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 | |
ad8d75ff | 32 | #include <trace/events/sched.h> |
8aef2d28 | 33 | |
395a59d0 | 34 | #include <asm/ftrace.h> |
2af15d6a | 35 | #include <asm/setup.h> |
395a59d0 | 36 | |
0706f1c4 | 37 | #include "trace_output.h" |
bac429f0 | 38 | #include "trace_stat.h" |
16444a8a | 39 | |
6912896e SR |
40 | #define FTRACE_WARN_ON(cond) \ |
41 | do { \ | |
42 | if (WARN_ON(cond)) \ | |
43 | ftrace_kill(); \ | |
44 | } while (0) | |
45 | ||
46 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
47 | do { \ | |
48 | if (WARN_ON_ONCE(cond)) \ | |
49 | ftrace_kill(); \ | |
50 | } while (0) | |
51 | ||
8fc0c701 SR |
52 | /* hash bits for specific function selection */ |
53 | #define FTRACE_HASH_BITS 7 | |
54 | #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS) | |
55 | ||
4eebcc81 SR |
56 | /* ftrace_enabled is a method to turn ftrace on or off */ |
57 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 58 | static int last_ftrace_enabled; |
b0fc494f | 59 | |
60a7ecf4 SR |
60 | /* Quick disabling of function tracer. */ |
61 | int function_trace_stop; | |
62 | ||
4eebcc81 SR |
63 | /* |
64 | * ftrace_disabled is set when an anomaly is discovered. | |
65 | * ftrace_disabled is much stronger than ftrace_enabled. | |
66 | */ | |
67 | static int ftrace_disabled __read_mostly; | |
68 | ||
52baf119 | 69 | static DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 70 | |
16444a8a ACM |
71 | static struct ftrace_ops ftrace_list_end __read_mostly = |
72 | { | |
fb9fb015 | 73 | .func = ftrace_stub, |
16444a8a ACM |
74 | }; |
75 | ||
76 | static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; | |
77 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; | |
60a7ecf4 | 78 | ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub; |
df4fc315 | 79 | ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; |
16444a8a | 80 | |
f2252935 | 81 | static void ftrace_list_func(unsigned long ip, unsigned long parent_ip) |
16444a8a ACM |
82 | { |
83 | struct ftrace_ops *op = ftrace_list; | |
84 | ||
85 | /* in case someone actually ports this to alpha! */ | |
86 | read_barrier_depends(); | |
87 | ||
88 | while (op != &ftrace_list_end) { | |
89 | /* silly alpha */ | |
90 | read_barrier_depends(); | |
91 | op->func(ip, parent_ip); | |
92 | op = op->next; | |
93 | }; | |
94 | } | |
95 | ||
df4fc315 SR |
96 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip) |
97 | { | |
0ef8cde5 | 98 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
99 | return; |
100 | ||
101 | ftrace_pid_function(ip, parent_ip); | |
102 | } | |
103 | ||
104 | static void set_ftrace_pid_function(ftrace_func_t func) | |
105 | { | |
106 | /* do not set ftrace_pid_function to itself! */ | |
107 | if (func != ftrace_pid_func) | |
108 | ftrace_pid_function = func; | |
109 | } | |
110 | ||
16444a8a | 111 | /** |
3d083395 | 112 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 113 | * |
3d083395 SR |
114 | * This NULLs the ftrace function and in essence stops |
115 | * tracing. There may be lag | |
16444a8a | 116 | */ |
3d083395 | 117 | void clear_ftrace_function(void) |
16444a8a | 118 | { |
3d083395 | 119 | ftrace_trace_function = ftrace_stub; |
60a7ecf4 | 120 | __ftrace_trace_function = ftrace_stub; |
df4fc315 | 121 | ftrace_pid_function = ftrace_stub; |
3d083395 SR |
122 | } |
123 | ||
60a7ecf4 SR |
124 | #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
125 | /* | |
126 | * For those archs that do not test ftrace_trace_stop in their | |
127 | * mcount call site, we need to do it from C. | |
128 | */ | |
129 | static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip) | |
130 | { | |
131 | if (function_trace_stop) | |
132 | return; | |
133 | ||
134 | __ftrace_trace_function(ip, parent_ip); | |
135 | } | |
136 | #endif | |
137 | ||
e309b41d | 138 | static int __register_ftrace_function(struct ftrace_ops *ops) |
3d083395 | 139 | { |
16444a8a ACM |
140 | ops->next = ftrace_list; |
141 | /* | |
142 | * We are entering ops into the ftrace_list but another | |
143 | * CPU might be walking that list. We need to make sure | |
144 | * the ops->next pointer is valid before another CPU sees | |
145 | * the ops pointer included into the ftrace_list. | |
146 | */ | |
147 | smp_wmb(); | |
148 | ftrace_list = ops; | |
3d083395 | 149 | |
b0fc494f | 150 | if (ftrace_enabled) { |
df4fc315 SR |
151 | ftrace_func_t func; |
152 | ||
153 | if (ops->next == &ftrace_list_end) | |
154 | func = ops->func; | |
155 | else | |
156 | func = ftrace_list_func; | |
157 | ||
978f3a45 | 158 | if (ftrace_pid_trace) { |
df4fc315 SR |
159 | set_ftrace_pid_function(func); |
160 | func = ftrace_pid_func; | |
161 | } | |
162 | ||
b0fc494f SR |
163 | /* |
164 | * For one func, simply call it directly. | |
165 | * For more than one func, call the chain. | |
166 | */ | |
60a7ecf4 | 167 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
df4fc315 | 168 | ftrace_trace_function = func; |
60a7ecf4 | 169 | #else |
df4fc315 | 170 | __ftrace_trace_function = func; |
60a7ecf4 SR |
171 | ftrace_trace_function = ftrace_test_stop_func; |
172 | #endif | |
b0fc494f | 173 | } |
3d083395 | 174 | |
16444a8a ACM |
175 | return 0; |
176 | } | |
177 | ||
e309b41d | 178 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 179 | { |
16444a8a | 180 | struct ftrace_ops **p; |
16444a8a ACM |
181 | |
182 | /* | |
3d083395 SR |
183 | * If we are removing the last function, then simply point |
184 | * to the ftrace_stub. | |
16444a8a ACM |
185 | */ |
186 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { | |
187 | ftrace_trace_function = ftrace_stub; | |
188 | ftrace_list = &ftrace_list_end; | |
e6ea44e9 | 189 | return 0; |
16444a8a ACM |
190 | } |
191 | ||
192 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) | |
193 | if (*p == ops) | |
194 | break; | |
195 | ||
e6ea44e9 SR |
196 | if (*p != ops) |
197 | return -1; | |
16444a8a ACM |
198 | |
199 | *p = (*p)->next; | |
200 | ||
b0fc494f SR |
201 | if (ftrace_enabled) { |
202 | /* If we only have one func left, then call that directly */ | |
df4fc315 SR |
203 | if (ftrace_list->next == &ftrace_list_end) { |
204 | ftrace_func_t func = ftrace_list->func; | |
205 | ||
978f3a45 | 206 | if (ftrace_pid_trace) { |
df4fc315 SR |
207 | set_ftrace_pid_function(func); |
208 | func = ftrace_pid_func; | |
209 | } | |
210 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
211 | ftrace_trace_function = func; | |
212 | #else | |
213 | __ftrace_trace_function = func; | |
214 | #endif | |
215 | } | |
b0fc494f | 216 | } |
16444a8a | 217 | |
e6ea44e9 | 218 | return 0; |
3d083395 SR |
219 | } |
220 | ||
df4fc315 SR |
221 | static void ftrace_update_pid_func(void) |
222 | { | |
223 | ftrace_func_t func; | |
224 | ||
df4fc315 | 225 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 226 | return; |
df4fc315 SR |
227 | |
228 | func = ftrace_trace_function; | |
229 | ||
978f3a45 | 230 | if (ftrace_pid_trace) { |
df4fc315 SR |
231 | set_ftrace_pid_function(func); |
232 | func = ftrace_pid_func; | |
233 | } else { | |
66eafebc LW |
234 | if (func == ftrace_pid_func) |
235 | func = ftrace_pid_function; | |
df4fc315 SR |
236 | } |
237 | ||
238 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
239 | ftrace_trace_function = func; | |
240 | #else | |
241 | __ftrace_trace_function = func; | |
242 | #endif | |
df4fc315 SR |
243 | } |
244 | ||
493762fc SR |
245 | #ifdef CONFIG_FUNCTION_PROFILER |
246 | struct ftrace_profile { | |
247 | struct hlist_node node; | |
248 | unsigned long ip; | |
249 | unsigned long counter; | |
0706f1c4 SR |
250 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
251 | unsigned long long time; | |
252 | #endif | |
8fc0c701 SR |
253 | }; |
254 | ||
493762fc SR |
255 | struct ftrace_profile_page { |
256 | struct ftrace_profile_page *next; | |
257 | unsigned long index; | |
258 | struct ftrace_profile records[]; | |
d61f82d0 SR |
259 | }; |
260 | ||
cafb168a SR |
261 | struct ftrace_profile_stat { |
262 | atomic_t disabled; | |
263 | struct hlist_head *hash; | |
264 | struct ftrace_profile_page *pages; | |
265 | struct ftrace_profile_page *start; | |
266 | struct tracer_stat stat; | |
267 | }; | |
268 | ||
493762fc SR |
269 | #define PROFILE_RECORDS_SIZE \ |
270 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 271 | |
493762fc SR |
272 | #define PROFILES_PER_PAGE \ |
273 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 274 | |
fb9fb015 SR |
275 | static int ftrace_profile_bits __read_mostly; |
276 | static int ftrace_profile_enabled __read_mostly; | |
277 | ||
278 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
279 | static DEFINE_MUTEX(ftrace_profile_lock); |
280 | ||
cafb168a | 281 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc SR |
282 | |
283 | #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */ | |
284 | ||
bac429f0 SR |
285 | static void * |
286 | function_stat_next(void *v, int idx) | |
287 | { | |
493762fc SR |
288 | struct ftrace_profile *rec = v; |
289 | struct ftrace_profile_page *pg; | |
bac429f0 | 290 | |
493762fc | 291 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
292 | |
293 | again: | |
294 | rec++; | |
295 | if ((void *)rec >= (void *)&pg->records[pg->index]) { | |
296 | pg = pg->next; | |
297 | if (!pg) | |
298 | return NULL; | |
299 | rec = &pg->records[0]; | |
493762fc SR |
300 | if (!rec->counter) |
301 | goto again; | |
bac429f0 SR |
302 | } |
303 | ||
bac429f0 SR |
304 | return rec; |
305 | } | |
306 | ||
307 | static void *function_stat_start(struct tracer_stat *trace) | |
308 | { | |
cafb168a SR |
309 | struct ftrace_profile_stat *stat = |
310 | container_of(trace, struct ftrace_profile_stat, stat); | |
311 | ||
312 | if (!stat || !stat->start) | |
313 | return NULL; | |
314 | ||
315 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
316 | } |
317 | ||
0706f1c4 SR |
318 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
319 | /* function graph compares on total time */ | |
320 | static int function_stat_cmp(void *p1, void *p2) | |
321 | { | |
322 | struct ftrace_profile *a = p1; | |
323 | struct ftrace_profile *b = p2; | |
324 | ||
325 | if (a->time < b->time) | |
326 | return -1; | |
327 | if (a->time > b->time) | |
328 | return 1; | |
329 | else | |
330 | return 0; | |
331 | } | |
332 | #else | |
333 | /* not function graph compares against hits */ | |
bac429f0 SR |
334 | static int function_stat_cmp(void *p1, void *p2) |
335 | { | |
493762fc SR |
336 | struct ftrace_profile *a = p1; |
337 | struct ftrace_profile *b = p2; | |
bac429f0 SR |
338 | |
339 | if (a->counter < b->counter) | |
340 | return -1; | |
341 | if (a->counter > b->counter) | |
342 | return 1; | |
343 | else | |
344 | return 0; | |
345 | } | |
0706f1c4 | 346 | #endif |
bac429f0 SR |
347 | |
348 | static int function_stat_headers(struct seq_file *m) | |
349 | { | |
0706f1c4 | 350 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
351 | seq_printf(m, " Function " |
352 | "Hit Time Avg\n" | |
353 | " -------- " | |
354 | "--- ---- ---\n"); | |
0706f1c4 | 355 | #else |
bac429f0 SR |
356 | seq_printf(m, " Function Hit\n" |
357 | " -------- ---\n"); | |
0706f1c4 | 358 | #endif |
bac429f0 SR |
359 | return 0; |
360 | } | |
361 | ||
362 | static int function_stat_show(struct seq_file *m, void *v) | |
363 | { | |
493762fc | 364 | struct ftrace_profile *rec = v; |
bac429f0 | 365 | char str[KSYM_SYMBOL_LEN]; |
0706f1c4 | 366 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
0706f1c4 | 367 | static DEFINE_MUTEX(mutex); |
34886c8b SR |
368 | static struct trace_seq s; |
369 | unsigned long long avg; | |
0706f1c4 | 370 | #endif |
bac429f0 SR |
371 | |
372 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
0706f1c4 SR |
373 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
374 | ||
375 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
376 | seq_printf(m, " "); | |
34886c8b SR |
377 | avg = rec->time; |
378 | do_div(avg, rec->counter); | |
379 | ||
380 | mutex_lock(&mutex); | |
381 | trace_seq_init(&s); | |
382 | trace_print_graph_duration(rec->time, &s); | |
383 | trace_seq_puts(&s, " "); | |
384 | trace_print_graph_duration(avg, &s); | |
0706f1c4 SR |
385 | trace_print_seq(m, &s); |
386 | mutex_unlock(&mutex); | |
387 | #endif | |
388 | seq_putc(m, '\n'); | |
bac429f0 | 389 | |
bac429f0 SR |
390 | return 0; |
391 | } | |
392 | ||
cafb168a | 393 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 394 | { |
493762fc | 395 | struct ftrace_profile_page *pg; |
bac429f0 | 396 | |
cafb168a | 397 | pg = stat->pages = stat->start; |
bac429f0 | 398 | |
493762fc SR |
399 | while (pg) { |
400 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
401 | pg->index = 0; | |
402 | pg = pg->next; | |
bac429f0 SR |
403 | } |
404 | ||
cafb168a | 405 | memset(stat->hash, 0, |
493762fc SR |
406 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
407 | } | |
bac429f0 | 408 | |
cafb168a | 409 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
410 | { |
411 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
412 | int functions; |
413 | int pages; | |
493762fc | 414 | int i; |
bac429f0 | 415 | |
493762fc | 416 | /* If we already allocated, do nothing */ |
cafb168a | 417 | if (stat->pages) |
493762fc | 418 | return 0; |
bac429f0 | 419 | |
cafb168a SR |
420 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
421 | if (!stat->pages) | |
493762fc | 422 | return -ENOMEM; |
bac429f0 | 423 | |
318e0a73 SR |
424 | #ifdef CONFIG_DYNAMIC_FTRACE |
425 | functions = ftrace_update_tot_cnt; | |
426 | #else | |
427 | /* | |
428 | * We do not know the number of functions that exist because | |
429 | * dynamic tracing is what counts them. With past experience | |
430 | * we have around 20K functions. That should be more than enough. | |
431 | * It is highly unlikely we will execute every function in | |
432 | * the kernel. | |
433 | */ | |
434 | functions = 20000; | |
435 | #endif | |
436 | ||
cafb168a | 437 | pg = stat->start = stat->pages; |
bac429f0 | 438 | |
318e0a73 SR |
439 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
440 | ||
441 | for (i = 0; i < pages; i++) { | |
493762fc | 442 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 443 | if (!pg->next) |
318e0a73 | 444 | goto out_free; |
493762fc SR |
445 | pg = pg->next; |
446 | } | |
447 | ||
448 | return 0; | |
318e0a73 SR |
449 | |
450 | out_free: | |
451 | pg = stat->start; | |
452 | while (pg) { | |
453 | unsigned long tmp = (unsigned long)pg; | |
454 | ||
455 | pg = pg->next; | |
456 | free_page(tmp); | |
457 | } | |
458 | ||
459 | free_page((unsigned long)stat->pages); | |
460 | stat->pages = NULL; | |
461 | stat->start = NULL; | |
462 | ||
463 | return -ENOMEM; | |
bac429f0 SR |
464 | } |
465 | ||
cafb168a | 466 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 467 | { |
cafb168a | 468 | struct ftrace_profile_stat *stat; |
493762fc | 469 | int size; |
bac429f0 | 470 | |
cafb168a SR |
471 | stat = &per_cpu(ftrace_profile_stats, cpu); |
472 | ||
473 | if (stat->hash) { | |
493762fc | 474 | /* If the profile is already created, simply reset it */ |
cafb168a | 475 | ftrace_profile_reset(stat); |
493762fc SR |
476 | return 0; |
477 | } | |
bac429f0 | 478 | |
493762fc SR |
479 | /* |
480 | * We are profiling all functions, but usually only a few thousand | |
481 | * functions are hit. We'll make a hash of 1024 items. | |
482 | */ | |
483 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 484 | |
cafb168a | 485 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
493762fc | 486 | |
cafb168a | 487 | if (!stat->hash) |
493762fc SR |
488 | return -ENOMEM; |
489 | ||
cafb168a SR |
490 | if (!ftrace_profile_bits) { |
491 | size--; | |
493762fc | 492 | |
cafb168a SR |
493 | for (; size; size >>= 1) |
494 | ftrace_profile_bits++; | |
495 | } | |
493762fc | 496 | |
318e0a73 | 497 | /* Preallocate the function profiling pages */ |
cafb168a SR |
498 | if (ftrace_profile_pages_init(stat) < 0) { |
499 | kfree(stat->hash); | |
500 | stat->hash = NULL; | |
493762fc SR |
501 | return -ENOMEM; |
502 | } | |
503 | ||
504 | return 0; | |
bac429f0 SR |
505 | } |
506 | ||
cafb168a SR |
507 | static int ftrace_profile_init(void) |
508 | { | |
509 | int cpu; | |
510 | int ret = 0; | |
511 | ||
512 | for_each_online_cpu(cpu) { | |
513 | ret = ftrace_profile_init_cpu(cpu); | |
514 | if (ret) | |
515 | break; | |
516 | } | |
517 | ||
518 | return ret; | |
519 | } | |
520 | ||
493762fc | 521 | /* interrupts must be disabled */ |
cafb168a SR |
522 | static struct ftrace_profile * |
523 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 524 | { |
493762fc | 525 | struct ftrace_profile *rec; |
bac429f0 SR |
526 | struct hlist_head *hhd; |
527 | struct hlist_node *n; | |
bac429f0 SR |
528 | unsigned long key; |
529 | ||
bac429f0 | 530 | key = hash_long(ip, ftrace_profile_bits); |
cafb168a | 531 | hhd = &stat->hash[key]; |
bac429f0 SR |
532 | |
533 | if (hlist_empty(hhd)) | |
534 | return NULL; | |
535 | ||
bac429f0 SR |
536 | hlist_for_each_entry_rcu(rec, n, hhd, node) { |
537 | if (rec->ip == ip) | |
493762fc SR |
538 | return rec; |
539 | } | |
540 | ||
541 | return NULL; | |
542 | } | |
543 | ||
cafb168a SR |
544 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
545 | struct ftrace_profile *rec) | |
493762fc SR |
546 | { |
547 | unsigned long key; | |
548 | ||
549 | key = hash_long(rec->ip, ftrace_profile_bits); | |
cafb168a | 550 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
551 | } |
552 | ||
318e0a73 SR |
553 | /* |
554 | * The memory is already allocated, this simply finds a new record to use. | |
555 | */ | |
493762fc | 556 | static struct ftrace_profile * |
318e0a73 | 557 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
558 | { |
559 | struct ftrace_profile *rec = NULL; | |
560 | ||
318e0a73 | 561 | /* prevent recursion (from NMIs) */ |
cafb168a | 562 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
563 | goto out; |
564 | ||
493762fc | 565 | /* |
318e0a73 SR |
566 | * Try to find the function again since an NMI |
567 | * could have added it | |
493762fc | 568 | */ |
cafb168a | 569 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 570 | if (rec) |
cafb168a | 571 | goto out; |
493762fc | 572 | |
cafb168a SR |
573 | if (stat->pages->index == PROFILES_PER_PAGE) { |
574 | if (!stat->pages->next) | |
575 | goto out; | |
576 | stat->pages = stat->pages->next; | |
bac429f0 | 577 | } |
493762fc | 578 | |
cafb168a | 579 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 580 | rec->ip = ip; |
cafb168a | 581 | ftrace_add_profile(stat, rec); |
493762fc | 582 | |
bac429f0 | 583 | out: |
cafb168a | 584 | atomic_dec(&stat->disabled); |
bac429f0 SR |
585 | |
586 | return rec; | |
587 | } | |
588 | ||
589 | static void | |
590 | function_profile_call(unsigned long ip, unsigned long parent_ip) | |
591 | { | |
cafb168a | 592 | struct ftrace_profile_stat *stat; |
493762fc | 593 | struct ftrace_profile *rec; |
bac429f0 SR |
594 | unsigned long flags; |
595 | ||
596 | if (!ftrace_profile_enabled) | |
597 | return; | |
598 | ||
599 | local_irq_save(flags); | |
cafb168a SR |
600 | |
601 | stat = &__get_cpu_var(ftrace_profile_stats); | |
0f6ce3de | 602 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
603 | goto out; |
604 | ||
605 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 606 | if (!rec) { |
318e0a73 | 607 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
608 | if (!rec) |
609 | goto out; | |
610 | } | |
bac429f0 SR |
611 | |
612 | rec->counter++; | |
613 | out: | |
614 | local_irq_restore(flags); | |
615 | } | |
616 | ||
0706f1c4 SR |
617 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
618 | static int profile_graph_entry(struct ftrace_graph_ent *trace) | |
619 | { | |
620 | function_profile_call(trace->func, 0); | |
621 | return 1; | |
622 | } | |
623 | ||
624 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
625 | { | |
cafb168a | 626 | struct ftrace_profile_stat *stat; |
a2a16d6a | 627 | unsigned long long calltime; |
0706f1c4 | 628 | struct ftrace_profile *rec; |
cafb168a | 629 | unsigned long flags; |
0706f1c4 SR |
630 | |
631 | local_irq_save(flags); | |
cafb168a | 632 | stat = &__get_cpu_var(ftrace_profile_stats); |
0f6ce3de | 633 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
634 | goto out; |
635 | ||
a2a16d6a SR |
636 | calltime = trace->rettime - trace->calltime; |
637 | ||
638 | if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) { | |
639 | int index; | |
640 | ||
641 | index = trace->depth; | |
642 | ||
643 | /* Append this call time to the parent time to subtract */ | |
644 | if (index) | |
645 | current->ret_stack[index - 1].subtime += calltime; | |
646 | ||
647 | if (current->ret_stack[index].subtime < calltime) | |
648 | calltime -= current->ret_stack[index].subtime; | |
649 | else | |
650 | calltime = 0; | |
651 | } | |
652 | ||
cafb168a | 653 | rec = ftrace_find_profiled_func(stat, trace->func); |
0706f1c4 | 654 | if (rec) |
a2a16d6a SR |
655 | rec->time += calltime; |
656 | ||
cafb168a | 657 | out: |
0706f1c4 SR |
658 | local_irq_restore(flags); |
659 | } | |
660 | ||
661 | static int register_ftrace_profiler(void) | |
662 | { | |
663 | return register_ftrace_graph(&profile_graph_return, | |
664 | &profile_graph_entry); | |
665 | } | |
666 | ||
667 | static void unregister_ftrace_profiler(void) | |
668 | { | |
669 | unregister_ftrace_graph(); | |
670 | } | |
671 | #else | |
bac429f0 SR |
672 | static struct ftrace_ops ftrace_profile_ops __read_mostly = |
673 | { | |
fb9fb015 | 674 | .func = function_profile_call, |
bac429f0 SR |
675 | }; |
676 | ||
0706f1c4 SR |
677 | static int register_ftrace_profiler(void) |
678 | { | |
679 | return register_ftrace_function(&ftrace_profile_ops); | |
680 | } | |
681 | ||
682 | static void unregister_ftrace_profiler(void) | |
683 | { | |
684 | unregister_ftrace_function(&ftrace_profile_ops); | |
685 | } | |
686 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
687 | ||
bac429f0 SR |
688 | static ssize_t |
689 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
690 | size_t cnt, loff_t *ppos) | |
691 | { | |
692 | unsigned long val; | |
fb9fb015 | 693 | char buf[64]; /* big enough to hold a number */ |
bac429f0 SR |
694 | int ret; |
695 | ||
bac429f0 SR |
696 | if (cnt >= sizeof(buf)) |
697 | return -EINVAL; | |
698 | ||
699 | if (copy_from_user(&buf, ubuf, cnt)) | |
700 | return -EFAULT; | |
701 | ||
702 | buf[cnt] = 0; | |
703 | ||
704 | ret = strict_strtoul(buf, 10, &val); | |
705 | if (ret < 0) | |
706 | return ret; | |
707 | ||
708 | val = !!val; | |
709 | ||
710 | mutex_lock(&ftrace_profile_lock); | |
711 | if (ftrace_profile_enabled ^ val) { | |
712 | if (val) { | |
493762fc SR |
713 | ret = ftrace_profile_init(); |
714 | if (ret < 0) { | |
715 | cnt = ret; | |
716 | goto out; | |
717 | } | |
718 | ||
0706f1c4 SR |
719 | ret = register_ftrace_profiler(); |
720 | if (ret < 0) { | |
721 | cnt = ret; | |
722 | goto out; | |
723 | } | |
bac429f0 SR |
724 | ftrace_profile_enabled = 1; |
725 | } else { | |
726 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
727 | /* |
728 | * unregister_ftrace_profiler calls stop_machine | |
729 | * so this acts like an synchronize_sched. | |
730 | */ | |
0706f1c4 | 731 | unregister_ftrace_profiler(); |
bac429f0 SR |
732 | } |
733 | } | |
493762fc | 734 | out: |
bac429f0 SR |
735 | mutex_unlock(&ftrace_profile_lock); |
736 | ||
737 | filp->f_pos += cnt; | |
738 | ||
739 | return cnt; | |
740 | } | |
741 | ||
493762fc SR |
742 | static ssize_t |
743 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
744 | size_t cnt, loff_t *ppos) | |
745 | { | |
fb9fb015 | 746 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
747 | int r; |
748 | ||
749 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
750 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
751 | } | |
752 | ||
bac429f0 SR |
753 | static const struct file_operations ftrace_profile_fops = { |
754 | .open = tracing_open_generic, | |
755 | .read = ftrace_profile_read, | |
756 | .write = ftrace_profile_write, | |
757 | }; | |
758 | ||
cafb168a SR |
759 | /* used to initialize the real stat files */ |
760 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
761 | .name = "functions", |
762 | .stat_start = function_stat_start, | |
763 | .stat_next = function_stat_next, | |
764 | .stat_cmp = function_stat_cmp, | |
765 | .stat_headers = function_stat_headers, | |
766 | .stat_show = function_stat_show | |
cafb168a SR |
767 | }; |
768 | ||
bac429f0 SR |
769 | static void ftrace_profile_debugfs(struct dentry *d_tracer) |
770 | { | |
cafb168a | 771 | struct ftrace_profile_stat *stat; |
bac429f0 | 772 | struct dentry *entry; |
cafb168a | 773 | char *name; |
bac429f0 | 774 | int ret; |
cafb168a SR |
775 | int cpu; |
776 | ||
777 | for_each_possible_cpu(cpu) { | |
778 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
779 | ||
780 | /* allocate enough for function name + cpu number */ | |
781 | name = kmalloc(32, GFP_KERNEL); | |
782 | if (!name) { | |
783 | /* | |
784 | * The files created are permanent, if something happens | |
785 | * we still do not free memory. | |
786 | */ | |
787 | kfree(stat); | |
788 | WARN(1, | |
789 | "Could not allocate stat file for cpu %d\n", | |
790 | cpu); | |
791 | return; | |
792 | } | |
793 | stat->stat = function_stats; | |
794 | snprintf(name, 32, "function%d", cpu); | |
795 | stat->stat.name = name; | |
796 | ret = register_stat_tracer(&stat->stat); | |
797 | if (ret) { | |
798 | WARN(1, | |
799 | "Could not register function stat for cpu %d\n", | |
800 | cpu); | |
801 | kfree(name); | |
802 | return; | |
803 | } | |
bac429f0 SR |
804 | } |
805 | ||
806 | entry = debugfs_create_file("function_profile_enabled", 0644, | |
807 | d_tracer, NULL, &ftrace_profile_fops); | |
808 | if (!entry) | |
809 | pr_warning("Could not create debugfs " | |
810 | "'function_profile_enabled' entry\n"); | |
811 | } | |
812 | ||
bac429f0 | 813 | #else /* CONFIG_FUNCTION_PROFILER */ |
bac429f0 SR |
814 | static void ftrace_profile_debugfs(struct dentry *d_tracer) |
815 | { | |
816 | } | |
bac429f0 SR |
817 | #endif /* CONFIG_FUNCTION_PROFILER */ |
818 | ||
493762fc SR |
819 | /* set when tracing only a pid */ |
820 | struct pid *ftrace_pid_trace; | |
821 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; | |
822 | ||
823 | #ifdef CONFIG_DYNAMIC_FTRACE | |
824 | ||
825 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD | |
826 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
827 | #endif | |
828 | ||
829 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; | |
830 | ||
831 | struct ftrace_func_probe { | |
832 | struct hlist_node node; | |
833 | struct ftrace_probe_ops *ops; | |
834 | unsigned long flags; | |
835 | unsigned long ip; | |
836 | void *data; | |
837 | struct rcu_head rcu; | |
838 | }; | |
839 | ||
840 | enum { | |
841 | FTRACE_ENABLE_CALLS = (1 << 0), | |
842 | FTRACE_DISABLE_CALLS = (1 << 1), | |
843 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
844 | FTRACE_ENABLE_MCOUNT = (1 << 3), | |
845 | FTRACE_DISABLE_MCOUNT = (1 << 4), | |
846 | FTRACE_START_FUNC_RET = (1 << 5), | |
847 | FTRACE_STOP_FUNC_RET = (1 << 6), | |
848 | }; | |
849 | ||
850 | static int ftrace_filtered; | |
851 | ||
852 | static struct dyn_ftrace *ftrace_new_addrs; | |
853 | ||
854 | static DEFINE_MUTEX(ftrace_regex_lock); | |
855 | ||
856 | struct ftrace_page { | |
857 | struct ftrace_page *next; | |
858 | int index; | |
859 | struct dyn_ftrace records[]; | |
860 | }; | |
861 | ||
862 | #define ENTRIES_PER_PAGE \ | |
863 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
864 | ||
865 | /* estimate from running different kernels */ | |
866 | #define NR_TO_INIT 10000 | |
867 | ||
868 | static struct ftrace_page *ftrace_pages_start; | |
869 | static struct ftrace_page *ftrace_pages; | |
870 | ||
871 | static struct dyn_ftrace *ftrace_free_records; | |
872 | ||
873 | /* | |
874 | * This is a double for. Do not use 'break' to break out of the loop, | |
875 | * you must use a goto. | |
876 | */ | |
877 | #define do_for_each_ftrace_rec(pg, rec) \ | |
878 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
879 | int _____i; \ | |
880 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
881 | rec = &pg->records[_____i]; | |
882 | ||
883 | #define while_for_each_ftrace_rec() \ | |
884 | } \ | |
885 | } | |
886 | ||
ecea656d | 887 | #ifdef CONFIG_KPROBES |
f17845e5 IM |
888 | |
889 | static int frozen_record_count; | |
890 | ||
ecea656d AS |
891 | static inline void freeze_record(struct dyn_ftrace *rec) |
892 | { | |
893 | if (!(rec->flags & FTRACE_FL_FROZEN)) { | |
894 | rec->flags |= FTRACE_FL_FROZEN; | |
895 | frozen_record_count++; | |
896 | } | |
897 | } | |
898 | ||
899 | static inline void unfreeze_record(struct dyn_ftrace *rec) | |
900 | { | |
901 | if (rec->flags & FTRACE_FL_FROZEN) { | |
902 | rec->flags &= ~FTRACE_FL_FROZEN; | |
903 | frozen_record_count--; | |
904 | } | |
905 | } | |
906 | ||
907 | static inline int record_frozen(struct dyn_ftrace *rec) | |
908 | { | |
909 | return rec->flags & FTRACE_FL_FROZEN; | |
910 | } | |
911 | #else | |
912 | # define freeze_record(rec) ({ 0; }) | |
913 | # define unfreeze_record(rec) ({ 0; }) | |
914 | # define record_frozen(rec) ({ 0; }) | |
915 | #endif /* CONFIG_KPROBES */ | |
916 | ||
e309b41d | 917 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
37ad5084 | 918 | { |
ee000b7f | 919 | rec->freelist = ftrace_free_records; |
37ad5084 SR |
920 | ftrace_free_records = rec; |
921 | rec->flags |= FTRACE_FL_FREE; | |
922 | } | |
923 | ||
e309b41d | 924 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 925 | { |
37ad5084 SR |
926 | struct dyn_ftrace *rec; |
927 | ||
928 | /* First check for freed records */ | |
929 | if (ftrace_free_records) { | |
930 | rec = ftrace_free_records; | |
931 | ||
37ad5084 | 932 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
6912896e | 933 | FTRACE_WARN_ON_ONCE(1); |
37ad5084 SR |
934 | ftrace_free_records = NULL; |
935 | return NULL; | |
936 | } | |
937 | ||
ee000b7f | 938 | ftrace_free_records = rec->freelist; |
37ad5084 SR |
939 | memset(rec, 0, sizeof(*rec)); |
940 | return rec; | |
941 | } | |
942 | ||
3c1720f0 | 943 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
08f5ac90 SR |
944 | if (!ftrace_pages->next) { |
945 | /* allocate another page */ | |
946 | ftrace_pages->next = | |
947 | (void *)get_zeroed_page(GFP_KERNEL); | |
948 | if (!ftrace_pages->next) | |
949 | return NULL; | |
950 | } | |
3c1720f0 SR |
951 | ftrace_pages = ftrace_pages->next; |
952 | } | |
953 | ||
954 | return &ftrace_pages->records[ftrace_pages->index++]; | |
955 | } | |
956 | ||
08f5ac90 | 957 | static struct dyn_ftrace * |
d61f82d0 | 958 | ftrace_record_ip(unsigned long ip) |
3d083395 | 959 | { |
08f5ac90 | 960 | struct dyn_ftrace *rec; |
3d083395 | 961 | |
f3c7ac40 | 962 | if (ftrace_disabled) |
08f5ac90 | 963 | return NULL; |
3d083395 | 964 | |
08f5ac90 SR |
965 | rec = ftrace_alloc_dyn_node(ip); |
966 | if (!rec) | |
967 | return NULL; | |
3d083395 | 968 | |
08f5ac90 | 969 | rec->ip = ip; |
ee000b7f | 970 | rec->newlist = ftrace_new_addrs; |
e94142a6 | 971 | ftrace_new_addrs = rec; |
3d083395 | 972 | |
08f5ac90 | 973 | return rec; |
3d083395 SR |
974 | } |
975 | ||
b17e8a37 SR |
976 | static void print_ip_ins(const char *fmt, unsigned char *p) |
977 | { | |
978 | int i; | |
979 | ||
980 | printk(KERN_CONT "%s", fmt); | |
981 | ||
982 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
983 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
984 | } | |
985 | ||
31e88909 | 986 | static void ftrace_bug(int failed, unsigned long ip) |
b17e8a37 SR |
987 | { |
988 | switch (failed) { | |
989 | case -EFAULT: | |
990 | FTRACE_WARN_ON_ONCE(1); | |
991 | pr_info("ftrace faulted on modifying "); | |
992 | print_ip_sym(ip); | |
993 | break; | |
994 | case -EINVAL: | |
995 | FTRACE_WARN_ON_ONCE(1); | |
996 | pr_info("ftrace failed to modify "); | |
997 | print_ip_sym(ip); | |
b17e8a37 | 998 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
999 | printk(KERN_CONT "\n"); |
1000 | break; | |
1001 | case -EPERM: | |
1002 | FTRACE_WARN_ON_ONCE(1); | |
1003 | pr_info("ftrace faulted on writing "); | |
1004 | print_ip_sym(ip); | |
1005 | break; | |
1006 | default: | |
1007 | FTRACE_WARN_ON_ONCE(1); | |
1008 | pr_info("ftrace faulted on unknown error "); | |
1009 | print_ip_sym(ip); | |
1010 | } | |
1011 | } | |
1012 | ||
3c1720f0 | 1013 | |
0eb96701 | 1014 | static int |
31e88909 | 1015 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) |
5072c59f | 1016 | { |
e7d3737e | 1017 | unsigned long ftrace_addr; |
6a24a244 | 1018 | unsigned long ip, fl; |
e7d3737e | 1019 | |
f0001207 | 1020 | ftrace_addr = (unsigned long)FTRACE_ADDR; |
5072c59f SR |
1021 | |
1022 | ip = rec->ip; | |
1023 | ||
982c350b SR |
1024 | /* |
1025 | * If this record is not to be traced and | |
1026 | * it is not enabled then do nothing. | |
1027 | * | |
1028 | * If this record is not to be traced and | |
57794a9d | 1029 | * it is enabled then disable it. |
982c350b SR |
1030 | * |
1031 | */ | |
1032 | if (rec->flags & FTRACE_FL_NOTRACE) { | |
1033 | if (rec->flags & FTRACE_FL_ENABLED) | |
1034 | rec->flags &= ~FTRACE_FL_ENABLED; | |
1035 | else | |
1036 | return 0; | |
1037 | ||
1038 | } else if (ftrace_filtered && enable) { | |
5072c59f | 1039 | /* |
982c350b | 1040 | * Filtering is on: |
5072c59f | 1041 | */ |
a4500b84 | 1042 | |
982c350b | 1043 | fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED); |
5072c59f | 1044 | |
982c350b SR |
1045 | /* Record is filtered and enabled, do nothing */ |
1046 | if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) | |
0eb96701 | 1047 | return 0; |
5072c59f | 1048 | |
57794a9d | 1049 | /* Record is not filtered or enabled, do nothing */ |
982c350b SR |
1050 | if (!fl) |
1051 | return 0; | |
1052 | ||
1053 | /* Record is not filtered but enabled, disable it */ | |
1054 | if (fl == FTRACE_FL_ENABLED) | |
5072c59f | 1055 | rec->flags &= ~FTRACE_FL_ENABLED; |
982c350b SR |
1056 | else |
1057 | /* Otherwise record is filtered but not enabled, enable it */ | |
5072c59f | 1058 | rec->flags |= FTRACE_FL_ENABLED; |
5072c59f | 1059 | } else { |
982c350b | 1060 | /* Disable or not filtered */ |
5072c59f | 1061 | |
41c52c0d | 1062 | if (enable) { |
982c350b | 1063 | /* if record is enabled, do nothing */ |
5072c59f | 1064 | if (rec->flags & FTRACE_FL_ENABLED) |
0eb96701 | 1065 | return 0; |
982c350b | 1066 | |
5072c59f | 1067 | rec->flags |= FTRACE_FL_ENABLED; |
982c350b | 1068 | |
5072c59f | 1069 | } else { |
982c350b | 1070 | |
57794a9d | 1071 | /* if record is not enabled, do nothing */ |
5072c59f | 1072 | if (!(rec->flags & FTRACE_FL_ENABLED)) |
0eb96701 | 1073 | return 0; |
982c350b | 1074 | |
5072c59f SR |
1075 | rec->flags &= ~FTRACE_FL_ENABLED; |
1076 | } | |
1077 | } | |
1078 | ||
982c350b | 1079 | if (rec->flags & FTRACE_FL_ENABLED) |
e7d3737e | 1080 | return ftrace_make_call(rec, ftrace_addr); |
31e88909 | 1081 | else |
e7d3737e | 1082 | return ftrace_make_nop(NULL, rec, ftrace_addr); |
5072c59f SR |
1083 | } |
1084 | ||
e309b41d | 1085 | static void ftrace_replace_code(int enable) |
3c1720f0 | 1086 | { |
3c1720f0 SR |
1087 | struct dyn_ftrace *rec; |
1088 | struct ftrace_page *pg; | |
6a24a244 | 1089 | int failed; |
3c1720f0 | 1090 | |
265c831c SR |
1091 | do_for_each_ftrace_rec(pg, rec) { |
1092 | /* | |
fa9d13cf Z |
1093 | * Skip over free records, records that have |
1094 | * failed and not converted. | |
265c831c SR |
1095 | */ |
1096 | if (rec->flags & FTRACE_FL_FREE || | |
fa9d13cf | 1097 | rec->flags & FTRACE_FL_FAILED || |
03303549 | 1098 | !(rec->flags & FTRACE_FL_CONVERTED)) |
265c831c SR |
1099 | continue; |
1100 | ||
1101 | /* ignore updates to this record's mcount site */ | |
1102 | if (get_kprobe((void *)rec->ip)) { | |
1103 | freeze_record(rec); | |
1104 | continue; | |
1105 | } else { | |
1106 | unfreeze_record(rec); | |
1107 | } | |
f22f9a89 | 1108 | |
265c831c | 1109 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 1110 | if (failed) { |
265c831c SR |
1111 | rec->flags |= FTRACE_FL_FAILED; |
1112 | if ((system_state == SYSTEM_BOOTING) || | |
1113 | !core_kernel_text(rec->ip)) { | |
1114 | ftrace_free_rec(rec); | |
4377245a | 1115 | } else { |
265c831c | 1116 | ftrace_bug(failed, rec->ip); |
4377245a SR |
1117 | /* Stop processing */ |
1118 | return; | |
1119 | } | |
3c1720f0 | 1120 | } |
265c831c | 1121 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
1122 | } |
1123 | ||
492a7ea5 | 1124 | static int |
31e88909 | 1125 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 SR |
1126 | { |
1127 | unsigned long ip; | |
593eb8a2 | 1128 | int ret; |
3c1720f0 SR |
1129 | |
1130 | ip = rec->ip; | |
1131 | ||
25aac9dc | 1132 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 1133 | if (ret) { |
31e88909 | 1134 | ftrace_bug(ret, ip); |
3c1720f0 | 1135 | rec->flags |= FTRACE_FL_FAILED; |
492a7ea5 | 1136 | return 0; |
37ad5084 | 1137 | } |
492a7ea5 | 1138 | return 1; |
3c1720f0 SR |
1139 | } |
1140 | ||
000ab691 SR |
1141 | /* |
1142 | * archs can override this function if they must do something | |
1143 | * before the modifying code is performed. | |
1144 | */ | |
1145 | int __weak ftrace_arch_code_modify_prepare(void) | |
1146 | { | |
1147 | return 0; | |
1148 | } | |
1149 | ||
1150 | /* | |
1151 | * archs can override this function if they must do something | |
1152 | * after the modifying code is performed. | |
1153 | */ | |
1154 | int __weak ftrace_arch_code_modify_post_process(void) | |
1155 | { | |
1156 | return 0; | |
1157 | } | |
1158 | ||
e309b41d | 1159 | static int __ftrace_modify_code(void *data) |
3d083395 | 1160 | { |
d61f82d0 SR |
1161 | int *command = data; |
1162 | ||
a3583244 | 1163 | if (*command & FTRACE_ENABLE_CALLS) |
d61f82d0 | 1164 | ftrace_replace_code(1); |
a3583244 | 1165 | else if (*command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
1166 | ftrace_replace_code(0); |
1167 | ||
1168 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
1169 | ftrace_update_ftrace_func(ftrace_trace_function); | |
1170 | ||
5a45cfe1 SR |
1171 | if (*command & FTRACE_START_FUNC_RET) |
1172 | ftrace_enable_ftrace_graph_caller(); | |
1173 | else if (*command & FTRACE_STOP_FUNC_RET) | |
1174 | ftrace_disable_ftrace_graph_caller(); | |
1175 | ||
d61f82d0 | 1176 | return 0; |
3d083395 SR |
1177 | } |
1178 | ||
e309b41d | 1179 | static void ftrace_run_update_code(int command) |
3d083395 | 1180 | { |
000ab691 SR |
1181 | int ret; |
1182 | ||
1183 | ret = ftrace_arch_code_modify_prepare(); | |
1184 | FTRACE_WARN_ON(ret); | |
1185 | if (ret) | |
1186 | return; | |
1187 | ||
784e2d76 | 1188 | stop_machine(__ftrace_modify_code, &command, NULL); |
000ab691 SR |
1189 | |
1190 | ret = ftrace_arch_code_modify_post_process(); | |
1191 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
1192 | } |
1193 | ||
d61f82d0 | 1194 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 1195 | static int ftrace_start_up; |
df4fc315 SR |
1196 | |
1197 | static void ftrace_startup_enable(int command) | |
1198 | { | |
1199 | if (saved_ftrace_func != ftrace_trace_function) { | |
1200 | saved_ftrace_func = ftrace_trace_function; | |
1201 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1202 | } | |
1203 | ||
1204 | if (!command || !ftrace_enabled) | |
1205 | return; | |
1206 | ||
1207 | ftrace_run_update_code(command); | |
1208 | } | |
d61f82d0 | 1209 | |
5a45cfe1 | 1210 | static void ftrace_startup(int command) |
3d083395 | 1211 | { |
4eebcc81 SR |
1212 | if (unlikely(ftrace_disabled)) |
1213 | return; | |
1214 | ||
60a7ecf4 | 1215 | ftrace_start_up++; |
982c350b | 1216 | command |= FTRACE_ENABLE_CALLS; |
d61f82d0 | 1217 | |
df4fc315 | 1218 | ftrace_startup_enable(command); |
3d083395 SR |
1219 | } |
1220 | ||
5a45cfe1 | 1221 | static void ftrace_shutdown(int command) |
3d083395 | 1222 | { |
4eebcc81 SR |
1223 | if (unlikely(ftrace_disabled)) |
1224 | return; | |
1225 | ||
60a7ecf4 | 1226 | ftrace_start_up--; |
9ea1a153 FW |
1227 | /* |
1228 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
1229 | * critical but the ftrace_call callers may be never nopped again after | |
1230 | * further ftrace uses. | |
1231 | */ | |
1232 | WARN_ON_ONCE(ftrace_start_up < 0); | |
1233 | ||
60a7ecf4 | 1234 | if (!ftrace_start_up) |
d61f82d0 | 1235 | command |= FTRACE_DISABLE_CALLS; |
3d083395 | 1236 | |
d61f82d0 SR |
1237 | if (saved_ftrace_func != ftrace_trace_function) { |
1238 | saved_ftrace_func = ftrace_trace_function; | |
1239 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1240 | } | |
3d083395 | 1241 | |
d61f82d0 | 1242 | if (!command || !ftrace_enabled) |
e6ea44e9 | 1243 | return; |
d61f82d0 SR |
1244 | |
1245 | ftrace_run_update_code(command); | |
3d083395 SR |
1246 | } |
1247 | ||
e309b41d | 1248 | static void ftrace_startup_sysctl(void) |
b0fc494f | 1249 | { |
d61f82d0 SR |
1250 | int command = FTRACE_ENABLE_MCOUNT; |
1251 | ||
4eebcc81 SR |
1252 | if (unlikely(ftrace_disabled)) |
1253 | return; | |
1254 | ||
d61f82d0 SR |
1255 | /* Force update next time */ |
1256 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
1257 | /* ftrace_start_up is true if we want ftrace running */ |
1258 | if (ftrace_start_up) | |
d61f82d0 SR |
1259 | command |= FTRACE_ENABLE_CALLS; |
1260 | ||
1261 | ftrace_run_update_code(command); | |
b0fc494f SR |
1262 | } |
1263 | ||
e309b41d | 1264 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 1265 | { |
d61f82d0 SR |
1266 | int command = FTRACE_DISABLE_MCOUNT; |
1267 | ||
4eebcc81 SR |
1268 | if (unlikely(ftrace_disabled)) |
1269 | return; | |
1270 | ||
60a7ecf4 SR |
1271 | /* ftrace_start_up is true if ftrace is running */ |
1272 | if (ftrace_start_up) | |
d61f82d0 SR |
1273 | command |= FTRACE_DISABLE_CALLS; |
1274 | ||
1275 | ftrace_run_update_code(command); | |
b0fc494f SR |
1276 | } |
1277 | ||
3d083395 SR |
1278 | static cycle_t ftrace_update_time; |
1279 | static unsigned long ftrace_update_cnt; | |
1280 | unsigned long ftrace_update_tot_cnt; | |
1281 | ||
31e88909 | 1282 | static int ftrace_update_code(struct module *mod) |
3d083395 | 1283 | { |
e94142a6 | 1284 | struct dyn_ftrace *p; |
f22f9a89 | 1285 | cycle_t start, stop; |
3d083395 | 1286 | |
750ed1a4 | 1287 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1288 | ftrace_update_cnt = 0; |
1289 | ||
e94142a6 | 1290 | while (ftrace_new_addrs) { |
3d083395 | 1291 | |
08f5ac90 SR |
1292 | /* If something went wrong, bail without enabling anything */ |
1293 | if (unlikely(ftrace_disabled)) | |
1294 | return -1; | |
f22f9a89 | 1295 | |
e94142a6 | 1296 | p = ftrace_new_addrs; |
ee000b7f | 1297 | ftrace_new_addrs = p->newlist; |
e94142a6 | 1298 | p->flags = 0L; |
f22f9a89 | 1299 | |
08f5ac90 | 1300 | /* convert record (i.e, patch mcount-call with NOP) */ |
31e88909 | 1301 | if (ftrace_code_disable(mod, p)) { |
08f5ac90 SR |
1302 | p->flags |= FTRACE_FL_CONVERTED; |
1303 | ftrace_update_cnt++; | |
1304 | } else | |
1305 | ftrace_free_rec(p); | |
3d083395 SR |
1306 | } |
1307 | ||
750ed1a4 | 1308 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1309 | ftrace_update_time = stop - start; |
1310 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
1311 | ||
16444a8a ACM |
1312 | return 0; |
1313 | } | |
1314 | ||
68bf21aa | 1315 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
1316 | { |
1317 | struct ftrace_page *pg; | |
1318 | int cnt; | |
1319 | int i; | |
3c1720f0 SR |
1320 | |
1321 | /* allocate a few pages */ | |
1322 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
1323 | if (!ftrace_pages_start) | |
1324 | return -1; | |
1325 | ||
1326 | /* | |
1327 | * Allocate a few more pages. | |
1328 | * | |
1329 | * TODO: have some parser search vmlinux before | |
1330 | * final linking to find all calls to ftrace. | |
1331 | * Then we can: | |
1332 | * a) know how many pages to allocate. | |
1333 | * and/or | |
1334 | * b) set up the table then. | |
1335 | * | |
1336 | * The dynamic code is still necessary for | |
1337 | * modules. | |
1338 | */ | |
1339 | ||
1340 | pg = ftrace_pages = ftrace_pages_start; | |
1341 | ||
68bf21aa | 1342 | cnt = num_to_init / ENTRIES_PER_PAGE; |
08f5ac90 | 1343 | pr_info("ftrace: allocating %ld entries in %d pages\n", |
5821e1b7 | 1344 | num_to_init, cnt + 1); |
3c1720f0 SR |
1345 | |
1346 | for (i = 0; i < cnt; i++) { | |
1347 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
1348 | ||
1349 | /* If we fail, we'll try later anyway */ | |
1350 | if (!pg->next) | |
1351 | break; | |
1352 | ||
1353 | pg = pg->next; | |
1354 | } | |
1355 | ||
1356 | return 0; | |
1357 | } | |
1358 | ||
5072c59f SR |
1359 | enum { |
1360 | FTRACE_ITER_FILTER = (1 << 0), | |
1361 | FTRACE_ITER_CONT = (1 << 1), | |
41c52c0d | 1362 | FTRACE_ITER_NOTRACE = (1 << 2), |
eb9a7bf0 | 1363 | FTRACE_ITER_FAILURES = (1 << 3), |
0c75a3ed | 1364 | FTRACE_ITER_PRINTALL = (1 << 4), |
8fc0c701 | 1365 | FTRACE_ITER_HASH = (1 << 5), |
5072c59f SR |
1366 | }; |
1367 | ||
1368 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
1369 | ||
1370 | struct ftrace_iterator { | |
5072c59f | 1371 | struct ftrace_page *pg; |
8fc0c701 | 1372 | int hidx; |
431aa3fb | 1373 | int idx; |
5072c59f SR |
1374 | unsigned flags; |
1375 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
1376 | unsigned buffer_idx; | |
1377 | unsigned filtered; | |
1378 | }; | |
1379 | ||
8fc0c701 SR |
1380 | static void * |
1381 | t_hash_next(struct seq_file *m, void *v, loff_t *pos) | |
1382 | { | |
1383 | struct ftrace_iterator *iter = m->private; | |
1384 | struct hlist_node *hnd = v; | |
1385 | struct hlist_head *hhd; | |
1386 | ||
1387 | WARN_ON(!(iter->flags & FTRACE_ITER_HASH)); | |
1388 | ||
1389 | (*pos)++; | |
1390 | ||
1391 | retry: | |
1392 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
1393 | return NULL; | |
1394 | ||
1395 | hhd = &ftrace_func_hash[iter->hidx]; | |
1396 | ||
1397 | if (hlist_empty(hhd)) { | |
1398 | iter->hidx++; | |
1399 | hnd = NULL; | |
1400 | goto retry; | |
1401 | } | |
1402 | ||
1403 | if (!hnd) | |
1404 | hnd = hhd->first; | |
1405 | else { | |
1406 | hnd = hnd->next; | |
1407 | if (!hnd) { | |
1408 | iter->hidx++; | |
1409 | goto retry; | |
1410 | } | |
1411 | } | |
1412 | ||
1413 | return hnd; | |
1414 | } | |
1415 | ||
1416 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
1417 | { | |
1418 | struct ftrace_iterator *iter = m->private; | |
1419 | void *p = NULL; | |
d82d6244 LZ |
1420 | loff_t l; |
1421 | ||
1422 | if (!(iter->flags & FTRACE_ITER_HASH)) | |
1423 | *pos = 0; | |
8fc0c701 SR |
1424 | |
1425 | iter->flags |= FTRACE_ITER_HASH; | |
1426 | ||
d82d6244 LZ |
1427 | iter->hidx = 0; |
1428 | for (l = 0; l <= *pos; ) { | |
1429 | p = t_hash_next(m, p, &l); | |
1430 | if (!p) | |
1431 | break; | |
1432 | } | |
1433 | return p; | |
8fc0c701 SR |
1434 | } |
1435 | ||
1436 | static int t_hash_show(struct seq_file *m, void *v) | |
1437 | { | |
b6887d79 | 1438 | struct ftrace_func_probe *rec; |
8fc0c701 SR |
1439 | struct hlist_node *hnd = v; |
1440 | char str[KSYM_SYMBOL_LEN]; | |
1441 | ||
b6887d79 | 1442 | rec = hlist_entry(hnd, struct ftrace_func_probe, node); |
8fc0c701 | 1443 | |
809dcf29 SR |
1444 | if (rec->ops->print) |
1445 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
1446 | ||
8fc0c701 SR |
1447 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
1448 | seq_printf(m, "%s:", str); | |
1449 | ||
1450 | kallsyms_lookup((unsigned long)rec->ops->func, NULL, NULL, NULL, str); | |
1451 | seq_printf(m, "%s", str); | |
1452 | ||
1453 | if (rec->data) | |
1454 | seq_printf(m, ":%p", rec->data); | |
1455 | seq_putc(m, '\n'); | |
1456 | ||
1457 | return 0; | |
1458 | } | |
1459 | ||
e309b41d | 1460 | static void * |
5072c59f SR |
1461 | t_next(struct seq_file *m, void *v, loff_t *pos) |
1462 | { | |
1463 | struct ftrace_iterator *iter = m->private; | |
1464 | struct dyn_ftrace *rec = NULL; | |
1465 | ||
8fc0c701 SR |
1466 | if (iter->flags & FTRACE_ITER_HASH) |
1467 | return t_hash_next(m, v, pos); | |
1468 | ||
5072c59f SR |
1469 | (*pos)++; |
1470 | ||
0c75a3ed SR |
1471 | if (iter->flags & FTRACE_ITER_PRINTALL) |
1472 | return NULL; | |
1473 | ||
5072c59f SR |
1474 | retry: |
1475 | if (iter->idx >= iter->pg->index) { | |
1476 | if (iter->pg->next) { | |
1477 | iter->pg = iter->pg->next; | |
1478 | iter->idx = 0; | |
1479 | goto retry; | |
1480 | } | |
1481 | } else { | |
1482 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
1483 | if ((rec->flags & FTRACE_FL_FREE) || |
1484 | ||
1485 | (!(iter->flags & FTRACE_ITER_FAILURES) && | |
eb9a7bf0 AS |
1486 | (rec->flags & FTRACE_FL_FAILED)) || |
1487 | ||
1488 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
a9fdda33 | 1489 | !(rec->flags & FTRACE_FL_FAILED)) || |
eb9a7bf0 | 1490 | |
0183fb1c SR |
1491 | ((iter->flags & FTRACE_ITER_FILTER) && |
1492 | !(rec->flags & FTRACE_FL_FILTER)) || | |
1493 | ||
41c52c0d SR |
1494 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
1495 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
1496 | rec = NULL; |
1497 | goto retry; | |
1498 | } | |
1499 | } | |
1500 | ||
5072c59f SR |
1501 | return rec; |
1502 | } | |
1503 | ||
1504 | static void *t_start(struct seq_file *m, loff_t *pos) | |
1505 | { | |
1506 | struct ftrace_iterator *iter = m->private; | |
1507 | void *p = NULL; | |
694ce0a5 | 1508 | loff_t l; |
5072c59f | 1509 | |
8fc0c701 | 1510 | mutex_lock(&ftrace_lock); |
0c75a3ed SR |
1511 | /* |
1512 | * For set_ftrace_filter reading, if we have the filter | |
1513 | * off, we can short cut and just print out that all | |
1514 | * functions are enabled. | |
1515 | */ | |
1516 | if (iter->flags & FTRACE_ITER_FILTER && !ftrace_filtered) { | |
1517 | if (*pos > 0) | |
8fc0c701 | 1518 | return t_hash_start(m, pos); |
0c75a3ed | 1519 | iter->flags |= FTRACE_ITER_PRINTALL; |
0c75a3ed SR |
1520 | return iter; |
1521 | } | |
1522 | ||
8fc0c701 SR |
1523 | if (iter->flags & FTRACE_ITER_HASH) |
1524 | return t_hash_start(m, pos); | |
1525 | ||
694ce0a5 LZ |
1526 | iter->pg = ftrace_pages_start; |
1527 | iter->idx = 0; | |
1528 | for (l = 0; l <= *pos; ) { | |
1529 | p = t_next(m, p, &l); | |
1530 | if (!p) | |
1531 | break; | |
50cdaf08 | 1532 | } |
5821e1b7 | 1533 | |
694ce0a5 | 1534 | if (!p && iter->flags & FTRACE_ITER_FILTER) |
8fc0c701 SR |
1535 | return t_hash_start(m, pos); |
1536 | ||
5072c59f SR |
1537 | return p; |
1538 | } | |
1539 | ||
1540 | static void t_stop(struct seq_file *m, void *p) | |
1541 | { | |
8fc0c701 | 1542 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1543 | } |
1544 | ||
1545 | static int t_show(struct seq_file *m, void *v) | |
1546 | { | |
0c75a3ed | 1547 | struct ftrace_iterator *iter = m->private; |
5072c59f SR |
1548 | struct dyn_ftrace *rec = v; |
1549 | char str[KSYM_SYMBOL_LEN]; | |
1550 | ||
8fc0c701 SR |
1551 | if (iter->flags & FTRACE_ITER_HASH) |
1552 | return t_hash_show(m, v); | |
1553 | ||
0c75a3ed SR |
1554 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
1555 | seq_printf(m, "#### all functions enabled ####\n"); | |
1556 | return 0; | |
1557 | } | |
1558 | ||
5072c59f SR |
1559 | if (!rec) |
1560 | return 0; | |
1561 | ||
1562 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1563 | ||
50cdaf08 | 1564 | seq_printf(m, "%s\n", str); |
5072c59f SR |
1565 | |
1566 | return 0; | |
1567 | } | |
1568 | ||
1569 | static struct seq_operations show_ftrace_seq_ops = { | |
1570 | .start = t_start, | |
1571 | .next = t_next, | |
1572 | .stop = t_stop, | |
1573 | .show = t_show, | |
1574 | }; | |
1575 | ||
e309b41d | 1576 | static int |
5072c59f SR |
1577 | ftrace_avail_open(struct inode *inode, struct file *file) |
1578 | { | |
1579 | struct ftrace_iterator *iter; | |
1580 | int ret; | |
1581 | ||
4eebcc81 SR |
1582 | if (unlikely(ftrace_disabled)) |
1583 | return -ENODEV; | |
1584 | ||
5072c59f SR |
1585 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1586 | if (!iter) | |
1587 | return -ENOMEM; | |
1588 | ||
1589 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
1590 | |
1591 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1592 | if (!ret) { | |
1593 | struct seq_file *m = file->private_data; | |
4bf39a94 | 1594 | |
5072c59f | 1595 | m->private = iter; |
4bf39a94 | 1596 | } else { |
5072c59f | 1597 | kfree(iter); |
4bf39a94 | 1598 | } |
5072c59f SR |
1599 | |
1600 | return ret; | |
1601 | } | |
1602 | ||
1603 | int ftrace_avail_release(struct inode *inode, struct file *file) | |
1604 | { | |
1605 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1606 | struct ftrace_iterator *iter = m->private; | |
1607 | ||
1608 | seq_release(inode, file); | |
1609 | kfree(iter); | |
4bf39a94 | 1610 | |
5072c59f SR |
1611 | return 0; |
1612 | } | |
1613 | ||
eb9a7bf0 AS |
1614 | static int |
1615 | ftrace_failures_open(struct inode *inode, struct file *file) | |
1616 | { | |
1617 | int ret; | |
1618 | struct seq_file *m; | |
1619 | struct ftrace_iterator *iter; | |
1620 | ||
1621 | ret = ftrace_avail_open(inode, file); | |
1622 | if (!ret) { | |
1623 | m = (struct seq_file *)file->private_data; | |
1624 | iter = (struct ftrace_iterator *)m->private; | |
1625 | iter->flags = FTRACE_ITER_FAILURES; | |
1626 | } | |
1627 | ||
1628 | return ret; | |
1629 | } | |
1630 | ||
1631 | ||
41c52c0d | 1632 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
1633 | { |
1634 | struct ftrace_page *pg; | |
1635 | struct dyn_ftrace *rec; | |
41c52c0d | 1636 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f | 1637 | |
52baf119 | 1638 | mutex_lock(&ftrace_lock); |
41c52c0d SR |
1639 | if (enable) |
1640 | ftrace_filtered = 0; | |
265c831c SR |
1641 | do_for_each_ftrace_rec(pg, rec) { |
1642 | if (rec->flags & FTRACE_FL_FAILED) | |
1643 | continue; | |
1644 | rec->flags &= ~type; | |
1645 | } while_for_each_ftrace_rec(); | |
52baf119 | 1646 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1647 | } |
1648 | ||
e309b41d | 1649 | static int |
41c52c0d | 1650 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1651 | { |
1652 | struct ftrace_iterator *iter; | |
1653 | int ret = 0; | |
1654 | ||
4eebcc81 SR |
1655 | if (unlikely(ftrace_disabled)) |
1656 | return -ENODEV; | |
1657 | ||
5072c59f SR |
1658 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1659 | if (!iter) | |
1660 | return -ENOMEM; | |
1661 | ||
41c52c0d | 1662 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1663 | if ((file->f_mode & FMODE_WRITE) && |
1664 | !(file->f_flags & O_APPEND)) | |
41c52c0d | 1665 | ftrace_filter_reset(enable); |
5072c59f SR |
1666 | |
1667 | if (file->f_mode & FMODE_READ) { | |
1668 | iter->pg = ftrace_pages_start; | |
41c52c0d SR |
1669 | iter->flags = enable ? FTRACE_ITER_FILTER : |
1670 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
1671 | |
1672 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1673 | if (!ret) { | |
1674 | struct seq_file *m = file->private_data; | |
1675 | m->private = iter; | |
1676 | } else | |
1677 | kfree(iter); | |
1678 | } else | |
1679 | file->private_data = iter; | |
41c52c0d | 1680 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1681 | |
1682 | return ret; | |
1683 | } | |
1684 | ||
41c52c0d SR |
1685 | static int |
1686 | ftrace_filter_open(struct inode *inode, struct file *file) | |
1687 | { | |
1688 | return ftrace_regex_open(inode, file, 1); | |
1689 | } | |
1690 | ||
1691 | static int | |
1692 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
1693 | { | |
1694 | return ftrace_regex_open(inode, file, 0); | |
1695 | } | |
1696 | ||
e309b41d | 1697 | static loff_t |
41c52c0d | 1698 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
1699 | { |
1700 | loff_t ret; | |
1701 | ||
1702 | if (file->f_mode & FMODE_READ) | |
1703 | ret = seq_lseek(file, offset, origin); | |
1704 | else | |
1705 | file->f_pos = ret = 1; | |
1706 | ||
1707 | return ret; | |
1708 | } | |
1709 | ||
1710 | enum { | |
1711 | MATCH_FULL, | |
1712 | MATCH_FRONT_ONLY, | |
1713 | MATCH_MIDDLE_ONLY, | |
1714 | MATCH_END_ONLY, | |
1715 | }; | |
1716 | ||
9f4801e3 SR |
1717 | /* |
1718 | * (static function - no need for kernel doc) | |
1719 | * | |
1720 | * Pass in a buffer containing a glob and this function will | |
1721 | * set search to point to the search part of the buffer and | |
1722 | * return the type of search it is (see enum above). | |
1723 | * This does modify buff. | |
1724 | * | |
1725 | * Returns enum type. | |
1726 | * search returns the pointer to use for comparison. | |
1727 | * not returns 1 if buff started with a '!' | |
1728 | * 0 otherwise. | |
1729 | */ | |
1730 | static int | |
64e7c440 | 1731 | ftrace_setup_glob(char *buff, int len, char **search, int *not) |
5072c59f | 1732 | { |
5072c59f | 1733 | int type = MATCH_FULL; |
9f4801e3 | 1734 | int i; |
ea3a6d6d SR |
1735 | |
1736 | if (buff[0] == '!') { | |
9f4801e3 | 1737 | *not = 1; |
ea3a6d6d SR |
1738 | buff++; |
1739 | len--; | |
9f4801e3 SR |
1740 | } else |
1741 | *not = 0; | |
1742 | ||
1743 | *search = buff; | |
5072c59f SR |
1744 | |
1745 | for (i = 0; i < len; i++) { | |
1746 | if (buff[i] == '*') { | |
1747 | if (!i) { | |
9f4801e3 | 1748 | *search = buff + 1; |
5072c59f | 1749 | type = MATCH_END_ONLY; |
5072c59f | 1750 | } else { |
9f4801e3 | 1751 | if (type == MATCH_END_ONLY) |
5072c59f | 1752 | type = MATCH_MIDDLE_ONLY; |
9f4801e3 | 1753 | else |
5072c59f | 1754 | type = MATCH_FRONT_ONLY; |
5072c59f SR |
1755 | buff[i] = 0; |
1756 | break; | |
1757 | } | |
1758 | } | |
1759 | } | |
1760 | ||
9f4801e3 SR |
1761 | return type; |
1762 | } | |
1763 | ||
64e7c440 | 1764 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 1765 | { |
9f4801e3 SR |
1766 | int matched = 0; |
1767 | char *ptr; | |
1768 | ||
9f4801e3 SR |
1769 | switch (type) { |
1770 | case MATCH_FULL: | |
1771 | if (strcmp(str, regex) == 0) | |
1772 | matched = 1; | |
1773 | break; | |
1774 | case MATCH_FRONT_ONLY: | |
1775 | if (strncmp(str, regex, len) == 0) | |
1776 | matched = 1; | |
1777 | break; | |
1778 | case MATCH_MIDDLE_ONLY: | |
1779 | if (strstr(str, regex)) | |
1780 | matched = 1; | |
1781 | break; | |
1782 | case MATCH_END_ONLY: | |
1783 | ptr = strstr(str, regex); | |
1784 | if (ptr && (ptr[len] == 0)) | |
1785 | matched = 1; | |
1786 | break; | |
1787 | } | |
1788 | ||
1789 | return matched; | |
1790 | } | |
1791 | ||
64e7c440 SR |
1792 | static int |
1793 | ftrace_match_record(struct dyn_ftrace *rec, char *regex, int len, int type) | |
1794 | { | |
1795 | char str[KSYM_SYMBOL_LEN]; | |
1796 | ||
1797 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1798 | return ftrace_match(str, regex, len, type); | |
1799 | } | |
1800 | ||
9f4801e3 SR |
1801 | static void ftrace_match_records(char *buff, int len, int enable) |
1802 | { | |
6a24a244 | 1803 | unsigned int search_len; |
9f4801e3 SR |
1804 | struct ftrace_page *pg; |
1805 | struct dyn_ftrace *rec; | |
6a24a244 SR |
1806 | unsigned long flag; |
1807 | char *search; | |
9f4801e3 | 1808 | int type; |
9f4801e3 SR |
1809 | int not; |
1810 | ||
6a24a244 | 1811 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
9f4801e3 SR |
1812 | type = ftrace_setup_glob(buff, len, &search, ¬); |
1813 | ||
1814 | search_len = strlen(search); | |
1815 | ||
52baf119 | 1816 | mutex_lock(&ftrace_lock); |
265c831c | 1817 | do_for_each_ftrace_rec(pg, rec) { |
265c831c SR |
1818 | |
1819 | if (rec->flags & FTRACE_FL_FAILED) | |
1820 | continue; | |
9f4801e3 SR |
1821 | |
1822 | if (ftrace_match_record(rec, search, search_len, type)) { | |
265c831c SR |
1823 | if (not) |
1824 | rec->flags &= ~flag; | |
1825 | else | |
1826 | rec->flags |= flag; | |
1827 | } | |
e68746a2 SR |
1828 | /* |
1829 | * Only enable filtering if we have a function that | |
1830 | * is filtered on. | |
1831 | */ | |
1832 | if (enable && (rec->flags & FTRACE_FL_FILTER)) | |
1833 | ftrace_filtered = 1; | |
265c831c | 1834 | } while_for_each_ftrace_rec(); |
52baf119 | 1835 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1836 | } |
1837 | ||
64e7c440 SR |
1838 | static int |
1839 | ftrace_match_module_record(struct dyn_ftrace *rec, char *mod, | |
1840 | char *regex, int len, int type) | |
1841 | { | |
1842 | char str[KSYM_SYMBOL_LEN]; | |
1843 | char *modname; | |
1844 | ||
1845 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
1846 | ||
1847 | if (!modname || strcmp(modname, mod)) | |
1848 | return 0; | |
1849 | ||
1850 | /* blank search means to match all funcs in the mod */ | |
1851 | if (len) | |
1852 | return ftrace_match(str, regex, len, type); | |
1853 | else | |
1854 | return 1; | |
1855 | } | |
1856 | ||
1857 | static void ftrace_match_module_records(char *buff, char *mod, int enable) | |
1858 | { | |
6a24a244 | 1859 | unsigned search_len = 0; |
64e7c440 SR |
1860 | struct ftrace_page *pg; |
1861 | struct dyn_ftrace *rec; | |
1862 | int type = MATCH_FULL; | |
6a24a244 SR |
1863 | char *search = buff; |
1864 | unsigned long flag; | |
64e7c440 SR |
1865 | int not = 0; |
1866 | ||
6a24a244 SR |
1867 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
1868 | ||
64e7c440 SR |
1869 | /* blank or '*' mean the same */ |
1870 | if (strcmp(buff, "*") == 0) | |
1871 | buff[0] = 0; | |
1872 | ||
1873 | /* handle the case of 'dont filter this module' */ | |
1874 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
1875 | buff[0] = 0; | |
1876 | not = 1; | |
1877 | } | |
1878 | ||
1879 | if (strlen(buff)) { | |
1880 | type = ftrace_setup_glob(buff, strlen(buff), &search, ¬); | |
1881 | search_len = strlen(search); | |
1882 | } | |
1883 | ||
52baf119 | 1884 | mutex_lock(&ftrace_lock); |
64e7c440 SR |
1885 | do_for_each_ftrace_rec(pg, rec) { |
1886 | ||
1887 | if (rec->flags & FTRACE_FL_FAILED) | |
1888 | continue; | |
1889 | ||
1890 | if (ftrace_match_module_record(rec, mod, | |
1891 | search, search_len, type)) { | |
1892 | if (not) | |
1893 | rec->flags &= ~flag; | |
1894 | else | |
1895 | rec->flags |= flag; | |
1896 | } | |
e68746a2 SR |
1897 | if (enable && (rec->flags & FTRACE_FL_FILTER)) |
1898 | ftrace_filtered = 1; | |
64e7c440 SR |
1899 | |
1900 | } while_for_each_ftrace_rec(); | |
52baf119 | 1901 | mutex_unlock(&ftrace_lock); |
64e7c440 SR |
1902 | } |
1903 | ||
f6180773 SR |
1904 | /* |
1905 | * We register the module command as a template to show others how | |
1906 | * to register the a command as well. | |
1907 | */ | |
1908 | ||
1909 | static int | |
1910 | ftrace_mod_callback(char *func, char *cmd, char *param, int enable) | |
1911 | { | |
1912 | char *mod; | |
1913 | ||
1914 | /* | |
1915 | * cmd == 'mod' because we only registered this func | |
1916 | * for the 'mod' ftrace_func_command. | |
1917 | * But if you register one func with multiple commands, | |
1918 | * you can tell which command was used by the cmd | |
1919 | * parameter. | |
1920 | */ | |
1921 | ||
1922 | /* we must have a module name */ | |
1923 | if (!param) | |
1924 | return -EINVAL; | |
1925 | ||
1926 | mod = strsep(¶m, ":"); | |
1927 | if (!strlen(mod)) | |
1928 | return -EINVAL; | |
1929 | ||
1930 | ftrace_match_module_records(func, mod, enable); | |
1931 | return 0; | |
1932 | } | |
1933 | ||
1934 | static struct ftrace_func_command ftrace_mod_cmd = { | |
1935 | .name = "mod", | |
1936 | .func = ftrace_mod_callback, | |
1937 | }; | |
1938 | ||
1939 | static int __init ftrace_mod_cmd_init(void) | |
1940 | { | |
1941 | return register_ftrace_command(&ftrace_mod_cmd); | |
1942 | } | |
1943 | device_initcall(ftrace_mod_cmd_init); | |
1944 | ||
59df055f | 1945 | static void |
b6887d79 | 1946 | function_trace_probe_call(unsigned long ip, unsigned long parent_ip) |
59df055f | 1947 | { |
b6887d79 | 1948 | struct ftrace_func_probe *entry; |
59df055f SR |
1949 | struct hlist_head *hhd; |
1950 | struct hlist_node *n; | |
1951 | unsigned long key; | |
1952 | int resched; | |
1953 | ||
1954 | key = hash_long(ip, FTRACE_HASH_BITS); | |
1955 | ||
1956 | hhd = &ftrace_func_hash[key]; | |
1957 | ||
1958 | if (hlist_empty(hhd)) | |
1959 | return; | |
1960 | ||
1961 | /* | |
1962 | * Disable preemption for these calls to prevent a RCU grace | |
1963 | * period. This syncs the hash iteration and freeing of items | |
1964 | * on the hash. rcu_read_lock is too dangerous here. | |
1965 | */ | |
1966 | resched = ftrace_preempt_disable(); | |
1967 | hlist_for_each_entry_rcu(entry, n, hhd, node) { | |
1968 | if (entry->ip == ip) | |
1969 | entry->ops->func(ip, parent_ip, &entry->data); | |
1970 | } | |
1971 | ftrace_preempt_enable(resched); | |
1972 | } | |
1973 | ||
b6887d79 | 1974 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 1975 | { |
fb9fb015 | 1976 | .func = function_trace_probe_call, |
59df055f SR |
1977 | }; |
1978 | ||
b6887d79 | 1979 | static int ftrace_probe_registered; |
59df055f | 1980 | |
b6887d79 | 1981 | static void __enable_ftrace_function_probe(void) |
59df055f SR |
1982 | { |
1983 | int i; | |
1984 | ||
b6887d79 | 1985 | if (ftrace_probe_registered) |
59df055f SR |
1986 | return; |
1987 | ||
1988 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1989 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1990 | if (hhd->first) | |
1991 | break; | |
1992 | } | |
1993 | /* Nothing registered? */ | |
1994 | if (i == FTRACE_FUNC_HASHSIZE) | |
1995 | return; | |
1996 | ||
b6887d79 | 1997 | __register_ftrace_function(&trace_probe_ops); |
59df055f | 1998 | ftrace_startup(0); |
b6887d79 | 1999 | ftrace_probe_registered = 1; |
59df055f SR |
2000 | } |
2001 | ||
b6887d79 | 2002 | static void __disable_ftrace_function_probe(void) |
59df055f SR |
2003 | { |
2004 | int i; | |
2005 | ||
b6887d79 | 2006 | if (!ftrace_probe_registered) |
59df055f SR |
2007 | return; |
2008 | ||
2009 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2010 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2011 | if (hhd->first) | |
2012 | return; | |
2013 | } | |
2014 | ||
2015 | /* no more funcs left */ | |
b6887d79 | 2016 | __unregister_ftrace_function(&trace_probe_ops); |
59df055f | 2017 | ftrace_shutdown(0); |
b6887d79 | 2018 | ftrace_probe_registered = 0; |
59df055f SR |
2019 | } |
2020 | ||
2021 | ||
2022 | static void ftrace_free_entry_rcu(struct rcu_head *rhp) | |
2023 | { | |
b6887d79 SR |
2024 | struct ftrace_func_probe *entry = |
2025 | container_of(rhp, struct ftrace_func_probe, rcu); | |
59df055f SR |
2026 | |
2027 | if (entry->ops->free) | |
2028 | entry->ops->free(&entry->data); | |
2029 | kfree(entry); | |
2030 | } | |
2031 | ||
2032 | ||
2033 | int | |
b6887d79 | 2034 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2035 | void *data) |
2036 | { | |
b6887d79 | 2037 | struct ftrace_func_probe *entry; |
59df055f SR |
2038 | struct ftrace_page *pg; |
2039 | struct dyn_ftrace *rec; | |
59df055f | 2040 | int type, len, not; |
6a24a244 | 2041 | unsigned long key; |
59df055f SR |
2042 | int count = 0; |
2043 | char *search; | |
2044 | ||
2045 | type = ftrace_setup_glob(glob, strlen(glob), &search, ¬); | |
2046 | len = strlen(search); | |
2047 | ||
b6887d79 | 2048 | /* we do not support '!' for function probes */ |
59df055f SR |
2049 | if (WARN_ON(not)) |
2050 | return -EINVAL; | |
2051 | ||
2052 | mutex_lock(&ftrace_lock); | |
2053 | do_for_each_ftrace_rec(pg, rec) { | |
2054 | ||
2055 | if (rec->flags & FTRACE_FL_FAILED) | |
2056 | continue; | |
2057 | ||
2058 | if (!ftrace_match_record(rec, search, len, type)) | |
2059 | continue; | |
2060 | ||
2061 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
2062 | if (!entry) { | |
b6887d79 | 2063 | /* If we did not process any, then return error */ |
59df055f SR |
2064 | if (!count) |
2065 | count = -ENOMEM; | |
2066 | goto out_unlock; | |
2067 | } | |
2068 | ||
2069 | count++; | |
2070 | ||
2071 | entry->data = data; | |
2072 | ||
2073 | /* | |
2074 | * The caller might want to do something special | |
2075 | * for each function we find. We call the callback | |
2076 | * to give the caller an opportunity to do so. | |
2077 | */ | |
2078 | if (ops->callback) { | |
2079 | if (ops->callback(rec->ip, &entry->data) < 0) { | |
2080 | /* caller does not like this func */ | |
2081 | kfree(entry); | |
2082 | continue; | |
2083 | } | |
2084 | } | |
2085 | ||
2086 | entry->ops = ops; | |
2087 | entry->ip = rec->ip; | |
2088 | ||
2089 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
2090 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
2091 | ||
2092 | } while_for_each_ftrace_rec(); | |
b6887d79 | 2093 | __enable_ftrace_function_probe(); |
59df055f SR |
2094 | |
2095 | out_unlock: | |
2096 | mutex_unlock(&ftrace_lock); | |
2097 | ||
2098 | return count; | |
2099 | } | |
2100 | ||
2101 | enum { | |
b6887d79 SR |
2102 | PROBE_TEST_FUNC = 1, |
2103 | PROBE_TEST_DATA = 2 | |
59df055f SR |
2104 | }; |
2105 | ||
2106 | static void | |
b6887d79 | 2107 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2108 | void *data, int flags) |
2109 | { | |
b6887d79 | 2110 | struct ftrace_func_probe *entry; |
59df055f SR |
2111 | struct hlist_node *n, *tmp; |
2112 | char str[KSYM_SYMBOL_LEN]; | |
2113 | int type = MATCH_FULL; | |
2114 | int i, len = 0; | |
2115 | char *search; | |
2116 | ||
2117 | if (glob && (strcmp(glob, "*") || !strlen(glob))) | |
2118 | glob = NULL; | |
2119 | else { | |
2120 | int not; | |
2121 | ||
2122 | type = ftrace_setup_glob(glob, strlen(glob), &search, ¬); | |
2123 | len = strlen(search); | |
2124 | ||
b6887d79 | 2125 | /* we do not support '!' for function probes */ |
59df055f SR |
2126 | if (WARN_ON(not)) |
2127 | return; | |
2128 | } | |
2129 | ||
2130 | mutex_lock(&ftrace_lock); | |
2131 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2132 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2133 | ||
2134 | hlist_for_each_entry_safe(entry, n, tmp, hhd, node) { | |
2135 | ||
2136 | /* break up if statements for readability */ | |
b6887d79 | 2137 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
2138 | continue; |
2139 | ||
b6887d79 | 2140 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
2141 | continue; |
2142 | ||
2143 | /* do this last, since it is the most expensive */ | |
2144 | if (glob) { | |
2145 | kallsyms_lookup(entry->ip, NULL, NULL, | |
2146 | NULL, str); | |
2147 | if (!ftrace_match(str, glob, len, type)) | |
2148 | continue; | |
2149 | } | |
2150 | ||
2151 | hlist_del(&entry->node); | |
2152 | call_rcu(&entry->rcu, ftrace_free_entry_rcu); | |
2153 | } | |
2154 | } | |
b6887d79 | 2155 | __disable_ftrace_function_probe(); |
59df055f SR |
2156 | mutex_unlock(&ftrace_lock); |
2157 | } | |
2158 | ||
2159 | void | |
b6887d79 | 2160 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2161 | void *data) |
2162 | { | |
b6887d79 SR |
2163 | __unregister_ftrace_function_probe(glob, ops, data, |
2164 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
2165 | } |
2166 | ||
2167 | void | |
b6887d79 | 2168 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 2169 | { |
b6887d79 | 2170 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
2171 | } |
2172 | ||
b6887d79 | 2173 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 2174 | { |
b6887d79 | 2175 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
2176 | } |
2177 | ||
f6180773 SR |
2178 | static LIST_HEAD(ftrace_commands); |
2179 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
2180 | ||
2181 | int register_ftrace_command(struct ftrace_func_command *cmd) | |
2182 | { | |
2183 | struct ftrace_func_command *p; | |
2184 | int ret = 0; | |
2185 | ||
2186 | mutex_lock(&ftrace_cmd_mutex); | |
2187 | list_for_each_entry(p, &ftrace_commands, list) { | |
2188 | if (strcmp(cmd->name, p->name) == 0) { | |
2189 | ret = -EBUSY; | |
2190 | goto out_unlock; | |
2191 | } | |
2192 | } | |
2193 | list_add(&cmd->list, &ftrace_commands); | |
2194 | out_unlock: | |
2195 | mutex_unlock(&ftrace_cmd_mutex); | |
2196 | ||
2197 | return ret; | |
2198 | } | |
2199 | ||
2200 | int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
2201 | { | |
2202 | struct ftrace_func_command *p, *n; | |
2203 | int ret = -ENODEV; | |
2204 | ||
2205 | mutex_lock(&ftrace_cmd_mutex); | |
2206 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
2207 | if (strcmp(cmd->name, p->name) == 0) { | |
2208 | ret = 0; | |
2209 | list_del_init(&p->list); | |
2210 | goto out_unlock; | |
2211 | } | |
2212 | } | |
2213 | out_unlock: | |
2214 | mutex_unlock(&ftrace_cmd_mutex); | |
2215 | ||
2216 | return ret; | |
2217 | } | |
2218 | ||
64e7c440 SR |
2219 | static int ftrace_process_regex(char *buff, int len, int enable) |
2220 | { | |
f6180773 | 2221 | char *func, *command, *next = buff; |
6a24a244 | 2222 | struct ftrace_func_command *p; |
f6180773 | 2223 | int ret = -EINVAL; |
64e7c440 SR |
2224 | |
2225 | func = strsep(&next, ":"); | |
2226 | ||
2227 | if (!next) { | |
2228 | ftrace_match_records(func, len, enable); | |
2229 | return 0; | |
2230 | } | |
2231 | ||
f6180773 | 2232 | /* command found */ |
64e7c440 SR |
2233 | |
2234 | command = strsep(&next, ":"); | |
2235 | ||
f6180773 SR |
2236 | mutex_lock(&ftrace_cmd_mutex); |
2237 | list_for_each_entry(p, &ftrace_commands, list) { | |
2238 | if (strcmp(p->name, command) == 0) { | |
2239 | ret = p->func(func, command, next, enable); | |
2240 | goto out_unlock; | |
2241 | } | |
64e7c440 | 2242 | } |
f6180773 SR |
2243 | out_unlock: |
2244 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 2245 | |
f6180773 | 2246 | return ret; |
64e7c440 SR |
2247 | } |
2248 | ||
e309b41d | 2249 | static ssize_t |
41c52c0d SR |
2250 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
2251 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
2252 | { |
2253 | struct ftrace_iterator *iter; | |
2254 | char ch; | |
2255 | size_t read = 0; | |
2256 | ssize_t ret; | |
2257 | ||
2258 | if (!cnt || cnt < 0) | |
2259 | return 0; | |
2260 | ||
41c52c0d | 2261 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
2262 | |
2263 | if (file->f_mode & FMODE_READ) { | |
2264 | struct seq_file *m = file->private_data; | |
2265 | iter = m->private; | |
2266 | } else | |
2267 | iter = file->private_data; | |
2268 | ||
2269 | if (!*ppos) { | |
2270 | iter->flags &= ~FTRACE_ITER_CONT; | |
2271 | iter->buffer_idx = 0; | |
2272 | } | |
2273 | ||
2274 | ret = get_user(ch, ubuf++); | |
2275 | if (ret) | |
2276 | goto out; | |
2277 | read++; | |
2278 | cnt--; | |
2279 | ||
2280 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { | |
2281 | /* skip white space */ | |
2282 | while (cnt && isspace(ch)) { | |
2283 | ret = get_user(ch, ubuf++); | |
2284 | if (ret) | |
2285 | goto out; | |
2286 | read++; | |
2287 | cnt--; | |
2288 | } | |
2289 | ||
5072c59f SR |
2290 | if (isspace(ch)) { |
2291 | file->f_pos += read; | |
2292 | ret = read; | |
2293 | goto out; | |
2294 | } | |
2295 | ||
2296 | iter->buffer_idx = 0; | |
2297 | } | |
2298 | ||
2299 | while (cnt && !isspace(ch)) { | |
2300 | if (iter->buffer_idx < FTRACE_BUFF_MAX) | |
2301 | iter->buffer[iter->buffer_idx++] = ch; | |
2302 | else { | |
2303 | ret = -EINVAL; | |
2304 | goto out; | |
2305 | } | |
2306 | ret = get_user(ch, ubuf++); | |
2307 | if (ret) | |
2308 | goto out; | |
2309 | read++; | |
2310 | cnt--; | |
2311 | } | |
2312 | ||
2313 | if (isspace(ch)) { | |
2314 | iter->filtered++; | |
2315 | iter->buffer[iter->buffer_idx] = 0; | |
64e7c440 SR |
2316 | ret = ftrace_process_regex(iter->buffer, |
2317 | iter->buffer_idx, enable); | |
2318 | if (ret) | |
2319 | goto out; | |
5072c59f SR |
2320 | iter->buffer_idx = 0; |
2321 | } else | |
2322 | iter->flags |= FTRACE_ITER_CONT; | |
2323 | ||
2324 | ||
2325 | file->f_pos += read; | |
2326 | ||
2327 | ret = read; | |
2328 | out: | |
41c52c0d | 2329 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
2330 | |
2331 | return ret; | |
2332 | } | |
2333 | ||
41c52c0d SR |
2334 | static ssize_t |
2335 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
2336 | size_t cnt, loff_t *ppos) | |
2337 | { | |
2338 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
2339 | } | |
2340 | ||
2341 | static ssize_t | |
2342 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
2343 | size_t cnt, loff_t *ppos) | |
2344 | { | |
2345 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
2346 | } | |
2347 | ||
2348 | static void | |
2349 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
2350 | { | |
2351 | if (unlikely(ftrace_disabled)) | |
2352 | return; | |
2353 | ||
2354 | mutex_lock(&ftrace_regex_lock); | |
2355 | if (reset) | |
2356 | ftrace_filter_reset(enable); | |
2357 | if (buf) | |
7f24b31b | 2358 | ftrace_match_records(buf, len, enable); |
41c52c0d SR |
2359 | mutex_unlock(&ftrace_regex_lock); |
2360 | } | |
2361 | ||
77a2b37d SR |
2362 | /** |
2363 | * ftrace_set_filter - set a function to filter on in ftrace | |
2364 | * @buf - the string that holds the function filter text. | |
2365 | * @len - the length of the string. | |
2366 | * @reset - non zero to reset all filters before applying this filter. | |
2367 | * | |
2368 | * Filters denote which functions should be enabled when tracing is enabled. | |
2369 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
2370 | */ | |
e309b41d | 2371 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 2372 | { |
41c52c0d SR |
2373 | ftrace_set_regex(buf, len, reset, 1); |
2374 | } | |
4eebcc81 | 2375 | |
41c52c0d SR |
2376 | /** |
2377 | * ftrace_set_notrace - set a function to not trace in ftrace | |
2378 | * @buf - the string that holds the function notrace text. | |
2379 | * @len - the length of the string. | |
2380 | * @reset - non zero to reset all filters before applying this filter. | |
2381 | * | |
2382 | * Notrace Filters denote which functions should not be enabled when tracing | |
2383 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
2384 | * for tracing. | |
2385 | */ | |
2386 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
2387 | { | |
2388 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
2389 | } |
2390 | ||
2af15d6a SR |
2391 | /* |
2392 | * command line interface to allow users to set filters on boot up. | |
2393 | */ | |
2394 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
2395 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
2396 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
2397 | ||
2398 | static int __init set_ftrace_notrace(char *str) | |
2399 | { | |
2400 | strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); | |
2401 | return 1; | |
2402 | } | |
2403 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
2404 | ||
2405 | static int __init set_ftrace_filter(char *str) | |
2406 | { | |
2407 | strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); | |
2408 | return 1; | |
2409 | } | |
2410 | __setup("ftrace_filter=", set_ftrace_filter); | |
2411 | ||
2412 | static void __init set_ftrace_early_filter(char *buf, int enable) | |
2413 | { | |
2414 | char *func; | |
2415 | ||
2416 | while (buf) { | |
2417 | func = strsep(&buf, ","); | |
2418 | ftrace_set_regex(func, strlen(func), 0, enable); | |
2419 | } | |
2420 | } | |
2421 | ||
2422 | static void __init set_ftrace_early_filters(void) | |
2423 | { | |
2424 | if (ftrace_filter_buf[0]) | |
2425 | set_ftrace_early_filter(ftrace_filter_buf, 1); | |
2426 | if (ftrace_notrace_buf[0]) | |
2427 | set_ftrace_early_filter(ftrace_notrace_buf, 0); | |
2428 | } | |
2429 | ||
e309b41d | 2430 | static int |
41c52c0d | 2431 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
2432 | { |
2433 | struct seq_file *m = (struct seq_file *)file->private_data; | |
2434 | struct ftrace_iterator *iter; | |
2435 | ||
41c52c0d | 2436 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
2437 | if (file->f_mode & FMODE_READ) { |
2438 | iter = m->private; | |
2439 | ||
2440 | seq_release(inode, file); | |
2441 | } else | |
2442 | iter = file->private_data; | |
2443 | ||
2444 | if (iter->buffer_idx) { | |
2445 | iter->filtered++; | |
2446 | iter->buffer[iter->buffer_idx] = 0; | |
7f24b31b | 2447 | ftrace_match_records(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
2448 | } |
2449 | ||
e6ea44e9 | 2450 | mutex_lock(&ftrace_lock); |
ee02a2e5 | 2451 | if (ftrace_start_up && ftrace_enabled) |
5072c59f | 2452 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
e6ea44e9 | 2453 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
2454 | |
2455 | kfree(iter); | |
41c52c0d | 2456 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
2457 | return 0; |
2458 | } | |
2459 | ||
41c52c0d SR |
2460 | static int |
2461 | ftrace_filter_release(struct inode *inode, struct file *file) | |
2462 | { | |
2463 | return ftrace_regex_release(inode, file, 1); | |
2464 | } | |
2465 | ||
2466 | static int | |
2467 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
2468 | { | |
2469 | return ftrace_regex_release(inode, file, 0); | |
2470 | } | |
2471 | ||
5e2336a0 | 2472 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
2473 | .open = ftrace_avail_open, |
2474 | .read = seq_read, | |
2475 | .llseek = seq_lseek, | |
2476 | .release = ftrace_avail_release, | |
2477 | }; | |
2478 | ||
5e2336a0 | 2479 | static const struct file_operations ftrace_failures_fops = { |
eb9a7bf0 AS |
2480 | .open = ftrace_failures_open, |
2481 | .read = seq_read, | |
2482 | .llseek = seq_lseek, | |
2483 | .release = ftrace_avail_release, | |
2484 | }; | |
2485 | ||
5e2336a0 | 2486 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 2487 | .open = ftrace_filter_open, |
850a80cf | 2488 | .read = seq_read, |
5072c59f | 2489 | .write = ftrace_filter_write, |
41c52c0d | 2490 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
2491 | .release = ftrace_filter_release, |
2492 | }; | |
2493 | ||
5e2336a0 | 2494 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 2495 | .open = ftrace_notrace_open, |
850a80cf | 2496 | .read = seq_read, |
41c52c0d SR |
2497 | .write = ftrace_notrace_write, |
2498 | .llseek = ftrace_regex_lseek, | |
2499 | .release = ftrace_notrace_release, | |
2500 | }; | |
2501 | ||
ea4e2bc4 SR |
2502 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
2503 | ||
2504 | static DEFINE_MUTEX(graph_lock); | |
2505 | ||
2506 | int ftrace_graph_count; | |
2507 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; | |
2508 | ||
2509 | static void * | |
85951842 | 2510 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 SR |
2511 | { |
2512 | unsigned long *array = m->private; | |
ea4e2bc4 | 2513 | |
85951842 | 2514 | if (*pos >= ftrace_graph_count) |
ea4e2bc4 | 2515 | return NULL; |
85951842 LZ |
2516 | return &array[*pos]; |
2517 | } | |
ea4e2bc4 | 2518 | |
85951842 LZ |
2519 | static void * |
2520 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
2521 | { | |
2522 | (*pos)++; | |
2523 | return __g_next(m, pos); | |
ea4e2bc4 SR |
2524 | } |
2525 | ||
2526 | static void *g_start(struct seq_file *m, loff_t *pos) | |
2527 | { | |
ea4e2bc4 SR |
2528 | mutex_lock(&graph_lock); |
2529 | ||
f9349a8f FW |
2530 | /* Nothing, tell g_show to print all functions are enabled */ |
2531 | if (!ftrace_graph_count && !*pos) | |
2532 | return (void *)1; | |
2533 | ||
85951842 | 2534 | return __g_next(m, pos); |
ea4e2bc4 SR |
2535 | } |
2536 | ||
2537 | static void g_stop(struct seq_file *m, void *p) | |
2538 | { | |
2539 | mutex_unlock(&graph_lock); | |
2540 | } | |
2541 | ||
2542 | static int g_show(struct seq_file *m, void *v) | |
2543 | { | |
2544 | unsigned long *ptr = v; | |
2545 | char str[KSYM_SYMBOL_LEN]; | |
2546 | ||
2547 | if (!ptr) | |
2548 | return 0; | |
2549 | ||
f9349a8f FW |
2550 | if (ptr == (unsigned long *)1) { |
2551 | seq_printf(m, "#### all functions enabled ####\n"); | |
2552 | return 0; | |
2553 | } | |
2554 | ||
ea4e2bc4 SR |
2555 | kallsyms_lookup(*ptr, NULL, NULL, NULL, str); |
2556 | ||
2557 | seq_printf(m, "%s\n", str); | |
2558 | ||
2559 | return 0; | |
2560 | } | |
2561 | ||
2562 | static struct seq_operations ftrace_graph_seq_ops = { | |
2563 | .start = g_start, | |
2564 | .next = g_next, | |
2565 | .stop = g_stop, | |
2566 | .show = g_show, | |
2567 | }; | |
2568 | ||
2569 | static int | |
2570 | ftrace_graph_open(struct inode *inode, struct file *file) | |
2571 | { | |
2572 | int ret = 0; | |
2573 | ||
2574 | if (unlikely(ftrace_disabled)) | |
2575 | return -ENODEV; | |
2576 | ||
2577 | mutex_lock(&graph_lock); | |
2578 | if ((file->f_mode & FMODE_WRITE) && | |
2579 | !(file->f_flags & O_APPEND)) { | |
2580 | ftrace_graph_count = 0; | |
2581 | memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); | |
2582 | } | |
2583 | ||
2584 | if (file->f_mode & FMODE_READ) { | |
2585 | ret = seq_open(file, &ftrace_graph_seq_ops); | |
2586 | if (!ret) { | |
2587 | struct seq_file *m = file->private_data; | |
2588 | m->private = ftrace_graph_funcs; | |
2589 | } | |
2590 | } else | |
2591 | file->private_data = ftrace_graph_funcs; | |
2592 | mutex_unlock(&graph_lock); | |
2593 | ||
2594 | return ret; | |
2595 | } | |
2596 | ||
ea4e2bc4 | 2597 | static int |
f9349a8f | 2598 | ftrace_set_func(unsigned long *array, int *idx, char *buffer) |
ea4e2bc4 | 2599 | { |
ea4e2bc4 SR |
2600 | struct dyn_ftrace *rec; |
2601 | struct ftrace_page *pg; | |
f9349a8f | 2602 | int search_len; |
ea4e2bc4 | 2603 | int found = 0; |
f9349a8f FW |
2604 | int type, not; |
2605 | char *search; | |
2606 | bool exists; | |
2607 | int i; | |
ea4e2bc4 SR |
2608 | |
2609 | if (ftrace_disabled) | |
2610 | return -ENODEV; | |
2611 | ||
f9349a8f FW |
2612 | /* decode regex */ |
2613 | type = ftrace_setup_glob(buffer, strlen(buffer), &search, ¬); | |
2614 | if (not) | |
2615 | return -EINVAL; | |
2616 | ||
2617 | search_len = strlen(search); | |
2618 | ||
52baf119 | 2619 | mutex_lock(&ftrace_lock); |
265c831c SR |
2620 | do_for_each_ftrace_rec(pg, rec) { |
2621 | ||
f9349a8f FW |
2622 | if (*idx >= FTRACE_GRAPH_MAX_FUNCS) |
2623 | break; | |
2624 | ||
265c831c SR |
2625 | if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE)) |
2626 | continue; | |
2627 | ||
f9349a8f FW |
2628 | if (ftrace_match_record(rec, search, search_len, type)) { |
2629 | /* ensure it is not already in the array */ | |
2630 | exists = false; | |
2631 | for (i = 0; i < *idx; i++) | |
2632 | if (array[i] == rec->ip) { | |
2633 | exists = true; | |
265c831c SR |
2634 | break; |
2635 | } | |
f9349a8f FW |
2636 | if (!exists) { |
2637 | array[(*idx)++] = rec->ip; | |
2638 | found = 1; | |
2639 | } | |
ea4e2bc4 | 2640 | } |
265c831c | 2641 | } while_for_each_ftrace_rec(); |
f9349a8f | 2642 | |
52baf119 | 2643 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 SR |
2644 | |
2645 | return found ? 0 : -EINVAL; | |
2646 | } | |
2647 | ||
2648 | static ssize_t | |
2649 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
2650 | size_t cnt, loff_t *ppos) | |
2651 | { | |
2652 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
2653 | unsigned long *array; | |
2654 | size_t read = 0; | |
2655 | ssize_t ret; | |
2656 | int index = 0; | |
2657 | char ch; | |
2658 | ||
2659 | if (!cnt || cnt < 0) | |
2660 | return 0; | |
2661 | ||
2662 | mutex_lock(&graph_lock); | |
2663 | ||
2664 | if (ftrace_graph_count >= FTRACE_GRAPH_MAX_FUNCS) { | |
2665 | ret = -EBUSY; | |
2666 | goto out; | |
2667 | } | |
2668 | ||
2669 | if (file->f_mode & FMODE_READ) { | |
2670 | struct seq_file *m = file->private_data; | |
2671 | array = m->private; | |
2672 | } else | |
2673 | array = file->private_data; | |
2674 | ||
2675 | ret = get_user(ch, ubuf++); | |
2676 | if (ret) | |
2677 | goto out; | |
2678 | read++; | |
2679 | cnt--; | |
2680 | ||
2681 | /* skip white space */ | |
2682 | while (cnt && isspace(ch)) { | |
2683 | ret = get_user(ch, ubuf++); | |
2684 | if (ret) | |
2685 | goto out; | |
2686 | read++; | |
2687 | cnt--; | |
2688 | } | |
2689 | ||
2690 | if (isspace(ch)) { | |
2691 | *ppos += read; | |
2692 | ret = read; | |
2693 | goto out; | |
2694 | } | |
2695 | ||
2696 | while (cnt && !isspace(ch)) { | |
2697 | if (index < FTRACE_BUFF_MAX) | |
2698 | buffer[index++] = ch; | |
2699 | else { | |
2700 | ret = -EINVAL; | |
2701 | goto out; | |
2702 | } | |
2703 | ret = get_user(ch, ubuf++); | |
2704 | if (ret) | |
2705 | goto out; | |
2706 | read++; | |
2707 | cnt--; | |
2708 | } | |
2709 | buffer[index] = 0; | |
2710 | ||
f9349a8f FW |
2711 | /* we allow only one expression at a time */ |
2712 | ret = ftrace_set_func(array, &ftrace_graph_count, buffer); | |
ea4e2bc4 SR |
2713 | if (ret) |
2714 | goto out; | |
2715 | ||
ea4e2bc4 SR |
2716 | file->f_pos += read; |
2717 | ||
2718 | ret = read; | |
2719 | out: | |
2720 | mutex_unlock(&graph_lock); | |
2721 | ||
2722 | return ret; | |
2723 | } | |
2724 | ||
2725 | static const struct file_operations ftrace_graph_fops = { | |
2726 | .open = ftrace_graph_open, | |
850a80cf | 2727 | .read = seq_read, |
ea4e2bc4 SR |
2728 | .write = ftrace_graph_write, |
2729 | }; | |
2730 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2731 | ||
df4fc315 | 2732 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 2733 | { |
5072c59f | 2734 | |
5452af66 FW |
2735 | trace_create_file("available_filter_functions", 0444, |
2736 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 2737 | |
5452af66 FW |
2738 | trace_create_file("failures", 0444, |
2739 | d_tracer, NULL, &ftrace_failures_fops); | |
eb9a7bf0 | 2740 | |
5452af66 FW |
2741 | trace_create_file("set_ftrace_filter", 0644, d_tracer, |
2742 | NULL, &ftrace_filter_fops); | |
41c52c0d | 2743 | |
5452af66 | 2744 | trace_create_file("set_ftrace_notrace", 0644, d_tracer, |
41c52c0d | 2745 | NULL, &ftrace_notrace_fops); |
ad90c0e3 | 2746 | |
ea4e2bc4 | 2747 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 2748 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
2749 | NULL, |
2750 | &ftrace_graph_fops); | |
ea4e2bc4 SR |
2751 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
2752 | ||
5072c59f SR |
2753 | return 0; |
2754 | } | |
2755 | ||
31e88909 SR |
2756 | static int ftrace_convert_nops(struct module *mod, |
2757 | unsigned long *start, | |
68bf21aa SR |
2758 | unsigned long *end) |
2759 | { | |
2760 | unsigned long *p; | |
2761 | unsigned long addr; | |
2762 | unsigned long flags; | |
2763 | ||
e6ea44e9 | 2764 | mutex_lock(&ftrace_lock); |
68bf21aa SR |
2765 | p = start; |
2766 | while (p < end) { | |
2767 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
2768 | /* |
2769 | * Some architecture linkers will pad between | |
2770 | * the different mcount_loc sections of different | |
2771 | * object files to satisfy alignments. | |
2772 | * Skip any NULL pointers. | |
2773 | */ | |
2774 | if (!addr) | |
2775 | continue; | |
68bf21aa | 2776 | ftrace_record_ip(addr); |
68bf21aa SR |
2777 | } |
2778 | ||
08f5ac90 | 2779 | /* disable interrupts to prevent kstop machine */ |
68bf21aa | 2780 | local_irq_save(flags); |
31e88909 | 2781 | ftrace_update_code(mod); |
68bf21aa | 2782 | local_irq_restore(flags); |
e6ea44e9 | 2783 | mutex_unlock(&ftrace_lock); |
68bf21aa SR |
2784 | |
2785 | return 0; | |
2786 | } | |
2787 | ||
93eb677d SR |
2788 | #ifdef CONFIG_MODULES |
2789 | void ftrace_release(void *start, void *end) | |
2790 | { | |
2791 | struct dyn_ftrace *rec; | |
2792 | struct ftrace_page *pg; | |
2793 | unsigned long s = (unsigned long)start; | |
2794 | unsigned long e = (unsigned long)end; | |
2795 | ||
2796 | if (ftrace_disabled || !start || start == end) | |
2797 | return; | |
2798 | ||
2799 | mutex_lock(&ftrace_lock); | |
2800 | do_for_each_ftrace_rec(pg, rec) { | |
2801 | if ((rec->ip >= s) && (rec->ip < e)) { | |
2802 | /* | |
2803 | * rec->ip is changed in ftrace_free_rec() | |
2804 | * It should not between s and e if record was freed. | |
2805 | */ | |
2806 | FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE); | |
2807 | ftrace_free_rec(rec); | |
2808 | } | |
2809 | } while_for_each_ftrace_rec(); | |
2810 | mutex_unlock(&ftrace_lock); | |
2811 | } | |
2812 | ||
2813 | static void ftrace_init_module(struct module *mod, | |
2814 | unsigned long *start, unsigned long *end) | |
90d595fe | 2815 | { |
00fd61ae | 2816 | if (ftrace_disabled || start == end) |
fed1939c | 2817 | return; |
31e88909 | 2818 | ftrace_convert_nops(mod, start, end); |
90d595fe SR |
2819 | } |
2820 | ||
93eb677d SR |
2821 | static int ftrace_module_notify(struct notifier_block *self, |
2822 | unsigned long val, void *data) | |
2823 | { | |
2824 | struct module *mod = data; | |
2825 | ||
2826 | switch (val) { | |
2827 | case MODULE_STATE_COMING: | |
2828 | ftrace_init_module(mod, mod->ftrace_callsites, | |
2829 | mod->ftrace_callsites + | |
2830 | mod->num_ftrace_callsites); | |
2831 | break; | |
2832 | case MODULE_STATE_GOING: | |
2833 | ftrace_release(mod->ftrace_callsites, | |
2834 | mod->ftrace_callsites + | |
2835 | mod->num_ftrace_callsites); | |
2836 | break; | |
2837 | } | |
2838 | ||
2839 | return 0; | |
2840 | } | |
2841 | #else | |
2842 | static int ftrace_module_notify(struct notifier_block *self, | |
2843 | unsigned long val, void *data) | |
2844 | { | |
2845 | return 0; | |
2846 | } | |
2847 | #endif /* CONFIG_MODULES */ | |
2848 | ||
2849 | struct notifier_block ftrace_module_nb = { | |
2850 | .notifier_call = ftrace_module_notify, | |
2851 | .priority = 0, | |
2852 | }; | |
2853 | ||
68bf21aa SR |
2854 | extern unsigned long __start_mcount_loc[]; |
2855 | extern unsigned long __stop_mcount_loc[]; | |
2856 | ||
2857 | void __init ftrace_init(void) | |
2858 | { | |
2859 | unsigned long count, addr, flags; | |
2860 | int ret; | |
2861 | ||
2862 | /* Keep the ftrace pointer to the stub */ | |
2863 | addr = (unsigned long)ftrace_stub; | |
2864 | ||
2865 | local_irq_save(flags); | |
2866 | ftrace_dyn_arch_init(&addr); | |
2867 | local_irq_restore(flags); | |
2868 | ||
2869 | /* ftrace_dyn_arch_init places the return code in addr */ | |
2870 | if (addr) | |
2871 | goto failed; | |
2872 | ||
2873 | count = __stop_mcount_loc - __start_mcount_loc; | |
2874 | ||
2875 | ret = ftrace_dyn_table_alloc(count); | |
2876 | if (ret) | |
2877 | goto failed; | |
2878 | ||
2879 | last_ftrace_enabled = ftrace_enabled = 1; | |
2880 | ||
31e88909 SR |
2881 | ret = ftrace_convert_nops(NULL, |
2882 | __start_mcount_loc, | |
68bf21aa SR |
2883 | __stop_mcount_loc); |
2884 | ||
93eb677d | 2885 | ret = register_module_notifier(&ftrace_module_nb); |
24ed0c4b | 2886 | if (ret) |
93eb677d SR |
2887 | pr_warning("Failed to register trace ftrace module notifier\n"); |
2888 | ||
2af15d6a SR |
2889 | set_ftrace_early_filters(); |
2890 | ||
68bf21aa SR |
2891 | return; |
2892 | failed: | |
2893 | ftrace_disabled = 1; | |
2894 | } | |
68bf21aa | 2895 | |
3d083395 | 2896 | #else |
0b6e4d56 FW |
2897 | |
2898 | static int __init ftrace_nodyn_init(void) | |
2899 | { | |
2900 | ftrace_enabled = 1; | |
2901 | return 0; | |
2902 | } | |
2903 | device_initcall(ftrace_nodyn_init); | |
2904 | ||
df4fc315 SR |
2905 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
2906 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 SR |
2907 | /* Keep as macros so we do not need to define the commands */ |
2908 | # define ftrace_startup(command) do { } while (0) | |
2909 | # define ftrace_shutdown(command) do { } while (0) | |
c7aafc54 IM |
2910 | # define ftrace_startup_sysctl() do { } while (0) |
2911 | # define ftrace_shutdown_sysctl() do { } while (0) | |
3d083395 SR |
2912 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
2913 | ||
df4fc315 SR |
2914 | static ssize_t |
2915 | ftrace_pid_read(struct file *file, char __user *ubuf, | |
2916 | size_t cnt, loff_t *ppos) | |
2917 | { | |
2918 | char buf[64]; | |
2919 | int r; | |
2920 | ||
e32d8956 SR |
2921 | if (ftrace_pid_trace == ftrace_swapper_pid) |
2922 | r = sprintf(buf, "swapper tasks\n"); | |
2923 | else if (ftrace_pid_trace) | |
cc59c9e8 | 2924 | r = sprintf(buf, "%u\n", pid_vnr(ftrace_pid_trace)); |
df4fc315 SR |
2925 | else |
2926 | r = sprintf(buf, "no pid\n"); | |
2927 | ||
2928 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
2929 | } | |
2930 | ||
e32d8956 | 2931 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
2932 | { |
2933 | struct task_struct *p; | |
e32d8956 | 2934 | int cpu; |
978f3a45 | 2935 | |
e32d8956 SR |
2936 | get_online_cpus(); |
2937 | for_each_online_cpu(cpu) { | |
2938 | p = idle_task(cpu); | |
978f3a45 | 2939 | clear_tsk_trace_trace(p); |
e32d8956 SR |
2940 | } |
2941 | put_online_cpus(); | |
2942 | } | |
978f3a45 | 2943 | |
e32d8956 SR |
2944 | static void set_ftrace_swapper(void) |
2945 | { | |
2946 | struct task_struct *p; | |
2947 | int cpu; | |
2948 | ||
2949 | get_online_cpus(); | |
2950 | for_each_online_cpu(cpu) { | |
2951 | p = idle_task(cpu); | |
2952 | set_tsk_trace_trace(p); | |
2953 | } | |
2954 | put_online_cpus(); | |
978f3a45 SR |
2955 | } |
2956 | ||
e32d8956 SR |
2957 | static void clear_ftrace_pid(struct pid *pid) |
2958 | { | |
2959 | struct task_struct *p; | |
2960 | ||
229c4ef8 | 2961 | rcu_read_lock(); |
e32d8956 SR |
2962 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2963 | clear_tsk_trace_trace(p); | |
2964 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
2965 | rcu_read_unlock(); |
2966 | ||
e32d8956 SR |
2967 | put_pid(pid); |
2968 | } | |
2969 | ||
2970 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
2971 | { |
2972 | struct task_struct *p; | |
2973 | ||
229c4ef8 | 2974 | rcu_read_lock(); |
978f3a45 SR |
2975 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2976 | set_tsk_trace_trace(p); | |
2977 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 2978 | rcu_read_unlock(); |
978f3a45 SR |
2979 | } |
2980 | ||
e32d8956 SR |
2981 | static void clear_ftrace_pid_task(struct pid **pid) |
2982 | { | |
2983 | if (*pid == ftrace_swapper_pid) | |
2984 | clear_ftrace_swapper(); | |
2985 | else | |
2986 | clear_ftrace_pid(*pid); | |
2987 | ||
2988 | *pid = NULL; | |
2989 | } | |
2990 | ||
2991 | static void set_ftrace_pid_task(struct pid *pid) | |
2992 | { | |
2993 | if (pid == ftrace_swapper_pid) | |
2994 | set_ftrace_swapper(); | |
2995 | else | |
2996 | set_ftrace_pid(pid); | |
2997 | } | |
2998 | ||
df4fc315 SR |
2999 | static ssize_t |
3000 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
3001 | size_t cnt, loff_t *ppos) | |
3002 | { | |
978f3a45 | 3003 | struct pid *pid; |
df4fc315 SR |
3004 | char buf[64]; |
3005 | long val; | |
3006 | int ret; | |
3007 | ||
3008 | if (cnt >= sizeof(buf)) | |
3009 | return -EINVAL; | |
3010 | ||
3011 | if (copy_from_user(&buf, ubuf, cnt)) | |
3012 | return -EFAULT; | |
3013 | ||
3014 | buf[cnt] = 0; | |
3015 | ||
3016 | ret = strict_strtol(buf, 10, &val); | |
3017 | if (ret < 0) | |
3018 | return ret; | |
3019 | ||
e6ea44e9 | 3020 | mutex_lock(&ftrace_lock); |
978f3a45 | 3021 | if (val < 0) { |
df4fc315 | 3022 | /* disable pid tracing */ |
978f3a45 | 3023 | if (!ftrace_pid_trace) |
df4fc315 | 3024 | goto out; |
978f3a45 SR |
3025 | |
3026 | clear_ftrace_pid_task(&ftrace_pid_trace); | |
df4fc315 SR |
3027 | |
3028 | } else { | |
e32d8956 SR |
3029 | /* swapper task is special */ |
3030 | if (!val) { | |
3031 | pid = ftrace_swapper_pid; | |
3032 | if (pid == ftrace_pid_trace) | |
3033 | goto out; | |
3034 | } else { | |
3035 | pid = find_get_pid(val); | |
df4fc315 | 3036 | |
e32d8956 SR |
3037 | if (pid == ftrace_pid_trace) { |
3038 | put_pid(pid); | |
3039 | goto out; | |
3040 | } | |
0ef8cde5 | 3041 | } |
0ef8cde5 | 3042 | |
978f3a45 SR |
3043 | if (ftrace_pid_trace) |
3044 | clear_ftrace_pid_task(&ftrace_pid_trace); | |
3045 | ||
3046 | if (!pid) | |
3047 | goto out; | |
3048 | ||
3049 | ftrace_pid_trace = pid; | |
3050 | ||
3051 | set_ftrace_pid_task(ftrace_pid_trace); | |
df4fc315 SR |
3052 | } |
3053 | ||
3054 | /* update the function call */ | |
3055 | ftrace_update_pid_func(); | |
3056 | ftrace_startup_enable(0); | |
3057 | ||
3058 | out: | |
e6ea44e9 | 3059 | mutex_unlock(&ftrace_lock); |
df4fc315 SR |
3060 | |
3061 | return cnt; | |
3062 | } | |
3063 | ||
5e2336a0 | 3064 | static const struct file_operations ftrace_pid_fops = { |
df4fc315 SR |
3065 | .read = ftrace_pid_read, |
3066 | .write = ftrace_pid_write, | |
3067 | }; | |
3068 | ||
3069 | static __init int ftrace_init_debugfs(void) | |
3070 | { | |
3071 | struct dentry *d_tracer; | |
df4fc315 SR |
3072 | |
3073 | d_tracer = tracing_init_dentry(); | |
3074 | if (!d_tracer) | |
3075 | return 0; | |
3076 | ||
3077 | ftrace_init_dyn_debugfs(d_tracer); | |
3078 | ||
5452af66 FW |
3079 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
3080 | NULL, &ftrace_pid_fops); | |
493762fc SR |
3081 | |
3082 | ftrace_profile_debugfs(d_tracer); | |
3083 | ||
df4fc315 SR |
3084 | return 0; |
3085 | } | |
df4fc315 SR |
3086 | fs_initcall(ftrace_init_debugfs); |
3087 | ||
a2bb6a3d | 3088 | /** |
81adbdc0 | 3089 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
3090 | * |
3091 | * This function should be used by panic code. It stops ftrace | |
3092 | * but in a not so nice way. If you need to simply kill ftrace | |
3093 | * from a non-atomic section, use ftrace_kill. | |
3094 | */ | |
81adbdc0 | 3095 | void ftrace_kill(void) |
a2bb6a3d SR |
3096 | { |
3097 | ftrace_disabled = 1; | |
3098 | ftrace_enabled = 0; | |
a2bb6a3d SR |
3099 | clear_ftrace_function(); |
3100 | } | |
3101 | ||
16444a8a | 3102 | /** |
3d083395 SR |
3103 | * register_ftrace_function - register a function for profiling |
3104 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 3105 | * |
3d083395 SR |
3106 | * Register a function to be called by all functions in the |
3107 | * kernel. | |
3108 | * | |
3109 | * Note: @ops->func and all the functions it calls must be labeled | |
3110 | * with "notrace", otherwise it will go into a | |
3111 | * recursive loop. | |
16444a8a | 3112 | */ |
3d083395 | 3113 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 3114 | { |
b0fc494f SR |
3115 | int ret; |
3116 | ||
4eebcc81 SR |
3117 | if (unlikely(ftrace_disabled)) |
3118 | return -1; | |
3119 | ||
e6ea44e9 | 3120 | mutex_lock(&ftrace_lock); |
e7d3737e | 3121 | |
b0fc494f | 3122 | ret = __register_ftrace_function(ops); |
5a45cfe1 | 3123 | ftrace_startup(0); |
b0fc494f | 3124 | |
e6ea44e9 | 3125 | mutex_unlock(&ftrace_lock); |
b0fc494f | 3126 | return ret; |
3d083395 SR |
3127 | } |
3128 | ||
3129 | /** | |
32632920 | 3130 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
3131 | * @ops - ops structure that holds the function to unregister |
3132 | * | |
3133 | * Unregister a function that was added to be called by ftrace profiling. | |
3134 | */ | |
3135 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
3136 | { | |
3137 | int ret; | |
3138 | ||
e6ea44e9 | 3139 | mutex_lock(&ftrace_lock); |
3d083395 | 3140 | ret = __unregister_ftrace_function(ops); |
5a45cfe1 | 3141 | ftrace_shutdown(0); |
e6ea44e9 | 3142 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
3143 | |
3144 | return ret; | |
3145 | } | |
3146 | ||
e309b41d | 3147 | int |
b0fc494f | 3148 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
5072c59f | 3149 | struct file *file, void __user *buffer, size_t *lenp, |
b0fc494f SR |
3150 | loff_t *ppos) |
3151 | { | |
3152 | int ret; | |
3153 | ||
4eebcc81 SR |
3154 | if (unlikely(ftrace_disabled)) |
3155 | return -ENODEV; | |
3156 | ||
e6ea44e9 | 3157 | mutex_lock(&ftrace_lock); |
b0fc494f | 3158 | |
5072c59f | 3159 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
b0fc494f SR |
3160 | |
3161 | if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) | |
3162 | goto out; | |
3163 | ||
3164 | last_ftrace_enabled = ftrace_enabled; | |
3165 | ||
3166 | if (ftrace_enabled) { | |
3167 | ||
3168 | ftrace_startup_sysctl(); | |
3169 | ||
3170 | /* we are starting ftrace again */ | |
3171 | if (ftrace_list != &ftrace_list_end) { | |
3172 | if (ftrace_list->next == &ftrace_list_end) | |
3173 | ftrace_trace_function = ftrace_list->func; | |
3174 | else | |
3175 | ftrace_trace_function = ftrace_list_func; | |
3176 | } | |
3177 | ||
3178 | } else { | |
3179 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
3180 | ftrace_trace_function = ftrace_stub; | |
3181 | ||
3182 | ftrace_shutdown_sysctl(); | |
3183 | } | |
3184 | ||
3185 | out: | |
e6ea44e9 | 3186 | mutex_unlock(&ftrace_lock); |
3d083395 | 3187 | return ret; |
16444a8a | 3188 | } |
f17845e5 | 3189 | |
fb52607a | 3190 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 3191 | |
597af815 | 3192 | static int ftrace_graph_active; |
4a2b8dda | 3193 | static struct notifier_block ftrace_suspend_notifier; |
e7d3737e | 3194 | |
e49dc19c SR |
3195 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
3196 | { | |
3197 | return 0; | |
3198 | } | |
3199 | ||
287b6e68 FW |
3200 | /* The callbacks that hook a function */ |
3201 | trace_func_graph_ret_t ftrace_graph_return = | |
3202 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 3203 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
3204 | |
3205 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
3206 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
3207 | { | |
3208 | int i; | |
3209 | int ret = 0; | |
3210 | unsigned long flags; | |
3211 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
3212 | struct task_struct *g, *t; | |
3213 | ||
3214 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
3215 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
3216 | * sizeof(struct ftrace_ret_stack), | |
3217 | GFP_KERNEL); | |
3218 | if (!ret_stack_list[i]) { | |
3219 | start = 0; | |
3220 | end = i; | |
3221 | ret = -ENOMEM; | |
3222 | goto free; | |
3223 | } | |
3224 | } | |
3225 | ||
3226 | read_lock_irqsave(&tasklist_lock, flags); | |
3227 | do_each_thread(g, t) { | |
3228 | if (start == end) { | |
3229 | ret = -EAGAIN; | |
3230 | goto unlock; | |
3231 | } | |
3232 | ||
3233 | if (t->ret_stack == NULL) { | |
380c4b14 | 3234 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 3235 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
3236 | t->curr_ret_stack = -1; |
3237 | /* Make sure the tasks see the -1 first: */ | |
3238 | smp_wmb(); | |
3239 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
3240 | } |
3241 | } while_each_thread(g, t); | |
3242 | ||
3243 | unlock: | |
3244 | read_unlock_irqrestore(&tasklist_lock, flags); | |
3245 | free: | |
3246 | for (i = start; i < end; i++) | |
3247 | kfree(ret_stack_list[i]); | |
3248 | return ret; | |
3249 | } | |
3250 | ||
8aef2d28 SR |
3251 | static void |
3252 | ftrace_graph_probe_sched_switch(struct rq *__rq, struct task_struct *prev, | |
3253 | struct task_struct *next) | |
3254 | { | |
3255 | unsigned long long timestamp; | |
3256 | int index; | |
3257 | ||
be6f164a SR |
3258 | /* |
3259 | * Does the user want to count the time a function was asleep. | |
3260 | * If so, do not update the time stamps. | |
3261 | */ | |
3262 | if (trace_flags & TRACE_ITER_SLEEP_TIME) | |
3263 | return; | |
3264 | ||
8aef2d28 SR |
3265 | timestamp = trace_clock_local(); |
3266 | ||
3267 | prev->ftrace_timestamp = timestamp; | |
3268 | ||
3269 | /* only process tasks that we timestamped */ | |
3270 | if (!next->ftrace_timestamp) | |
3271 | return; | |
3272 | ||
3273 | /* | |
3274 | * Update all the counters in next to make up for the | |
3275 | * time next was sleeping. | |
3276 | */ | |
3277 | timestamp -= next->ftrace_timestamp; | |
3278 | ||
3279 | for (index = next->curr_ret_stack; index >= 0; index--) | |
3280 | next->ret_stack[index].calltime += timestamp; | |
3281 | } | |
3282 | ||
f201ae23 | 3283 | /* Allocate a return stack for each task */ |
fb52607a | 3284 | static int start_graph_tracing(void) |
f201ae23 FW |
3285 | { |
3286 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 3287 | int ret, cpu; |
f201ae23 FW |
3288 | |
3289 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
3290 | sizeof(struct ftrace_ret_stack *), | |
3291 | GFP_KERNEL); | |
3292 | ||
3293 | if (!ret_stack_list) | |
3294 | return -ENOMEM; | |
3295 | ||
5b058bcd | 3296 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
3297 | for_each_online_cpu(cpu) { |
3298 | if (!idle_task(cpu)->ret_stack) | |
3299 | ftrace_graph_init_task(idle_task(cpu)); | |
3300 | } | |
5b058bcd | 3301 | |
f201ae23 FW |
3302 | do { |
3303 | ret = alloc_retstack_tasklist(ret_stack_list); | |
3304 | } while (ret == -EAGAIN); | |
3305 | ||
8aef2d28 SR |
3306 | if (!ret) { |
3307 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch); | |
3308 | if (ret) | |
3309 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
3310 | " probe to kernel_sched_switch\n"); | |
3311 | } | |
3312 | ||
f201ae23 FW |
3313 | kfree(ret_stack_list); |
3314 | return ret; | |
3315 | } | |
3316 | ||
4a2b8dda FW |
3317 | /* |
3318 | * Hibernation protection. | |
3319 | * The state of the current task is too much unstable during | |
3320 | * suspend/restore to disk. We want to protect against that. | |
3321 | */ | |
3322 | static int | |
3323 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
3324 | void *unused) | |
3325 | { | |
3326 | switch (state) { | |
3327 | case PM_HIBERNATION_PREPARE: | |
3328 | pause_graph_tracing(); | |
3329 | break; | |
3330 | ||
3331 | case PM_POST_HIBERNATION: | |
3332 | unpause_graph_tracing(); | |
3333 | break; | |
3334 | } | |
3335 | return NOTIFY_DONE; | |
3336 | } | |
3337 | ||
287b6e68 FW |
3338 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
3339 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 3340 | { |
e7d3737e FW |
3341 | int ret = 0; |
3342 | ||
e6ea44e9 | 3343 | mutex_lock(&ftrace_lock); |
e7d3737e | 3344 | |
05ce5818 | 3345 | /* we currently allow only one tracer registered at a time */ |
597af815 | 3346 | if (ftrace_graph_active) { |
05ce5818 SR |
3347 | ret = -EBUSY; |
3348 | goto out; | |
3349 | } | |
3350 | ||
4a2b8dda FW |
3351 | ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; |
3352 | register_pm_notifier(&ftrace_suspend_notifier); | |
3353 | ||
597af815 | 3354 | ftrace_graph_active++; |
fb52607a | 3355 | ret = start_graph_tracing(); |
f201ae23 | 3356 | if (ret) { |
597af815 | 3357 | ftrace_graph_active--; |
f201ae23 FW |
3358 | goto out; |
3359 | } | |
e53a6319 | 3360 | |
287b6e68 FW |
3361 | ftrace_graph_return = retfunc; |
3362 | ftrace_graph_entry = entryfunc; | |
e53a6319 | 3363 | |
5a45cfe1 | 3364 | ftrace_startup(FTRACE_START_FUNC_RET); |
e7d3737e FW |
3365 | |
3366 | out: | |
e6ea44e9 | 3367 | mutex_unlock(&ftrace_lock); |
e7d3737e | 3368 | return ret; |
15e6cb36 FW |
3369 | } |
3370 | ||
fb52607a | 3371 | void unregister_ftrace_graph(void) |
15e6cb36 | 3372 | { |
e6ea44e9 | 3373 | mutex_lock(&ftrace_lock); |
e7d3737e | 3374 | |
597af815 | 3375 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
3376 | goto out; |
3377 | ||
597af815 | 3378 | ftrace_graph_active--; |
8aef2d28 | 3379 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch); |
287b6e68 | 3380 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 3381 | ftrace_graph_entry = ftrace_graph_entry_stub; |
5a45cfe1 | 3382 | ftrace_shutdown(FTRACE_STOP_FUNC_RET); |
4a2b8dda | 3383 | unregister_pm_notifier(&ftrace_suspend_notifier); |
e7d3737e | 3384 | |
2aad1b76 | 3385 | out: |
e6ea44e9 | 3386 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 3387 | } |
f201ae23 FW |
3388 | |
3389 | /* Allocate a return stack for newly created task */ | |
fb52607a | 3390 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 3391 | { |
84047e36 SR |
3392 | /* Make sure we do not use the parent ret_stack */ |
3393 | t->ret_stack = NULL; | |
3394 | ||
597af815 | 3395 | if (ftrace_graph_active) { |
82310a32 SR |
3396 | struct ftrace_ret_stack *ret_stack; |
3397 | ||
3398 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
3399 | * sizeof(struct ftrace_ret_stack), |
3400 | GFP_KERNEL); | |
82310a32 | 3401 | if (!ret_stack) |
f201ae23 FW |
3402 | return; |
3403 | t->curr_ret_stack = -1; | |
380c4b14 | 3404 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 3405 | atomic_set(&t->trace_overrun, 0); |
8aef2d28 | 3406 | t->ftrace_timestamp = 0; |
82310a32 SR |
3407 | /* make curr_ret_stack visable before we add the ret_stack */ |
3408 | smp_wmb(); | |
3409 | t->ret_stack = ret_stack; | |
84047e36 | 3410 | } |
f201ae23 FW |
3411 | } |
3412 | ||
fb52607a | 3413 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 3414 | { |
eae849ca FW |
3415 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
3416 | ||
f201ae23 | 3417 | t->ret_stack = NULL; |
eae849ca FW |
3418 | /* NULL must become visible to IRQs before we free it: */ |
3419 | barrier(); | |
3420 | ||
3421 | kfree(ret_stack); | |
f201ae23 | 3422 | } |
14a866c5 SR |
3423 | |
3424 | void ftrace_graph_stop(void) | |
3425 | { | |
3426 | ftrace_stop(); | |
3427 | } | |
15e6cb36 FW |
3428 | #endif |
3429 |