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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> |
f22f9a89 | 25 | #include <linux/kprobes.h> |
2d8b820b | 26 | #include <linux/ftrace.h> |
b0fc494f | 27 | #include <linux/sysctl.h> |
5072c59f | 28 | #include <linux/ctype.h> |
3d083395 | 29 | #include <linux/list.h> |
59df055f | 30 | #include <linux/hash.h> |
3d083395 | 31 | |
8aef2d28 SR |
32 | #include <trace/sched.h> |
33 | ||
395a59d0 AS |
34 | #include <asm/ftrace.h> |
35 | ||
0706f1c4 | 36 | #include "trace_output.h" |
bac429f0 | 37 | #include "trace_stat.h" |
16444a8a | 38 | |
6912896e SR |
39 | #define FTRACE_WARN_ON(cond) \ |
40 | do { \ | |
41 | if (WARN_ON(cond)) \ | |
42 | ftrace_kill(); \ | |
43 | } while (0) | |
44 | ||
45 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
46 | do { \ | |
47 | if (WARN_ON_ONCE(cond)) \ | |
48 | ftrace_kill(); \ | |
49 | } while (0) | |
50 | ||
8fc0c701 SR |
51 | /* hash bits for specific function selection */ |
52 | #define FTRACE_HASH_BITS 7 | |
53 | #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS) | |
54 | ||
4eebcc81 SR |
55 | /* ftrace_enabled is a method to turn ftrace on or off */ |
56 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 57 | static int last_ftrace_enabled; |
b0fc494f | 58 | |
60a7ecf4 SR |
59 | /* Quick disabling of function tracer. */ |
60 | int function_trace_stop; | |
61 | ||
4eebcc81 SR |
62 | /* |
63 | * ftrace_disabled is set when an anomaly is discovered. | |
64 | * ftrace_disabled is much stronger than ftrace_enabled. | |
65 | */ | |
66 | static int ftrace_disabled __read_mostly; | |
67 | ||
52baf119 | 68 | static DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 69 | |
16444a8a ACM |
70 | static struct ftrace_ops ftrace_list_end __read_mostly = |
71 | { | |
72 | .func = ftrace_stub, | |
73 | }; | |
74 | ||
75 | static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; | |
76 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; | |
60a7ecf4 | 77 | ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub; |
df4fc315 | 78 | ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; |
16444a8a | 79 | |
f2252935 | 80 | static void ftrace_list_func(unsigned long ip, unsigned long parent_ip) |
16444a8a ACM |
81 | { |
82 | struct ftrace_ops *op = ftrace_list; | |
83 | ||
84 | /* in case someone actually ports this to alpha! */ | |
85 | read_barrier_depends(); | |
86 | ||
87 | while (op != &ftrace_list_end) { | |
88 | /* silly alpha */ | |
89 | read_barrier_depends(); | |
90 | op->func(ip, parent_ip); | |
91 | op = op->next; | |
92 | }; | |
93 | } | |
94 | ||
df4fc315 SR |
95 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip) |
96 | { | |
0ef8cde5 | 97 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
98 | return; |
99 | ||
100 | ftrace_pid_function(ip, parent_ip); | |
101 | } | |
102 | ||
103 | static void set_ftrace_pid_function(ftrace_func_t func) | |
104 | { | |
105 | /* do not set ftrace_pid_function to itself! */ | |
106 | if (func != ftrace_pid_func) | |
107 | ftrace_pid_function = func; | |
108 | } | |
109 | ||
16444a8a | 110 | /** |
3d083395 | 111 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 112 | * |
3d083395 SR |
113 | * This NULLs the ftrace function and in essence stops |
114 | * tracing. There may be lag | |
16444a8a | 115 | */ |
3d083395 | 116 | void clear_ftrace_function(void) |
16444a8a | 117 | { |
3d083395 | 118 | ftrace_trace_function = ftrace_stub; |
60a7ecf4 | 119 | __ftrace_trace_function = ftrace_stub; |
df4fc315 | 120 | ftrace_pid_function = ftrace_stub; |
3d083395 SR |
121 | } |
122 | ||
60a7ecf4 SR |
123 | #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
124 | /* | |
125 | * For those archs that do not test ftrace_trace_stop in their | |
126 | * mcount call site, we need to do it from C. | |
127 | */ | |
128 | static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip) | |
129 | { | |
130 | if (function_trace_stop) | |
131 | return; | |
132 | ||
133 | __ftrace_trace_function(ip, parent_ip); | |
134 | } | |
135 | #endif | |
136 | ||
e309b41d | 137 | static int __register_ftrace_function(struct ftrace_ops *ops) |
3d083395 | 138 | { |
16444a8a ACM |
139 | ops->next = ftrace_list; |
140 | /* | |
141 | * We are entering ops into the ftrace_list but another | |
142 | * CPU might be walking that list. We need to make sure | |
143 | * the ops->next pointer is valid before another CPU sees | |
144 | * the ops pointer included into the ftrace_list. | |
145 | */ | |
146 | smp_wmb(); | |
147 | ftrace_list = ops; | |
3d083395 | 148 | |
b0fc494f | 149 | if (ftrace_enabled) { |
df4fc315 SR |
150 | ftrace_func_t func; |
151 | ||
152 | if (ops->next == &ftrace_list_end) | |
153 | func = ops->func; | |
154 | else | |
155 | func = ftrace_list_func; | |
156 | ||
978f3a45 | 157 | if (ftrace_pid_trace) { |
df4fc315 SR |
158 | set_ftrace_pid_function(func); |
159 | func = ftrace_pid_func; | |
160 | } | |
161 | ||
b0fc494f SR |
162 | /* |
163 | * For one func, simply call it directly. | |
164 | * For more than one func, call the chain. | |
165 | */ | |
60a7ecf4 | 166 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
df4fc315 | 167 | ftrace_trace_function = func; |
60a7ecf4 | 168 | #else |
df4fc315 | 169 | __ftrace_trace_function = func; |
60a7ecf4 SR |
170 | ftrace_trace_function = ftrace_test_stop_func; |
171 | #endif | |
b0fc494f | 172 | } |
3d083395 | 173 | |
16444a8a ACM |
174 | return 0; |
175 | } | |
176 | ||
e309b41d | 177 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 178 | { |
16444a8a | 179 | struct ftrace_ops **p; |
16444a8a ACM |
180 | |
181 | /* | |
3d083395 SR |
182 | * If we are removing the last function, then simply point |
183 | * to the ftrace_stub. | |
16444a8a ACM |
184 | */ |
185 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { | |
186 | ftrace_trace_function = ftrace_stub; | |
187 | ftrace_list = &ftrace_list_end; | |
e6ea44e9 | 188 | return 0; |
16444a8a ACM |
189 | } |
190 | ||
191 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) | |
192 | if (*p == ops) | |
193 | break; | |
194 | ||
e6ea44e9 SR |
195 | if (*p != ops) |
196 | return -1; | |
16444a8a ACM |
197 | |
198 | *p = (*p)->next; | |
199 | ||
b0fc494f SR |
200 | if (ftrace_enabled) { |
201 | /* If we only have one func left, then call that directly */ | |
df4fc315 SR |
202 | if (ftrace_list->next == &ftrace_list_end) { |
203 | ftrace_func_t func = ftrace_list->func; | |
204 | ||
978f3a45 | 205 | if (ftrace_pid_trace) { |
df4fc315 SR |
206 | set_ftrace_pid_function(func); |
207 | func = ftrace_pid_func; | |
208 | } | |
209 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
210 | ftrace_trace_function = func; | |
211 | #else | |
212 | __ftrace_trace_function = func; | |
213 | #endif | |
214 | } | |
b0fc494f | 215 | } |
16444a8a | 216 | |
e6ea44e9 | 217 | return 0; |
3d083395 SR |
218 | } |
219 | ||
df4fc315 SR |
220 | static void ftrace_update_pid_func(void) |
221 | { | |
222 | ftrace_func_t func; | |
223 | ||
df4fc315 | 224 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 225 | return; |
df4fc315 SR |
226 | |
227 | func = ftrace_trace_function; | |
228 | ||
978f3a45 | 229 | if (ftrace_pid_trace) { |
df4fc315 SR |
230 | set_ftrace_pid_function(func); |
231 | func = ftrace_pid_func; | |
232 | } else { | |
66eafebc LW |
233 | if (func == ftrace_pid_func) |
234 | func = ftrace_pid_function; | |
df4fc315 SR |
235 | } |
236 | ||
237 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
238 | ftrace_trace_function = func; | |
239 | #else | |
240 | __ftrace_trace_function = func; | |
241 | #endif | |
df4fc315 SR |
242 | } |
243 | ||
493762fc SR |
244 | #ifdef CONFIG_FUNCTION_PROFILER |
245 | struct ftrace_profile { | |
246 | struct hlist_node node; | |
247 | unsigned long ip; | |
248 | unsigned long counter; | |
0706f1c4 SR |
249 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
250 | unsigned long long time; | |
251 | #endif | |
8fc0c701 SR |
252 | }; |
253 | ||
493762fc SR |
254 | struct ftrace_profile_page { |
255 | struct ftrace_profile_page *next; | |
256 | unsigned long index; | |
257 | struct ftrace_profile records[]; | |
d61f82d0 SR |
258 | }; |
259 | ||
cafb168a SR |
260 | struct ftrace_profile_stat { |
261 | atomic_t disabled; | |
262 | struct hlist_head *hash; | |
263 | struct ftrace_profile_page *pages; | |
264 | struct ftrace_profile_page *start; | |
265 | struct tracer_stat stat; | |
266 | }; | |
267 | ||
493762fc SR |
268 | #define PROFILE_RECORDS_SIZE \ |
269 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 270 | |
493762fc SR |
271 | #define PROFILES_PER_PAGE \ |
272 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 273 | |
bac429f0 SR |
274 | static int ftrace_profile_bits; |
275 | static int ftrace_profile_enabled; | |
276 | static DEFINE_MUTEX(ftrace_profile_lock); | |
277 | ||
cafb168a | 278 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc SR |
279 | |
280 | #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */ | |
281 | ||
bac429f0 SR |
282 | static void * |
283 | function_stat_next(void *v, int idx) | |
284 | { | |
493762fc SR |
285 | struct ftrace_profile *rec = v; |
286 | struct ftrace_profile_page *pg; | |
bac429f0 | 287 | |
493762fc | 288 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
289 | |
290 | again: | |
291 | rec++; | |
292 | if ((void *)rec >= (void *)&pg->records[pg->index]) { | |
293 | pg = pg->next; | |
294 | if (!pg) | |
295 | return NULL; | |
296 | rec = &pg->records[0]; | |
493762fc SR |
297 | if (!rec->counter) |
298 | goto again; | |
bac429f0 SR |
299 | } |
300 | ||
bac429f0 SR |
301 | return rec; |
302 | } | |
303 | ||
304 | static void *function_stat_start(struct tracer_stat *trace) | |
305 | { | |
cafb168a SR |
306 | struct ftrace_profile_stat *stat = |
307 | container_of(trace, struct ftrace_profile_stat, stat); | |
308 | ||
309 | if (!stat || !stat->start) | |
310 | return NULL; | |
311 | ||
312 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
313 | } |
314 | ||
0706f1c4 SR |
315 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
316 | /* function graph compares on total time */ | |
317 | static int function_stat_cmp(void *p1, void *p2) | |
318 | { | |
319 | struct ftrace_profile *a = p1; | |
320 | struct ftrace_profile *b = p2; | |
321 | ||
322 | if (a->time < b->time) | |
323 | return -1; | |
324 | if (a->time > b->time) | |
325 | return 1; | |
326 | else | |
327 | return 0; | |
328 | } | |
329 | #else | |
330 | /* not function graph compares against hits */ | |
bac429f0 SR |
331 | static int function_stat_cmp(void *p1, void *p2) |
332 | { | |
493762fc SR |
333 | struct ftrace_profile *a = p1; |
334 | struct ftrace_profile *b = p2; | |
bac429f0 SR |
335 | |
336 | if (a->counter < b->counter) | |
337 | return -1; | |
338 | if (a->counter > b->counter) | |
339 | return 1; | |
340 | else | |
341 | return 0; | |
342 | } | |
0706f1c4 | 343 | #endif |
bac429f0 SR |
344 | |
345 | static int function_stat_headers(struct seq_file *m) | |
346 | { | |
0706f1c4 SR |
347 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
348 | seq_printf(m, " Function Hit Time\n" | |
349 | " -------- --- ----\n"); | |
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]; |
0706f1c4 SR |
361 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
362 | static struct trace_seq s; | |
363 | static DEFINE_MUTEX(mutex); | |
364 | ||
365 | mutex_lock(&mutex); | |
366 | trace_seq_init(&s); | |
367 | trace_print_graph_duration(rec->time, &s); | |
368 | #endif | |
bac429f0 SR |
369 | |
370 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
0706f1c4 SR |
371 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
372 | ||
373 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
374 | seq_printf(m, " "); | |
375 | trace_print_seq(m, &s); | |
376 | mutex_unlock(&mutex); | |
377 | #endif | |
378 | seq_putc(m, '\n'); | |
bac429f0 | 379 | |
bac429f0 SR |
380 | return 0; |
381 | } | |
382 | ||
cafb168a | 383 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 384 | { |
493762fc | 385 | struct ftrace_profile_page *pg; |
bac429f0 | 386 | |
cafb168a | 387 | pg = stat->pages = stat->start; |
bac429f0 | 388 | |
493762fc SR |
389 | while (pg) { |
390 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
391 | pg->index = 0; | |
392 | pg = pg->next; | |
bac429f0 SR |
393 | } |
394 | ||
cafb168a | 395 | memset(stat->hash, 0, |
493762fc SR |
396 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
397 | } | |
bac429f0 | 398 | |
cafb168a | 399 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
400 | { |
401 | struct ftrace_profile_page *pg; | |
402 | int i; | |
bac429f0 | 403 | |
493762fc | 404 | /* If we already allocated, do nothing */ |
cafb168a | 405 | if (stat->pages) |
493762fc | 406 | return 0; |
bac429f0 | 407 | |
cafb168a SR |
408 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
409 | if (!stat->pages) | |
493762fc | 410 | return -ENOMEM; |
bac429f0 | 411 | |
cafb168a | 412 | pg = stat->start = stat->pages; |
bac429f0 | 413 | |
493762fc SR |
414 | /* allocate 10 more pages to start */ |
415 | for (i = 0; i < 10; i++) { | |
416 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
417 | /* | |
418 | * We only care about allocating profile_pages, if | |
419 | * we failed to allocate here, hopefully we will allocate | |
420 | * later. | |
421 | */ | |
422 | if (!pg->next) | |
423 | break; | |
424 | pg = pg->next; | |
425 | } | |
426 | ||
427 | return 0; | |
bac429f0 SR |
428 | } |
429 | ||
cafb168a | 430 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 431 | { |
cafb168a | 432 | struct ftrace_profile_stat *stat; |
493762fc | 433 | int size; |
bac429f0 | 434 | |
cafb168a SR |
435 | stat = &per_cpu(ftrace_profile_stats, cpu); |
436 | ||
437 | if (stat->hash) { | |
493762fc | 438 | /* If the profile is already created, simply reset it */ |
cafb168a | 439 | ftrace_profile_reset(stat); |
493762fc SR |
440 | return 0; |
441 | } | |
bac429f0 | 442 | |
493762fc SR |
443 | /* |
444 | * We are profiling all functions, but usually only a few thousand | |
445 | * functions are hit. We'll make a hash of 1024 items. | |
446 | */ | |
447 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 448 | |
cafb168a | 449 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
493762fc | 450 | |
cafb168a | 451 | if (!stat->hash) |
493762fc SR |
452 | return -ENOMEM; |
453 | ||
cafb168a SR |
454 | if (!ftrace_profile_bits) { |
455 | size--; | |
493762fc | 456 | |
cafb168a SR |
457 | for (; size; size >>= 1) |
458 | ftrace_profile_bits++; | |
459 | } | |
493762fc SR |
460 | |
461 | /* Preallocate a few pages */ | |
cafb168a SR |
462 | if (ftrace_profile_pages_init(stat) < 0) { |
463 | kfree(stat->hash); | |
464 | stat->hash = NULL; | |
493762fc SR |
465 | return -ENOMEM; |
466 | } | |
467 | ||
468 | return 0; | |
bac429f0 SR |
469 | } |
470 | ||
cafb168a SR |
471 | static int ftrace_profile_init(void) |
472 | { | |
473 | int cpu; | |
474 | int ret = 0; | |
475 | ||
476 | for_each_online_cpu(cpu) { | |
477 | ret = ftrace_profile_init_cpu(cpu); | |
478 | if (ret) | |
479 | break; | |
480 | } | |
481 | ||
482 | return ret; | |
483 | } | |
484 | ||
493762fc | 485 | /* interrupts must be disabled */ |
cafb168a SR |
486 | static struct ftrace_profile * |
487 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 488 | { |
493762fc | 489 | struct ftrace_profile *rec; |
bac429f0 SR |
490 | struct hlist_head *hhd; |
491 | struct hlist_node *n; | |
bac429f0 SR |
492 | unsigned long key; |
493 | ||
bac429f0 | 494 | key = hash_long(ip, ftrace_profile_bits); |
cafb168a | 495 | hhd = &stat->hash[key]; |
bac429f0 SR |
496 | |
497 | if (hlist_empty(hhd)) | |
498 | return NULL; | |
499 | ||
bac429f0 SR |
500 | hlist_for_each_entry_rcu(rec, n, hhd, node) { |
501 | if (rec->ip == ip) | |
493762fc SR |
502 | return rec; |
503 | } | |
504 | ||
505 | return NULL; | |
506 | } | |
507 | ||
cafb168a SR |
508 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
509 | struct ftrace_profile *rec) | |
493762fc SR |
510 | { |
511 | unsigned long key; | |
512 | ||
513 | key = hash_long(rec->ip, ftrace_profile_bits); | |
cafb168a | 514 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
515 | } |
516 | ||
517 | /* Interrupts must be disabled calling this */ | |
518 | static struct ftrace_profile * | |
cafb168a SR |
519 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, |
520 | unsigned long ip, bool alloc_safe) | |
493762fc SR |
521 | { |
522 | struct ftrace_profile *rec = NULL; | |
523 | ||
524 | /* prevent recursion */ | |
cafb168a | 525 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
526 | goto out; |
527 | ||
493762fc | 528 | /* Try to always keep another page available */ |
cafb168a SR |
529 | if (!stat->pages->next && alloc_safe) |
530 | stat->pages->next = (void *)get_zeroed_page(GFP_ATOMIC); | |
493762fc SR |
531 | |
532 | /* | |
533 | * Try to find the function again since another | |
534 | * task on another CPU could have added it | |
535 | */ | |
cafb168a | 536 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 537 | if (rec) |
cafb168a | 538 | goto out; |
493762fc | 539 | |
cafb168a SR |
540 | if (stat->pages->index == PROFILES_PER_PAGE) { |
541 | if (!stat->pages->next) | |
542 | goto out; | |
543 | stat->pages = stat->pages->next; | |
bac429f0 | 544 | } |
493762fc | 545 | |
cafb168a | 546 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 547 | rec->ip = ip; |
cafb168a | 548 | ftrace_add_profile(stat, rec); |
493762fc | 549 | |
bac429f0 | 550 | out: |
cafb168a | 551 | atomic_dec(&stat->disabled); |
bac429f0 SR |
552 | |
553 | return rec; | |
554 | } | |
555 | ||
493762fc SR |
556 | /* |
557 | * If we are not in an interrupt, or softirq and | |
558 | * and interrupts are disabled and preemption is not enabled | |
559 | * (not in a spinlock) then it should be safe to allocate memory. | |
560 | */ | |
561 | static bool ftrace_safe_to_allocate(void) | |
562 | { | |
563 | return !in_interrupt() && irqs_disabled() && !preempt_count(); | |
564 | } | |
565 | ||
bac429f0 SR |
566 | static void |
567 | function_profile_call(unsigned long ip, unsigned long parent_ip) | |
568 | { | |
cafb168a | 569 | struct ftrace_profile_stat *stat; |
493762fc | 570 | struct ftrace_profile *rec; |
bac429f0 | 571 | unsigned long flags; |
493762fc | 572 | bool alloc_safe; |
bac429f0 SR |
573 | |
574 | if (!ftrace_profile_enabled) | |
575 | return; | |
576 | ||
493762fc SR |
577 | alloc_safe = ftrace_safe_to_allocate(); |
578 | ||
bac429f0 | 579 | local_irq_save(flags); |
cafb168a SR |
580 | |
581 | stat = &__get_cpu_var(ftrace_profile_stats); | |
582 | if (!stat->hash) | |
583 | goto out; | |
584 | ||
585 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 586 | if (!rec) { |
cafb168a | 587 | rec = ftrace_profile_alloc(stat, ip, alloc_safe); |
493762fc SR |
588 | if (!rec) |
589 | goto out; | |
590 | } | |
bac429f0 SR |
591 | |
592 | rec->counter++; | |
593 | out: | |
594 | local_irq_restore(flags); | |
595 | } | |
596 | ||
0706f1c4 SR |
597 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
598 | static int profile_graph_entry(struct ftrace_graph_ent *trace) | |
599 | { | |
600 | function_profile_call(trace->func, 0); | |
601 | return 1; | |
602 | } | |
603 | ||
604 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
605 | { | |
cafb168a | 606 | struct ftrace_profile_stat *stat; |
a2a16d6a | 607 | unsigned long long calltime; |
0706f1c4 | 608 | struct ftrace_profile *rec; |
cafb168a | 609 | unsigned long flags; |
0706f1c4 SR |
610 | |
611 | local_irq_save(flags); | |
cafb168a SR |
612 | stat = &__get_cpu_var(ftrace_profile_stats); |
613 | if (!stat->hash) | |
614 | goto out; | |
615 | ||
a2a16d6a SR |
616 | calltime = trace->rettime - trace->calltime; |
617 | ||
618 | if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) { | |
619 | int index; | |
620 | ||
621 | index = trace->depth; | |
622 | ||
623 | /* Append this call time to the parent time to subtract */ | |
624 | if (index) | |
625 | current->ret_stack[index - 1].subtime += calltime; | |
626 | ||
627 | if (current->ret_stack[index].subtime < calltime) | |
628 | calltime -= current->ret_stack[index].subtime; | |
629 | else | |
630 | calltime = 0; | |
631 | } | |
632 | ||
cafb168a | 633 | rec = ftrace_find_profiled_func(stat, trace->func); |
0706f1c4 | 634 | if (rec) |
a2a16d6a SR |
635 | rec->time += calltime; |
636 | ||
cafb168a | 637 | out: |
0706f1c4 SR |
638 | local_irq_restore(flags); |
639 | } | |
640 | ||
641 | static int register_ftrace_profiler(void) | |
642 | { | |
643 | return register_ftrace_graph(&profile_graph_return, | |
644 | &profile_graph_entry); | |
645 | } | |
646 | ||
647 | static void unregister_ftrace_profiler(void) | |
648 | { | |
649 | unregister_ftrace_graph(); | |
650 | } | |
651 | #else | |
bac429f0 SR |
652 | static struct ftrace_ops ftrace_profile_ops __read_mostly = |
653 | { | |
654 | .func = function_profile_call, | |
655 | }; | |
656 | ||
0706f1c4 SR |
657 | static int register_ftrace_profiler(void) |
658 | { | |
659 | return register_ftrace_function(&ftrace_profile_ops); | |
660 | } | |
661 | ||
662 | static void unregister_ftrace_profiler(void) | |
663 | { | |
664 | unregister_ftrace_function(&ftrace_profile_ops); | |
665 | } | |
666 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
667 | ||
bac429f0 SR |
668 | static ssize_t |
669 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
670 | size_t cnt, loff_t *ppos) | |
671 | { | |
672 | unsigned long val; | |
673 | char buf[64]; | |
674 | int ret; | |
675 | ||
bac429f0 SR |
676 | if (cnt >= sizeof(buf)) |
677 | return -EINVAL; | |
678 | ||
679 | if (copy_from_user(&buf, ubuf, cnt)) | |
680 | return -EFAULT; | |
681 | ||
682 | buf[cnt] = 0; | |
683 | ||
684 | ret = strict_strtoul(buf, 10, &val); | |
685 | if (ret < 0) | |
686 | return ret; | |
687 | ||
688 | val = !!val; | |
689 | ||
690 | mutex_lock(&ftrace_profile_lock); | |
691 | if (ftrace_profile_enabled ^ val) { | |
692 | if (val) { | |
493762fc SR |
693 | ret = ftrace_profile_init(); |
694 | if (ret < 0) { | |
695 | cnt = ret; | |
696 | goto out; | |
697 | } | |
698 | ||
0706f1c4 SR |
699 | ret = register_ftrace_profiler(); |
700 | if (ret < 0) { | |
701 | cnt = ret; | |
702 | goto out; | |
703 | } | |
bac429f0 SR |
704 | ftrace_profile_enabled = 1; |
705 | } else { | |
706 | ftrace_profile_enabled = 0; | |
0706f1c4 | 707 | unregister_ftrace_profiler(); |
bac429f0 SR |
708 | } |
709 | } | |
493762fc | 710 | out: |
bac429f0 SR |
711 | mutex_unlock(&ftrace_profile_lock); |
712 | ||
713 | filp->f_pos += cnt; | |
714 | ||
715 | return cnt; | |
716 | } | |
717 | ||
493762fc SR |
718 | static ssize_t |
719 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
720 | size_t cnt, loff_t *ppos) | |
721 | { | |
722 | char buf[64]; | |
723 | int r; | |
724 | ||
725 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
726 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
727 | } | |
728 | ||
bac429f0 SR |
729 | static const struct file_operations ftrace_profile_fops = { |
730 | .open = tracing_open_generic, | |
731 | .read = ftrace_profile_read, | |
732 | .write = ftrace_profile_write, | |
733 | }; | |
734 | ||
cafb168a SR |
735 | /* used to initialize the real stat files */ |
736 | static struct tracer_stat function_stats __initdata = { | |
737 | .name = "functions", | |
738 | .stat_start = function_stat_start, | |
739 | .stat_next = function_stat_next, | |
740 | .stat_cmp = function_stat_cmp, | |
741 | .stat_headers = function_stat_headers, | |
742 | .stat_show = function_stat_show | |
743 | }; | |
744 | ||
bac429f0 SR |
745 | static void ftrace_profile_debugfs(struct dentry *d_tracer) |
746 | { | |
cafb168a | 747 | struct ftrace_profile_stat *stat; |
bac429f0 | 748 | struct dentry *entry; |
cafb168a | 749 | char *name; |
bac429f0 | 750 | int ret; |
cafb168a SR |
751 | int cpu; |
752 | ||
753 | for_each_possible_cpu(cpu) { | |
754 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
755 | ||
756 | /* allocate enough for function name + cpu number */ | |
757 | name = kmalloc(32, GFP_KERNEL); | |
758 | if (!name) { | |
759 | /* | |
760 | * The files created are permanent, if something happens | |
761 | * we still do not free memory. | |
762 | */ | |
763 | kfree(stat); | |
764 | WARN(1, | |
765 | "Could not allocate stat file for cpu %d\n", | |
766 | cpu); | |
767 | return; | |
768 | } | |
769 | stat->stat = function_stats; | |
770 | snprintf(name, 32, "function%d", cpu); | |
771 | stat->stat.name = name; | |
772 | ret = register_stat_tracer(&stat->stat); | |
773 | if (ret) { | |
774 | WARN(1, | |
775 | "Could not register function stat for cpu %d\n", | |
776 | cpu); | |
777 | kfree(name); | |
778 | return; | |
779 | } | |
bac429f0 SR |
780 | } |
781 | ||
782 | entry = debugfs_create_file("function_profile_enabled", 0644, | |
783 | d_tracer, NULL, &ftrace_profile_fops); | |
784 | if (!entry) | |
785 | pr_warning("Could not create debugfs " | |
786 | "'function_profile_enabled' entry\n"); | |
787 | } | |
788 | ||
bac429f0 | 789 | #else /* CONFIG_FUNCTION_PROFILER */ |
bac429f0 SR |
790 | static void ftrace_profile_debugfs(struct dentry *d_tracer) |
791 | { | |
792 | } | |
bac429f0 SR |
793 | #endif /* CONFIG_FUNCTION_PROFILER */ |
794 | ||
493762fc SR |
795 | /* set when tracing only a pid */ |
796 | struct pid *ftrace_pid_trace; | |
797 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; | |
798 | ||
799 | #ifdef CONFIG_DYNAMIC_FTRACE | |
800 | ||
801 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD | |
802 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
803 | #endif | |
804 | ||
805 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; | |
806 | ||
807 | struct ftrace_func_probe { | |
808 | struct hlist_node node; | |
809 | struct ftrace_probe_ops *ops; | |
810 | unsigned long flags; | |
811 | unsigned long ip; | |
812 | void *data; | |
813 | struct rcu_head rcu; | |
814 | }; | |
815 | ||
816 | enum { | |
817 | FTRACE_ENABLE_CALLS = (1 << 0), | |
818 | FTRACE_DISABLE_CALLS = (1 << 1), | |
819 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
820 | FTRACE_ENABLE_MCOUNT = (1 << 3), | |
821 | FTRACE_DISABLE_MCOUNT = (1 << 4), | |
822 | FTRACE_START_FUNC_RET = (1 << 5), | |
823 | FTRACE_STOP_FUNC_RET = (1 << 6), | |
824 | }; | |
825 | ||
826 | static int ftrace_filtered; | |
827 | ||
828 | static struct dyn_ftrace *ftrace_new_addrs; | |
829 | ||
830 | static DEFINE_MUTEX(ftrace_regex_lock); | |
831 | ||
832 | struct ftrace_page { | |
833 | struct ftrace_page *next; | |
834 | int index; | |
835 | struct dyn_ftrace records[]; | |
836 | }; | |
837 | ||
838 | #define ENTRIES_PER_PAGE \ | |
839 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
840 | ||
841 | /* estimate from running different kernels */ | |
842 | #define NR_TO_INIT 10000 | |
843 | ||
844 | static struct ftrace_page *ftrace_pages_start; | |
845 | static struct ftrace_page *ftrace_pages; | |
846 | ||
847 | static struct dyn_ftrace *ftrace_free_records; | |
848 | ||
849 | /* | |
850 | * This is a double for. Do not use 'break' to break out of the loop, | |
851 | * you must use a goto. | |
852 | */ | |
853 | #define do_for_each_ftrace_rec(pg, rec) \ | |
854 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
855 | int _____i; \ | |
856 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
857 | rec = &pg->records[_____i]; | |
858 | ||
859 | #define while_for_each_ftrace_rec() \ | |
860 | } \ | |
861 | } | |
862 | ||
ecea656d | 863 | #ifdef CONFIG_KPROBES |
f17845e5 IM |
864 | |
865 | static int frozen_record_count; | |
866 | ||
ecea656d AS |
867 | static inline void freeze_record(struct dyn_ftrace *rec) |
868 | { | |
869 | if (!(rec->flags & FTRACE_FL_FROZEN)) { | |
870 | rec->flags |= FTRACE_FL_FROZEN; | |
871 | frozen_record_count++; | |
872 | } | |
873 | } | |
874 | ||
875 | static inline void unfreeze_record(struct dyn_ftrace *rec) | |
876 | { | |
877 | if (rec->flags & FTRACE_FL_FROZEN) { | |
878 | rec->flags &= ~FTRACE_FL_FROZEN; | |
879 | frozen_record_count--; | |
880 | } | |
881 | } | |
882 | ||
883 | static inline int record_frozen(struct dyn_ftrace *rec) | |
884 | { | |
885 | return rec->flags & FTRACE_FL_FROZEN; | |
886 | } | |
887 | #else | |
888 | # define freeze_record(rec) ({ 0; }) | |
889 | # define unfreeze_record(rec) ({ 0; }) | |
890 | # define record_frozen(rec) ({ 0; }) | |
891 | #endif /* CONFIG_KPROBES */ | |
892 | ||
e309b41d | 893 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
37ad5084 | 894 | { |
ee000b7f | 895 | rec->freelist = ftrace_free_records; |
37ad5084 SR |
896 | ftrace_free_records = rec; |
897 | rec->flags |= FTRACE_FL_FREE; | |
898 | } | |
899 | ||
fed1939c SR |
900 | void ftrace_release(void *start, unsigned long size) |
901 | { | |
902 | struct dyn_ftrace *rec; | |
903 | struct ftrace_page *pg; | |
904 | unsigned long s = (unsigned long)start; | |
905 | unsigned long e = s + size; | |
fed1939c | 906 | |
00fd61ae | 907 | if (ftrace_disabled || !start) |
fed1939c SR |
908 | return; |
909 | ||
52baf119 | 910 | mutex_lock(&ftrace_lock); |
265c831c | 911 | do_for_each_ftrace_rec(pg, rec) { |
b00f0b6d | 912 | if ((rec->ip >= s) && (rec->ip < e) && |
493762fc | 913 | !(rec->flags & FTRACE_FL_FREE)) |
265c831c SR |
914 | ftrace_free_rec(rec); |
915 | } while_for_each_ftrace_rec(); | |
52baf119 | 916 | mutex_unlock(&ftrace_lock); |
fed1939c SR |
917 | } |
918 | ||
e309b41d | 919 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 920 | { |
37ad5084 SR |
921 | struct dyn_ftrace *rec; |
922 | ||
923 | /* First check for freed records */ | |
924 | if (ftrace_free_records) { | |
925 | rec = ftrace_free_records; | |
926 | ||
37ad5084 | 927 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
6912896e | 928 | FTRACE_WARN_ON_ONCE(1); |
37ad5084 SR |
929 | ftrace_free_records = NULL; |
930 | return NULL; | |
931 | } | |
932 | ||
ee000b7f | 933 | ftrace_free_records = rec->freelist; |
37ad5084 SR |
934 | memset(rec, 0, sizeof(*rec)); |
935 | return rec; | |
936 | } | |
937 | ||
3c1720f0 | 938 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
08f5ac90 SR |
939 | if (!ftrace_pages->next) { |
940 | /* allocate another page */ | |
941 | ftrace_pages->next = | |
942 | (void *)get_zeroed_page(GFP_KERNEL); | |
943 | if (!ftrace_pages->next) | |
944 | return NULL; | |
945 | } | |
3c1720f0 SR |
946 | ftrace_pages = ftrace_pages->next; |
947 | } | |
948 | ||
949 | return &ftrace_pages->records[ftrace_pages->index++]; | |
950 | } | |
951 | ||
08f5ac90 | 952 | static struct dyn_ftrace * |
d61f82d0 | 953 | ftrace_record_ip(unsigned long ip) |
3d083395 | 954 | { |
08f5ac90 | 955 | struct dyn_ftrace *rec; |
3d083395 | 956 | |
f3c7ac40 | 957 | if (ftrace_disabled) |
08f5ac90 | 958 | return NULL; |
3d083395 | 959 | |
08f5ac90 SR |
960 | rec = ftrace_alloc_dyn_node(ip); |
961 | if (!rec) | |
962 | return NULL; | |
3d083395 | 963 | |
08f5ac90 | 964 | rec->ip = ip; |
ee000b7f | 965 | rec->newlist = ftrace_new_addrs; |
e94142a6 | 966 | ftrace_new_addrs = rec; |
3d083395 | 967 | |
08f5ac90 | 968 | return rec; |
3d083395 SR |
969 | } |
970 | ||
b17e8a37 SR |
971 | static void print_ip_ins(const char *fmt, unsigned char *p) |
972 | { | |
973 | int i; | |
974 | ||
975 | printk(KERN_CONT "%s", fmt); | |
976 | ||
977 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
978 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
979 | } | |
980 | ||
31e88909 | 981 | static void ftrace_bug(int failed, unsigned long ip) |
b17e8a37 SR |
982 | { |
983 | switch (failed) { | |
984 | case -EFAULT: | |
985 | FTRACE_WARN_ON_ONCE(1); | |
986 | pr_info("ftrace faulted on modifying "); | |
987 | print_ip_sym(ip); | |
988 | break; | |
989 | case -EINVAL: | |
990 | FTRACE_WARN_ON_ONCE(1); | |
991 | pr_info("ftrace failed to modify "); | |
992 | print_ip_sym(ip); | |
b17e8a37 | 993 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
994 | printk(KERN_CONT "\n"); |
995 | break; | |
996 | case -EPERM: | |
997 | FTRACE_WARN_ON_ONCE(1); | |
998 | pr_info("ftrace faulted on writing "); | |
999 | print_ip_sym(ip); | |
1000 | break; | |
1001 | default: | |
1002 | FTRACE_WARN_ON_ONCE(1); | |
1003 | pr_info("ftrace faulted on unknown error "); | |
1004 | print_ip_sym(ip); | |
1005 | } | |
1006 | } | |
1007 | ||
3c1720f0 | 1008 | |
0eb96701 | 1009 | static int |
31e88909 | 1010 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) |
5072c59f | 1011 | { |
e7d3737e | 1012 | unsigned long ftrace_addr; |
6a24a244 | 1013 | unsigned long ip, fl; |
e7d3737e | 1014 | |
f0001207 | 1015 | ftrace_addr = (unsigned long)FTRACE_ADDR; |
5072c59f SR |
1016 | |
1017 | ip = rec->ip; | |
1018 | ||
982c350b SR |
1019 | /* |
1020 | * If this record is not to be traced and | |
1021 | * it is not enabled then do nothing. | |
1022 | * | |
1023 | * If this record is not to be traced and | |
57794a9d | 1024 | * it is enabled then disable it. |
982c350b SR |
1025 | * |
1026 | */ | |
1027 | if (rec->flags & FTRACE_FL_NOTRACE) { | |
1028 | if (rec->flags & FTRACE_FL_ENABLED) | |
1029 | rec->flags &= ~FTRACE_FL_ENABLED; | |
1030 | else | |
1031 | return 0; | |
1032 | ||
1033 | } else if (ftrace_filtered && enable) { | |
5072c59f | 1034 | /* |
982c350b | 1035 | * Filtering is on: |
5072c59f | 1036 | */ |
a4500b84 | 1037 | |
982c350b | 1038 | fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED); |
5072c59f | 1039 | |
982c350b SR |
1040 | /* Record is filtered and enabled, do nothing */ |
1041 | if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) | |
0eb96701 | 1042 | return 0; |
5072c59f | 1043 | |
57794a9d | 1044 | /* Record is not filtered or enabled, do nothing */ |
982c350b SR |
1045 | if (!fl) |
1046 | return 0; | |
1047 | ||
1048 | /* Record is not filtered but enabled, disable it */ | |
1049 | if (fl == FTRACE_FL_ENABLED) | |
5072c59f | 1050 | rec->flags &= ~FTRACE_FL_ENABLED; |
982c350b SR |
1051 | else |
1052 | /* Otherwise record is filtered but not enabled, enable it */ | |
5072c59f | 1053 | rec->flags |= FTRACE_FL_ENABLED; |
5072c59f | 1054 | } else { |
982c350b | 1055 | /* Disable or not filtered */ |
5072c59f | 1056 | |
41c52c0d | 1057 | if (enable) { |
982c350b | 1058 | /* if record is enabled, do nothing */ |
5072c59f | 1059 | if (rec->flags & FTRACE_FL_ENABLED) |
0eb96701 | 1060 | return 0; |
982c350b | 1061 | |
5072c59f | 1062 | rec->flags |= FTRACE_FL_ENABLED; |
982c350b | 1063 | |
5072c59f | 1064 | } else { |
982c350b | 1065 | |
57794a9d | 1066 | /* if record is not enabled, do nothing */ |
5072c59f | 1067 | if (!(rec->flags & FTRACE_FL_ENABLED)) |
0eb96701 | 1068 | return 0; |
982c350b | 1069 | |
5072c59f SR |
1070 | rec->flags &= ~FTRACE_FL_ENABLED; |
1071 | } | |
1072 | } | |
1073 | ||
982c350b | 1074 | if (rec->flags & FTRACE_FL_ENABLED) |
e7d3737e | 1075 | return ftrace_make_call(rec, ftrace_addr); |
31e88909 | 1076 | else |
e7d3737e | 1077 | return ftrace_make_nop(NULL, rec, ftrace_addr); |
5072c59f SR |
1078 | } |
1079 | ||
e309b41d | 1080 | static void ftrace_replace_code(int enable) |
3c1720f0 | 1081 | { |
3c1720f0 SR |
1082 | struct dyn_ftrace *rec; |
1083 | struct ftrace_page *pg; | |
6a24a244 | 1084 | int failed; |
3c1720f0 | 1085 | |
265c831c SR |
1086 | do_for_each_ftrace_rec(pg, rec) { |
1087 | /* | |
fa9d13cf Z |
1088 | * Skip over free records, records that have |
1089 | * failed and not converted. | |
265c831c SR |
1090 | */ |
1091 | if (rec->flags & FTRACE_FL_FREE || | |
fa9d13cf | 1092 | rec->flags & FTRACE_FL_FAILED || |
03303549 | 1093 | !(rec->flags & FTRACE_FL_CONVERTED)) |
265c831c SR |
1094 | continue; |
1095 | ||
1096 | /* ignore updates to this record's mcount site */ | |
1097 | if (get_kprobe((void *)rec->ip)) { | |
1098 | freeze_record(rec); | |
1099 | continue; | |
1100 | } else { | |
1101 | unfreeze_record(rec); | |
1102 | } | |
f22f9a89 | 1103 | |
265c831c | 1104 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 1105 | if (failed) { |
265c831c SR |
1106 | rec->flags |= FTRACE_FL_FAILED; |
1107 | if ((system_state == SYSTEM_BOOTING) || | |
1108 | !core_kernel_text(rec->ip)) { | |
1109 | ftrace_free_rec(rec); | |
4377245a | 1110 | } else { |
265c831c | 1111 | ftrace_bug(failed, rec->ip); |
4377245a SR |
1112 | /* Stop processing */ |
1113 | return; | |
1114 | } | |
3c1720f0 | 1115 | } |
265c831c | 1116 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
1117 | } |
1118 | ||
492a7ea5 | 1119 | static int |
31e88909 | 1120 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 SR |
1121 | { |
1122 | unsigned long ip; | |
593eb8a2 | 1123 | int ret; |
3c1720f0 SR |
1124 | |
1125 | ip = rec->ip; | |
1126 | ||
25aac9dc | 1127 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 1128 | if (ret) { |
31e88909 | 1129 | ftrace_bug(ret, ip); |
3c1720f0 | 1130 | rec->flags |= FTRACE_FL_FAILED; |
492a7ea5 | 1131 | return 0; |
37ad5084 | 1132 | } |
492a7ea5 | 1133 | return 1; |
3c1720f0 SR |
1134 | } |
1135 | ||
000ab691 SR |
1136 | /* |
1137 | * archs can override this function if they must do something | |
1138 | * before the modifying code is performed. | |
1139 | */ | |
1140 | int __weak ftrace_arch_code_modify_prepare(void) | |
1141 | { | |
1142 | return 0; | |
1143 | } | |
1144 | ||
1145 | /* | |
1146 | * archs can override this function if they must do something | |
1147 | * after the modifying code is performed. | |
1148 | */ | |
1149 | int __weak ftrace_arch_code_modify_post_process(void) | |
1150 | { | |
1151 | return 0; | |
1152 | } | |
1153 | ||
e309b41d | 1154 | static int __ftrace_modify_code(void *data) |
3d083395 | 1155 | { |
d61f82d0 SR |
1156 | int *command = data; |
1157 | ||
a3583244 | 1158 | if (*command & FTRACE_ENABLE_CALLS) |
d61f82d0 | 1159 | ftrace_replace_code(1); |
a3583244 | 1160 | else if (*command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
1161 | ftrace_replace_code(0); |
1162 | ||
1163 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
1164 | ftrace_update_ftrace_func(ftrace_trace_function); | |
1165 | ||
5a45cfe1 SR |
1166 | if (*command & FTRACE_START_FUNC_RET) |
1167 | ftrace_enable_ftrace_graph_caller(); | |
1168 | else if (*command & FTRACE_STOP_FUNC_RET) | |
1169 | ftrace_disable_ftrace_graph_caller(); | |
1170 | ||
d61f82d0 | 1171 | return 0; |
3d083395 SR |
1172 | } |
1173 | ||
e309b41d | 1174 | static void ftrace_run_update_code(int command) |
3d083395 | 1175 | { |
000ab691 SR |
1176 | int ret; |
1177 | ||
1178 | ret = ftrace_arch_code_modify_prepare(); | |
1179 | FTRACE_WARN_ON(ret); | |
1180 | if (ret) | |
1181 | return; | |
1182 | ||
784e2d76 | 1183 | stop_machine(__ftrace_modify_code, &command, NULL); |
000ab691 SR |
1184 | |
1185 | ret = ftrace_arch_code_modify_post_process(); | |
1186 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
1187 | } |
1188 | ||
d61f82d0 | 1189 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 1190 | static int ftrace_start_up; |
df4fc315 SR |
1191 | |
1192 | static void ftrace_startup_enable(int command) | |
1193 | { | |
1194 | if (saved_ftrace_func != ftrace_trace_function) { | |
1195 | saved_ftrace_func = ftrace_trace_function; | |
1196 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1197 | } | |
1198 | ||
1199 | if (!command || !ftrace_enabled) | |
1200 | return; | |
1201 | ||
1202 | ftrace_run_update_code(command); | |
1203 | } | |
d61f82d0 | 1204 | |
5a45cfe1 | 1205 | static void ftrace_startup(int command) |
3d083395 | 1206 | { |
4eebcc81 SR |
1207 | if (unlikely(ftrace_disabled)) |
1208 | return; | |
1209 | ||
60a7ecf4 | 1210 | ftrace_start_up++; |
982c350b | 1211 | command |= FTRACE_ENABLE_CALLS; |
d61f82d0 | 1212 | |
df4fc315 | 1213 | ftrace_startup_enable(command); |
3d083395 SR |
1214 | } |
1215 | ||
5a45cfe1 | 1216 | static void ftrace_shutdown(int command) |
3d083395 | 1217 | { |
4eebcc81 SR |
1218 | if (unlikely(ftrace_disabled)) |
1219 | return; | |
1220 | ||
60a7ecf4 SR |
1221 | ftrace_start_up--; |
1222 | if (!ftrace_start_up) | |
d61f82d0 | 1223 | command |= FTRACE_DISABLE_CALLS; |
3d083395 | 1224 | |
d61f82d0 SR |
1225 | if (saved_ftrace_func != ftrace_trace_function) { |
1226 | saved_ftrace_func = ftrace_trace_function; | |
1227 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1228 | } | |
3d083395 | 1229 | |
d61f82d0 | 1230 | if (!command || !ftrace_enabled) |
e6ea44e9 | 1231 | return; |
d61f82d0 SR |
1232 | |
1233 | ftrace_run_update_code(command); | |
3d083395 SR |
1234 | } |
1235 | ||
e309b41d | 1236 | static void ftrace_startup_sysctl(void) |
b0fc494f | 1237 | { |
d61f82d0 SR |
1238 | int command = FTRACE_ENABLE_MCOUNT; |
1239 | ||
4eebcc81 SR |
1240 | if (unlikely(ftrace_disabled)) |
1241 | return; | |
1242 | ||
d61f82d0 SR |
1243 | /* Force update next time */ |
1244 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
1245 | /* ftrace_start_up is true if we want ftrace running */ |
1246 | if (ftrace_start_up) | |
d61f82d0 SR |
1247 | command |= FTRACE_ENABLE_CALLS; |
1248 | ||
1249 | ftrace_run_update_code(command); | |
b0fc494f SR |
1250 | } |
1251 | ||
e309b41d | 1252 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 1253 | { |
d61f82d0 SR |
1254 | int command = FTRACE_DISABLE_MCOUNT; |
1255 | ||
4eebcc81 SR |
1256 | if (unlikely(ftrace_disabled)) |
1257 | return; | |
1258 | ||
60a7ecf4 SR |
1259 | /* ftrace_start_up is true if ftrace is running */ |
1260 | if (ftrace_start_up) | |
d61f82d0 SR |
1261 | command |= FTRACE_DISABLE_CALLS; |
1262 | ||
1263 | ftrace_run_update_code(command); | |
b0fc494f SR |
1264 | } |
1265 | ||
3d083395 SR |
1266 | static cycle_t ftrace_update_time; |
1267 | static unsigned long ftrace_update_cnt; | |
1268 | unsigned long ftrace_update_tot_cnt; | |
1269 | ||
31e88909 | 1270 | static int ftrace_update_code(struct module *mod) |
3d083395 | 1271 | { |
e94142a6 | 1272 | struct dyn_ftrace *p; |
f22f9a89 | 1273 | cycle_t start, stop; |
3d083395 | 1274 | |
750ed1a4 | 1275 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1276 | ftrace_update_cnt = 0; |
1277 | ||
e94142a6 | 1278 | while (ftrace_new_addrs) { |
3d083395 | 1279 | |
08f5ac90 SR |
1280 | /* If something went wrong, bail without enabling anything */ |
1281 | if (unlikely(ftrace_disabled)) | |
1282 | return -1; | |
f22f9a89 | 1283 | |
e94142a6 | 1284 | p = ftrace_new_addrs; |
ee000b7f | 1285 | ftrace_new_addrs = p->newlist; |
e94142a6 | 1286 | p->flags = 0L; |
f22f9a89 | 1287 | |
08f5ac90 | 1288 | /* convert record (i.e, patch mcount-call with NOP) */ |
31e88909 | 1289 | if (ftrace_code_disable(mod, p)) { |
08f5ac90 SR |
1290 | p->flags |= FTRACE_FL_CONVERTED; |
1291 | ftrace_update_cnt++; | |
1292 | } else | |
1293 | ftrace_free_rec(p); | |
3d083395 SR |
1294 | } |
1295 | ||
750ed1a4 | 1296 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1297 | ftrace_update_time = stop - start; |
1298 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
1299 | ||
16444a8a ACM |
1300 | return 0; |
1301 | } | |
1302 | ||
68bf21aa | 1303 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
1304 | { |
1305 | struct ftrace_page *pg; | |
1306 | int cnt; | |
1307 | int i; | |
3c1720f0 SR |
1308 | |
1309 | /* allocate a few pages */ | |
1310 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
1311 | if (!ftrace_pages_start) | |
1312 | return -1; | |
1313 | ||
1314 | /* | |
1315 | * Allocate a few more pages. | |
1316 | * | |
1317 | * TODO: have some parser search vmlinux before | |
1318 | * final linking to find all calls to ftrace. | |
1319 | * Then we can: | |
1320 | * a) know how many pages to allocate. | |
1321 | * and/or | |
1322 | * b) set up the table then. | |
1323 | * | |
1324 | * The dynamic code is still necessary for | |
1325 | * modules. | |
1326 | */ | |
1327 | ||
1328 | pg = ftrace_pages = ftrace_pages_start; | |
1329 | ||
68bf21aa | 1330 | cnt = num_to_init / ENTRIES_PER_PAGE; |
08f5ac90 | 1331 | pr_info("ftrace: allocating %ld entries in %d pages\n", |
5821e1b7 | 1332 | num_to_init, cnt + 1); |
3c1720f0 SR |
1333 | |
1334 | for (i = 0; i < cnt; i++) { | |
1335 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
1336 | ||
1337 | /* If we fail, we'll try later anyway */ | |
1338 | if (!pg->next) | |
1339 | break; | |
1340 | ||
1341 | pg = pg->next; | |
1342 | } | |
1343 | ||
1344 | return 0; | |
1345 | } | |
1346 | ||
5072c59f SR |
1347 | enum { |
1348 | FTRACE_ITER_FILTER = (1 << 0), | |
1349 | FTRACE_ITER_CONT = (1 << 1), | |
41c52c0d | 1350 | FTRACE_ITER_NOTRACE = (1 << 2), |
eb9a7bf0 | 1351 | FTRACE_ITER_FAILURES = (1 << 3), |
0c75a3ed | 1352 | FTRACE_ITER_PRINTALL = (1 << 4), |
8fc0c701 | 1353 | FTRACE_ITER_HASH = (1 << 5), |
5072c59f SR |
1354 | }; |
1355 | ||
1356 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
1357 | ||
1358 | struct ftrace_iterator { | |
5072c59f | 1359 | struct ftrace_page *pg; |
8fc0c701 | 1360 | int hidx; |
431aa3fb | 1361 | int idx; |
5072c59f SR |
1362 | unsigned flags; |
1363 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
1364 | unsigned buffer_idx; | |
1365 | unsigned filtered; | |
1366 | }; | |
1367 | ||
8fc0c701 SR |
1368 | static void * |
1369 | t_hash_next(struct seq_file *m, void *v, loff_t *pos) | |
1370 | { | |
1371 | struct ftrace_iterator *iter = m->private; | |
1372 | struct hlist_node *hnd = v; | |
1373 | struct hlist_head *hhd; | |
1374 | ||
1375 | WARN_ON(!(iter->flags & FTRACE_ITER_HASH)); | |
1376 | ||
1377 | (*pos)++; | |
1378 | ||
1379 | retry: | |
1380 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
1381 | return NULL; | |
1382 | ||
1383 | hhd = &ftrace_func_hash[iter->hidx]; | |
1384 | ||
1385 | if (hlist_empty(hhd)) { | |
1386 | iter->hidx++; | |
1387 | hnd = NULL; | |
1388 | goto retry; | |
1389 | } | |
1390 | ||
1391 | if (!hnd) | |
1392 | hnd = hhd->first; | |
1393 | else { | |
1394 | hnd = hnd->next; | |
1395 | if (!hnd) { | |
1396 | iter->hidx++; | |
1397 | goto retry; | |
1398 | } | |
1399 | } | |
1400 | ||
1401 | return hnd; | |
1402 | } | |
1403 | ||
1404 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
1405 | { | |
1406 | struct ftrace_iterator *iter = m->private; | |
1407 | void *p = NULL; | |
1408 | ||
1409 | iter->flags |= FTRACE_ITER_HASH; | |
1410 | ||
1411 | return t_hash_next(m, p, pos); | |
1412 | } | |
1413 | ||
1414 | static int t_hash_show(struct seq_file *m, void *v) | |
1415 | { | |
b6887d79 | 1416 | struct ftrace_func_probe *rec; |
8fc0c701 SR |
1417 | struct hlist_node *hnd = v; |
1418 | char str[KSYM_SYMBOL_LEN]; | |
1419 | ||
b6887d79 | 1420 | rec = hlist_entry(hnd, struct ftrace_func_probe, node); |
8fc0c701 | 1421 | |
809dcf29 SR |
1422 | if (rec->ops->print) |
1423 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
1424 | ||
8fc0c701 SR |
1425 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
1426 | seq_printf(m, "%s:", str); | |
1427 | ||
1428 | kallsyms_lookup((unsigned long)rec->ops->func, NULL, NULL, NULL, str); | |
1429 | seq_printf(m, "%s", str); | |
1430 | ||
1431 | if (rec->data) | |
1432 | seq_printf(m, ":%p", rec->data); | |
1433 | seq_putc(m, '\n'); | |
1434 | ||
1435 | return 0; | |
1436 | } | |
1437 | ||
e309b41d | 1438 | static void * |
5072c59f SR |
1439 | t_next(struct seq_file *m, void *v, loff_t *pos) |
1440 | { | |
1441 | struct ftrace_iterator *iter = m->private; | |
1442 | struct dyn_ftrace *rec = NULL; | |
1443 | ||
8fc0c701 SR |
1444 | if (iter->flags & FTRACE_ITER_HASH) |
1445 | return t_hash_next(m, v, pos); | |
1446 | ||
5072c59f SR |
1447 | (*pos)++; |
1448 | ||
0c75a3ed SR |
1449 | if (iter->flags & FTRACE_ITER_PRINTALL) |
1450 | return NULL; | |
1451 | ||
5072c59f SR |
1452 | retry: |
1453 | if (iter->idx >= iter->pg->index) { | |
1454 | if (iter->pg->next) { | |
1455 | iter->pg = iter->pg->next; | |
1456 | iter->idx = 0; | |
1457 | goto retry; | |
50cdaf08 LW |
1458 | } else { |
1459 | iter->idx = -1; | |
5072c59f SR |
1460 | } |
1461 | } else { | |
1462 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
1463 | if ((rec->flags & FTRACE_FL_FREE) || |
1464 | ||
1465 | (!(iter->flags & FTRACE_ITER_FAILURES) && | |
eb9a7bf0 AS |
1466 | (rec->flags & FTRACE_FL_FAILED)) || |
1467 | ||
1468 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
a9fdda33 | 1469 | !(rec->flags & FTRACE_FL_FAILED)) || |
eb9a7bf0 | 1470 | |
0183fb1c SR |
1471 | ((iter->flags & FTRACE_ITER_FILTER) && |
1472 | !(rec->flags & FTRACE_FL_FILTER)) || | |
1473 | ||
41c52c0d SR |
1474 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
1475 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
1476 | rec = NULL; |
1477 | goto retry; | |
1478 | } | |
1479 | } | |
1480 | ||
5072c59f SR |
1481 | return rec; |
1482 | } | |
1483 | ||
1484 | static void *t_start(struct seq_file *m, loff_t *pos) | |
1485 | { | |
1486 | struct ftrace_iterator *iter = m->private; | |
1487 | void *p = NULL; | |
5072c59f | 1488 | |
8fc0c701 | 1489 | mutex_lock(&ftrace_lock); |
0c75a3ed SR |
1490 | /* |
1491 | * For set_ftrace_filter reading, if we have the filter | |
1492 | * off, we can short cut and just print out that all | |
1493 | * functions are enabled. | |
1494 | */ | |
1495 | if (iter->flags & FTRACE_ITER_FILTER && !ftrace_filtered) { | |
1496 | if (*pos > 0) | |
8fc0c701 | 1497 | return t_hash_start(m, pos); |
0c75a3ed SR |
1498 | iter->flags |= FTRACE_ITER_PRINTALL; |
1499 | (*pos)++; | |
1500 | return iter; | |
1501 | } | |
1502 | ||
8fc0c701 SR |
1503 | if (iter->flags & FTRACE_ITER_HASH) |
1504 | return t_hash_start(m, pos); | |
1505 | ||
50cdaf08 LW |
1506 | if (*pos > 0) { |
1507 | if (iter->idx < 0) | |
1508 | return p; | |
1509 | (*pos)--; | |
1510 | iter->idx--; | |
1511 | } | |
5821e1b7 | 1512 | |
50cdaf08 | 1513 | p = t_next(m, p, pos); |
5072c59f | 1514 | |
8fc0c701 SR |
1515 | if (!p) |
1516 | return t_hash_start(m, pos); | |
1517 | ||
5072c59f SR |
1518 | return p; |
1519 | } | |
1520 | ||
1521 | static void t_stop(struct seq_file *m, void *p) | |
1522 | { | |
8fc0c701 | 1523 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1524 | } |
1525 | ||
1526 | static int t_show(struct seq_file *m, void *v) | |
1527 | { | |
0c75a3ed | 1528 | struct ftrace_iterator *iter = m->private; |
5072c59f SR |
1529 | struct dyn_ftrace *rec = v; |
1530 | char str[KSYM_SYMBOL_LEN]; | |
1531 | ||
8fc0c701 SR |
1532 | if (iter->flags & FTRACE_ITER_HASH) |
1533 | return t_hash_show(m, v); | |
1534 | ||
0c75a3ed SR |
1535 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
1536 | seq_printf(m, "#### all functions enabled ####\n"); | |
1537 | return 0; | |
1538 | } | |
1539 | ||
5072c59f SR |
1540 | if (!rec) |
1541 | return 0; | |
1542 | ||
1543 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1544 | ||
50cdaf08 | 1545 | seq_printf(m, "%s\n", str); |
5072c59f SR |
1546 | |
1547 | return 0; | |
1548 | } | |
1549 | ||
1550 | static struct seq_operations show_ftrace_seq_ops = { | |
1551 | .start = t_start, | |
1552 | .next = t_next, | |
1553 | .stop = t_stop, | |
1554 | .show = t_show, | |
1555 | }; | |
1556 | ||
e309b41d | 1557 | static int |
5072c59f SR |
1558 | ftrace_avail_open(struct inode *inode, struct file *file) |
1559 | { | |
1560 | struct ftrace_iterator *iter; | |
1561 | int ret; | |
1562 | ||
4eebcc81 SR |
1563 | if (unlikely(ftrace_disabled)) |
1564 | return -ENODEV; | |
1565 | ||
5072c59f SR |
1566 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1567 | if (!iter) | |
1568 | return -ENOMEM; | |
1569 | ||
1570 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
1571 | |
1572 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1573 | if (!ret) { | |
1574 | struct seq_file *m = file->private_data; | |
4bf39a94 | 1575 | |
5072c59f | 1576 | m->private = iter; |
4bf39a94 | 1577 | } else { |
5072c59f | 1578 | kfree(iter); |
4bf39a94 | 1579 | } |
5072c59f SR |
1580 | |
1581 | return ret; | |
1582 | } | |
1583 | ||
1584 | int ftrace_avail_release(struct inode *inode, struct file *file) | |
1585 | { | |
1586 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1587 | struct ftrace_iterator *iter = m->private; | |
1588 | ||
1589 | seq_release(inode, file); | |
1590 | kfree(iter); | |
4bf39a94 | 1591 | |
5072c59f SR |
1592 | return 0; |
1593 | } | |
1594 | ||
eb9a7bf0 AS |
1595 | static int |
1596 | ftrace_failures_open(struct inode *inode, struct file *file) | |
1597 | { | |
1598 | int ret; | |
1599 | struct seq_file *m; | |
1600 | struct ftrace_iterator *iter; | |
1601 | ||
1602 | ret = ftrace_avail_open(inode, file); | |
1603 | if (!ret) { | |
1604 | m = (struct seq_file *)file->private_data; | |
1605 | iter = (struct ftrace_iterator *)m->private; | |
1606 | iter->flags = FTRACE_ITER_FAILURES; | |
1607 | } | |
1608 | ||
1609 | return ret; | |
1610 | } | |
1611 | ||
1612 | ||
41c52c0d | 1613 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
1614 | { |
1615 | struct ftrace_page *pg; | |
1616 | struct dyn_ftrace *rec; | |
41c52c0d | 1617 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f | 1618 | |
52baf119 | 1619 | mutex_lock(&ftrace_lock); |
41c52c0d SR |
1620 | if (enable) |
1621 | ftrace_filtered = 0; | |
265c831c SR |
1622 | do_for_each_ftrace_rec(pg, rec) { |
1623 | if (rec->flags & FTRACE_FL_FAILED) | |
1624 | continue; | |
1625 | rec->flags &= ~type; | |
1626 | } while_for_each_ftrace_rec(); | |
52baf119 | 1627 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1628 | } |
1629 | ||
e309b41d | 1630 | static int |
41c52c0d | 1631 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1632 | { |
1633 | struct ftrace_iterator *iter; | |
1634 | int ret = 0; | |
1635 | ||
4eebcc81 SR |
1636 | if (unlikely(ftrace_disabled)) |
1637 | return -ENODEV; | |
1638 | ||
5072c59f SR |
1639 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1640 | if (!iter) | |
1641 | return -ENOMEM; | |
1642 | ||
41c52c0d | 1643 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1644 | if ((file->f_mode & FMODE_WRITE) && |
1645 | !(file->f_flags & O_APPEND)) | |
41c52c0d | 1646 | ftrace_filter_reset(enable); |
5072c59f SR |
1647 | |
1648 | if (file->f_mode & FMODE_READ) { | |
1649 | iter->pg = ftrace_pages_start; | |
41c52c0d SR |
1650 | iter->flags = enable ? FTRACE_ITER_FILTER : |
1651 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
1652 | |
1653 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1654 | if (!ret) { | |
1655 | struct seq_file *m = file->private_data; | |
1656 | m->private = iter; | |
1657 | } else | |
1658 | kfree(iter); | |
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 | ||
1691 | enum { | |
1692 | MATCH_FULL, | |
1693 | MATCH_FRONT_ONLY, | |
1694 | MATCH_MIDDLE_ONLY, | |
1695 | MATCH_END_ONLY, | |
1696 | }; | |
1697 | ||
9f4801e3 SR |
1698 | /* |
1699 | * (static function - no need for kernel doc) | |
1700 | * | |
1701 | * Pass in a buffer containing a glob and this function will | |
1702 | * set search to point to the search part of the buffer and | |
1703 | * return the type of search it is (see enum above). | |
1704 | * This does modify buff. | |
1705 | * | |
1706 | * Returns enum type. | |
1707 | * search returns the pointer to use for comparison. | |
1708 | * not returns 1 if buff started with a '!' | |
1709 | * 0 otherwise. | |
1710 | */ | |
1711 | static int | |
64e7c440 | 1712 | ftrace_setup_glob(char *buff, int len, char **search, int *not) |
5072c59f | 1713 | { |
5072c59f | 1714 | int type = MATCH_FULL; |
9f4801e3 | 1715 | int i; |
ea3a6d6d SR |
1716 | |
1717 | if (buff[0] == '!') { | |
9f4801e3 | 1718 | *not = 1; |
ea3a6d6d SR |
1719 | buff++; |
1720 | len--; | |
9f4801e3 SR |
1721 | } else |
1722 | *not = 0; | |
1723 | ||
1724 | *search = buff; | |
5072c59f SR |
1725 | |
1726 | for (i = 0; i < len; i++) { | |
1727 | if (buff[i] == '*') { | |
1728 | if (!i) { | |
9f4801e3 | 1729 | *search = buff + 1; |
5072c59f | 1730 | type = MATCH_END_ONLY; |
5072c59f | 1731 | } else { |
9f4801e3 | 1732 | if (type == MATCH_END_ONLY) |
5072c59f | 1733 | type = MATCH_MIDDLE_ONLY; |
9f4801e3 | 1734 | else |
5072c59f | 1735 | type = MATCH_FRONT_ONLY; |
5072c59f SR |
1736 | buff[i] = 0; |
1737 | break; | |
1738 | } | |
1739 | } | |
1740 | } | |
1741 | ||
9f4801e3 SR |
1742 | return type; |
1743 | } | |
1744 | ||
64e7c440 | 1745 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 1746 | { |
9f4801e3 SR |
1747 | int matched = 0; |
1748 | char *ptr; | |
1749 | ||
9f4801e3 SR |
1750 | switch (type) { |
1751 | case MATCH_FULL: | |
1752 | if (strcmp(str, regex) == 0) | |
1753 | matched = 1; | |
1754 | break; | |
1755 | case MATCH_FRONT_ONLY: | |
1756 | if (strncmp(str, regex, len) == 0) | |
1757 | matched = 1; | |
1758 | break; | |
1759 | case MATCH_MIDDLE_ONLY: | |
1760 | if (strstr(str, regex)) | |
1761 | matched = 1; | |
1762 | break; | |
1763 | case MATCH_END_ONLY: | |
1764 | ptr = strstr(str, regex); | |
1765 | if (ptr && (ptr[len] == 0)) | |
1766 | matched = 1; | |
1767 | break; | |
1768 | } | |
1769 | ||
1770 | return matched; | |
1771 | } | |
1772 | ||
64e7c440 SR |
1773 | static int |
1774 | ftrace_match_record(struct dyn_ftrace *rec, char *regex, int len, int type) | |
1775 | { | |
1776 | char str[KSYM_SYMBOL_LEN]; | |
1777 | ||
1778 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1779 | return ftrace_match(str, regex, len, type); | |
1780 | } | |
1781 | ||
9f4801e3 SR |
1782 | static void ftrace_match_records(char *buff, int len, int enable) |
1783 | { | |
6a24a244 | 1784 | unsigned int search_len; |
9f4801e3 SR |
1785 | struct ftrace_page *pg; |
1786 | struct dyn_ftrace *rec; | |
6a24a244 SR |
1787 | unsigned long flag; |
1788 | char *search; | |
9f4801e3 | 1789 | int type; |
9f4801e3 SR |
1790 | int not; |
1791 | ||
6a24a244 | 1792 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
9f4801e3 SR |
1793 | type = ftrace_setup_glob(buff, len, &search, ¬); |
1794 | ||
1795 | search_len = strlen(search); | |
1796 | ||
52baf119 | 1797 | mutex_lock(&ftrace_lock); |
265c831c | 1798 | do_for_each_ftrace_rec(pg, rec) { |
265c831c SR |
1799 | |
1800 | if (rec->flags & FTRACE_FL_FAILED) | |
1801 | continue; | |
9f4801e3 SR |
1802 | |
1803 | if (ftrace_match_record(rec, search, search_len, type)) { | |
265c831c SR |
1804 | if (not) |
1805 | rec->flags &= ~flag; | |
1806 | else | |
1807 | rec->flags |= flag; | |
1808 | } | |
e68746a2 SR |
1809 | /* |
1810 | * Only enable filtering if we have a function that | |
1811 | * is filtered on. | |
1812 | */ | |
1813 | if (enable && (rec->flags & FTRACE_FL_FILTER)) | |
1814 | ftrace_filtered = 1; | |
265c831c | 1815 | } while_for_each_ftrace_rec(); |
52baf119 | 1816 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1817 | } |
1818 | ||
64e7c440 SR |
1819 | static int |
1820 | ftrace_match_module_record(struct dyn_ftrace *rec, char *mod, | |
1821 | char *regex, int len, int type) | |
1822 | { | |
1823 | char str[KSYM_SYMBOL_LEN]; | |
1824 | char *modname; | |
1825 | ||
1826 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
1827 | ||
1828 | if (!modname || strcmp(modname, mod)) | |
1829 | return 0; | |
1830 | ||
1831 | /* blank search means to match all funcs in the mod */ | |
1832 | if (len) | |
1833 | return ftrace_match(str, regex, len, type); | |
1834 | else | |
1835 | return 1; | |
1836 | } | |
1837 | ||
1838 | static void ftrace_match_module_records(char *buff, char *mod, int enable) | |
1839 | { | |
6a24a244 | 1840 | unsigned search_len = 0; |
64e7c440 SR |
1841 | struct ftrace_page *pg; |
1842 | struct dyn_ftrace *rec; | |
1843 | int type = MATCH_FULL; | |
6a24a244 SR |
1844 | char *search = buff; |
1845 | unsigned long flag; | |
64e7c440 SR |
1846 | int not = 0; |
1847 | ||
6a24a244 SR |
1848 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
1849 | ||
64e7c440 SR |
1850 | /* blank or '*' mean the same */ |
1851 | if (strcmp(buff, "*") == 0) | |
1852 | buff[0] = 0; | |
1853 | ||
1854 | /* handle the case of 'dont filter this module' */ | |
1855 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
1856 | buff[0] = 0; | |
1857 | not = 1; | |
1858 | } | |
1859 | ||
1860 | if (strlen(buff)) { | |
1861 | type = ftrace_setup_glob(buff, strlen(buff), &search, ¬); | |
1862 | search_len = strlen(search); | |
1863 | } | |
1864 | ||
52baf119 | 1865 | mutex_lock(&ftrace_lock); |
64e7c440 SR |
1866 | do_for_each_ftrace_rec(pg, rec) { |
1867 | ||
1868 | if (rec->flags & FTRACE_FL_FAILED) | |
1869 | continue; | |
1870 | ||
1871 | if (ftrace_match_module_record(rec, mod, | |
1872 | search, search_len, type)) { | |
1873 | if (not) | |
1874 | rec->flags &= ~flag; | |
1875 | else | |
1876 | rec->flags |= flag; | |
1877 | } | |
e68746a2 SR |
1878 | if (enable && (rec->flags & FTRACE_FL_FILTER)) |
1879 | ftrace_filtered = 1; | |
64e7c440 SR |
1880 | |
1881 | } while_for_each_ftrace_rec(); | |
52baf119 | 1882 | mutex_unlock(&ftrace_lock); |
64e7c440 SR |
1883 | } |
1884 | ||
f6180773 SR |
1885 | /* |
1886 | * We register the module command as a template to show others how | |
1887 | * to register the a command as well. | |
1888 | */ | |
1889 | ||
1890 | static int | |
1891 | ftrace_mod_callback(char *func, char *cmd, char *param, int enable) | |
1892 | { | |
1893 | char *mod; | |
1894 | ||
1895 | /* | |
1896 | * cmd == 'mod' because we only registered this func | |
1897 | * for the 'mod' ftrace_func_command. | |
1898 | * But if you register one func with multiple commands, | |
1899 | * you can tell which command was used by the cmd | |
1900 | * parameter. | |
1901 | */ | |
1902 | ||
1903 | /* we must have a module name */ | |
1904 | if (!param) | |
1905 | return -EINVAL; | |
1906 | ||
1907 | mod = strsep(¶m, ":"); | |
1908 | if (!strlen(mod)) | |
1909 | return -EINVAL; | |
1910 | ||
1911 | ftrace_match_module_records(func, mod, enable); | |
1912 | return 0; | |
1913 | } | |
1914 | ||
1915 | static struct ftrace_func_command ftrace_mod_cmd = { | |
1916 | .name = "mod", | |
1917 | .func = ftrace_mod_callback, | |
1918 | }; | |
1919 | ||
1920 | static int __init ftrace_mod_cmd_init(void) | |
1921 | { | |
1922 | return register_ftrace_command(&ftrace_mod_cmd); | |
1923 | } | |
1924 | device_initcall(ftrace_mod_cmd_init); | |
1925 | ||
59df055f | 1926 | static void |
b6887d79 | 1927 | function_trace_probe_call(unsigned long ip, unsigned long parent_ip) |
59df055f | 1928 | { |
b6887d79 | 1929 | struct ftrace_func_probe *entry; |
59df055f SR |
1930 | struct hlist_head *hhd; |
1931 | struct hlist_node *n; | |
1932 | unsigned long key; | |
1933 | int resched; | |
1934 | ||
1935 | key = hash_long(ip, FTRACE_HASH_BITS); | |
1936 | ||
1937 | hhd = &ftrace_func_hash[key]; | |
1938 | ||
1939 | if (hlist_empty(hhd)) | |
1940 | return; | |
1941 | ||
1942 | /* | |
1943 | * Disable preemption for these calls to prevent a RCU grace | |
1944 | * period. This syncs the hash iteration and freeing of items | |
1945 | * on the hash. rcu_read_lock is too dangerous here. | |
1946 | */ | |
1947 | resched = ftrace_preempt_disable(); | |
1948 | hlist_for_each_entry_rcu(entry, n, hhd, node) { | |
1949 | if (entry->ip == ip) | |
1950 | entry->ops->func(ip, parent_ip, &entry->data); | |
1951 | } | |
1952 | ftrace_preempt_enable(resched); | |
1953 | } | |
1954 | ||
b6887d79 | 1955 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 1956 | { |
b6887d79 | 1957 | .func = function_trace_probe_call, |
59df055f SR |
1958 | }; |
1959 | ||
b6887d79 | 1960 | static int ftrace_probe_registered; |
59df055f | 1961 | |
b6887d79 | 1962 | static void __enable_ftrace_function_probe(void) |
59df055f SR |
1963 | { |
1964 | int i; | |
1965 | ||
b6887d79 | 1966 | if (ftrace_probe_registered) |
59df055f SR |
1967 | return; |
1968 | ||
1969 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1970 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1971 | if (hhd->first) | |
1972 | break; | |
1973 | } | |
1974 | /* Nothing registered? */ | |
1975 | if (i == FTRACE_FUNC_HASHSIZE) | |
1976 | return; | |
1977 | ||
b6887d79 | 1978 | __register_ftrace_function(&trace_probe_ops); |
59df055f | 1979 | ftrace_startup(0); |
b6887d79 | 1980 | ftrace_probe_registered = 1; |
59df055f SR |
1981 | } |
1982 | ||
b6887d79 | 1983 | static void __disable_ftrace_function_probe(void) |
59df055f SR |
1984 | { |
1985 | int i; | |
1986 | ||
b6887d79 | 1987 | if (!ftrace_probe_registered) |
59df055f SR |
1988 | return; |
1989 | ||
1990 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1991 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1992 | if (hhd->first) | |
1993 | return; | |
1994 | } | |
1995 | ||
1996 | /* no more funcs left */ | |
b6887d79 | 1997 | __unregister_ftrace_function(&trace_probe_ops); |
59df055f | 1998 | ftrace_shutdown(0); |
b6887d79 | 1999 | ftrace_probe_registered = 0; |
59df055f SR |
2000 | } |
2001 | ||
2002 | ||
2003 | static void ftrace_free_entry_rcu(struct rcu_head *rhp) | |
2004 | { | |
b6887d79 SR |
2005 | struct ftrace_func_probe *entry = |
2006 | container_of(rhp, struct ftrace_func_probe, rcu); | |
59df055f SR |
2007 | |
2008 | if (entry->ops->free) | |
2009 | entry->ops->free(&entry->data); | |
2010 | kfree(entry); | |
2011 | } | |
2012 | ||
2013 | ||
2014 | int | |
b6887d79 | 2015 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2016 | void *data) |
2017 | { | |
b6887d79 | 2018 | struct ftrace_func_probe *entry; |
59df055f SR |
2019 | struct ftrace_page *pg; |
2020 | struct dyn_ftrace *rec; | |
59df055f | 2021 | int type, len, not; |
6a24a244 | 2022 | unsigned long key; |
59df055f SR |
2023 | int count = 0; |
2024 | char *search; | |
2025 | ||
2026 | type = ftrace_setup_glob(glob, strlen(glob), &search, ¬); | |
2027 | len = strlen(search); | |
2028 | ||
b6887d79 | 2029 | /* we do not support '!' for function probes */ |
59df055f SR |
2030 | if (WARN_ON(not)) |
2031 | return -EINVAL; | |
2032 | ||
2033 | mutex_lock(&ftrace_lock); | |
2034 | do_for_each_ftrace_rec(pg, rec) { | |
2035 | ||
2036 | if (rec->flags & FTRACE_FL_FAILED) | |
2037 | continue; | |
2038 | ||
2039 | if (!ftrace_match_record(rec, search, len, type)) | |
2040 | continue; | |
2041 | ||
2042 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
2043 | if (!entry) { | |
b6887d79 | 2044 | /* If we did not process any, then return error */ |
59df055f SR |
2045 | if (!count) |
2046 | count = -ENOMEM; | |
2047 | goto out_unlock; | |
2048 | } | |
2049 | ||
2050 | count++; | |
2051 | ||
2052 | entry->data = data; | |
2053 | ||
2054 | /* | |
2055 | * The caller might want to do something special | |
2056 | * for each function we find. We call the callback | |
2057 | * to give the caller an opportunity to do so. | |
2058 | */ | |
2059 | if (ops->callback) { | |
2060 | if (ops->callback(rec->ip, &entry->data) < 0) { | |
2061 | /* caller does not like this func */ | |
2062 | kfree(entry); | |
2063 | continue; | |
2064 | } | |
2065 | } | |
2066 | ||
2067 | entry->ops = ops; | |
2068 | entry->ip = rec->ip; | |
2069 | ||
2070 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
2071 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
2072 | ||
2073 | } while_for_each_ftrace_rec(); | |
b6887d79 | 2074 | __enable_ftrace_function_probe(); |
59df055f SR |
2075 | |
2076 | out_unlock: | |
2077 | mutex_unlock(&ftrace_lock); | |
2078 | ||
2079 | return count; | |
2080 | } | |
2081 | ||
2082 | enum { | |
b6887d79 SR |
2083 | PROBE_TEST_FUNC = 1, |
2084 | PROBE_TEST_DATA = 2 | |
59df055f SR |
2085 | }; |
2086 | ||
2087 | static void | |
b6887d79 | 2088 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2089 | void *data, int flags) |
2090 | { | |
b6887d79 | 2091 | struct ftrace_func_probe *entry; |
59df055f SR |
2092 | struct hlist_node *n, *tmp; |
2093 | char str[KSYM_SYMBOL_LEN]; | |
2094 | int type = MATCH_FULL; | |
2095 | int i, len = 0; | |
2096 | char *search; | |
2097 | ||
2098 | if (glob && (strcmp(glob, "*") || !strlen(glob))) | |
2099 | glob = NULL; | |
2100 | else { | |
2101 | int not; | |
2102 | ||
2103 | type = ftrace_setup_glob(glob, strlen(glob), &search, ¬); | |
2104 | len = strlen(search); | |
2105 | ||
b6887d79 | 2106 | /* we do not support '!' for function probes */ |
59df055f SR |
2107 | if (WARN_ON(not)) |
2108 | return; | |
2109 | } | |
2110 | ||
2111 | mutex_lock(&ftrace_lock); | |
2112 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2113 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2114 | ||
2115 | hlist_for_each_entry_safe(entry, n, tmp, hhd, node) { | |
2116 | ||
2117 | /* break up if statements for readability */ | |
b6887d79 | 2118 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
2119 | continue; |
2120 | ||
b6887d79 | 2121 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
2122 | continue; |
2123 | ||
2124 | /* do this last, since it is the most expensive */ | |
2125 | if (glob) { | |
2126 | kallsyms_lookup(entry->ip, NULL, NULL, | |
2127 | NULL, str); | |
2128 | if (!ftrace_match(str, glob, len, type)) | |
2129 | continue; | |
2130 | } | |
2131 | ||
2132 | hlist_del(&entry->node); | |
2133 | call_rcu(&entry->rcu, ftrace_free_entry_rcu); | |
2134 | } | |
2135 | } | |
b6887d79 | 2136 | __disable_ftrace_function_probe(); |
59df055f SR |
2137 | mutex_unlock(&ftrace_lock); |
2138 | } | |
2139 | ||
2140 | void | |
b6887d79 | 2141 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2142 | void *data) |
2143 | { | |
b6887d79 SR |
2144 | __unregister_ftrace_function_probe(glob, ops, data, |
2145 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
2146 | } |
2147 | ||
2148 | void | |
b6887d79 | 2149 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 2150 | { |
b6887d79 | 2151 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
2152 | } |
2153 | ||
b6887d79 | 2154 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 2155 | { |
b6887d79 | 2156 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
2157 | } |
2158 | ||
f6180773 SR |
2159 | static LIST_HEAD(ftrace_commands); |
2160 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
2161 | ||
2162 | int register_ftrace_command(struct ftrace_func_command *cmd) | |
2163 | { | |
2164 | struct ftrace_func_command *p; | |
2165 | int ret = 0; | |
2166 | ||
2167 | mutex_lock(&ftrace_cmd_mutex); | |
2168 | list_for_each_entry(p, &ftrace_commands, list) { | |
2169 | if (strcmp(cmd->name, p->name) == 0) { | |
2170 | ret = -EBUSY; | |
2171 | goto out_unlock; | |
2172 | } | |
2173 | } | |
2174 | list_add(&cmd->list, &ftrace_commands); | |
2175 | out_unlock: | |
2176 | mutex_unlock(&ftrace_cmd_mutex); | |
2177 | ||
2178 | return ret; | |
2179 | } | |
2180 | ||
2181 | int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
2182 | { | |
2183 | struct ftrace_func_command *p, *n; | |
2184 | int ret = -ENODEV; | |
2185 | ||
2186 | mutex_lock(&ftrace_cmd_mutex); | |
2187 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
2188 | if (strcmp(cmd->name, p->name) == 0) { | |
2189 | ret = 0; | |
2190 | list_del_init(&p->list); | |
2191 | goto out_unlock; | |
2192 | } | |
2193 | } | |
2194 | out_unlock: | |
2195 | mutex_unlock(&ftrace_cmd_mutex); | |
2196 | ||
2197 | return ret; | |
2198 | } | |
2199 | ||
64e7c440 SR |
2200 | static int ftrace_process_regex(char *buff, int len, int enable) |
2201 | { | |
f6180773 | 2202 | char *func, *command, *next = buff; |
6a24a244 | 2203 | struct ftrace_func_command *p; |
f6180773 | 2204 | int ret = -EINVAL; |
64e7c440 SR |
2205 | |
2206 | func = strsep(&next, ":"); | |
2207 | ||
2208 | if (!next) { | |
2209 | ftrace_match_records(func, len, enable); | |
2210 | return 0; | |
2211 | } | |
2212 | ||
f6180773 | 2213 | /* command found */ |
64e7c440 SR |
2214 | |
2215 | command = strsep(&next, ":"); | |
2216 | ||
f6180773 SR |
2217 | mutex_lock(&ftrace_cmd_mutex); |
2218 | list_for_each_entry(p, &ftrace_commands, list) { | |
2219 | if (strcmp(p->name, command) == 0) { | |
2220 | ret = p->func(func, command, next, enable); | |
2221 | goto out_unlock; | |
2222 | } | |
64e7c440 | 2223 | } |
f6180773 SR |
2224 | out_unlock: |
2225 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 2226 | |
f6180773 | 2227 | return ret; |
64e7c440 SR |
2228 | } |
2229 | ||
e309b41d | 2230 | static ssize_t |
41c52c0d SR |
2231 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
2232 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
2233 | { |
2234 | struct ftrace_iterator *iter; | |
2235 | char ch; | |
2236 | size_t read = 0; | |
2237 | ssize_t ret; | |
2238 | ||
2239 | if (!cnt || cnt < 0) | |
2240 | return 0; | |
2241 | ||
41c52c0d | 2242 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
2243 | |
2244 | if (file->f_mode & FMODE_READ) { | |
2245 | struct seq_file *m = file->private_data; | |
2246 | iter = m->private; | |
2247 | } else | |
2248 | iter = file->private_data; | |
2249 | ||
2250 | if (!*ppos) { | |
2251 | iter->flags &= ~FTRACE_ITER_CONT; | |
2252 | iter->buffer_idx = 0; | |
2253 | } | |
2254 | ||
2255 | ret = get_user(ch, ubuf++); | |
2256 | if (ret) | |
2257 | goto out; | |
2258 | read++; | |
2259 | cnt--; | |
2260 | ||
2261 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { | |
2262 | /* skip white space */ | |
2263 | while (cnt && isspace(ch)) { | |
2264 | ret = get_user(ch, ubuf++); | |
2265 | if (ret) | |
2266 | goto out; | |
2267 | read++; | |
2268 | cnt--; | |
2269 | } | |
2270 | ||
5072c59f SR |
2271 | if (isspace(ch)) { |
2272 | file->f_pos += read; | |
2273 | ret = read; | |
2274 | goto out; | |
2275 | } | |
2276 | ||
2277 | iter->buffer_idx = 0; | |
2278 | } | |
2279 | ||
2280 | while (cnt && !isspace(ch)) { | |
2281 | if (iter->buffer_idx < FTRACE_BUFF_MAX) | |
2282 | iter->buffer[iter->buffer_idx++] = ch; | |
2283 | else { | |
2284 | ret = -EINVAL; | |
2285 | goto out; | |
2286 | } | |
2287 | ret = get_user(ch, ubuf++); | |
2288 | if (ret) | |
2289 | goto out; | |
2290 | read++; | |
2291 | cnt--; | |
2292 | } | |
2293 | ||
2294 | if (isspace(ch)) { | |
2295 | iter->filtered++; | |
2296 | iter->buffer[iter->buffer_idx] = 0; | |
64e7c440 SR |
2297 | ret = ftrace_process_regex(iter->buffer, |
2298 | iter->buffer_idx, enable); | |
2299 | if (ret) | |
2300 | goto out; | |
5072c59f SR |
2301 | iter->buffer_idx = 0; |
2302 | } else | |
2303 | iter->flags |= FTRACE_ITER_CONT; | |
2304 | ||
2305 | ||
2306 | file->f_pos += read; | |
2307 | ||
2308 | ret = read; | |
2309 | out: | |
41c52c0d | 2310 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
2311 | |
2312 | return ret; | |
2313 | } | |
2314 | ||
41c52c0d SR |
2315 | static ssize_t |
2316 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
2317 | size_t cnt, loff_t *ppos) | |
2318 | { | |
2319 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
2320 | } | |
2321 | ||
2322 | static ssize_t | |
2323 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
2324 | size_t cnt, loff_t *ppos) | |
2325 | { | |
2326 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
2327 | } | |
2328 | ||
2329 | static void | |
2330 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
2331 | { | |
2332 | if (unlikely(ftrace_disabled)) | |
2333 | return; | |
2334 | ||
2335 | mutex_lock(&ftrace_regex_lock); | |
2336 | if (reset) | |
2337 | ftrace_filter_reset(enable); | |
2338 | if (buf) | |
7f24b31b | 2339 | ftrace_match_records(buf, len, enable); |
41c52c0d SR |
2340 | mutex_unlock(&ftrace_regex_lock); |
2341 | } | |
2342 | ||
77a2b37d SR |
2343 | /** |
2344 | * ftrace_set_filter - set a function to filter on in ftrace | |
2345 | * @buf - the string that holds the function filter text. | |
2346 | * @len - the length of the string. | |
2347 | * @reset - non zero to reset all filters before applying this filter. | |
2348 | * | |
2349 | * Filters denote which functions should be enabled when tracing is enabled. | |
2350 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
2351 | */ | |
e309b41d | 2352 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 2353 | { |
41c52c0d SR |
2354 | ftrace_set_regex(buf, len, reset, 1); |
2355 | } | |
4eebcc81 | 2356 | |
41c52c0d SR |
2357 | /** |
2358 | * ftrace_set_notrace - set a function to not trace in ftrace | |
2359 | * @buf - the string that holds the function notrace text. | |
2360 | * @len - the length of the string. | |
2361 | * @reset - non zero to reset all filters before applying this filter. | |
2362 | * | |
2363 | * Notrace Filters denote which functions should not be enabled when tracing | |
2364 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
2365 | * for tracing. | |
2366 | */ | |
2367 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
2368 | { | |
2369 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
2370 | } |
2371 | ||
e309b41d | 2372 | static int |
41c52c0d | 2373 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
2374 | { |
2375 | struct seq_file *m = (struct seq_file *)file->private_data; | |
2376 | struct ftrace_iterator *iter; | |
2377 | ||
41c52c0d | 2378 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
2379 | if (file->f_mode & FMODE_READ) { |
2380 | iter = m->private; | |
2381 | ||
2382 | seq_release(inode, file); | |
2383 | } else | |
2384 | iter = file->private_data; | |
2385 | ||
2386 | if (iter->buffer_idx) { | |
2387 | iter->filtered++; | |
2388 | iter->buffer[iter->buffer_idx] = 0; | |
7f24b31b | 2389 | ftrace_match_records(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
2390 | } |
2391 | ||
e6ea44e9 | 2392 | mutex_lock(&ftrace_lock); |
ee02a2e5 | 2393 | if (ftrace_start_up && ftrace_enabled) |
5072c59f | 2394 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
e6ea44e9 | 2395 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
2396 | |
2397 | kfree(iter); | |
41c52c0d | 2398 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
2399 | return 0; |
2400 | } | |
2401 | ||
41c52c0d SR |
2402 | static int |
2403 | ftrace_filter_release(struct inode *inode, struct file *file) | |
2404 | { | |
2405 | return ftrace_regex_release(inode, file, 1); | |
2406 | } | |
2407 | ||
2408 | static int | |
2409 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
2410 | { | |
2411 | return ftrace_regex_release(inode, file, 0); | |
2412 | } | |
2413 | ||
5e2336a0 | 2414 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
2415 | .open = ftrace_avail_open, |
2416 | .read = seq_read, | |
2417 | .llseek = seq_lseek, | |
2418 | .release = ftrace_avail_release, | |
2419 | }; | |
2420 | ||
5e2336a0 | 2421 | static const struct file_operations ftrace_failures_fops = { |
eb9a7bf0 AS |
2422 | .open = ftrace_failures_open, |
2423 | .read = seq_read, | |
2424 | .llseek = seq_lseek, | |
2425 | .release = ftrace_avail_release, | |
2426 | }; | |
2427 | ||
5e2336a0 | 2428 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 2429 | .open = ftrace_filter_open, |
850a80cf | 2430 | .read = seq_read, |
5072c59f | 2431 | .write = ftrace_filter_write, |
41c52c0d | 2432 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
2433 | .release = ftrace_filter_release, |
2434 | }; | |
2435 | ||
5e2336a0 | 2436 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 2437 | .open = ftrace_notrace_open, |
850a80cf | 2438 | .read = seq_read, |
41c52c0d SR |
2439 | .write = ftrace_notrace_write, |
2440 | .llseek = ftrace_regex_lseek, | |
2441 | .release = ftrace_notrace_release, | |
2442 | }; | |
2443 | ||
ea4e2bc4 SR |
2444 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
2445 | ||
2446 | static DEFINE_MUTEX(graph_lock); | |
2447 | ||
2448 | int ftrace_graph_count; | |
2449 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; | |
2450 | ||
2451 | static void * | |
2452 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
2453 | { | |
2454 | unsigned long *array = m->private; | |
2455 | int index = *pos; | |
2456 | ||
2457 | (*pos)++; | |
2458 | ||
2459 | if (index >= ftrace_graph_count) | |
2460 | return NULL; | |
2461 | ||
2462 | return &array[index]; | |
2463 | } | |
2464 | ||
2465 | static void *g_start(struct seq_file *m, loff_t *pos) | |
2466 | { | |
2467 | void *p = NULL; | |
2468 | ||
2469 | mutex_lock(&graph_lock); | |
2470 | ||
f9349a8f FW |
2471 | /* Nothing, tell g_show to print all functions are enabled */ |
2472 | if (!ftrace_graph_count && !*pos) | |
2473 | return (void *)1; | |
2474 | ||
ea4e2bc4 SR |
2475 | p = g_next(m, p, pos); |
2476 | ||
2477 | return p; | |
2478 | } | |
2479 | ||
2480 | static void g_stop(struct seq_file *m, void *p) | |
2481 | { | |
2482 | mutex_unlock(&graph_lock); | |
2483 | } | |
2484 | ||
2485 | static int g_show(struct seq_file *m, void *v) | |
2486 | { | |
2487 | unsigned long *ptr = v; | |
2488 | char str[KSYM_SYMBOL_LEN]; | |
2489 | ||
2490 | if (!ptr) | |
2491 | return 0; | |
2492 | ||
f9349a8f FW |
2493 | if (ptr == (unsigned long *)1) { |
2494 | seq_printf(m, "#### all functions enabled ####\n"); | |
2495 | return 0; | |
2496 | } | |
2497 | ||
ea4e2bc4 SR |
2498 | kallsyms_lookup(*ptr, NULL, NULL, NULL, str); |
2499 | ||
2500 | seq_printf(m, "%s\n", str); | |
2501 | ||
2502 | return 0; | |
2503 | } | |
2504 | ||
2505 | static struct seq_operations ftrace_graph_seq_ops = { | |
2506 | .start = g_start, | |
2507 | .next = g_next, | |
2508 | .stop = g_stop, | |
2509 | .show = g_show, | |
2510 | }; | |
2511 | ||
2512 | static int | |
2513 | ftrace_graph_open(struct inode *inode, struct file *file) | |
2514 | { | |
2515 | int ret = 0; | |
2516 | ||
2517 | if (unlikely(ftrace_disabled)) | |
2518 | return -ENODEV; | |
2519 | ||
2520 | mutex_lock(&graph_lock); | |
2521 | if ((file->f_mode & FMODE_WRITE) && | |
2522 | !(file->f_flags & O_APPEND)) { | |
2523 | ftrace_graph_count = 0; | |
2524 | memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); | |
2525 | } | |
2526 | ||
2527 | if (file->f_mode & FMODE_READ) { | |
2528 | ret = seq_open(file, &ftrace_graph_seq_ops); | |
2529 | if (!ret) { | |
2530 | struct seq_file *m = file->private_data; | |
2531 | m->private = ftrace_graph_funcs; | |
2532 | } | |
2533 | } else | |
2534 | file->private_data = ftrace_graph_funcs; | |
2535 | mutex_unlock(&graph_lock); | |
2536 | ||
2537 | return ret; | |
2538 | } | |
2539 | ||
ea4e2bc4 | 2540 | static int |
f9349a8f | 2541 | ftrace_set_func(unsigned long *array, int *idx, char *buffer) |
ea4e2bc4 | 2542 | { |
ea4e2bc4 SR |
2543 | struct dyn_ftrace *rec; |
2544 | struct ftrace_page *pg; | |
f9349a8f | 2545 | int search_len; |
ea4e2bc4 | 2546 | int found = 0; |
f9349a8f FW |
2547 | int type, not; |
2548 | char *search; | |
2549 | bool exists; | |
2550 | int i; | |
ea4e2bc4 SR |
2551 | |
2552 | if (ftrace_disabled) | |
2553 | return -ENODEV; | |
2554 | ||
f9349a8f FW |
2555 | /* decode regex */ |
2556 | type = ftrace_setup_glob(buffer, strlen(buffer), &search, ¬); | |
2557 | if (not) | |
2558 | return -EINVAL; | |
2559 | ||
2560 | search_len = strlen(search); | |
2561 | ||
52baf119 | 2562 | mutex_lock(&ftrace_lock); |
265c831c SR |
2563 | do_for_each_ftrace_rec(pg, rec) { |
2564 | ||
f9349a8f FW |
2565 | if (*idx >= FTRACE_GRAPH_MAX_FUNCS) |
2566 | break; | |
2567 | ||
265c831c SR |
2568 | if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE)) |
2569 | continue; | |
2570 | ||
f9349a8f FW |
2571 | if (ftrace_match_record(rec, search, search_len, type)) { |
2572 | /* ensure it is not already in the array */ | |
2573 | exists = false; | |
2574 | for (i = 0; i < *idx; i++) | |
2575 | if (array[i] == rec->ip) { | |
2576 | exists = true; | |
265c831c SR |
2577 | break; |
2578 | } | |
f9349a8f FW |
2579 | if (!exists) { |
2580 | array[(*idx)++] = rec->ip; | |
2581 | found = 1; | |
2582 | } | |
ea4e2bc4 | 2583 | } |
265c831c | 2584 | } while_for_each_ftrace_rec(); |
f9349a8f | 2585 | |
52baf119 | 2586 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 SR |
2587 | |
2588 | return found ? 0 : -EINVAL; | |
2589 | } | |
2590 | ||
2591 | static ssize_t | |
2592 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
2593 | size_t cnt, loff_t *ppos) | |
2594 | { | |
2595 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
2596 | unsigned long *array; | |
2597 | size_t read = 0; | |
2598 | ssize_t ret; | |
2599 | int index = 0; | |
2600 | char ch; | |
2601 | ||
2602 | if (!cnt || cnt < 0) | |
2603 | return 0; | |
2604 | ||
2605 | mutex_lock(&graph_lock); | |
2606 | ||
2607 | if (ftrace_graph_count >= FTRACE_GRAPH_MAX_FUNCS) { | |
2608 | ret = -EBUSY; | |
2609 | goto out; | |
2610 | } | |
2611 | ||
2612 | if (file->f_mode & FMODE_READ) { | |
2613 | struct seq_file *m = file->private_data; | |
2614 | array = m->private; | |
2615 | } else | |
2616 | array = file->private_data; | |
2617 | ||
2618 | ret = get_user(ch, ubuf++); | |
2619 | if (ret) | |
2620 | goto out; | |
2621 | read++; | |
2622 | cnt--; | |
2623 | ||
2624 | /* skip white space */ | |
2625 | while (cnt && isspace(ch)) { | |
2626 | ret = get_user(ch, ubuf++); | |
2627 | if (ret) | |
2628 | goto out; | |
2629 | read++; | |
2630 | cnt--; | |
2631 | } | |
2632 | ||
2633 | if (isspace(ch)) { | |
2634 | *ppos += read; | |
2635 | ret = read; | |
2636 | goto out; | |
2637 | } | |
2638 | ||
2639 | while (cnt && !isspace(ch)) { | |
2640 | if (index < FTRACE_BUFF_MAX) | |
2641 | buffer[index++] = ch; | |
2642 | else { | |
2643 | ret = -EINVAL; | |
2644 | goto out; | |
2645 | } | |
2646 | ret = get_user(ch, ubuf++); | |
2647 | if (ret) | |
2648 | goto out; | |
2649 | read++; | |
2650 | cnt--; | |
2651 | } | |
2652 | buffer[index] = 0; | |
2653 | ||
f9349a8f FW |
2654 | /* we allow only one expression at a time */ |
2655 | ret = ftrace_set_func(array, &ftrace_graph_count, buffer); | |
ea4e2bc4 SR |
2656 | if (ret) |
2657 | goto out; | |
2658 | ||
ea4e2bc4 SR |
2659 | file->f_pos += read; |
2660 | ||
2661 | ret = read; | |
2662 | out: | |
2663 | mutex_unlock(&graph_lock); | |
2664 | ||
2665 | return ret; | |
2666 | } | |
2667 | ||
2668 | static const struct file_operations ftrace_graph_fops = { | |
2669 | .open = ftrace_graph_open, | |
850a80cf | 2670 | .read = seq_read, |
ea4e2bc4 SR |
2671 | .write = ftrace_graph_write, |
2672 | }; | |
2673 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2674 | ||
df4fc315 | 2675 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 2676 | { |
5072c59f SR |
2677 | struct dentry *entry; |
2678 | ||
5072c59f SR |
2679 | entry = debugfs_create_file("available_filter_functions", 0444, |
2680 | d_tracer, NULL, &ftrace_avail_fops); | |
2681 | if (!entry) | |
2682 | pr_warning("Could not create debugfs " | |
2683 | "'available_filter_functions' entry\n"); | |
2684 | ||
eb9a7bf0 AS |
2685 | entry = debugfs_create_file("failures", 0444, |
2686 | d_tracer, NULL, &ftrace_failures_fops); | |
2687 | if (!entry) | |
2688 | pr_warning("Could not create debugfs 'failures' entry\n"); | |
2689 | ||
5072c59f SR |
2690 | entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer, |
2691 | NULL, &ftrace_filter_fops); | |
2692 | if (!entry) | |
2693 | pr_warning("Could not create debugfs " | |
2694 | "'set_ftrace_filter' entry\n"); | |
41c52c0d SR |
2695 | |
2696 | entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer, | |
2697 | NULL, &ftrace_notrace_fops); | |
2698 | if (!entry) | |
2699 | pr_warning("Could not create debugfs " | |
2700 | "'set_ftrace_notrace' entry\n"); | |
ad90c0e3 | 2701 | |
ea4e2bc4 SR |
2702 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
2703 | entry = debugfs_create_file("set_graph_function", 0444, d_tracer, | |
2704 | NULL, | |
2705 | &ftrace_graph_fops); | |
2706 | if (!entry) | |
2707 | pr_warning("Could not create debugfs " | |
2708 | "'set_graph_function' entry\n"); | |
2709 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2710 | ||
5072c59f SR |
2711 | return 0; |
2712 | } | |
2713 | ||
31e88909 SR |
2714 | static int ftrace_convert_nops(struct module *mod, |
2715 | unsigned long *start, | |
68bf21aa SR |
2716 | unsigned long *end) |
2717 | { | |
2718 | unsigned long *p; | |
2719 | unsigned long addr; | |
2720 | unsigned long flags; | |
2721 | ||
e6ea44e9 | 2722 | mutex_lock(&ftrace_lock); |
68bf21aa SR |
2723 | p = start; |
2724 | while (p < end) { | |
2725 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
2726 | /* |
2727 | * Some architecture linkers will pad between | |
2728 | * the different mcount_loc sections of different | |
2729 | * object files to satisfy alignments. | |
2730 | * Skip any NULL pointers. | |
2731 | */ | |
2732 | if (!addr) | |
2733 | continue; | |
68bf21aa | 2734 | ftrace_record_ip(addr); |
68bf21aa SR |
2735 | } |
2736 | ||
08f5ac90 | 2737 | /* disable interrupts to prevent kstop machine */ |
68bf21aa | 2738 | local_irq_save(flags); |
31e88909 | 2739 | ftrace_update_code(mod); |
68bf21aa | 2740 | local_irq_restore(flags); |
e6ea44e9 | 2741 | mutex_unlock(&ftrace_lock); |
68bf21aa SR |
2742 | |
2743 | return 0; | |
2744 | } | |
2745 | ||
31e88909 SR |
2746 | void ftrace_init_module(struct module *mod, |
2747 | unsigned long *start, unsigned long *end) | |
90d595fe | 2748 | { |
00fd61ae | 2749 | if (ftrace_disabled || start == end) |
fed1939c | 2750 | return; |
31e88909 | 2751 | ftrace_convert_nops(mod, start, end); |
90d595fe SR |
2752 | } |
2753 | ||
68bf21aa SR |
2754 | extern unsigned long __start_mcount_loc[]; |
2755 | extern unsigned long __stop_mcount_loc[]; | |
2756 | ||
2757 | void __init ftrace_init(void) | |
2758 | { | |
2759 | unsigned long count, addr, flags; | |
2760 | int ret; | |
2761 | ||
2762 | /* Keep the ftrace pointer to the stub */ | |
2763 | addr = (unsigned long)ftrace_stub; | |
2764 | ||
2765 | local_irq_save(flags); | |
2766 | ftrace_dyn_arch_init(&addr); | |
2767 | local_irq_restore(flags); | |
2768 | ||
2769 | /* ftrace_dyn_arch_init places the return code in addr */ | |
2770 | if (addr) | |
2771 | goto failed; | |
2772 | ||
2773 | count = __stop_mcount_loc - __start_mcount_loc; | |
2774 | ||
2775 | ret = ftrace_dyn_table_alloc(count); | |
2776 | if (ret) | |
2777 | goto failed; | |
2778 | ||
2779 | last_ftrace_enabled = ftrace_enabled = 1; | |
2780 | ||
31e88909 SR |
2781 | ret = ftrace_convert_nops(NULL, |
2782 | __start_mcount_loc, | |
68bf21aa SR |
2783 | __stop_mcount_loc); |
2784 | ||
2785 | return; | |
2786 | failed: | |
2787 | ftrace_disabled = 1; | |
2788 | } | |
68bf21aa | 2789 | |
3d083395 | 2790 | #else |
0b6e4d56 FW |
2791 | |
2792 | static int __init ftrace_nodyn_init(void) | |
2793 | { | |
2794 | ftrace_enabled = 1; | |
2795 | return 0; | |
2796 | } | |
2797 | device_initcall(ftrace_nodyn_init); | |
2798 | ||
df4fc315 SR |
2799 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
2800 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 SR |
2801 | /* Keep as macros so we do not need to define the commands */ |
2802 | # define ftrace_startup(command) do { } while (0) | |
2803 | # define ftrace_shutdown(command) do { } while (0) | |
c7aafc54 IM |
2804 | # define ftrace_startup_sysctl() do { } while (0) |
2805 | # define ftrace_shutdown_sysctl() do { } while (0) | |
3d083395 SR |
2806 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
2807 | ||
df4fc315 SR |
2808 | static ssize_t |
2809 | ftrace_pid_read(struct file *file, char __user *ubuf, | |
2810 | size_t cnt, loff_t *ppos) | |
2811 | { | |
2812 | char buf[64]; | |
2813 | int r; | |
2814 | ||
e32d8956 SR |
2815 | if (ftrace_pid_trace == ftrace_swapper_pid) |
2816 | r = sprintf(buf, "swapper tasks\n"); | |
2817 | else if (ftrace_pid_trace) | |
cc59c9e8 | 2818 | r = sprintf(buf, "%u\n", pid_vnr(ftrace_pid_trace)); |
df4fc315 SR |
2819 | else |
2820 | r = sprintf(buf, "no pid\n"); | |
2821 | ||
2822 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
2823 | } | |
2824 | ||
e32d8956 | 2825 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
2826 | { |
2827 | struct task_struct *p; | |
e32d8956 | 2828 | int cpu; |
978f3a45 | 2829 | |
e32d8956 SR |
2830 | get_online_cpus(); |
2831 | for_each_online_cpu(cpu) { | |
2832 | p = idle_task(cpu); | |
978f3a45 | 2833 | clear_tsk_trace_trace(p); |
e32d8956 SR |
2834 | } |
2835 | put_online_cpus(); | |
2836 | } | |
978f3a45 | 2837 | |
e32d8956 SR |
2838 | static void set_ftrace_swapper(void) |
2839 | { | |
2840 | struct task_struct *p; | |
2841 | int cpu; | |
2842 | ||
2843 | get_online_cpus(); | |
2844 | for_each_online_cpu(cpu) { | |
2845 | p = idle_task(cpu); | |
2846 | set_tsk_trace_trace(p); | |
2847 | } | |
2848 | put_online_cpus(); | |
978f3a45 SR |
2849 | } |
2850 | ||
e32d8956 SR |
2851 | static void clear_ftrace_pid(struct pid *pid) |
2852 | { | |
2853 | struct task_struct *p; | |
2854 | ||
229c4ef8 | 2855 | rcu_read_lock(); |
e32d8956 SR |
2856 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2857 | clear_tsk_trace_trace(p); | |
2858 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
2859 | rcu_read_unlock(); |
2860 | ||
e32d8956 SR |
2861 | put_pid(pid); |
2862 | } | |
2863 | ||
2864 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
2865 | { |
2866 | struct task_struct *p; | |
2867 | ||
229c4ef8 | 2868 | rcu_read_lock(); |
978f3a45 SR |
2869 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2870 | set_tsk_trace_trace(p); | |
2871 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 2872 | rcu_read_unlock(); |
978f3a45 SR |
2873 | } |
2874 | ||
e32d8956 SR |
2875 | static void clear_ftrace_pid_task(struct pid **pid) |
2876 | { | |
2877 | if (*pid == ftrace_swapper_pid) | |
2878 | clear_ftrace_swapper(); | |
2879 | else | |
2880 | clear_ftrace_pid(*pid); | |
2881 | ||
2882 | *pid = NULL; | |
2883 | } | |
2884 | ||
2885 | static void set_ftrace_pid_task(struct pid *pid) | |
2886 | { | |
2887 | if (pid == ftrace_swapper_pid) | |
2888 | set_ftrace_swapper(); | |
2889 | else | |
2890 | set_ftrace_pid(pid); | |
2891 | } | |
2892 | ||
df4fc315 SR |
2893 | static ssize_t |
2894 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
2895 | size_t cnt, loff_t *ppos) | |
2896 | { | |
978f3a45 | 2897 | struct pid *pid; |
df4fc315 SR |
2898 | char buf[64]; |
2899 | long val; | |
2900 | int ret; | |
2901 | ||
2902 | if (cnt >= sizeof(buf)) | |
2903 | return -EINVAL; | |
2904 | ||
2905 | if (copy_from_user(&buf, ubuf, cnt)) | |
2906 | return -EFAULT; | |
2907 | ||
2908 | buf[cnt] = 0; | |
2909 | ||
2910 | ret = strict_strtol(buf, 10, &val); | |
2911 | if (ret < 0) | |
2912 | return ret; | |
2913 | ||
e6ea44e9 | 2914 | mutex_lock(&ftrace_lock); |
978f3a45 | 2915 | if (val < 0) { |
df4fc315 | 2916 | /* disable pid tracing */ |
978f3a45 | 2917 | if (!ftrace_pid_trace) |
df4fc315 | 2918 | goto out; |
978f3a45 SR |
2919 | |
2920 | clear_ftrace_pid_task(&ftrace_pid_trace); | |
df4fc315 SR |
2921 | |
2922 | } else { | |
e32d8956 SR |
2923 | /* swapper task is special */ |
2924 | if (!val) { | |
2925 | pid = ftrace_swapper_pid; | |
2926 | if (pid == ftrace_pid_trace) | |
2927 | goto out; | |
2928 | } else { | |
2929 | pid = find_get_pid(val); | |
df4fc315 | 2930 | |
e32d8956 SR |
2931 | if (pid == ftrace_pid_trace) { |
2932 | put_pid(pid); | |
2933 | goto out; | |
2934 | } | |
0ef8cde5 | 2935 | } |
0ef8cde5 | 2936 | |
978f3a45 SR |
2937 | if (ftrace_pid_trace) |
2938 | clear_ftrace_pid_task(&ftrace_pid_trace); | |
2939 | ||
2940 | if (!pid) | |
2941 | goto out; | |
2942 | ||
2943 | ftrace_pid_trace = pid; | |
2944 | ||
2945 | set_ftrace_pid_task(ftrace_pid_trace); | |
df4fc315 SR |
2946 | } |
2947 | ||
2948 | /* update the function call */ | |
2949 | ftrace_update_pid_func(); | |
2950 | ftrace_startup_enable(0); | |
2951 | ||
2952 | out: | |
e6ea44e9 | 2953 | mutex_unlock(&ftrace_lock); |
df4fc315 SR |
2954 | |
2955 | return cnt; | |
2956 | } | |
2957 | ||
5e2336a0 | 2958 | static const struct file_operations ftrace_pid_fops = { |
df4fc315 SR |
2959 | .read = ftrace_pid_read, |
2960 | .write = ftrace_pid_write, | |
2961 | }; | |
2962 | ||
2963 | static __init int ftrace_init_debugfs(void) | |
2964 | { | |
2965 | struct dentry *d_tracer; | |
2966 | struct dentry *entry; | |
2967 | ||
2968 | d_tracer = tracing_init_dentry(); | |
2969 | if (!d_tracer) | |
2970 | return 0; | |
2971 | ||
2972 | ftrace_init_dyn_debugfs(d_tracer); | |
2973 | ||
2974 | entry = debugfs_create_file("set_ftrace_pid", 0644, d_tracer, | |
2975 | NULL, &ftrace_pid_fops); | |
2976 | if (!entry) | |
2977 | pr_warning("Could not create debugfs " | |
2978 | "'set_ftrace_pid' entry\n"); | |
493762fc SR |
2979 | |
2980 | ftrace_profile_debugfs(d_tracer); | |
2981 | ||
df4fc315 SR |
2982 | return 0; |
2983 | } | |
df4fc315 SR |
2984 | fs_initcall(ftrace_init_debugfs); |
2985 | ||
a2bb6a3d | 2986 | /** |
81adbdc0 | 2987 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
2988 | * |
2989 | * This function should be used by panic code. It stops ftrace | |
2990 | * but in a not so nice way. If you need to simply kill ftrace | |
2991 | * from a non-atomic section, use ftrace_kill. | |
2992 | */ | |
81adbdc0 | 2993 | void ftrace_kill(void) |
a2bb6a3d SR |
2994 | { |
2995 | ftrace_disabled = 1; | |
2996 | ftrace_enabled = 0; | |
a2bb6a3d SR |
2997 | clear_ftrace_function(); |
2998 | } | |
2999 | ||
16444a8a | 3000 | /** |
3d083395 SR |
3001 | * register_ftrace_function - register a function for profiling |
3002 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 3003 | * |
3d083395 SR |
3004 | * Register a function to be called by all functions in the |
3005 | * kernel. | |
3006 | * | |
3007 | * Note: @ops->func and all the functions it calls must be labeled | |
3008 | * with "notrace", otherwise it will go into a | |
3009 | * recursive loop. | |
16444a8a | 3010 | */ |
3d083395 | 3011 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 3012 | { |
b0fc494f SR |
3013 | int ret; |
3014 | ||
4eebcc81 SR |
3015 | if (unlikely(ftrace_disabled)) |
3016 | return -1; | |
3017 | ||
e6ea44e9 | 3018 | mutex_lock(&ftrace_lock); |
e7d3737e | 3019 | |
b0fc494f | 3020 | ret = __register_ftrace_function(ops); |
5a45cfe1 | 3021 | ftrace_startup(0); |
b0fc494f | 3022 | |
e6ea44e9 | 3023 | mutex_unlock(&ftrace_lock); |
b0fc494f | 3024 | return ret; |
3d083395 SR |
3025 | } |
3026 | ||
3027 | /** | |
32632920 | 3028 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
3029 | * @ops - ops structure that holds the function to unregister |
3030 | * | |
3031 | * Unregister a function that was added to be called by ftrace profiling. | |
3032 | */ | |
3033 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
3034 | { | |
3035 | int ret; | |
3036 | ||
e6ea44e9 | 3037 | mutex_lock(&ftrace_lock); |
3d083395 | 3038 | ret = __unregister_ftrace_function(ops); |
5a45cfe1 | 3039 | ftrace_shutdown(0); |
e6ea44e9 | 3040 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
3041 | |
3042 | return ret; | |
3043 | } | |
3044 | ||
e309b41d | 3045 | int |
b0fc494f | 3046 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
5072c59f | 3047 | struct file *file, void __user *buffer, size_t *lenp, |
b0fc494f SR |
3048 | loff_t *ppos) |
3049 | { | |
3050 | int ret; | |
3051 | ||
4eebcc81 SR |
3052 | if (unlikely(ftrace_disabled)) |
3053 | return -ENODEV; | |
3054 | ||
e6ea44e9 | 3055 | mutex_lock(&ftrace_lock); |
b0fc494f | 3056 | |
5072c59f | 3057 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
b0fc494f SR |
3058 | |
3059 | if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) | |
3060 | goto out; | |
3061 | ||
3062 | last_ftrace_enabled = ftrace_enabled; | |
3063 | ||
3064 | if (ftrace_enabled) { | |
3065 | ||
3066 | ftrace_startup_sysctl(); | |
3067 | ||
3068 | /* we are starting ftrace again */ | |
3069 | if (ftrace_list != &ftrace_list_end) { | |
3070 | if (ftrace_list->next == &ftrace_list_end) | |
3071 | ftrace_trace_function = ftrace_list->func; | |
3072 | else | |
3073 | ftrace_trace_function = ftrace_list_func; | |
3074 | } | |
3075 | ||
3076 | } else { | |
3077 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
3078 | ftrace_trace_function = ftrace_stub; | |
3079 | ||
3080 | ftrace_shutdown_sysctl(); | |
3081 | } | |
3082 | ||
3083 | out: | |
e6ea44e9 | 3084 | mutex_unlock(&ftrace_lock); |
3d083395 | 3085 | return ret; |
16444a8a | 3086 | } |
f17845e5 | 3087 | |
fb52607a | 3088 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 3089 | |
287b6e68 | 3090 | static atomic_t ftrace_graph_active; |
4a2b8dda | 3091 | static struct notifier_block ftrace_suspend_notifier; |
e7d3737e | 3092 | |
e49dc19c SR |
3093 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
3094 | { | |
3095 | return 0; | |
3096 | } | |
3097 | ||
287b6e68 FW |
3098 | /* The callbacks that hook a function */ |
3099 | trace_func_graph_ret_t ftrace_graph_return = | |
3100 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 3101 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
3102 | |
3103 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
3104 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
3105 | { | |
3106 | int i; | |
3107 | int ret = 0; | |
3108 | unsigned long flags; | |
3109 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
3110 | struct task_struct *g, *t; | |
3111 | ||
3112 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
3113 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
3114 | * sizeof(struct ftrace_ret_stack), | |
3115 | GFP_KERNEL); | |
3116 | if (!ret_stack_list[i]) { | |
3117 | start = 0; | |
3118 | end = i; | |
3119 | ret = -ENOMEM; | |
3120 | goto free; | |
3121 | } | |
3122 | } | |
3123 | ||
3124 | read_lock_irqsave(&tasklist_lock, flags); | |
3125 | do_each_thread(g, t) { | |
3126 | if (start == end) { | |
3127 | ret = -EAGAIN; | |
3128 | goto unlock; | |
3129 | } | |
3130 | ||
3131 | if (t->ret_stack == NULL) { | |
f201ae23 | 3132 | t->curr_ret_stack = -1; |
48d68b20 FW |
3133 | /* Make sure IRQs see the -1 first: */ |
3134 | barrier(); | |
3135 | t->ret_stack = ret_stack_list[start++]; | |
380c4b14 | 3136 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 FW |
3137 | atomic_set(&t->trace_overrun, 0); |
3138 | } | |
3139 | } while_each_thread(g, t); | |
3140 | ||
3141 | unlock: | |
3142 | read_unlock_irqrestore(&tasklist_lock, flags); | |
3143 | free: | |
3144 | for (i = start; i < end; i++) | |
3145 | kfree(ret_stack_list[i]); | |
3146 | return ret; | |
3147 | } | |
3148 | ||
8aef2d28 SR |
3149 | static void |
3150 | ftrace_graph_probe_sched_switch(struct rq *__rq, struct task_struct *prev, | |
3151 | struct task_struct *next) | |
3152 | { | |
3153 | unsigned long long timestamp; | |
3154 | int index; | |
3155 | ||
be6f164a SR |
3156 | /* |
3157 | * Does the user want to count the time a function was asleep. | |
3158 | * If so, do not update the time stamps. | |
3159 | */ | |
3160 | if (trace_flags & TRACE_ITER_SLEEP_TIME) | |
3161 | return; | |
3162 | ||
8aef2d28 SR |
3163 | timestamp = trace_clock_local(); |
3164 | ||
3165 | prev->ftrace_timestamp = timestamp; | |
3166 | ||
3167 | /* only process tasks that we timestamped */ | |
3168 | if (!next->ftrace_timestamp) | |
3169 | return; | |
3170 | ||
3171 | /* | |
3172 | * Update all the counters in next to make up for the | |
3173 | * time next was sleeping. | |
3174 | */ | |
3175 | timestamp -= next->ftrace_timestamp; | |
3176 | ||
3177 | for (index = next->curr_ret_stack; index >= 0; index--) | |
3178 | next->ret_stack[index].calltime += timestamp; | |
3179 | } | |
3180 | ||
f201ae23 | 3181 | /* Allocate a return stack for each task */ |
fb52607a | 3182 | static int start_graph_tracing(void) |
f201ae23 FW |
3183 | { |
3184 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 3185 | int ret, cpu; |
f201ae23 FW |
3186 | |
3187 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
3188 | sizeof(struct ftrace_ret_stack *), | |
3189 | GFP_KERNEL); | |
3190 | ||
3191 | if (!ret_stack_list) | |
3192 | return -ENOMEM; | |
3193 | ||
5b058bcd FW |
3194 | /* The cpu_boot init_task->ret_stack will never be freed */ |
3195 | for_each_online_cpu(cpu) | |
3196 | ftrace_graph_init_task(idle_task(cpu)); | |
3197 | ||
f201ae23 FW |
3198 | do { |
3199 | ret = alloc_retstack_tasklist(ret_stack_list); | |
3200 | } while (ret == -EAGAIN); | |
3201 | ||
8aef2d28 SR |
3202 | if (!ret) { |
3203 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch); | |
3204 | if (ret) | |
3205 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
3206 | " probe to kernel_sched_switch\n"); | |
3207 | } | |
3208 | ||
f201ae23 FW |
3209 | kfree(ret_stack_list); |
3210 | return ret; | |
3211 | } | |
3212 | ||
4a2b8dda FW |
3213 | /* |
3214 | * Hibernation protection. | |
3215 | * The state of the current task is too much unstable during | |
3216 | * suspend/restore to disk. We want to protect against that. | |
3217 | */ | |
3218 | static int | |
3219 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
3220 | void *unused) | |
3221 | { | |
3222 | switch (state) { | |
3223 | case PM_HIBERNATION_PREPARE: | |
3224 | pause_graph_tracing(); | |
3225 | break; | |
3226 | ||
3227 | case PM_POST_HIBERNATION: | |
3228 | unpause_graph_tracing(); | |
3229 | break; | |
3230 | } | |
3231 | return NOTIFY_DONE; | |
3232 | } | |
3233 | ||
287b6e68 FW |
3234 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
3235 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 3236 | { |
e7d3737e FW |
3237 | int ret = 0; |
3238 | ||
e6ea44e9 | 3239 | mutex_lock(&ftrace_lock); |
e7d3737e | 3240 | |
05ce5818 SR |
3241 | /* we currently allow only one tracer registered at a time */ |
3242 | if (atomic_read(&ftrace_graph_active)) { | |
3243 | ret = -EBUSY; | |
3244 | goto out; | |
3245 | } | |
3246 | ||
4a2b8dda FW |
3247 | ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; |
3248 | register_pm_notifier(&ftrace_suspend_notifier); | |
3249 | ||
287b6e68 | 3250 | atomic_inc(&ftrace_graph_active); |
fb52607a | 3251 | ret = start_graph_tracing(); |
f201ae23 | 3252 | if (ret) { |
287b6e68 | 3253 | atomic_dec(&ftrace_graph_active); |
f201ae23 FW |
3254 | goto out; |
3255 | } | |
e53a6319 | 3256 | |
287b6e68 FW |
3257 | ftrace_graph_return = retfunc; |
3258 | ftrace_graph_entry = entryfunc; | |
e53a6319 | 3259 | |
5a45cfe1 | 3260 | ftrace_startup(FTRACE_START_FUNC_RET); |
e7d3737e FW |
3261 | |
3262 | out: | |
e6ea44e9 | 3263 | mutex_unlock(&ftrace_lock); |
e7d3737e | 3264 | return ret; |
15e6cb36 FW |
3265 | } |
3266 | ||
fb52607a | 3267 | void unregister_ftrace_graph(void) |
15e6cb36 | 3268 | { |
e6ea44e9 | 3269 | mutex_lock(&ftrace_lock); |
e7d3737e | 3270 | |
287b6e68 | 3271 | atomic_dec(&ftrace_graph_active); |
8aef2d28 | 3272 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch); |
287b6e68 | 3273 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 3274 | ftrace_graph_entry = ftrace_graph_entry_stub; |
5a45cfe1 | 3275 | ftrace_shutdown(FTRACE_STOP_FUNC_RET); |
4a2b8dda | 3276 | unregister_pm_notifier(&ftrace_suspend_notifier); |
e7d3737e | 3277 | |
e6ea44e9 | 3278 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 3279 | } |
f201ae23 FW |
3280 | |
3281 | /* Allocate a return stack for newly created task */ | |
fb52607a | 3282 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 3283 | { |
287b6e68 | 3284 | if (atomic_read(&ftrace_graph_active)) { |
f201ae23 FW |
3285 | t->ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH |
3286 | * sizeof(struct ftrace_ret_stack), | |
3287 | GFP_KERNEL); | |
3288 | if (!t->ret_stack) | |
3289 | return; | |
3290 | t->curr_ret_stack = -1; | |
380c4b14 | 3291 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 3292 | atomic_set(&t->trace_overrun, 0); |
8aef2d28 | 3293 | t->ftrace_timestamp = 0; |
f201ae23 FW |
3294 | } else |
3295 | t->ret_stack = NULL; | |
3296 | } | |
3297 | ||
fb52607a | 3298 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 3299 | { |
eae849ca FW |
3300 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
3301 | ||
f201ae23 | 3302 | t->ret_stack = NULL; |
eae849ca FW |
3303 | /* NULL must become visible to IRQs before we free it: */ |
3304 | barrier(); | |
3305 | ||
3306 | kfree(ret_stack); | |
f201ae23 | 3307 | } |
14a866c5 SR |
3308 | |
3309 | void ftrace_graph_stop(void) | |
3310 | { | |
3311 | ftrace_stop(); | |
3312 | } | |
15e6cb36 FW |
3313 | #endif |
3314 |