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 | |
369bc18f SA |
81 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
82 | static int ftrace_set_func(unsigned long *array, int *idx, char *buffer); | |
83 | #endif | |
84 | ||
f2252935 | 85 | static void ftrace_list_func(unsigned long ip, unsigned long parent_ip) |
16444a8a ACM |
86 | { |
87 | struct ftrace_ops *op = ftrace_list; | |
88 | ||
89 | /* in case someone actually ports this to alpha! */ | |
90 | read_barrier_depends(); | |
91 | ||
92 | while (op != &ftrace_list_end) { | |
93 | /* silly alpha */ | |
94 | read_barrier_depends(); | |
95 | op->func(ip, parent_ip); | |
96 | op = op->next; | |
97 | }; | |
98 | } | |
99 | ||
df4fc315 SR |
100 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip) |
101 | { | |
0ef8cde5 | 102 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
103 | return; |
104 | ||
105 | ftrace_pid_function(ip, parent_ip); | |
106 | } | |
107 | ||
108 | static void set_ftrace_pid_function(ftrace_func_t func) | |
109 | { | |
110 | /* do not set ftrace_pid_function to itself! */ | |
111 | if (func != ftrace_pid_func) | |
112 | ftrace_pid_function = func; | |
113 | } | |
114 | ||
16444a8a | 115 | /** |
3d083395 | 116 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 117 | * |
3d083395 SR |
118 | * This NULLs the ftrace function and in essence stops |
119 | * tracing. There may be lag | |
16444a8a | 120 | */ |
3d083395 | 121 | void clear_ftrace_function(void) |
16444a8a | 122 | { |
3d083395 | 123 | ftrace_trace_function = ftrace_stub; |
60a7ecf4 | 124 | __ftrace_trace_function = ftrace_stub; |
df4fc315 | 125 | ftrace_pid_function = ftrace_stub; |
3d083395 SR |
126 | } |
127 | ||
60a7ecf4 SR |
128 | #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
129 | /* | |
130 | * For those archs that do not test ftrace_trace_stop in their | |
131 | * mcount call site, we need to do it from C. | |
132 | */ | |
133 | static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip) | |
134 | { | |
135 | if (function_trace_stop) | |
136 | return; | |
137 | ||
138 | __ftrace_trace_function(ip, parent_ip); | |
139 | } | |
140 | #endif | |
141 | ||
e309b41d | 142 | static int __register_ftrace_function(struct ftrace_ops *ops) |
3d083395 | 143 | { |
16444a8a ACM |
144 | ops->next = ftrace_list; |
145 | /* | |
146 | * We are entering ops into the ftrace_list but another | |
147 | * CPU might be walking that list. We need to make sure | |
148 | * the ops->next pointer is valid before another CPU sees | |
149 | * the ops pointer included into the ftrace_list. | |
150 | */ | |
151 | smp_wmb(); | |
152 | ftrace_list = ops; | |
3d083395 | 153 | |
b0fc494f | 154 | if (ftrace_enabled) { |
df4fc315 SR |
155 | ftrace_func_t func; |
156 | ||
157 | if (ops->next == &ftrace_list_end) | |
158 | func = ops->func; | |
159 | else | |
160 | func = ftrace_list_func; | |
161 | ||
978f3a45 | 162 | if (ftrace_pid_trace) { |
df4fc315 SR |
163 | set_ftrace_pid_function(func); |
164 | func = ftrace_pid_func; | |
165 | } | |
166 | ||
b0fc494f SR |
167 | /* |
168 | * For one func, simply call it directly. | |
169 | * For more than one func, call the chain. | |
170 | */ | |
60a7ecf4 | 171 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
df4fc315 | 172 | ftrace_trace_function = func; |
60a7ecf4 | 173 | #else |
df4fc315 | 174 | __ftrace_trace_function = func; |
60a7ecf4 SR |
175 | ftrace_trace_function = ftrace_test_stop_func; |
176 | #endif | |
b0fc494f | 177 | } |
3d083395 | 178 | |
16444a8a ACM |
179 | return 0; |
180 | } | |
181 | ||
e309b41d | 182 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 183 | { |
16444a8a | 184 | struct ftrace_ops **p; |
16444a8a ACM |
185 | |
186 | /* | |
3d083395 SR |
187 | * If we are removing the last function, then simply point |
188 | * to the ftrace_stub. | |
16444a8a ACM |
189 | */ |
190 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { | |
191 | ftrace_trace_function = ftrace_stub; | |
192 | ftrace_list = &ftrace_list_end; | |
e6ea44e9 | 193 | return 0; |
16444a8a ACM |
194 | } |
195 | ||
196 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) | |
197 | if (*p == ops) | |
198 | break; | |
199 | ||
e6ea44e9 SR |
200 | if (*p != ops) |
201 | return -1; | |
16444a8a ACM |
202 | |
203 | *p = (*p)->next; | |
204 | ||
b0fc494f SR |
205 | if (ftrace_enabled) { |
206 | /* If we only have one func left, then call that directly */ | |
df4fc315 SR |
207 | if (ftrace_list->next == &ftrace_list_end) { |
208 | ftrace_func_t func = ftrace_list->func; | |
209 | ||
978f3a45 | 210 | if (ftrace_pid_trace) { |
df4fc315 SR |
211 | set_ftrace_pid_function(func); |
212 | func = ftrace_pid_func; | |
213 | } | |
214 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
215 | ftrace_trace_function = func; | |
216 | #else | |
217 | __ftrace_trace_function = func; | |
218 | #endif | |
219 | } | |
b0fc494f | 220 | } |
16444a8a | 221 | |
e6ea44e9 | 222 | return 0; |
3d083395 SR |
223 | } |
224 | ||
df4fc315 SR |
225 | static void ftrace_update_pid_func(void) |
226 | { | |
227 | ftrace_func_t func; | |
228 | ||
df4fc315 | 229 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 230 | return; |
df4fc315 | 231 | |
33974093 | 232 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
df4fc315 | 233 | func = ftrace_trace_function; |
33974093 MF |
234 | #else |
235 | func = __ftrace_trace_function; | |
236 | #endif | |
df4fc315 | 237 | |
978f3a45 | 238 | if (ftrace_pid_trace) { |
df4fc315 SR |
239 | set_ftrace_pid_function(func); |
240 | func = ftrace_pid_func; | |
241 | } else { | |
66eafebc LW |
242 | if (func == ftrace_pid_func) |
243 | func = ftrace_pid_function; | |
df4fc315 SR |
244 | } |
245 | ||
246 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
247 | ftrace_trace_function = func; | |
248 | #else | |
249 | __ftrace_trace_function = func; | |
250 | #endif | |
df4fc315 SR |
251 | } |
252 | ||
493762fc SR |
253 | #ifdef CONFIG_FUNCTION_PROFILER |
254 | struct ftrace_profile { | |
255 | struct hlist_node node; | |
256 | unsigned long ip; | |
257 | unsigned long counter; | |
0706f1c4 SR |
258 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
259 | unsigned long long time; | |
260 | #endif | |
8fc0c701 SR |
261 | }; |
262 | ||
493762fc SR |
263 | struct ftrace_profile_page { |
264 | struct ftrace_profile_page *next; | |
265 | unsigned long index; | |
266 | struct ftrace_profile records[]; | |
d61f82d0 SR |
267 | }; |
268 | ||
cafb168a SR |
269 | struct ftrace_profile_stat { |
270 | atomic_t disabled; | |
271 | struct hlist_head *hash; | |
272 | struct ftrace_profile_page *pages; | |
273 | struct ftrace_profile_page *start; | |
274 | struct tracer_stat stat; | |
275 | }; | |
276 | ||
493762fc SR |
277 | #define PROFILE_RECORDS_SIZE \ |
278 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 279 | |
493762fc SR |
280 | #define PROFILES_PER_PAGE \ |
281 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 282 | |
fb9fb015 SR |
283 | static int ftrace_profile_bits __read_mostly; |
284 | static int ftrace_profile_enabled __read_mostly; | |
285 | ||
286 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
287 | static DEFINE_MUTEX(ftrace_profile_lock); |
288 | ||
cafb168a | 289 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc SR |
290 | |
291 | #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */ | |
292 | ||
bac429f0 SR |
293 | static void * |
294 | function_stat_next(void *v, int idx) | |
295 | { | |
493762fc SR |
296 | struct ftrace_profile *rec = v; |
297 | struct ftrace_profile_page *pg; | |
bac429f0 | 298 | |
493762fc | 299 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
300 | |
301 | again: | |
0296e425 LZ |
302 | if (idx != 0) |
303 | rec++; | |
304 | ||
bac429f0 SR |
305 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
306 | pg = pg->next; | |
307 | if (!pg) | |
308 | return NULL; | |
309 | rec = &pg->records[0]; | |
493762fc SR |
310 | if (!rec->counter) |
311 | goto again; | |
bac429f0 SR |
312 | } |
313 | ||
bac429f0 SR |
314 | return rec; |
315 | } | |
316 | ||
317 | static void *function_stat_start(struct tracer_stat *trace) | |
318 | { | |
cafb168a SR |
319 | struct ftrace_profile_stat *stat = |
320 | container_of(trace, struct ftrace_profile_stat, stat); | |
321 | ||
322 | if (!stat || !stat->start) | |
323 | return NULL; | |
324 | ||
325 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
326 | } |
327 | ||
0706f1c4 SR |
328 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
329 | /* function graph compares on total time */ | |
330 | static int function_stat_cmp(void *p1, void *p2) | |
331 | { | |
332 | struct ftrace_profile *a = p1; | |
333 | struct ftrace_profile *b = p2; | |
334 | ||
335 | if (a->time < b->time) | |
336 | return -1; | |
337 | if (a->time > b->time) | |
338 | return 1; | |
339 | else | |
340 | return 0; | |
341 | } | |
342 | #else | |
343 | /* not function graph compares against hits */ | |
bac429f0 SR |
344 | static int function_stat_cmp(void *p1, void *p2) |
345 | { | |
493762fc SR |
346 | struct ftrace_profile *a = p1; |
347 | struct ftrace_profile *b = p2; | |
bac429f0 SR |
348 | |
349 | if (a->counter < b->counter) | |
350 | return -1; | |
351 | if (a->counter > b->counter) | |
352 | return 1; | |
353 | else | |
354 | return 0; | |
355 | } | |
0706f1c4 | 356 | #endif |
bac429f0 SR |
357 | |
358 | static int function_stat_headers(struct seq_file *m) | |
359 | { | |
0706f1c4 | 360 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
361 | seq_printf(m, " Function " |
362 | "Hit Time Avg\n" | |
363 | " -------- " | |
364 | "--- ---- ---\n"); | |
0706f1c4 | 365 | #else |
bac429f0 SR |
366 | seq_printf(m, " Function Hit\n" |
367 | " -------- ---\n"); | |
0706f1c4 | 368 | #endif |
bac429f0 SR |
369 | return 0; |
370 | } | |
371 | ||
372 | static int function_stat_show(struct seq_file *m, void *v) | |
373 | { | |
493762fc | 374 | struct ftrace_profile *rec = v; |
bac429f0 | 375 | char str[KSYM_SYMBOL_LEN]; |
0706f1c4 | 376 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
0706f1c4 | 377 | static DEFINE_MUTEX(mutex); |
34886c8b SR |
378 | static struct trace_seq s; |
379 | unsigned long long avg; | |
0706f1c4 | 380 | #endif |
bac429f0 SR |
381 | |
382 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
0706f1c4 SR |
383 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
384 | ||
385 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
386 | seq_printf(m, " "); | |
34886c8b SR |
387 | avg = rec->time; |
388 | do_div(avg, rec->counter); | |
389 | ||
390 | mutex_lock(&mutex); | |
391 | trace_seq_init(&s); | |
392 | trace_print_graph_duration(rec->time, &s); | |
393 | trace_seq_puts(&s, " "); | |
394 | trace_print_graph_duration(avg, &s); | |
0706f1c4 SR |
395 | trace_print_seq(m, &s); |
396 | mutex_unlock(&mutex); | |
397 | #endif | |
398 | seq_putc(m, '\n'); | |
bac429f0 | 399 | |
bac429f0 SR |
400 | return 0; |
401 | } | |
402 | ||
cafb168a | 403 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 404 | { |
493762fc | 405 | struct ftrace_profile_page *pg; |
bac429f0 | 406 | |
cafb168a | 407 | pg = stat->pages = stat->start; |
bac429f0 | 408 | |
493762fc SR |
409 | while (pg) { |
410 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
411 | pg->index = 0; | |
412 | pg = pg->next; | |
bac429f0 SR |
413 | } |
414 | ||
cafb168a | 415 | memset(stat->hash, 0, |
493762fc SR |
416 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
417 | } | |
bac429f0 | 418 | |
cafb168a | 419 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
420 | { |
421 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
422 | int functions; |
423 | int pages; | |
493762fc | 424 | int i; |
bac429f0 | 425 | |
493762fc | 426 | /* If we already allocated, do nothing */ |
cafb168a | 427 | if (stat->pages) |
493762fc | 428 | return 0; |
bac429f0 | 429 | |
cafb168a SR |
430 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
431 | if (!stat->pages) | |
493762fc | 432 | return -ENOMEM; |
bac429f0 | 433 | |
318e0a73 SR |
434 | #ifdef CONFIG_DYNAMIC_FTRACE |
435 | functions = ftrace_update_tot_cnt; | |
436 | #else | |
437 | /* | |
438 | * We do not know the number of functions that exist because | |
439 | * dynamic tracing is what counts them. With past experience | |
440 | * we have around 20K functions. That should be more than enough. | |
441 | * It is highly unlikely we will execute every function in | |
442 | * the kernel. | |
443 | */ | |
444 | functions = 20000; | |
445 | #endif | |
446 | ||
cafb168a | 447 | pg = stat->start = stat->pages; |
bac429f0 | 448 | |
318e0a73 SR |
449 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
450 | ||
451 | for (i = 0; i < pages; i++) { | |
493762fc | 452 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 453 | if (!pg->next) |
318e0a73 | 454 | goto out_free; |
493762fc SR |
455 | pg = pg->next; |
456 | } | |
457 | ||
458 | return 0; | |
318e0a73 SR |
459 | |
460 | out_free: | |
461 | pg = stat->start; | |
462 | while (pg) { | |
463 | unsigned long tmp = (unsigned long)pg; | |
464 | ||
465 | pg = pg->next; | |
466 | free_page(tmp); | |
467 | } | |
468 | ||
469 | free_page((unsigned long)stat->pages); | |
470 | stat->pages = NULL; | |
471 | stat->start = NULL; | |
472 | ||
473 | return -ENOMEM; | |
bac429f0 SR |
474 | } |
475 | ||
cafb168a | 476 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 477 | { |
cafb168a | 478 | struct ftrace_profile_stat *stat; |
493762fc | 479 | int size; |
bac429f0 | 480 | |
cafb168a SR |
481 | stat = &per_cpu(ftrace_profile_stats, cpu); |
482 | ||
483 | if (stat->hash) { | |
493762fc | 484 | /* If the profile is already created, simply reset it */ |
cafb168a | 485 | ftrace_profile_reset(stat); |
493762fc SR |
486 | return 0; |
487 | } | |
bac429f0 | 488 | |
493762fc SR |
489 | /* |
490 | * We are profiling all functions, but usually only a few thousand | |
491 | * functions are hit. We'll make a hash of 1024 items. | |
492 | */ | |
493 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 494 | |
cafb168a | 495 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
493762fc | 496 | |
cafb168a | 497 | if (!stat->hash) |
493762fc SR |
498 | return -ENOMEM; |
499 | ||
cafb168a SR |
500 | if (!ftrace_profile_bits) { |
501 | size--; | |
493762fc | 502 | |
cafb168a SR |
503 | for (; size; size >>= 1) |
504 | ftrace_profile_bits++; | |
505 | } | |
493762fc | 506 | |
318e0a73 | 507 | /* Preallocate the function profiling pages */ |
cafb168a SR |
508 | if (ftrace_profile_pages_init(stat) < 0) { |
509 | kfree(stat->hash); | |
510 | stat->hash = NULL; | |
493762fc SR |
511 | return -ENOMEM; |
512 | } | |
513 | ||
514 | return 0; | |
bac429f0 SR |
515 | } |
516 | ||
cafb168a SR |
517 | static int ftrace_profile_init(void) |
518 | { | |
519 | int cpu; | |
520 | int ret = 0; | |
521 | ||
522 | for_each_online_cpu(cpu) { | |
523 | ret = ftrace_profile_init_cpu(cpu); | |
524 | if (ret) | |
525 | break; | |
526 | } | |
527 | ||
528 | return ret; | |
529 | } | |
530 | ||
493762fc | 531 | /* interrupts must be disabled */ |
cafb168a SR |
532 | static struct ftrace_profile * |
533 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 534 | { |
493762fc | 535 | struct ftrace_profile *rec; |
bac429f0 SR |
536 | struct hlist_head *hhd; |
537 | struct hlist_node *n; | |
bac429f0 SR |
538 | unsigned long key; |
539 | ||
bac429f0 | 540 | key = hash_long(ip, ftrace_profile_bits); |
cafb168a | 541 | hhd = &stat->hash[key]; |
bac429f0 SR |
542 | |
543 | if (hlist_empty(hhd)) | |
544 | return NULL; | |
545 | ||
bac429f0 SR |
546 | hlist_for_each_entry_rcu(rec, n, hhd, node) { |
547 | if (rec->ip == ip) | |
493762fc SR |
548 | return rec; |
549 | } | |
550 | ||
551 | return NULL; | |
552 | } | |
553 | ||
cafb168a SR |
554 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
555 | struct ftrace_profile *rec) | |
493762fc SR |
556 | { |
557 | unsigned long key; | |
558 | ||
559 | key = hash_long(rec->ip, ftrace_profile_bits); | |
cafb168a | 560 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
561 | } |
562 | ||
318e0a73 SR |
563 | /* |
564 | * The memory is already allocated, this simply finds a new record to use. | |
565 | */ | |
493762fc | 566 | static struct ftrace_profile * |
318e0a73 | 567 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
568 | { |
569 | struct ftrace_profile *rec = NULL; | |
570 | ||
318e0a73 | 571 | /* prevent recursion (from NMIs) */ |
cafb168a | 572 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
573 | goto out; |
574 | ||
493762fc | 575 | /* |
318e0a73 SR |
576 | * Try to find the function again since an NMI |
577 | * could have added it | |
493762fc | 578 | */ |
cafb168a | 579 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 580 | if (rec) |
cafb168a | 581 | goto out; |
493762fc | 582 | |
cafb168a SR |
583 | if (stat->pages->index == PROFILES_PER_PAGE) { |
584 | if (!stat->pages->next) | |
585 | goto out; | |
586 | stat->pages = stat->pages->next; | |
bac429f0 | 587 | } |
493762fc | 588 | |
cafb168a | 589 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 590 | rec->ip = ip; |
cafb168a | 591 | ftrace_add_profile(stat, rec); |
493762fc | 592 | |
bac429f0 | 593 | out: |
cafb168a | 594 | atomic_dec(&stat->disabled); |
bac429f0 SR |
595 | |
596 | return rec; | |
597 | } | |
598 | ||
599 | static void | |
600 | function_profile_call(unsigned long ip, unsigned long parent_ip) | |
601 | { | |
cafb168a | 602 | struct ftrace_profile_stat *stat; |
493762fc | 603 | struct ftrace_profile *rec; |
bac429f0 SR |
604 | unsigned long flags; |
605 | ||
606 | if (!ftrace_profile_enabled) | |
607 | return; | |
608 | ||
609 | local_irq_save(flags); | |
cafb168a SR |
610 | |
611 | stat = &__get_cpu_var(ftrace_profile_stats); | |
0f6ce3de | 612 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
613 | goto out; |
614 | ||
615 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 616 | if (!rec) { |
318e0a73 | 617 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
618 | if (!rec) |
619 | goto out; | |
620 | } | |
bac429f0 SR |
621 | |
622 | rec->counter++; | |
623 | out: | |
624 | local_irq_restore(flags); | |
625 | } | |
626 | ||
0706f1c4 SR |
627 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
628 | static int profile_graph_entry(struct ftrace_graph_ent *trace) | |
629 | { | |
630 | function_profile_call(trace->func, 0); | |
631 | return 1; | |
632 | } | |
633 | ||
634 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
635 | { | |
cafb168a | 636 | struct ftrace_profile_stat *stat; |
a2a16d6a | 637 | unsigned long long calltime; |
0706f1c4 | 638 | struct ftrace_profile *rec; |
cafb168a | 639 | unsigned long flags; |
0706f1c4 SR |
640 | |
641 | local_irq_save(flags); | |
cafb168a | 642 | stat = &__get_cpu_var(ftrace_profile_stats); |
0f6ce3de | 643 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
644 | goto out; |
645 | ||
a2a16d6a SR |
646 | calltime = trace->rettime - trace->calltime; |
647 | ||
648 | if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) { | |
649 | int index; | |
650 | ||
651 | index = trace->depth; | |
652 | ||
653 | /* Append this call time to the parent time to subtract */ | |
654 | if (index) | |
655 | current->ret_stack[index - 1].subtime += calltime; | |
656 | ||
657 | if (current->ret_stack[index].subtime < calltime) | |
658 | calltime -= current->ret_stack[index].subtime; | |
659 | else | |
660 | calltime = 0; | |
661 | } | |
662 | ||
cafb168a | 663 | rec = ftrace_find_profiled_func(stat, trace->func); |
0706f1c4 | 664 | if (rec) |
a2a16d6a SR |
665 | rec->time += calltime; |
666 | ||
cafb168a | 667 | out: |
0706f1c4 SR |
668 | local_irq_restore(flags); |
669 | } | |
670 | ||
671 | static int register_ftrace_profiler(void) | |
672 | { | |
673 | return register_ftrace_graph(&profile_graph_return, | |
674 | &profile_graph_entry); | |
675 | } | |
676 | ||
677 | static void unregister_ftrace_profiler(void) | |
678 | { | |
679 | unregister_ftrace_graph(); | |
680 | } | |
681 | #else | |
bac429f0 SR |
682 | static struct ftrace_ops ftrace_profile_ops __read_mostly = |
683 | { | |
fb9fb015 | 684 | .func = function_profile_call, |
bac429f0 SR |
685 | }; |
686 | ||
0706f1c4 SR |
687 | static int register_ftrace_profiler(void) |
688 | { | |
689 | return register_ftrace_function(&ftrace_profile_ops); | |
690 | } | |
691 | ||
692 | static void unregister_ftrace_profiler(void) | |
693 | { | |
694 | unregister_ftrace_function(&ftrace_profile_ops); | |
695 | } | |
696 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
697 | ||
bac429f0 SR |
698 | static ssize_t |
699 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
700 | size_t cnt, loff_t *ppos) | |
701 | { | |
702 | unsigned long val; | |
fb9fb015 | 703 | char buf[64]; /* big enough to hold a number */ |
bac429f0 SR |
704 | int ret; |
705 | ||
bac429f0 SR |
706 | if (cnt >= sizeof(buf)) |
707 | return -EINVAL; | |
708 | ||
709 | if (copy_from_user(&buf, ubuf, cnt)) | |
710 | return -EFAULT; | |
711 | ||
712 | buf[cnt] = 0; | |
713 | ||
714 | ret = strict_strtoul(buf, 10, &val); | |
715 | if (ret < 0) | |
716 | return ret; | |
717 | ||
718 | val = !!val; | |
719 | ||
720 | mutex_lock(&ftrace_profile_lock); | |
721 | if (ftrace_profile_enabled ^ val) { | |
722 | if (val) { | |
493762fc SR |
723 | ret = ftrace_profile_init(); |
724 | if (ret < 0) { | |
725 | cnt = ret; | |
726 | goto out; | |
727 | } | |
728 | ||
0706f1c4 SR |
729 | ret = register_ftrace_profiler(); |
730 | if (ret < 0) { | |
731 | cnt = ret; | |
732 | goto out; | |
733 | } | |
bac429f0 SR |
734 | ftrace_profile_enabled = 1; |
735 | } else { | |
736 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
737 | /* |
738 | * unregister_ftrace_profiler calls stop_machine | |
739 | * so this acts like an synchronize_sched. | |
740 | */ | |
0706f1c4 | 741 | unregister_ftrace_profiler(); |
bac429f0 SR |
742 | } |
743 | } | |
493762fc | 744 | out: |
bac429f0 SR |
745 | mutex_unlock(&ftrace_profile_lock); |
746 | ||
747 | filp->f_pos += cnt; | |
748 | ||
749 | return cnt; | |
750 | } | |
751 | ||
493762fc SR |
752 | static ssize_t |
753 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
754 | size_t cnt, loff_t *ppos) | |
755 | { | |
fb9fb015 | 756 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
757 | int r; |
758 | ||
759 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
760 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
761 | } | |
762 | ||
bac429f0 SR |
763 | static const struct file_operations ftrace_profile_fops = { |
764 | .open = tracing_open_generic, | |
765 | .read = ftrace_profile_read, | |
766 | .write = ftrace_profile_write, | |
767 | }; | |
768 | ||
cafb168a SR |
769 | /* used to initialize the real stat files */ |
770 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
771 | .name = "functions", |
772 | .stat_start = function_stat_start, | |
773 | .stat_next = function_stat_next, | |
774 | .stat_cmp = function_stat_cmp, | |
775 | .stat_headers = function_stat_headers, | |
776 | .stat_show = function_stat_show | |
cafb168a SR |
777 | }; |
778 | ||
6ab5d668 | 779 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 | 780 | { |
cafb168a | 781 | struct ftrace_profile_stat *stat; |
bac429f0 | 782 | struct dentry *entry; |
cafb168a | 783 | char *name; |
bac429f0 | 784 | int ret; |
cafb168a SR |
785 | int cpu; |
786 | ||
787 | for_each_possible_cpu(cpu) { | |
788 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
789 | ||
790 | /* allocate enough for function name + cpu number */ | |
791 | name = kmalloc(32, GFP_KERNEL); | |
792 | if (!name) { | |
793 | /* | |
794 | * The files created are permanent, if something happens | |
795 | * we still do not free memory. | |
796 | */ | |
cafb168a SR |
797 | WARN(1, |
798 | "Could not allocate stat file for cpu %d\n", | |
799 | cpu); | |
800 | return; | |
801 | } | |
802 | stat->stat = function_stats; | |
803 | snprintf(name, 32, "function%d", cpu); | |
804 | stat->stat.name = name; | |
805 | ret = register_stat_tracer(&stat->stat); | |
806 | if (ret) { | |
807 | WARN(1, | |
808 | "Could not register function stat for cpu %d\n", | |
809 | cpu); | |
810 | kfree(name); | |
811 | return; | |
812 | } | |
bac429f0 SR |
813 | } |
814 | ||
815 | entry = debugfs_create_file("function_profile_enabled", 0644, | |
816 | d_tracer, NULL, &ftrace_profile_fops); | |
817 | if (!entry) | |
818 | pr_warning("Could not create debugfs " | |
819 | "'function_profile_enabled' entry\n"); | |
820 | } | |
821 | ||
bac429f0 | 822 | #else /* CONFIG_FUNCTION_PROFILER */ |
6ab5d668 | 823 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 SR |
824 | { |
825 | } | |
bac429f0 SR |
826 | #endif /* CONFIG_FUNCTION_PROFILER */ |
827 | ||
493762fc SR |
828 | /* set when tracing only a pid */ |
829 | struct pid *ftrace_pid_trace; | |
830 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; | |
831 | ||
832 | #ifdef CONFIG_DYNAMIC_FTRACE | |
833 | ||
834 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD | |
835 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
836 | #endif | |
837 | ||
838 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; | |
839 | ||
840 | struct ftrace_func_probe { | |
841 | struct hlist_node node; | |
842 | struct ftrace_probe_ops *ops; | |
843 | unsigned long flags; | |
844 | unsigned long ip; | |
845 | void *data; | |
846 | struct rcu_head rcu; | |
847 | }; | |
848 | ||
849 | enum { | |
850 | FTRACE_ENABLE_CALLS = (1 << 0), | |
851 | FTRACE_DISABLE_CALLS = (1 << 1), | |
852 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
853 | FTRACE_ENABLE_MCOUNT = (1 << 3), | |
854 | FTRACE_DISABLE_MCOUNT = (1 << 4), | |
855 | FTRACE_START_FUNC_RET = (1 << 5), | |
856 | FTRACE_STOP_FUNC_RET = (1 << 6), | |
857 | }; | |
858 | ||
859 | static int ftrace_filtered; | |
860 | ||
861 | static struct dyn_ftrace *ftrace_new_addrs; | |
862 | ||
863 | static DEFINE_MUTEX(ftrace_regex_lock); | |
864 | ||
865 | struct ftrace_page { | |
866 | struct ftrace_page *next; | |
867 | int index; | |
868 | struct dyn_ftrace records[]; | |
869 | }; | |
870 | ||
871 | #define ENTRIES_PER_PAGE \ | |
872 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
873 | ||
874 | /* estimate from running different kernels */ | |
875 | #define NR_TO_INIT 10000 | |
876 | ||
877 | static struct ftrace_page *ftrace_pages_start; | |
878 | static struct ftrace_page *ftrace_pages; | |
879 | ||
880 | static struct dyn_ftrace *ftrace_free_records; | |
881 | ||
882 | /* | |
883 | * This is a double for. Do not use 'break' to break out of the loop, | |
884 | * you must use a goto. | |
885 | */ | |
886 | #define do_for_each_ftrace_rec(pg, rec) \ | |
887 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
888 | int _____i; \ | |
889 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
890 | rec = &pg->records[_____i]; | |
891 | ||
892 | #define while_for_each_ftrace_rec() \ | |
893 | } \ | |
894 | } | |
895 | ||
ecea656d | 896 | #ifdef CONFIG_KPROBES |
f17845e5 IM |
897 | |
898 | static int frozen_record_count; | |
899 | ||
ecea656d AS |
900 | static inline void freeze_record(struct dyn_ftrace *rec) |
901 | { | |
902 | if (!(rec->flags & FTRACE_FL_FROZEN)) { | |
903 | rec->flags |= FTRACE_FL_FROZEN; | |
904 | frozen_record_count++; | |
905 | } | |
906 | } | |
907 | ||
908 | static inline void unfreeze_record(struct dyn_ftrace *rec) | |
909 | { | |
910 | if (rec->flags & FTRACE_FL_FROZEN) { | |
911 | rec->flags &= ~FTRACE_FL_FROZEN; | |
912 | frozen_record_count--; | |
913 | } | |
914 | } | |
915 | ||
916 | static inline int record_frozen(struct dyn_ftrace *rec) | |
917 | { | |
918 | return rec->flags & FTRACE_FL_FROZEN; | |
919 | } | |
920 | #else | |
921 | # define freeze_record(rec) ({ 0; }) | |
922 | # define unfreeze_record(rec) ({ 0; }) | |
923 | # define record_frozen(rec) ({ 0; }) | |
924 | #endif /* CONFIG_KPROBES */ | |
925 | ||
e309b41d | 926 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
37ad5084 | 927 | { |
ee000b7f | 928 | rec->freelist = ftrace_free_records; |
37ad5084 SR |
929 | ftrace_free_records = rec; |
930 | rec->flags |= FTRACE_FL_FREE; | |
931 | } | |
932 | ||
e309b41d | 933 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 934 | { |
37ad5084 SR |
935 | struct dyn_ftrace *rec; |
936 | ||
937 | /* First check for freed records */ | |
938 | if (ftrace_free_records) { | |
939 | rec = ftrace_free_records; | |
940 | ||
37ad5084 | 941 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
6912896e | 942 | FTRACE_WARN_ON_ONCE(1); |
37ad5084 SR |
943 | ftrace_free_records = NULL; |
944 | return NULL; | |
945 | } | |
946 | ||
ee000b7f | 947 | ftrace_free_records = rec->freelist; |
37ad5084 SR |
948 | memset(rec, 0, sizeof(*rec)); |
949 | return rec; | |
950 | } | |
951 | ||
3c1720f0 | 952 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
08f5ac90 SR |
953 | if (!ftrace_pages->next) { |
954 | /* allocate another page */ | |
955 | ftrace_pages->next = | |
956 | (void *)get_zeroed_page(GFP_KERNEL); | |
957 | if (!ftrace_pages->next) | |
958 | return NULL; | |
959 | } | |
3c1720f0 SR |
960 | ftrace_pages = ftrace_pages->next; |
961 | } | |
962 | ||
963 | return &ftrace_pages->records[ftrace_pages->index++]; | |
964 | } | |
965 | ||
08f5ac90 | 966 | static struct dyn_ftrace * |
d61f82d0 | 967 | ftrace_record_ip(unsigned long ip) |
3d083395 | 968 | { |
08f5ac90 | 969 | struct dyn_ftrace *rec; |
3d083395 | 970 | |
f3c7ac40 | 971 | if (ftrace_disabled) |
08f5ac90 | 972 | return NULL; |
3d083395 | 973 | |
08f5ac90 SR |
974 | rec = ftrace_alloc_dyn_node(ip); |
975 | if (!rec) | |
976 | return NULL; | |
3d083395 | 977 | |
08f5ac90 | 978 | rec->ip = ip; |
ee000b7f | 979 | rec->newlist = ftrace_new_addrs; |
e94142a6 | 980 | ftrace_new_addrs = rec; |
3d083395 | 981 | |
08f5ac90 | 982 | return rec; |
3d083395 SR |
983 | } |
984 | ||
b17e8a37 SR |
985 | static void print_ip_ins(const char *fmt, unsigned char *p) |
986 | { | |
987 | int i; | |
988 | ||
989 | printk(KERN_CONT "%s", fmt); | |
990 | ||
991 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
992 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
993 | } | |
994 | ||
31e88909 | 995 | static void ftrace_bug(int failed, unsigned long ip) |
b17e8a37 SR |
996 | { |
997 | switch (failed) { | |
998 | case -EFAULT: | |
999 | FTRACE_WARN_ON_ONCE(1); | |
1000 | pr_info("ftrace faulted on modifying "); | |
1001 | print_ip_sym(ip); | |
1002 | break; | |
1003 | case -EINVAL: | |
1004 | FTRACE_WARN_ON_ONCE(1); | |
1005 | pr_info("ftrace failed to modify "); | |
1006 | print_ip_sym(ip); | |
b17e8a37 | 1007 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
1008 | printk(KERN_CONT "\n"); |
1009 | break; | |
1010 | case -EPERM: | |
1011 | FTRACE_WARN_ON_ONCE(1); | |
1012 | pr_info("ftrace faulted on writing "); | |
1013 | print_ip_sym(ip); | |
1014 | break; | |
1015 | default: | |
1016 | FTRACE_WARN_ON_ONCE(1); | |
1017 | pr_info("ftrace faulted on unknown error "); | |
1018 | print_ip_sym(ip); | |
1019 | } | |
1020 | } | |
1021 | ||
3c1720f0 | 1022 | |
0eb96701 | 1023 | static int |
31e88909 | 1024 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) |
5072c59f | 1025 | { |
e7d3737e | 1026 | unsigned long ftrace_addr; |
64fbcd16 | 1027 | unsigned long flag = 0UL; |
e7d3737e | 1028 | |
f0001207 | 1029 | ftrace_addr = (unsigned long)FTRACE_ADDR; |
5072c59f | 1030 | |
982c350b | 1031 | /* |
64fbcd16 XG |
1032 | * If this record is not to be traced or we want to disable it, |
1033 | * then disable it. | |
982c350b | 1034 | * |
64fbcd16 | 1035 | * If we want to enable it and filtering is off, then enable it. |
982c350b | 1036 | * |
64fbcd16 XG |
1037 | * If we want to enable it and filtering is on, enable it only if |
1038 | * it's filtered | |
982c350b | 1039 | */ |
64fbcd16 XG |
1040 | if (enable && !(rec->flags & FTRACE_FL_NOTRACE)) { |
1041 | if (!ftrace_filtered || (rec->flags & FTRACE_FL_FILTER)) | |
1042 | flag = FTRACE_FL_ENABLED; | |
1043 | } | |
982c350b | 1044 | |
64fbcd16 XG |
1045 | /* If the state of this record hasn't changed, then do nothing */ |
1046 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
1047 | return 0; | |
982c350b | 1048 | |
64fbcd16 XG |
1049 | if (flag) { |
1050 | rec->flags |= FTRACE_FL_ENABLED; | |
1051 | return ftrace_make_call(rec, ftrace_addr); | |
5072c59f SR |
1052 | } |
1053 | ||
64fbcd16 XG |
1054 | rec->flags &= ~FTRACE_FL_ENABLED; |
1055 | return ftrace_make_nop(NULL, rec, ftrace_addr); | |
5072c59f SR |
1056 | } |
1057 | ||
e309b41d | 1058 | static void ftrace_replace_code(int enable) |
3c1720f0 | 1059 | { |
3c1720f0 SR |
1060 | struct dyn_ftrace *rec; |
1061 | struct ftrace_page *pg; | |
6a24a244 | 1062 | int failed; |
3c1720f0 | 1063 | |
265c831c SR |
1064 | do_for_each_ftrace_rec(pg, rec) { |
1065 | /* | |
fa9d13cf Z |
1066 | * Skip over free records, records that have |
1067 | * failed and not converted. | |
265c831c SR |
1068 | */ |
1069 | if (rec->flags & FTRACE_FL_FREE || | |
fa9d13cf | 1070 | rec->flags & FTRACE_FL_FAILED || |
03303549 | 1071 | !(rec->flags & FTRACE_FL_CONVERTED)) |
265c831c SR |
1072 | continue; |
1073 | ||
1074 | /* ignore updates to this record's mcount site */ | |
1075 | if (get_kprobe((void *)rec->ip)) { | |
1076 | freeze_record(rec); | |
1077 | continue; | |
1078 | } else { | |
1079 | unfreeze_record(rec); | |
1080 | } | |
f22f9a89 | 1081 | |
265c831c | 1082 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 1083 | if (failed) { |
265c831c | 1084 | rec->flags |= FTRACE_FL_FAILED; |
3279ba37 SR |
1085 | ftrace_bug(failed, rec->ip); |
1086 | /* Stop processing */ | |
1087 | return; | |
3c1720f0 | 1088 | } |
265c831c | 1089 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
1090 | } |
1091 | ||
492a7ea5 | 1092 | static int |
31e88909 | 1093 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 SR |
1094 | { |
1095 | unsigned long ip; | |
593eb8a2 | 1096 | int ret; |
3c1720f0 SR |
1097 | |
1098 | ip = rec->ip; | |
1099 | ||
25aac9dc | 1100 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 1101 | if (ret) { |
31e88909 | 1102 | ftrace_bug(ret, ip); |
3c1720f0 | 1103 | rec->flags |= FTRACE_FL_FAILED; |
492a7ea5 | 1104 | return 0; |
37ad5084 | 1105 | } |
492a7ea5 | 1106 | return 1; |
3c1720f0 SR |
1107 | } |
1108 | ||
000ab691 SR |
1109 | /* |
1110 | * archs can override this function if they must do something | |
1111 | * before the modifying code is performed. | |
1112 | */ | |
1113 | int __weak ftrace_arch_code_modify_prepare(void) | |
1114 | { | |
1115 | return 0; | |
1116 | } | |
1117 | ||
1118 | /* | |
1119 | * archs can override this function if they must do something | |
1120 | * after the modifying code is performed. | |
1121 | */ | |
1122 | int __weak ftrace_arch_code_modify_post_process(void) | |
1123 | { | |
1124 | return 0; | |
1125 | } | |
1126 | ||
e309b41d | 1127 | static int __ftrace_modify_code(void *data) |
3d083395 | 1128 | { |
d61f82d0 SR |
1129 | int *command = data; |
1130 | ||
a3583244 | 1131 | if (*command & FTRACE_ENABLE_CALLS) |
d61f82d0 | 1132 | ftrace_replace_code(1); |
a3583244 | 1133 | else if (*command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
1134 | ftrace_replace_code(0); |
1135 | ||
1136 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
1137 | ftrace_update_ftrace_func(ftrace_trace_function); | |
1138 | ||
5a45cfe1 SR |
1139 | if (*command & FTRACE_START_FUNC_RET) |
1140 | ftrace_enable_ftrace_graph_caller(); | |
1141 | else if (*command & FTRACE_STOP_FUNC_RET) | |
1142 | ftrace_disable_ftrace_graph_caller(); | |
1143 | ||
d61f82d0 | 1144 | return 0; |
3d083395 SR |
1145 | } |
1146 | ||
e309b41d | 1147 | static void ftrace_run_update_code(int command) |
3d083395 | 1148 | { |
000ab691 SR |
1149 | int ret; |
1150 | ||
1151 | ret = ftrace_arch_code_modify_prepare(); | |
1152 | FTRACE_WARN_ON(ret); | |
1153 | if (ret) | |
1154 | return; | |
1155 | ||
784e2d76 | 1156 | stop_machine(__ftrace_modify_code, &command, NULL); |
000ab691 SR |
1157 | |
1158 | ret = ftrace_arch_code_modify_post_process(); | |
1159 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
1160 | } |
1161 | ||
d61f82d0 | 1162 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 1163 | static int ftrace_start_up; |
df4fc315 SR |
1164 | |
1165 | static void ftrace_startup_enable(int command) | |
1166 | { | |
1167 | if (saved_ftrace_func != ftrace_trace_function) { | |
1168 | saved_ftrace_func = ftrace_trace_function; | |
1169 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1170 | } | |
1171 | ||
1172 | if (!command || !ftrace_enabled) | |
1173 | return; | |
1174 | ||
1175 | ftrace_run_update_code(command); | |
1176 | } | |
d61f82d0 | 1177 | |
5a45cfe1 | 1178 | static void ftrace_startup(int command) |
3d083395 | 1179 | { |
4eebcc81 SR |
1180 | if (unlikely(ftrace_disabled)) |
1181 | return; | |
1182 | ||
60a7ecf4 | 1183 | ftrace_start_up++; |
982c350b | 1184 | command |= FTRACE_ENABLE_CALLS; |
d61f82d0 | 1185 | |
df4fc315 | 1186 | ftrace_startup_enable(command); |
3d083395 SR |
1187 | } |
1188 | ||
5a45cfe1 | 1189 | static void ftrace_shutdown(int command) |
3d083395 | 1190 | { |
4eebcc81 SR |
1191 | if (unlikely(ftrace_disabled)) |
1192 | return; | |
1193 | ||
60a7ecf4 | 1194 | ftrace_start_up--; |
9ea1a153 FW |
1195 | /* |
1196 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
1197 | * critical but the ftrace_call callers may be never nopped again after | |
1198 | * further ftrace uses. | |
1199 | */ | |
1200 | WARN_ON_ONCE(ftrace_start_up < 0); | |
1201 | ||
60a7ecf4 | 1202 | if (!ftrace_start_up) |
d61f82d0 | 1203 | command |= FTRACE_DISABLE_CALLS; |
3d083395 | 1204 | |
d61f82d0 SR |
1205 | if (saved_ftrace_func != ftrace_trace_function) { |
1206 | saved_ftrace_func = ftrace_trace_function; | |
1207 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1208 | } | |
3d083395 | 1209 | |
d61f82d0 | 1210 | if (!command || !ftrace_enabled) |
e6ea44e9 | 1211 | return; |
d61f82d0 SR |
1212 | |
1213 | ftrace_run_update_code(command); | |
3d083395 SR |
1214 | } |
1215 | ||
e309b41d | 1216 | static void ftrace_startup_sysctl(void) |
b0fc494f | 1217 | { |
d61f82d0 SR |
1218 | int command = FTRACE_ENABLE_MCOUNT; |
1219 | ||
4eebcc81 SR |
1220 | if (unlikely(ftrace_disabled)) |
1221 | return; | |
1222 | ||
d61f82d0 SR |
1223 | /* Force update next time */ |
1224 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
1225 | /* ftrace_start_up is true if we want ftrace running */ |
1226 | if (ftrace_start_up) | |
d61f82d0 SR |
1227 | command |= FTRACE_ENABLE_CALLS; |
1228 | ||
1229 | ftrace_run_update_code(command); | |
b0fc494f SR |
1230 | } |
1231 | ||
e309b41d | 1232 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 1233 | { |
d61f82d0 SR |
1234 | int command = FTRACE_DISABLE_MCOUNT; |
1235 | ||
4eebcc81 SR |
1236 | if (unlikely(ftrace_disabled)) |
1237 | return; | |
1238 | ||
60a7ecf4 SR |
1239 | /* ftrace_start_up is true if ftrace is running */ |
1240 | if (ftrace_start_up) | |
d61f82d0 SR |
1241 | command |= FTRACE_DISABLE_CALLS; |
1242 | ||
1243 | ftrace_run_update_code(command); | |
b0fc494f SR |
1244 | } |
1245 | ||
3d083395 SR |
1246 | static cycle_t ftrace_update_time; |
1247 | static unsigned long ftrace_update_cnt; | |
1248 | unsigned long ftrace_update_tot_cnt; | |
1249 | ||
31e88909 | 1250 | static int ftrace_update_code(struct module *mod) |
3d083395 | 1251 | { |
e94142a6 | 1252 | struct dyn_ftrace *p; |
f22f9a89 | 1253 | cycle_t start, stop; |
3d083395 | 1254 | |
750ed1a4 | 1255 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1256 | ftrace_update_cnt = 0; |
1257 | ||
e94142a6 | 1258 | while (ftrace_new_addrs) { |
3d083395 | 1259 | |
08f5ac90 SR |
1260 | /* If something went wrong, bail without enabling anything */ |
1261 | if (unlikely(ftrace_disabled)) | |
1262 | return -1; | |
f22f9a89 | 1263 | |
e94142a6 | 1264 | p = ftrace_new_addrs; |
ee000b7f | 1265 | ftrace_new_addrs = p->newlist; |
e94142a6 | 1266 | p->flags = 0L; |
f22f9a89 | 1267 | |
08f5ac90 | 1268 | /* convert record (i.e, patch mcount-call with NOP) */ |
31e88909 | 1269 | if (ftrace_code_disable(mod, p)) { |
08f5ac90 SR |
1270 | p->flags |= FTRACE_FL_CONVERTED; |
1271 | ftrace_update_cnt++; | |
1272 | } else | |
1273 | ftrace_free_rec(p); | |
3d083395 SR |
1274 | } |
1275 | ||
750ed1a4 | 1276 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1277 | ftrace_update_time = stop - start; |
1278 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
1279 | ||
16444a8a ACM |
1280 | return 0; |
1281 | } | |
1282 | ||
68bf21aa | 1283 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
1284 | { |
1285 | struct ftrace_page *pg; | |
1286 | int cnt; | |
1287 | int i; | |
3c1720f0 SR |
1288 | |
1289 | /* allocate a few pages */ | |
1290 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
1291 | if (!ftrace_pages_start) | |
1292 | return -1; | |
1293 | ||
1294 | /* | |
1295 | * Allocate a few more pages. | |
1296 | * | |
1297 | * TODO: have some parser search vmlinux before | |
1298 | * final linking to find all calls to ftrace. | |
1299 | * Then we can: | |
1300 | * a) know how many pages to allocate. | |
1301 | * and/or | |
1302 | * b) set up the table then. | |
1303 | * | |
1304 | * The dynamic code is still necessary for | |
1305 | * modules. | |
1306 | */ | |
1307 | ||
1308 | pg = ftrace_pages = ftrace_pages_start; | |
1309 | ||
68bf21aa | 1310 | cnt = num_to_init / ENTRIES_PER_PAGE; |
08f5ac90 | 1311 | pr_info("ftrace: allocating %ld entries in %d pages\n", |
5821e1b7 | 1312 | num_to_init, cnt + 1); |
3c1720f0 SR |
1313 | |
1314 | for (i = 0; i < cnt; i++) { | |
1315 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
1316 | ||
1317 | /* If we fail, we'll try later anyway */ | |
1318 | if (!pg->next) | |
1319 | break; | |
1320 | ||
1321 | pg = pg->next; | |
1322 | } | |
1323 | ||
1324 | return 0; | |
1325 | } | |
1326 | ||
5072c59f SR |
1327 | enum { |
1328 | FTRACE_ITER_FILTER = (1 << 0), | |
689fd8b6 | 1329 | FTRACE_ITER_NOTRACE = (1 << 1), |
1330 | FTRACE_ITER_FAILURES = (1 << 2), | |
1331 | FTRACE_ITER_PRINTALL = (1 << 3), | |
1332 | FTRACE_ITER_HASH = (1 << 4), | |
5072c59f SR |
1333 | }; |
1334 | ||
1335 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
1336 | ||
1337 | struct ftrace_iterator { | |
5072c59f | 1338 | struct ftrace_page *pg; |
8fc0c701 | 1339 | int hidx; |
431aa3fb | 1340 | int idx; |
5072c59f | 1341 | unsigned flags; |
689fd8b6 | 1342 | struct trace_parser parser; |
5072c59f SR |
1343 | }; |
1344 | ||
8fc0c701 SR |
1345 | static void * |
1346 | t_hash_next(struct seq_file *m, void *v, loff_t *pos) | |
1347 | { | |
1348 | struct ftrace_iterator *iter = m->private; | |
1349 | struct hlist_node *hnd = v; | |
1350 | struct hlist_head *hhd; | |
1351 | ||
1352 | WARN_ON(!(iter->flags & FTRACE_ITER_HASH)); | |
1353 | ||
1354 | (*pos)++; | |
1355 | ||
1356 | retry: | |
1357 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
1358 | return NULL; | |
1359 | ||
1360 | hhd = &ftrace_func_hash[iter->hidx]; | |
1361 | ||
1362 | if (hlist_empty(hhd)) { | |
1363 | iter->hidx++; | |
1364 | hnd = NULL; | |
1365 | goto retry; | |
1366 | } | |
1367 | ||
1368 | if (!hnd) | |
1369 | hnd = hhd->first; | |
1370 | else { | |
1371 | hnd = hnd->next; | |
1372 | if (!hnd) { | |
1373 | iter->hidx++; | |
1374 | goto retry; | |
1375 | } | |
1376 | } | |
1377 | ||
1378 | return hnd; | |
1379 | } | |
1380 | ||
1381 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
1382 | { | |
1383 | struct ftrace_iterator *iter = m->private; | |
1384 | void *p = NULL; | |
d82d6244 LZ |
1385 | loff_t l; |
1386 | ||
1387 | if (!(iter->flags & FTRACE_ITER_HASH)) | |
1388 | *pos = 0; | |
8fc0c701 SR |
1389 | |
1390 | iter->flags |= FTRACE_ITER_HASH; | |
1391 | ||
d82d6244 LZ |
1392 | iter->hidx = 0; |
1393 | for (l = 0; l <= *pos; ) { | |
1394 | p = t_hash_next(m, p, &l); | |
1395 | if (!p) | |
1396 | break; | |
1397 | } | |
1398 | return p; | |
8fc0c701 SR |
1399 | } |
1400 | ||
1401 | static int t_hash_show(struct seq_file *m, void *v) | |
1402 | { | |
b6887d79 | 1403 | struct ftrace_func_probe *rec; |
8fc0c701 | 1404 | struct hlist_node *hnd = v; |
8fc0c701 | 1405 | |
b6887d79 | 1406 | rec = hlist_entry(hnd, struct ftrace_func_probe, node); |
8fc0c701 | 1407 | |
809dcf29 SR |
1408 | if (rec->ops->print) |
1409 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
1410 | ||
b375a11a | 1411 | seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func); |
8fc0c701 SR |
1412 | |
1413 | if (rec->data) | |
1414 | seq_printf(m, ":%p", rec->data); | |
1415 | seq_putc(m, '\n'); | |
1416 | ||
1417 | return 0; | |
1418 | } | |
1419 | ||
e309b41d | 1420 | static void * |
5072c59f SR |
1421 | t_next(struct seq_file *m, void *v, loff_t *pos) |
1422 | { | |
1423 | struct ftrace_iterator *iter = m->private; | |
1424 | struct dyn_ftrace *rec = NULL; | |
1425 | ||
8fc0c701 SR |
1426 | if (iter->flags & FTRACE_ITER_HASH) |
1427 | return t_hash_next(m, v, pos); | |
1428 | ||
5072c59f SR |
1429 | (*pos)++; |
1430 | ||
0c75a3ed SR |
1431 | if (iter->flags & FTRACE_ITER_PRINTALL) |
1432 | return NULL; | |
1433 | ||
5072c59f SR |
1434 | retry: |
1435 | if (iter->idx >= iter->pg->index) { | |
1436 | if (iter->pg->next) { | |
1437 | iter->pg = iter->pg->next; | |
1438 | iter->idx = 0; | |
1439 | goto retry; | |
1440 | } | |
1441 | } else { | |
1442 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
1443 | if ((rec->flags & FTRACE_FL_FREE) || |
1444 | ||
1445 | (!(iter->flags & FTRACE_ITER_FAILURES) && | |
eb9a7bf0 AS |
1446 | (rec->flags & FTRACE_FL_FAILED)) || |
1447 | ||
1448 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
a9fdda33 | 1449 | !(rec->flags & FTRACE_FL_FAILED)) || |
eb9a7bf0 | 1450 | |
0183fb1c SR |
1451 | ((iter->flags & FTRACE_ITER_FILTER) && |
1452 | !(rec->flags & FTRACE_FL_FILTER)) || | |
1453 | ||
41c52c0d SR |
1454 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
1455 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
1456 | rec = NULL; |
1457 | goto retry; | |
1458 | } | |
1459 | } | |
1460 | ||
5072c59f SR |
1461 | return rec; |
1462 | } | |
1463 | ||
1464 | static void *t_start(struct seq_file *m, loff_t *pos) | |
1465 | { | |
1466 | struct ftrace_iterator *iter = m->private; | |
1467 | void *p = NULL; | |
694ce0a5 | 1468 | loff_t l; |
5072c59f | 1469 | |
8fc0c701 | 1470 | mutex_lock(&ftrace_lock); |
0c75a3ed SR |
1471 | /* |
1472 | * For set_ftrace_filter reading, if we have the filter | |
1473 | * off, we can short cut and just print out that all | |
1474 | * functions are enabled. | |
1475 | */ | |
1476 | if (iter->flags & FTRACE_ITER_FILTER && !ftrace_filtered) { | |
1477 | if (*pos > 0) | |
8fc0c701 | 1478 | return t_hash_start(m, pos); |
0c75a3ed | 1479 | iter->flags |= FTRACE_ITER_PRINTALL; |
0c75a3ed SR |
1480 | return iter; |
1481 | } | |
1482 | ||
8fc0c701 SR |
1483 | if (iter->flags & FTRACE_ITER_HASH) |
1484 | return t_hash_start(m, pos); | |
1485 | ||
694ce0a5 LZ |
1486 | iter->pg = ftrace_pages_start; |
1487 | iter->idx = 0; | |
1488 | for (l = 0; l <= *pos; ) { | |
1489 | p = t_next(m, p, &l); | |
1490 | if (!p) | |
1491 | break; | |
50cdaf08 | 1492 | } |
5821e1b7 | 1493 | |
694ce0a5 | 1494 | if (!p && iter->flags & FTRACE_ITER_FILTER) |
8fc0c701 SR |
1495 | return t_hash_start(m, pos); |
1496 | ||
5072c59f SR |
1497 | return p; |
1498 | } | |
1499 | ||
1500 | static void t_stop(struct seq_file *m, void *p) | |
1501 | { | |
8fc0c701 | 1502 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1503 | } |
1504 | ||
1505 | static int t_show(struct seq_file *m, void *v) | |
1506 | { | |
0c75a3ed | 1507 | struct ftrace_iterator *iter = m->private; |
5072c59f | 1508 | struct dyn_ftrace *rec = v; |
5072c59f | 1509 | |
8fc0c701 SR |
1510 | if (iter->flags & FTRACE_ITER_HASH) |
1511 | return t_hash_show(m, v); | |
1512 | ||
0c75a3ed SR |
1513 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
1514 | seq_printf(m, "#### all functions enabled ####\n"); | |
1515 | return 0; | |
1516 | } | |
1517 | ||
5072c59f SR |
1518 | if (!rec) |
1519 | return 0; | |
1520 | ||
b375a11a | 1521 | seq_printf(m, "%ps\n", (void *)rec->ip); |
5072c59f SR |
1522 | |
1523 | return 0; | |
1524 | } | |
1525 | ||
88e9d34c | 1526 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
1527 | .start = t_start, |
1528 | .next = t_next, | |
1529 | .stop = t_stop, | |
1530 | .show = t_show, | |
1531 | }; | |
1532 | ||
e309b41d | 1533 | static int |
5072c59f SR |
1534 | ftrace_avail_open(struct inode *inode, struct file *file) |
1535 | { | |
1536 | struct ftrace_iterator *iter; | |
1537 | int ret; | |
1538 | ||
4eebcc81 SR |
1539 | if (unlikely(ftrace_disabled)) |
1540 | return -ENODEV; | |
1541 | ||
5072c59f SR |
1542 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1543 | if (!iter) | |
1544 | return -ENOMEM; | |
1545 | ||
1546 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
1547 | |
1548 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1549 | if (!ret) { | |
1550 | struct seq_file *m = file->private_data; | |
4bf39a94 | 1551 | |
5072c59f | 1552 | m->private = iter; |
4bf39a94 | 1553 | } else { |
5072c59f | 1554 | kfree(iter); |
4bf39a94 | 1555 | } |
5072c59f SR |
1556 | |
1557 | return ret; | |
1558 | } | |
1559 | ||
eb9a7bf0 AS |
1560 | static int |
1561 | ftrace_failures_open(struct inode *inode, struct file *file) | |
1562 | { | |
1563 | int ret; | |
1564 | struct seq_file *m; | |
1565 | struct ftrace_iterator *iter; | |
1566 | ||
1567 | ret = ftrace_avail_open(inode, file); | |
1568 | if (!ret) { | |
1569 | m = (struct seq_file *)file->private_data; | |
1570 | iter = (struct ftrace_iterator *)m->private; | |
1571 | iter->flags = FTRACE_ITER_FAILURES; | |
1572 | } | |
1573 | ||
1574 | return ret; | |
1575 | } | |
1576 | ||
1577 | ||
41c52c0d | 1578 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
1579 | { |
1580 | struct ftrace_page *pg; | |
1581 | struct dyn_ftrace *rec; | |
41c52c0d | 1582 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f | 1583 | |
52baf119 | 1584 | mutex_lock(&ftrace_lock); |
41c52c0d SR |
1585 | if (enable) |
1586 | ftrace_filtered = 0; | |
265c831c SR |
1587 | do_for_each_ftrace_rec(pg, rec) { |
1588 | if (rec->flags & FTRACE_FL_FAILED) | |
1589 | continue; | |
1590 | rec->flags &= ~type; | |
1591 | } while_for_each_ftrace_rec(); | |
52baf119 | 1592 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1593 | } |
1594 | ||
e309b41d | 1595 | static int |
41c52c0d | 1596 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1597 | { |
1598 | struct ftrace_iterator *iter; | |
1599 | int ret = 0; | |
1600 | ||
4eebcc81 SR |
1601 | if (unlikely(ftrace_disabled)) |
1602 | return -ENODEV; | |
1603 | ||
5072c59f SR |
1604 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1605 | if (!iter) | |
1606 | return -ENOMEM; | |
1607 | ||
689fd8b6 | 1608 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { |
1609 | kfree(iter); | |
1610 | return -ENOMEM; | |
1611 | } | |
1612 | ||
41c52c0d | 1613 | mutex_lock(&ftrace_regex_lock); |
5072c59f | 1614 | if ((file->f_mode & FMODE_WRITE) && |
8650ae32 | 1615 | (file->f_flags & O_TRUNC)) |
41c52c0d | 1616 | ftrace_filter_reset(enable); |
5072c59f SR |
1617 | |
1618 | if (file->f_mode & FMODE_READ) { | |
1619 | iter->pg = ftrace_pages_start; | |
41c52c0d SR |
1620 | iter->flags = enable ? FTRACE_ITER_FILTER : |
1621 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
1622 | |
1623 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1624 | if (!ret) { | |
1625 | struct seq_file *m = file->private_data; | |
1626 | m->private = iter; | |
79fe249c LZ |
1627 | } else { |
1628 | trace_parser_put(&iter->parser); | |
5072c59f | 1629 | kfree(iter); |
79fe249c | 1630 | } |
5072c59f SR |
1631 | } else |
1632 | file->private_data = iter; | |
41c52c0d | 1633 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1634 | |
1635 | return ret; | |
1636 | } | |
1637 | ||
41c52c0d SR |
1638 | static int |
1639 | ftrace_filter_open(struct inode *inode, struct file *file) | |
1640 | { | |
1641 | return ftrace_regex_open(inode, file, 1); | |
1642 | } | |
1643 | ||
1644 | static int | |
1645 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
1646 | { | |
1647 | return ftrace_regex_open(inode, file, 0); | |
1648 | } | |
1649 | ||
e309b41d | 1650 | static loff_t |
41c52c0d | 1651 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
1652 | { |
1653 | loff_t ret; | |
1654 | ||
1655 | if (file->f_mode & FMODE_READ) | |
1656 | ret = seq_lseek(file, offset, origin); | |
1657 | else | |
1658 | file->f_pos = ret = 1; | |
1659 | ||
1660 | return ret; | |
1661 | } | |
1662 | ||
64e7c440 | 1663 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 1664 | { |
9f4801e3 SR |
1665 | int matched = 0; |
1666 | char *ptr; | |
1667 | ||
9f4801e3 SR |
1668 | switch (type) { |
1669 | case MATCH_FULL: | |
1670 | if (strcmp(str, regex) == 0) | |
1671 | matched = 1; | |
1672 | break; | |
1673 | case MATCH_FRONT_ONLY: | |
1674 | if (strncmp(str, regex, len) == 0) | |
1675 | matched = 1; | |
1676 | break; | |
1677 | case MATCH_MIDDLE_ONLY: | |
1678 | if (strstr(str, regex)) | |
1679 | matched = 1; | |
1680 | break; | |
1681 | case MATCH_END_ONLY: | |
1682 | ptr = strstr(str, regex); | |
1683 | if (ptr && (ptr[len] == 0)) | |
1684 | matched = 1; | |
1685 | break; | |
1686 | } | |
1687 | ||
1688 | return matched; | |
1689 | } | |
1690 | ||
64e7c440 SR |
1691 | static int |
1692 | ftrace_match_record(struct dyn_ftrace *rec, char *regex, int len, int type) | |
1693 | { | |
1694 | char str[KSYM_SYMBOL_LEN]; | |
1695 | ||
1696 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1697 | return ftrace_match(str, regex, len, type); | |
1698 | } | |
1699 | ||
9f4801e3 SR |
1700 | static void ftrace_match_records(char *buff, int len, int enable) |
1701 | { | |
6a24a244 | 1702 | unsigned int search_len; |
9f4801e3 SR |
1703 | struct ftrace_page *pg; |
1704 | struct dyn_ftrace *rec; | |
6a24a244 SR |
1705 | unsigned long flag; |
1706 | char *search; | |
9f4801e3 | 1707 | int type; |
9f4801e3 SR |
1708 | int not; |
1709 | ||
6a24a244 | 1710 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
3f6fe06d | 1711 | type = filter_parse_regex(buff, len, &search, ¬); |
9f4801e3 SR |
1712 | |
1713 | search_len = strlen(search); | |
1714 | ||
52baf119 | 1715 | mutex_lock(&ftrace_lock); |
265c831c | 1716 | do_for_each_ftrace_rec(pg, rec) { |
265c831c SR |
1717 | |
1718 | if (rec->flags & FTRACE_FL_FAILED) | |
1719 | continue; | |
9f4801e3 SR |
1720 | |
1721 | if (ftrace_match_record(rec, search, search_len, type)) { | |
265c831c SR |
1722 | if (not) |
1723 | rec->flags &= ~flag; | |
1724 | else | |
1725 | rec->flags |= flag; | |
1726 | } | |
e68746a2 SR |
1727 | /* |
1728 | * Only enable filtering if we have a function that | |
1729 | * is filtered on. | |
1730 | */ | |
1731 | if (enable && (rec->flags & FTRACE_FL_FILTER)) | |
1732 | ftrace_filtered = 1; | |
265c831c | 1733 | } while_for_each_ftrace_rec(); |
52baf119 | 1734 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1735 | } |
1736 | ||
64e7c440 SR |
1737 | static int |
1738 | ftrace_match_module_record(struct dyn_ftrace *rec, char *mod, | |
1739 | char *regex, int len, int type) | |
1740 | { | |
1741 | char str[KSYM_SYMBOL_LEN]; | |
1742 | char *modname; | |
1743 | ||
1744 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
1745 | ||
1746 | if (!modname || strcmp(modname, mod)) | |
1747 | return 0; | |
1748 | ||
1749 | /* blank search means to match all funcs in the mod */ | |
1750 | if (len) | |
1751 | return ftrace_match(str, regex, len, type); | |
1752 | else | |
1753 | return 1; | |
1754 | } | |
1755 | ||
1756 | static void ftrace_match_module_records(char *buff, char *mod, int enable) | |
1757 | { | |
6a24a244 | 1758 | unsigned search_len = 0; |
64e7c440 SR |
1759 | struct ftrace_page *pg; |
1760 | struct dyn_ftrace *rec; | |
1761 | int type = MATCH_FULL; | |
6a24a244 SR |
1762 | char *search = buff; |
1763 | unsigned long flag; | |
64e7c440 SR |
1764 | int not = 0; |
1765 | ||
6a24a244 SR |
1766 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
1767 | ||
64e7c440 SR |
1768 | /* blank or '*' mean the same */ |
1769 | if (strcmp(buff, "*") == 0) | |
1770 | buff[0] = 0; | |
1771 | ||
1772 | /* handle the case of 'dont filter this module' */ | |
1773 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
1774 | buff[0] = 0; | |
1775 | not = 1; | |
1776 | } | |
1777 | ||
1778 | if (strlen(buff)) { | |
3f6fe06d | 1779 | type = filter_parse_regex(buff, strlen(buff), &search, ¬); |
64e7c440 SR |
1780 | search_len = strlen(search); |
1781 | } | |
1782 | ||
52baf119 | 1783 | mutex_lock(&ftrace_lock); |
64e7c440 SR |
1784 | do_for_each_ftrace_rec(pg, rec) { |
1785 | ||
1786 | if (rec->flags & FTRACE_FL_FAILED) | |
1787 | continue; | |
1788 | ||
1789 | if (ftrace_match_module_record(rec, mod, | |
1790 | search, search_len, type)) { | |
1791 | if (not) | |
1792 | rec->flags &= ~flag; | |
1793 | else | |
1794 | rec->flags |= flag; | |
1795 | } | |
e68746a2 SR |
1796 | if (enable && (rec->flags & FTRACE_FL_FILTER)) |
1797 | ftrace_filtered = 1; | |
64e7c440 SR |
1798 | |
1799 | } while_for_each_ftrace_rec(); | |
52baf119 | 1800 | mutex_unlock(&ftrace_lock); |
64e7c440 SR |
1801 | } |
1802 | ||
f6180773 SR |
1803 | /* |
1804 | * We register the module command as a template to show others how | |
1805 | * to register the a command as well. | |
1806 | */ | |
1807 | ||
1808 | static int | |
1809 | ftrace_mod_callback(char *func, char *cmd, char *param, int enable) | |
1810 | { | |
1811 | char *mod; | |
1812 | ||
1813 | /* | |
1814 | * cmd == 'mod' because we only registered this func | |
1815 | * for the 'mod' ftrace_func_command. | |
1816 | * But if you register one func with multiple commands, | |
1817 | * you can tell which command was used by the cmd | |
1818 | * parameter. | |
1819 | */ | |
1820 | ||
1821 | /* we must have a module name */ | |
1822 | if (!param) | |
1823 | return -EINVAL; | |
1824 | ||
1825 | mod = strsep(¶m, ":"); | |
1826 | if (!strlen(mod)) | |
1827 | return -EINVAL; | |
1828 | ||
1829 | ftrace_match_module_records(func, mod, enable); | |
1830 | return 0; | |
1831 | } | |
1832 | ||
1833 | static struct ftrace_func_command ftrace_mod_cmd = { | |
1834 | .name = "mod", | |
1835 | .func = ftrace_mod_callback, | |
1836 | }; | |
1837 | ||
1838 | static int __init ftrace_mod_cmd_init(void) | |
1839 | { | |
1840 | return register_ftrace_command(&ftrace_mod_cmd); | |
1841 | } | |
1842 | device_initcall(ftrace_mod_cmd_init); | |
1843 | ||
59df055f | 1844 | static void |
b6887d79 | 1845 | function_trace_probe_call(unsigned long ip, unsigned long parent_ip) |
59df055f | 1846 | { |
b6887d79 | 1847 | struct ftrace_func_probe *entry; |
59df055f SR |
1848 | struct hlist_head *hhd; |
1849 | struct hlist_node *n; | |
1850 | unsigned long key; | |
1851 | int resched; | |
1852 | ||
1853 | key = hash_long(ip, FTRACE_HASH_BITS); | |
1854 | ||
1855 | hhd = &ftrace_func_hash[key]; | |
1856 | ||
1857 | if (hlist_empty(hhd)) | |
1858 | return; | |
1859 | ||
1860 | /* | |
1861 | * Disable preemption for these calls to prevent a RCU grace | |
1862 | * period. This syncs the hash iteration and freeing of items | |
1863 | * on the hash. rcu_read_lock is too dangerous here. | |
1864 | */ | |
1865 | resched = ftrace_preempt_disable(); | |
1866 | hlist_for_each_entry_rcu(entry, n, hhd, node) { | |
1867 | if (entry->ip == ip) | |
1868 | entry->ops->func(ip, parent_ip, &entry->data); | |
1869 | } | |
1870 | ftrace_preempt_enable(resched); | |
1871 | } | |
1872 | ||
b6887d79 | 1873 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 1874 | { |
fb9fb015 | 1875 | .func = function_trace_probe_call, |
59df055f SR |
1876 | }; |
1877 | ||
b6887d79 | 1878 | static int ftrace_probe_registered; |
59df055f | 1879 | |
b6887d79 | 1880 | static void __enable_ftrace_function_probe(void) |
59df055f SR |
1881 | { |
1882 | int i; | |
1883 | ||
b6887d79 | 1884 | if (ftrace_probe_registered) |
59df055f SR |
1885 | return; |
1886 | ||
1887 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1888 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1889 | if (hhd->first) | |
1890 | break; | |
1891 | } | |
1892 | /* Nothing registered? */ | |
1893 | if (i == FTRACE_FUNC_HASHSIZE) | |
1894 | return; | |
1895 | ||
b6887d79 | 1896 | __register_ftrace_function(&trace_probe_ops); |
59df055f | 1897 | ftrace_startup(0); |
b6887d79 | 1898 | ftrace_probe_registered = 1; |
59df055f SR |
1899 | } |
1900 | ||
b6887d79 | 1901 | static void __disable_ftrace_function_probe(void) |
59df055f SR |
1902 | { |
1903 | int i; | |
1904 | ||
b6887d79 | 1905 | if (!ftrace_probe_registered) |
59df055f SR |
1906 | return; |
1907 | ||
1908 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1909 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1910 | if (hhd->first) | |
1911 | return; | |
1912 | } | |
1913 | ||
1914 | /* no more funcs left */ | |
b6887d79 | 1915 | __unregister_ftrace_function(&trace_probe_ops); |
59df055f | 1916 | ftrace_shutdown(0); |
b6887d79 | 1917 | ftrace_probe_registered = 0; |
59df055f SR |
1918 | } |
1919 | ||
1920 | ||
1921 | static void ftrace_free_entry_rcu(struct rcu_head *rhp) | |
1922 | { | |
b6887d79 SR |
1923 | struct ftrace_func_probe *entry = |
1924 | container_of(rhp, struct ftrace_func_probe, rcu); | |
59df055f SR |
1925 | |
1926 | if (entry->ops->free) | |
1927 | entry->ops->free(&entry->data); | |
1928 | kfree(entry); | |
1929 | } | |
1930 | ||
1931 | ||
1932 | int | |
b6887d79 | 1933 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
1934 | void *data) |
1935 | { | |
b6887d79 | 1936 | struct ftrace_func_probe *entry; |
59df055f SR |
1937 | struct ftrace_page *pg; |
1938 | struct dyn_ftrace *rec; | |
59df055f | 1939 | int type, len, not; |
6a24a244 | 1940 | unsigned long key; |
59df055f SR |
1941 | int count = 0; |
1942 | char *search; | |
1943 | ||
3f6fe06d | 1944 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
1945 | len = strlen(search); |
1946 | ||
b6887d79 | 1947 | /* we do not support '!' for function probes */ |
59df055f SR |
1948 | if (WARN_ON(not)) |
1949 | return -EINVAL; | |
1950 | ||
1951 | mutex_lock(&ftrace_lock); | |
1952 | do_for_each_ftrace_rec(pg, rec) { | |
1953 | ||
1954 | if (rec->flags & FTRACE_FL_FAILED) | |
1955 | continue; | |
1956 | ||
1957 | if (!ftrace_match_record(rec, search, len, type)) | |
1958 | continue; | |
1959 | ||
1960 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1961 | if (!entry) { | |
b6887d79 | 1962 | /* If we did not process any, then return error */ |
59df055f SR |
1963 | if (!count) |
1964 | count = -ENOMEM; | |
1965 | goto out_unlock; | |
1966 | } | |
1967 | ||
1968 | count++; | |
1969 | ||
1970 | entry->data = data; | |
1971 | ||
1972 | /* | |
1973 | * The caller might want to do something special | |
1974 | * for each function we find. We call the callback | |
1975 | * to give the caller an opportunity to do so. | |
1976 | */ | |
1977 | if (ops->callback) { | |
1978 | if (ops->callback(rec->ip, &entry->data) < 0) { | |
1979 | /* caller does not like this func */ | |
1980 | kfree(entry); | |
1981 | continue; | |
1982 | } | |
1983 | } | |
1984 | ||
1985 | entry->ops = ops; | |
1986 | entry->ip = rec->ip; | |
1987 | ||
1988 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
1989 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
1990 | ||
1991 | } while_for_each_ftrace_rec(); | |
b6887d79 | 1992 | __enable_ftrace_function_probe(); |
59df055f SR |
1993 | |
1994 | out_unlock: | |
1995 | mutex_unlock(&ftrace_lock); | |
1996 | ||
1997 | return count; | |
1998 | } | |
1999 | ||
2000 | enum { | |
b6887d79 SR |
2001 | PROBE_TEST_FUNC = 1, |
2002 | PROBE_TEST_DATA = 2 | |
59df055f SR |
2003 | }; |
2004 | ||
2005 | static void | |
b6887d79 | 2006 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2007 | void *data, int flags) |
2008 | { | |
b6887d79 | 2009 | struct ftrace_func_probe *entry; |
59df055f SR |
2010 | struct hlist_node *n, *tmp; |
2011 | char str[KSYM_SYMBOL_LEN]; | |
2012 | int type = MATCH_FULL; | |
2013 | int i, len = 0; | |
2014 | char *search; | |
2015 | ||
b36461da | 2016 | if (glob && (strcmp(glob, "*") == 0 || !strlen(glob))) |
59df055f | 2017 | glob = NULL; |
b36461da | 2018 | else if (glob) { |
59df055f SR |
2019 | int not; |
2020 | ||
3f6fe06d | 2021 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
2022 | len = strlen(search); |
2023 | ||
b6887d79 | 2024 | /* we do not support '!' for function probes */ |
59df055f SR |
2025 | if (WARN_ON(not)) |
2026 | return; | |
2027 | } | |
2028 | ||
2029 | mutex_lock(&ftrace_lock); | |
2030 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2031 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2032 | ||
2033 | hlist_for_each_entry_safe(entry, n, tmp, hhd, node) { | |
2034 | ||
2035 | /* break up if statements for readability */ | |
b6887d79 | 2036 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
2037 | continue; |
2038 | ||
b6887d79 | 2039 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
2040 | continue; |
2041 | ||
2042 | /* do this last, since it is the most expensive */ | |
2043 | if (glob) { | |
2044 | kallsyms_lookup(entry->ip, NULL, NULL, | |
2045 | NULL, str); | |
2046 | if (!ftrace_match(str, glob, len, type)) | |
2047 | continue; | |
2048 | } | |
2049 | ||
2050 | hlist_del(&entry->node); | |
2051 | call_rcu(&entry->rcu, ftrace_free_entry_rcu); | |
2052 | } | |
2053 | } | |
b6887d79 | 2054 | __disable_ftrace_function_probe(); |
59df055f SR |
2055 | mutex_unlock(&ftrace_lock); |
2056 | } | |
2057 | ||
2058 | void | |
b6887d79 | 2059 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2060 | void *data) |
2061 | { | |
b6887d79 SR |
2062 | __unregister_ftrace_function_probe(glob, ops, data, |
2063 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
2064 | } |
2065 | ||
2066 | void | |
b6887d79 | 2067 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 2068 | { |
b6887d79 | 2069 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
2070 | } |
2071 | ||
b6887d79 | 2072 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 2073 | { |
b6887d79 | 2074 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
2075 | } |
2076 | ||
f6180773 SR |
2077 | static LIST_HEAD(ftrace_commands); |
2078 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
2079 | ||
2080 | int register_ftrace_command(struct ftrace_func_command *cmd) | |
2081 | { | |
2082 | struct ftrace_func_command *p; | |
2083 | int ret = 0; | |
2084 | ||
2085 | mutex_lock(&ftrace_cmd_mutex); | |
2086 | list_for_each_entry(p, &ftrace_commands, list) { | |
2087 | if (strcmp(cmd->name, p->name) == 0) { | |
2088 | ret = -EBUSY; | |
2089 | goto out_unlock; | |
2090 | } | |
2091 | } | |
2092 | list_add(&cmd->list, &ftrace_commands); | |
2093 | out_unlock: | |
2094 | mutex_unlock(&ftrace_cmd_mutex); | |
2095 | ||
2096 | return ret; | |
2097 | } | |
2098 | ||
2099 | int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
2100 | { | |
2101 | struct ftrace_func_command *p, *n; | |
2102 | int ret = -ENODEV; | |
2103 | ||
2104 | mutex_lock(&ftrace_cmd_mutex); | |
2105 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
2106 | if (strcmp(cmd->name, p->name) == 0) { | |
2107 | ret = 0; | |
2108 | list_del_init(&p->list); | |
2109 | goto out_unlock; | |
2110 | } | |
2111 | } | |
2112 | out_unlock: | |
2113 | mutex_unlock(&ftrace_cmd_mutex); | |
2114 | ||
2115 | return ret; | |
2116 | } | |
2117 | ||
64e7c440 SR |
2118 | static int ftrace_process_regex(char *buff, int len, int enable) |
2119 | { | |
f6180773 | 2120 | char *func, *command, *next = buff; |
6a24a244 | 2121 | struct ftrace_func_command *p; |
f6180773 | 2122 | int ret = -EINVAL; |
64e7c440 SR |
2123 | |
2124 | func = strsep(&next, ":"); | |
2125 | ||
2126 | if (!next) { | |
2127 | ftrace_match_records(func, len, enable); | |
2128 | return 0; | |
2129 | } | |
2130 | ||
f6180773 | 2131 | /* command found */ |
64e7c440 SR |
2132 | |
2133 | command = strsep(&next, ":"); | |
2134 | ||
f6180773 SR |
2135 | mutex_lock(&ftrace_cmd_mutex); |
2136 | list_for_each_entry(p, &ftrace_commands, list) { | |
2137 | if (strcmp(p->name, command) == 0) { | |
2138 | ret = p->func(func, command, next, enable); | |
2139 | goto out_unlock; | |
2140 | } | |
64e7c440 | 2141 | } |
f6180773 SR |
2142 | out_unlock: |
2143 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 2144 | |
f6180773 | 2145 | return ret; |
64e7c440 SR |
2146 | } |
2147 | ||
e309b41d | 2148 | static ssize_t |
41c52c0d SR |
2149 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
2150 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
2151 | { |
2152 | struct ftrace_iterator *iter; | |
689fd8b6 | 2153 | struct trace_parser *parser; |
2154 | ssize_t ret, read; | |
5072c59f | 2155 | |
4ba7978e | 2156 | if (!cnt) |
5072c59f SR |
2157 | return 0; |
2158 | ||
41c52c0d | 2159 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
2160 | |
2161 | if (file->f_mode & FMODE_READ) { | |
2162 | struct seq_file *m = file->private_data; | |
2163 | iter = m->private; | |
2164 | } else | |
2165 | iter = file->private_data; | |
2166 | ||
689fd8b6 | 2167 | parser = &iter->parser; |
2168 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 2169 | |
4ba7978e | 2170 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 2171 | !trace_parser_cont(parser)) { |
2172 | ret = ftrace_process_regex(parser->buffer, | |
2173 | parser->idx, enable); | |
5072c59f SR |
2174 | if (ret) |
2175 | goto out; | |
5072c59f | 2176 | |
689fd8b6 | 2177 | trace_parser_clear(parser); |
eda1e328 | 2178 | } |
5072c59f | 2179 | |
5072c59f | 2180 | ret = read; |
5072c59f | 2181 | |
689fd8b6 | 2182 | mutex_unlock(&ftrace_regex_lock); |
2183 | out: | |
5072c59f SR |
2184 | return ret; |
2185 | } | |
2186 | ||
41c52c0d SR |
2187 | static ssize_t |
2188 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
2189 | size_t cnt, loff_t *ppos) | |
2190 | { | |
2191 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
2192 | } | |
2193 | ||
2194 | static ssize_t | |
2195 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
2196 | size_t cnt, loff_t *ppos) | |
2197 | { | |
2198 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
2199 | } | |
2200 | ||
2201 | static void | |
2202 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
2203 | { | |
2204 | if (unlikely(ftrace_disabled)) | |
2205 | return; | |
2206 | ||
2207 | mutex_lock(&ftrace_regex_lock); | |
2208 | if (reset) | |
2209 | ftrace_filter_reset(enable); | |
2210 | if (buf) | |
7f24b31b | 2211 | ftrace_match_records(buf, len, enable); |
41c52c0d SR |
2212 | mutex_unlock(&ftrace_regex_lock); |
2213 | } | |
2214 | ||
77a2b37d SR |
2215 | /** |
2216 | * ftrace_set_filter - set a function to filter on in ftrace | |
2217 | * @buf - the string that holds the function filter text. | |
2218 | * @len - the length of the string. | |
2219 | * @reset - non zero to reset all filters before applying this filter. | |
2220 | * | |
2221 | * Filters denote which functions should be enabled when tracing is enabled. | |
2222 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
2223 | */ | |
e309b41d | 2224 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 2225 | { |
41c52c0d SR |
2226 | ftrace_set_regex(buf, len, reset, 1); |
2227 | } | |
4eebcc81 | 2228 | |
41c52c0d SR |
2229 | /** |
2230 | * ftrace_set_notrace - set a function to not trace in ftrace | |
2231 | * @buf - the string that holds the function notrace text. | |
2232 | * @len - the length of the string. | |
2233 | * @reset - non zero to reset all filters before applying this filter. | |
2234 | * | |
2235 | * Notrace Filters denote which functions should not be enabled when tracing | |
2236 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
2237 | * for tracing. | |
2238 | */ | |
2239 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
2240 | { | |
2241 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
2242 | } |
2243 | ||
2af15d6a SR |
2244 | /* |
2245 | * command line interface to allow users to set filters on boot up. | |
2246 | */ | |
2247 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
2248 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
2249 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
369bc18f | 2250 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
2af15d6a SR |
2251 | |
2252 | static int __init set_ftrace_notrace(char *str) | |
2253 | { | |
2254 | strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); | |
2255 | return 1; | |
2256 | } | |
2257 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
2258 | ||
2259 | static int __init set_ftrace_filter(char *str) | |
2260 | { | |
2261 | strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); | |
2262 | return 1; | |
2263 | } | |
2264 | __setup("ftrace_filter=", set_ftrace_filter); | |
2265 | ||
369bc18f SA |
2266 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
2267 | static int __init set_graph_function(char *str) | |
2268 | { | |
2269 | strncpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); | |
2270 | return 1; | |
2271 | } | |
2272 | __setup("ftrace_graph_filter=", set_graph_function); | |
2273 | ||
2274 | static void __init set_ftrace_early_graph(char *buf) | |
2275 | { | |
2276 | int ret; | |
2277 | char *func; | |
2278 | ||
2279 | while (buf) { | |
2280 | func = strsep(&buf, ","); | |
2281 | /* we allow only one expression at a time */ | |
2282 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, | |
2283 | func); | |
2284 | if (ret) | |
2285 | printk(KERN_DEBUG "ftrace: function %s not " | |
2286 | "traceable\n", func); | |
2287 | } | |
2288 | } | |
2289 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2290 | ||
2af15d6a SR |
2291 | static void __init set_ftrace_early_filter(char *buf, int enable) |
2292 | { | |
2293 | char *func; | |
2294 | ||
2295 | while (buf) { | |
2296 | func = strsep(&buf, ","); | |
2297 | ftrace_set_regex(func, strlen(func), 0, enable); | |
2298 | } | |
2299 | } | |
2300 | ||
2301 | static void __init set_ftrace_early_filters(void) | |
2302 | { | |
2303 | if (ftrace_filter_buf[0]) | |
2304 | set_ftrace_early_filter(ftrace_filter_buf, 1); | |
2305 | if (ftrace_notrace_buf[0]) | |
2306 | set_ftrace_early_filter(ftrace_notrace_buf, 0); | |
369bc18f SA |
2307 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
2308 | if (ftrace_graph_buf[0]) | |
2309 | set_ftrace_early_graph(ftrace_graph_buf); | |
2310 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2af15d6a SR |
2311 | } |
2312 | ||
e309b41d | 2313 | static int |
41c52c0d | 2314 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
2315 | { |
2316 | struct seq_file *m = (struct seq_file *)file->private_data; | |
2317 | struct ftrace_iterator *iter; | |
689fd8b6 | 2318 | struct trace_parser *parser; |
5072c59f | 2319 | |
41c52c0d | 2320 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
2321 | if (file->f_mode & FMODE_READ) { |
2322 | iter = m->private; | |
2323 | ||
2324 | seq_release(inode, file); | |
2325 | } else | |
2326 | iter = file->private_data; | |
2327 | ||
689fd8b6 | 2328 | parser = &iter->parser; |
2329 | if (trace_parser_loaded(parser)) { | |
2330 | parser->buffer[parser->idx] = 0; | |
2331 | ftrace_match_records(parser->buffer, parser->idx, enable); | |
5072c59f SR |
2332 | } |
2333 | ||
e6ea44e9 | 2334 | mutex_lock(&ftrace_lock); |
ee02a2e5 | 2335 | if (ftrace_start_up && ftrace_enabled) |
5072c59f | 2336 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
e6ea44e9 | 2337 | mutex_unlock(&ftrace_lock); |
5072c59f | 2338 | |
689fd8b6 | 2339 | trace_parser_put(parser); |
5072c59f | 2340 | kfree(iter); |
689fd8b6 | 2341 | |
41c52c0d | 2342 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
2343 | return 0; |
2344 | } | |
2345 | ||
41c52c0d SR |
2346 | static int |
2347 | ftrace_filter_release(struct inode *inode, struct file *file) | |
2348 | { | |
2349 | return ftrace_regex_release(inode, file, 1); | |
2350 | } | |
2351 | ||
2352 | static int | |
2353 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
2354 | { | |
2355 | return ftrace_regex_release(inode, file, 0); | |
2356 | } | |
2357 | ||
5e2336a0 | 2358 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
2359 | .open = ftrace_avail_open, |
2360 | .read = seq_read, | |
2361 | .llseek = seq_lseek, | |
3be04b47 | 2362 | .release = seq_release_private, |
5072c59f SR |
2363 | }; |
2364 | ||
5e2336a0 | 2365 | static const struct file_operations ftrace_failures_fops = { |
eb9a7bf0 AS |
2366 | .open = ftrace_failures_open, |
2367 | .read = seq_read, | |
2368 | .llseek = seq_lseek, | |
3be04b47 | 2369 | .release = seq_release_private, |
eb9a7bf0 AS |
2370 | }; |
2371 | ||
5e2336a0 | 2372 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 2373 | .open = ftrace_filter_open, |
850a80cf | 2374 | .read = seq_read, |
5072c59f | 2375 | .write = ftrace_filter_write, |
41c52c0d | 2376 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
2377 | .release = ftrace_filter_release, |
2378 | }; | |
2379 | ||
5e2336a0 | 2380 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 2381 | .open = ftrace_notrace_open, |
850a80cf | 2382 | .read = seq_read, |
41c52c0d SR |
2383 | .write = ftrace_notrace_write, |
2384 | .llseek = ftrace_regex_lseek, | |
2385 | .release = ftrace_notrace_release, | |
2386 | }; | |
2387 | ||
ea4e2bc4 SR |
2388 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
2389 | ||
2390 | static DEFINE_MUTEX(graph_lock); | |
2391 | ||
2392 | int ftrace_graph_count; | |
2393 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; | |
2394 | ||
2395 | static void * | |
85951842 | 2396 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 2397 | { |
85951842 | 2398 | if (*pos >= ftrace_graph_count) |
ea4e2bc4 | 2399 | return NULL; |
a4ec5e0c | 2400 | return &ftrace_graph_funcs[*pos]; |
85951842 | 2401 | } |
ea4e2bc4 | 2402 | |
85951842 LZ |
2403 | static void * |
2404 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
2405 | { | |
2406 | (*pos)++; | |
2407 | return __g_next(m, pos); | |
ea4e2bc4 SR |
2408 | } |
2409 | ||
2410 | static void *g_start(struct seq_file *m, loff_t *pos) | |
2411 | { | |
ea4e2bc4 SR |
2412 | mutex_lock(&graph_lock); |
2413 | ||
f9349a8f FW |
2414 | /* Nothing, tell g_show to print all functions are enabled */ |
2415 | if (!ftrace_graph_count && !*pos) | |
2416 | return (void *)1; | |
2417 | ||
85951842 | 2418 | return __g_next(m, pos); |
ea4e2bc4 SR |
2419 | } |
2420 | ||
2421 | static void g_stop(struct seq_file *m, void *p) | |
2422 | { | |
2423 | mutex_unlock(&graph_lock); | |
2424 | } | |
2425 | ||
2426 | static int g_show(struct seq_file *m, void *v) | |
2427 | { | |
2428 | unsigned long *ptr = v; | |
ea4e2bc4 SR |
2429 | |
2430 | if (!ptr) | |
2431 | return 0; | |
2432 | ||
f9349a8f FW |
2433 | if (ptr == (unsigned long *)1) { |
2434 | seq_printf(m, "#### all functions enabled ####\n"); | |
2435 | return 0; | |
2436 | } | |
2437 | ||
b375a11a | 2438 | seq_printf(m, "%ps\n", (void *)*ptr); |
ea4e2bc4 SR |
2439 | |
2440 | return 0; | |
2441 | } | |
2442 | ||
88e9d34c | 2443 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
2444 | .start = g_start, |
2445 | .next = g_next, | |
2446 | .stop = g_stop, | |
2447 | .show = g_show, | |
2448 | }; | |
2449 | ||
2450 | static int | |
2451 | ftrace_graph_open(struct inode *inode, struct file *file) | |
2452 | { | |
2453 | int ret = 0; | |
2454 | ||
2455 | if (unlikely(ftrace_disabled)) | |
2456 | return -ENODEV; | |
2457 | ||
2458 | mutex_lock(&graph_lock); | |
2459 | if ((file->f_mode & FMODE_WRITE) && | |
8650ae32 | 2460 | (file->f_flags & O_TRUNC)) { |
ea4e2bc4 SR |
2461 | ftrace_graph_count = 0; |
2462 | memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); | |
2463 | } | |
a4ec5e0c | 2464 | mutex_unlock(&graph_lock); |
ea4e2bc4 | 2465 | |
a4ec5e0c | 2466 | if (file->f_mode & FMODE_READ) |
ea4e2bc4 | 2467 | ret = seq_open(file, &ftrace_graph_seq_ops); |
ea4e2bc4 SR |
2468 | |
2469 | return ret; | |
2470 | } | |
2471 | ||
87827111 LZ |
2472 | static int |
2473 | ftrace_graph_release(struct inode *inode, struct file *file) | |
2474 | { | |
2475 | if (file->f_mode & FMODE_READ) | |
2476 | seq_release(inode, file); | |
2477 | return 0; | |
2478 | } | |
2479 | ||
ea4e2bc4 | 2480 | static int |
f9349a8f | 2481 | ftrace_set_func(unsigned long *array, int *idx, char *buffer) |
ea4e2bc4 | 2482 | { |
ea4e2bc4 SR |
2483 | struct dyn_ftrace *rec; |
2484 | struct ftrace_page *pg; | |
f9349a8f | 2485 | int search_len; |
ea4e2bc4 | 2486 | int found = 0; |
f9349a8f FW |
2487 | int type, not; |
2488 | char *search; | |
2489 | bool exists; | |
2490 | int i; | |
ea4e2bc4 SR |
2491 | |
2492 | if (ftrace_disabled) | |
2493 | return -ENODEV; | |
2494 | ||
f9349a8f | 2495 | /* decode regex */ |
3f6fe06d | 2496 | type = filter_parse_regex(buffer, strlen(buffer), &search, ¬); |
f9349a8f FW |
2497 | if (not) |
2498 | return -EINVAL; | |
2499 | ||
2500 | search_len = strlen(search); | |
2501 | ||
52baf119 | 2502 | mutex_lock(&ftrace_lock); |
265c831c SR |
2503 | do_for_each_ftrace_rec(pg, rec) { |
2504 | ||
f9349a8f FW |
2505 | if (*idx >= FTRACE_GRAPH_MAX_FUNCS) |
2506 | break; | |
2507 | ||
265c831c SR |
2508 | if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE)) |
2509 | continue; | |
2510 | ||
f9349a8f FW |
2511 | if (ftrace_match_record(rec, search, search_len, type)) { |
2512 | /* ensure it is not already in the array */ | |
2513 | exists = false; | |
2514 | for (i = 0; i < *idx; i++) | |
2515 | if (array[i] == rec->ip) { | |
2516 | exists = true; | |
265c831c SR |
2517 | break; |
2518 | } | |
f9349a8f FW |
2519 | if (!exists) { |
2520 | array[(*idx)++] = rec->ip; | |
2521 | found = 1; | |
2522 | } | |
ea4e2bc4 | 2523 | } |
265c831c | 2524 | } while_for_each_ftrace_rec(); |
f9349a8f | 2525 | |
52baf119 | 2526 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 SR |
2527 | |
2528 | return found ? 0 : -EINVAL; | |
2529 | } | |
2530 | ||
2531 | static ssize_t | |
2532 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
2533 | size_t cnt, loff_t *ppos) | |
2534 | { | |
689fd8b6 | 2535 | struct trace_parser parser; |
4ba7978e | 2536 | ssize_t read, ret; |
ea4e2bc4 SR |
2537 | |
2538 | if (!cnt || cnt < 0) | |
2539 | return 0; | |
2540 | ||
2541 | mutex_lock(&graph_lock); | |
2542 | ||
2543 | if (ftrace_graph_count >= FTRACE_GRAPH_MAX_FUNCS) { | |
2544 | ret = -EBUSY; | |
1eb90f13 | 2545 | goto out_unlock; |
ea4e2bc4 SR |
2546 | } |
2547 | ||
689fd8b6 | 2548 | if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) { |
2549 | ret = -ENOMEM; | |
1eb90f13 | 2550 | goto out_unlock; |
ea4e2bc4 SR |
2551 | } |
2552 | ||
689fd8b6 | 2553 | read = trace_get_user(&parser, ubuf, cnt, ppos); |
ea4e2bc4 | 2554 | |
4ba7978e | 2555 | if (read >= 0 && trace_parser_loaded((&parser))) { |
689fd8b6 | 2556 | parser.buffer[parser.idx] = 0; |
2557 | ||
2558 | /* we allow only one expression at a time */ | |
a4ec5e0c | 2559 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, |
689fd8b6 | 2560 | parser.buffer); |
ea4e2bc4 | 2561 | if (ret) |
1eb90f13 | 2562 | goto out_free; |
ea4e2bc4 | 2563 | } |
ea4e2bc4 SR |
2564 | |
2565 | ret = read; | |
1eb90f13 LZ |
2566 | |
2567 | out_free: | |
689fd8b6 | 2568 | trace_parser_put(&parser); |
1eb90f13 | 2569 | out_unlock: |
ea4e2bc4 SR |
2570 | mutex_unlock(&graph_lock); |
2571 | ||
2572 | return ret; | |
2573 | } | |
2574 | ||
2575 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
2576 | .open = ftrace_graph_open, |
2577 | .read = seq_read, | |
2578 | .write = ftrace_graph_write, | |
2579 | .release = ftrace_graph_release, | |
ea4e2bc4 SR |
2580 | }; |
2581 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2582 | ||
df4fc315 | 2583 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 2584 | { |
5072c59f | 2585 | |
5452af66 FW |
2586 | trace_create_file("available_filter_functions", 0444, |
2587 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 2588 | |
5452af66 FW |
2589 | trace_create_file("failures", 0444, |
2590 | d_tracer, NULL, &ftrace_failures_fops); | |
eb9a7bf0 | 2591 | |
5452af66 FW |
2592 | trace_create_file("set_ftrace_filter", 0644, d_tracer, |
2593 | NULL, &ftrace_filter_fops); | |
41c52c0d | 2594 | |
5452af66 | 2595 | trace_create_file("set_ftrace_notrace", 0644, d_tracer, |
41c52c0d | 2596 | NULL, &ftrace_notrace_fops); |
ad90c0e3 | 2597 | |
ea4e2bc4 | 2598 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 2599 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
2600 | NULL, |
2601 | &ftrace_graph_fops); | |
ea4e2bc4 SR |
2602 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
2603 | ||
5072c59f SR |
2604 | return 0; |
2605 | } | |
2606 | ||
31e88909 SR |
2607 | static int ftrace_convert_nops(struct module *mod, |
2608 | unsigned long *start, | |
68bf21aa SR |
2609 | unsigned long *end) |
2610 | { | |
2611 | unsigned long *p; | |
2612 | unsigned long addr; | |
2613 | unsigned long flags; | |
2614 | ||
e6ea44e9 | 2615 | mutex_lock(&ftrace_lock); |
68bf21aa SR |
2616 | p = start; |
2617 | while (p < end) { | |
2618 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
2619 | /* |
2620 | * Some architecture linkers will pad between | |
2621 | * the different mcount_loc sections of different | |
2622 | * object files to satisfy alignments. | |
2623 | * Skip any NULL pointers. | |
2624 | */ | |
2625 | if (!addr) | |
2626 | continue; | |
68bf21aa | 2627 | ftrace_record_ip(addr); |
68bf21aa SR |
2628 | } |
2629 | ||
08f5ac90 | 2630 | /* disable interrupts to prevent kstop machine */ |
68bf21aa | 2631 | local_irq_save(flags); |
31e88909 | 2632 | ftrace_update_code(mod); |
68bf21aa | 2633 | local_irq_restore(flags); |
e6ea44e9 | 2634 | mutex_unlock(&ftrace_lock); |
68bf21aa SR |
2635 | |
2636 | return 0; | |
2637 | } | |
2638 | ||
93eb677d | 2639 | #ifdef CONFIG_MODULES |
e7247a15 | 2640 | void ftrace_release_mod(struct module *mod) |
93eb677d SR |
2641 | { |
2642 | struct dyn_ftrace *rec; | |
2643 | struct ftrace_page *pg; | |
93eb677d | 2644 | |
e7247a15 | 2645 | if (ftrace_disabled) |
93eb677d SR |
2646 | return; |
2647 | ||
2648 | mutex_lock(&ftrace_lock); | |
2649 | do_for_each_ftrace_rec(pg, rec) { | |
e7247a15 | 2650 | if (within_module_core(rec->ip, mod)) { |
93eb677d SR |
2651 | /* |
2652 | * rec->ip is changed in ftrace_free_rec() | |
2653 | * It should not between s and e if record was freed. | |
2654 | */ | |
2655 | FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE); | |
2656 | ftrace_free_rec(rec); | |
2657 | } | |
2658 | } while_for_each_ftrace_rec(); | |
2659 | mutex_unlock(&ftrace_lock); | |
2660 | } | |
2661 | ||
2662 | static void ftrace_init_module(struct module *mod, | |
2663 | unsigned long *start, unsigned long *end) | |
90d595fe | 2664 | { |
00fd61ae | 2665 | if (ftrace_disabled || start == end) |
fed1939c | 2666 | return; |
31e88909 | 2667 | ftrace_convert_nops(mod, start, end); |
90d595fe SR |
2668 | } |
2669 | ||
93eb677d SR |
2670 | static int ftrace_module_notify(struct notifier_block *self, |
2671 | unsigned long val, void *data) | |
2672 | { | |
2673 | struct module *mod = data; | |
2674 | ||
2675 | switch (val) { | |
2676 | case MODULE_STATE_COMING: | |
2677 | ftrace_init_module(mod, mod->ftrace_callsites, | |
2678 | mod->ftrace_callsites + | |
2679 | mod->num_ftrace_callsites); | |
2680 | break; | |
2681 | case MODULE_STATE_GOING: | |
e7247a15 | 2682 | ftrace_release_mod(mod); |
93eb677d SR |
2683 | break; |
2684 | } | |
2685 | ||
2686 | return 0; | |
2687 | } | |
2688 | #else | |
2689 | static int ftrace_module_notify(struct notifier_block *self, | |
2690 | unsigned long val, void *data) | |
2691 | { | |
2692 | return 0; | |
2693 | } | |
2694 | #endif /* CONFIG_MODULES */ | |
2695 | ||
2696 | struct notifier_block ftrace_module_nb = { | |
2697 | .notifier_call = ftrace_module_notify, | |
2698 | .priority = 0, | |
2699 | }; | |
2700 | ||
68bf21aa SR |
2701 | extern unsigned long __start_mcount_loc[]; |
2702 | extern unsigned long __stop_mcount_loc[]; | |
2703 | ||
2704 | void __init ftrace_init(void) | |
2705 | { | |
2706 | unsigned long count, addr, flags; | |
2707 | int ret; | |
2708 | ||
2709 | /* Keep the ftrace pointer to the stub */ | |
2710 | addr = (unsigned long)ftrace_stub; | |
2711 | ||
2712 | local_irq_save(flags); | |
2713 | ftrace_dyn_arch_init(&addr); | |
2714 | local_irq_restore(flags); | |
2715 | ||
2716 | /* ftrace_dyn_arch_init places the return code in addr */ | |
2717 | if (addr) | |
2718 | goto failed; | |
2719 | ||
2720 | count = __stop_mcount_loc - __start_mcount_loc; | |
2721 | ||
2722 | ret = ftrace_dyn_table_alloc(count); | |
2723 | if (ret) | |
2724 | goto failed; | |
2725 | ||
2726 | last_ftrace_enabled = ftrace_enabled = 1; | |
2727 | ||
31e88909 SR |
2728 | ret = ftrace_convert_nops(NULL, |
2729 | __start_mcount_loc, | |
68bf21aa SR |
2730 | __stop_mcount_loc); |
2731 | ||
93eb677d | 2732 | ret = register_module_notifier(&ftrace_module_nb); |
24ed0c4b | 2733 | if (ret) |
93eb677d SR |
2734 | pr_warning("Failed to register trace ftrace module notifier\n"); |
2735 | ||
2af15d6a SR |
2736 | set_ftrace_early_filters(); |
2737 | ||
68bf21aa SR |
2738 | return; |
2739 | failed: | |
2740 | ftrace_disabled = 1; | |
2741 | } | |
68bf21aa | 2742 | |
3d083395 | 2743 | #else |
0b6e4d56 FW |
2744 | |
2745 | static int __init ftrace_nodyn_init(void) | |
2746 | { | |
2747 | ftrace_enabled = 1; | |
2748 | return 0; | |
2749 | } | |
2750 | device_initcall(ftrace_nodyn_init); | |
2751 | ||
df4fc315 SR |
2752 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
2753 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 SR |
2754 | /* Keep as macros so we do not need to define the commands */ |
2755 | # define ftrace_startup(command) do { } while (0) | |
2756 | # define ftrace_shutdown(command) do { } while (0) | |
c7aafc54 IM |
2757 | # define ftrace_startup_sysctl() do { } while (0) |
2758 | # define ftrace_shutdown_sysctl() do { } while (0) | |
3d083395 SR |
2759 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
2760 | ||
df4fc315 SR |
2761 | static ssize_t |
2762 | ftrace_pid_read(struct file *file, char __user *ubuf, | |
2763 | size_t cnt, loff_t *ppos) | |
2764 | { | |
2765 | char buf[64]; | |
2766 | int r; | |
2767 | ||
e32d8956 SR |
2768 | if (ftrace_pid_trace == ftrace_swapper_pid) |
2769 | r = sprintf(buf, "swapper tasks\n"); | |
2770 | else if (ftrace_pid_trace) | |
cc59c9e8 | 2771 | r = sprintf(buf, "%u\n", pid_vnr(ftrace_pid_trace)); |
df4fc315 SR |
2772 | else |
2773 | r = sprintf(buf, "no pid\n"); | |
2774 | ||
2775 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
2776 | } | |
2777 | ||
e32d8956 | 2778 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
2779 | { |
2780 | struct task_struct *p; | |
e32d8956 | 2781 | int cpu; |
978f3a45 | 2782 | |
e32d8956 SR |
2783 | get_online_cpus(); |
2784 | for_each_online_cpu(cpu) { | |
2785 | p = idle_task(cpu); | |
978f3a45 | 2786 | clear_tsk_trace_trace(p); |
e32d8956 SR |
2787 | } |
2788 | put_online_cpus(); | |
2789 | } | |
978f3a45 | 2790 | |
e32d8956 SR |
2791 | static void set_ftrace_swapper(void) |
2792 | { | |
2793 | struct task_struct *p; | |
2794 | int cpu; | |
2795 | ||
2796 | get_online_cpus(); | |
2797 | for_each_online_cpu(cpu) { | |
2798 | p = idle_task(cpu); | |
2799 | set_tsk_trace_trace(p); | |
2800 | } | |
2801 | put_online_cpus(); | |
978f3a45 SR |
2802 | } |
2803 | ||
e32d8956 SR |
2804 | static void clear_ftrace_pid(struct pid *pid) |
2805 | { | |
2806 | struct task_struct *p; | |
2807 | ||
229c4ef8 | 2808 | rcu_read_lock(); |
e32d8956 SR |
2809 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2810 | clear_tsk_trace_trace(p); | |
2811 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
2812 | rcu_read_unlock(); |
2813 | ||
e32d8956 SR |
2814 | put_pid(pid); |
2815 | } | |
2816 | ||
2817 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
2818 | { |
2819 | struct task_struct *p; | |
2820 | ||
229c4ef8 | 2821 | rcu_read_lock(); |
978f3a45 SR |
2822 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2823 | set_tsk_trace_trace(p); | |
2824 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 2825 | rcu_read_unlock(); |
978f3a45 SR |
2826 | } |
2827 | ||
e32d8956 SR |
2828 | static void clear_ftrace_pid_task(struct pid **pid) |
2829 | { | |
2830 | if (*pid == ftrace_swapper_pid) | |
2831 | clear_ftrace_swapper(); | |
2832 | else | |
2833 | clear_ftrace_pid(*pid); | |
2834 | ||
2835 | *pid = NULL; | |
2836 | } | |
2837 | ||
2838 | static void set_ftrace_pid_task(struct pid *pid) | |
2839 | { | |
2840 | if (pid == ftrace_swapper_pid) | |
2841 | set_ftrace_swapper(); | |
2842 | else | |
2843 | set_ftrace_pid(pid); | |
2844 | } | |
2845 | ||
df4fc315 SR |
2846 | static ssize_t |
2847 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
2848 | size_t cnt, loff_t *ppos) | |
2849 | { | |
978f3a45 | 2850 | struct pid *pid; |
df4fc315 SR |
2851 | char buf[64]; |
2852 | long val; | |
2853 | int ret; | |
2854 | ||
2855 | if (cnt >= sizeof(buf)) | |
2856 | return -EINVAL; | |
2857 | ||
2858 | if (copy_from_user(&buf, ubuf, cnt)) | |
2859 | return -EFAULT; | |
2860 | ||
2861 | buf[cnt] = 0; | |
2862 | ||
2863 | ret = strict_strtol(buf, 10, &val); | |
2864 | if (ret < 0) | |
2865 | return ret; | |
2866 | ||
e6ea44e9 | 2867 | mutex_lock(&ftrace_lock); |
978f3a45 | 2868 | if (val < 0) { |
df4fc315 | 2869 | /* disable pid tracing */ |
978f3a45 | 2870 | if (!ftrace_pid_trace) |
df4fc315 | 2871 | goto out; |
978f3a45 SR |
2872 | |
2873 | clear_ftrace_pid_task(&ftrace_pid_trace); | |
df4fc315 SR |
2874 | |
2875 | } else { | |
e32d8956 SR |
2876 | /* swapper task is special */ |
2877 | if (!val) { | |
2878 | pid = ftrace_swapper_pid; | |
2879 | if (pid == ftrace_pid_trace) | |
2880 | goto out; | |
2881 | } else { | |
2882 | pid = find_get_pid(val); | |
df4fc315 | 2883 | |
e32d8956 SR |
2884 | if (pid == ftrace_pid_trace) { |
2885 | put_pid(pid); | |
2886 | goto out; | |
2887 | } | |
0ef8cde5 | 2888 | } |
0ef8cde5 | 2889 | |
978f3a45 SR |
2890 | if (ftrace_pid_trace) |
2891 | clear_ftrace_pid_task(&ftrace_pid_trace); | |
2892 | ||
2893 | if (!pid) | |
2894 | goto out; | |
2895 | ||
2896 | ftrace_pid_trace = pid; | |
2897 | ||
2898 | set_ftrace_pid_task(ftrace_pid_trace); | |
df4fc315 SR |
2899 | } |
2900 | ||
2901 | /* update the function call */ | |
2902 | ftrace_update_pid_func(); | |
2903 | ftrace_startup_enable(0); | |
2904 | ||
2905 | out: | |
e6ea44e9 | 2906 | mutex_unlock(&ftrace_lock); |
df4fc315 SR |
2907 | |
2908 | return cnt; | |
2909 | } | |
2910 | ||
5e2336a0 | 2911 | static const struct file_operations ftrace_pid_fops = { |
df4fc315 SR |
2912 | .read = ftrace_pid_read, |
2913 | .write = ftrace_pid_write, | |
2914 | }; | |
2915 | ||
2916 | static __init int ftrace_init_debugfs(void) | |
2917 | { | |
2918 | struct dentry *d_tracer; | |
df4fc315 SR |
2919 | |
2920 | d_tracer = tracing_init_dentry(); | |
2921 | if (!d_tracer) | |
2922 | return 0; | |
2923 | ||
2924 | ftrace_init_dyn_debugfs(d_tracer); | |
2925 | ||
5452af66 FW |
2926 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
2927 | NULL, &ftrace_pid_fops); | |
493762fc SR |
2928 | |
2929 | ftrace_profile_debugfs(d_tracer); | |
2930 | ||
df4fc315 SR |
2931 | return 0; |
2932 | } | |
df4fc315 SR |
2933 | fs_initcall(ftrace_init_debugfs); |
2934 | ||
a2bb6a3d | 2935 | /** |
81adbdc0 | 2936 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
2937 | * |
2938 | * This function should be used by panic code. It stops ftrace | |
2939 | * but in a not so nice way. If you need to simply kill ftrace | |
2940 | * from a non-atomic section, use ftrace_kill. | |
2941 | */ | |
81adbdc0 | 2942 | void ftrace_kill(void) |
a2bb6a3d SR |
2943 | { |
2944 | ftrace_disabled = 1; | |
2945 | ftrace_enabled = 0; | |
a2bb6a3d SR |
2946 | clear_ftrace_function(); |
2947 | } | |
2948 | ||
16444a8a | 2949 | /** |
3d083395 SR |
2950 | * register_ftrace_function - register a function for profiling |
2951 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 2952 | * |
3d083395 SR |
2953 | * Register a function to be called by all functions in the |
2954 | * kernel. | |
2955 | * | |
2956 | * Note: @ops->func and all the functions it calls must be labeled | |
2957 | * with "notrace", otherwise it will go into a | |
2958 | * recursive loop. | |
16444a8a | 2959 | */ |
3d083395 | 2960 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 2961 | { |
b0fc494f SR |
2962 | int ret; |
2963 | ||
4eebcc81 SR |
2964 | if (unlikely(ftrace_disabled)) |
2965 | return -1; | |
2966 | ||
e6ea44e9 | 2967 | mutex_lock(&ftrace_lock); |
e7d3737e | 2968 | |
b0fc494f | 2969 | ret = __register_ftrace_function(ops); |
5a45cfe1 | 2970 | ftrace_startup(0); |
b0fc494f | 2971 | |
e6ea44e9 | 2972 | mutex_unlock(&ftrace_lock); |
b0fc494f | 2973 | return ret; |
3d083395 SR |
2974 | } |
2975 | ||
2976 | /** | |
32632920 | 2977 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
2978 | * @ops - ops structure that holds the function to unregister |
2979 | * | |
2980 | * Unregister a function that was added to be called by ftrace profiling. | |
2981 | */ | |
2982 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
2983 | { | |
2984 | int ret; | |
2985 | ||
e6ea44e9 | 2986 | mutex_lock(&ftrace_lock); |
3d083395 | 2987 | ret = __unregister_ftrace_function(ops); |
5a45cfe1 | 2988 | ftrace_shutdown(0); |
e6ea44e9 | 2989 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
2990 | |
2991 | return ret; | |
2992 | } | |
2993 | ||
e309b41d | 2994 | int |
b0fc494f | 2995 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
8d65af78 | 2996 | void __user *buffer, size_t *lenp, |
b0fc494f SR |
2997 | loff_t *ppos) |
2998 | { | |
2999 | int ret; | |
3000 | ||
4eebcc81 SR |
3001 | if (unlikely(ftrace_disabled)) |
3002 | return -ENODEV; | |
3003 | ||
e6ea44e9 | 3004 | mutex_lock(&ftrace_lock); |
b0fc494f | 3005 | |
8d65af78 | 3006 | ret = proc_dointvec(table, write, buffer, lenp, ppos); |
b0fc494f | 3007 | |
a32c7765 | 3008 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
3009 | goto out; |
3010 | ||
a32c7765 | 3011 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f SR |
3012 | |
3013 | if (ftrace_enabled) { | |
3014 | ||
3015 | ftrace_startup_sysctl(); | |
3016 | ||
3017 | /* we are starting ftrace again */ | |
3018 | if (ftrace_list != &ftrace_list_end) { | |
3019 | if (ftrace_list->next == &ftrace_list_end) | |
3020 | ftrace_trace_function = ftrace_list->func; | |
3021 | else | |
3022 | ftrace_trace_function = ftrace_list_func; | |
3023 | } | |
3024 | ||
3025 | } else { | |
3026 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
3027 | ftrace_trace_function = ftrace_stub; | |
3028 | ||
3029 | ftrace_shutdown_sysctl(); | |
3030 | } | |
3031 | ||
3032 | out: | |
e6ea44e9 | 3033 | mutex_unlock(&ftrace_lock); |
3d083395 | 3034 | return ret; |
16444a8a | 3035 | } |
f17845e5 | 3036 | |
fb52607a | 3037 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 3038 | |
597af815 | 3039 | static int ftrace_graph_active; |
4a2b8dda | 3040 | static struct notifier_block ftrace_suspend_notifier; |
e7d3737e | 3041 | |
e49dc19c SR |
3042 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
3043 | { | |
3044 | return 0; | |
3045 | } | |
3046 | ||
287b6e68 FW |
3047 | /* The callbacks that hook a function */ |
3048 | trace_func_graph_ret_t ftrace_graph_return = | |
3049 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 3050 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
3051 | |
3052 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
3053 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
3054 | { | |
3055 | int i; | |
3056 | int ret = 0; | |
3057 | unsigned long flags; | |
3058 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
3059 | struct task_struct *g, *t; | |
3060 | ||
3061 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
3062 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
3063 | * sizeof(struct ftrace_ret_stack), | |
3064 | GFP_KERNEL); | |
3065 | if (!ret_stack_list[i]) { | |
3066 | start = 0; | |
3067 | end = i; | |
3068 | ret = -ENOMEM; | |
3069 | goto free; | |
3070 | } | |
3071 | } | |
3072 | ||
3073 | read_lock_irqsave(&tasklist_lock, flags); | |
3074 | do_each_thread(g, t) { | |
3075 | if (start == end) { | |
3076 | ret = -EAGAIN; | |
3077 | goto unlock; | |
3078 | } | |
3079 | ||
3080 | if (t->ret_stack == NULL) { | |
380c4b14 | 3081 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 3082 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
3083 | t->curr_ret_stack = -1; |
3084 | /* Make sure the tasks see the -1 first: */ | |
3085 | smp_wmb(); | |
3086 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
3087 | } |
3088 | } while_each_thread(g, t); | |
3089 | ||
3090 | unlock: | |
3091 | read_unlock_irqrestore(&tasklist_lock, flags); | |
3092 | free: | |
3093 | for (i = start; i < end; i++) | |
3094 | kfree(ret_stack_list[i]); | |
3095 | return ret; | |
3096 | } | |
3097 | ||
8aef2d28 SR |
3098 | static void |
3099 | ftrace_graph_probe_sched_switch(struct rq *__rq, struct task_struct *prev, | |
3100 | struct task_struct *next) | |
3101 | { | |
3102 | unsigned long long timestamp; | |
3103 | int index; | |
3104 | ||
be6f164a SR |
3105 | /* |
3106 | * Does the user want to count the time a function was asleep. | |
3107 | * If so, do not update the time stamps. | |
3108 | */ | |
3109 | if (trace_flags & TRACE_ITER_SLEEP_TIME) | |
3110 | return; | |
3111 | ||
8aef2d28 SR |
3112 | timestamp = trace_clock_local(); |
3113 | ||
3114 | prev->ftrace_timestamp = timestamp; | |
3115 | ||
3116 | /* only process tasks that we timestamped */ | |
3117 | if (!next->ftrace_timestamp) | |
3118 | return; | |
3119 | ||
3120 | /* | |
3121 | * Update all the counters in next to make up for the | |
3122 | * time next was sleeping. | |
3123 | */ | |
3124 | timestamp -= next->ftrace_timestamp; | |
3125 | ||
3126 | for (index = next->curr_ret_stack; index >= 0; index--) | |
3127 | next->ret_stack[index].calltime += timestamp; | |
3128 | } | |
3129 | ||
f201ae23 | 3130 | /* Allocate a return stack for each task */ |
fb52607a | 3131 | static int start_graph_tracing(void) |
f201ae23 FW |
3132 | { |
3133 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 3134 | int ret, cpu; |
f201ae23 FW |
3135 | |
3136 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
3137 | sizeof(struct ftrace_ret_stack *), | |
3138 | GFP_KERNEL); | |
3139 | ||
3140 | if (!ret_stack_list) | |
3141 | return -ENOMEM; | |
3142 | ||
5b058bcd | 3143 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
3144 | for_each_online_cpu(cpu) { |
3145 | if (!idle_task(cpu)->ret_stack) | |
3146 | ftrace_graph_init_task(idle_task(cpu)); | |
3147 | } | |
5b058bcd | 3148 | |
f201ae23 FW |
3149 | do { |
3150 | ret = alloc_retstack_tasklist(ret_stack_list); | |
3151 | } while (ret == -EAGAIN); | |
3152 | ||
8aef2d28 SR |
3153 | if (!ret) { |
3154 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch); | |
3155 | if (ret) | |
3156 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
3157 | " probe to kernel_sched_switch\n"); | |
3158 | } | |
3159 | ||
f201ae23 FW |
3160 | kfree(ret_stack_list); |
3161 | return ret; | |
3162 | } | |
3163 | ||
4a2b8dda FW |
3164 | /* |
3165 | * Hibernation protection. | |
3166 | * The state of the current task is too much unstable during | |
3167 | * suspend/restore to disk. We want to protect against that. | |
3168 | */ | |
3169 | static int | |
3170 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
3171 | void *unused) | |
3172 | { | |
3173 | switch (state) { | |
3174 | case PM_HIBERNATION_PREPARE: | |
3175 | pause_graph_tracing(); | |
3176 | break; | |
3177 | ||
3178 | case PM_POST_HIBERNATION: | |
3179 | unpause_graph_tracing(); | |
3180 | break; | |
3181 | } | |
3182 | return NOTIFY_DONE; | |
3183 | } | |
3184 | ||
287b6e68 FW |
3185 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
3186 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 3187 | { |
e7d3737e FW |
3188 | int ret = 0; |
3189 | ||
e6ea44e9 | 3190 | mutex_lock(&ftrace_lock); |
e7d3737e | 3191 | |
05ce5818 | 3192 | /* we currently allow only one tracer registered at a time */ |
597af815 | 3193 | if (ftrace_graph_active) { |
05ce5818 SR |
3194 | ret = -EBUSY; |
3195 | goto out; | |
3196 | } | |
3197 | ||
4a2b8dda FW |
3198 | ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; |
3199 | register_pm_notifier(&ftrace_suspend_notifier); | |
3200 | ||
597af815 | 3201 | ftrace_graph_active++; |
fb52607a | 3202 | ret = start_graph_tracing(); |
f201ae23 | 3203 | if (ret) { |
597af815 | 3204 | ftrace_graph_active--; |
f201ae23 FW |
3205 | goto out; |
3206 | } | |
e53a6319 | 3207 | |
287b6e68 FW |
3208 | ftrace_graph_return = retfunc; |
3209 | ftrace_graph_entry = entryfunc; | |
e53a6319 | 3210 | |
5a45cfe1 | 3211 | ftrace_startup(FTRACE_START_FUNC_RET); |
e7d3737e FW |
3212 | |
3213 | out: | |
e6ea44e9 | 3214 | mutex_unlock(&ftrace_lock); |
e7d3737e | 3215 | return ret; |
15e6cb36 FW |
3216 | } |
3217 | ||
fb52607a | 3218 | void unregister_ftrace_graph(void) |
15e6cb36 | 3219 | { |
e6ea44e9 | 3220 | mutex_lock(&ftrace_lock); |
e7d3737e | 3221 | |
597af815 | 3222 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
3223 | goto out; |
3224 | ||
597af815 | 3225 | ftrace_graph_active--; |
8aef2d28 | 3226 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch); |
287b6e68 | 3227 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 3228 | ftrace_graph_entry = ftrace_graph_entry_stub; |
5a45cfe1 | 3229 | ftrace_shutdown(FTRACE_STOP_FUNC_RET); |
4a2b8dda | 3230 | unregister_pm_notifier(&ftrace_suspend_notifier); |
e7d3737e | 3231 | |
2aad1b76 | 3232 | out: |
e6ea44e9 | 3233 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 3234 | } |
f201ae23 FW |
3235 | |
3236 | /* Allocate a return stack for newly created task */ | |
fb52607a | 3237 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 3238 | { |
84047e36 SR |
3239 | /* Make sure we do not use the parent ret_stack */ |
3240 | t->ret_stack = NULL; | |
3241 | ||
597af815 | 3242 | if (ftrace_graph_active) { |
82310a32 SR |
3243 | struct ftrace_ret_stack *ret_stack; |
3244 | ||
3245 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
3246 | * sizeof(struct ftrace_ret_stack), |
3247 | GFP_KERNEL); | |
82310a32 | 3248 | if (!ret_stack) |
f201ae23 FW |
3249 | return; |
3250 | t->curr_ret_stack = -1; | |
380c4b14 | 3251 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 3252 | atomic_set(&t->trace_overrun, 0); |
8aef2d28 | 3253 | t->ftrace_timestamp = 0; |
82310a32 SR |
3254 | /* make curr_ret_stack visable before we add the ret_stack */ |
3255 | smp_wmb(); | |
3256 | t->ret_stack = ret_stack; | |
84047e36 | 3257 | } |
f201ae23 FW |
3258 | } |
3259 | ||
fb52607a | 3260 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 3261 | { |
eae849ca FW |
3262 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
3263 | ||
f201ae23 | 3264 | t->ret_stack = NULL; |
eae849ca FW |
3265 | /* NULL must become visible to IRQs before we free it: */ |
3266 | barrier(); | |
3267 | ||
3268 | kfree(ret_stack); | |
f201ae23 | 3269 | } |
14a866c5 SR |
3270 | |
3271 | void ftrace_graph_stop(void) | |
3272 | { | |
3273 | ftrace_stop(); | |
3274 | } | |
15e6cb36 FW |
3275 | #endif |
3276 |