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Commit | Line | Data |
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16444a8a ACM |
1 | /* |
2 | * Infrastructure for profiling code inserted by 'gcc -pg'. | |
3 | * | |
4 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> | |
5 | * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com> | |
6 | * | |
7 | * Originally ported from the -rt patch by: | |
8 | * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com> | |
9 | * | |
10 | * Based on code in the latency_tracer, that is: | |
11 | * | |
12 | * Copyright (C) 2004-2006 Ingo Molnar | |
13 | * Copyright (C) 2004 William Lee Irwin III | |
14 | */ | |
15 | ||
3d083395 SR |
16 | #include <linux/stop_machine.h> |
17 | #include <linux/clocksource.h> | |
18 | #include <linux/kallsyms.h> | |
5072c59f | 19 | #include <linux/seq_file.h> |
4a2b8dda | 20 | #include <linux/suspend.h> |
5072c59f | 21 | #include <linux/debugfs.h> |
3d083395 | 22 | #include <linux/hardirq.h> |
2d8b820b | 23 | #include <linux/kthread.h> |
5072c59f | 24 | #include <linux/uaccess.h> |
2d8b820b | 25 | #include <linux/ftrace.h> |
b0fc494f | 26 | #include <linux/sysctl.h> |
5a0e3ad6 | 27 | #include <linux/slab.h> |
5072c59f | 28 | #include <linux/ctype.h> |
3d083395 | 29 | #include <linux/list.h> |
59df055f | 30 | #include <linux/hash.h> |
3f379b03 | 31 | #include <linux/rcupdate.h> |
3d083395 | 32 | |
ad8d75ff | 33 | #include <trace/events/sched.h> |
8aef2d28 | 34 | |
395a59d0 | 35 | #include <asm/ftrace.h> |
2af15d6a | 36 | #include <asm/setup.h> |
395a59d0 | 37 | |
0706f1c4 | 38 | #include "trace_output.h" |
bac429f0 | 39 | #include "trace_stat.h" |
16444a8a | 40 | |
6912896e | 41 | #define FTRACE_WARN_ON(cond) \ |
0778d9ad SR |
42 | ({ \ |
43 | int ___r = cond; \ | |
44 | if (WARN_ON(___r)) \ | |
6912896e | 45 | ftrace_kill(); \ |
0778d9ad SR |
46 | ___r; \ |
47 | }) | |
6912896e SR |
48 | |
49 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
0778d9ad SR |
50 | ({ \ |
51 | int ___r = cond; \ | |
52 | if (WARN_ON_ONCE(___r)) \ | |
6912896e | 53 | ftrace_kill(); \ |
0778d9ad SR |
54 | ___r; \ |
55 | }) | |
6912896e | 56 | |
8fc0c701 SR |
57 | /* hash bits for specific function selection */ |
58 | #define FTRACE_HASH_BITS 7 | |
59 | #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS) | |
60 | ||
4eebcc81 SR |
61 | /* ftrace_enabled is a method to turn ftrace on or off */ |
62 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 63 | static int last_ftrace_enabled; |
b0fc494f | 64 | |
60a7ecf4 SR |
65 | /* Quick disabling of function tracer. */ |
66 | int function_trace_stop; | |
67 | ||
756d17ee | 68 | /* List for set_ftrace_pid's pids. */ |
69 | LIST_HEAD(ftrace_pids); | |
70 | struct ftrace_pid { | |
71 | struct list_head list; | |
72 | struct pid *pid; | |
73 | }; | |
74 | ||
4eebcc81 SR |
75 | /* |
76 | * ftrace_disabled is set when an anomaly is discovered. | |
77 | * ftrace_disabled is much stronger than ftrace_enabled. | |
78 | */ | |
79 | static int ftrace_disabled __read_mostly; | |
80 | ||
52baf119 | 81 | static DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 82 | |
16444a8a ACM |
83 | static struct ftrace_ops ftrace_list_end __read_mostly = |
84 | { | |
fb9fb015 | 85 | .func = ftrace_stub, |
16444a8a ACM |
86 | }; |
87 | ||
88 | static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; | |
89 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; | |
60a7ecf4 | 90 | ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub; |
df4fc315 | 91 | ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; |
16444a8a | 92 | |
3f379b03 PM |
93 | /* |
94 | * Traverse the ftrace_list, invoking all entries. The reason that we | |
95 | * can use rcu_dereference_raw() is that elements removed from this list | |
96 | * are simply leaked, so there is no need to interact with a grace-period | |
97 | * mechanism. The rcu_dereference_raw() calls are needed to handle | |
98 | * concurrent insertions into the ftrace_list. | |
99 | * | |
100 | * Silly Alpha and silly pointer-speculation compiler optimizations! | |
101 | */ | |
f2252935 | 102 | static void ftrace_list_func(unsigned long ip, unsigned long parent_ip) |
16444a8a | 103 | { |
3f379b03 | 104 | struct ftrace_ops *op = rcu_dereference_raw(ftrace_list); /*see above*/ |
16444a8a ACM |
105 | |
106 | while (op != &ftrace_list_end) { | |
16444a8a | 107 | op->func(ip, parent_ip); |
3f379b03 | 108 | op = rcu_dereference_raw(op->next); /*see above*/ |
16444a8a ACM |
109 | }; |
110 | } | |
111 | ||
df4fc315 SR |
112 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip) |
113 | { | |
0ef8cde5 | 114 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
115 | return; |
116 | ||
117 | ftrace_pid_function(ip, parent_ip); | |
118 | } | |
119 | ||
120 | static void set_ftrace_pid_function(ftrace_func_t func) | |
121 | { | |
122 | /* do not set ftrace_pid_function to itself! */ | |
123 | if (func != ftrace_pid_func) | |
124 | ftrace_pid_function = func; | |
125 | } | |
126 | ||
16444a8a | 127 | /** |
3d083395 | 128 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 129 | * |
3d083395 SR |
130 | * This NULLs the ftrace function and in essence stops |
131 | * tracing. There may be lag | |
16444a8a | 132 | */ |
3d083395 | 133 | void clear_ftrace_function(void) |
16444a8a | 134 | { |
3d083395 | 135 | ftrace_trace_function = ftrace_stub; |
60a7ecf4 | 136 | __ftrace_trace_function = ftrace_stub; |
df4fc315 | 137 | ftrace_pid_function = ftrace_stub; |
3d083395 SR |
138 | } |
139 | ||
60a7ecf4 SR |
140 | #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
141 | /* | |
142 | * For those archs that do not test ftrace_trace_stop in their | |
143 | * mcount call site, we need to do it from C. | |
144 | */ | |
145 | static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip) | |
146 | { | |
147 | if (function_trace_stop) | |
148 | return; | |
149 | ||
150 | __ftrace_trace_function(ip, parent_ip); | |
151 | } | |
152 | #endif | |
153 | ||
491d0dcf SR |
154 | static void update_ftrace_function(void) |
155 | { | |
156 | ftrace_func_t func; | |
157 | ||
158 | /* | |
159 | * If there's only one function registered, then call that | |
160 | * function directly. Otherwise, we need to iterate over the | |
161 | * registered callers. | |
162 | */ | |
163 | if (ftrace_list == &ftrace_list_end || | |
164 | ftrace_list->next == &ftrace_list_end) | |
165 | func = ftrace_list->func; | |
166 | else | |
167 | func = ftrace_list_func; | |
168 | ||
169 | /* If we filter on pids, update to use the pid function */ | |
170 | if (!list_empty(&ftrace_pids)) { | |
171 | set_ftrace_pid_function(func); | |
172 | func = ftrace_pid_func; | |
173 | } | |
174 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
175 | ftrace_trace_function = func; | |
176 | #else | |
177 | __ftrace_trace_function = func; | |
178 | ftrace_trace_function = ftrace_test_stop_func; | |
179 | #endif | |
180 | } | |
181 | ||
e309b41d | 182 | static int __register_ftrace_function(struct ftrace_ops *ops) |
3d083395 | 183 | { |
16444a8a ACM |
184 | ops->next = ftrace_list; |
185 | /* | |
186 | * We are entering ops into the ftrace_list but another | |
187 | * CPU might be walking that list. We need to make sure | |
188 | * the ops->next pointer is valid before another CPU sees | |
189 | * the ops pointer included into the ftrace_list. | |
190 | */ | |
3f379b03 | 191 | rcu_assign_pointer(ftrace_list, ops); |
3d083395 | 192 | |
491d0dcf SR |
193 | if (ftrace_enabled) |
194 | update_ftrace_function(); | |
3d083395 | 195 | |
16444a8a ACM |
196 | return 0; |
197 | } | |
198 | ||
e309b41d | 199 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 200 | { |
16444a8a | 201 | struct ftrace_ops **p; |
16444a8a ACM |
202 | |
203 | /* | |
3d083395 SR |
204 | * If we are removing the last function, then simply point |
205 | * to the ftrace_stub. | |
16444a8a ACM |
206 | */ |
207 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { | |
208 | ftrace_trace_function = ftrace_stub; | |
209 | ftrace_list = &ftrace_list_end; | |
e6ea44e9 | 210 | return 0; |
16444a8a ACM |
211 | } |
212 | ||
213 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) | |
214 | if (*p == ops) | |
215 | break; | |
216 | ||
e6ea44e9 SR |
217 | if (*p != ops) |
218 | return -1; | |
16444a8a ACM |
219 | |
220 | *p = (*p)->next; | |
221 | ||
491d0dcf SR |
222 | if (ftrace_enabled) |
223 | update_ftrace_function(); | |
16444a8a | 224 | |
e6ea44e9 | 225 | return 0; |
3d083395 SR |
226 | } |
227 | ||
df4fc315 SR |
228 | static void ftrace_update_pid_func(void) |
229 | { | |
491d0dcf | 230 | /* Only do something if we are tracing something */ |
df4fc315 | 231 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 232 | return; |
df4fc315 | 233 | |
491d0dcf | 234 | update_ftrace_function(); |
df4fc315 SR |
235 | } |
236 | ||
493762fc SR |
237 | #ifdef CONFIG_FUNCTION_PROFILER |
238 | struct ftrace_profile { | |
239 | struct hlist_node node; | |
240 | unsigned long ip; | |
241 | unsigned long counter; | |
0706f1c4 SR |
242 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
243 | unsigned long long time; | |
e330b3bc | 244 | unsigned long long time_squared; |
0706f1c4 | 245 | #endif |
8fc0c701 SR |
246 | }; |
247 | ||
493762fc SR |
248 | struct ftrace_profile_page { |
249 | struct ftrace_profile_page *next; | |
250 | unsigned long index; | |
251 | struct ftrace_profile records[]; | |
d61f82d0 SR |
252 | }; |
253 | ||
cafb168a SR |
254 | struct ftrace_profile_stat { |
255 | atomic_t disabled; | |
256 | struct hlist_head *hash; | |
257 | struct ftrace_profile_page *pages; | |
258 | struct ftrace_profile_page *start; | |
259 | struct tracer_stat stat; | |
260 | }; | |
261 | ||
493762fc SR |
262 | #define PROFILE_RECORDS_SIZE \ |
263 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 264 | |
493762fc SR |
265 | #define PROFILES_PER_PAGE \ |
266 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 267 | |
fb9fb015 SR |
268 | static int ftrace_profile_bits __read_mostly; |
269 | static int ftrace_profile_enabled __read_mostly; | |
270 | ||
271 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
272 | static DEFINE_MUTEX(ftrace_profile_lock); |
273 | ||
cafb168a | 274 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc SR |
275 | |
276 | #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */ | |
277 | ||
bac429f0 SR |
278 | static void * |
279 | function_stat_next(void *v, int idx) | |
280 | { | |
493762fc SR |
281 | struct ftrace_profile *rec = v; |
282 | struct ftrace_profile_page *pg; | |
bac429f0 | 283 | |
493762fc | 284 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
285 | |
286 | again: | |
0296e425 LZ |
287 | if (idx != 0) |
288 | rec++; | |
289 | ||
bac429f0 SR |
290 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
291 | pg = pg->next; | |
292 | if (!pg) | |
293 | return NULL; | |
294 | rec = &pg->records[0]; | |
493762fc SR |
295 | if (!rec->counter) |
296 | goto again; | |
bac429f0 SR |
297 | } |
298 | ||
bac429f0 SR |
299 | return rec; |
300 | } | |
301 | ||
302 | static void *function_stat_start(struct tracer_stat *trace) | |
303 | { | |
cafb168a SR |
304 | struct ftrace_profile_stat *stat = |
305 | container_of(trace, struct ftrace_profile_stat, stat); | |
306 | ||
307 | if (!stat || !stat->start) | |
308 | return NULL; | |
309 | ||
310 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
311 | } |
312 | ||
0706f1c4 SR |
313 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
314 | /* function graph compares on total time */ | |
315 | static int function_stat_cmp(void *p1, void *p2) | |
316 | { | |
317 | struct ftrace_profile *a = p1; | |
318 | struct ftrace_profile *b = p2; | |
319 | ||
320 | if (a->time < b->time) | |
321 | return -1; | |
322 | if (a->time > b->time) | |
323 | return 1; | |
324 | else | |
325 | return 0; | |
326 | } | |
327 | #else | |
328 | /* not function graph compares against hits */ | |
bac429f0 SR |
329 | static int function_stat_cmp(void *p1, void *p2) |
330 | { | |
493762fc SR |
331 | struct ftrace_profile *a = p1; |
332 | struct ftrace_profile *b = p2; | |
bac429f0 SR |
333 | |
334 | if (a->counter < b->counter) | |
335 | return -1; | |
336 | if (a->counter > b->counter) | |
337 | return 1; | |
338 | else | |
339 | return 0; | |
340 | } | |
0706f1c4 | 341 | #endif |
bac429f0 SR |
342 | |
343 | static int function_stat_headers(struct seq_file *m) | |
344 | { | |
0706f1c4 | 345 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b | 346 | seq_printf(m, " Function " |
e330b3bc | 347 | "Hit Time Avg s^2\n" |
34886c8b | 348 | " -------- " |
e330b3bc | 349 | "--- ---- --- ---\n"); |
0706f1c4 | 350 | #else |
bac429f0 SR |
351 | seq_printf(m, " Function Hit\n" |
352 | " -------- ---\n"); | |
0706f1c4 | 353 | #endif |
bac429f0 SR |
354 | return 0; |
355 | } | |
356 | ||
357 | static int function_stat_show(struct seq_file *m, void *v) | |
358 | { | |
493762fc | 359 | struct ftrace_profile *rec = v; |
bac429f0 | 360 | char str[KSYM_SYMBOL_LEN]; |
3aaba20f | 361 | int ret = 0; |
0706f1c4 | 362 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
363 | static struct trace_seq s; |
364 | unsigned long long avg; | |
e330b3bc | 365 | unsigned long long stddev; |
0706f1c4 | 366 | #endif |
3aaba20f LZ |
367 | mutex_lock(&ftrace_profile_lock); |
368 | ||
369 | /* we raced with function_profile_reset() */ | |
370 | if (unlikely(rec->counter == 0)) { | |
371 | ret = -EBUSY; | |
372 | goto out; | |
373 | } | |
bac429f0 SR |
374 | |
375 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
0706f1c4 SR |
376 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
377 | ||
378 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
379 | seq_printf(m, " "); | |
34886c8b SR |
380 | avg = rec->time; |
381 | do_div(avg, rec->counter); | |
382 | ||
e330b3bc CD |
383 | /* Sample standard deviation (s^2) */ |
384 | if (rec->counter <= 1) | |
385 | stddev = 0; | |
386 | else { | |
387 | stddev = rec->time_squared - rec->counter * avg * avg; | |
388 | /* | |
389 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
390 | * trace_print_graph_duration will divide 1000 again. | |
391 | */ | |
392 | do_div(stddev, (rec->counter - 1) * 1000); | |
393 | } | |
394 | ||
34886c8b SR |
395 | trace_seq_init(&s); |
396 | trace_print_graph_duration(rec->time, &s); | |
397 | trace_seq_puts(&s, " "); | |
398 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
399 | trace_seq_puts(&s, " "); |
400 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 | 401 | trace_print_seq(m, &s); |
0706f1c4 SR |
402 | #endif |
403 | seq_putc(m, '\n'); | |
3aaba20f LZ |
404 | out: |
405 | mutex_unlock(&ftrace_profile_lock); | |
bac429f0 | 406 | |
3aaba20f | 407 | return ret; |
bac429f0 SR |
408 | } |
409 | ||
cafb168a | 410 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 411 | { |
493762fc | 412 | struct ftrace_profile_page *pg; |
bac429f0 | 413 | |
cafb168a | 414 | pg = stat->pages = stat->start; |
bac429f0 | 415 | |
493762fc SR |
416 | while (pg) { |
417 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
418 | pg->index = 0; | |
419 | pg = pg->next; | |
bac429f0 SR |
420 | } |
421 | ||
cafb168a | 422 | memset(stat->hash, 0, |
493762fc SR |
423 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
424 | } | |
bac429f0 | 425 | |
cafb168a | 426 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
427 | { |
428 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
429 | int functions; |
430 | int pages; | |
493762fc | 431 | int i; |
bac429f0 | 432 | |
493762fc | 433 | /* If we already allocated, do nothing */ |
cafb168a | 434 | if (stat->pages) |
493762fc | 435 | return 0; |
bac429f0 | 436 | |
cafb168a SR |
437 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
438 | if (!stat->pages) | |
493762fc | 439 | return -ENOMEM; |
bac429f0 | 440 | |
318e0a73 SR |
441 | #ifdef CONFIG_DYNAMIC_FTRACE |
442 | functions = ftrace_update_tot_cnt; | |
443 | #else | |
444 | /* | |
445 | * We do not know the number of functions that exist because | |
446 | * dynamic tracing is what counts them. With past experience | |
447 | * we have around 20K functions. That should be more than enough. | |
448 | * It is highly unlikely we will execute every function in | |
449 | * the kernel. | |
450 | */ | |
451 | functions = 20000; | |
452 | #endif | |
453 | ||
cafb168a | 454 | pg = stat->start = stat->pages; |
bac429f0 | 455 | |
318e0a73 SR |
456 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
457 | ||
458 | for (i = 0; i < pages; i++) { | |
493762fc | 459 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 460 | if (!pg->next) |
318e0a73 | 461 | goto out_free; |
493762fc SR |
462 | pg = pg->next; |
463 | } | |
464 | ||
465 | return 0; | |
318e0a73 SR |
466 | |
467 | out_free: | |
468 | pg = stat->start; | |
469 | while (pg) { | |
470 | unsigned long tmp = (unsigned long)pg; | |
471 | ||
472 | pg = pg->next; | |
473 | free_page(tmp); | |
474 | } | |
475 | ||
476 | free_page((unsigned long)stat->pages); | |
477 | stat->pages = NULL; | |
478 | stat->start = NULL; | |
479 | ||
480 | return -ENOMEM; | |
bac429f0 SR |
481 | } |
482 | ||
cafb168a | 483 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 484 | { |
cafb168a | 485 | struct ftrace_profile_stat *stat; |
493762fc | 486 | int size; |
bac429f0 | 487 | |
cafb168a SR |
488 | stat = &per_cpu(ftrace_profile_stats, cpu); |
489 | ||
490 | if (stat->hash) { | |
493762fc | 491 | /* If the profile is already created, simply reset it */ |
cafb168a | 492 | ftrace_profile_reset(stat); |
493762fc SR |
493 | return 0; |
494 | } | |
bac429f0 | 495 | |
493762fc SR |
496 | /* |
497 | * We are profiling all functions, but usually only a few thousand | |
498 | * functions are hit. We'll make a hash of 1024 items. | |
499 | */ | |
500 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 501 | |
cafb168a | 502 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
493762fc | 503 | |
cafb168a | 504 | if (!stat->hash) |
493762fc SR |
505 | return -ENOMEM; |
506 | ||
cafb168a SR |
507 | if (!ftrace_profile_bits) { |
508 | size--; | |
493762fc | 509 | |
cafb168a SR |
510 | for (; size; size >>= 1) |
511 | ftrace_profile_bits++; | |
512 | } | |
493762fc | 513 | |
318e0a73 | 514 | /* Preallocate the function profiling pages */ |
cafb168a SR |
515 | if (ftrace_profile_pages_init(stat) < 0) { |
516 | kfree(stat->hash); | |
517 | stat->hash = NULL; | |
493762fc SR |
518 | return -ENOMEM; |
519 | } | |
520 | ||
521 | return 0; | |
bac429f0 SR |
522 | } |
523 | ||
cafb168a SR |
524 | static int ftrace_profile_init(void) |
525 | { | |
526 | int cpu; | |
527 | int ret = 0; | |
528 | ||
529 | for_each_online_cpu(cpu) { | |
530 | ret = ftrace_profile_init_cpu(cpu); | |
531 | if (ret) | |
532 | break; | |
533 | } | |
534 | ||
535 | return ret; | |
536 | } | |
537 | ||
493762fc | 538 | /* interrupts must be disabled */ |
cafb168a SR |
539 | static struct ftrace_profile * |
540 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 541 | { |
493762fc | 542 | struct ftrace_profile *rec; |
bac429f0 SR |
543 | struct hlist_head *hhd; |
544 | struct hlist_node *n; | |
bac429f0 SR |
545 | unsigned long key; |
546 | ||
bac429f0 | 547 | key = hash_long(ip, ftrace_profile_bits); |
cafb168a | 548 | hhd = &stat->hash[key]; |
bac429f0 SR |
549 | |
550 | if (hlist_empty(hhd)) | |
551 | return NULL; | |
552 | ||
bac429f0 SR |
553 | hlist_for_each_entry_rcu(rec, n, hhd, node) { |
554 | if (rec->ip == ip) | |
493762fc SR |
555 | return rec; |
556 | } | |
557 | ||
558 | return NULL; | |
559 | } | |
560 | ||
cafb168a SR |
561 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
562 | struct ftrace_profile *rec) | |
493762fc SR |
563 | { |
564 | unsigned long key; | |
565 | ||
566 | key = hash_long(rec->ip, ftrace_profile_bits); | |
cafb168a | 567 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
568 | } |
569 | ||
318e0a73 SR |
570 | /* |
571 | * The memory is already allocated, this simply finds a new record to use. | |
572 | */ | |
493762fc | 573 | static struct ftrace_profile * |
318e0a73 | 574 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
575 | { |
576 | struct ftrace_profile *rec = NULL; | |
577 | ||
318e0a73 | 578 | /* prevent recursion (from NMIs) */ |
cafb168a | 579 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
580 | goto out; |
581 | ||
493762fc | 582 | /* |
318e0a73 SR |
583 | * Try to find the function again since an NMI |
584 | * could have added it | |
493762fc | 585 | */ |
cafb168a | 586 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 587 | if (rec) |
cafb168a | 588 | goto out; |
493762fc | 589 | |
cafb168a SR |
590 | if (stat->pages->index == PROFILES_PER_PAGE) { |
591 | if (!stat->pages->next) | |
592 | goto out; | |
593 | stat->pages = stat->pages->next; | |
bac429f0 | 594 | } |
493762fc | 595 | |
cafb168a | 596 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 597 | rec->ip = ip; |
cafb168a | 598 | ftrace_add_profile(stat, rec); |
493762fc | 599 | |
bac429f0 | 600 | out: |
cafb168a | 601 | atomic_dec(&stat->disabled); |
bac429f0 SR |
602 | |
603 | return rec; | |
604 | } | |
605 | ||
606 | static void | |
607 | function_profile_call(unsigned long ip, unsigned long parent_ip) | |
608 | { | |
cafb168a | 609 | struct ftrace_profile_stat *stat; |
493762fc | 610 | struct ftrace_profile *rec; |
bac429f0 SR |
611 | unsigned long flags; |
612 | ||
613 | if (!ftrace_profile_enabled) | |
614 | return; | |
615 | ||
616 | local_irq_save(flags); | |
cafb168a SR |
617 | |
618 | stat = &__get_cpu_var(ftrace_profile_stats); | |
0f6ce3de | 619 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
620 | goto out; |
621 | ||
622 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 623 | if (!rec) { |
318e0a73 | 624 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
625 | if (!rec) |
626 | goto out; | |
627 | } | |
bac429f0 SR |
628 | |
629 | rec->counter++; | |
630 | out: | |
631 | local_irq_restore(flags); | |
632 | } | |
633 | ||
0706f1c4 SR |
634 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
635 | static int profile_graph_entry(struct ftrace_graph_ent *trace) | |
636 | { | |
637 | function_profile_call(trace->func, 0); | |
638 | return 1; | |
639 | } | |
640 | ||
641 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
642 | { | |
cafb168a | 643 | struct ftrace_profile_stat *stat; |
a2a16d6a | 644 | unsigned long long calltime; |
0706f1c4 | 645 | struct ftrace_profile *rec; |
cafb168a | 646 | unsigned long flags; |
0706f1c4 SR |
647 | |
648 | local_irq_save(flags); | |
cafb168a | 649 | stat = &__get_cpu_var(ftrace_profile_stats); |
0f6ce3de | 650 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
651 | goto out; |
652 | ||
37e44bc5 SR |
653 | /* If the calltime was zero'd ignore it */ |
654 | if (!trace->calltime) | |
655 | goto out; | |
656 | ||
a2a16d6a SR |
657 | calltime = trace->rettime - trace->calltime; |
658 | ||
659 | if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) { | |
660 | int index; | |
661 | ||
662 | index = trace->depth; | |
663 | ||
664 | /* Append this call time to the parent time to subtract */ | |
665 | if (index) | |
666 | current->ret_stack[index - 1].subtime += calltime; | |
667 | ||
668 | if (current->ret_stack[index].subtime < calltime) | |
669 | calltime -= current->ret_stack[index].subtime; | |
670 | else | |
671 | calltime = 0; | |
672 | } | |
673 | ||
cafb168a | 674 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 675 | if (rec) { |
a2a16d6a | 676 | rec->time += calltime; |
e330b3bc CD |
677 | rec->time_squared += calltime * calltime; |
678 | } | |
a2a16d6a | 679 | |
cafb168a | 680 | out: |
0706f1c4 SR |
681 | local_irq_restore(flags); |
682 | } | |
683 | ||
684 | static int register_ftrace_profiler(void) | |
685 | { | |
686 | return register_ftrace_graph(&profile_graph_return, | |
687 | &profile_graph_entry); | |
688 | } | |
689 | ||
690 | static void unregister_ftrace_profiler(void) | |
691 | { | |
692 | unregister_ftrace_graph(); | |
693 | } | |
694 | #else | |
bac429f0 SR |
695 | static struct ftrace_ops ftrace_profile_ops __read_mostly = |
696 | { | |
fb9fb015 | 697 | .func = function_profile_call, |
bac429f0 SR |
698 | }; |
699 | ||
0706f1c4 SR |
700 | static int register_ftrace_profiler(void) |
701 | { | |
702 | return register_ftrace_function(&ftrace_profile_ops); | |
703 | } | |
704 | ||
705 | static void unregister_ftrace_profiler(void) | |
706 | { | |
707 | unregister_ftrace_function(&ftrace_profile_ops); | |
708 | } | |
709 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
710 | ||
bac429f0 SR |
711 | static ssize_t |
712 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
713 | size_t cnt, loff_t *ppos) | |
714 | { | |
715 | unsigned long val; | |
fb9fb015 | 716 | char buf[64]; /* big enough to hold a number */ |
bac429f0 SR |
717 | int ret; |
718 | ||
bac429f0 SR |
719 | if (cnt >= sizeof(buf)) |
720 | return -EINVAL; | |
721 | ||
722 | if (copy_from_user(&buf, ubuf, cnt)) | |
723 | return -EFAULT; | |
724 | ||
725 | buf[cnt] = 0; | |
726 | ||
727 | ret = strict_strtoul(buf, 10, &val); | |
728 | if (ret < 0) | |
729 | return ret; | |
730 | ||
731 | val = !!val; | |
732 | ||
733 | mutex_lock(&ftrace_profile_lock); | |
734 | if (ftrace_profile_enabled ^ val) { | |
735 | if (val) { | |
493762fc SR |
736 | ret = ftrace_profile_init(); |
737 | if (ret < 0) { | |
738 | cnt = ret; | |
739 | goto out; | |
740 | } | |
741 | ||
0706f1c4 SR |
742 | ret = register_ftrace_profiler(); |
743 | if (ret < 0) { | |
744 | cnt = ret; | |
745 | goto out; | |
746 | } | |
bac429f0 SR |
747 | ftrace_profile_enabled = 1; |
748 | } else { | |
749 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
750 | /* |
751 | * unregister_ftrace_profiler calls stop_machine | |
752 | * so this acts like an synchronize_sched. | |
753 | */ | |
0706f1c4 | 754 | unregister_ftrace_profiler(); |
bac429f0 SR |
755 | } |
756 | } | |
493762fc | 757 | out: |
bac429f0 SR |
758 | mutex_unlock(&ftrace_profile_lock); |
759 | ||
cf8517cf | 760 | *ppos += cnt; |
bac429f0 SR |
761 | |
762 | return cnt; | |
763 | } | |
764 | ||
493762fc SR |
765 | static ssize_t |
766 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
767 | size_t cnt, loff_t *ppos) | |
768 | { | |
fb9fb015 | 769 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
770 | int r; |
771 | ||
772 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
773 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
774 | } | |
775 | ||
bac429f0 SR |
776 | static const struct file_operations ftrace_profile_fops = { |
777 | .open = tracing_open_generic, | |
778 | .read = ftrace_profile_read, | |
779 | .write = ftrace_profile_write, | |
6038f373 | 780 | .llseek = default_llseek, |
bac429f0 SR |
781 | }; |
782 | ||
cafb168a SR |
783 | /* used to initialize the real stat files */ |
784 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
785 | .name = "functions", |
786 | .stat_start = function_stat_start, | |
787 | .stat_next = function_stat_next, | |
788 | .stat_cmp = function_stat_cmp, | |
789 | .stat_headers = function_stat_headers, | |
790 | .stat_show = function_stat_show | |
cafb168a SR |
791 | }; |
792 | ||
6ab5d668 | 793 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 | 794 | { |
cafb168a | 795 | struct ftrace_profile_stat *stat; |
bac429f0 | 796 | struct dentry *entry; |
cafb168a | 797 | char *name; |
bac429f0 | 798 | int ret; |
cafb168a SR |
799 | int cpu; |
800 | ||
801 | for_each_possible_cpu(cpu) { | |
802 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
803 | ||
804 | /* allocate enough for function name + cpu number */ | |
805 | name = kmalloc(32, GFP_KERNEL); | |
806 | if (!name) { | |
807 | /* | |
808 | * The files created are permanent, if something happens | |
809 | * we still do not free memory. | |
810 | */ | |
cafb168a SR |
811 | WARN(1, |
812 | "Could not allocate stat file for cpu %d\n", | |
813 | cpu); | |
814 | return; | |
815 | } | |
816 | stat->stat = function_stats; | |
817 | snprintf(name, 32, "function%d", cpu); | |
818 | stat->stat.name = name; | |
819 | ret = register_stat_tracer(&stat->stat); | |
820 | if (ret) { | |
821 | WARN(1, | |
822 | "Could not register function stat for cpu %d\n", | |
823 | cpu); | |
824 | kfree(name); | |
825 | return; | |
826 | } | |
bac429f0 SR |
827 | } |
828 | ||
829 | entry = debugfs_create_file("function_profile_enabled", 0644, | |
830 | d_tracer, NULL, &ftrace_profile_fops); | |
831 | if (!entry) | |
832 | pr_warning("Could not create debugfs " | |
833 | "'function_profile_enabled' entry\n"); | |
834 | } | |
835 | ||
bac429f0 | 836 | #else /* CONFIG_FUNCTION_PROFILER */ |
6ab5d668 | 837 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 SR |
838 | { |
839 | } | |
bac429f0 SR |
840 | #endif /* CONFIG_FUNCTION_PROFILER */ |
841 | ||
493762fc SR |
842 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; |
843 | ||
844 | #ifdef CONFIG_DYNAMIC_FTRACE | |
845 | ||
846 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD | |
847 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
848 | #endif | |
849 | ||
850 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; | |
851 | ||
852 | struct ftrace_func_probe { | |
853 | struct hlist_node node; | |
854 | struct ftrace_probe_ops *ops; | |
855 | unsigned long flags; | |
856 | unsigned long ip; | |
857 | void *data; | |
858 | struct rcu_head rcu; | |
859 | }; | |
860 | ||
861 | enum { | |
862 | FTRACE_ENABLE_CALLS = (1 << 0), | |
863 | FTRACE_DISABLE_CALLS = (1 << 1), | |
864 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
79e406d7 SR |
865 | FTRACE_START_FUNC_RET = (1 << 3), |
866 | FTRACE_STOP_FUNC_RET = (1 << 4), | |
493762fc SR |
867 | }; |
868 | ||
869 | static int ftrace_filtered; | |
870 | ||
871 | static struct dyn_ftrace *ftrace_new_addrs; | |
872 | ||
873 | static DEFINE_MUTEX(ftrace_regex_lock); | |
874 | ||
875 | struct ftrace_page { | |
876 | struct ftrace_page *next; | |
877 | int index; | |
878 | struct dyn_ftrace records[]; | |
879 | }; | |
880 | ||
881 | #define ENTRIES_PER_PAGE \ | |
882 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
883 | ||
884 | /* estimate from running different kernels */ | |
885 | #define NR_TO_INIT 10000 | |
886 | ||
887 | static struct ftrace_page *ftrace_pages_start; | |
888 | static struct ftrace_page *ftrace_pages; | |
889 | ||
890 | static struct dyn_ftrace *ftrace_free_records; | |
891 | ||
892 | /* | |
893 | * This is a double for. Do not use 'break' to break out of the loop, | |
894 | * you must use a goto. | |
895 | */ | |
896 | #define do_for_each_ftrace_rec(pg, rec) \ | |
897 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
898 | int _____i; \ | |
899 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
900 | rec = &pg->records[_____i]; | |
901 | ||
902 | #define while_for_each_ftrace_rec() \ | |
903 | } \ | |
904 | } | |
905 | ||
e309b41d | 906 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
37ad5084 | 907 | { |
ee000b7f | 908 | rec->freelist = ftrace_free_records; |
37ad5084 SR |
909 | ftrace_free_records = rec; |
910 | rec->flags |= FTRACE_FL_FREE; | |
911 | } | |
912 | ||
e309b41d | 913 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 914 | { |
37ad5084 SR |
915 | struct dyn_ftrace *rec; |
916 | ||
917 | /* First check for freed records */ | |
918 | if (ftrace_free_records) { | |
919 | rec = ftrace_free_records; | |
920 | ||
37ad5084 | 921 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
6912896e | 922 | FTRACE_WARN_ON_ONCE(1); |
37ad5084 SR |
923 | ftrace_free_records = NULL; |
924 | return NULL; | |
925 | } | |
926 | ||
ee000b7f | 927 | ftrace_free_records = rec->freelist; |
37ad5084 SR |
928 | memset(rec, 0, sizeof(*rec)); |
929 | return rec; | |
930 | } | |
931 | ||
3c1720f0 | 932 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
08f5ac90 SR |
933 | if (!ftrace_pages->next) { |
934 | /* allocate another page */ | |
935 | ftrace_pages->next = | |
936 | (void *)get_zeroed_page(GFP_KERNEL); | |
937 | if (!ftrace_pages->next) | |
938 | return NULL; | |
939 | } | |
3c1720f0 SR |
940 | ftrace_pages = ftrace_pages->next; |
941 | } | |
942 | ||
943 | return &ftrace_pages->records[ftrace_pages->index++]; | |
944 | } | |
945 | ||
08f5ac90 | 946 | static struct dyn_ftrace * |
d61f82d0 | 947 | ftrace_record_ip(unsigned long ip) |
3d083395 | 948 | { |
08f5ac90 | 949 | struct dyn_ftrace *rec; |
3d083395 | 950 | |
f3c7ac40 | 951 | if (ftrace_disabled) |
08f5ac90 | 952 | return NULL; |
3d083395 | 953 | |
08f5ac90 SR |
954 | rec = ftrace_alloc_dyn_node(ip); |
955 | if (!rec) | |
956 | return NULL; | |
3d083395 | 957 | |
08f5ac90 | 958 | rec->ip = ip; |
ee000b7f | 959 | rec->newlist = ftrace_new_addrs; |
e94142a6 | 960 | ftrace_new_addrs = rec; |
3d083395 | 961 | |
08f5ac90 | 962 | return rec; |
3d083395 SR |
963 | } |
964 | ||
b17e8a37 SR |
965 | static void print_ip_ins(const char *fmt, unsigned char *p) |
966 | { | |
967 | int i; | |
968 | ||
969 | printk(KERN_CONT "%s", fmt); | |
970 | ||
971 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
972 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
973 | } | |
974 | ||
31e88909 | 975 | static void ftrace_bug(int failed, unsigned long ip) |
b17e8a37 SR |
976 | { |
977 | switch (failed) { | |
978 | case -EFAULT: | |
979 | FTRACE_WARN_ON_ONCE(1); | |
980 | pr_info("ftrace faulted on modifying "); | |
981 | print_ip_sym(ip); | |
982 | break; | |
983 | case -EINVAL: | |
984 | FTRACE_WARN_ON_ONCE(1); | |
985 | pr_info("ftrace failed to modify "); | |
986 | print_ip_sym(ip); | |
b17e8a37 | 987 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
988 | printk(KERN_CONT "\n"); |
989 | break; | |
990 | case -EPERM: | |
991 | FTRACE_WARN_ON_ONCE(1); | |
992 | pr_info("ftrace faulted on writing "); | |
993 | print_ip_sym(ip); | |
994 | break; | |
995 | default: | |
996 | FTRACE_WARN_ON_ONCE(1); | |
997 | pr_info("ftrace faulted on unknown error "); | |
998 | print_ip_sym(ip); | |
999 | } | |
1000 | } | |
1001 | ||
3c1720f0 | 1002 | |
2cfa1978 MH |
1003 | /* Return 1 if the address range is reserved for ftrace */ |
1004 | int ftrace_text_reserved(void *start, void *end) | |
1005 | { | |
1006 | struct dyn_ftrace *rec; | |
1007 | struct ftrace_page *pg; | |
1008 | ||
1009 | do_for_each_ftrace_rec(pg, rec) { | |
1010 | if (rec->ip <= (unsigned long)end && | |
1011 | rec->ip + MCOUNT_INSN_SIZE > (unsigned long)start) | |
1012 | return 1; | |
1013 | } while_for_each_ftrace_rec(); | |
1014 | return 0; | |
1015 | } | |
1016 | ||
1017 | ||
0eb96701 | 1018 | static int |
31e88909 | 1019 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) |
5072c59f | 1020 | { |
e7d3737e | 1021 | unsigned long ftrace_addr; |
64fbcd16 | 1022 | unsigned long flag = 0UL; |
e7d3737e | 1023 | |
f0001207 | 1024 | ftrace_addr = (unsigned long)FTRACE_ADDR; |
5072c59f | 1025 | |
982c350b | 1026 | /* |
64fbcd16 XG |
1027 | * If this record is not to be traced or we want to disable it, |
1028 | * then disable it. | |
982c350b | 1029 | * |
64fbcd16 | 1030 | * If we want to enable it and filtering is off, then enable it. |
982c350b | 1031 | * |
64fbcd16 XG |
1032 | * If we want to enable it and filtering is on, enable it only if |
1033 | * it's filtered | |
982c350b | 1034 | */ |
64fbcd16 XG |
1035 | if (enable && !(rec->flags & FTRACE_FL_NOTRACE)) { |
1036 | if (!ftrace_filtered || (rec->flags & FTRACE_FL_FILTER)) | |
1037 | flag = FTRACE_FL_ENABLED; | |
1038 | } | |
982c350b | 1039 | |
64fbcd16 XG |
1040 | /* If the state of this record hasn't changed, then do nothing */ |
1041 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
1042 | return 0; | |
982c350b | 1043 | |
64fbcd16 XG |
1044 | if (flag) { |
1045 | rec->flags |= FTRACE_FL_ENABLED; | |
1046 | return ftrace_make_call(rec, ftrace_addr); | |
5072c59f SR |
1047 | } |
1048 | ||
64fbcd16 XG |
1049 | rec->flags &= ~FTRACE_FL_ENABLED; |
1050 | return ftrace_make_nop(NULL, rec, ftrace_addr); | |
5072c59f SR |
1051 | } |
1052 | ||
e309b41d | 1053 | static void ftrace_replace_code(int enable) |
3c1720f0 | 1054 | { |
3c1720f0 SR |
1055 | struct dyn_ftrace *rec; |
1056 | struct ftrace_page *pg; | |
6a24a244 | 1057 | int failed; |
3c1720f0 | 1058 | |
45a4a237 SR |
1059 | if (unlikely(ftrace_disabled)) |
1060 | return; | |
1061 | ||
265c831c | 1062 | do_for_each_ftrace_rec(pg, rec) { |
d2c8c3ea SR |
1063 | /* Skip over free records */ |
1064 | if (rec->flags & FTRACE_FL_FREE) | |
265c831c SR |
1065 | continue; |
1066 | ||
265c831c | 1067 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 1068 | if (failed) { |
3279ba37 SR |
1069 | ftrace_bug(failed, rec->ip); |
1070 | /* Stop processing */ | |
1071 | return; | |
3c1720f0 | 1072 | } |
265c831c | 1073 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
1074 | } |
1075 | ||
492a7ea5 | 1076 | static int |
31e88909 | 1077 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 SR |
1078 | { |
1079 | unsigned long ip; | |
593eb8a2 | 1080 | int ret; |
3c1720f0 SR |
1081 | |
1082 | ip = rec->ip; | |
1083 | ||
45a4a237 SR |
1084 | if (unlikely(ftrace_disabled)) |
1085 | return 0; | |
1086 | ||
25aac9dc | 1087 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 1088 | if (ret) { |
31e88909 | 1089 | ftrace_bug(ret, ip); |
492a7ea5 | 1090 | return 0; |
37ad5084 | 1091 | } |
492a7ea5 | 1092 | return 1; |
3c1720f0 SR |
1093 | } |
1094 | ||
000ab691 SR |
1095 | /* |
1096 | * archs can override this function if they must do something | |
1097 | * before the modifying code is performed. | |
1098 | */ | |
1099 | int __weak ftrace_arch_code_modify_prepare(void) | |
1100 | { | |
1101 | return 0; | |
1102 | } | |
1103 | ||
1104 | /* | |
1105 | * archs can override this function if they must do something | |
1106 | * after the modifying code is performed. | |
1107 | */ | |
1108 | int __weak ftrace_arch_code_modify_post_process(void) | |
1109 | { | |
1110 | return 0; | |
1111 | } | |
1112 | ||
e309b41d | 1113 | static int __ftrace_modify_code(void *data) |
3d083395 | 1114 | { |
d61f82d0 SR |
1115 | int *command = data; |
1116 | ||
a3583244 | 1117 | if (*command & FTRACE_ENABLE_CALLS) |
d61f82d0 | 1118 | ftrace_replace_code(1); |
a3583244 | 1119 | else if (*command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
1120 | ftrace_replace_code(0); |
1121 | ||
1122 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
1123 | ftrace_update_ftrace_func(ftrace_trace_function); | |
1124 | ||
5a45cfe1 SR |
1125 | if (*command & FTRACE_START_FUNC_RET) |
1126 | ftrace_enable_ftrace_graph_caller(); | |
1127 | else if (*command & FTRACE_STOP_FUNC_RET) | |
1128 | ftrace_disable_ftrace_graph_caller(); | |
1129 | ||
d61f82d0 | 1130 | return 0; |
3d083395 SR |
1131 | } |
1132 | ||
e309b41d | 1133 | static void ftrace_run_update_code(int command) |
3d083395 | 1134 | { |
000ab691 SR |
1135 | int ret; |
1136 | ||
1137 | ret = ftrace_arch_code_modify_prepare(); | |
1138 | FTRACE_WARN_ON(ret); | |
1139 | if (ret) | |
1140 | return; | |
1141 | ||
784e2d76 | 1142 | stop_machine(__ftrace_modify_code, &command, NULL); |
000ab691 SR |
1143 | |
1144 | ret = ftrace_arch_code_modify_post_process(); | |
1145 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
1146 | } |
1147 | ||
d61f82d0 | 1148 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 1149 | static int ftrace_start_up; |
df4fc315 SR |
1150 | |
1151 | static void ftrace_startup_enable(int command) | |
1152 | { | |
1153 | if (saved_ftrace_func != ftrace_trace_function) { | |
1154 | saved_ftrace_func = ftrace_trace_function; | |
1155 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1156 | } | |
1157 | ||
1158 | if (!command || !ftrace_enabled) | |
1159 | return; | |
1160 | ||
1161 | ftrace_run_update_code(command); | |
1162 | } | |
d61f82d0 | 1163 | |
5a45cfe1 | 1164 | static void ftrace_startup(int command) |
3d083395 | 1165 | { |
4eebcc81 SR |
1166 | if (unlikely(ftrace_disabled)) |
1167 | return; | |
1168 | ||
60a7ecf4 | 1169 | ftrace_start_up++; |
982c350b | 1170 | command |= FTRACE_ENABLE_CALLS; |
d61f82d0 | 1171 | |
df4fc315 | 1172 | ftrace_startup_enable(command); |
3d083395 SR |
1173 | } |
1174 | ||
5a45cfe1 | 1175 | static void ftrace_shutdown(int command) |
3d083395 | 1176 | { |
4eebcc81 SR |
1177 | if (unlikely(ftrace_disabled)) |
1178 | return; | |
1179 | ||
60a7ecf4 | 1180 | ftrace_start_up--; |
9ea1a153 FW |
1181 | /* |
1182 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
1183 | * critical but the ftrace_call callers may be never nopped again after | |
1184 | * further ftrace uses. | |
1185 | */ | |
1186 | WARN_ON_ONCE(ftrace_start_up < 0); | |
1187 | ||
60a7ecf4 | 1188 | if (!ftrace_start_up) |
d61f82d0 | 1189 | command |= FTRACE_DISABLE_CALLS; |
3d083395 | 1190 | |
d61f82d0 SR |
1191 | if (saved_ftrace_func != ftrace_trace_function) { |
1192 | saved_ftrace_func = ftrace_trace_function; | |
1193 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1194 | } | |
3d083395 | 1195 | |
d61f82d0 | 1196 | if (!command || !ftrace_enabled) |
e6ea44e9 | 1197 | return; |
d61f82d0 SR |
1198 | |
1199 | ftrace_run_update_code(command); | |
3d083395 SR |
1200 | } |
1201 | ||
e309b41d | 1202 | static void ftrace_startup_sysctl(void) |
b0fc494f | 1203 | { |
4eebcc81 SR |
1204 | if (unlikely(ftrace_disabled)) |
1205 | return; | |
1206 | ||
d61f82d0 SR |
1207 | /* Force update next time */ |
1208 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
1209 | /* ftrace_start_up is true if we want ftrace running */ |
1210 | if (ftrace_start_up) | |
79e406d7 | 1211 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
b0fc494f SR |
1212 | } |
1213 | ||
e309b41d | 1214 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 1215 | { |
4eebcc81 SR |
1216 | if (unlikely(ftrace_disabled)) |
1217 | return; | |
1218 | ||
60a7ecf4 SR |
1219 | /* ftrace_start_up is true if ftrace is running */ |
1220 | if (ftrace_start_up) | |
79e406d7 | 1221 | ftrace_run_update_code(FTRACE_DISABLE_CALLS); |
b0fc494f SR |
1222 | } |
1223 | ||
3d083395 SR |
1224 | static cycle_t ftrace_update_time; |
1225 | static unsigned long ftrace_update_cnt; | |
1226 | unsigned long ftrace_update_tot_cnt; | |
1227 | ||
31e88909 | 1228 | static int ftrace_update_code(struct module *mod) |
3d083395 | 1229 | { |
e94142a6 | 1230 | struct dyn_ftrace *p; |
f22f9a89 | 1231 | cycle_t start, stop; |
3d083395 | 1232 | |
750ed1a4 | 1233 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1234 | ftrace_update_cnt = 0; |
1235 | ||
e94142a6 | 1236 | while (ftrace_new_addrs) { |
3d083395 | 1237 | |
08f5ac90 SR |
1238 | /* If something went wrong, bail without enabling anything */ |
1239 | if (unlikely(ftrace_disabled)) | |
1240 | return -1; | |
f22f9a89 | 1241 | |
e94142a6 | 1242 | p = ftrace_new_addrs; |
ee000b7f | 1243 | ftrace_new_addrs = p->newlist; |
e94142a6 | 1244 | p->flags = 0L; |
f22f9a89 | 1245 | |
5cb084bb | 1246 | /* |
25985edc | 1247 | * Do the initial record conversion from mcount jump |
5cb084bb JO |
1248 | * to the NOP instructions. |
1249 | */ | |
1250 | if (!ftrace_code_disable(mod, p)) { | |
08f5ac90 | 1251 | ftrace_free_rec(p); |
d2c8c3ea SR |
1252 | /* Game over */ |
1253 | break; | |
5cb084bb JO |
1254 | } |
1255 | ||
5cb084bb JO |
1256 | ftrace_update_cnt++; |
1257 | ||
1258 | /* | |
1259 | * If the tracing is enabled, go ahead and enable the record. | |
1260 | * | |
1261 | * The reason not to enable the record immediatelly is the | |
1262 | * inherent check of ftrace_make_nop/ftrace_make_call for | |
1263 | * correct previous instructions. Making first the NOP | |
1264 | * conversion puts the module to the correct state, thus | |
1265 | * passing the ftrace_make_call check. | |
1266 | */ | |
1267 | if (ftrace_start_up) { | |
1268 | int failed = __ftrace_replace_code(p, 1); | |
1269 | if (failed) { | |
1270 | ftrace_bug(failed, p->ip); | |
1271 | ftrace_free_rec(p); | |
1272 | } | |
1273 | } | |
3d083395 SR |
1274 | } |
1275 | ||
750ed1a4 | 1276 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1277 | ftrace_update_time = stop - start; |
1278 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
1279 | ||
16444a8a ACM |
1280 | return 0; |
1281 | } | |
1282 | ||
68bf21aa | 1283 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
1284 | { |
1285 | struct ftrace_page *pg; | |
1286 | int cnt; | |
1287 | int i; | |
3c1720f0 SR |
1288 | |
1289 | /* allocate a few pages */ | |
1290 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
1291 | if (!ftrace_pages_start) | |
1292 | return -1; | |
1293 | ||
1294 | /* | |
1295 | * Allocate a few more pages. | |
1296 | * | |
1297 | * TODO: have some parser search vmlinux before | |
1298 | * final linking to find all calls to ftrace. | |
1299 | * Then we can: | |
1300 | * a) know how many pages to allocate. | |
1301 | * and/or | |
1302 | * b) set up the table then. | |
1303 | * | |
1304 | * The dynamic code is still necessary for | |
1305 | * modules. | |
1306 | */ | |
1307 | ||
1308 | pg = ftrace_pages = ftrace_pages_start; | |
1309 | ||
68bf21aa | 1310 | cnt = num_to_init / ENTRIES_PER_PAGE; |
08f5ac90 | 1311 | pr_info("ftrace: allocating %ld entries in %d pages\n", |
5821e1b7 | 1312 | num_to_init, cnt + 1); |
3c1720f0 SR |
1313 | |
1314 | for (i = 0; i < cnt; i++) { | |
1315 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
1316 | ||
1317 | /* If we fail, we'll try later anyway */ | |
1318 | if (!pg->next) | |
1319 | break; | |
1320 | ||
1321 | pg = pg->next; | |
1322 | } | |
1323 | ||
1324 | return 0; | |
1325 | } | |
1326 | ||
5072c59f SR |
1327 | enum { |
1328 | FTRACE_ITER_FILTER = (1 << 0), | |
689fd8b6 | 1329 | FTRACE_ITER_NOTRACE = (1 << 1), |
3499e461 SR |
1330 | FTRACE_ITER_PRINTALL = (1 << 2), |
1331 | FTRACE_ITER_HASH = (1 << 3), | |
5072c59f SR |
1332 | }; |
1333 | ||
1334 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
1335 | ||
1336 | struct ftrace_iterator { | |
98c4fd04 | 1337 | loff_t pos; |
4aeb6967 SR |
1338 | loff_t func_pos; |
1339 | struct ftrace_page *pg; | |
1340 | struct dyn_ftrace *func; | |
1341 | struct ftrace_func_probe *probe; | |
1342 | struct trace_parser parser; | |
1343 | int hidx; | |
1344 | int idx; | |
1345 | unsigned flags; | |
5072c59f SR |
1346 | }; |
1347 | ||
8fc0c701 | 1348 | static void * |
4aeb6967 | 1349 | t_hash_next(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
1350 | { |
1351 | struct ftrace_iterator *iter = m->private; | |
4aeb6967 | 1352 | struct hlist_node *hnd = NULL; |
8fc0c701 SR |
1353 | struct hlist_head *hhd; |
1354 | ||
8fc0c701 | 1355 | (*pos)++; |
98c4fd04 | 1356 | iter->pos = *pos; |
8fc0c701 | 1357 | |
4aeb6967 SR |
1358 | if (iter->probe) |
1359 | hnd = &iter->probe->node; | |
8fc0c701 SR |
1360 | retry: |
1361 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
1362 | return NULL; | |
1363 | ||
1364 | hhd = &ftrace_func_hash[iter->hidx]; | |
1365 | ||
1366 | if (hlist_empty(hhd)) { | |
1367 | iter->hidx++; | |
1368 | hnd = NULL; | |
1369 | goto retry; | |
1370 | } | |
1371 | ||
1372 | if (!hnd) | |
1373 | hnd = hhd->first; | |
1374 | else { | |
1375 | hnd = hnd->next; | |
1376 | if (!hnd) { | |
1377 | iter->hidx++; | |
1378 | goto retry; | |
1379 | } | |
1380 | } | |
1381 | ||
4aeb6967 SR |
1382 | if (WARN_ON_ONCE(!hnd)) |
1383 | return NULL; | |
1384 | ||
1385 | iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node); | |
1386 | ||
1387 | return iter; | |
8fc0c701 SR |
1388 | } |
1389 | ||
1390 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
1391 | { | |
1392 | struct ftrace_iterator *iter = m->private; | |
1393 | void *p = NULL; | |
d82d6244 LZ |
1394 | loff_t l; |
1395 | ||
2bccfffd SR |
1396 | if (iter->func_pos > *pos) |
1397 | return NULL; | |
8fc0c701 | 1398 | |
d82d6244 | 1399 | iter->hidx = 0; |
2bccfffd | 1400 | for (l = 0; l <= (*pos - iter->func_pos); ) { |
4aeb6967 | 1401 | p = t_hash_next(m, &l); |
d82d6244 LZ |
1402 | if (!p) |
1403 | break; | |
1404 | } | |
4aeb6967 SR |
1405 | if (!p) |
1406 | return NULL; | |
1407 | ||
98c4fd04 SR |
1408 | /* Only set this if we have an item */ |
1409 | iter->flags |= FTRACE_ITER_HASH; | |
1410 | ||
4aeb6967 | 1411 | return iter; |
8fc0c701 SR |
1412 | } |
1413 | ||
4aeb6967 SR |
1414 | static int |
1415 | t_hash_show(struct seq_file *m, struct ftrace_iterator *iter) | |
8fc0c701 | 1416 | { |
b6887d79 | 1417 | struct ftrace_func_probe *rec; |
8fc0c701 | 1418 | |
4aeb6967 SR |
1419 | rec = iter->probe; |
1420 | if (WARN_ON_ONCE(!rec)) | |
1421 | return -EIO; | |
8fc0c701 | 1422 | |
809dcf29 SR |
1423 | if (rec->ops->print) |
1424 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
1425 | ||
b375a11a | 1426 | seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func); |
8fc0c701 SR |
1427 | |
1428 | if (rec->data) | |
1429 | seq_printf(m, ":%p", rec->data); | |
1430 | seq_putc(m, '\n'); | |
1431 | ||
1432 | return 0; | |
1433 | } | |
1434 | ||
e309b41d | 1435 | static void * |
5072c59f SR |
1436 | t_next(struct seq_file *m, void *v, loff_t *pos) |
1437 | { | |
1438 | struct ftrace_iterator *iter = m->private; | |
1439 | struct dyn_ftrace *rec = NULL; | |
1440 | ||
45a4a237 SR |
1441 | if (unlikely(ftrace_disabled)) |
1442 | return NULL; | |
1443 | ||
8fc0c701 | 1444 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 1445 | return t_hash_next(m, pos); |
8fc0c701 | 1446 | |
5072c59f | 1447 | (*pos)++; |
1106b699 | 1448 | iter->pos = iter->func_pos = *pos; |
5072c59f | 1449 | |
0c75a3ed | 1450 | if (iter->flags & FTRACE_ITER_PRINTALL) |
57c072c7 | 1451 | return t_hash_start(m, pos); |
0c75a3ed | 1452 | |
5072c59f SR |
1453 | retry: |
1454 | if (iter->idx >= iter->pg->index) { | |
1455 | if (iter->pg->next) { | |
1456 | iter->pg = iter->pg->next; | |
1457 | iter->idx = 0; | |
1458 | goto retry; | |
1459 | } | |
1460 | } else { | |
1461 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
1462 | if ((rec->flags & FTRACE_FL_FREE) || |
1463 | ||
0183fb1c SR |
1464 | ((iter->flags & FTRACE_ITER_FILTER) && |
1465 | !(rec->flags & FTRACE_FL_FILTER)) || | |
1466 | ||
41c52c0d SR |
1467 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
1468 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
1469 | rec = NULL; |
1470 | goto retry; | |
1471 | } | |
1472 | } | |
1473 | ||
4aeb6967 | 1474 | if (!rec) |
57c072c7 | 1475 | return t_hash_start(m, pos); |
4aeb6967 SR |
1476 | |
1477 | iter->func = rec; | |
1478 | ||
1479 | return iter; | |
5072c59f SR |
1480 | } |
1481 | ||
98c4fd04 SR |
1482 | static void reset_iter_read(struct ftrace_iterator *iter) |
1483 | { | |
1484 | iter->pos = 0; | |
1485 | iter->func_pos = 0; | |
1486 | iter->flags &= ~(FTRACE_ITER_PRINTALL & FTRACE_ITER_HASH); | |
5072c59f SR |
1487 | } |
1488 | ||
1489 | static void *t_start(struct seq_file *m, loff_t *pos) | |
1490 | { | |
1491 | struct ftrace_iterator *iter = m->private; | |
1492 | void *p = NULL; | |
694ce0a5 | 1493 | loff_t l; |
5072c59f | 1494 | |
8fc0c701 | 1495 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
1496 | |
1497 | if (unlikely(ftrace_disabled)) | |
1498 | return NULL; | |
1499 | ||
98c4fd04 SR |
1500 | /* |
1501 | * If an lseek was done, then reset and start from beginning. | |
1502 | */ | |
1503 | if (*pos < iter->pos) | |
1504 | reset_iter_read(iter); | |
1505 | ||
0c75a3ed SR |
1506 | /* |
1507 | * For set_ftrace_filter reading, if we have the filter | |
1508 | * off, we can short cut and just print out that all | |
1509 | * functions are enabled. | |
1510 | */ | |
1511 | if (iter->flags & FTRACE_ITER_FILTER && !ftrace_filtered) { | |
1512 | if (*pos > 0) | |
8fc0c701 | 1513 | return t_hash_start(m, pos); |
0c75a3ed | 1514 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 CW |
1515 | /* reset in case of seek/pread */ |
1516 | iter->flags &= ~FTRACE_ITER_HASH; | |
0c75a3ed SR |
1517 | return iter; |
1518 | } | |
1519 | ||
8fc0c701 SR |
1520 | if (iter->flags & FTRACE_ITER_HASH) |
1521 | return t_hash_start(m, pos); | |
1522 | ||
98c4fd04 SR |
1523 | /* |
1524 | * Unfortunately, we need to restart at ftrace_pages_start | |
1525 | * every time we let go of the ftrace_mutex. This is because | |
1526 | * those pointers can change without the lock. | |
1527 | */ | |
694ce0a5 LZ |
1528 | iter->pg = ftrace_pages_start; |
1529 | iter->idx = 0; | |
1530 | for (l = 0; l <= *pos; ) { | |
1531 | p = t_next(m, p, &l); | |
1532 | if (!p) | |
1533 | break; | |
50cdaf08 | 1534 | } |
5821e1b7 | 1535 | |
4aeb6967 SR |
1536 | if (!p) { |
1537 | if (iter->flags & FTRACE_ITER_FILTER) | |
1538 | return t_hash_start(m, pos); | |
8fc0c701 | 1539 | |
4aeb6967 SR |
1540 | return NULL; |
1541 | } | |
1542 | ||
1543 | return iter; | |
5072c59f SR |
1544 | } |
1545 | ||
1546 | static void t_stop(struct seq_file *m, void *p) | |
1547 | { | |
8fc0c701 | 1548 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1549 | } |
1550 | ||
1551 | static int t_show(struct seq_file *m, void *v) | |
1552 | { | |
0c75a3ed | 1553 | struct ftrace_iterator *iter = m->private; |
4aeb6967 | 1554 | struct dyn_ftrace *rec; |
5072c59f | 1555 | |
8fc0c701 | 1556 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 1557 | return t_hash_show(m, iter); |
8fc0c701 | 1558 | |
0c75a3ed SR |
1559 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
1560 | seq_printf(m, "#### all functions enabled ####\n"); | |
1561 | return 0; | |
1562 | } | |
1563 | ||
4aeb6967 SR |
1564 | rec = iter->func; |
1565 | ||
5072c59f SR |
1566 | if (!rec) |
1567 | return 0; | |
1568 | ||
b375a11a | 1569 | seq_printf(m, "%ps\n", (void *)rec->ip); |
5072c59f SR |
1570 | |
1571 | return 0; | |
1572 | } | |
1573 | ||
88e9d34c | 1574 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
1575 | .start = t_start, |
1576 | .next = t_next, | |
1577 | .stop = t_stop, | |
1578 | .show = t_show, | |
1579 | }; | |
1580 | ||
e309b41d | 1581 | static int |
5072c59f SR |
1582 | ftrace_avail_open(struct inode *inode, struct file *file) |
1583 | { | |
1584 | struct ftrace_iterator *iter; | |
1585 | int ret; | |
1586 | ||
4eebcc81 SR |
1587 | if (unlikely(ftrace_disabled)) |
1588 | return -ENODEV; | |
1589 | ||
5072c59f SR |
1590 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1591 | if (!iter) | |
1592 | return -ENOMEM; | |
1593 | ||
1594 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
1595 | |
1596 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1597 | if (!ret) { | |
1598 | struct seq_file *m = file->private_data; | |
4bf39a94 | 1599 | |
5072c59f | 1600 | m->private = iter; |
4bf39a94 | 1601 | } else { |
5072c59f | 1602 | kfree(iter); |
4bf39a94 | 1603 | } |
5072c59f SR |
1604 | |
1605 | return ret; | |
1606 | } | |
1607 | ||
41c52c0d | 1608 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
1609 | { |
1610 | struct ftrace_page *pg; | |
1611 | struct dyn_ftrace *rec; | |
41c52c0d | 1612 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f | 1613 | |
52baf119 | 1614 | mutex_lock(&ftrace_lock); |
41c52c0d SR |
1615 | if (enable) |
1616 | ftrace_filtered = 0; | |
265c831c | 1617 | do_for_each_ftrace_rec(pg, rec) { |
265c831c SR |
1618 | rec->flags &= ~type; |
1619 | } while_for_each_ftrace_rec(); | |
52baf119 | 1620 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1621 | } |
1622 | ||
e309b41d | 1623 | static int |
41c52c0d | 1624 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1625 | { |
1626 | struct ftrace_iterator *iter; | |
1627 | int ret = 0; | |
1628 | ||
4eebcc81 SR |
1629 | if (unlikely(ftrace_disabled)) |
1630 | return -ENODEV; | |
1631 | ||
5072c59f SR |
1632 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1633 | if (!iter) | |
1634 | return -ENOMEM; | |
1635 | ||
689fd8b6 | 1636 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { |
1637 | kfree(iter); | |
1638 | return -ENOMEM; | |
1639 | } | |
1640 | ||
41c52c0d | 1641 | mutex_lock(&ftrace_regex_lock); |
5072c59f | 1642 | if ((file->f_mode & FMODE_WRITE) && |
8650ae32 | 1643 | (file->f_flags & O_TRUNC)) |
41c52c0d | 1644 | ftrace_filter_reset(enable); |
5072c59f SR |
1645 | |
1646 | if (file->f_mode & FMODE_READ) { | |
1647 | iter->pg = ftrace_pages_start; | |
41c52c0d SR |
1648 | iter->flags = enable ? FTRACE_ITER_FILTER : |
1649 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
1650 | |
1651 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1652 | if (!ret) { | |
1653 | struct seq_file *m = file->private_data; | |
1654 | m->private = iter; | |
79fe249c LZ |
1655 | } else { |
1656 | trace_parser_put(&iter->parser); | |
5072c59f | 1657 | kfree(iter); |
79fe249c | 1658 | } |
5072c59f SR |
1659 | } else |
1660 | file->private_data = iter; | |
41c52c0d | 1661 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1662 | |
1663 | return ret; | |
1664 | } | |
1665 | ||
41c52c0d SR |
1666 | static int |
1667 | ftrace_filter_open(struct inode *inode, struct file *file) | |
1668 | { | |
1669 | return ftrace_regex_open(inode, file, 1); | |
1670 | } | |
1671 | ||
1672 | static int | |
1673 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
1674 | { | |
1675 | return ftrace_regex_open(inode, file, 0); | |
1676 | } | |
1677 | ||
e309b41d | 1678 | static loff_t |
41c52c0d | 1679 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
1680 | { |
1681 | loff_t ret; | |
1682 | ||
1683 | if (file->f_mode & FMODE_READ) | |
1684 | ret = seq_lseek(file, offset, origin); | |
1685 | else | |
1686 | file->f_pos = ret = 1; | |
1687 | ||
1688 | return ret; | |
1689 | } | |
1690 | ||
64e7c440 | 1691 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 1692 | { |
9f4801e3 | 1693 | int matched = 0; |
751e9983 | 1694 | int slen; |
9f4801e3 | 1695 | |
9f4801e3 SR |
1696 | switch (type) { |
1697 | case MATCH_FULL: | |
1698 | if (strcmp(str, regex) == 0) | |
1699 | matched = 1; | |
1700 | break; | |
1701 | case MATCH_FRONT_ONLY: | |
1702 | if (strncmp(str, regex, len) == 0) | |
1703 | matched = 1; | |
1704 | break; | |
1705 | case MATCH_MIDDLE_ONLY: | |
1706 | if (strstr(str, regex)) | |
1707 | matched = 1; | |
1708 | break; | |
1709 | case MATCH_END_ONLY: | |
751e9983 LZ |
1710 | slen = strlen(str); |
1711 | if (slen >= len && memcmp(str + slen - len, regex, len) == 0) | |
9f4801e3 SR |
1712 | matched = 1; |
1713 | break; | |
1714 | } | |
1715 | ||
1716 | return matched; | |
1717 | } | |
1718 | ||
996e87be SR |
1719 | static void |
1720 | update_record(struct dyn_ftrace *rec, unsigned long flag, int not) | |
1721 | { | |
1722 | if (not) | |
1723 | rec->flags &= ~flag; | |
1724 | else | |
1725 | rec->flags |= flag; | |
1726 | } | |
1727 | ||
64e7c440 | 1728 | static int |
b9df92d2 SR |
1729 | ftrace_match_record(struct dyn_ftrace *rec, char *mod, |
1730 | char *regex, int len, int type) | |
64e7c440 SR |
1731 | { |
1732 | char str[KSYM_SYMBOL_LEN]; | |
b9df92d2 SR |
1733 | char *modname; |
1734 | ||
1735 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
1736 | ||
1737 | if (mod) { | |
1738 | /* module lookup requires matching the module */ | |
1739 | if (!modname || strcmp(modname, mod)) | |
1740 | return 0; | |
1741 | ||
1742 | /* blank search means to match all funcs in the mod */ | |
1743 | if (!len) | |
1744 | return 1; | |
1745 | } | |
64e7c440 | 1746 | |
64e7c440 SR |
1747 | return ftrace_match(str, regex, len, type); |
1748 | } | |
1749 | ||
b9df92d2 | 1750 | static int match_records(char *buff, int len, char *mod, int enable, int not) |
9f4801e3 | 1751 | { |
b9df92d2 | 1752 | unsigned search_len = 0; |
9f4801e3 SR |
1753 | struct ftrace_page *pg; |
1754 | struct dyn_ftrace *rec; | |
b9df92d2 SR |
1755 | int type = MATCH_FULL; |
1756 | char *search = buff; | |
6a24a244 | 1757 | unsigned long flag; |
311d16da | 1758 | int found = 0; |
9f4801e3 | 1759 | |
b9df92d2 SR |
1760 | if (len) { |
1761 | type = filter_parse_regex(buff, len, &search, ¬); | |
1762 | search_len = strlen(search); | |
1763 | } | |
9f4801e3 | 1764 | |
b9df92d2 | 1765 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
9f4801e3 | 1766 | |
52baf119 | 1767 | mutex_lock(&ftrace_lock); |
265c831c | 1768 | |
b9df92d2 SR |
1769 | if (unlikely(ftrace_disabled)) |
1770 | goto out_unlock; | |
9f4801e3 | 1771 | |
265c831c | 1772 | do_for_each_ftrace_rec(pg, rec) { |
265c831c | 1773 | |
b9df92d2 | 1774 | if (ftrace_match_record(rec, mod, search, search_len, type)) { |
996e87be | 1775 | update_record(rec, flag, not); |
311d16da | 1776 | found = 1; |
265c831c | 1777 | } |
e68746a2 SR |
1778 | /* |
1779 | * Only enable filtering if we have a function that | |
1780 | * is filtered on. | |
1781 | */ | |
1782 | if (enable && (rec->flags & FTRACE_FL_FILTER)) | |
1783 | ftrace_filtered = 1; | |
b9df92d2 | 1784 | |
265c831c | 1785 | } while_for_each_ftrace_rec(); |
b9df92d2 | 1786 | out_unlock: |
52baf119 | 1787 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
1788 | |
1789 | return found; | |
5072c59f SR |
1790 | } |
1791 | ||
64e7c440 | 1792 | static int |
b9df92d2 | 1793 | ftrace_match_records(char *buff, int len, int enable) |
64e7c440 | 1794 | { |
b9df92d2 | 1795 | return match_records(buff, len, NULL, enable, 0); |
64e7c440 SR |
1796 | } |
1797 | ||
311d16da | 1798 | static int ftrace_match_module_records(char *buff, char *mod, int enable) |
64e7c440 | 1799 | { |
64e7c440 | 1800 | int not = 0; |
6a24a244 | 1801 | |
64e7c440 SR |
1802 | /* blank or '*' mean the same */ |
1803 | if (strcmp(buff, "*") == 0) | |
1804 | buff[0] = 0; | |
1805 | ||
1806 | /* handle the case of 'dont filter this module' */ | |
1807 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
1808 | buff[0] = 0; | |
1809 | not = 1; | |
1810 | } | |
1811 | ||
b9df92d2 | 1812 | return match_records(buff, strlen(buff), mod, enable, not); |
64e7c440 SR |
1813 | } |
1814 | ||
f6180773 SR |
1815 | /* |
1816 | * We register the module command as a template to show others how | |
1817 | * to register the a command as well. | |
1818 | */ | |
1819 | ||
1820 | static int | |
1821 | ftrace_mod_callback(char *func, char *cmd, char *param, int enable) | |
1822 | { | |
1823 | char *mod; | |
1824 | ||
1825 | /* | |
1826 | * cmd == 'mod' because we only registered this func | |
1827 | * for the 'mod' ftrace_func_command. | |
1828 | * But if you register one func with multiple commands, | |
1829 | * you can tell which command was used by the cmd | |
1830 | * parameter. | |
1831 | */ | |
1832 | ||
1833 | /* we must have a module name */ | |
1834 | if (!param) | |
1835 | return -EINVAL; | |
1836 | ||
1837 | mod = strsep(¶m, ":"); | |
1838 | if (!strlen(mod)) | |
1839 | return -EINVAL; | |
1840 | ||
311d16da LZ |
1841 | if (ftrace_match_module_records(func, mod, enable)) |
1842 | return 0; | |
1843 | return -EINVAL; | |
f6180773 SR |
1844 | } |
1845 | ||
1846 | static struct ftrace_func_command ftrace_mod_cmd = { | |
1847 | .name = "mod", | |
1848 | .func = ftrace_mod_callback, | |
1849 | }; | |
1850 | ||
1851 | static int __init ftrace_mod_cmd_init(void) | |
1852 | { | |
1853 | return register_ftrace_command(&ftrace_mod_cmd); | |
1854 | } | |
1855 | device_initcall(ftrace_mod_cmd_init); | |
1856 | ||
59df055f | 1857 | static void |
b6887d79 | 1858 | function_trace_probe_call(unsigned long ip, unsigned long parent_ip) |
59df055f | 1859 | { |
b6887d79 | 1860 | struct ftrace_func_probe *entry; |
59df055f SR |
1861 | struct hlist_head *hhd; |
1862 | struct hlist_node *n; | |
1863 | unsigned long key; | |
59df055f SR |
1864 | |
1865 | key = hash_long(ip, FTRACE_HASH_BITS); | |
1866 | ||
1867 | hhd = &ftrace_func_hash[key]; | |
1868 | ||
1869 | if (hlist_empty(hhd)) | |
1870 | return; | |
1871 | ||
1872 | /* | |
1873 | * Disable preemption for these calls to prevent a RCU grace | |
1874 | * period. This syncs the hash iteration and freeing of items | |
1875 | * on the hash. rcu_read_lock is too dangerous here. | |
1876 | */ | |
5168ae50 | 1877 | preempt_disable_notrace(); |
59df055f SR |
1878 | hlist_for_each_entry_rcu(entry, n, hhd, node) { |
1879 | if (entry->ip == ip) | |
1880 | entry->ops->func(ip, parent_ip, &entry->data); | |
1881 | } | |
5168ae50 | 1882 | preempt_enable_notrace(); |
59df055f SR |
1883 | } |
1884 | ||
b6887d79 | 1885 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 1886 | { |
fb9fb015 | 1887 | .func = function_trace_probe_call, |
59df055f SR |
1888 | }; |
1889 | ||
b6887d79 | 1890 | static int ftrace_probe_registered; |
59df055f | 1891 | |
b6887d79 | 1892 | static void __enable_ftrace_function_probe(void) |
59df055f SR |
1893 | { |
1894 | int i; | |
1895 | ||
b6887d79 | 1896 | if (ftrace_probe_registered) |
59df055f SR |
1897 | return; |
1898 | ||
1899 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1900 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1901 | if (hhd->first) | |
1902 | break; | |
1903 | } | |
1904 | /* Nothing registered? */ | |
1905 | if (i == FTRACE_FUNC_HASHSIZE) | |
1906 | return; | |
1907 | ||
b6887d79 | 1908 | __register_ftrace_function(&trace_probe_ops); |
59df055f | 1909 | ftrace_startup(0); |
b6887d79 | 1910 | ftrace_probe_registered = 1; |
59df055f SR |
1911 | } |
1912 | ||
b6887d79 | 1913 | static void __disable_ftrace_function_probe(void) |
59df055f SR |
1914 | { |
1915 | int i; | |
1916 | ||
b6887d79 | 1917 | if (!ftrace_probe_registered) |
59df055f SR |
1918 | return; |
1919 | ||
1920 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1921 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1922 | if (hhd->first) | |
1923 | return; | |
1924 | } | |
1925 | ||
1926 | /* no more funcs left */ | |
b6887d79 | 1927 | __unregister_ftrace_function(&trace_probe_ops); |
59df055f | 1928 | ftrace_shutdown(0); |
b6887d79 | 1929 | ftrace_probe_registered = 0; |
59df055f SR |
1930 | } |
1931 | ||
1932 | ||
1933 | static void ftrace_free_entry_rcu(struct rcu_head *rhp) | |
1934 | { | |
b6887d79 SR |
1935 | struct ftrace_func_probe *entry = |
1936 | container_of(rhp, struct ftrace_func_probe, rcu); | |
59df055f SR |
1937 | |
1938 | if (entry->ops->free) | |
1939 | entry->ops->free(&entry->data); | |
1940 | kfree(entry); | |
1941 | } | |
1942 | ||
1943 | ||
1944 | int | |
b6887d79 | 1945 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
1946 | void *data) |
1947 | { | |
b6887d79 | 1948 | struct ftrace_func_probe *entry; |
59df055f SR |
1949 | struct ftrace_page *pg; |
1950 | struct dyn_ftrace *rec; | |
59df055f | 1951 | int type, len, not; |
6a24a244 | 1952 | unsigned long key; |
59df055f SR |
1953 | int count = 0; |
1954 | char *search; | |
1955 | ||
3f6fe06d | 1956 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
1957 | len = strlen(search); |
1958 | ||
b6887d79 | 1959 | /* we do not support '!' for function probes */ |
59df055f SR |
1960 | if (WARN_ON(not)) |
1961 | return -EINVAL; | |
1962 | ||
1963 | mutex_lock(&ftrace_lock); | |
59df055f | 1964 | |
45a4a237 SR |
1965 | if (unlikely(ftrace_disabled)) |
1966 | goto out_unlock; | |
59df055f | 1967 | |
45a4a237 | 1968 | do_for_each_ftrace_rec(pg, rec) { |
59df055f | 1969 | |
b9df92d2 | 1970 | if (!ftrace_match_record(rec, NULL, search, len, type)) |
59df055f SR |
1971 | continue; |
1972 | ||
1973 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1974 | if (!entry) { | |
b6887d79 | 1975 | /* If we did not process any, then return error */ |
59df055f SR |
1976 | if (!count) |
1977 | count = -ENOMEM; | |
1978 | goto out_unlock; | |
1979 | } | |
1980 | ||
1981 | count++; | |
1982 | ||
1983 | entry->data = data; | |
1984 | ||
1985 | /* | |
1986 | * The caller might want to do something special | |
1987 | * for each function we find. We call the callback | |
1988 | * to give the caller an opportunity to do so. | |
1989 | */ | |
1990 | if (ops->callback) { | |
1991 | if (ops->callback(rec->ip, &entry->data) < 0) { | |
1992 | /* caller does not like this func */ | |
1993 | kfree(entry); | |
1994 | continue; | |
1995 | } | |
1996 | } | |
1997 | ||
1998 | entry->ops = ops; | |
1999 | entry->ip = rec->ip; | |
2000 | ||
2001 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
2002 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
2003 | ||
2004 | } while_for_each_ftrace_rec(); | |
b6887d79 | 2005 | __enable_ftrace_function_probe(); |
59df055f SR |
2006 | |
2007 | out_unlock: | |
2008 | mutex_unlock(&ftrace_lock); | |
2009 | ||
2010 | return count; | |
2011 | } | |
2012 | ||
2013 | enum { | |
b6887d79 SR |
2014 | PROBE_TEST_FUNC = 1, |
2015 | PROBE_TEST_DATA = 2 | |
59df055f SR |
2016 | }; |
2017 | ||
2018 | static void | |
b6887d79 | 2019 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2020 | void *data, int flags) |
2021 | { | |
b6887d79 | 2022 | struct ftrace_func_probe *entry; |
59df055f SR |
2023 | struct hlist_node *n, *tmp; |
2024 | char str[KSYM_SYMBOL_LEN]; | |
2025 | int type = MATCH_FULL; | |
2026 | int i, len = 0; | |
2027 | char *search; | |
2028 | ||
b36461da | 2029 | if (glob && (strcmp(glob, "*") == 0 || !strlen(glob))) |
59df055f | 2030 | glob = NULL; |
b36461da | 2031 | else if (glob) { |
59df055f SR |
2032 | int not; |
2033 | ||
3f6fe06d | 2034 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
2035 | len = strlen(search); |
2036 | ||
b6887d79 | 2037 | /* we do not support '!' for function probes */ |
59df055f SR |
2038 | if (WARN_ON(not)) |
2039 | return; | |
2040 | } | |
2041 | ||
2042 | mutex_lock(&ftrace_lock); | |
2043 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2044 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2045 | ||
2046 | hlist_for_each_entry_safe(entry, n, tmp, hhd, node) { | |
2047 | ||
2048 | /* break up if statements for readability */ | |
b6887d79 | 2049 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
2050 | continue; |
2051 | ||
b6887d79 | 2052 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
2053 | continue; |
2054 | ||
2055 | /* do this last, since it is the most expensive */ | |
2056 | if (glob) { | |
2057 | kallsyms_lookup(entry->ip, NULL, NULL, | |
2058 | NULL, str); | |
2059 | if (!ftrace_match(str, glob, len, type)) | |
2060 | continue; | |
2061 | } | |
2062 | ||
2063 | hlist_del(&entry->node); | |
2064 | call_rcu(&entry->rcu, ftrace_free_entry_rcu); | |
2065 | } | |
2066 | } | |
b6887d79 | 2067 | __disable_ftrace_function_probe(); |
59df055f SR |
2068 | mutex_unlock(&ftrace_lock); |
2069 | } | |
2070 | ||
2071 | void | |
b6887d79 | 2072 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2073 | void *data) |
2074 | { | |
b6887d79 SR |
2075 | __unregister_ftrace_function_probe(glob, ops, data, |
2076 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
2077 | } |
2078 | ||
2079 | void | |
b6887d79 | 2080 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 2081 | { |
b6887d79 | 2082 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
2083 | } |
2084 | ||
b6887d79 | 2085 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 2086 | { |
b6887d79 | 2087 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
2088 | } |
2089 | ||
f6180773 SR |
2090 | static LIST_HEAD(ftrace_commands); |
2091 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
2092 | ||
2093 | int register_ftrace_command(struct ftrace_func_command *cmd) | |
2094 | { | |
2095 | struct ftrace_func_command *p; | |
2096 | int ret = 0; | |
2097 | ||
2098 | mutex_lock(&ftrace_cmd_mutex); | |
2099 | list_for_each_entry(p, &ftrace_commands, list) { | |
2100 | if (strcmp(cmd->name, p->name) == 0) { | |
2101 | ret = -EBUSY; | |
2102 | goto out_unlock; | |
2103 | } | |
2104 | } | |
2105 | list_add(&cmd->list, &ftrace_commands); | |
2106 | out_unlock: | |
2107 | mutex_unlock(&ftrace_cmd_mutex); | |
2108 | ||
2109 | return ret; | |
2110 | } | |
2111 | ||
2112 | int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
2113 | { | |
2114 | struct ftrace_func_command *p, *n; | |
2115 | int ret = -ENODEV; | |
2116 | ||
2117 | mutex_lock(&ftrace_cmd_mutex); | |
2118 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
2119 | if (strcmp(cmd->name, p->name) == 0) { | |
2120 | ret = 0; | |
2121 | list_del_init(&p->list); | |
2122 | goto out_unlock; | |
2123 | } | |
2124 | } | |
2125 | out_unlock: | |
2126 | mutex_unlock(&ftrace_cmd_mutex); | |
2127 | ||
2128 | return ret; | |
2129 | } | |
2130 | ||
64e7c440 SR |
2131 | static int ftrace_process_regex(char *buff, int len, int enable) |
2132 | { | |
f6180773 | 2133 | char *func, *command, *next = buff; |
6a24a244 | 2134 | struct ftrace_func_command *p; |
f6180773 | 2135 | int ret = -EINVAL; |
64e7c440 SR |
2136 | |
2137 | func = strsep(&next, ":"); | |
2138 | ||
2139 | if (!next) { | |
311d16da LZ |
2140 | if (ftrace_match_records(func, len, enable)) |
2141 | return 0; | |
2142 | return ret; | |
64e7c440 SR |
2143 | } |
2144 | ||
f6180773 | 2145 | /* command found */ |
64e7c440 SR |
2146 | |
2147 | command = strsep(&next, ":"); | |
2148 | ||
f6180773 SR |
2149 | mutex_lock(&ftrace_cmd_mutex); |
2150 | list_for_each_entry(p, &ftrace_commands, list) { | |
2151 | if (strcmp(p->name, command) == 0) { | |
2152 | ret = p->func(func, command, next, enable); | |
2153 | goto out_unlock; | |
2154 | } | |
64e7c440 | 2155 | } |
f6180773 SR |
2156 | out_unlock: |
2157 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 2158 | |
f6180773 | 2159 | return ret; |
64e7c440 SR |
2160 | } |
2161 | ||
e309b41d | 2162 | static ssize_t |
41c52c0d SR |
2163 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
2164 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
2165 | { |
2166 | struct ftrace_iterator *iter; | |
689fd8b6 | 2167 | struct trace_parser *parser; |
2168 | ssize_t ret, read; | |
5072c59f | 2169 | |
4ba7978e | 2170 | if (!cnt) |
5072c59f SR |
2171 | return 0; |
2172 | ||
41c52c0d | 2173 | mutex_lock(&ftrace_regex_lock); |
5072c59f | 2174 | |
45a4a237 SR |
2175 | ret = -ENODEV; |
2176 | if (unlikely(ftrace_disabled)) | |
2177 | goto out_unlock; | |
2178 | ||
5072c59f SR |
2179 | if (file->f_mode & FMODE_READ) { |
2180 | struct seq_file *m = file->private_data; | |
2181 | iter = m->private; | |
2182 | } else | |
2183 | iter = file->private_data; | |
2184 | ||
689fd8b6 | 2185 | parser = &iter->parser; |
2186 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 2187 | |
4ba7978e | 2188 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 2189 | !trace_parser_cont(parser)) { |
2190 | ret = ftrace_process_regex(parser->buffer, | |
2191 | parser->idx, enable); | |
313254a9 | 2192 | trace_parser_clear(parser); |
5072c59f | 2193 | if (ret) |
ed146b25 | 2194 | goto out_unlock; |
eda1e328 | 2195 | } |
5072c59f | 2196 | |
5072c59f | 2197 | ret = read; |
ed146b25 | 2198 | out_unlock: |
689fd8b6 | 2199 | mutex_unlock(&ftrace_regex_lock); |
ed146b25 | 2200 | |
5072c59f SR |
2201 | return ret; |
2202 | } | |
2203 | ||
41c52c0d SR |
2204 | static ssize_t |
2205 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
2206 | size_t cnt, loff_t *ppos) | |
2207 | { | |
2208 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
2209 | } | |
2210 | ||
2211 | static ssize_t | |
2212 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
2213 | size_t cnt, loff_t *ppos) | |
2214 | { | |
2215 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
2216 | } | |
2217 | ||
2218 | static void | |
2219 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
2220 | { | |
2221 | if (unlikely(ftrace_disabled)) | |
2222 | return; | |
2223 | ||
2224 | mutex_lock(&ftrace_regex_lock); | |
2225 | if (reset) | |
2226 | ftrace_filter_reset(enable); | |
2227 | if (buf) | |
7f24b31b | 2228 | ftrace_match_records(buf, len, enable); |
41c52c0d SR |
2229 | mutex_unlock(&ftrace_regex_lock); |
2230 | } | |
2231 | ||
77a2b37d SR |
2232 | /** |
2233 | * ftrace_set_filter - set a function to filter on in ftrace | |
2234 | * @buf - the string that holds the function filter text. | |
2235 | * @len - the length of the string. | |
2236 | * @reset - non zero to reset all filters before applying this filter. | |
2237 | * | |
2238 | * Filters denote which functions should be enabled when tracing is enabled. | |
2239 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
2240 | */ | |
e309b41d | 2241 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 2242 | { |
41c52c0d SR |
2243 | ftrace_set_regex(buf, len, reset, 1); |
2244 | } | |
4eebcc81 | 2245 | |
41c52c0d SR |
2246 | /** |
2247 | * ftrace_set_notrace - set a function to not trace in ftrace | |
2248 | * @buf - the string that holds the function notrace text. | |
2249 | * @len - the length of the string. | |
2250 | * @reset - non zero to reset all filters before applying this filter. | |
2251 | * | |
2252 | * Notrace Filters denote which functions should not be enabled when tracing | |
2253 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
2254 | * for tracing. | |
2255 | */ | |
2256 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
2257 | { | |
2258 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
2259 | } |
2260 | ||
2af15d6a SR |
2261 | /* |
2262 | * command line interface to allow users to set filters on boot up. | |
2263 | */ | |
2264 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
2265 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
2266 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
2267 | ||
2268 | static int __init set_ftrace_notrace(char *str) | |
2269 | { | |
2270 | strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); | |
2271 | return 1; | |
2272 | } | |
2273 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
2274 | ||
2275 | static int __init set_ftrace_filter(char *str) | |
2276 | { | |
2277 | strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); | |
2278 | return 1; | |
2279 | } | |
2280 | __setup("ftrace_filter=", set_ftrace_filter); | |
2281 | ||
369bc18f | 2282 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 2283 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
801c29fd SR |
2284 | static int ftrace_set_func(unsigned long *array, int *idx, char *buffer); |
2285 | ||
369bc18f SA |
2286 | static int __init set_graph_function(char *str) |
2287 | { | |
06f43d66 | 2288 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
2289 | return 1; |
2290 | } | |
2291 | __setup("ftrace_graph_filter=", set_graph_function); | |
2292 | ||
2293 | static void __init set_ftrace_early_graph(char *buf) | |
2294 | { | |
2295 | int ret; | |
2296 | char *func; | |
2297 | ||
2298 | while (buf) { | |
2299 | func = strsep(&buf, ","); | |
2300 | /* we allow only one expression at a time */ | |
2301 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, | |
2302 | func); | |
2303 | if (ret) | |
2304 | printk(KERN_DEBUG "ftrace: function %s not " | |
2305 | "traceable\n", func); | |
2306 | } | |
2307 | } | |
2308 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2309 | ||
2af15d6a SR |
2310 | static void __init set_ftrace_early_filter(char *buf, int enable) |
2311 | { | |
2312 | char *func; | |
2313 | ||
2314 | while (buf) { | |
2315 | func = strsep(&buf, ","); | |
2316 | ftrace_set_regex(func, strlen(func), 0, enable); | |
2317 | } | |
2318 | } | |
2319 | ||
2320 | static void __init set_ftrace_early_filters(void) | |
2321 | { | |
2322 | if (ftrace_filter_buf[0]) | |
2323 | set_ftrace_early_filter(ftrace_filter_buf, 1); | |
2324 | if (ftrace_notrace_buf[0]) | |
2325 | set_ftrace_early_filter(ftrace_notrace_buf, 0); | |
369bc18f SA |
2326 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
2327 | if (ftrace_graph_buf[0]) | |
2328 | set_ftrace_early_graph(ftrace_graph_buf); | |
2329 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2af15d6a SR |
2330 | } |
2331 | ||
e309b41d | 2332 | static int |
41c52c0d | 2333 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
2334 | { |
2335 | struct seq_file *m = (struct seq_file *)file->private_data; | |
2336 | struct ftrace_iterator *iter; | |
689fd8b6 | 2337 | struct trace_parser *parser; |
5072c59f | 2338 | |
41c52c0d | 2339 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
2340 | if (file->f_mode & FMODE_READ) { |
2341 | iter = m->private; | |
2342 | ||
2343 | seq_release(inode, file); | |
2344 | } else | |
2345 | iter = file->private_data; | |
2346 | ||
689fd8b6 | 2347 | parser = &iter->parser; |
2348 | if (trace_parser_loaded(parser)) { | |
2349 | parser->buffer[parser->idx] = 0; | |
2350 | ftrace_match_records(parser->buffer, parser->idx, enable); | |
5072c59f SR |
2351 | } |
2352 | ||
689fd8b6 | 2353 | trace_parser_put(parser); |
5072c59f | 2354 | kfree(iter); |
689fd8b6 | 2355 | |
058e297d SR |
2356 | if (file->f_mode & FMODE_WRITE) { |
2357 | mutex_lock(&ftrace_lock); | |
2358 | if (ftrace_start_up && ftrace_enabled) | |
2359 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); | |
2360 | mutex_unlock(&ftrace_lock); | |
2361 | } | |
2362 | ||
41c52c0d | 2363 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
2364 | return 0; |
2365 | } | |
2366 | ||
41c52c0d SR |
2367 | static int |
2368 | ftrace_filter_release(struct inode *inode, struct file *file) | |
2369 | { | |
2370 | return ftrace_regex_release(inode, file, 1); | |
2371 | } | |
2372 | ||
2373 | static int | |
2374 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
2375 | { | |
2376 | return ftrace_regex_release(inode, file, 0); | |
2377 | } | |
2378 | ||
5e2336a0 | 2379 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
2380 | .open = ftrace_avail_open, |
2381 | .read = seq_read, | |
2382 | .llseek = seq_lseek, | |
3be04b47 | 2383 | .release = seq_release_private, |
5072c59f SR |
2384 | }; |
2385 | ||
5e2336a0 | 2386 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 2387 | .open = ftrace_filter_open, |
850a80cf | 2388 | .read = seq_read, |
5072c59f | 2389 | .write = ftrace_filter_write, |
98c4fd04 | 2390 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
2391 | .release = ftrace_filter_release, |
2392 | }; | |
2393 | ||
5e2336a0 | 2394 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 2395 | .open = ftrace_notrace_open, |
850a80cf | 2396 | .read = seq_read, |
41c52c0d SR |
2397 | .write = ftrace_notrace_write, |
2398 | .llseek = ftrace_regex_lseek, | |
2399 | .release = ftrace_notrace_release, | |
2400 | }; | |
2401 | ||
ea4e2bc4 SR |
2402 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
2403 | ||
2404 | static DEFINE_MUTEX(graph_lock); | |
2405 | ||
2406 | int ftrace_graph_count; | |
c7c6b1fe | 2407 | int ftrace_graph_filter_enabled; |
ea4e2bc4 SR |
2408 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
2409 | ||
2410 | static void * | |
85951842 | 2411 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 2412 | { |
85951842 | 2413 | if (*pos >= ftrace_graph_count) |
ea4e2bc4 | 2414 | return NULL; |
a4ec5e0c | 2415 | return &ftrace_graph_funcs[*pos]; |
85951842 | 2416 | } |
ea4e2bc4 | 2417 | |
85951842 LZ |
2418 | static void * |
2419 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
2420 | { | |
2421 | (*pos)++; | |
2422 | return __g_next(m, pos); | |
ea4e2bc4 SR |
2423 | } |
2424 | ||
2425 | static void *g_start(struct seq_file *m, loff_t *pos) | |
2426 | { | |
ea4e2bc4 SR |
2427 | mutex_lock(&graph_lock); |
2428 | ||
f9349a8f | 2429 | /* Nothing, tell g_show to print all functions are enabled */ |
c7c6b1fe | 2430 | if (!ftrace_graph_filter_enabled && !*pos) |
f9349a8f FW |
2431 | return (void *)1; |
2432 | ||
85951842 | 2433 | return __g_next(m, pos); |
ea4e2bc4 SR |
2434 | } |
2435 | ||
2436 | static void g_stop(struct seq_file *m, void *p) | |
2437 | { | |
2438 | mutex_unlock(&graph_lock); | |
2439 | } | |
2440 | ||
2441 | static int g_show(struct seq_file *m, void *v) | |
2442 | { | |
2443 | unsigned long *ptr = v; | |
ea4e2bc4 SR |
2444 | |
2445 | if (!ptr) | |
2446 | return 0; | |
2447 | ||
f9349a8f FW |
2448 | if (ptr == (unsigned long *)1) { |
2449 | seq_printf(m, "#### all functions enabled ####\n"); | |
2450 | return 0; | |
2451 | } | |
2452 | ||
b375a11a | 2453 | seq_printf(m, "%ps\n", (void *)*ptr); |
ea4e2bc4 SR |
2454 | |
2455 | return 0; | |
2456 | } | |
2457 | ||
88e9d34c | 2458 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
2459 | .start = g_start, |
2460 | .next = g_next, | |
2461 | .stop = g_stop, | |
2462 | .show = g_show, | |
2463 | }; | |
2464 | ||
2465 | static int | |
2466 | ftrace_graph_open(struct inode *inode, struct file *file) | |
2467 | { | |
2468 | int ret = 0; | |
2469 | ||
2470 | if (unlikely(ftrace_disabled)) | |
2471 | return -ENODEV; | |
2472 | ||
2473 | mutex_lock(&graph_lock); | |
2474 | if ((file->f_mode & FMODE_WRITE) && | |
8650ae32 | 2475 | (file->f_flags & O_TRUNC)) { |
c7c6b1fe | 2476 | ftrace_graph_filter_enabled = 0; |
ea4e2bc4 SR |
2477 | ftrace_graph_count = 0; |
2478 | memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); | |
2479 | } | |
a4ec5e0c | 2480 | mutex_unlock(&graph_lock); |
ea4e2bc4 | 2481 | |
a4ec5e0c | 2482 | if (file->f_mode & FMODE_READ) |
ea4e2bc4 | 2483 | ret = seq_open(file, &ftrace_graph_seq_ops); |
ea4e2bc4 SR |
2484 | |
2485 | return ret; | |
2486 | } | |
2487 | ||
87827111 LZ |
2488 | static int |
2489 | ftrace_graph_release(struct inode *inode, struct file *file) | |
2490 | { | |
2491 | if (file->f_mode & FMODE_READ) | |
2492 | seq_release(inode, file); | |
2493 | return 0; | |
2494 | } | |
2495 | ||
ea4e2bc4 | 2496 | static int |
f9349a8f | 2497 | ftrace_set_func(unsigned long *array, int *idx, char *buffer) |
ea4e2bc4 | 2498 | { |
ea4e2bc4 SR |
2499 | struct dyn_ftrace *rec; |
2500 | struct ftrace_page *pg; | |
f9349a8f | 2501 | int search_len; |
c7c6b1fe | 2502 | int fail = 1; |
f9349a8f FW |
2503 | int type, not; |
2504 | char *search; | |
2505 | bool exists; | |
2506 | int i; | |
ea4e2bc4 | 2507 | |
f9349a8f | 2508 | /* decode regex */ |
3f6fe06d | 2509 | type = filter_parse_regex(buffer, strlen(buffer), &search, ¬); |
c7c6b1fe LZ |
2510 | if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS) |
2511 | return -EBUSY; | |
f9349a8f FW |
2512 | |
2513 | search_len = strlen(search); | |
2514 | ||
52baf119 | 2515 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
2516 | |
2517 | if (unlikely(ftrace_disabled)) { | |
2518 | mutex_unlock(&ftrace_lock); | |
2519 | return -ENODEV; | |
2520 | } | |
2521 | ||
265c831c SR |
2522 | do_for_each_ftrace_rec(pg, rec) { |
2523 | ||
45a4a237 | 2524 | if (rec->flags & FTRACE_FL_FREE) |
265c831c SR |
2525 | continue; |
2526 | ||
b9df92d2 | 2527 | if (ftrace_match_record(rec, NULL, search, search_len, type)) { |
c7c6b1fe | 2528 | /* if it is in the array */ |
f9349a8f | 2529 | exists = false; |
c7c6b1fe | 2530 | for (i = 0; i < *idx; i++) { |
f9349a8f FW |
2531 | if (array[i] == rec->ip) { |
2532 | exists = true; | |
265c831c SR |
2533 | break; |
2534 | } | |
c7c6b1fe LZ |
2535 | } |
2536 | ||
2537 | if (!not) { | |
2538 | fail = 0; | |
2539 | if (!exists) { | |
2540 | array[(*idx)++] = rec->ip; | |
2541 | if (*idx >= FTRACE_GRAPH_MAX_FUNCS) | |
2542 | goto out; | |
2543 | } | |
2544 | } else { | |
2545 | if (exists) { | |
2546 | array[i] = array[--(*idx)]; | |
2547 | array[*idx] = 0; | |
2548 | fail = 0; | |
2549 | } | |
2550 | } | |
ea4e2bc4 | 2551 | } |
265c831c | 2552 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 2553 | out: |
52baf119 | 2554 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 2555 | |
c7c6b1fe LZ |
2556 | if (fail) |
2557 | return -EINVAL; | |
2558 | ||
2559 | ftrace_graph_filter_enabled = 1; | |
2560 | return 0; | |
ea4e2bc4 SR |
2561 | } |
2562 | ||
2563 | static ssize_t | |
2564 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
2565 | size_t cnt, loff_t *ppos) | |
2566 | { | |
689fd8b6 | 2567 | struct trace_parser parser; |
4ba7978e | 2568 | ssize_t read, ret; |
ea4e2bc4 | 2569 | |
c7c6b1fe | 2570 | if (!cnt) |
ea4e2bc4 SR |
2571 | return 0; |
2572 | ||
2573 | mutex_lock(&graph_lock); | |
2574 | ||
689fd8b6 | 2575 | if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) { |
2576 | ret = -ENOMEM; | |
1eb90f13 | 2577 | goto out_unlock; |
ea4e2bc4 SR |
2578 | } |
2579 | ||
689fd8b6 | 2580 | read = trace_get_user(&parser, ubuf, cnt, ppos); |
ea4e2bc4 | 2581 | |
4ba7978e | 2582 | if (read >= 0 && trace_parser_loaded((&parser))) { |
689fd8b6 | 2583 | parser.buffer[parser.idx] = 0; |
2584 | ||
2585 | /* we allow only one expression at a time */ | |
a4ec5e0c | 2586 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, |
689fd8b6 | 2587 | parser.buffer); |
ea4e2bc4 | 2588 | if (ret) |
1eb90f13 | 2589 | goto out_free; |
ea4e2bc4 | 2590 | } |
ea4e2bc4 SR |
2591 | |
2592 | ret = read; | |
1eb90f13 LZ |
2593 | |
2594 | out_free: | |
689fd8b6 | 2595 | trace_parser_put(&parser); |
1eb90f13 | 2596 | out_unlock: |
ea4e2bc4 SR |
2597 | mutex_unlock(&graph_lock); |
2598 | ||
2599 | return ret; | |
2600 | } | |
2601 | ||
2602 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
2603 | .open = ftrace_graph_open, |
2604 | .read = seq_read, | |
2605 | .write = ftrace_graph_write, | |
2606 | .release = ftrace_graph_release, | |
6038f373 | 2607 | .llseek = seq_lseek, |
ea4e2bc4 SR |
2608 | }; |
2609 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2610 | ||
df4fc315 | 2611 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 2612 | { |
5072c59f | 2613 | |
5452af66 FW |
2614 | trace_create_file("available_filter_functions", 0444, |
2615 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 2616 | |
5452af66 FW |
2617 | trace_create_file("set_ftrace_filter", 0644, d_tracer, |
2618 | NULL, &ftrace_filter_fops); | |
41c52c0d | 2619 | |
5452af66 | 2620 | trace_create_file("set_ftrace_notrace", 0644, d_tracer, |
41c52c0d | 2621 | NULL, &ftrace_notrace_fops); |
ad90c0e3 | 2622 | |
ea4e2bc4 | 2623 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 2624 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
2625 | NULL, |
2626 | &ftrace_graph_fops); | |
ea4e2bc4 SR |
2627 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
2628 | ||
5072c59f SR |
2629 | return 0; |
2630 | } | |
2631 | ||
5cb084bb | 2632 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 2633 | unsigned long *start, |
68bf21aa SR |
2634 | unsigned long *end) |
2635 | { | |
2636 | unsigned long *p; | |
2637 | unsigned long addr; | |
68bf21aa | 2638 | |
e6ea44e9 | 2639 | mutex_lock(&ftrace_lock); |
68bf21aa SR |
2640 | p = start; |
2641 | while (p < end) { | |
2642 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
2643 | /* |
2644 | * Some architecture linkers will pad between | |
2645 | * the different mcount_loc sections of different | |
2646 | * object files to satisfy alignments. | |
2647 | * Skip any NULL pointers. | |
2648 | */ | |
2649 | if (!addr) | |
2650 | continue; | |
68bf21aa | 2651 | ftrace_record_ip(addr); |
68bf21aa SR |
2652 | } |
2653 | ||
31e88909 | 2654 | ftrace_update_code(mod); |
e6ea44e9 | 2655 | mutex_unlock(&ftrace_lock); |
68bf21aa SR |
2656 | |
2657 | return 0; | |
2658 | } | |
2659 | ||
93eb677d | 2660 | #ifdef CONFIG_MODULES |
e7247a15 | 2661 | void ftrace_release_mod(struct module *mod) |
93eb677d SR |
2662 | { |
2663 | struct dyn_ftrace *rec; | |
2664 | struct ftrace_page *pg; | |
93eb677d | 2665 | |
45a4a237 SR |
2666 | mutex_lock(&ftrace_lock); |
2667 | ||
e7247a15 | 2668 | if (ftrace_disabled) |
45a4a237 | 2669 | goto out_unlock; |
93eb677d | 2670 | |
93eb677d | 2671 | do_for_each_ftrace_rec(pg, rec) { |
e7247a15 | 2672 | if (within_module_core(rec->ip, mod)) { |
93eb677d SR |
2673 | /* |
2674 | * rec->ip is changed in ftrace_free_rec() | |
2675 | * It should not between s and e if record was freed. | |
2676 | */ | |
2677 | FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE); | |
2678 | ftrace_free_rec(rec); | |
2679 | } | |
2680 | } while_for_each_ftrace_rec(); | |
45a4a237 | 2681 | out_unlock: |
93eb677d SR |
2682 | mutex_unlock(&ftrace_lock); |
2683 | } | |
2684 | ||
2685 | static void ftrace_init_module(struct module *mod, | |
2686 | unsigned long *start, unsigned long *end) | |
90d595fe | 2687 | { |
00fd61ae | 2688 | if (ftrace_disabled || start == end) |
fed1939c | 2689 | return; |
5cb084bb | 2690 | ftrace_process_locs(mod, start, end); |
90d595fe SR |
2691 | } |
2692 | ||
93eb677d SR |
2693 | static int ftrace_module_notify(struct notifier_block *self, |
2694 | unsigned long val, void *data) | |
2695 | { | |
2696 | struct module *mod = data; | |
2697 | ||
2698 | switch (val) { | |
2699 | case MODULE_STATE_COMING: | |
2700 | ftrace_init_module(mod, mod->ftrace_callsites, | |
2701 | mod->ftrace_callsites + | |
2702 | mod->num_ftrace_callsites); | |
2703 | break; | |
2704 | case MODULE_STATE_GOING: | |
e7247a15 | 2705 | ftrace_release_mod(mod); |
93eb677d SR |
2706 | break; |
2707 | } | |
2708 | ||
2709 | return 0; | |
2710 | } | |
2711 | #else | |
2712 | static int ftrace_module_notify(struct notifier_block *self, | |
2713 | unsigned long val, void *data) | |
2714 | { | |
2715 | return 0; | |
2716 | } | |
2717 | #endif /* CONFIG_MODULES */ | |
2718 | ||
2719 | struct notifier_block ftrace_module_nb = { | |
2720 | .notifier_call = ftrace_module_notify, | |
2721 | .priority = 0, | |
2722 | }; | |
2723 | ||
68bf21aa SR |
2724 | extern unsigned long __start_mcount_loc[]; |
2725 | extern unsigned long __stop_mcount_loc[]; | |
2726 | ||
2727 | void __init ftrace_init(void) | |
2728 | { | |
2729 | unsigned long count, addr, flags; | |
2730 | int ret; | |
2731 | ||
2732 | /* Keep the ftrace pointer to the stub */ | |
2733 | addr = (unsigned long)ftrace_stub; | |
2734 | ||
2735 | local_irq_save(flags); | |
2736 | ftrace_dyn_arch_init(&addr); | |
2737 | local_irq_restore(flags); | |
2738 | ||
2739 | /* ftrace_dyn_arch_init places the return code in addr */ | |
2740 | if (addr) | |
2741 | goto failed; | |
2742 | ||
2743 | count = __stop_mcount_loc - __start_mcount_loc; | |
2744 | ||
2745 | ret = ftrace_dyn_table_alloc(count); | |
2746 | if (ret) | |
2747 | goto failed; | |
2748 | ||
2749 | last_ftrace_enabled = ftrace_enabled = 1; | |
2750 | ||
5cb084bb | 2751 | ret = ftrace_process_locs(NULL, |
31e88909 | 2752 | __start_mcount_loc, |
68bf21aa SR |
2753 | __stop_mcount_loc); |
2754 | ||
93eb677d | 2755 | ret = register_module_notifier(&ftrace_module_nb); |
24ed0c4b | 2756 | if (ret) |
93eb677d SR |
2757 | pr_warning("Failed to register trace ftrace module notifier\n"); |
2758 | ||
2af15d6a SR |
2759 | set_ftrace_early_filters(); |
2760 | ||
68bf21aa SR |
2761 | return; |
2762 | failed: | |
2763 | ftrace_disabled = 1; | |
2764 | } | |
68bf21aa | 2765 | |
3d083395 | 2766 | #else |
0b6e4d56 FW |
2767 | |
2768 | static int __init ftrace_nodyn_init(void) | |
2769 | { | |
2770 | ftrace_enabled = 1; | |
2771 | return 0; | |
2772 | } | |
2773 | device_initcall(ftrace_nodyn_init); | |
2774 | ||
df4fc315 SR |
2775 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
2776 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 SR |
2777 | /* Keep as macros so we do not need to define the commands */ |
2778 | # define ftrace_startup(command) do { } while (0) | |
2779 | # define ftrace_shutdown(command) do { } while (0) | |
c7aafc54 IM |
2780 | # define ftrace_startup_sysctl() do { } while (0) |
2781 | # define ftrace_shutdown_sysctl() do { } while (0) | |
3d083395 SR |
2782 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
2783 | ||
e32d8956 | 2784 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
2785 | { |
2786 | struct task_struct *p; | |
e32d8956 | 2787 | int cpu; |
978f3a45 | 2788 | |
e32d8956 SR |
2789 | get_online_cpus(); |
2790 | for_each_online_cpu(cpu) { | |
2791 | p = idle_task(cpu); | |
978f3a45 | 2792 | clear_tsk_trace_trace(p); |
e32d8956 SR |
2793 | } |
2794 | put_online_cpus(); | |
2795 | } | |
978f3a45 | 2796 | |
e32d8956 SR |
2797 | static void set_ftrace_swapper(void) |
2798 | { | |
2799 | struct task_struct *p; | |
2800 | int cpu; | |
2801 | ||
2802 | get_online_cpus(); | |
2803 | for_each_online_cpu(cpu) { | |
2804 | p = idle_task(cpu); | |
2805 | set_tsk_trace_trace(p); | |
2806 | } | |
2807 | put_online_cpus(); | |
978f3a45 SR |
2808 | } |
2809 | ||
e32d8956 SR |
2810 | static void clear_ftrace_pid(struct pid *pid) |
2811 | { | |
2812 | struct task_struct *p; | |
2813 | ||
229c4ef8 | 2814 | rcu_read_lock(); |
e32d8956 SR |
2815 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2816 | clear_tsk_trace_trace(p); | |
2817 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
2818 | rcu_read_unlock(); |
2819 | ||
e32d8956 SR |
2820 | put_pid(pid); |
2821 | } | |
2822 | ||
2823 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
2824 | { |
2825 | struct task_struct *p; | |
2826 | ||
229c4ef8 | 2827 | rcu_read_lock(); |
978f3a45 SR |
2828 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2829 | set_tsk_trace_trace(p); | |
2830 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 2831 | rcu_read_unlock(); |
978f3a45 SR |
2832 | } |
2833 | ||
756d17ee | 2834 | static void clear_ftrace_pid_task(struct pid *pid) |
e32d8956 | 2835 | { |
756d17ee | 2836 | if (pid == ftrace_swapper_pid) |
e32d8956 SR |
2837 | clear_ftrace_swapper(); |
2838 | else | |
756d17ee | 2839 | clear_ftrace_pid(pid); |
e32d8956 SR |
2840 | } |
2841 | ||
2842 | static void set_ftrace_pid_task(struct pid *pid) | |
2843 | { | |
2844 | if (pid == ftrace_swapper_pid) | |
2845 | set_ftrace_swapper(); | |
2846 | else | |
2847 | set_ftrace_pid(pid); | |
2848 | } | |
2849 | ||
756d17ee | 2850 | static int ftrace_pid_add(int p) |
df4fc315 | 2851 | { |
978f3a45 | 2852 | struct pid *pid; |
756d17ee | 2853 | struct ftrace_pid *fpid; |
2854 | int ret = -EINVAL; | |
df4fc315 | 2855 | |
756d17ee | 2856 | mutex_lock(&ftrace_lock); |
df4fc315 | 2857 | |
756d17ee | 2858 | if (!p) |
2859 | pid = ftrace_swapper_pid; | |
2860 | else | |
2861 | pid = find_get_pid(p); | |
df4fc315 | 2862 | |
756d17ee | 2863 | if (!pid) |
2864 | goto out; | |
df4fc315 | 2865 | |
756d17ee | 2866 | ret = 0; |
df4fc315 | 2867 | |
756d17ee | 2868 | list_for_each_entry(fpid, &ftrace_pids, list) |
2869 | if (fpid->pid == pid) | |
2870 | goto out_put; | |
978f3a45 | 2871 | |
756d17ee | 2872 | ret = -ENOMEM; |
df4fc315 | 2873 | |
756d17ee | 2874 | fpid = kmalloc(sizeof(*fpid), GFP_KERNEL); |
2875 | if (!fpid) | |
2876 | goto out_put; | |
df4fc315 | 2877 | |
756d17ee | 2878 | list_add(&fpid->list, &ftrace_pids); |
2879 | fpid->pid = pid; | |
0ef8cde5 | 2880 | |
756d17ee | 2881 | set_ftrace_pid_task(pid); |
978f3a45 | 2882 | |
756d17ee | 2883 | ftrace_update_pid_func(); |
2884 | ftrace_startup_enable(0); | |
2885 | ||
2886 | mutex_unlock(&ftrace_lock); | |
2887 | return 0; | |
2888 | ||
2889 | out_put: | |
2890 | if (pid != ftrace_swapper_pid) | |
2891 | put_pid(pid); | |
978f3a45 | 2892 | |
756d17ee | 2893 | out: |
2894 | mutex_unlock(&ftrace_lock); | |
2895 | return ret; | |
2896 | } | |
2897 | ||
2898 | static void ftrace_pid_reset(void) | |
2899 | { | |
2900 | struct ftrace_pid *fpid, *safe; | |
978f3a45 | 2901 | |
756d17ee | 2902 | mutex_lock(&ftrace_lock); |
2903 | list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) { | |
2904 | struct pid *pid = fpid->pid; | |
2905 | ||
2906 | clear_ftrace_pid_task(pid); | |
2907 | ||
2908 | list_del(&fpid->list); | |
2909 | kfree(fpid); | |
df4fc315 SR |
2910 | } |
2911 | ||
df4fc315 SR |
2912 | ftrace_update_pid_func(); |
2913 | ftrace_startup_enable(0); | |
2914 | ||
e6ea44e9 | 2915 | mutex_unlock(&ftrace_lock); |
756d17ee | 2916 | } |
df4fc315 | 2917 | |
756d17ee | 2918 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
2919 | { | |
2920 | mutex_lock(&ftrace_lock); | |
2921 | ||
2922 | if (list_empty(&ftrace_pids) && (!*pos)) | |
2923 | return (void *) 1; | |
2924 | ||
2925 | return seq_list_start(&ftrace_pids, *pos); | |
2926 | } | |
2927 | ||
2928 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
2929 | { | |
2930 | if (v == (void *)1) | |
2931 | return NULL; | |
2932 | ||
2933 | return seq_list_next(v, &ftrace_pids, pos); | |
2934 | } | |
2935 | ||
2936 | static void fpid_stop(struct seq_file *m, void *p) | |
2937 | { | |
2938 | mutex_unlock(&ftrace_lock); | |
2939 | } | |
2940 | ||
2941 | static int fpid_show(struct seq_file *m, void *v) | |
2942 | { | |
2943 | const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list); | |
2944 | ||
2945 | if (v == (void *)1) { | |
2946 | seq_printf(m, "no pid\n"); | |
2947 | return 0; | |
2948 | } | |
2949 | ||
2950 | if (fpid->pid == ftrace_swapper_pid) | |
2951 | seq_printf(m, "swapper tasks\n"); | |
2952 | else | |
2953 | seq_printf(m, "%u\n", pid_vnr(fpid->pid)); | |
2954 | ||
2955 | return 0; | |
2956 | } | |
2957 | ||
2958 | static const struct seq_operations ftrace_pid_sops = { | |
2959 | .start = fpid_start, | |
2960 | .next = fpid_next, | |
2961 | .stop = fpid_stop, | |
2962 | .show = fpid_show, | |
2963 | }; | |
2964 | ||
2965 | static int | |
2966 | ftrace_pid_open(struct inode *inode, struct file *file) | |
2967 | { | |
2968 | int ret = 0; | |
2969 | ||
2970 | if ((file->f_mode & FMODE_WRITE) && | |
2971 | (file->f_flags & O_TRUNC)) | |
2972 | ftrace_pid_reset(); | |
2973 | ||
2974 | if (file->f_mode & FMODE_READ) | |
2975 | ret = seq_open(file, &ftrace_pid_sops); | |
2976 | ||
2977 | return ret; | |
2978 | } | |
2979 | ||
df4fc315 SR |
2980 | static ssize_t |
2981 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
2982 | size_t cnt, loff_t *ppos) | |
2983 | { | |
457dc928 | 2984 | char buf[64], *tmp; |
df4fc315 SR |
2985 | long val; |
2986 | int ret; | |
2987 | ||
2988 | if (cnt >= sizeof(buf)) | |
2989 | return -EINVAL; | |
2990 | ||
2991 | if (copy_from_user(&buf, ubuf, cnt)) | |
2992 | return -EFAULT; | |
2993 | ||
2994 | buf[cnt] = 0; | |
2995 | ||
756d17ee | 2996 | /* |
2997 | * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid" | |
2998 | * to clean the filter quietly. | |
2999 | */ | |
457dc928 IM |
3000 | tmp = strstrip(buf); |
3001 | if (strlen(tmp) == 0) | |
756d17ee | 3002 | return 1; |
3003 | ||
457dc928 | 3004 | ret = strict_strtol(tmp, 10, &val); |
df4fc315 SR |
3005 | if (ret < 0) |
3006 | return ret; | |
3007 | ||
756d17ee | 3008 | ret = ftrace_pid_add(val); |
df4fc315 | 3009 | |
756d17ee | 3010 | return ret ? ret : cnt; |
3011 | } | |
df4fc315 | 3012 | |
756d17ee | 3013 | static int |
3014 | ftrace_pid_release(struct inode *inode, struct file *file) | |
3015 | { | |
3016 | if (file->f_mode & FMODE_READ) | |
3017 | seq_release(inode, file); | |
df4fc315 | 3018 | |
756d17ee | 3019 | return 0; |
df4fc315 SR |
3020 | } |
3021 | ||
5e2336a0 | 3022 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 3023 | .open = ftrace_pid_open, |
3024 | .write = ftrace_pid_write, | |
3025 | .read = seq_read, | |
3026 | .llseek = seq_lseek, | |
3027 | .release = ftrace_pid_release, | |
df4fc315 SR |
3028 | }; |
3029 | ||
3030 | static __init int ftrace_init_debugfs(void) | |
3031 | { | |
3032 | struct dentry *d_tracer; | |
df4fc315 SR |
3033 | |
3034 | d_tracer = tracing_init_dentry(); | |
3035 | if (!d_tracer) | |
3036 | return 0; | |
3037 | ||
3038 | ftrace_init_dyn_debugfs(d_tracer); | |
3039 | ||
5452af66 FW |
3040 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
3041 | NULL, &ftrace_pid_fops); | |
493762fc SR |
3042 | |
3043 | ftrace_profile_debugfs(d_tracer); | |
3044 | ||
df4fc315 SR |
3045 | return 0; |
3046 | } | |
df4fc315 SR |
3047 | fs_initcall(ftrace_init_debugfs); |
3048 | ||
a2bb6a3d | 3049 | /** |
81adbdc0 | 3050 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
3051 | * |
3052 | * This function should be used by panic code. It stops ftrace | |
3053 | * but in a not so nice way. If you need to simply kill ftrace | |
3054 | * from a non-atomic section, use ftrace_kill. | |
3055 | */ | |
81adbdc0 | 3056 | void ftrace_kill(void) |
a2bb6a3d SR |
3057 | { |
3058 | ftrace_disabled = 1; | |
3059 | ftrace_enabled = 0; | |
a2bb6a3d SR |
3060 | clear_ftrace_function(); |
3061 | } | |
3062 | ||
16444a8a | 3063 | /** |
3d083395 SR |
3064 | * register_ftrace_function - register a function for profiling |
3065 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 3066 | * |
3d083395 SR |
3067 | * Register a function to be called by all functions in the |
3068 | * kernel. | |
3069 | * | |
3070 | * Note: @ops->func and all the functions it calls must be labeled | |
3071 | * with "notrace", otherwise it will go into a | |
3072 | * recursive loop. | |
16444a8a | 3073 | */ |
3d083395 | 3074 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 3075 | { |
45a4a237 | 3076 | int ret = -1; |
4eebcc81 | 3077 | |
e6ea44e9 | 3078 | mutex_lock(&ftrace_lock); |
e7d3737e | 3079 | |
45a4a237 SR |
3080 | if (unlikely(ftrace_disabled)) |
3081 | goto out_unlock; | |
3082 | ||
b0fc494f | 3083 | ret = __register_ftrace_function(ops); |
5a45cfe1 | 3084 | ftrace_startup(0); |
b0fc494f | 3085 | |
45a4a237 | 3086 | out_unlock: |
e6ea44e9 | 3087 | mutex_unlock(&ftrace_lock); |
b0fc494f | 3088 | return ret; |
3d083395 SR |
3089 | } |
3090 | ||
3091 | /** | |
32632920 | 3092 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
3093 | * @ops - ops structure that holds the function to unregister |
3094 | * | |
3095 | * Unregister a function that was added to be called by ftrace profiling. | |
3096 | */ | |
3097 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
3098 | { | |
3099 | int ret; | |
3100 | ||
e6ea44e9 | 3101 | mutex_lock(&ftrace_lock); |
3d083395 | 3102 | ret = __unregister_ftrace_function(ops); |
5a45cfe1 | 3103 | ftrace_shutdown(0); |
e6ea44e9 | 3104 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
3105 | |
3106 | return ret; | |
3107 | } | |
3108 | ||
e309b41d | 3109 | int |
b0fc494f | 3110 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
8d65af78 | 3111 | void __user *buffer, size_t *lenp, |
b0fc494f SR |
3112 | loff_t *ppos) |
3113 | { | |
45a4a237 | 3114 | int ret = -ENODEV; |
4eebcc81 | 3115 | |
e6ea44e9 | 3116 | mutex_lock(&ftrace_lock); |
b0fc494f | 3117 | |
45a4a237 SR |
3118 | if (unlikely(ftrace_disabled)) |
3119 | goto out; | |
3120 | ||
3121 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
b0fc494f | 3122 | |
a32c7765 | 3123 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
3124 | goto out; |
3125 | ||
a32c7765 | 3126 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f SR |
3127 | |
3128 | if (ftrace_enabled) { | |
3129 | ||
3130 | ftrace_startup_sysctl(); | |
3131 | ||
3132 | /* we are starting ftrace again */ | |
3133 | if (ftrace_list != &ftrace_list_end) { | |
3134 | if (ftrace_list->next == &ftrace_list_end) | |
3135 | ftrace_trace_function = ftrace_list->func; | |
3136 | else | |
3137 | ftrace_trace_function = ftrace_list_func; | |
3138 | } | |
3139 | ||
3140 | } else { | |
3141 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
3142 | ftrace_trace_function = ftrace_stub; | |
3143 | ||
3144 | ftrace_shutdown_sysctl(); | |
3145 | } | |
3146 | ||
3147 | out: | |
e6ea44e9 | 3148 | mutex_unlock(&ftrace_lock); |
3d083395 | 3149 | return ret; |
16444a8a | 3150 | } |
f17845e5 | 3151 | |
fb52607a | 3152 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 3153 | |
597af815 | 3154 | static int ftrace_graph_active; |
4a2b8dda | 3155 | static struct notifier_block ftrace_suspend_notifier; |
e7d3737e | 3156 | |
e49dc19c SR |
3157 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
3158 | { | |
3159 | return 0; | |
3160 | } | |
3161 | ||
287b6e68 FW |
3162 | /* The callbacks that hook a function */ |
3163 | trace_func_graph_ret_t ftrace_graph_return = | |
3164 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 3165 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
3166 | |
3167 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
3168 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
3169 | { | |
3170 | int i; | |
3171 | int ret = 0; | |
3172 | unsigned long flags; | |
3173 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
3174 | struct task_struct *g, *t; | |
3175 | ||
3176 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
3177 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
3178 | * sizeof(struct ftrace_ret_stack), | |
3179 | GFP_KERNEL); | |
3180 | if (!ret_stack_list[i]) { | |
3181 | start = 0; | |
3182 | end = i; | |
3183 | ret = -ENOMEM; | |
3184 | goto free; | |
3185 | } | |
3186 | } | |
3187 | ||
3188 | read_lock_irqsave(&tasklist_lock, flags); | |
3189 | do_each_thread(g, t) { | |
3190 | if (start == end) { | |
3191 | ret = -EAGAIN; | |
3192 | goto unlock; | |
3193 | } | |
3194 | ||
3195 | if (t->ret_stack == NULL) { | |
380c4b14 | 3196 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 3197 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
3198 | t->curr_ret_stack = -1; |
3199 | /* Make sure the tasks see the -1 first: */ | |
3200 | smp_wmb(); | |
3201 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
3202 | } |
3203 | } while_each_thread(g, t); | |
3204 | ||
3205 | unlock: | |
3206 | read_unlock_irqrestore(&tasklist_lock, flags); | |
3207 | free: | |
3208 | for (i = start; i < end; i++) | |
3209 | kfree(ret_stack_list[i]); | |
3210 | return ret; | |
3211 | } | |
3212 | ||
8aef2d28 | 3213 | static void |
38516ab5 SR |
3214 | ftrace_graph_probe_sched_switch(void *ignore, |
3215 | struct task_struct *prev, struct task_struct *next) | |
8aef2d28 SR |
3216 | { |
3217 | unsigned long long timestamp; | |
3218 | int index; | |
3219 | ||
be6f164a SR |
3220 | /* |
3221 | * Does the user want to count the time a function was asleep. | |
3222 | * If so, do not update the time stamps. | |
3223 | */ | |
3224 | if (trace_flags & TRACE_ITER_SLEEP_TIME) | |
3225 | return; | |
3226 | ||
8aef2d28 SR |
3227 | timestamp = trace_clock_local(); |
3228 | ||
3229 | prev->ftrace_timestamp = timestamp; | |
3230 | ||
3231 | /* only process tasks that we timestamped */ | |
3232 | if (!next->ftrace_timestamp) | |
3233 | return; | |
3234 | ||
3235 | /* | |
3236 | * Update all the counters in next to make up for the | |
3237 | * time next was sleeping. | |
3238 | */ | |
3239 | timestamp -= next->ftrace_timestamp; | |
3240 | ||
3241 | for (index = next->curr_ret_stack; index >= 0; index--) | |
3242 | next->ret_stack[index].calltime += timestamp; | |
3243 | } | |
3244 | ||
f201ae23 | 3245 | /* Allocate a return stack for each task */ |
fb52607a | 3246 | static int start_graph_tracing(void) |
f201ae23 FW |
3247 | { |
3248 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 3249 | int ret, cpu; |
f201ae23 FW |
3250 | |
3251 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
3252 | sizeof(struct ftrace_ret_stack *), | |
3253 | GFP_KERNEL); | |
3254 | ||
3255 | if (!ret_stack_list) | |
3256 | return -ENOMEM; | |
3257 | ||
5b058bcd | 3258 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
3259 | for_each_online_cpu(cpu) { |
3260 | if (!idle_task(cpu)->ret_stack) | |
868baf07 | 3261 | ftrace_graph_init_idle_task(idle_task(cpu), cpu); |
179c498a | 3262 | } |
5b058bcd | 3263 | |
f201ae23 FW |
3264 | do { |
3265 | ret = alloc_retstack_tasklist(ret_stack_list); | |
3266 | } while (ret == -EAGAIN); | |
3267 | ||
8aef2d28 | 3268 | if (!ret) { |
38516ab5 | 3269 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
8aef2d28 SR |
3270 | if (ret) |
3271 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
3272 | " probe to kernel_sched_switch\n"); | |
3273 | } | |
3274 | ||
f201ae23 FW |
3275 | kfree(ret_stack_list); |
3276 | return ret; | |
3277 | } | |
3278 | ||
4a2b8dda FW |
3279 | /* |
3280 | * Hibernation protection. | |
3281 | * The state of the current task is too much unstable during | |
3282 | * suspend/restore to disk. We want to protect against that. | |
3283 | */ | |
3284 | static int | |
3285 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
3286 | void *unused) | |
3287 | { | |
3288 | switch (state) { | |
3289 | case PM_HIBERNATION_PREPARE: | |
3290 | pause_graph_tracing(); | |
3291 | break; | |
3292 | ||
3293 | case PM_POST_HIBERNATION: | |
3294 | unpause_graph_tracing(); | |
3295 | break; | |
3296 | } | |
3297 | return NOTIFY_DONE; | |
3298 | } | |
3299 | ||
287b6e68 FW |
3300 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
3301 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 3302 | { |
e7d3737e FW |
3303 | int ret = 0; |
3304 | ||
e6ea44e9 | 3305 | mutex_lock(&ftrace_lock); |
e7d3737e | 3306 | |
05ce5818 | 3307 | /* we currently allow only one tracer registered at a time */ |
597af815 | 3308 | if (ftrace_graph_active) { |
05ce5818 SR |
3309 | ret = -EBUSY; |
3310 | goto out; | |
3311 | } | |
3312 | ||
4a2b8dda FW |
3313 | ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; |
3314 | register_pm_notifier(&ftrace_suspend_notifier); | |
3315 | ||
597af815 | 3316 | ftrace_graph_active++; |
fb52607a | 3317 | ret = start_graph_tracing(); |
f201ae23 | 3318 | if (ret) { |
597af815 | 3319 | ftrace_graph_active--; |
f201ae23 FW |
3320 | goto out; |
3321 | } | |
e53a6319 | 3322 | |
287b6e68 FW |
3323 | ftrace_graph_return = retfunc; |
3324 | ftrace_graph_entry = entryfunc; | |
e53a6319 | 3325 | |
5a45cfe1 | 3326 | ftrace_startup(FTRACE_START_FUNC_RET); |
e7d3737e FW |
3327 | |
3328 | out: | |
e6ea44e9 | 3329 | mutex_unlock(&ftrace_lock); |
e7d3737e | 3330 | return ret; |
15e6cb36 FW |
3331 | } |
3332 | ||
fb52607a | 3333 | void unregister_ftrace_graph(void) |
15e6cb36 | 3334 | { |
e6ea44e9 | 3335 | mutex_lock(&ftrace_lock); |
e7d3737e | 3336 | |
597af815 | 3337 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
3338 | goto out; |
3339 | ||
597af815 | 3340 | ftrace_graph_active--; |
287b6e68 | 3341 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 3342 | ftrace_graph_entry = ftrace_graph_entry_stub; |
5a45cfe1 | 3343 | ftrace_shutdown(FTRACE_STOP_FUNC_RET); |
4a2b8dda | 3344 | unregister_pm_notifier(&ftrace_suspend_notifier); |
38516ab5 | 3345 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
e7d3737e | 3346 | |
2aad1b76 | 3347 | out: |
e6ea44e9 | 3348 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 3349 | } |
f201ae23 | 3350 | |
868baf07 SR |
3351 | static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack); |
3352 | ||
3353 | static void | |
3354 | graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack) | |
3355 | { | |
3356 | atomic_set(&t->tracing_graph_pause, 0); | |
3357 | atomic_set(&t->trace_overrun, 0); | |
3358 | t->ftrace_timestamp = 0; | |
25985edc | 3359 | /* make curr_ret_stack visible before we add the ret_stack */ |
868baf07 SR |
3360 | smp_wmb(); |
3361 | t->ret_stack = ret_stack; | |
3362 | } | |
3363 | ||
3364 | /* | |
3365 | * Allocate a return stack for the idle task. May be the first | |
3366 | * time through, or it may be done by CPU hotplug online. | |
3367 | */ | |
3368 | void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) | |
3369 | { | |
3370 | t->curr_ret_stack = -1; | |
3371 | /* | |
3372 | * The idle task has no parent, it either has its own | |
3373 | * stack or no stack at all. | |
3374 | */ | |
3375 | if (t->ret_stack) | |
3376 | WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu)); | |
3377 | ||
3378 | if (ftrace_graph_active) { | |
3379 | struct ftrace_ret_stack *ret_stack; | |
3380 | ||
3381 | ret_stack = per_cpu(idle_ret_stack, cpu); | |
3382 | if (!ret_stack) { | |
3383 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
3384 | * sizeof(struct ftrace_ret_stack), | |
3385 | GFP_KERNEL); | |
3386 | if (!ret_stack) | |
3387 | return; | |
3388 | per_cpu(idle_ret_stack, cpu) = ret_stack; | |
3389 | } | |
3390 | graph_init_task(t, ret_stack); | |
3391 | } | |
3392 | } | |
3393 | ||
f201ae23 | 3394 | /* Allocate a return stack for newly created task */ |
fb52607a | 3395 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 3396 | { |
84047e36 SR |
3397 | /* Make sure we do not use the parent ret_stack */ |
3398 | t->ret_stack = NULL; | |
ea14eb71 | 3399 | t->curr_ret_stack = -1; |
84047e36 | 3400 | |
597af815 | 3401 | if (ftrace_graph_active) { |
82310a32 SR |
3402 | struct ftrace_ret_stack *ret_stack; |
3403 | ||
3404 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
3405 | * sizeof(struct ftrace_ret_stack), |
3406 | GFP_KERNEL); | |
82310a32 | 3407 | if (!ret_stack) |
f201ae23 | 3408 | return; |
868baf07 | 3409 | graph_init_task(t, ret_stack); |
84047e36 | 3410 | } |
f201ae23 FW |
3411 | } |
3412 | ||
fb52607a | 3413 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 3414 | { |
eae849ca FW |
3415 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
3416 | ||
f201ae23 | 3417 | t->ret_stack = NULL; |
eae849ca FW |
3418 | /* NULL must become visible to IRQs before we free it: */ |
3419 | barrier(); | |
3420 | ||
3421 | kfree(ret_stack); | |
f201ae23 | 3422 | } |
14a866c5 SR |
3423 | |
3424 | void ftrace_graph_stop(void) | |
3425 | { | |
3426 | ftrace_stop(); | |
3427 | } | |
15e6cb36 | 3428 | #endif |