Commit | Line | Data |
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16444a8a ACM |
1 | /* |
2 | * Infrastructure for profiling code inserted by 'gcc -pg'. | |
3 | * | |
4 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> | |
5 | * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com> | |
6 | * | |
7 | * Originally ported from the -rt patch by: | |
8 | * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com> | |
9 | * | |
10 | * Based on code in the latency_tracer, that is: | |
11 | * | |
12 | * Copyright (C) 2004-2006 Ingo Molnar | |
13 | * Copyright (C) 2004 William Lee Irwin III | |
14 | */ | |
15 | ||
3d083395 SR |
16 | #include <linux/stop_machine.h> |
17 | #include <linux/clocksource.h> | |
18 | #include <linux/kallsyms.h> | |
5072c59f | 19 | #include <linux/seq_file.h> |
4a2b8dda | 20 | #include <linux/suspend.h> |
5072c59f | 21 | #include <linux/debugfs.h> |
3d083395 | 22 | #include <linux/hardirq.h> |
2d8b820b | 23 | #include <linux/kthread.h> |
5072c59f | 24 | #include <linux/uaccess.h> |
f22f9a89 | 25 | #include <linux/kprobes.h> |
2d8b820b | 26 | #include <linux/ftrace.h> |
b0fc494f | 27 | #include <linux/sysctl.h> |
5072c59f | 28 | #include <linux/ctype.h> |
3d083395 | 29 | #include <linux/list.h> |
59df055f | 30 | #include <linux/hash.h> |
3d083395 | 31 | |
ad8d75ff | 32 | #include <trace/events/sched.h> |
8aef2d28 | 33 | |
395a59d0 | 34 | #include <asm/ftrace.h> |
2af15d6a | 35 | #include <asm/setup.h> |
395a59d0 | 36 | |
0706f1c4 | 37 | #include "trace_output.h" |
bac429f0 | 38 | #include "trace_stat.h" |
16444a8a | 39 | |
6912896e SR |
40 | #define FTRACE_WARN_ON(cond) \ |
41 | do { \ | |
42 | if (WARN_ON(cond)) \ | |
43 | ftrace_kill(); \ | |
44 | } while (0) | |
45 | ||
46 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
47 | do { \ | |
48 | if (WARN_ON_ONCE(cond)) \ | |
49 | ftrace_kill(); \ | |
50 | } while (0) | |
51 | ||
8fc0c701 SR |
52 | /* hash bits for specific function selection */ |
53 | #define FTRACE_HASH_BITS 7 | |
54 | #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS) | |
55 | ||
4eebcc81 SR |
56 | /* ftrace_enabled is a method to turn ftrace on or off */ |
57 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 58 | static int last_ftrace_enabled; |
b0fc494f | 59 | |
60a7ecf4 SR |
60 | /* Quick disabling of function tracer. */ |
61 | int function_trace_stop; | |
62 | ||
4eebcc81 SR |
63 | /* |
64 | * ftrace_disabled is set when an anomaly is discovered. | |
65 | * ftrace_disabled is much stronger than ftrace_enabled. | |
66 | */ | |
67 | static int ftrace_disabled __read_mostly; | |
68 | ||
52baf119 | 69 | static DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 70 | |
16444a8a ACM |
71 | static struct ftrace_ops ftrace_list_end __read_mostly = |
72 | { | |
fb9fb015 | 73 | .func = ftrace_stub, |
16444a8a ACM |
74 | }; |
75 | ||
76 | static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; | |
77 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; | |
60a7ecf4 | 78 | ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub; |
df4fc315 | 79 | ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; |
16444a8a | 80 | |
f2252935 | 81 | static void ftrace_list_func(unsigned long ip, unsigned long parent_ip) |
16444a8a ACM |
82 | { |
83 | struct ftrace_ops *op = ftrace_list; | |
84 | ||
85 | /* in case someone actually ports this to alpha! */ | |
86 | read_barrier_depends(); | |
87 | ||
88 | while (op != &ftrace_list_end) { | |
89 | /* silly alpha */ | |
90 | read_barrier_depends(); | |
91 | op->func(ip, parent_ip); | |
92 | op = op->next; | |
93 | }; | |
94 | } | |
95 | ||
df4fc315 SR |
96 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip) |
97 | { | |
0ef8cde5 | 98 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
99 | return; |
100 | ||
101 | ftrace_pid_function(ip, parent_ip); | |
102 | } | |
103 | ||
104 | static void set_ftrace_pid_function(ftrace_func_t func) | |
105 | { | |
106 | /* do not set ftrace_pid_function to itself! */ | |
107 | if (func != ftrace_pid_func) | |
108 | ftrace_pid_function = func; | |
109 | } | |
110 | ||
16444a8a | 111 | /** |
3d083395 | 112 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 113 | * |
3d083395 SR |
114 | * This NULLs the ftrace function and in essence stops |
115 | * tracing. There may be lag | |
16444a8a | 116 | */ |
3d083395 | 117 | void clear_ftrace_function(void) |
16444a8a | 118 | { |
3d083395 | 119 | ftrace_trace_function = ftrace_stub; |
60a7ecf4 | 120 | __ftrace_trace_function = ftrace_stub; |
df4fc315 | 121 | ftrace_pid_function = ftrace_stub; |
3d083395 SR |
122 | } |
123 | ||
60a7ecf4 SR |
124 | #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
125 | /* | |
126 | * For those archs that do not test ftrace_trace_stop in their | |
127 | * mcount call site, we need to do it from C. | |
128 | */ | |
129 | static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip) | |
130 | { | |
131 | if (function_trace_stop) | |
132 | return; | |
133 | ||
134 | __ftrace_trace_function(ip, parent_ip); | |
135 | } | |
136 | #endif | |
137 | ||
e309b41d | 138 | static int __register_ftrace_function(struct ftrace_ops *ops) |
3d083395 | 139 | { |
16444a8a ACM |
140 | ops->next = ftrace_list; |
141 | /* | |
142 | * We are entering ops into the ftrace_list but another | |
143 | * CPU might be walking that list. We need to make sure | |
144 | * the ops->next pointer is valid before another CPU sees | |
145 | * the ops pointer included into the ftrace_list. | |
146 | */ | |
147 | smp_wmb(); | |
148 | ftrace_list = ops; | |
3d083395 | 149 | |
b0fc494f | 150 | if (ftrace_enabled) { |
df4fc315 SR |
151 | ftrace_func_t func; |
152 | ||
153 | if (ops->next == &ftrace_list_end) | |
154 | func = ops->func; | |
155 | else | |
156 | func = ftrace_list_func; | |
157 | ||
978f3a45 | 158 | if (ftrace_pid_trace) { |
df4fc315 SR |
159 | set_ftrace_pid_function(func); |
160 | func = ftrace_pid_func; | |
161 | } | |
162 | ||
b0fc494f SR |
163 | /* |
164 | * For one func, simply call it directly. | |
165 | * For more than one func, call the chain. | |
166 | */ | |
60a7ecf4 | 167 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
df4fc315 | 168 | ftrace_trace_function = func; |
60a7ecf4 | 169 | #else |
df4fc315 | 170 | __ftrace_trace_function = func; |
60a7ecf4 SR |
171 | ftrace_trace_function = ftrace_test_stop_func; |
172 | #endif | |
b0fc494f | 173 | } |
3d083395 | 174 | |
16444a8a ACM |
175 | return 0; |
176 | } | |
177 | ||
e309b41d | 178 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 179 | { |
16444a8a | 180 | struct ftrace_ops **p; |
16444a8a ACM |
181 | |
182 | /* | |
3d083395 SR |
183 | * If we are removing the last function, then simply point |
184 | * to the ftrace_stub. | |
16444a8a ACM |
185 | */ |
186 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { | |
187 | ftrace_trace_function = ftrace_stub; | |
188 | ftrace_list = &ftrace_list_end; | |
e6ea44e9 | 189 | return 0; |
16444a8a ACM |
190 | } |
191 | ||
192 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) | |
193 | if (*p == ops) | |
194 | break; | |
195 | ||
e6ea44e9 SR |
196 | if (*p != ops) |
197 | return -1; | |
16444a8a ACM |
198 | |
199 | *p = (*p)->next; | |
200 | ||
b0fc494f SR |
201 | if (ftrace_enabled) { |
202 | /* If we only have one func left, then call that directly */ | |
df4fc315 SR |
203 | if (ftrace_list->next == &ftrace_list_end) { |
204 | ftrace_func_t func = ftrace_list->func; | |
205 | ||
978f3a45 | 206 | if (ftrace_pid_trace) { |
df4fc315 SR |
207 | set_ftrace_pid_function(func); |
208 | func = ftrace_pid_func; | |
209 | } | |
210 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
211 | ftrace_trace_function = func; | |
212 | #else | |
213 | __ftrace_trace_function = func; | |
214 | #endif | |
215 | } | |
b0fc494f | 216 | } |
16444a8a | 217 | |
e6ea44e9 | 218 | return 0; |
3d083395 SR |
219 | } |
220 | ||
df4fc315 SR |
221 | static void ftrace_update_pid_func(void) |
222 | { | |
223 | ftrace_func_t func; | |
224 | ||
df4fc315 | 225 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 226 | return; |
df4fc315 | 227 | |
33974093 | 228 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
df4fc315 | 229 | func = ftrace_trace_function; |
33974093 MF |
230 | #else |
231 | func = __ftrace_trace_function; | |
232 | #endif | |
df4fc315 | 233 | |
978f3a45 | 234 | if (ftrace_pid_trace) { |
df4fc315 SR |
235 | set_ftrace_pid_function(func); |
236 | func = ftrace_pid_func; | |
237 | } else { | |
66eafebc LW |
238 | if (func == ftrace_pid_func) |
239 | func = ftrace_pid_function; | |
df4fc315 SR |
240 | } |
241 | ||
242 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
243 | ftrace_trace_function = func; | |
244 | #else | |
245 | __ftrace_trace_function = func; | |
246 | #endif | |
df4fc315 SR |
247 | } |
248 | ||
493762fc SR |
249 | #ifdef CONFIG_FUNCTION_PROFILER |
250 | struct ftrace_profile { | |
251 | struct hlist_node node; | |
252 | unsigned long ip; | |
253 | unsigned long counter; | |
0706f1c4 SR |
254 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
255 | unsigned long long time; | |
256 | #endif | |
8fc0c701 SR |
257 | }; |
258 | ||
493762fc SR |
259 | struct ftrace_profile_page { |
260 | struct ftrace_profile_page *next; | |
261 | unsigned long index; | |
262 | struct ftrace_profile records[]; | |
d61f82d0 SR |
263 | }; |
264 | ||
cafb168a SR |
265 | struct ftrace_profile_stat { |
266 | atomic_t disabled; | |
267 | struct hlist_head *hash; | |
268 | struct ftrace_profile_page *pages; | |
269 | struct ftrace_profile_page *start; | |
270 | struct tracer_stat stat; | |
271 | }; | |
272 | ||
493762fc SR |
273 | #define PROFILE_RECORDS_SIZE \ |
274 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 275 | |
493762fc SR |
276 | #define PROFILES_PER_PAGE \ |
277 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 278 | |
fb9fb015 SR |
279 | static int ftrace_profile_bits __read_mostly; |
280 | static int ftrace_profile_enabled __read_mostly; | |
281 | ||
282 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
283 | static DEFINE_MUTEX(ftrace_profile_lock); |
284 | ||
cafb168a | 285 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc SR |
286 | |
287 | #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */ | |
288 | ||
bac429f0 SR |
289 | static void * |
290 | function_stat_next(void *v, int idx) | |
291 | { | |
493762fc SR |
292 | struct ftrace_profile *rec = v; |
293 | struct ftrace_profile_page *pg; | |
bac429f0 | 294 | |
493762fc | 295 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
296 | |
297 | again: | |
0296e425 LZ |
298 | if (idx != 0) |
299 | rec++; | |
300 | ||
bac429f0 SR |
301 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
302 | pg = pg->next; | |
303 | if (!pg) | |
304 | return NULL; | |
305 | rec = &pg->records[0]; | |
493762fc SR |
306 | if (!rec->counter) |
307 | goto again; | |
bac429f0 SR |
308 | } |
309 | ||
bac429f0 SR |
310 | return rec; |
311 | } | |
312 | ||
313 | static void *function_stat_start(struct tracer_stat *trace) | |
314 | { | |
cafb168a SR |
315 | struct ftrace_profile_stat *stat = |
316 | container_of(trace, struct ftrace_profile_stat, stat); | |
317 | ||
318 | if (!stat || !stat->start) | |
319 | return NULL; | |
320 | ||
321 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
322 | } |
323 | ||
0706f1c4 SR |
324 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
325 | /* function graph compares on total time */ | |
326 | static int function_stat_cmp(void *p1, void *p2) | |
327 | { | |
328 | struct ftrace_profile *a = p1; | |
329 | struct ftrace_profile *b = p2; | |
330 | ||
331 | if (a->time < b->time) | |
332 | return -1; | |
333 | if (a->time > b->time) | |
334 | return 1; | |
335 | else | |
336 | return 0; | |
337 | } | |
338 | #else | |
339 | /* not function graph compares against hits */ | |
bac429f0 SR |
340 | static int function_stat_cmp(void *p1, void *p2) |
341 | { | |
493762fc SR |
342 | struct ftrace_profile *a = p1; |
343 | struct ftrace_profile *b = p2; | |
bac429f0 SR |
344 | |
345 | if (a->counter < b->counter) | |
346 | return -1; | |
347 | if (a->counter > b->counter) | |
348 | return 1; | |
349 | else | |
350 | return 0; | |
351 | } | |
0706f1c4 | 352 | #endif |
bac429f0 SR |
353 | |
354 | static int function_stat_headers(struct seq_file *m) | |
355 | { | |
0706f1c4 | 356 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
357 | seq_printf(m, " Function " |
358 | "Hit Time Avg\n" | |
359 | " -------- " | |
360 | "--- ---- ---\n"); | |
0706f1c4 | 361 | #else |
bac429f0 SR |
362 | seq_printf(m, " Function Hit\n" |
363 | " -------- ---\n"); | |
0706f1c4 | 364 | #endif |
bac429f0 SR |
365 | return 0; |
366 | } | |
367 | ||
368 | static int function_stat_show(struct seq_file *m, void *v) | |
369 | { | |
493762fc | 370 | struct ftrace_profile *rec = v; |
bac429f0 | 371 | char str[KSYM_SYMBOL_LEN]; |
0706f1c4 | 372 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
0706f1c4 | 373 | static DEFINE_MUTEX(mutex); |
34886c8b SR |
374 | static struct trace_seq s; |
375 | unsigned long long avg; | |
0706f1c4 | 376 | #endif |
bac429f0 SR |
377 | |
378 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
0706f1c4 SR |
379 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
380 | ||
381 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
382 | seq_printf(m, " "); | |
34886c8b SR |
383 | avg = rec->time; |
384 | do_div(avg, rec->counter); | |
385 | ||
386 | mutex_lock(&mutex); | |
387 | trace_seq_init(&s); | |
388 | trace_print_graph_duration(rec->time, &s); | |
389 | trace_seq_puts(&s, " "); | |
390 | trace_print_graph_duration(avg, &s); | |
0706f1c4 SR |
391 | trace_print_seq(m, &s); |
392 | mutex_unlock(&mutex); | |
393 | #endif | |
394 | seq_putc(m, '\n'); | |
bac429f0 | 395 | |
bac429f0 SR |
396 | return 0; |
397 | } | |
398 | ||
cafb168a | 399 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 400 | { |
493762fc | 401 | struct ftrace_profile_page *pg; |
bac429f0 | 402 | |
cafb168a | 403 | pg = stat->pages = stat->start; |
bac429f0 | 404 | |
493762fc SR |
405 | while (pg) { |
406 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
407 | pg->index = 0; | |
408 | pg = pg->next; | |
bac429f0 SR |
409 | } |
410 | ||
cafb168a | 411 | memset(stat->hash, 0, |
493762fc SR |
412 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
413 | } | |
bac429f0 | 414 | |
cafb168a | 415 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
416 | { |
417 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
418 | int functions; |
419 | int pages; | |
493762fc | 420 | int i; |
bac429f0 | 421 | |
493762fc | 422 | /* If we already allocated, do nothing */ |
cafb168a | 423 | if (stat->pages) |
493762fc | 424 | return 0; |
bac429f0 | 425 | |
cafb168a SR |
426 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
427 | if (!stat->pages) | |
493762fc | 428 | return -ENOMEM; |
bac429f0 | 429 | |
318e0a73 SR |
430 | #ifdef CONFIG_DYNAMIC_FTRACE |
431 | functions = ftrace_update_tot_cnt; | |
432 | #else | |
433 | /* | |
434 | * We do not know the number of functions that exist because | |
435 | * dynamic tracing is what counts them. With past experience | |
436 | * we have around 20K functions. That should be more than enough. | |
437 | * It is highly unlikely we will execute every function in | |
438 | * the kernel. | |
439 | */ | |
440 | functions = 20000; | |
441 | #endif | |
442 | ||
cafb168a | 443 | pg = stat->start = stat->pages; |
bac429f0 | 444 | |
318e0a73 SR |
445 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
446 | ||
447 | for (i = 0; i < pages; i++) { | |
493762fc | 448 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 449 | if (!pg->next) |
318e0a73 | 450 | goto out_free; |
493762fc SR |
451 | pg = pg->next; |
452 | } | |
453 | ||
454 | return 0; | |
318e0a73 SR |
455 | |
456 | out_free: | |
457 | pg = stat->start; | |
458 | while (pg) { | |
459 | unsigned long tmp = (unsigned long)pg; | |
460 | ||
461 | pg = pg->next; | |
462 | free_page(tmp); | |
463 | } | |
464 | ||
465 | free_page((unsigned long)stat->pages); | |
466 | stat->pages = NULL; | |
467 | stat->start = NULL; | |
468 | ||
469 | return -ENOMEM; | |
bac429f0 SR |
470 | } |
471 | ||
cafb168a | 472 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 473 | { |
cafb168a | 474 | struct ftrace_profile_stat *stat; |
493762fc | 475 | int size; |
bac429f0 | 476 | |
cafb168a SR |
477 | stat = &per_cpu(ftrace_profile_stats, cpu); |
478 | ||
479 | if (stat->hash) { | |
493762fc | 480 | /* If the profile is already created, simply reset it */ |
cafb168a | 481 | ftrace_profile_reset(stat); |
493762fc SR |
482 | return 0; |
483 | } | |
bac429f0 | 484 | |
493762fc SR |
485 | /* |
486 | * We are profiling all functions, but usually only a few thousand | |
487 | * functions are hit. We'll make a hash of 1024 items. | |
488 | */ | |
489 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 490 | |
cafb168a | 491 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
493762fc | 492 | |
cafb168a | 493 | if (!stat->hash) |
493762fc SR |
494 | return -ENOMEM; |
495 | ||
cafb168a SR |
496 | if (!ftrace_profile_bits) { |
497 | size--; | |
493762fc | 498 | |
cafb168a SR |
499 | for (; size; size >>= 1) |
500 | ftrace_profile_bits++; | |
501 | } | |
493762fc | 502 | |
318e0a73 | 503 | /* Preallocate the function profiling pages */ |
cafb168a SR |
504 | if (ftrace_profile_pages_init(stat) < 0) { |
505 | kfree(stat->hash); | |
506 | stat->hash = NULL; | |
493762fc SR |
507 | return -ENOMEM; |
508 | } | |
509 | ||
510 | return 0; | |
bac429f0 SR |
511 | } |
512 | ||
cafb168a SR |
513 | static int ftrace_profile_init(void) |
514 | { | |
515 | int cpu; | |
516 | int ret = 0; | |
517 | ||
518 | for_each_online_cpu(cpu) { | |
519 | ret = ftrace_profile_init_cpu(cpu); | |
520 | if (ret) | |
521 | break; | |
522 | } | |
523 | ||
524 | return ret; | |
525 | } | |
526 | ||
493762fc | 527 | /* interrupts must be disabled */ |
cafb168a SR |
528 | static struct ftrace_profile * |
529 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 530 | { |
493762fc | 531 | struct ftrace_profile *rec; |
bac429f0 SR |
532 | struct hlist_head *hhd; |
533 | struct hlist_node *n; | |
bac429f0 SR |
534 | unsigned long key; |
535 | ||
bac429f0 | 536 | key = hash_long(ip, ftrace_profile_bits); |
cafb168a | 537 | hhd = &stat->hash[key]; |
bac429f0 SR |
538 | |
539 | if (hlist_empty(hhd)) | |
540 | return NULL; | |
541 | ||
bac429f0 SR |
542 | hlist_for_each_entry_rcu(rec, n, hhd, node) { |
543 | if (rec->ip == ip) | |
493762fc SR |
544 | return rec; |
545 | } | |
546 | ||
547 | return NULL; | |
548 | } | |
549 | ||
cafb168a SR |
550 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
551 | struct ftrace_profile *rec) | |
493762fc SR |
552 | { |
553 | unsigned long key; | |
554 | ||
555 | key = hash_long(rec->ip, ftrace_profile_bits); | |
cafb168a | 556 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
557 | } |
558 | ||
318e0a73 SR |
559 | /* |
560 | * The memory is already allocated, this simply finds a new record to use. | |
561 | */ | |
493762fc | 562 | static struct ftrace_profile * |
318e0a73 | 563 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
564 | { |
565 | struct ftrace_profile *rec = NULL; | |
566 | ||
318e0a73 | 567 | /* prevent recursion (from NMIs) */ |
cafb168a | 568 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
569 | goto out; |
570 | ||
493762fc | 571 | /* |
318e0a73 SR |
572 | * Try to find the function again since an NMI |
573 | * could have added it | |
493762fc | 574 | */ |
cafb168a | 575 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 576 | if (rec) |
cafb168a | 577 | goto out; |
493762fc | 578 | |
cafb168a SR |
579 | if (stat->pages->index == PROFILES_PER_PAGE) { |
580 | if (!stat->pages->next) | |
581 | goto out; | |
582 | stat->pages = stat->pages->next; | |
bac429f0 | 583 | } |
493762fc | 584 | |
cafb168a | 585 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 586 | rec->ip = ip; |
cafb168a | 587 | ftrace_add_profile(stat, rec); |
493762fc | 588 | |
bac429f0 | 589 | out: |
cafb168a | 590 | atomic_dec(&stat->disabled); |
bac429f0 SR |
591 | |
592 | return rec; | |
593 | } | |
594 | ||
595 | static void | |
596 | function_profile_call(unsigned long ip, unsigned long parent_ip) | |
597 | { | |
cafb168a | 598 | struct ftrace_profile_stat *stat; |
493762fc | 599 | struct ftrace_profile *rec; |
bac429f0 SR |
600 | unsigned long flags; |
601 | ||
602 | if (!ftrace_profile_enabled) | |
603 | return; | |
604 | ||
605 | local_irq_save(flags); | |
cafb168a SR |
606 | |
607 | stat = &__get_cpu_var(ftrace_profile_stats); | |
0f6ce3de | 608 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
609 | goto out; |
610 | ||
611 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 612 | if (!rec) { |
318e0a73 | 613 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
614 | if (!rec) |
615 | goto out; | |
616 | } | |
bac429f0 SR |
617 | |
618 | rec->counter++; | |
619 | out: | |
620 | local_irq_restore(flags); | |
621 | } | |
622 | ||
0706f1c4 SR |
623 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
624 | static int profile_graph_entry(struct ftrace_graph_ent *trace) | |
625 | { | |
626 | function_profile_call(trace->func, 0); | |
627 | return 1; | |
628 | } | |
629 | ||
630 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
631 | { | |
cafb168a | 632 | struct ftrace_profile_stat *stat; |
a2a16d6a | 633 | unsigned long long calltime; |
0706f1c4 | 634 | struct ftrace_profile *rec; |
cafb168a | 635 | unsigned long flags; |
0706f1c4 SR |
636 | |
637 | local_irq_save(flags); | |
cafb168a | 638 | stat = &__get_cpu_var(ftrace_profile_stats); |
0f6ce3de | 639 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
640 | goto out; |
641 | ||
a2a16d6a SR |
642 | calltime = trace->rettime - trace->calltime; |
643 | ||
644 | if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) { | |
645 | int index; | |
646 | ||
647 | index = trace->depth; | |
648 | ||
649 | /* Append this call time to the parent time to subtract */ | |
650 | if (index) | |
651 | current->ret_stack[index - 1].subtime += calltime; | |
652 | ||
653 | if (current->ret_stack[index].subtime < calltime) | |
654 | calltime -= current->ret_stack[index].subtime; | |
655 | else | |
656 | calltime = 0; | |
657 | } | |
658 | ||
cafb168a | 659 | rec = ftrace_find_profiled_func(stat, trace->func); |
0706f1c4 | 660 | if (rec) |
a2a16d6a SR |
661 | rec->time += calltime; |
662 | ||
cafb168a | 663 | out: |
0706f1c4 SR |
664 | local_irq_restore(flags); |
665 | } | |
666 | ||
667 | static int register_ftrace_profiler(void) | |
668 | { | |
669 | return register_ftrace_graph(&profile_graph_return, | |
670 | &profile_graph_entry); | |
671 | } | |
672 | ||
673 | static void unregister_ftrace_profiler(void) | |
674 | { | |
675 | unregister_ftrace_graph(); | |
676 | } | |
677 | #else | |
bac429f0 SR |
678 | static struct ftrace_ops ftrace_profile_ops __read_mostly = |
679 | { | |
fb9fb015 | 680 | .func = function_profile_call, |
bac429f0 SR |
681 | }; |
682 | ||
0706f1c4 SR |
683 | static int register_ftrace_profiler(void) |
684 | { | |
685 | return register_ftrace_function(&ftrace_profile_ops); | |
686 | } | |
687 | ||
688 | static void unregister_ftrace_profiler(void) | |
689 | { | |
690 | unregister_ftrace_function(&ftrace_profile_ops); | |
691 | } | |
692 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
693 | ||
bac429f0 SR |
694 | static ssize_t |
695 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
696 | size_t cnt, loff_t *ppos) | |
697 | { | |
698 | unsigned long val; | |
fb9fb015 | 699 | char buf[64]; /* big enough to hold a number */ |
bac429f0 SR |
700 | int ret; |
701 | ||
bac429f0 SR |
702 | if (cnt >= sizeof(buf)) |
703 | return -EINVAL; | |
704 | ||
705 | if (copy_from_user(&buf, ubuf, cnt)) | |
706 | return -EFAULT; | |
707 | ||
708 | buf[cnt] = 0; | |
709 | ||
710 | ret = strict_strtoul(buf, 10, &val); | |
711 | if (ret < 0) | |
712 | return ret; | |
713 | ||
714 | val = !!val; | |
715 | ||
716 | mutex_lock(&ftrace_profile_lock); | |
717 | if (ftrace_profile_enabled ^ val) { | |
718 | if (val) { | |
493762fc SR |
719 | ret = ftrace_profile_init(); |
720 | if (ret < 0) { | |
721 | cnt = ret; | |
722 | goto out; | |
723 | } | |
724 | ||
0706f1c4 SR |
725 | ret = register_ftrace_profiler(); |
726 | if (ret < 0) { | |
727 | cnt = ret; | |
728 | goto out; | |
729 | } | |
bac429f0 SR |
730 | ftrace_profile_enabled = 1; |
731 | } else { | |
732 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
733 | /* |
734 | * unregister_ftrace_profiler calls stop_machine | |
735 | * so this acts like an synchronize_sched. | |
736 | */ | |
0706f1c4 | 737 | unregister_ftrace_profiler(); |
bac429f0 SR |
738 | } |
739 | } | |
493762fc | 740 | out: |
bac429f0 SR |
741 | mutex_unlock(&ftrace_profile_lock); |
742 | ||
cf8517cf | 743 | *ppos += cnt; |
bac429f0 SR |
744 | |
745 | return cnt; | |
746 | } | |
747 | ||
493762fc SR |
748 | static ssize_t |
749 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
750 | size_t cnt, loff_t *ppos) | |
751 | { | |
fb9fb015 | 752 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
753 | int r; |
754 | ||
755 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
756 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
757 | } | |
758 | ||
bac429f0 SR |
759 | static const struct file_operations ftrace_profile_fops = { |
760 | .open = tracing_open_generic, | |
761 | .read = ftrace_profile_read, | |
762 | .write = ftrace_profile_write, | |
763 | }; | |
764 | ||
cafb168a SR |
765 | /* used to initialize the real stat files */ |
766 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
767 | .name = "functions", |
768 | .stat_start = function_stat_start, | |
769 | .stat_next = function_stat_next, | |
770 | .stat_cmp = function_stat_cmp, | |
771 | .stat_headers = function_stat_headers, | |
772 | .stat_show = function_stat_show | |
cafb168a SR |
773 | }; |
774 | ||
6ab5d668 | 775 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 | 776 | { |
cafb168a | 777 | struct ftrace_profile_stat *stat; |
bac429f0 | 778 | struct dentry *entry; |
cafb168a | 779 | char *name; |
bac429f0 | 780 | int ret; |
cafb168a SR |
781 | int cpu; |
782 | ||
783 | for_each_possible_cpu(cpu) { | |
784 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
785 | ||
786 | /* allocate enough for function name + cpu number */ | |
787 | name = kmalloc(32, GFP_KERNEL); | |
788 | if (!name) { | |
789 | /* | |
790 | * The files created are permanent, if something happens | |
791 | * we still do not free memory. | |
792 | */ | |
cafb168a SR |
793 | WARN(1, |
794 | "Could not allocate stat file for cpu %d\n", | |
795 | cpu); | |
796 | return; | |
797 | } | |
798 | stat->stat = function_stats; | |
799 | snprintf(name, 32, "function%d", cpu); | |
800 | stat->stat.name = name; | |
801 | ret = register_stat_tracer(&stat->stat); | |
802 | if (ret) { | |
803 | WARN(1, | |
804 | "Could not register function stat for cpu %d\n", | |
805 | cpu); | |
806 | kfree(name); | |
807 | return; | |
808 | } | |
bac429f0 SR |
809 | } |
810 | ||
811 | entry = debugfs_create_file("function_profile_enabled", 0644, | |
812 | d_tracer, NULL, &ftrace_profile_fops); | |
813 | if (!entry) | |
814 | pr_warning("Could not create debugfs " | |
815 | "'function_profile_enabled' entry\n"); | |
816 | } | |
817 | ||
bac429f0 | 818 | #else /* CONFIG_FUNCTION_PROFILER */ |
6ab5d668 | 819 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 SR |
820 | { |
821 | } | |
bac429f0 SR |
822 | #endif /* CONFIG_FUNCTION_PROFILER */ |
823 | ||
493762fc SR |
824 | /* set when tracing only a pid */ |
825 | struct pid *ftrace_pid_trace; | |
826 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; | |
827 | ||
828 | #ifdef CONFIG_DYNAMIC_FTRACE | |
829 | ||
830 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD | |
831 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
832 | #endif | |
833 | ||
834 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; | |
835 | ||
836 | struct ftrace_func_probe { | |
837 | struct hlist_node node; | |
838 | struct ftrace_probe_ops *ops; | |
839 | unsigned long flags; | |
840 | unsigned long ip; | |
841 | void *data; | |
842 | struct rcu_head rcu; | |
843 | }; | |
844 | ||
845 | enum { | |
846 | FTRACE_ENABLE_CALLS = (1 << 0), | |
847 | FTRACE_DISABLE_CALLS = (1 << 1), | |
848 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
849 | FTRACE_ENABLE_MCOUNT = (1 << 3), | |
850 | FTRACE_DISABLE_MCOUNT = (1 << 4), | |
851 | FTRACE_START_FUNC_RET = (1 << 5), | |
852 | FTRACE_STOP_FUNC_RET = (1 << 6), | |
853 | }; | |
854 | ||
855 | static int ftrace_filtered; | |
856 | ||
857 | static struct dyn_ftrace *ftrace_new_addrs; | |
858 | ||
859 | static DEFINE_MUTEX(ftrace_regex_lock); | |
860 | ||
861 | struct ftrace_page { | |
862 | struct ftrace_page *next; | |
863 | int index; | |
864 | struct dyn_ftrace records[]; | |
865 | }; | |
866 | ||
867 | #define ENTRIES_PER_PAGE \ | |
868 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
869 | ||
870 | /* estimate from running different kernels */ | |
871 | #define NR_TO_INIT 10000 | |
872 | ||
873 | static struct ftrace_page *ftrace_pages_start; | |
874 | static struct ftrace_page *ftrace_pages; | |
875 | ||
876 | static struct dyn_ftrace *ftrace_free_records; | |
877 | ||
878 | /* | |
879 | * This is a double for. Do not use 'break' to break out of the loop, | |
880 | * you must use a goto. | |
881 | */ | |
882 | #define do_for_each_ftrace_rec(pg, rec) \ | |
883 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
884 | int _____i; \ | |
885 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
886 | rec = &pg->records[_____i]; | |
887 | ||
888 | #define while_for_each_ftrace_rec() \ | |
889 | } \ | |
890 | } | |
891 | ||
ecea656d | 892 | #ifdef CONFIG_KPROBES |
f17845e5 IM |
893 | |
894 | static int frozen_record_count; | |
895 | ||
ecea656d AS |
896 | static inline void freeze_record(struct dyn_ftrace *rec) |
897 | { | |
898 | if (!(rec->flags & FTRACE_FL_FROZEN)) { | |
899 | rec->flags |= FTRACE_FL_FROZEN; | |
900 | frozen_record_count++; | |
901 | } | |
902 | } | |
903 | ||
904 | static inline void unfreeze_record(struct dyn_ftrace *rec) | |
905 | { | |
906 | if (rec->flags & FTRACE_FL_FROZEN) { | |
907 | rec->flags &= ~FTRACE_FL_FROZEN; | |
908 | frozen_record_count--; | |
909 | } | |
910 | } | |
911 | ||
912 | static inline int record_frozen(struct dyn_ftrace *rec) | |
913 | { | |
914 | return rec->flags & FTRACE_FL_FROZEN; | |
915 | } | |
916 | #else | |
917 | # define freeze_record(rec) ({ 0; }) | |
918 | # define unfreeze_record(rec) ({ 0; }) | |
919 | # define record_frozen(rec) ({ 0; }) | |
920 | #endif /* CONFIG_KPROBES */ | |
921 | ||
e309b41d | 922 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
37ad5084 | 923 | { |
ee000b7f | 924 | rec->freelist = ftrace_free_records; |
37ad5084 SR |
925 | ftrace_free_records = rec; |
926 | rec->flags |= FTRACE_FL_FREE; | |
927 | } | |
928 | ||
e309b41d | 929 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 930 | { |
37ad5084 SR |
931 | struct dyn_ftrace *rec; |
932 | ||
933 | /* First check for freed records */ | |
934 | if (ftrace_free_records) { | |
935 | rec = ftrace_free_records; | |
936 | ||
37ad5084 | 937 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
6912896e | 938 | FTRACE_WARN_ON_ONCE(1); |
37ad5084 SR |
939 | ftrace_free_records = NULL; |
940 | return NULL; | |
941 | } | |
942 | ||
ee000b7f | 943 | ftrace_free_records = rec->freelist; |
37ad5084 SR |
944 | memset(rec, 0, sizeof(*rec)); |
945 | return rec; | |
946 | } | |
947 | ||
3c1720f0 | 948 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
08f5ac90 SR |
949 | if (!ftrace_pages->next) { |
950 | /* allocate another page */ | |
951 | ftrace_pages->next = | |
952 | (void *)get_zeroed_page(GFP_KERNEL); | |
953 | if (!ftrace_pages->next) | |
954 | return NULL; | |
955 | } | |
3c1720f0 SR |
956 | ftrace_pages = ftrace_pages->next; |
957 | } | |
958 | ||
959 | return &ftrace_pages->records[ftrace_pages->index++]; | |
960 | } | |
961 | ||
08f5ac90 | 962 | static struct dyn_ftrace * |
d61f82d0 | 963 | ftrace_record_ip(unsigned long ip) |
3d083395 | 964 | { |
08f5ac90 | 965 | struct dyn_ftrace *rec; |
3d083395 | 966 | |
f3c7ac40 | 967 | if (ftrace_disabled) |
08f5ac90 | 968 | return NULL; |
3d083395 | 969 | |
08f5ac90 SR |
970 | rec = ftrace_alloc_dyn_node(ip); |
971 | if (!rec) | |
972 | return NULL; | |
3d083395 | 973 | |
08f5ac90 | 974 | rec->ip = ip; |
ee000b7f | 975 | rec->newlist = ftrace_new_addrs; |
e94142a6 | 976 | ftrace_new_addrs = rec; |
3d083395 | 977 | |
08f5ac90 | 978 | return rec; |
3d083395 SR |
979 | } |
980 | ||
b17e8a37 SR |
981 | static void print_ip_ins(const char *fmt, unsigned char *p) |
982 | { | |
983 | int i; | |
984 | ||
985 | printk(KERN_CONT "%s", fmt); | |
986 | ||
987 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
988 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
989 | } | |
990 | ||
31e88909 | 991 | static void ftrace_bug(int failed, unsigned long ip) |
b17e8a37 SR |
992 | { |
993 | switch (failed) { | |
994 | case -EFAULT: | |
995 | FTRACE_WARN_ON_ONCE(1); | |
996 | pr_info("ftrace faulted on modifying "); | |
997 | print_ip_sym(ip); | |
998 | break; | |
999 | case -EINVAL: | |
1000 | FTRACE_WARN_ON_ONCE(1); | |
1001 | pr_info("ftrace failed to modify "); | |
1002 | print_ip_sym(ip); | |
b17e8a37 | 1003 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
1004 | printk(KERN_CONT "\n"); |
1005 | break; | |
1006 | case -EPERM: | |
1007 | FTRACE_WARN_ON_ONCE(1); | |
1008 | pr_info("ftrace faulted on writing "); | |
1009 | print_ip_sym(ip); | |
1010 | break; | |
1011 | default: | |
1012 | FTRACE_WARN_ON_ONCE(1); | |
1013 | pr_info("ftrace faulted on unknown error "); | |
1014 | print_ip_sym(ip); | |
1015 | } | |
1016 | } | |
1017 | ||
3c1720f0 | 1018 | |
0eb96701 | 1019 | static int |
31e88909 | 1020 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) |
5072c59f | 1021 | { |
e7d3737e | 1022 | unsigned long ftrace_addr; |
64fbcd16 | 1023 | unsigned long flag = 0UL; |
e7d3737e | 1024 | |
f0001207 | 1025 | ftrace_addr = (unsigned long)FTRACE_ADDR; |
5072c59f | 1026 | |
982c350b | 1027 | /* |
64fbcd16 XG |
1028 | * If this record is not to be traced or we want to disable it, |
1029 | * then disable it. | |
982c350b | 1030 | * |
64fbcd16 | 1031 | * If we want to enable it and filtering is off, then enable it. |
982c350b | 1032 | * |
64fbcd16 XG |
1033 | * If we want to enable it and filtering is on, enable it only if |
1034 | * it's filtered | |
982c350b | 1035 | */ |
64fbcd16 XG |
1036 | if (enable && !(rec->flags & FTRACE_FL_NOTRACE)) { |
1037 | if (!ftrace_filtered || (rec->flags & FTRACE_FL_FILTER)) | |
1038 | flag = FTRACE_FL_ENABLED; | |
1039 | } | |
982c350b | 1040 | |
64fbcd16 XG |
1041 | /* If the state of this record hasn't changed, then do nothing */ |
1042 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
1043 | return 0; | |
982c350b | 1044 | |
64fbcd16 XG |
1045 | if (flag) { |
1046 | rec->flags |= FTRACE_FL_ENABLED; | |
1047 | return ftrace_make_call(rec, ftrace_addr); | |
5072c59f SR |
1048 | } |
1049 | ||
64fbcd16 XG |
1050 | rec->flags &= ~FTRACE_FL_ENABLED; |
1051 | return ftrace_make_nop(NULL, rec, ftrace_addr); | |
5072c59f SR |
1052 | } |
1053 | ||
e309b41d | 1054 | static void ftrace_replace_code(int enable) |
3c1720f0 | 1055 | { |
3c1720f0 SR |
1056 | struct dyn_ftrace *rec; |
1057 | struct ftrace_page *pg; | |
6a24a244 | 1058 | int failed; |
3c1720f0 | 1059 | |
265c831c SR |
1060 | do_for_each_ftrace_rec(pg, rec) { |
1061 | /* | |
fa9d13cf Z |
1062 | * Skip over free records, records that have |
1063 | * failed and not converted. | |
265c831c SR |
1064 | */ |
1065 | if (rec->flags & FTRACE_FL_FREE || | |
fa9d13cf | 1066 | rec->flags & FTRACE_FL_FAILED || |
03303549 | 1067 | !(rec->flags & FTRACE_FL_CONVERTED)) |
265c831c SR |
1068 | continue; |
1069 | ||
1070 | /* ignore updates to this record's mcount site */ | |
1071 | if (get_kprobe((void *)rec->ip)) { | |
1072 | freeze_record(rec); | |
1073 | continue; | |
1074 | } else { | |
1075 | unfreeze_record(rec); | |
1076 | } | |
f22f9a89 | 1077 | |
265c831c | 1078 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 1079 | if (failed) { |
265c831c | 1080 | rec->flags |= FTRACE_FL_FAILED; |
3279ba37 SR |
1081 | ftrace_bug(failed, rec->ip); |
1082 | /* Stop processing */ | |
1083 | return; | |
3c1720f0 | 1084 | } |
265c831c | 1085 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
1086 | } |
1087 | ||
492a7ea5 | 1088 | static int |
31e88909 | 1089 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 SR |
1090 | { |
1091 | unsigned long ip; | |
593eb8a2 | 1092 | int ret; |
3c1720f0 SR |
1093 | |
1094 | ip = rec->ip; | |
1095 | ||
25aac9dc | 1096 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 1097 | if (ret) { |
31e88909 | 1098 | ftrace_bug(ret, ip); |
3c1720f0 | 1099 | rec->flags |= FTRACE_FL_FAILED; |
492a7ea5 | 1100 | return 0; |
37ad5084 | 1101 | } |
492a7ea5 | 1102 | return 1; |
3c1720f0 SR |
1103 | } |
1104 | ||
000ab691 SR |
1105 | /* |
1106 | * archs can override this function if they must do something | |
1107 | * before the modifying code is performed. | |
1108 | */ | |
1109 | int __weak ftrace_arch_code_modify_prepare(void) | |
1110 | { | |
1111 | return 0; | |
1112 | } | |
1113 | ||
1114 | /* | |
1115 | * archs can override this function if they must do something | |
1116 | * after the modifying code is performed. | |
1117 | */ | |
1118 | int __weak ftrace_arch_code_modify_post_process(void) | |
1119 | { | |
1120 | return 0; | |
1121 | } | |
1122 | ||
e309b41d | 1123 | static int __ftrace_modify_code(void *data) |
3d083395 | 1124 | { |
d61f82d0 SR |
1125 | int *command = data; |
1126 | ||
a3583244 | 1127 | if (*command & FTRACE_ENABLE_CALLS) |
d61f82d0 | 1128 | ftrace_replace_code(1); |
a3583244 | 1129 | else if (*command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
1130 | ftrace_replace_code(0); |
1131 | ||
1132 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
1133 | ftrace_update_ftrace_func(ftrace_trace_function); | |
1134 | ||
5a45cfe1 SR |
1135 | if (*command & FTRACE_START_FUNC_RET) |
1136 | ftrace_enable_ftrace_graph_caller(); | |
1137 | else if (*command & FTRACE_STOP_FUNC_RET) | |
1138 | ftrace_disable_ftrace_graph_caller(); | |
1139 | ||
d61f82d0 | 1140 | return 0; |
3d083395 SR |
1141 | } |
1142 | ||
e309b41d | 1143 | static void ftrace_run_update_code(int command) |
3d083395 | 1144 | { |
000ab691 SR |
1145 | int ret; |
1146 | ||
1147 | ret = ftrace_arch_code_modify_prepare(); | |
1148 | FTRACE_WARN_ON(ret); | |
1149 | if (ret) | |
1150 | return; | |
1151 | ||
784e2d76 | 1152 | stop_machine(__ftrace_modify_code, &command, NULL); |
000ab691 SR |
1153 | |
1154 | ret = ftrace_arch_code_modify_post_process(); | |
1155 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
1156 | } |
1157 | ||
d61f82d0 | 1158 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 1159 | static int ftrace_start_up; |
df4fc315 SR |
1160 | |
1161 | static void ftrace_startup_enable(int command) | |
1162 | { | |
1163 | if (saved_ftrace_func != ftrace_trace_function) { | |
1164 | saved_ftrace_func = ftrace_trace_function; | |
1165 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1166 | } | |
1167 | ||
1168 | if (!command || !ftrace_enabled) | |
1169 | return; | |
1170 | ||
1171 | ftrace_run_update_code(command); | |
1172 | } | |
d61f82d0 | 1173 | |
5a45cfe1 | 1174 | static void ftrace_startup(int command) |
3d083395 | 1175 | { |
4eebcc81 SR |
1176 | if (unlikely(ftrace_disabled)) |
1177 | return; | |
1178 | ||
60a7ecf4 | 1179 | ftrace_start_up++; |
982c350b | 1180 | command |= FTRACE_ENABLE_CALLS; |
d61f82d0 | 1181 | |
df4fc315 | 1182 | ftrace_startup_enable(command); |
3d083395 SR |
1183 | } |
1184 | ||
5a45cfe1 | 1185 | static void ftrace_shutdown(int command) |
3d083395 | 1186 | { |
4eebcc81 SR |
1187 | if (unlikely(ftrace_disabled)) |
1188 | return; | |
1189 | ||
60a7ecf4 | 1190 | ftrace_start_up--; |
9ea1a153 FW |
1191 | /* |
1192 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
1193 | * critical but the ftrace_call callers may be never nopped again after | |
1194 | * further ftrace uses. | |
1195 | */ | |
1196 | WARN_ON_ONCE(ftrace_start_up < 0); | |
1197 | ||
60a7ecf4 | 1198 | if (!ftrace_start_up) |
d61f82d0 | 1199 | command |= FTRACE_DISABLE_CALLS; |
3d083395 | 1200 | |
d61f82d0 SR |
1201 | if (saved_ftrace_func != ftrace_trace_function) { |
1202 | saved_ftrace_func = ftrace_trace_function; | |
1203 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1204 | } | |
3d083395 | 1205 | |
d61f82d0 | 1206 | if (!command || !ftrace_enabled) |
e6ea44e9 | 1207 | return; |
d61f82d0 SR |
1208 | |
1209 | ftrace_run_update_code(command); | |
3d083395 SR |
1210 | } |
1211 | ||
e309b41d | 1212 | static void ftrace_startup_sysctl(void) |
b0fc494f | 1213 | { |
d61f82d0 SR |
1214 | int command = FTRACE_ENABLE_MCOUNT; |
1215 | ||
4eebcc81 SR |
1216 | if (unlikely(ftrace_disabled)) |
1217 | return; | |
1218 | ||
d61f82d0 SR |
1219 | /* Force update next time */ |
1220 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
1221 | /* ftrace_start_up is true if we want ftrace running */ |
1222 | if (ftrace_start_up) | |
d61f82d0 SR |
1223 | command |= FTRACE_ENABLE_CALLS; |
1224 | ||
1225 | ftrace_run_update_code(command); | |
b0fc494f SR |
1226 | } |
1227 | ||
e309b41d | 1228 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 1229 | { |
d61f82d0 SR |
1230 | int command = FTRACE_DISABLE_MCOUNT; |
1231 | ||
4eebcc81 SR |
1232 | if (unlikely(ftrace_disabled)) |
1233 | return; | |
1234 | ||
60a7ecf4 SR |
1235 | /* ftrace_start_up is true if ftrace is running */ |
1236 | if (ftrace_start_up) | |
d61f82d0 SR |
1237 | command |= FTRACE_DISABLE_CALLS; |
1238 | ||
1239 | ftrace_run_update_code(command); | |
b0fc494f SR |
1240 | } |
1241 | ||
3d083395 SR |
1242 | static cycle_t ftrace_update_time; |
1243 | static unsigned long ftrace_update_cnt; | |
1244 | unsigned long ftrace_update_tot_cnt; | |
1245 | ||
31e88909 | 1246 | static int ftrace_update_code(struct module *mod) |
3d083395 | 1247 | { |
e94142a6 | 1248 | struct dyn_ftrace *p; |
f22f9a89 | 1249 | cycle_t start, stop; |
3d083395 | 1250 | |
750ed1a4 | 1251 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1252 | ftrace_update_cnt = 0; |
1253 | ||
e94142a6 | 1254 | while (ftrace_new_addrs) { |
3d083395 | 1255 | |
08f5ac90 SR |
1256 | /* If something went wrong, bail without enabling anything */ |
1257 | if (unlikely(ftrace_disabled)) | |
1258 | return -1; | |
f22f9a89 | 1259 | |
e94142a6 | 1260 | p = ftrace_new_addrs; |
ee000b7f | 1261 | ftrace_new_addrs = p->newlist; |
e94142a6 | 1262 | p->flags = 0L; |
f22f9a89 | 1263 | |
08f5ac90 | 1264 | /* convert record (i.e, patch mcount-call with NOP) */ |
31e88909 | 1265 | if (ftrace_code_disable(mod, p)) { |
08f5ac90 SR |
1266 | p->flags |= FTRACE_FL_CONVERTED; |
1267 | ftrace_update_cnt++; | |
1268 | } else | |
1269 | ftrace_free_rec(p); | |
3d083395 SR |
1270 | } |
1271 | ||
750ed1a4 | 1272 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1273 | ftrace_update_time = stop - start; |
1274 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
1275 | ||
16444a8a ACM |
1276 | return 0; |
1277 | } | |
1278 | ||
68bf21aa | 1279 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
1280 | { |
1281 | struct ftrace_page *pg; | |
1282 | int cnt; | |
1283 | int i; | |
3c1720f0 SR |
1284 | |
1285 | /* allocate a few pages */ | |
1286 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
1287 | if (!ftrace_pages_start) | |
1288 | return -1; | |
1289 | ||
1290 | /* | |
1291 | * Allocate a few more pages. | |
1292 | * | |
1293 | * TODO: have some parser search vmlinux before | |
1294 | * final linking to find all calls to ftrace. | |
1295 | * Then we can: | |
1296 | * a) know how many pages to allocate. | |
1297 | * and/or | |
1298 | * b) set up the table then. | |
1299 | * | |
1300 | * The dynamic code is still necessary for | |
1301 | * modules. | |
1302 | */ | |
1303 | ||
1304 | pg = ftrace_pages = ftrace_pages_start; | |
1305 | ||
68bf21aa | 1306 | cnt = num_to_init / ENTRIES_PER_PAGE; |
08f5ac90 | 1307 | pr_info("ftrace: allocating %ld entries in %d pages\n", |
5821e1b7 | 1308 | num_to_init, cnt + 1); |
3c1720f0 SR |
1309 | |
1310 | for (i = 0; i < cnt; i++) { | |
1311 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
1312 | ||
1313 | /* If we fail, we'll try later anyway */ | |
1314 | if (!pg->next) | |
1315 | break; | |
1316 | ||
1317 | pg = pg->next; | |
1318 | } | |
1319 | ||
1320 | return 0; | |
1321 | } | |
1322 | ||
5072c59f SR |
1323 | enum { |
1324 | FTRACE_ITER_FILTER = (1 << 0), | |
689fd8b6 | 1325 | FTRACE_ITER_NOTRACE = (1 << 1), |
1326 | FTRACE_ITER_FAILURES = (1 << 2), | |
1327 | FTRACE_ITER_PRINTALL = (1 << 3), | |
1328 | FTRACE_ITER_HASH = (1 << 4), | |
5072c59f SR |
1329 | }; |
1330 | ||
1331 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
1332 | ||
1333 | struct ftrace_iterator { | |
5072c59f | 1334 | struct ftrace_page *pg; |
8fc0c701 | 1335 | int hidx; |
431aa3fb | 1336 | int idx; |
5072c59f | 1337 | unsigned flags; |
689fd8b6 | 1338 | struct trace_parser parser; |
5072c59f SR |
1339 | }; |
1340 | ||
8fc0c701 SR |
1341 | static void * |
1342 | t_hash_next(struct seq_file *m, void *v, loff_t *pos) | |
1343 | { | |
1344 | struct ftrace_iterator *iter = m->private; | |
1345 | struct hlist_node *hnd = v; | |
1346 | struct hlist_head *hhd; | |
1347 | ||
1348 | WARN_ON(!(iter->flags & FTRACE_ITER_HASH)); | |
1349 | ||
1350 | (*pos)++; | |
1351 | ||
1352 | retry: | |
1353 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
1354 | return NULL; | |
1355 | ||
1356 | hhd = &ftrace_func_hash[iter->hidx]; | |
1357 | ||
1358 | if (hlist_empty(hhd)) { | |
1359 | iter->hidx++; | |
1360 | hnd = NULL; | |
1361 | goto retry; | |
1362 | } | |
1363 | ||
1364 | if (!hnd) | |
1365 | hnd = hhd->first; | |
1366 | else { | |
1367 | hnd = hnd->next; | |
1368 | if (!hnd) { | |
1369 | iter->hidx++; | |
1370 | goto retry; | |
1371 | } | |
1372 | } | |
1373 | ||
1374 | return hnd; | |
1375 | } | |
1376 | ||
1377 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
1378 | { | |
1379 | struct ftrace_iterator *iter = m->private; | |
1380 | void *p = NULL; | |
d82d6244 LZ |
1381 | loff_t l; |
1382 | ||
1383 | if (!(iter->flags & FTRACE_ITER_HASH)) | |
1384 | *pos = 0; | |
8fc0c701 SR |
1385 | |
1386 | iter->flags |= FTRACE_ITER_HASH; | |
1387 | ||
d82d6244 LZ |
1388 | iter->hidx = 0; |
1389 | for (l = 0; l <= *pos; ) { | |
1390 | p = t_hash_next(m, p, &l); | |
1391 | if (!p) | |
1392 | break; | |
1393 | } | |
1394 | return p; | |
8fc0c701 SR |
1395 | } |
1396 | ||
1397 | static int t_hash_show(struct seq_file *m, void *v) | |
1398 | { | |
b6887d79 | 1399 | struct ftrace_func_probe *rec; |
8fc0c701 | 1400 | struct hlist_node *hnd = v; |
8fc0c701 | 1401 | |
b6887d79 | 1402 | rec = hlist_entry(hnd, struct ftrace_func_probe, node); |
8fc0c701 | 1403 | |
809dcf29 SR |
1404 | if (rec->ops->print) |
1405 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
1406 | ||
b375a11a | 1407 | seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func); |
8fc0c701 SR |
1408 | |
1409 | if (rec->data) | |
1410 | seq_printf(m, ":%p", rec->data); | |
1411 | seq_putc(m, '\n'); | |
1412 | ||
1413 | return 0; | |
1414 | } | |
1415 | ||
e309b41d | 1416 | static void * |
5072c59f SR |
1417 | t_next(struct seq_file *m, void *v, loff_t *pos) |
1418 | { | |
1419 | struct ftrace_iterator *iter = m->private; | |
1420 | struct dyn_ftrace *rec = NULL; | |
1421 | ||
8fc0c701 SR |
1422 | if (iter->flags & FTRACE_ITER_HASH) |
1423 | return t_hash_next(m, v, pos); | |
1424 | ||
5072c59f SR |
1425 | (*pos)++; |
1426 | ||
0c75a3ed SR |
1427 | if (iter->flags & FTRACE_ITER_PRINTALL) |
1428 | return NULL; | |
1429 | ||
5072c59f SR |
1430 | retry: |
1431 | if (iter->idx >= iter->pg->index) { | |
1432 | if (iter->pg->next) { | |
1433 | iter->pg = iter->pg->next; | |
1434 | iter->idx = 0; | |
1435 | goto retry; | |
1436 | } | |
1437 | } else { | |
1438 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
1439 | if ((rec->flags & FTRACE_FL_FREE) || |
1440 | ||
1441 | (!(iter->flags & FTRACE_ITER_FAILURES) && | |
eb9a7bf0 AS |
1442 | (rec->flags & FTRACE_FL_FAILED)) || |
1443 | ||
1444 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
a9fdda33 | 1445 | !(rec->flags & FTRACE_FL_FAILED)) || |
eb9a7bf0 | 1446 | |
0183fb1c SR |
1447 | ((iter->flags & FTRACE_ITER_FILTER) && |
1448 | !(rec->flags & FTRACE_FL_FILTER)) || | |
1449 | ||
41c52c0d SR |
1450 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
1451 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
1452 | rec = NULL; |
1453 | goto retry; | |
1454 | } | |
1455 | } | |
1456 | ||
5072c59f SR |
1457 | return rec; |
1458 | } | |
1459 | ||
1460 | static void *t_start(struct seq_file *m, loff_t *pos) | |
1461 | { | |
1462 | struct ftrace_iterator *iter = m->private; | |
1463 | void *p = NULL; | |
694ce0a5 | 1464 | loff_t l; |
5072c59f | 1465 | |
8fc0c701 | 1466 | mutex_lock(&ftrace_lock); |
0c75a3ed SR |
1467 | /* |
1468 | * For set_ftrace_filter reading, if we have the filter | |
1469 | * off, we can short cut and just print out that all | |
1470 | * functions are enabled. | |
1471 | */ | |
1472 | if (iter->flags & FTRACE_ITER_FILTER && !ftrace_filtered) { | |
1473 | if (*pos > 0) | |
8fc0c701 | 1474 | return t_hash_start(m, pos); |
0c75a3ed | 1475 | iter->flags |= FTRACE_ITER_PRINTALL; |
0c75a3ed SR |
1476 | return iter; |
1477 | } | |
1478 | ||
8fc0c701 SR |
1479 | if (iter->flags & FTRACE_ITER_HASH) |
1480 | return t_hash_start(m, pos); | |
1481 | ||
694ce0a5 LZ |
1482 | iter->pg = ftrace_pages_start; |
1483 | iter->idx = 0; | |
1484 | for (l = 0; l <= *pos; ) { | |
1485 | p = t_next(m, p, &l); | |
1486 | if (!p) | |
1487 | break; | |
50cdaf08 | 1488 | } |
5821e1b7 | 1489 | |
694ce0a5 | 1490 | if (!p && iter->flags & FTRACE_ITER_FILTER) |
8fc0c701 SR |
1491 | return t_hash_start(m, pos); |
1492 | ||
5072c59f SR |
1493 | return p; |
1494 | } | |
1495 | ||
1496 | static void t_stop(struct seq_file *m, void *p) | |
1497 | { | |
8fc0c701 | 1498 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1499 | } |
1500 | ||
1501 | static int t_show(struct seq_file *m, void *v) | |
1502 | { | |
0c75a3ed | 1503 | struct ftrace_iterator *iter = m->private; |
5072c59f | 1504 | struct dyn_ftrace *rec = v; |
5072c59f | 1505 | |
8fc0c701 SR |
1506 | if (iter->flags & FTRACE_ITER_HASH) |
1507 | return t_hash_show(m, v); | |
1508 | ||
0c75a3ed SR |
1509 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
1510 | seq_printf(m, "#### all functions enabled ####\n"); | |
1511 | return 0; | |
1512 | } | |
1513 | ||
5072c59f SR |
1514 | if (!rec) |
1515 | return 0; | |
1516 | ||
b375a11a | 1517 | seq_printf(m, "%ps\n", (void *)rec->ip); |
5072c59f SR |
1518 | |
1519 | return 0; | |
1520 | } | |
1521 | ||
88e9d34c | 1522 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
1523 | .start = t_start, |
1524 | .next = t_next, | |
1525 | .stop = t_stop, | |
1526 | .show = t_show, | |
1527 | }; | |
1528 | ||
e309b41d | 1529 | static int |
5072c59f SR |
1530 | ftrace_avail_open(struct inode *inode, struct file *file) |
1531 | { | |
1532 | struct ftrace_iterator *iter; | |
1533 | int ret; | |
1534 | ||
4eebcc81 SR |
1535 | if (unlikely(ftrace_disabled)) |
1536 | return -ENODEV; | |
1537 | ||
5072c59f SR |
1538 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1539 | if (!iter) | |
1540 | return -ENOMEM; | |
1541 | ||
1542 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
1543 | |
1544 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1545 | if (!ret) { | |
1546 | struct seq_file *m = file->private_data; | |
4bf39a94 | 1547 | |
5072c59f | 1548 | m->private = iter; |
4bf39a94 | 1549 | } else { |
5072c59f | 1550 | kfree(iter); |
4bf39a94 | 1551 | } |
5072c59f SR |
1552 | |
1553 | return ret; | |
1554 | } | |
1555 | ||
eb9a7bf0 AS |
1556 | static int |
1557 | ftrace_failures_open(struct inode *inode, struct file *file) | |
1558 | { | |
1559 | int ret; | |
1560 | struct seq_file *m; | |
1561 | struct ftrace_iterator *iter; | |
1562 | ||
1563 | ret = ftrace_avail_open(inode, file); | |
1564 | if (!ret) { | |
1565 | m = (struct seq_file *)file->private_data; | |
1566 | iter = (struct ftrace_iterator *)m->private; | |
1567 | iter->flags = FTRACE_ITER_FAILURES; | |
1568 | } | |
1569 | ||
1570 | return ret; | |
1571 | } | |
1572 | ||
1573 | ||
41c52c0d | 1574 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
1575 | { |
1576 | struct ftrace_page *pg; | |
1577 | struct dyn_ftrace *rec; | |
41c52c0d | 1578 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f | 1579 | |
52baf119 | 1580 | mutex_lock(&ftrace_lock); |
41c52c0d SR |
1581 | if (enable) |
1582 | ftrace_filtered = 0; | |
265c831c SR |
1583 | do_for_each_ftrace_rec(pg, rec) { |
1584 | if (rec->flags & FTRACE_FL_FAILED) | |
1585 | continue; | |
1586 | rec->flags &= ~type; | |
1587 | } while_for_each_ftrace_rec(); | |
52baf119 | 1588 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1589 | } |
1590 | ||
e309b41d | 1591 | static int |
41c52c0d | 1592 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1593 | { |
1594 | struct ftrace_iterator *iter; | |
1595 | int ret = 0; | |
1596 | ||
4eebcc81 SR |
1597 | if (unlikely(ftrace_disabled)) |
1598 | return -ENODEV; | |
1599 | ||
5072c59f SR |
1600 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1601 | if (!iter) | |
1602 | return -ENOMEM; | |
1603 | ||
689fd8b6 | 1604 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { |
1605 | kfree(iter); | |
1606 | return -ENOMEM; | |
1607 | } | |
1608 | ||
41c52c0d | 1609 | mutex_lock(&ftrace_regex_lock); |
5072c59f | 1610 | if ((file->f_mode & FMODE_WRITE) && |
8650ae32 | 1611 | (file->f_flags & O_TRUNC)) |
41c52c0d | 1612 | ftrace_filter_reset(enable); |
5072c59f SR |
1613 | |
1614 | if (file->f_mode & FMODE_READ) { | |
1615 | iter->pg = ftrace_pages_start; | |
41c52c0d SR |
1616 | iter->flags = enable ? FTRACE_ITER_FILTER : |
1617 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
1618 | |
1619 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1620 | if (!ret) { | |
1621 | struct seq_file *m = file->private_data; | |
1622 | m->private = iter; | |
79fe249c LZ |
1623 | } else { |
1624 | trace_parser_put(&iter->parser); | |
5072c59f | 1625 | kfree(iter); |
79fe249c | 1626 | } |
5072c59f SR |
1627 | } else |
1628 | file->private_data = iter; | |
41c52c0d | 1629 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1630 | |
1631 | return ret; | |
1632 | } | |
1633 | ||
41c52c0d SR |
1634 | static int |
1635 | ftrace_filter_open(struct inode *inode, struct file *file) | |
1636 | { | |
1637 | return ftrace_regex_open(inode, file, 1); | |
1638 | } | |
1639 | ||
1640 | static int | |
1641 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
1642 | { | |
1643 | return ftrace_regex_open(inode, file, 0); | |
1644 | } | |
1645 | ||
e309b41d | 1646 | static loff_t |
41c52c0d | 1647 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
1648 | { |
1649 | loff_t ret; | |
1650 | ||
1651 | if (file->f_mode & FMODE_READ) | |
1652 | ret = seq_lseek(file, offset, origin); | |
1653 | else | |
1654 | file->f_pos = ret = 1; | |
1655 | ||
1656 | return ret; | |
1657 | } | |
1658 | ||
1659 | enum { | |
1660 | MATCH_FULL, | |
1661 | MATCH_FRONT_ONLY, | |
1662 | MATCH_MIDDLE_ONLY, | |
1663 | MATCH_END_ONLY, | |
1664 | }; | |
1665 | ||
9f4801e3 SR |
1666 | /* |
1667 | * (static function - no need for kernel doc) | |
1668 | * | |
1669 | * Pass in a buffer containing a glob and this function will | |
1670 | * set search to point to the search part of the buffer and | |
1671 | * return the type of search it is (see enum above). | |
1672 | * This does modify buff. | |
1673 | * | |
1674 | * Returns enum type. | |
1675 | * search returns the pointer to use for comparison. | |
1676 | * not returns 1 if buff started with a '!' | |
1677 | * 0 otherwise. | |
1678 | */ | |
1679 | static int | |
64e7c440 | 1680 | ftrace_setup_glob(char *buff, int len, char **search, int *not) |
5072c59f | 1681 | { |
5072c59f | 1682 | int type = MATCH_FULL; |
9f4801e3 | 1683 | int i; |
ea3a6d6d SR |
1684 | |
1685 | if (buff[0] == '!') { | |
9f4801e3 | 1686 | *not = 1; |
ea3a6d6d SR |
1687 | buff++; |
1688 | len--; | |
9f4801e3 SR |
1689 | } else |
1690 | *not = 0; | |
1691 | ||
1692 | *search = buff; | |
5072c59f SR |
1693 | |
1694 | for (i = 0; i < len; i++) { | |
1695 | if (buff[i] == '*') { | |
1696 | if (!i) { | |
9f4801e3 | 1697 | *search = buff + 1; |
5072c59f | 1698 | type = MATCH_END_ONLY; |
5072c59f | 1699 | } else { |
9f4801e3 | 1700 | if (type == MATCH_END_ONLY) |
5072c59f | 1701 | type = MATCH_MIDDLE_ONLY; |
9f4801e3 | 1702 | else |
5072c59f | 1703 | type = MATCH_FRONT_ONLY; |
5072c59f SR |
1704 | buff[i] = 0; |
1705 | break; | |
1706 | } | |
1707 | } | |
1708 | } | |
1709 | ||
9f4801e3 SR |
1710 | return type; |
1711 | } | |
1712 | ||
64e7c440 | 1713 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 1714 | { |
9f4801e3 SR |
1715 | int matched = 0; |
1716 | char *ptr; | |
1717 | ||
9f4801e3 SR |
1718 | switch (type) { |
1719 | case MATCH_FULL: | |
1720 | if (strcmp(str, regex) == 0) | |
1721 | matched = 1; | |
1722 | break; | |
1723 | case MATCH_FRONT_ONLY: | |
1724 | if (strncmp(str, regex, len) == 0) | |
1725 | matched = 1; | |
1726 | break; | |
1727 | case MATCH_MIDDLE_ONLY: | |
1728 | if (strstr(str, regex)) | |
1729 | matched = 1; | |
1730 | break; | |
1731 | case MATCH_END_ONLY: | |
1732 | ptr = strstr(str, regex); | |
1733 | if (ptr && (ptr[len] == 0)) | |
1734 | matched = 1; | |
1735 | break; | |
1736 | } | |
1737 | ||
1738 | return matched; | |
1739 | } | |
1740 | ||
64e7c440 SR |
1741 | static int |
1742 | ftrace_match_record(struct dyn_ftrace *rec, char *regex, int len, int type) | |
1743 | { | |
1744 | char str[KSYM_SYMBOL_LEN]; | |
1745 | ||
1746 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1747 | return ftrace_match(str, regex, len, type); | |
1748 | } | |
1749 | ||
9f4801e3 SR |
1750 | static void ftrace_match_records(char *buff, int len, int enable) |
1751 | { | |
6a24a244 | 1752 | unsigned int search_len; |
9f4801e3 SR |
1753 | struct ftrace_page *pg; |
1754 | struct dyn_ftrace *rec; | |
6a24a244 SR |
1755 | unsigned long flag; |
1756 | char *search; | |
9f4801e3 | 1757 | int type; |
9f4801e3 SR |
1758 | int not; |
1759 | ||
6a24a244 | 1760 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
9f4801e3 SR |
1761 | type = ftrace_setup_glob(buff, len, &search, ¬); |
1762 | ||
1763 | search_len = strlen(search); | |
1764 | ||
52baf119 | 1765 | mutex_lock(&ftrace_lock); |
265c831c | 1766 | do_for_each_ftrace_rec(pg, rec) { |
265c831c SR |
1767 | |
1768 | if (rec->flags & FTRACE_FL_FAILED) | |
1769 | continue; | |
9f4801e3 SR |
1770 | |
1771 | if (ftrace_match_record(rec, search, search_len, type)) { | |
265c831c SR |
1772 | if (not) |
1773 | rec->flags &= ~flag; | |
1774 | else | |
1775 | rec->flags |= flag; | |
1776 | } | |
e68746a2 SR |
1777 | /* |
1778 | * Only enable filtering if we have a function that | |
1779 | * is filtered on. | |
1780 | */ | |
1781 | if (enable && (rec->flags & FTRACE_FL_FILTER)) | |
1782 | ftrace_filtered = 1; | |
265c831c | 1783 | } while_for_each_ftrace_rec(); |
52baf119 | 1784 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1785 | } |
1786 | ||
64e7c440 SR |
1787 | static int |
1788 | ftrace_match_module_record(struct dyn_ftrace *rec, char *mod, | |
1789 | char *regex, int len, int type) | |
1790 | { | |
1791 | char str[KSYM_SYMBOL_LEN]; | |
1792 | char *modname; | |
1793 | ||
1794 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
1795 | ||
1796 | if (!modname || strcmp(modname, mod)) | |
1797 | return 0; | |
1798 | ||
1799 | /* blank search means to match all funcs in the mod */ | |
1800 | if (len) | |
1801 | return ftrace_match(str, regex, len, type); | |
1802 | else | |
1803 | return 1; | |
1804 | } | |
1805 | ||
1806 | static void ftrace_match_module_records(char *buff, char *mod, int enable) | |
1807 | { | |
6a24a244 | 1808 | unsigned search_len = 0; |
64e7c440 SR |
1809 | struct ftrace_page *pg; |
1810 | struct dyn_ftrace *rec; | |
1811 | int type = MATCH_FULL; | |
6a24a244 SR |
1812 | char *search = buff; |
1813 | unsigned long flag; | |
64e7c440 SR |
1814 | int not = 0; |
1815 | ||
6a24a244 SR |
1816 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
1817 | ||
64e7c440 SR |
1818 | /* blank or '*' mean the same */ |
1819 | if (strcmp(buff, "*") == 0) | |
1820 | buff[0] = 0; | |
1821 | ||
1822 | /* handle the case of 'dont filter this module' */ | |
1823 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
1824 | buff[0] = 0; | |
1825 | not = 1; | |
1826 | } | |
1827 | ||
1828 | if (strlen(buff)) { | |
1829 | type = ftrace_setup_glob(buff, strlen(buff), &search, ¬); | |
1830 | search_len = strlen(search); | |
1831 | } | |
1832 | ||
52baf119 | 1833 | mutex_lock(&ftrace_lock); |
64e7c440 SR |
1834 | do_for_each_ftrace_rec(pg, rec) { |
1835 | ||
1836 | if (rec->flags & FTRACE_FL_FAILED) | |
1837 | continue; | |
1838 | ||
1839 | if (ftrace_match_module_record(rec, mod, | |
1840 | search, search_len, type)) { | |
1841 | if (not) | |
1842 | rec->flags &= ~flag; | |
1843 | else | |
1844 | rec->flags |= flag; | |
1845 | } | |
e68746a2 SR |
1846 | if (enable && (rec->flags & FTRACE_FL_FILTER)) |
1847 | ftrace_filtered = 1; | |
64e7c440 SR |
1848 | |
1849 | } while_for_each_ftrace_rec(); | |
52baf119 | 1850 | mutex_unlock(&ftrace_lock); |
64e7c440 SR |
1851 | } |
1852 | ||
f6180773 SR |
1853 | /* |
1854 | * We register the module command as a template to show others how | |
1855 | * to register the a command as well. | |
1856 | */ | |
1857 | ||
1858 | static int | |
1859 | ftrace_mod_callback(char *func, char *cmd, char *param, int enable) | |
1860 | { | |
1861 | char *mod; | |
1862 | ||
1863 | /* | |
1864 | * cmd == 'mod' because we only registered this func | |
1865 | * for the 'mod' ftrace_func_command. | |
1866 | * But if you register one func with multiple commands, | |
1867 | * you can tell which command was used by the cmd | |
1868 | * parameter. | |
1869 | */ | |
1870 | ||
1871 | /* we must have a module name */ | |
1872 | if (!param) | |
1873 | return -EINVAL; | |
1874 | ||
1875 | mod = strsep(¶m, ":"); | |
1876 | if (!strlen(mod)) | |
1877 | return -EINVAL; | |
1878 | ||
1879 | ftrace_match_module_records(func, mod, enable); | |
1880 | return 0; | |
1881 | } | |
1882 | ||
1883 | static struct ftrace_func_command ftrace_mod_cmd = { | |
1884 | .name = "mod", | |
1885 | .func = ftrace_mod_callback, | |
1886 | }; | |
1887 | ||
1888 | static int __init ftrace_mod_cmd_init(void) | |
1889 | { | |
1890 | return register_ftrace_command(&ftrace_mod_cmd); | |
1891 | } | |
1892 | device_initcall(ftrace_mod_cmd_init); | |
1893 | ||
59df055f | 1894 | static void |
b6887d79 | 1895 | function_trace_probe_call(unsigned long ip, unsigned long parent_ip) |
59df055f | 1896 | { |
b6887d79 | 1897 | struct ftrace_func_probe *entry; |
59df055f SR |
1898 | struct hlist_head *hhd; |
1899 | struct hlist_node *n; | |
1900 | unsigned long key; | |
1901 | int resched; | |
1902 | ||
1903 | key = hash_long(ip, FTRACE_HASH_BITS); | |
1904 | ||
1905 | hhd = &ftrace_func_hash[key]; | |
1906 | ||
1907 | if (hlist_empty(hhd)) | |
1908 | return; | |
1909 | ||
1910 | /* | |
1911 | * Disable preemption for these calls to prevent a RCU grace | |
1912 | * period. This syncs the hash iteration and freeing of items | |
1913 | * on the hash. rcu_read_lock is too dangerous here. | |
1914 | */ | |
1915 | resched = ftrace_preempt_disable(); | |
1916 | hlist_for_each_entry_rcu(entry, n, hhd, node) { | |
1917 | if (entry->ip == ip) | |
1918 | entry->ops->func(ip, parent_ip, &entry->data); | |
1919 | } | |
1920 | ftrace_preempt_enable(resched); | |
1921 | } | |
1922 | ||
b6887d79 | 1923 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 1924 | { |
fb9fb015 | 1925 | .func = function_trace_probe_call, |
59df055f SR |
1926 | }; |
1927 | ||
b6887d79 | 1928 | static int ftrace_probe_registered; |
59df055f | 1929 | |
b6887d79 | 1930 | static void __enable_ftrace_function_probe(void) |
59df055f SR |
1931 | { |
1932 | int i; | |
1933 | ||
b6887d79 | 1934 | if (ftrace_probe_registered) |
59df055f SR |
1935 | return; |
1936 | ||
1937 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1938 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1939 | if (hhd->first) | |
1940 | break; | |
1941 | } | |
1942 | /* Nothing registered? */ | |
1943 | if (i == FTRACE_FUNC_HASHSIZE) | |
1944 | return; | |
1945 | ||
b6887d79 | 1946 | __register_ftrace_function(&trace_probe_ops); |
59df055f | 1947 | ftrace_startup(0); |
b6887d79 | 1948 | ftrace_probe_registered = 1; |
59df055f SR |
1949 | } |
1950 | ||
b6887d79 | 1951 | static void __disable_ftrace_function_probe(void) |
59df055f SR |
1952 | { |
1953 | int i; | |
1954 | ||
b6887d79 | 1955 | if (!ftrace_probe_registered) |
59df055f SR |
1956 | return; |
1957 | ||
1958 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1959 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1960 | if (hhd->first) | |
1961 | return; | |
1962 | } | |
1963 | ||
1964 | /* no more funcs left */ | |
b6887d79 | 1965 | __unregister_ftrace_function(&trace_probe_ops); |
59df055f | 1966 | ftrace_shutdown(0); |
b6887d79 | 1967 | ftrace_probe_registered = 0; |
59df055f SR |
1968 | } |
1969 | ||
1970 | ||
1971 | static void ftrace_free_entry_rcu(struct rcu_head *rhp) | |
1972 | { | |
b6887d79 SR |
1973 | struct ftrace_func_probe *entry = |
1974 | container_of(rhp, struct ftrace_func_probe, rcu); | |
59df055f SR |
1975 | |
1976 | if (entry->ops->free) | |
1977 | entry->ops->free(&entry->data); | |
1978 | kfree(entry); | |
1979 | } | |
1980 | ||
1981 | ||
1982 | int | |
b6887d79 | 1983 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
1984 | void *data) |
1985 | { | |
b6887d79 | 1986 | struct ftrace_func_probe *entry; |
59df055f SR |
1987 | struct ftrace_page *pg; |
1988 | struct dyn_ftrace *rec; | |
59df055f | 1989 | int type, len, not; |
6a24a244 | 1990 | unsigned long key; |
59df055f SR |
1991 | int count = 0; |
1992 | char *search; | |
1993 | ||
1994 | type = ftrace_setup_glob(glob, strlen(glob), &search, ¬); | |
1995 | len = strlen(search); | |
1996 | ||
b6887d79 | 1997 | /* we do not support '!' for function probes */ |
59df055f SR |
1998 | if (WARN_ON(not)) |
1999 | return -EINVAL; | |
2000 | ||
2001 | mutex_lock(&ftrace_lock); | |
2002 | do_for_each_ftrace_rec(pg, rec) { | |
2003 | ||
2004 | if (rec->flags & FTRACE_FL_FAILED) | |
2005 | continue; | |
2006 | ||
2007 | if (!ftrace_match_record(rec, search, len, type)) | |
2008 | continue; | |
2009 | ||
2010 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
2011 | if (!entry) { | |
b6887d79 | 2012 | /* If we did not process any, then return error */ |
59df055f SR |
2013 | if (!count) |
2014 | count = -ENOMEM; | |
2015 | goto out_unlock; | |
2016 | } | |
2017 | ||
2018 | count++; | |
2019 | ||
2020 | entry->data = data; | |
2021 | ||
2022 | /* | |
2023 | * The caller might want to do something special | |
2024 | * for each function we find. We call the callback | |
2025 | * to give the caller an opportunity to do so. | |
2026 | */ | |
2027 | if (ops->callback) { | |
2028 | if (ops->callback(rec->ip, &entry->data) < 0) { | |
2029 | /* caller does not like this func */ | |
2030 | kfree(entry); | |
2031 | continue; | |
2032 | } | |
2033 | } | |
2034 | ||
2035 | entry->ops = ops; | |
2036 | entry->ip = rec->ip; | |
2037 | ||
2038 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
2039 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
2040 | ||
2041 | } while_for_each_ftrace_rec(); | |
b6887d79 | 2042 | __enable_ftrace_function_probe(); |
59df055f SR |
2043 | |
2044 | out_unlock: | |
2045 | mutex_unlock(&ftrace_lock); | |
2046 | ||
2047 | return count; | |
2048 | } | |
2049 | ||
2050 | enum { | |
b6887d79 SR |
2051 | PROBE_TEST_FUNC = 1, |
2052 | PROBE_TEST_DATA = 2 | |
59df055f SR |
2053 | }; |
2054 | ||
2055 | static void | |
b6887d79 | 2056 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2057 | void *data, int flags) |
2058 | { | |
b6887d79 | 2059 | struct ftrace_func_probe *entry; |
59df055f SR |
2060 | struct hlist_node *n, *tmp; |
2061 | char str[KSYM_SYMBOL_LEN]; | |
2062 | int type = MATCH_FULL; | |
2063 | int i, len = 0; | |
2064 | char *search; | |
2065 | ||
b36461da | 2066 | if (glob && (strcmp(glob, "*") == 0 || !strlen(glob))) |
59df055f | 2067 | glob = NULL; |
b36461da | 2068 | else if (glob) { |
59df055f SR |
2069 | int not; |
2070 | ||
2071 | type = ftrace_setup_glob(glob, strlen(glob), &search, ¬); | |
2072 | len = strlen(search); | |
2073 | ||
b6887d79 | 2074 | /* we do not support '!' for function probes */ |
59df055f SR |
2075 | if (WARN_ON(not)) |
2076 | return; | |
2077 | } | |
2078 | ||
2079 | mutex_lock(&ftrace_lock); | |
2080 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2081 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2082 | ||
2083 | hlist_for_each_entry_safe(entry, n, tmp, hhd, node) { | |
2084 | ||
2085 | /* break up if statements for readability */ | |
b6887d79 | 2086 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
2087 | continue; |
2088 | ||
b6887d79 | 2089 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
2090 | continue; |
2091 | ||
2092 | /* do this last, since it is the most expensive */ | |
2093 | if (glob) { | |
2094 | kallsyms_lookup(entry->ip, NULL, NULL, | |
2095 | NULL, str); | |
2096 | if (!ftrace_match(str, glob, len, type)) | |
2097 | continue; | |
2098 | } | |
2099 | ||
2100 | hlist_del(&entry->node); | |
2101 | call_rcu(&entry->rcu, ftrace_free_entry_rcu); | |
2102 | } | |
2103 | } | |
b6887d79 | 2104 | __disable_ftrace_function_probe(); |
59df055f SR |
2105 | mutex_unlock(&ftrace_lock); |
2106 | } | |
2107 | ||
2108 | void | |
b6887d79 | 2109 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2110 | void *data) |
2111 | { | |
b6887d79 SR |
2112 | __unregister_ftrace_function_probe(glob, ops, data, |
2113 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
2114 | } |
2115 | ||
2116 | void | |
b6887d79 | 2117 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 2118 | { |
b6887d79 | 2119 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
2120 | } |
2121 | ||
b6887d79 | 2122 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 2123 | { |
b6887d79 | 2124 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
2125 | } |
2126 | ||
f6180773 SR |
2127 | static LIST_HEAD(ftrace_commands); |
2128 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
2129 | ||
2130 | int register_ftrace_command(struct ftrace_func_command *cmd) | |
2131 | { | |
2132 | struct ftrace_func_command *p; | |
2133 | int ret = 0; | |
2134 | ||
2135 | mutex_lock(&ftrace_cmd_mutex); | |
2136 | list_for_each_entry(p, &ftrace_commands, list) { | |
2137 | if (strcmp(cmd->name, p->name) == 0) { | |
2138 | ret = -EBUSY; | |
2139 | goto out_unlock; | |
2140 | } | |
2141 | } | |
2142 | list_add(&cmd->list, &ftrace_commands); | |
2143 | out_unlock: | |
2144 | mutex_unlock(&ftrace_cmd_mutex); | |
2145 | ||
2146 | return ret; | |
2147 | } | |
2148 | ||
2149 | int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
2150 | { | |
2151 | struct ftrace_func_command *p, *n; | |
2152 | int ret = -ENODEV; | |
2153 | ||
2154 | mutex_lock(&ftrace_cmd_mutex); | |
2155 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
2156 | if (strcmp(cmd->name, p->name) == 0) { | |
2157 | ret = 0; | |
2158 | list_del_init(&p->list); | |
2159 | goto out_unlock; | |
2160 | } | |
2161 | } | |
2162 | out_unlock: | |
2163 | mutex_unlock(&ftrace_cmd_mutex); | |
2164 | ||
2165 | return ret; | |
2166 | } | |
2167 | ||
64e7c440 SR |
2168 | static int ftrace_process_regex(char *buff, int len, int enable) |
2169 | { | |
f6180773 | 2170 | char *func, *command, *next = buff; |
6a24a244 | 2171 | struct ftrace_func_command *p; |
f6180773 | 2172 | int ret = -EINVAL; |
64e7c440 SR |
2173 | |
2174 | func = strsep(&next, ":"); | |
2175 | ||
2176 | if (!next) { | |
2177 | ftrace_match_records(func, len, enable); | |
2178 | return 0; | |
2179 | } | |
2180 | ||
f6180773 | 2181 | /* command found */ |
64e7c440 SR |
2182 | |
2183 | command = strsep(&next, ":"); | |
2184 | ||
f6180773 SR |
2185 | mutex_lock(&ftrace_cmd_mutex); |
2186 | list_for_each_entry(p, &ftrace_commands, list) { | |
2187 | if (strcmp(p->name, command) == 0) { | |
2188 | ret = p->func(func, command, next, enable); | |
2189 | goto out_unlock; | |
2190 | } | |
64e7c440 | 2191 | } |
f6180773 SR |
2192 | out_unlock: |
2193 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 2194 | |
f6180773 | 2195 | return ret; |
64e7c440 SR |
2196 | } |
2197 | ||
e309b41d | 2198 | static ssize_t |
41c52c0d SR |
2199 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
2200 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
2201 | { |
2202 | struct ftrace_iterator *iter; | |
689fd8b6 | 2203 | struct trace_parser *parser; |
2204 | ssize_t ret, read; | |
5072c59f | 2205 | |
4ba7978e | 2206 | if (!cnt) |
5072c59f SR |
2207 | return 0; |
2208 | ||
41c52c0d | 2209 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
2210 | |
2211 | if (file->f_mode & FMODE_READ) { | |
2212 | struct seq_file *m = file->private_data; | |
2213 | iter = m->private; | |
2214 | } else | |
2215 | iter = file->private_data; | |
2216 | ||
689fd8b6 | 2217 | parser = &iter->parser; |
2218 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 2219 | |
4ba7978e | 2220 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 2221 | !trace_parser_cont(parser)) { |
2222 | ret = ftrace_process_regex(parser->buffer, | |
2223 | parser->idx, enable); | |
5072c59f | 2224 | if (ret) |
ed146b25 | 2225 | goto out_unlock; |
5072c59f | 2226 | |
689fd8b6 | 2227 | trace_parser_clear(parser); |
eda1e328 | 2228 | } |
5072c59f | 2229 | |
5072c59f | 2230 | ret = read; |
ed146b25 | 2231 | out_unlock: |
689fd8b6 | 2232 | mutex_unlock(&ftrace_regex_lock); |
ed146b25 | 2233 | |
5072c59f SR |
2234 | return ret; |
2235 | } | |
2236 | ||
41c52c0d SR |
2237 | static ssize_t |
2238 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
2239 | size_t cnt, loff_t *ppos) | |
2240 | { | |
2241 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
2242 | } | |
2243 | ||
2244 | static ssize_t | |
2245 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
2246 | size_t cnt, loff_t *ppos) | |
2247 | { | |
2248 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
2249 | } | |
2250 | ||
2251 | static void | |
2252 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
2253 | { | |
2254 | if (unlikely(ftrace_disabled)) | |
2255 | return; | |
2256 | ||
2257 | mutex_lock(&ftrace_regex_lock); | |
2258 | if (reset) | |
2259 | ftrace_filter_reset(enable); | |
2260 | if (buf) | |
7f24b31b | 2261 | ftrace_match_records(buf, len, enable); |
41c52c0d SR |
2262 | mutex_unlock(&ftrace_regex_lock); |
2263 | } | |
2264 | ||
77a2b37d SR |
2265 | /** |
2266 | * ftrace_set_filter - set a function to filter on in ftrace | |
2267 | * @buf - the string that holds the function filter text. | |
2268 | * @len - the length of the string. | |
2269 | * @reset - non zero to reset all filters before applying this filter. | |
2270 | * | |
2271 | * Filters denote which functions should be enabled when tracing is enabled. | |
2272 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
2273 | */ | |
e309b41d | 2274 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 2275 | { |
41c52c0d SR |
2276 | ftrace_set_regex(buf, len, reset, 1); |
2277 | } | |
4eebcc81 | 2278 | |
41c52c0d SR |
2279 | /** |
2280 | * ftrace_set_notrace - set a function to not trace in ftrace | |
2281 | * @buf - the string that holds the function notrace text. | |
2282 | * @len - the length of the string. | |
2283 | * @reset - non zero to reset all filters before applying this filter. | |
2284 | * | |
2285 | * Notrace Filters denote which functions should not be enabled when tracing | |
2286 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
2287 | * for tracing. | |
2288 | */ | |
2289 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
2290 | { | |
2291 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
2292 | } |
2293 | ||
2af15d6a SR |
2294 | /* |
2295 | * command line interface to allow users to set filters on boot up. | |
2296 | */ | |
2297 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
2298 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
2299 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
2300 | ||
2301 | static int __init set_ftrace_notrace(char *str) | |
2302 | { | |
2303 | strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); | |
2304 | return 1; | |
2305 | } | |
2306 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
2307 | ||
2308 | static int __init set_ftrace_filter(char *str) | |
2309 | { | |
2310 | strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); | |
2311 | return 1; | |
2312 | } | |
2313 | __setup("ftrace_filter=", set_ftrace_filter); | |
2314 | ||
2315 | static void __init set_ftrace_early_filter(char *buf, int enable) | |
2316 | { | |
2317 | char *func; | |
2318 | ||
2319 | while (buf) { | |
2320 | func = strsep(&buf, ","); | |
2321 | ftrace_set_regex(func, strlen(func), 0, enable); | |
2322 | } | |
2323 | } | |
2324 | ||
2325 | static void __init set_ftrace_early_filters(void) | |
2326 | { | |
2327 | if (ftrace_filter_buf[0]) | |
2328 | set_ftrace_early_filter(ftrace_filter_buf, 1); | |
2329 | if (ftrace_notrace_buf[0]) | |
2330 | set_ftrace_early_filter(ftrace_notrace_buf, 0); | |
2331 | } | |
2332 | ||
e309b41d | 2333 | static int |
41c52c0d | 2334 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
2335 | { |
2336 | struct seq_file *m = (struct seq_file *)file->private_data; | |
2337 | struct ftrace_iterator *iter; | |
689fd8b6 | 2338 | struct trace_parser *parser; |
5072c59f | 2339 | |
41c52c0d | 2340 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
2341 | if (file->f_mode & FMODE_READ) { |
2342 | iter = m->private; | |
2343 | ||
2344 | seq_release(inode, file); | |
2345 | } else | |
2346 | iter = file->private_data; | |
2347 | ||
689fd8b6 | 2348 | parser = &iter->parser; |
2349 | if (trace_parser_loaded(parser)) { | |
2350 | parser->buffer[parser->idx] = 0; | |
2351 | ftrace_match_records(parser->buffer, parser->idx, enable); | |
5072c59f SR |
2352 | } |
2353 | ||
e6ea44e9 | 2354 | mutex_lock(&ftrace_lock); |
ee02a2e5 | 2355 | if (ftrace_start_up && ftrace_enabled) |
5072c59f | 2356 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
e6ea44e9 | 2357 | mutex_unlock(&ftrace_lock); |
5072c59f | 2358 | |
689fd8b6 | 2359 | trace_parser_put(parser); |
5072c59f | 2360 | kfree(iter); |
689fd8b6 | 2361 | |
41c52c0d | 2362 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
2363 | return 0; |
2364 | } | |
2365 | ||
41c52c0d SR |
2366 | static int |
2367 | ftrace_filter_release(struct inode *inode, struct file *file) | |
2368 | { | |
2369 | return ftrace_regex_release(inode, file, 1); | |
2370 | } | |
2371 | ||
2372 | static int | |
2373 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
2374 | { | |
2375 | return ftrace_regex_release(inode, file, 0); | |
2376 | } | |
2377 | ||
5e2336a0 | 2378 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
2379 | .open = ftrace_avail_open, |
2380 | .read = seq_read, | |
2381 | .llseek = seq_lseek, | |
3be04b47 | 2382 | .release = seq_release_private, |
5072c59f SR |
2383 | }; |
2384 | ||
5e2336a0 | 2385 | static const struct file_operations ftrace_failures_fops = { |
eb9a7bf0 AS |
2386 | .open = ftrace_failures_open, |
2387 | .read = seq_read, | |
2388 | .llseek = seq_lseek, | |
3be04b47 | 2389 | .release = seq_release_private, |
eb9a7bf0 AS |
2390 | }; |
2391 | ||
5e2336a0 | 2392 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 2393 | .open = ftrace_filter_open, |
850a80cf | 2394 | .read = seq_read, |
5072c59f | 2395 | .write = ftrace_filter_write, |
41c52c0d | 2396 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
2397 | .release = ftrace_filter_release, |
2398 | }; | |
2399 | ||
5e2336a0 | 2400 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 2401 | .open = ftrace_notrace_open, |
850a80cf | 2402 | .read = seq_read, |
41c52c0d SR |
2403 | .write = ftrace_notrace_write, |
2404 | .llseek = ftrace_regex_lseek, | |
2405 | .release = ftrace_notrace_release, | |
2406 | }; | |
2407 | ||
ea4e2bc4 SR |
2408 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
2409 | ||
2410 | static DEFINE_MUTEX(graph_lock); | |
2411 | ||
2412 | int ftrace_graph_count; | |
2413 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; | |
2414 | ||
2415 | static void * | |
85951842 | 2416 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 2417 | { |
85951842 | 2418 | if (*pos >= ftrace_graph_count) |
ea4e2bc4 | 2419 | return NULL; |
a4ec5e0c | 2420 | return &ftrace_graph_funcs[*pos]; |
85951842 | 2421 | } |
ea4e2bc4 | 2422 | |
85951842 LZ |
2423 | static void * |
2424 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
2425 | { | |
2426 | (*pos)++; | |
2427 | return __g_next(m, pos); | |
ea4e2bc4 SR |
2428 | } |
2429 | ||
2430 | static void *g_start(struct seq_file *m, loff_t *pos) | |
2431 | { | |
ea4e2bc4 SR |
2432 | mutex_lock(&graph_lock); |
2433 | ||
f9349a8f FW |
2434 | /* Nothing, tell g_show to print all functions are enabled */ |
2435 | if (!ftrace_graph_count && !*pos) | |
2436 | return (void *)1; | |
2437 | ||
85951842 | 2438 | return __g_next(m, pos); |
ea4e2bc4 SR |
2439 | } |
2440 | ||
2441 | static void g_stop(struct seq_file *m, void *p) | |
2442 | { | |
2443 | mutex_unlock(&graph_lock); | |
2444 | } | |
2445 | ||
2446 | static int g_show(struct seq_file *m, void *v) | |
2447 | { | |
2448 | unsigned long *ptr = v; | |
ea4e2bc4 SR |
2449 | |
2450 | if (!ptr) | |
2451 | return 0; | |
2452 | ||
f9349a8f FW |
2453 | if (ptr == (unsigned long *)1) { |
2454 | seq_printf(m, "#### all functions enabled ####\n"); | |
2455 | return 0; | |
2456 | } | |
2457 | ||
b375a11a | 2458 | seq_printf(m, "%ps\n", (void *)*ptr); |
ea4e2bc4 SR |
2459 | |
2460 | return 0; | |
2461 | } | |
2462 | ||
88e9d34c | 2463 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
2464 | .start = g_start, |
2465 | .next = g_next, | |
2466 | .stop = g_stop, | |
2467 | .show = g_show, | |
2468 | }; | |
2469 | ||
2470 | static int | |
2471 | ftrace_graph_open(struct inode *inode, struct file *file) | |
2472 | { | |
2473 | int ret = 0; | |
2474 | ||
2475 | if (unlikely(ftrace_disabled)) | |
2476 | return -ENODEV; | |
2477 | ||
2478 | mutex_lock(&graph_lock); | |
2479 | if ((file->f_mode & FMODE_WRITE) && | |
8650ae32 | 2480 | (file->f_flags & O_TRUNC)) { |
ea4e2bc4 SR |
2481 | ftrace_graph_count = 0; |
2482 | memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); | |
2483 | } | |
a4ec5e0c | 2484 | mutex_unlock(&graph_lock); |
ea4e2bc4 | 2485 | |
a4ec5e0c | 2486 | if (file->f_mode & FMODE_READ) |
ea4e2bc4 | 2487 | ret = seq_open(file, &ftrace_graph_seq_ops); |
ea4e2bc4 SR |
2488 | |
2489 | return ret; | |
2490 | } | |
2491 | ||
87827111 LZ |
2492 | static int |
2493 | ftrace_graph_release(struct inode *inode, struct file *file) | |
2494 | { | |
2495 | if (file->f_mode & FMODE_READ) | |
2496 | seq_release(inode, file); | |
2497 | return 0; | |
2498 | } | |
2499 | ||
ea4e2bc4 | 2500 | static int |
f9349a8f | 2501 | ftrace_set_func(unsigned long *array, int *idx, char *buffer) |
ea4e2bc4 | 2502 | { |
ea4e2bc4 SR |
2503 | struct dyn_ftrace *rec; |
2504 | struct ftrace_page *pg; | |
f9349a8f | 2505 | int search_len; |
ea4e2bc4 | 2506 | int found = 0; |
f9349a8f FW |
2507 | int type, not; |
2508 | char *search; | |
2509 | bool exists; | |
2510 | int i; | |
ea4e2bc4 SR |
2511 | |
2512 | if (ftrace_disabled) | |
2513 | return -ENODEV; | |
2514 | ||
f9349a8f FW |
2515 | /* decode regex */ |
2516 | type = ftrace_setup_glob(buffer, strlen(buffer), &search, ¬); | |
2517 | if (not) | |
2518 | return -EINVAL; | |
2519 | ||
2520 | search_len = strlen(search); | |
2521 | ||
52baf119 | 2522 | mutex_lock(&ftrace_lock); |
265c831c SR |
2523 | do_for_each_ftrace_rec(pg, rec) { |
2524 | ||
f9349a8f FW |
2525 | if (*idx >= FTRACE_GRAPH_MAX_FUNCS) |
2526 | break; | |
2527 | ||
265c831c SR |
2528 | if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE)) |
2529 | continue; | |
2530 | ||
f9349a8f FW |
2531 | if (ftrace_match_record(rec, search, search_len, type)) { |
2532 | /* ensure it is not already in the array */ | |
2533 | exists = false; | |
2534 | for (i = 0; i < *idx; i++) | |
2535 | if (array[i] == rec->ip) { | |
2536 | exists = true; | |
265c831c SR |
2537 | break; |
2538 | } | |
f9349a8f FW |
2539 | if (!exists) { |
2540 | array[(*idx)++] = rec->ip; | |
2541 | found = 1; | |
2542 | } | |
ea4e2bc4 | 2543 | } |
265c831c | 2544 | } while_for_each_ftrace_rec(); |
f9349a8f | 2545 | |
52baf119 | 2546 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 SR |
2547 | |
2548 | return found ? 0 : -EINVAL; | |
2549 | } | |
2550 | ||
2551 | static ssize_t | |
2552 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
2553 | size_t cnt, loff_t *ppos) | |
2554 | { | |
689fd8b6 | 2555 | struct trace_parser parser; |
4ba7978e | 2556 | ssize_t read, ret; |
ea4e2bc4 SR |
2557 | |
2558 | if (!cnt || cnt < 0) | |
2559 | return 0; | |
2560 | ||
2561 | mutex_lock(&graph_lock); | |
2562 | ||
2563 | if (ftrace_graph_count >= FTRACE_GRAPH_MAX_FUNCS) { | |
2564 | ret = -EBUSY; | |
1eb90f13 | 2565 | goto out_unlock; |
ea4e2bc4 SR |
2566 | } |
2567 | ||
689fd8b6 | 2568 | if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) { |
2569 | ret = -ENOMEM; | |
1eb90f13 | 2570 | goto out_unlock; |
ea4e2bc4 SR |
2571 | } |
2572 | ||
689fd8b6 | 2573 | read = trace_get_user(&parser, ubuf, cnt, ppos); |
ea4e2bc4 | 2574 | |
4ba7978e | 2575 | if (read >= 0 && trace_parser_loaded((&parser))) { |
689fd8b6 | 2576 | parser.buffer[parser.idx] = 0; |
2577 | ||
2578 | /* we allow only one expression at a time */ | |
a4ec5e0c | 2579 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, |
689fd8b6 | 2580 | parser.buffer); |
ea4e2bc4 | 2581 | if (ret) |
1eb90f13 | 2582 | goto out_free; |
ea4e2bc4 | 2583 | } |
ea4e2bc4 SR |
2584 | |
2585 | ret = read; | |
1eb90f13 LZ |
2586 | |
2587 | out_free: | |
689fd8b6 | 2588 | trace_parser_put(&parser); |
1eb90f13 | 2589 | out_unlock: |
ea4e2bc4 SR |
2590 | mutex_unlock(&graph_lock); |
2591 | ||
2592 | return ret; | |
2593 | } | |
2594 | ||
2595 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
2596 | .open = ftrace_graph_open, |
2597 | .read = seq_read, | |
2598 | .write = ftrace_graph_write, | |
2599 | .release = ftrace_graph_release, | |
ea4e2bc4 SR |
2600 | }; |
2601 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2602 | ||
df4fc315 | 2603 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 2604 | { |
5072c59f | 2605 | |
5452af66 FW |
2606 | trace_create_file("available_filter_functions", 0444, |
2607 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 2608 | |
5452af66 FW |
2609 | trace_create_file("failures", 0444, |
2610 | d_tracer, NULL, &ftrace_failures_fops); | |
eb9a7bf0 | 2611 | |
5452af66 FW |
2612 | trace_create_file("set_ftrace_filter", 0644, d_tracer, |
2613 | NULL, &ftrace_filter_fops); | |
41c52c0d | 2614 | |
5452af66 | 2615 | trace_create_file("set_ftrace_notrace", 0644, d_tracer, |
41c52c0d | 2616 | NULL, &ftrace_notrace_fops); |
ad90c0e3 | 2617 | |
ea4e2bc4 | 2618 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 2619 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
2620 | NULL, |
2621 | &ftrace_graph_fops); | |
ea4e2bc4 SR |
2622 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
2623 | ||
5072c59f SR |
2624 | return 0; |
2625 | } | |
2626 | ||
31e88909 SR |
2627 | static int ftrace_convert_nops(struct module *mod, |
2628 | unsigned long *start, | |
68bf21aa SR |
2629 | unsigned long *end) |
2630 | { | |
2631 | unsigned long *p; | |
2632 | unsigned long addr; | |
2633 | unsigned long flags; | |
2634 | ||
e6ea44e9 | 2635 | mutex_lock(&ftrace_lock); |
68bf21aa SR |
2636 | p = start; |
2637 | while (p < end) { | |
2638 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
2639 | /* |
2640 | * Some architecture linkers will pad between | |
2641 | * the different mcount_loc sections of different | |
2642 | * object files to satisfy alignments. | |
2643 | * Skip any NULL pointers. | |
2644 | */ | |
2645 | if (!addr) | |
2646 | continue; | |
68bf21aa | 2647 | ftrace_record_ip(addr); |
68bf21aa SR |
2648 | } |
2649 | ||
08f5ac90 | 2650 | /* disable interrupts to prevent kstop machine */ |
68bf21aa | 2651 | local_irq_save(flags); |
31e88909 | 2652 | ftrace_update_code(mod); |
68bf21aa | 2653 | local_irq_restore(flags); |
e6ea44e9 | 2654 | mutex_unlock(&ftrace_lock); |
68bf21aa SR |
2655 | |
2656 | return 0; | |
2657 | } | |
2658 | ||
93eb677d | 2659 | #ifdef CONFIG_MODULES |
e7247a15 | 2660 | void ftrace_release_mod(struct module *mod) |
93eb677d SR |
2661 | { |
2662 | struct dyn_ftrace *rec; | |
2663 | struct ftrace_page *pg; | |
93eb677d | 2664 | |
e7247a15 | 2665 | if (ftrace_disabled) |
93eb677d SR |
2666 | return; |
2667 | ||
2668 | mutex_lock(&ftrace_lock); | |
2669 | do_for_each_ftrace_rec(pg, rec) { | |
e7247a15 | 2670 | if (within_module_core(rec->ip, mod)) { |
93eb677d SR |
2671 | /* |
2672 | * rec->ip is changed in ftrace_free_rec() | |
2673 | * It should not between s and e if record was freed. | |
2674 | */ | |
2675 | FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE); | |
2676 | ftrace_free_rec(rec); | |
2677 | } | |
2678 | } while_for_each_ftrace_rec(); | |
2679 | mutex_unlock(&ftrace_lock); | |
2680 | } | |
2681 | ||
2682 | static void ftrace_init_module(struct module *mod, | |
2683 | unsigned long *start, unsigned long *end) | |
90d595fe | 2684 | { |
00fd61ae | 2685 | if (ftrace_disabled || start == end) |
fed1939c | 2686 | return; |
31e88909 | 2687 | ftrace_convert_nops(mod, start, end); |
90d595fe SR |
2688 | } |
2689 | ||
93eb677d SR |
2690 | static int ftrace_module_notify(struct notifier_block *self, |
2691 | unsigned long val, void *data) | |
2692 | { | |
2693 | struct module *mod = data; | |
2694 | ||
2695 | switch (val) { | |
2696 | case MODULE_STATE_COMING: | |
2697 | ftrace_init_module(mod, mod->ftrace_callsites, | |
2698 | mod->ftrace_callsites + | |
2699 | mod->num_ftrace_callsites); | |
2700 | break; | |
2701 | case MODULE_STATE_GOING: | |
e7247a15 | 2702 | ftrace_release_mod(mod); |
93eb677d SR |
2703 | break; |
2704 | } | |
2705 | ||
2706 | return 0; | |
2707 | } | |
2708 | #else | |
2709 | static int ftrace_module_notify(struct notifier_block *self, | |
2710 | unsigned long val, void *data) | |
2711 | { | |
2712 | return 0; | |
2713 | } | |
2714 | #endif /* CONFIG_MODULES */ | |
2715 | ||
2716 | struct notifier_block ftrace_module_nb = { | |
2717 | .notifier_call = ftrace_module_notify, | |
2718 | .priority = 0, | |
2719 | }; | |
2720 | ||
68bf21aa SR |
2721 | extern unsigned long __start_mcount_loc[]; |
2722 | extern unsigned long __stop_mcount_loc[]; | |
2723 | ||
2724 | void __init ftrace_init(void) | |
2725 | { | |
2726 | unsigned long count, addr, flags; | |
2727 | int ret; | |
2728 | ||
2729 | /* Keep the ftrace pointer to the stub */ | |
2730 | addr = (unsigned long)ftrace_stub; | |
2731 | ||
2732 | local_irq_save(flags); | |
2733 | ftrace_dyn_arch_init(&addr); | |
2734 | local_irq_restore(flags); | |
2735 | ||
2736 | /* ftrace_dyn_arch_init places the return code in addr */ | |
2737 | if (addr) | |
2738 | goto failed; | |
2739 | ||
2740 | count = __stop_mcount_loc - __start_mcount_loc; | |
2741 | ||
2742 | ret = ftrace_dyn_table_alloc(count); | |
2743 | if (ret) | |
2744 | goto failed; | |
2745 | ||
2746 | last_ftrace_enabled = ftrace_enabled = 1; | |
2747 | ||
31e88909 SR |
2748 | ret = ftrace_convert_nops(NULL, |
2749 | __start_mcount_loc, | |
68bf21aa SR |
2750 | __stop_mcount_loc); |
2751 | ||
93eb677d | 2752 | ret = register_module_notifier(&ftrace_module_nb); |
24ed0c4b | 2753 | if (ret) |
93eb677d SR |
2754 | pr_warning("Failed to register trace ftrace module notifier\n"); |
2755 | ||
2af15d6a SR |
2756 | set_ftrace_early_filters(); |
2757 | ||
68bf21aa SR |
2758 | return; |
2759 | failed: | |
2760 | ftrace_disabled = 1; | |
2761 | } | |
68bf21aa | 2762 | |
3d083395 | 2763 | #else |
0b6e4d56 FW |
2764 | |
2765 | static int __init ftrace_nodyn_init(void) | |
2766 | { | |
2767 | ftrace_enabled = 1; | |
2768 | return 0; | |
2769 | } | |
2770 | device_initcall(ftrace_nodyn_init); | |
2771 | ||
df4fc315 SR |
2772 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
2773 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 SR |
2774 | /* Keep as macros so we do not need to define the commands */ |
2775 | # define ftrace_startup(command) do { } while (0) | |
2776 | # define ftrace_shutdown(command) do { } while (0) | |
c7aafc54 IM |
2777 | # define ftrace_startup_sysctl() do { } while (0) |
2778 | # define ftrace_shutdown_sysctl() do { } while (0) | |
3d083395 SR |
2779 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
2780 | ||
df4fc315 SR |
2781 | static ssize_t |
2782 | ftrace_pid_read(struct file *file, char __user *ubuf, | |
2783 | size_t cnt, loff_t *ppos) | |
2784 | { | |
2785 | char buf[64]; | |
2786 | int r; | |
2787 | ||
e32d8956 SR |
2788 | if (ftrace_pid_trace == ftrace_swapper_pid) |
2789 | r = sprintf(buf, "swapper tasks\n"); | |
2790 | else if (ftrace_pid_trace) | |
cc59c9e8 | 2791 | r = sprintf(buf, "%u\n", pid_vnr(ftrace_pid_trace)); |
df4fc315 SR |
2792 | else |
2793 | r = sprintf(buf, "no pid\n"); | |
2794 | ||
2795 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
2796 | } | |
2797 | ||
e32d8956 | 2798 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
2799 | { |
2800 | struct task_struct *p; | |
e32d8956 | 2801 | int cpu; |
978f3a45 | 2802 | |
e32d8956 SR |
2803 | get_online_cpus(); |
2804 | for_each_online_cpu(cpu) { | |
2805 | p = idle_task(cpu); | |
978f3a45 | 2806 | clear_tsk_trace_trace(p); |
e32d8956 SR |
2807 | } |
2808 | put_online_cpus(); | |
2809 | } | |
978f3a45 | 2810 | |
e32d8956 SR |
2811 | static void set_ftrace_swapper(void) |
2812 | { | |
2813 | struct task_struct *p; | |
2814 | int cpu; | |
2815 | ||
2816 | get_online_cpus(); | |
2817 | for_each_online_cpu(cpu) { | |
2818 | p = idle_task(cpu); | |
2819 | set_tsk_trace_trace(p); | |
2820 | } | |
2821 | put_online_cpus(); | |
978f3a45 SR |
2822 | } |
2823 | ||
e32d8956 SR |
2824 | static void clear_ftrace_pid(struct pid *pid) |
2825 | { | |
2826 | struct task_struct *p; | |
2827 | ||
229c4ef8 | 2828 | rcu_read_lock(); |
e32d8956 SR |
2829 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2830 | clear_tsk_trace_trace(p); | |
2831 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
2832 | rcu_read_unlock(); |
2833 | ||
e32d8956 SR |
2834 | put_pid(pid); |
2835 | } | |
2836 | ||
2837 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
2838 | { |
2839 | struct task_struct *p; | |
2840 | ||
229c4ef8 | 2841 | rcu_read_lock(); |
978f3a45 SR |
2842 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2843 | set_tsk_trace_trace(p); | |
2844 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 2845 | rcu_read_unlock(); |
978f3a45 SR |
2846 | } |
2847 | ||
e32d8956 SR |
2848 | static void clear_ftrace_pid_task(struct pid **pid) |
2849 | { | |
2850 | if (*pid == ftrace_swapper_pid) | |
2851 | clear_ftrace_swapper(); | |
2852 | else | |
2853 | clear_ftrace_pid(*pid); | |
2854 | ||
2855 | *pid = NULL; | |
2856 | } | |
2857 | ||
2858 | static void set_ftrace_pid_task(struct pid *pid) | |
2859 | { | |
2860 | if (pid == ftrace_swapper_pid) | |
2861 | set_ftrace_swapper(); | |
2862 | else | |
2863 | set_ftrace_pid(pid); | |
2864 | } | |
2865 | ||
df4fc315 SR |
2866 | static ssize_t |
2867 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
2868 | size_t cnt, loff_t *ppos) | |
2869 | { | |
978f3a45 | 2870 | struct pid *pid; |
df4fc315 SR |
2871 | char buf[64]; |
2872 | long val; | |
2873 | int ret; | |
2874 | ||
2875 | if (cnt >= sizeof(buf)) | |
2876 | return -EINVAL; | |
2877 | ||
2878 | if (copy_from_user(&buf, ubuf, cnt)) | |
2879 | return -EFAULT; | |
2880 | ||
2881 | buf[cnt] = 0; | |
2882 | ||
2883 | ret = strict_strtol(buf, 10, &val); | |
2884 | if (ret < 0) | |
2885 | return ret; | |
2886 | ||
e6ea44e9 | 2887 | mutex_lock(&ftrace_lock); |
978f3a45 | 2888 | if (val < 0) { |
df4fc315 | 2889 | /* disable pid tracing */ |
978f3a45 | 2890 | if (!ftrace_pid_trace) |
df4fc315 | 2891 | goto out; |
978f3a45 SR |
2892 | |
2893 | clear_ftrace_pid_task(&ftrace_pid_trace); | |
df4fc315 SR |
2894 | |
2895 | } else { | |
e32d8956 SR |
2896 | /* swapper task is special */ |
2897 | if (!val) { | |
2898 | pid = ftrace_swapper_pid; | |
2899 | if (pid == ftrace_pid_trace) | |
2900 | goto out; | |
2901 | } else { | |
2902 | pid = find_get_pid(val); | |
df4fc315 | 2903 | |
e32d8956 SR |
2904 | if (pid == ftrace_pid_trace) { |
2905 | put_pid(pid); | |
2906 | goto out; | |
2907 | } | |
0ef8cde5 | 2908 | } |
0ef8cde5 | 2909 | |
978f3a45 SR |
2910 | if (ftrace_pid_trace) |
2911 | clear_ftrace_pid_task(&ftrace_pid_trace); | |
2912 | ||
2913 | if (!pid) | |
2914 | goto out; | |
2915 | ||
2916 | ftrace_pid_trace = pid; | |
2917 | ||
2918 | set_ftrace_pid_task(ftrace_pid_trace); | |
df4fc315 SR |
2919 | } |
2920 | ||
2921 | /* update the function call */ | |
2922 | ftrace_update_pid_func(); | |
2923 | ftrace_startup_enable(0); | |
2924 | ||
2925 | out: | |
e6ea44e9 | 2926 | mutex_unlock(&ftrace_lock); |
df4fc315 SR |
2927 | |
2928 | return cnt; | |
2929 | } | |
2930 | ||
5e2336a0 | 2931 | static const struct file_operations ftrace_pid_fops = { |
df4fc315 SR |
2932 | .read = ftrace_pid_read, |
2933 | .write = ftrace_pid_write, | |
2934 | }; | |
2935 | ||
2936 | static __init int ftrace_init_debugfs(void) | |
2937 | { | |
2938 | struct dentry *d_tracer; | |
df4fc315 SR |
2939 | |
2940 | d_tracer = tracing_init_dentry(); | |
2941 | if (!d_tracer) | |
2942 | return 0; | |
2943 | ||
2944 | ftrace_init_dyn_debugfs(d_tracer); | |
2945 | ||
5452af66 FW |
2946 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
2947 | NULL, &ftrace_pid_fops); | |
493762fc SR |
2948 | |
2949 | ftrace_profile_debugfs(d_tracer); | |
2950 | ||
df4fc315 SR |
2951 | return 0; |
2952 | } | |
df4fc315 SR |
2953 | fs_initcall(ftrace_init_debugfs); |
2954 | ||
a2bb6a3d | 2955 | /** |
81adbdc0 | 2956 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
2957 | * |
2958 | * This function should be used by panic code. It stops ftrace | |
2959 | * but in a not so nice way. If you need to simply kill ftrace | |
2960 | * from a non-atomic section, use ftrace_kill. | |
2961 | */ | |
81adbdc0 | 2962 | void ftrace_kill(void) |
a2bb6a3d SR |
2963 | { |
2964 | ftrace_disabled = 1; | |
2965 | ftrace_enabled = 0; | |
a2bb6a3d SR |
2966 | clear_ftrace_function(); |
2967 | } | |
2968 | ||
16444a8a | 2969 | /** |
3d083395 SR |
2970 | * register_ftrace_function - register a function for profiling |
2971 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 2972 | * |
3d083395 SR |
2973 | * Register a function to be called by all functions in the |
2974 | * kernel. | |
2975 | * | |
2976 | * Note: @ops->func and all the functions it calls must be labeled | |
2977 | * with "notrace", otherwise it will go into a | |
2978 | * recursive loop. | |
16444a8a | 2979 | */ |
3d083395 | 2980 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 2981 | { |
b0fc494f SR |
2982 | int ret; |
2983 | ||
4eebcc81 SR |
2984 | if (unlikely(ftrace_disabled)) |
2985 | return -1; | |
2986 | ||
e6ea44e9 | 2987 | mutex_lock(&ftrace_lock); |
e7d3737e | 2988 | |
b0fc494f | 2989 | ret = __register_ftrace_function(ops); |
5a45cfe1 | 2990 | ftrace_startup(0); |
b0fc494f | 2991 | |
e6ea44e9 | 2992 | mutex_unlock(&ftrace_lock); |
b0fc494f | 2993 | return ret; |
3d083395 SR |
2994 | } |
2995 | ||
2996 | /** | |
32632920 | 2997 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
2998 | * @ops - ops structure that holds the function to unregister |
2999 | * | |
3000 | * Unregister a function that was added to be called by ftrace profiling. | |
3001 | */ | |
3002 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
3003 | { | |
3004 | int ret; | |
3005 | ||
e6ea44e9 | 3006 | mutex_lock(&ftrace_lock); |
3d083395 | 3007 | ret = __unregister_ftrace_function(ops); |
5a45cfe1 | 3008 | ftrace_shutdown(0); |
e6ea44e9 | 3009 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
3010 | |
3011 | return ret; | |
3012 | } | |
3013 | ||
e309b41d | 3014 | int |
b0fc494f | 3015 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
8d65af78 | 3016 | void __user *buffer, size_t *lenp, |
b0fc494f SR |
3017 | loff_t *ppos) |
3018 | { | |
3019 | int ret; | |
3020 | ||
4eebcc81 SR |
3021 | if (unlikely(ftrace_disabled)) |
3022 | return -ENODEV; | |
3023 | ||
e6ea44e9 | 3024 | mutex_lock(&ftrace_lock); |
b0fc494f | 3025 | |
8d65af78 | 3026 | ret = proc_dointvec(table, write, buffer, lenp, ppos); |
b0fc494f | 3027 | |
a32c7765 | 3028 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
3029 | goto out; |
3030 | ||
a32c7765 | 3031 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f SR |
3032 | |
3033 | if (ftrace_enabled) { | |
3034 | ||
3035 | ftrace_startup_sysctl(); | |
3036 | ||
3037 | /* we are starting ftrace again */ | |
3038 | if (ftrace_list != &ftrace_list_end) { | |
3039 | if (ftrace_list->next == &ftrace_list_end) | |
3040 | ftrace_trace_function = ftrace_list->func; | |
3041 | else | |
3042 | ftrace_trace_function = ftrace_list_func; | |
3043 | } | |
3044 | ||
3045 | } else { | |
3046 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
3047 | ftrace_trace_function = ftrace_stub; | |
3048 | ||
3049 | ftrace_shutdown_sysctl(); | |
3050 | } | |
3051 | ||
3052 | out: | |
e6ea44e9 | 3053 | mutex_unlock(&ftrace_lock); |
3d083395 | 3054 | return ret; |
16444a8a | 3055 | } |
f17845e5 | 3056 | |
fb52607a | 3057 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 3058 | |
597af815 | 3059 | static int ftrace_graph_active; |
4a2b8dda | 3060 | static struct notifier_block ftrace_suspend_notifier; |
e7d3737e | 3061 | |
e49dc19c SR |
3062 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
3063 | { | |
3064 | return 0; | |
3065 | } | |
3066 | ||
287b6e68 FW |
3067 | /* The callbacks that hook a function */ |
3068 | trace_func_graph_ret_t ftrace_graph_return = | |
3069 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 3070 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
3071 | |
3072 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
3073 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
3074 | { | |
3075 | int i; | |
3076 | int ret = 0; | |
3077 | unsigned long flags; | |
3078 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
3079 | struct task_struct *g, *t; | |
3080 | ||
3081 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
3082 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
3083 | * sizeof(struct ftrace_ret_stack), | |
3084 | GFP_KERNEL); | |
3085 | if (!ret_stack_list[i]) { | |
3086 | start = 0; | |
3087 | end = i; | |
3088 | ret = -ENOMEM; | |
3089 | goto free; | |
3090 | } | |
3091 | } | |
3092 | ||
3093 | read_lock_irqsave(&tasklist_lock, flags); | |
3094 | do_each_thread(g, t) { | |
3095 | if (start == end) { | |
3096 | ret = -EAGAIN; | |
3097 | goto unlock; | |
3098 | } | |
3099 | ||
3100 | if (t->ret_stack == NULL) { | |
380c4b14 | 3101 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 3102 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
3103 | t->curr_ret_stack = -1; |
3104 | /* Make sure the tasks see the -1 first: */ | |
3105 | smp_wmb(); | |
3106 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
3107 | } |
3108 | } while_each_thread(g, t); | |
3109 | ||
3110 | unlock: | |
3111 | read_unlock_irqrestore(&tasklist_lock, flags); | |
3112 | free: | |
3113 | for (i = start; i < end; i++) | |
3114 | kfree(ret_stack_list[i]); | |
3115 | return ret; | |
3116 | } | |
3117 | ||
8aef2d28 SR |
3118 | static void |
3119 | ftrace_graph_probe_sched_switch(struct rq *__rq, struct task_struct *prev, | |
3120 | struct task_struct *next) | |
3121 | { | |
3122 | unsigned long long timestamp; | |
3123 | int index; | |
3124 | ||
be6f164a SR |
3125 | /* |
3126 | * Does the user want to count the time a function was asleep. | |
3127 | * If so, do not update the time stamps. | |
3128 | */ | |
3129 | if (trace_flags & TRACE_ITER_SLEEP_TIME) | |
3130 | return; | |
3131 | ||
8aef2d28 SR |
3132 | timestamp = trace_clock_local(); |
3133 | ||
3134 | prev->ftrace_timestamp = timestamp; | |
3135 | ||
3136 | /* only process tasks that we timestamped */ | |
3137 | if (!next->ftrace_timestamp) | |
3138 | return; | |
3139 | ||
3140 | /* | |
3141 | * Update all the counters in next to make up for the | |
3142 | * time next was sleeping. | |
3143 | */ | |
3144 | timestamp -= next->ftrace_timestamp; | |
3145 | ||
3146 | for (index = next->curr_ret_stack; index >= 0; index--) | |
3147 | next->ret_stack[index].calltime += timestamp; | |
3148 | } | |
3149 | ||
f201ae23 | 3150 | /* Allocate a return stack for each task */ |
fb52607a | 3151 | static int start_graph_tracing(void) |
f201ae23 FW |
3152 | { |
3153 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 3154 | int ret, cpu; |
f201ae23 FW |
3155 | |
3156 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
3157 | sizeof(struct ftrace_ret_stack *), | |
3158 | GFP_KERNEL); | |
3159 | ||
3160 | if (!ret_stack_list) | |
3161 | return -ENOMEM; | |
3162 | ||
5b058bcd | 3163 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
3164 | for_each_online_cpu(cpu) { |
3165 | if (!idle_task(cpu)->ret_stack) | |
3166 | ftrace_graph_init_task(idle_task(cpu)); | |
3167 | } | |
5b058bcd | 3168 | |
f201ae23 FW |
3169 | do { |
3170 | ret = alloc_retstack_tasklist(ret_stack_list); | |
3171 | } while (ret == -EAGAIN); | |
3172 | ||
8aef2d28 SR |
3173 | if (!ret) { |
3174 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch); | |
3175 | if (ret) | |
3176 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
3177 | " probe to kernel_sched_switch\n"); | |
3178 | } | |
3179 | ||
f201ae23 FW |
3180 | kfree(ret_stack_list); |
3181 | return ret; | |
3182 | } | |
3183 | ||
4a2b8dda FW |
3184 | /* |
3185 | * Hibernation protection. | |
3186 | * The state of the current task is too much unstable during | |
3187 | * suspend/restore to disk. We want to protect against that. | |
3188 | */ | |
3189 | static int | |
3190 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
3191 | void *unused) | |
3192 | { | |
3193 | switch (state) { | |
3194 | case PM_HIBERNATION_PREPARE: | |
3195 | pause_graph_tracing(); | |
3196 | break; | |
3197 | ||
3198 | case PM_POST_HIBERNATION: | |
3199 | unpause_graph_tracing(); | |
3200 | break; | |
3201 | } | |
3202 | return NOTIFY_DONE; | |
3203 | } | |
3204 | ||
287b6e68 FW |
3205 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
3206 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 3207 | { |
e7d3737e FW |
3208 | int ret = 0; |
3209 | ||
e6ea44e9 | 3210 | mutex_lock(&ftrace_lock); |
e7d3737e | 3211 | |
05ce5818 | 3212 | /* we currently allow only one tracer registered at a time */ |
597af815 | 3213 | if (ftrace_graph_active) { |
05ce5818 SR |
3214 | ret = -EBUSY; |
3215 | goto out; | |
3216 | } | |
3217 | ||
4a2b8dda FW |
3218 | ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; |
3219 | register_pm_notifier(&ftrace_suspend_notifier); | |
3220 | ||
597af815 | 3221 | ftrace_graph_active++; |
fb52607a | 3222 | ret = start_graph_tracing(); |
f201ae23 | 3223 | if (ret) { |
597af815 | 3224 | ftrace_graph_active--; |
f201ae23 FW |
3225 | goto out; |
3226 | } | |
e53a6319 | 3227 | |
287b6e68 FW |
3228 | ftrace_graph_return = retfunc; |
3229 | ftrace_graph_entry = entryfunc; | |
e53a6319 | 3230 | |
5a45cfe1 | 3231 | ftrace_startup(FTRACE_START_FUNC_RET); |
e7d3737e FW |
3232 | |
3233 | out: | |
e6ea44e9 | 3234 | mutex_unlock(&ftrace_lock); |
e7d3737e | 3235 | return ret; |
15e6cb36 FW |
3236 | } |
3237 | ||
fb52607a | 3238 | void unregister_ftrace_graph(void) |
15e6cb36 | 3239 | { |
e6ea44e9 | 3240 | mutex_lock(&ftrace_lock); |
e7d3737e | 3241 | |
597af815 | 3242 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
3243 | goto out; |
3244 | ||
597af815 | 3245 | ftrace_graph_active--; |
8aef2d28 | 3246 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch); |
287b6e68 | 3247 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 3248 | ftrace_graph_entry = ftrace_graph_entry_stub; |
5a45cfe1 | 3249 | ftrace_shutdown(FTRACE_STOP_FUNC_RET); |
4a2b8dda | 3250 | unregister_pm_notifier(&ftrace_suspend_notifier); |
e7d3737e | 3251 | |
2aad1b76 | 3252 | out: |
e6ea44e9 | 3253 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 3254 | } |
f201ae23 FW |
3255 | |
3256 | /* Allocate a return stack for newly created task */ | |
fb52607a | 3257 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 3258 | { |
84047e36 SR |
3259 | /* Make sure we do not use the parent ret_stack */ |
3260 | t->ret_stack = NULL; | |
3261 | ||
597af815 | 3262 | if (ftrace_graph_active) { |
82310a32 SR |
3263 | struct ftrace_ret_stack *ret_stack; |
3264 | ||
3265 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
3266 | * sizeof(struct ftrace_ret_stack), |
3267 | GFP_KERNEL); | |
82310a32 | 3268 | if (!ret_stack) |
f201ae23 FW |
3269 | return; |
3270 | t->curr_ret_stack = -1; | |
380c4b14 | 3271 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 3272 | atomic_set(&t->trace_overrun, 0); |
8aef2d28 | 3273 | t->ftrace_timestamp = 0; |
82310a32 SR |
3274 | /* make curr_ret_stack visable before we add the ret_stack */ |
3275 | smp_wmb(); | |
3276 | t->ret_stack = ret_stack; | |
84047e36 | 3277 | } |
f201ae23 FW |
3278 | } |
3279 | ||
fb52607a | 3280 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 3281 | { |
eae849ca FW |
3282 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
3283 | ||
f201ae23 | 3284 | t->ret_stack = NULL; |
eae849ca FW |
3285 | /* NULL must become visible to IRQs before we free it: */ |
3286 | barrier(); | |
3287 | ||
3288 | kfree(ret_stack); | |
f201ae23 | 3289 | } |
14a866c5 SR |
3290 | |
3291 | void ftrace_graph_stop(void) | |
3292 | { | |
3293 | ftrace_stop(); | |
3294 | } | |
15e6cb36 FW |
3295 | #endif |
3296 |