Commit | Line | Data |
---|---|---|
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 | 41 | #define FTRACE_WARN_ON(cond) \ |
0778d9ad SR |
42 | ({ \ |
43 | int ___r = cond; \ | |
44 | if (WARN_ON(___r)) \ | |
6912896e | 45 | ftrace_kill(); \ |
0778d9ad SR |
46 | ___r; \ |
47 | }) | |
6912896e SR |
48 | |
49 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
0778d9ad SR |
50 | ({ \ |
51 | int ___r = cond; \ | |
52 | if (WARN_ON_ONCE(___r)) \ | |
6912896e | 53 | ftrace_kill(); \ |
0778d9ad SR |
54 | ___r; \ |
55 | }) | |
6912896e | 56 | |
8fc0c701 SR |
57 | /* hash bits for specific function selection */ |
58 | #define FTRACE_HASH_BITS 7 | |
59 | #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS) | |
60 | ||
4eebcc81 SR |
61 | /* ftrace_enabled is a method to turn ftrace on or off */ |
62 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 63 | static int last_ftrace_enabled; |
b0fc494f | 64 | |
60a7ecf4 SR |
65 | /* Quick disabling of function tracer. */ |
66 | int function_trace_stop; | |
67 | ||
756d17ee | 68 | /* List for set_ftrace_pid's pids. */ |
69 | LIST_HEAD(ftrace_pids); | |
70 | struct ftrace_pid { | |
71 | struct list_head list; | |
72 | struct pid *pid; | |
73 | }; | |
74 | ||
4eebcc81 SR |
75 | /* |
76 | * ftrace_disabled is set when an anomaly is discovered. | |
77 | * ftrace_disabled is much stronger than ftrace_enabled. | |
78 | */ | |
79 | static int ftrace_disabled __read_mostly; | |
80 | ||
52baf119 | 81 | static DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 82 | |
16444a8a ACM |
83 | static struct ftrace_ops ftrace_list_end __read_mostly = |
84 | { | |
fb9fb015 | 85 | .func = ftrace_stub, |
16444a8a ACM |
86 | }; |
87 | ||
88 | static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; | |
89 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; | |
60a7ecf4 | 90 | ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub; |
df4fc315 | 91 | ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; |
16444a8a | 92 | |
3f379b03 PM |
93 | /* |
94 | * Traverse the ftrace_list, invoking all entries. The reason that we | |
95 | * can use rcu_dereference_raw() is that elements removed from this list | |
96 | * are simply leaked, so there is no need to interact with a grace-period | |
97 | * mechanism. The rcu_dereference_raw() calls are needed to handle | |
98 | * concurrent insertions into the ftrace_list. | |
99 | * | |
100 | * Silly Alpha and silly pointer-speculation compiler optimizations! | |
101 | */ | |
f2252935 | 102 | static void ftrace_list_func(unsigned long ip, unsigned long parent_ip) |
16444a8a | 103 | { |
3f379b03 | 104 | struct ftrace_ops *op = rcu_dereference_raw(ftrace_list); /*see above*/ |
16444a8a ACM |
105 | |
106 | while (op != &ftrace_list_end) { | |
16444a8a | 107 | op->func(ip, parent_ip); |
3f379b03 | 108 | op = rcu_dereference_raw(op->next); /*see above*/ |
16444a8a ACM |
109 | }; |
110 | } | |
111 | ||
df4fc315 SR |
112 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip) |
113 | { | |
0ef8cde5 | 114 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
115 | return; |
116 | ||
117 | ftrace_pid_function(ip, parent_ip); | |
118 | } | |
119 | ||
120 | static void set_ftrace_pid_function(ftrace_func_t func) | |
121 | { | |
122 | /* do not set ftrace_pid_function to itself! */ | |
123 | if (func != ftrace_pid_func) | |
124 | ftrace_pid_function = func; | |
125 | } | |
126 | ||
16444a8a | 127 | /** |
3d083395 | 128 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 129 | * |
3d083395 SR |
130 | * This NULLs the ftrace function and in essence stops |
131 | * tracing. There may be lag | |
16444a8a | 132 | */ |
3d083395 | 133 | void clear_ftrace_function(void) |
16444a8a | 134 | { |
3d083395 | 135 | ftrace_trace_function = ftrace_stub; |
60a7ecf4 | 136 | __ftrace_trace_function = ftrace_stub; |
df4fc315 | 137 | ftrace_pid_function = ftrace_stub; |
3d083395 SR |
138 | } |
139 | ||
60a7ecf4 SR |
140 | #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
141 | /* | |
142 | * For those archs that do not test ftrace_trace_stop in their | |
143 | * mcount call site, we need to do it from C. | |
144 | */ | |
145 | static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip) | |
146 | { | |
147 | if (function_trace_stop) | |
148 | return; | |
149 | ||
150 | __ftrace_trace_function(ip, parent_ip); | |
151 | } | |
152 | #endif | |
153 | ||
e309b41d | 154 | static int __register_ftrace_function(struct ftrace_ops *ops) |
3d083395 | 155 | { |
16444a8a ACM |
156 | ops->next = ftrace_list; |
157 | /* | |
158 | * We are entering ops into the ftrace_list but another | |
159 | * CPU might be walking that list. We need to make sure | |
160 | * the ops->next pointer is valid before another CPU sees | |
161 | * the ops pointer included into the ftrace_list. | |
162 | */ | |
3f379b03 | 163 | rcu_assign_pointer(ftrace_list, ops); |
3d083395 | 164 | |
b0fc494f | 165 | if (ftrace_enabled) { |
df4fc315 SR |
166 | ftrace_func_t func; |
167 | ||
168 | if (ops->next == &ftrace_list_end) | |
169 | func = ops->func; | |
170 | else | |
171 | func = ftrace_list_func; | |
172 | ||
756d17ee | 173 | if (!list_empty(&ftrace_pids)) { |
df4fc315 SR |
174 | set_ftrace_pid_function(func); |
175 | func = ftrace_pid_func; | |
176 | } | |
177 | ||
b0fc494f SR |
178 | /* |
179 | * For one func, simply call it directly. | |
180 | * For more than one func, call the chain. | |
181 | */ | |
60a7ecf4 | 182 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
df4fc315 | 183 | ftrace_trace_function = func; |
60a7ecf4 | 184 | #else |
df4fc315 | 185 | __ftrace_trace_function = func; |
60a7ecf4 SR |
186 | ftrace_trace_function = ftrace_test_stop_func; |
187 | #endif | |
b0fc494f | 188 | } |
3d083395 | 189 | |
16444a8a ACM |
190 | return 0; |
191 | } | |
192 | ||
e309b41d | 193 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 194 | { |
16444a8a | 195 | struct ftrace_ops **p; |
16444a8a ACM |
196 | |
197 | /* | |
3d083395 SR |
198 | * If we are removing the last function, then simply point |
199 | * to the ftrace_stub. | |
16444a8a ACM |
200 | */ |
201 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { | |
202 | ftrace_trace_function = ftrace_stub; | |
203 | ftrace_list = &ftrace_list_end; | |
e6ea44e9 | 204 | return 0; |
16444a8a ACM |
205 | } |
206 | ||
207 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) | |
208 | if (*p == ops) | |
209 | break; | |
210 | ||
e6ea44e9 SR |
211 | if (*p != ops) |
212 | return -1; | |
16444a8a ACM |
213 | |
214 | *p = (*p)->next; | |
215 | ||
b0fc494f SR |
216 | if (ftrace_enabled) { |
217 | /* If we only have one func left, then call that directly */ | |
df4fc315 SR |
218 | if (ftrace_list->next == &ftrace_list_end) { |
219 | ftrace_func_t func = ftrace_list->func; | |
220 | ||
756d17ee | 221 | if (!list_empty(&ftrace_pids)) { |
df4fc315 SR |
222 | set_ftrace_pid_function(func); |
223 | func = ftrace_pid_func; | |
224 | } | |
225 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
226 | ftrace_trace_function = func; | |
227 | #else | |
228 | __ftrace_trace_function = func; | |
229 | #endif | |
230 | } | |
b0fc494f | 231 | } |
16444a8a | 232 | |
e6ea44e9 | 233 | return 0; |
3d083395 SR |
234 | } |
235 | ||
df4fc315 SR |
236 | static void ftrace_update_pid_func(void) |
237 | { | |
238 | ftrace_func_t func; | |
239 | ||
df4fc315 | 240 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 241 | return; |
df4fc315 | 242 | |
33974093 | 243 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
df4fc315 | 244 | func = ftrace_trace_function; |
33974093 MF |
245 | #else |
246 | func = __ftrace_trace_function; | |
247 | #endif | |
df4fc315 | 248 | |
756d17ee | 249 | if (!list_empty(&ftrace_pids)) { |
df4fc315 SR |
250 | set_ftrace_pid_function(func); |
251 | func = ftrace_pid_func; | |
252 | } else { | |
66eafebc LW |
253 | if (func == ftrace_pid_func) |
254 | func = ftrace_pid_function; | |
df4fc315 SR |
255 | } |
256 | ||
257 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
258 | ftrace_trace_function = func; | |
259 | #else | |
260 | __ftrace_trace_function = func; | |
261 | #endif | |
df4fc315 SR |
262 | } |
263 | ||
493762fc SR |
264 | #ifdef CONFIG_FUNCTION_PROFILER |
265 | struct ftrace_profile { | |
266 | struct hlist_node node; | |
267 | unsigned long ip; | |
268 | unsigned long counter; | |
0706f1c4 SR |
269 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
270 | unsigned long long time; | |
e330b3bc | 271 | unsigned long long time_squared; |
0706f1c4 | 272 | #endif |
8fc0c701 SR |
273 | }; |
274 | ||
493762fc SR |
275 | struct ftrace_profile_page { |
276 | struct ftrace_profile_page *next; | |
277 | unsigned long index; | |
278 | struct ftrace_profile records[]; | |
d61f82d0 SR |
279 | }; |
280 | ||
cafb168a SR |
281 | struct ftrace_profile_stat { |
282 | atomic_t disabled; | |
283 | struct hlist_head *hash; | |
284 | struct ftrace_profile_page *pages; | |
285 | struct ftrace_profile_page *start; | |
286 | struct tracer_stat stat; | |
287 | }; | |
288 | ||
493762fc SR |
289 | #define PROFILE_RECORDS_SIZE \ |
290 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 291 | |
493762fc SR |
292 | #define PROFILES_PER_PAGE \ |
293 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 294 | |
fb9fb015 SR |
295 | static int ftrace_profile_bits __read_mostly; |
296 | static int ftrace_profile_enabled __read_mostly; | |
297 | ||
298 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
299 | static DEFINE_MUTEX(ftrace_profile_lock); |
300 | ||
cafb168a | 301 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc SR |
302 | |
303 | #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */ | |
304 | ||
bac429f0 SR |
305 | static void * |
306 | function_stat_next(void *v, int idx) | |
307 | { | |
493762fc SR |
308 | struct ftrace_profile *rec = v; |
309 | struct ftrace_profile_page *pg; | |
bac429f0 | 310 | |
493762fc | 311 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
312 | |
313 | again: | |
0296e425 LZ |
314 | if (idx != 0) |
315 | rec++; | |
316 | ||
bac429f0 SR |
317 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
318 | pg = pg->next; | |
319 | if (!pg) | |
320 | return NULL; | |
321 | rec = &pg->records[0]; | |
493762fc SR |
322 | if (!rec->counter) |
323 | goto again; | |
bac429f0 SR |
324 | } |
325 | ||
bac429f0 SR |
326 | return rec; |
327 | } | |
328 | ||
329 | static void *function_stat_start(struct tracer_stat *trace) | |
330 | { | |
cafb168a SR |
331 | struct ftrace_profile_stat *stat = |
332 | container_of(trace, struct ftrace_profile_stat, stat); | |
333 | ||
334 | if (!stat || !stat->start) | |
335 | return NULL; | |
336 | ||
337 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
338 | } |
339 | ||
0706f1c4 SR |
340 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
341 | /* function graph compares on total time */ | |
342 | static int function_stat_cmp(void *p1, void *p2) | |
343 | { | |
344 | struct ftrace_profile *a = p1; | |
345 | struct ftrace_profile *b = p2; | |
346 | ||
347 | if (a->time < b->time) | |
348 | return -1; | |
349 | if (a->time > b->time) | |
350 | return 1; | |
351 | else | |
352 | return 0; | |
353 | } | |
354 | #else | |
355 | /* not function graph compares against hits */ | |
bac429f0 SR |
356 | static int function_stat_cmp(void *p1, void *p2) |
357 | { | |
493762fc SR |
358 | struct ftrace_profile *a = p1; |
359 | struct ftrace_profile *b = p2; | |
bac429f0 SR |
360 | |
361 | if (a->counter < b->counter) | |
362 | return -1; | |
363 | if (a->counter > b->counter) | |
364 | return 1; | |
365 | else | |
366 | return 0; | |
367 | } | |
0706f1c4 | 368 | #endif |
bac429f0 SR |
369 | |
370 | static int function_stat_headers(struct seq_file *m) | |
371 | { | |
0706f1c4 | 372 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b | 373 | seq_printf(m, " Function " |
e330b3bc | 374 | "Hit Time Avg s^2\n" |
34886c8b | 375 | " -------- " |
e330b3bc | 376 | "--- ---- --- ---\n"); |
0706f1c4 | 377 | #else |
bac429f0 SR |
378 | seq_printf(m, " Function Hit\n" |
379 | " -------- ---\n"); | |
0706f1c4 | 380 | #endif |
bac429f0 SR |
381 | return 0; |
382 | } | |
383 | ||
384 | static int function_stat_show(struct seq_file *m, void *v) | |
385 | { | |
493762fc | 386 | struct ftrace_profile *rec = v; |
bac429f0 | 387 | char str[KSYM_SYMBOL_LEN]; |
3aaba20f | 388 | int ret = 0; |
0706f1c4 | 389 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
390 | static struct trace_seq s; |
391 | unsigned long long avg; | |
e330b3bc | 392 | unsigned long long stddev; |
0706f1c4 | 393 | #endif |
3aaba20f LZ |
394 | mutex_lock(&ftrace_profile_lock); |
395 | ||
396 | /* we raced with function_profile_reset() */ | |
397 | if (unlikely(rec->counter == 0)) { | |
398 | ret = -EBUSY; | |
399 | goto out; | |
400 | } | |
bac429f0 SR |
401 | |
402 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
0706f1c4 SR |
403 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
404 | ||
405 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
406 | seq_printf(m, " "); | |
34886c8b SR |
407 | avg = rec->time; |
408 | do_div(avg, rec->counter); | |
409 | ||
e330b3bc CD |
410 | /* Sample standard deviation (s^2) */ |
411 | if (rec->counter <= 1) | |
412 | stddev = 0; | |
413 | else { | |
414 | stddev = rec->time_squared - rec->counter * avg * avg; | |
415 | /* | |
416 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
417 | * trace_print_graph_duration will divide 1000 again. | |
418 | */ | |
419 | do_div(stddev, (rec->counter - 1) * 1000); | |
420 | } | |
421 | ||
34886c8b SR |
422 | trace_seq_init(&s); |
423 | trace_print_graph_duration(rec->time, &s); | |
424 | trace_seq_puts(&s, " "); | |
425 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
426 | trace_seq_puts(&s, " "); |
427 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 | 428 | trace_print_seq(m, &s); |
0706f1c4 SR |
429 | #endif |
430 | seq_putc(m, '\n'); | |
3aaba20f LZ |
431 | out: |
432 | mutex_unlock(&ftrace_profile_lock); | |
bac429f0 | 433 | |
3aaba20f | 434 | return ret; |
bac429f0 SR |
435 | } |
436 | ||
cafb168a | 437 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 438 | { |
493762fc | 439 | struct ftrace_profile_page *pg; |
bac429f0 | 440 | |
cafb168a | 441 | pg = stat->pages = stat->start; |
bac429f0 | 442 | |
493762fc SR |
443 | while (pg) { |
444 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
445 | pg->index = 0; | |
446 | pg = pg->next; | |
bac429f0 SR |
447 | } |
448 | ||
cafb168a | 449 | memset(stat->hash, 0, |
493762fc SR |
450 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
451 | } | |
bac429f0 | 452 | |
cafb168a | 453 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
454 | { |
455 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
456 | int functions; |
457 | int pages; | |
493762fc | 458 | int i; |
bac429f0 | 459 | |
493762fc | 460 | /* If we already allocated, do nothing */ |
cafb168a | 461 | if (stat->pages) |
493762fc | 462 | return 0; |
bac429f0 | 463 | |
cafb168a SR |
464 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
465 | if (!stat->pages) | |
493762fc | 466 | return -ENOMEM; |
bac429f0 | 467 | |
318e0a73 SR |
468 | #ifdef CONFIG_DYNAMIC_FTRACE |
469 | functions = ftrace_update_tot_cnt; | |
470 | #else | |
471 | /* | |
472 | * We do not know the number of functions that exist because | |
473 | * dynamic tracing is what counts them. With past experience | |
474 | * we have around 20K functions. That should be more than enough. | |
475 | * It is highly unlikely we will execute every function in | |
476 | * the kernel. | |
477 | */ | |
478 | functions = 20000; | |
479 | #endif | |
480 | ||
cafb168a | 481 | pg = stat->start = stat->pages; |
bac429f0 | 482 | |
318e0a73 SR |
483 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
484 | ||
485 | for (i = 0; i < pages; i++) { | |
493762fc | 486 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 487 | if (!pg->next) |
318e0a73 | 488 | goto out_free; |
493762fc SR |
489 | pg = pg->next; |
490 | } | |
491 | ||
492 | return 0; | |
318e0a73 SR |
493 | |
494 | out_free: | |
495 | pg = stat->start; | |
496 | while (pg) { | |
497 | unsigned long tmp = (unsigned long)pg; | |
498 | ||
499 | pg = pg->next; | |
500 | free_page(tmp); | |
501 | } | |
502 | ||
503 | free_page((unsigned long)stat->pages); | |
504 | stat->pages = NULL; | |
505 | stat->start = NULL; | |
506 | ||
507 | return -ENOMEM; | |
bac429f0 SR |
508 | } |
509 | ||
cafb168a | 510 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 511 | { |
cafb168a | 512 | struct ftrace_profile_stat *stat; |
493762fc | 513 | int size; |
bac429f0 | 514 | |
cafb168a SR |
515 | stat = &per_cpu(ftrace_profile_stats, cpu); |
516 | ||
517 | if (stat->hash) { | |
493762fc | 518 | /* If the profile is already created, simply reset it */ |
cafb168a | 519 | ftrace_profile_reset(stat); |
493762fc SR |
520 | return 0; |
521 | } | |
bac429f0 | 522 | |
493762fc SR |
523 | /* |
524 | * We are profiling all functions, but usually only a few thousand | |
525 | * functions are hit. We'll make a hash of 1024 items. | |
526 | */ | |
527 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 528 | |
cafb168a | 529 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
493762fc | 530 | |
cafb168a | 531 | if (!stat->hash) |
493762fc SR |
532 | return -ENOMEM; |
533 | ||
cafb168a SR |
534 | if (!ftrace_profile_bits) { |
535 | size--; | |
493762fc | 536 | |
cafb168a SR |
537 | for (; size; size >>= 1) |
538 | ftrace_profile_bits++; | |
539 | } | |
493762fc | 540 | |
318e0a73 | 541 | /* Preallocate the function profiling pages */ |
cafb168a SR |
542 | if (ftrace_profile_pages_init(stat) < 0) { |
543 | kfree(stat->hash); | |
544 | stat->hash = NULL; | |
493762fc SR |
545 | return -ENOMEM; |
546 | } | |
547 | ||
548 | return 0; | |
bac429f0 SR |
549 | } |
550 | ||
cafb168a SR |
551 | static int ftrace_profile_init(void) |
552 | { | |
553 | int cpu; | |
554 | int ret = 0; | |
555 | ||
556 | for_each_online_cpu(cpu) { | |
557 | ret = ftrace_profile_init_cpu(cpu); | |
558 | if (ret) | |
559 | break; | |
560 | } | |
561 | ||
562 | return ret; | |
563 | } | |
564 | ||
493762fc | 565 | /* interrupts must be disabled */ |
cafb168a SR |
566 | static struct ftrace_profile * |
567 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 568 | { |
493762fc | 569 | struct ftrace_profile *rec; |
bac429f0 SR |
570 | struct hlist_head *hhd; |
571 | struct hlist_node *n; | |
bac429f0 SR |
572 | unsigned long key; |
573 | ||
bac429f0 | 574 | key = hash_long(ip, ftrace_profile_bits); |
cafb168a | 575 | hhd = &stat->hash[key]; |
bac429f0 SR |
576 | |
577 | if (hlist_empty(hhd)) | |
578 | return NULL; | |
579 | ||
bac429f0 SR |
580 | hlist_for_each_entry_rcu(rec, n, hhd, node) { |
581 | if (rec->ip == ip) | |
493762fc SR |
582 | return rec; |
583 | } | |
584 | ||
585 | return NULL; | |
586 | } | |
587 | ||
cafb168a SR |
588 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
589 | struct ftrace_profile *rec) | |
493762fc SR |
590 | { |
591 | unsigned long key; | |
592 | ||
593 | key = hash_long(rec->ip, ftrace_profile_bits); | |
cafb168a | 594 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
595 | } |
596 | ||
318e0a73 SR |
597 | /* |
598 | * The memory is already allocated, this simply finds a new record to use. | |
599 | */ | |
493762fc | 600 | static struct ftrace_profile * |
318e0a73 | 601 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
602 | { |
603 | struct ftrace_profile *rec = NULL; | |
604 | ||
318e0a73 | 605 | /* prevent recursion (from NMIs) */ |
cafb168a | 606 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
607 | goto out; |
608 | ||
493762fc | 609 | /* |
318e0a73 SR |
610 | * Try to find the function again since an NMI |
611 | * could have added it | |
493762fc | 612 | */ |
cafb168a | 613 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 614 | if (rec) |
cafb168a | 615 | goto out; |
493762fc | 616 | |
cafb168a SR |
617 | if (stat->pages->index == PROFILES_PER_PAGE) { |
618 | if (!stat->pages->next) | |
619 | goto out; | |
620 | stat->pages = stat->pages->next; | |
bac429f0 | 621 | } |
493762fc | 622 | |
cafb168a | 623 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 624 | rec->ip = ip; |
cafb168a | 625 | ftrace_add_profile(stat, rec); |
493762fc | 626 | |
bac429f0 | 627 | out: |
cafb168a | 628 | atomic_dec(&stat->disabled); |
bac429f0 SR |
629 | |
630 | return rec; | |
631 | } | |
632 | ||
633 | static void | |
634 | function_profile_call(unsigned long ip, unsigned long parent_ip) | |
635 | { | |
cafb168a | 636 | struct ftrace_profile_stat *stat; |
493762fc | 637 | struct ftrace_profile *rec; |
bac429f0 SR |
638 | unsigned long flags; |
639 | ||
640 | if (!ftrace_profile_enabled) | |
641 | return; | |
642 | ||
643 | local_irq_save(flags); | |
cafb168a SR |
644 | |
645 | stat = &__get_cpu_var(ftrace_profile_stats); | |
0f6ce3de | 646 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
647 | goto out; |
648 | ||
649 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 650 | if (!rec) { |
318e0a73 | 651 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
652 | if (!rec) |
653 | goto out; | |
654 | } | |
bac429f0 SR |
655 | |
656 | rec->counter++; | |
657 | out: | |
658 | local_irq_restore(flags); | |
659 | } | |
660 | ||
0706f1c4 SR |
661 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
662 | static int profile_graph_entry(struct ftrace_graph_ent *trace) | |
663 | { | |
664 | function_profile_call(trace->func, 0); | |
665 | return 1; | |
666 | } | |
667 | ||
668 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
669 | { | |
cafb168a | 670 | struct ftrace_profile_stat *stat; |
a2a16d6a | 671 | unsigned long long calltime; |
0706f1c4 | 672 | struct ftrace_profile *rec; |
cafb168a | 673 | unsigned long flags; |
0706f1c4 SR |
674 | |
675 | local_irq_save(flags); | |
cafb168a | 676 | stat = &__get_cpu_var(ftrace_profile_stats); |
0f6ce3de | 677 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
678 | goto out; |
679 | ||
37e44bc5 SR |
680 | /* If the calltime was zero'd ignore it */ |
681 | if (!trace->calltime) | |
682 | goto out; | |
683 | ||
a2a16d6a SR |
684 | calltime = trace->rettime - trace->calltime; |
685 | ||
686 | if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) { | |
687 | int index; | |
688 | ||
689 | index = trace->depth; | |
690 | ||
691 | /* Append this call time to the parent time to subtract */ | |
692 | if (index) | |
693 | current->ret_stack[index - 1].subtime += calltime; | |
694 | ||
695 | if (current->ret_stack[index].subtime < calltime) | |
696 | calltime -= current->ret_stack[index].subtime; | |
697 | else | |
698 | calltime = 0; | |
699 | } | |
700 | ||
cafb168a | 701 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 702 | if (rec) { |
a2a16d6a | 703 | rec->time += calltime; |
e330b3bc CD |
704 | rec->time_squared += calltime * calltime; |
705 | } | |
a2a16d6a | 706 | |
cafb168a | 707 | out: |
0706f1c4 SR |
708 | local_irq_restore(flags); |
709 | } | |
710 | ||
711 | static int register_ftrace_profiler(void) | |
712 | { | |
713 | return register_ftrace_graph(&profile_graph_return, | |
714 | &profile_graph_entry); | |
715 | } | |
716 | ||
717 | static void unregister_ftrace_profiler(void) | |
718 | { | |
719 | unregister_ftrace_graph(); | |
720 | } | |
721 | #else | |
bac429f0 SR |
722 | static struct ftrace_ops ftrace_profile_ops __read_mostly = |
723 | { | |
fb9fb015 | 724 | .func = function_profile_call, |
bac429f0 SR |
725 | }; |
726 | ||
0706f1c4 SR |
727 | static int register_ftrace_profiler(void) |
728 | { | |
729 | return register_ftrace_function(&ftrace_profile_ops); | |
730 | } | |
731 | ||
732 | static void unregister_ftrace_profiler(void) | |
733 | { | |
734 | unregister_ftrace_function(&ftrace_profile_ops); | |
735 | } | |
736 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
737 | ||
bac429f0 SR |
738 | static ssize_t |
739 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
740 | size_t cnt, loff_t *ppos) | |
741 | { | |
742 | unsigned long val; | |
fb9fb015 | 743 | char buf[64]; /* big enough to hold a number */ |
bac429f0 SR |
744 | int ret; |
745 | ||
bac429f0 SR |
746 | if (cnt >= sizeof(buf)) |
747 | return -EINVAL; | |
748 | ||
749 | if (copy_from_user(&buf, ubuf, cnt)) | |
750 | return -EFAULT; | |
751 | ||
752 | buf[cnt] = 0; | |
753 | ||
754 | ret = strict_strtoul(buf, 10, &val); | |
755 | if (ret < 0) | |
756 | return ret; | |
757 | ||
758 | val = !!val; | |
759 | ||
760 | mutex_lock(&ftrace_profile_lock); | |
761 | if (ftrace_profile_enabled ^ val) { | |
762 | if (val) { | |
493762fc SR |
763 | ret = ftrace_profile_init(); |
764 | if (ret < 0) { | |
765 | cnt = ret; | |
766 | goto out; | |
767 | } | |
768 | ||
0706f1c4 SR |
769 | ret = register_ftrace_profiler(); |
770 | if (ret < 0) { | |
771 | cnt = ret; | |
772 | goto out; | |
773 | } | |
bac429f0 SR |
774 | ftrace_profile_enabled = 1; |
775 | } else { | |
776 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
777 | /* |
778 | * unregister_ftrace_profiler calls stop_machine | |
779 | * so this acts like an synchronize_sched. | |
780 | */ | |
0706f1c4 | 781 | unregister_ftrace_profiler(); |
bac429f0 SR |
782 | } |
783 | } | |
493762fc | 784 | out: |
bac429f0 SR |
785 | mutex_unlock(&ftrace_profile_lock); |
786 | ||
cf8517cf | 787 | *ppos += cnt; |
bac429f0 SR |
788 | |
789 | return cnt; | |
790 | } | |
791 | ||
493762fc SR |
792 | static ssize_t |
793 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
794 | size_t cnt, loff_t *ppos) | |
795 | { | |
fb9fb015 | 796 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
797 | int r; |
798 | ||
799 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
800 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
801 | } | |
802 | ||
bac429f0 SR |
803 | static const struct file_operations ftrace_profile_fops = { |
804 | .open = tracing_open_generic, | |
805 | .read = ftrace_profile_read, | |
806 | .write = ftrace_profile_write, | |
6038f373 | 807 | .llseek = default_llseek, |
bac429f0 SR |
808 | }; |
809 | ||
cafb168a SR |
810 | /* used to initialize the real stat files */ |
811 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
812 | .name = "functions", |
813 | .stat_start = function_stat_start, | |
814 | .stat_next = function_stat_next, | |
815 | .stat_cmp = function_stat_cmp, | |
816 | .stat_headers = function_stat_headers, | |
817 | .stat_show = function_stat_show | |
cafb168a SR |
818 | }; |
819 | ||
6ab5d668 | 820 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 | 821 | { |
cafb168a | 822 | struct ftrace_profile_stat *stat; |
bac429f0 | 823 | struct dentry *entry; |
cafb168a | 824 | char *name; |
bac429f0 | 825 | int ret; |
cafb168a SR |
826 | int cpu; |
827 | ||
828 | for_each_possible_cpu(cpu) { | |
829 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
830 | ||
831 | /* allocate enough for function name + cpu number */ | |
832 | name = kmalloc(32, GFP_KERNEL); | |
833 | if (!name) { | |
834 | /* | |
835 | * The files created are permanent, if something happens | |
836 | * we still do not free memory. | |
837 | */ | |
cafb168a SR |
838 | WARN(1, |
839 | "Could not allocate stat file for cpu %d\n", | |
840 | cpu); | |
841 | return; | |
842 | } | |
843 | stat->stat = function_stats; | |
844 | snprintf(name, 32, "function%d", cpu); | |
845 | stat->stat.name = name; | |
846 | ret = register_stat_tracer(&stat->stat); | |
847 | if (ret) { | |
848 | WARN(1, | |
849 | "Could not register function stat for cpu %d\n", | |
850 | cpu); | |
851 | kfree(name); | |
852 | return; | |
853 | } | |
bac429f0 SR |
854 | } |
855 | ||
856 | entry = debugfs_create_file("function_profile_enabled", 0644, | |
857 | d_tracer, NULL, &ftrace_profile_fops); | |
858 | if (!entry) | |
859 | pr_warning("Could not create debugfs " | |
860 | "'function_profile_enabled' entry\n"); | |
861 | } | |
862 | ||
bac429f0 | 863 | #else /* CONFIG_FUNCTION_PROFILER */ |
6ab5d668 | 864 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 SR |
865 | { |
866 | } | |
bac429f0 SR |
867 | #endif /* CONFIG_FUNCTION_PROFILER */ |
868 | ||
493762fc SR |
869 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; |
870 | ||
871 | #ifdef CONFIG_DYNAMIC_FTRACE | |
872 | ||
873 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD | |
874 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
875 | #endif | |
876 | ||
877 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; | |
878 | ||
879 | struct ftrace_func_probe { | |
880 | struct hlist_node node; | |
881 | struct ftrace_probe_ops *ops; | |
882 | unsigned long flags; | |
883 | unsigned long ip; | |
884 | void *data; | |
885 | struct rcu_head rcu; | |
886 | }; | |
887 | ||
888 | enum { | |
889 | FTRACE_ENABLE_CALLS = (1 << 0), | |
890 | FTRACE_DISABLE_CALLS = (1 << 1), | |
891 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
79e406d7 SR |
892 | FTRACE_START_FUNC_RET = (1 << 3), |
893 | FTRACE_STOP_FUNC_RET = (1 << 4), | |
493762fc SR |
894 | }; |
895 | ||
896 | static int ftrace_filtered; | |
897 | ||
898 | static struct dyn_ftrace *ftrace_new_addrs; | |
899 | ||
900 | static DEFINE_MUTEX(ftrace_regex_lock); | |
901 | ||
902 | struct ftrace_page { | |
903 | struct ftrace_page *next; | |
904 | int index; | |
905 | struct dyn_ftrace records[]; | |
906 | }; | |
907 | ||
908 | #define ENTRIES_PER_PAGE \ | |
909 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
910 | ||
911 | /* estimate from running different kernels */ | |
912 | #define NR_TO_INIT 10000 | |
913 | ||
914 | static struct ftrace_page *ftrace_pages_start; | |
915 | static struct ftrace_page *ftrace_pages; | |
916 | ||
917 | static struct dyn_ftrace *ftrace_free_records; | |
918 | ||
919 | /* | |
920 | * This is a double for. Do not use 'break' to break out of the loop, | |
921 | * you must use a goto. | |
922 | */ | |
923 | #define do_for_each_ftrace_rec(pg, rec) \ | |
924 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
925 | int _____i; \ | |
926 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
927 | rec = &pg->records[_____i]; | |
928 | ||
929 | #define while_for_each_ftrace_rec() \ | |
930 | } \ | |
931 | } | |
932 | ||
e309b41d | 933 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
37ad5084 | 934 | { |
ee000b7f | 935 | rec->freelist = ftrace_free_records; |
37ad5084 SR |
936 | ftrace_free_records = rec; |
937 | rec->flags |= FTRACE_FL_FREE; | |
938 | } | |
939 | ||
e309b41d | 940 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 941 | { |
37ad5084 SR |
942 | struct dyn_ftrace *rec; |
943 | ||
944 | /* First check for freed records */ | |
945 | if (ftrace_free_records) { | |
946 | rec = ftrace_free_records; | |
947 | ||
37ad5084 | 948 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
6912896e | 949 | FTRACE_WARN_ON_ONCE(1); |
37ad5084 SR |
950 | ftrace_free_records = NULL; |
951 | return NULL; | |
952 | } | |
953 | ||
ee000b7f | 954 | ftrace_free_records = rec->freelist; |
37ad5084 SR |
955 | memset(rec, 0, sizeof(*rec)); |
956 | return rec; | |
957 | } | |
958 | ||
3c1720f0 | 959 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
08f5ac90 SR |
960 | if (!ftrace_pages->next) { |
961 | /* allocate another page */ | |
962 | ftrace_pages->next = | |
963 | (void *)get_zeroed_page(GFP_KERNEL); | |
964 | if (!ftrace_pages->next) | |
965 | return NULL; | |
966 | } | |
3c1720f0 SR |
967 | ftrace_pages = ftrace_pages->next; |
968 | } | |
969 | ||
970 | return &ftrace_pages->records[ftrace_pages->index++]; | |
971 | } | |
972 | ||
08f5ac90 | 973 | static struct dyn_ftrace * |
d61f82d0 | 974 | ftrace_record_ip(unsigned long ip) |
3d083395 | 975 | { |
08f5ac90 | 976 | struct dyn_ftrace *rec; |
3d083395 | 977 | |
f3c7ac40 | 978 | if (ftrace_disabled) |
08f5ac90 | 979 | return NULL; |
3d083395 | 980 | |
08f5ac90 SR |
981 | rec = ftrace_alloc_dyn_node(ip); |
982 | if (!rec) | |
983 | return NULL; | |
3d083395 | 984 | |
08f5ac90 | 985 | rec->ip = ip; |
ee000b7f | 986 | rec->newlist = ftrace_new_addrs; |
e94142a6 | 987 | ftrace_new_addrs = rec; |
3d083395 | 988 | |
08f5ac90 | 989 | return rec; |
3d083395 SR |
990 | } |
991 | ||
b17e8a37 SR |
992 | static void print_ip_ins(const char *fmt, unsigned char *p) |
993 | { | |
994 | int i; | |
995 | ||
996 | printk(KERN_CONT "%s", fmt); | |
997 | ||
998 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
999 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
1000 | } | |
1001 | ||
31e88909 | 1002 | static void ftrace_bug(int failed, unsigned long ip) |
b17e8a37 SR |
1003 | { |
1004 | switch (failed) { | |
1005 | case -EFAULT: | |
1006 | FTRACE_WARN_ON_ONCE(1); | |
1007 | pr_info("ftrace faulted on modifying "); | |
1008 | print_ip_sym(ip); | |
1009 | break; | |
1010 | case -EINVAL: | |
1011 | FTRACE_WARN_ON_ONCE(1); | |
1012 | pr_info("ftrace failed to modify "); | |
1013 | print_ip_sym(ip); | |
b17e8a37 | 1014 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
1015 | printk(KERN_CONT "\n"); |
1016 | break; | |
1017 | case -EPERM: | |
1018 | FTRACE_WARN_ON_ONCE(1); | |
1019 | pr_info("ftrace faulted on writing "); | |
1020 | print_ip_sym(ip); | |
1021 | break; | |
1022 | default: | |
1023 | FTRACE_WARN_ON_ONCE(1); | |
1024 | pr_info("ftrace faulted on unknown error "); | |
1025 | print_ip_sym(ip); | |
1026 | } | |
1027 | } | |
1028 | ||
3c1720f0 | 1029 | |
2cfa1978 MH |
1030 | /* Return 1 if the address range is reserved for ftrace */ |
1031 | int ftrace_text_reserved(void *start, void *end) | |
1032 | { | |
1033 | struct dyn_ftrace *rec; | |
1034 | struct ftrace_page *pg; | |
1035 | ||
1036 | do_for_each_ftrace_rec(pg, rec) { | |
1037 | if (rec->ip <= (unsigned long)end && | |
1038 | rec->ip + MCOUNT_INSN_SIZE > (unsigned long)start) | |
1039 | return 1; | |
1040 | } while_for_each_ftrace_rec(); | |
1041 | return 0; | |
1042 | } | |
1043 | ||
1044 | ||
0eb96701 | 1045 | static int |
31e88909 | 1046 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) |
5072c59f | 1047 | { |
e7d3737e | 1048 | unsigned long ftrace_addr; |
64fbcd16 | 1049 | unsigned long flag = 0UL; |
e7d3737e | 1050 | |
f0001207 | 1051 | ftrace_addr = (unsigned long)FTRACE_ADDR; |
5072c59f | 1052 | |
982c350b | 1053 | /* |
64fbcd16 XG |
1054 | * If this record is not to be traced or we want to disable it, |
1055 | * then disable it. | |
982c350b | 1056 | * |
64fbcd16 | 1057 | * If we want to enable it and filtering is off, then enable it. |
982c350b | 1058 | * |
64fbcd16 XG |
1059 | * If we want to enable it and filtering is on, enable it only if |
1060 | * it's filtered | |
982c350b | 1061 | */ |
64fbcd16 XG |
1062 | if (enable && !(rec->flags & FTRACE_FL_NOTRACE)) { |
1063 | if (!ftrace_filtered || (rec->flags & FTRACE_FL_FILTER)) | |
1064 | flag = FTRACE_FL_ENABLED; | |
1065 | } | |
982c350b | 1066 | |
64fbcd16 XG |
1067 | /* If the state of this record hasn't changed, then do nothing */ |
1068 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
1069 | return 0; | |
982c350b | 1070 | |
64fbcd16 XG |
1071 | if (flag) { |
1072 | rec->flags |= FTRACE_FL_ENABLED; | |
1073 | return ftrace_make_call(rec, ftrace_addr); | |
5072c59f SR |
1074 | } |
1075 | ||
64fbcd16 XG |
1076 | rec->flags &= ~FTRACE_FL_ENABLED; |
1077 | return ftrace_make_nop(NULL, rec, ftrace_addr); | |
5072c59f SR |
1078 | } |
1079 | ||
e309b41d | 1080 | static void ftrace_replace_code(int enable) |
3c1720f0 | 1081 | { |
3c1720f0 SR |
1082 | struct dyn_ftrace *rec; |
1083 | struct ftrace_page *pg; | |
6a24a244 | 1084 | int failed; |
3c1720f0 | 1085 | |
45a4a237 SR |
1086 | if (unlikely(ftrace_disabled)) |
1087 | return; | |
1088 | ||
265c831c SR |
1089 | do_for_each_ftrace_rec(pg, rec) { |
1090 | /* | |
fa9d13cf Z |
1091 | * Skip over free records, records that have |
1092 | * failed and not converted. | |
265c831c SR |
1093 | */ |
1094 | if (rec->flags & FTRACE_FL_FREE || | |
03303549 | 1095 | !(rec->flags & FTRACE_FL_CONVERTED)) |
265c831c SR |
1096 | continue; |
1097 | ||
265c831c | 1098 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 1099 | if (failed) { |
3279ba37 SR |
1100 | ftrace_bug(failed, rec->ip); |
1101 | /* Stop processing */ | |
1102 | return; | |
3c1720f0 | 1103 | } |
265c831c | 1104 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
1105 | } |
1106 | ||
492a7ea5 | 1107 | static int |
31e88909 | 1108 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 SR |
1109 | { |
1110 | unsigned long ip; | |
593eb8a2 | 1111 | int ret; |
3c1720f0 SR |
1112 | |
1113 | ip = rec->ip; | |
1114 | ||
45a4a237 SR |
1115 | if (unlikely(ftrace_disabled)) |
1116 | return 0; | |
1117 | ||
25aac9dc | 1118 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 1119 | if (ret) { |
31e88909 | 1120 | ftrace_bug(ret, ip); |
492a7ea5 | 1121 | return 0; |
37ad5084 | 1122 | } |
492a7ea5 | 1123 | return 1; |
3c1720f0 SR |
1124 | } |
1125 | ||
000ab691 SR |
1126 | /* |
1127 | * archs can override this function if they must do something | |
1128 | * before the modifying code is performed. | |
1129 | */ | |
1130 | int __weak ftrace_arch_code_modify_prepare(void) | |
1131 | { | |
1132 | return 0; | |
1133 | } | |
1134 | ||
1135 | /* | |
1136 | * archs can override this function if they must do something | |
1137 | * after the modifying code is performed. | |
1138 | */ | |
1139 | int __weak ftrace_arch_code_modify_post_process(void) | |
1140 | { | |
1141 | return 0; | |
1142 | } | |
1143 | ||
e309b41d | 1144 | static int __ftrace_modify_code(void *data) |
3d083395 | 1145 | { |
d61f82d0 SR |
1146 | int *command = data; |
1147 | ||
a3583244 | 1148 | if (*command & FTRACE_ENABLE_CALLS) |
d61f82d0 | 1149 | ftrace_replace_code(1); |
a3583244 | 1150 | else if (*command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
1151 | ftrace_replace_code(0); |
1152 | ||
1153 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
1154 | ftrace_update_ftrace_func(ftrace_trace_function); | |
1155 | ||
5a45cfe1 SR |
1156 | if (*command & FTRACE_START_FUNC_RET) |
1157 | ftrace_enable_ftrace_graph_caller(); | |
1158 | else if (*command & FTRACE_STOP_FUNC_RET) | |
1159 | ftrace_disable_ftrace_graph_caller(); | |
1160 | ||
d61f82d0 | 1161 | return 0; |
3d083395 SR |
1162 | } |
1163 | ||
e309b41d | 1164 | static void ftrace_run_update_code(int command) |
3d083395 | 1165 | { |
000ab691 SR |
1166 | int ret; |
1167 | ||
1168 | ret = ftrace_arch_code_modify_prepare(); | |
1169 | FTRACE_WARN_ON(ret); | |
1170 | if (ret) | |
1171 | return; | |
1172 | ||
784e2d76 | 1173 | stop_machine(__ftrace_modify_code, &command, NULL); |
000ab691 SR |
1174 | |
1175 | ret = ftrace_arch_code_modify_post_process(); | |
1176 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
1177 | } |
1178 | ||
d61f82d0 | 1179 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 1180 | static int ftrace_start_up; |
df4fc315 SR |
1181 | |
1182 | static void ftrace_startup_enable(int command) | |
1183 | { | |
1184 | if (saved_ftrace_func != ftrace_trace_function) { | |
1185 | saved_ftrace_func = ftrace_trace_function; | |
1186 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1187 | } | |
1188 | ||
1189 | if (!command || !ftrace_enabled) | |
1190 | return; | |
1191 | ||
1192 | ftrace_run_update_code(command); | |
1193 | } | |
d61f82d0 | 1194 | |
5a45cfe1 | 1195 | static void ftrace_startup(int command) |
3d083395 | 1196 | { |
4eebcc81 SR |
1197 | if (unlikely(ftrace_disabled)) |
1198 | return; | |
1199 | ||
60a7ecf4 | 1200 | ftrace_start_up++; |
982c350b | 1201 | command |= FTRACE_ENABLE_CALLS; |
d61f82d0 | 1202 | |
df4fc315 | 1203 | ftrace_startup_enable(command); |
3d083395 SR |
1204 | } |
1205 | ||
5a45cfe1 | 1206 | static void ftrace_shutdown(int command) |
3d083395 | 1207 | { |
4eebcc81 SR |
1208 | if (unlikely(ftrace_disabled)) |
1209 | return; | |
1210 | ||
60a7ecf4 | 1211 | ftrace_start_up--; |
9ea1a153 FW |
1212 | /* |
1213 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
1214 | * critical but the ftrace_call callers may be never nopped again after | |
1215 | * further ftrace uses. | |
1216 | */ | |
1217 | WARN_ON_ONCE(ftrace_start_up < 0); | |
1218 | ||
60a7ecf4 | 1219 | if (!ftrace_start_up) |
d61f82d0 | 1220 | command |= FTRACE_DISABLE_CALLS; |
3d083395 | 1221 | |
d61f82d0 SR |
1222 | if (saved_ftrace_func != ftrace_trace_function) { |
1223 | saved_ftrace_func = ftrace_trace_function; | |
1224 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1225 | } | |
3d083395 | 1226 | |
d61f82d0 | 1227 | if (!command || !ftrace_enabled) |
e6ea44e9 | 1228 | return; |
d61f82d0 SR |
1229 | |
1230 | ftrace_run_update_code(command); | |
3d083395 SR |
1231 | } |
1232 | ||
e309b41d | 1233 | static void ftrace_startup_sysctl(void) |
b0fc494f | 1234 | { |
4eebcc81 SR |
1235 | if (unlikely(ftrace_disabled)) |
1236 | return; | |
1237 | ||
d61f82d0 SR |
1238 | /* Force update next time */ |
1239 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
1240 | /* ftrace_start_up is true if we want ftrace running */ |
1241 | if (ftrace_start_up) | |
79e406d7 | 1242 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
b0fc494f SR |
1243 | } |
1244 | ||
e309b41d | 1245 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 1246 | { |
4eebcc81 SR |
1247 | if (unlikely(ftrace_disabled)) |
1248 | return; | |
1249 | ||
60a7ecf4 SR |
1250 | /* ftrace_start_up is true if ftrace is running */ |
1251 | if (ftrace_start_up) | |
79e406d7 | 1252 | ftrace_run_update_code(FTRACE_DISABLE_CALLS); |
b0fc494f SR |
1253 | } |
1254 | ||
3d083395 SR |
1255 | static cycle_t ftrace_update_time; |
1256 | static unsigned long ftrace_update_cnt; | |
1257 | unsigned long ftrace_update_tot_cnt; | |
1258 | ||
31e88909 | 1259 | static int ftrace_update_code(struct module *mod) |
3d083395 | 1260 | { |
e94142a6 | 1261 | struct dyn_ftrace *p; |
f22f9a89 | 1262 | cycle_t start, stop; |
3d083395 | 1263 | |
750ed1a4 | 1264 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1265 | ftrace_update_cnt = 0; |
1266 | ||
e94142a6 | 1267 | while (ftrace_new_addrs) { |
3d083395 | 1268 | |
08f5ac90 SR |
1269 | /* If something went wrong, bail without enabling anything */ |
1270 | if (unlikely(ftrace_disabled)) | |
1271 | return -1; | |
f22f9a89 | 1272 | |
e94142a6 | 1273 | p = ftrace_new_addrs; |
ee000b7f | 1274 | ftrace_new_addrs = p->newlist; |
e94142a6 | 1275 | p->flags = 0L; |
f22f9a89 | 1276 | |
5cb084bb | 1277 | /* |
25985edc | 1278 | * Do the initial record conversion from mcount jump |
5cb084bb JO |
1279 | * to the NOP instructions. |
1280 | */ | |
1281 | if (!ftrace_code_disable(mod, p)) { | |
08f5ac90 | 1282 | ftrace_free_rec(p); |
5cb084bb JO |
1283 | continue; |
1284 | } | |
1285 | ||
1286 | p->flags |= FTRACE_FL_CONVERTED; | |
1287 | ftrace_update_cnt++; | |
1288 | ||
1289 | /* | |
1290 | * If the tracing is enabled, go ahead and enable the record. | |
1291 | * | |
1292 | * The reason not to enable the record immediatelly is the | |
1293 | * inherent check of ftrace_make_nop/ftrace_make_call for | |
1294 | * correct previous instructions. Making first the NOP | |
1295 | * conversion puts the module to the correct state, thus | |
1296 | * passing the ftrace_make_call check. | |
1297 | */ | |
1298 | if (ftrace_start_up) { | |
1299 | int failed = __ftrace_replace_code(p, 1); | |
1300 | if (failed) { | |
1301 | ftrace_bug(failed, p->ip); | |
1302 | ftrace_free_rec(p); | |
1303 | } | |
1304 | } | |
3d083395 SR |
1305 | } |
1306 | ||
750ed1a4 | 1307 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1308 | ftrace_update_time = stop - start; |
1309 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
1310 | ||
16444a8a ACM |
1311 | return 0; |
1312 | } | |
1313 | ||
68bf21aa | 1314 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
1315 | { |
1316 | struct ftrace_page *pg; | |
1317 | int cnt; | |
1318 | int i; | |
3c1720f0 SR |
1319 | |
1320 | /* allocate a few pages */ | |
1321 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
1322 | if (!ftrace_pages_start) | |
1323 | return -1; | |
1324 | ||
1325 | /* | |
1326 | * Allocate a few more pages. | |
1327 | * | |
1328 | * TODO: have some parser search vmlinux before | |
1329 | * final linking to find all calls to ftrace. | |
1330 | * Then we can: | |
1331 | * a) know how many pages to allocate. | |
1332 | * and/or | |
1333 | * b) set up the table then. | |
1334 | * | |
1335 | * The dynamic code is still necessary for | |
1336 | * modules. | |
1337 | */ | |
1338 | ||
1339 | pg = ftrace_pages = ftrace_pages_start; | |
1340 | ||
68bf21aa | 1341 | cnt = num_to_init / ENTRIES_PER_PAGE; |
08f5ac90 | 1342 | pr_info("ftrace: allocating %ld entries in %d pages\n", |
5821e1b7 | 1343 | num_to_init, cnt + 1); |
3c1720f0 SR |
1344 | |
1345 | for (i = 0; i < cnt; i++) { | |
1346 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
1347 | ||
1348 | /* If we fail, we'll try later anyway */ | |
1349 | if (!pg->next) | |
1350 | break; | |
1351 | ||
1352 | pg = pg->next; | |
1353 | } | |
1354 | ||
1355 | return 0; | |
1356 | } | |
1357 | ||
5072c59f SR |
1358 | enum { |
1359 | FTRACE_ITER_FILTER = (1 << 0), | |
689fd8b6 | 1360 | FTRACE_ITER_NOTRACE = (1 << 1), |
3499e461 SR |
1361 | FTRACE_ITER_PRINTALL = (1 << 2), |
1362 | FTRACE_ITER_HASH = (1 << 3), | |
5072c59f SR |
1363 | }; |
1364 | ||
1365 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
1366 | ||
1367 | struct ftrace_iterator { | |
98c4fd04 | 1368 | loff_t pos; |
4aeb6967 SR |
1369 | loff_t func_pos; |
1370 | struct ftrace_page *pg; | |
1371 | struct dyn_ftrace *func; | |
1372 | struct ftrace_func_probe *probe; | |
1373 | struct trace_parser parser; | |
1374 | int hidx; | |
1375 | int idx; | |
1376 | unsigned flags; | |
5072c59f SR |
1377 | }; |
1378 | ||
8fc0c701 | 1379 | static void * |
4aeb6967 | 1380 | t_hash_next(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
1381 | { |
1382 | struct ftrace_iterator *iter = m->private; | |
4aeb6967 | 1383 | struct hlist_node *hnd = NULL; |
8fc0c701 SR |
1384 | struct hlist_head *hhd; |
1385 | ||
8fc0c701 | 1386 | (*pos)++; |
98c4fd04 | 1387 | iter->pos = *pos; |
8fc0c701 | 1388 | |
4aeb6967 SR |
1389 | if (iter->probe) |
1390 | hnd = &iter->probe->node; | |
8fc0c701 SR |
1391 | retry: |
1392 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
1393 | return NULL; | |
1394 | ||
1395 | hhd = &ftrace_func_hash[iter->hidx]; | |
1396 | ||
1397 | if (hlist_empty(hhd)) { | |
1398 | iter->hidx++; | |
1399 | hnd = NULL; | |
1400 | goto retry; | |
1401 | } | |
1402 | ||
1403 | if (!hnd) | |
1404 | hnd = hhd->first; | |
1405 | else { | |
1406 | hnd = hnd->next; | |
1407 | if (!hnd) { | |
1408 | iter->hidx++; | |
1409 | goto retry; | |
1410 | } | |
1411 | } | |
1412 | ||
4aeb6967 SR |
1413 | if (WARN_ON_ONCE(!hnd)) |
1414 | return NULL; | |
1415 | ||
1416 | iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node); | |
1417 | ||
1418 | return iter; | |
8fc0c701 SR |
1419 | } |
1420 | ||
1421 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
1422 | { | |
1423 | struct ftrace_iterator *iter = m->private; | |
1424 | void *p = NULL; | |
d82d6244 LZ |
1425 | loff_t l; |
1426 | ||
2bccfffd SR |
1427 | if (iter->func_pos > *pos) |
1428 | return NULL; | |
8fc0c701 | 1429 | |
d82d6244 | 1430 | iter->hidx = 0; |
2bccfffd | 1431 | for (l = 0; l <= (*pos - iter->func_pos); ) { |
4aeb6967 | 1432 | p = t_hash_next(m, &l); |
d82d6244 LZ |
1433 | if (!p) |
1434 | break; | |
1435 | } | |
4aeb6967 SR |
1436 | if (!p) |
1437 | return NULL; | |
1438 | ||
98c4fd04 SR |
1439 | /* Only set this if we have an item */ |
1440 | iter->flags |= FTRACE_ITER_HASH; | |
1441 | ||
4aeb6967 | 1442 | return iter; |
8fc0c701 SR |
1443 | } |
1444 | ||
4aeb6967 SR |
1445 | static int |
1446 | t_hash_show(struct seq_file *m, struct ftrace_iterator *iter) | |
8fc0c701 | 1447 | { |
b6887d79 | 1448 | struct ftrace_func_probe *rec; |
8fc0c701 | 1449 | |
4aeb6967 SR |
1450 | rec = iter->probe; |
1451 | if (WARN_ON_ONCE(!rec)) | |
1452 | return -EIO; | |
8fc0c701 | 1453 | |
809dcf29 SR |
1454 | if (rec->ops->print) |
1455 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
1456 | ||
b375a11a | 1457 | seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func); |
8fc0c701 SR |
1458 | |
1459 | if (rec->data) | |
1460 | seq_printf(m, ":%p", rec->data); | |
1461 | seq_putc(m, '\n'); | |
1462 | ||
1463 | return 0; | |
1464 | } | |
1465 | ||
e309b41d | 1466 | static void * |
5072c59f SR |
1467 | t_next(struct seq_file *m, void *v, loff_t *pos) |
1468 | { | |
1469 | struct ftrace_iterator *iter = m->private; | |
1470 | struct dyn_ftrace *rec = NULL; | |
1471 | ||
45a4a237 SR |
1472 | if (unlikely(ftrace_disabled)) |
1473 | return NULL; | |
1474 | ||
8fc0c701 | 1475 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 1476 | return t_hash_next(m, pos); |
8fc0c701 | 1477 | |
5072c59f | 1478 | (*pos)++; |
1106b699 | 1479 | iter->pos = iter->func_pos = *pos; |
5072c59f | 1480 | |
0c75a3ed | 1481 | if (iter->flags & FTRACE_ITER_PRINTALL) |
57c072c7 | 1482 | return t_hash_start(m, pos); |
0c75a3ed | 1483 | |
5072c59f SR |
1484 | retry: |
1485 | if (iter->idx >= iter->pg->index) { | |
1486 | if (iter->pg->next) { | |
1487 | iter->pg = iter->pg->next; | |
1488 | iter->idx = 0; | |
1489 | goto retry; | |
1490 | } | |
1491 | } else { | |
1492 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
1493 | if ((rec->flags & FTRACE_FL_FREE) || |
1494 | ||
0183fb1c SR |
1495 | ((iter->flags & FTRACE_ITER_FILTER) && |
1496 | !(rec->flags & FTRACE_FL_FILTER)) || | |
1497 | ||
41c52c0d SR |
1498 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
1499 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
1500 | rec = NULL; |
1501 | goto retry; | |
1502 | } | |
1503 | } | |
1504 | ||
4aeb6967 | 1505 | if (!rec) |
57c072c7 | 1506 | return t_hash_start(m, pos); |
4aeb6967 SR |
1507 | |
1508 | iter->func = rec; | |
1509 | ||
1510 | return iter; | |
5072c59f SR |
1511 | } |
1512 | ||
98c4fd04 SR |
1513 | static void reset_iter_read(struct ftrace_iterator *iter) |
1514 | { | |
1515 | iter->pos = 0; | |
1516 | iter->func_pos = 0; | |
1517 | iter->flags &= ~(FTRACE_ITER_PRINTALL & FTRACE_ITER_HASH); | |
5072c59f SR |
1518 | } |
1519 | ||
1520 | static void *t_start(struct seq_file *m, loff_t *pos) | |
1521 | { | |
1522 | struct ftrace_iterator *iter = m->private; | |
1523 | void *p = NULL; | |
694ce0a5 | 1524 | loff_t l; |
5072c59f | 1525 | |
8fc0c701 | 1526 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
1527 | |
1528 | if (unlikely(ftrace_disabled)) | |
1529 | return NULL; | |
1530 | ||
98c4fd04 SR |
1531 | /* |
1532 | * If an lseek was done, then reset and start from beginning. | |
1533 | */ | |
1534 | if (*pos < iter->pos) | |
1535 | reset_iter_read(iter); | |
1536 | ||
0c75a3ed SR |
1537 | /* |
1538 | * For set_ftrace_filter reading, if we have the filter | |
1539 | * off, we can short cut and just print out that all | |
1540 | * functions are enabled. | |
1541 | */ | |
1542 | if (iter->flags & FTRACE_ITER_FILTER && !ftrace_filtered) { | |
1543 | if (*pos > 0) | |
8fc0c701 | 1544 | return t_hash_start(m, pos); |
0c75a3ed | 1545 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 CW |
1546 | /* reset in case of seek/pread */ |
1547 | iter->flags &= ~FTRACE_ITER_HASH; | |
0c75a3ed SR |
1548 | return iter; |
1549 | } | |
1550 | ||
8fc0c701 SR |
1551 | if (iter->flags & FTRACE_ITER_HASH) |
1552 | return t_hash_start(m, pos); | |
1553 | ||
98c4fd04 SR |
1554 | /* |
1555 | * Unfortunately, we need to restart at ftrace_pages_start | |
1556 | * every time we let go of the ftrace_mutex. This is because | |
1557 | * those pointers can change without the lock. | |
1558 | */ | |
694ce0a5 LZ |
1559 | iter->pg = ftrace_pages_start; |
1560 | iter->idx = 0; | |
1561 | for (l = 0; l <= *pos; ) { | |
1562 | p = t_next(m, p, &l); | |
1563 | if (!p) | |
1564 | break; | |
50cdaf08 | 1565 | } |
5821e1b7 | 1566 | |
4aeb6967 SR |
1567 | if (!p) { |
1568 | if (iter->flags & FTRACE_ITER_FILTER) | |
1569 | return t_hash_start(m, pos); | |
8fc0c701 | 1570 | |
4aeb6967 SR |
1571 | return NULL; |
1572 | } | |
1573 | ||
1574 | return iter; | |
5072c59f SR |
1575 | } |
1576 | ||
1577 | static void t_stop(struct seq_file *m, void *p) | |
1578 | { | |
8fc0c701 | 1579 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1580 | } |
1581 | ||
1582 | static int t_show(struct seq_file *m, void *v) | |
1583 | { | |
0c75a3ed | 1584 | struct ftrace_iterator *iter = m->private; |
4aeb6967 | 1585 | struct dyn_ftrace *rec; |
5072c59f | 1586 | |
8fc0c701 | 1587 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 1588 | return t_hash_show(m, iter); |
8fc0c701 | 1589 | |
0c75a3ed SR |
1590 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
1591 | seq_printf(m, "#### all functions enabled ####\n"); | |
1592 | return 0; | |
1593 | } | |
1594 | ||
4aeb6967 SR |
1595 | rec = iter->func; |
1596 | ||
5072c59f SR |
1597 | if (!rec) |
1598 | return 0; | |
1599 | ||
b375a11a | 1600 | seq_printf(m, "%ps\n", (void *)rec->ip); |
5072c59f SR |
1601 | |
1602 | return 0; | |
1603 | } | |
1604 | ||
88e9d34c | 1605 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
1606 | .start = t_start, |
1607 | .next = t_next, | |
1608 | .stop = t_stop, | |
1609 | .show = t_show, | |
1610 | }; | |
1611 | ||
e309b41d | 1612 | static int |
5072c59f SR |
1613 | ftrace_avail_open(struct inode *inode, struct file *file) |
1614 | { | |
1615 | struct ftrace_iterator *iter; | |
1616 | int ret; | |
1617 | ||
4eebcc81 SR |
1618 | if (unlikely(ftrace_disabled)) |
1619 | return -ENODEV; | |
1620 | ||
5072c59f SR |
1621 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1622 | if (!iter) | |
1623 | return -ENOMEM; | |
1624 | ||
1625 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
1626 | |
1627 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1628 | if (!ret) { | |
1629 | struct seq_file *m = file->private_data; | |
4bf39a94 | 1630 | |
5072c59f | 1631 | m->private = iter; |
4bf39a94 | 1632 | } else { |
5072c59f | 1633 | kfree(iter); |
4bf39a94 | 1634 | } |
5072c59f SR |
1635 | |
1636 | return ret; | |
1637 | } | |
1638 | ||
41c52c0d | 1639 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
1640 | { |
1641 | struct ftrace_page *pg; | |
1642 | struct dyn_ftrace *rec; | |
41c52c0d | 1643 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f | 1644 | |
52baf119 | 1645 | mutex_lock(&ftrace_lock); |
41c52c0d SR |
1646 | if (enable) |
1647 | ftrace_filtered = 0; | |
265c831c | 1648 | do_for_each_ftrace_rec(pg, rec) { |
265c831c SR |
1649 | rec->flags &= ~type; |
1650 | } while_for_each_ftrace_rec(); | |
52baf119 | 1651 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1652 | } |
1653 | ||
e309b41d | 1654 | static int |
41c52c0d | 1655 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1656 | { |
1657 | struct ftrace_iterator *iter; | |
1658 | int ret = 0; | |
1659 | ||
4eebcc81 SR |
1660 | if (unlikely(ftrace_disabled)) |
1661 | return -ENODEV; | |
1662 | ||
5072c59f SR |
1663 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1664 | if (!iter) | |
1665 | return -ENOMEM; | |
1666 | ||
689fd8b6 | 1667 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { |
1668 | kfree(iter); | |
1669 | return -ENOMEM; | |
1670 | } | |
1671 | ||
41c52c0d | 1672 | mutex_lock(&ftrace_regex_lock); |
5072c59f | 1673 | if ((file->f_mode & FMODE_WRITE) && |
8650ae32 | 1674 | (file->f_flags & O_TRUNC)) |
41c52c0d | 1675 | ftrace_filter_reset(enable); |
5072c59f SR |
1676 | |
1677 | if (file->f_mode & FMODE_READ) { | |
1678 | iter->pg = ftrace_pages_start; | |
41c52c0d SR |
1679 | iter->flags = enable ? FTRACE_ITER_FILTER : |
1680 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
1681 | |
1682 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1683 | if (!ret) { | |
1684 | struct seq_file *m = file->private_data; | |
1685 | m->private = iter; | |
79fe249c LZ |
1686 | } else { |
1687 | trace_parser_put(&iter->parser); | |
5072c59f | 1688 | kfree(iter); |
79fe249c | 1689 | } |
5072c59f SR |
1690 | } else |
1691 | file->private_data = iter; | |
41c52c0d | 1692 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1693 | |
1694 | return ret; | |
1695 | } | |
1696 | ||
41c52c0d SR |
1697 | static int |
1698 | ftrace_filter_open(struct inode *inode, struct file *file) | |
1699 | { | |
1700 | return ftrace_regex_open(inode, file, 1); | |
1701 | } | |
1702 | ||
1703 | static int | |
1704 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
1705 | { | |
1706 | return ftrace_regex_open(inode, file, 0); | |
1707 | } | |
1708 | ||
e309b41d | 1709 | static loff_t |
41c52c0d | 1710 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
1711 | { |
1712 | loff_t ret; | |
1713 | ||
1714 | if (file->f_mode & FMODE_READ) | |
1715 | ret = seq_lseek(file, offset, origin); | |
1716 | else | |
1717 | file->f_pos = ret = 1; | |
1718 | ||
1719 | return ret; | |
1720 | } | |
1721 | ||
64e7c440 | 1722 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 1723 | { |
9f4801e3 | 1724 | int matched = 0; |
751e9983 | 1725 | int slen; |
9f4801e3 | 1726 | |
9f4801e3 SR |
1727 | switch (type) { |
1728 | case MATCH_FULL: | |
1729 | if (strcmp(str, regex) == 0) | |
1730 | matched = 1; | |
1731 | break; | |
1732 | case MATCH_FRONT_ONLY: | |
1733 | if (strncmp(str, regex, len) == 0) | |
1734 | matched = 1; | |
1735 | break; | |
1736 | case MATCH_MIDDLE_ONLY: | |
1737 | if (strstr(str, regex)) | |
1738 | matched = 1; | |
1739 | break; | |
1740 | case MATCH_END_ONLY: | |
751e9983 LZ |
1741 | slen = strlen(str); |
1742 | if (slen >= len && memcmp(str + slen - len, regex, len) == 0) | |
9f4801e3 SR |
1743 | matched = 1; |
1744 | break; | |
1745 | } | |
1746 | ||
1747 | return matched; | |
1748 | } | |
1749 | ||
64e7c440 SR |
1750 | static int |
1751 | ftrace_match_record(struct dyn_ftrace *rec, char *regex, int len, int type) | |
1752 | { | |
1753 | char str[KSYM_SYMBOL_LEN]; | |
1754 | ||
1755 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1756 | return ftrace_match(str, regex, len, type); | |
1757 | } | |
1758 | ||
311d16da | 1759 | static int ftrace_match_records(char *buff, int len, int enable) |
9f4801e3 | 1760 | { |
6a24a244 | 1761 | unsigned int search_len; |
9f4801e3 SR |
1762 | struct ftrace_page *pg; |
1763 | struct dyn_ftrace *rec; | |
6a24a244 SR |
1764 | unsigned long flag; |
1765 | char *search; | |
9f4801e3 | 1766 | int type; |
9f4801e3 | 1767 | int not; |
311d16da | 1768 | int found = 0; |
9f4801e3 | 1769 | |
6a24a244 | 1770 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
3f6fe06d | 1771 | type = filter_parse_regex(buff, len, &search, ¬); |
9f4801e3 SR |
1772 | |
1773 | search_len = strlen(search); | |
1774 | ||
52baf119 | 1775 | mutex_lock(&ftrace_lock); |
265c831c | 1776 | do_for_each_ftrace_rec(pg, rec) { |
265c831c | 1777 | |
9f4801e3 | 1778 | if (ftrace_match_record(rec, search, search_len, type)) { |
265c831c SR |
1779 | if (not) |
1780 | rec->flags &= ~flag; | |
1781 | else | |
1782 | rec->flags |= flag; | |
311d16da | 1783 | found = 1; |
265c831c | 1784 | } |
e68746a2 SR |
1785 | /* |
1786 | * Only enable filtering if we have a function that | |
1787 | * is filtered on. | |
1788 | */ | |
1789 | if (enable && (rec->flags & FTRACE_FL_FILTER)) | |
1790 | ftrace_filtered = 1; | |
265c831c | 1791 | } while_for_each_ftrace_rec(); |
52baf119 | 1792 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
1793 | |
1794 | return found; | |
5072c59f SR |
1795 | } |
1796 | ||
64e7c440 SR |
1797 | static int |
1798 | ftrace_match_module_record(struct dyn_ftrace *rec, char *mod, | |
1799 | char *regex, int len, int type) | |
1800 | { | |
1801 | char str[KSYM_SYMBOL_LEN]; | |
1802 | char *modname; | |
1803 | ||
1804 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
1805 | ||
1806 | if (!modname || strcmp(modname, mod)) | |
1807 | return 0; | |
1808 | ||
1809 | /* blank search means to match all funcs in the mod */ | |
1810 | if (len) | |
1811 | return ftrace_match(str, regex, len, type); | |
1812 | else | |
1813 | return 1; | |
1814 | } | |
1815 | ||
311d16da | 1816 | static int ftrace_match_module_records(char *buff, char *mod, int enable) |
64e7c440 | 1817 | { |
6a24a244 | 1818 | unsigned search_len = 0; |
64e7c440 SR |
1819 | struct ftrace_page *pg; |
1820 | struct dyn_ftrace *rec; | |
1821 | int type = MATCH_FULL; | |
6a24a244 SR |
1822 | char *search = buff; |
1823 | unsigned long flag; | |
64e7c440 | 1824 | int not = 0; |
311d16da | 1825 | int found = 0; |
64e7c440 | 1826 | |
6a24a244 SR |
1827 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
1828 | ||
64e7c440 SR |
1829 | /* blank or '*' mean the same */ |
1830 | if (strcmp(buff, "*") == 0) | |
1831 | buff[0] = 0; | |
1832 | ||
1833 | /* handle the case of 'dont filter this module' */ | |
1834 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
1835 | buff[0] = 0; | |
1836 | not = 1; | |
1837 | } | |
1838 | ||
1839 | if (strlen(buff)) { | |
3f6fe06d | 1840 | type = filter_parse_regex(buff, strlen(buff), &search, ¬); |
64e7c440 SR |
1841 | search_len = strlen(search); |
1842 | } | |
1843 | ||
52baf119 | 1844 | mutex_lock(&ftrace_lock); |
64e7c440 | 1845 | |
45a4a237 SR |
1846 | if (unlikely(ftrace_disabled)) |
1847 | goto out_unlock; | |
1848 | ||
1849 | do_for_each_ftrace_rec(pg, rec) { | |
64e7c440 SR |
1850 | |
1851 | if (ftrace_match_module_record(rec, mod, | |
1852 | search, search_len, type)) { | |
1853 | if (not) | |
1854 | rec->flags &= ~flag; | |
1855 | else | |
1856 | rec->flags |= flag; | |
311d16da | 1857 | found = 1; |
64e7c440 | 1858 | } |
e68746a2 SR |
1859 | if (enable && (rec->flags & FTRACE_FL_FILTER)) |
1860 | ftrace_filtered = 1; | |
64e7c440 SR |
1861 | |
1862 | } while_for_each_ftrace_rec(); | |
45a4a237 | 1863 | out_unlock: |
52baf119 | 1864 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
1865 | |
1866 | return found; | |
64e7c440 SR |
1867 | } |
1868 | ||
f6180773 SR |
1869 | /* |
1870 | * We register the module command as a template to show others how | |
1871 | * to register the a command as well. | |
1872 | */ | |
1873 | ||
1874 | static int | |
1875 | ftrace_mod_callback(char *func, char *cmd, char *param, int enable) | |
1876 | { | |
1877 | char *mod; | |
1878 | ||
1879 | /* | |
1880 | * cmd == 'mod' because we only registered this func | |
1881 | * for the 'mod' ftrace_func_command. | |
1882 | * But if you register one func with multiple commands, | |
1883 | * you can tell which command was used by the cmd | |
1884 | * parameter. | |
1885 | */ | |
1886 | ||
1887 | /* we must have a module name */ | |
1888 | if (!param) | |
1889 | return -EINVAL; | |
1890 | ||
1891 | mod = strsep(¶m, ":"); | |
1892 | if (!strlen(mod)) | |
1893 | return -EINVAL; | |
1894 | ||
311d16da LZ |
1895 | if (ftrace_match_module_records(func, mod, enable)) |
1896 | return 0; | |
1897 | return -EINVAL; | |
f6180773 SR |
1898 | } |
1899 | ||
1900 | static struct ftrace_func_command ftrace_mod_cmd = { | |
1901 | .name = "mod", | |
1902 | .func = ftrace_mod_callback, | |
1903 | }; | |
1904 | ||
1905 | static int __init ftrace_mod_cmd_init(void) | |
1906 | { | |
1907 | return register_ftrace_command(&ftrace_mod_cmd); | |
1908 | } | |
1909 | device_initcall(ftrace_mod_cmd_init); | |
1910 | ||
59df055f | 1911 | static void |
b6887d79 | 1912 | function_trace_probe_call(unsigned long ip, unsigned long parent_ip) |
59df055f | 1913 | { |
b6887d79 | 1914 | struct ftrace_func_probe *entry; |
59df055f SR |
1915 | struct hlist_head *hhd; |
1916 | struct hlist_node *n; | |
1917 | unsigned long key; | |
59df055f SR |
1918 | |
1919 | key = hash_long(ip, FTRACE_HASH_BITS); | |
1920 | ||
1921 | hhd = &ftrace_func_hash[key]; | |
1922 | ||
1923 | if (hlist_empty(hhd)) | |
1924 | return; | |
1925 | ||
1926 | /* | |
1927 | * Disable preemption for these calls to prevent a RCU grace | |
1928 | * period. This syncs the hash iteration and freeing of items | |
1929 | * on the hash. rcu_read_lock is too dangerous here. | |
1930 | */ | |
5168ae50 | 1931 | preempt_disable_notrace(); |
59df055f SR |
1932 | hlist_for_each_entry_rcu(entry, n, hhd, node) { |
1933 | if (entry->ip == ip) | |
1934 | entry->ops->func(ip, parent_ip, &entry->data); | |
1935 | } | |
5168ae50 | 1936 | preempt_enable_notrace(); |
59df055f SR |
1937 | } |
1938 | ||
b6887d79 | 1939 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 1940 | { |
fb9fb015 | 1941 | .func = function_trace_probe_call, |
59df055f SR |
1942 | }; |
1943 | ||
b6887d79 | 1944 | static int ftrace_probe_registered; |
59df055f | 1945 | |
b6887d79 | 1946 | static void __enable_ftrace_function_probe(void) |
59df055f SR |
1947 | { |
1948 | int i; | |
1949 | ||
b6887d79 | 1950 | if (ftrace_probe_registered) |
59df055f SR |
1951 | return; |
1952 | ||
1953 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1954 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1955 | if (hhd->first) | |
1956 | break; | |
1957 | } | |
1958 | /* Nothing registered? */ | |
1959 | if (i == FTRACE_FUNC_HASHSIZE) | |
1960 | return; | |
1961 | ||
b6887d79 | 1962 | __register_ftrace_function(&trace_probe_ops); |
59df055f | 1963 | ftrace_startup(0); |
b6887d79 | 1964 | ftrace_probe_registered = 1; |
59df055f SR |
1965 | } |
1966 | ||
b6887d79 | 1967 | static void __disable_ftrace_function_probe(void) |
59df055f SR |
1968 | { |
1969 | int i; | |
1970 | ||
b6887d79 | 1971 | if (!ftrace_probe_registered) |
59df055f SR |
1972 | return; |
1973 | ||
1974 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1975 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1976 | if (hhd->first) | |
1977 | return; | |
1978 | } | |
1979 | ||
1980 | /* no more funcs left */ | |
b6887d79 | 1981 | __unregister_ftrace_function(&trace_probe_ops); |
59df055f | 1982 | ftrace_shutdown(0); |
b6887d79 | 1983 | ftrace_probe_registered = 0; |
59df055f SR |
1984 | } |
1985 | ||
1986 | ||
1987 | static void ftrace_free_entry_rcu(struct rcu_head *rhp) | |
1988 | { | |
b6887d79 SR |
1989 | struct ftrace_func_probe *entry = |
1990 | container_of(rhp, struct ftrace_func_probe, rcu); | |
59df055f SR |
1991 | |
1992 | if (entry->ops->free) | |
1993 | entry->ops->free(&entry->data); | |
1994 | kfree(entry); | |
1995 | } | |
1996 | ||
1997 | ||
1998 | int | |
b6887d79 | 1999 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2000 | void *data) |
2001 | { | |
b6887d79 | 2002 | struct ftrace_func_probe *entry; |
59df055f SR |
2003 | struct ftrace_page *pg; |
2004 | struct dyn_ftrace *rec; | |
59df055f | 2005 | int type, len, not; |
6a24a244 | 2006 | unsigned long key; |
59df055f SR |
2007 | int count = 0; |
2008 | char *search; | |
2009 | ||
3f6fe06d | 2010 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
2011 | len = strlen(search); |
2012 | ||
b6887d79 | 2013 | /* we do not support '!' for function probes */ |
59df055f SR |
2014 | if (WARN_ON(not)) |
2015 | return -EINVAL; | |
2016 | ||
2017 | mutex_lock(&ftrace_lock); | |
59df055f | 2018 | |
45a4a237 SR |
2019 | if (unlikely(ftrace_disabled)) |
2020 | goto out_unlock; | |
2021 | ||
2022 | do_for_each_ftrace_rec(pg, rec) { | |
59df055f SR |
2023 | |
2024 | if (!ftrace_match_record(rec, search, len, type)) | |
2025 | continue; | |
2026 | ||
2027 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
2028 | if (!entry) { | |
b6887d79 | 2029 | /* If we did not process any, then return error */ |
59df055f SR |
2030 | if (!count) |
2031 | count = -ENOMEM; | |
2032 | goto out_unlock; | |
2033 | } | |
2034 | ||
2035 | count++; | |
2036 | ||
2037 | entry->data = data; | |
2038 | ||
2039 | /* | |
2040 | * The caller might want to do something special | |
2041 | * for each function we find. We call the callback | |
2042 | * to give the caller an opportunity to do so. | |
2043 | */ | |
2044 | if (ops->callback) { | |
2045 | if (ops->callback(rec->ip, &entry->data) < 0) { | |
2046 | /* caller does not like this func */ | |
2047 | kfree(entry); | |
2048 | continue; | |
2049 | } | |
2050 | } | |
2051 | ||
2052 | entry->ops = ops; | |
2053 | entry->ip = rec->ip; | |
2054 | ||
2055 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
2056 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
2057 | ||
2058 | } while_for_each_ftrace_rec(); | |
b6887d79 | 2059 | __enable_ftrace_function_probe(); |
59df055f SR |
2060 | |
2061 | out_unlock: | |
2062 | mutex_unlock(&ftrace_lock); | |
2063 | ||
2064 | return count; | |
2065 | } | |
2066 | ||
2067 | enum { | |
b6887d79 SR |
2068 | PROBE_TEST_FUNC = 1, |
2069 | PROBE_TEST_DATA = 2 | |
59df055f SR |
2070 | }; |
2071 | ||
2072 | static void | |
b6887d79 | 2073 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2074 | void *data, int flags) |
2075 | { | |
b6887d79 | 2076 | struct ftrace_func_probe *entry; |
59df055f SR |
2077 | struct hlist_node *n, *tmp; |
2078 | char str[KSYM_SYMBOL_LEN]; | |
2079 | int type = MATCH_FULL; | |
2080 | int i, len = 0; | |
2081 | char *search; | |
2082 | ||
b36461da | 2083 | if (glob && (strcmp(glob, "*") == 0 || !strlen(glob))) |
59df055f | 2084 | glob = NULL; |
b36461da | 2085 | else if (glob) { |
59df055f SR |
2086 | int not; |
2087 | ||
3f6fe06d | 2088 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
2089 | len = strlen(search); |
2090 | ||
b6887d79 | 2091 | /* we do not support '!' for function probes */ |
59df055f SR |
2092 | if (WARN_ON(not)) |
2093 | return; | |
2094 | } | |
2095 | ||
2096 | mutex_lock(&ftrace_lock); | |
2097 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2098 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2099 | ||
2100 | hlist_for_each_entry_safe(entry, n, tmp, hhd, node) { | |
2101 | ||
2102 | /* break up if statements for readability */ | |
b6887d79 | 2103 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
2104 | continue; |
2105 | ||
b6887d79 | 2106 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
2107 | continue; |
2108 | ||
2109 | /* do this last, since it is the most expensive */ | |
2110 | if (glob) { | |
2111 | kallsyms_lookup(entry->ip, NULL, NULL, | |
2112 | NULL, str); | |
2113 | if (!ftrace_match(str, glob, len, type)) | |
2114 | continue; | |
2115 | } | |
2116 | ||
2117 | hlist_del(&entry->node); | |
2118 | call_rcu(&entry->rcu, ftrace_free_entry_rcu); | |
2119 | } | |
2120 | } | |
b6887d79 | 2121 | __disable_ftrace_function_probe(); |
59df055f SR |
2122 | mutex_unlock(&ftrace_lock); |
2123 | } | |
2124 | ||
2125 | void | |
b6887d79 | 2126 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2127 | void *data) |
2128 | { | |
b6887d79 SR |
2129 | __unregister_ftrace_function_probe(glob, ops, data, |
2130 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
2131 | } |
2132 | ||
2133 | void | |
b6887d79 | 2134 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 2135 | { |
b6887d79 | 2136 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
2137 | } |
2138 | ||
b6887d79 | 2139 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 2140 | { |
b6887d79 | 2141 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
2142 | } |
2143 | ||
f6180773 SR |
2144 | static LIST_HEAD(ftrace_commands); |
2145 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
2146 | ||
2147 | int register_ftrace_command(struct ftrace_func_command *cmd) | |
2148 | { | |
2149 | struct ftrace_func_command *p; | |
2150 | int ret = 0; | |
2151 | ||
2152 | mutex_lock(&ftrace_cmd_mutex); | |
2153 | list_for_each_entry(p, &ftrace_commands, list) { | |
2154 | if (strcmp(cmd->name, p->name) == 0) { | |
2155 | ret = -EBUSY; | |
2156 | goto out_unlock; | |
2157 | } | |
2158 | } | |
2159 | list_add(&cmd->list, &ftrace_commands); | |
2160 | out_unlock: | |
2161 | mutex_unlock(&ftrace_cmd_mutex); | |
2162 | ||
2163 | return ret; | |
2164 | } | |
2165 | ||
2166 | int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
2167 | { | |
2168 | struct ftrace_func_command *p, *n; | |
2169 | int ret = -ENODEV; | |
2170 | ||
2171 | mutex_lock(&ftrace_cmd_mutex); | |
2172 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
2173 | if (strcmp(cmd->name, p->name) == 0) { | |
2174 | ret = 0; | |
2175 | list_del_init(&p->list); | |
2176 | goto out_unlock; | |
2177 | } | |
2178 | } | |
2179 | out_unlock: | |
2180 | mutex_unlock(&ftrace_cmd_mutex); | |
2181 | ||
2182 | return ret; | |
2183 | } | |
2184 | ||
64e7c440 SR |
2185 | static int ftrace_process_regex(char *buff, int len, int enable) |
2186 | { | |
f6180773 | 2187 | char *func, *command, *next = buff; |
6a24a244 | 2188 | struct ftrace_func_command *p; |
f6180773 | 2189 | int ret = -EINVAL; |
64e7c440 SR |
2190 | |
2191 | func = strsep(&next, ":"); | |
2192 | ||
2193 | if (!next) { | |
311d16da LZ |
2194 | if (ftrace_match_records(func, len, enable)) |
2195 | return 0; | |
2196 | return ret; | |
64e7c440 SR |
2197 | } |
2198 | ||
f6180773 | 2199 | /* command found */ |
64e7c440 SR |
2200 | |
2201 | command = strsep(&next, ":"); | |
2202 | ||
f6180773 SR |
2203 | mutex_lock(&ftrace_cmd_mutex); |
2204 | list_for_each_entry(p, &ftrace_commands, list) { | |
2205 | if (strcmp(p->name, command) == 0) { | |
2206 | ret = p->func(func, command, next, enable); | |
2207 | goto out_unlock; | |
2208 | } | |
64e7c440 | 2209 | } |
f6180773 SR |
2210 | out_unlock: |
2211 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 2212 | |
f6180773 | 2213 | return ret; |
64e7c440 SR |
2214 | } |
2215 | ||
e309b41d | 2216 | static ssize_t |
41c52c0d SR |
2217 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
2218 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
2219 | { |
2220 | struct ftrace_iterator *iter; | |
689fd8b6 | 2221 | struct trace_parser *parser; |
2222 | ssize_t ret, read; | |
5072c59f | 2223 | |
4ba7978e | 2224 | if (!cnt) |
5072c59f SR |
2225 | return 0; |
2226 | ||
41c52c0d | 2227 | mutex_lock(&ftrace_regex_lock); |
5072c59f | 2228 | |
45a4a237 SR |
2229 | ret = -ENODEV; |
2230 | if (unlikely(ftrace_disabled)) | |
2231 | goto out_unlock; | |
2232 | ||
5072c59f SR |
2233 | if (file->f_mode & FMODE_READ) { |
2234 | struct seq_file *m = file->private_data; | |
2235 | iter = m->private; | |
2236 | } else | |
2237 | iter = file->private_data; | |
2238 | ||
689fd8b6 | 2239 | parser = &iter->parser; |
2240 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 2241 | |
4ba7978e | 2242 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 2243 | !trace_parser_cont(parser)) { |
2244 | ret = ftrace_process_regex(parser->buffer, | |
2245 | parser->idx, enable); | |
313254a9 | 2246 | trace_parser_clear(parser); |
5072c59f | 2247 | if (ret) |
ed146b25 | 2248 | goto out_unlock; |
eda1e328 | 2249 | } |
5072c59f | 2250 | |
5072c59f | 2251 | ret = read; |
ed146b25 | 2252 | out_unlock: |
689fd8b6 | 2253 | mutex_unlock(&ftrace_regex_lock); |
ed146b25 | 2254 | |
5072c59f SR |
2255 | return ret; |
2256 | } | |
2257 | ||
41c52c0d SR |
2258 | static ssize_t |
2259 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
2260 | size_t cnt, loff_t *ppos) | |
2261 | { | |
2262 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
2263 | } | |
2264 | ||
2265 | static ssize_t | |
2266 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
2267 | size_t cnt, loff_t *ppos) | |
2268 | { | |
2269 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
2270 | } | |
2271 | ||
2272 | static void | |
2273 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
2274 | { | |
2275 | if (unlikely(ftrace_disabled)) | |
2276 | return; | |
2277 | ||
2278 | mutex_lock(&ftrace_regex_lock); | |
2279 | if (reset) | |
2280 | ftrace_filter_reset(enable); | |
2281 | if (buf) | |
7f24b31b | 2282 | ftrace_match_records(buf, len, enable); |
41c52c0d SR |
2283 | mutex_unlock(&ftrace_regex_lock); |
2284 | } | |
2285 | ||
77a2b37d SR |
2286 | /** |
2287 | * ftrace_set_filter - set a function to filter on in ftrace | |
2288 | * @buf - the string that holds the function filter text. | |
2289 | * @len - the length of the string. | |
2290 | * @reset - non zero to reset all filters before applying this filter. | |
2291 | * | |
2292 | * Filters denote which functions should be enabled when tracing is enabled. | |
2293 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
2294 | */ | |
e309b41d | 2295 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 2296 | { |
41c52c0d SR |
2297 | ftrace_set_regex(buf, len, reset, 1); |
2298 | } | |
4eebcc81 | 2299 | |
41c52c0d SR |
2300 | /** |
2301 | * ftrace_set_notrace - set a function to not trace in ftrace | |
2302 | * @buf - the string that holds the function notrace text. | |
2303 | * @len - the length of the string. | |
2304 | * @reset - non zero to reset all filters before applying this filter. | |
2305 | * | |
2306 | * Notrace Filters denote which functions should not be enabled when tracing | |
2307 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
2308 | * for tracing. | |
2309 | */ | |
2310 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
2311 | { | |
2312 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
2313 | } |
2314 | ||
2af15d6a SR |
2315 | /* |
2316 | * command line interface to allow users to set filters on boot up. | |
2317 | */ | |
2318 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
2319 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
2320 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
2321 | ||
2322 | static int __init set_ftrace_notrace(char *str) | |
2323 | { | |
2324 | strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); | |
2325 | return 1; | |
2326 | } | |
2327 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
2328 | ||
2329 | static int __init set_ftrace_filter(char *str) | |
2330 | { | |
2331 | strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); | |
2332 | return 1; | |
2333 | } | |
2334 | __setup("ftrace_filter=", set_ftrace_filter); | |
2335 | ||
369bc18f | 2336 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 2337 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
801c29fd SR |
2338 | static int ftrace_set_func(unsigned long *array, int *idx, char *buffer); |
2339 | ||
369bc18f SA |
2340 | static int __init set_graph_function(char *str) |
2341 | { | |
06f43d66 | 2342 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
2343 | return 1; |
2344 | } | |
2345 | __setup("ftrace_graph_filter=", set_graph_function); | |
2346 | ||
2347 | static void __init set_ftrace_early_graph(char *buf) | |
2348 | { | |
2349 | int ret; | |
2350 | char *func; | |
2351 | ||
2352 | while (buf) { | |
2353 | func = strsep(&buf, ","); | |
2354 | /* we allow only one expression at a time */ | |
2355 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, | |
2356 | func); | |
2357 | if (ret) | |
2358 | printk(KERN_DEBUG "ftrace: function %s not " | |
2359 | "traceable\n", func); | |
2360 | } | |
2361 | } | |
2362 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2363 | ||
2af15d6a SR |
2364 | static void __init set_ftrace_early_filter(char *buf, int enable) |
2365 | { | |
2366 | char *func; | |
2367 | ||
2368 | while (buf) { | |
2369 | func = strsep(&buf, ","); | |
2370 | ftrace_set_regex(func, strlen(func), 0, enable); | |
2371 | } | |
2372 | } | |
2373 | ||
2374 | static void __init set_ftrace_early_filters(void) | |
2375 | { | |
2376 | if (ftrace_filter_buf[0]) | |
2377 | set_ftrace_early_filter(ftrace_filter_buf, 1); | |
2378 | if (ftrace_notrace_buf[0]) | |
2379 | set_ftrace_early_filter(ftrace_notrace_buf, 0); | |
369bc18f SA |
2380 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
2381 | if (ftrace_graph_buf[0]) | |
2382 | set_ftrace_early_graph(ftrace_graph_buf); | |
2383 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2af15d6a SR |
2384 | } |
2385 | ||
e309b41d | 2386 | static int |
41c52c0d | 2387 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
2388 | { |
2389 | struct seq_file *m = (struct seq_file *)file->private_data; | |
2390 | struct ftrace_iterator *iter; | |
689fd8b6 | 2391 | struct trace_parser *parser; |
5072c59f | 2392 | |
41c52c0d | 2393 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
2394 | if (file->f_mode & FMODE_READ) { |
2395 | iter = m->private; | |
2396 | ||
2397 | seq_release(inode, file); | |
2398 | } else | |
2399 | iter = file->private_data; | |
2400 | ||
689fd8b6 | 2401 | parser = &iter->parser; |
2402 | if (trace_parser_loaded(parser)) { | |
2403 | parser->buffer[parser->idx] = 0; | |
2404 | ftrace_match_records(parser->buffer, parser->idx, enable); | |
5072c59f SR |
2405 | } |
2406 | ||
e6ea44e9 | 2407 | mutex_lock(&ftrace_lock); |
ee02a2e5 | 2408 | if (ftrace_start_up && ftrace_enabled) |
5072c59f | 2409 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
e6ea44e9 | 2410 | mutex_unlock(&ftrace_lock); |
5072c59f | 2411 | |
689fd8b6 | 2412 | trace_parser_put(parser); |
5072c59f | 2413 | kfree(iter); |
689fd8b6 | 2414 | |
41c52c0d | 2415 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
2416 | return 0; |
2417 | } | |
2418 | ||
41c52c0d SR |
2419 | static int |
2420 | ftrace_filter_release(struct inode *inode, struct file *file) | |
2421 | { | |
2422 | return ftrace_regex_release(inode, file, 1); | |
2423 | } | |
2424 | ||
2425 | static int | |
2426 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
2427 | { | |
2428 | return ftrace_regex_release(inode, file, 0); | |
2429 | } | |
2430 | ||
5e2336a0 | 2431 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
2432 | .open = ftrace_avail_open, |
2433 | .read = seq_read, | |
2434 | .llseek = seq_lseek, | |
3be04b47 | 2435 | .release = seq_release_private, |
5072c59f SR |
2436 | }; |
2437 | ||
5e2336a0 | 2438 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 2439 | .open = ftrace_filter_open, |
850a80cf | 2440 | .read = seq_read, |
5072c59f | 2441 | .write = ftrace_filter_write, |
98c4fd04 | 2442 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
2443 | .release = ftrace_filter_release, |
2444 | }; | |
2445 | ||
5e2336a0 | 2446 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 2447 | .open = ftrace_notrace_open, |
850a80cf | 2448 | .read = seq_read, |
41c52c0d SR |
2449 | .write = ftrace_notrace_write, |
2450 | .llseek = ftrace_regex_lseek, | |
2451 | .release = ftrace_notrace_release, | |
2452 | }; | |
2453 | ||
ea4e2bc4 SR |
2454 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
2455 | ||
2456 | static DEFINE_MUTEX(graph_lock); | |
2457 | ||
2458 | int ftrace_graph_count; | |
c7c6b1fe | 2459 | int ftrace_graph_filter_enabled; |
ea4e2bc4 SR |
2460 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
2461 | ||
2462 | static void * | |
85951842 | 2463 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 2464 | { |
85951842 | 2465 | if (*pos >= ftrace_graph_count) |
ea4e2bc4 | 2466 | return NULL; |
a4ec5e0c | 2467 | return &ftrace_graph_funcs[*pos]; |
85951842 | 2468 | } |
ea4e2bc4 | 2469 | |
85951842 LZ |
2470 | static void * |
2471 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
2472 | { | |
2473 | (*pos)++; | |
2474 | return __g_next(m, pos); | |
ea4e2bc4 SR |
2475 | } |
2476 | ||
2477 | static void *g_start(struct seq_file *m, loff_t *pos) | |
2478 | { | |
ea4e2bc4 SR |
2479 | mutex_lock(&graph_lock); |
2480 | ||
f9349a8f | 2481 | /* Nothing, tell g_show to print all functions are enabled */ |
c7c6b1fe | 2482 | if (!ftrace_graph_filter_enabled && !*pos) |
f9349a8f FW |
2483 | return (void *)1; |
2484 | ||
85951842 | 2485 | return __g_next(m, pos); |
ea4e2bc4 SR |
2486 | } |
2487 | ||
2488 | static void g_stop(struct seq_file *m, void *p) | |
2489 | { | |
2490 | mutex_unlock(&graph_lock); | |
2491 | } | |
2492 | ||
2493 | static int g_show(struct seq_file *m, void *v) | |
2494 | { | |
2495 | unsigned long *ptr = v; | |
ea4e2bc4 SR |
2496 | |
2497 | if (!ptr) | |
2498 | return 0; | |
2499 | ||
f9349a8f FW |
2500 | if (ptr == (unsigned long *)1) { |
2501 | seq_printf(m, "#### all functions enabled ####\n"); | |
2502 | return 0; | |
2503 | } | |
2504 | ||
b375a11a | 2505 | seq_printf(m, "%ps\n", (void *)*ptr); |
ea4e2bc4 SR |
2506 | |
2507 | return 0; | |
2508 | } | |
2509 | ||
88e9d34c | 2510 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
2511 | .start = g_start, |
2512 | .next = g_next, | |
2513 | .stop = g_stop, | |
2514 | .show = g_show, | |
2515 | }; | |
2516 | ||
2517 | static int | |
2518 | ftrace_graph_open(struct inode *inode, struct file *file) | |
2519 | { | |
2520 | int ret = 0; | |
2521 | ||
2522 | if (unlikely(ftrace_disabled)) | |
2523 | return -ENODEV; | |
2524 | ||
2525 | mutex_lock(&graph_lock); | |
2526 | if ((file->f_mode & FMODE_WRITE) && | |
8650ae32 | 2527 | (file->f_flags & O_TRUNC)) { |
c7c6b1fe | 2528 | ftrace_graph_filter_enabled = 0; |
ea4e2bc4 SR |
2529 | ftrace_graph_count = 0; |
2530 | memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); | |
2531 | } | |
a4ec5e0c | 2532 | mutex_unlock(&graph_lock); |
ea4e2bc4 | 2533 | |
a4ec5e0c | 2534 | if (file->f_mode & FMODE_READ) |
ea4e2bc4 | 2535 | ret = seq_open(file, &ftrace_graph_seq_ops); |
ea4e2bc4 SR |
2536 | |
2537 | return ret; | |
2538 | } | |
2539 | ||
87827111 LZ |
2540 | static int |
2541 | ftrace_graph_release(struct inode *inode, struct file *file) | |
2542 | { | |
2543 | if (file->f_mode & FMODE_READ) | |
2544 | seq_release(inode, file); | |
2545 | return 0; | |
2546 | } | |
2547 | ||
ea4e2bc4 | 2548 | static int |
f9349a8f | 2549 | ftrace_set_func(unsigned long *array, int *idx, char *buffer) |
ea4e2bc4 | 2550 | { |
ea4e2bc4 SR |
2551 | struct dyn_ftrace *rec; |
2552 | struct ftrace_page *pg; | |
f9349a8f | 2553 | int search_len; |
c7c6b1fe | 2554 | int fail = 1; |
f9349a8f FW |
2555 | int type, not; |
2556 | char *search; | |
2557 | bool exists; | |
2558 | int i; | |
ea4e2bc4 | 2559 | |
f9349a8f | 2560 | /* decode regex */ |
3f6fe06d | 2561 | type = filter_parse_regex(buffer, strlen(buffer), &search, ¬); |
c7c6b1fe LZ |
2562 | if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS) |
2563 | return -EBUSY; | |
f9349a8f FW |
2564 | |
2565 | search_len = strlen(search); | |
2566 | ||
52baf119 | 2567 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
2568 | |
2569 | if (unlikely(ftrace_disabled)) { | |
2570 | mutex_unlock(&ftrace_lock); | |
2571 | return -ENODEV; | |
2572 | } | |
2573 | ||
265c831c SR |
2574 | do_for_each_ftrace_rec(pg, rec) { |
2575 | ||
45a4a237 | 2576 | if (rec->flags & FTRACE_FL_FREE) |
265c831c SR |
2577 | continue; |
2578 | ||
f9349a8f | 2579 | if (ftrace_match_record(rec, search, search_len, type)) { |
c7c6b1fe | 2580 | /* if it is in the array */ |
f9349a8f | 2581 | exists = false; |
c7c6b1fe | 2582 | for (i = 0; i < *idx; i++) { |
f9349a8f FW |
2583 | if (array[i] == rec->ip) { |
2584 | exists = true; | |
265c831c SR |
2585 | break; |
2586 | } | |
c7c6b1fe LZ |
2587 | } |
2588 | ||
2589 | if (!not) { | |
2590 | fail = 0; | |
2591 | if (!exists) { | |
2592 | array[(*idx)++] = rec->ip; | |
2593 | if (*idx >= FTRACE_GRAPH_MAX_FUNCS) | |
2594 | goto out; | |
2595 | } | |
2596 | } else { | |
2597 | if (exists) { | |
2598 | array[i] = array[--(*idx)]; | |
2599 | array[*idx] = 0; | |
2600 | fail = 0; | |
2601 | } | |
2602 | } | |
ea4e2bc4 | 2603 | } |
265c831c | 2604 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 2605 | out: |
52baf119 | 2606 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 2607 | |
c7c6b1fe LZ |
2608 | if (fail) |
2609 | return -EINVAL; | |
2610 | ||
2611 | ftrace_graph_filter_enabled = 1; | |
2612 | return 0; | |
ea4e2bc4 SR |
2613 | } |
2614 | ||
2615 | static ssize_t | |
2616 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
2617 | size_t cnt, loff_t *ppos) | |
2618 | { | |
689fd8b6 | 2619 | struct trace_parser parser; |
4ba7978e | 2620 | ssize_t read, ret; |
ea4e2bc4 | 2621 | |
c7c6b1fe | 2622 | if (!cnt) |
ea4e2bc4 SR |
2623 | return 0; |
2624 | ||
2625 | mutex_lock(&graph_lock); | |
2626 | ||
689fd8b6 | 2627 | if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) { |
2628 | ret = -ENOMEM; | |
1eb90f13 | 2629 | goto out_unlock; |
ea4e2bc4 SR |
2630 | } |
2631 | ||
689fd8b6 | 2632 | read = trace_get_user(&parser, ubuf, cnt, ppos); |
ea4e2bc4 | 2633 | |
4ba7978e | 2634 | if (read >= 0 && trace_parser_loaded((&parser))) { |
689fd8b6 | 2635 | parser.buffer[parser.idx] = 0; |
2636 | ||
2637 | /* we allow only one expression at a time */ | |
a4ec5e0c | 2638 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, |
689fd8b6 | 2639 | parser.buffer); |
ea4e2bc4 | 2640 | if (ret) |
1eb90f13 | 2641 | goto out_free; |
ea4e2bc4 | 2642 | } |
ea4e2bc4 SR |
2643 | |
2644 | ret = read; | |
1eb90f13 LZ |
2645 | |
2646 | out_free: | |
689fd8b6 | 2647 | trace_parser_put(&parser); |
1eb90f13 | 2648 | out_unlock: |
ea4e2bc4 SR |
2649 | mutex_unlock(&graph_lock); |
2650 | ||
2651 | return ret; | |
2652 | } | |
2653 | ||
2654 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
2655 | .open = ftrace_graph_open, |
2656 | .read = seq_read, | |
2657 | .write = ftrace_graph_write, | |
2658 | .release = ftrace_graph_release, | |
6038f373 | 2659 | .llseek = seq_lseek, |
ea4e2bc4 SR |
2660 | }; |
2661 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2662 | ||
df4fc315 | 2663 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 2664 | { |
5072c59f | 2665 | |
5452af66 FW |
2666 | trace_create_file("available_filter_functions", 0444, |
2667 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 2668 | |
5452af66 FW |
2669 | trace_create_file("set_ftrace_filter", 0644, d_tracer, |
2670 | NULL, &ftrace_filter_fops); | |
41c52c0d | 2671 | |
5452af66 | 2672 | trace_create_file("set_ftrace_notrace", 0644, d_tracer, |
41c52c0d | 2673 | NULL, &ftrace_notrace_fops); |
ad90c0e3 | 2674 | |
ea4e2bc4 | 2675 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 2676 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
2677 | NULL, |
2678 | &ftrace_graph_fops); | |
ea4e2bc4 SR |
2679 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
2680 | ||
5072c59f SR |
2681 | return 0; |
2682 | } | |
2683 | ||
5cb084bb | 2684 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 2685 | unsigned long *start, |
68bf21aa SR |
2686 | unsigned long *end) |
2687 | { | |
2688 | unsigned long *p; | |
2689 | unsigned long addr; | |
68bf21aa | 2690 | |
e6ea44e9 | 2691 | mutex_lock(&ftrace_lock); |
68bf21aa SR |
2692 | p = start; |
2693 | while (p < end) { | |
2694 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
2695 | /* |
2696 | * Some architecture linkers will pad between | |
2697 | * the different mcount_loc sections of different | |
2698 | * object files to satisfy alignments. | |
2699 | * Skip any NULL pointers. | |
2700 | */ | |
2701 | if (!addr) | |
2702 | continue; | |
68bf21aa | 2703 | ftrace_record_ip(addr); |
68bf21aa SR |
2704 | } |
2705 | ||
31e88909 | 2706 | ftrace_update_code(mod); |
e6ea44e9 | 2707 | mutex_unlock(&ftrace_lock); |
68bf21aa SR |
2708 | |
2709 | return 0; | |
2710 | } | |
2711 | ||
93eb677d | 2712 | #ifdef CONFIG_MODULES |
e7247a15 | 2713 | void ftrace_release_mod(struct module *mod) |
93eb677d SR |
2714 | { |
2715 | struct dyn_ftrace *rec; | |
2716 | struct ftrace_page *pg; | |
93eb677d | 2717 | |
45a4a237 SR |
2718 | mutex_lock(&ftrace_lock); |
2719 | ||
e7247a15 | 2720 | if (ftrace_disabled) |
45a4a237 | 2721 | goto out_unlock; |
93eb677d | 2722 | |
93eb677d | 2723 | do_for_each_ftrace_rec(pg, rec) { |
e7247a15 | 2724 | if (within_module_core(rec->ip, mod)) { |
93eb677d SR |
2725 | /* |
2726 | * rec->ip is changed in ftrace_free_rec() | |
2727 | * It should not between s and e if record was freed. | |
2728 | */ | |
2729 | FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE); | |
2730 | ftrace_free_rec(rec); | |
2731 | } | |
2732 | } while_for_each_ftrace_rec(); | |
45a4a237 | 2733 | out_unlock: |
93eb677d SR |
2734 | mutex_unlock(&ftrace_lock); |
2735 | } | |
2736 | ||
2737 | static void ftrace_init_module(struct module *mod, | |
2738 | unsigned long *start, unsigned long *end) | |
90d595fe | 2739 | { |
00fd61ae | 2740 | if (ftrace_disabled || start == end) |
fed1939c | 2741 | return; |
5cb084bb | 2742 | ftrace_process_locs(mod, start, end); |
90d595fe SR |
2743 | } |
2744 | ||
93eb677d SR |
2745 | static int ftrace_module_notify(struct notifier_block *self, |
2746 | unsigned long val, void *data) | |
2747 | { | |
2748 | struct module *mod = data; | |
2749 | ||
2750 | switch (val) { | |
2751 | case MODULE_STATE_COMING: | |
2752 | ftrace_init_module(mod, mod->ftrace_callsites, | |
2753 | mod->ftrace_callsites + | |
2754 | mod->num_ftrace_callsites); | |
2755 | break; | |
2756 | case MODULE_STATE_GOING: | |
e7247a15 | 2757 | ftrace_release_mod(mod); |
93eb677d SR |
2758 | break; |
2759 | } | |
2760 | ||
2761 | return 0; | |
2762 | } | |
2763 | #else | |
2764 | static int ftrace_module_notify(struct notifier_block *self, | |
2765 | unsigned long val, void *data) | |
2766 | { | |
2767 | return 0; | |
2768 | } | |
2769 | #endif /* CONFIG_MODULES */ | |
2770 | ||
2771 | struct notifier_block ftrace_module_nb = { | |
2772 | .notifier_call = ftrace_module_notify, | |
2773 | .priority = 0, | |
2774 | }; | |
2775 | ||
68bf21aa SR |
2776 | extern unsigned long __start_mcount_loc[]; |
2777 | extern unsigned long __stop_mcount_loc[]; | |
2778 | ||
2779 | void __init ftrace_init(void) | |
2780 | { | |
2781 | unsigned long count, addr, flags; | |
2782 | int ret; | |
2783 | ||
2784 | /* Keep the ftrace pointer to the stub */ | |
2785 | addr = (unsigned long)ftrace_stub; | |
2786 | ||
2787 | local_irq_save(flags); | |
2788 | ftrace_dyn_arch_init(&addr); | |
2789 | local_irq_restore(flags); | |
2790 | ||
2791 | /* ftrace_dyn_arch_init places the return code in addr */ | |
2792 | if (addr) | |
2793 | goto failed; | |
2794 | ||
2795 | count = __stop_mcount_loc - __start_mcount_loc; | |
2796 | ||
2797 | ret = ftrace_dyn_table_alloc(count); | |
2798 | if (ret) | |
2799 | goto failed; | |
2800 | ||
2801 | last_ftrace_enabled = ftrace_enabled = 1; | |
2802 | ||
5cb084bb | 2803 | ret = ftrace_process_locs(NULL, |
31e88909 | 2804 | __start_mcount_loc, |
68bf21aa SR |
2805 | __stop_mcount_loc); |
2806 | ||
93eb677d | 2807 | ret = register_module_notifier(&ftrace_module_nb); |
24ed0c4b | 2808 | if (ret) |
93eb677d SR |
2809 | pr_warning("Failed to register trace ftrace module notifier\n"); |
2810 | ||
2af15d6a SR |
2811 | set_ftrace_early_filters(); |
2812 | ||
68bf21aa SR |
2813 | return; |
2814 | failed: | |
2815 | ftrace_disabled = 1; | |
2816 | } | |
68bf21aa | 2817 | |
3d083395 | 2818 | #else |
0b6e4d56 FW |
2819 | |
2820 | static int __init ftrace_nodyn_init(void) | |
2821 | { | |
2822 | ftrace_enabled = 1; | |
2823 | return 0; | |
2824 | } | |
2825 | device_initcall(ftrace_nodyn_init); | |
2826 | ||
df4fc315 SR |
2827 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
2828 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 SR |
2829 | /* Keep as macros so we do not need to define the commands */ |
2830 | # define ftrace_startup(command) do { } while (0) | |
2831 | # define ftrace_shutdown(command) do { } while (0) | |
c7aafc54 IM |
2832 | # define ftrace_startup_sysctl() do { } while (0) |
2833 | # define ftrace_shutdown_sysctl() do { } while (0) | |
3d083395 SR |
2834 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
2835 | ||
e32d8956 | 2836 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
2837 | { |
2838 | struct task_struct *p; | |
e32d8956 | 2839 | int cpu; |
978f3a45 | 2840 | |
e32d8956 SR |
2841 | get_online_cpus(); |
2842 | for_each_online_cpu(cpu) { | |
2843 | p = idle_task(cpu); | |
978f3a45 | 2844 | clear_tsk_trace_trace(p); |
e32d8956 SR |
2845 | } |
2846 | put_online_cpus(); | |
2847 | } | |
978f3a45 | 2848 | |
e32d8956 SR |
2849 | static void set_ftrace_swapper(void) |
2850 | { | |
2851 | struct task_struct *p; | |
2852 | int cpu; | |
2853 | ||
2854 | get_online_cpus(); | |
2855 | for_each_online_cpu(cpu) { | |
2856 | p = idle_task(cpu); | |
2857 | set_tsk_trace_trace(p); | |
2858 | } | |
2859 | put_online_cpus(); | |
978f3a45 SR |
2860 | } |
2861 | ||
e32d8956 SR |
2862 | static void clear_ftrace_pid(struct pid *pid) |
2863 | { | |
2864 | struct task_struct *p; | |
2865 | ||
229c4ef8 | 2866 | rcu_read_lock(); |
e32d8956 SR |
2867 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2868 | clear_tsk_trace_trace(p); | |
2869 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
2870 | rcu_read_unlock(); |
2871 | ||
e32d8956 SR |
2872 | put_pid(pid); |
2873 | } | |
2874 | ||
2875 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
2876 | { |
2877 | struct task_struct *p; | |
2878 | ||
229c4ef8 | 2879 | rcu_read_lock(); |
978f3a45 SR |
2880 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2881 | set_tsk_trace_trace(p); | |
2882 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 2883 | rcu_read_unlock(); |
978f3a45 SR |
2884 | } |
2885 | ||
756d17ee | 2886 | static void clear_ftrace_pid_task(struct pid *pid) |
e32d8956 | 2887 | { |
756d17ee | 2888 | if (pid == ftrace_swapper_pid) |
e32d8956 SR |
2889 | clear_ftrace_swapper(); |
2890 | else | |
756d17ee | 2891 | clear_ftrace_pid(pid); |
e32d8956 SR |
2892 | } |
2893 | ||
2894 | static void set_ftrace_pid_task(struct pid *pid) | |
2895 | { | |
2896 | if (pid == ftrace_swapper_pid) | |
2897 | set_ftrace_swapper(); | |
2898 | else | |
2899 | set_ftrace_pid(pid); | |
2900 | } | |
2901 | ||
756d17ee | 2902 | static int ftrace_pid_add(int p) |
df4fc315 | 2903 | { |
978f3a45 | 2904 | struct pid *pid; |
756d17ee | 2905 | struct ftrace_pid *fpid; |
2906 | int ret = -EINVAL; | |
df4fc315 | 2907 | |
756d17ee | 2908 | mutex_lock(&ftrace_lock); |
df4fc315 | 2909 | |
756d17ee | 2910 | if (!p) |
2911 | pid = ftrace_swapper_pid; | |
2912 | else | |
2913 | pid = find_get_pid(p); | |
df4fc315 | 2914 | |
756d17ee | 2915 | if (!pid) |
2916 | goto out; | |
df4fc315 | 2917 | |
756d17ee | 2918 | ret = 0; |
df4fc315 | 2919 | |
756d17ee | 2920 | list_for_each_entry(fpid, &ftrace_pids, list) |
2921 | if (fpid->pid == pid) | |
2922 | goto out_put; | |
978f3a45 | 2923 | |
756d17ee | 2924 | ret = -ENOMEM; |
df4fc315 | 2925 | |
756d17ee | 2926 | fpid = kmalloc(sizeof(*fpid), GFP_KERNEL); |
2927 | if (!fpid) | |
2928 | goto out_put; | |
df4fc315 | 2929 | |
756d17ee | 2930 | list_add(&fpid->list, &ftrace_pids); |
2931 | fpid->pid = pid; | |
0ef8cde5 | 2932 | |
756d17ee | 2933 | set_ftrace_pid_task(pid); |
978f3a45 | 2934 | |
756d17ee | 2935 | ftrace_update_pid_func(); |
2936 | ftrace_startup_enable(0); | |
2937 | ||
2938 | mutex_unlock(&ftrace_lock); | |
2939 | return 0; | |
2940 | ||
2941 | out_put: | |
2942 | if (pid != ftrace_swapper_pid) | |
2943 | put_pid(pid); | |
978f3a45 | 2944 | |
756d17ee | 2945 | out: |
2946 | mutex_unlock(&ftrace_lock); | |
2947 | return ret; | |
2948 | } | |
2949 | ||
2950 | static void ftrace_pid_reset(void) | |
2951 | { | |
2952 | struct ftrace_pid *fpid, *safe; | |
978f3a45 | 2953 | |
756d17ee | 2954 | mutex_lock(&ftrace_lock); |
2955 | list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) { | |
2956 | struct pid *pid = fpid->pid; | |
2957 | ||
2958 | clear_ftrace_pid_task(pid); | |
2959 | ||
2960 | list_del(&fpid->list); | |
2961 | kfree(fpid); | |
df4fc315 SR |
2962 | } |
2963 | ||
df4fc315 SR |
2964 | ftrace_update_pid_func(); |
2965 | ftrace_startup_enable(0); | |
2966 | ||
e6ea44e9 | 2967 | mutex_unlock(&ftrace_lock); |
756d17ee | 2968 | } |
df4fc315 | 2969 | |
756d17ee | 2970 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
2971 | { | |
2972 | mutex_lock(&ftrace_lock); | |
2973 | ||
2974 | if (list_empty(&ftrace_pids) && (!*pos)) | |
2975 | return (void *) 1; | |
2976 | ||
2977 | return seq_list_start(&ftrace_pids, *pos); | |
2978 | } | |
2979 | ||
2980 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
2981 | { | |
2982 | if (v == (void *)1) | |
2983 | return NULL; | |
2984 | ||
2985 | return seq_list_next(v, &ftrace_pids, pos); | |
2986 | } | |
2987 | ||
2988 | static void fpid_stop(struct seq_file *m, void *p) | |
2989 | { | |
2990 | mutex_unlock(&ftrace_lock); | |
2991 | } | |
2992 | ||
2993 | static int fpid_show(struct seq_file *m, void *v) | |
2994 | { | |
2995 | const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list); | |
2996 | ||
2997 | if (v == (void *)1) { | |
2998 | seq_printf(m, "no pid\n"); | |
2999 | return 0; | |
3000 | } | |
3001 | ||
3002 | if (fpid->pid == ftrace_swapper_pid) | |
3003 | seq_printf(m, "swapper tasks\n"); | |
3004 | else | |
3005 | seq_printf(m, "%u\n", pid_vnr(fpid->pid)); | |
3006 | ||
3007 | return 0; | |
3008 | } | |
3009 | ||
3010 | static const struct seq_operations ftrace_pid_sops = { | |
3011 | .start = fpid_start, | |
3012 | .next = fpid_next, | |
3013 | .stop = fpid_stop, | |
3014 | .show = fpid_show, | |
3015 | }; | |
3016 | ||
3017 | static int | |
3018 | ftrace_pid_open(struct inode *inode, struct file *file) | |
3019 | { | |
3020 | int ret = 0; | |
3021 | ||
3022 | if ((file->f_mode & FMODE_WRITE) && | |
3023 | (file->f_flags & O_TRUNC)) | |
3024 | ftrace_pid_reset(); | |
3025 | ||
3026 | if (file->f_mode & FMODE_READ) | |
3027 | ret = seq_open(file, &ftrace_pid_sops); | |
3028 | ||
3029 | return ret; | |
3030 | } | |
3031 | ||
df4fc315 SR |
3032 | static ssize_t |
3033 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
3034 | size_t cnt, loff_t *ppos) | |
3035 | { | |
457dc928 | 3036 | char buf[64], *tmp; |
df4fc315 SR |
3037 | long val; |
3038 | int ret; | |
3039 | ||
3040 | if (cnt >= sizeof(buf)) | |
3041 | return -EINVAL; | |
3042 | ||
3043 | if (copy_from_user(&buf, ubuf, cnt)) | |
3044 | return -EFAULT; | |
3045 | ||
3046 | buf[cnt] = 0; | |
3047 | ||
756d17ee | 3048 | /* |
3049 | * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid" | |
3050 | * to clean the filter quietly. | |
3051 | */ | |
457dc928 IM |
3052 | tmp = strstrip(buf); |
3053 | if (strlen(tmp) == 0) | |
756d17ee | 3054 | return 1; |
3055 | ||
457dc928 | 3056 | ret = strict_strtol(tmp, 10, &val); |
df4fc315 SR |
3057 | if (ret < 0) |
3058 | return ret; | |
3059 | ||
756d17ee | 3060 | ret = ftrace_pid_add(val); |
df4fc315 | 3061 | |
756d17ee | 3062 | return ret ? ret : cnt; |
3063 | } | |
df4fc315 | 3064 | |
756d17ee | 3065 | static int |
3066 | ftrace_pid_release(struct inode *inode, struct file *file) | |
3067 | { | |
3068 | if (file->f_mode & FMODE_READ) | |
3069 | seq_release(inode, file); | |
df4fc315 | 3070 | |
756d17ee | 3071 | return 0; |
df4fc315 SR |
3072 | } |
3073 | ||
5e2336a0 | 3074 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 3075 | .open = ftrace_pid_open, |
3076 | .write = ftrace_pid_write, | |
3077 | .read = seq_read, | |
3078 | .llseek = seq_lseek, | |
3079 | .release = ftrace_pid_release, | |
df4fc315 SR |
3080 | }; |
3081 | ||
3082 | static __init int ftrace_init_debugfs(void) | |
3083 | { | |
3084 | struct dentry *d_tracer; | |
df4fc315 SR |
3085 | |
3086 | d_tracer = tracing_init_dentry(); | |
3087 | if (!d_tracer) | |
3088 | return 0; | |
3089 | ||
3090 | ftrace_init_dyn_debugfs(d_tracer); | |
3091 | ||
5452af66 FW |
3092 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
3093 | NULL, &ftrace_pid_fops); | |
493762fc SR |
3094 | |
3095 | ftrace_profile_debugfs(d_tracer); | |
3096 | ||
df4fc315 SR |
3097 | return 0; |
3098 | } | |
df4fc315 SR |
3099 | fs_initcall(ftrace_init_debugfs); |
3100 | ||
a2bb6a3d | 3101 | /** |
81adbdc0 | 3102 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
3103 | * |
3104 | * This function should be used by panic code. It stops ftrace | |
3105 | * but in a not so nice way. If you need to simply kill ftrace | |
3106 | * from a non-atomic section, use ftrace_kill. | |
3107 | */ | |
81adbdc0 | 3108 | void ftrace_kill(void) |
a2bb6a3d SR |
3109 | { |
3110 | ftrace_disabled = 1; | |
3111 | ftrace_enabled = 0; | |
a2bb6a3d SR |
3112 | clear_ftrace_function(); |
3113 | } | |
3114 | ||
16444a8a | 3115 | /** |
3d083395 SR |
3116 | * register_ftrace_function - register a function for profiling |
3117 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 3118 | * |
3d083395 SR |
3119 | * Register a function to be called by all functions in the |
3120 | * kernel. | |
3121 | * | |
3122 | * Note: @ops->func and all the functions it calls must be labeled | |
3123 | * with "notrace", otherwise it will go into a | |
3124 | * recursive loop. | |
16444a8a | 3125 | */ |
3d083395 | 3126 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 3127 | { |
45a4a237 | 3128 | int ret = -1; |
4eebcc81 | 3129 | |
e6ea44e9 | 3130 | mutex_lock(&ftrace_lock); |
e7d3737e | 3131 | |
45a4a237 SR |
3132 | if (unlikely(ftrace_disabled)) |
3133 | goto out_unlock; | |
3134 | ||
b0fc494f | 3135 | ret = __register_ftrace_function(ops); |
5a45cfe1 | 3136 | ftrace_startup(0); |
b0fc494f | 3137 | |
45a4a237 | 3138 | out_unlock: |
e6ea44e9 | 3139 | mutex_unlock(&ftrace_lock); |
b0fc494f | 3140 | return ret; |
3d083395 SR |
3141 | } |
3142 | ||
3143 | /** | |
32632920 | 3144 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
3145 | * @ops - ops structure that holds the function to unregister |
3146 | * | |
3147 | * Unregister a function that was added to be called by ftrace profiling. | |
3148 | */ | |
3149 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
3150 | { | |
3151 | int ret; | |
3152 | ||
e6ea44e9 | 3153 | mutex_lock(&ftrace_lock); |
3d083395 | 3154 | ret = __unregister_ftrace_function(ops); |
5a45cfe1 | 3155 | ftrace_shutdown(0); |
e6ea44e9 | 3156 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
3157 | |
3158 | return ret; | |
3159 | } | |
3160 | ||
e309b41d | 3161 | int |
b0fc494f | 3162 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
8d65af78 | 3163 | void __user *buffer, size_t *lenp, |
b0fc494f SR |
3164 | loff_t *ppos) |
3165 | { | |
45a4a237 | 3166 | int ret = -ENODEV; |
4eebcc81 | 3167 | |
e6ea44e9 | 3168 | mutex_lock(&ftrace_lock); |
b0fc494f | 3169 | |
45a4a237 SR |
3170 | if (unlikely(ftrace_disabled)) |
3171 | goto out; | |
3172 | ||
3173 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
b0fc494f | 3174 | |
a32c7765 | 3175 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
3176 | goto out; |
3177 | ||
a32c7765 | 3178 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f SR |
3179 | |
3180 | if (ftrace_enabled) { | |
3181 | ||
3182 | ftrace_startup_sysctl(); | |
3183 | ||
3184 | /* we are starting ftrace again */ | |
3185 | if (ftrace_list != &ftrace_list_end) { | |
3186 | if (ftrace_list->next == &ftrace_list_end) | |
3187 | ftrace_trace_function = ftrace_list->func; | |
3188 | else | |
3189 | ftrace_trace_function = ftrace_list_func; | |
3190 | } | |
3191 | ||
3192 | } else { | |
3193 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
3194 | ftrace_trace_function = ftrace_stub; | |
3195 | ||
3196 | ftrace_shutdown_sysctl(); | |
3197 | } | |
3198 | ||
3199 | out: | |
e6ea44e9 | 3200 | mutex_unlock(&ftrace_lock); |
3d083395 | 3201 | return ret; |
16444a8a | 3202 | } |
f17845e5 | 3203 | |
fb52607a | 3204 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 3205 | |
597af815 | 3206 | static int ftrace_graph_active; |
4a2b8dda | 3207 | static struct notifier_block ftrace_suspend_notifier; |
e7d3737e | 3208 | |
e49dc19c SR |
3209 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
3210 | { | |
3211 | return 0; | |
3212 | } | |
3213 | ||
287b6e68 FW |
3214 | /* The callbacks that hook a function */ |
3215 | trace_func_graph_ret_t ftrace_graph_return = | |
3216 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 3217 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
3218 | |
3219 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
3220 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
3221 | { | |
3222 | int i; | |
3223 | int ret = 0; | |
3224 | unsigned long flags; | |
3225 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
3226 | struct task_struct *g, *t; | |
3227 | ||
3228 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
3229 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
3230 | * sizeof(struct ftrace_ret_stack), | |
3231 | GFP_KERNEL); | |
3232 | if (!ret_stack_list[i]) { | |
3233 | start = 0; | |
3234 | end = i; | |
3235 | ret = -ENOMEM; | |
3236 | goto free; | |
3237 | } | |
3238 | } | |
3239 | ||
3240 | read_lock_irqsave(&tasklist_lock, flags); | |
3241 | do_each_thread(g, t) { | |
3242 | if (start == end) { | |
3243 | ret = -EAGAIN; | |
3244 | goto unlock; | |
3245 | } | |
3246 | ||
3247 | if (t->ret_stack == NULL) { | |
380c4b14 | 3248 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 3249 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
3250 | t->curr_ret_stack = -1; |
3251 | /* Make sure the tasks see the -1 first: */ | |
3252 | smp_wmb(); | |
3253 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
3254 | } |
3255 | } while_each_thread(g, t); | |
3256 | ||
3257 | unlock: | |
3258 | read_unlock_irqrestore(&tasklist_lock, flags); | |
3259 | free: | |
3260 | for (i = start; i < end; i++) | |
3261 | kfree(ret_stack_list[i]); | |
3262 | return ret; | |
3263 | } | |
3264 | ||
8aef2d28 | 3265 | static void |
38516ab5 SR |
3266 | ftrace_graph_probe_sched_switch(void *ignore, |
3267 | struct task_struct *prev, struct task_struct *next) | |
8aef2d28 SR |
3268 | { |
3269 | unsigned long long timestamp; | |
3270 | int index; | |
3271 | ||
be6f164a SR |
3272 | /* |
3273 | * Does the user want to count the time a function was asleep. | |
3274 | * If so, do not update the time stamps. | |
3275 | */ | |
3276 | if (trace_flags & TRACE_ITER_SLEEP_TIME) | |
3277 | return; | |
3278 | ||
8aef2d28 SR |
3279 | timestamp = trace_clock_local(); |
3280 | ||
3281 | prev->ftrace_timestamp = timestamp; | |
3282 | ||
3283 | /* only process tasks that we timestamped */ | |
3284 | if (!next->ftrace_timestamp) | |
3285 | return; | |
3286 | ||
3287 | /* | |
3288 | * Update all the counters in next to make up for the | |
3289 | * time next was sleeping. | |
3290 | */ | |
3291 | timestamp -= next->ftrace_timestamp; | |
3292 | ||
3293 | for (index = next->curr_ret_stack; index >= 0; index--) | |
3294 | next->ret_stack[index].calltime += timestamp; | |
3295 | } | |
3296 | ||
f201ae23 | 3297 | /* Allocate a return stack for each task */ |
fb52607a | 3298 | static int start_graph_tracing(void) |
f201ae23 FW |
3299 | { |
3300 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 3301 | int ret, cpu; |
f201ae23 FW |
3302 | |
3303 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
3304 | sizeof(struct ftrace_ret_stack *), | |
3305 | GFP_KERNEL); | |
3306 | ||
3307 | if (!ret_stack_list) | |
3308 | return -ENOMEM; | |
3309 | ||
5b058bcd | 3310 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
3311 | for_each_online_cpu(cpu) { |
3312 | if (!idle_task(cpu)->ret_stack) | |
868baf07 | 3313 | ftrace_graph_init_idle_task(idle_task(cpu), cpu); |
179c498a | 3314 | } |
5b058bcd | 3315 | |
f201ae23 FW |
3316 | do { |
3317 | ret = alloc_retstack_tasklist(ret_stack_list); | |
3318 | } while (ret == -EAGAIN); | |
3319 | ||
8aef2d28 | 3320 | if (!ret) { |
38516ab5 | 3321 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
8aef2d28 SR |
3322 | if (ret) |
3323 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
3324 | " probe to kernel_sched_switch\n"); | |
3325 | } | |
3326 | ||
f201ae23 FW |
3327 | kfree(ret_stack_list); |
3328 | return ret; | |
3329 | } | |
3330 | ||
4a2b8dda FW |
3331 | /* |
3332 | * Hibernation protection. | |
3333 | * The state of the current task is too much unstable during | |
3334 | * suspend/restore to disk. We want to protect against that. | |
3335 | */ | |
3336 | static int | |
3337 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
3338 | void *unused) | |
3339 | { | |
3340 | switch (state) { | |
3341 | case PM_HIBERNATION_PREPARE: | |
3342 | pause_graph_tracing(); | |
3343 | break; | |
3344 | ||
3345 | case PM_POST_HIBERNATION: | |
3346 | unpause_graph_tracing(); | |
3347 | break; | |
3348 | } | |
3349 | return NOTIFY_DONE; | |
3350 | } | |
3351 | ||
287b6e68 FW |
3352 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
3353 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 3354 | { |
e7d3737e FW |
3355 | int ret = 0; |
3356 | ||
e6ea44e9 | 3357 | mutex_lock(&ftrace_lock); |
e7d3737e | 3358 | |
05ce5818 | 3359 | /* we currently allow only one tracer registered at a time */ |
597af815 | 3360 | if (ftrace_graph_active) { |
05ce5818 SR |
3361 | ret = -EBUSY; |
3362 | goto out; | |
3363 | } | |
3364 | ||
4a2b8dda FW |
3365 | ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; |
3366 | register_pm_notifier(&ftrace_suspend_notifier); | |
3367 | ||
597af815 | 3368 | ftrace_graph_active++; |
fb52607a | 3369 | ret = start_graph_tracing(); |
f201ae23 | 3370 | if (ret) { |
597af815 | 3371 | ftrace_graph_active--; |
f201ae23 FW |
3372 | goto out; |
3373 | } | |
e53a6319 | 3374 | |
287b6e68 FW |
3375 | ftrace_graph_return = retfunc; |
3376 | ftrace_graph_entry = entryfunc; | |
e53a6319 | 3377 | |
5a45cfe1 | 3378 | ftrace_startup(FTRACE_START_FUNC_RET); |
e7d3737e FW |
3379 | |
3380 | out: | |
e6ea44e9 | 3381 | mutex_unlock(&ftrace_lock); |
e7d3737e | 3382 | return ret; |
15e6cb36 FW |
3383 | } |
3384 | ||
fb52607a | 3385 | void unregister_ftrace_graph(void) |
15e6cb36 | 3386 | { |
e6ea44e9 | 3387 | mutex_lock(&ftrace_lock); |
e7d3737e | 3388 | |
597af815 | 3389 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
3390 | goto out; |
3391 | ||
597af815 | 3392 | ftrace_graph_active--; |
287b6e68 | 3393 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 3394 | ftrace_graph_entry = ftrace_graph_entry_stub; |
5a45cfe1 | 3395 | ftrace_shutdown(FTRACE_STOP_FUNC_RET); |
4a2b8dda | 3396 | unregister_pm_notifier(&ftrace_suspend_notifier); |
38516ab5 | 3397 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
e7d3737e | 3398 | |
2aad1b76 | 3399 | out: |
e6ea44e9 | 3400 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 3401 | } |
f201ae23 | 3402 | |
868baf07 SR |
3403 | static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack); |
3404 | ||
3405 | static void | |
3406 | graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack) | |
3407 | { | |
3408 | atomic_set(&t->tracing_graph_pause, 0); | |
3409 | atomic_set(&t->trace_overrun, 0); | |
3410 | t->ftrace_timestamp = 0; | |
25985edc | 3411 | /* make curr_ret_stack visible before we add the ret_stack */ |
868baf07 SR |
3412 | smp_wmb(); |
3413 | t->ret_stack = ret_stack; | |
3414 | } | |
3415 | ||
3416 | /* | |
3417 | * Allocate a return stack for the idle task. May be the first | |
3418 | * time through, or it may be done by CPU hotplug online. | |
3419 | */ | |
3420 | void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) | |
3421 | { | |
3422 | t->curr_ret_stack = -1; | |
3423 | /* | |
3424 | * The idle task has no parent, it either has its own | |
3425 | * stack or no stack at all. | |
3426 | */ | |
3427 | if (t->ret_stack) | |
3428 | WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu)); | |
3429 | ||
3430 | if (ftrace_graph_active) { | |
3431 | struct ftrace_ret_stack *ret_stack; | |
3432 | ||
3433 | ret_stack = per_cpu(idle_ret_stack, cpu); | |
3434 | if (!ret_stack) { | |
3435 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
3436 | * sizeof(struct ftrace_ret_stack), | |
3437 | GFP_KERNEL); | |
3438 | if (!ret_stack) | |
3439 | return; | |
3440 | per_cpu(idle_ret_stack, cpu) = ret_stack; | |
3441 | } | |
3442 | graph_init_task(t, ret_stack); | |
3443 | } | |
3444 | } | |
3445 | ||
f201ae23 | 3446 | /* Allocate a return stack for newly created task */ |
fb52607a | 3447 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 3448 | { |
84047e36 SR |
3449 | /* Make sure we do not use the parent ret_stack */ |
3450 | t->ret_stack = NULL; | |
ea14eb71 | 3451 | t->curr_ret_stack = -1; |
84047e36 | 3452 | |
597af815 | 3453 | if (ftrace_graph_active) { |
82310a32 SR |
3454 | struct ftrace_ret_stack *ret_stack; |
3455 | ||
3456 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
3457 | * sizeof(struct ftrace_ret_stack), |
3458 | GFP_KERNEL); | |
82310a32 | 3459 | if (!ret_stack) |
f201ae23 | 3460 | return; |
868baf07 | 3461 | graph_init_task(t, ret_stack); |
84047e36 | 3462 | } |
f201ae23 FW |
3463 | } |
3464 | ||
fb52607a | 3465 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 3466 | { |
eae849ca FW |
3467 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
3468 | ||
f201ae23 | 3469 | t->ret_stack = NULL; |
eae849ca FW |
3470 | /* NULL must become visible to IRQs before we free it: */ |
3471 | barrier(); | |
3472 | ||
3473 | kfree(ret_stack); | |
f201ae23 | 3474 | } |
14a866c5 SR |
3475 | |
3476 | void ftrace_graph_stop(void) | |
3477 | { | |
3478 | ftrace_stop(); | |
3479 | } | |
15e6cb36 | 3480 | #endif |