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> |
2d8b820b | 25 | #include <linux/ftrace.h> |
b0fc494f | 26 | #include <linux/sysctl.h> |
5a0e3ad6 | 27 | #include <linux/slab.h> |
5072c59f | 28 | #include <linux/ctype.h> |
3d083395 | 29 | #include <linux/list.h> |
59df055f | 30 | #include <linux/hash.h> |
3f379b03 | 31 | #include <linux/rcupdate.h> |
3d083395 | 32 | |
ad8d75ff | 33 | #include <trace/events/sched.h> |
8aef2d28 | 34 | |
395a59d0 | 35 | #include <asm/ftrace.h> |
2af15d6a | 36 | #include <asm/setup.h> |
395a59d0 | 37 | |
0706f1c4 | 38 | #include "trace_output.h" |
bac429f0 | 39 | #include "trace_stat.h" |
16444a8a | 40 | |
6912896e SR |
41 | #define FTRACE_WARN_ON(cond) \ |
42 | do { \ | |
43 | if (WARN_ON(cond)) \ | |
44 | ftrace_kill(); \ | |
45 | } while (0) | |
46 | ||
47 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
48 | do { \ | |
49 | if (WARN_ON_ONCE(cond)) \ | |
50 | ftrace_kill(); \ | |
51 | } while (0) | |
52 | ||
8fc0c701 SR |
53 | /* hash bits for specific function selection */ |
54 | #define FTRACE_HASH_BITS 7 | |
55 | #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS) | |
56 | ||
4eebcc81 SR |
57 | /* ftrace_enabled is a method to turn ftrace on or off */ |
58 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 59 | static int last_ftrace_enabled; |
b0fc494f | 60 | |
60a7ecf4 SR |
61 | /* Quick disabling of function tracer. */ |
62 | int function_trace_stop; | |
63 | ||
756d17ee | 64 | /* List for set_ftrace_pid's pids. */ |
65 | LIST_HEAD(ftrace_pids); | |
66 | struct ftrace_pid { | |
67 | struct list_head list; | |
68 | struct pid *pid; | |
69 | }; | |
70 | ||
4eebcc81 SR |
71 | /* |
72 | * ftrace_disabled is set when an anomaly is discovered. | |
73 | * ftrace_disabled is much stronger than ftrace_enabled. | |
74 | */ | |
75 | static int ftrace_disabled __read_mostly; | |
76 | ||
52baf119 | 77 | static DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 78 | |
16444a8a ACM |
79 | static struct ftrace_ops ftrace_list_end __read_mostly = |
80 | { | |
fb9fb015 | 81 | .func = ftrace_stub, |
16444a8a ACM |
82 | }; |
83 | ||
84 | static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; | |
85 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; | |
60a7ecf4 | 86 | ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub; |
df4fc315 | 87 | ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; |
16444a8a | 88 | |
3f379b03 PM |
89 | /* |
90 | * Traverse the ftrace_list, invoking all entries. The reason that we | |
91 | * can use rcu_dereference_raw() is that elements removed from this list | |
92 | * are simply leaked, so there is no need to interact with a grace-period | |
93 | * mechanism. The rcu_dereference_raw() calls are needed to handle | |
94 | * concurrent insertions into the ftrace_list. | |
95 | * | |
96 | * Silly Alpha and silly pointer-speculation compiler optimizations! | |
97 | */ | |
f2252935 | 98 | static void ftrace_list_func(unsigned long ip, unsigned long parent_ip) |
16444a8a | 99 | { |
3f379b03 | 100 | struct ftrace_ops *op = rcu_dereference_raw(ftrace_list); /*see above*/ |
16444a8a ACM |
101 | |
102 | while (op != &ftrace_list_end) { | |
16444a8a | 103 | op->func(ip, parent_ip); |
3f379b03 | 104 | op = rcu_dereference_raw(op->next); /*see above*/ |
16444a8a ACM |
105 | }; |
106 | } | |
107 | ||
df4fc315 SR |
108 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip) |
109 | { | |
0ef8cde5 | 110 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
111 | return; |
112 | ||
113 | ftrace_pid_function(ip, parent_ip); | |
114 | } | |
115 | ||
116 | static void set_ftrace_pid_function(ftrace_func_t func) | |
117 | { | |
118 | /* do not set ftrace_pid_function to itself! */ | |
119 | if (func != ftrace_pid_func) | |
120 | ftrace_pid_function = func; | |
121 | } | |
122 | ||
16444a8a | 123 | /** |
3d083395 | 124 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 125 | * |
3d083395 SR |
126 | * This NULLs the ftrace function and in essence stops |
127 | * tracing. There may be lag | |
16444a8a | 128 | */ |
3d083395 | 129 | void clear_ftrace_function(void) |
16444a8a | 130 | { |
3d083395 | 131 | ftrace_trace_function = ftrace_stub; |
60a7ecf4 | 132 | __ftrace_trace_function = ftrace_stub; |
df4fc315 | 133 | ftrace_pid_function = ftrace_stub; |
3d083395 SR |
134 | } |
135 | ||
60a7ecf4 SR |
136 | #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
137 | /* | |
138 | * For those archs that do not test ftrace_trace_stop in their | |
139 | * mcount call site, we need to do it from C. | |
140 | */ | |
141 | static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip) | |
142 | { | |
143 | if (function_trace_stop) | |
144 | return; | |
145 | ||
146 | __ftrace_trace_function(ip, parent_ip); | |
147 | } | |
148 | #endif | |
149 | ||
e309b41d | 150 | static int __register_ftrace_function(struct ftrace_ops *ops) |
3d083395 | 151 | { |
16444a8a ACM |
152 | ops->next = ftrace_list; |
153 | /* | |
154 | * We are entering ops into the ftrace_list but another | |
155 | * CPU might be walking that list. We need to make sure | |
156 | * the ops->next pointer is valid before another CPU sees | |
157 | * the ops pointer included into the ftrace_list. | |
158 | */ | |
3f379b03 | 159 | rcu_assign_pointer(ftrace_list, ops); |
3d083395 | 160 | |
b0fc494f | 161 | if (ftrace_enabled) { |
df4fc315 SR |
162 | ftrace_func_t func; |
163 | ||
164 | if (ops->next == &ftrace_list_end) | |
165 | func = ops->func; | |
166 | else | |
167 | func = ftrace_list_func; | |
168 | ||
756d17ee | 169 | if (!list_empty(&ftrace_pids)) { |
df4fc315 SR |
170 | set_ftrace_pid_function(func); |
171 | func = ftrace_pid_func; | |
172 | } | |
173 | ||
b0fc494f SR |
174 | /* |
175 | * For one func, simply call it directly. | |
176 | * For more than one func, call the chain. | |
177 | */ | |
60a7ecf4 | 178 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
df4fc315 | 179 | ftrace_trace_function = func; |
60a7ecf4 | 180 | #else |
df4fc315 | 181 | __ftrace_trace_function = func; |
60a7ecf4 SR |
182 | ftrace_trace_function = ftrace_test_stop_func; |
183 | #endif | |
b0fc494f | 184 | } |
3d083395 | 185 | |
16444a8a ACM |
186 | return 0; |
187 | } | |
188 | ||
e309b41d | 189 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 190 | { |
16444a8a | 191 | struct ftrace_ops **p; |
16444a8a ACM |
192 | |
193 | /* | |
3d083395 SR |
194 | * If we are removing the last function, then simply point |
195 | * to the ftrace_stub. | |
16444a8a ACM |
196 | */ |
197 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { | |
198 | ftrace_trace_function = ftrace_stub; | |
199 | ftrace_list = &ftrace_list_end; | |
e6ea44e9 | 200 | return 0; |
16444a8a ACM |
201 | } |
202 | ||
203 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) | |
204 | if (*p == ops) | |
205 | break; | |
206 | ||
e6ea44e9 SR |
207 | if (*p != ops) |
208 | return -1; | |
16444a8a ACM |
209 | |
210 | *p = (*p)->next; | |
211 | ||
b0fc494f SR |
212 | if (ftrace_enabled) { |
213 | /* If we only have one func left, then call that directly */ | |
df4fc315 SR |
214 | if (ftrace_list->next == &ftrace_list_end) { |
215 | ftrace_func_t func = ftrace_list->func; | |
216 | ||
756d17ee | 217 | if (!list_empty(&ftrace_pids)) { |
df4fc315 SR |
218 | set_ftrace_pid_function(func); |
219 | func = ftrace_pid_func; | |
220 | } | |
221 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
222 | ftrace_trace_function = func; | |
223 | #else | |
224 | __ftrace_trace_function = func; | |
225 | #endif | |
226 | } | |
b0fc494f | 227 | } |
16444a8a | 228 | |
e6ea44e9 | 229 | return 0; |
3d083395 SR |
230 | } |
231 | ||
df4fc315 SR |
232 | static void ftrace_update_pid_func(void) |
233 | { | |
234 | ftrace_func_t func; | |
235 | ||
df4fc315 | 236 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 237 | return; |
df4fc315 | 238 | |
33974093 | 239 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
df4fc315 | 240 | func = ftrace_trace_function; |
33974093 MF |
241 | #else |
242 | func = __ftrace_trace_function; | |
243 | #endif | |
df4fc315 | 244 | |
756d17ee | 245 | if (!list_empty(&ftrace_pids)) { |
df4fc315 SR |
246 | set_ftrace_pid_function(func); |
247 | func = ftrace_pid_func; | |
248 | } else { | |
66eafebc LW |
249 | if (func == ftrace_pid_func) |
250 | func = ftrace_pid_function; | |
df4fc315 SR |
251 | } |
252 | ||
253 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
254 | ftrace_trace_function = func; | |
255 | #else | |
256 | __ftrace_trace_function = func; | |
257 | #endif | |
df4fc315 SR |
258 | } |
259 | ||
493762fc SR |
260 | #ifdef CONFIG_FUNCTION_PROFILER |
261 | struct ftrace_profile { | |
262 | struct hlist_node node; | |
263 | unsigned long ip; | |
264 | unsigned long counter; | |
0706f1c4 SR |
265 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
266 | unsigned long long time; | |
e330b3bc | 267 | unsigned long long time_squared; |
0706f1c4 | 268 | #endif |
8fc0c701 SR |
269 | }; |
270 | ||
493762fc SR |
271 | struct ftrace_profile_page { |
272 | struct ftrace_profile_page *next; | |
273 | unsigned long index; | |
274 | struct ftrace_profile records[]; | |
d61f82d0 SR |
275 | }; |
276 | ||
cafb168a SR |
277 | struct ftrace_profile_stat { |
278 | atomic_t disabled; | |
279 | struct hlist_head *hash; | |
280 | struct ftrace_profile_page *pages; | |
281 | struct ftrace_profile_page *start; | |
282 | struct tracer_stat stat; | |
283 | }; | |
284 | ||
493762fc SR |
285 | #define PROFILE_RECORDS_SIZE \ |
286 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 287 | |
493762fc SR |
288 | #define PROFILES_PER_PAGE \ |
289 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 290 | |
fb9fb015 SR |
291 | static int ftrace_profile_bits __read_mostly; |
292 | static int ftrace_profile_enabled __read_mostly; | |
293 | ||
294 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
295 | static DEFINE_MUTEX(ftrace_profile_lock); |
296 | ||
cafb168a | 297 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc SR |
298 | |
299 | #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */ | |
300 | ||
bac429f0 SR |
301 | static void * |
302 | function_stat_next(void *v, int idx) | |
303 | { | |
493762fc SR |
304 | struct ftrace_profile *rec = v; |
305 | struct ftrace_profile_page *pg; | |
bac429f0 | 306 | |
493762fc | 307 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
308 | |
309 | again: | |
0296e425 LZ |
310 | if (idx != 0) |
311 | rec++; | |
312 | ||
bac429f0 SR |
313 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
314 | pg = pg->next; | |
315 | if (!pg) | |
316 | return NULL; | |
317 | rec = &pg->records[0]; | |
493762fc SR |
318 | if (!rec->counter) |
319 | goto again; | |
bac429f0 SR |
320 | } |
321 | ||
bac429f0 SR |
322 | return rec; |
323 | } | |
324 | ||
325 | static void *function_stat_start(struct tracer_stat *trace) | |
326 | { | |
cafb168a SR |
327 | struct ftrace_profile_stat *stat = |
328 | container_of(trace, struct ftrace_profile_stat, stat); | |
329 | ||
330 | if (!stat || !stat->start) | |
331 | return NULL; | |
332 | ||
333 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
334 | } |
335 | ||
0706f1c4 SR |
336 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
337 | /* function graph compares on total time */ | |
338 | static int function_stat_cmp(void *p1, void *p2) | |
339 | { | |
340 | struct ftrace_profile *a = p1; | |
341 | struct ftrace_profile *b = p2; | |
342 | ||
343 | if (a->time < b->time) | |
344 | return -1; | |
345 | if (a->time > b->time) | |
346 | return 1; | |
347 | else | |
348 | return 0; | |
349 | } | |
350 | #else | |
351 | /* not function graph compares against hits */ | |
bac429f0 SR |
352 | static int function_stat_cmp(void *p1, void *p2) |
353 | { | |
493762fc SR |
354 | struct ftrace_profile *a = p1; |
355 | struct ftrace_profile *b = p2; | |
bac429f0 SR |
356 | |
357 | if (a->counter < b->counter) | |
358 | return -1; | |
359 | if (a->counter > b->counter) | |
360 | return 1; | |
361 | else | |
362 | return 0; | |
363 | } | |
0706f1c4 | 364 | #endif |
bac429f0 SR |
365 | |
366 | static int function_stat_headers(struct seq_file *m) | |
367 | { | |
0706f1c4 | 368 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b | 369 | seq_printf(m, " Function " |
e330b3bc | 370 | "Hit Time Avg s^2\n" |
34886c8b | 371 | " -------- " |
e330b3bc | 372 | "--- ---- --- ---\n"); |
0706f1c4 | 373 | #else |
bac429f0 SR |
374 | seq_printf(m, " Function Hit\n" |
375 | " -------- ---\n"); | |
0706f1c4 | 376 | #endif |
bac429f0 SR |
377 | return 0; |
378 | } | |
379 | ||
380 | static int function_stat_show(struct seq_file *m, void *v) | |
381 | { | |
493762fc | 382 | struct ftrace_profile *rec = v; |
bac429f0 | 383 | char str[KSYM_SYMBOL_LEN]; |
0706f1c4 | 384 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
0706f1c4 | 385 | static DEFINE_MUTEX(mutex); |
34886c8b SR |
386 | static struct trace_seq s; |
387 | unsigned long long avg; | |
e330b3bc | 388 | unsigned long long stddev; |
0706f1c4 | 389 | #endif |
bac429f0 SR |
390 | |
391 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
0706f1c4 SR |
392 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
393 | ||
394 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
395 | seq_printf(m, " "); | |
34886c8b SR |
396 | avg = rec->time; |
397 | do_div(avg, rec->counter); | |
398 | ||
e330b3bc CD |
399 | /* Sample standard deviation (s^2) */ |
400 | if (rec->counter <= 1) | |
401 | stddev = 0; | |
402 | else { | |
403 | stddev = rec->time_squared - rec->counter * avg * avg; | |
404 | /* | |
405 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
406 | * trace_print_graph_duration will divide 1000 again. | |
407 | */ | |
408 | do_div(stddev, (rec->counter - 1) * 1000); | |
409 | } | |
410 | ||
34886c8b SR |
411 | mutex_lock(&mutex); |
412 | trace_seq_init(&s); | |
413 | trace_print_graph_duration(rec->time, &s); | |
414 | trace_seq_puts(&s, " "); | |
415 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
416 | trace_seq_puts(&s, " "); |
417 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 SR |
418 | trace_print_seq(m, &s); |
419 | mutex_unlock(&mutex); | |
420 | #endif | |
421 | seq_putc(m, '\n'); | |
bac429f0 | 422 | |
bac429f0 SR |
423 | return 0; |
424 | } | |
425 | ||
cafb168a | 426 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 427 | { |
493762fc | 428 | struct ftrace_profile_page *pg; |
bac429f0 | 429 | |
cafb168a | 430 | pg = stat->pages = stat->start; |
bac429f0 | 431 | |
493762fc SR |
432 | while (pg) { |
433 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
434 | pg->index = 0; | |
435 | pg = pg->next; | |
bac429f0 SR |
436 | } |
437 | ||
cafb168a | 438 | memset(stat->hash, 0, |
493762fc SR |
439 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
440 | } | |
bac429f0 | 441 | |
cafb168a | 442 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
443 | { |
444 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
445 | int functions; |
446 | int pages; | |
493762fc | 447 | int i; |
bac429f0 | 448 | |
493762fc | 449 | /* If we already allocated, do nothing */ |
cafb168a | 450 | if (stat->pages) |
493762fc | 451 | return 0; |
bac429f0 | 452 | |
cafb168a SR |
453 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
454 | if (!stat->pages) | |
493762fc | 455 | return -ENOMEM; |
bac429f0 | 456 | |
318e0a73 SR |
457 | #ifdef CONFIG_DYNAMIC_FTRACE |
458 | functions = ftrace_update_tot_cnt; | |
459 | #else | |
460 | /* | |
461 | * We do not know the number of functions that exist because | |
462 | * dynamic tracing is what counts them. With past experience | |
463 | * we have around 20K functions. That should be more than enough. | |
464 | * It is highly unlikely we will execute every function in | |
465 | * the kernel. | |
466 | */ | |
467 | functions = 20000; | |
468 | #endif | |
469 | ||
cafb168a | 470 | pg = stat->start = stat->pages; |
bac429f0 | 471 | |
318e0a73 SR |
472 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
473 | ||
474 | for (i = 0; i < pages; i++) { | |
493762fc | 475 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 476 | if (!pg->next) |
318e0a73 | 477 | goto out_free; |
493762fc SR |
478 | pg = pg->next; |
479 | } | |
480 | ||
481 | return 0; | |
318e0a73 SR |
482 | |
483 | out_free: | |
484 | pg = stat->start; | |
485 | while (pg) { | |
486 | unsigned long tmp = (unsigned long)pg; | |
487 | ||
488 | pg = pg->next; | |
489 | free_page(tmp); | |
490 | } | |
491 | ||
492 | free_page((unsigned long)stat->pages); | |
493 | stat->pages = NULL; | |
494 | stat->start = NULL; | |
495 | ||
496 | return -ENOMEM; | |
bac429f0 SR |
497 | } |
498 | ||
cafb168a | 499 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 500 | { |
cafb168a | 501 | struct ftrace_profile_stat *stat; |
493762fc | 502 | int size; |
bac429f0 | 503 | |
cafb168a SR |
504 | stat = &per_cpu(ftrace_profile_stats, cpu); |
505 | ||
506 | if (stat->hash) { | |
493762fc | 507 | /* If the profile is already created, simply reset it */ |
cafb168a | 508 | ftrace_profile_reset(stat); |
493762fc SR |
509 | return 0; |
510 | } | |
bac429f0 | 511 | |
493762fc SR |
512 | /* |
513 | * We are profiling all functions, but usually only a few thousand | |
514 | * functions are hit. We'll make a hash of 1024 items. | |
515 | */ | |
516 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 517 | |
cafb168a | 518 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
493762fc | 519 | |
cafb168a | 520 | if (!stat->hash) |
493762fc SR |
521 | return -ENOMEM; |
522 | ||
cafb168a SR |
523 | if (!ftrace_profile_bits) { |
524 | size--; | |
493762fc | 525 | |
cafb168a SR |
526 | for (; size; size >>= 1) |
527 | ftrace_profile_bits++; | |
528 | } | |
493762fc | 529 | |
318e0a73 | 530 | /* Preallocate the function profiling pages */ |
cafb168a SR |
531 | if (ftrace_profile_pages_init(stat) < 0) { |
532 | kfree(stat->hash); | |
533 | stat->hash = NULL; | |
493762fc SR |
534 | return -ENOMEM; |
535 | } | |
536 | ||
537 | return 0; | |
bac429f0 SR |
538 | } |
539 | ||
cafb168a SR |
540 | static int ftrace_profile_init(void) |
541 | { | |
542 | int cpu; | |
543 | int ret = 0; | |
544 | ||
545 | for_each_online_cpu(cpu) { | |
546 | ret = ftrace_profile_init_cpu(cpu); | |
547 | if (ret) | |
548 | break; | |
549 | } | |
550 | ||
551 | return ret; | |
552 | } | |
553 | ||
493762fc | 554 | /* interrupts must be disabled */ |
cafb168a SR |
555 | static struct ftrace_profile * |
556 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 557 | { |
493762fc | 558 | struct ftrace_profile *rec; |
bac429f0 SR |
559 | struct hlist_head *hhd; |
560 | struct hlist_node *n; | |
bac429f0 SR |
561 | unsigned long key; |
562 | ||
bac429f0 | 563 | key = hash_long(ip, ftrace_profile_bits); |
cafb168a | 564 | hhd = &stat->hash[key]; |
bac429f0 SR |
565 | |
566 | if (hlist_empty(hhd)) | |
567 | return NULL; | |
568 | ||
bac429f0 SR |
569 | hlist_for_each_entry_rcu(rec, n, hhd, node) { |
570 | if (rec->ip == ip) | |
493762fc SR |
571 | return rec; |
572 | } | |
573 | ||
574 | return NULL; | |
575 | } | |
576 | ||
cafb168a SR |
577 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
578 | struct ftrace_profile *rec) | |
493762fc SR |
579 | { |
580 | unsigned long key; | |
581 | ||
582 | key = hash_long(rec->ip, ftrace_profile_bits); | |
cafb168a | 583 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
584 | } |
585 | ||
318e0a73 SR |
586 | /* |
587 | * The memory is already allocated, this simply finds a new record to use. | |
588 | */ | |
493762fc | 589 | static struct ftrace_profile * |
318e0a73 | 590 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
591 | { |
592 | struct ftrace_profile *rec = NULL; | |
593 | ||
318e0a73 | 594 | /* prevent recursion (from NMIs) */ |
cafb168a | 595 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
596 | goto out; |
597 | ||
493762fc | 598 | /* |
318e0a73 SR |
599 | * Try to find the function again since an NMI |
600 | * could have added it | |
493762fc | 601 | */ |
cafb168a | 602 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 603 | if (rec) |
cafb168a | 604 | goto out; |
493762fc | 605 | |
cafb168a SR |
606 | if (stat->pages->index == PROFILES_PER_PAGE) { |
607 | if (!stat->pages->next) | |
608 | goto out; | |
609 | stat->pages = stat->pages->next; | |
bac429f0 | 610 | } |
493762fc | 611 | |
cafb168a | 612 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 613 | rec->ip = ip; |
cafb168a | 614 | ftrace_add_profile(stat, rec); |
493762fc | 615 | |
bac429f0 | 616 | out: |
cafb168a | 617 | atomic_dec(&stat->disabled); |
bac429f0 SR |
618 | |
619 | return rec; | |
620 | } | |
621 | ||
622 | static void | |
623 | function_profile_call(unsigned long ip, unsigned long parent_ip) | |
624 | { | |
cafb168a | 625 | struct ftrace_profile_stat *stat; |
493762fc | 626 | struct ftrace_profile *rec; |
bac429f0 SR |
627 | unsigned long flags; |
628 | ||
629 | if (!ftrace_profile_enabled) | |
630 | return; | |
631 | ||
632 | local_irq_save(flags); | |
cafb168a SR |
633 | |
634 | stat = &__get_cpu_var(ftrace_profile_stats); | |
0f6ce3de | 635 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
636 | goto out; |
637 | ||
638 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 639 | if (!rec) { |
318e0a73 | 640 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
641 | if (!rec) |
642 | goto out; | |
643 | } | |
bac429f0 SR |
644 | |
645 | rec->counter++; | |
646 | out: | |
647 | local_irq_restore(flags); | |
648 | } | |
649 | ||
0706f1c4 SR |
650 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
651 | static int profile_graph_entry(struct ftrace_graph_ent *trace) | |
652 | { | |
653 | function_profile_call(trace->func, 0); | |
654 | return 1; | |
655 | } | |
656 | ||
657 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
658 | { | |
cafb168a | 659 | struct ftrace_profile_stat *stat; |
a2a16d6a | 660 | unsigned long long calltime; |
0706f1c4 | 661 | struct ftrace_profile *rec; |
cafb168a | 662 | unsigned long flags; |
0706f1c4 SR |
663 | |
664 | local_irq_save(flags); | |
cafb168a | 665 | stat = &__get_cpu_var(ftrace_profile_stats); |
0f6ce3de | 666 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
667 | goto out; |
668 | ||
37e44bc5 SR |
669 | /* If the calltime was zero'd ignore it */ |
670 | if (!trace->calltime) | |
671 | goto out; | |
672 | ||
a2a16d6a SR |
673 | calltime = trace->rettime - trace->calltime; |
674 | ||
675 | if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) { | |
676 | int index; | |
677 | ||
678 | index = trace->depth; | |
679 | ||
680 | /* Append this call time to the parent time to subtract */ | |
681 | if (index) | |
682 | current->ret_stack[index - 1].subtime += calltime; | |
683 | ||
684 | if (current->ret_stack[index].subtime < calltime) | |
685 | calltime -= current->ret_stack[index].subtime; | |
686 | else | |
687 | calltime = 0; | |
688 | } | |
689 | ||
cafb168a | 690 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 691 | if (rec) { |
a2a16d6a | 692 | rec->time += calltime; |
e330b3bc CD |
693 | rec->time_squared += calltime * calltime; |
694 | } | |
a2a16d6a | 695 | |
cafb168a | 696 | out: |
0706f1c4 SR |
697 | local_irq_restore(flags); |
698 | } | |
699 | ||
700 | static int register_ftrace_profiler(void) | |
701 | { | |
702 | return register_ftrace_graph(&profile_graph_return, | |
703 | &profile_graph_entry); | |
704 | } | |
705 | ||
706 | static void unregister_ftrace_profiler(void) | |
707 | { | |
708 | unregister_ftrace_graph(); | |
709 | } | |
710 | #else | |
bac429f0 SR |
711 | static struct ftrace_ops ftrace_profile_ops __read_mostly = |
712 | { | |
fb9fb015 | 713 | .func = function_profile_call, |
bac429f0 SR |
714 | }; |
715 | ||
0706f1c4 SR |
716 | static int register_ftrace_profiler(void) |
717 | { | |
718 | return register_ftrace_function(&ftrace_profile_ops); | |
719 | } | |
720 | ||
721 | static void unregister_ftrace_profiler(void) | |
722 | { | |
723 | unregister_ftrace_function(&ftrace_profile_ops); | |
724 | } | |
725 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
726 | ||
bac429f0 SR |
727 | static ssize_t |
728 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
729 | size_t cnt, loff_t *ppos) | |
730 | { | |
731 | unsigned long val; | |
fb9fb015 | 732 | char buf[64]; /* big enough to hold a number */ |
bac429f0 SR |
733 | int ret; |
734 | ||
bac429f0 SR |
735 | if (cnt >= sizeof(buf)) |
736 | return -EINVAL; | |
737 | ||
738 | if (copy_from_user(&buf, ubuf, cnt)) | |
739 | return -EFAULT; | |
740 | ||
741 | buf[cnt] = 0; | |
742 | ||
743 | ret = strict_strtoul(buf, 10, &val); | |
744 | if (ret < 0) | |
745 | return ret; | |
746 | ||
747 | val = !!val; | |
748 | ||
749 | mutex_lock(&ftrace_profile_lock); | |
750 | if (ftrace_profile_enabled ^ val) { | |
751 | if (val) { | |
493762fc SR |
752 | ret = ftrace_profile_init(); |
753 | if (ret < 0) { | |
754 | cnt = ret; | |
755 | goto out; | |
756 | } | |
757 | ||
0706f1c4 SR |
758 | ret = register_ftrace_profiler(); |
759 | if (ret < 0) { | |
760 | cnt = ret; | |
761 | goto out; | |
762 | } | |
bac429f0 SR |
763 | ftrace_profile_enabled = 1; |
764 | } else { | |
765 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
766 | /* |
767 | * unregister_ftrace_profiler calls stop_machine | |
768 | * so this acts like an synchronize_sched. | |
769 | */ | |
0706f1c4 | 770 | unregister_ftrace_profiler(); |
bac429f0 SR |
771 | } |
772 | } | |
493762fc | 773 | out: |
bac429f0 SR |
774 | mutex_unlock(&ftrace_profile_lock); |
775 | ||
cf8517cf | 776 | *ppos += cnt; |
bac429f0 SR |
777 | |
778 | return cnt; | |
779 | } | |
780 | ||
493762fc SR |
781 | static ssize_t |
782 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
783 | size_t cnt, loff_t *ppos) | |
784 | { | |
fb9fb015 | 785 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
786 | int r; |
787 | ||
788 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
789 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
790 | } | |
791 | ||
bac429f0 SR |
792 | static const struct file_operations ftrace_profile_fops = { |
793 | .open = tracing_open_generic, | |
794 | .read = ftrace_profile_read, | |
795 | .write = ftrace_profile_write, | |
796 | }; | |
797 | ||
cafb168a SR |
798 | /* used to initialize the real stat files */ |
799 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
800 | .name = "functions", |
801 | .stat_start = function_stat_start, | |
802 | .stat_next = function_stat_next, | |
803 | .stat_cmp = function_stat_cmp, | |
804 | .stat_headers = function_stat_headers, | |
805 | .stat_show = function_stat_show | |
cafb168a SR |
806 | }; |
807 | ||
6ab5d668 | 808 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 | 809 | { |
cafb168a | 810 | struct ftrace_profile_stat *stat; |
bac429f0 | 811 | struct dentry *entry; |
cafb168a | 812 | char *name; |
bac429f0 | 813 | int ret; |
cafb168a SR |
814 | int cpu; |
815 | ||
816 | for_each_possible_cpu(cpu) { | |
817 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
818 | ||
819 | /* allocate enough for function name + cpu number */ | |
820 | name = kmalloc(32, GFP_KERNEL); | |
821 | if (!name) { | |
822 | /* | |
823 | * The files created are permanent, if something happens | |
824 | * we still do not free memory. | |
825 | */ | |
cafb168a SR |
826 | WARN(1, |
827 | "Could not allocate stat file for cpu %d\n", | |
828 | cpu); | |
829 | return; | |
830 | } | |
831 | stat->stat = function_stats; | |
832 | snprintf(name, 32, "function%d", cpu); | |
833 | stat->stat.name = name; | |
834 | ret = register_stat_tracer(&stat->stat); | |
835 | if (ret) { | |
836 | WARN(1, | |
837 | "Could not register function stat for cpu %d\n", | |
838 | cpu); | |
839 | kfree(name); | |
840 | return; | |
841 | } | |
bac429f0 SR |
842 | } |
843 | ||
844 | entry = debugfs_create_file("function_profile_enabled", 0644, | |
845 | d_tracer, NULL, &ftrace_profile_fops); | |
846 | if (!entry) | |
847 | pr_warning("Could not create debugfs " | |
848 | "'function_profile_enabled' entry\n"); | |
849 | } | |
850 | ||
bac429f0 | 851 | #else /* CONFIG_FUNCTION_PROFILER */ |
6ab5d668 | 852 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 SR |
853 | { |
854 | } | |
bac429f0 SR |
855 | #endif /* CONFIG_FUNCTION_PROFILER */ |
856 | ||
493762fc SR |
857 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; |
858 | ||
859 | #ifdef CONFIG_DYNAMIC_FTRACE | |
860 | ||
861 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD | |
862 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
863 | #endif | |
864 | ||
865 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; | |
866 | ||
867 | struct ftrace_func_probe { | |
868 | struct hlist_node node; | |
869 | struct ftrace_probe_ops *ops; | |
870 | unsigned long flags; | |
871 | unsigned long ip; | |
872 | void *data; | |
873 | struct rcu_head rcu; | |
874 | }; | |
875 | ||
876 | enum { | |
877 | FTRACE_ENABLE_CALLS = (1 << 0), | |
878 | FTRACE_DISABLE_CALLS = (1 << 1), | |
879 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
880 | FTRACE_ENABLE_MCOUNT = (1 << 3), | |
881 | FTRACE_DISABLE_MCOUNT = (1 << 4), | |
882 | FTRACE_START_FUNC_RET = (1 << 5), | |
883 | FTRACE_STOP_FUNC_RET = (1 << 6), | |
884 | }; | |
885 | ||
886 | static int ftrace_filtered; | |
887 | ||
888 | static struct dyn_ftrace *ftrace_new_addrs; | |
889 | ||
890 | static DEFINE_MUTEX(ftrace_regex_lock); | |
891 | ||
892 | struct ftrace_page { | |
893 | struct ftrace_page *next; | |
894 | int index; | |
895 | struct dyn_ftrace records[]; | |
896 | }; | |
897 | ||
898 | #define ENTRIES_PER_PAGE \ | |
899 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
900 | ||
901 | /* estimate from running different kernels */ | |
902 | #define NR_TO_INIT 10000 | |
903 | ||
904 | static struct ftrace_page *ftrace_pages_start; | |
905 | static struct ftrace_page *ftrace_pages; | |
906 | ||
907 | static struct dyn_ftrace *ftrace_free_records; | |
908 | ||
909 | /* | |
910 | * This is a double for. Do not use 'break' to break out of the loop, | |
911 | * you must use a goto. | |
912 | */ | |
913 | #define do_for_each_ftrace_rec(pg, rec) \ | |
914 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
915 | int _____i; \ | |
916 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
917 | rec = &pg->records[_____i]; | |
918 | ||
919 | #define while_for_each_ftrace_rec() \ | |
920 | } \ | |
921 | } | |
922 | ||
e309b41d | 923 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
37ad5084 | 924 | { |
ee000b7f | 925 | rec->freelist = ftrace_free_records; |
37ad5084 SR |
926 | ftrace_free_records = rec; |
927 | rec->flags |= FTRACE_FL_FREE; | |
928 | } | |
929 | ||
e309b41d | 930 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 931 | { |
37ad5084 SR |
932 | struct dyn_ftrace *rec; |
933 | ||
934 | /* First check for freed records */ | |
935 | if (ftrace_free_records) { | |
936 | rec = ftrace_free_records; | |
937 | ||
37ad5084 | 938 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
6912896e | 939 | FTRACE_WARN_ON_ONCE(1); |
37ad5084 SR |
940 | ftrace_free_records = NULL; |
941 | return NULL; | |
942 | } | |
943 | ||
ee000b7f | 944 | ftrace_free_records = rec->freelist; |
37ad5084 SR |
945 | memset(rec, 0, sizeof(*rec)); |
946 | return rec; | |
947 | } | |
948 | ||
3c1720f0 | 949 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
08f5ac90 SR |
950 | if (!ftrace_pages->next) { |
951 | /* allocate another page */ | |
952 | ftrace_pages->next = | |
953 | (void *)get_zeroed_page(GFP_KERNEL); | |
954 | if (!ftrace_pages->next) | |
955 | return NULL; | |
956 | } | |
3c1720f0 SR |
957 | ftrace_pages = ftrace_pages->next; |
958 | } | |
959 | ||
960 | return &ftrace_pages->records[ftrace_pages->index++]; | |
961 | } | |
962 | ||
08f5ac90 | 963 | static struct dyn_ftrace * |
d61f82d0 | 964 | ftrace_record_ip(unsigned long ip) |
3d083395 | 965 | { |
08f5ac90 | 966 | struct dyn_ftrace *rec; |
3d083395 | 967 | |
f3c7ac40 | 968 | if (ftrace_disabled) |
08f5ac90 | 969 | return NULL; |
3d083395 | 970 | |
08f5ac90 SR |
971 | rec = ftrace_alloc_dyn_node(ip); |
972 | if (!rec) | |
973 | return NULL; | |
3d083395 | 974 | |
08f5ac90 | 975 | rec->ip = ip; |
ee000b7f | 976 | rec->newlist = ftrace_new_addrs; |
e94142a6 | 977 | ftrace_new_addrs = rec; |
3d083395 | 978 | |
08f5ac90 | 979 | return rec; |
3d083395 SR |
980 | } |
981 | ||
b17e8a37 SR |
982 | static void print_ip_ins(const char *fmt, unsigned char *p) |
983 | { | |
984 | int i; | |
985 | ||
986 | printk(KERN_CONT "%s", fmt); | |
987 | ||
988 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
989 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
990 | } | |
991 | ||
31e88909 | 992 | static void ftrace_bug(int failed, unsigned long ip) |
b17e8a37 SR |
993 | { |
994 | switch (failed) { | |
995 | case -EFAULT: | |
996 | FTRACE_WARN_ON_ONCE(1); | |
997 | pr_info("ftrace faulted on modifying "); | |
998 | print_ip_sym(ip); | |
999 | break; | |
1000 | case -EINVAL: | |
1001 | FTRACE_WARN_ON_ONCE(1); | |
1002 | pr_info("ftrace failed to modify "); | |
1003 | print_ip_sym(ip); | |
b17e8a37 | 1004 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
1005 | printk(KERN_CONT "\n"); |
1006 | break; | |
1007 | case -EPERM: | |
1008 | FTRACE_WARN_ON_ONCE(1); | |
1009 | pr_info("ftrace faulted on writing "); | |
1010 | print_ip_sym(ip); | |
1011 | break; | |
1012 | default: | |
1013 | FTRACE_WARN_ON_ONCE(1); | |
1014 | pr_info("ftrace faulted on unknown error "); | |
1015 | print_ip_sym(ip); | |
1016 | } | |
1017 | } | |
1018 | ||
3c1720f0 | 1019 | |
2cfa1978 MH |
1020 | /* Return 1 if the address range is reserved for ftrace */ |
1021 | int ftrace_text_reserved(void *start, void *end) | |
1022 | { | |
1023 | struct dyn_ftrace *rec; | |
1024 | struct ftrace_page *pg; | |
1025 | ||
1026 | do_for_each_ftrace_rec(pg, rec) { | |
1027 | if (rec->ip <= (unsigned long)end && | |
1028 | rec->ip + MCOUNT_INSN_SIZE > (unsigned long)start) | |
1029 | return 1; | |
1030 | } while_for_each_ftrace_rec(); | |
1031 | return 0; | |
1032 | } | |
1033 | ||
1034 | ||
0eb96701 | 1035 | static int |
31e88909 | 1036 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) |
5072c59f | 1037 | { |
e7d3737e | 1038 | unsigned long ftrace_addr; |
64fbcd16 | 1039 | unsigned long flag = 0UL; |
e7d3737e | 1040 | |
f0001207 | 1041 | ftrace_addr = (unsigned long)FTRACE_ADDR; |
5072c59f | 1042 | |
982c350b | 1043 | /* |
64fbcd16 XG |
1044 | * If this record is not to be traced or we want to disable it, |
1045 | * then disable it. | |
982c350b | 1046 | * |
64fbcd16 | 1047 | * If we want to enable it and filtering is off, then enable it. |
982c350b | 1048 | * |
64fbcd16 XG |
1049 | * If we want to enable it and filtering is on, enable it only if |
1050 | * it's filtered | |
982c350b | 1051 | */ |
64fbcd16 XG |
1052 | if (enable && !(rec->flags & FTRACE_FL_NOTRACE)) { |
1053 | if (!ftrace_filtered || (rec->flags & FTRACE_FL_FILTER)) | |
1054 | flag = FTRACE_FL_ENABLED; | |
1055 | } | |
982c350b | 1056 | |
64fbcd16 XG |
1057 | /* If the state of this record hasn't changed, then do nothing */ |
1058 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
1059 | return 0; | |
982c350b | 1060 | |
64fbcd16 XG |
1061 | if (flag) { |
1062 | rec->flags |= FTRACE_FL_ENABLED; | |
1063 | return ftrace_make_call(rec, ftrace_addr); | |
5072c59f SR |
1064 | } |
1065 | ||
64fbcd16 XG |
1066 | rec->flags &= ~FTRACE_FL_ENABLED; |
1067 | return ftrace_make_nop(NULL, rec, ftrace_addr); | |
5072c59f SR |
1068 | } |
1069 | ||
e309b41d | 1070 | static void ftrace_replace_code(int enable) |
3c1720f0 | 1071 | { |
3c1720f0 SR |
1072 | struct dyn_ftrace *rec; |
1073 | struct ftrace_page *pg; | |
6a24a244 | 1074 | int failed; |
3c1720f0 | 1075 | |
265c831c SR |
1076 | do_for_each_ftrace_rec(pg, rec) { |
1077 | /* | |
fa9d13cf Z |
1078 | * Skip over free records, records that have |
1079 | * failed and not converted. | |
265c831c SR |
1080 | */ |
1081 | if (rec->flags & FTRACE_FL_FREE || | |
fa9d13cf | 1082 | rec->flags & FTRACE_FL_FAILED || |
03303549 | 1083 | !(rec->flags & FTRACE_FL_CONVERTED)) |
265c831c SR |
1084 | continue; |
1085 | ||
265c831c | 1086 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 1087 | if (failed) { |
265c831c | 1088 | rec->flags |= FTRACE_FL_FAILED; |
3279ba37 SR |
1089 | ftrace_bug(failed, rec->ip); |
1090 | /* Stop processing */ | |
1091 | return; | |
3c1720f0 | 1092 | } |
265c831c | 1093 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
1094 | } |
1095 | ||
492a7ea5 | 1096 | static int |
31e88909 | 1097 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 SR |
1098 | { |
1099 | unsigned long ip; | |
593eb8a2 | 1100 | int ret; |
3c1720f0 SR |
1101 | |
1102 | ip = rec->ip; | |
1103 | ||
25aac9dc | 1104 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 1105 | if (ret) { |
31e88909 | 1106 | ftrace_bug(ret, ip); |
3c1720f0 | 1107 | rec->flags |= FTRACE_FL_FAILED; |
492a7ea5 | 1108 | return 0; |
37ad5084 | 1109 | } |
492a7ea5 | 1110 | return 1; |
3c1720f0 SR |
1111 | } |
1112 | ||
000ab691 SR |
1113 | /* |
1114 | * archs can override this function if they must do something | |
1115 | * before the modifying code is performed. | |
1116 | */ | |
1117 | int __weak ftrace_arch_code_modify_prepare(void) | |
1118 | { | |
1119 | return 0; | |
1120 | } | |
1121 | ||
1122 | /* | |
1123 | * archs can override this function if they must do something | |
1124 | * after the modifying code is performed. | |
1125 | */ | |
1126 | int __weak ftrace_arch_code_modify_post_process(void) | |
1127 | { | |
1128 | return 0; | |
1129 | } | |
1130 | ||
e309b41d | 1131 | static int __ftrace_modify_code(void *data) |
3d083395 | 1132 | { |
d61f82d0 SR |
1133 | int *command = data; |
1134 | ||
a3583244 | 1135 | if (*command & FTRACE_ENABLE_CALLS) |
d61f82d0 | 1136 | ftrace_replace_code(1); |
a3583244 | 1137 | else if (*command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
1138 | ftrace_replace_code(0); |
1139 | ||
1140 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
1141 | ftrace_update_ftrace_func(ftrace_trace_function); | |
1142 | ||
5a45cfe1 SR |
1143 | if (*command & FTRACE_START_FUNC_RET) |
1144 | ftrace_enable_ftrace_graph_caller(); | |
1145 | else if (*command & FTRACE_STOP_FUNC_RET) | |
1146 | ftrace_disable_ftrace_graph_caller(); | |
1147 | ||
d61f82d0 | 1148 | return 0; |
3d083395 SR |
1149 | } |
1150 | ||
e309b41d | 1151 | static void ftrace_run_update_code(int command) |
3d083395 | 1152 | { |
000ab691 SR |
1153 | int ret; |
1154 | ||
1155 | ret = ftrace_arch_code_modify_prepare(); | |
1156 | FTRACE_WARN_ON(ret); | |
1157 | if (ret) | |
1158 | return; | |
1159 | ||
784e2d76 | 1160 | stop_machine(__ftrace_modify_code, &command, NULL); |
000ab691 SR |
1161 | |
1162 | ret = ftrace_arch_code_modify_post_process(); | |
1163 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
1164 | } |
1165 | ||
d61f82d0 | 1166 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 1167 | static int ftrace_start_up; |
df4fc315 SR |
1168 | |
1169 | static void ftrace_startup_enable(int command) | |
1170 | { | |
1171 | if (saved_ftrace_func != ftrace_trace_function) { | |
1172 | saved_ftrace_func = ftrace_trace_function; | |
1173 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1174 | } | |
1175 | ||
1176 | if (!command || !ftrace_enabled) | |
1177 | return; | |
1178 | ||
1179 | ftrace_run_update_code(command); | |
1180 | } | |
d61f82d0 | 1181 | |
5a45cfe1 | 1182 | static void ftrace_startup(int command) |
3d083395 | 1183 | { |
4eebcc81 SR |
1184 | if (unlikely(ftrace_disabled)) |
1185 | return; | |
1186 | ||
60a7ecf4 | 1187 | ftrace_start_up++; |
982c350b | 1188 | command |= FTRACE_ENABLE_CALLS; |
d61f82d0 | 1189 | |
df4fc315 | 1190 | ftrace_startup_enable(command); |
3d083395 SR |
1191 | } |
1192 | ||
5a45cfe1 | 1193 | static void ftrace_shutdown(int command) |
3d083395 | 1194 | { |
4eebcc81 SR |
1195 | if (unlikely(ftrace_disabled)) |
1196 | return; | |
1197 | ||
60a7ecf4 | 1198 | ftrace_start_up--; |
9ea1a153 FW |
1199 | /* |
1200 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
1201 | * critical but the ftrace_call callers may be never nopped again after | |
1202 | * further ftrace uses. | |
1203 | */ | |
1204 | WARN_ON_ONCE(ftrace_start_up < 0); | |
1205 | ||
60a7ecf4 | 1206 | if (!ftrace_start_up) |
d61f82d0 | 1207 | command |= FTRACE_DISABLE_CALLS; |
3d083395 | 1208 | |
d61f82d0 SR |
1209 | if (saved_ftrace_func != ftrace_trace_function) { |
1210 | saved_ftrace_func = ftrace_trace_function; | |
1211 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1212 | } | |
3d083395 | 1213 | |
d61f82d0 | 1214 | if (!command || !ftrace_enabled) |
e6ea44e9 | 1215 | return; |
d61f82d0 SR |
1216 | |
1217 | ftrace_run_update_code(command); | |
3d083395 SR |
1218 | } |
1219 | ||
e309b41d | 1220 | static void ftrace_startup_sysctl(void) |
b0fc494f | 1221 | { |
d61f82d0 SR |
1222 | int command = FTRACE_ENABLE_MCOUNT; |
1223 | ||
4eebcc81 SR |
1224 | if (unlikely(ftrace_disabled)) |
1225 | return; | |
1226 | ||
d61f82d0 SR |
1227 | /* Force update next time */ |
1228 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
1229 | /* ftrace_start_up is true if we want ftrace running */ |
1230 | if (ftrace_start_up) | |
d61f82d0 SR |
1231 | command |= FTRACE_ENABLE_CALLS; |
1232 | ||
1233 | ftrace_run_update_code(command); | |
b0fc494f SR |
1234 | } |
1235 | ||
e309b41d | 1236 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 1237 | { |
d61f82d0 SR |
1238 | int command = FTRACE_DISABLE_MCOUNT; |
1239 | ||
4eebcc81 SR |
1240 | if (unlikely(ftrace_disabled)) |
1241 | return; | |
1242 | ||
60a7ecf4 SR |
1243 | /* ftrace_start_up is true if ftrace is running */ |
1244 | if (ftrace_start_up) | |
d61f82d0 SR |
1245 | command |= FTRACE_DISABLE_CALLS; |
1246 | ||
1247 | ftrace_run_update_code(command); | |
b0fc494f SR |
1248 | } |
1249 | ||
3d083395 SR |
1250 | static cycle_t ftrace_update_time; |
1251 | static unsigned long ftrace_update_cnt; | |
1252 | unsigned long ftrace_update_tot_cnt; | |
1253 | ||
31e88909 | 1254 | static int ftrace_update_code(struct module *mod) |
3d083395 | 1255 | { |
e94142a6 | 1256 | struct dyn_ftrace *p; |
f22f9a89 | 1257 | cycle_t start, stop; |
3d083395 | 1258 | |
750ed1a4 | 1259 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1260 | ftrace_update_cnt = 0; |
1261 | ||
e94142a6 | 1262 | while (ftrace_new_addrs) { |
3d083395 | 1263 | |
08f5ac90 SR |
1264 | /* If something went wrong, bail without enabling anything */ |
1265 | if (unlikely(ftrace_disabled)) | |
1266 | return -1; | |
f22f9a89 | 1267 | |
e94142a6 | 1268 | p = ftrace_new_addrs; |
ee000b7f | 1269 | ftrace_new_addrs = p->newlist; |
e94142a6 | 1270 | p->flags = 0L; |
f22f9a89 | 1271 | |
5cb084bb JO |
1272 | /* |
1273 | * Do the initial record convertion from mcount jump | |
1274 | * to the NOP instructions. | |
1275 | */ | |
1276 | if (!ftrace_code_disable(mod, p)) { | |
08f5ac90 | 1277 | ftrace_free_rec(p); |
5cb084bb JO |
1278 | continue; |
1279 | } | |
1280 | ||
1281 | p->flags |= FTRACE_FL_CONVERTED; | |
1282 | ftrace_update_cnt++; | |
1283 | ||
1284 | /* | |
1285 | * If the tracing is enabled, go ahead and enable the record. | |
1286 | * | |
1287 | * The reason not to enable the record immediatelly is the | |
1288 | * inherent check of ftrace_make_nop/ftrace_make_call for | |
1289 | * correct previous instructions. Making first the NOP | |
1290 | * conversion puts the module to the correct state, thus | |
1291 | * passing the ftrace_make_call check. | |
1292 | */ | |
1293 | if (ftrace_start_up) { | |
1294 | int failed = __ftrace_replace_code(p, 1); | |
1295 | if (failed) { | |
1296 | ftrace_bug(failed, p->ip); | |
1297 | ftrace_free_rec(p); | |
1298 | } | |
1299 | } | |
3d083395 SR |
1300 | } |
1301 | ||
750ed1a4 | 1302 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1303 | ftrace_update_time = stop - start; |
1304 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
1305 | ||
16444a8a ACM |
1306 | return 0; |
1307 | } | |
1308 | ||
68bf21aa | 1309 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
1310 | { |
1311 | struct ftrace_page *pg; | |
1312 | int cnt; | |
1313 | int i; | |
3c1720f0 SR |
1314 | |
1315 | /* allocate a few pages */ | |
1316 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
1317 | if (!ftrace_pages_start) | |
1318 | return -1; | |
1319 | ||
1320 | /* | |
1321 | * Allocate a few more pages. | |
1322 | * | |
1323 | * TODO: have some parser search vmlinux before | |
1324 | * final linking to find all calls to ftrace. | |
1325 | * Then we can: | |
1326 | * a) know how many pages to allocate. | |
1327 | * and/or | |
1328 | * b) set up the table then. | |
1329 | * | |
1330 | * The dynamic code is still necessary for | |
1331 | * modules. | |
1332 | */ | |
1333 | ||
1334 | pg = ftrace_pages = ftrace_pages_start; | |
1335 | ||
68bf21aa | 1336 | cnt = num_to_init / ENTRIES_PER_PAGE; |
08f5ac90 | 1337 | pr_info("ftrace: allocating %ld entries in %d pages\n", |
5821e1b7 | 1338 | num_to_init, cnt + 1); |
3c1720f0 SR |
1339 | |
1340 | for (i = 0; i < cnt; i++) { | |
1341 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
1342 | ||
1343 | /* If we fail, we'll try later anyway */ | |
1344 | if (!pg->next) | |
1345 | break; | |
1346 | ||
1347 | pg = pg->next; | |
1348 | } | |
1349 | ||
1350 | return 0; | |
1351 | } | |
1352 | ||
5072c59f SR |
1353 | enum { |
1354 | FTRACE_ITER_FILTER = (1 << 0), | |
689fd8b6 | 1355 | FTRACE_ITER_NOTRACE = (1 << 1), |
1356 | FTRACE_ITER_FAILURES = (1 << 2), | |
1357 | FTRACE_ITER_PRINTALL = (1 << 3), | |
1358 | FTRACE_ITER_HASH = (1 << 4), | |
5072c59f SR |
1359 | }; |
1360 | ||
1361 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
1362 | ||
1363 | struct ftrace_iterator { | |
5072c59f | 1364 | struct ftrace_page *pg; |
8fc0c701 | 1365 | int hidx; |
431aa3fb | 1366 | int idx; |
5072c59f | 1367 | unsigned flags; |
689fd8b6 | 1368 | struct trace_parser parser; |
5072c59f SR |
1369 | }; |
1370 | ||
8fc0c701 SR |
1371 | static void * |
1372 | t_hash_next(struct seq_file *m, void *v, loff_t *pos) | |
1373 | { | |
1374 | struct ftrace_iterator *iter = m->private; | |
1375 | struct hlist_node *hnd = v; | |
1376 | struct hlist_head *hhd; | |
1377 | ||
1378 | WARN_ON(!(iter->flags & FTRACE_ITER_HASH)); | |
1379 | ||
1380 | (*pos)++; | |
1381 | ||
1382 | retry: | |
1383 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
1384 | return NULL; | |
1385 | ||
1386 | hhd = &ftrace_func_hash[iter->hidx]; | |
1387 | ||
1388 | if (hlist_empty(hhd)) { | |
1389 | iter->hidx++; | |
1390 | hnd = NULL; | |
1391 | goto retry; | |
1392 | } | |
1393 | ||
1394 | if (!hnd) | |
1395 | hnd = hhd->first; | |
1396 | else { | |
1397 | hnd = hnd->next; | |
1398 | if (!hnd) { | |
1399 | iter->hidx++; | |
1400 | goto retry; | |
1401 | } | |
1402 | } | |
1403 | ||
1404 | return hnd; | |
1405 | } | |
1406 | ||
1407 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
1408 | { | |
1409 | struct ftrace_iterator *iter = m->private; | |
1410 | void *p = NULL; | |
d82d6244 LZ |
1411 | loff_t l; |
1412 | ||
1413 | if (!(iter->flags & FTRACE_ITER_HASH)) | |
1414 | *pos = 0; | |
8fc0c701 SR |
1415 | |
1416 | iter->flags |= FTRACE_ITER_HASH; | |
1417 | ||
d82d6244 LZ |
1418 | iter->hidx = 0; |
1419 | for (l = 0; l <= *pos; ) { | |
1420 | p = t_hash_next(m, p, &l); | |
1421 | if (!p) | |
1422 | break; | |
1423 | } | |
1424 | return p; | |
8fc0c701 SR |
1425 | } |
1426 | ||
1427 | static int t_hash_show(struct seq_file *m, void *v) | |
1428 | { | |
b6887d79 | 1429 | struct ftrace_func_probe *rec; |
8fc0c701 | 1430 | struct hlist_node *hnd = v; |
8fc0c701 | 1431 | |
b6887d79 | 1432 | rec = hlist_entry(hnd, struct ftrace_func_probe, node); |
8fc0c701 | 1433 | |
809dcf29 SR |
1434 | if (rec->ops->print) |
1435 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
1436 | ||
b375a11a | 1437 | seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func); |
8fc0c701 SR |
1438 | |
1439 | if (rec->data) | |
1440 | seq_printf(m, ":%p", rec->data); | |
1441 | seq_putc(m, '\n'); | |
1442 | ||
1443 | return 0; | |
1444 | } | |
1445 | ||
e309b41d | 1446 | static void * |
5072c59f SR |
1447 | t_next(struct seq_file *m, void *v, loff_t *pos) |
1448 | { | |
1449 | struct ftrace_iterator *iter = m->private; | |
1450 | struct dyn_ftrace *rec = NULL; | |
1451 | ||
8fc0c701 SR |
1452 | if (iter->flags & FTRACE_ITER_HASH) |
1453 | return t_hash_next(m, v, pos); | |
1454 | ||
5072c59f SR |
1455 | (*pos)++; |
1456 | ||
0c75a3ed SR |
1457 | if (iter->flags & FTRACE_ITER_PRINTALL) |
1458 | return NULL; | |
1459 | ||
5072c59f SR |
1460 | retry: |
1461 | if (iter->idx >= iter->pg->index) { | |
1462 | if (iter->pg->next) { | |
1463 | iter->pg = iter->pg->next; | |
1464 | iter->idx = 0; | |
1465 | goto retry; | |
1466 | } | |
1467 | } else { | |
1468 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
1469 | if ((rec->flags & FTRACE_FL_FREE) || |
1470 | ||
1471 | (!(iter->flags & FTRACE_ITER_FAILURES) && | |
eb9a7bf0 AS |
1472 | (rec->flags & FTRACE_FL_FAILED)) || |
1473 | ||
1474 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
a9fdda33 | 1475 | !(rec->flags & FTRACE_FL_FAILED)) || |
eb9a7bf0 | 1476 | |
0183fb1c SR |
1477 | ((iter->flags & FTRACE_ITER_FILTER) && |
1478 | !(rec->flags & FTRACE_FL_FILTER)) || | |
1479 | ||
41c52c0d SR |
1480 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
1481 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
1482 | rec = NULL; |
1483 | goto retry; | |
1484 | } | |
1485 | } | |
1486 | ||
5072c59f SR |
1487 | return rec; |
1488 | } | |
1489 | ||
1490 | static void *t_start(struct seq_file *m, loff_t *pos) | |
1491 | { | |
1492 | struct ftrace_iterator *iter = m->private; | |
1493 | void *p = NULL; | |
694ce0a5 | 1494 | loff_t l; |
5072c59f | 1495 | |
8fc0c701 | 1496 | mutex_lock(&ftrace_lock); |
0c75a3ed SR |
1497 | /* |
1498 | * For set_ftrace_filter reading, if we have the filter | |
1499 | * off, we can short cut and just print out that all | |
1500 | * functions are enabled. | |
1501 | */ | |
1502 | if (iter->flags & FTRACE_ITER_FILTER && !ftrace_filtered) { | |
1503 | if (*pos > 0) | |
8fc0c701 | 1504 | return t_hash_start(m, pos); |
0c75a3ed | 1505 | iter->flags |= FTRACE_ITER_PRINTALL; |
0c75a3ed SR |
1506 | return iter; |
1507 | } | |
1508 | ||
8fc0c701 SR |
1509 | if (iter->flags & FTRACE_ITER_HASH) |
1510 | return t_hash_start(m, pos); | |
1511 | ||
694ce0a5 LZ |
1512 | iter->pg = ftrace_pages_start; |
1513 | iter->idx = 0; | |
1514 | for (l = 0; l <= *pos; ) { | |
1515 | p = t_next(m, p, &l); | |
1516 | if (!p) | |
1517 | break; | |
50cdaf08 | 1518 | } |
5821e1b7 | 1519 | |
694ce0a5 | 1520 | if (!p && iter->flags & FTRACE_ITER_FILTER) |
8fc0c701 SR |
1521 | return t_hash_start(m, pos); |
1522 | ||
5072c59f SR |
1523 | return p; |
1524 | } | |
1525 | ||
1526 | static void t_stop(struct seq_file *m, void *p) | |
1527 | { | |
8fc0c701 | 1528 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1529 | } |
1530 | ||
1531 | static int t_show(struct seq_file *m, void *v) | |
1532 | { | |
0c75a3ed | 1533 | struct ftrace_iterator *iter = m->private; |
5072c59f | 1534 | struct dyn_ftrace *rec = v; |
5072c59f | 1535 | |
8fc0c701 SR |
1536 | if (iter->flags & FTRACE_ITER_HASH) |
1537 | return t_hash_show(m, v); | |
1538 | ||
0c75a3ed SR |
1539 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
1540 | seq_printf(m, "#### all functions enabled ####\n"); | |
1541 | return 0; | |
1542 | } | |
1543 | ||
5072c59f SR |
1544 | if (!rec) |
1545 | return 0; | |
1546 | ||
b375a11a | 1547 | seq_printf(m, "%ps\n", (void *)rec->ip); |
5072c59f SR |
1548 | |
1549 | return 0; | |
1550 | } | |
1551 | ||
88e9d34c | 1552 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
1553 | .start = t_start, |
1554 | .next = t_next, | |
1555 | .stop = t_stop, | |
1556 | .show = t_show, | |
1557 | }; | |
1558 | ||
e309b41d | 1559 | static int |
5072c59f SR |
1560 | ftrace_avail_open(struct inode *inode, struct file *file) |
1561 | { | |
1562 | struct ftrace_iterator *iter; | |
1563 | int ret; | |
1564 | ||
4eebcc81 SR |
1565 | if (unlikely(ftrace_disabled)) |
1566 | return -ENODEV; | |
1567 | ||
5072c59f SR |
1568 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1569 | if (!iter) | |
1570 | return -ENOMEM; | |
1571 | ||
1572 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
1573 | |
1574 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1575 | if (!ret) { | |
1576 | struct seq_file *m = file->private_data; | |
4bf39a94 | 1577 | |
5072c59f | 1578 | m->private = iter; |
4bf39a94 | 1579 | } else { |
5072c59f | 1580 | kfree(iter); |
4bf39a94 | 1581 | } |
5072c59f SR |
1582 | |
1583 | return ret; | |
1584 | } | |
1585 | ||
eb9a7bf0 AS |
1586 | static int |
1587 | ftrace_failures_open(struct inode *inode, struct file *file) | |
1588 | { | |
1589 | int ret; | |
1590 | struct seq_file *m; | |
1591 | struct ftrace_iterator *iter; | |
1592 | ||
1593 | ret = ftrace_avail_open(inode, file); | |
1594 | if (!ret) { | |
1595 | m = (struct seq_file *)file->private_data; | |
1596 | iter = (struct ftrace_iterator *)m->private; | |
1597 | iter->flags = FTRACE_ITER_FAILURES; | |
1598 | } | |
1599 | ||
1600 | return ret; | |
1601 | } | |
1602 | ||
1603 | ||
41c52c0d | 1604 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
1605 | { |
1606 | struct ftrace_page *pg; | |
1607 | struct dyn_ftrace *rec; | |
41c52c0d | 1608 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f | 1609 | |
52baf119 | 1610 | mutex_lock(&ftrace_lock); |
41c52c0d SR |
1611 | if (enable) |
1612 | ftrace_filtered = 0; | |
265c831c SR |
1613 | do_for_each_ftrace_rec(pg, rec) { |
1614 | if (rec->flags & FTRACE_FL_FAILED) | |
1615 | continue; | |
1616 | rec->flags &= ~type; | |
1617 | } while_for_each_ftrace_rec(); | |
52baf119 | 1618 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1619 | } |
1620 | ||
e309b41d | 1621 | static int |
41c52c0d | 1622 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1623 | { |
1624 | struct ftrace_iterator *iter; | |
1625 | int ret = 0; | |
1626 | ||
4eebcc81 SR |
1627 | if (unlikely(ftrace_disabled)) |
1628 | return -ENODEV; | |
1629 | ||
5072c59f SR |
1630 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1631 | if (!iter) | |
1632 | return -ENOMEM; | |
1633 | ||
689fd8b6 | 1634 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { |
1635 | kfree(iter); | |
1636 | return -ENOMEM; | |
1637 | } | |
1638 | ||
41c52c0d | 1639 | mutex_lock(&ftrace_regex_lock); |
5072c59f | 1640 | if ((file->f_mode & FMODE_WRITE) && |
8650ae32 | 1641 | (file->f_flags & O_TRUNC)) |
41c52c0d | 1642 | ftrace_filter_reset(enable); |
5072c59f SR |
1643 | |
1644 | if (file->f_mode & FMODE_READ) { | |
1645 | iter->pg = ftrace_pages_start; | |
41c52c0d SR |
1646 | iter->flags = enable ? FTRACE_ITER_FILTER : |
1647 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
1648 | |
1649 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1650 | if (!ret) { | |
1651 | struct seq_file *m = file->private_data; | |
1652 | m->private = iter; | |
79fe249c LZ |
1653 | } else { |
1654 | trace_parser_put(&iter->parser); | |
5072c59f | 1655 | kfree(iter); |
79fe249c | 1656 | } |
5072c59f SR |
1657 | } else |
1658 | file->private_data = iter; | |
41c52c0d | 1659 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1660 | |
1661 | return ret; | |
1662 | } | |
1663 | ||
41c52c0d SR |
1664 | static int |
1665 | ftrace_filter_open(struct inode *inode, struct file *file) | |
1666 | { | |
1667 | return ftrace_regex_open(inode, file, 1); | |
1668 | } | |
1669 | ||
1670 | static int | |
1671 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
1672 | { | |
1673 | return ftrace_regex_open(inode, file, 0); | |
1674 | } | |
1675 | ||
e309b41d | 1676 | static loff_t |
41c52c0d | 1677 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
1678 | { |
1679 | loff_t ret; | |
1680 | ||
1681 | if (file->f_mode & FMODE_READ) | |
1682 | ret = seq_lseek(file, offset, origin); | |
1683 | else | |
1684 | file->f_pos = ret = 1; | |
1685 | ||
1686 | return ret; | |
1687 | } | |
1688 | ||
64e7c440 | 1689 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 1690 | { |
9f4801e3 | 1691 | int matched = 0; |
751e9983 | 1692 | int slen; |
9f4801e3 | 1693 | |
9f4801e3 SR |
1694 | switch (type) { |
1695 | case MATCH_FULL: | |
1696 | if (strcmp(str, regex) == 0) | |
1697 | matched = 1; | |
1698 | break; | |
1699 | case MATCH_FRONT_ONLY: | |
1700 | if (strncmp(str, regex, len) == 0) | |
1701 | matched = 1; | |
1702 | break; | |
1703 | case MATCH_MIDDLE_ONLY: | |
1704 | if (strstr(str, regex)) | |
1705 | matched = 1; | |
1706 | break; | |
1707 | case MATCH_END_ONLY: | |
751e9983 LZ |
1708 | slen = strlen(str); |
1709 | if (slen >= len && memcmp(str + slen - len, regex, len) == 0) | |
9f4801e3 SR |
1710 | matched = 1; |
1711 | break; | |
1712 | } | |
1713 | ||
1714 | return matched; | |
1715 | } | |
1716 | ||
64e7c440 SR |
1717 | static int |
1718 | ftrace_match_record(struct dyn_ftrace *rec, char *regex, int len, int type) | |
1719 | { | |
1720 | char str[KSYM_SYMBOL_LEN]; | |
1721 | ||
1722 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1723 | return ftrace_match(str, regex, len, type); | |
1724 | } | |
1725 | ||
311d16da | 1726 | static int ftrace_match_records(char *buff, int len, int enable) |
9f4801e3 | 1727 | { |
6a24a244 | 1728 | unsigned int search_len; |
9f4801e3 SR |
1729 | struct ftrace_page *pg; |
1730 | struct dyn_ftrace *rec; | |
6a24a244 SR |
1731 | unsigned long flag; |
1732 | char *search; | |
9f4801e3 | 1733 | int type; |
9f4801e3 | 1734 | int not; |
311d16da | 1735 | int found = 0; |
9f4801e3 | 1736 | |
6a24a244 | 1737 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
3f6fe06d | 1738 | type = filter_parse_regex(buff, len, &search, ¬); |
9f4801e3 SR |
1739 | |
1740 | search_len = strlen(search); | |
1741 | ||
52baf119 | 1742 | mutex_lock(&ftrace_lock); |
265c831c | 1743 | do_for_each_ftrace_rec(pg, rec) { |
265c831c SR |
1744 | |
1745 | if (rec->flags & FTRACE_FL_FAILED) | |
1746 | continue; | |
9f4801e3 SR |
1747 | |
1748 | if (ftrace_match_record(rec, search, search_len, type)) { | |
265c831c SR |
1749 | if (not) |
1750 | rec->flags &= ~flag; | |
1751 | else | |
1752 | rec->flags |= flag; | |
311d16da | 1753 | found = 1; |
265c831c | 1754 | } |
e68746a2 SR |
1755 | /* |
1756 | * Only enable filtering if we have a function that | |
1757 | * is filtered on. | |
1758 | */ | |
1759 | if (enable && (rec->flags & FTRACE_FL_FILTER)) | |
1760 | ftrace_filtered = 1; | |
265c831c | 1761 | } while_for_each_ftrace_rec(); |
52baf119 | 1762 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
1763 | |
1764 | return found; | |
5072c59f SR |
1765 | } |
1766 | ||
64e7c440 SR |
1767 | static int |
1768 | ftrace_match_module_record(struct dyn_ftrace *rec, char *mod, | |
1769 | char *regex, int len, int type) | |
1770 | { | |
1771 | char str[KSYM_SYMBOL_LEN]; | |
1772 | char *modname; | |
1773 | ||
1774 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
1775 | ||
1776 | if (!modname || strcmp(modname, mod)) | |
1777 | return 0; | |
1778 | ||
1779 | /* blank search means to match all funcs in the mod */ | |
1780 | if (len) | |
1781 | return ftrace_match(str, regex, len, type); | |
1782 | else | |
1783 | return 1; | |
1784 | } | |
1785 | ||
311d16da | 1786 | static int ftrace_match_module_records(char *buff, char *mod, int enable) |
64e7c440 | 1787 | { |
6a24a244 | 1788 | unsigned search_len = 0; |
64e7c440 SR |
1789 | struct ftrace_page *pg; |
1790 | struct dyn_ftrace *rec; | |
1791 | int type = MATCH_FULL; | |
6a24a244 SR |
1792 | char *search = buff; |
1793 | unsigned long flag; | |
64e7c440 | 1794 | int not = 0; |
311d16da | 1795 | int found = 0; |
64e7c440 | 1796 | |
6a24a244 SR |
1797 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
1798 | ||
64e7c440 SR |
1799 | /* blank or '*' mean the same */ |
1800 | if (strcmp(buff, "*") == 0) | |
1801 | buff[0] = 0; | |
1802 | ||
1803 | /* handle the case of 'dont filter this module' */ | |
1804 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
1805 | buff[0] = 0; | |
1806 | not = 1; | |
1807 | } | |
1808 | ||
1809 | if (strlen(buff)) { | |
3f6fe06d | 1810 | type = filter_parse_regex(buff, strlen(buff), &search, ¬); |
64e7c440 SR |
1811 | search_len = strlen(search); |
1812 | } | |
1813 | ||
52baf119 | 1814 | mutex_lock(&ftrace_lock); |
64e7c440 SR |
1815 | do_for_each_ftrace_rec(pg, rec) { |
1816 | ||
1817 | if (rec->flags & FTRACE_FL_FAILED) | |
1818 | continue; | |
1819 | ||
1820 | if (ftrace_match_module_record(rec, mod, | |
1821 | search, search_len, type)) { | |
1822 | if (not) | |
1823 | rec->flags &= ~flag; | |
1824 | else | |
1825 | rec->flags |= flag; | |
311d16da | 1826 | found = 1; |
64e7c440 | 1827 | } |
e68746a2 SR |
1828 | if (enable && (rec->flags & FTRACE_FL_FILTER)) |
1829 | ftrace_filtered = 1; | |
64e7c440 SR |
1830 | |
1831 | } while_for_each_ftrace_rec(); | |
52baf119 | 1832 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
1833 | |
1834 | return found; | |
64e7c440 SR |
1835 | } |
1836 | ||
f6180773 SR |
1837 | /* |
1838 | * We register the module command as a template to show others how | |
1839 | * to register the a command as well. | |
1840 | */ | |
1841 | ||
1842 | static int | |
1843 | ftrace_mod_callback(char *func, char *cmd, char *param, int enable) | |
1844 | { | |
1845 | char *mod; | |
1846 | ||
1847 | /* | |
1848 | * cmd == 'mod' because we only registered this func | |
1849 | * for the 'mod' ftrace_func_command. | |
1850 | * But if you register one func with multiple commands, | |
1851 | * you can tell which command was used by the cmd | |
1852 | * parameter. | |
1853 | */ | |
1854 | ||
1855 | /* we must have a module name */ | |
1856 | if (!param) | |
1857 | return -EINVAL; | |
1858 | ||
1859 | mod = strsep(¶m, ":"); | |
1860 | if (!strlen(mod)) | |
1861 | return -EINVAL; | |
1862 | ||
311d16da LZ |
1863 | if (ftrace_match_module_records(func, mod, enable)) |
1864 | return 0; | |
1865 | return -EINVAL; | |
f6180773 SR |
1866 | } |
1867 | ||
1868 | static struct ftrace_func_command ftrace_mod_cmd = { | |
1869 | .name = "mod", | |
1870 | .func = ftrace_mod_callback, | |
1871 | }; | |
1872 | ||
1873 | static int __init ftrace_mod_cmd_init(void) | |
1874 | { | |
1875 | return register_ftrace_command(&ftrace_mod_cmd); | |
1876 | } | |
1877 | device_initcall(ftrace_mod_cmd_init); | |
1878 | ||
59df055f | 1879 | static void |
b6887d79 | 1880 | function_trace_probe_call(unsigned long ip, unsigned long parent_ip) |
59df055f | 1881 | { |
b6887d79 | 1882 | struct ftrace_func_probe *entry; |
59df055f SR |
1883 | struct hlist_head *hhd; |
1884 | struct hlist_node *n; | |
1885 | unsigned long key; | |
1886 | int resched; | |
1887 | ||
1888 | key = hash_long(ip, FTRACE_HASH_BITS); | |
1889 | ||
1890 | hhd = &ftrace_func_hash[key]; | |
1891 | ||
1892 | if (hlist_empty(hhd)) | |
1893 | return; | |
1894 | ||
1895 | /* | |
1896 | * Disable preemption for these calls to prevent a RCU grace | |
1897 | * period. This syncs the hash iteration and freeing of items | |
1898 | * on the hash. rcu_read_lock is too dangerous here. | |
1899 | */ | |
1900 | resched = ftrace_preempt_disable(); | |
1901 | hlist_for_each_entry_rcu(entry, n, hhd, node) { | |
1902 | if (entry->ip == ip) | |
1903 | entry->ops->func(ip, parent_ip, &entry->data); | |
1904 | } | |
1905 | ftrace_preempt_enable(resched); | |
1906 | } | |
1907 | ||
b6887d79 | 1908 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 1909 | { |
fb9fb015 | 1910 | .func = function_trace_probe_call, |
59df055f SR |
1911 | }; |
1912 | ||
b6887d79 | 1913 | static int ftrace_probe_registered; |
59df055f | 1914 | |
b6887d79 | 1915 | static void __enable_ftrace_function_probe(void) |
59df055f SR |
1916 | { |
1917 | int i; | |
1918 | ||
b6887d79 | 1919 | if (ftrace_probe_registered) |
59df055f SR |
1920 | return; |
1921 | ||
1922 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1923 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1924 | if (hhd->first) | |
1925 | break; | |
1926 | } | |
1927 | /* Nothing registered? */ | |
1928 | if (i == FTRACE_FUNC_HASHSIZE) | |
1929 | return; | |
1930 | ||
b6887d79 | 1931 | __register_ftrace_function(&trace_probe_ops); |
59df055f | 1932 | ftrace_startup(0); |
b6887d79 | 1933 | ftrace_probe_registered = 1; |
59df055f SR |
1934 | } |
1935 | ||
b6887d79 | 1936 | static void __disable_ftrace_function_probe(void) |
59df055f SR |
1937 | { |
1938 | int i; | |
1939 | ||
b6887d79 | 1940 | if (!ftrace_probe_registered) |
59df055f SR |
1941 | return; |
1942 | ||
1943 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1944 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1945 | if (hhd->first) | |
1946 | return; | |
1947 | } | |
1948 | ||
1949 | /* no more funcs left */ | |
b6887d79 | 1950 | __unregister_ftrace_function(&trace_probe_ops); |
59df055f | 1951 | ftrace_shutdown(0); |
b6887d79 | 1952 | ftrace_probe_registered = 0; |
59df055f SR |
1953 | } |
1954 | ||
1955 | ||
1956 | static void ftrace_free_entry_rcu(struct rcu_head *rhp) | |
1957 | { | |
b6887d79 SR |
1958 | struct ftrace_func_probe *entry = |
1959 | container_of(rhp, struct ftrace_func_probe, rcu); | |
59df055f SR |
1960 | |
1961 | if (entry->ops->free) | |
1962 | entry->ops->free(&entry->data); | |
1963 | kfree(entry); | |
1964 | } | |
1965 | ||
1966 | ||
1967 | int | |
b6887d79 | 1968 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
1969 | void *data) |
1970 | { | |
b6887d79 | 1971 | struct ftrace_func_probe *entry; |
59df055f SR |
1972 | struct ftrace_page *pg; |
1973 | struct dyn_ftrace *rec; | |
59df055f | 1974 | int type, len, not; |
6a24a244 | 1975 | unsigned long key; |
59df055f SR |
1976 | int count = 0; |
1977 | char *search; | |
1978 | ||
3f6fe06d | 1979 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
1980 | len = strlen(search); |
1981 | ||
b6887d79 | 1982 | /* we do not support '!' for function probes */ |
59df055f SR |
1983 | if (WARN_ON(not)) |
1984 | return -EINVAL; | |
1985 | ||
1986 | mutex_lock(&ftrace_lock); | |
1987 | do_for_each_ftrace_rec(pg, rec) { | |
1988 | ||
1989 | if (rec->flags & FTRACE_FL_FAILED) | |
1990 | continue; | |
1991 | ||
1992 | if (!ftrace_match_record(rec, search, len, type)) | |
1993 | continue; | |
1994 | ||
1995 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1996 | if (!entry) { | |
b6887d79 | 1997 | /* If we did not process any, then return error */ |
59df055f SR |
1998 | if (!count) |
1999 | count = -ENOMEM; | |
2000 | goto out_unlock; | |
2001 | } | |
2002 | ||
2003 | count++; | |
2004 | ||
2005 | entry->data = data; | |
2006 | ||
2007 | /* | |
2008 | * The caller might want to do something special | |
2009 | * for each function we find. We call the callback | |
2010 | * to give the caller an opportunity to do so. | |
2011 | */ | |
2012 | if (ops->callback) { | |
2013 | if (ops->callback(rec->ip, &entry->data) < 0) { | |
2014 | /* caller does not like this func */ | |
2015 | kfree(entry); | |
2016 | continue; | |
2017 | } | |
2018 | } | |
2019 | ||
2020 | entry->ops = ops; | |
2021 | entry->ip = rec->ip; | |
2022 | ||
2023 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
2024 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
2025 | ||
2026 | } while_for_each_ftrace_rec(); | |
b6887d79 | 2027 | __enable_ftrace_function_probe(); |
59df055f SR |
2028 | |
2029 | out_unlock: | |
2030 | mutex_unlock(&ftrace_lock); | |
2031 | ||
2032 | return count; | |
2033 | } | |
2034 | ||
2035 | enum { | |
b6887d79 SR |
2036 | PROBE_TEST_FUNC = 1, |
2037 | PROBE_TEST_DATA = 2 | |
59df055f SR |
2038 | }; |
2039 | ||
2040 | static void | |
b6887d79 | 2041 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2042 | void *data, int flags) |
2043 | { | |
b6887d79 | 2044 | struct ftrace_func_probe *entry; |
59df055f SR |
2045 | struct hlist_node *n, *tmp; |
2046 | char str[KSYM_SYMBOL_LEN]; | |
2047 | int type = MATCH_FULL; | |
2048 | int i, len = 0; | |
2049 | char *search; | |
2050 | ||
b36461da | 2051 | if (glob && (strcmp(glob, "*") == 0 || !strlen(glob))) |
59df055f | 2052 | glob = NULL; |
b36461da | 2053 | else if (glob) { |
59df055f SR |
2054 | int not; |
2055 | ||
3f6fe06d | 2056 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
2057 | len = strlen(search); |
2058 | ||
b6887d79 | 2059 | /* we do not support '!' for function probes */ |
59df055f SR |
2060 | if (WARN_ON(not)) |
2061 | return; | |
2062 | } | |
2063 | ||
2064 | mutex_lock(&ftrace_lock); | |
2065 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2066 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2067 | ||
2068 | hlist_for_each_entry_safe(entry, n, tmp, hhd, node) { | |
2069 | ||
2070 | /* break up if statements for readability */ | |
b6887d79 | 2071 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
2072 | continue; |
2073 | ||
b6887d79 | 2074 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
2075 | continue; |
2076 | ||
2077 | /* do this last, since it is the most expensive */ | |
2078 | if (glob) { | |
2079 | kallsyms_lookup(entry->ip, NULL, NULL, | |
2080 | NULL, str); | |
2081 | if (!ftrace_match(str, glob, len, type)) | |
2082 | continue; | |
2083 | } | |
2084 | ||
2085 | hlist_del(&entry->node); | |
2086 | call_rcu(&entry->rcu, ftrace_free_entry_rcu); | |
2087 | } | |
2088 | } | |
b6887d79 | 2089 | __disable_ftrace_function_probe(); |
59df055f SR |
2090 | mutex_unlock(&ftrace_lock); |
2091 | } | |
2092 | ||
2093 | void | |
b6887d79 | 2094 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2095 | void *data) |
2096 | { | |
b6887d79 SR |
2097 | __unregister_ftrace_function_probe(glob, ops, data, |
2098 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
2099 | } |
2100 | ||
2101 | void | |
b6887d79 | 2102 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 2103 | { |
b6887d79 | 2104 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
2105 | } |
2106 | ||
b6887d79 | 2107 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 2108 | { |
b6887d79 | 2109 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
2110 | } |
2111 | ||
f6180773 SR |
2112 | static LIST_HEAD(ftrace_commands); |
2113 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
2114 | ||
2115 | int register_ftrace_command(struct ftrace_func_command *cmd) | |
2116 | { | |
2117 | struct ftrace_func_command *p; | |
2118 | int ret = 0; | |
2119 | ||
2120 | mutex_lock(&ftrace_cmd_mutex); | |
2121 | list_for_each_entry(p, &ftrace_commands, list) { | |
2122 | if (strcmp(cmd->name, p->name) == 0) { | |
2123 | ret = -EBUSY; | |
2124 | goto out_unlock; | |
2125 | } | |
2126 | } | |
2127 | list_add(&cmd->list, &ftrace_commands); | |
2128 | out_unlock: | |
2129 | mutex_unlock(&ftrace_cmd_mutex); | |
2130 | ||
2131 | return ret; | |
2132 | } | |
2133 | ||
2134 | int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
2135 | { | |
2136 | struct ftrace_func_command *p, *n; | |
2137 | int ret = -ENODEV; | |
2138 | ||
2139 | mutex_lock(&ftrace_cmd_mutex); | |
2140 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
2141 | if (strcmp(cmd->name, p->name) == 0) { | |
2142 | ret = 0; | |
2143 | list_del_init(&p->list); | |
2144 | goto out_unlock; | |
2145 | } | |
2146 | } | |
2147 | out_unlock: | |
2148 | mutex_unlock(&ftrace_cmd_mutex); | |
2149 | ||
2150 | return ret; | |
2151 | } | |
2152 | ||
64e7c440 SR |
2153 | static int ftrace_process_regex(char *buff, int len, int enable) |
2154 | { | |
f6180773 | 2155 | char *func, *command, *next = buff; |
6a24a244 | 2156 | struct ftrace_func_command *p; |
f6180773 | 2157 | int ret = -EINVAL; |
64e7c440 SR |
2158 | |
2159 | func = strsep(&next, ":"); | |
2160 | ||
2161 | if (!next) { | |
311d16da LZ |
2162 | if (ftrace_match_records(func, len, enable)) |
2163 | return 0; | |
2164 | return ret; | |
64e7c440 SR |
2165 | } |
2166 | ||
f6180773 | 2167 | /* command found */ |
64e7c440 SR |
2168 | |
2169 | command = strsep(&next, ":"); | |
2170 | ||
f6180773 SR |
2171 | mutex_lock(&ftrace_cmd_mutex); |
2172 | list_for_each_entry(p, &ftrace_commands, list) { | |
2173 | if (strcmp(p->name, command) == 0) { | |
2174 | ret = p->func(func, command, next, enable); | |
2175 | goto out_unlock; | |
2176 | } | |
64e7c440 | 2177 | } |
f6180773 SR |
2178 | out_unlock: |
2179 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 2180 | |
f6180773 | 2181 | return ret; |
64e7c440 SR |
2182 | } |
2183 | ||
e309b41d | 2184 | static ssize_t |
41c52c0d SR |
2185 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
2186 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
2187 | { |
2188 | struct ftrace_iterator *iter; | |
689fd8b6 | 2189 | struct trace_parser *parser; |
2190 | ssize_t ret, read; | |
5072c59f | 2191 | |
4ba7978e | 2192 | if (!cnt) |
5072c59f SR |
2193 | return 0; |
2194 | ||
41c52c0d | 2195 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
2196 | |
2197 | if (file->f_mode & FMODE_READ) { | |
2198 | struct seq_file *m = file->private_data; | |
2199 | iter = m->private; | |
2200 | } else | |
2201 | iter = file->private_data; | |
2202 | ||
689fd8b6 | 2203 | parser = &iter->parser; |
2204 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 2205 | |
4ba7978e | 2206 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 2207 | !trace_parser_cont(parser)) { |
2208 | ret = ftrace_process_regex(parser->buffer, | |
2209 | parser->idx, enable); | |
313254a9 | 2210 | trace_parser_clear(parser); |
5072c59f | 2211 | if (ret) |
ed146b25 | 2212 | goto out_unlock; |
eda1e328 | 2213 | } |
5072c59f | 2214 | |
5072c59f | 2215 | ret = read; |
ed146b25 | 2216 | out_unlock: |
689fd8b6 | 2217 | mutex_unlock(&ftrace_regex_lock); |
ed146b25 | 2218 | |
5072c59f SR |
2219 | return ret; |
2220 | } | |
2221 | ||
41c52c0d SR |
2222 | static ssize_t |
2223 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
2224 | size_t cnt, loff_t *ppos) | |
2225 | { | |
2226 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
2227 | } | |
2228 | ||
2229 | static ssize_t | |
2230 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
2231 | size_t cnt, loff_t *ppos) | |
2232 | { | |
2233 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
2234 | } | |
2235 | ||
2236 | static void | |
2237 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
2238 | { | |
2239 | if (unlikely(ftrace_disabled)) | |
2240 | return; | |
2241 | ||
2242 | mutex_lock(&ftrace_regex_lock); | |
2243 | if (reset) | |
2244 | ftrace_filter_reset(enable); | |
2245 | if (buf) | |
7f24b31b | 2246 | ftrace_match_records(buf, len, enable); |
41c52c0d SR |
2247 | mutex_unlock(&ftrace_regex_lock); |
2248 | } | |
2249 | ||
77a2b37d SR |
2250 | /** |
2251 | * ftrace_set_filter - set a function to filter on in ftrace | |
2252 | * @buf - the string that holds the function filter text. | |
2253 | * @len - the length of the string. | |
2254 | * @reset - non zero to reset all filters before applying this filter. | |
2255 | * | |
2256 | * Filters denote which functions should be enabled when tracing is enabled. | |
2257 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
2258 | */ | |
e309b41d | 2259 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 2260 | { |
41c52c0d SR |
2261 | ftrace_set_regex(buf, len, reset, 1); |
2262 | } | |
4eebcc81 | 2263 | |
41c52c0d SR |
2264 | /** |
2265 | * ftrace_set_notrace - set a function to not trace in ftrace | |
2266 | * @buf - the string that holds the function notrace text. | |
2267 | * @len - the length of the string. | |
2268 | * @reset - non zero to reset all filters before applying this filter. | |
2269 | * | |
2270 | * Notrace Filters denote which functions should not be enabled when tracing | |
2271 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
2272 | * for tracing. | |
2273 | */ | |
2274 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
2275 | { | |
2276 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
2277 | } |
2278 | ||
2af15d6a SR |
2279 | /* |
2280 | * command line interface to allow users to set filters on boot up. | |
2281 | */ | |
2282 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
2283 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
2284 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
2285 | ||
2286 | static int __init set_ftrace_notrace(char *str) | |
2287 | { | |
2288 | strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); | |
2289 | return 1; | |
2290 | } | |
2291 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
2292 | ||
2293 | static int __init set_ftrace_filter(char *str) | |
2294 | { | |
2295 | strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); | |
2296 | return 1; | |
2297 | } | |
2298 | __setup("ftrace_filter=", set_ftrace_filter); | |
2299 | ||
369bc18f | 2300 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 2301 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
801c29fd SR |
2302 | static int ftrace_set_func(unsigned long *array, int *idx, char *buffer); |
2303 | ||
369bc18f SA |
2304 | static int __init set_graph_function(char *str) |
2305 | { | |
06f43d66 | 2306 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
2307 | return 1; |
2308 | } | |
2309 | __setup("ftrace_graph_filter=", set_graph_function); | |
2310 | ||
2311 | static void __init set_ftrace_early_graph(char *buf) | |
2312 | { | |
2313 | int ret; | |
2314 | char *func; | |
2315 | ||
2316 | while (buf) { | |
2317 | func = strsep(&buf, ","); | |
2318 | /* we allow only one expression at a time */ | |
2319 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, | |
2320 | func); | |
2321 | if (ret) | |
2322 | printk(KERN_DEBUG "ftrace: function %s not " | |
2323 | "traceable\n", func); | |
2324 | } | |
2325 | } | |
2326 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2327 | ||
2af15d6a SR |
2328 | static void __init set_ftrace_early_filter(char *buf, int enable) |
2329 | { | |
2330 | char *func; | |
2331 | ||
2332 | while (buf) { | |
2333 | func = strsep(&buf, ","); | |
2334 | ftrace_set_regex(func, strlen(func), 0, enable); | |
2335 | } | |
2336 | } | |
2337 | ||
2338 | static void __init set_ftrace_early_filters(void) | |
2339 | { | |
2340 | if (ftrace_filter_buf[0]) | |
2341 | set_ftrace_early_filter(ftrace_filter_buf, 1); | |
2342 | if (ftrace_notrace_buf[0]) | |
2343 | set_ftrace_early_filter(ftrace_notrace_buf, 0); | |
369bc18f SA |
2344 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
2345 | if (ftrace_graph_buf[0]) | |
2346 | set_ftrace_early_graph(ftrace_graph_buf); | |
2347 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2af15d6a SR |
2348 | } |
2349 | ||
e309b41d | 2350 | static int |
41c52c0d | 2351 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
2352 | { |
2353 | struct seq_file *m = (struct seq_file *)file->private_data; | |
2354 | struct ftrace_iterator *iter; | |
689fd8b6 | 2355 | struct trace_parser *parser; |
5072c59f | 2356 | |
41c52c0d | 2357 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
2358 | if (file->f_mode & FMODE_READ) { |
2359 | iter = m->private; | |
2360 | ||
2361 | seq_release(inode, file); | |
2362 | } else | |
2363 | iter = file->private_data; | |
2364 | ||
689fd8b6 | 2365 | parser = &iter->parser; |
2366 | if (trace_parser_loaded(parser)) { | |
2367 | parser->buffer[parser->idx] = 0; | |
2368 | ftrace_match_records(parser->buffer, parser->idx, enable); | |
5072c59f SR |
2369 | } |
2370 | ||
e6ea44e9 | 2371 | mutex_lock(&ftrace_lock); |
ee02a2e5 | 2372 | if (ftrace_start_up && ftrace_enabled) |
5072c59f | 2373 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
e6ea44e9 | 2374 | mutex_unlock(&ftrace_lock); |
5072c59f | 2375 | |
689fd8b6 | 2376 | trace_parser_put(parser); |
5072c59f | 2377 | kfree(iter); |
689fd8b6 | 2378 | |
41c52c0d | 2379 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
2380 | return 0; |
2381 | } | |
2382 | ||
41c52c0d SR |
2383 | static int |
2384 | ftrace_filter_release(struct inode *inode, struct file *file) | |
2385 | { | |
2386 | return ftrace_regex_release(inode, file, 1); | |
2387 | } | |
2388 | ||
2389 | static int | |
2390 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
2391 | { | |
2392 | return ftrace_regex_release(inode, file, 0); | |
2393 | } | |
2394 | ||
5e2336a0 | 2395 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
2396 | .open = ftrace_avail_open, |
2397 | .read = seq_read, | |
2398 | .llseek = seq_lseek, | |
3be04b47 | 2399 | .release = seq_release_private, |
5072c59f SR |
2400 | }; |
2401 | ||
5e2336a0 | 2402 | static const struct file_operations ftrace_failures_fops = { |
eb9a7bf0 AS |
2403 | .open = ftrace_failures_open, |
2404 | .read = seq_read, | |
2405 | .llseek = seq_lseek, | |
3be04b47 | 2406 | .release = seq_release_private, |
eb9a7bf0 AS |
2407 | }; |
2408 | ||
5e2336a0 | 2409 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 2410 | .open = ftrace_filter_open, |
850a80cf | 2411 | .read = seq_read, |
5072c59f | 2412 | .write = ftrace_filter_write, |
41c52c0d | 2413 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
2414 | .release = ftrace_filter_release, |
2415 | }; | |
2416 | ||
5e2336a0 | 2417 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 2418 | .open = ftrace_notrace_open, |
850a80cf | 2419 | .read = seq_read, |
41c52c0d SR |
2420 | .write = ftrace_notrace_write, |
2421 | .llseek = ftrace_regex_lseek, | |
2422 | .release = ftrace_notrace_release, | |
2423 | }; | |
2424 | ||
ea4e2bc4 SR |
2425 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
2426 | ||
2427 | static DEFINE_MUTEX(graph_lock); | |
2428 | ||
2429 | int ftrace_graph_count; | |
c7c6b1fe | 2430 | int ftrace_graph_filter_enabled; |
ea4e2bc4 SR |
2431 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
2432 | ||
2433 | static void * | |
85951842 | 2434 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 2435 | { |
85951842 | 2436 | if (*pos >= ftrace_graph_count) |
ea4e2bc4 | 2437 | return NULL; |
a4ec5e0c | 2438 | return &ftrace_graph_funcs[*pos]; |
85951842 | 2439 | } |
ea4e2bc4 | 2440 | |
85951842 LZ |
2441 | static void * |
2442 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
2443 | { | |
2444 | (*pos)++; | |
2445 | return __g_next(m, pos); | |
ea4e2bc4 SR |
2446 | } |
2447 | ||
2448 | static void *g_start(struct seq_file *m, loff_t *pos) | |
2449 | { | |
ea4e2bc4 SR |
2450 | mutex_lock(&graph_lock); |
2451 | ||
f9349a8f | 2452 | /* Nothing, tell g_show to print all functions are enabled */ |
c7c6b1fe | 2453 | if (!ftrace_graph_filter_enabled && !*pos) |
f9349a8f FW |
2454 | return (void *)1; |
2455 | ||
85951842 | 2456 | return __g_next(m, pos); |
ea4e2bc4 SR |
2457 | } |
2458 | ||
2459 | static void g_stop(struct seq_file *m, void *p) | |
2460 | { | |
2461 | mutex_unlock(&graph_lock); | |
2462 | } | |
2463 | ||
2464 | static int g_show(struct seq_file *m, void *v) | |
2465 | { | |
2466 | unsigned long *ptr = v; | |
ea4e2bc4 SR |
2467 | |
2468 | if (!ptr) | |
2469 | return 0; | |
2470 | ||
f9349a8f FW |
2471 | if (ptr == (unsigned long *)1) { |
2472 | seq_printf(m, "#### all functions enabled ####\n"); | |
2473 | return 0; | |
2474 | } | |
2475 | ||
b375a11a | 2476 | seq_printf(m, "%ps\n", (void *)*ptr); |
ea4e2bc4 SR |
2477 | |
2478 | return 0; | |
2479 | } | |
2480 | ||
88e9d34c | 2481 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
2482 | .start = g_start, |
2483 | .next = g_next, | |
2484 | .stop = g_stop, | |
2485 | .show = g_show, | |
2486 | }; | |
2487 | ||
2488 | static int | |
2489 | ftrace_graph_open(struct inode *inode, struct file *file) | |
2490 | { | |
2491 | int ret = 0; | |
2492 | ||
2493 | if (unlikely(ftrace_disabled)) | |
2494 | return -ENODEV; | |
2495 | ||
2496 | mutex_lock(&graph_lock); | |
2497 | if ((file->f_mode & FMODE_WRITE) && | |
8650ae32 | 2498 | (file->f_flags & O_TRUNC)) { |
c7c6b1fe | 2499 | ftrace_graph_filter_enabled = 0; |
ea4e2bc4 SR |
2500 | ftrace_graph_count = 0; |
2501 | memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); | |
2502 | } | |
a4ec5e0c | 2503 | mutex_unlock(&graph_lock); |
ea4e2bc4 | 2504 | |
a4ec5e0c | 2505 | if (file->f_mode & FMODE_READ) |
ea4e2bc4 | 2506 | ret = seq_open(file, &ftrace_graph_seq_ops); |
ea4e2bc4 SR |
2507 | |
2508 | return ret; | |
2509 | } | |
2510 | ||
87827111 LZ |
2511 | static int |
2512 | ftrace_graph_release(struct inode *inode, struct file *file) | |
2513 | { | |
2514 | if (file->f_mode & FMODE_READ) | |
2515 | seq_release(inode, file); | |
2516 | return 0; | |
2517 | } | |
2518 | ||
ea4e2bc4 | 2519 | static int |
f9349a8f | 2520 | ftrace_set_func(unsigned long *array, int *idx, char *buffer) |
ea4e2bc4 | 2521 | { |
ea4e2bc4 SR |
2522 | struct dyn_ftrace *rec; |
2523 | struct ftrace_page *pg; | |
f9349a8f | 2524 | int search_len; |
c7c6b1fe | 2525 | int fail = 1; |
f9349a8f FW |
2526 | int type, not; |
2527 | char *search; | |
2528 | bool exists; | |
2529 | int i; | |
ea4e2bc4 SR |
2530 | |
2531 | if (ftrace_disabled) | |
2532 | return -ENODEV; | |
2533 | ||
f9349a8f | 2534 | /* decode regex */ |
3f6fe06d | 2535 | type = filter_parse_regex(buffer, strlen(buffer), &search, ¬); |
c7c6b1fe LZ |
2536 | if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS) |
2537 | return -EBUSY; | |
f9349a8f FW |
2538 | |
2539 | search_len = strlen(search); | |
2540 | ||
52baf119 | 2541 | mutex_lock(&ftrace_lock); |
265c831c SR |
2542 | do_for_each_ftrace_rec(pg, rec) { |
2543 | ||
2544 | if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE)) | |
2545 | continue; | |
2546 | ||
f9349a8f | 2547 | if (ftrace_match_record(rec, search, search_len, type)) { |
c7c6b1fe | 2548 | /* if it is in the array */ |
f9349a8f | 2549 | exists = false; |
c7c6b1fe | 2550 | for (i = 0; i < *idx; i++) { |
f9349a8f FW |
2551 | if (array[i] == rec->ip) { |
2552 | exists = true; | |
265c831c SR |
2553 | break; |
2554 | } | |
c7c6b1fe LZ |
2555 | } |
2556 | ||
2557 | if (!not) { | |
2558 | fail = 0; | |
2559 | if (!exists) { | |
2560 | array[(*idx)++] = rec->ip; | |
2561 | if (*idx >= FTRACE_GRAPH_MAX_FUNCS) | |
2562 | goto out; | |
2563 | } | |
2564 | } else { | |
2565 | if (exists) { | |
2566 | array[i] = array[--(*idx)]; | |
2567 | array[*idx] = 0; | |
2568 | fail = 0; | |
2569 | } | |
2570 | } | |
ea4e2bc4 | 2571 | } |
265c831c | 2572 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 2573 | out: |
52baf119 | 2574 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 2575 | |
c7c6b1fe LZ |
2576 | if (fail) |
2577 | return -EINVAL; | |
2578 | ||
2579 | ftrace_graph_filter_enabled = 1; | |
2580 | return 0; | |
ea4e2bc4 SR |
2581 | } |
2582 | ||
2583 | static ssize_t | |
2584 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
2585 | size_t cnt, loff_t *ppos) | |
2586 | { | |
689fd8b6 | 2587 | struct trace_parser parser; |
4ba7978e | 2588 | ssize_t read, ret; |
ea4e2bc4 | 2589 | |
c7c6b1fe | 2590 | if (!cnt) |
ea4e2bc4 SR |
2591 | return 0; |
2592 | ||
2593 | mutex_lock(&graph_lock); | |
2594 | ||
689fd8b6 | 2595 | if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) { |
2596 | ret = -ENOMEM; | |
1eb90f13 | 2597 | goto out_unlock; |
ea4e2bc4 SR |
2598 | } |
2599 | ||
689fd8b6 | 2600 | read = trace_get_user(&parser, ubuf, cnt, ppos); |
ea4e2bc4 | 2601 | |
4ba7978e | 2602 | if (read >= 0 && trace_parser_loaded((&parser))) { |
689fd8b6 | 2603 | parser.buffer[parser.idx] = 0; |
2604 | ||
2605 | /* we allow only one expression at a time */ | |
a4ec5e0c | 2606 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, |
689fd8b6 | 2607 | parser.buffer); |
ea4e2bc4 | 2608 | if (ret) |
1eb90f13 | 2609 | goto out_free; |
ea4e2bc4 | 2610 | } |
ea4e2bc4 SR |
2611 | |
2612 | ret = read; | |
1eb90f13 LZ |
2613 | |
2614 | out_free: | |
689fd8b6 | 2615 | trace_parser_put(&parser); |
1eb90f13 | 2616 | out_unlock: |
ea4e2bc4 SR |
2617 | mutex_unlock(&graph_lock); |
2618 | ||
2619 | return ret; | |
2620 | } | |
2621 | ||
2622 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
2623 | .open = ftrace_graph_open, |
2624 | .read = seq_read, | |
2625 | .write = ftrace_graph_write, | |
2626 | .release = ftrace_graph_release, | |
ea4e2bc4 SR |
2627 | }; |
2628 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2629 | ||
df4fc315 | 2630 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 2631 | { |
5072c59f | 2632 | |
5452af66 FW |
2633 | trace_create_file("available_filter_functions", 0444, |
2634 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 2635 | |
5452af66 FW |
2636 | trace_create_file("failures", 0444, |
2637 | d_tracer, NULL, &ftrace_failures_fops); | |
eb9a7bf0 | 2638 | |
5452af66 FW |
2639 | trace_create_file("set_ftrace_filter", 0644, d_tracer, |
2640 | NULL, &ftrace_filter_fops); | |
41c52c0d | 2641 | |
5452af66 | 2642 | trace_create_file("set_ftrace_notrace", 0644, d_tracer, |
41c52c0d | 2643 | NULL, &ftrace_notrace_fops); |
ad90c0e3 | 2644 | |
ea4e2bc4 | 2645 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 2646 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
2647 | NULL, |
2648 | &ftrace_graph_fops); | |
ea4e2bc4 SR |
2649 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
2650 | ||
5072c59f SR |
2651 | return 0; |
2652 | } | |
2653 | ||
5cb084bb | 2654 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 2655 | unsigned long *start, |
68bf21aa SR |
2656 | unsigned long *end) |
2657 | { | |
2658 | unsigned long *p; | |
2659 | unsigned long addr; | |
2660 | unsigned long flags; | |
2661 | ||
e6ea44e9 | 2662 | mutex_lock(&ftrace_lock); |
68bf21aa SR |
2663 | p = start; |
2664 | while (p < end) { | |
2665 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
2666 | /* |
2667 | * Some architecture linkers will pad between | |
2668 | * the different mcount_loc sections of different | |
2669 | * object files to satisfy alignments. | |
2670 | * Skip any NULL pointers. | |
2671 | */ | |
2672 | if (!addr) | |
2673 | continue; | |
68bf21aa | 2674 | ftrace_record_ip(addr); |
68bf21aa SR |
2675 | } |
2676 | ||
08f5ac90 | 2677 | /* disable interrupts to prevent kstop machine */ |
68bf21aa | 2678 | local_irq_save(flags); |
31e88909 | 2679 | ftrace_update_code(mod); |
68bf21aa | 2680 | local_irq_restore(flags); |
e6ea44e9 | 2681 | mutex_unlock(&ftrace_lock); |
68bf21aa SR |
2682 | |
2683 | return 0; | |
2684 | } | |
2685 | ||
93eb677d | 2686 | #ifdef CONFIG_MODULES |
e7247a15 | 2687 | void ftrace_release_mod(struct module *mod) |
93eb677d SR |
2688 | { |
2689 | struct dyn_ftrace *rec; | |
2690 | struct ftrace_page *pg; | |
93eb677d | 2691 | |
e7247a15 | 2692 | if (ftrace_disabled) |
93eb677d SR |
2693 | return; |
2694 | ||
2695 | mutex_lock(&ftrace_lock); | |
2696 | do_for_each_ftrace_rec(pg, rec) { | |
e7247a15 | 2697 | if (within_module_core(rec->ip, mod)) { |
93eb677d SR |
2698 | /* |
2699 | * rec->ip is changed in ftrace_free_rec() | |
2700 | * It should not between s and e if record was freed. | |
2701 | */ | |
2702 | FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE); | |
2703 | ftrace_free_rec(rec); | |
2704 | } | |
2705 | } while_for_each_ftrace_rec(); | |
2706 | mutex_unlock(&ftrace_lock); | |
2707 | } | |
2708 | ||
2709 | static void ftrace_init_module(struct module *mod, | |
2710 | unsigned long *start, unsigned long *end) | |
90d595fe | 2711 | { |
00fd61ae | 2712 | if (ftrace_disabled || start == end) |
fed1939c | 2713 | return; |
5cb084bb | 2714 | ftrace_process_locs(mod, start, end); |
90d595fe SR |
2715 | } |
2716 | ||
93eb677d SR |
2717 | static int ftrace_module_notify(struct notifier_block *self, |
2718 | unsigned long val, void *data) | |
2719 | { | |
2720 | struct module *mod = data; | |
2721 | ||
2722 | switch (val) { | |
2723 | case MODULE_STATE_COMING: | |
2724 | ftrace_init_module(mod, mod->ftrace_callsites, | |
2725 | mod->ftrace_callsites + | |
2726 | mod->num_ftrace_callsites); | |
2727 | break; | |
2728 | case MODULE_STATE_GOING: | |
e7247a15 | 2729 | ftrace_release_mod(mod); |
93eb677d SR |
2730 | break; |
2731 | } | |
2732 | ||
2733 | return 0; | |
2734 | } | |
2735 | #else | |
2736 | static int ftrace_module_notify(struct notifier_block *self, | |
2737 | unsigned long val, void *data) | |
2738 | { | |
2739 | return 0; | |
2740 | } | |
2741 | #endif /* CONFIG_MODULES */ | |
2742 | ||
2743 | struct notifier_block ftrace_module_nb = { | |
2744 | .notifier_call = ftrace_module_notify, | |
2745 | .priority = 0, | |
2746 | }; | |
2747 | ||
68bf21aa SR |
2748 | extern unsigned long __start_mcount_loc[]; |
2749 | extern unsigned long __stop_mcount_loc[]; | |
2750 | ||
2751 | void __init ftrace_init(void) | |
2752 | { | |
2753 | unsigned long count, addr, flags; | |
2754 | int ret; | |
2755 | ||
2756 | /* Keep the ftrace pointer to the stub */ | |
2757 | addr = (unsigned long)ftrace_stub; | |
2758 | ||
2759 | local_irq_save(flags); | |
2760 | ftrace_dyn_arch_init(&addr); | |
2761 | local_irq_restore(flags); | |
2762 | ||
2763 | /* ftrace_dyn_arch_init places the return code in addr */ | |
2764 | if (addr) | |
2765 | goto failed; | |
2766 | ||
2767 | count = __stop_mcount_loc - __start_mcount_loc; | |
2768 | ||
2769 | ret = ftrace_dyn_table_alloc(count); | |
2770 | if (ret) | |
2771 | goto failed; | |
2772 | ||
2773 | last_ftrace_enabled = ftrace_enabled = 1; | |
2774 | ||
5cb084bb | 2775 | ret = ftrace_process_locs(NULL, |
31e88909 | 2776 | __start_mcount_loc, |
68bf21aa SR |
2777 | __stop_mcount_loc); |
2778 | ||
93eb677d | 2779 | ret = register_module_notifier(&ftrace_module_nb); |
24ed0c4b | 2780 | if (ret) |
93eb677d SR |
2781 | pr_warning("Failed to register trace ftrace module notifier\n"); |
2782 | ||
2af15d6a SR |
2783 | set_ftrace_early_filters(); |
2784 | ||
68bf21aa SR |
2785 | return; |
2786 | failed: | |
2787 | ftrace_disabled = 1; | |
2788 | } | |
68bf21aa | 2789 | |
3d083395 | 2790 | #else |
0b6e4d56 FW |
2791 | |
2792 | static int __init ftrace_nodyn_init(void) | |
2793 | { | |
2794 | ftrace_enabled = 1; | |
2795 | return 0; | |
2796 | } | |
2797 | device_initcall(ftrace_nodyn_init); | |
2798 | ||
df4fc315 SR |
2799 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
2800 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 SR |
2801 | /* Keep as macros so we do not need to define the commands */ |
2802 | # define ftrace_startup(command) do { } while (0) | |
2803 | # define ftrace_shutdown(command) do { } while (0) | |
c7aafc54 IM |
2804 | # define ftrace_startup_sysctl() do { } while (0) |
2805 | # define ftrace_shutdown_sysctl() do { } while (0) | |
3d083395 SR |
2806 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
2807 | ||
e32d8956 | 2808 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
2809 | { |
2810 | struct task_struct *p; | |
e32d8956 | 2811 | int cpu; |
978f3a45 | 2812 | |
e32d8956 SR |
2813 | get_online_cpus(); |
2814 | for_each_online_cpu(cpu) { | |
2815 | p = idle_task(cpu); | |
978f3a45 | 2816 | clear_tsk_trace_trace(p); |
e32d8956 SR |
2817 | } |
2818 | put_online_cpus(); | |
2819 | } | |
978f3a45 | 2820 | |
e32d8956 SR |
2821 | static void set_ftrace_swapper(void) |
2822 | { | |
2823 | struct task_struct *p; | |
2824 | int cpu; | |
2825 | ||
2826 | get_online_cpus(); | |
2827 | for_each_online_cpu(cpu) { | |
2828 | p = idle_task(cpu); | |
2829 | set_tsk_trace_trace(p); | |
2830 | } | |
2831 | put_online_cpus(); | |
978f3a45 SR |
2832 | } |
2833 | ||
e32d8956 SR |
2834 | static void clear_ftrace_pid(struct pid *pid) |
2835 | { | |
2836 | struct task_struct *p; | |
2837 | ||
229c4ef8 | 2838 | rcu_read_lock(); |
e32d8956 SR |
2839 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2840 | clear_tsk_trace_trace(p); | |
2841 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
2842 | rcu_read_unlock(); |
2843 | ||
e32d8956 SR |
2844 | put_pid(pid); |
2845 | } | |
2846 | ||
2847 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
2848 | { |
2849 | struct task_struct *p; | |
2850 | ||
229c4ef8 | 2851 | rcu_read_lock(); |
978f3a45 SR |
2852 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2853 | set_tsk_trace_trace(p); | |
2854 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 2855 | rcu_read_unlock(); |
978f3a45 SR |
2856 | } |
2857 | ||
756d17ee | 2858 | static void clear_ftrace_pid_task(struct pid *pid) |
e32d8956 | 2859 | { |
756d17ee | 2860 | if (pid == ftrace_swapper_pid) |
e32d8956 SR |
2861 | clear_ftrace_swapper(); |
2862 | else | |
756d17ee | 2863 | clear_ftrace_pid(pid); |
e32d8956 SR |
2864 | } |
2865 | ||
2866 | static void set_ftrace_pid_task(struct pid *pid) | |
2867 | { | |
2868 | if (pid == ftrace_swapper_pid) | |
2869 | set_ftrace_swapper(); | |
2870 | else | |
2871 | set_ftrace_pid(pid); | |
2872 | } | |
2873 | ||
756d17ee | 2874 | static int ftrace_pid_add(int p) |
df4fc315 | 2875 | { |
978f3a45 | 2876 | struct pid *pid; |
756d17ee | 2877 | struct ftrace_pid *fpid; |
2878 | int ret = -EINVAL; | |
df4fc315 | 2879 | |
756d17ee | 2880 | mutex_lock(&ftrace_lock); |
df4fc315 | 2881 | |
756d17ee | 2882 | if (!p) |
2883 | pid = ftrace_swapper_pid; | |
2884 | else | |
2885 | pid = find_get_pid(p); | |
df4fc315 | 2886 | |
756d17ee | 2887 | if (!pid) |
2888 | goto out; | |
df4fc315 | 2889 | |
756d17ee | 2890 | ret = 0; |
df4fc315 | 2891 | |
756d17ee | 2892 | list_for_each_entry(fpid, &ftrace_pids, list) |
2893 | if (fpid->pid == pid) | |
2894 | goto out_put; | |
978f3a45 | 2895 | |
756d17ee | 2896 | ret = -ENOMEM; |
df4fc315 | 2897 | |
756d17ee | 2898 | fpid = kmalloc(sizeof(*fpid), GFP_KERNEL); |
2899 | if (!fpid) | |
2900 | goto out_put; | |
df4fc315 | 2901 | |
756d17ee | 2902 | list_add(&fpid->list, &ftrace_pids); |
2903 | fpid->pid = pid; | |
0ef8cde5 | 2904 | |
756d17ee | 2905 | set_ftrace_pid_task(pid); |
978f3a45 | 2906 | |
756d17ee | 2907 | ftrace_update_pid_func(); |
2908 | ftrace_startup_enable(0); | |
2909 | ||
2910 | mutex_unlock(&ftrace_lock); | |
2911 | return 0; | |
2912 | ||
2913 | out_put: | |
2914 | if (pid != ftrace_swapper_pid) | |
2915 | put_pid(pid); | |
978f3a45 | 2916 | |
756d17ee | 2917 | out: |
2918 | mutex_unlock(&ftrace_lock); | |
2919 | return ret; | |
2920 | } | |
2921 | ||
2922 | static void ftrace_pid_reset(void) | |
2923 | { | |
2924 | struct ftrace_pid *fpid, *safe; | |
978f3a45 | 2925 | |
756d17ee | 2926 | mutex_lock(&ftrace_lock); |
2927 | list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) { | |
2928 | struct pid *pid = fpid->pid; | |
2929 | ||
2930 | clear_ftrace_pid_task(pid); | |
2931 | ||
2932 | list_del(&fpid->list); | |
2933 | kfree(fpid); | |
df4fc315 SR |
2934 | } |
2935 | ||
df4fc315 SR |
2936 | ftrace_update_pid_func(); |
2937 | ftrace_startup_enable(0); | |
2938 | ||
e6ea44e9 | 2939 | mutex_unlock(&ftrace_lock); |
756d17ee | 2940 | } |
df4fc315 | 2941 | |
756d17ee | 2942 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
2943 | { | |
2944 | mutex_lock(&ftrace_lock); | |
2945 | ||
2946 | if (list_empty(&ftrace_pids) && (!*pos)) | |
2947 | return (void *) 1; | |
2948 | ||
2949 | return seq_list_start(&ftrace_pids, *pos); | |
2950 | } | |
2951 | ||
2952 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
2953 | { | |
2954 | if (v == (void *)1) | |
2955 | return NULL; | |
2956 | ||
2957 | return seq_list_next(v, &ftrace_pids, pos); | |
2958 | } | |
2959 | ||
2960 | static void fpid_stop(struct seq_file *m, void *p) | |
2961 | { | |
2962 | mutex_unlock(&ftrace_lock); | |
2963 | } | |
2964 | ||
2965 | static int fpid_show(struct seq_file *m, void *v) | |
2966 | { | |
2967 | const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list); | |
2968 | ||
2969 | if (v == (void *)1) { | |
2970 | seq_printf(m, "no pid\n"); | |
2971 | return 0; | |
2972 | } | |
2973 | ||
2974 | if (fpid->pid == ftrace_swapper_pid) | |
2975 | seq_printf(m, "swapper tasks\n"); | |
2976 | else | |
2977 | seq_printf(m, "%u\n", pid_vnr(fpid->pid)); | |
2978 | ||
2979 | return 0; | |
2980 | } | |
2981 | ||
2982 | static const struct seq_operations ftrace_pid_sops = { | |
2983 | .start = fpid_start, | |
2984 | .next = fpid_next, | |
2985 | .stop = fpid_stop, | |
2986 | .show = fpid_show, | |
2987 | }; | |
2988 | ||
2989 | static int | |
2990 | ftrace_pid_open(struct inode *inode, struct file *file) | |
2991 | { | |
2992 | int ret = 0; | |
2993 | ||
2994 | if ((file->f_mode & FMODE_WRITE) && | |
2995 | (file->f_flags & O_TRUNC)) | |
2996 | ftrace_pid_reset(); | |
2997 | ||
2998 | if (file->f_mode & FMODE_READ) | |
2999 | ret = seq_open(file, &ftrace_pid_sops); | |
3000 | ||
3001 | return ret; | |
3002 | } | |
3003 | ||
df4fc315 SR |
3004 | static ssize_t |
3005 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
3006 | size_t cnt, loff_t *ppos) | |
3007 | { | |
457dc928 | 3008 | char buf[64], *tmp; |
df4fc315 SR |
3009 | long val; |
3010 | int ret; | |
3011 | ||
3012 | if (cnt >= sizeof(buf)) | |
3013 | return -EINVAL; | |
3014 | ||
3015 | if (copy_from_user(&buf, ubuf, cnt)) | |
3016 | return -EFAULT; | |
3017 | ||
3018 | buf[cnt] = 0; | |
3019 | ||
756d17ee | 3020 | /* |
3021 | * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid" | |
3022 | * to clean the filter quietly. | |
3023 | */ | |
457dc928 IM |
3024 | tmp = strstrip(buf); |
3025 | if (strlen(tmp) == 0) | |
756d17ee | 3026 | return 1; |
3027 | ||
457dc928 | 3028 | ret = strict_strtol(tmp, 10, &val); |
df4fc315 SR |
3029 | if (ret < 0) |
3030 | return ret; | |
3031 | ||
756d17ee | 3032 | ret = ftrace_pid_add(val); |
df4fc315 | 3033 | |
756d17ee | 3034 | return ret ? ret : cnt; |
3035 | } | |
df4fc315 | 3036 | |
756d17ee | 3037 | static int |
3038 | ftrace_pid_release(struct inode *inode, struct file *file) | |
3039 | { | |
3040 | if (file->f_mode & FMODE_READ) | |
3041 | seq_release(inode, file); | |
df4fc315 | 3042 | |
756d17ee | 3043 | return 0; |
df4fc315 SR |
3044 | } |
3045 | ||
5e2336a0 | 3046 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 3047 | .open = ftrace_pid_open, |
3048 | .write = ftrace_pid_write, | |
3049 | .read = seq_read, | |
3050 | .llseek = seq_lseek, | |
3051 | .release = ftrace_pid_release, | |
df4fc315 SR |
3052 | }; |
3053 | ||
3054 | static __init int ftrace_init_debugfs(void) | |
3055 | { | |
3056 | struct dentry *d_tracer; | |
df4fc315 SR |
3057 | |
3058 | d_tracer = tracing_init_dentry(); | |
3059 | if (!d_tracer) | |
3060 | return 0; | |
3061 | ||
3062 | ftrace_init_dyn_debugfs(d_tracer); | |
3063 | ||
5452af66 FW |
3064 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
3065 | NULL, &ftrace_pid_fops); | |
493762fc SR |
3066 | |
3067 | ftrace_profile_debugfs(d_tracer); | |
3068 | ||
df4fc315 SR |
3069 | return 0; |
3070 | } | |
df4fc315 SR |
3071 | fs_initcall(ftrace_init_debugfs); |
3072 | ||
a2bb6a3d | 3073 | /** |
81adbdc0 | 3074 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
3075 | * |
3076 | * This function should be used by panic code. It stops ftrace | |
3077 | * but in a not so nice way. If you need to simply kill ftrace | |
3078 | * from a non-atomic section, use ftrace_kill. | |
3079 | */ | |
81adbdc0 | 3080 | void ftrace_kill(void) |
a2bb6a3d SR |
3081 | { |
3082 | ftrace_disabled = 1; | |
3083 | ftrace_enabled = 0; | |
a2bb6a3d SR |
3084 | clear_ftrace_function(); |
3085 | } | |
3086 | ||
16444a8a | 3087 | /** |
3d083395 SR |
3088 | * register_ftrace_function - register a function for profiling |
3089 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 3090 | * |
3d083395 SR |
3091 | * Register a function to be called by all functions in the |
3092 | * kernel. | |
3093 | * | |
3094 | * Note: @ops->func and all the functions it calls must be labeled | |
3095 | * with "notrace", otherwise it will go into a | |
3096 | * recursive loop. | |
16444a8a | 3097 | */ |
3d083395 | 3098 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 3099 | { |
b0fc494f SR |
3100 | int ret; |
3101 | ||
4eebcc81 SR |
3102 | if (unlikely(ftrace_disabled)) |
3103 | return -1; | |
3104 | ||
e6ea44e9 | 3105 | mutex_lock(&ftrace_lock); |
e7d3737e | 3106 | |
b0fc494f | 3107 | ret = __register_ftrace_function(ops); |
5a45cfe1 | 3108 | ftrace_startup(0); |
b0fc494f | 3109 | |
e6ea44e9 | 3110 | mutex_unlock(&ftrace_lock); |
b0fc494f | 3111 | return ret; |
3d083395 SR |
3112 | } |
3113 | ||
3114 | /** | |
32632920 | 3115 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
3116 | * @ops - ops structure that holds the function to unregister |
3117 | * | |
3118 | * Unregister a function that was added to be called by ftrace profiling. | |
3119 | */ | |
3120 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
3121 | { | |
3122 | int ret; | |
3123 | ||
e6ea44e9 | 3124 | mutex_lock(&ftrace_lock); |
3d083395 | 3125 | ret = __unregister_ftrace_function(ops); |
5a45cfe1 | 3126 | ftrace_shutdown(0); |
e6ea44e9 | 3127 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
3128 | |
3129 | return ret; | |
3130 | } | |
3131 | ||
e309b41d | 3132 | int |
b0fc494f | 3133 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
8d65af78 | 3134 | void __user *buffer, size_t *lenp, |
b0fc494f SR |
3135 | loff_t *ppos) |
3136 | { | |
3137 | int ret; | |
3138 | ||
4eebcc81 SR |
3139 | if (unlikely(ftrace_disabled)) |
3140 | return -ENODEV; | |
3141 | ||
e6ea44e9 | 3142 | mutex_lock(&ftrace_lock); |
b0fc494f | 3143 | |
8d65af78 | 3144 | ret = proc_dointvec(table, write, buffer, lenp, ppos); |
b0fc494f | 3145 | |
a32c7765 | 3146 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
3147 | goto out; |
3148 | ||
a32c7765 | 3149 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f SR |
3150 | |
3151 | if (ftrace_enabled) { | |
3152 | ||
3153 | ftrace_startup_sysctl(); | |
3154 | ||
3155 | /* we are starting ftrace again */ | |
3156 | if (ftrace_list != &ftrace_list_end) { | |
3157 | if (ftrace_list->next == &ftrace_list_end) | |
3158 | ftrace_trace_function = ftrace_list->func; | |
3159 | else | |
3160 | ftrace_trace_function = ftrace_list_func; | |
3161 | } | |
3162 | ||
3163 | } else { | |
3164 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
3165 | ftrace_trace_function = ftrace_stub; | |
3166 | ||
3167 | ftrace_shutdown_sysctl(); | |
3168 | } | |
3169 | ||
3170 | out: | |
e6ea44e9 | 3171 | mutex_unlock(&ftrace_lock); |
3d083395 | 3172 | return ret; |
16444a8a | 3173 | } |
f17845e5 | 3174 | |
fb52607a | 3175 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 3176 | |
597af815 | 3177 | static int ftrace_graph_active; |
4a2b8dda | 3178 | static struct notifier_block ftrace_suspend_notifier; |
e7d3737e | 3179 | |
e49dc19c SR |
3180 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
3181 | { | |
3182 | return 0; | |
3183 | } | |
3184 | ||
287b6e68 FW |
3185 | /* The callbacks that hook a function */ |
3186 | trace_func_graph_ret_t ftrace_graph_return = | |
3187 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 3188 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
3189 | |
3190 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
3191 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
3192 | { | |
3193 | int i; | |
3194 | int ret = 0; | |
3195 | unsigned long flags; | |
3196 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
3197 | struct task_struct *g, *t; | |
3198 | ||
3199 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
3200 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
3201 | * sizeof(struct ftrace_ret_stack), | |
3202 | GFP_KERNEL); | |
3203 | if (!ret_stack_list[i]) { | |
3204 | start = 0; | |
3205 | end = i; | |
3206 | ret = -ENOMEM; | |
3207 | goto free; | |
3208 | } | |
3209 | } | |
3210 | ||
3211 | read_lock_irqsave(&tasklist_lock, flags); | |
3212 | do_each_thread(g, t) { | |
3213 | if (start == end) { | |
3214 | ret = -EAGAIN; | |
3215 | goto unlock; | |
3216 | } | |
3217 | ||
3218 | if (t->ret_stack == NULL) { | |
380c4b14 | 3219 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 3220 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
3221 | t->curr_ret_stack = -1; |
3222 | /* Make sure the tasks see the -1 first: */ | |
3223 | smp_wmb(); | |
3224 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
3225 | } |
3226 | } while_each_thread(g, t); | |
3227 | ||
3228 | unlock: | |
3229 | read_unlock_irqrestore(&tasklist_lock, flags); | |
3230 | free: | |
3231 | for (i = start; i < end; i++) | |
3232 | kfree(ret_stack_list[i]); | |
3233 | return ret; | |
3234 | } | |
3235 | ||
8aef2d28 | 3236 | static void |
27a9da65 | 3237 | ftrace_graph_probe_sched_switch(struct task_struct *prev, struct task_struct *next) |
8aef2d28 SR |
3238 | { |
3239 | unsigned long long timestamp; | |
3240 | int index; | |
3241 | ||
be6f164a SR |
3242 | /* |
3243 | * Does the user want to count the time a function was asleep. | |
3244 | * If so, do not update the time stamps. | |
3245 | */ | |
3246 | if (trace_flags & TRACE_ITER_SLEEP_TIME) | |
3247 | return; | |
3248 | ||
8aef2d28 SR |
3249 | timestamp = trace_clock_local(); |
3250 | ||
3251 | prev->ftrace_timestamp = timestamp; | |
3252 | ||
3253 | /* only process tasks that we timestamped */ | |
3254 | if (!next->ftrace_timestamp) | |
3255 | return; | |
3256 | ||
3257 | /* | |
3258 | * Update all the counters in next to make up for the | |
3259 | * time next was sleeping. | |
3260 | */ | |
3261 | timestamp -= next->ftrace_timestamp; | |
3262 | ||
3263 | for (index = next->curr_ret_stack; index >= 0; index--) | |
3264 | next->ret_stack[index].calltime += timestamp; | |
3265 | } | |
3266 | ||
f201ae23 | 3267 | /* Allocate a return stack for each task */ |
fb52607a | 3268 | static int start_graph_tracing(void) |
f201ae23 FW |
3269 | { |
3270 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 3271 | int ret, cpu; |
f201ae23 FW |
3272 | |
3273 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
3274 | sizeof(struct ftrace_ret_stack *), | |
3275 | GFP_KERNEL); | |
3276 | ||
3277 | if (!ret_stack_list) | |
3278 | return -ENOMEM; | |
3279 | ||
5b058bcd | 3280 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
3281 | for_each_online_cpu(cpu) { |
3282 | if (!idle_task(cpu)->ret_stack) | |
3283 | ftrace_graph_init_task(idle_task(cpu)); | |
3284 | } | |
5b058bcd | 3285 | |
f201ae23 FW |
3286 | do { |
3287 | ret = alloc_retstack_tasklist(ret_stack_list); | |
3288 | } while (ret == -EAGAIN); | |
3289 | ||
8aef2d28 SR |
3290 | if (!ret) { |
3291 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch); | |
3292 | if (ret) | |
3293 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
3294 | " probe to kernel_sched_switch\n"); | |
3295 | } | |
3296 | ||
f201ae23 FW |
3297 | kfree(ret_stack_list); |
3298 | return ret; | |
3299 | } | |
3300 | ||
4a2b8dda FW |
3301 | /* |
3302 | * Hibernation protection. | |
3303 | * The state of the current task is too much unstable during | |
3304 | * suspend/restore to disk. We want to protect against that. | |
3305 | */ | |
3306 | static int | |
3307 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
3308 | void *unused) | |
3309 | { | |
3310 | switch (state) { | |
3311 | case PM_HIBERNATION_PREPARE: | |
3312 | pause_graph_tracing(); | |
3313 | break; | |
3314 | ||
3315 | case PM_POST_HIBERNATION: | |
3316 | unpause_graph_tracing(); | |
3317 | break; | |
3318 | } | |
3319 | return NOTIFY_DONE; | |
3320 | } | |
3321 | ||
287b6e68 FW |
3322 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
3323 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 3324 | { |
e7d3737e FW |
3325 | int ret = 0; |
3326 | ||
e6ea44e9 | 3327 | mutex_lock(&ftrace_lock); |
e7d3737e | 3328 | |
05ce5818 | 3329 | /* we currently allow only one tracer registered at a time */ |
597af815 | 3330 | if (ftrace_graph_active) { |
05ce5818 SR |
3331 | ret = -EBUSY; |
3332 | goto out; | |
3333 | } | |
3334 | ||
4a2b8dda FW |
3335 | ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; |
3336 | register_pm_notifier(&ftrace_suspend_notifier); | |
3337 | ||
597af815 | 3338 | ftrace_graph_active++; |
fb52607a | 3339 | ret = start_graph_tracing(); |
f201ae23 | 3340 | if (ret) { |
597af815 | 3341 | ftrace_graph_active--; |
f201ae23 FW |
3342 | goto out; |
3343 | } | |
e53a6319 | 3344 | |
287b6e68 FW |
3345 | ftrace_graph_return = retfunc; |
3346 | ftrace_graph_entry = entryfunc; | |
e53a6319 | 3347 | |
5a45cfe1 | 3348 | ftrace_startup(FTRACE_START_FUNC_RET); |
e7d3737e FW |
3349 | |
3350 | out: | |
e6ea44e9 | 3351 | mutex_unlock(&ftrace_lock); |
e7d3737e | 3352 | return ret; |
15e6cb36 FW |
3353 | } |
3354 | ||
fb52607a | 3355 | void unregister_ftrace_graph(void) |
15e6cb36 | 3356 | { |
e6ea44e9 | 3357 | mutex_lock(&ftrace_lock); |
e7d3737e | 3358 | |
597af815 | 3359 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
3360 | goto out; |
3361 | ||
597af815 | 3362 | ftrace_graph_active--; |
287b6e68 | 3363 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 3364 | ftrace_graph_entry = ftrace_graph_entry_stub; |
5a45cfe1 | 3365 | ftrace_shutdown(FTRACE_STOP_FUNC_RET); |
4a2b8dda | 3366 | unregister_pm_notifier(&ftrace_suspend_notifier); |
37e44bc5 | 3367 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch); |
e7d3737e | 3368 | |
2aad1b76 | 3369 | out: |
e6ea44e9 | 3370 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 3371 | } |
f201ae23 FW |
3372 | |
3373 | /* Allocate a return stack for newly created task */ | |
fb52607a | 3374 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 3375 | { |
84047e36 SR |
3376 | /* Make sure we do not use the parent ret_stack */ |
3377 | t->ret_stack = NULL; | |
ea14eb71 | 3378 | t->curr_ret_stack = -1; |
84047e36 | 3379 | |
597af815 | 3380 | if (ftrace_graph_active) { |
82310a32 SR |
3381 | struct ftrace_ret_stack *ret_stack; |
3382 | ||
3383 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
3384 | * sizeof(struct ftrace_ret_stack), |
3385 | GFP_KERNEL); | |
82310a32 | 3386 | if (!ret_stack) |
f201ae23 | 3387 | return; |
380c4b14 | 3388 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 3389 | atomic_set(&t->trace_overrun, 0); |
8aef2d28 | 3390 | t->ftrace_timestamp = 0; |
82310a32 SR |
3391 | /* make curr_ret_stack visable before we add the ret_stack */ |
3392 | smp_wmb(); | |
3393 | t->ret_stack = ret_stack; | |
84047e36 | 3394 | } |
f201ae23 FW |
3395 | } |
3396 | ||
fb52607a | 3397 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 3398 | { |
eae849ca FW |
3399 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
3400 | ||
f201ae23 | 3401 | t->ret_stack = NULL; |
eae849ca FW |
3402 | /* NULL must become visible to IRQs before we free it: */ |
3403 | barrier(); | |
3404 | ||
3405 | kfree(ret_stack); | |
f201ae23 | 3406 | } |
14a866c5 SR |
3407 | |
3408 | void ftrace_graph_stop(void) | |
3409 | { | |
3410 | ftrace_stop(); | |
3411 | } | |
15e6cb36 | 3412 | #endif |