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Commit | Line | Data |
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16444a8a ACM |
1 | /* |
2 | * Infrastructure for profiling code inserted by 'gcc -pg'. | |
3 | * | |
4 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> | |
5 | * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com> | |
6 | * | |
7 | * Originally ported from the -rt patch by: | |
8 | * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com> | |
9 | * | |
10 | * Based on code in the latency_tracer, that is: | |
11 | * | |
12 | * Copyright (C) 2004-2006 Ingo Molnar | |
13 | * Copyright (C) 2004 William Lee Irwin III | |
14 | */ | |
15 | ||
3d083395 SR |
16 | #include <linux/stop_machine.h> |
17 | #include <linux/clocksource.h> | |
18 | #include <linux/kallsyms.h> | |
5072c59f | 19 | #include <linux/seq_file.h> |
4a2b8dda | 20 | #include <linux/suspend.h> |
5072c59f | 21 | #include <linux/debugfs.h> |
3d083395 | 22 | #include <linux/hardirq.h> |
2d8b820b | 23 | #include <linux/kthread.h> |
5072c59f | 24 | #include <linux/uaccess.h> |
f22f9a89 | 25 | #include <linux/kprobes.h> |
2d8b820b | 26 | #include <linux/ftrace.h> |
b0fc494f | 27 | #include <linux/sysctl.h> |
5072c59f | 28 | #include <linux/ctype.h> |
3d083395 | 29 | #include <linux/list.h> |
59df055f | 30 | #include <linux/hash.h> |
3d083395 | 31 | |
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; | |
1420 | ||
1421 | iter->flags |= FTRACE_ITER_HASH; | |
1422 | ||
1423 | return t_hash_next(m, p, pos); | |
1424 | } | |
1425 | ||
1426 | static int t_hash_show(struct seq_file *m, void *v) | |
1427 | { | |
b6887d79 | 1428 | struct ftrace_func_probe *rec; |
8fc0c701 SR |
1429 | struct hlist_node *hnd = v; |
1430 | char str[KSYM_SYMBOL_LEN]; | |
1431 | ||
b6887d79 | 1432 | rec = hlist_entry(hnd, struct ftrace_func_probe, node); |
8fc0c701 | 1433 | |
809dcf29 SR |
1434 | if (rec->ops->print) |
1435 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
1436 | ||
8fc0c701 SR |
1437 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
1438 | seq_printf(m, "%s:", str); | |
1439 | ||
1440 | kallsyms_lookup((unsigned long)rec->ops->func, NULL, NULL, NULL, str); | |
1441 | seq_printf(m, "%s", str); | |
1442 | ||
1443 | if (rec->data) | |
1444 | seq_printf(m, ":%p", rec->data); | |
1445 | seq_putc(m, '\n'); | |
1446 | ||
1447 | return 0; | |
1448 | } | |
1449 | ||
e309b41d | 1450 | static void * |
5072c59f SR |
1451 | t_next(struct seq_file *m, void *v, loff_t *pos) |
1452 | { | |
1453 | struct ftrace_iterator *iter = m->private; | |
1454 | struct dyn_ftrace *rec = NULL; | |
1455 | ||
8fc0c701 SR |
1456 | if (iter->flags & FTRACE_ITER_HASH) |
1457 | return t_hash_next(m, v, pos); | |
1458 | ||
5072c59f SR |
1459 | (*pos)++; |
1460 | ||
0c75a3ed SR |
1461 | if (iter->flags & FTRACE_ITER_PRINTALL) |
1462 | return NULL; | |
1463 | ||
5072c59f SR |
1464 | retry: |
1465 | if (iter->idx >= iter->pg->index) { | |
1466 | if (iter->pg->next) { | |
1467 | iter->pg = iter->pg->next; | |
1468 | iter->idx = 0; | |
1469 | goto retry; | |
50cdaf08 LW |
1470 | } else { |
1471 | iter->idx = -1; | |
5072c59f SR |
1472 | } |
1473 | } else { | |
1474 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
1475 | if ((rec->flags & FTRACE_FL_FREE) || |
1476 | ||
1477 | (!(iter->flags & FTRACE_ITER_FAILURES) && | |
eb9a7bf0 AS |
1478 | (rec->flags & FTRACE_FL_FAILED)) || |
1479 | ||
1480 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
a9fdda33 | 1481 | !(rec->flags & FTRACE_FL_FAILED)) || |
eb9a7bf0 | 1482 | |
0183fb1c SR |
1483 | ((iter->flags & FTRACE_ITER_FILTER) && |
1484 | !(rec->flags & FTRACE_FL_FILTER)) || | |
1485 | ||
41c52c0d SR |
1486 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
1487 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
1488 | rec = NULL; |
1489 | goto retry; | |
1490 | } | |
1491 | } | |
1492 | ||
5072c59f SR |
1493 | return rec; |
1494 | } | |
1495 | ||
1496 | static void *t_start(struct seq_file *m, loff_t *pos) | |
1497 | { | |
1498 | struct ftrace_iterator *iter = m->private; | |
1499 | void *p = NULL; | |
5072c59f | 1500 | |
8fc0c701 | 1501 | mutex_lock(&ftrace_lock); |
0c75a3ed SR |
1502 | /* |
1503 | * For set_ftrace_filter reading, if we have the filter | |
1504 | * off, we can short cut and just print out that all | |
1505 | * functions are enabled. | |
1506 | */ | |
1507 | if (iter->flags & FTRACE_ITER_FILTER && !ftrace_filtered) { | |
1508 | if (*pos > 0) | |
8fc0c701 | 1509 | return t_hash_start(m, pos); |
0c75a3ed SR |
1510 | iter->flags |= FTRACE_ITER_PRINTALL; |
1511 | (*pos)++; | |
1512 | return iter; | |
1513 | } | |
1514 | ||
8fc0c701 SR |
1515 | if (iter->flags & FTRACE_ITER_HASH) |
1516 | return t_hash_start(m, pos); | |
1517 | ||
50cdaf08 LW |
1518 | if (*pos > 0) { |
1519 | if (iter->idx < 0) | |
1520 | return p; | |
1521 | (*pos)--; | |
1522 | iter->idx--; | |
1523 | } | |
5821e1b7 | 1524 | |
50cdaf08 | 1525 | p = t_next(m, p, pos); |
5072c59f | 1526 | |
8fc0c701 SR |
1527 | if (!p) |
1528 | return t_hash_start(m, pos); | |
1529 | ||
5072c59f SR |
1530 | return p; |
1531 | } | |
1532 | ||
1533 | static void t_stop(struct seq_file *m, void *p) | |
1534 | { | |
8fc0c701 | 1535 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1536 | } |
1537 | ||
1538 | static int t_show(struct seq_file *m, void *v) | |
1539 | { | |
0c75a3ed | 1540 | struct ftrace_iterator *iter = m->private; |
5072c59f SR |
1541 | struct dyn_ftrace *rec = v; |
1542 | char str[KSYM_SYMBOL_LEN]; | |
1543 | ||
8fc0c701 SR |
1544 | if (iter->flags & FTRACE_ITER_HASH) |
1545 | return t_hash_show(m, v); | |
1546 | ||
0c75a3ed SR |
1547 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
1548 | seq_printf(m, "#### all functions enabled ####\n"); | |
1549 | return 0; | |
1550 | } | |
1551 | ||
5072c59f SR |
1552 | if (!rec) |
1553 | return 0; | |
1554 | ||
1555 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1556 | ||
50cdaf08 | 1557 | seq_printf(m, "%s\n", str); |
5072c59f SR |
1558 | |
1559 | return 0; | |
1560 | } | |
1561 | ||
1562 | static struct seq_operations show_ftrace_seq_ops = { | |
1563 | .start = t_start, | |
1564 | .next = t_next, | |
1565 | .stop = t_stop, | |
1566 | .show = t_show, | |
1567 | }; | |
1568 | ||
e309b41d | 1569 | static int |
5072c59f SR |
1570 | ftrace_avail_open(struct inode *inode, struct file *file) |
1571 | { | |
1572 | struct ftrace_iterator *iter; | |
1573 | int ret; | |
1574 | ||
4eebcc81 SR |
1575 | if (unlikely(ftrace_disabled)) |
1576 | return -ENODEV; | |
1577 | ||
5072c59f SR |
1578 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1579 | if (!iter) | |
1580 | return -ENOMEM; | |
1581 | ||
1582 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
1583 | |
1584 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1585 | if (!ret) { | |
1586 | struct seq_file *m = file->private_data; | |
4bf39a94 | 1587 | |
5072c59f | 1588 | m->private = iter; |
4bf39a94 | 1589 | } else { |
5072c59f | 1590 | kfree(iter); |
4bf39a94 | 1591 | } |
5072c59f SR |
1592 | |
1593 | return ret; | |
1594 | } | |
1595 | ||
1596 | int ftrace_avail_release(struct inode *inode, struct file *file) | |
1597 | { | |
1598 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1599 | struct ftrace_iterator *iter = m->private; | |
1600 | ||
1601 | seq_release(inode, file); | |
1602 | kfree(iter); | |
4bf39a94 | 1603 | |
5072c59f SR |
1604 | return 0; |
1605 | } | |
1606 | ||
eb9a7bf0 AS |
1607 | static int |
1608 | ftrace_failures_open(struct inode *inode, struct file *file) | |
1609 | { | |
1610 | int ret; | |
1611 | struct seq_file *m; | |
1612 | struct ftrace_iterator *iter; | |
1613 | ||
1614 | ret = ftrace_avail_open(inode, file); | |
1615 | if (!ret) { | |
1616 | m = (struct seq_file *)file->private_data; | |
1617 | iter = (struct ftrace_iterator *)m->private; | |
1618 | iter->flags = FTRACE_ITER_FAILURES; | |
1619 | } | |
1620 | ||
1621 | return ret; | |
1622 | } | |
1623 | ||
1624 | ||
41c52c0d | 1625 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
1626 | { |
1627 | struct ftrace_page *pg; | |
1628 | struct dyn_ftrace *rec; | |
41c52c0d | 1629 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f | 1630 | |
52baf119 | 1631 | mutex_lock(&ftrace_lock); |
41c52c0d SR |
1632 | if (enable) |
1633 | ftrace_filtered = 0; | |
265c831c SR |
1634 | do_for_each_ftrace_rec(pg, rec) { |
1635 | if (rec->flags & FTRACE_FL_FAILED) | |
1636 | continue; | |
1637 | rec->flags &= ~type; | |
1638 | } while_for_each_ftrace_rec(); | |
52baf119 | 1639 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1640 | } |
1641 | ||
e309b41d | 1642 | static int |
41c52c0d | 1643 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1644 | { |
1645 | struct ftrace_iterator *iter; | |
1646 | int ret = 0; | |
1647 | ||
4eebcc81 SR |
1648 | if (unlikely(ftrace_disabled)) |
1649 | return -ENODEV; | |
1650 | ||
5072c59f SR |
1651 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1652 | if (!iter) | |
1653 | return -ENOMEM; | |
1654 | ||
41c52c0d | 1655 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1656 | if ((file->f_mode & FMODE_WRITE) && |
1657 | !(file->f_flags & O_APPEND)) | |
41c52c0d | 1658 | ftrace_filter_reset(enable); |
5072c59f SR |
1659 | |
1660 | if (file->f_mode & FMODE_READ) { | |
1661 | iter->pg = ftrace_pages_start; | |
41c52c0d SR |
1662 | iter->flags = enable ? FTRACE_ITER_FILTER : |
1663 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
1664 | |
1665 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1666 | if (!ret) { | |
1667 | struct seq_file *m = file->private_data; | |
1668 | m->private = iter; | |
1669 | } else | |
1670 | kfree(iter); | |
1671 | } else | |
1672 | file->private_data = iter; | |
41c52c0d | 1673 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1674 | |
1675 | return ret; | |
1676 | } | |
1677 | ||
41c52c0d SR |
1678 | static int |
1679 | ftrace_filter_open(struct inode *inode, struct file *file) | |
1680 | { | |
1681 | return ftrace_regex_open(inode, file, 1); | |
1682 | } | |
1683 | ||
1684 | static int | |
1685 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
1686 | { | |
1687 | return ftrace_regex_open(inode, file, 0); | |
1688 | } | |
1689 | ||
e309b41d | 1690 | static loff_t |
41c52c0d | 1691 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
1692 | { |
1693 | loff_t ret; | |
1694 | ||
1695 | if (file->f_mode & FMODE_READ) | |
1696 | ret = seq_lseek(file, offset, origin); | |
1697 | else | |
1698 | file->f_pos = ret = 1; | |
1699 | ||
1700 | return ret; | |
1701 | } | |
1702 | ||
1703 | enum { | |
1704 | MATCH_FULL, | |
1705 | MATCH_FRONT_ONLY, | |
1706 | MATCH_MIDDLE_ONLY, | |
1707 | MATCH_END_ONLY, | |
1708 | }; | |
1709 | ||
9f4801e3 SR |
1710 | /* |
1711 | * (static function - no need for kernel doc) | |
1712 | * | |
1713 | * Pass in a buffer containing a glob and this function will | |
1714 | * set search to point to the search part of the buffer and | |
1715 | * return the type of search it is (see enum above). | |
1716 | * This does modify buff. | |
1717 | * | |
1718 | * Returns enum type. | |
1719 | * search returns the pointer to use for comparison. | |
1720 | * not returns 1 if buff started with a '!' | |
1721 | * 0 otherwise. | |
1722 | */ | |
1723 | static int | |
64e7c440 | 1724 | ftrace_setup_glob(char *buff, int len, char **search, int *not) |
5072c59f | 1725 | { |
5072c59f | 1726 | int type = MATCH_FULL; |
9f4801e3 | 1727 | int i; |
ea3a6d6d SR |
1728 | |
1729 | if (buff[0] == '!') { | |
9f4801e3 | 1730 | *not = 1; |
ea3a6d6d SR |
1731 | buff++; |
1732 | len--; | |
9f4801e3 SR |
1733 | } else |
1734 | *not = 0; | |
1735 | ||
1736 | *search = buff; | |
5072c59f SR |
1737 | |
1738 | for (i = 0; i < len; i++) { | |
1739 | if (buff[i] == '*') { | |
1740 | if (!i) { | |
9f4801e3 | 1741 | *search = buff + 1; |
5072c59f | 1742 | type = MATCH_END_ONLY; |
5072c59f | 1743 | } else { |
9f4801e3 | 1744 | if (type == MATCH_END_ONLY) |
5072c59f | 1745 | type = MATCH_MIDDLE_ONLY; |
9f4801e3 | 1746 | else |
5072c59f | 1747 | type = MATCH_FRONT_ONLY; |
5072c59f SR |
1748 | buff[i] = 0; |
1749 | break; | |
1750 | } | |
1751 | } | |
1752 | } | |
1753 | ||
9f4801e3 SR |
1754 | return type; |
1755 | } | |
1756 | ||
64e7c440 | 1757 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 1758 | { |
9f4801e3 SR |
1759 | int matched = 0; |
1760 | char *ptr; | |
1761 | ||
9f4801e3 SR |
1762 | switch (type) { |
1763 | case MATCH_FULL: | |
1764 | if (strcmp(str, regex) == 0) | |
1765 | matched = 1; | |
1766 | break; | |
1767 | case MATCH_FRONT_ONLY: | |
1768 | if (strncmp(str, regex, len) == 0) | |
1769 | matched = 1; | |
1770 | break; | |
1771 | case MATCH_MIDDLE_ONLY: | |
1772 | if (strstr(str, regex)) | |
1773 | matched = 1; | |
1774 | break; | |
1775 | case MATCH_END_ONLY: | |
1776 | ptr = strstr(str, regex); | |
1777 | if (ptr && (ptr[len] == 0)) | |
1778 | matched = 1; | |
1779 | break; | |
1780 | } | |
1781 | ||
1782 | return matched; | |
1783 | } | |
1784 | ||
64e7c440 SR |
1785 | static int |
1786 | ftrace_match_record(struct dyn_ftrace *rec, char *regex, int len, int type) | |
1787 | { | |
1788 | char str[KSYM_SYMBOL_LEN]; | |
1789 | ||
1790 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1791 | return ftrace_match(str, regex, len, type); | |
1792 | } | |
1793 | ||
9f4801e3 SR |
1794 | static void ftrace_match_records(char *buff, int len, int enable) |
1795 | { | |
6a24a244 | 1796 | unsigned int search_len; |
9f4801e3 SR |
1797 | struct ftrace_page *pg; |
1798 | struct dyn_ftrace *rec; | |
6a24a244 SR |
1799 | unsigned long flag; |
1800 | char *search; | |
9f4801e3 | 1801 | int type; |
9f4801e3 SR |
1802 | int not; |
1803 | ||
6a24a244 | 1804 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
9f4801e3 SR |
1805 | type = ftrace_setup_glob(buff, len, &search, ¬); |
1806 | ||
1807 | search_len = strlen(search); | |
1808 | ||
52baf119 | 1809 | mutex_lock(&ftrace_lock); |
265c831c | 1810 | do_for_each_ftrace_rec(pg, rec) { |
265c831c SR |
1811 | |
1812 | if (rec->flags & FTRACE_FL_FAILED) | |
1813 | continue; | |
9f4801e3 SR |
1814 | |
1815 | if (ftrace_match_record(rec, search, search_len, type)) { | |
265c831c SR |
1816 | if (not) |
1817 | rec->flags &= ~flag; | |
1818 | else | |
1819 | rec->flags |= flag; | |
1820 | } | |
e68746a2 SR |
1821 | /* |
1822 | * Only enable filtering if we have a function that | |
1823 | * is filtered on. | |
1824 | */ | |
1825 | if (enable && (rec->flags & FTRACE_FL_FILTER)) | |
1826 | ftrace_filtered = 1; | |
265c831c | 1827 | } while_for_each_ftrace_rec(); |
52baf119 | 1828 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1829 | } |
1830 | ||
64e7c440 SR |
1831 | static int |
1832 | ftrace_match_module_record(struct dyn_ftrace *rec, char *mod, | |
1833 | char *regex, int len, int type) | |
1834 | { | |
1835 | char str[KSYM_SYMBOL_LEN]; | |
1836 | char *modname; | |
1837 | ||
1838 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
1839 | ||
1840 | if (!modname || strcmp(modname, mod)) | |
1841 | return 0; | |
1842 | ||
1843 | /* blank search means to match all funcs in the mod */ | |
1844 | if (len) | |
1845 | return ftrace_match(str, regex, len, type); | |
1846 | else | |
1847 | return 1; | |
1848 | } | |
1849 | ||
1850 | static void ftrace_match_module_records(char *buff, char *mod, int enable) | |
1851 | { | |
6a24a244 | 1852 | unsigned search_len = 0; |
64e7c440 SR |
1853 | struct ftrace_page *pg; |
1854 | struct dyn_ftrace *rec; | |
1855 | int type = MATCH_FULL; | |
6a24a244 SR |
1856 | char *search = buff; |
1857 | unsigned long flag; | |
64e7c440 SR |
1858 | int not = 0; |
1859 | ||
6a24a244 SR |
1860 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
1861 | ||
64e7c440 SR |
1862 | /* blank or '*' mean the same */ |
1863 | if (strcmp(buff, "*") == 0) | |
1864 | buff[0] = 0; | |
1865 | ||
1866 | /* handle the case of 'dont filter this module' */ | |
1867 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
1868 | buff[0] = 0; | |
1869 | not = 1; | |
1870 | } | |
1871 | ||
1872 | if (strlen(buff)) { | |
1873 | type = ftrace_setup_glob(buff, strlen(buff), &search, ¬); | |
1874 | search_len = strlen(search); | |
1875 | } | |
1876 | ||
52baf119 | 1877 | mutex_lock(&ftrace_lock); |
64e7c440 SR |
1878 | do_for_each_ftrace_rec(pg, rec) { |
1879 | ||
1880 | if (rec->flags & FTRACE_FL_FAILED) | |
1881 | continue; | |
1882 | ||
1883 | if (ftrace_match_module_record(rec, mod, | |
1884 | search, search_len, type)) { | |
1885 | if (not) | |
1886 | rec->flags &= ~flag; | |
1887 | else | |
1888 | rec->flags |= flag; | |
1889 | } | |
e68746a2 SR |
1890 | if (enable && (rec->flags & FTRACE_FL_FILTER)) |
1891 | ftrace_filtered = 1; | |
64e7c440 SR |
1892 | |
1893 | } while_for_each_ftrace_rec(); | |
52baf119 | 1894 | mutex_unlock(&ftrace_lock); |
64e7c440 SR |
1895 | } |
1896 | ||
f6180773 SR |
1897 | /* |
1898 | * We register the module command as a template to show others how | |
1899 | * to register the a command as well. | |
1900 | */ | |
1901 | ||
1902 | static int | |
1903 | ftrace_mod_callback(char *func, char *cmd, char *param, int enable) | |
1904 | { | |
1905 | char *mod; | |
1906 | ||
1907 | /* | |
1908 | * cmd == 'mod' because we only registered this func | |
1909 | * for the 'mod' ftrace_func_command. | |
1910 | * But if you register one func with multiple commands, | |
1911 | * you can tell which command was used by the cmd | |
1912 | * parameter. | |
1913 | */ | |
1914 | ||
1915 | /* we must have a module name */ | |
1916 | if (!param) | |
1917 | return -EINVAL; | |
1918 | ||
1919 | mod = strsep(¶m, ":"); | |
1920 | if (!strlen(mod)) | |
1921 | return -EINVAL; | |
1922 | ||
1923 | ftrace_match_module_records(func, mod, enable); | |
1924 | return 0; | |
1925 | } | |
1926 | ||
1927 | static struct ftrace_func_command ftrace_mod_cmd = { | |
1928 | .name = "mod", | |
1929 | .func = ftrace_mod_callback, | |
1930 | }; | |
1931 | ||
1932 | static int __init ftrace_mod_cmd_init(void) | |
1933 | { | |
1934 | return register_ftrace_command(&ftrace_mod_cmd); | |
1935 | } | |
1936 | device_initcall(ftrace_mod_cmd_init); | |
1937 | ||
59df055f | 1938 | static void |
b6887d79 | 1939 | function_trace_probe_call(unsigned long ip, unsigned long parent_ip) |
59df055f | 1940 | { |
b6887d79 | 1941 | struct ftrace_func_probe *entry; |
59df055f SR |
1942 | struct hlist_head *hhd; |
1943 | struct hlist_node *n; | |
1944 | unsigned long key; | |
1945 | int resched; | |
1946 | ||
1947 | key = hash_long(ip, FTRACE_HASH_BITS); | |
1948 | ||
1949 | hhd = &ftrace_func_hash[key]; | |
1950 | ||
1951 | if (hlist_empty(hhd)) | |
1952 | return; | |
1953 | ||
1954 | /* | |
1955 | * Disable preemption for these calls to prevent a RCU grace | |
1956 | * period. This syncs the hash iteration and freeing of items | |
1957 | * on the hash. rcu_read_lock is too dangerous here. | |
1958 | */ | |
1959 | resched = ftrace_preempt_disable(); | |
1960 | hlist_for_each_entry_rcu(entry, n, hhd, node) { | |
1961 | if (entry->ip == ip) | |
1962 | entry->ops->func(ip, parent_ip, &entry->data); | |
1963 | } | |
1964 | ftrace_preempt_enable(resched); | |
1965 | } | |
1966 | ||
b6887d79 | 1967 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 1968 | { |
fb9fb015 | 1969 | .func = function_trace_probe_call, |
59df055f SR |
1970 | }; |
1971 | ||
b6887d79 | 1972 | static int ftrace_probe_registered; |
59df055f | 1973 | |
b6887d79 | 1974 | static void __enable_ftrace_function_probe(void) |
59df055f SR |
1975 | { |
1976 | int i; | |
1977 | ||
b6887d79 | 1978 | if (ftrace_probe_registered) |
59df055f SR |
1979 | return; |
1980 | ||
1981 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1982 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1983 | if (hhd->first) | |
1984 | break; | |
1985 | } | |
1986 | /* Nothing registered? */ | |
1987 | if (i == FTRACE_FUNC_HASHSIZE) | |
1988 | return; | |
1989 | ||
b6887d79 | 1990 | __register_ftrace_function(&trace_probe_ops); |
59df055f | 1991 | ftrace_startup(0); |
b6887d79 | 1992 | ftrace_probe_registered = 1; |
59df055f SR |
1993 | } |
1994 | ||
b6887d79 | 1995 | static void __disable_ftrace_function_probe(void) |
59df055f SR |
1996 | { |
1997 | int i; | |
1998 | ||
b6887d79 | 1999 | if (!ftrace_probe_registered) |
59df055f SR |
2000 | return; |
2001 | ||
2002 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2003 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2004 | if (hhd->first) | |
2005 | return; | |
2006 | } | |
2007 | ||
2008 | /* no more funcs left */ | |
b6887d79 | 2009 | __unregister_ftrace_function(&trace_probe_ops); |
59df055f | 2010 | ftrace_shutdown(0); |
b6887d79 | 2011 | ftrace_probe_registered = 0; |
59df055f SR |
2012 | } |
2013 | ||
2014 | ||
2015 | static void ftrace_free_entry_rcu(struct rcu_head *rhp) | |
2016 | { | |
b6887d79 SR |
2017 | struct ftrace_func_probe *entry = |
2018 | container_of(rhp, struct ftrace_func_probe, rcu); | |
59df055f SR |
2019 | |
2020 | if (entry->ops->free) | |
2021 | entry->ops->free(&entry->data); | |
2022 | kfree(entry); | |
2023 | } | |
2024 | ||
2025 | ||
2026 | int | |
b6887d79 | 2027 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2028 | void *data) |
2029 | { | |
b6887d79 | 2030 | struct ftrace_func_probe *entry; |
59df055f SR |
2031 | struct ftrace_page *pg; |
2032 | struct dyn_ftrace *rec; | |
59df055f | 2033 | int type, len, not; |
6a24a244 | 2034 | unsigned long key; |
59df055f SR |
2035 | int count = 0; |
2036 | char *search; | |
2037 | ||
2038 | type = ftrace_setup_glob(glob, strlen(glob), &search, ¬); | |
2039 | len = strlen(search); | |
2040 | ||
b6887d79 | 2041 | /* we do not support '!' for function probes */ |
59df055f SR |
2042 | if (WARN_ON(not)) |
2043 | return -EINVAL; | |
2044 | ||
2045 | mutex_lock(&ftrace_lock); | |
2046 | do_for_each_ftrace_rec(pg, rec) { | |
2047 | ||
2048 | if (rec->flags & FTRACE_FL_FAILED) | |
2049 | continue; | |
2050 | ||
2051 | if (!ftrace_match_record(rec, search, len, type)) | |
2052 | continue; | |
2053 | ||
2054 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
2055 | if (!entry) { | |
b6887d79 | 2056 | /* If we did not process any, then return error */ |
59df055f SR |
2057 | if (!count) |
2058 | count = -ENOMEM; | |
2059 | goto out_unlock; | |
2060 | } | |
2061 | ||
2062 | count++; | |
2063 | ||
2064 | entry->data = data; | |
2065 | ||
2066 | /* | |
2067 | * The caller might want to do something special | |
2068 | * for each function we find. We call the callback | |
2069 | * to give the caller an opportunity to do so. | |
2070 | */ | |
2071 | if (ops->callback) { | |
2072 | if (ops->callback(rec->ip, &entry->data) < 0) { | |
2073 | /* caller does not like this func */ | |
2074 | kfree(entry); | |
2075 | continue; | |
2076 | } | |
2077 | } | |
2078 | ||
2079 | entry->ops = ops; | |
2080 | entry->ip = rec->ip; | |
2081 | ||
2082 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
2083 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
2084 | ||
2085 | } while_for_each_ftrace_rec(); | |
b6887d79 | 2086 | __enable_ftrace_function_probe(); |
59df055f SR |
2087 | |
2088 | out_unlock: | |
2089 | mutex_unlock(&ftrace_lock); | |
2090 | ||
2091 | return count; | |
2092 | } | |
2093 | ||
2094 | enum { | |
b6887d79 SR |
2095 | PROBE_TEST_FUNC = 1, |
2096 | PROBE_TEST_DATA = 2 | |
59df055f SR |
2097 | }; |
2098 | ||
2099 | static void | |
b6887d79 | 2100 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2101 | void *data, int flags) |
2102 | { | |
b6887d79 | 2103 | struct ftrace_func_probe *entry; |
59df055f SR |
2104 | struct hlist_node *n, *tmp; |
2105 | char str[KSYM_SYMBOL_LEN]; | |
2106 | int type = MATCH_FULL; | |
2107 | int i, len = 0; | |
2108 | char *search; | |
2109 | ||
2110 | if (glob && (strcmp(glob, "*") || !strlen(glob))) | |
2111 | glob = NULL; | |
2112 | else { | |
2113 | int not; | |
2114 | ||
2115 | type = ftrace_setup_glob(glob, strlen(glob), &search, ¬); | |
2116 | len = strlen(search); | |
2117 | ||
b6887d79 | 2118 | /* we do not support '!' for function probes */ |
59df055f SR |
2119 | if (WARN_ON(not)) |
2120 | return; | |
2121 | } | |
2122 | ||
2123 | mutex_lock(&ftrace_lock); | |
2124 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2125 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2126 | ||
2127 | hlist_for_each_entry_safe(entry, n, tmp, hhd, node) { | |
2128 | ||
2129 | /* break up if statements for readability */ | |
b6887d79 | 2130 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
2131 | continue; |
2132 | ||
b6887d79 | 2133 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
2134 | continue; |
2135 | ||
2136 | /* do this last, since it is the most expensive */ | |
2137 | if (glob) { | |
2138 | kallsyms_lookup(entry->ip, NULL, NULL, | |
2139 | NULL, str); | |
2140 | if (!ftrace_match(str, glob, len, type)) | |
2141 | continue; | |
2142 | } | |
2143 | ||
2144 | hlist_del(&entry->node); | |
2145 | call_rcu(&entry->rcu, ftrace_free_entry_rcu); | |
2146 | } | |
2147 | } | |
b6887d79 | 2148 | __disable_ftrace_function_probe(); |
59df055f SR |
2149 | mutex_unlock(&ftrace_lock); |
2150 | } | |
2151 | ||
2152 | void | |
b6887d79 | 2153 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2154 | void *data) |
2155 | { | |
b6887d79 SR |
2156 | __unregister_ftrace_function_probe(glob, ops, data, |
2157 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
2158 | } |
2159 | ||
2160 | void | |
b6887d79 | 2161 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 2162 | { |
b6887d79 | 2163 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
2164 | } |
2165 | ||
b6887d79 | 2166 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 2167 | { |
b6887d79 | 2168 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
2169 | } |
2170 | ||
f6180773 SR |
2171 | static LIST_HEAD(ftrace_commands); |
2172 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
2173 | ||
2174 | int register_ftrace_command(struct ftrace_func_command *cmd) | |
2175 | { | |
2176 | struct ftrace_func_command *p; | |
2177 | int ret = 0; | |
2178 | ||
2179 | mutex_lock(&ftrace_cmd_mutex); | |
2180 | list_for_each_entry(p, &ftrace_commands, list) { | |
2181 | if (strcmp(cmd->name, p->name) == 0) { | |
2182 | ret = -EBUSY; | |
2183 | goto out_unlock; | |
2184 | } | |
2185 | } | |
2186 | list_add(&cmd->list, &ftrace_commands); | |
2187 | out_unlock: | |
2188 | mutex_unlock(&ftrace_cmd_mutex); | |
2189 | ||
2190 | return ret; | |
2191 | } | |
2192 | ||
2193 | int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
2194 | { | |
2195 | struct ftrace_func_command *p, *n; | |
2196 | int ret = -ENODEV; | |
2197 | ||
2198 | mutex_lock(&ftrace_cmd_mutex); | |
2199 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
2200 | if (strcmp(cmd->name, p->name) == 0) { | |
2201 | ret = 0; | |
2202 | list_del_init(&p->list); | |
2203 | goto out_unlock; | |
2204 | } | |
2205 | } | |
2206 | out_unlock: | |
2207 | mutex_unlock(&ftrace_cmd_mutex); | |
2208 | ||
2209 | return ret; | |
2210 | } | |
2211 | ||
64e7c440 SR |
2212 | static int ftrace_process_regex(char *buff, int len, int enable) |
2213 | { | |
f6180773 | 2214 | char *func, *command, *next = buff; |
6a24a244 | 2215 | struct ftrace_func_command *p; |
f6180773 | 2216 | int ret = -EINVAL; |
64e7c440 SR |
2217 | |
2218 | func = strsep(&next, ":"); | |
2219 | ||
2220 | if (!next) { | |
2221 | ftrace_match_records(func, len, enable); | |
2222 | return 0; | |
2223 | } | |
2224 | ||
f6180773 | 2225 | /* command found */ |
64e7c440 SR |
2226 | |
2227 | command = strsep(&next, ":"); | |
2228 | ||
f6180773 SR |
2229 | mutex_lock(&ftrace_cmd_mutex); |
2230 | list_for_each_entry(p, &ftrace_commands, list) { | |
2231 | if (strcmp(p->name, command) == 0) { | |
2232 | ret = p->func(func, command, next, enable); | |
2233 | goto out_unlock; | |
2234 | } | |
64e7c440 | 2235 | } |
f6180773 SR |
2236 | out_unlock: |
2237 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 2238 | |
f6180773 | 2239 | return ret; |
64e7c440 SR |
2240 | } |
2241 | ||
e309b41d | 2242 | static ssize_t |
41c52c0d SR |
2243 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
2244 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
2245 | { |
2246 | struct ftrace_iterator *iter; | |
2247 | char ch; | |
2248 | size_t read = 0; | |
2249 | ssize_t ret; | |
2250 | ||
2251 | if (!cnt || cnt < 0) | |
2252 | return 0; | |
2253 | ||
41c52c0d | 2254 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
2255 | |
2256 | if (file->f_mode & FMODE_READ) { | |
2257 | struct seq_file *m = file->private_data; | |
2258 | iter = m->private; | |
2259 | } else | |
2260 | iter = file->private_data; | |
2261 | ||
2262 | if (!*ppos) { | |
2263 | iter->flags &= ~FTRACE_ITER_CONT; | |
2264 | iter->buffer_idx = 0; | |
2265 | } | |
2266 | ||
2267 | ret = get_user(ch, ubuf++); | |
2268 | if (ret) | |
2269 | goto out; | |
2270 | read++; | |
2271 | cnt--; | |
2272 | ||
2273 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { | |
2274 | /* skip white space */ | |
2275 | while (cnt && isspace(ch)) { | |
2276 | ret = get_user(ch, ubuf++); | |
2277 | if (ret) | |
2278 | goto out; | |
2279 | read++; | |
2280 | cnt--; | |
2281 | } | |
2282 | ||
5072c59f SR |
2283 | if (isspace(ch)) { |
2284 | file->f_pos += read; | |
2285 | ret = read; | |
2286 | goto out; | |
2287 | } | |
2288 | ||
2289 | iter->buffer_idx = 0; | |
2290 | } | |
2291 | ||
2292 | while (cnt && !isspace(ch)) { | |
2293 | if (iter->buffer_idx < FTRACE_BUFF_MAX) | |
2294 | iter->buffer[iter->buffer_idx++] = ch; | |
2295 | else { | |
2296 | ret = -EINVAL; | |
2297 | goto out; | |
2298 | } | |
2299 | ret = get_user(ch, ubuf++); | |
2300 | if (ret) | |
2301 | goto out; | |
2302 | read++; | |
2303 | cnt--; | |
2304 | } | |
2305 | ||
2306 | if (isspace(ch)) { | |
2307 | iter->filtered++; | |
2308 | iter->buffer[iter->buffer_idx] = 0; | |
64e7c440 SR |
2309 | ret = ftrace_process_regex(iter->buffer, |
2310 | iter->buffer_idx, enable); | |
2311 | if (ret) | |
2312 | goto out; | |
5072c59f SR |
2313 | iter->buffer_idx = 0; |
2314 | } else | |
2315 | iter->flags |= FTRACE_ITER_CONT; | |
2316 | ||
2317 | ||
2318 | file->f_pos += read; | |
2319 | ||
2320 | ret = read; | |
2321 | out: | |
41c52c0d | 2322 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
2323 | |
2324 | return ret; | |
2325 | } | |
2326 | ||
41c52c0d SR |
2327 | static ssize_t |
2328 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
2329 | size_t cnt, loff_t *ppos) | |
2330 | { | |
2331 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
2332 | } | |
2333 | ||
2334 | static ssize_t | |
2335 | ftrace_notrace_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, 0); | |
2339 | } | |
2340 | ||
2341 | static void | |
2342 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
2343 | { | |
2344 | if (unlikely(ftrace_disabled)) | |
2345 | return; | |
2346 | ||
2347 | mutex_lock(&ftrace_regex_lock); | |
2348 | if (reset) | |
2349 | ftrace_filter_reset(enable); | |
2350 | if (buf) | |
7f24b31b | 2351 | ftrace_match_records(buf, len, enable); |
41c52c0d SR |
2352 | mutex_unlock(&ftrace_regex_lock); |
2353 | } | |
2354 | ||
77a2b37d SR |
2355 | /** |
2356 | * ftrace_set_filter - set a function to filter on in ftrace | |
2357 | * @buf - the string that holds the function filter text. | |
2358 | * @len - the length of the string. | |
2359 | * @reset - non zero to reset all filters before applying this filter. | |
2360 | * | |
2361 | * Filters denote which functions should be enabled when tracing is enabled. | |
2362 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
2363 | */ | |
e309b41d | 2364 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 2365 | { |
41c52c0d SR |
2366 | ftrace_set_regex(buf, len, reset, 1); |
2367 | } | |
4eebcc81 | 2368 | |
41c52c0d SR |
2369 | /** |
2370 | * ftrace_set_notrace - set a function to not trace in ftrace | |
2371 | * @buf - the string that holds the function notrace text. | |
2372 | * @len - the length of the string. | |
2373 | * @reset - non zero to reset all filters before applying this filter. | |
2374 | * | |
2375 | * Notrace Filters denote which functions should not be enabled when tracing | |
2376 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
2377 | * for tracing. | |
2378 | */ | |
2379 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
2380 | { | |
2381 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
2382 | } |
2383 | ||
2af15d6a SR |
2384 | /* |
2385 | * command line interface to allow users to set filters on boot up. | |
2386 | */ | |
2387 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
2388 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
2389 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
2390 | ||
2391 | static int __init set_ftrace_notrace(char *str) | |
2392 | { | |
2393 | strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); | |
2394 | return 1; | |
2395 | } | |
2396 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
2397 | ||
2398 | static int __init set_ftrace_filter(char *str) | |
2399 | { | |
2400 | strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); | |
2401 | return 1; | |
2402 | } | |
2403 | __setup("ftrace_filter=", set_ftrace_filter); | |
2404 | ||
2405 | static void __init set_ftrace_early_filter(char *buf, int enable) | |
2406 | { | |
2407 | char *func; | |
2408 | ||
2409 | while (buf) { | |
2410 | func = strsep(&buf, ","); | |
2411 | ftrace_set_regex(func, strlen(func), 0, enable); | |
2412 | } | |
2413 | } | |
2414 | ||
2415 | static void __init set_ftrace_early_filters(void) | |
2416 | { | |
2417 | if (ftrace_filter_buf[0]) | |
2418 | set_ftrace_early_filter(ftrace_filter_buf, 1); | |
2419 | if (ftrace_notrace_buf[0]) | |
2420 | set_ftrace_early_filter(ftrace_notrace_buf, 0); | |
2421 | } | |
2422 | ||
e309b41d | 2423 | static int |
41c52c0d | 2424 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
2425 | { |
2426 | struct seq_file *m = (struct seq_file *)file->private_data; | |
2427 | struct ftrace_iterator *iter; | |
2428 | ||
41c52c0d | 2429 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
2430 | if (file->f_mode & FMODE_READ) { |
2431 | iter = m->private; | |
2432 | ||
2433 | seq_release(inode, file); | |
2434 | } else | |
2435 | iter = file->private_data; | |
2436 | ||
2437 | if (iter->buffer_idx) { | |
2438 | iter->filtered++; | |
2439 | iter->buffer[iter->buffer_idx] = 0; | |
7f24b31b | 2440 | ftrace_match_records(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
2441 | } |
2442 | ||
e6ea44e9 | 2443 | mutex_lock(&ftrace_lock); |
ee02a2e5 | 2444 | if (ftrace_start_up && ftrace_enabled) |
5072c59f | 2445 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
e6ea44e9 | 2446 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
2447 | |
2448 | kfree(iter); | |
41c52c0d | 2449 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
2450 | return 0; |
2451 | } | |
2452 | ||
41c52c0d SR |
2453 | static int |
2454 | ftrace_filter_release(struct inode *inode, struct file *file) | |
2455 | { | |
2456 | return ftrace_regex_release(inode, file, 1); | |
2457 | } | |
2458 | ||
2459 | static int | |
2460 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
2461 | { | |
2462 | return ftrace_regex_release(inode, file, 0); | |
2463 | } | |
2464 | ||
5e2336a0 | 2465 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
2466 | .open = ftrace_avail_open, |
2467 | .read = seq_read, | |
2468 | .llseek = seq_lseek, | |
2469 | .release = ftrace_avail_release, | |
2470 | }; | |
2471 | ||
5e2336a0 | 2472 | static const struct file_operations ftrace_failures_fops = { |
eb9a7bf0 AS |
2473 | .open = ftrace_failures_open, |
2474 | .read = seq_read, | |
2475 | .llseek = seq_lseek, | |
2476 | .release = ftrace_avail_release, | |
2477 | }; | |
2478 | ||
5e2336a0 | 2479 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 2480 | .open = ftrace_filter_open, |
850a80cf | 2481 | .read = seq_read, |
5072c59f | 2482 | .write = ftrace_filter_write, |
41c52c0d | 2483 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
2484 | .release = ftrace_filter_release, |
2485 | }; | |
2486 | ||
5e2336a0 | 2487 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 2488 | .open = ftrace_notrace_open, |
850a80cf | 2489 | .read = seq_read, |
41c52c0d SR |
2490 | .write = ftrace_notrace_write, |
2491 | .llseek = ftrace_regex_lseek, | |
2492 | .release = ftrace_notrace_release, | |
2493 | }; | |
2494 | ||
ea4e2bc4 SR |
2495 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
2496 | ||
2497 | static DEFINE_MUTEX(graph_lock); | |
2498 | ||
2499 | int ftrace_graph_count; | |
2500 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; | |
2501 | ||
2502 | static void * | |
85951842 | 2503 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 SR |
2504 | { |
2505 | unsigned long *array = m->private; | |
ea4e2bc4 | 2506 | |
85951842 | 2507 | if (*pos >= ftrace_graph_count) |
ea4e2bc4 | 2508 | return NULL; |
85951842 LZ |
2509 | return &array[*pos]; |
2510 | } | |
ea4e2bc4 | 2511 | |
85951842 LZ |
2512 | static void * |
2513 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
2514 | { | |
2515 | (*pos)++; | |
2516 | return __g_next(m, pos); | |
ea4e2bc4 SR |
2517 | } |
2518 | ||
2519 | static void *g_start(struct seq_file *m, loff_t *pos) | |
2520 | { | |
ea4e2bc4 SR |
2521 | mutex_lock(&graph_lock); |
2522 | ||
f9349a8f FW |
2523 | /* Nothing, tell g_show to print all functions are enabled */ |
2524 | if (!ftrace_graph_count && !*pos) | |
2525 | return (void *)1; | |
2526 | ||
85951842 | 2527 | return __g_next(m, pos); |
ea4e2bc4 SR |
2528 | } |
2529 | ||
2530 | static void g_stop(struct seq_file *m, void *p) | |
2531 | { | |
2532 | mutex_unlock(&graph_lock); | |
2533 | } | |
2534 | ||
2535 | static int g_show(struct seq_file *m, void *v) | |
2536 | { | |
2537 | unsigned long *ptr = v; | |
2538 | char str[KSYM_SYMBOL_LEN]; | |
2539 | ||
2540 | if (!ptr) | |
2541 | return 0; | |
2542 | ||
f9349a8f FW |
2543 | if (ptr == (unsigned long *)1) { |
2544 | seq_printf(m, "#### all functions enabled ####\n"); | |
2545 | return 0; | |
2546 | } | |
2547 | ||
ea4e2bc4 SR |
2548 | kallsyms_lookup(*ptr, NULL, NULL, NULL, str); |
2549 | ||
2550 | seq_printf(m, "%s\n", str); | |
2551 | ||
2552 | return 0; | |
2553 | } | |
2554 | ||
2555 | static struct seq_operations ftrace_graph_seq_ops = { | |
2556 | .start = g_start, | |
2557 | .next = g_next, | |
2558 | .stop = g_stop, | |
2559 | .show = g_show, | |
2560 | }; | |
2561 | ||
2562 | static int | |
2563 | ftrace_graph_open(struct inode *inode, struct file *file) | |
2564 | { | |
2565 | int ret = 0; | |
2566 | ||
2567 | if (unlikely(ftrace_disabled)) | |
2568 | return -ENODEV; | |
2569 | ||
2570 | mutex_lock(&graph_lock); | |
2571 | if ((file->f_mode & FMODE_WRITE) && | |
2572 | !(file->f_flags & O_APPEND)) { | |
2573 | ftrace_graph_count = 0; | |
2574 | memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); | |
2575 | } | |
2576 | ||
2577 | if (file->f_mode & FMODE_READ) { | |
2578 | ret = seq_open(file, &ftrace_graph_seq_ops); | |
2579 | if (!ret) { | |
2580 | struct seq_file *m = file->private_data; | |
2581 | m->private = ftrace_graph_funcs; | |
2582 | } | |
2583 | } else | |
2584 | file->private_data = ftrace_graph_funcs; | |
2585 | mutex_unlock(&graph_lock); | |
2586 | ||
2587 | return ret; | |
2588 | } | |
2589 | ||
ea4e2bc4 | 2590 | static int |
f9349a8f | 2591 | ftrace_set_func(unsigned long *array, int *idx, char *buffer) |
ea4e2bc4 | 2592 | { |
ea4e2bc4 SR |
2593 | struct dyn_ftrace *rec; |
2594 | struct ftrace_page *pg; | |
f9349a8f | 2595 | int search_len; |
ea4e2bc4 | 2596 | int found = 0; |
f9349a8f FW |
2597 | int type, not; |
2598 | char *search; | |
2599 | bool exists; | |
2600 | int i; | |
ea4e2bc4 SR |
2601 | |
2602 | if (ftrace_disabled) | |
2603 | return -ENODEV; | |
2604 | ||
f9349a8f FW |
2605 | /* decode regex */ |
2606 | type = ftrace_setup_glob(buffer, strlen(buffer), &search, ¬); | |
2607 | if (not) | |
2608 | return -EINVAL; | |
2609 | ||
2610 | search_len = strlen(search); | |
2611 | ||
52baf119 | 2612 | mutex_lock(&ftrace_lock); |
265c831c SR |
2613 | do_for_each_ftrace_rec(pg, rec) { |
2614 | ||
f9349a8f FW |
2615 | if (*idx >= FTRACE_GRAPH_MAX_FUNCS) |
2616 | break; | |
2617 | ||
265c831c SR |
2618 | if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE)) |
2619 | continue; | |
2620 | ||
f9349a8f FW |
2621 | if (ftrace_match_record(rec, search, search_len, type)) { |
2622 | /* ensure it is not already in the array */ | |
2623 | exists = false; | |
2624 | for (i = 0; i < *idx; i++) | |
2625 | if (array[i] == rec->ip) { | |
2626 | exists = true; | |
265c831c SR |
2627 | break; |
2628 | } | |
f9349a8f FW |
2629 | if (!exists) { |
2630 | array[(*idx)++] = rec->ip; | |
2631 | found = 1; | |
2632 | } | |
ea4e2bc4 | 2633 | } |
265c831c | 2634 | } while_for_each_ftrace_rec(); |
f9349a8f | 2635 | |
52baf119 | 2636 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 SR |
2637 | |
2638 | return found ? 0 : -EINVAL; | |
2639 | } | |
2640 | ||
2641 | static ssize_t | |
2642 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
2643 | size_t cnt, loff_t *ppos) | |
2644 | { | |
2645 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
2646 | unsigned long *array; | |
2647 | size_t read = 0; | |
2648 | ssize_t ret; | |
2649 | int index = 0; | |
2650 | char ch; | |
2651 | ||
2652 | if (!cnt || cnt < 0) | |
2653 | return 0; | |
2654 | ||
2655 | mutex_lock(&graph_lock); | |
2656 | ||
2657 | if (ftrace_graph_count >= FTRACE_GRAPH_MAX_FUNCS) { | |
2658 | ret = -EBUSY; | |
2659 | goto out; | |
2660 | } | |
2661 | ||
2662 | if (file->f_mode & FMODE_READ) { | |
2663 | struct seq_file *m = file->private_data; | |
2664 | array = m->private; | |
2665 | } else | |
2666 | array = file->private_data; | |
2667 | ||
2668 | ret = get_user(ch, ubuf++); | |
2669 | if (ret) | |
2670 | goto out; | |
2671 | read++; | |
2672 | cnt--; | |
2673 | ||
2674 | /* skip white space */ | |
2675 | while (cnt && isspace(ch)) { | |
2676 | ret = get_user(ch, ubuf++); | |
2677 | if (ret) | |
2678 | goto out; | |
2679 | read++; | |
2680 | cnt--; | |
2681 | } | |
2682 | ||
2683 | if (isspace(ch)) { | |
2684 | *ppos += read; | |
2685 | ret = read; | |
2686 | goto out; | |
2687 | } | |
2688 | ||
2689 | while (cnt && !isspace(ch)) { | |
2690 | if (index < FTRACE_BUFF_MAX) | |
2691 | buffer[index++] = ch; | |
2692 | else { | |
2693 | ret = -EINVAL; | |
2694 | goto out; | |
2695 | } | |
2696 | ret = get_user(ch, ubuf++); | |
2697 | if (ret) | |
2698 | goto out; | |
2699 | read++; | |
2700 | cnt--; | |
2701 | } | |
2702 | buffer[index] = 0; | |
2703 | ||
f9349a8f FW |
2704 | /* we allow only one expression at a time */ |
2705 | ret = ftrace_set_func(array, &ftrace_graph_count, buffer); | |
ea4e2bc4 SR |
2706 | if (ret) |
2707 | goto out; | |
2708 | ||
ea4e2bc4 SR |
2709 | file->f_pos += read; |
2710 | ||
2711 | ret = read; | |
2712 | out: | |
2713 | mutex_unlock(&graph_lock); | |
2714 | ||
2715 | return ret; | |
2716 | } | |
2717 | ||
2718 | static const struct file_operations ftrace_graph_fops = { | |
2719 | .open = ftrace_graph_open, | |
850a80cf | 2720 | .read = seq_read, |
ea4e2bc4 SR |
2721 | .write = ftrace_graph_write, |
2722 | }; | |
2723 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2724 | ||
df4fc315 | 2725 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 2726 | { |
5072c59f | 2727 | |
5452af66 FW |
2728 | trace_create_file("available_filter_functions", 0444, |
2729 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 2730 | |
5452af66 FW |
2731 | trace_create_file("failures", 0444, |
2732 | d_tracer, NULL, &ftrace_failures_fops); | |
eb9a7bf0 | 2733 | |
5452af66 FW |
2734 | trace_create_file("set_ftrace_filter", 0644, d_tracer, |
2735 | NULL, &ftrace_filter_fops); | |
41c52c0d | 2736 | |
5452af66 | 2737 | trace_create_file("set_ftrace_notrace", 0644, d_tracer, |
41c52c0d | 2738 | NULL, &ftrace_notrace_fops); |
ad90c0e3 | 2739 | |
ea4e2bc4 | 2740 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 2741 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
2742 | NULL, |
2743 | &ftrace_graph_fops); | |
ea4e2bc4 SR |
2744 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
2745 | ||
5072c59f SR |
2746 | return 0; |
2747 | } | |
2748 | ||
31e88909 SR |
2749 | static int ftrace_convert_nops(struct module *mod, |
2750 | unsigned long *start, | |
68bf21aa SR |
2751 | unsigned long *end) |
2752 | { | |
2753 | unsigned long *p; | |
2754 | unsigned long addr; | |
2755 | unsigned long flags; | |
2756 | ||
e6ea44e9 | 2757 | mutex_lock(&ftrace_lock); |
68bf21aa SR |
2758 | p = start; |
2759 | while (p < end) { | |
2760 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
2761 | /* |
2762 | * Some architecture linkers will pad between | |
2763 | * the different mcount_loc sections of different | |
2764 | * object files to satisfy alignments. | |
2765 | * Skip any NULL pointers. | |
2766 | */ | |
2767 | if (!addr) | |
2768 | continue; | |
68bf21aa | 2769 | ftrace_record_ip(addr); |
68bf21aa SR |
2770 | } |
2771 | ||
08f5ac90 | 2772 | /* disable interrupts to prevent kstop machine */ |
68bf21aa | 2773 | local_irq_save(flags); |
31e88909 | 2774 | ftrace_update_code(mod); |
68bf21aa | 2775 | local_irq_restore(flags); |
e6ea44e9 | 2776 | mutex_unlock(&ftrace_lock); |
68bf21aa SR |
2777 | |
2778 | return 0; | |
2779 | } | |
2780 | ||
93eb677d SR |
2781 | #ifdef CONFIG_MODULES |
2782 | void ftrace_release(void *start, void *end) | |
2783 | { | |
2784 | struct dyn_ftrace *rec; | |
2785 | struct ftrace_page *pg; | |
2786 | unsigned long s = (unsigned long)start; | |
2787 | unsigned long e = (unsigned long)end; | |
2788 | ||
2789 | if (ftrace_disabled || !start || start == end) | |
2790 | return; | |
2791 | ||
2792 | mutex_lock(&ftrace_lock); | |
2793 | do_for_each_ftrace_rec(pg, rec) { | |
2794 | if ((rec->ip >= s) && (rec->ip < e)) { | |
2795 | /* | |
2796 | * rec->ip is changed in ftrace_free_rec() | |
2797 | * It should not between s and e if record was freed. | |
2798 | */ | |
2799 | FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE); | |
2800 | ftrace_free_rec(rec); | |
2801 | } | |
2802 | } while_for_each_ftrace_rec(); | |
2803 | mutex_unlock(&ftrace_lock); | |
2804 | } | |
2805 | ||
2806 | static void ftrace_init_module(struct module *mod, | |
2807 | unsigned long *start, unsigned long *end) | |
90d595fe | 2808 | { |
00fd61ae | 2809 | if (ftrace_disabled || start == end) |
fed1939c | 2810 | return; |
31e88909 | 2811 | ftrace_convert_nops(mod, start, end); |
90d595fe SR |
2812 | } |
2813 | ||
93eb677d SR |
2814 | static int ftrace_module_notify(struct notifier_block *self, |
2815 | unsigned long val, void *data) | |
2816 | { | |
2817 | struct module *mod = data; | |
2818 | ||
2819 | switch (val) { | |
2820 | case MODULE_STATE_COMING: | |
2821 | ftrace_init_module(mod, mod->ftrace_callsites, | |
2822 | mod->ftrace_callsites + | |
2823 | mod->num_ftrace_callsites); | |
2824 | break; | |
2825 | case MODULE_STATE_GOING: | |
2826 | ftrace_release(mod->ftrace_callsites, | |
2827 | mod->ftrace_callsites + | |
2828 | mod->num_ftrace_callsites); | |
2829 | break; | |
2830 | } | |
2831 | ||
2832 | return 0; | |
2833 | } | |
2834 | #else | |
2835 | static int ftrace_module_notify(struct notifier_block *self, | |
2836 | unsigned long val, void *data) | |
2837 | { | |
2838 | return 0; | |
2839 | } | |
2840 | #endif /* CONFIG_MODULES */ | |
2841 | ||
2842 | struct notifier_block ftrace_module_nb = { | |
2843 | .notifier_call = ftrace_module_notify, | |
2844 | .priority = 0, | |
2845 | }; | |
2846 | ||
68bf21aa SR |
2847 | extern unsigned long __start_mcount_loc[]; |
2848 | extern unsigned long __stop_mcount_loc[]; | |
2849 | ||
2850 | void __init ftrace_init(void) | |
2851 | { | |
2852 | unsigned long count, addr, flags; | |
2853 | int ret; | |
2854 | ||
2855 | /* Keep the ftrace pointer to the stub */ | |
2856 | addr = (unsigned long)ftrace_stub; | |
2857 | ||
2858 | local_irq_save(flags); | |
2859 | ftrace_dyn_arch_init(&addr); | |
2860 | local_irq_restore(flags); | |
2861 | ||
2862 | /* ftrace_dyn_arch_init places the return code in addr */ | |
2863 | if (addr) | |
2864 | goto failed; | |
2865 | ||
2866 | count = __stop_mcount_loc - __start_mcount_loc; | |
2867 | ||
2868 | ret = ftrace_dyn_table_alloc(count); | |
2869 | if (ret) | |
2870 | goto failed; | |
2871 | ||
2872 | last_ftrace_enabled = ftrace_enabled = 1; | |
2873 | ||
31e88909 SR |
2874 | ret = ftrace_convert_nops(NULL, |
2875 | __start_mcount_loc, | |
68bf21aa SR |
2876 | __stop_mcount_loc); |
2877 | ||
93eb677d | 2878 | ret = register_module_notifier(&ftrace_module_nb); |
24ed0c4b | 2879 | if (ret) |
93eb677d SR |
2880 | pr_warning("Failed to register trace ftrace module notifier\n"); |
2881 | ||
2af15d6a SR |
2882 | set_ftrace_early_filters(); |
2883 | ||
68bf21aa SR |
2884 | return; |
2885 | failed: | |
2886 | ftrace_disabled = 1; | |
2887 | } | |
68bf21aa | 2888 | |
3d083395 | 2889 | #else |
0b6e4d56 FW |
2890 | |
2891 | static int __init ftrace_nodyn_init(void) | |
2892 | { | |
2893 | ftrace_enabled = 1; | |
2894 | return 0; | |
2895 | } | |
2896 | device_initcall(ftrace_nodyn_init); | |
2897 | ||
df4fc315 SR |
2898 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
2899 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 SR |
2900 | /* Keep as macros so we do not need to define the commands */ |
2901 | # define ftrace_startup(command) do { } while (0) | |
2902 | # define ftrace_shutdown(command) do { } while (0) | |
c7aafc54 IM |
2903 | # define ftrace_startup_sysctl() do { } while (0) |
2904 | # define ftrace_shutdown_sysctl() do { } while (0) | |
3d083395 SR |
2905 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
2906 | ||
df4fc315 SR |
2907 | static ssize_t |
2908 | ftrace_pid_read(struct file *file, char __user *ubuf, | |
2909 | size_t cnt, loff_t *ppos) | |
2910 | { | |
2911 | char buf[64]; | |
2912 | int r; | |
2913 | ||
e32d8956 SR |
2914 | if (ftrace_pid_trace == ftrace_swapper_pid) |
2915 | r = sprintf(buf, "swapper tasks\n"); | |
2916 | else if (ftrace_pid_trace) | |
cc59c9e8 | 2917 | r = sprintf(buf, "%u\n", pid_vnr(ftrace_pid_trace)); |
df4fc315 SR |
2918 | else |
2919 | r = sprintf(buf, "no pid\n"); | |
2920 | ||
2921 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
2922 | } | |
2923 | ||
e32d8956 | 2924 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
2925 | { |
2926 | struct task_struct *p; | |
e32d8956 | 2927 | int cpu; |
978f3a45 | 2928 | |
e32d8956 SR |
2929 | get_online_cpus(); |
2930 | for_each_online_cpu(cpu) { | |
2931 | p = idle_task(cpu); | |
978f3a45 | 2932 | clear_tsk_trace_trace(p); |
e32d8956 SR |
2933 | } |
2934 | put_online_cpus(); | |
2935 | } | |
978f3a45 | 2936 | |
e32d8956 SR |
2937 | static void set_ftrace_swapper(void) |
2938 | { | |
2939 | struct task_struct *p; | |
2940 | int cpu; | |
2941 | ||
2942 | get_online_cpus(); | |
2943 | for_each_online_cpu(cpu) { | |
2944 | p = idle_task(cpu); | |
2945 | set_tsk_trace_trace(p); | |
2946 | } | |
2947 | put_online_cpus(); | |
978f3a45 SR |
2948 | } |
2949 | ||
e32d8956 SR |
2950 | static void clear_ftrace_pid(struct pid *pid) |
2951 | { | |
2952 | struct task_struct *p; | |
2953 | ||
229c4ef8 | 2954 | rcu_read_lock(); |
e32d8956 SR |
2955 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2956 | clear_tsk_trace_trace(p); | |
2957 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
2958 | rcu_read_unlock(); |
2959 | ||
e32d8956 SR |
2960 | put_pid(pid); |
2961 | } | |
2962 | ||
2963 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
2964 | { |
2965 | struct task_struct *p; | |
2966 | ||
229c4ef8 | 2967 | rcu_read_lock(); |
978f3a45 SR |
2968 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2969 | set_tsk_trace_trace(p); | |
2970 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 2971 | rcu_read_unlock(); |
978f3a45 SR |
2972 | } |
2973 | ||
e32d8956 SR |
2974 | static void clear_ftrace_pid_task(struct pid **pid) |
2975 | { | |
2976 | if (*pid == ftrace_swapper_pid) | |
2977 | clear_ftrace_swapper(); | |
2978 | else | |
2979 | clear_ftrace_pid(*pid); | |
2980 | ||
2981 | *pid = NULL; | |
2982 | } | |
2983 | ||
2984 | static void set_ftrace_pid_task(struct pid *pid) | |
2985 | { | |
2986 | if (pid == ftrace_swapper_pid) | |
2987 | set_ftrace_swapper(); | |
2988 | else | |
2989 | set_ftrace_pid(pid); | |
2990 | } | |
2991 | ||
df4fc315 SR |
2992 | static ssize_t |
2993 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
2994 | size_t cnt, loff_t *ppos) | |
2995 | { | |
978f3a45 | 2996 | struct pid *pid; |
df4fc315 SR |
2997 | char buf[64]; |
2998 | long val; | |
2999 | int ret; | |
3000 | ||
3001 | if (cnt >= sizeof(buf)) | |
3002 | return -EINVAL; | |
3003 | ||
3004 | if (copy_from_user(&buf, ubuf, cnt)) | |
3005 | return -EFAULT; | |
3006 | ||
3007 | buf[cnt] = 0; | |
3008 | ||
3009 | ret = strict_strtol(buf, 10, &val); | |
3010 | if (ret < 0) | |
3011 | return ret; | |
3012 | ||
e6ea44e9 | 3013 | mutex_lock(&ftrace_lock); |
978f3a45 | 3014 | if (val < 0) { |
df4fc315 | 3015 | /* disable pid tracing */ |
978f3a45 | 3016 | if (!ftrace_pid_trace) |
df4fc315 | 3017 | goto out; |
978f3a45 SR |
3018 | |
3019 | clear_ftrace_pid_task(&ftrace_pid_trace); | |
df4fc315 SR |
3020 | |
3021 | } else { | |
e32d8956 SR |
3022 | /* swapper task is special */ |
3023 | if (!val) { | |
3024 | pid = ftrace_swapper_pid; | |
3025 | if (pid == ftrace_pid_trace) | |
3026 | goto out; | |
3027 | } else { | |
3028 | pid = find_get_pid(val); | |
df4fc315 | 3029 | |
e32d8956 SR |
3030 | if (pid == ftrace_pid_trace) { |
3031 | put_pid(pid); | |
3032 | goto out; | |
3033 | } | |
0ef8cde5 | 3034 | } |
0ef8cde5 | 3035 | |
978f3a45 SR |
3036 | if (ftrace_pid_trace) |
3037 | clear_ftrace_pid_task(&ftrace_pid_trace); | |
3038 | ||
3039 | if (!pid) | |
3040 | goto out; | |
3041 | ||
3042 | ftrace_pid_trace = pid; | |
3043 | ||
3044 | set_ftrace_pid_task(ftrace_pid_trace); | |
df4fc315 SR |
3045 | } |
3046 | ||
3047 | /* update the function call */ | |
3048 | ftrace_update_pid_func(); | |
3049 | ftrace_startup_enable(0); | |
3050 | ||
3051 | out: | |
e6ea44e9 | 3052 | mutex_unlock(&ftrace_lock); |
df4fc315 SR |
3053 | |
3054 | return cnt; | |
3055 | } | |
3056 | ||
5e2336a0 | 3057 | static const struct file_operations ftrace_pid_fops = { |
df4fc315 SR |
3058 | .read = ftrace_pid_read, |
3059 | .write = ftrace_pid_write, | |
3060 | }; | |
3061 | ||
3062 | static __init int ftrace_init_debugfs(void) | |
3063 | { | |
3064 | struct dentry *d_tracer; | |
df4fc315 SR |
3065 | |
3066 | d_tracer = tracing_init_dentry(); | |
3067 | if (!d_tracer) | |
3068 | return 0; | |
3069 | ||
3070 | ftrace_init_dyn_debugfs(d_tracer); | |
3071 | ||
5452af66 FW |
3072 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
3073 | NULL, &ftrace_pid_fops); | |
493762fc SR |
3074 | |
3075 | ftrace_profile_debugfs(d_tracer); | |
3076 | ||
df4fc315 SR |
3077 | return 0; |
3078 | } | |
df4fc315 SR |
3079 | fs_initcall(ftrace_init_debugfs); |
3080 | ||
a2bb6a3d | 3081 | /** |
81adbdc0 | 3082 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
3083 | * |
3084 | * This function should be used by panic code. It stops ftrace | |
3085 | * but in a not so nice way. If you need to simply kill ftrace | |
3086 | * from a non-atomic section, use ftrace_kill. | |
3087 | */ | |
81adbdc0 | 3088 | void ftrace_kill(void) |
a2bb6a3d SR |
3089 | { |
3090 | ftrace_disabled = 1; | |
3091 | ftrace_enabled = 0; | |
a2bb6a3d SR |
3092 | clear_ftrace_function(); |
3093 | } | |
3094 | ||
16444a8a | 3095 | /** |
3d083395 SR |
3096 | * register_ftrace_function - register a function for profiling |
3097 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 3098 | * |
3d083395 SR |
3099 | * Register a function to be called by all functions in the |
3100 | * kernel. | |
3101 | * | |
3102 | * Note: @ops->func and all the functions it calls must be labeled | |
3103 | * with "notrace", otherwise it will go into a | |
3104 | * recursive loop. | |
16444a8a | 3105 | */ |
3d083395 | 3106 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 3107 | { |
b0fc494f SR |
3108 | int ret; |
3109 | ||
4eebcc81 SR |
3110 | if (unlikely(ftrace_disabled)) |
3111 | return -1; | |
3112 | ||
e6ea44e9 | 3113 | mutex_lock(&ftrace_lock); |
e7d3737e | 3114 | |
b0fc494f | 3115 | ret = __register_ftrace_function(ops); |
5a45cfe1 | 3116 | ftrace_startup(0); |
b0fc494f | 3117 | |
e6ea44e9 | 3118 | mutex_unlock(&ftrace_lock); |
b0fc494f | 3119 | return ret; |
3d083395 SR |
3120 | } |
3121 | ||
3122 | /** | |
32632920 | 3123 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
3124 | * @ops - ops structure that holds the function to unregister |
3125 | * | |
3126 | * Unregister a function that was added to be called by ftrace profiling. | |
3127 | */ | |
3128 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
3129 | { | |
3130 | int ret; | |
3131 | ||
e6ea44e9 | 3132 | mutex_lock(&ftrace_lock); |
3d083395 | 3133 | ret = __unregister_ftrace_function(ops); |
5a45cfe1 | 3134 | ftrace_shutdown(0); |
e6ea44e9 | 3135 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
3136 | |
3137 | return ret; | |
3138 | } | |
3139 | ||
e309b41d | 3140 | int |
b0fc494f | 3141 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
5072c59f | 3142 | struct file *file, void __user *buffer, size_t *lenp, |
b0fc494f SR |
3143 | loff_t *ppos) |
3144 | { | |
3145 | int ret; | |
3146 | ||
4eebcc81 SR |
3147 | if (unlikely(ftrace_disabled)) |
3148 | return -ENODEV; | |
3149 | ||
e6ea44e9 | 3150 | mutex_lock(&ftrace_lock); |
b0fc494f | 3151 | |
5072c59f | 3152 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
b0fc494f SR |
3153 | |
3154 | if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) | |
3155 | goto out; | |
3156 | ||
3157 | last_ftrace_enabled = ftrace_enabled; | |
3158 | ||
3159 | if (ftrace_enabled) { | |
3160 | ||
3161 | ftrace_startup_sysctl(); | |
3162 | ||
3163 | /* we are starting ftrace again */ | |
3164 | if (ftrace_list != &ftrace_list_end) { | |
3165 | if (ftrace_list->next == &ftrace_list_end) | |
3166 | ftrace_trace_function = ftrace_list->func; | |
3167 | else | |
3168 | ftrace_trace_function = ftrace_list_func; | |
3169 | } | |
3170 | ||
3171 | } else { | |
3172 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
3173 | ftrace_trace_function = ftrace_stub; | |
3174 | ||
3175 | ftrace_shutdown_sysctl(); | |
3176 | } | |
3177 | ||
3178 | out: | |
e6ea44e9 | 3179 | mutex_unlock(&ftrace_lock); |
3d083395 | 3180 | return ret; |
16444a8a | 3181 | } |
f17845e5 | 3182 | |
fb52607a | 3183 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 3184 | |
597af815 | 3185 | static int ftrace_graph_active; |
4a2b8dda | 3186 | static struct notifier_block ftrace_suspend_notifier; |
e7d3737e | 3187 | |
e49dc19c SR |
3188 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
3189 | { | |
3190 | return 0; | |
3191 | } | |
3192 | ||
287b6e68 FW |
3193 | /* The callbacks that hook a function */ |
3194 | trace_func_graph_ret_t ftrace_graph_return = | |
3195 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 3196 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
3197 | |
3198 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
3199 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
3200 | { | |
3201 | int i; | |
3202 | int ret = 0; | |
3203 | unsigned long flags; | |
3204 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
3205 | struct task_struct *g, *t; | |
3206 | ||
3207 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
3208 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
3209 | * sizeof(struct ftrace_ret_stack), | |
3210 | GFP_KERNEL); | |
3211 | if (!ret_stack_list[i]) { | |
3212 | start = 0; | |
3213 | end = i; | |
3214 | ret = -ENOMEM; | |
3215 | goto free; | |
3216 | } | |
3217 | } | |
3218 | ||
3219 | read_lock_irqsave(&tasklist_lock, flags); | |
3220 | do_each_thread(g, t) { | |
3221 | if (start == end) { | |
3222 | ret = -EAGAIN; | |
3223 | goto unlock; | |
3224 | } | |
3225 | ||
3226 | if (t->ret_stack == NULL) { | |
380c4b14 | 3227 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 3228 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
3229 | t->curr_ret_stack = -1; |
3230 | /* Make sure the tasks see the -1 first: */ | |
3231 | smp_wmb(); | |
3232 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
3233 | } |
3234 | } while_each_thread(g, t); | |
3235 | ||
3236 | unlock: | |
3237 | read_unlock_irqrestore(&tasklist_lock, flags); | |
3238 | free: | |
3239 | for (i = start; i < end; i++) | |
3240 | kfree(ret_stack_list[i]); | |
3241 | return ret; | |
3242 | } | |
3243 | ||
8aef2d28 SR |
3244 | static void |
3245 | ftrace_graph_probe_sched_switch(struct rq *__rq, struct task_struct *prev, | |
3246 | struct task_struct *next) | |
3247 | { | |
3248 | unsigned long long timestamp; | |
3249 | int index; | |
3250 | ||
be6f164a SR |
3251 | /* |
3252 | * Does the user want to count the time a function was asleep. | |
3253 | * If so, do not update the time stamps. | |
3254 | */ | |
3255 | if (trace_flags & TRACE_ITER_SLEEP_TIME) | |
3256 | return; | |
3257 | ||
8aef2d28 SR |
3258 | timestamp = trace_clock_local(); |
3259 | ||
3260 | prev->ftrace_timestamp = timestamp; | |
3261 | ||
3262 | /* only process tasks that we timestamped */ | |
3263 | if (!next->ftrace_timestamp) | |
3264 | return; | |
3265 | ||
3266 | /* | |
3267 | * Update all the counters in next to make up for the | |
3268 | * time next was sleeping. | |
3269 | */ | |
3270 | timestamp -= next->ftrace_timestamp; | |
3271 | ||
3272 | for (index = next->curr_ret_stack; index >= 0; index--) | |
3273 | next->ret_stack[index].calltime += timestamp; | |
3274 | } | |
3275 | ||
f201ae23 | 3276 | /* Allocate a return stack for each task */ |
fb52607a | 3277 | static int start_graph_tracing(void) |
f201ae23 FW |
3278 | { |
3279 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 3280 | int ret, cpu; |
f201ae23 FW |
3281 | |
3282 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
3283 | sizeof(struct ftrace_ret_stack *), | |
3284 | GFP_KERNEL); | |
3285 | ||
3286 | if (!ret_stack_list) | |
3287 | return -ENOMEM; | |
3288 | ||
5b058bcd | 3289 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
3290 | for_each_online_cpu(cpu) { |
3291 | if (!idle_task(cpu)->ret_stack) | |
3292 | ftrace_graph_init_task(idle_task(cpu)); | |
3293 | } | |
5b058bcd | 3294 | |
f201ae23 FW |
3295 | do { |
3296 | ret = alloc_retstack_tasklist(ret_stack_list); | |
3297 | } while (ret == -EAGAIN); | |
3298 | ||
8aef2d28 SR |
3299 | if (!ret) { |
3300 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch); | |
3301 | if (ret) | |
3302 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
3303 | " probe to kernel_sched_switch\n"); | |
3304 | } | |
3305 | ||
f201ae23 FW |
3306 | kfree(ret_stack_list); |
3307 | return ret; | |
3308 | } | |
3309 | ||
4a2b8dda FW |
3310 | /* |
3311 | * Hibernation protection. | |
3312 | * The state of the current task is too much unstable during | |
3313 | * suspend/restore to disk. We want to protect against that. | |
3314 | */ | |
3315 | static int | |
3316 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
3317 | void *unused) | |
3318 | { | |
3319 | switch (state) { | |
3320 | case PM_HIBERNATION_PREPARE: | |
3321 | pause_graph_tracing(); | |
3322 | break; | |
3323 | ||
3324 | case PM_POST_HIBERNATION: | |
3325 | unpause_graph_tracing(); | |
3326 | break; | |
3327 | } | |
3328 | return NOTIFY_DONE; | |
3329 | } | |
3330 | ||
287b6e68 FW |
3331 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
3332 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 3333 | { |
e7d3737e FW |
3334 | int ret = 0; |
3335 | ||
e6ea44e9 | 3336 | mutex_lock(&ftrace_lock); |
e7d3737e | 3337 | |
05ce5818 | 3338 | /* we currently allow only one tracer registered at a time */ |
597af815 | 3339 | if (ftrace_graph_active) { |
05ce5818 SR |
3340 | ret = -EBUSY; |
3341 | goto out; | |
3342 | } | |
3343 | ||
4a2b8dda FW |
3344 | ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; |
3345 | register_pm_notifier(&ftrace_suspend_notifier); | |
3346 | ||
597af815 | 3347 | ftrace_graph_active++; |
fb52607a | 3348 | ret = start_graph_tracing(); |
f201ae23 | 3349 | if (ret) { |
597af815 | 3350 | ftrace_graph_active--; |
f201ae23 FW |
3351 | goto out; |
3352 | } | |
e53a6319 | 3353 | |
287b6e68 FW |
3354 | ftrace_graph_return = retfunc; |
3355 | ftrace_graph_entry = entryfunc; | |
e53a6319 | 3356 | |
5a45cfe1 | 3357 | ftrace_startup(FTRACE_START_FUNC_RET); |
e7d3737e FW |
3358 | |
3359 | out: | |
e6ea44e9 | 3360 | mutex_unlock(&ftrace_lock); |
e7d3737e | 3361 | return ret; |
15e6cb36 FW |
3362 | } |
3363 | ||
fb52607a | 3364 | void unregister_ftrace_graph(void) |
15e6cb36 | 3365 | { |
e6ea44e9 | 3366 | mutex_lock(&ftrace_lock); |
e7d3737e | 3367 | |
597af815 | 3368 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
3369 | goto out; |
3370 | ||
597af815 | 3371 | ftrace_graph_active--; |
8aef2d28 | 3372 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch); |
287b6e68 | 3373 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 3374 | ftrace_graph_entry = ftrace_graph_entry_stub; |
5a45cfe1 | 3375 | ftrace_shutdown(FTRACE_STOP_FUNC_RET); |
4a2b8dda | 3376 | unregister_pm_notifier(&ftrace_suspend_notifier); |
e7d3737e | 3377 | |
2aad1b76 | 3378 | out: |
e6ea44e9 | 3379 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 3380 | } |
f201ae23 FW |
3381 | |
3382 | /* Allocate a return stack for newly created task */ | |
fb52607a | 3383 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 3384 | { |
84047e36 SR |
3385 | /* Make sure we do not use the parent ret_stack */ |
3386 | t->ret_stack = NULL; | |
3387 | ||
597af815 | 3388 | if (ftrace_graph_active) { |
82310a32 SR |
3389 | struct ftrace_ret_stack *ret_stack; |
3390 | ||
3391 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
3392 | * sizeof(struct ftrace_ret_stack), |
3393 | GFP_KERNEL); | |
82310a32 | 3394 | if (!ret_stack) |
f201ae23 FW |
3395 | return; |
3396 | t->curr_ret_stack = -1; | |
380c4b14 | 3397 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 3398 | atomic_set(&t->trace_overrun, 0); |
8aef2d28 | 3399 | t->ftrace_timestamp = 0; |
82310a32 SR |
3400 | /* make curr_ret_stack visable before we add the ret_stack */ |
3401 | smp_wmb(); | |
3402 | t->ret_stack = ret_stack; | |
84047e36 | 3403 | } |
f201ae23 FW |
3404 | } |
3405 | ||
fb52607a | 3406 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 3407 | { |
eae849ca FW |
3408 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
3409 | ||
f201ae23 | 3410 | t->ret_stack = NULL; |
eae849ca FW |
3411 | /* NULL must become visible to IRQs before we free it: */ |
3412 | barrier(); | |
3413 | ||
3414 | kfree(ret_stack); | |
f201ae23 | 3415 | } |
14a866c5 SR |
3416 | |
3417 | void ftrace_graph_stop(void) | |
3418 | { | |
3419 | ftrace_stop(); | |
3420 | } | |
15e6cb36 FW |
3421 | #endif |
3422 |