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; | |
593eb8a2 | 599 | int ret; |
3c1720f0 SR |
600 | |
601 | ip = rec->ip; | |
602 | ||
603 | nop = ftrace_nop_replace(); | |
3b47bfc1 | 604 | call = ftrace_call_replace(ip, mcount_addr); |
3c1720f0 | 605 | |
593eb8a2 SR |
606 | ret = ftrace_modify_code(ip, call, nop); |
607 | if (ret) { | |
608 | switch (ret) { | |
609 | case -EFAULT: | |
05736a42 SR |
610 | WARN_ON_ONCE(1); |
611 | pr_info("ftrace faulted on modifying "); | |
612 | print_ip_sym(ip); | |
613 | break; | |
593eb8a2 | 614 | case -EINVAL: |
05736a42 SR |
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; | |
593eb8a2 SR |
623 | case -EPERM: |
624 | WARN_ON_ONCE(1); | |
625 | pr_info("ftrace faulted on writing "); | |
626 | print_ip_sym(ip); | |
627 | break; | |
628 | default: | |
629 | WARN_ON_ONCE(1); | |
630 | pr_info("ftrace faulted on unknown error "); | |
631 | print_ip_sym(ip); | |
05736a42 SR |
632 | } |
633 | ||
3c1720f0 | 634 | rec->flags |= FTRACE_FL_FAILED; |
492a7ea5 | 635 | return 0; |
37ad5084 | 636 | } |
492a7ea5 | 637 | return 1; |
3c1720f0 SR |
638 | } |
639 | ||
ad90c0e3 SR |
640 | static int __ftrace_update_code(void *ignore); |
641 | ||
e309b41d | 642 | static int __ftrace_modify_code(void *data) |
3d083395 | 643 | { |
d61f82d0 SR |
644 | unsigned long addr; |
645 | int *command = data; | |
646 | ||
ad90c0e3 SR |
647 | if (*command & FTRACE_ENABLE_CALLS) { |
648 | /* | |
649 | * Update any recorded ips now that we have the | |
650 | * machine stopped | |
651 | */ | |
652 | __ftrace_update_code(NULL); | |
d61f82d0 | 653 | ftrace_replace_code(1); |
ecea656d AS |
654 | tracing_on = 1; |
655 | } else if (*command & FTRACE_DISABLE_CALLS) { | |
d61f82d0 | 656 | ftrace_replace_code(0); |
ecea656d AS |
657 | tracing_on = 0; |
658 | } | |
d61f82d0 SR |
659 | |
660 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
661 | ftrace_update_ftrace_func(ftrace_trace_function); | |
662 | ||
663 | if (*command & FTRACE_ENABLE_MCOUNT) { | |
664 | addr = (unsigned long)ftrace_record_ip; | |
665 | ftrace_mcount_set(&addr); | |
666 | } else if (*command & FTRACE_DISABLE_MCOUNT) { | |
667 | addr = (unsigned long)ftrace_stub; | |
668 | ftrace_mcount_set(&addr); | |
669 | } | |
670 | ||
671 | return 0; | |
3d083395 SR |
672 | } |
673 | ||
e309b41d | 674 | static void ftrace_run_update_code(int command) |
3d083395 | 675 | { |
784e2d76 | 676 | stop_machine(__ftrace_modify_code, &command, NULL); |
3d083395 SR |
677 | } |
678 | ||
ad90c0e3 SR |
679 | void ftrace_disable_daemon(void) |
680 | { | |
681 | /* Stop the daemon from calling kstop_machine */ | |
682 | mutex_lock(&ftraced_lock); | |
683 | ftraced_stop = 1; | |
684 | mutex_unlock(&ftraced_lock); | |
685 | ||
686 | ftrace_force_update(); | |
687 | } | |
688 | ||
689 | void ftrace_enable_daemon(void) | |
690 | { | |
691 | mutex_lock(&ftraced_lock); | |
692 | ftraced_stop = 0; | |
693 | mutex_unlock(&ftraced_lock); | |
694 | ||
695 | ftrace_force_update(); | |
696 | } | |
697 | ||
d61f82d0 SR |
698 | static ftrace_func_t saved_ftrace_func; |
699 | ||
e309b41d | 700 | static void ftrace_startup(void) |
3d083395 | 701 | { |
d61f82d0 SR |
702 | int command = 0; |
703 | ||
4eebcc81 SR |
704 | if (unlikely(ftrace_disabled)) |
705 | return; | |
706 | ||
3d083395 SR |
707 | mutex_lock(&ftraced_lock); |
708 | ftraced_suspend++; | |
d61f82d0 SR |
709 | if (ftraced_suspend == 1) |
710 | command |= FTRACE_ENABLE_CALLS; | |
711 | ||
712 | if (saved_ftrace_func != ftrace_trace_function) { | |
713 | saved_ftrace_func = ftrace_trace_function; | |
714 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
715 | } | |
716 | ||
717 | if (!command || !ftrace_enabled) | |
3d083395 | 718 | goto out; |
3d083395 | 719 | |
d61f82d0 | 720 | ftrace_run_update_code(command); |
3d083395 SR |
721 | out: |
722 | mutex_unlock(&ftraced_lock); | |
723 | } | |
724 | ||
e309b41d | 725 | static void ftrace_shutdown(void) |
3d083395 | 726 | { |
d61f82d0 SR |
727 | int command = 0; |
728 | ||
4eebcc81 SR |
729 | if (unlikely(ftrace_disabled)) |
730 | return; | |
731 | ||
3d083395 SR |
732 | mutex_lock(&ftraced_lock); |
733 | ftraced_suspend--; | |
d61f82d0 SR |
734 | if (!ftraced_suspend) |
735 | command |= FTRACE_DISABLE_CALLS; | |
3d083395 | 736 | |
d61f82d0 SR |
737 | if (saved_ftrace_func != ftrace_trace_function) { |
738 | saved_ftrace_func = ftrace_trace_function; | |
739 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
740 | } | |
3d083395 | 741 | |
d61f82d0 SR |
742 | if (!command || !ftrace_enabled) |
743 | goto out; | |
744 | ||
745 | ftrace_run_update_code(command); | |
3d083395 SR |
746 | out: |
747 | mutex_unlock(&ftraced_lock); | |
748 | } | |
749 | ||
e309b41d | 750 | static void ftrace_startup_sysctl(void) |
b0fc494f | 751 | { |
d61f82d0 SR |
752 | int command = FTRACE_ENABLE_MCOUNT; |
753 | ||
4eebcc81 SR |
754 | if (unlikely(ftrace_disabled)) |
755 | return; | |
756 | ||
b0fc494f | 757 | mutex_lock(&ftraced_lock); |
d61f82d0 SR |
758 | /* Force update next time */ |
759 | saved_ftrace_func = NULL; | |
b0fc494f SR |
760 | /* ftraced_suspend is true if we want ftrace running */ |
761 | if (ftraced_suspend) | |
d61f82d0 SR |
762 | command |= FTRACE_ENABLE_CALLS; |
763 | ||
764 | ftrace_run_update_code(command); | |
b0fc494f SR |
765 | mutex_unlock(&ftraced_lock); |
766 | } | |
767 | ||
e309b41d | 768 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 769 | { |
d61f82d0 SR |
770 | int command = FTRACE_DISABLE_MCOUNT; |
771 | ||
4eebcc81 SR |
772 | if (unlikely(ftrace_disabled)) |
773 | return; | |
774 | ||
b0fc494f SR |
775 | mutex_lock(&ftraced_lock); |
776 | /* ftraced_suspend is true if ftrace is running */ | |
777 | if (ftraced_suspend) | |
d61f82d0 SR |
778 | command |= FTRACE_DISABLE_CALLS; |
779 | ||
780 | ftrace_run_update_code(command); | |
b0fc494f SR |
781 | mutex_unlock(&ftraced_lock); |
782 | } | |
783 | ||
3d083395 SR |
784 | static cycle_t ftrace_update_time; |
785 | static unsigned long ftrace_update_cnt; | |
786 | unsigned long ftrace_update_tot_cnt; | |
787 | ||
e309b41d | 788 | static int __ftrace_update_code(void *ignore) |
3d083395 | 789 | { |
f22f9a89 AS |
790 | int i, save_ftrace_enabled; |
791 | cycle_t start, stop; | |
3d083395 | 792 | struct dyn_ftrace *p; |
0eb96701 | 793 | struct hlist_node *t, *n; |
f22f9a89 | 794 | struct hlist_head *head, temp_list; |
3d083395 | 795 | |
d61f82d0 | 796 | /* Don't be recording funcs now */ |
ad90c0e3 | 797 | ftrace_record_suspend++; |
d61f82d0 SR |
798 | save_ftrace_enabled = ftrace_enabled; |
799 | ftrace_enabled = 0; | |
3d083395 | 800 | |
750ed1a4 | 801 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
802 | ftrace_update_cnt = 0; |
803 | ||
804 | /* No locks needed, the machine is stopped! */ | |
805 | for (i = 0; i < FTRACE_HASHSIZE; i++) { | |
f22f9a89 AS |
806 | INIT_HLIST_HEAD(&temp_list); |
807 | head = &ftrace_hash[i]; | |
808 | ||
0eb96701 | 809 | /* all CPUS are stopped, we are safe to modify code */ |
f22f9a89 | 810 | hlist_for_each_entry_safe(p, t, n, head, node) { |
0eb96701 AS |
811 | /* Skip over failed records which have not been |
812 | * freed. */ | |
813 | if (p->flags & FTRACE_FL_FAILED) | |
814 | continue; | |
3d083395 | 815 | |
0eb96701 AS |
816 | /* Unconverted records are always at the head of the |
817 | * hash bucket. Once we encounter a converted record, | |
818 | * simply skip over to the next bucket. Saves ftraced | |
819 | * some processor cycles (ftrace does its bid for | |
820 | * global warming :-p ). */ | |
821 | if (p->flags & (FTRACE_FL_CONVERTED)) | |
822 | break; | |
3d083395 | 823 | |
f22f9a89 AS |
824 | /* Ignore updates to this record's mcount site. |
825 | * Reintroduce this record at the head of this | |
826 | * bucket to attempt to "convert" it again if | |
827 | * the kprobe on it is unregistered before the | |
828 | * next run. */ | |
829 | if (get_kprobe((void *)p->ip)) { | |
830 | ftrace_del_hash(p); | |
831 | INIT_HLIST_NODE(&p->node); | |
832 | hlist_add_head(&p->node, &temp_list); | |
98a05ed4 | 833 | freeze_record(p); |
f22f9a89 | 834 | continue; |
98a05ed4 AS |
835 | } else { |
836 | unfreeze_record(p); | |
f22f9a89 AS |
837 | } |
838 | ||
839 | /* convert record (i.e, patch mcount-call with NOP) */ | |
0eb96701 AS |
840 | if (ftrace_code_disable(p)) { |
841 | p->flags |= FTRACE_FL_CONVERTED; | |
492a7ea5 | 842 | ftrace_update_cnt++; |
0eb96701 AS |
843 | } else { |
844 | if ((system_state == SYSTEM_BOOTING) || | |
34078a5e | 845 | !core_kernel_text(p->ip)) { |
0eb96701 AS |
846 | ftrace_del_hash(p); |
847 | ftrace_free_rec(p); | |
0eb96701 AS |
848 | } |
849 | } | |
3d083395 | 850 | } |
f22f9a89 AS |
851 | |
852 | hlist_for_each_entry_safe(p, t, n, &temp_list, node) { | |
853 | hlist_del(&p->node); | |
854 | INIT_HLIST_NODE(&p->node); | |
855 | hlist_add_head(&p->node, head); | |
856 | } | |
3d083395 SR |
857 | } |
858 | ||
750ed1a4 | 859 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
860 | ftrace_update_time = stop - start; |
861 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
ad90c0e3 | 862 | ftraced_trigger = 0; |
3d083395 | 863 | |
d61f82d0 | 864 | ftrace_enabled = save_ftrace_enabled; |
ad90c0e3 | 865 | ftrace_record_suspend--; |
16444a8a ACM |
866 | |
867 | return 0; | |
868 | } | |
869 | ||
ad90c0e3 | 870 | static int ftrace_update_code(void) |
3d083395 | 871 | { |
ad90c0e3 SR |
872 | if (unlikely(ftrace_disabled) || |
873 | !ftrace_enabled || !ftraced_trigger) | |
874 | return 0; | |
4eebcc81 | 875 | |
784e2d76 | 876 | stop_machine(__ftrace_update_code, NULL, NULL); |
ad90c0e3 SR |
877 | |
878 | return 1; | |
3d083395 SR |
879 | } |
880 | ||
68bf21aa | 881 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
882 | { |
883 | struct ftrace_page *pg; | |
884 | int cnt; | |
885 | int i; | |
3c1720f0 SR |
886 | |
887 | /* allocate a few pages */ | |
888 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
889 | if (!ftrace_pages_start) | |
890 | return -1; | |
891 | ||
892 | /* | |
893 | * Allocate a few more pages. | |
894 | * | |
895 | * TODO: have some parser search vmlinux before | |
896 | * final linking to find all calls to ftrace. | |
897 | * Then we can: | |
898 | * a) know how many pages to allocate. | |
899 | * and/or | |
900 | * b) set up the table then. | |
901 | * | |
902 | * The dynamic code is still necessary for | |
903 | * modules. | |
904 | */ | |
905 | ||
906 | pg = ftrace_pages = ftrace_pages_start; | |
907 | ||
68bf21aa SR |
908 | cnt = num_to_init / ENTRIES_PER_PAGE; |
909 | pr_info("ftrace: allocating %ld hash entries in %d pages\n", | |
910 | num_to_init, cnt); | |
3c1720f0 SR |
911 | |
912 | for (i = 0; i < cnt; i++) { | |
913 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
914 | ||
915 | /* If we fail, we'll try later anyway */ | |
916 | if (!pg->next) | |
917 | break; | |
918 | ||
919 | pg = pg->next; | |
920 | } | |
921 | ||
922 | return 0; | |
923 | } | |
924 | ||
5072c59f SR |
925 | enum { |
926 | FTRACE_ITER_FILTER = (1 << 0), | |
927 | FTRACE_ITER_CONT = (1 << 1), | |
41c52c0d | 928 | FTRACE_ITER_NOTRACE = (1 << 2), |
eb9a7bf0 | 929 | FTRACE_ITER_FAILURES = (1 << 3), |
5072c59f SR |
930 | }; |
931 | ||
932 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
933 | ||
934 | struct ftrace_iterator { | |
935 | loff_t pos; | |
936 | struct ftrace_page *pg; | |
937 | unsigned idx; | |
938 | unsigned flags; | |
939 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
940 | unsigned buffer_idx; | |
941 | unsigned filtered; | |
942 | }; | |
943 | ||
e309b41d | 944 | static void * |
5072c59f SR |
945 | t_next(struct seq_file *m, void *v, loff_t *pos) |
946 | { | |
947 | struct ftrace_iterator *iter = m->private; | |
948 | struct dyn_ftrace *rec = NULL; | |
949 | ||
950 | (*pos)++; | |
951 | ||
99ecdc43 SR |
952 | /* should not be called from interrupt context */ |
953 | spin_lock(&ftrace_lock); | |
5072c59f SR |
954 | retry: |
955 | if (iter->idx >= iter->pg->index) { | |
956 | if (iter->pg->next) { | |
957 | iter->pg = iter->pg->next; | |
958 | iter->idx = 0; | |
959 | goto retry; | |
960 | } | |
961 | } else { | |
962 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
963 | if ((rec->flags & FTRACE_FL_FREE) || |
964 | ||
965 | (!(iter->flags & FTRACE_ITER_FAILURES) && | |
eb9a7bf0 AS |
966 | (rec->flags & FTRACE_FL_FAILED)) || |
967 | ||
968 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
a9fdda33 | 969 | !(rec->flags & FTRACE_FL_FAILED)) || |
eb9a7bf0 | 970 | |
41c52c0d SR |
971 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
972 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
973 | rec = NULL; |
974 | goto retry; | |
975 | } | |
976 | } | |
99ecdc43 | 977 | spin_unlock(&ftrace_lock); |
5072c59f SR |
978 | |
979 | iter->pos = *pos; | |
980 | ||
981 | return rec; | |
982 | } | |
983 | ||
984 | static void *t_start(struct seq_file *m, loff_t *pos) | |
985 | { | |
986 | struct ftrace_iterator *iter = m->private; | |
987 | void *p = NULL; | |
988 | loff_t l = -1; | |
989 | ||
990 | if (*pos != iter->pos) { | |
991 | for (p = t_next(m, p, &l); p && l < *pos; p = t_next(m, p, &l)) | |
992 | ; | |
993 | } else { | |
994 | l = *pos; | |
995 | p = t_next(m, p, &l); | |
996 | } | |
997 | ||
998 | return p; | |
999 | } | |
1000 | ||
1001 | static void t_stop(struct seq_file *m, void *p) | |
1002 | { | |
1003 | } | |
1004 | ||
1005 | static int t_show(struct seq_file *m, void *v) | |
1006 | { | |
1007 | struct dyn_ftrace *rec = v; | |
1008 | char str[KSYM_SYMBOL_LEN]; | |
1009 | ||
1010 | if (!rec) | |
1011 | return 0; | |
1012 | ||
1013 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1014 | ||
1015 | seq_printf(m, "%s\n", str); | |
1016 | ||
1017 | return 0; | |
1018 | } | |
1019 | ||
1020 | static struct seq_operations show_ftrace_seq_ops = { | |
1021 | .start = t_start, | |
1022 | .next = t_next, | |
1023 | .stop = t_stop, | |
1024 | .show = t_show, | |
1025 | }; | |
1026 | ||
e309b41d | 1027 | static int |
5072c59f SR |
1028 | ftrace_avail_open(struct inode *inode, struct file *file) |
1029 | { | |
1030 | struct ftrace_iterator *iter; | |
1031 | int ret; | |
1032 | ||
4eebcc81 SR |
1033 | if (unlikely(ftrace_disabled)) |
1034 | return -ENODEV; | |
1035 | ||
5072c59f SR |
1036 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1037 | if (!iter) | |
1038 | return -ENOMEM; | |
1039 | ||
1040 | iter->pg = ftrace_pages_start; | |
1041 | iter->pos = -1; | |
1042 | ||
1043 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1044 | if (!ret) { | |
1045 | struct seq_file *m = file->private_data; | |
4bf39a94 | 1046 | |
5072c59f | 1047 | m->private = iter; |
4bf39a94 | 1048 | } else { |
5072c59f | 1049 | kfree(iter); |
4bf39a94 | 1050 | } |
5072c59f SR |
1051 | |
1052 | return ret; | |
1053 | } | |
1054 | ||
1055 | int ftrace_avail_release(struct inode *inode, struct file *file) | |
1056 | { | |
1057 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1058 | struct ftrace_iterator *iter = m->private; | |
1059 | ||
1060 | seq_release(inode, file); | |
1061 | kfree(iter); | |
4bf39a94 | 1062 | |
5072c59f SR |
1063 | return 0; |
1064 | } | |
1065 | ||
eb9a7bf0 AS |
1066 | static int |
1067 | ftrace_failures_open(struct inode *inode, struct file *file) | |
1068 | { | |
1069 | int ret; | |
1070 | struct seq_file *m; | |
1071 | struct ftrace_iterator *iter; | |
1072 | ||
1073 | ret = ftrace_avail_open(inode, file); | |
1074 | if (!ret) { | |
1075 | m = (struct seq_file *)file->private_data; | |
1076 | iter = (struct ftrace_iterator *)m->private; | |
1077 | iter->flags = FTRACE_ITER_FAILURES; | |
1078 | } | |
1079 | ||
1080 | return ret; | |
1081 | } | |
1082 | ||
1083 | ||
41c52c0d | 1084 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
1085 | { |
1086 | struct ftrace_page *pg; | |
1087 | struct dyn_ftrace *rec; | |
41c52c0d | 1088 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f SR |
1089 | unsigned i; |
1090 | ||
99ecdc43 SR |
1091 | /* should not be called from interrupt context */ |
1092 | spin_lock(&ftrace_lock); | |
41c52c0d SR |
1093 | if (enable) |
1094 | ftrace_filtered = 0; | |
5072c59f SR |
1095 | pg = ftrace_pages_start; |
1096 | while (pg) { | |
1097 | for (i = 0; i < pg->index; i++) { | |
1098 | rec = &pg->records[i]; | |
1099 | if (rec->flags & FTRACE_FL_FAILED) | |
1100 | continue; | |
41c52c0d | 1101 | rec->flags &= ~type; |
5072c59f SR |
1102 | } |
1103 | pg = pg->next; | |
1104 | } | |
99ecdc43 | 1105 | spin_unlock(&ftrace_lock); |
5072c59f SR |
1106 | } |
1107 | ||
e309b41d | 1108 | static int |
41c52c0d | 1109 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1110 | { |
1111 | struct ftrace_iterator *iter; | |
1112 | int ret = 0; | |
1113 | ||
4eebcc81 SR |
1114 | if (unlikely(ftrace_disabled)) |
1115 | return -ENODEV; | |
1116 | ||
5072c59f SR |
1117 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1118 | if (!iter) | |
1119 | return -ENOMEM; | |
1120 | ||
41c52c0d | 1121 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1122 | if ((file->f_mode & FMODE_WRITE) && |
1123 | !(file->f_flags & O_APPEND)) | |
41c52c0d | 1124 | ftrace_filter_reset(enable); |
5072c59f SR |
1125 | |
1126 | if (file->f_mode & FMODE_READ) { | |
1127 | iter->pg = ftrace_pages_start; | |
1128 | iter->pos = -1; | |
41c52c0d SR |
1129 | iter->flags = enable ? FTRACE_ITER_FILTER : |
1130 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
1131 | |
1132 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1133 | if (!ret) { | |
1134 | struct seq_file *m = file->private_data; | |
1135 | m->private = iter; | |
1136 | } else | |
1137 | kfree(iter); | |
1138 | } else | |
1139 | file->private_data = iter; | |
41c52c0d | 1140 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1141 | |
1142 | return ret; | |
1143 | } | |
1144 | ||
41c52c0d SR |
1145 | static int |
1146 | ftrace_filter_open(struct inode *inode, struct file *file) | |
1147 | { | |
1148 | return ftrace_regex_open(inode, file, 1); | |
1149 | } | |
1150 | ||
1151 | static int | |
1152 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
1153 | { | |
1154 | return ftrace_regex_open(inode, file, 0); | |
1155 | } | |
1156 | ||
e309b41d | 1157 | static ssize_t |
41c52c0d | 1158 | ftrace_regex_read(struct file *file, char __user *ubuf, |
5072c59f SR |
1159 | size_t cnt, loff_t *ppos) |
1160 | { | |
1161 | if (file->f_mode & FMODE_READ) | |
1162 | return seq_read(file, ubuf, cnt, ppos); | |
1163 | else | |
1164 | return -EPERM; | |
1165 | } | |
1166 | ||
e309b41d | 1167 | static loff_t |
41c52c0d | 1168 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
1169 | { |
1170 | loff_t ret; | |
1171 | ||
1172 | if (file->f_mode & FMODE_READ) | |
1173 | ret = seq_lseek(file, offset, origin); | |
1174 | else | |
1175 | file->f_pos = ret = 1; | |
1176 | ||
1177 | return ret; | |
1178 | } | |
1179 | ||
1180 | enum { | |
1181 | MATCH_FULL, | |
1182 | MATCH_FRONT_ONLY, | |
1183 | MATCH_MIDDLE_ONLY, | |
1184 | MATCH_END_ONLY, | |
1185 | }; | |
1186 | ||
e309b41d | 1187 | static void |
41c52c0d | 1188 | ftrace_match(unsigned char *buff, int len, int enable) |
5072c59f SR |
1189 | { |
1190 | char str[KSYM_SYMBOL_LEN]; | |
1191 | char *search = NULL; | |
1192 | struct ftrace_page *pg; | |
1193 | struct dyn_ftrace *rec; | |
1194 | int type = MATCH_FULL; | |
41c52c0d | 1195 | unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f SR |
1196 | unsigned i, match = 0, search_len = 0; |
1197 | ||
1198 | for (i = 0; i < len; i++) { | |
1199 | if (buff[i] == '*') { | |
1200 | if (!i) { | |
1201 | search = buff + i + 1; | |
1202 | type = MATCH_END_ONLY; | |
1203 | search_len = len - (i + 1); | |
1204 | } else { | |
1205 | if (type == MATCH_END_ONLY) { | |
1206 | type = MATCH_MIDDLE_ONLY; | |
1207 | } else { | |
1208 | match = i; | |
1209 | type = MATCH_FRONT_ONLY; | |
1210 | } | |
1211 | buff[i] = 0; | |
1212 | break; | |
1213 | } | |
1214 | } | |
1215 | } | |
1216 | ||
99ecdc43 SR |
1217 | /* should not be called from interrupt context */ |
1218 | spin_lock(&ftrace_lock); | |
41c52c0d SR |
1219 | if (enable) |
1220 | ftrace_filtered = 1; | |
5072c59f SR |
1221 | pg = ftrace_pages_start; |
1222 | while (pg) { | |
1223 | for (i = 0; i < pg->index; i++) { | |
1224 | int matched = 0; | |
1225 | char *ptr; | |
1226 | ||
1227 | rec = &pg->records[i]; | |
1228 | if (rec->flags & FTRACE_FL_FAILED) | |
1229 | continue; | |
1230 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1231 | switch (type) { | |
1232 | case MATCH_FULL: | |
1233 | if (strcmp(str, buff) == 0) | |
1234 | matched = 1; | |
1235 | break; | |
1236 | case MATCH_FRONT_ONLY: | |
1237 | if (memcmp(str, buff, match) == 0) | |
1238 | matched = 1; | |
1239 | break; | |
1240 | case MATCH_MIDDLE_ONLY: | |
1241 | if (strstr(str, search)) | |
1242 | matched = 1; | |
1243 | break; | |
1244 | case MATCH_END_ONLY: | |
1245 | ptr = strstr(str, search); | |
1246 | if (ptr && (ptr[search_len] == 0)) | |
1247 | matched = 1; | |
1248 | break; | |
1249 | } | |
1250 | if (matched) | |
41c52c0d | 1251 | rec->flags |= flag; |
5072c59f SR |
1252 | } |
1253 | pg = pg->next; | |
1254 | } | |
99ecdc43 | 1255 | spin_unlock(&ftrace_lock); |
5072c59f SR |
1256 | } |
1257 | ||
e309b41d | 1258 | static ssize_t |
41c52c0d SR |
1259 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
1260 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
1261 | { |
1262 | struct ftrace_iterator *iter; | |
1263 | char ch; | |
1264 | size_t read = 0; | |
1265 | ssize_t ret; | |
1266 | ||
1267 | if (!cnt || cnt < 0) | |
1268 | return 0; | |
1269 | ||
41c52c0d | 1270 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1271 | |
1272 | if (file->f_mode & FMODE_READ) { | |
1273 | struct seq_file *m = file->private_data; | |
1274 | iter = m->private; | |
1275 | } else | |
1276 | iter = file->private_data; | |
1277 | ||
1278 | if (!*ppos) { | |
1279 | iter->flags &= ~FTRACE_ITER_CONT; | |
1280 | iter->buffer_idx = 0; | |
1281 | } | |
1282 | ||
1283 | ret = get_user(ch, ubuf++); | |
1284 | if (ret) | |
1285 | goto out; | |
1286 | read++; | |
1287 | cnt--; | |
1288 | ||
1289 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { | |
1290 | /* skip white space */ | |
1291 | while (cnt && isspace(ch)) { | |
1292 | ret = get_user(ch, ubuf++); | |
1293 | if (ret) | |
1294 | goto out; | |
1295 | read++; | |
1296 | cnt--; | |
1297 | } | |
1298 | ||
5072c59f SR |
1299 | if (isspace(ch)) { |
1300 | file->f_pos += read; | |
1301 | ret = read; | |
1302 | goto out; | |
1303 | } | |
1304 | ||
1305 | iter->buffer_idx = 0; | |
1306 | } | |
1307 | ||
1308 | while (cnt && !isspace(ch)) { | |
1309 | if (iter->buffer_idx < FTRACE_BUFF_MAX) | |
1310 | iter->buffer[iter->buffer_idx++] = ch; | |
1311 | else { | |
1312 | ret = -EINVAL; | |
1313 | goto out; | |
1314 | } | |
1315 | ret = get_user(ch, ubuf++); | |
1316 | if (ret) | |
1317 | goto out; | |
1318 | read++; | |
1319 | cnt--; | |
1320 | } | |
1321 | ||
1322 | if (isspace(ch)) { | |
1323 | iter->filtered++; | |
1324 | iter->buffer[iter->buffer_idx] = 0; | |
41c52c0d | 1325 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1326 | iter->buffer_idx = 0; |
1327 | } else | |
1328 | iter->flags |= FTRACE_ITER_CONT; | |
1329 | ||
1330 | ||
1331 | file->f_pos += read; | |
1332 | ||
1333 | ret = read; | |
1334 | out: | |
41c52c0d | 1335 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1336 | |
1337 | return ret; | |
1338 | } | |
1339 | ||
41c52c0d SR |
1340 | static ssize_t |
1341 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
1342 | size_t cnt, loff_t *ppos) | |
1343 | { | |
1344 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
1345 | } | |
1346 | ||
1347 | static ssize_t | |
1348 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
1349 | size_t cnt, loff_t *ppos) | |
1350 | { | |
1351 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
1352 | } | |
1353 | ||
1354 | static void | |
1355 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
1356 | { | |
1357 | if (unlikely(ftrace_disabled)) | |
1358 | return; | |
1359 | ||
1360 | mutex_lock(&ftrace_regex_lock); | |
1361 | if (reset) | |
1362 | ftrace_filter_reset(enable); | |
1363 | if (buf) | |
1364 | ftrace_match(buf, len, enable); | |
1365 | mutex_unlock(&ftrace_regex_lock); | |
1366 | } | |
1367 | ||
77a2b37d SR |
1368 | /** |
1369 | * ftrace_set_filter - set a function to filter on in ftrace | |
1370 | * @buf - the string that holds the function filter text. | |
1371 | * @len - the length of the string. | |
1372 | * @reset - non zero to reset all filters before applying this filter. | |
1373 | * | |
1374 | * Filters denote which functions should be enabled when tracing is enabled. | |
1375 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
1376 | */ | |
e309b41d | 1377 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 1378 | { |
41c52c0d SR |
1379 | ftrace_set_regex(buf, len, reset, 1); |
1380 | } | |
4eebcc81 | 1381 | |
41c52c0d SR |
1382 | /** |
1383 | * ftrace_set_notrace - set a function to not trace in ftrace | |
1384 | * @buf - the string that holds the function notrace text. | |
1385 | * @len - the length of the string. | |
1386 | * @reset - non zero to reset all filters before applying this filter. | |
1387 | * | |
1388 | * Notrace Filters denote which functions should not be enabled when tracing | |
1389 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
1390 | * for tracing. | |
1391 | */ | |
1392 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
1393 | { | |
1394 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
1395 | } |
1396 | ||
e309b41d | 1397 | static int |
41c52c0d | 1398 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1399 | { |
1400 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1401 | struct ftrace_iterator *iter; | |
1402 | ||
41c52c0d | 1403 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1404 | if (file->f_mode & FMODE_READ) { |
1405 | iter = m->private; | |
1406 | ||
1407 | seq_release(inode, file); | |
1408 | } else | |
1409 | iter = file->private_data; | |
1410 | ||
1411 | if (iter->buffer_idx) { | |
1412 | iter->filtered++; | |
1413 | iter->buffer[iter->buffer_idx] = 0; | |
41c52c0d | 1414 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1415 | } |
1416 | ||
1417 | mutex_lock(&ftrace_sysctl_lock); | |
1418 | mutex_lock(&ftraced_lock); | |
1419 | if (iter->filtered && ftraced_suspend && ftrace_enabled) | |
1420 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); | |
1421 | mutex_unlock(&ftraced_lock); | |
1422 | mutex_unlock(&ftrace_sysctl_lock); | |
1423 | ||
1424 | kfree(iter); | |
41c52c0d | 1425 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1426 | return 0; |
1427 | } | |
1428 | ||
41c52c0d SR |
1429 | static int |
1430 | ftrace_filter_release(struct inode *inode, struct file *file) | |
1431 | { | |
1432 | return ftrace_regex_release(inode, file, 1); | |
1433 | } | |
1434 | ||
1435 | static int | |
1436 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
1437 | { | |
1438 | return ftrace_regex_release(inode, file, 0); | |
1439 | } | |
1440 | ||
ad90c0e3 SR |
1441 | static ssize_t |
1442 | ftraced_read(struct file *filp, char __user *ubuf, | |
1443 | size_t cnt, loff_t *ppos) | |
1444 | { | |
1445 | /* don't worry about races */ | |
1446 | char *buf = ftraced_stop ? "disabled\n" : "enabled\n"; | |
1447 | int r = strlen(buf); | |
1448 | ||
1449 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
1450 | } | |
1451 | ||
1452 | static ssize_t | |
1453 | ftraced_write(struct file *filp, const char __user *ubuf, | |
1454 | size_t cnt, loff_t *ppos) | |
1455 | { | |
1456 | char buf[64]; | |
1457 | long val; | |
1458 | int ret; | |
1459 | ||
1460 | if (cnt >= sizeof(buf)) | |
1461 | return -EINVAL; | |
1462 | ||
1463 | if (copy_from_user(&buf, ubuf, cnt)) | |
1464 | return -EFAULT; | |
1465 | ||
1466 | if (strncmp(buf, "enable", 6) == 0) | |
1467 | val = 1; | |
1468 | else if (strncmp(buf, "disable", 7) == 0) | |
1469 | val = 0; | |
1470 | else { | |
1471 | buf[cnt] = 0; | |
1472 | ||
1473 | ret = strict_strtoul(buf, 10, &val); | |
1474 | if (ret < 0) | |
1475 | return ret; | |
1476 | ||
1477 | val = !!val; | |
1478 | } | |
1479 | ||
1480 | if (val) | |
1481 | ftrace_enable_daemon(); | |
1482 | else | |
1483 | ftrace_disable_daemon(); | |
1484 | ||
1485 | filp->f_pos += cnt; | |
1486 | ||
1487 | return cnt; | |
1488 | } | |
1489 | ||
5072c59f SR |
1490 | static struct file_operations ftrace_avail_fops = { |
1491 | .open = ftrace_avail_open, | |
1492 | .read = seq_read, | |
1493 | .llseek = seq_lseek, | |
1494 | .release = ftrace_avail_release, | |
1495 | }; | |
1496 | ||
eb9a7bf0 AS |
1497 | static struct file_operations ftrace_failures_fops = { |
1498 | .open = ftrace_failures_open, | |
1499 | .read = seq_read, | |
1500 | .llseek = seq_lseek, | |
1501 | .release = ftrace_avail_release, | |
1502 | }; | |
1503 | ||
5072c59f SR |
1504 | static struct file_operations ftrace_filter_fops = { |
1505 | .open = ftrace_filter_open, | |
41c52c0d | 1506 | .read = ftrace_regex_read, |
5072c59f | 1507 | .write = ftrace_filter_write, |
41c52c0d | 1508 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
1509 | .release = ftrace_filter_release, |
1510 | }; | |
1511 | ||
41c52c0d SR |
1512 | static struct file_operations ftrace_notrace_fops = { |
1513 | .open = ftrace_notrace_open, | |
1514 | .read = ftrace_regex_read, | |
1515 | .write = ftrace_notrace_write, | |
1516 | .llseek = ftrace_regex_lseek, | |
1517 | .release = ftrace_notrace_release, | |
1518 | }; | |
1519 | ||
ad90c0e3 SR |
1520 | static struct file_operations ftraced_fops = { |
1521 | .open = tracing_open_generic, | |
1522 | .read = ftraced_read, | |
1523 | .write = ftraced_write, | |
1524 | }; | |
1525 | ||
e1c08bdd SR |
1526 | /** |
1527 | * ftrace_force_update - force an update to all recording ftrace functions | |
e1c08bdd SR |
1528 | */ |
1529 | int ftrace_force_update(void) | |
1530 | { | |
e1c08bdd SR |
1531 | int ret = 0; |
1532 | ||
4eebcc81 | 1533 | if (unlikely(ftrace_disabled)) |
e1c08bdd SR |
1534 | return -ENODEV; |
1535 | ||
ad90c0e3 | 1536 | mutex_lock(&ftrace_sysctl_lock); |
e1c08bdd | 1537 | mutex_lock(&ftraced_lock); |
e1c08bdd | 1538 | |
ad90c0e3 SR |
1539 | /* |
1540 | * If ftraced_trigger is not set, then there is nothing | |
1541 | * to update. | |
1542 | */ | |
1543 | if (ftraced_trigger && !ftrace_update_code()) | |
1544 | ret = -EBUSY; | |
e1c08bdd SR |
1545 | |
1546 | mutex_unlock(&ftraced_lock); | |
ad90c0e3 | 1547 | mutex_unlock(&ftrace_sysctl_lock); |
e1c08bdd SR |
1548 | |
1549 | return ret; | |
1550 | } | |
1551 | ||
4eebcc81 SR |
1552 | static void ftrace_force_shutdown(void) |
1553 | { | |
1554 | struct task_struct *task; | |
1555 | int command = FTRACE_DISABLE_CALLS | FTRACE_UPDATE_TRACE_FUNC; | |
1556 | ||
1557 | mutex_lock(&ftraced_lock); | |
1558 | task = ftraced_task; | |
1559 | ftraced_task = NULL; | |
1560 | ftraced_suspend = -1; | |
1561 | ftrace_run_update_code(command); | |
1562 | mutex_unlock(&ftraced_lock); | |
1563 | ||
1564 | if (task) | |
1565 | kthread_stop(task); | |
1566 | } | |
1567 | ||
5072c59f SR |
1568 | static __init int ftrace_init_debugfs(void) |
1569 | { | |
1570 | struct dentry *d_tracer; | |
1571 | struct dentry *entry; | |
1572 | ||
1573 | d_tracer = tracing_init_dentry(); | |
1574 | ||
1575 | entry = debugfs_create_file("available_filter_functions", 0444, | |
1576 | d_tracer, NULL, &ftrace_avail_fops); | |
1577 | if (!entry) | |
1578 | pr_warning("Could not create debugfs " | |
1579 | "'available_filter_functions' entry\n"); | |
1580 | ||
eb9a7bf0 AS |
1581 | entry = debugfs_create_file("failures", 0444, |
1582 | d_tracer, NULL, &ftrace_failures_fops); | |
1583 | if (!entry) | |
1584 | pr_warning("Could not create debugfs 'failures' entry\n"); | |
1585 | ||
5072c59f SR |
1586 | entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer, |
1587 | NULL, &ftrace_filter_fops); | |
1588 | if (!entry) | |
1589 | pr_warning("Could not create debugfs " | |
1590 | "'set_ftrace_filter' entry\n"); | |
41c52c0d SR |
1591 | |
1592 | entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer, | |
1593 | NULL, &ftrace_notrace_fops); | |
1594 | if (!entry) | |
1595 | pr_warning("Could not create debugfs " | |
1596 | "'set_ftrace_notrace' entry\n"); | |
ad90c0e3 SR |
1597 | |
1598 | entry = debugfs_create_file("ftraced_enabled", 0644, d_tracer, | |
1599 | NULL, &ftraced_fops); | |
1600 | if (!entry) | |
1601 | pr_warning("Could not create debugfs " | |
1602 | "'ftraced_enabled' entry\n"); | |
5072c59f SR |
1603 | return 0; |
1604 | } | |
1605 | ||
1606 | fs_initcall(ftrace_init_debugfs); | |
1607 | ||
68bf21aa SR |
1608 | #ifdef CONFIG_FTRACE_MCOUNT_RECORD |
1609 | static int ftrace_convert_nops(unsigned long *start, | |
1610 | unsigned long *end) | |
1611 | { | |
1612 | unsigned long *p; | |
1613 | unsigned long addr; | |
1614 | unsigned long flags; | |
1615 | ||
1616 | p = start; | |
1617 | while (p < end) { | |
1618 | addr = ftrace_call_adjust(*p++); | |
99ecdc43 | 1619 | /* should not be called from interrupt context */ |
fed1939c | 1620 | spin_lock(&ftrace_lock); |
68bf21aa | 1621 | ftrace_record_ip(addr); |
fed1939c | 1622 | spin_unlock(&ftrace_lock); |
68bf21aa SR |
1623 | ftrace_shutdown_replenish(); |
1624 | } | |
1625 | ||
1626 | /* p is ignored */ | |
1627 | local_irq_save(flags); | |
1628 | __ftrace_update_code(p); | |
1629 | local_irq_restore(flags); | |
1630 | ||
1631 | return 0; | |
1632 | } | |
1633 | ||
90d595fe SR |
1634 | void ftrace_init_module(unsigned long *start, unsigned long *end) |
1635 | { | |
00fd61ae | 1636 | if (ftrace_disabled || start == end) |
fed1939c | 1637 | return; |
90d595fe SR |
1638 | ftrace_convert_nops(start, end); |
1639 | } | |
1640 | ||
68bf21aa SR |
1641 | extern unsigned long __start_mcount_loc[]; |
1642 | extern unsigned long __stop_mcount_loc[]; | |
1643 | ||
1644 | void __init ftrace_init(void) | |
1645 | { | |
1646 | unsigned long count, addr, flags; | |
1647 | int ret; | |
1648 | ||
1649 | /* Keep the ftrace pointer to the stub */ | |
1650 | addr = (unsigned long)ftrace_stub; | |
1651 | ||
1652 | local_irq_save(flags); | |
1653 | ftrace_dyn_arch_init(&addr); | |
1654 | local_irq_restore(flags); | |
1655 | ||
1656 | /* ftrace_dyn_arch_init places the return code in addr */ | |
1657 | if (addr) | |
1658 | goto failed; | |
1659 | ||
1660 | count = __stop_mcount_loc - __start_mcount_loc; | |
1661 | ||
1662 | ret = ftrace_dyn_table_alloc(count); | |
1663 | if (ret) | |
1664 | goto failed; | |
1665 | ||
1666 | last_ftrace_enabled = ftrace_enabled = 1; | |
1667 | ||
1668 | ret = ftrace_convert_nops(__start_mcount_loc, | |
1669 | __stop_mcount_loc); | |
1670 | ||
1671 | return; | |
1672 | failed: | |
1673 | ftrace_disabled = 1; | |
1674 | } | |
1675 | #else /* CONFIG_FTRACE_MCOUNT_RECORD */ | |
bd95b88d SR |
1676 | |
1677 | static void ftrace_release_hash(unsigned long start, unsigned long end) | |
1678 | { | |
1679 | struct dyn_ftrace *rec; | |
1680 | struct hlist_node *t, *n; | |
1681 | struct hlist_head *head, temp_list; | |
1682 | unsigned long flags; | |
1683 | int i, cpu; | |
1684 | ||
1685 | preempt_disable_notrace(); | |
1686 | ||
1687 | /* disable incase we call something that calls mcount */ | |
1688 | cpu = raw_smp_processor_id(); | |
1689 | per_cpu(ftrace_shutdown_disable_cpu, cpu)++; | |
1690 | ||
1691 | ftrace_hash_lock(flags); | |
1692 | ||
1693 | for (i = 0; i < FTRACE_HASHSIZE; i++) { | |
1694 | INIT_HLIST_HEAD(&temp_list); | |
1695 | head = &ftrace_hash[i]; | |
1696 | ||
1697 | /* all CPUS are stopped, we are safe to modify code */ | |
1698 | hlist_for_each_entry_safe(rec, t, n, head, node) { | |
1699 | if (rec->flags & FTRACE_FL_FREE) | |
1700 | continue; | |
1701 | ||
1702 | if ((rec->ip >= start) && (rec->ip < end)) | |
1703 | ftrace_free_rec(rec); | |
1704 | } | |
1705 | } | |
1706 | ||
1707 | ftrace_hash_unlock(flags); | |
1708 | ||
1709 | per_cpu(ftrace_shutdown_disable_cpu, cpu)--; | |
1710 | preempt_enable_notrace(); | |
1711 | ||
1712 | } | |
1713 | ||
68bf21aa SR |
1714 | static int ftraced(void *ignore) |
1715 | { | |
1716 | unsigned long usecs; | |
1717 | ||
1718 | while (!kthread_should_stop()) { | |
1719 | ||
1720 | set_current_state(TASK_INTERRUPTIBLE); | |
1721 | ||
1722 | /* check once a second */ | |
1723 | schedule_timeout(HZ); | |
1724 | ||
1725 | if (unlikely(ftrace_disabled)) | |
1726 | continue; | |
1727 | ||
1728 | mutex_lock(&ftrace_sysctl_lock); | |
1729 | mutex_lock(&ftraced_lock); | |
1730 | if (!ftraced_suspend && !ftraced_stop && | |
1731 | ftrace_update_code()) { | |
1732 | usecs = nsecs_to_usecs(ftrace_update_time); | |
1733 | if (ftrace_update_tot_cnt > 100000) { | |
1734 | ftrace_update_tot_cnt = 0; | |
1735 | pr_info("hm, dftrace overflow: %lu change%s" | |
1736 | " (%lu total) in %lu usec%s\n", | |
1737 | ftrace_update_cnt, | |
1738 | ftrace_update_cnt != 1 ? "s" : "", | |
1739 | ftrace_update_tot_cnt, | |
1740 | usecs, usecs != 1 ? "s" : ""); | |
1741 | ftrace_disabled = 1; | |
1742 | WARN_ON_ONCE(1); | |
1743 | } | |
1744 | } | |
1745 | mutex_unlock(&ftraced_lock); | |
1746 | mutex_unlock(&ftrace_sysctl_lock); | |
1747 | ||
1748 | ftrace_shutdown_replenish(); | |
1749 | } | |
1750 | __set_current_state(TASK_RUNNING); | |
1751 | return 0; | |
1752 | } | |
1753 | ||
e309b41d | 1754 | static int __init ftrace_dynamic_init(void) |
3d083395 SR |
1755 | { |
1756 | struct task_struct *p; | |
d61f82d0 | 1757 | unsigned long addr; |
3d083395 SR |
1758 | int ret; |
1759 | ||
d61f82d0 | 1760 | addr = (unsigned long)ftrace_record_ip; |
9ff9cdb2 | 1761 | |
784e2d76 | 1762 | stop_machine(ftrace_dyn_arch_init, &addr, NULL); |
d61f82d0 SR |
1763 | |
1764 | /* ftrace_dyn_arch_init places the return code in addr */ | |
4eebcc81 SR |
1765 | if (addr) { |
1766 | ret = (int)addr; | |
1767 | goto failed; | |
1768 | } | |
d61f82d0 | 1769 | |
68bf21aa | 1770 | ret = ftrace_dyn_table_alloc(NR_TO_INIT); |
3d083395 | 1771 | if (ret) |
4eebcc81 | 1772 | goto failed; |
3d083395 SR |
1773 | |
1774 | p = kthread_run(ftraced, NULL, "ftraced"); | |
4eebcc81 SR |
1775 | if (IS_ERR(p)) { |
1776 | ret = -1; | |
1777 | goto failed; | |
1778 | } | |
3d083395 | 1779 | |
d61f82d0 | 1780 | last_ftrace_enabled = ftrace_enabled = 1; |
e1c08bdd | 1781 | ftraced_task = p; |
3d083395 SR |
1782 | |
1783 | return 0; | |
4eebcc81 SR |
1784 | |
1785 | failed: | |
1786 | ftrace_disabled = 1; | |
1787 | return ret; | |
3d083395 SR |
1788 | } |
1789 | ||
d61f82d0 | 1790 | core_initcall(ftrace_dynamic_init); |
68bf21aa SR |
1791 | #endif /* CONFIG_FTRACE_MCOUNT_RECORD */ |
1792 | ||
3d083395 | 1793 | #else |
c7aafc54 IM |
1794 | # define ftrace_startup() do { } while (0) |
1795 | # define ftrace_shutdown() do { } while (0) | |
1796 | # define ftrace_startup_sysctl() do { } while (0) | |
1797 | # define ftrace_shutdown_sysctl() do { } while (0) | |
4eebcc81 | 1798 | # define ftrace_force_shutdown() do { } while (0) |
3d083395 SR |
1799 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
1800 | ||
a2bb6a3d SR |
1801 | /** |
1802 | * ftrace_kill_atomic - kill ftrace from critical sections | |
1803 | * | |
1804 | * This function should be used by panic code. It stops ftrace | |
1805 | * but in a not so nice way. If you need to simply kill ftrace | |
1806 | * from a non-atomic section, use ftrace_kill. | |
1807 | */ | |
1808 | void ftrace_kill_atomic(void) | |
1809 | { | |
1810 | ftrace_disabled = 1; | |
1811 | ftrace_enabled = 0; | |
b2613e37 | 1812 | #ifdef CONFIG_DYNAMIC_FTRACE |
a2bb6a3d | 1813 | ftraced_suspend = -1; |
b2613e37 | 1814 | #endif |
a2bb6a3d SR |
1815 | clear_ftrace_function(); |
1816 | } | |
1817 | ||
4eebcc81 SR |
1818 | /** |
1819 | * ftrace_kill - totally shutdown ftrace | |
1820 | * | |
1821 | * This is a safety measure. If something was detected that seems | |
1822 | * wrong, calling this function will keep ftrace from doing | |
1823 | * any more modifications, and updates. | |
1824 | * used when something went wrong. | |
1825 | */ | |
1826 | void ftrace_kill(void) | |
1827 | { | |
1828 | mutex_lock(&ftrace_sysctl_lock); | |
1829 | ftrace_disabled = 1; | |
1830 | ftrace_enabled = 0; | |
1831 | ||
1832 | clear_ftrace_function(); | |
1833 | mutex_unlock(&ftrace_sysctl_lock); | |
1834 | ||
1835 | /* Try to totally disable ftrace */ | |
1836 | ftrace_force_shutdown(); | |
1837 | } | |
1838 | ||
16444a8a | 1839 | /** |
3d083395 SR |
1840 | * register_ftrace_function - register a function for profiling |
1841 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 1842 | * |
3d083395 SR |
1843 | * Register a function to be called by all functions in the |
1844 | * kernel. | |
1845 | * | |
1846 | * Note: @ops->func and all the functions it calls must be labeled | |
1847 | * with "notrace", otherwise it will go into a | |
1848 | * recursive loop. | |
16444a8a | 1849 | */ |
3d083395 | 1850 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 1851 | { |
b0fc494f SR |
1852 | int ret; |
1853 | ||
4eebcc81 SR |
1854 | if (unlikely(ftrace_disabled)) |
1855 | return -1; | |
1856 | ||
b0fc494f | 1857 | mutex_lock(&ftrace_sysctl_lock); |
b0fc494f | 1858 | ret = __register_ftrace_function(ops); |
d61f82d0 | 1859 | ftrace_startup(); |
b0fc494f SR |
1860 | mutex_unlock(&ftrace_sysctl_lock); |
1861 | ||
1862 | return ret; | |
3d083395 SR |
1863 | } |
1864 | ||
1865 | /** | |
1866 | * unregister_ftrace_function - unresgister a function for profiling. | |
1867 | * @ops - ops structure that holds the function to unregister | |
1868 | * | |
1869 | * Unregister a function that was added to be called by ftrace profiling. | |
1870 | */ | |
1871 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
1872 | { | |
1873 | int ret; | |
1874 | ||
b0fc494f | 1875 | mutex_lock(&ftrace_sysctl_lock); |
3d083395 | 1876 | ret = __unregister_ftrace_function(ops); |
d61f82d0 | 1877 | ftrace_shutdown(); |
b0fc494f SR |
1878 | mutex_unlock(&ftrace_sysctl_lock); |
1879 | ||
1880 | return ret; | |
1881 | } | |
1882 | ||
e309b41d | 1883 | int |
b0fc494f | 1884 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
5072c59f | 1885 | struct file *file, void __user *buffer, size_t *lenp, |
b0fc494f SR |
1886 | loff_t *ppos) |
1887 | { | |
1888 | int ret; | |
1889 | ||
4eebcc81 SR |
1890 | if (unlikely(ftrace_disabled)) |
1891 | return -ENODEV; | |
1892 | ||
b0fc494f SR |
1893 | mutex_lock(&ftrace_sysctl_lock); |
1894 | ||
5072c59f | 1895 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
b0fc494f SR |
1896 | |
1897 | if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) | |
1898 | goto out; | |
1899 | ||
1900 | last_ftrace_enabled = ftrace_enabled; | |
1901 | ||
1902 | if (ftrace_enabled) { | |
1903 | ||
1904 | ftrace_startup_sysctl(); | |
1905 | ||
1906 | /* we are starting ftrace again */ | |
1907 | if (ftrace_list != &ftrace_list_end) { | |
1908 | if (ftrace_list->next == &ftrace_list_end) | |
1909 | ftrace_trace_function = ftrace_list->func; | |
1910 | else | |
1911 | ftrace_trace_function = ftrace_list_func; | |
1912 | } | |
1913 | ||
1914 | } else { | |
1915 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
1916 | ftrace_trace_function = ftrace_stub; | |
1917 | ||
1918 | ftrace_shutdown_sysctl(); | |
1919 | } | |
1920 | ||
1921 | out: | |
1922 | mutex_unlock(&ftrace_sysctl_lock); | |
3d083395 | 1923 | return ret; |
16444a8a | 1924 | } |