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Commit | Line | Data |
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16444a8a ACM |
1 | /* |
2 | * Infrastructure for profiling code inserted by 'gcc -pg'. | |
3 | * | |
4 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> | |
5 | * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com> | |
6 | * | |
7 | * Originally ported from the -rt patch by: | |
8 | * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com> | |
9 | * | |
10 | * Based on code in the latency_tracer, that is: | |
11 | * | |
12 | * Copyright (C) 2004-2006 Ingo Molnar | |
13 | * Copyright (C) 2004 William Lee Irwin III | |
14 | */ | |
15 | ||
3d083395 SR |
16 | #include <linux/stop_machine.h> |
17 | #include <linux/clocksource.h> | |
18 | #include <linux/kallsyms.h> | |
5072c59f | 19 | #include <linux/seq_file.h> |
4a2b8dda | 20 | #include <linux/suspend.h> |
5072c59f | 21 | #include <linux/debugfs.h> |
3d083395 | 22 | #include <linux/hardirq.h> |
2d8b820b | 23 | #include <linux/kthread.h> |
5072c59f | 24 | #include <linux/uaccess.h> |
f22f9a89 | 25 | #include <linux/kprobes.h> |
2d8b820b | 26 | #include <linux/ftrace.h> |
b0fc494f | 27 | #include <linux/sysctl.h> |
5072c59f | 28 | #include <linux/ctype.h> |
3d083395 | 29 | #include <linux/list.h> |
59df055f | 30 | #include <linux/hash.h> |
3d083395 | 31 | |
ad8d75ff | 32 | #include <trace/events/sched.h> |
8aef2d28 | 33 | |
395a59d0 | 34 | #include <asm/ftrace.h> |
2af15d6a | 35 | #include <asm/setup.h> |
395a59d0 | 36 | |
0706f1c4 | 37 | #include "trace_output.h" |
bac429f0 | 38 | #include "trace_stat.h" |
16444a8a | 39 | |
6912896e SR |
40 | #define FTRACE_WARN_ON(cond) \ |
41 | do { \ | |
42 | if (WARN_ON(cond)) \ | |
43 | ftrace_kill(); \ | |
44 | } while (0) | |
45 | ||
46 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
47 | do { \ | |
48 | if (WARN_ON_ONCE(cond)) \ | |
49 | ftrace_kill(); \ | |
50 | } while (0) | |
51 | ||
8fc0c701 SR |
52 | /* hash bits for specific function selection */ |
53 | #define FTRACE_HASH_BITS 7 | |
54 | #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS) | |
55 | ||
4eebcc81 SR |
56 | /* ftrace_enabled is a method to turn ftrace on or off */ |
57 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 58 | static int last_ftrace_enabled; |
b0fc494f | 59 | |
60a7ecf4 SR |
60 | /* Quick disabling of function tracer. */ |
61 | int function_trace_stop; | |
62 | ||
4eebcc81 SR |
63 | /* |
64 | * ftrace_disabled is set when an anomaly is discovered. | |
65 | * ftrace_disabled is much stronger than ftrace_enabled. | |
66 | */ | |
67 | static int ftrace_disabled __read_mostly; | |
68 | ||
52baf119 | 69 | static DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 70 | |
16444a8a ACM |
71 | static struct ftrace_ops ftrace_list_end __read_mostly = |
72 | { | |
fb9fb015 | 73 | .func = ftrace_stub, |
16444a8a ACM |
74 | }; |
75 | ||
76 | static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; | |
77 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; | |
60a7ecf4 | 78 | ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub; |
df4fc315 | 79 | ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; |
16444a8a | 80 | |
f2252935 | 81 | static void ftrace_list_func(unsigned long ip, unsigned long parent_ip) |
16444a8a ACM |
82 | { |
83 | struct ftrace_ops *op = ftrace_list; | |
84 | ||
85 | /* in case someone actually ports this to alpha! */ | |
86 | read_barrier_depends(); | |
87 | ||
88 | while (op != &ftrace_list_end) { | |
89 | /* silly alpha */ | |
90 | read_barrier_depends(); | |
91 | op->func(ip, parent_ip); | |
92 | op = op->next; | |
93 | }; | |
94 | } | |
95 | ||
df4fc315 SR |
96 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip) |
97 | { | |
0ef8cde5 | 98 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
99 | return; |
100 | ||
101 | ftrace_pid_function(ip, parent_ip); | |
102 | } | |
103 | ||
104 | static void set_ftrace_pid_function(ftrace_func_t func) | |
105 | { | |
106 | /* do not set ftrace_pid_function to itself! */ | |
107 | if (func != ftrace_pid_func) | |
108 | ftrace_pid_function = func; | |
109 | } | |
110 | ||
16444a8a | 111 | /** |
3d083395 | 112 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 113 | * |
3d083395 SR |
114 | * This NULLs the ftrace function and in essence stops |
115 | * tracing. There may be lag | |
16444a8a | 116 | */ |
3d083395 | 117 | void clear_ftrace_function(void) |
16444a8a | 118 | { |
3d083395 | 119 | ftrace_trace_function = ftrace_stub; |
60a7ecf4 | 120 | __ftrace_trace_function = ftrace_stub; |
df4fc315 | 121 | ftrace_pid_function = ftrace_stub; |
3d083395 SR |
122 | } |
123 | ||
60a7ecf4 SR |
124 | #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
125 | /* | |
126 | * For those archs that do not test ftrace_trace_stop in their | |
127 | * mcount call site, we need to do it from C. | |
128 | */ | |
129 | static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip) | |
130 | { | |
131 | if (function_trace_stop) | |
132 | return; | |
133 | ||
134 | __ftrace_trace_function(ip, parent_ip); | |
135 | } | |
136 | #endif | |
137 | ||
e309b41d | 138 | static int __register_ftrace_function(struct ftrace_ops *ops) |
3d083395 | 139 | { |
16444a8a ACM |
140 | ops->next = ftrace_list; |
141 | /* | |
142 | * We are entering ops into the ftrace_list but another | |
143 | * CPU might be walking that list. We need to make sure | |
144 | * the ops->next pointer is valid before another CPU sees | |
145 | * the ops pointer included into the ftrace_list. | |
146 | */ | |
147 | smp_wmb(); | |
148 | ftrace_list = ops; | |
3d083395 | 149 | |
b0fc494f | 150 | if (ftrace_enabled) { |
df4fc315 SR |
151 | ftrace_func_t func; |
152 | ||
153 | if (ops->next == &ftrace_list_end) | |
154 | func = ops->func; | |
155 | else | |
156 | func = ftrace_list_func; | |
157 | ||
978f3a45 | 158 | if (ftrace_pid_trace) { |
df4fc315 SR |
159 | set_ftrace_pid_function(func); |
160 | func = ftrace_pid_func; | |
161 | } | |
162 | ||
b0fc494f SR |
163 | /* |
164 | * For one func, simply call it directly. | |
165 | * For more than one func, call the chain. | |
166 | */ | |
60a7ecf4 | 167 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
df4fc315 | 168 | ftrace_trace_function = func; |
60a7ecf4 | 169 | #else |
df4fc315 | 170 | __ftrace_trace_function = func; |
60a7ecf4 SR |
171 | ftrace_trace_function = ftrace_test_stop_func; |
172 | #endif | |
b0fc494f | 173 | } |
3d083395 | 174 | |
16444a8a ACM |
175 | return 0; |
176 | } | |
177 | ||
e309b41d | 178 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 179 | { |
16444a8a | 180 | struct ftrace_ops **p; |
16444a8a ACM |
181 | |
182 | /* | |
3d083395 SR |
183 | * If we are removing the last function, then simply point |
184 | * to the ftrace_stub. | |
16444a8a ACM |
185 | */ |
186 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { | |
187 | ftrace_trace_function = ftrace_stub; | |
188 | ftrace_list = &ftrace_list_end; | |
e6ea44e9 | 189 | return 0; |
16444a8a ACM |
190 | } |
191 | ||
192 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) | |
193 | if (*p == ops) | |
194 | break; | |
195 | ||
e6ea44e9 SR |
196 | if (*p != ops) |
197 | return -1; | |
16444a8a ACM |
198 | |
199 | *p = (*p)->next; | |
200 | ||
b0fc494f SR |
201 | if (ftrace_enabled) { |
202 | /* If we only have one func left, then call that directly */ | |
df4fc315 SR |
203 | if (ftrace_list->next == &ftrace_list_end) { |
204 | ftrace_func_t func = ftrace_list->func; | |
205 | ||
978f3a45 | 206 | if (ftrace_pid_trace) { |
df4fc315 SR |
207 | set_ftrace_pid_function(func); |
208 | func = ftrace_pid_func; | |
209 | } | |
210 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
211 | ftrace_trace_function = func; | |
212 | #else | |
213 | __ftrace_trace_function = func; | |
214 | #endif | |
215 | } | |
b0fc494f | 216 | } |
16444a8a | 217 | |
e6ea44e9 | 218 | return 0; |
3d083395 SR |
219 | } |
220 | ||
df4fc315 SR |
221 | static void ftrace_update_pid_func(void) |
222 | { | |
223 | ftrace_func_t func; | |
224 | ||
df4fc315 | 225 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 226 | return; |
df4fc315 SR |
227 | |
228 | func = ftrace_trace_function; | |
229 | ||
978f3a45 | 230 | if (ftrace_pid_trace) { |
df4fc315 SR |
231 | set_ftrace_pid_function(func); |
232 | func = ftrace_pid_func; | |
233 | } else { | |
66eafebc LW |
234 | if (func == ftrace_pid_func) |
235 | func = ftrace_pid_function; | |
df4fc315 SR |
236 | } |
237 | ||
238 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
239 | ftrace_trace_function = func; | |
240 | #else | |
241 | __ftrace_trace_function = func; | |
242 | #endif | |
df4fc315 SR |
243 | } |
244 | ||
493762fc SR |
245 | #ifdef CONFIG_FUNCTION_PROFILER |
246 | struct ftrace_profile { | |
247 | struct hlist_node node; | |
248 | unsigned long ip; | |
249 | unsigned long counter; | |
0706f1c4 SR |
250 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
251 | unsigned long long time; | |
252 | #endif | |
8fc0c701 SR |
253 | }; |
254 | ||
493762fc SR |
255 | struct ftrace_profile_page { |
256 | struct ftrace_profile_page *next; | |
257 | unsigned long index; | |
258 | struct ftrace_profile records[]; | |
d61f82d0 SR |
259 | }; |
260 | ||
cafb168a SR |
261 | struct ftrace_profile_stat { |
262 | atomic_t disabled; | |
263 | struct hlist_head *hash; | |
264 | struct ftrace_profile_page *pages; | |
265 | struct ftrace_profile_page *start; | |
266 | struct tracer_stat stat; | |
267 | }; | |
268 | ||
493762fc SR |
269 | #define PROFILE_RECORDS_SIZE \ |
270 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 271 | |
493762fc SR |
272 | #define PROFILES_PER_PAGE \ |
273 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 274 | |
fb9fb015 SR |
275 | static int ftrace_profile_bits __read_mostly; |
276 | static int ftrace_profile_enabled __read_mostly; | |
277 | ||
278 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
279 | static DEFINE_MUTEX(ftrace_profile_lock); |
280 | ||
cafb168a | 281 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc SR |
282 | |
283 | #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */ | |
284 | ||
bac429f0 SR |
285 | static void * |
286 | function_stat_next(void *v, int idx) | |
287 | { | |
493762fc SR |
288 | struct ftrace_profile *rec = v; |
289 | struct ftrace_profile_page *pg; | |
bac429f0 | 290 | |
493762fc | 291 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
292 | |
293 | again: | |
0296e425 LZ |
294 | if (idx != 0) |
295 | rec++; | |
296 | ||
bac429f0 SR |
297 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
298 | pg = pg->next; | |
299 | if (!pg) | |
300 | return NULL; | |
301 | rec = &pg->records[0]; | |
493762fc SR |
302 | if (!rec->counter) |
303 | goto again; | |
bac429f0 SR |
304 | } |
305 | ||
bac429f0 SR |
306 | return rec; |
307 | } | |
308 | ||
309 | static void *function_stat_start(struct tracer_stat *trace) | |
310 | { | |
cafb168a SR |
311 | struct ftrace_profile_stat *stat = |
312 | container_of(trace, struct ftrace_profile_stat, stat); | |
313 | ||
314 | if (!stat || !stat->start) | |
315 | return NULL; | |
316 | ||
317 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
318 | } |
319 | ||
0706f1c4 SR |
320 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
321 | /* function graph compares on total time */ | |
322 | static int function_stat_cmp(void *p1, void *p2) | |
323 | { | |
324 | struct ftrace_profile *a = p1; | |
325 | struct ftrace_profile *b = p2; | |
326 | ||
327 | if (a->time < b->time) | |
328 | return -1; | |
329 | if (a->time > b->time) | |
330 | return 1; | |
331 | else | |
332 | return 0; | |
333 | } | |
334 | #else | |
335 | /* not function graph compares against hits */ | |
bac429f0 SR |
336 | static int function_stat_cmp(void *p1, void *p2) |
337 | { | |
493762fc SR |
338 | struct ftrace_profile *a = p1; |
339 | struct ftrace_profile *b = p2; | |
bac429f0 SR |
340 | |
341 | if (a->counter < b->counter) | |
342 | return -1; | |
343 | if (a->counter > b->counter) | |
344 | return 1; | |
345 | else | |
346 | return 0; | |
347 | } | |
0706f1c4 | 348 | #endif |
bac429f0 SR |
349 | |
350 | static int function_stat_headers(struct seq_file *m) | |
351 | { | |
0706f1c4 | 352 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
353 | seq_printf(m, " Function " |
354 | "Hit Time Avg\n" | |
355 | " -------- " | |
356 | "--- ---- ---\n"); | |
0706f1c4 | 357 | #else |
bac429f0 SR |
358 | seq_printf(m, " Function Hit\n" |
359 | " -------- ---\n"); | |
0706f1c4 | 360 | #endif |
bac429f0 SR |
361 | return 0; |
362 | } | |
363 | ||
364 | static int function_stat_show(struct seq_file *m, void *v) | |
365 | { | |
493762fc | 366 | struct ftrace_profile *rec = v; |
bac429f0 | 367 | char str[KSYM_SYMBOL_LEN]; |
0706f1c4 | 368 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
0706f1c4 | 369 | static DEFINE_MUTEX(mutex); |
34886c8b SR |
370 | static struct trace_seq s; |
371 | unsigned long long avg; | |
0706f1c4 | 372 | #endif |
bac429f0 SR |
373 | |
374 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
0706f1c4 SR |
375 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
376 | ||
377 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
378 | seq_printf(m, " "); | |
34886c8b SR |
379 | avg = rec->time; |
380 | do_div(avg, rec->counter); | |
381 | ||
382 | mutex_lock(&mutex); | |
383 | trace_seq_init(&s); | |
384 | trace_print_graph_duration(rec->time, &s); | |
385 | trace_seq_puts(&s, " "); | |
386 | trace_print_graph_duration(avg, &s); | |
0706f1c4 SR |
387 | trace_print_seq(m, &s); |
388 | mutex_unlock(&mutex); | |
389 | #endif | |
390 | seq_putc(m, '\n'); | |
bac429f0 | 391 | |
bac429f0 SR |
392 | return 0; |
393 | } | |
394 | ||
cafb168a | 395 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 396 | { |
493762fc | 397 | struct ftrace_profile_page *pg; |
bac429f0 | 398 | |
cafb168a | 399 | pg = stat->pages = stat->start; |
bac429f0 | 400 | |
493762fc SR |
401 | while (pg) { |
402 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
403 | pg->index = 0; | |
404 | pg = pg->next; | |
bac429f0 SR |
405 | } |
406 | ||
cafb168a | 407 | memset(stat->hash, 0, |
493762fc SR |
408 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
409 | } | |
bac429f0 | 410 | |
cafb168a | 411 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
412 | { |
413 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
414 | int functions; |
415 | int pages; | |
493762fc | 416 | int i; |
bac429f0 | 417 | |
493762fc | 418 | /* If we already allocated, do nothing */ |
cafb168a | 419 | if (stat->pages) |
493762fc | 420 | return 0; |
bac429f0 | 421 | |
cafb168a SR |
422 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
423 | if (!stat->pages) | |
493762fc | 424 | return -ENOMEM; |
bac429f0 | 425 | |
318e0a73 SR |
426 | #ifdef CONFIG_DYNAMIC_FTRACE |
427 | functions = ftrace_update_tot_cnt; | |
428 | #else | |
429 | /* | |
430 | * We do not know the number of functions that exist because | |
431 | * dynamic tracing is what counts them. With past experience | |
432 | * we have around 20K functions. That should be more than enough. | |
433 | * It is highly unlikely we will execute every function in | |
434 | * the kernel. | |
435 | */ | |
436 | functions = 20000; | |
437 | #endif | |
438 | ||
cafb168a | 439 | pg = stat->start = stat->pages; |
bac429f0 | 440 | |
318e0a73 SR |
441 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
442 | ||
443 | for (i = 0; i < pages; i++) { | |
493762fc | 444 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 445 | if (!pg->next) |
318e0a73 | 446 | goto out_free; |
493762fc SR |
447 | pg = pg->next; |
448 | } | |
449 | ||
450 | return 0; | |
318e0a73 SR |
451 | |
452 | out_free: | |
453 | pg = stat->start; | |
454 | while (pg) { | |
455 | unsigned long tmp = (unsigned long)pg; | |
456 | ||
457 | pg = pg->next; | |
458 | free_page(tmp); | |
459 | } | |
460 | ||
461 | free_page((unsigned long)stat->pages); | |
462 | stat->pages = NULL; | |
463 | stat->start = NULL; | |
464 | ||
465 | return -ENOMEM; | |
bac429f0 SR |
466 | } |
467 | ||
cafb168a | 468 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 469 | { |
cafb168a | 470 | struct ftrace_profile_stat *stat; |
493762fc | 471 | int size; |
bac429f0 | 472 | |
cafb168a SR |
473 | stat = &per_cpu(ftrace_profile_stats, cpu); |
474 | ||
475 | if (stat->hash) { | |
493762fc | 476 | /* If the profile is already created, simply reset it */ |
cafb168a | 477 | ftrace_profile_reset(stat); |
493762fc SR |
478 | return 0; |
479 | } | |
bac429f0 | 480 | |
493762fc SR |
481 | /* |
482 | * We are profiling all functions, but usually only a few thousand | |
483 | * functions are hit. We'll make a hash of 1024 items. | |
484 | */ | |
485 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 486 | |
cafb168a | 487 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
493762fc | 488 | |
cafb168a | 489 | if (!stat->hash) |
493762fc SR |
490 | return -ENOMEM; |
491 | ||
cafb168a SR |
492 | if (!ftrace_profile_bits) { |
493 | size--; | |
493762fc | 494 | |
cafb168a SR |
495 | for (; size; size >>= 1) |
496 | ftrace_profile_bits++; | |
497 | } | |
493762fc | 498 | |
318e0a73 | 499 | /* Preallocate the function profiling pages */ |
cafb168a SR |
500 | if (ftrace_profile_pages_init(stat) < 0) { |
501 | kfree(stat->hash); | |
502 | stat->hash = NULL; | |
493762fc SR |
503 | return -ENOMEM; |
504 | } | |
505 | ||
506 | return 0; | |
bac429f0 SR |
507 | } |
508 | ||
cafb168a SR |
509 | static int ftrace_profile_init(void) |
510 | { | |
511 | int cpu; | |
512 | int ret = 0; | |
513 | ||
514 | for_each_online_cpu(cpu) { | |
515 | ret = ftrace_profile_init_cpu(cpu); | |
516 | if (ret) | |
517 | break; | |
518 | } | |
519 | ||
520 | return ret; | |
521 | } | |
522 | ||
493762fc | 523 | /* interrupts must be disabled */ |
cafb168a SR |
524 | static struct ftrace_profile * |
525 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 526 | { |
493762fc | 527 | struct ftrace_profile *rec; |
bac429f0 SR |
528 | struct hlist_head *hhd; |
529 | struct hlist_node *n; | |
bac429f0 SR |
530 | unsigned long key; |
531 | ||
bac429f0 | 532 | key = hash_long(ip, ftrace_profile_bits); |
cafb168a | 533 | hhd = &stat->hash[key]; |
bac429f0 SR |
534 | |
535 | if (hlist_empty(hhd)) | |
536 | return NULL; | |
537 | ||
bac429f0 SR |
538 | hlist_for_each_entry_rcu(rec, n, hhd, node) { |
539 | if (rec->ip == ip) | |
493762fc SR |
540 | return rec; |
541 | } | |
542 | ||
543 | return NULL; | |
544 | } | |
545 | ||
cafb168a SR |
546 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
547 | struct ftrace_profile *rec) | |
493762fc SR |
548 | { |
549 | unsigned long key; | |
550 | ||
551 | key = hash_long(rec->ip, ftrace_profile_bits); | |
cafb168a | 552 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
553 | } |
554 | ||
318e0a73 SR |
555 | /* |
556 | * The memory is already allocated, this simply finds a new record to use. | |
557 | */ | |
493762fc | 558 | static struct ftrace_profile * |
318e0a73 | 559 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
560 | { |
561 | struct ftrace_profile *rec = NULL; | |
562 | ||
318e0a73 | 563 | /* prevent recursion (from NMIs) */ |
cafb168a | 564 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
565 | goto out; |
566 | ||
493762fc | 567 | /* |
318e0a73 SR |
568 | * Try to find the function again since an NMI |
569 | * could have added it | |
493762fc | 570 | */ |
cafb168a | 571 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 572 | if (rec) |
cafb168a | 573 | goto out; |
493762fc | 574 | |
cafb168a SR |
575 | if (stat->pages->index == PROFILES_PER_PAGE) { |
576 | if (!stat->pages->next) | |
577 | goto out; | |
578 | stat->pages = stat->pages->next; | |
bac429f0 | 579 | } |
493762fc | 580 | |
cafb168a | 581 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 582 | rec->ip = ip; |
cafb168a | 583 | ftrace_add_profile(stat, rec); |
493762fc | 584 | |
bac429f0 | 585 | out: |
cafb168a | 586 | atomic_dec(&stat->disabled); |
bac429f0 SR |
587 | |
588 | return rec; | |
589 | } | |
590 | ||
591 | static void | |
592 | function_profile_call(unsigned long ip, unsigned long parent_ip) | |
593 | { | |
cafb168a | 594 | struct ftrace_profile_stat *stat; |
493762fc | 595 | struct ftrace_profile *rec; |
bac429f0 SR |
596 | unsigned long flags; |
597 | ||
598 | if (!ftrace_profile_enabled) | |
599 | return; | |
600 | ||
601 | local_irq_save(flags); | |
cafb168a SR |
602 | |
603 | stat = &__get_cpu_var(ftrace_profile_stats); | |
0f6ce3de | 604 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
605 | goto out; |
606 | ||
607 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 608 | if (!rec) { |
318e0a73 | 609 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
610 | if (!rec) |
611 | goto out; | |
612 | } | |
bac429f0 SR |
613 | |
614 | rec->counter++; | |
615 | out: | |
616 | local_irq_restore(flags); | |
617 | } | |
618 | ||
0706f1c4 SR |
619 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
620 | static int profile_graph_entry(struct ftrace_graph_ent *trace) | |
621 | { | |
622 | function_profile_call(trace->func, 0); | |
623 | return 1; | |
624 | } | |
625 | ||
626 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
627 | { | |
cafb168a | 628 | struct ftrace_profile_stat *stat; |
a2a16d6a | 629 | unsigned long long calltime; |
0706f1c4 | 630 | struct ftrace_profile *rec; |
cafb168a | 631 | unsigned long flags; |
0706f1c4 SR |
632 | |
633 | local_irq_save(flags); | |
cafb168a | 634 | stat = &__get_cpu_var(ftrace_profile_stats); |
0f6ce3de | 635 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
636 | goto out; |
637 | ||
a2a16d6a SR |
638 | calltime = trace->rettime - trace->calltime; |
639 | ||
640 | if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) { | |
641 | int index; | |
642 | ||
643 | index = trace->depth; | |
644 | ||
645 | /* Append this call time to the parent time to subtract */ | |
646 | if (index) | |
647 | current->ret_stack[index - 1].subtime += calltime; | |
648 | ||
649 | if (current->ret_stack[index].subtime < calltime) | |
650 | calltime -= current->ret_stack[index].subtime; | |
651 | else | |
652 | calltime = 0; | |
653 | } | |
654 | ||
cafb168a | 655 | rec = ftrace_find_profiled_func(stat, trace->func); |
0706f1c4 | 656 | if (rec) |
a2a16d6a SR |
657 | rec->time += calltime; |
658 | ||
cafb168a | 659 | out: |
0706f1c4 SR |
660 | local_irq_restore(flags); |
661 | } | |
662 | ||
663 | static int register_ftrace_profiler(void) | |
664 | { | |
665 | return register_ftrace_graph(&profile_graph_return, | |
666 | &profile_graph_entry); | |
667 | } | |
668 | ||
669 | static void unregister_ftrace_profiler(void) | |
670 | { | |
671 | unregister_ftrace_graph(); | |
672 | } | |
673 | #else | |
bac429f0 SR |
674 | static struct ftrace_ops ftrace_profile_ops __read_mostly = |
675 | { | |
fb9fb015 | 676 | .func = function_profile_call, |
bac429f0 SR |
677 | }; |
678 | ||
0706f1c4 SR |
679 | static int register_ftrace_profiler(void) |
680 | { | |
681 | return register_ftrace_function(&ftrace_profile_ops); | |
682 | } | |
683 | ||
684 | static void unregister_ftrace_profiler(void) | |
685 | { | |
686 | unregister_ftrace_function(&ftrace_profile_ops); | |
687 | } | |
688 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
689 | ||
bac429f0 SR |
690 | static ssize_t |
691 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
692 | size_t cnt, loff_t *ppos) | |
693 | { | |
694 | unsigned long val; | |
fb9fb015 | 695 | char buf[64]; /* big enough to hold a number */ |
bac429f0 SR |
696 | int ret; |
697 | ||
bac429f0 SR |
698 | if (cnt >= sizeof(buf)) |
699 | return -EINVAL; | |
700 | ||
701 | if (copy_from_user(&buf, ubuf, cnt)) | |
702 | return -EFAULT; | |
703 | ||
704 | buf[cnt] = 0; | |
705 | ||
706 | ret = strict_strtoul(buf, 10, &val); | |
707 | if (ret < 0) | |
708 | return ret; | |
709 | ||
710 | val = !!val; | |
711 | ||
712 | mutex_lock(&ftrace_profile_lock); | |
713 | if (ftrace_profile_enabled ^ val) { | |
714 | if (val) { | |
493762fc SR |
715 | ret = ftrace_profile_init(); |
716 | if (ret < 0) { | |
717 | cnt = ret; | |
718 | goto out; | |
719 | } | |
720 | ||
0706f1c4 SR |
721 | ret = register_ftrace_profiler(); |
722 | if (ret < 0) { | |
723 | cnt = ret; | |
724 | goto out; | |
725 | } | |
bac429f0 SR |
726 | ftrace_profile_enabled = 1; |
727 | } else { | |
728 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
729 | /* |
730 | * unregister_ftrace_profiler calls stop_machine | |
731 | * so this acts like an synchronize_sched. | |
732 | */ | |
0706f1c4 | 733 | unregister_ftrace_profiler(); |
bac429f0 SR |
734 | } |
735 | } | |
493762fc | 736 | out: |
bac429f0 SR |
737 | mutex_unlock(&ftrace_profile_lock); |
738 | ||
739 | filp->f_pos += cnt; | |
740 | ||
741 | return cnt; | |
742 | } | |
743 | ||
493762fc SR |
744 | static ssize_t |
745 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
746 | size_t cnt, loff_t *ppos) | |
747 | { | |
fb9fb015 | 748 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
749 | int r; |
750 | ||
751 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
752 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
753 | } | |
754 | ||
bac429f0 SR |
755 | static const struct file_operations ftrace_profile_fops = { |
756 | .open = tracing_open_generic, | |
757 | .read = ftrace_profile_read, | |
758 | .write = ftrace_profile_write, | |
759 | }; | |
760 | ||
cafb168a SR |
761 | /* used to initialize the real stat files */ |
762 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
763 | .name = "functions", |
764 | .stat_start = function_stat_start, | |
765 | .stat_next = function_stat_next, | |
766 | .stat_cmp = function_stat_cmp, | |
767 | .stat_headers = function_stat_headers, | |
768 | .stat_show = function_stat_show | |
cafb168a SR |
769 | }; |
770 | ||
bac429f0 SR |
771 | static void ftrace_profile_debugfs(struct dentry *d_tracer) |
772 | { | |
cafb168a | 773 | struct ftrace_profile_stat *stat; |
bac429f0 | 774 | struct dentry *entry; |
cafb168a | 775 | char *name; |
bac429f0 | 776 | int ret; |
cafb168a SR |
777 | int cpu; |
778 | ||
779 | for_each_possible_cpu(cpu) { | |
780 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
781 | ||
782 | /* allocate enough for function name + cpu number */ | |
783 | name = kmalloc(32, GFP_KERNEL); | |
784 | if (!name) { | |
785 | /* | |
786 | * The files created are permanent, if something happens | |
787 | * we still do not free memory. | |
788 | */ | |
789 | kfree(stat); | |
790 | WARN(1, | |
791 | "Could not allocate stat file for cpu %d\n", | |
792 | cpu); | |
793 | return; | |
794 | } | |
795 | stat->stat = function_stats; | |
796 | snprintf(name, 32, "function%d", cpu); | |
797 | stat->stat.name = name; | |
798 | ret = register_stat_tracer(&stat->stat); | |
799 | if (ret) { | |
800 | WARN(1, | |
801 | "Could not register function stat for cpu %d\n", | |
802 | cpu); | |
803 | kfree(name); | |
804 | return; | |
805 | } | |
bac429f0 SR |
806 | } |
807 | ||
808 | entry = debugfs_create_file("function_profile_enabled", 0644, | |
809 | d_tracer, NULL, &ftrace_profile_fops); | |
810 | if (!entry) | |
811 | pr_warning("Could not create debugfs " | |
812 | "'function_profile_enabled' entry\n"); | |
813 | } | |
814 | ||
bac429f0 | 815 | #else /* CONFIG_FUNCTION_PROFILER */ |
bac429f0 SR |
816 | static void ftrace_profile_debugfs(struct dentry *d_tracer) |
817 | { | |
818 | } | |
bac429f0 SR |
819 | #endif /* CONFIG_FUNCTION_PROFILER */ |
820 | ||
493762fc SR |
821 | /* set when tracing only a pid */ |
822 | struct pid *ftrace_pid_trace; | |
823 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; | |
824 | ||
825 | #ifdef CONFIG_DYNAMIC_FTRACE | |
826 | ||
827 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD | |
828 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
829 | #endif | |
830 | ||
831 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; | |
832 | ||
833 | struct ftrace_func_probe { | |
834 | struct hlist_node node; | |
835 | struct ftrace_probe_ops *ops; | |
836 | unsigned long flags; | |
837 | unsigned long ip; | |
838 | void *data; | |
839 | struct rcu_head rcu; | |
840 | }; | |
841 | ||
842 | enum { | |
843 | FTRACE_ENABLE_CALLS = (1 << 0), | |
844 | FTRACE_DISABLE_CALLS = (1 << 1), | |
845 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
846 | FTRACE_ENABLE_MCOUNT = (1 << 3), | |
847 | FTRACE_DISABLE_MCOUNT = (1 << 4), | |
848 | FTRACE_START_FUNC_RET = (1 << 5), | |
849 | FTRACE_STOP_FUNC_RET = (1 << 6), | |
850 | }; | |
851 | ||
852 | static int ftrace_filtered; | |
853 | ||
854 | static struct dyn_ftrace *ftrace_new_addrs; | |
855 | ||
856 | static DEFINE_MUTEX(ftrace_regex_lock); | |
857 | ||
858 | struct ftrace_page { | |
859 | struct ftrace_page *next; | |
860 | int index; | |
861 | struct dyn_ftrace records[]; | |
862 | }; | |
863 | ||
864 | #define ENTRIES_PER_PAGE \ | |
865 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
866 | ||
867 | /* estimate from running different kernels */ | |
868 | #define NR_TO_INIT 10000 | |
869 | ||
870 | static struct ftrace_page *ftrace_pages_start; | |
871 | static struct ftrace_page *ftrace_pages; | |
872 | ||
873 | static struct dyn_ftrace *ftrace_free_records; | |
874 | ||
875 | /* | |
876 | * This is a double for. Do not use 'break' to break out of the loop, | |
877 | * you must use a goto. | |
878 | */ | |
879 | #define do_for_each_ftrace_rec(pg, rec) \ | |
880 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
881 | int _____i; \ | |
882 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
883 | rec = &pg->records[_____i]; | |
884 | ||
885 | #define while_for_each_ftrace_rec() \ | |
886 | } \ | |
887 | } | |
888 | ||
ecea656d | 889 | #ifdef CONFIG_KPROBES |
f17845e5 IM |
890 | |
891 | static int frozen_record_count; | |
892 | ||
ecea656d AS |
893 | static inline void freeze_record(struct dyn_ftrace *rec) |
894 | { | |
895 | if (!(rec->flags & FTRACE_FL_FROZEN)) { | |
896 | rec->flags |= FTRACE_FL_FROZEN; | |
897 | frozen_record_count++; | |
898 | } | |
899 | } | |
900 | ||
901 | static inline void unfreeze_record(struct dyn_ftrace *rec) | |
902 | { | |
903 | if (rec->flags & FTRACE_FL_FROZEN) { | |
904 | rec->flags &= ~FTRACE_FL_FROZEN; | |
905 | frozen_record_count--; | |
906 | } | |
907 | } | |
908 | ||
909 | static inline int record_frozen(struct dyn_ftrace *rec) | |
910 | { | |
911 | return rec->flags & FTRACE_FL_FROZEN; | |
912 | } | |
913 | #else | |
914 | # define freeze_record(rec) ({ 0; }) | |
915 | # define unfreeze_record(rec) ({ 0; }) | |
916 | # define record_frozen(rec) ({ 0; }) | |
917 | #endif /* CONFIG_KPROBES */ | |
918 | ||
e309b41d | 919 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
37ad5084 | 920 | { |
ee000b7f | 921 | rec->freelist = ftrace_free_records; |
37ad5084 SR |
922 | ftrace_free_records = rec; |
923 | rec->flags |= FTRACE_FL_FREE; | |
924 | } | |
925 | ||
e309b41d | 926 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 927 | { |
37ad5084 SR |
928 | struct dyn_ftrace *rec; |
929 | ||
930 | /* First check for freed records */ | |
931 | if (ftrace_free_records) { | |
932 | rec = ftrace_free_records; | |
933 | ||
37ad5084 | 934 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
6912896e | 935 | FTRACE_WARN_ON_ONCE(1); |
37ad5084 SR |
936 | ftrace_free_records = NULL; |
937 | return NULL; | |
938 | } | |
939 | ||
ee000b7f | 940 | ftrace_free_records = rec->freelist; |
37ad5084 SR |
941 | memset(rec, 0, sizeof(*rec)); |
942 | return rec; | |
943 | } | |
944 | ||
3c1720f0 | 945 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
08f5ac90 SR |
946 | if (!ftrace_pages->next) { |
947 | /* allocate another page */ | |
948 | ftrace_pages->next = | |
949 | (void *)get_zeroed_page(GFP_KERNEL); | |
950 | if (!ftrace_pages->next) | |
951 | return NULL; | |
952 | } | |
3c1720f0 SR |
953 | ftrace_pages = ftrace_pages->next; |
954 | } | |
955 | ||
956 | return &ftrace_pages->records[ftrace_pages->index++]; | |
957 | } | |
958 | ||
08f5ac90 | 959 | static struct dyn_ftrace * |
d61f82d0 | 960 | ftrace_record_ip(unsigned long ip) |
3d083395 | 961 | { |
08f5ac90 | 962 | struct dyn_ftrace *rec; |
3d083395 | 963 | |
f3c7ac40 | 964 | if (ftrace_disabled) |
08f5ac90 | 965 | return NULL; |
3d083395 | 966 | |
08f5ac90 SR |
967 | rec = ftrace_alloc_dyn_node(ip); |
968 | if (!rec) | |
969 | return NULL; | |
3d083395 | 970 | |
08f5ac90 | 971 | rec->ip = ip; |
ee000b7f | 972 | rec->newlist = ftrace_new_addrs; |
e94142a6 | 973 | ftrace_new_addrs = rec; |
3d083395 | 974 | |
08f5ac90 | 975 | return rec; |
3d083395 SR |
976 | } |
977 | ||
b17e8a37 SR |
978 | static void print_ip_ins(const char *fmt, unsigned char *p) |
979 | { | |
980 | int i; | |
981 | ||
982 | printk(KERN_CONT "%s", fmt); | |
983 | ||
984 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
985 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
986 | } | |
987 | ||
31e88909 | 988 | static void ftrace_bug(int failed, unsigned long ip) |
b17e8a37 SR |
989 | { |
990 | switch (failed) { | |
991 | case -EFAULT: | |
992 | FTRACE_WARN_ON_ONCE(1); | |
993 | pr_info("ftrace faulted on modifying "); | |
994 | print_ip_sym(ip); | |
995 | break; | |
996 | case -EINVAL: | |
997 | FTRACE_WARN_ON_ONCE(1); | |
998 | pr_info("ftrace failed to modify "); | |
999 | print_ip_sym(ip); | |
b17e8a37 | 1000 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
1001 | printk(KERN_CONT "\n"); |
1002 | break; | |
1003 | case -EPERM: | |
1004 | FTRACE_WARN_ON_ONCE(1); | |
1005 | pr_info("ftrace faulted on writing "); | |
1006 | print_ip_sym(ip); | |
1007 | break; | |
1008 | default: | |
1009 | FTRACE_WARN_ON_ONCE(1); | |
1010 | pr_info("ftrace faulted on unknown error "); | |
1011 | print_ip_sym(ip); | |
1012 | } | |
1013 | } | |
1014 | ||
3c1720f0 | 1015 | |
0eb96701 | 1016 | static int |
31e88909 | 1017 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) |
5072c59f | 1018 | { |
e7d3737e | 1019 | unsigned long ftrace_addr; |
6a24a244 | 1020 | unsigned long ip, fl; |
e7d3737e | 1021 | |
f0001207 | 1022 | ftrace_addr = (unsigned long)FTRACE_ADDR; |
5072c59f SR |
1023 | |
1024 | ip = rec->ip; | |
1025 | ||
982c350b SR |
1026 | /* |
1027 | * If this record is not to be traced and | |
1028 | * it is not enabled then do nothing. | |
1029 | * | |
1030 | * If this record is not to be traced and | |
57794a9d | 1031 | * it is enabled then disable it. |
982c350b SR |
1032 | * |
1033 | */ | |
1034 | if (rec->flags & FTRACE_FL_NOTRACE) { | |
1035 | if (rec->flags & FTRACE_FL_ENABLED) | |
1036 | rec->flags &= ~FTRACE_FL_ENABLED; | |
1037 | else | |
1038 | return 0; | |
1039 | ||
1040 | } else if (ftrace_filtered && enable) { | |
5072c59f | 1041 | /* |
982c350b | 1042 | * Filtering is on: |
5072c59f | 1043 | */ |
a4500b84 | 1044 | |
982c350b | 1045 | fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED); |
5072c59f | 1046 | |
982c350b SR |
1047 | /* Record is filtered and enabled, do nothing */ |
1048 | if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) | |
0eb96701 | 1049 | return 0; |
5072c59f | 1050 | |
57794a9d | 1051 | /* Record is not filtered or enabled, do nothing */ |
982c350b SR |
1052 | if (!fl) |
1053 | return 0; | |
1054 | ||
1055 | /* Record is not filtered but enabled, disable it */ | |
1056 | if (fl == FTRACE_FL_ENABLED) | |
5072c59f | 1057 | rec->flags &= ~FTRACE_FL_ENABLED; |
982c350b SR |
1058 | else |
1059 | /* Otherwise record is filtered but not enabled, enable it */ | |
5072c59f | 1060 | rec->flags |= FTRACE_FL_ENABLED; |
5072c59f | 1061 | } else { |
982c350b | 1062 | /* Disable or not filtered */ |
5072c59f | 1063 | |
41c52c0d | 1064 | if (enable) { |
982c350b | 1065 | /* if record is enabled, do nothing */ |
5072c59f | 1066 | if (rec->flags & FTRACE_FL_ENABLED) |
0eb96701 | 1067 | return 0; |
982c350b | 1068 | |
5072c59f | 1069 | rec->flags |= FTRACE_FL_ENABLED; |
982c350b | 1070 | |
5072c59f | 1071 | } else { |
982c350b | 1072 | |
57794a9d | 1073 | /* if record is not enabled, do nothing */ |
5072c59f | 1074 | if (!(rec->flags & FTRACE_FL_ENABLED)) |
0eb96701 | 1075 | return 0; |
982c350b | 1076 | |
5072c59f SR |
1077 | rec->flags &= ~FTRACE_FL_ENABLED; |
1078 | } | |
1079 | } | |
1080 | ||
982c350b | 1081 | if (rec->flags & FTRACE_FL_ENABLED) |
e7d3737e | 1082 | return ftrace_make_call(rec, ftrace_addr); |
31e88909 | 1083 | else |
e7d3737e | 1084 | return ftrace_make_nop(NULL, rec, ftrace_addr); |
5072c59f SR |
1085 | } |
1086 | ||
e309b41d | 1087 | static void ftrace_replace_code(int enable) |
3c1720f0 | 1088 | { |
3c1720f0 SR |
1089 | struct dyn_ftrace *rec; |
1090 | struct ftrace_page *pg; | |
6a24a244 | 1091 | int failed; |
3c1720f0 | 1092 | |
265c831c SR |
1093 | do_for_each_ftrace_rec(pg, rec) { |
1094 | /* | |
fa9d13cf Z |
1095 | * Skip over free records, records that have |
1096 | * failed and not converted. | |
265c831c SR |
1097 | */ |
1098 | if (rec->flags & FTRACE_FL_FREE || | |
fa9d13cf | 1099 | rec->flags & FTRACE_FL_FAILED || |
03303549 | 1100 | !(rec->flags & FTRACE_FL_CONVERTED)) |
265c831c SR |
1101 | continue; |
1102 | ||
1103 | /* ignore updates to this record's mcount site */ | |
1104 | if (get_kprobe((void *)rec->ip)) { | |
1105 | freeze_record(rec); | |
1106 | continue; | |
1107 | } else { | |
1108 | unfreeze_record(rec); | |
1109 | } | |
f22f9a89 | 1110 | |
265c831c | 1111 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 1112 | if (failed) { |
265c831c SR |
1113 | rec->flags |= FTRACE_FL_FAILED; |
1114 | if ((system_state == SYSTEM_BOOTING) || | |
1115 | !core_kernel_text(rec->ip)) { | |
1116 | ftrace_free_rec(rec); | |
4377245a | 1117 | } else { |
265c831c | 1118 | ftrace_bug(failed, rec->ip); |
4377245a SR |
1119 | /* Stop processing */ |
1120 | return; | |
1121 | } | |
3c1720f0 | 1122 | } |
265c831c | 1123 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
1124 | } |
1125 | ||
492a7ea5 | 1126 | static int |
31e88909 | 1127 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 SR |
1128 | { |
1129 | unsigned long ip; | |
593eb8a2 | 1130 | int ret; |
3c1720f0 SR |
1131 | |
1132 | ip = rec->ip; | |
1133 | ||
25aac9dc | 1134 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 1135 | if (ret) { |
31e88909 | 1136 | ftrace_bug(ret, ip); |
3c1720f0 | 1137 | rec->flags |= FTRACE_FL_FAILED; |
492a7ea5 | 1138 | return 0; |
37ad5084 | 1139 | } |
492a7ea5 | 1140 | return 1; |
3c1720f0 SR |
1141 | } |
1142 | ||
000ab691 SR |
1143 | /* |
1144 | * archs can override this function if they must do something | |
1145 | * before the modifying code is performed. | |
1146 | */ | |
1147 | int __weak ftrace_arch_code_modify_prepare(void) | |
1148 | { | |
1149 | return 0; | |
1150 | } | |
1151 | ||
1152 | /* | |
1153 | * archs can override this function if they must do something | |
1154 | * after the modifying code is performed. | |
1155 | */ | |
1156 | int __weak ftrace_arch_code_modify_post_process(void) | |
1157 | { | |
1158 | return 0; | |
1159 | } | |
1160 | ||
e309b41d | 1161 | static int __ftrace_modify_code(void *data) |
3d083395 | 1162 | { |
d61f82d0 SR |
1163 | int *command = data; |
1164 | ||
a3583244 | 1165 | if (*command & FTRACE_ENABLE_CALLS) |
d61f82d0 | 1166 | ftrace_replace_code(1); |
a3583244 | 1167 | else if (*command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
1168 | ftrace_replace_code(0); |
1169 | ||
1170 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
1171 | ftrace_update_ftrace_func(ftrace_trace_function); | |
1172 | ||
5a45cfe1 SR |
1173 | if (*command & FTRACE_START_FUNC_RET) |
1174 | ftrace_enable_ftrace_graph_caller(); | |
1175 | else if (*command & FTRACE_STOP_FUNC_RET) | |
1176 | ftrace_disable_ftrace_graph_caller(); | |
1177 | ||
d61f82d0 | 1178 | return 0; |
3d083395 SR |
1179 | } |
1180 | ||
e309b41d | 1181 | static void ftrace_run_update_code(int command) |
3d083395 | 1182 | { |
000ab691 SR |
1183 | int ret; |
1184 | ||
1185 | ret = ftrace_arch_code_modify_prepare(); | |
1186 | FTRACE_WARN_ON(ret); | |
1187 | if (ret) | |
1188 | return; | |
1189 | ||
784e2d76 | 1190 | stop_machine(__ftrace_modify_code, &command, NULL); |
000ab691 SR |
1191 | |
1192 | ret = ftrace_arch_code_modify_post_process(); | |
1193 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
1194 | } |
1195 | ||
d61f82d0 | 1196 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 1197 | static int ftrace_start_up; |
df4fc315 SR |
1198 | |
1199 | static void ftrace_startup_enable(int command) | |
1200 | { | |
1201 | if (saved_ftrace_func != ftrace_trace_function) { | |
1202 | saved_ftrace_func = ftrace_trace_function; | |
1203 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1204 | } | |
1205 | ||
1206 | if (!command || !ftrace_enabled) | |
1207 | return; | |
1208 | ||
1209 | ftrace_run_update_code(command); | |
1210 | } | |
d61f82d0 | 1211 | |
5a45cfe1 | 1212 | static void ftrace_startup(int command) |
3d083395 | 1213 | { |
4eebcc81 SR |
1214 | if (unlikely(ftrace_disabled)) |
1215 | return; | |
1216 | ||
60a7ecf4 | 1217 | ftrace_start_up++; |
982c350b | 1218 | command |= FTRACE_ENABLE_CALLS; |
d61f82d0 | 1219 | |
df4fc315 | 1220 | ftrace_startup_enable(command); |
3d083395 SR |
1221 | } |
1222 | ||
5a45cfe1 | 1223 | static void ftrace_shutdown(int command) |
3d083395 | 1224 | { |
4eebcc81 SR |
1225 | if (unlikely(ftrace_disabled)) |
1226 | return; | |
1227 | ||
60a7ecf4 | 1228 | ftrace_start_up--; |
9ea1a153 FW |
1229 | /* |
1230 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
1231 | * critical but the ftrace_call callers may be never nopped again after | |
1232 | * further ftrace uses. | |
1233 | */ | |
1234 | WARN_ON_ONCE(ftrace_start_up < 0); | |
1235 | ||
60a7ecf4 | 1236 | if (!ftrace_start_up) |
d61f82d0 | 1237 | command |= FTRACE_DISABLE_CALLS; |
3d083395 | 1238 | |
d61f82d0 SR |
1239 | if (saved_ftrace_func != ftrace_trace_function) { |
1240 | saved_ftrace_func = ftrace_trace_function; | |
1241 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1242 | } | |
3d083395 | 1243 | |
d61f82d0 | 1244 | if (!command || !ftrace_enabled) |
e6ea44e9 | 1245 | return; |
d61f82d0 SR |
1246 | |
1247 | ftrace_run_update_code(command); | |
3d083395 SR |
1248 | } |
1249 | ||
e309b41d | 1250 | static void ftrace_startup_sysctl(void) |
b0fc494f | 1251 | { |
d61f82d0 SR |
1252 | int command = FTRACE_ENABLE_MCOUNT; |
1253 | ||
4eebcc81 SR |
1254 | if (unlikely(ftrace_disabled)) |
1255 | return; | |
1256 | ||
d61f82d0 SR |
1257 | /* Force update next time */ |
1258 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
1259 | /* ftrace_start_up is true if we want ftrace running */ |
1260 | if (ftrace_start_up) | |
d61f82d0 SR |
1261 | command |= FTRACE_ENABLE_CALLS; |
1262 | ||
1263 | ftrace_run_update_code(command); | |
b0fc494f SR |
1264 | } |
1265 | ||
e309b41d | 1266 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 1267 | { |
d61f82d0 SR |
1268 | int command = FTRACE_DISABLE_MCOUNT; |
1269 | ||
4eebcc81 SR |
1270 | if (unlikely(ftrace_disabled)) |
1271 | return; | |
1272 | ||
60a7ecf4 SR |
1273 | /* ftrace_start_up is true if ftrace is running */ |
1274 | if (ftrace_start_up) | |
d61f82d0 SR |
1275 | command |= FTRACE_DISABLE_CALLS; |
1276 | ||
1277 | ftrace_run_update_code(command); | |
b0fc494f SR |
1278 | } |
1279 | ||
3d083395 SR |
1280 | static cycle_t ftrace_update_time; |
1281 | static unsigned long ftrace_update_cnt; | |
1282 | unsigned long ftrace_update_tot_cnt; | |
1283 | ||
31e88909 | 1284 | static int ftrace_update_code(struct module *mod) |
3d083395 | 1285 | { |
e94142a6 | 1286 | struct dyn_ftrace *p; |
f22f9a89 | 1287 | cycle_t start, stop; |
3d083395 | 1288 | |
750ed1a4 | 1289 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1290 | ftrace_update_cnt = 0; |
1291 | ||
e94142a6 | 1292 | while (ftrace_new_addrs) { |
3d083395 | 1293 | |
08f5ac90 SR |
1294 | /* If something went wrong, bail without enabling anything */ |
1295 | if (unlikely(ftrace_disabled)) | |
1296 | return -1; | |
f22f9a89 | 1297 | |
e94142a6 | 1298 | p = ftrace_new_addrs; |
ee000b7f | 1299 | ftrace_new_addrs = p->newlist; |
e94142a6 | 1300 | p->flags = 0L; |
f22f9a89 | 1301 | |
08f5ac90 | 1302 | /* convert record (i.e, patch mcount-call with NOP) */ |
31e88909 | 1303 | if (ftrace_code_disable(mod, p)) { |
08f5ac90 SR |
1304 | p->flags |= FTRACE_FL_CONVERTED; |
1305 | ftrace_update_cnt++; | |
1306 | } else | |
1307 | ftrace_free_rec(p); | |
3d083395 SR |
1308 | } |
1309 | ||
750ed1a4 | 1310 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1311 | ftrace_update_time = stop - start; |
1312 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
1313 | ||
16444a8a ACM |
1314 | return 0; |
1315 | } | |
1316 | ||
68bf21aa | 1317 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
1318 | { |
1319 | struct ftrace_page *pg; | |
1320 | int cnt; | |
1321 | int i; | |
3c1720f0 SR |
1322 | |
1323 | /* allocate a few pages */ | |
1324 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
1325 | if (!ftrace_pages_start) | |
1326 | return -1; | |
1327 | ||
1328 | /* | |
1329 | * Allocate a few more pages. | |
1330 | * | |
1331 | * TODO: have some parser search vmlinux before | |
1332 | * final linking to find all calls to ftrace. | |
1333 | * Then we can: | |
1334 | * a) know how many pages to allocate. | |
1335 | * and/or | |
1336 | * b) set up the table then. | |
1337 | * | |
1338 | * The dynamic code is still necessary for | |
1339 | * modules. | |
1340 | */ | |
1341 | ||
1342 | pg = ftrace_pages = ftrace_pages_start; | |
1343 | ||
68bf21aa | 1344 | cnt = num_to_init / ENTRIES_PER_PAGE; |
08f5ac90 | 1345 | pr_info("ftrace: allocating %ld entries in %d pages\n", |
5821e1b7 | 1346 | num_to_init, cnt + 1); |
3c1720f0 SR |
1347 | |
1348 | for (i = 0; i < cnt; i++) { | |
1349 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
1350 | ||
1351 | /* If we fail, we'll try later anyway */ | |
1352 | if (!pg->next) | |
1353 | break; | |
1354 | ||
1355 | pg = pg->next; | |
1356 | } | |
1357 | ||
1358 | return 0; | |
1359 | } | |
1360 | ||
5072c59f SR |
1361 | enum { |
1362 | FTRACE_ITER_FILTER = (1 << 0), | |
1363 | FTRACE_ITER_CONT = (1 << 1), | |
41c52c0d | 1364 | FTRACE_ITER_NOTRACE = (1 << 2), |
eb9a7bf0 | 1365 | FTRACE_ITER_FAILURES = (1 << 3), |
0c75a3ed | 1366 | FTRACE_ITER_PRINTALL = (1 << 4), |
8fc0c701 | 1367 | FTRACE_ITER_HASH = (1 << 5), |
5072c59f SR |
1368 | }; |
1369 | ||
1370 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
1371 | ||
1372 | struct ftrace_iterator { | |
5072c59f | 1373 | struct ftrace_page *pg; |
8fc0c701 | 1374 | int hidx; |
431aa3fb | 1375 | int idx; |
5072c59f SR |
1376 | unsigned flags; |
1377 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
1378 | unsigned buffer_idx; | |
1379 | unsigned filtered; | |
1380 | }; | |
1381 | ||
8fc0c701 SR |
1382 | static void * |
1383 | t_hash_next(struct seq_file *m, void *v, loff_t *pos) | |
1384 | { | |
1385 | struct ftrace_iterator *iter = m->private; | |
1386 | struct hlist_node *hnd = v; | |
1387 | struct hlist_head *hhd; | |
1388 | ||
1389 | WARN_ON(!(iter->flags & FTRACE_ITER_HASH)); | |
1390 | ||
1391 | (*pos)++; | |
1392 | ||
1393 | retry: | |
1394 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
1395 | return NULL; | |
1396 | ||
1397 | hhd = &ftrace_func_hash[iter->hidx]; | |
1398 | ||
1399 | if (hlist_empty(hhd)) { | |
1400 | iter->hidx++; | |
1401 | hnd = NULL; | |
1402 | goto retry; | |
1403 | } | |
1404 | ||
1405 | if (!hnd) | |
1406 | hnd = hhd->first; | |
1407 | else { | |
1408 | hnd = hnd->next; | |
1409 | if (!hnd) { | |
1410 | iter->hidx++; | |
1411 | goto retry; | |
1412 | } | |
1413 | } | |
1414 | ||
1415 | return hnd; | |
1416 | } | |
1417 | ||
1418 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
1419 | { | |
1420 | struct ftrace_iterator *iter = m->private; | |
1421 | void *p = NULL; | |
d82d6244 LZ |
1422 | loff_t l; |
1423 | ||
1424 | if (!(iter->flags & FTRACE_ITER_HASH)) | |
1425 | *pos = 0; | |
8fc0c701 SR |
1426 | |
1427 | iter->flags |= FTRACE_ITER_HASH; | |
1428 | ||
d82d6244 LZ |
1429 | iter->hidx = 0; |
1430 | for (l = 0; l <= *pos; ) { | |
1431 | p = t_hash_next(m, p, &l); | |
1432 | if (!p) | |
1433 | break; | |
1434 | } | |
1435 | return p; | |
8fc0c701 SR |
1436 | } |
1437 | ||
1438 | static int t_hash_show(struct seq_file *m, void *v) | |
1439 | { | |
b6887d79 | 1440 | struct ftrace_func_probe *rec; |
8fc0c701 SR |
1441 | struct hlist_node *hnd = v; |
1442 | char str[KSYM_SYMBOL_LEN]; | |
1443 | ||
b6887d79 | 1444 | rec = hlist_entry(hnd, struct ftrace_func_probe, node); |
8fc0c701 | 1445 | |
809dcf29 SR |
1446 | if (rec->ops->print) |
1447 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
1448 | ||
8fc0c701 SR |
1449 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
1450 | seq_printf(m, "%s:", str); | |
1451 | ||
1452 | kallsyms_lookup((unsigned long)rec->ops->func, NULL, NULL, NULL, str); | |
1453 | seq_printf(m, "%s", str); | |
1454 | ||
1455 | if (rec->data) | |
1456 | seq_printf(m, ":%p", rec->data); | |
1457 | seq_putc(m, '\n'); | |
1458 | ||
1459 | return 0; | |
1460 | } | |
1461 | ||
e309b41d | 1462 | static void * |
5072c59f SR |
1463 | t_next(struct seq_file *m, void *v, loff_t *pos) |
1464 | { | |
1465 | struct ftrace_iterator *iter = m->private; | |
1466 | struct dyn_ftrace *rec = NULL; | |
1467 | ||
8fc0c701 SR |
1468 | if (iter->flags & FTRACE_ITER_HASH) |
1469 | return t_hash_next(m, v, pos); | |
1470 | ||
5072c59f SR |
1471 | (*pos)++; |
1472 | ||
0c75a3ed SR |
1473 | if (iter->flags & FTRACE_ITER_PRINTALL) |
1474 | return NULL; | |
1475 | ||
5072c59f SR |
1476 | retry: |
1477 | if (iter->idx >= iter->pg->index) { | |
1478 | if (iter->pg->next) { | |
1479 | iter->pg = iter->pg->next; | |
1480 | iter->idx = 0; | |
1481 | goto retry; | |
1482 | } | |
1483 | } else { | |
1484 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
1485 | if ((rec->flags & FTRACE_FL_FREE) || |
1486 | ||
1487 | (!(iter->flags & FTRACE_ITER_FAILURES) && | |
eb9a7bf0 AS |
1488 | (rec->flags & FTRACE_FL_FAILED)) || |
1489 | ||
1490 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
a9fdda33 | 1491 | !(rec->flags & FTRACE_FL_FAILED)) || |
eb9a7bf0 | 1492 | |
0183fb1c SR |
1493 | ((iter->flags & FTRACE_ITER_FILTER) && |
1494 | !(rec->flags & FTRACE_FL_FILTER)) || | |
1495 | ||
41c52c0d SR |
1496 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
1497 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
1498 | rec = NULL; |
1499 | goto retry; | |
1500 | } | |
1501 | } | |
1502 | ||
5072c59f SR |
1503 | return rec; |
1504 | } | |
1505 | ||
1506 | static void *t_start(struct seq_file *m, loff_t *pos) | |
1507 | { | |
1508 | struct ftrace_iterator *iter = m->private; | |
1509 | void *p = NULL; | |
694ce0a5 | 1510 | loff_t l; |
5072c59f | 1511 | |
8fc0c701 | 1512 | mutex_lock(&ftrace_lock); |
0c75a3ed SR |
1513 | /* |
1514 | * For set_ftrace_filter reading, if we have the filter | |
1515 | * off, we can short cut and just print out that all | |
1516 | * functions are enabled. | |
1517 | */ | |
1518 | if (iter->flags & FTRACE_ITER_FILTER && !ftrace_filtered) { | |
1519 | if (*pos > 0) | |
8fc0c701 | 1520 | return t_hash_start(m, pos); |
0c75a3ed | 1521 | iter->flags |= FTRACE_ITER_PRINTALL; |
0c75a3ed SR |
1522 | return iter; |
1523 | } | |
1524 | ||
8fc0c701 SR |
1525 | if (iter->flags & FTRACE_ITER_HASH) |
1526 | return t_hash_start(m, pos); | |
1527 | ||
694ce0a5 LZ |
1528 | iter->pg = ftrace_pages_start; |
1529 | iter->idx = 0; | |
1530 | for (l = 0; l <= *pos; ) { | |
1531 | p = t_next(m, p, &l); | |
1532 | if (!p) | |
1533 | break; | |
50cdaf08 | 1534 | } |
5821e1b7 | 1535 | |
694ce0a5 | 1536 | if (!p && iter->flags & FTRACE_ITER_FILTER) |
8fc0c701 SR |
1537 | return t_hash_start(m, pos); |
1538 | ||
5072c59f SR |
1539 | return p; |
1540 | } | |
1541 | ||
1542 | static void t_stop(struct seq_file *m, void *p) | |
1543 | { | |
8fc0c701 | 1544 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1545 | } |
1546 | ||
1547 | static int t_show(struct seq_file *m, void *v) | |
1548 | { | |
0c75a3ed | 1549 | struct ftrace_iterator *iter = m->private; |
5072c59f SR |
1550 | struct dyn_ftrace *rec = v; |
1551 | char str[KSYM_SYMBOL_LEN]; | |
1552 | ||
8fc0c701 SR |
1553 | if (iter->flags & FTRACE_ITER_HASH) |
1554 | return t_hash_show(m, v); | |
1555 | ||
0c75a3ed SR |
1556 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
1557 | seq_printf(m, "#### all functions enabled ####\n"); | |
1558 | return 0; | |
1559 | } | |
1560 | ||
5072c59f SR |
1561 | if (!rec) |
1562 | return 0; | |
1563 | ||
1564 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1565 | ||
50cdaf08 | 1566 | seq_printf(m, "%s\n", str); |
5072c59f SR |
1567 | |
1568 | return 0; | |
1569 | } | |
1570 | ||
1571 | static struct seq_operations show_ftrace_seq_ops = { | |
1572 | .start = t_start, | |
1573 | .next = t_next, | |
1574 | .stop = t_stop, | |
1575 | .show = t_show, | |
1576 | }; | |
1577 | ||
e309b41d | 1578 | static int |
5072c59f SR |
1579 | ftrace_avail_open(struct inode *inode, struct file *file) |
1580 | { | |
1581 | struct ftrace_iterator *iter; | |
1582 | int ret; | |
1583 | ||
4eebcc81 SR |
1584 | if (unlikely(ftrace_disabled)) |
1585 | return -ENODEV; | |
1586 | ||
5072c59f SR |
1587 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1588 | if (!iter) | |
1589 | return -ENOMEM; | |
1590 | ||
1591 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
1592 | |
1593 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1594 | if (!ret) { | |
1595 | struct seq_file *m = file->private_data; | |
4bf39a94 | 1596 | |
5072c59f | 1597 | m->private = iter; |
4bf39a94 | 1598 | } else { |
5072c59f | 1599 | kfree(iter); |
4bf39a94 | 1600 | } |
5072c59f SR |
1601 | |
1602 | return ret; | |
1603 | } | |
1604 | ||
1605 | int ftrace_avail_release(struct inode *inode, struct file *file) | |
1606 | { | |
1607 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1608 | struct ftrace_iterator *iter = m->private; | |
1609 | ||
1610 | seq_release(inode, file); | |
1611 | kfree(iter); | |
4bf39a94 | 1612 | |
5072c59f SR |
1613 | return 0; |
1614 | } | |
1615 | ||
eb9a7bf0 AS |
1616 | static int |
1617 | ftrace_failures_open(struct inode *inode, struct file *file) | |
1618 | { | |
1619 | int ret; | |
1620 | struct seq_file *m; | |
1621 | struct ftrace_iterator *iter; | |
1622 | ||
1623 | ret = ftrace_avail_open(inode, file); | |
1624 | if (!ret) { | |
1625 | m = (struct seq_file *)file->private_data; | |
1626 | iter = (struct ftrace_iterator *)m->private; | |
1627 | iter->flags = FTRACE_ITER_FAILURES; | |
1628 | } | |
1629 | ||
1630 | return ret; | |
1631 | } | |
1632 | ||
1633 | ||
41c52c0d | 1634 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
1635 | { |
1636 | struct ftrace_page *pg; | |
1637 | struct dyn_ftrace *rec; | |
41c52c0d | 1638 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f | 1639 | |
52baf119 | 1640 | mutex_lock(&ftrace_lock); |
41c52c0d SR |
1641 | if (enable) |
1642 | ftrace_filtered = 0; | |
265c831c SR |
1643 | do_for_each_ftrace_rec(pg, rec) { |
1644 | if (rec->flags & FTRACE_FL_FAILED) | |
1645 | continue; | |
1646 | rec->flags &= ~type; | |
1647 | } while_for_each_ftrace_rec(); | |
52baf119 | 1648 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1649 | } |
1650 | ||
e309b41d | 1651 | static int |
41c52c0d | 1652 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1653 | { |
1654 | struct ftrace_iterator *iter; | |
1655 | int ret = 0; | |
1656 | ||
4eebcc81 SR |
1657 | if (unlikely(ftrace_disabled)) |
1658 | return -ENODEV; | |
1659 | ||
5072c59f SR |
1660 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1661 | if (!iter) | |
1662 | return -ENOMEM; | |
1663 | ||
41c52c0d | 1664 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1665 | if ((file->f_mode & FMODE_WRITE) && |
1666 | !(file->f_flags & O_APPEND)) | |
41c52c0d | 1667 | ftrace_filter_reset(enable); |
5072c59f SR |
1668 | |
1669 | if (file->f_mode & FMODE_READ) { | |
1670 | iter->pg = ftrace_pages_start; | |
41c52c0d SR |
1671 | iter->flags = enable ? FTRACE_ITER_FILTER : |
1672 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
1673 | |
1674 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1675 | if (!ret) { | |
1676 | struct seq_file *m = file->private_data; | |
1677 | m->private = iter; | |
1678 | } else | |
1679 | kfree(iter); | |
1680 | } else | |
1681 | file->private_data = iter; | |
41c52c0d | 1682 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1683 | |
1684 | return ret; | |
1685 | } | |
1686 | ||
41c52c0d SR |
1687 | static int |
1688 | ftrace_filter_open(struct inode *inode, struct file *file) | |
1689 | { | |
1690 | return ftrace_regex_open(inode, file, 1); | |
1691 | } | |
1692 | ||
1693 | static int | |
1694 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
1695 | { | |
1696 | return ftrace_regex_open(inode, file, 0); | |
1697 | } | |
1698 | ||
e309b41d | 1699 | static loff_t |
41c52c0d | 1700 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
1701 | { |
1702 | loff_t ret; | |
1703 | ||
1704 | if (file->f_mode & FMODE_READ) | |
1705 | ret = seq_lseek(file, offset, origin); | |
1706 | else | |
1707 | file->f_pos = ret = 1; | |
1708 | ||
1709 | return ret; | |
1710 | } | |
1711 | ||
1712 | enum { | |
1713 | MATCH_FULL, | |
1714 | MATCH_FRONT_ONLY, | |
1715 | MATCH_MIDDLE_ONLY, | |
1716 | MATCH_END_ONLY, | |
1717 | }; | |
1718 | ||
9f4801e3 SR |
1719 | /* |
1720 | * (static function - no need for kernel doc) | |
1721 | * | |
1722 | * Pass in a buffer containing a glob and this function will | |
1723 | * set search to point to the search part of the buffer and | |
1724 | * return the type of search it is (see enum above). | |
1725 | * This does modify buff. | |
1726 | * | |
1727 | * Returns enum type. | |
1728 | * search returns the pointer to use for comparison. | |
1729 | * not returns 1 if buff started with a '!' | |
1730 | * 0 otherwise. | |
1731 | */ | |
1732 | static int | |
64e7c440 | 1733 | ftrace_setup_glob(char *buff, int len, char **search, int *not) |
5072c59f | 1734 | { |
5072c59f | 1735 | int type = MATCH_FULL; |
9f4801e3 | 1736 | int i; |
ea3a6d6d SR |
1737 | |
1738 | if (buff[0] == '!') { | |
9f4801e3 | 1739 | *not = 1; |
ea3a6d6d SR |
1740 | buff++; |
1741 | len--; | |
9f4801e3 SR |
1742 | } else |
1743 | *not = 0; | |
1744 | ||
1745 | *search = buff; | |
5072c59f SR |
1746 | |
1747 | for (i = 0; i < len; i++) { | |
1748 | if (buff[i] == '*') { | |
1749 | if (!i) { | |
9f4801e3 | 1750 | *search = buff + 1; |
5072c59f | 1751 | type = MATCH_END_ONLY; |
5072c59f | 1752 | } else { |
9f4801e3 | 1753 | if (type == MATCH_END_ONLY) |
5072c59f | 1754 | type = MATCH_MIDDLE_ONLY; |
9f4801e3 | 1755 | else |
5072c59f | 1756 | type = MATCH_FRONT_ONLY; |
5072c59f SR |
1757 | buff[i] = 0; |
1758 | break; | |
1759 | } | |
1760 | } | |
1761 | } | |
1762 | ||
9f4801e3 SR |
1763 | return type; |
1764 | } | |
1765 | ||
64e7c440 | 1766 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 1767 | { |
9f4801e3 SR |
1768 | int matched = 0; |
1769 | char *ptr; | |
1770 | ||
9f4801e3 SR |
1771 | switch (type) { |
1772 | case MATCH_FULL: | |
1773 | if (strcmp(str, regex) == 0) | |
1774 | matched = 1; | |
1775 | break; | |
1776 | case MATCH_FRONT_ONLY: | |
1777 | if (strncmp(str, regex, len) == 0) | |
1778 | matched = 1; | |
1779 | break; | |
1780 | case MATCH_MIDDLE_ONLY: | |
1781 | if (strstr(str, regex)) | |
1782 | matched = 1; | |
1783 | break; | |
1784 | case MATCH_END_ONLY: | |
1785 | ptr = strstr(str, regex); | |
1786 | if (ptr && (ptr[len] == 0)) | |
1787 | matched = 1; | |
1788 | break; | |
1789 | } | |
1790 | ||
1791 | return matched; | |
1792 | } | |
1793 | ||
64e7c440 SR |
1794 | static int |
1795 | ftrace_match_record(struct dyn_ftrace *rec, char *regex, int len, int type) | |
1796 | { | |
1797 | char str[KSYM_SYMBOL_LEN]; | |
1798 | ||
1799 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1800 | return ftrace_match(str, regex, len, type); | |
1801 | } | |
1802 | ||
9f4801e3 SR |
1803 | static void ftrace_match_records(char *buff, int len, int enable) |
1804 | { | |
6a24a244 | 1805 | unsigned int search_len; |
9f4801e3 SR |
1806 | struct ftrace_page *pg; |
1807 | struct dyn_ftrace *rec; | |
6a24a244 SR |
1808 | unsigned long flag; |
1809 | char *search; | |
9f4801e3 | 1810 | int type; |
9f4801e3 SR |
1811 | int not; |
1812 | ||
6a24a244 | 1813 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
9f4801e3 SR |
1814 | type = ftrace_setup_glob(buff, len, &search, ¬); |
1815 | ||
1816 | search_len = strlen(search); | |
1817 | ||
52baf119 | 1818 | mutex_lock(&ftrace_lock); |
265c831c | 1819 | do_for_each_ftrace_rec(pg, rec) { |
265c831c SR |
1820 | |
1821 | if (rec->flags & FTRACE_FL_FAILED) | |
1822 | continue; | |
9f4801e3 SR |
1823 | |
1824 | if (ftrace_match_record(rec, search, search_len, type)) { | |
265c831c SR |
1825 | if (not) |
1826 | rec->flags &= ~flag; | |
1827 | else | |
1828 | rec->flags |= flag; | |
1829 | } | |
e68746a2 SR |
1830 | /* |
1831 | * Only enable filtering if we have a function that | |
1832 | * is filtered on. | |
1833 | */ | |
1834 | if (enable && (rec->flags & FTRACE_FL_FILTER)) | |
1835 | ftrace_filtered = 1; | |
265c831c | 1836 | } while_for_each_ftrace_rec(); |
52baf119 | 1837 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1838 | } |
1839 | ||
64e7c440 SR |
1840 | static int |
1841 | ftrace_match_module_record(struct dyn_ftrace *rec, char *mod, | |
1842 | char *regex, int len, int type) | |
1843 | { | |
1844 | char str[KSYM_SYMBOL_LEN]; | |
1845 | char *modname; | |
1846 | ||
1847 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
1848 | ||
1849 | if (!modname || strcmp(modname, mod)) | |
1850 | return 0; | |
1851 | ||
1852 | /* blank search means to match all funcs in the mod */ | |
1853 | if (len) | |
1854 | return ftrace_match(str, regex, len, type); | |
1855 | else | |
1856 | return 1; | |
1857 | } | |
1858 | ||
1859 | static void ftrace_match_module_records(char *buff, char *mod, int enable) | |
1860 | { | |
6a24a244 | 1861 | unsigned search_len = 0; |
64e7c440 SR |
1862 | struct ftrace_page *pg; |
1863 | struct dyn_ftrace *rec; | |
1864 | int type = MATCH_FULL; | |
6a24a244 SR |
1865 | char *search = buff; |
1866 | unsigned long flag; | |
64e7c440 SR |
1867 | int not = 0; |
1868 | ||
6a24a244 SR |
1869 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
1870 | ||
64e7c440 SR |
1871 | /* blank or '*' mean the same */ |
1872 | if (strcmp(buff, "*") == 0) | |
1873 | buff[0] = 0; | |
1874 | ||
1875 | /* handle the case of 'dont filter this module' */ | |
1876 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
1877 | buff[0] = 0; | |
1878 | not = 1; | |
1879 | } | |
1880 | ||
1881 | if (strlen(buff)) { | |
1882 | type = ftrace_setup_glob(buff, strlen(buff), &search, ¬); | |
1883 | search_len = strlen(search); | |
1884 | } | |
1885 | ||
52baf119 | 1886 | mutex_lock(&ftrace_lock); |
64e7c440 SR |
1887 | do_for_each_ftrace_rec(pg, rec) { |
1888 | ||
1889 | if (rec->flags & FTRACE_FL_FAILED) | |
1890 | continue; | |
1891 | ||
1892 | if (ftrace_match_module_record(rec, mod, | |
1893 | search, search_len, type)) { | |
1894 | if (not) | |
1895 | rec->flags &= ~flag; | |
1896 | else | |
1897 | rec->flags |= flag; | |
1898 | } | |
e68746a2 SR |
1899 | if (enable && (rec->flags & FTRACE_FL_FILTER)) |
1900 | ftrace_filtered = 1; | |
64e7c440 SR |
1901 | |
1902 | } while_for_each_ftrace_rec(); | |
52baf119 | 1903 | mutex_unlock(&ftrace_lock); |
64e7c440 SR |
1904 | } |
1905 | ||
f6180773 SR |
1906 | /* |
1907 | * We register the module command as a template to show others how | |
1908 | * to register the a command as well. | |
1909 | */ | |
1910 | ||
1911 | static int | |
1912 | ftrace_mod_callback(char *func, char *cmd, char *param, int enable) | |
1913 | { | |
1914 | char *mod; | |
1915 | ||
1916 | /* | |
1917 | * cmd == 'mod' because we only registered this func | |
1918 | * for the 'mod' ftrace_func_command. | |
1919 | * But if you register one func with multiple commands, | |
1920 | * you can tell which command was used by the cmd | |
1921 | * parameter. | |
1922 | */ | |
1923 | ||
1924 | /* we must have a module name */ | |
1925 | if (!param) | |
1926 | return -EINVAL; | |
1927 | ||
1928 | mod = strsep(¶m, ":"); | |
1929 | if (!strlen(mod)) | |
1930 | return -EINVAL; | |
1931 | ||
1932 | ftrace_match_module_records(func, mod, enable); | |
1933 | return 0; | |
1934 | } | |
1935 | ||
1936 | static struct ftrace_func_command ftrace_mod_cmd = { | |
1937 | .name = "mod", | |
1938 | .func = ftrace_mod_callback, | |
1939 | }; | |
1940 | ||
1941 | static int __init ftrace_mod_cmd_init(void) | |
1942 | { | |
1943 | return register_ftrace_command(&ftrace_mod_cmd); | |
1944 | } | |
1945 | device_initcall(ftrace_mod_cmd_init); | |
1946 | ||
59df055f | 1947 | static void |
b6887d79 | 1948 | function_trace_probe_call(unsigned long ip, unsigned long parent_ip) |
59df055f | 1949 | { |
b6887d79 | 1950 | struct ftrace_func_probe *entry; |
59df055f SR |
1951 | struct hlist_head *hhd; |
1952 | struct hlist_node *n; | |
1953 | unsigned long key; | |
1954 | int resched; | |
1955 | ||
1956 | key = hash_long(ip, FTRACE_HASH_BITS); | |
1957 | ||
1958 | hhd = &ftrace_func_hash[key]; | |
1959 | ||
1960 | if (hlist_empty(hhd)) | |
1961 | return; | |
1962 | ||
1963 | /* | |
1964 | * Disable preemption for these calls to prevent a RCU grace | |
1965 | * period. This syncs the hash iteration and freeing of items | |
1966 | * on the hash. rcu_read_lock is too dangerous here. | |
1967 | */ | |
1968 | resched = ftrace_preempt_disable(); | |
1969 | hlist_for_each_entry_rcu(entry, n, hhd, node) { | |
1970 | if (entry->ip == ip) | |
1971 | entry->ops->func(ip, parent_ip, &entry->data); | |
1972 | } | |
1973 | ftrace_preempt_enable(resched); | |
1974 | } | |
1975 | ||
b6887d79 | 1976 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 1977 | { |
fb9fb015 | 1978 | .func = function_trace_probe_call, |
59df055f SR |
1979 | }; |
1980 | ||
b6887d79 | 1981 | static int ftrace_probe_registered; |
59df055f | 1982 | |
b6887d79 | 1983 | static void __enable_ftrace_function_probe(void) |
59df055f SR |
1984 | { |
1985 | int i; | |
1986 | ||
b6887d79 | 1987 | if (ftrace_probe_registered) |
59df055f SR |
1988 | return; |
1989 | ||
1990 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1991 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1992 | if (hhd->first) | |
1993 | break; | |
1994 | } | |
1995 | /* Nothing registered? */ | |
1996 | if (i == FTRACE_FUNC_HASHSIZE) | |
1997 | return; | |
1998 | ||
b6887d79 | 1999 | __register_ftrace_function(&trace_probe_ops); |
59df055f | 2000 | ftrace_startup(0); |
b6887d79 | 2001 | ftrace_probe_registered = 1; |
59df055f SR |
2002 | } |
2003 | ||
b6887d79 | 2004 | static void __disable_ftrace_function_probe(void) |
59df055f SR |
2005 | { |
2006 | int i; | |
2007 | ||
b6887d79 | 2008 | if (!ftrace_probe_registered) |
59df055f SR |
2009 | return; |
2010 | ||
2011 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2012 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2013 | if (hhd->first) | |
2014 | return; | |
2015 | } | |
2016 | ||
2017 | /* no more funcs left */ | |
b6887d79 | 2018 | __unregister_ftrace_function(&trace_probe_ops); |
59df055f | 2019 | ftrace_shutdown(0); |
b6887d79 | 2020 | ftrace_probe_registered = 0; |
59df055f SR |
2021 | } |
2022 | ||
2023 | ||
2024 | static void ftrace_free_entry_rcu(struct rcu_head *rhp) | |
2025 | { | |
b6887d79 SR |
2026 | struct ftrace_func_probe *entry = |
2027 | container_of(rhp, struct ftrace_func_probe, rcu); | |
59df055f SR |
2028 | |
2029 | if (entry->ops->free) | |
2030 | entry->ops->free(&entry->data); | |
2031 | kfree(entry); | |
2032 | } | |
2033 | ||
2034 | ||
2035 | int | |
b6887d79 | 2036 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2037 | void *data) |
2038 | { | |
b6887d79 | 2039 | struct ftrace_func_probe *entry; |
59df055f SR |
2040 | struct ftrace_page *pg; |
2041 | struct dyn_ftrace *rec; | |
59df055f | 2042 | int type, len, not; |
6a24a244 | 2043 | unsigned long key; |
59df055f SR |
2044 | int count = 0; |
2045 | char *search; | |
2046 | ||
2047 | type = ftrace_setup_glob(glob, strlen(glob), &search, ¬); | |
2048 | len = strlen(search); | |
2049 | ||
b6887d79 | 2050 | /* we do not support '!' for function probes */ |
59df055f SR |
2051 | if (WARN_ON(not)) |
2052 | return -EINVAL; | |
2053 | ||
2054 | mutex_lock(&ftrace_lock); | |
2055 | do_for_each_ftrace_rec(pg, rec) { | |
2056 | ||
2057 | if (rec->flags & FTRACE_FL_FAILED) | |
2058 | continue; | |
2059 | ||
2060 | if (!ftrace_match_record(rec, search, len, type)) | |
2061 | continue; | |
2062 | ||
2063 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
2064 | if (!entry) { | |
b6887d79 | 2065 | /* If we did not process any, then return error */ |
59df055f SR |
2066 | if (!count) |
2067 | count = -ENOMEM; | |
2068 | goto out_unlock; | |
2069 | } | |
2070 | ||
2071 | count++; | |
2072 | ||
2073 | entry->data = data; | |
2074 | ||
2075 | /* | |
2076 | * The caller might want to do something special | |
2077 | * for each function we find. We call the callback | |
2078 | * to give the caller an opportunity to do so. | |
2079 | */ | |
2080 | if (ops->callback) { | |
2081 | if (ops->callback(rec->ip, &entry->data) < 0) { | |
2082 | /* caller does not like this func */ | |
2083 | kfree(entry); | |
2084 | continue; | |
2085 | } | |
2086 | } | |
2087 | ||
2088 | entry->ops = ops; | |
2089 | entry->ip = rec->ip; | |
2090 | ||
2091 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
2092 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
2093 | ||
2094 | } while_for_each_ftrace_rec(); | |
b6887d79 | 2095 | __enable_ftrace_function_probe(); |
59df055f SR |
2096 | |
2097 | out_unlock: | |
2098 | mutex_unlock(&ftrace_lock); | |
2099 | ||
2100 | return count; | |
2101 | } | |
2102 | ||
2103 | enum { | |
b6887d79 SR |
2104 | PROBE_TEST_FUNC = 1, |
2105 | PROBE_TEST_DATA = 2 | |
59df055f SR |
2106 | }; |
2107 | ||
2108 | static void | |
b6887d79 | 2109 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2110 | void *data, int flags) |
2111 | { | |
b6887d79 | 2112 | struct ftrace_func_probe *entry; |
59df055f SR |
2113 | struct hlist_node *n, *tmp; |
2114 | char str[KSYM_SYMBOL_LEN]; | |
2115 | int type = MATCH_FULL; | |
2116 | int i, len = 0; | |
2117 | char *search; | |
2118 | ||
2119 | if (glob && (strcmp(glob, "*") || !strlen(glob))) | |
2120 | glob = NULL; | |
2121 | else { | |
2122 | int not; | |
2123 | ||
2124 | type = ftrace_setup_glob(glob, strlen(glob), &search, ¬); | |
2125 | len = strlen(search); | |
2126 | ||
b6887d79 | 2127 | /* we do not support '!' for function probes */ |
59df055f SR |
2128 | if (WARN_ON(not)) |
2129 | return; | |
2130 | } | |
2131 | ||
2132 | mutex_lock(&ftrace_lock); | |
2133 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2134 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2135 | ||
2136 | hlist_for_each_entry_safe(entry, n, tmp, hhd, node) { | |
2137 | ||
2138 | /* break up if statements for readability */ | |
b6887d79 | 2139 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
2140 | continue; |
2141 | ||
b6887d79 | 2142 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
2143 | continue; |
2144 | ||
2145 | /* do this last, since it is the most expensive */ | |
2146 | if (glob) { | |
2147 | kallsyms_lookup(entry->ip, NULL, NULL, | |
2148 | NULL, str); | |
2149 | if (!ftrace_match(str, glob, len, type)) | |
2150 | continue; | |
2151 | } | |
2152 | ||
2153 | hlist_del(&entry->node); | |
2154 | call_rcu(&entry->rcu, ftrace_free_entry_rcu); | |
2155 | } | |
2156 | } | |
b6887d79 | 2157 | __disable_ftrace_function_probe(); |
59df055f SR |
2158 | mutex_unlock(&ftrace_lock); |
2159 | } | |
2160 | ||
2161 | void | |
b6887d79 | 2162 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2163 | void *data) |
2164 | { | |
b6887d79 SR |
2165 | __unregister_ftrace_function_probe(glob, ops, data, |
2166 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
2167 | } |
2168 | ||
2169 | void | |
b6887d79 | 2170 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 2171 | { |
b6887d79 | 2172 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
2173 | } |
2174 | ||
b6887d79 | 2175 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 2176 | { |
b6887d79 | 2177 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
2178 | } |
2179 | ||
f6180773 SR |
2180 | static LIST_HEAD(ftrace_commands); |
2181 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
2182 | ||
2183 | int register_ftrace_command(struct ftrace_func_command *cmd) | |
2184 | { | |
2185 | struct ftrace_func_command *p; | |
2186 | int ret = 0; | |
2187 | ||
2188 | mutex_lock(&ftrace_cmd_mutex); | |
2189 | list_for_each_entry(p, &ftrace_commands, list) { | |
2190 | if (strcmp(cmd->name, p->name) == 0) { | |
2191 | ret = -EBUSY; | |
2192 | goto out_unlock; | |
2193 | } | |
2194 | } | |
2195 | list_add(&cmd->list, &ftrace_commands); | |
2196 | out_unlock: | |
2197 | mutex_unlock(&ftrace_cmd_mutex); | |
2198 | ||
2199 | return ret; | |
2200 | } | |
2201 | ||
2202 | int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
2203 | { | |
2204 | struct ftrace_func_command *p, *n; | |
2205 | int ret = -ENODEV; | |
2206 | ||
2207 | mutex_lock(&ftrace_cmd_mutex); | |
2208 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
2209 | if (strcmp(cmd->name, p->name) == 0) { | |
2210 | ret = 0; | |
2211 | list_del_init(&p->list); | |
2212 | goto out_unlock; | |
2213 | } | |
2214 | } | |
2215 | out_unlock: | |
2216 | mutex_unlock(&ftrace_cmd_mutex); | |
2217 | ||
2218 | return ret; | |
2219 | } | |
2220 | ||
64e7c440 SR |
2221 | static int ftrace_process_regex(char *buff, int len, int enable) |
2222 | { | |
f6180773 | 2223 | char *func, *command, *next = buff; |
6a24a244 | 2224 | struct ftrace_func_command *p; |
f6180773 | 2225 | int ret = -EINVAL; |
64e7c440 SR |
2226 | |
2227 | func = strsep(&next, ":"); | |
2228 | ||
2229 | if (!next) { | |
2230 | ftrace_match_records(func, len, enable); | |
2231 | return 0; | |
2232 | } | |
2233 | ||
f6180773 | 2234 | /* command found */ |
64e7c440 SR |
2235 | |
2236 | command = strsep(&next, ":"); | |
2237 | ||
f6180773 SR |
2238 | mutex_lock(&ftrace_cmd_mutex); |
2239 | list_for_each_entry(p, &ftrace_commands, list) { | |
2240 | if (strcmp(p->name, command) == 0) { | |
2241 | ret = p->func(func, command, next, enable); | |
2242 | goto out_unlock; | |
2243 | } | |
64e7c440 | 2244 | } |
f6180773 SR |
2245 | out_unlock: |
2246 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 2247 | |
f6180773 | 2248 | return ret; |
64e7c440 SR |
2249 | } |
2250 | ||
e309b41d | 2251 | static ssize_t |
41c52c0d SR |
2252 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
2253 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
2254 | { |
2255 | struct ftrace_iterator *iter; | |
2256 | char ch; | |
2257 | size_t read = 0; | |
2258 | ssize_t ret; | |
2259 | ||
2260 | if (!cnt || cnt < 0) | |
2261 | return 0; | |
2262 | ||
41c52c0d | 2263 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
2264 | |
2265 | if (file->f_mode & FMODE_READ) { | |
2266 | struct seq_file *m = file->private_data; | |
2267 | iter = m->private; | |
2268 | } else | |
2269 | iter = file->private_data; | |
2270 | ||
2271 | if (!*ppos) { | |
2272 | iter->flags &= ~FTRACE_ITER_CONT; | |
2273 | iter->buffer_idx = 0; | |
2274 | } | |
2275 | ||
2276 | ret = get_user(ch, ubuf++); | |
2277 | if (ret) | |
2278 | goto out; | |
2279 | read++; | |
2280 | cnt--; | |
2281 | ||
2282 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { | |
2283 | /* skip white space */ | |
2284 | while (cnt && isspace(ch)) { | |
2285 | ret = get_user(ch, ubuf++); | |
2286 | if (ret) | |
2287 | goto out; | |
2288 | read++; | |
2289 | cnt--; | |
2290 | } | |
2291 | ||
5072c59f SR |
2292 | if (isspace(ch)) { |
2293 | file->f_pos += read; | |
2294 | ret = read; | |
2295 | goto out; | |
2296 | } | |
2297 | ||
2298 | iter->buffer_idx = 0; | |
2299 | } | |
2300 | ||
2301 | while (cnt && !isspace(ch)) { | |
2302 | if (iter->buffer_idx < FTRACE_BUFF_MAX) | |
2303 | iter->buffer[iter->buffer_idx++] = ch; | |
2304 | else { | |
2305 | ret = -EINVAL; | |
2306 | goto out; | |
2307 | } | |
2308 | ret = get_user(ch, ubuf++); | |
2309 | if (ret) | |
2310 | goto out; | |
2311 | read++; | |
2312 | cnt--; | |
2313 | } | |
2314 | ||
2315 | if (isspace(ch)) { | |
2316 | iter->filtered++; | |
2317 | iter->buffer[iter->buffer_idx] = 0; | |
64e7c440 SR |
2318 | ret = ftrace_process_regex(iter->buffer, |
2319 | iter->buffer_idx, enable); | |
2320 | if (ret) | |
2321 | goto out; | |
5072c59f SR |
2322 | iter->buffer_idx = 0; |
2323 | } else | |
2324 | iter->flags |= FTRACE_ITER_CONT; | |
2325 | ||
2326 | ||
2327 | file->f_pos += read; | |
2328 | ||
2329 | ret = read; | |
2330 | out: | |
41c52c0d | 2331 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
2332 | |
2333 | return ret; | |
2334 | } | |
2335 | ||
41c52c0d SR |
2336 | static ssize_t |
2337 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
2338 | size_t cnt, loff_t *ppos) | |
2339 | { | |
2340 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
2341 | } | |
2342 | ||
2343 | static ssize_t | |
2344 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
2345 | size_t cnt, loff_t *ppos) | |
2346 | { | |
2347 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
2348 | } | |
2349 | ||
2350 | static void | |
2351 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
2352 | { | |
2353 | if (unlikely(ftrace_disabled)) | |
2354 | return; | |
2355 | ||
2356 | mutex_lock(&ftrace_regex_lock); | |
2357 | if (reset) | |
2358 | ftrace_filter_reset(enable); | |
2359 | if (buf) | |
7f24b31b | 2360 | ftrace_match_records(buf, len, enable); |
41c52c0d SR |
2361 | mutex_unlock(&ftrace_regex_lock); |
2362 | } | |
2363 | ||
77a2b37d SR |
2364 | /** |
2365 | * ftrace_set_filter - set a function to filter on in ftrace | |
2366 | * @buf - the string that holds the function filter text. | |
2367 | * @len - the length of the string. | |
2368 | * @reset - non zero to reset all filters before applying this filter. | |
2369 | * | |
2370 | * Filters denote which functions should be enabled when tracing is enabled. | |
2371 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
2372 | */ | |
e309b41d | 2373 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 2374 | { |
41c52c0d SR |
2375 | ftrace_set_regex(buf, len, reset, 1); |
2376 | } | |
4eebcc81 | 2377 | |
41c52c0d SR |
2378 | /** |
2379 | * ftrace_set_notrace - set a function to not trace in ftrace | |
2380 | * @buf - the string that holds the function notrace text. | |
2381 | * @len - the length of the string. | |
2382 | * @reset - non zero to reset all filters before applying this filter. | |
2383 | * | |
2384 | * Notrace Filters denote which functions should not be enabled when tracing | |
2385 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
2386 | * for tracing. | |
2387 | */ | |
2388 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
2389 | { | |
2390 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
2391 | } |
2392 | ||
2af15d6a SR |
2393 | /* |
2394 | * command line interface to allow users to set filters on boot up. | |
2395 | */ | |
2396 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
2397 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
2398 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
2399 | ||
2400 | static int __init set_ftrace_notrace(char *str) | |
2401 | { | |
2402 | strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); | |
2403 | return 1; | |
2404 | } | |
2405 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
2406 | ||
2407 | static int __init set_ftrace_filter(char *str) | |
2408 | { | |
2409 | strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); | |
2410 | return 1; | |
2411 | } | |
2412 | __setup("ftrace_filter=", set_ftrace_filter); | |
2413 | ||
2414 | static void __init set_ftrace_early_filter(char *buf, int enable) | |
2415 | { | |
2416 | char *func; | |
2417 | ||
2418 | while (buf) { | |
2419 | func = strsep(&buf, ","); | |
2420 | ftrace_set_regex(func, strlen(func), 0, enable); | |
2421 | } | |
2422 | } | |
2423 | ||
2424 | static void __init set_ftrace_early_filters(void) | |
2425 | { | |
2426 | if (ftrace_filter_buf[0]) | |
2427 | set_ftrace_early_filter(ftrace_filter_buf, 1); | |
2428 | if (ftrace_notrace_buf[0]) | |
2429 | set_ftrace_early_filter(ftrace_notrace_buf, 0); | |
2430 | } | |
2431 | ||
e309b41d | 2432 | static int |
41c52c0d | 2433 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
2434 | { |
2435 | struct seq_file *m = (struct seq_file *)file->private_data; | |
2436 | struct ftrace_iterator *iter; | |
2437 | ||
41c52c0d | 2438 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
2439 | if (file->f_mode & FMODE_READ) { |
2440 | iter = m->private; | |
2441 | ||
2442 | seq_release(inode, file); | |
2443 | } else | |
2444 | iter = file->private_data; | |
2445 | ||
2446 | if (iter->buffer_idx) { | |
2447 | iter->filtered++; | |
2448 | iter->buffer[iter->buffer_idx] = 0; | |
7f24b31b | 2449 | ftrace_match_records(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
2450 | } |
2451 | ||
e6ea44e9 | 2452 | mutex_lock(&ftrace_lock); |
ee02a2e5 | 2453 | if (ftrace_start_up && ftrace_enabled) |
5072c59f | 2454 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
e6ea44e9 | 2455 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
2456 | |
2457 | kfree(iter); | |
41c52c0d | 2458 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
2459 | return 0; |
2460 | } | |
2461 | ||
41c52c0d SR |
2462 | static int |
2463 | ftrace_filter_release(struct inode *inode, struct file *file) | |
2464 | { | |
2465 | return ftrace_regex_release(inode, file, 1); | |
2466 | } | |
2467 | ||
2468 | static int | |
2469 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
2470 | { | |
2471 | return ftrace_regex_release(inode, file, 0); | |
2472 | } | |
2473 | ||
5e2336a0 | 2474 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
2475 | .open = ftrace_avail_open, |
2476 | .read = seq_read, | |
2477 | .llseek = seq_lseek, | |
2478 | .release = ftrace_avail_release, | |
2479 | }; | |
2480 | ||
5e2336a0 | 2481 | static const struct file_operations ftrace_failures_fops = { |
eb9a7bf0 AS |
2482 | .open = ftrace_failures_open, |
2483 | .read = seq_read, | |
2484 | .llseek = seq_lseek, | |
2485 | .release = ftrace_avail_release, | |
2486 | }; | |
2487 | ||
5e2336a0 | 2488 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 2489 | .open = ftrace_filter_open, |
850a80cf | 2490 | .read = seq_read, |
5072c59f | 2491 | .write = ftrace_filter_write, |
41c52c0d | 2492 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
2493 | .release = ftrace_filter_release, |
2494 | }; | |
2495 | ||
5e2336a0 | 2496 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 2497 | .open = ftrace_notrace_open, |
850a80cf | 2498 | .read = seq_read, |
41c52c0d SR |
2499 | .write = ftrace_notrace_write, |
2500 | .llseek = ftrace_regex_lseek, | |
2501 | .release = ftrace_notrace_release, | |
2502 | }; | |
2503 | ||
ea4e2bc4 SR |
2504 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
2505 | ||
2506 | static DEFINE_MUTEX(graph_lock); | |
2507 | ||
2508 | int ftrace_graph_count; | |
2509 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; | |
2510 | ||
2511 | static void * | |
85951842 | 2512 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 SR |
2513 | { |
2514 | unsigned long *array = m->private; | |
ea4e2bc4 | 2515 | |
85951842 | 2516 | if (*pos >= ftrace_graph_count) |
ea4e2bc4 | 2517 | return NULL; |
85951842 LZ |
2518 | return &array[*pos]; |
2519 | } | |
ea4e2bc4 | 2520 | |
85951842 LZ |
2521 | static void * |
2522 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
2523 | { | |
2524 | (*pos)++; | |
2525 | return __g_next(m, pos); | |
ea4e2bc4 SR |
2526 | } |
2527 | ||
2528 | static void *g_start(struct seq_file *m, loff_t *pos) | |
2529 | { | |
ea4e2bc4 SR |
2530 | mutex_lock(&graph_lock); |
2531 | ||
f9349a8f FW |
2532 | /* Nothing, tell g_show to print all functions are enabled */ |
2533 | if (!ftrace_graph_count && !*pos) | |
2534 | return (void *)1; | |
2535 | ||
85951842 | 2536 | return __g_next(m, pos); |
ea4e2bc4 SR |
2537 | } |
2538 | ||
2539 | static void g_stop(struct seq_file *m, void *p) | |
2540 | { | |
2541 | mutex_unlock(&graph_lock); | |
2542 | } | |
2543 | ||
2544 | static int g_show(struct seq_file *m, void *v) | |
2545 | { | |
2546 | unsigned long *ptr = v; | |
2547 | char str[KSYM_SYMBOL_LEN]; | |
2548 | ||
2549 | if (!ptr) | |
2550 | return 0; | |
2551 | ||
f9349a8f FW |
2552 | if (ptr == (unsigned long *)1) { |
2553 | seq_printf(m, "#### all functions enabled ####\n"); | |
2554 | return 0; | |
2555 | } | |
2556 | ||
ea4e2bc4 SR |
2557 | kallsyms_lookup(*ptr, NULL, NULL, NULL, str); |
2558 | ||
2559 | seq_printf(m, "%s\n", str); | |
2560 | ||
2561 | return 0; | |
2562 | } | |
2563 | ||
2564 | static struct seq_operations ftrace_graph_seq_ops = { | |
2565 | .start = g_start, | |
2566 | .next = g_next, | |
2567 | .stop = g_stop, | |
2568 | .show = g_show, | |
2569 | }; | |
2570 | ||
2571 | static int | |
2572 | ftrace_graph_open(struct inode *inode, struct file *file) | |
2573 | { | |
2574 | int ret = 0; | |
2575 | ||
2576 | if (unlikely(ftrace_disabled)) | |
2577 | return -ENODEV; | |
2578 | ||
2579 | mutex_lock(&graph_lock); | |
2580 | if ((file->f_mode & FMODE_WRITE) && | |
2581 | !(file->f_flags & O_APPEND)) { | |
2582 | ftrace_graph_count = 0; | |
2583 | memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); | |
2584 | } | |
2585 | ||
2586 | if (file->f_mode & FMODE_READ) { | |
2587 | ret = seq_open(file, &ftrace_graph_seq_ops); | |
2588 | if (!ret) { | |
2589 | struct seq_file *m = file->private_data; | |
2590 | m->private = ftrace_graph_funcs; | |
2591 | } | |
2592 | } else | |
2593 | file->private_data = ftrace_graph_funcs; | |
2594 | mutex_unlock(&graph_lock); | |
2595 | ||
2596 | return ret; | |
2597 | } | |
2598 | ||
ea4e2bc4 | 2599 | static int |
f9349a8f | 2600 | ftrace_set_func(unsigned long *array, int *idx, char *buffer) |
ea4e2bc4 | 2601 | { |
ea4e2bc4 SR |
2602 | struct dyn_ftrace *rec; |
2603 | struct ftrace_page *pg; | |
f9349a8f | 2604 | int search_len; |
ea4e2bc4 | 2605 | int found = 0; |
f9349a8f FW |
2606 | int type, not; |
2607 | char *search; | |
2608 | bool exists; | |
2609 | int i; | |
ea4e2bc4 SR |
2610 | |
2611 | if (ftrace_disabled) | |
2612 | return -ENODEV; | |
2613 | ||
f9349a8f FW |
2614 | /* decode regex */ |
2615 | type = ftrace_setup_glob(buffer, strlen(buffer), &search, ¬); | |
2616 | if (not) | |
2617 | return -EINVAL; | |
2618 | ||
2619 | search_len = strlen(search); | |
2620 | ||
52baf119 | 2621 | mutex_lock(&ftrace_lock); |
265c831c SR |
2622 | do_for_each_ftrace_rec(pg, rec) { |
2623 | ||
f9349a8f FW |
2624 | if (*idx >= FTRACE_GRAPH_MAX_FUNCS) |
2625 | break; | |
2626 | ||
265c831c SR |
2627 | if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE)) |
2628 | continue; | |
2629 | ||
f9349a8f FW |
2630 | if (ftrace_match_record(rec, search, search_len, type)) { |
2631 | /* ensure it is not already in the array */ | |
2632 | exists = false; | |
2633 | for (i = 0; i < *idx; i++) | |
2634 | if (array[i] == rec->ip) { | |
2635 | exists = true; | |
265c831c SR |
2636 | break; |
2637 | } | |
f9349a8f FW |
2638 | if (!exists) { |
2639 | array[(*idx)++] = rec->ip; | |
2640 | found = 1; | |
2641 | } | |
ea4e2bc4 | 2642 | } |
265c831c | 2643 | } while_for_each_ftrace_rec(); |
f9349a8f | 2644 | |
52baf119 | 2645 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 SR |
2646 | |
2647 | return found ? 0 : -EINVAL; | |
2648 | } | |
2649 | ||
2650 | static ssize_t | |
2651 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
2652 | size_t cnt, loff_t *ppos) | |
2653 | { | |
2654 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
2655 | unsigned long *array; | |
2656 | size_t read = 0; | |
2657 | ssize_t ret; | |
2658 | int index = 0; | |
2659 | char ch; | |
2660 | ||
2661 | if (!cnt || cnt < 0) | |
2662 | return 0; | |
2663 | ||
2664 | mutex_lock(&graph_lock); | |
2665 | ||
2666 | if (ftrace_graph_count >= FTRACE_GRAPH_MAX_FUNCS) { | |
2667 | ret = -EBUSY; | |
2668 | goto out; | |
2669 | } | |
2670 | ||
2671 | if (file->f_mode & FMODE_READ) { | |
2672 | struct seq_file *m = file->private_data; | |
2673 | array = m->private; | |
2674 | } else | |
2675 | array = file->private_data; | |
2676 | ||
2677 | ret = get_user(ch, ubuf++); | |
2678 | if (ret) | |
2679 | goto out; | |
2680 | read++; | |
2681 | cnt--; | |
2682 | ||
2683 | /* skip white space */ | |
2684 | while (cnt && isspace(ch)) { | |
2685 | ret = get_user(ch, ubuf++); | |
2686 | if (ret) | |
2687 | goto out; | |
2688 | read++; | |
2689 | cnt--; | |
2690 | } | |
2691 | ||
2692 | if (isspace(ch)) { | |
2693 | *ppos += read; | |
2694 | ret = read; | |
2695 | goto out; | |
2696 | } | |
2697 | ||
2698 | while (cnt && !isspace(ch)) { | |
2699 | if (index < FTRACE_BUFF_MAX) | |
2700 | buffer[index++] = ch; | |
2701 | else { | |
2702 | ret = -EINVAL; | |
2703 | goto out; | |
2704 | } | |
2705 | ret = get_user(ch, ubuf++); | |
2706 | if (ret) | |
2707 | goto out; | |
2708 | read++; | |
2709 | cnt--; | |
2710 | } | |
2711 | buffer[index] = 0; | |
2712 | ||
f9349a8f FW |
2713 | /* we allow only one expression at a time */ |
2714 | ret = ftrace_set_func(array, &ftrace_graph_count, buffer); | |
ea4e2bc4 SR |
2715 | if (ret) |
2716 | goto out; | |
2717 | ||
ea4e2bc4 SR |
2718 | file->f_pos += read; |
2719 | ||
2720 | ret = read; | |
2721 | out: | |
2722 | mutex_unlock(&graph_lock); | |
2723 | ||
2724 | return ret; | |
2725 | } | |
2726 | ||
2727 | static const struct file_operations ftrace_graph_fops = { | |
2728 | .open = ftrace_graph_open, | |
850a80cf | 2729 | .read = seq_read, |
ea4e2bc4 SR |
2730 | .write = ftrace_graph_write, |
2731 | }; | |
2732 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2733 | ||
df4fc315 | 2734 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 2735 | { |
5072c59f | 2736 | |
5452af66 FW |
2737 | trace_create_file("available_filter_functions", 0444, |
2738 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 2739 | |
5452af66 FW |
2740 | trace_create_file("failures", 0444, |
2741 | d_tracer, NULL, &ftrace_failures_fops); | |
eb9a7bf0 | 2742 | |
5452af66 FW |
2743 | trace_create_file("set_ftrace_filter", 0644, d_tracer, |
2744 | NULL, &ftrace_filter_fops); | |
41c52c0d | 2745 | |
5452af66 | 2746 | trace_create_file("set_ftrace_notrace", 0644, d_tracer, |
41c52c0d | 2747 | NULL, &ftrace_notrace_fops); |
ad90c0e3 | 2748 | |
ea4e2bc4 | 2749 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 2750 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
2751 | NULL, |
2752 | &ftrace_graph_fops); | |
ea4e2bc4 SR |
2753 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
2754 | ||
5072c59f SR |
2755 | return 0; |
2756 | } | |
2757 | ||
31e88909 SR |
2758 | static int ftrace_convert_nops(struct module *mod, |
2759 | unsigned long *start, | |
68bf21aa SR |
2760 | unsigned long *end) |
2761 | { | |
2762 | unsigned long *p; | |
2763 | unsigned long addr; | |
2764 | unsigned long flags; | |
2765 | ||
e6ea44e9 | 2766 | mutex_lock(&ftrace_lock); |
68bf21aa SR |
2767 | p = start; |
2768 | while (p < end) { | |
2769 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
2770 | /* |
2771 | * Some architecture linkers will pad between | |
2772 | * the different mcount_loc sections of different | |
2773 | * object files to satisfy alignments. | |
2774 | * Skip any NULL pointers. | |
2775 | */ | |
2776 | if (!addr) | |
2777 | continue; | |
68bf21aa | 2778 | ftrace_record_ip(addr); |
68bf21aa SR |
2779 | } |
2780 | ||
08f5ac90 | 2781 | /* disable interrupts to prevent kstop machine */ |
68bf21aa | 2782 | local_irq_save(flags); |
31e88909 | 2783 | ftrace_update_code(mod); |
68bf21aa | 2784 | local_irq_restore(flags); |
e6ea44e9 | 2785 | mutex_unlock(&ftrace_lock); |
68bf21aa SR |
2786 | |
2787 | return 0; | |
2788 | } | |
2789 | ||
93eb677d SR |
2790 | #ifdef CONFIG_MODULES |
2791 | void ftrace_release(void *start, void *end) | |
2792 | { | |
2793 | struct dyn_ftrace *rec; | |
2794 | struct ftrace_page *pg; | |
2795 | unsigned long s = (unsigned long)start; | |
2796 | unsigned long e = (unsigned long)end; | |
2797 | ||
2798 | if (ftrace_disabled || !start || start == end) | |
2799 | return; | |
2800 | ||
2801 | mutex_lock(&ftrace_lock); | |
2802 | do_for_each_ftrace_rec(pg, rec) { | |
2803 | if ((rec->ip >= s) && (rec->ip < e)) { | |
2804 | /* | |
2805 | * rec->ip is changed in ftrace_free_rec() | |
2806 | * It should not between s and e if record was freed. | |
2807 | */ | |
2808 | FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE); | |
2809 | ftrace_free_rec(rec); | |
2810 | } | |
2811 | } while_for_each_ftrace_rec(); | |
2812 | mutex_unlock(&ftrace_lock); | |
2813 | } | |
2814 | ||
2815 | static void ftrace_init_module(struct module *mod, | |
2816 | unsigned long *start, unsigned long *end) | |
90d595fe | 2817 | { |
00fd61ae | 2818 | if (ftrace_disabled || start == end) |
fed1939c | 2819 | return; |
31e88909 | 2820 | ftrace_convert_nops(mod, start, end); |
90d595fe SR |
2821 | } |
2822 | ||
93eb677d SR |
2823 | static int ftrace_module_notify(struct notifier_block *self, |
2824 | unsigned long val, void *data) | |
2825 | { | |
2826 | struct module *mod = data; | |
2827 | ||
2828 | switch (val) { | |
2829 | case MODULE_STATE_COMING: | |
2830 | ftrace_init_module(mod, mod->ftrace_callsites, | |
2831 | mod->ftrace_callsites + | |
2832 | mod->num_ftrace_callsites); | |
2833 | break; | |
2834 | case MODULE_STATE_GOING: | |
2835 | ftrace_release(mod->ftrace_callsites, | |
2836 | mod->ftrace_callsites + | |
2837 | mod->num_ftrace_callsites); | |
2838 | break; | |
2839 | } | |
2840 | ||
2841 | return 0; | |
2842 | } | |
2843 | #else | |
2844 | static int ftrace_module_notify(struct notifier_block *self, | |
2845 | unsigned long val, void *data) | |
2846 | { | |
2847 | return 0; | |
2848 | } | |
2849 | #endif /* CONFIG_MODULES */ | |
2850 | ||
2851 | struct notifier_block ftrace_module_nb = { | |
2852 | .notifier_call = ftrace_module_notify, | |
2853 | .priority = 0, | |
2854 | }; | |
2855 | ||
68bf21aa SR |
2856 | extern unsigned long __start_mcount_loc[]; |
2857 | extern unsigned long __stop_mcount_loc[]; | |
2858 | ||
2859 | void __init ftrace_init(void) | |
2860 | { | |
2861 | unsigned long count, addr, flags; | |
2862 | int ret; | |
2863 | ||
2864 | /* Keep the ftrace pointer to the stub */ | |
2865 | addr = (unsigned long)ftrace_stub; | |
2866 | ||
2867 | local_irq_save(flags); | |
2868 | ftrace_dyn_arch_init(&addr); | |
2869 | local_irq_restore(flags); | |
2870 | ||
2871 | /* ftrace_dyn_arch_init places the return code in addr */ | |
2872 | if (addr) | |
2873 | goto failed; | |
2874 | ||
2875 | count = __stop_mcount_loc - __start_mcount_loc; | |
2876 | ||
2877 | ret = ftrace_dyn_table_alloc(count); | |
2878 | if (ret) | |
2879 | goto failed; | |
2880 | ||
2881 | last_ftrace_enabled = ftrace_enabled = 1; | |
2882 | ||
31e88909 SR |
2883 | ret = ftrace_convert_nops(NULL, |
2884 | __start_mcount_loc, | |
68bf21aa SR |
2885 | __stop_mcount_loc); |
2886 | ||
93eb677d | 2887 | ret = register_module_notifier(&ftrace_module_nb); |
24ed0c4b | 2888 | if (ret) |
93eb677d SR |
2889 | pr_warning("Failed to register trace ftrace module notifier\n"); |
2890 | ||
2af15d6a SR |
2891 | set_ftrace_early_filters(); |
2892 | ||
68bf21aa SR |
2893 | return; |
2894 | failed: | |
2895 | ftrace_disabled = 1; | |
2896 | } | |
68bf21aa | 2897 | |
3d083395 | 2898 | #else |
0b6e4d56 FW |
2899 | |
2900 | static int __init ftrace_nodyn_init(void) | |
2901 | { | |
2902 | ftrace_enabled = 1; | |
2903 | return 0; | |
2904 | } | |
2905 | device_initcall(ftrace_nodyn_init); | |
2906 | ||
df4fc315 SR |
2907 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
2908 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 SR |
2909 | /* Keep as macros so we do not need to define the commands */ |
2910 | # define ftrace_startup(command) do { } while (0) | |
2911 | # define ftrace_shutdown(command) do { } while (0) | |
c7aafc54 IM |
2912 | # define ftrace_startup_sysctl() do { } while (0) |
2913 | # define ftrace_shutdown_sysctl() do { } while (0) | |
3d083395 SR |
2914 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
2915 | ||
df4fc315 SR |
2916 | static ssize_t |
2917 | ftrace_pid_read(struct file *file, char __user *ubuf, | |
2918 | size_t cnt, loff_t *ppos) | |
2919 | { | |
2920 | char buf[64]; | |
2921 | int r; | |
2922 | ||
e32d8956 SR |
2923 | if (ftrace_pid_trace == ftrace_swapper_pid) |
2924 | r = sprintf(buf, "swapper tasks\n"); | |
2925 | else if (ftrace_pid_trace) | |
cc59c9e8 | 2926 | r = sprintf(buf, "%u\n", pid_vnr(ftrace_pid_trace)); |
df4fc315 SR |
2927 | else |
2928 | r = sprintf(buf, "no pid\n"); | |
2929 | ||
2930 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
2931 | } | |
2932 | ||
e32d8956 | 2933 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
2934 | { |
2935 | struct task_struct *p; | |
e32d8956 | 2936 | int cpu; |
978f3a45 | 2937 | |
e32d8956 SR |
2938 | get_online_cpus(); |
2939 | for_each_online_cpu(cpu) { | |
2940 | p = idle_task(cpu); | |
978f3a45 | 2941 | clear_tsk_trace_trace(p); |
e32d8956 SR |
2942 | } |
2943 | put_online_cpus(); | |
2944 | } | |
978f3a45 | 2945 | |
e32d8956 SR |
2946 | static void set_ftrace_swapper(void) |
2947 | { | |
2948 | struct task_struct *p; | |
2949 | int cpu; | |
2950 | ||
2951 | get_online_cpus(); | |
2952 | for_each_online_cpu(cpu) { | |
2953 | p = idle_task(cpu); | |
2954 | set_tsk_trace_trace(p); | |
2955 | } | |
2956 | put_online_cpus(); | |
978f3a45 SR |
2957 | } |
2958 | ||
e32d8956 SR |
2959 | static void clear_ftrace_pid(struct pid *pid) |
2960 | { | |
2961 | struct task_struct *p; | |
2962 | ||
229c4ef8 | 2963 | rcu_read_lock(); |
e32d8956 SR |
2964 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2965 | clear_tsk_trace_trace(p); | |
2966 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
2967 | rcu_read_unlock(); |
2968 | ||
e32d8956 SR |
2969 | put_pid(pid); |
2970 | } | |
2971 | ||
2972 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
2973 | { |
2974 | struct task_struct *p; | |
2975 | ||
229c4ef8 | 2976 | rcu_read_lock(); |
978f3a45 SR |
2977 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2978 | set_tsk_trace_trace(p); | |
2979 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 2980 | rcu_read_unlock(); |
978f3a45 SR |
2981 | } |
2982 | ||
e32d8956 SR |
2983 | static void clear_ftrace_pid_task(struct pid **pid) |
2984 | { | |
2985 | if (*pid == ftrace_swapper_pid) | |
2986 | clear_ftrace_swapper(); | |
2987 | else | |
2988 | clear_ftrace_pid(*pid); | |
2989 | ||
2990 | *pid = NULL; | |
2991 | } | |
2992 | ||
2993 | static void set_ftrace_pid_task(struct pid *pid) | |
2994 | { | |
2995 | if (pid == ftrace_swapper_pid) | |
2996 | set_ftrace_swapper(); | |
2997 | else | |
2998 | set_ftrace_pid(pid); | |
2999 | } | |
3000 | ||
df4fc315 SR |
3001 | static ssize_t |
3002 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
3003 | size_t cnt, loff_t *ppos) | |
3004 | { | |
978f3a45 | 3005 | struct pid *pid; |
df4fc315 SR |
3006 | char buf[64]; |
3007 | long val; | |
3008 | int ret; | |
3009 | ||
3010 | if (cnt >= sizeof(buf)) | |
3011 | return -EINVAL; | |
3012 | ||
3013 | if (copy_from_user(&buf, ubuf, cnt)) | |
3014 | return -EFAULT; | |
3015 | ||
3016 | buf[cnt] = 0; | |
3017 | ||
3018 | ret = strict_strtol(buf, 10, &val); | |
3019 | if (ret < 0) | |
3020 | return ret; | |
3021 | ||
e6ea44e9 | 3022 | mutex_lock(&ftrace_lock); |
978f3a45 | 3023 | if (val < 0) { |
df4fc315 | 3024 | /* disable pid tracing */ |
978f3a45 | 3025 | if (!ftrace_pid_trace) |
df4fc315 | 3026 | goto out; |
978f3a45 SR |
3027 | |
3028 | clear_ftrace_pid_task(&ftrace_pid_trace); | |
df4fc315 SR |
3029 | |
3030 | } else { | |
e32d8956 SR |
3031 | /* swapper task is special */ |
3032 | if (!val) { | |
3033 | pid = ftrace_swapper_pid; | |
3034 | if (pid == ftrace_pid_trace) | |
3035 | goto out; | |
3036 | } else { | |
3037 | pid = find_get_pid(val); | |
df4fc315 | 3038 | |
e32d8956 SR |
3039 | if (pid == ftrace_pid_trace) { |
3040 | put_pid(pid); | |
3041 | goto out; | |
3042 | } | |
0ef8cde5 | 3043 | } |
0ef8cde5 | 3044 | |
978f3a45 SR |
3045 | if (ftrace_pid_trace) |
3046 | clear_ftrace_pid_task(&ftrace_pid_trace); | |
3047 | ||
3048 | if (!pid) | |
3049 | goto out; | |
3050 | ||
3051 | ftrace_pid_trace = pid; | |
3052 | ||
3053 | set_ftrace_pid_task(ftrace_pid_trace); | |
df4fc315 SR |
3054 | } |
3055 | ||
3056 | /* update the function call */ | |
3057 | ftrace_update_pid_func(); | |
3058 | ftrace_startup_enable(0); | |
3059 | ||
3060 | out: | |
e6ea44e9 | 3061 | mutex_unlock(&ftrace_lock); |
df4fc315 SR |
3062 | |
3063 | return cnt; | |
3064 | } | |
3065 | ||
5e2336a0 | 3066 | static const struct file_operations ftrace_pid_fops = { |
df4fc315 SR |
3067 | .read = ftrace_pid_read, |
3068 | .write = ftrace_pid_write, | |
3069 | }; | |
3070 | ||
3071 | static __init int ftrace_init_debugfs(void) | |
3072 | { | |
3073 | struct dentry *d_tracer; | |
df4fc315 SR |
3074 | |
3075 | d_tracer = tracing_init_dentry(); | |
3076 | if (!d_tracer) | |
3077 | return 0; | |
3078 | ||
3079 | ftrace_init_dyn_debugfs(d_tracer); | |
3080 | ||
5452af66 FW |
3081 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
3082 | NULL, &ftrace_pid_fops); | |
493762fc SR |
3083 | |
3084 | ftrace_profile_debugfs(d_tracer); | |
3085 | ||
df4fc315 SR |
3086 | return 0; |
3087 | } | |
df4fc315 SR |
3088 | fs_initcall(ftrace_init_debugfs); |
3089 | ||
a2bb6a3d | 3090 | /** |
81adbdc0 | 3091 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
3092 | * |
3093 | * This function should be used by panic code. It stops ftrace | |
3094 | * but in a not so nice way. If you need to simply kill ftrace | |
3095 | * from a non-atomic section, use ftrace_kill. | |
3096 | */ | |
81adbdc0 | 3097 | void ftrace_kill(void) |
a2bb6a3d SR |
3098 | { |
3099 | ftrace_disabled = 1; | |
3100 | ftrace_enabled = 0; | |
a2bb6a3d SR |
3101 | clear_ftrace_function(); |
3102 | } | |
3103 | ||
16444a8a | 3104 | /** |
3d083395 SR |
3105 | * register_ftrace_function - register a function for profiling |
3106 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 3107 | * |
3d083395 SR |
3108 | * Register a function to be called by all functions in the |
3109 | * kernel. | |
3110 | * | |
3111 | * Note: @ops->func and all the functions it calls must be labeled | |
3112 | * with "notrace", otherwise it will go into a | |
3113 | * recursive loop. | |
16444a8a | 3114 | */ |
3d083395 | 3115 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 3116 | { |
b0fc494f SR |
3117 | int ret; |
3118 | ||
4eebcc81 SR |
3119 | if (unlikely(ftrace_disabled)) |
3120 | return -1; | |
3121 | ||
e6ea44e9 | 3122 | mutex_lock(&ftrace_lock); |
e7d3737e | 3123 | |
b0fc494f | 3124 | ret = __register_ftrace_function(ops); |
5a45cfe1 | 3125 | ftrace_startup(0); |
b0fc494f | 3126 | |
e6ea44e9 | 3127 | mutex_unlock(&ftrace_lock); |
b0fc494f | 3128 | return ret; |
3d083395 SR |
3129 | } |
3130 | ||
3131 | /** | |
32632920 | 3132 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
3133 | * @ops - ops structure that holds the function to unregister |
3134 | * | |
3135 | * Unregister a function that was added to be called by ftrace profiling. | |
3136 | */ | |
3137 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
3138 | { | |
3139 | int ret; | |
3140 | ||
e6ea44e9 | 3141 | mutex_lock(&ftrace_lock); |
3d083395 | 3142 | ret = __unregister_ftrace_function(ops); |
5a45cfe1 | 3143 | ftrace_shutdown(0); |
e6ea44e9 | 3144 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
3145 | |
3146 | return ret; | |
3147 | } | |
3148 | ||
e309b41d | 3149 | int |
b0fc494f | 3150 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
5072c59f | 3151 | struct file *file, void __user *buffer, size_t *lenp, |
b0fc494f SR |
3152 | loff_t *ppos) |
3153 | { | |
3154 | int ret; | |
3155 | ||
4eebcc81 SR |
3156 | if (unlikely(ftrace_disabled)) |
3157 | return -ENODEV; | |
3158 | ||
e6ea44e9 | 3159 | mutex_lock(&ftrace_lock); |
b0fc494f | 3160 | |
5072c59f | 3161 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
b0fc494f | 3162 | |
a32c7765 | 3163 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
3164 | goto out; |
3165 | ||
a32c7765 | 3166 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f SR |
3167 | |
3168 | if (ftrace_enabled) { | |
3169 | ||
3170 | ftrace_startup_sysctl(); | |
3171 | ||
3172 | /* we are starting ftrace again */ | |
3173 | if (ftrace_list != &ftrace_list_end) { | |
3174 | if (ftrace_list->next == &ftrace_list_end) | |
3175 | ftrace_trace_function = ftrace_list->func; | |
3176 | else | |
3177 | ftrace_trace_function = ftrace_list_func; | |
3178 | } | |
3179 | ||
3180 | } else { | |
3181 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
3182 | ftrace_trace_function = ftrace_stub; | |
3183 | ||
3184 | ftrace_shutdown_sysctl(); | |
3185 | } | |
3186 | ||
3187 | out: | |
e6ea44e9 | 3188 | mutex_unlock(&ftrace_lock); |
3d083395 | 3189 | return ret; |
16444a8a | 3190 | } |
f17845e5 | 3191 | |
fb52607a | 3192 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 3193 | |
597af815 | 3194 | static int ftrace_graph_active; |
4a2b8dda | 3195 | static struct notifier_block ftrace_suspend_notifier; |
e7d3737e | 3196 | |
e49dc19c SR |
3197 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
3198 | { | |
3199 | return 0; | |
3200 | } | |
3201 | ||
287b6e68 FW |
3202 | /* The callbacks that hook a function */ |
3203 | trace_func_graph_ret_t ftrace_graph_return = | |
3204 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 3205 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
3206 | |
3207 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
3208 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
3209 | { | |
3210 | int i; | |
3211 | int ret = 0; | |
3212 | unsigned long flags; | |
3213 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
3214 | struct task_struct *g, *t; | |
3215 | ||
3216 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
3217 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
3218 | * sizeof(struct ftrace_ret_stack), | |
3219 | GFP_KERNEL); | |
3220 | if (!ret_stack_list[i]) { | |
3221 | start = 0; | |
3222 | end = i; | |
3223 | ret = -ENOMEM; | |
3224 | goto free; | |
3225 | } | |
3226 | } | |
3227 | ||
3228 | read_lock_irqsave(&tasklist_lock, flags); | |
3229 | do_each_thread(g, t) { | |
3230 | if (start == end) { | |
3231 | ret = -EAGAIN; | |
3232 | goto unlock; | |
3233 | } | |
3234 | ||
3235 | if (t->ret_stack == NULL) { | |
380c4b14 | 3236 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 3237 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
3238 | t->curr_ret_stack = -1; |
3239 | /* Make sure the tasks see the -1 first: */ | |
3240 | smp_wmb(); | |
3241 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
3242 | } |
3243 | } while_each_thread(g, t); | |
3244 | ||
3245 | unlock: | |
3246 | read_unlock_irqrestore(&tasklist_lock, flags); | |
3247 | free: | |
3248 | for (i = start; i < end; i++) | |
3249 | kfree(ret_stack_list[i]); | |
3250 | return ret; | |
3251 | } | |
3252 | ||
8aef2d28 SR |
3253 | static void |
3254 | ftrace_graph_probe_sched_switch(struct rq *__rq, struct task_struct *prev, | |
3255 | struct task_struct *next) | |
3256 | { | |
3257 | unsigned long long timestamp; | |
3258 | int index; | |
3259 | ||
be6f164a SR |
3260 | /* |
3261 | * Does the user want to count the time a function was asleep. | |
3262 | * If so, do not update the time stamps. | |
3263 | */ | |
3264 | if (trace_flags & TRACE_ITER_SLEEP_TIME) | |
3265 | return; | |
3266 | ||
8aef2d28 SR |
3267 | timestamp = trace_clock_local(); |
3268 | ||
3269 | prev->ftrace_timestamp = timestamp; | |
3270 | ||
3271 | /* only process tasks that we timestamped */ | |
3272 | if (!next->ftrace_timestamp) | |
3273 | return; | |
3274 | ||
3275 | /* | |
3276 | * Update all the counters in next to make up for the | |
3277 | * time next was sleeping. | |
3278 | */ | |
3279 | timestamp -= next->ftrace_timestamp; | |
3280 | ||
3281 | for (index = next->curr_ret_stack; index >= 0; index--) | |
3282 | next->ret_stack[index].calltime += timestamp; | |
3283 | } | |
3284 | ||
f201ae23 | 3285 | /* Allocate a return stack for each task */ |
fb52607a | 3286 | static int start_graph_tracing(void) |
f201ae23 FW |
3287 | { |
3288 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 3289 | int ret, cpu; |
f201ae23 FW |
3290 | |
3291 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
3292 | sizeof(struct ftrace_ret_stack *), | |
3293 | GFP_KERNEL); | |
3294 | ||
3295 | if (!ret_stack_list) | |
3296 | return -ENOMEM; | |
3297 | ||
5b058bcd | 3298 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
3299 | for_each_online_cpu(cpu) { |
3300 | if (!idle_task(cpu)->ret_stack) | |
3301 | ftrace_graph_init_task(idle_task(cpu)); | |
3302 | } | |
5b058bcd | 3303 | |
f201ae23 FW |
3304 | do { |
3305 | ret = alloc_retstack_tasklist(ret_stack_list); | |
3306 | } while (ret == -EAGAIN); | |
3307 | ||
8aef2d28 SR |
3308 | if (!ret) { |
3309 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch); | |
3310 | if (ret) | |
3311 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
3312 | " probe to kernel_sched_switch\n"); | |
3313 | } | |
3314 | ||
f201ae23 FW |
3315 | kfree(ret_stack_list); |
3316 | return ret; | |
3317 | } | |
3318 | ||
4a2b8dda FW |
3319 | /* |
3320 | * Hibernation protection. | |
3321 | * The state of the current task is too much unstable during | |
3322 | * suspend/restore to disk. We want to protect against that. | |
3323 | */ | |
3324 | static int | |
3325 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
3326 | void *unused) | |
3327 | { | |
3328 | switch (state) { | |
3329 | case PM_HIBERNATION_PREPARE: | |
3330 | pause_graph_tracing(); | |
3331 | break; | |
3332 | ||
3333 | case PM_POST_HIBERNATION: | |
3334 | unpause_graph_tracing(); | |
3335 | break; | |
3336 | } | |
3337 | return NOTIFY_DONE; | |
3338 | } | |
3339 | ||
287b6e68 FW |
3340 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
3341 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 3342 | { |
e7d3737e FW |
3343 | int ret = 0; |
3344 | ||
e6ea44e9 | 3345 | mutex_lock(&ftrace_lock); |
e7d3737e | 3346 | |
05ce5818 | 3347 | /* we currently allow only one tracer registered at a time */ |
597af815 | 3348 | if (ftrace_graph_active) { |
05ce5818 SR |
3349 | ret = -EBUSY; |
3350 | goto out; | |
3351 | } | |
3352 | ||
4a2b8dda FW |
3353 | ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; |
3354 | register_pm_notifier(&ftrace_suspend_notifier); | |
3355 | ||
597af815 | 3356 | ftrace_graph_active++; |
fb52607a | 3357 | ret = start_graph_tracing(); |
f201ae23 | 3358 | if (ret) { |
597af815 | 3359 | ftrace_graph_active--; |
f201ae23 FW |
3360 | goto out; |
3361 | } | |
e53a6319 | 3362 | |
287b6e68 FW |
3363 | ftrace_graph_return = retfunc; |
3364 | ftrace_graph_entry = entryfunc; | |
e53a6319 | 3365 | |
5a45cfe1 | 3366 | ftrace_startup(FTRACE_START_FUNC_RET); |
e7d3737e FW |
3367 | |
3368 | out: | |
e6ea44e9 | 3369 | mutex_unlock(&ftrace_lock); |
e7d3737e | 3370 | return ret; |
15e6cb36 FW |
3371 | } |
3372 | ||
fb52607a | 3373 | void unregister_ftrace_graph(void) |
15e6cb36 | 3374 | { |
e6ea44e9 | 3375 | mutex_lock(&ftrace_lock); |
e7d3737e | 3376 | |
597af815 | 3377 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
3378 | goto out; |
3379 | ||
597af815 | 3380 | ftrace_graph_active--; |
8aef2d28 | 3381 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch); |
287b6e68 | 3382 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 3383 | ftrace_graph_entry = ftrace_graph_entry_stub; |
5a45cfe1 | 3384 | ftrace_shutdown(FTRACE_STOP_FUNC_RET); |
4a2b8dda | 3385 | unregister_pm_notifier(&ftrace_suspend_notifier); |
e7d3737e | 3386 | |
2aad1b76 | 3387 | out: |
e6ea44e9 | 3388 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 3389 | } |
f201ae23 FW |
3390 | |
3391 | /* Allocate a return stack for newly created task */ | |
fb52607a | 3392 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 3393 | { |
84047e36 SR |
3394 | /* Make sure we do not use the parent ret_stack */ |
3395 | t->ret_stack = NULL; | |
3396 | ||
597af815 | 3397 | if (ftrace_graph_active) { |
82310a32 SR |
3398 | struct ftrace_ret_stack *ret_stack; |
3399 | ||
3400 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
3401 | * sizeof(struct ftrace_ret_stack), |
3402 | GFP_KERNEL); | |
82310a32 | 3403 | if (!ret_stack) |
f201ae23 FW |
3404 | return; |
3405 | t->curr_ret_stack = -1; | |
380c4b14 | 3406 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 3407 | atomic_set(&t->trace_overrun, 0); |
8aef2d28 | 3408 | t->ftrace_timestamp = 0; |
82310a32 SR |
3409 | /* make curr_ret_stack visable before we add the ret_stack */ |
3410 | smp_wmb(); | |
3411 | t->ret_stack = ret_stack; | |
84047e36 | 3412 | } |
f201ae23 FW |
3413 | } |
3414 | ||
fb52607a | 3415 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 3416 | { |
eae849ca FW |
3417 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
3418 | ||
f201ae23 | 3419 | t->ret_stack = NULL; |
eae849ca FW |
3420 | /* NULL must become visible to IRQs before we free it: */ |
3421 | barrier(); | |
3422 | ||
3423 | kfree(ret_stack); | |
f201ae23 | 3424 | } |
14a866c5 SR |
3425 | |
3426 | void ftrace_graph_stop(void) | |
3427 | { | |
3428 | ftrace_stop(); | |
3429 | } | |
15e6cb36 FW |
3430 | #endif |
3431 |