 667 | stop_machine(__ftrace_modify_code, &command, NULL); |
3d083395 SR |
668 | } |
669 | ||
ad90c0e3 SR |
670 | void ftrace_disable_daemon(void) |
671 | { | |
672 | /* Stop the daemon from calling kstop_machine */ | |
673 | mutex_lock(&ftraced_lock); | |
674 | ftraced_stop = 1; | |
675 | mutex_unlock(&ftraced_lock); | |
676 | ||
677 | ftrace_force_update(); | |
678 | } | |
679 | ||
680 | void ftrace_enable_daemon(void) | |
681 | { | |
682 | mutex_lock(&ftraced_lock); | |
683 | ftraced_stop = 0; | |
684 | mutex_unlock(&ftraced_lock); | |
685 | ||
686 | ftrace_force_update(); | |
687 | } | |
688 | ||
d61f82d0 SR |
689 | static ftrace_func_t saved_ftrace_func; |
690 | ||
e309b41d | 691 | static void ftrace_startup(void) |
3d083395 | 692 | { |
d61f82d0 SR |
693 | int command = 0; |
694 | ||
4eebcc81 SR |
695 | if (unlikely(ftrace_disabled)) |
696 | return; | |
697 | ||
3d083395 SR |
698 | mutex_lock(&ftraced_lock); |
699 | ftraced_suspend++; | |
d61f82d0 SR |
700 | if (ftraced_suspend == 1) |
701 | command |= FTRACE_ENABLE_CALLS; | |
702 | ||
703 | if (saved_ftrace_func != ftrace_trace_function) { | |
704 | saved_ftrace_func = ftrace_trace_function; | |
705 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
706 | } | |
707 | ||
708 | if (!command || !ftrace_enabled) | |
3d083395 | 709 | goto out; |
3d083395 | 710 | |
d61f82d0 | 711 | ftrace_run_update_code(command); |
3d083395 SR |
712 | out: |
713 | mutex_unlock(&ftraced_lock); | |
714 | } | |
715 | ||
e309b41d | 716 | static void ftrace_shutdown(void) |
3d083395 | 717 | { |
d61f82d0 SR |
718 | int command = 0; |
719 | ||
4eebcc81 SR |
720 | if (unlikely(ftrace_disabled)) |
721 | return; | |
722 | ||
3d083395 SR |
723 | mutex_lock(&ftraced_lock); |
724 | ftraced_suspend--; | |
d61f82d0 SR |
725 | if (!ftraced_suspend) |
726 | command |= FTRACE_DISABLE_CALLS; | |
3d083395 | 727 | |
d61f82d0 SR |
728 | if (saved_ftrace_func != ftrace_trace_function) { |
729 | saved_ftrace_func = ftrace_trace_function; | |
730 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
731 | } | |
3d083395 | 732 | |
d61f82d0 SR |
733 | if (!command || !ftrace_enabled) |
734 | goto out; | |
735 | ||
736 | ftrace_run_update_code(command); | |
3d083395 SR |
737 | out: |
738 | mutex_unlock(&ftraced_lock); | |
739 | } | |
740 | ||
e309b41d | 741 | static void ftrace_startup_sysctl(void) |
b0fc494f | 742 | { |
d61f82d0 SR |
743 | int command = FTRACE_ENABLE_MCOUNT; |
744 | ||
4eebcc81 SR |
745 | if (unlikely(ftrace_disabled)) |
746 | return; | |
747 | ||
b0fc494f | 748 | mutex_lock(&ftraced_lock); |
d61f82d0 SR |
749 | /* Force update next time */ |
750 | saved_ftrace_func = NULL; | |
b0fc494f SR |
751 | /* ftraced_suspend is true if we want ftrace running */ |
752 | if (ftraced_suspend) | |
d61f82d0 SR |
753 | command |= FTRACE_ENABLE_CALLS; |
754 | ||
755 | ftrace_run_update_code(command); | |
b0fc494f SR |
756 | mutex_unlock(&ftraced_lock); |
757 | } | |
758 | ||
e309b41d | 759 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 760 | { |
d61f82d0 SR |
761 | int command = FTRACE_DISABLE_MCOUNT; |
762 | ||
4eebcc81 SR |
763 | if (unlikely(ftrace_disabled)) |
764 | return; | |
765 | ||
b0fc494f SR |
766 | mutex_lock(&ftraced_lock); |
767 | /* ftraced_suspend is true if ftrace is running */ | |
768 | if (ftraced_suspend) | |
d61f82d0 SR |
769 | command |= FTRACE_DISABLE_CALLS; |
770 | ||
771 | ftrace_run_update_code(command); | |
b0fc494f SR |
772 | mutex_unlock(&ftraced_lock); |
773 | } | |
774 | ||
3d083395 SR |
775 | static cycle_t ftrace_update_time; |
776 | static unsigned long ftrace_update_cnt; | |
777 | unsigned long ftrace_update_tot_cnt; | |
778 | ||
e309b41d | 779 | static int __ftrace_update_code(void *ignore) |
3d083395 | 780 | { |
f22f9a89 AS |
781 | int i, save_ftrace_enabled; |
782 | cycle_t start, stop; | |
3d083395 | 783 | struct dyn_ftrace *p; |
0eb96701 | 784 | struct hlist_node *t, *n; |
f22f9a89 | 785 | struct hlist_head *head, temp_list; |
3d083395 | 786 | |
d61f82d0 | 787 | /* Don't be recording funcs now */ |
ad90c0e3 | 788 | ftrace_record_suspend++; |
d61f82d0 SR |
789 | save_ftrace_enabled = ftrace_enabled; |
790 | ftrace_enabled = 0; | |
3d083395 | 791 | |
750ed1a4 | 792 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
793 | ftrace_update_cnt = 0; |
794 | ||
795 | /* No locks needed, the machine is stopped! */ | |
796 | for (i = 0; i < FTRACE_HASHSIZE; i++) { | |
f22f9a89 AS |
797 | INIT_HLIST_HEAD(&temp_list); |
798 | head = &ftrace_hash[i]; | |
799 | ||
0eb96701 | 800 | /* all CPUS are stopped, we are safe to modify code */ |
f22f9a89 | 801 | hlist_for_each_entry_safe(p, t, n, head, node) { |
0eb96701 AS |
802 | /* Skip over failed records which have not been |
803 | * freed. */ | |
804 | if (p->flags & FTRACE_FL_FAILED) | |
805 | continue; | |
3d083395 | 806 | |
0eb96701 AS |
807 | /* Unconverted records are always at the head of the |
808 | * hash bucket. Once we encounter a converted record, | |
809 | * simply skip over to the next bucket. Saves ftraced | |
810 | * some processor cycles (ftrace does its bid for | |
811 | * global warming :-p ). */ | |
812 | if (p->flags & (FTRACE_FL_CONVERTED)) | |
813 | break; | |
3d083395 | 814 | |
f22f9a89 AS |
815 | /* Ignore updates to this record's mcount site. |
816 | * Reintroduce this record at the head of this | |
817 | * bucket to attempt to "convert" it again if | |
818 | * the kprobe on it is unregistered before the | |
819 | * next run. */ | |
820 | if (get_kprobe((void *)p->ip)) { | |
821 | ftrace_del_hash(p); | |
822 | INIT_HLIST_NODE(&p->node); | |
823 | hlist_add_head(&p->node, &temp_list); | |
98a05ed4 | 824 | freeze_record(p); |
f22f9a89 | 825 | continue; |
98a05ed4 AS |
826 | } else { |
827 | unfreeze_record(p); | |
f22f9a89 AS |
828 | } |
829 | ||
830 | /* convert record (i.e, patch mcount-call with NOP) */ | |
0eb96701 AS |
831 | if (ftrace_code_disable(p)) { |
832 | p->flags |= FTRACE_FL_CONVERTED; | |
492a7ea5 | 833 | ftrace_update_cnt++; |
0eb96701 AS |
834 | } else { |
835 | if ((system_state == SYSTEM_BOOTING) || | |
34078a5e | 836 | !core_kernel_text(p->ip)) { |
0eb96701 AS |
837 | ftrace_del_hash(p); |
838 | ftrace_free_rec(p); | |
0eb96701 AS |
839 | } |
840 | } | |
3d083395 | 841 | } |
f22f9a89 AS |
842 | |
843 | hlist_for_each_entry_safe(p, t, n, &temp_list, node) { | |
844 | hlist_del(&p->node); | |
845 | INIT_HLIST_NODE(&p->node); | |
846 | hlist_add_head(&p->node, head); | |
847 | } | |
3d083395 SR |
848 | } |
849 | ||
750ed1a4 | 850 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
851 | ftrace_update_time = stop - start; |
852 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
ad90c0e3 | 853 | ftraced_trigger = 0; |
3d083395 | 854 | |
d61f82d0 | 855 | ftrace_enabled = save_ftrace_enabled; |
ad90c0e3 | 856 | ftrace_record_suspend--; |
16444a8a ACM |
857 | |
858 | return 0; | |
859 | } | |
860 | ||
ad90c0e3 | 861 | static int ftrace_update_code(void) |
3d083395 | 862 | { |
ad90c0e3 SR |
863 | if (unlikely(ftrace_disabled) || |
864 | !ftrace_enabled || !ftraced_trigger) | |
865 | return 0; | |
4eebcc81 | 866 | |
784e2d76 | 867 | stop_machine(__ftrace_update_code, NULL, NULL); |
ad90c0e3 SR |
868 | |
869 | return 1; | |
3d083395 SR |
870 | } |
871 | ||
68bf21aa | 872 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
873 | { |
874 | struct ftrace_page *pg; | |
875 | int cnt; | |
876 | int i; | |
3c1720f0 SR |
877 | |
878 | /* allocate a few pages */ | |
879 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
880 | if (!ftrace_pages_start) | |
881 | return -1; | |
882 | ||
883 | /* | |
884 | * Allocate a few more pages. | |
885 | * | |
886 | * TODO: have some parser search vmlinux before | |
887 | * final linking to find all calls to ftrace. | |
888 | * Then we can: | |
889 | * a) know how many pages to allocate. | |
890 | * and/or | |
891 | * b) set up the table then. | |
892 | * | |
893 | * The dynamic code is still necessary for | |
894 | * modules. | |
895 | */ | |
896 | ||
897 | pg = ftrace_pages = ftrace_pages_start; | |
898 | ||
68bf21aa SR |
899 | cnt = num_to_init / ENTRIES_PER_PAGE; |
900 | pr_info("ftrace: allocating %ld hash entries in %d pages\n", | |
901 | num_to_init, cnt); | |
3c1720f0 SR |
902 | |
903 | for (i = 0; i < cnt; i++) { | |
904 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
905 | ||
906 | /* If we fail, we'll try later anyway */ | |
907 | if (!pg->next) | |
908 | break; | |
909 | ||
910 | pg = pg->next; | |
911 | } | |
912 | ||
913 | return 0; | |
914 | } | |
915 | ||
5072c59f SR |
916 | enum { |
917 | FTRACE_ITER_FILTER = (1 << 0), | |
918 | FTRACE_ITER_CONT = (1 << 1), | |
41c52c0d | 919 | FTRACE_ITER_NOTRACE = (1 << 2), |
eb9a7bf0 | 920 | FTRACE_ITER_FAILURES = (1 << 3), |
5072c59f SR |
921 | }; |
922 | ||
923 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
924 | ||
925 | struct ftrace_iterator { | |
926 | loff_t pos; | |
927 | struct ftrace_page *pg; | |
928 | unsigned idx; | |
929 | unsigned flags; | |
930 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
931 | unsigned buffer_idx; | |
932 | unsigned filtered; | |
933 | }; | |
934 | ||
e309b41d | 935 | static void * |
5072c59f SR |
936 | t_next(struct seq_file *m, void *v, loff_t *pos) |
937 | { | |
938 | struct ftrace_iterator *iter = m->private; | |
939 | struct dyn_ftrace *rec = NULL; | |
940 | ||
941 | (*pos)++; | |
942 | ||
99ecdc43 SR |
943 | /* should not be called from interrupt context */ |
944 | spin_lock(&ftrace_lock); | |
5072c59f SR |
945 | retry: |
946 | if (iter->idx >= iter->pg->index) { | |
947 | if (iter->pg->next) { | |
948 | iter->pg = iter->pg->next; | |
949 | iter->idx = 0; | |
950 | goto retry; | |
951 | } | |
952 | } else { | |
953 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
954 | if ((rec->flags & FTRACE_FL_FREE) || |
955 | ||
956 | (!(iter->flags & FTRACE_ITER_FAILURES) && | |
eb9a7bf0 AS |
957 | (rec->flags & FTRACE_FL_FAILED)) || |
958 | ||
959 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
a9fdda33 | 960 | !(rec->flags & FTRACE_FL_FAILED)) || |
eb9a7bf0 | 961 | |
41c52c0d SR |
962 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
963 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
964 | rec = NULL; |
965 | goto retry; | |
966 | } | |
967 | } | |
99ecdc43 | 968 | spin_unlock(&ftrace_lock); |
5072c59f SR |
969 | |
970 | iter->pos = *pos; | |
971 | ||
972 | return rec; | |
973 | } | |
974 | ||
975 | static void *t_start(struct seq_file *m, loff_t *pos) | |
976 | { | |
977 | struct ftrace_iterator *iter = m->private; | |
978 | void *p = NULL; | |
979 | loff_t l = -1; | |
980 | ||
981 | if (*pos != iter->pos) { | |
982 | for (p = t_next(m, p, &l); p && l < *pos; p = t_next(m, p, &l)) | |
983 | ; | |
984 | } else { | |
985 | l = *pos; | |
986 | p = t_next(m, p, &l); | |
987 | } | |
988 | ||
989 | return p; | |
990 | } | |
991 | ||
992 | static void t_stop(struct seq_file *m, void *p) | |
993 | { | |
994 | } | |
995 | ||
996 | static int t_show(struct seq_file *m, void *v) | |
997 | { | |
998 | struct dyn_ftrace *rec = v; | |
999 | char str[KSYM_SYMBOL_LEN]; | |
1000 | ||
1001 | if (!rec) | |
1002 | return 0; | |
1003 | ||
1004 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1005 | ||
1006 | seq_printf(m, "%s\n", str); | |
1007 | ||
1008 | return 0; | |
1009 | } | |
1010 | ||
1011 | static struct seq_operations show_ftrace_seq_ops = { | |
1012 | .start = t_start, | |
1013 | .next = t_next, | |
1014 | .stop = t_stop, | |
1015 | .show = t_show, | |
1016 | }; | |
1017 | ||
e309b41d | 1018 | static int |
5072c59f SR |
1019 | ftrace_avail_open(struct inode *inode, struct file *file) |
1020 | { | |
1021 | struct ftrace_iterator *iter; | |
1022 | int ret; | |
1023 | ||
4eebcc81 SR |
1024 | if (unlikely(ftrace_disabled)) |
1025 | return -ENODEV; | |
1026 | ||
5072c59f SR |
1027 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1028 | if (!iter) | |
1029 | return -ENOMEM; | |
1030 | ||
1031 | iter->pg = ftrace_pages_start; | |
1032 | iter->pos = -1; | |
1033 | ||
1034 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1035 | if (!ret) { | |
1036 | struct seq_file *m = file->private_data; | |
4bf39a94 | 1037 | |
5072c59f | 1038 | m->private = iter; |
4bf39a94 | 1039 | } else { |
5072c59f | 1040 | kfree(iter); |
4bf39a94 | 1041 | } |
5072c59f SR |
1042 | |
1043 | return ret; | |
1044 | } | |
1045 | ||
1046 | int ftrace_avail_release(struct inode *inode, struct file *file) | |
1047 | { | |
1048 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1049 | struct ftrace_iterator *iter = m->private; | |
1050 | ||
1051 | seq_release(inode, file); | |
1052 | kfree(iter); | |
4bf39a94 | 1053 | |
5072c59f SR |
1054 | return 0; |
1055 | } | |
1056 | ||
eb9a7bf0 AS |
1057 | static int |
1058 | ftrace_failures_open(struct inode *inode, struct file *file) | |
1059 | { | |
1060 | int ret; | |
1061 | struct seq_file *m; | |
1062 | struct ftrace_iterator *iter; | |
1063 | ||
1064 | ret = ftrace_avail_open(inode, file); | |
1065 | if (!ret) { | |
1066 | m = (struct seq_file *)file->private_data; | |
1067 | iter = (struct ftrace_iterator *)m->private; | |
1068 | iter->flags = FTRACE_ITER_FAILURES; | |
1069 | } | |
1070 | ||
1071 | return ret; | |
1072 | } | |
1073 | ||
1074 | ||
41c52c0d | 1075 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
1076 | { |
1077 | struct ftrace_page *pg; | |
1078 | struct dyn_ftrace *rec; | |
41c52c0d | 1079 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f SR |
1080 | unsigned i; |
1081 | ||
99ecdc43 SR |
1082 | /* should not be called from interrupt context */ |
1083 | spin_lock(&ftrace_lock); | |
41c52c0d SR |
1084 | if (enable) |
1085 | ftrace_filtered = 0; | |
5072c59f SR |
1086 | pg = ftrace_pages_start; |
1087 | while (pg) { | |
1088 | for (i = 0; i < pg->index; i++) { | |
1089 | rec = &pg->records[i]; | |
1090 | if (rec->flags & FTRACE_FL_FAILED) | |
1091 | continue; | |
41c52c0d | 1092 | rec->flags &= ~type; |
5072c59f SR |
1093 | } |
1094 | pg = pg->next; | |
1095 | } | |
99ecdc43 | 1096 | spin_unlock(&ftrace_lock); |
5072c59f SR |
1097 | } |
1098 | ||
e309b41d | 1099 | static int |
41c52c0d | 1100 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1101 | { |
1102 | struct ftrace_iterator *iter; | |
1103 | int ret = 0; | |
1104 | ||
4eebcc81 SR |
1105 | if (unlikely(ftrace_disabled)) |
1106 | return -ENODEV; | |
1107 | ||
5072c59f SR |
1108 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1109 | if (!iter) | |
1110 | return -ENOMEM; | |
1111 | ||
41c52c0d | 1112 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1113 | if ((file->f_mode & FMODE_WRITE) && |
1114 | !(file->f_flags & O_APPEND)) | |
41c52c0d | 1115 | ftrace_filter_reset(enable); |
5072c59f SR |
1116 | |
1117 | if (file->f_mode & FMODE_READ) { | |
1118 | iter->pg = ftrace_pages_start; | |
1119 | iter->pos = -1; | |
41c52c0d SR |
1120 | iter->flags = enable ? FTRACE_ITER_FILTER : |
1121 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
1122 | |
1123 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1124 | if (!ret) { | |
1125 | struct seq_file *m = file->private_data; | |
1126 | m->private = iter; | |
1127 | } else | |
1128 | kfree(iter); | |
1129 | } else | |
1130 | file->private_data = iter; | |
41c52c0d | 1131 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1132 | |
1133 | return ret; | |
1134 | } | |
1135 | ||
41c52c0d SR |
1136 | static int |
1137 | ftrace_filter_open(struct inode *inode, struct file *file) | |
1138 | { | |
1139 | return ftrace_regex_open(inode, file, 1); | |
1140 | } | |
1141 | ||
1142 | static int | |
1143 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
1144 | { | |
1145 | return ftrace_regex_open(inode, file, 0); | |
1146 | } | |
1147 | ||
e309b41d | 1148 | static ssize_t |
41c52c0d | 1149 | ftrace_regex_read(struct file *file, char __user *ubuf, |
5072c59f SR |
1150 | size_t cnt, loff_t *ppos) |
1151 | { | |
1152 | if (file->f_mode & FMODE_READ) | |
1153 | return seq_read(file, ubuf, cnt, ppos); | |
1154 | else | |
1155 | return -EPERM; | |
1156 | } | |
1157 | ||
e309b41d | 1158 | static loff_t |
41c52c0d | 1159 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
1160 | { |
1161 | loff_t ret; | |
1162 | ||
1163 | if (file->f_mode & FMODE_READ) | |
1164 | ret = seq_lseek(file, offset, origin); | |
1165 | else | |
1166 | file->f_pos = ret = 1; | |
1167 | ||
1168 | return ret; | |
1169 | } | |
1170 | ||
1171 | enum { | |
1172 | MATCH_FULL, | |
1173 | MATCH_FRONT_ONLY, | |
1174 | MATCH_MIDDLE_ONLY, | |
1175 | MATCH_END_ONLY, | |
1176 | }; | |
1177 | ||
e309b41d | 1178 | static void |
41c52c0d | 1179 | ftrace_match(unsigned char *buff, int len, int enable) |
5072c59f SR |
1180 | { |
1181 | char str[KSYM_SYMBOL_LEN]; | |
1182 | char *search = NULL; | |
1183 | struct ftrace_page *pg; | |
1184 | struct dyn_ftrace *rec; | |
1185 | int type = MATCH_FULL; | |
41c52c0d | 1186 | unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f SR |
1187 | unsigned i, match = 0, search_len = 0; |
1188 | ||
1189 | for (i = 0; i < len; i++) { | |
1190 | if (buff[i] == '*') { | |
1191 | if (!i) { | |
1192 | search = buff + i + 1; | |
1193 | type = MATCH_END_ONLY; | |
1194 | search_len = len - (i + 1); | |
1195 | } else { | |
1196 | if (type == MATCH_END_ONLY) { | |
1197 | type = MATCH_MIDDLE_ONLY; | |
1198 | } else { | |
1199 | match = i; | |
1200 | type = MATCH_FRONT_ONLY; | |
1201 | } | |
1202 | buff[i] = 0; | |
1203 | break; | |
1204 | } | |
1205 | } | |
1206 | } | |
1207 | ||
99ecdc43 SR |
1208 | /* should not be called from interrupt context */ |
1209 | spin_lock(&ftrace_lock); | |
41c52c0d SR |
1210 | if (enable) |
1211 | ftrace_filtered = 1; | |
5072c59f SR |
1212 | pg = ftrace_pages_start; |
1213 | while (pg) { | |
1214 | for (i = 0; i < pg->index; i++) { | |
1215 | int matched = 0; | |
1216 | char *ptr; | |
1217 | ||
1218 | rec = &pg->records[i]; | |
1219 | if (rec->flags & FTRACE_FL_FAILED) | |
1220 | continue; | |
1221 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1222 | switch (type) { | |
1223 | case MATCH_FULL: | |
1224 | if (strcmp(str, buff) == 0) | |
1225 | matched = 1; | |
1226 | break; | |
1227 | case MATCH_FRONT_ONLY: | |
1228 | if (memcmp(str, buff, match) == 0) | |
1229 | matched = 1; | |
1230 | break; | |
1231 | case MATCH_MIDDLE_ONLY: | |
1232 | if (strstr(str, search)) | |
1233 | matched = 1; | |
1234 | break; | |
1235 | case MATCH_END_ONLY: | |
1236 | ptr = strstr(str, search); | |
1237 | if (ptr && (ptr[search_len] == 0)) | |
1238 | matched = 1; | |
1239 | break; | |
1240 | } | |
1241 | if (matched) | |
41c52c0d | 1242 | rec->flags |= flag; |
5072c59f SR |
1243 | } |
1244 | pg = pg->next; | |
1245 | } | |
99ecdc43 | 1246 | spin_unlock(&ftrace_lock); |
5072c59f SR |
1247 | } |
1248 | ||
e309b41d | 1249 | static ssize_t |
41c52c0d SR |
1250 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
1251 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
1252 | { |
1253 | struct ftrace_iterator *iter; | |
1254 | char ch; | |
1255 | size_t read = 0; | |
1256 | ssize_t ret; | |
1257 | ||
1258 | if (!cnt || cnt < 0) | |
1259 | return 0; | |
1260 | ||
41c52c0d | 1261 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1262 | |
1263 | if (file->f_mode & FMODE_READ) { | |
1264 | struct seq_file *m = file->private_data; | |
1265 | iter = m->private; | |
1266 | } else | |
1267 | iter = file->private_data; | |
1268 | ||
1269 | if (!*ppos) { | |
1270 | iter->flags &= ~FTRACE_ITER_CONT; | |
1271 | iter->buffer_idx = 0; | |
1272 | } | |
1273 | ||
1274 | ret = get_user(ch, ubuf++); | |
1275 | if (ret) | |
1276 | goto out; | |
1277 | read++; | |
1278 | cnt--; | |
1279 | ||
1280 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { | |
1281 | /* skip white space */ | |
1282 | while (cnt && isspace(ch)) { | |
1283 | ret = get_user(ch, ubuf++); | |
1284 | if (ret) | |
1285 | goto out; | |
1286 | read++; | |
1287 | cnt--; | |
1288 | } | |
1289 | ||
5072c59f SR |
1290 | if (isspace(ch)) { |
1291 | file->f_pos += read; | |
1292 | ret = read; | |
1293 | goto out; | |
1294 | } | |
1295 | ||
1296 | iter->buffer_idx = 0; | |
1297 | } | |
1298 | ||
1299 | while (cnt && !isspace(ch)) { | |
1300 | if (iter->buffer_idx < FTRACE_BUFF_MAX) | |
1301 | iter->buffer[iter->buffer_idx++] = ch; | |
1302 | else { | |
1303 | ret = -EINVAL; | |
1304 | goto out; | |
1305 | } | |
1306 | ret = get_user(ch, ubuf++); | |
1307 | if (ret) | |
1308 | goto out; | |
1309 | read++; | |
1310 | cnt--; | |
1311 | } | |
1312 | ||
1313 | if (isspace(ch)) { | |
1314 | iter->filtered++; | |
1315 | iter->buffer[iter->buffer_idx] = 0; | |
41c52c0d | 1316 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1317 | iter->buffer_idx = 0; |
1318 | } else | |
1319 | iter->flags |= FTRACE_ITER_CONT; | |
1320 | ||
1321 | ||
1322 | file->f_pos += read; | |
1323 | ||
1324 | ret = read; | |
1325 | out: | |
41c52c0d | 1326 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1327 | |
1328 | return ret; | |
1329 | } | |
1330 | ||
41c52c0d SR |
1331 | static ssize_t |
1332 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
1333 | size_t cnt, loff_t *ppos) | |
1334 | { | |
1335 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
1336 | } | |
1337 | ||
1338 | static ssize_t | |
1339 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
1340 | size_t cnt, loff_t *ppos) | |
1341 | { | |
1342 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
1343 | } | |
1344 | ||
1345 | static void | |
1346 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
1347 | { | |
1348 | if (unlikely(ftrace_disabled)) | |
1349 | return; | |
1350 | ||
1351 | mutex_lock(&ftrace_regex_lock); | |
1352 | if (reset) | |
1353 | ftrace_filter_reset(enable); | |
1354 | if (buf) | |
1355 | ftrace_match(buf, len, enable); | |
1356 | mutex_unlock(&ftrace_regex_lock); | |
1357 | } | |
1358 | ||
77a2b37d SR |
1359 | /** |
1360 | * ftrace_set_filter - set a function to filter on in ftrace | |
1361 | * @buf - the string that holds the function filter text. | |
1362 | * @len - the length of the string. | |
1363 | * @reset - non zero to reset all filters before applying this filter. | |
1364 | * | |
1365 | * Filters denote which functions should be enabled when tracing is enabled. | |
1366 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
1367 | */ | |
e309b41d | 1368 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 1369 | { |
41c52c0d SR |
1370 | ftrace_set_regex(buf, len, reset, 1); |
1371 | } | |
4eebcc81 | 1372 | |
41c52c0d SR |
1373 | /** |
1374 | * ftrace_set_notrace - set a function to not trace in ftrace | |
1375 | * @buf - the string that holds the function notrace text. | |
1376 | * @len - the length of the string. | |
1377 | * @reset - non zero to reset all filters before applying this filter. | |
1378 | * | |
1379 | * Notrace Filters denote which functions should not be enabled when tracing | |
1380 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
1381 | * for tracing. | |
1382 | */ | |
1383 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
1384 | { | |
1385 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
1386 | } |
1387 | ||
e309b41d | 1388 | static int |
41c52c0d | 1389 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1390 | { |
1391 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1392 | struct ftrace_iterator *iter; | |
1393 | ||
41c52c0d | 1394 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1395 | if (file->f_mode & FMODE_READ) { |
1396 | iter = m->private; | |
1397 | ||
1398 | seq_release(inode, file); | |
1399 | } else | |
1400 | iter = file->private_data; | |
1401 | ||
1402 | if (iter->buffer_idx) { | |
1403 | iter->filtered++; | |
1404 | iter->buffer[iter->buffer_idx] = 0; | |
41c52c0d | 1405 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1406 | } |
1407 | ||
1408 | mutex_lock(&ftrace_sysctl_lock); | |
1409 | mutex_lock(&ftraced_lock); | |
1410 | if (iter->filtered && ftraced_suspend && ftrace_enabled) | |
1411 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); | |
1412 | mutex_unlock(&ftraced_lock); | |
1413 | mutex_unlock(&ftrace_sysctl_lock); | |
1414 | ||
1415 | kfree(iter); | |
41c52c0d | 1416 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1417 | return 0; |
1418 | } | |
1419 | ||
41c52c0d SR |
1420 | static int |
1421 | ftrace_filter_release(struct inode *inode, struct file *file) | |
1422 | { | |
1423 | return ftrace_regex_release(inode, file, 1); | |
1424 | } | |
1425 | ||
1426 | static int | |
1427 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
1428 | { | |
1429 | return ftrace_regex_release(inode, file, 0); | |
1430 | } | |
1431 | ||
ad90c0e3 SR |
1432 | static ssize_t |
1433 | ftraced_read(struct file *filp, char __user *ubuf, | |
1434 | size_t cnt, loff_t *ppos) | |
1435 | { | |
1436 | /* don't worry about races */ | |
1437 | char *buf = ftraced_stop ? "disabled\n" : "enabled\n"; | |
1438 | int r = strlen(buf); | |
1439 | ||
1440 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
1441 | } | |
1442 | ||
1443 | static ssize_t | |
1444 | ftraced_write(struct file *filp, const char __user *ubuf, | |
1445 | size_t cnt, loff_t *ppos) | |
1446 | { | |
1447 | char buf[64]; | |
1448 | long val; | |
1449 | int ret; | |
1450 | ||
1451 | if (cnt >= sizeof(buf)) | |
1452 | return -EINVAL; | |
1453 | ||
1454 | if (copy_from_user(&buf, ubuf, cnt)) | |
1455 | return -EFAULT; | |
1456 | ||
1457 | if (strncmp(buf, "enable", 6) == 0) | |
1458 | val = 1; | |
1459 | else if (strncmp(buf, "disable", 7) == 0) | |
1460 | val = 0; | |
1461 | else { | |
1462 | buf[cnt] = 0; | |
1463 | ||
1464 | ret = strict_strtoul(buf, 10, &val); | |
1465 | if (ret < 0) | |
1466 | return ret; | |
1467 | ||
1468 | val = !!val; | |
1469 | } | |
1470 | ||
1471 | if (val) | |
1472 | ftrace_enable_daemon(); | |
1473 | else | |
1474 | ftrace_disable_daemon(); | |
1475 | ||
1476 | filp->f_pos += cnt; | |
1477 | ||
1478 | return cnt; | |
1479 | } | |
1480 | ||
5072c59f SR |
1481 | static struct file_operations ftrace_avail_fops = { |
1482 | .open = ftrace_avail_open, | |
1483 | .read = seq_read, | |
1484 | .llseek = seq_lseek, | |
1485 | .release = ftrace_avail_release, | |
1486 | }; | |
1487 | ||
eb9a7bf0 AS |
1488 | static struct file_operations ftrace_failures_fops = { |
1489 | .open = ftrace_failures_open, | |
1490 | .read = seq_read, | |
1491 | .llseek = seq_lseek, | |
1492 | .release = ftrace_avail_release, | |
1493 | }; | |
1494 | ||
5072c59f SR |
1495 | static struct file_operations ftrace_filter_fops = { |
1496 | .open = ftrace_filter_open, | |
41c52c0d | 1497 | .read = ftrace_regex_read, |
5072c59f | 1498 | .write = ftrace_filter_write, |
41c52c0d | 1499 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
1500 | .release = ftrace_filter_release, |
1501 | }; | |
1502 | ||
41c52c0d SR |
1503 | static struct file_operations ftrace_notrace_fops = { |
1504 | .open = ftrace_notrace_open, | |
1505 | .read = ftrace_regex_read, | |
1506 | .write = ftrace_notrace_write, | |
1507 | .llseek = ftrace_regex_lseek, | |
1508 | .release = ftrace_notrace_release, | |
1509 | }; | |
1510 | ||
ad90c0e3 SR |
1511 | static struct file_operations ftraced_fops = { |
1512 | .open = tracing_open_generic, | |
1513 | .read = ftraced_read, | |
1514 | .write = ftraced_write, | |
1515 | }; | |
1516 | ||
e1c08bdd SR |
1517 | /** |
1518 | * ftrace_force_update - force an update to all recording ftrace functions | |
e1c08bdd SR |
1519 | */ |
1520 | int ftrace_force_update(void) | |
1521 | { | |
e1c08bdd SR |
1522 | int ret = 0; |
1523 | ||
4eebcc81 | 1524 | if (unlikely(ftrace_disabled)) |
e1c08bdd SR |
1525 | return -ENODEV; |
1526 | ||
ad90c0e3 | 1527 | mutex_lock(&ftrace_sysctl_lock); |
e1c08bdd | 1528 | mutex_lock(&ftraced_lock); |
e1c08bdd | 1529 | |
ad90c0e3 SR |
1530 | /* |
1531 | * If ftraced_trigger is not set, then there is nothing | |
1532 | * to update. | |
1533 | */ | |
1534 | if (ftraced_trigger && !ftrace_update_code()) | |
1535 | ret = -EBUSY; | |
e1c08bdd SR |
1536 | |
1537 | mutex_unlock(&ftraced_lock); | |
ad90c0e3 | 1538 | mutex_unlock(&ftrace_sysctl_lock); |
e1c08bdd SR |
1539 | |
1540 | return ret; | |
1541 | } | |
1542 | ||
4eebcc81 SR |
1543 | static void ftrace_force_shutdown(void) |
1544 | { | |
1545 | struct task_struct *task; | |
1546 | int command = FTRACE_DISABLE_CALLS | FTRACE_UPDATE_TRACE_FUNC; | |
1547 | ||
1548 | mutex_lock(&ftraced_lock); | |
1549 | task = ftraced_task; | |
1550 | ftraced_task = NULL; | |
1551 | ftraced_suspend = -1; | |
1552 | ftrace_run_update_code(command); | |
1553 | mutex_unlock(&ftraced_lock); | |
1554 | ||
1555 | if (task) | |
1556 | kthread_stop(task); | |
1557 | } | |
1558 | ||
5072c59f SR |
1559 | static __init int ftrace_init_debugfs(void) |
1560 | { | |
1561 | struct dentry *d_tracer; | |
1562 | struct dentry *entry; | |
1563 | ||
1564 | d_tracer = tracing_init_dentry(); | |
1565 | ||
1566 | entry = debugfs_create_file("available_filter_functions", 0444, | |
1567 | d_tracer, NULL, &ftrace_avail_fops); | |
1568 | if (!entry) | |
1569 | pr_warning("Could not create debugfs " | |
1570 | "'available_filter_functions' entry\n"); | |
1571 | ||
eb9a7bf0 AS |
1572 | entry = debugfs_create_file("failures", 0444, |
1573 | d_tracer, NULL, &ftrace_failures_fops); | |
1574 | if (!entry) | |
1575 | pr_warning("Could not create debugfs 'failures' entry\n"); | |
1576 | ||
5072c59f SR |
1577 | entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer, |
1578 | NULL, &ftrace_filter_fops); | |
1579 | if (!entry) | |
1580 | pr_warning("Could not create debugfs " | |
1581 | "'set_ftrace_filter' entry\n"); | |
41c52c0d SR |
1582 | |
1583 | entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer, | |
1584 | NULL, &ftrace_notrace_fops); | |
1585 | if (!entry) | |
1586 | pr_warning("Could not create debugfs " | |
1587 | "'set_ftrace_notrace' entry\n"); | |
ad90c0e3 SR |
1588 | |
1589 | entry = debugfs_create_file("ftraced_enabled", 0644, d_tracer, | |
1590 | NULL, &ftraced_fops); | |
1591 | if (!entry) | |
1592 | pr_warning("Could not create debugfs " | |
1593 | "'ftraced_enabled' entry\n"); | |
5072c59f SR |
1594 | return 0; |
1595 | } | |
1596 | ||
1597 | fs_initcall(ftrace_init_debugfs); | |
1598 | ||
68bf21aa SR |
1599 | #ifdef CONFIG_FTRACE_MCOUNT_RECORD |
1600 | static int ftrace_convert_nops(unsigned long *start, | |
1601 | unsigned long *end) | |
1602 | { | |
1603 | unsigned long *p; | |
1604 | unsigned long addr; | |
1605 | unsigned long flags; | |
1606 | ||
1607 | p = start; | |
1608 | while (p < end) { | |
1609 | addr = ftrace_call_adjust(*p++); | |
99ecdc43 | 1610 | /* should not be called from interrupt context */ |
fed1939c | 1611 | spin_lock(&ftrace_lock); |
68bf21aa | 1612 | ftrace_record_ip(addr); |
fed1939c | 1613 | spin_unlock(&ftrace_lock); |
68bf21aa SR |
1614 | ftrace_shutdown_replenish(); |
1615 | } | |
1616 | ||
1617 | /* p is ignored */ | |
1618 | local_irq_save(flags); | |
1619 | __ftrace_update_code(p); | |
1620 | local_irq_restore(flags); | |
1621 | ||
1622 | return 0; | |
1623 | } | |
1624 | ||
90d595fe SR |
1625 | void ftrace_init_module(unsigned long *start, unsigned long *end) |
1626 | { | |
00fd61ae | 1627 | if (ftrace_disabled || start == end) |
fed1939c | 1628 | return; |
90d595fe SR |
1629 | ftrace_convert_nops(start, end); |
1630 | } | |
1631 | ||
68bf21aa SR |
1632 | extern unsigned long __start_mcount_loc[]; |
1633 | extern unsigned long __stop_mcount_loc[]; | |
1634 | ||
1635 | void __init ftrace_init(void) | |
1636 | { | |
1637 | unsigned long count, addr, flags; | |
1638 | int ret; | |
1639 | ||
1640 | /* Keep the ftrace pointer to the stub */ | |
1641 | addr = (unsigned long)ftrace_stub; | |
1642 | ||
1643 | local_irq_save(flags); | |
1644 | ftrace_dyn_arch_init(&addr); | |
1645 | local_irq_restore(flags); | |
1646 | ||
1647 | /* ftrace_dyn_arch_init places the return code in addr */ | |
1648 | if (addr) | |
1649 | goto failed; | |
1650 | ||
1651 | count = __stop_mcount_loc - __start_mcount_loc; | |
1652 | ||
1653 | ret = ftrace_dyn_table_alloc(count); | |
1654 | if (ret) | |
1655 | goto failed; | |
1656 | ||
1657 | last_ftrace_enabled = ftrace_enabled = 1; | |
1658 | ||
1659 | ret = ftrace_convert_nops(__start_mcount_loc, | |
1660 | __stop_mcount_loc); | |
1661 | ||
1662 | return; | |
1663 | failed: | |
1664 | ftrace_disabled = 1; | |
1665 | } | |
1666 | #else /* CONFIG_FTRACE_MCOUNT_RECORD */ | |
bd95b88d SR |
1667 | |
1668 | static void ftrace_release_hash(unsigned long start, unsigned long end) | |
1669 | { | |
1670 | struct dyn_ftrace *rec; | |
1671 | struct hlist_node *t, *n; | |
1672 | struct hlist_head *head, temp_list; | |
1673 | unsigned long flags; | |
1674 | int i, cpu; | |
1675 | ||
1676 | preempt_disable_notrace(); | |
1677 | ||
1678 | /* disable incase we call something that calls mcount */ | |
1679 | cpu = raw_smp_processor_id(); | |
1680 | per_cpu(ftrace_shutdown_disable_cpu, cpu)++; | |
1681 | ||
1682 | ftrace_hash_lock(flags); | |
1683 | ||
1684 | for (i = 0; i < FTRACE_HASHSIZE; i++) { | |
1685 | INIT_HLIST_HEAD(&temp_list); | |
1686 | head = &ftrace_hash[i]; | |
1687 | ||
1688 | /* all CPUS are stopped, we are safe to modify code */ | |
1689 | hlist_for_each_entry_safe(rec, t, n, head, node) { | |
1690 | if (rec->flags & FTRACE_FL_FREE) | |
1691 | continue; | |
1692 | ||
1693 | if ((rec->ip >= start) && (rec->ip < end)) | |
1694 | ftrace_free_rec(rec); | |
1695 | } | |
1696 | } | |
1697 | ||
1698 | ftrace_hash_unlock(flags); | |
1699 | ||
1700 | per_cpu(ftrace_shutdown_disable_cpu, cpu)--; | |
1701 | preempt_enable_notrace(); | |
1702 | ||
1703 | } | |
1704 | ||
68bf21aa SR |
1705 | static int ftraced(void *ignore) |
1706 | { | |
1707 | unsigned long usecs; | |
1708 | ||
1709 | while (!kthread_should_stop()) { | |
1710 | ||
1711 | set_current_state(TASK_INTERRUPTIBLE); | |
1712 | ||
1713 | /* check once a second */ | |
1714 | schedule_timeout(HZ); | |
1715 | ||
1716 | if (unlikely(ftrace_disabled)) | |
1717 | continue; | |
1718 | ||
1719 | mutex_lock(&ftrace_sysctl_lock); | |
1720 | mutex_lock(&ftraced_lock); | |
1721 | if (!ftraced_suspend && !ftraced_stop && | |
1722 | ftrace_update_code()) { | |
1723 | usecs = nsecs_to_usecs(ftrace_update_time); | |
1724 | if (ftrace_update_tot_cnt > 100000) { | |
1725 | ftrace_update_tot_cnt = 0; | |
1726 | pr_info("hm, dftrace overflow: %lu change%s" | |
1727 | " (%lu total) in %lu usec%s\n", | |
1728 | ftrace_update_cnt, | |
1729 | ftrace_update_cnt != 1 ? "s" : "", | |
1730 | ftrace_update_tot_cnt, | |
1731 | usecs, usecs != 1 ? "s" : ""); | |
1732 | ftrace_disabled = 1; | |
1733 | WARN_ON_ONCE(1); | |
1734 | } | |
1735 | } | |
1736 | mutex_unlock(&ftraced_lock); | |
1737 | mutex_unlock(&ftrace_sysctl_lock); | |
1738 | ||
1739 | ftrace_shutdown_replenish(); | |
1740 | } | |
1741 | __set_current_state(TASK_RUNNING); | |
1742 | return 0; | |
1743 | } | |
1744 | ||
e309b41d | 1745 | static int __init ftrace_dynamic_init(void) |
3d083395 SR |
1746 | { |
1747 | struct task_struct *p; | |
d61f82d0 | 1748 | unsigned long addr; |
3d083395 SR |
1749 | int ret; |
1750 | ||
d61f82d0 | 1751 | addr = (unsigned long)ftrace_record_ip; |
9ff9cdb2 | 1752 | |
784e2d76 | 1753 | stop_machine(ftrace_dyn_arch_init, &addr, NULL); |
d61f82d0 SR |
1754 | |
1755 | /* ftrace_dyn_arch_init places the return code in addr */ | |
4eebcc81 SR |
1756 | if (addr) { |
1757 | ret = (int)addr; | |
1758 | goto failed; | |
1759 | } | |
d61f82d0 | 1760 | |
68bf21aa | 1761 | ret = ftrace_dyn_table_alloc(NR_TO_INIT); |
3d083395 | 1762 | if (ret) |
4eebcc81 | 1763 | goto failed; |
3d083395 SR |
1764 | |
1765 | p = kthread_run(ftraced, NULL, "ftraced"); | |
4eebcc81 SR |
1766 | if (IS_ERR(p)) { |
1767 | ret = -1; | |
1768 | goto failed; | |
1769 | } | |
3d083395 | 1770 | |
d61f82d0 | 1771 | last_ftrace_enabled = ftrace_enabled = 1; |
e1c08bdd | 1772 | ftraced_task = p; |
3d083395 SR |
1773 | |
1774 | return 0; | |
4eebcc81 SR |
1775 | |
1776 | failed: | |
1777 | ftrace_disabled = 1; | |
1778 | return ret; | |
3d083395 SR |
1779 | } |
1780 | ||
d61f82d0 | 1781 | core_initcall(ftrace_dynamic_init); |
68bf21aa SR |
1782 | #endif /* CONFIG_FTRACE_MCOUNT_RECORD */ |
1783 | ||
3d083395 | 1784 | #else |
c7aafc54 IM |
1785 | # define ftrace_startup() do { } while (0) |
1786 | # define ftrace_shutdown() do { } while (0) | |
1787 | # define ftrace_startup_sysctl() do { } while (0) | |
1788 | # define ftrace_shutdown_sysctl() do { } while (0) | |
4eebcc81 | 1789 | # define ftrace_force_shutdown() do { } while (0) |
3d083395 SR |
1790 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
1791 | ||
a2bb6a3d SR |
1792 | /** |
1793 | * ftrace_kill_atomic - kill ftrace from critical sections | |
1794 | * | |
1795 | * This function should be used by panic code. It stops ftrace | |
1796 | * but in a not so nice way. If you need to simply kill ftrace | |
1797 | * from a non-atomic section, use ftrace_kill. | |
1798 | */ | |
1799 | void ftrace_kill_atomic(void) | |
1800 | { | |
1801 | ftrace_disabled = 1; | |
1802 | ftrace_enabled = 0; | |
b2613e37 | 1803 | #ifdef CONFIG_DYNAMIC_FTRACE |
a2bb6a3d | 1804 | ftraced_suspend = -1; |
b2613e37 | 1805 | #endif |
a2bb6a3d SR |
1806 | clear_ftrace_function(); |
1807 | } | |
1808 | ||
4eebcc81 SR |
1809 | /** |
1810 | * ftrace_kill - totally shutdown ftrace | |
1811 | * | |
1812 | * This is a safety measure. If something was detected that seems | |
1813 | * wrong, calling this function will keep ftrace from doing | |
1814 | * any more modifications, and updates. | |
1815 | * used when something went wrong. | |
1816 | */ | |
1817 | void ftrace_kill(void) | |
1818 | { | |
1819 | mutex_lock(&ftrace_sysctl_lock); | |
1820 | ftrace_disabled = 1; | |
1821 | ftrace_enabled = 0; | |
1822 | ||
1823 | clear_ftrace_function(); | |
1824 | mutex_unlock(&ftrace_sysctl_lock); | |
1825 | ||
1826 | /* Try to totally disable ftrace */ | |
1827 | ftrace_force_shutdown(); | |
1828 | } | |
1829 | ||
16444a8a | 1830 | /** |
3d083395 SR |
1831 | * register_ftrace_function - register a function for profiling |
1832 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 1833 | * |
3d083395 SR |
1834 | * Register a function to be called by all functions in the |
1835 | * kernel. | |
1836 | * | |
1837 | * Note: @ops->func and all the functions it calls must be labeled | |
1838 | * with "notrace", otherwise it will go into a | |
1839 | * recursive loop. | |
16444a8a | 1840 | */ |
3d083395 | 1841 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 1842 | { |
b0fc494f SR |
1843 | int ret; |
1844 | ||
4eebcc81 SR |
1845 | if (unlikely(ftrace_disabled)) |
1846 | return -1; | |
1847 | ||
b0fc494f | 1848 | mutex_lock(&ftrace_sysctl_lock); |
b0fc494f | 1849 | ret = __register_ftrace_function(ops); |
d61f82d0 | 1850 | ftrace_startup(); |
b0fc494f SR |
1851 | mutex_unlock(&ftrace_sysctl_lock); |
1852 | ||
1853 | return ret; | |
3d083395 SR |
1854 | } |
1855 | ||
1856 | /** | |
1857 | * unregister_ftrace_function - unresgister a function for profiling. | |
1858 | * @ops - ops structure that holds the function to unregister | |
1859 | * | |
1860 | * Unregister a function that was added to be called by ftrace profiling. | |
1861 | */ | |
1862 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
1863 | { | |
1864 | int ret; | |
1865 | ||
b0fc494f | 1866 | mutex_lock(&ftrace_sysctl_lock); |
3d083395 | 1867 | ret = __unregister_ftrace_function(ops); |
d61f82d0 | 1868 | ftrace_shutdown(); |
b0fc494f SR |
1869 | mutex_unlock(&ftrace_sysctl_lock); |
1870 | ||
1871 | return ret; | |
1872 | } | |
1873 | ||
e309b41d | 1874 | int |
b0fc494f | 1875 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
5072c59f | 1876 | struct file *file, void __user *buffer, size_t *lenp, |
b0fc494f SR |
1877 | loff_t *ppos) |
1878 | { | |
1879 | int ret; | |
1880 | ||
4eebcc81 SR |
1881 | if (unlikely(ftrace_disabled)) |
1882 | return -ENODEV; | |
1883 | ||
b0fc494f SR |
1884 | mutex_lock(&ftrace_sysctl_lock); |
1885 | ||
5072c59f | 1886 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
b0fc494f SR |
1887 | |
1888 | if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) | |
1889 | goto out; | |
1890 | ||
1891 | last_ftrace_enabled = ftrace_enabled; | |
1892 | ||
1893 | if (ftrace_enabled) { | |
1894 | ||
1895 | ftrace_startup_sysctl(); | |
1896 | ||
1897 | /* we are starting ftrace again */ | |
1898 | if (ftrace_list != &ftrace_list_end) { | |
1899 | if (ftrace_list->next == &ftrace_list_end) | |
1900 | ftrace_trace_function = ftrace_list->func; | |
1901 | else | |
1902 | ftrace_trace_function = ftrace_list_func; | |
1903 | } | |
1904 | ||
1905 | } else { | |
1906 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
1907 | ftrace_trace_function = ftrace_stub; | |
1908 | ||
1909 | ftrace_shutdown_sysctl(); | |
1910 | } | |
1911 | ||
1912 | out: | |
1913 | mutex_unlock(&ftrace_sysctl_lock); | |
3d083395 | 1914 | return ret; |
16444a8a | 1915 | } |