Commit | Line | Data |
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16444a8a ACM |
1 | /* |
2 | * Infrastructure for profiling code inserted by 'gcc -pg'. | |
3 | * | |
4 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> | |
5 | * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com> | |
6 | * | |
7 | * Originally ported from the -rt patch by: | |
8 | * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com> | |
9 | * | |
10 | * Based on code in the latency_tracer, that is: | |
11 | * | |
12 | * Copyright (C) 2004-2006 Ingo Molnar | |
13 | * Copyright (C) 2004 William Lee Irwin III | |
14 | */ | |
15 | ||
3d083395 SR |
16 | #include <linux/stop_machine.h> |
17 | #include <linux/clocksource.h> | |
18 | #include <linux/kallsyms.h> | |
5072c59f | 19 | #include <linux/seq_file.h> |
4a2b8dda | 20 | #include <linux/suspend.h> |
5072c59f | 21 | #include <linux/debugfs.h> |
3d083395 | 22 | #include <linux/hardirq.h> |
2d8b820b | 23 | #include <linux/kthread.h> |
5072c59f | 24 | #include <linux/uaccess.h> |
2d8b820b | 25 | #include <linux/ftrace.h> |
b0fc494f | 26 | #include <linux/sysctl.h> |
5a0e3ad6 | 27 | #include <linux/slab.h> |
5072c59f | 28 | #include <linux/ctype.h> |
3d083395 | 29 | #include <linux/list.h> |
59df055f | 30 | #include <linux/hash.h> |
3f379b03 | 31 | #include <linux/rcupdate.h> |
3d083395 | 32 | |
ad8d75ff | 33 | #include <trace/events/sched.h> |
8aef2d28 | 34 | |
395a59d0 | 35 | #include <asm/ftrace.h> |
2af15d6a | 36 | #include <asm/setup.h> |
395a59d0 | 37 | |
0706f1c4 | 38 | #include "trace_output.h" |
bac429f0 | 39 | #include "trace_stat.h" |
16444a8a | 40 | |
6912896e SR |
41 | #define FTRACE_WARN_ON(cond) \ |
42 | do { \ | |
43 | if (WARN_ON(cond)) \ | |
44 | ftrace_kill(); \ | |
45 | } while (0) | |
46 | ||
47 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
48 | do { \ | |
49 | if (WARN_ON_ONCE(cond)) \ | |
50 | ftrace_kill(); \ | |
51 | } while (0) | |
52 | ||
8fc0c701 SR |
53 | /* hash bits for specific function selection */ |
54 | #define FTRACE_HASH_BITS 7 | |
55 | #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS) | |
56 | ||
4eebcc81 SR |
57 | /* ftrace_enabled is a method to turn ftrace on or off */ |
58 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 59 | static int last_ftrace_enabled; |
b0fc494f | 60 | |
60a7ecf4 SR |
61 | /* Quick disabling of function tracer. */ |
62 | int function_trace_stop; | |
63 | ||
756d17ee | 64 | /* List for set_ftrace_pid's pids. */ |
65 | LIST_HEAD(ftrace_pids); | |
66 | struct ftrace_pid { | |
67 | struct list_head list; | |
68 | struct pid *pid; | |
69 | }; | |
70 | ||
4eebcc81 SR |
71 | /* |
72 | * ftrace_disabled is set when an anomaly is discovered. | |
73 | * ftrace_disabled is much stronger than ftrace_enabled. | |
74 | */ | |
75 | static int ftrace_disabled __read_mostly; | |
76 | ||
52baf119 | 77 | static DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 78 | |
16444a8a ACM |
79 | static struct ftrace_ops ftrace_list_end __read_mostly = |
80 | { | |
fb9fb015 | 81 | .func = ftrace_stub, |
16444a8a ACM |
82 | }; |
83 | ||
84 | static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; | |
85 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; | |
60a7ecf4 | 86 | ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub; |
df4fc315 | 87 | ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; |
16444a8a | 88 | |
3f379b03 PM |
89 | /* |
90 | * Traverse the ftrace_list, invoking all entries. The reason that we | |
91 | * can use rcu_dereference_raw() is that elements removed from this list | |
92 | * are simply leaked, so there is no need to interact with a grace-period | |
93 | * mechanism. The rcu_dereference_raw() calls are needed to handle | |
94 | * concurrent insertions into the ftrace_list. | |
95 | * | |
96 | * Silly Alpha and silly pointer-speculation compiler optimizations! | |
97 | */ | |
f2252935 | 98 | static void ftrace_list_func(unsigned long ip, unsigned long parent_ip) |
16444a8a | 99 | { |
3f379b03 | 100 | struct ftrace_ops *op = rcu_dereference_raw(ftrace_list); /*see above*/ |
16444a8a ACM |
101 | |
102 | while (op != &ftrace_list_end) { | |
16444a8a | 103 | op->func(ip, parent_ip); |
3f379b03 | 104 | op = rcu_dereference_raw(op->next); /*see above*/ |
16444a8a ACM |
105 | }; |
106 | } | |
107 | ||
df4fc315 SR |
108 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip) |
109 | { | |
0ef8cde5 | 110 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
111 | return; |
112 | ||
113 | ftrace_pid_function(ip, parent_ip); | |
114 | } | |
115 | ||
116 | static void set_ftrace_pid_function(ftrace_func_t func) | |
117 | { | |
118 | /* do not set ftrace_pid_function to itself! */ | |
119 | if (func != ftrace_pid_func) | |
120 | ftrace_pid_function = func; | |
121 | } | |
122 | ||
16444a8a | 123 | /** |
3d083395 | 124 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 125 | * |
3d083395 SR |
126 | * This NULLs the ftrace function and in essence stops |
127 | * tracing. There may be lag | |
16444a8a | 128 | */ |
3d083395 | 129 | void clear_ftrace_function(void) |
16444a8a | 130 | { |
3d083395 | 131 | ftrace_trace_function = ftrace_stub; |
60a7ecf4 | 132 | __ftrace_trace_function = ftrace_stub; |
df4fc315 | 133 | ftrace_pid_function = ftrace_stub; |
3d083395 SR |
134 | } |
135 | ||
60a7ecf4 SR |
136 | #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
137 | /* | |
138 | * For those archs that do not test ftrace_trace_stop in their | |
139 | * mcount call site, we need to do it from C. | |
140 | */ | |
141 | static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip) | |
142 | { | |
143 | if (function_trace_stop) | |
144 | return; | |
145 | ||
146 | __ftrace_trace_function(ip, parent_ip); | |
147 | } | |
148 | #endif | |
149 | ||
e309b41d | 150 | static int __register_ftrace_function(struct ftrace_ops *ops) |
3d083395 | 151 | { |
16444a8a ACM |
152 | ops->next = ftrace_list; |
153 | /* | |
154 | * We are entering ops into the ftrace_list but another | |
155 | * CPU might be walking that list. We need to make sure | |
156 | * the ops->next pointer is valid before another CPU sees | |
157 | * the ops pointer included into the ftrace_list. | |
158 | */ | |
3f379b03 | 159 | rcu_assign_pointer(ftrace_list, ops); |
3d083395 | 160 | |
b0fc494f | 161 | if (ftrace_enabled) { |
df4fc315 SR |
162 | ftrace_func_t func; |
163 | ||
164 | if (ops->next == &ftrace_list_end) | |
165 | func = ops->func; | |
166 | else | |
167 | func = ftrace_list_func; | |
168 | ||
756d17ee | 169 | if (!list_empty(&ftrace_pids)) { |
df4fc315 SR |
170 | set_ftrace_pid_function(func); |
171 | func = ftrace_pid_func; | |
172 | } | |
173 | ||
b0fc494f SR |
174 | /* |
175 | * For one func, simply call it directly. | |
176 | * For more than one func, call the chain. | |
177 | */ | |
60a7ecf4 | 178 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
df4fc315 | 179 | ftrace_trace_function = func; |
60a7ecf4 | 180 | #else |
df4fc315 | 181 | __ftrace_trace_function = func; |
60a7ecf4 SR |
182 | ftrace_trace_function = ftrace_test_stop_func; |
183 | #endif | |
b0fc494f | 184 | } |
3d083395 | 185 | |
16444a8a ACM |
186 | return 0; |
187 | } | |
188 | ||
e309b41d | 189 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 190 | { |
16444a8a | 191 | struct ftrace_ops **p; |
16444a8a ACM |
192 | |
193 | /* | |
3d083395 SR |
194 | * If we are removing the last function, then simply point |
195 | * to the ftrace_stub. | |
16444a8a ACM |
196 | */ |
197 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { | |
198 | ftrace_trace_function = ftrace_stub; | |
199 | ftrace_list = &ftrace_list_end; | |
e6ea44e9 | 200 | return 0; |
16444a8a ACM |
201 | } |
202 | ||
203 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) | |
204 | if (*p == ops) | |
205 | break; | |
206 | ||
e6ea44e9 SR |
207 | if (*p != ops) |
208 | return -1; | |
16444a8a ACM |
209 | |
210 | *p = (*p)->next; | |
211 | ||
b0fc494f SR |
212 | if (ftrace_enabled) { |
213 | /* If we only have one func left, then call that directly */ | |
df4fc315 SR |
214 | if (ftrace_list->next == &ftrace_list_end) { |
215 | ftrace_func_t func = ftrace_list->func; | |
216 | ||
756d17ee | 217 | if (!list_empty(&ftrace_pids)) { |
df4fc315 SR |
218 | set_ftrace_pid_function(func); |
219 | func = ftrace_pid_func; | |
220 | } | |
221 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
222 | ftrace_trace_function = func; | |
223 | #else | |
224 | __ftrace_trace_function = func; | |
225 | #endif | |
226 | } | |
b0fc494f | 227 | } |
16444a8a | 228 | |
e6ea44e9 | 229 | return 0; |
3d083395 SR |
230 | } |
231 | ||
df4fc315 SR |
232 | static void ftrace_update_pid_func(void) |
233 | { | |
234 | ftrace_func_t func; | |
235 | ||
df4fc315 | 236 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 237 | return; |
df4fc315 | 238 | |
33974093 | 239 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
df4fc315 | 240 | func = ftrace_trace_function; |
33974093 MF |
241 | #else |
242 | func = __ftrace_trace_function; | |
243 | #endif | |
df4fc315 | 244 | |
756d17ee | 245 | if (!list_empty(&ftrace_pids)) { |
df4fc315 SR |
246 | set_ftrace_pid_function(func); |
247 | func = ftrace_pid_func; | |
248 | } else { | |
66eafebc LW |
249 | if (func == ftrace_pid_func) |
250 | func = ftrace_pid_function; | |
df4fc315 SR |
251 | } |
252 | ||
253 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
254 | ftrace_trace_function = func; | |
255 | #else | |
256 | __ftrace_trace_function = func; | |
257 | #endif | |
df4fc315 SR |
258 | } |
259 | ||
493762fc SR |
260 | #ifdef CONFIG_FUNCTION_PROFILER |
261 | struct ftrace_profile { | |
262 | struct hlist_node node; | |
263 | unsigned long ip; | |
264 | unsigned long counter; | |
0706f1c4 SR |
265 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
266 | unsigned long long time; | |
e330b3bc | 267 | unsigned long long time_squared; |
0706f1c4 | 268 | #endif |
8fc0c701 SR |
269 | }; |
270 | ||
493762fc SR |
271 | struct ftrace_profile_page { |
272 | struct ftrace_profile_page *next; | |
273 | unsigned long index; | |
274 | struct ftrace_profile records[]; | |
d61f82d0 SR |
275 | }; |
276 | ||
cafb168a SR |
277 | struct ftrace_profile_stat { |
278 | atomic_t disabled; | |
279 | struct hlist_head *hash; | |
280 | struct ftrace_profile_page *pages; | |
281 | struct ftrace_profile_page *start; | |
282 | struct tracer_stat stat; | |
283 | }; | |
284 | ||
493762fc SR |
285 | #define PROFILE_RECORDS_SIZE \ |
286 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 287 | |
493762fc SR |
288 | #define PROFILES_PER_PAGE \ |
289 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 290 | |
fb9fb015 SR |
291 | static int ftrace_profile_bits __read_mostly; |
292 | static int ftrace_profile_enabled __read_mostly; | |
293 | ||
294 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
295 | static DEFINE_MUTEX(ftrace_profile_lock); |
296 | ||
cafb168a | 297 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc SR |
298 | |
299 | #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */ | |
300 | ||
bac429f0 SR |
301 | static void * |
302 | function_stat_next(void *v, int idx) | |
303 | { | |
493762fc SR |
304 | struct ftrace_profile *rec = v; |
305 | struct ftrace_profile_page *pg; | |
bac429f0 | 306 | |
493762fc | 307 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
308 | |
309 | again: | |
0296e425 LZ |
310 | if (idx != 0) |
311 | rec++; | |
312 | ||
bac429f0 SR |
313 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
314 | pg = pg->next; | |
315 | if (!pg) | |
316 | return NULL; | |
317 | rec = &pg->records[0]; | |
493762fc SR |
318 | if (!rec->counter) |
319 | goto again; | |
bac429f0 SR |
320 | } |
321 | ||
bac429f0 SR |
322 | return rec; |
323 | } | |
324 | ||
325 | static void *function_stat_start(struct tracer_stat *trace) | |
326 | { | |
cafb168a SR |
327 | struct ftrace_profile_stat *stat = |
328 | container_of(trace, struct ftrace_profile_stat, stat); | |
329 | ||
330 | if (!stat || !stat->start) | |
331 | return NULL; | |
332 | ||
333 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
334 | } |
335 | ||
0706f1c4 SR |
336 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
337 | /* function graph compares on total time */ | |
338 | static int function_stat_cmp(void *p1, void *p2) | |
339 | { | |
340 | struct ftrace_profile *a = p1; | |
341 | struct ftrace_profile *b = p2; | |
342 | ||
343 | if (a->time < b->time) | |
344 | return -1; | |
345 | if (a->time > b->time) | |
346 | return 1; | |
347 | else | |
348 | return 0; | |
349 | } | |
350 | #else | |
351 | /* not function graph compares against hits */ | |
bac429f0 SR |
352 | static int function_stat_cmp(void *p1, void *p2) |
353 | { | |
493762fc SR |
354 | struct ftrace_profile *a = p1; |
355 | struct ftrace_profile *b = p2; | |
bac429f0 SR |
356 | |
357 | if (a->counter < b->counter) | |
358 | return -1; | |
359 | if (a->counter > b->counter) | |
360 | return 1; | |
361 | else | |
362 | return 0; | |
363 | } | |
0706f1c4 | 364 | #endif |
bac429f0 SR |
365 | |
366 | static int function_stat_headers(struct seq_file *m) | |
367 | { | |
0706f1c4 | 368 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b | 369 | seq_printf(m, " Function " |
e330b3bc | 370 | "Hit Time Avg s^2\n" |
34886c8b | 371 | " -------- " |
e330b3bc | 372 | "--- ---- --- ---\n"); |
0706f1c4 | 373 | #else |
bac429f0 SR |
374 | seq_printf(m, " Function Hit\n" |
375 | " -------- ---\n"); | |
0706f1c4 | 376 | #endif |
bac429f0 SR |
377 | return 0; |
378 | } | |
379 | ||
380 | static int function_stat_show(struct seq_file *m, void *v) | |
381 | { | |
493762fc | 382 | struct ftrace_profile *rec = v; |
bac429f0 | 383 | char str[KSYM_SYMBOL_LEN]; |
3aaba20f | 384 | int ret = 0; |
0706f1c4 | 385 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
386 | static struct trace_seq s; |
387 | unsigned long long avg; | |
e330b3bc | 388 | unsigned long long stddev; |
0706f1c4 | 389 | #endif |
3aaba20f LZ |
390 | mutex_lock(&ftrace_profile_lock); |
391 | ||
392 | /* we raced with function_profile_reset() */ | |
393 | if (unlikely(rec->counter == 0)) { | |
394 | ret = -EBUSY; | |
395 | goto out; | |
396 | } | |
bac429f0 SR |
397 | |
398 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
0706f1c4 SR |
399 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
400 | ||
401 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
402 | seq_printf(m, " "); | |
34886c8b SR |
403 | avg = rec->time; |
404 | do_div(avg, rec->counter); | |
405 | ||
e330b3bc CD |
406 | /* Sample standard deviation (s^2) */ |
407 | if (rec->counter <= 1) | |
408 | stddev = 0; | |
409 | else { | |
410 | stddev = rec->time_squared - rec->counter * avg * avg; | |
411 | /* | |
412 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
413 | * trace_print_graph_duration will divide 1000 again. | |
414 | */ | |
415 | do_div(stddev, (rec->counter - 1) * 1000); | |
416 | } | |
417 | ||
34886c8b SR |
418 | trace_seq_init(&s); |
419 | trace_print_graph_duration(rec->time, &s); | |
420 | trace_seq_puts(&s, " "); | |
421 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
422 | trace_seq_puts(&s, " "); |
423 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 | 424 | trace_print_seq(m, &s); |
0706f1c4 SR |
425 | #endif |
426 | seq_putc(m, '\n'); | |
3aaba20f LZ |
427 | out: |
428 | mutex_unlock(&ftrace_profile_lock); | |
bac429f0 | 429 | |
3aaba20f | 430 | return ret; |
bac429f0 SR |
431 | } |
432 | ||
cafb168a | 433 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 434 | { |
493762fc | 435 | struct ftrace_profile_page *pg; |
bac429f0 | 436 | |
cafb168a | 437 | pg = stat->pages = stat->start; |
bac429f0 | 438 | |
493762fc SR |
439 | while (pg) { |
440 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
441 | pg->index = 0; | |
442 | pg = pg->next; | |
bac429f0 SR |
443 | } |
444 | ||
cafb168a | 445 | memset(stat->hash, 0, |
493762fc SR |
446 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
447 | } | |
bac429f0 | 448 | |
cafb168a | 449 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
450 | { |
451 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
452 | int functions; |
453 | int pages; | |
493762fc | 454 | int i; |
bac429f0 | 455 | |
493762fc | 456 | /* If we already allocated, do nothing */ |
cafb168a | 457 | if (stat->pages) |
493762fc | 458 | return 0; |
bac429f0 | 459 | |
cafb168a SR |
460 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
461 | if (!stat->pages) | |
493762fc | 462 | return -ENOMEM; |
bac429f0 | 463 | |
318e0a73 SR |
464 | #ifdef CONFIG_DYNAMIC_FTRACE |
465 | functions = ftrace_update_tot_cnt; | |
466 | #else | |
467 | /* | |
468 | * We do not know the number of functions that exist because | |
469 | * dynamic tracing is what counts them. With past experience | |
470 | * we have around 20K functions. That should be more than enough. | |
471 | * It is highly unlikely we will execute every function in | |
472 | * the kernel. | |
473 | */ | |
474 | functions = 20000; | |
475 | #endif | |
476 | ||
cafb168a | 477 | pg = stat->start = stat->pages; |
bac429f0 | 478 | |
318e0a73 SR |
479 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
480 | ||
481 | for (i = 0; i < pages; i++) { | |
493762fc | 482 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 483 | if (!pg->next) |
318e0a73 | 484 | goto out_free; |
493762fc SR |
485 | pg = pg->next; |
486 | } | |
487 | ||
488 | return 0; | |
318e0a73 SR |
489 | |
490 | out_free: | |
491 | pg = stat->start; | |
492 | while (pg) { | |
493 | unsigned long tmp = (unsigned long)pg; | |
494 | ||
495 | pg = pg->next; | |
496 | free_page(tmp); | |
497 | } | |
498 | ||
499 | free_page((unsigned long)stat->pages); | |
500 | stat->pages = NULL; | |
501 | stat->start = NULL; | |
502 | ||
503 | return -ENOMEM; | |
bac429f0 SR |
504 | } |
505 | ||
cafb168a | 506 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 507 | { |
cafb168a | 508 | struct ftrace_profile_stat *stat; |
493762fc | 509 | int size; |
bac429f0 | 510 | |
cafb168a SR |
511 | stat = &per_cpu(ftrace_profile_stats, cpu); |
512 | ||
513 | if (stat->hash) { | |
493762fc | 514 | /* If the profile is already created, simply reset it */ |
cafb168a | 515 | ftrace_profile_reset(stat); |
493762fc SR |
516 | return 0; |
517 | } | |
bac429f0 | 518 | |
493762fc SR |
519 | /* |
520 | * We are profiling all functions, but usually only a few thousand | |
521 | * functions are hit. We'll make a hash of 1024 items. | |
522 | */ | |
523 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 524 | |
cafb168a | 525 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
493762fc | 526 | |
cafb168a | 527 | if (!stat->hash) |
493762fc SR |
528 | return -ENOMEM; |
529 | ||
cafb168a SR |
530 | if (!ftrace_profile_bits) { |
531 | size--; | |
493762fc | 532 | |
cafb168a SR |
533 | for (; size; size >>= 1) |
534 | ftrace_profile_bits++; | |
535 | } | |
493762fc | 536 | |
318e0a73 | 537 | /* Preallocate the function profiling pages */ |
cafb168a SR |
538 | if (ftrace_profile_pages_init(stat) < 0) { |
539 | kfree(stat->hash); | |
540 | stat->hash = NULL; | |
493762fc SR |
541 | return -ENOMEM; |
542 | } | |
543 | ||
544 | return 0; | |
bac429f0 SR |
545 | } |
546 | ||
cafb168a SR |
547 | static int ftrace_profile_init(void) |
548 | { | |
549 | int cpu; | |
550 | int ret = 0; | |
551 | ||
552 | for_each_online_cpu(cpu) { | |
553 | ret = ftrace_profile_init_cpu(cpu); | |
554 | if (ret) | |
555 | break; | |
556 | } | |
557 | ||
558 | return ret; | |
559 | } | |
560 | ||
493762fc | 561 | /* interrupts must be disabled */ |
cafb168a SR |
562 | static struct ftrace_profile * |
563 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 564 | { |
493762fc | 565 | struct ftrace_profile *rec; |
bac429f0 SR |
566 | struct hlist_head *hhd; |
567 | struct hlist_node *n; | |
bac429f0 SR |
568 | unsigned long key; |
569 | ||
bac429f0 | 570 | key = hash_long(ip, ftrace_profile_bits); |
cafb168a | 571 | hhd = &stat->hash[key]; |
bac429f0 SR |
572 | |
573 | if (hlist_empty(hhd)) | |
574 | return NULL; | |
575 | ||
bac429f0 SR |
576 | hlist_for_each_entry_rcu(rec, n, hhd, node) { |
577 | if (rec->ip == ip) | |
493762fc SR |
578 | return rec; |
579 | } | |
580 | ||
581 | return NULL; | |
582 | } | |
583 | ||
cafb168a SR |
584 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
585 | struct ftrace_profile *rec) | |
493762fc SR |
586 | { |
587 | unsigned long key; | |
588 | ||
589 | key = hash_long(rec->ip, ftrace_profile_bits); | |
cafb168a | 590 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
591 | } |
592 | ||
318e0a73 SR |
593 | /* |
594 | * The memory is already allocated, this simply finds a new record to use. | |
595 | */ | |
493762fc | 596 | static struct ftrace_profile * |
318e0a73 | 597 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
598 | { |
599 | struct ftrace_profile *rec = NULL; | |
600 | ||
318e0a73 | 601 | /* prevent recursion (from NMIs) */ |
cafb168a | 602 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
603 | goto out; |
604 | ||
493762fc | 605 | /* |
318e0a73 SR |
606 | * Try to find the function again since an NMI |
607 | * could have added it | |
493762fc | 608 | */ |
cafb168a | 609 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 610 | if (rec) |
cafb168a | 611 | goto out; |
493762fc | 612 | |
cafb168a SR |
613 | if (stat->pages->index == PROFILES_PER_PAGE) { |
614 | if (!stat->pages->next) | |
615 | goto out; | |
616 | stat->pages = stat->pages->next; | |
bac429f0 | 617 | } |
493762fc | 618 | |
cafb168a | 619 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 620 | rec->ip = ip; |
cafb168a | 621 | ftrace_add_profile(stat, rec); |
493762fc | 622 | |
bac429f0 | 623 | out: |
cafb168a | 624 | atomic_dec(&stat->disabled); |
bac429f0 SR |
625 | |
626 | return rec; | |
627 | } | |
628 | ||
629 | static void | |
630 | function_profile_call(unsigned long ip, unsigned long parent_ip) | |
631 | { | |
cafb168a | 632 | struct ftrace_profile_stat *stat; |
493762fc | 633 | struct ftrace_profile *rec; |
bac429f0 SR |
634 | unsigned long flags; |
635 | ||
636 | if (!ftrace_profile_enabled) | |
637 | return; | |
638 | ||
639 | local_irq_save(flags); | |
cafb168a SR |
640 | |
641 | stat = &__get_cpu_var(ftrace_profile_stats); | |
0f6ce3de | 642 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
643 | goto out; |
644 | ||
645 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 646 | if (!rec) { |
318e0a73 | 647 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
648 | if (!rec) |
649 | goto out; | |
650 | } | |
bac429f0 SR |
651 | |
652 | rec->counter++; | |
653 | out: | |
654 | local_irq_restore(flags); | |
655 | } | |
656 | ||
0706f1c4 SR |
657 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
658 | static int profile_graph_entry(struct ftrace_graph_ent *trace) | |
659 | { | |
660 | function_profile_call(trace->func, 0); | |
661 | return 1; | |
662 | } | |
663 | ||
664 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
665 | { | |
cafb168a | 666 | struct ftrace_profile_stat *stat; |
a2a16d6a | 667 | unsigned long long calltime; |
0706f1c4 | 668 | struct ftrace_profile *rec; |
cafb168a | 669 | unsigned long flags; |
0706f1c4 SR |
670 | |
671 | local_irq_save(flags); | |
cafb168a | 672 | stat = &__get_cpu_var(ftrace_profile_stats); |
0f6ce3de | 673 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
674 | goto out; |
675 | ||
37e44bc5 SR |
676 | /* If the calltime was zero'd ignore it */ |
677 | if (!trace->calltime) | |
678 | goto out; | |
679 | ||
a2a16d6a SR |
680 | calltime = trace->rettime - trace->calltime; |
681 | ||
682 | if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) { | |
683 | int index; | |
684 | ||
685 | index = trace->depth; | |
686 | ||
687 | /* Append this call time to the parent time to subtract */ | |
688 | if (index) | |
689 | current->ret_stack[index - 1].subtime += calltime; | |
690 | ||
691 | if (current->ret_stack[index].subtime < calltime) | |
692 | calltime -= current->ret_stack[index].subtime; | |
693 | else | |
694 | calltime = 0; | |
695 | } | |
696 | ||
cafb168a | 697 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 698 | if (rec) { |
a2a16d6a | 699 | rec->time += calltime; |
e330b3bc CD |
700 | rec->time_squared += calltime * calltime; |
701 | } | |
a2a16d6a | 702 | |
cafb168a | 703 | out: |
0706f1c4 SR |
704 | local_irq_restore(flags); |
705 | } | |
706 | ||
707 | static int register_ftrace_profiler(void) | |
708 | { | |
709 | return register_ftrace_graph(&profile_graph_return, | |
710 | &profile_graph_entry); | |
711 | } | |
712 | ||
713 | static void unregister_ftrace_profiler(void) | |
714 | { | |
715 | unregister_ftrace_graph(); | |
716 | } | |
717 | #else | |
bac429f0 SR |
718 | static struct ftrace_ops ftrace_profile_ops __read_mostly = |
719 | { | |
fb9fb015 | 720 | .func = function_profile_call, |
bac429f0 SR |
721 | }; |
722 | ||
0706f1c4 SR |
723 | static int register_ftrace_profiler(void) |
724 | { | |
725 | return register_ftrace_function(&ftrace_profile_ops); | |
726 | } | |
727 | ||
728 | static void unregister_ftrace_profiler(void) | |
729 | { | |
730 | unregister_ftrace_function(&ftrace_profile_ops); | |
731 | } | |
732 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
733 | ||
bac429f0 SR |
734 | static ssize_t |
735 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
736 | size_t cnt, loff_t *ppos) | |
737 | { | |
738 | unsigned long val; | |
fb9fb015 | 739 | char buf[64]; /* big enough to hold a number */ |
bac429f0 SR |
740 | int ret; |
741 | ||
bac429f0 SR |
742 | if (cnt >= sizeof(buf)) |
743 | return -EINVAL; | |
744 | ||
745 | if (copy_from_user(&buf, ubuf, cnt)) | |
746 | return -EFAULT; | |
747 | ||
748 | buf[cnt] = 0; | |
749 | ||
750 | ret = strict_strtoul(buf, 10, &val); | |
751 | if (ret < 0) | |
752 | return ret; | |
753 | ||
754 | val = !!val; | |
755 | ||
756 | mutex_lock(&ftrace_profile_lock); | |
757 | if (ftrace_profile_enabled ^ val) { | |
758 | if (val) { | |
493762fc SR |
759 | ret = ftrace_profile_init(); |
760 | if (ret < 0) { | |
761 | cnt = ret; | |
762 | goto out; | |
763 | } | |
764 | ||
0706f1c4 SR |
765 | ret = register_ftrace_profiler(); |
766 | if (ret < 0) { | |
767 | cnt = ret; | |
768 | goto out; | |
769 | } | |
bac429f0 SR |
770 | ftrace_profile_enabled = 1; |
771 | } else { | |
772 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
773 | /* |
774 | * unregister_ftrace_profiler calls stop_machine | |
775 | * so this acts like an synchronize_sched. | |
776 | */ | |
0706f1c4 | 777 | unregister_ftrace_profiler(); |
bac429f0 SR |
778 | } |
779 | } | |
493762fc | 780 | out: |
bac429f0 SR |
781 | mutex_unlock(&ftrace_profile_lock); |
782 | ||
cf8517cf | 783 | *ppos += cnt; |
bac429f0 SR |
784 | |
785 | return cnt; | |
786 | } | |
787 | ||
493762fc SR |
788 | static ssize_t |
789 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
790 | size_t cnt, loff_t *ppos) | |
791 | { | |
fb9fb015 | 792 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
793 | int r; |
794 | ||
795 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
796 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
797 | } | |
798 | ||
bac429f0 SR |
799 | static const struct file_operations ftrace_profile_fops = { |
800 | .open = tracing_open_generic, | |
801 | .read = ftrace_profile_read, | |
802 | .write = ftrace_profile_write, | |
6038f373 | 803 | .llseek = default_llseek, |
bac429f0 SR |
804 | }; |
805 | ||
cafb168a SR |
806 | /* used to initialize the real stat files */ |
807 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
808 | .name = "functions", |
809 | .stat_start = function_stat_start, | |
810 | .stat_next = function_stat_next, | |
811 | .stat_cmp = function_stat_cmp, | |
812 | .stat_headers = function_stat_headers, | |
813 | .stat_show = function_stat_show | |
cafb168a SR |
814 | }; |
815 | ||
6ab5d668 | 816 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 | 817 | { |
cafb168a | 818 | struct ftrace_profile_stat *stat; |
bac429f0 | 819 | struct dentry *entry; |
cafb168a | 820 | char *name; |
bac429f0 | 821 | int ret; |
cafb168a SR |
822 | int cpu; |
823 | ||
824 | for_each_possible_cpu(cpu) { | |
825 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
826 | ||
827 | /* allocate enough for function name + cpu number */ | |
828 | name = kmalloc(32, GFP_KERNEL); | |
829 | if (!name) { | |
830 | /* | |
831 | * The files created are permanent, if something happens | |
832 | * we still do not free memory. | |
833 | */ | |
cafb168a SR |
834 | WARN(1, |
835 | "Could not allocate stat file for cpu %d\n", | |
836 | cpu); | |
837 | return; | |
838 | } | |
839 | stat->stat = function_stats; | |
840 | snprintf(name, 32, "function%d", cpu); | |
841 | stat->stat.name = name; | |
842 | ret = register_stat_tracer(&stat->stat); | |
843 | if (ret) { | |
844 | WARN(1, | |
845 | "Could not register function stat for cpu %d\n", | |
846 | cpu); | |
847 | kfree(name); | |
848 | return; | |
849 | } | |
bac429f0 SR |
850 | } |
851 | ||
852 | entry = debugfs_create_file("function_profile_enabled", 0644, | |
853 | d_tracer, NULL, &ftrace_profile_fops); | |
854 | if (!entry) | |
855 | pr_warning("Could not create debugfs " | |
856 | "'function_profile_enabled' entry\n"); | |
857 | } | |
858 | ||
bac429f0 | 859 | #else /* CONFIG_FUNCTION_PROFILER */ |
6ab5d668 | 860 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 SR |
861 | { |
862 | } | |
bac429f0 SR |
863 | #endif /* CONFIG_FUNCTION_PROFILER */ |
864 | ||
493762fc SR |
865 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; |
866 | ||
867 | #ifdef CONFIG_DYNAMIC_FTRACE | |
868 | ||
869 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD | |
870 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
871 | #endif | |
872 | ||
873 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; | |
874 | ||
875 | struct ftrace_func_probe { | |
876 | struct hlist_node node; | |
877 | struct ftrace_probe_ops *ops; | |
878 | unsigned long flags; | |
879 | unsigned long ip; | |
880 | void *data; | |
881 | struct rcu_head rcu; | |
882 | }; | |
883 | ||
884 | enum { | |
885 | FTRACE_ENABLE_CALLS = (1 << 0), | |
886 | FTRACE_DISABLE_CALLS = (1 << 1), | |
887 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
888 | FTRACE_ENABLE_MCOUNT = (1 << 3), | |
889 | FTRACE_DISABLE_MCOUNT = (1 << 4), | |
890 | FTRACE_START_FUNC_RET = (1 << 5), | |
891 | FTRACE_STOP_FUNC_RET = (1 << 6), | |
892 | }; | |
893 | ||
894 | static int ftrace_filtered; | |
895 | ||
896 | static struct dyn_ftrace *ftrace_new_addrs; | |
897 | ||
898 | static DEFINE_MUTEX(ftrace_regex_lock); | |
899 | ||
900 | struct ftrace_page { | |
901 | struct ftrace_page *next; | |
902 | int index; | |
903 | struct dyn_ftrace records[]; | |
904 | }; | |
905 | ||
906 | #define ENTRIES_PER_PAGE \ | |
907 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
908 | ||
909 | /* estimate from running different kernels */ | |
910 | #define NR_TO_INIT 10000 | |
911 | ||
912 | static struct ftrace_page *ftrace_pages_start; | |
913 | static struct ftrace_page *ftrace_pages; | |
914 | ||
915 | static struct dyn_ftrace *ftrace_free_records; | |
916 | ||
917 | /* | |
918 | * This is a double for. Do not use 'break' to break out of the loop, | |
919 | * you must use a goto. | |
920 | */ | |
921 | #define do_for_each_ftrace_rec(pg, rec) \ | |
922 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
923 | int _____i; \ | |
924 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
925 | rec = &pg->records[_____i]; | |
926 | ||
927 | #define while_for_each_ftrace_rec() \ | |
928 | } \ | |
929 | } | |
930 | ||
e309b41d | 931 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
37ad5084 | 932 | { |
ee000b7f | 933 | rec->freelist = ftrace_free_records; |
37ad5084 SR |
934 | ftrace_free_records = rec; |
935 | rec->flags |= FTRACE_FL_FREE; | |
936 | } | |
937 | ||
e309b41d | 938 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 939 | { |
37ad5084 SR |
940 | struct dyn_ftrace *rec; |
941 | ||
942 | /* First check for freed records */ | |
943 | if (ftrace_free_records) { | |
944 | rec = ftrace_free_records; | |
945 | ||
37ad5084 | 946 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
6912896e | 947 | FTRACE_WARN_ON_ONCE(1); |
37ad5084 SR |
948 | ftrace_free_records = NULL; |
949 | return NULL; | |
950 | } | |
951 | ||
ee000b7f | 952 | ftrace_free_records = rec->freelist; |
37ad5084 SR |
953 | memset(rec, 0, sizeof(*rec)); |
954 | return rec; | |
955 | } | |
956 | ||
3c1720f0 | 957 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
08f5ac90 SR |
958 | if (!ftrace_pages->next) { |
959 | /* allocate another page */ | |
960 | ftrace_pages->next = | |
961 | (void *)get_zeroed_page(GFP_KERNEL); | |
962 | if (!ftrace_pages->next) | |
963 | return NULL; | |
964 | } | |
3c1720f0 SR |
965 | ftrace_pages = ftrace_pages->next; |
966 | } | |
967 | ||
968 | return &ftrace_pages->records[ftrace_pages->index++]; | |
969 | } | |
970 | ||
08f5ac90 | 971 | static struct dyn_ftrace * |
d61f82d0 | 972 | ftrace_record_ip(unsigned long ip) |
3d083395 | 973 | { |
08f5ac90 | 974 | struct dyn_ftrace *rec; |
3d083395 | 975 | |
f3c7ac40 | 976 | if (ftrace_disabled) |
08f5ac90 | 977 | return NULL; |
3d083395 | 978 | |
08f5ac90 SR |
979 | rec = ftrace_alloc_dyn_node(ip); |
980 | if (!rec) | |
981 | return NULL; | |
3d083395 | 982 | |
08f5ac90 | 983 | rec->ip = ip; |
ee000b7f | 984 | rec->newlist = ftrace_new_addrs; |
e94142a6 | 985 | ftrace_new_addrs = rec; |
3d083395 | 986 | |
08f5ac90 | 987 | return rec; |
3d083395 SR |
988 | } |
989 | ||
b17e8a37 SR |
990 | static void print_ip_ins(const char *fmt, unsigned char *p) |
991 | { | |
992 | int i; | |
993 | ||
994 | printk(KERN_CONT "%s", fmt); | |
995 | ||
996 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
997 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
998 | } | |
999 | ||
31e88909 | 1000 | static void ftrace_bug(int failed, unsigned long ip) |
b17e8a37 SR |
1001 | { |
1002 | switch (failed) { | |
1003 | case -EFAULT: | |
1004 | FTRACE_WARN_ON_ONCE(1); | |
1005 | pr_info("ftrace faulted on modifying "); | |
1006 | print_ip_sym(ip); | |
1007 | break; | |
1008 | case -EINVAL: | |
1009 | FTRACE_WARN_ON_ONCE(1); | |
1010 | pr_info("ftrace failed to modify "); | |
1011 | print_ip_sym(ip); | |
b17e8a37 | 1012 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
1013 | printk(KERN_CONT "\n"); |
1014 | break; | |
1015 | case -EPERM: | |
1016 | FTRACE_WARN_ON_ONCE(1); | |
1017 | pr_info("ftrace faulted on writing "); | |
1018 | print_ip_sym(ip); | |
1019 | break; | |
1020 | default: | |
1021 | FTRACE_WARN_ON_ONCE(1); | |
1022 | pr_info("ftrace faulted on unknown error "); | |
1023 | print_ip_sym(ip); | |
1024 | } | |
1025 | } | |
1026 | ||
3c1720f0 | 1027 | |
2cfa1978 MH |
1028 | /* Return 1 if the address range is reserved for ftrace */ |
1029 | int ftrace_text_reserved(void *start, void *end) | |
1030 | { | |
1031 | struct dyn_ftrace *rec; | |
1032 | struct ftrace_page *pg; | |
1033 | ||
1034 | do_for_each_ftrace_rec(pg, rec) { | |
1035 | if (rec->ip <= (unsigned long)end && | |
1036 | rec->ip + MCOUNT_INSN_SIZE > (unsigned long)start) | |
1037 | return 1; | |
1038 | } while_for_each_ftrace_rec(); | |
1039 | return 0; | |
1040 | } | |
1041 | ||
1042 | ||
0eb96701 | 1043 | static int |
31e88909 | 1044 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) |
5072c59f | 1045 | { |
e7d3737e | 1046 | unsigned long ftrace_addr; |
64fbcd16 | 1047 | unsigned long flag = 0UL; |
e7d3737e | 1048 | |
f0001207 | 1049 | ftrace_addr = (unsigned long)FTRACE_ADDR; |
5072c59f | 1050 | |
982c350b | 1051 | /* |
64fbcd16 XG |
1052 | * If this record is not to be traced or we want to disable it, |
1053 | * then disable it. | |
982c350b | 1054 | * |
64fbcd16 | 1055 | * If we want to enable it and filtering is off, then enable it. |
982c350b | 1056 | * |
64fbcd16 XG |
1057 | * If we want to enable it and filtering is on, enable it only if |
1058 | * it's filtered | |
982c350b | 1059 | */ |
64fbcd16 XG |
1060 | if (enable && !(rec->flags & FTRACE_FL_NOTRACE)) { |
1061 | if (!ftrace_filtered || (rec->flags & FTRACE_FL_FILTER)) | |
1062 | flag = FTRACE_FL_ENABLED; | |
1063 | } | |
982c350b | 1064 | |
64fbcd16 XG |
1065 | /* If the state of this record hasn't changed, then do nothing */ |
1066 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
1067 | return 0; | |
982c350b | 1068 | |
64fbcd16 XG |
1069 | if (flag) { |
1070 | rec->flags |= FTRACE_FL_ENABLED; | |
1071 | return ftrace_make_call(rec, ftrace_addr); | |
5072c59f SR |
1072 | } |
1073 | ||
64fbcd16 XG |
1074 | rec->flags &= ~FTRACE_FL_ENABLED; |
1075 | return ftrace_make_nop(NULL, rec, ftrace_addr); | |
5072c59f SR |
1076 | } |
1077 | ||
e309b41d | 1078 | static void ftrace_replace_code(int enable) |
3c1720f0 | 1079 | { |
3c1720f0 SR |
1080 | struct dyn_ftrace *rec; |
1081 | struct ftrace_page *pg; | |
6a24a244 | 1082 | int failed; |
3c1720f0 | 1083 | |
265c831c SR |
1084 | do_for_each_ftrace_rec(pg, rec) { |
1085 | /* | |
fa9d13cf Z |
1086 | * Skip over free records, records that have |
1087 | * failed and not converted. | |
265c831c SR |
1088 | */ |
1089 | if (rec->flags & FTRACE_FL_FREE || | |
fa9d13cf | 1090 | rec->flags & FTRACE_FL_FAILED || |
03303549 | 1091 | !(rec->flags & FTRACE_FL_CONVERTED)) |
265c831c SR |
1092 | continue; |
1093 | ||
265c831c | 1094 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 1095 | if (failed) { |
265c831c | 1096 | rec->flags |= FTRACE_FL_FAILED; |
3279ba37 SR |
1097 | ftrace_bug(failed, rec->ip); |
1098 | /* Stop processing */ | |
1099 | return; | |
3c1720f0 | 1100 | } |
265c831c | 1101 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
1102 | } |
1103 | ||
492a7ea5 | 1104 | static int |
31e88909 | 1105 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 SR |
1106 | { |
1107 | unsigned long ip; | |
593eb8a2 | 1108 | int ret; |
3c1720f0 SR |
1109 | |
1110 | ip = rec->ip; | |
1111 | ||
25aac9dc | 1112 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 1113 | if (ret) { |
31e88909 | 1114 | ftrace_bug(ret, ip); |
3c1720f0 | 1115 | rec->flags |= FTRACE_FL_FAILED; |
492a7ea5 | 1116 | return 0; |
37ad5084 | 1117 | } |
492a7ea5 | 1118 | return 1; |
3c1720f0 SR |
1119 | } |
1120 | ||
000ab691 SR |
1121 | /* |
1122 | * archs can override this function if they must do something | |
1123 | * before the modifying code is performed. | |
1124 | */ | |
1125 | int __weak ftrace_arch_code_modify_prepare(void) | |
1126 | { | |
1127 | return 0; | |
1128 | } | |
1129 | ||
1130 | /* | |
1131 | * archs can override this function if they must do something | |
1132 | * after the modifying code is performed. | |
1133 | */ | |
1134 | int __weak ftrace_arch_code_modify_post_process(void) | |
1135 | { | |
1136 | return 0; | |
1137 | } | |
1138 | ||
e309b41d | 1139 | static int __ftrace_modify_code(void *data) |
3d083395 | 1140 | { |
d61f82d0 SR |
1141 | int *command = data; |
1142 | ||
a3583244 | 1143 | if (*command & FTRACE_ENABLE_CALLS) |
d61f82d0 | 1144 | ftrace_replace_code(1); |
a3583244 | 1145 | else if (*command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
1146 | ftrace_replace_code(0); |
1147 | ||
1148 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
1149 | ftrace_update_ftrace_func(ftrace_trace_function); | |
1150 | ||
5a45cfe1 SR |
1151 | if (*command & FTRACE_START_FUNC_RET) |
1152 | ftrace_enable_ftrace_graph_caller(); | |
1153 | else if (*command & FTRACE_STOP_FUNC_RET) | |
1154 | ftrace_disable_ftrace_graph_caller(); | |
1155 | ||
d61f82d0 | 1156 | return 0; |
3d083395 SR |
1157 | } |
1158 | ||
e309b41d | 1159 | static void ftrace_run_update_code(int command) |
3d083395 | 1160 | { |
000ab691 SR |
1161 | int ret; |
1162 | ||
1163 | ret = ftrace_arch_code_modify_prepare(); | |
1164 | FTRACE_WARN_ON(ret); | |
1165 | if (ret) | |
1166 | return; | |
1167 | ||
784e2d76 | 1168 | stop_machine(__ftrace_modify_code, &command, NULL); |
000ab691 SR |
1169 | |
1170 | ret = ftrace_arch_code_modify_post_process(); | |
1171 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
1172 | } |
1173 | ||
d61f82d0 | 1174 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 1175 | static int ftrace_start_up; |
df4fc315 SR |
1176 | |
1177 | static void ftrace_startup_enable(int command) | |
1178 | { | |
1179 | if (saved_ftrace_func != ftrace_trace_function) { | |
1180 | saved_ftrace_func = ftrace_trace_function; | |
1181 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1182 | } | |
1183 | ||
1184 | if (!command || !ftrace_enabled) | |
1185 | return; | |
1186 | ||
1187 | ftrace_run_update_code(command); | |
1188 | } | |
d61f82d0 | 1189 | |
5a45cfe1 | 1190 | static void ftrace_startup(int command) |
3d083395 | 1191 | { |
4eebcc81 SR |
1192 | if (unlikely(ftrace_disabled)) |
1193 | return; | |
1194 | ||
60a7ecf4 | 1195 | ftrace_start_up++; |
982c350b | 1196 | command |= FTRACE_ENABLE_CALLS; |
d61f82d0 | 1197 | |
df4fc315 | 1198 | ftrace_startup_enable(command); |
3d083395 SR |
1199 | } |
1200 | ||
5a45cfe1 | 1201 | static void ftrace_shutdown(int command) |
3d083395 | 1202 | { |
4eebcc81 SR |
1203 | if (unlikely(ftrace_disabled)) |
1204 | return; | |
1205 | ||
60a7ecf4 | 1206 | ftrace_start_up--; |
9ea1a153 FW |
1207 | /* |
1208 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
1209 | * critical but the ftrace_call callers may be never nopped again after | |
1210 | * further ftrace uses. | |
1211 | */ | |
1212 | WARN_ON_ONCE(ftrace_start_up < 0); | |
1213 | ||
60a7ecf4 | 1214 | if (!ftrace_start_up) |
d61f82d0 | 1215 | command |= FTRACE_DISABLE_CALLS; |
3d083395 | 1216 | |
d61f82d0 SR |
1217 | if (saved_ftrace_func != ftrace_trace_function) { |
1218 | saved_ftrace_func = ftrace_trace_function; | |
1219 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1220 | } | |
3d083395 | 1221 | |
d61f82d0 | 1222 | if (!command || !ftrace_enabled) |
e6ea44e9 | 1223 | return; |
d61f82d0 SR |
1224 | |
1225 | ftrace_run_update_code(command); | |
3d083395 SR |
1226 | } |
1227 | ||
e309b41d | 1228 | static void ftrace_startup_sysctl(void) |
b0fc494f | 1229 | { |
d61f82d0 SR |
1230 | int command = FTRACE_ENABLE_MCOUNT; |
1231 | ||
4eebcc81 SR |
1232 | if (unlikely(ftrace_disabled)) |
1233 | return; | |
1234 | ||
d61f82d0 SR |
1235 | /* Force update next time */ |
1236 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
1237 | /* ftrace_start_up is true if we want ftrace running */ |
1238 | if (ftrace_start_up) | |
d61f82d0 SR |
1239 | command |= FTRACE_ENABLE_CALLS; |
1240 | ||
1241 | ftrace_run_update_code(command); | |
b0fc494f SR |
1242 | } |
1243 | ||
e309b41d | 1244 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 1245 | { |
d61f82d0 SR |
1246 | int command = FTRACE_DISABLE_MCOUNT; |
1247 | ||
4eebcc81 SR |
1248 | if (unlikely(ftrace_disabled)) |
1249 | return; | |
1250 | ||
60a7ecf4 SR |
1251 | /* ftrace_start_up is true if ftrace is running */ |
1252 | if (ftrace_start_up) | |
d61f82d0 SR |
1253 | command |= FTRACE_DISABLE_CALLS; |
1254 | ||
1255 | ftrace_run_update_code(command); | |
b0fc494f SR |
1256 | } |
1257 | ||
3d083395 SR |
1258 | static cycle_t ftrace_update_time; |
1259 | static unsigned long ftrace_update_cnt; | |
1260 | unsigned long ftrace_update_tot_cnt; | |
1261 | ||
31e88909 | 1262 | static int ftrace_update_code(struct module *mod) |
3d083395 | 1263 | { |
e94142a6 | 1264 | struct dyn_ftrace *p; |
f22f9a89 | 1265 | cycle_t start, stop; |
3d083395 | 1266 | |
750ed1a4 | 1267 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1268 | ftrace_update_cnt = 0; |
1269 | ||
e94142a6 | 1270 | while (ftrace_new_addrs) { |
3d083395 | 1271 | |
08f5ac90 SR |
1272 | /* If something went wrong, bail without enabling anything */ |
1273 | if (unlikely(ftrace_disabled)) | |
1274 | return -1; | |
f22f9a89 | 1275 | |
e94142a6 | 1276 | p = ftrace_new_addrs; |
ee000b7f | 1277 | ftrace_new_addrs = p->newlist; |
e94142a6 | 1278 | p->flags = 0L; |
f22f9a89 | 1279 | |
5cb084bb JO |
1280 | /* |
1281 | * Do the initial record convertion from mcount jump | |
1282 | * to the NOP instructions. | |
1283 | */ | |
1284 | if (!ftrace_code_disable(mod, p)) { | |
08f5ac90 | 1285 | ftrace_free_rec(p); |
5cb084bb JO |
1286 | continue; |
1287 | } | |
1288 | ||
1289 | p->flags |= FTRACE_FL_CONVERTED; | |
1290 | ftrace_update_cnt++; | |
1291 | ||
1292 | /* | |
1293 | * If the tracing is enabled, go ahead and enable the record. | |
1294 | * | |
1295 | * The reason not to enable the record immediatelly is the | |
1296 | * inherent check of ftrace_make_nop/ftrace_make_call for | |
1297 | * correct previous instructions. Making first the NOP | |
1298 | * conversion puts the module to the correct state, thus | |
1299 | * passing the ftrace_make_call check. | |
1300 | */ | |
1301 | if (ftrace_start_up) { | |
1302 | int failed = __ftrace_replace_code(p, 1); | |
1303 | if (failed) { | |
1304 | ftrace_bug(failed, p->ip); | |
1305 | ftrace_free_rec(p); | |
1306 | } | |
1307 | } | |
3d083395 SR |
1308 | } |
1309 | ||
750ed1a4 | 1310 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1311 | ftrace_update_time = stop - start; |
1312 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
1313 | ||
16444a8a ACM |
1314 | return 0; |
1315 | } | |
1316 | ||
68bf21aa | 1317 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
1318 | { |
1319 | struct ftrace_page *pg; | |
1320 | int cnt; | |
1321 | int i; | |
3c1720f0 SR |
1322 | |
1323 | /* allocate a few pages */ | |
1324 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
1325 | if (!ftrace_pages_start) | |
1326 | return -1; | |
1327 | ||
1328 | /* | |
1329 | * Allocate a few more pages. | |
1330 | * | |
1331 | * TODO: have some parser search vmlinux before | |
1332 | * final linking to find all calls to ftrace. | |
1333 | * Then we can: | |
1334 | * a) know how many pages to allocate. | |
1335 | * and/or | |
1336 | * b) set up the table then. | |
1337 | * | |
1338 | * The dynamic code is still necessary for | |
1339 | * modules. | |
1340 | */ | |
1341 | ||
1342 | pg = ftrace_pages = ftrace_pages_start; | |
1343 | ||
68bf21aa | 1344 | cnt = num_to_init / ENTRIES_PER_PAGE; |
08f5ac90 | 1345 | pr_info("ftrace: allocating %ld entries in %d pages\n", |
5821e1b7 | 1346 | num_to_init, cnt + 1); |
3c1720f0 SR |
1347 | |
1348 | for (i = 0; i < cnt; i++) { | |
1349 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
1350 | ||
1351 | /* If we fail, we'll try later anyway */ | |
1352 | if (!pg->next) | |
1353 | break; | |
1354 | ||
1355 | pg = pg->next; | |
1356 | } | |
1357 | ||
1358 | return 0; | |
1359 | } | |
1360 | ||
5072c59f SR |
1361 | enum { |
1362 | FTRACE_ITER_FILTER = (1 << 0), | |
689fd8b6 | 1363 | FTRACE_ITER_NOTRACE = (1 << 1), |
1364 | FTRACE_ITER_FAILURES = (1 << 2), | |
1365 | FTRACE_ITER_PRINTALL = (1 << 3), | |
1366 | FTRACE_ITER_HASH = (1 << 4), | |
5072c59f SR |
1367 | }; |
1368 | ||
1369 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
1370 | ||
1371 | struct ftrace_iterator { | |
5072c59f | 1372 | struct ftrace_page *pg; |
8fc0c701 | 1373 | int hidx; |
431aa3fb | 1374 | int idx; |
5072c59f | 1375 | unsigned flags; |
689fd8b6 | 1376 | struct trace_parser parser; |
5072c59f SR |
1377 | }; |
1378 | ||
8fc0c701 SR |
1379 | static void * |
1380 | t_hash_next(struct seq_file *m, void *v, loff_t *pos) | |
1381 | { | |
1382 | struct ftrace_iterator *iter = m->private; | |
1383 | struct hlist_node *hnd = v; | |
1384 | struct hlist_head *hhd; | |
1385 | ||
1386 | WARN_ON(!(iter->flags & FTRACE_ITER_HASH)); | |
1387 | ||
1388 | (*pos)++; | |
1389 | ||
1390 | retry: | |
1391 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
1392 | return NULL; | |
1393 | ||
1394 | hhd = &ftrace_func_hash[iter->hidx]; | |
1395 | ||
1396 | if (hlist_empty(hhd)) { | |
1397 | iter->hidx++; | |
1398 | hnd = NULL; | |
1399 | goto retry; | |
1400 | } | |
1401 | ||
1402 | if (!hnd) | |
1403 | hnd = hhd->first; | |
1404 | else { | |
1405 | hnd = hnd->next; | |
1406 | if (!hnd) { | |
1407 | iter->hidx++; | |
1408 | goto retry; | |
1409 | } | |
1410 | } | |
1411 | ||
1412 | return hnd; | |
1413 | } | |
1414 | ||
1415 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
1416 | { | |
1417 | struct ftrace_iterator *iter = m->private; | |
1418 | void *p = NULL; | |
d82d6244 LZ |
1419 | loff_t l; |
1420 | ||
1421 | if (!(iter->flags & FTRACE_ITER_HASH)) | |
1422 | *pos = 0; | |
8fc0c701 SR |
1423 | |
1424 | iter->flags |= FTRACE_ITER_HASH; | |
1425 | ||
d82d6244 LZ |
1426 | iter->hidx = 0; |
1427 | for (l = 0; l <= *pos; ) { | |
1428 | p = t_hash_next(m, p, &l); | |
1429 | if (!p) | |
1430 | break; | |
1431 | } | |
1432 | return p; | |
8fc0c701 SR |
1433 | } |
1434 | ||
1435 | static int t_hash_show(struct seq_file *m, void *v) | |
1436 | { | |
b6887d79 | 1437 | struct ftrace_func_probe *rec; |
8fc0c701 | 1438 | struct hlist_node *hnd = v; |
8fc0c701 | 1439 | |
b6887d79 | 1440 | rec = hlist_entry(hnd, struct ftrace_func_probe, node); |
8fc0c701 | 1441 | |
809dcf29 SR |
1442 | if (rec->ops->print) |
1443 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
1444 | ||
b375a11a | 1445 | seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func); |
8fc0c701 SR |
1446 | |
1447 | if (rec->data) | |
1448 | seq_printf(m, ":%p", rec->data); | |
1449 | seq_putc(m, '\n'); | |
1450 | ||
1451 | return 0; | |
1452 | } | |
1453 | ||
e309b41d | 1454 | static void * |
5072c59f SR |
1455 | t_next(struct seq_file *m, void *v, loff_t *pos) |
1456 | { | |
1457 | struct ftrace_iterator *iter = m->private; | |
1458 | struct dyn_ftrace *rec = NULL; | |
1459 | ||
8fc0c701 SR |
1460 | if (iter->flags & FTRACE_ITER_HASH) |
1461 | return t_hash_next(m, v, pos); | |
1462 | ||
5072c59f SR |
1463 | (*pos)++; |
1464 | ||
0c75a3ed SR |
1465 | if (iter->flags & FTRACE_ITER_PRINTALL) |
1466 | return NULL; | |
1467 | ||
5072c59f SR |
1468 | retry: |
1469 | if (iter->idx >= iter->pg->index) { | |
1470 | if (iter->pg->next) { | |
1471 | iter->pg = iter->pg->next; | |
1472 | iter->idx = 0; | |
1473 | goto retry; | |
1474 | } | |
1475 | } else { | |
1476 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
1477 | if ((rec->flags & FTRACE_FL_FREE) || |
1478 | ||
1479 | (!(iter->flags & FTRACE_ITER_FAILURES) && | |
eb9a7bf0 AS |
1480 | (rec->flags & FTRACE_FL_FAILED)) || |
1481 | ||
1482 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
a9fdda33 | 1483 | !(rec->flags & FTRACE_FL_FAILED)) || |
eb9a7bf0 | 1484 | |
0183fb1c SR |
1485 | ((iter->flags & FTRACE_ITER_FILTER) && |
1486 | !(rec->flags & FTRACE_FL_FILTER)) || | |
1487 | ||
41c52c0d SR |
1488 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
1489 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
1490 | rec = NULL; |
1491 | goto retry; | |
1492 | } | |
1493 | } | |
1494 | ||
5072c59f SR |
1495 | return rec; |
1496 | } | |
1497 | ||
1498 | static void *t_start(struct seq_file *m, loff_t *pos) | |
1499 | { | |
1500 | struct ftrace_iterator *iter = m->private; | |
1501 | void *p = NULL; | |
694ce0a5 | 1502 | loff_t l; |
5072c59f | 1503 | |
8fc0c701 | 1504 | mutex_lock(&ftrace_lock); |
0c75a3ed SR |
1505 | /* |
1506 | * For set_ftrace_filter reading, if we have the filter | |
1507 | * off, we can short cut and just print out that all | |
1508 | * functions are enabled. | |
1509 | */ | |
1510 | if (iter->flags & FTRACE_ITER_FILTER && !ftrace_filtered) { | |
1511 | if (*pos > 0) | |
8fc0c701 | 1512 | return t_hash_start(m, pos); |
0c75a3ed | 1513 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 CW |
1514 | /* reset in case of seek/pread */ |
1515 | iter->flags &= ~FTRACE_ITER_HASH; | |
0c75a3ed SR |
1516 | return iter; |
1517 | } | |
1518 | ||
8fc0c701 SR |
1519 | if (iter->flags & FTRACE_ITER_HASH) |
1520 | return t_hash_start(m, pos); | |
1521 | ||
694ce0a5 LZ |
1522 | iter->pg = ftrace_pages_start; |
1523 | iter->idx = 0; | |
1524 | for (l = 0; l <= *pos; ) { | |
1525 | p = t_next(m, p, &l); | |
1526 | if (!p) | |
1527 | break; | |
50cdaf08 | 1528 | } |
5821e1b7 | 1529 | |
694ce0a5 | 1530 | if (!p && iter->flags & FTRACE_ITER_FILTER) |
8fc0c701 SR |
1531 | return t_hash_start(m, pos); |
1532 | ||
5072c59f SR |
1533 | return p; |
1534 | } | |
1535 | ||
1536 | static void t_stop(struct seq_file *m, void *p) | |
1537 | { | |
8fc0c701 | 1538 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1539 | } |
1540 | ||
1541 | static int t_show(struct seq_file *m, void *v) | |
1542 | { | |
0c75a3ed | 1543 | struct ftrace_iterator *iter = m->private; |
5072c59f | 1544 | struct dyn_ftrace *rec = v; |
5072c59f | 1545 | |
8fc0c701 SR |
1546 | if (iter->flags & FTRACE_ITER_HASH) |
1547 | return t_hash_show(m, v); | |
1548 | ||
0c75a3ed SR |
1549 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
1550 | seq_printf(m, "#### all functions enabled ####\n"); | |
1551 | return 0; | |
1552 | } | |
1553 | ||
5072c59f SR |
1554 | if (!rec) |
1555 | return 0; | |
1556 | ||
b375a11a | 1557 | seq_printf(m, "%ps\n", (void *)rec->ip); |
5072c59f SR |
1558 | |
1559 | return 0; | |
1560 | } | |
1561 | ||
88e9d34c | 1562 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
1563 | .start = t_start, |
1564 | .next = t_next, | |
1565 | .stop = t_stop, | |
1566 | .show = t_show, | |
1567 | }; | |
1568 | ||
e309b41d | 1569 | static int |
5072c59f SR |
1570 | ftrace_avail_open(struct inode *inode, struct file *file) |
1571 | { | |
1572 | struct ftrace_iterator *iter; | |
1573 | int ret; | |
1574 | ||
4eebcc81 SR |
1575 | if (unlikely(ftrace_disabled)) |
1576 | return -ENODEV; | |
1577 | ||
5072c59f SR |
1578 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1579 | if (!iter) | |
1580 | return -ENOMEM; | |
1581 | ||
1582 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
1583 | |
1584 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1585 | if (!ret) { | |
1586 | struct seq_file *m = file->private_data; | |
4bf39a94 | 1587 | |
5072c59f | 1588 | m->private = iter; |
4bf39a94 | 1589 | } else { |
5072c59f | 1590 | kfree(iter); |
4bf39a94 | 1591 | } |
5072c59f SR |
1592 | |
1593 | return ret; | |
1594 | } | |
1595 | ||
eb9a7bf0 AS |
1596 | static int |
1597 | ftrace_failures_open(struct inode *inode, struct file *file) | |
1598 | { | |
1599 | int ret; | |
1600 | struct seq_file *m; | |
1601 | struct ftrace_iterator *iter; | |
1602 | ||
1603 | ret = ftrace_avail_open(inode, file); | |
1604 | if (!ret) { | |
1605 | m = (struct seq_file *)file->private_data; | |
1606 | iter = (struct ftrace_iterator *)m->private; | |
1607 | iter->flags = FTRACE_ITER_FAILURES; | |
1608 | } | |
1609 | ||
1610 | return ret; | |
1611 | } | |
1612 | ||
1613 | ||
41c52c0d | 1614 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
1615 | { |
1616 | struct ftrace_page *pg; | |
1617 | struct dyn_ftrace *rec; | |
41c52c0d | 1618 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f | 1619 | |
52baf119 | 1620 | mutex_lock(&ftrace_lock); |
41c52c0d SR |
1621 | if (enable) |
1622 | ftrace_filtered = 0; | |
265c831c SR |
1623 | do_for_each_ftrace_rec(pg, rec) { |
1624 | if (rec->flags & FTRACE_FL_FAILED) | |
1625 | continue; | |
1626 | rec->flags &= ~type; | |
1627 | } while_for_each_ftrace_rec(); | |
52baf119 | 1628 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1629 | } |
1630 | ||
e309b41d | 1631 | static int |
41c52c0d | 1632 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1633 | { |
1634 | struct ftrace_iterator *iter; | |
1635 | int ret = 0; | |
1636 | ||
4eebcc81 SR |
1637 | if (unlikely(ftrace_disabled)) |
1638 | return -ENODEV; | |
1639 | ||
5072c59f SR |
1640 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1641 | if (!iter) | |
1642 | return -ENOMEM; | |
1643 | ||
689fd8b6 | 1644 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { |
1645 | kfree(iter); | |
1646 | return -ENOMEM; | |
1647 | } | |
1648 | ||
41c52c0d | 1649 | mutex_lock(&ftrace_regex_lock); |
5072c59f | 1650 | if ((file->f_mode & FMODE_WRITE) && |
8650ae32 | 1651 | (file->f_flags & O_TRUNC)) |
41c52c0d | 1652 | ftrace_filter_reset(enable); |
5072c59f SR |
1653 | |
1654 | if (file->f_mode & FMODE_READ) { | |
1655 | iter->pg = ftrace_pages_start; | |
41c52c0d SR |
1656 | iter->flags = enable ? FTRACE_ITER_FILTER : |
1657 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
1658 | |
1659 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1660 | if (!ret) { | |
1661 | struct seq_file *m = file->private_data; | |
1662 | m->private = iter; | |
79fe249c LZ |
1663 | } else { |
1664 | trace_parser_put(&iter->parser); | |
5072c59f | 1665 | kfree(iter); |
79fe249c | 1666 | } |
5072c59f SR |
1667 | } else |
1668 | file->private_data = iter; | |
41c52c0d | 1669 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1670 | |
1671 | return ret; | |
1672 | } | |
1673 | ||
41c52c0d SR |
1674 | static int |
1675 | ftrace_filter_open(struct inode *inode, struct file *file) | |
1676 | { | |
1677 | return ftrace_regex_open(inode, file, 1); | |
1678 | } | |
1679 | ||
1680 | static int | |
1681 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
1682 | { | |
1683 | return ftrace_regex_open(inode, file, 0); | |
1684 | } | |
1685 | ||
e309b41d | 1686 | static loff_t |
41c52c0d | 1687 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
1688 | { |
1689 | loff_t ret; | |
1690 | ||
1691 | if (file->f_mode & FMODE_READ) | |
1692 | ret = seq_lseek(file, offset, origin); | |
1693 | else | |
1694 | file->f_pos = ret = 1; | |
1695 | ||
1696 | return ret; | |
1697 | } | |
1698 | ||
64e7c440 | 1699 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 1700 | { |
9f4801e3 | 1701 | int matched = 0; |
751e9983 | 1702 | int slen; |
9f4801e3 | 1703 | |
9f4801e3 SR |
1704 | switch (type) { |
1705 | case MATCH_FULL: | |
1706 | if (strcmp(str, regex) == 0) | |
1707 | matched = 1; | |
1708 | break; | |
1709 | case MATCH_FRONT_ONLY: | |
1710 | if (strncmp(str, regex, len) == 0) | |
1711 | matched = 1; | |
1712 | break; | |
1713 | case MATCH_MIDDLE_ONLY: | |
1714 | if (strstr(str, regex)) | |
1715 | matched = 1; | |
1716 | break; | |
1717 | case MATCH_END_ONLY: | |
751e9983 LZ |
1718 | slen = strlen(str); |
1719 | if (slen >= len && memcmp(str + slen - len, regex, len) == 0) | |
9f4801e3 SR |
1720 | matched = 1; |
1721 | break; | |
1722 | } | |
1723 | ||
1724 | return matched; | |
1725 | } | |
1726 | ||
64e7c440 SR |
1727 | static int |
1728 | ftrace_match_record(struct dyn_ftrace *rec, char *regex, int len, int type) | |
1729 | { | |
1730 | char str[KSYM_SYMBOL_LEN]; | |
1731 | ||
1732 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1733 | return ftrace_match(str, regex, len, type); | |
1734 | } | |
1735 | ||
311d16da | 1736 | static int ftrace_match_records(char *buff, int len, int enable) |
9f4801e3 | 1737 | { |
6a24a244 | 1738 | unsigned int search_len; |
9f4801e3 SR |
1739 | struct ftrace_page *pg; |
1740 | struct dyn_ftrace *rec; | |
6a24a244 SR |
1741 | unsigned long flag; |
1742 | char *search; | |
9f4801e3 | 1743 | int type; |
9f4801e3 | 1744 | int not; |
311d16da | 1745 | int found = 0; |
9f4801e3 | 1746 | |
6a24a244 | 1747 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
3f6fe06d | 1748 | type = filter_parse_regex(buff, len, &search, ¬); |
9f4801e3 SR |
1749 | |
1750 | search_len = strlen(search); | |
1751 | ||
52baf119 | 1752 | mutex_lock(&ftrace_lock); |
265c831c | 1753 | do_for_each_ftrace_rec(pg, rec) { |
265c831c SR |
1754 | |
1755 | if (rec->flags & FTRACE_FL_FAILED) | |
1756 | continue; | |
9f4801e3 SR |
1757 | |
1758 | if (ftrace_match_record(rec, search, search_len, type)) { | |
265c831c SR |
1759 | if (not) |
1760 | rec->flags &= ~flag; | |
1761 | else | |
1762 | rec->flags |= flag; | |
311d16da | 1763 | found = 1; |
265c831c | 1764 | } |
e68746a2 SR |
1765 | /* |
1766 | * Only enable filtering if we have a function that | |
1767 | * is filtered on. | |
1768 | */ | |
1769 | if (enable && (rec->flags & FTRACE_FL_FILTER)) | |
1770 | ftrace_filtered = 1; | |
265c831c | 1771 | } while_for_each_ftrace_rec(); |
52baf119 | 1772 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
1773 | |
1774 | return found; | |
5072c59f SR |
1775 | } |
1776 | ||
64e7c440 SR |
1777 | static int |
1778 | ftrace_match_module_record(struct dyn_ftrace *rec, char *mod, | |
1779 | char *regex, int len, int type) | |
1780 | { | |
1781 | char str[KSYM_SYMBOL_LEN]; | |
1782 | char *modname; | |
1783 | ||
1784 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
1785 | ||
1786 | if (!modname || strcmp(modname, mod)) | |
1787 | return 0; | |
1788 | ||
1789 | /* blank search means to match all funcs in the mod */ | |
1790 | if (len) | |
1791 | return ftrace_match(str, regex, len, type); | |
1792 | else | |
1793 | return 1; | |
1794 | } | |
1795 | ||
311d16da | 1796 | static int ftrace_match_module_records(char *buff, char *mod, int enable) |
64e7c440 | 1797 | { |
6a24a244 | 1798 | unsigned search_len = 0; |
64e7c440 SR |
1799 | struct ftrace_page *pg; |
1800 | struct dyn_ftrace *rec; | |
1801 | int type = MATCH_FULL; | |
6a24a244 SR |
1802 | char *search = buff; |
1803 | unsigned long flag; | |
64e7c440 | 1804 | int not = 0; |
311d16da | 1805 | int found = 0; |
64e7c440 | 1806 | |
6a24a244 SR |
1807 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
1808 | ||
64e7c440 SR |
1809 | /* blank or '*' mean the same */ |
1810 | if (strcmp(buff, "*") == 0) | |
1811 | buff[0] = 0; | |
1812 | ||
1813 | /* handle the case of 'dont filter this module' */ | |
1814 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
1815 | buff[0] = 0; | |
1816 | not = 1; | |
1817 | } | |
1818 | ||
1819 | if (strlen(buff)) { | |
3f6fe06d | 1820 | type = filter_parse_regex(buff, strlen(buff), &search, ¬); |
64e7c440 SR |
1821 | search_len = strlen(search); |
1822 | } | |
1823 | ||
52baf119 | 1824 | mutex_lock(&ftrace_lock); |
64e7c440 SR |
1825 | do_for_each_ftrace_rec(pg, rec) { |
1826 | ||
1827 | if (rec->flags & FTRACE_FL_FAILED) | |
1828 | continue; | |
1829 | ||
1830 | if (ftrace_match_module_record(rec, mod, | |
1831 | search, search_len, type)) { | |
1832 | if (not) | |
1833 | rec->flags &= ~flag; | |
1834 | else | |
1835 | rec->flags |= flag; | |
311d16da | 1836 | found = 1; |
64e7c440 | 1837 | } |
e68746a2 SR |
1838 | if (enable && (rec->flags & FTRACE_FL_FILTER)) |
1839 | ftrace_filtered = 1; | |
64e7c440 SR |
1840 | |
1841 | } while_for_each_ftrace_rec(); | |
52baf119 | 1842 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
1843 | |
1844 | return found; | |
64e7c440 SR |
1845 | } |
1846 | ||
f6180773 SR |
1847 | /* |
1848 | * We register the module command as a template to show others how | |
1849 | * to register the a command as well. | |
1850 | */ | |
1851 | ||
1852 | static int | |
1853 | ftrace_mod_callback(char *func, char *cmd, char *param, int enable) | |
1854 | { | |
1855 | char *mod; | |
1856 | ||
1857 | /* | |
1858 | * cmd == 'mod' because we only registered this func | |
1859 | * for the 'mod' ftrace_func_command. | |
1860 | * But if you register one func with multiple commands, | |
1861 | * you can tell which command was used by the cmd | |
1862 | * parameter. | |
1863 | */ | |
1864 | ||
1865 | /* we must have a module name */ | |
1866 | if (!param) | |
1867 | return -EINVAL; | |
1868 | ||
1869 | mod = strsep(¶m, ":"); | |
1870 | if (!strlen(mod)) | |
1871 | return -EINVAL; | |
1872 | ||
311d16da LZ |
1873 | if (ftrace_match_module_records(func, mod, enable)) |
1874 | return 0; | |
1875 | return -EINVAL; | |
f6180773 SR |
1876 | } |
1877 | ||
1878 | static struct ftrace_func_command ftrace_mod_cmd = { | |
1879 | .name = "mod", | |
1880 | .func = ftrace_mod_callback, | |
1881 | }; | |
1882 | ||
1883 | static int __init ftrace_mod_cmd_init(void) | |
1884 | { | |
1885 | return register_ftrace_command(&ftrace_mod_cmd); | |
1886 | } | |
1887 | device_initcall(ftrace_mod_cmd_init); | |
1888 | ||
59df055f | 1889 | static void |
b6887d79 | 1890 | function_trace_probe_call(unsigned long ip, unsigned long parent_ip) |
59df055f | 1891 | { |
b6887d79 | 1892 | struct ftrace_func_probe *entry; |
59df055f SR |
1893 | struct hlist_head *hhd; |
1894 | struct hlist_node *n; | |
1895 | unsigned long key; | |
59df055f SR |
1896 | |
1897 | key = hash_long(ip, FTRACE_HASH_BITS); | |
1898 | ||
1899 | hhd = &ftrace_func_hash[key]; | |
1900 | ||
1901 | if (hlist_empty(hhd)) | |
1902 | return; | |
1903 | ||
1904 | /* | |
1905 | * Disable preemption for these calls to prevent a RCU grace | |
1906 | * period. This syncs the hash iteration and freeing of items | |
1907 | * on the hash. rcu_read_lock is too dangerous here. | |
1908 | */ | |
5168ae50 | 1909 | preempt_disable_notrace(); |
59df055f SR |
1910 | hlist_for_each_entry_rcu(entry, n, hhd, node) { |
1911 | if (entry->ip == ip) | |
1912 | entry->ops->func(ip, parent_ip, &entry->data); | |
1913 | } | |
5168ae50 | 1914 | preempt_enable_notrace(); |
59df055f SR |
1915 | } |
1916 | ||
b6887d79 | 1917 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 1918 | { |
fb9fb015 | 1919 | .func = function_trace_probe_call, |
59df055f SR |
1920 | }; |
1921 | ||
b6887d79 | 1922 | static int ftrace_probe_registered; |
59df055f | 1923 | |
b6887d79 | 1924 | static void __enable_ftrace_function_probe(void) |
59df055f SR |
1925 | { |
1926 | int i; | |
1927 | ||
b6887d79 | 1928 | if (ftrace_probe_registered) |
59df055f SR |
1929 | return; |
1930 | ||
1931 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1932 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1933 | if (hhd->first) | |
1934 | break; | |
1935 | } | |
1936 | /* Nothing registered? */ | |
1937 | if (i == FTRACE_FUNC_HASHSIZE) | |
1938 | return; | |
1939 | ||
b6887d79 | 1940 | __register_ftrace_function(&trace_probe_ops); |
59df055f | 1941 | ftrace_startup(0); |
b6887d79 | 1942 | ftrace_probe_registered = 1; |
59df055f SR |
1943 | } |
1944 | ||
b6887d79 | 1945 | static void __disable_ftrace_function_probe(void) |
59df055f SR |
1946 | { |
1947 | int i; | |
1948 | ||
b6887d79 | 1949 | if (!ftrace_probe_registered) |
59df055f SR |
1950 | return; |
1951 | ||
1952 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1953 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1954 | if (hhd->first) | |
1955 | return; | |
1956 | } | |
1957 | ||
1958 | /* no more funcs left */ | |
b6887d79 | 1959 | __unregister_ftrace_function(&trace_probe_ops); |
59df055f | 1960 | ftrace_shutdown(0); |
b6887d79 | 1961 | ftrace_probe_registered = 0; |
59df055f SR |
1962 | } |
1963 | ||
1964 | ||
1965 | static void ftrace_free_entry_rcu(struct rcu_head *rhp) | |
1966 | { | |
b6887d79 SR |
1967 | struct ftrace_func_probe *entry = |
1968 | container_of(rhp, struct ftrace_func_probe, rcu); | |
59df055f SR |
1969 | |
1970 | if (entry->ops->free) | |
1971 | entry->ops->free(&entry->data); | |
1972 | kfree(entry); | |
1973 | } | |
1974 | ||
1975 | ||
1976 | int | |
b6887d79 | 1977 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
1978 | void *data) |
1979 | { | |
b6887d79 | 1980 | struct ftrace_func_probe *entry; |
59df055f SR |
1981 | struct ftrace_page *pg; |
1982 | struct dyn_ftrace *rec; | |
59df055f | 1983 | int type, len, not; |
6a24a244 | 1984 | unsigned long key; |
59df055f SR |
1985 | int count = 0; |
1986 | char *search; | |
1987 | ||
3f6fe06d | 1988 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
1989 | len = strlen(search); |
1990 | ||
b6887d79 | 1991 | /* we do not support '!' for function probes */ |
59df055f SR |
1992 | if (WARN_ON(not)) |
1993 | return -EINVAL; | |
1994 | ||
1995 | mutex_lock(&ftrace_lock); | |
1996 | do_for_each_ftrace_rec(pg, rec) { | |
1997 | ||
1998 | if (rec->flags & FTRACE_FL_FAILED) | |
1999 | continue; | |
2000 | ||
2001 | if (!ftrace_match_record(rec, search, len, type)) | |
2002 | continue; | |
2003 | ||
2004 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
2005 | if (!entry) { | |
b6887d79 | 2006 | /* If we did not process any, then return error */ |
59df055f SR |
2007 | if (!count) |
2008 | count = -ENOMEM; | |
2009 | goto out_unlock; | |
2010 | } | |
2011 | ||
2012 | count++; | |
2013 | ||
2014 | entry->data = data; | |
2015 | ||
2016 | /* | |
2017 | * The caller might want to do something special | |
2018 | * for each function we find. We call the callback | |
2019 | * to give the caller an opportunity to do so. | |
2020 | */ | |
2021 | if (ops->callback) { | |
2022 | if (ops->callback(rec->ip, &entry->data) < 0) { | |
2023 | /* caller does not like this func */ | |
2024 | kfree(entry); | |
2025 | continue; | |
2026 | } | |
2027 | } | |
2028 | ||
2029 | entry->ops = ops; | |
2030 | entry->ip = rec->ip; | |
2031 | ||
2032 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
2033 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
2034 | ||
2035 | } while_for_each_ftrace_rec(); | |
b6887d79 | 2036 | __enable_ftrace_function_probe(); |
59df055f SR |
2037 | |
2038 | out_unlock: | |
2039 | mutex_unlock(&ftrace_lock); | |
2040 | ||
2041 | return count; | |
2042 | } | |
2043 | ||
2044 | enum { | |
b6887d79 SR |
2045 | PROBE_TEST_FUNC = 1, |
2046 | PROBE_TEST_DATA = 2 | |
59df055f SR |
2047 | }; |
2048 | ||
2049 | static void | |
b6887d79 | 2050 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2051 | void *data, int flags) |
2052 | { | |
b6887d79 | 2053 | struct ftrace_func_probe *entry; |
59df055f SR |
2054 | struct hlist_node *n, *tmp; |
2055 | char str[KSYM_SYMBOL_LEN]; | |
2056 | int type = MATCH_FULL; | |
2057 | int i, len = 0; | |
2058 | char *search; | |
2059 | ||
b36461da | 2060 | if (glob && (strcmp(glob, "*") == 0 || !strlen(glob))) |
59df055f | 2061 | glob = NULL; |
b36461da | 2062 | else if (glob) { |
59df055f SR |
2063 | int not; |
2064 | ||
3f6fe06d | 2065 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
2066 | len = strlen(search); |
2067 | ||
b6887d79 | 2068 | /* we do not support '!' for function probes */ |
59df055f SR |
2069 | if (WARN_ON(not)) |
2070 | return; | |
2071 | } | |
2072 | ||
2073 | mutex_lock(&ftrace_lock); | |
2074 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2075 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2076 | ||
2077 | hlist_for_each_entry_safe(entry, n, tmp, hhd, node) { | |
2078 | ||
2079 | /* break up if statements for readability */ | |
b6887d79 | 2080 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
2081 | continue; |
2082 | ||
b6887d79 | 2083 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
2084 | continue; |
2085 | ||
2086 | /* do this last, since it is the most expensive */ | |
2087 | if (glob) { | |
2088 | kallsyms_lookup(entry->ip, NULL, NULL, | |
2089 | NULL, str); | |
2090 | if (!ftrace_match(str, glob, len, type)) | |
2091 | continue; | |
2092 | } | |
2093 | ||
2094 | hlist_del(&entry->node); | |
2095 | call_rcu(&entry->rcu, ftrace_free_entry_rcu); | |
2096 | } | |
2097 | } | |
b6887d79 | 2098 | __disable_ftrace_function_probe(); |
59df055f SR |
2099 | mutex_unlock(&ftrace_lock); |
2100 | } | |
2101 | ||
2102 | void | |
b6887d79 | 2103 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2104 | void *data) |
2105 | { | |
b6887d79 SR |
2106 | __unregister_ftrace_function_probe(glob, ops, data, |
2107 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
2108 | } |
2109 | ||
2110 | void | |
b6887d79 | 2111 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 2112 | { |
b6887d79 | 2113 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
2114 | } |
2115 | ||
b6887d79 | 2116 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 2117 | { |
b6887d79 | 2118 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
2119 | } |
2120 | ||
f6180773 SR |
2121 | static LIST_HEAD(ftrace_commands); |
2122 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
2123 | ||
2124 | int register_ftrace_command(struct ftrace_func_command *cmd) | |
2125 | { | |
2126 | struct ftrace_func_command *p; | |
2127 | int ret = 0; | |
2128 | ||
2129 | mutex_lock(&ftrace_cmd_mutex); | |
2130 | list_for_each_entry(p, &ftrace_commands, list) { | |
2131 | if (strcmp(cmd->name, p->name) == 0) { | |
2132 | ret = -EBUSY; | |
2133 | goto out_unlock; | |
2134 | } | |
2135 | } | |
2136 | list_add(&cmd->list, &ftrace_commands); | |
2137 | out_unlock: | |
2138 | mutex_unlock(&ftrace_cmd_mutex); | |
2139 | ||
2140 | return ret; | |
2141 | } | |
2142 | ||
2143 | int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
2144 | { | |
2145 | struct ftrace_func_command *p, *n; | |
2146 | int ret = -ENODEV; | |
2147 | ||
2148 | mutex_lock(&ftrace_cmd_mutex); | |
2149 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
2150 | if (strcmp(cmd->name, p->name) == 0) { | |
2151 | ret = 0; | |
2152 | list_del_init(&p->list); | |
2153 | goto out_unlock; | |
2154 | } | |
2155 | } | |
2156 | out_unlock: | |
2157 | mutex_unlock(&ftrace_cmd_mutex); | |
2158 | ||
2159 | return ret; | |
2160 | } | |
2161 | ||
64e7c440 SR |
2162 | static int ftrace_process_regex(char *buff, int len, int enable) |
2163 | { | |
f6180773 | 2164 | char *func, *command, *next = buff; |
6a24a244 | 2165 | struct ftrace_func_command *p; |
f6180773 | 2166 | int ret = -EINVAL; |
64e7c440 SR |
2167 | |
2168 | func = strsep(&next, ":"); | |
2169 | ||
2170 | if (!next) { | |
311d16da LZ |
2171 | if (ftrace_match_records(func, len, enable)) |
2172 | return 0; | |
2173 | return ret; | |
64e7c440 SR |
2174 | } |
2175 | ||
f6180773 | 2176 | /* command found */ |
64e7c440 SR |
2177 | |
2178 | command = strsep(&next, ":"); | |
2179 | ||
f6180773 SR |
2180 | mutex_lock(&ftrace_cmd_mutex); |
2181 | list_for_each_entry(p, &ftrace_commands, list) { | |
2182 | if (strcmp(p->name, command) == 0) { | |
2183 | ret = p->func(func, command, next, enable); | |
2184 | goto out_unlock; | |
2185 | } | |
64e7c440 | 2186 | } |
f6180773 SR |
2187 | out_unlock: |
2188 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 2189 | |
f6180773 | 2190 | return ret; |
64e7c440 SR |
2191 | } |
2192 | ||
e309b41d | 2193 | static ssize_t |
41c52c0d SR |
2194 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
2195 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
2196 | { |
2197 | struct ftrace_iterator *iter; | |
689fd8b6 | 2198 | struct trace_parser *parser; |
2199 | ssize_t ret, read; | |
5072c59f | 2200 | |
4ba7978e | 2201 | if (!cnt) |
5072c59f SR |
2202 | return 0; |
2203 | ||
41c52c0d | 2204 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
2205 | |
2206 | if (file->f_mode & FMODE_READ) { | |
2207 | struct seq_file *m = file->private_data; | |
2208 | iter = m->private; | |
2209 | } else | |
2210 | iter = file->private_data; | |
2211 | ||
689fd8b6 | 2212 | parser = &iter->parser; |
2213 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 2214 | |
4ba7978e | 2215 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 2216 | !trace_parser_cont(parser)) { |
2217 | ret = ftrace_process_regex(parser->buffer, | |
2218 | parser->idx, enable); | |
313254a9 | 2219 | trace_parser_clear(parser); |
5072c59f | 2220 | if (ret) |
ed146b25 | 2221 | goto out_unlock; |
eda1e328 | 2222 | } |
5072c59f | 2223 | |
5072c59f | 2224 | ret = read; |
ed146b25 | 2225 | out_unlock: |
689fd8b6 | 2226 | mutex_unlock(&ftrace_regex_lock); |
ed146b25 | 2227 | |
5072c59f SR |
2228 | return ret; |
2229 | } | |
2230 | ||
41c52c0d SR |
2231 | static ssize_t |
2232 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
2233 | size_t cnt, loff_t *ppos) | |
2234 | { | |
2235 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
2236 | } | |
2237 | ||
2238 | static ssize_t | |
2239 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
2240 | size_t cnt, loff_t *ppos) | |
2241 | { | |
2242 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
2243 | } | |
2244 | ||
2245 | static void | |
2246 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
2247 | { | |
2248 | if (unlikely(ftrace_disabled)) | |
2249 | return; | |
2250 | ||
2251 | mutex_lock(&ftrace_regex_lock); | |
2252 | if (reset) | |
2253 | ftrace_filter_reset(enable); | |
2254 | if (buf) | |
7f24b31b | 2255 | ftrace_match_records(buf, len, enable); |
41c52c0d SR |
2256 | mutex_unlock(&ftrace_regex_lock); |
2257 | } | |
2258 | ||
77a2b37d SR |
2259 | /** |
2260 | * ftrace_set_filter - set a function to filter on in ftrace | |
2261 | * @buf - the string that holds the function filter text. | |
2262 | * @len - the length of the string. | |
2263 | * @reset - non zero to reset all filters before applying this filter. | |
2264 | * | |
2265 | * Filters denote which functions should be enabled when tracing is enabled. | |
2266 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
2267 | */ | |
e309b41d | 2268 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 2269 | { |
41c52c0d SR |
2270 | ftrace_set_regex(buf, len, reset, 1); |
2271 | } | |
4eebcc81 | 2272 | |
41c52c0d SR |
2273 | /** |
2274 | * ftrace_set_notrace - set a function to not trace in ftrace | |
2275 | * @buf - the string that holds the function notrace text. | |
2276 | * @len - the length of the string. | |
2277 | * @reset - non zero to reset all filters before applying this filter. | |
2278 | * | |
2279 | * Notrace Filters denote which functions should not be enabled when tracing | |
2280 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
2281 | * for tracing. | |
2282 | */ | |
2283 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
2284 | { | |
2285 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
2286 | } |
2287 | ||
2af15d6a SR |
2288 | /* |
2289 | * command line interface to allow users to set filters on boot up. | |
2290 | */ | |
2291 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
2292 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
2293 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
2294 | ||
2295 | static int __init set_ftrace_notrace(char *str) | |
2296 | { | |
2297 | strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); | |
2298 | return 1; | |
2299 | } | |
2300 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
2301 | ||
2302 | static int __init set_ftrace_filter(char *str) | |
2303 | { | |
2304 | strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); | |
2305 | return 1; | |
2306 | } | |
2307 | __setup("ftrace_filter=", set_ftrace_filter); | |
2308 | ||
369bc18f | 2309 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 2310 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
801c29fd SR |
2311 | static int ftrace_set_func(unsigned long *array, int *idx, char *buffer); |
2312 | ||
369bc18f SA |
2313 | static int __init set_graph_function(char *str) |
2314 | { | |
06f43d66 | 2315 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
2316 | return 1; |
2317 | } | |
2318 | __setup("ftrace_graph_filter=", set_graph_function); | |
2319 | ||
2320 | static void __init set_ftrace_early_graph(char *buf) | |
2321 | { | |
2322 | int ret; | |
2323 | char *func; | |
2324 | ||
2325 | while (buf) { | |
2326 | func = strsep(&buf, ","); | |
2327 | /* we allow only one expression at a time */ | |
2328 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, | |
2329 | func); | |
2330 | if (ret) | |
2331 | printk(KERN_DEBUG "ftrace: function %s not " | |
2332 | "traceable\n", func); | |
2333 | } | |
2334 | } | |
2335 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2336 | ||
2af15d6a SR |
2337 | static void __init set_ftrace_early_filter(char *buf, int enable) |
2338 | { | |
2339 | char *func; | |
2340 | ||
2341 | while (buf) { | |
2342 | func = strsep(&buf, ","); | |
2343 | ftrace_set_regex(func, strlen(func), 0, enable); | |
2344 | } | |
2345 | } | |
2346 | ||
2347 | static void __init set_ftrace_early_filters(void) | |
2348 | { | |
2349 | if (ftrace_filter_buf[0]) | |
2350 | set_ftrace_early_filter(ftrace_filter_buf, 1); | |
2351 | if (ftrace_notrace_buf[0]) | |
2352 | set_ftrace_early_filter(ftrace_notrace_buf, 0); | |
369bc18f SA |
2353 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
2354 | if (ftrace_graph_buf[0]) | |
2355 | set_ftrace_early_graph(ftrace_graph_buf); | |
2356 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2af15d6a SR |
2357 | } |
2358 | ||
e309b41d | 2359 | static int |
41c52c0d | 2360 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
2361 | { |
2362 | struct seq_file *m = (struct seq_file *)file->private_data; | |
2363 | struct ftrace_iterator *iter; | |
689fd8b6 | 2364 | struct trace_parser *parser; |
5072c59f | 2365 | |
41c52c0d | 2366 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
2367 | if (file->f_mode & FMODE_READ) { |
2368 | iter = m->private; | |
2369 | ||
2370 | seq_release(inode, file); | |
2371 | } else | |
2372 | iter = file->private_data; | |
2373 | ||
689fd8b6 | 2374 | parser = &iter->parser; |
2375 | if (trace_parser_loaded(parser)) { | |
2376 | parser->buffer[parser->idx] = 0; | |
2377 | ftrace_match_records(parser->buffer, parser->idx, enable); | |
5072c59f SR |
2378 | } |
2379 | ||
e6ea44e9 | 2380 | mutex_lock(&ftrace_lock); |
ee02a2e5 | 2381 | if (ftrace_start_up && ftrace_enabled) |
5072c59f | 2382 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
e6ea44e9 | 2383 | mutex_unlock(&ftrace_lock); |
5072c59f | 2384 | |
689fd8b6 | 2385 | trace_parser_put(parser); |
5072c59f | 2386 | kfree(iter); |
689fd8b6 | 2387 | |
41c52c0d | 2388 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
2389 | return 0; |
2390 | } | |
2391 | ||
41c52c0d SR |
2392 | static int |
2393 | ftrace_filter_release(struct inode *inode, struct file *file) | |
2394 | { | |
2395 | return ftrace_regex_release(inode, file, 1); | |
2396 | } | |
2397 | ||
2398 | static int | |
2399 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
2400 | { | |
2401 | return ftrace_regex_release(inode, file, 0); | |
2402 | } | |
2403 | ||
5e2336a0 | 2404 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
2405 | .open = ftrace_avail_open, |
2406 | .read = seq_read, | |
2407 | .llseek = seq_lseek, | |
3be04b47 | 2408 | .release = seq_release_private, |
5072c59f SR |
2409 | }; |
2410 | ||
5e2336a0 | 2411 | static const struct file_operations ftrace_failures_fops = { |
eb9a7bf0 AS |
2412 | .open = ftrace_failures_open, |
2413 | .read = seq_read, | |
2414 | .llseek = seq_lseek, | |
3be04b47 | 2415 | .release = seq_release_private, |
eb9a7bf0 AS |
2416 | }; |
2417 | ||
5e2336a0 | 2418 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 2419 | .open = ftrace_filter_open, |
850a80cf | 2420 | .read = seq_read, |
5072c59f | 2421 | .write = ftrace_filter_write, |
9c55cb12 | 2422 | .llseek = no_llseek, |
5072c59f SR |
2423 | .release = ftrace_filter_release, |
2424 | }; | |
2425 | ||
5e2336a0 | 2426 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 2427 | .open = ftrace_notrace_open, |
850a80cf | 2428 | .read = seq_read, |
41c52c0d SR |
2429 | .write = ftrace_notrace_write, |
2430 | .llseek = ftrace_regex_lseek, | |
2431 | .release = ftrace_notrace_release, | |
2432 | }; | |
2433 | ||
ea4e2bc4 SR |
2434 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
2435 | ||
2436 | static DEFINE_MUTEX(graph_lock); | |
2437 | ||
2438 | int ftrace_graph_count; | |
c7c6b1fe | 2439 | int ftrace_graph_filter_enabled; |
ea4e2bc4 SR |
2440 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
2441 | ||
2442 | static void * | |
85951842 | 2443 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 2444 | { |
85951842 | 2445 | if (*pos >= ftrace_graph_count) |
ea4e2bc4 | 2446 | return NULL; |
a4ec5e0c | 2447 | return &ftrace_graph_funcs[*pos]; |
85951842 | 2448 | } |
ea4e2bc4 | 2449 | |
85951842 LZ |
2450 | static void * |
2451 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
2452 | { | |
2453 | (*pos)++; | |
2454 | return __g_next(m, pos); | |
ea4e2bc4 SR |
2455 | } |
2456 | ||
2457 | static void *g_start(struct seq_file *m, loff_t *pos) | |
2458 | { | |
ea4e2bc4 SR |
2459 | mutex_lock(&graph_lock); |
2460 | ||
f9349a8f | 2461 | /* Nothing, tell g_show to print all functions are enabled */ |
c7c6b1fe | 2462 | if (!ftrace_graph_filter_enabled && !*pos) |
f9349a8f FW |
2463 | return (void *)1; |
2464 | ||
85951842 | 2465 | return __g_next(m, pos); |
ea4e2bc4 SR |
2466 | } |
2467 | ||
2468 | static void g_stop(struct seq_file *m, void *p) | |
2469 | { | |
2470 | mutex_unlock(&graph_lock); | |
2471 | } | |
2472 | ||
2473 | static int g_show(struct seq_file *m, void *v) | |
2474 | { | |
2475 | unsigned long *ptr = v; | |
ea4e2bc4 SR |
2476 | |
2477 | if (!ptr) | |
2478 | return 0; | |
2479 | ||
f9349a8f FW |
2480 | if (ptr == (unsigned long *)1) { |
2481 | seq_printf(m, "#### all functions enabled ####\n"); | |
2482 | return 0; | |
2483 | } | |
2484 | ||
b375a11a | 2485 | seq_printf(m, "%ps\n", (void *)*ptr); |
ea4e2bc4 SR |
2486 | |
2487 | return 0; | |
2488 | } | |
2489 | ||
88e9d34c | 2490 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
2491 | .start = g_start, |
2492 | .next = g_next, | |
2493 | .stop = g_stop, | |
2494 | .show = g_show, | |
2495 | }; | |
2496 | ||
2497 | static int | |
2498 | ftrace_graph_open(struct inode *inode, struct file *file) | |
2499 | { | |
2500 | int ret = 0; | |
2501 | ||
2502 | if (unlikely(ftrace_disabled)) | |
2503 | return -ENODEV; | |
2504 | ||
2505 | mutex_lock(&graph_lock); | |
2506 | if ((file->f_mode & FMODE_WRITE) && | |
8650ae32 | 2507 | (file->f_flags & O_TRUNC)) { |
c7c6b1fe | 2508 | ftrace_graph_filter_enabled = 0; |
ea4e2bc4 SR |
2509 | ftrace_graph_count = 0; |
2510 | memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); | |
2511 | } | |
a4ec5e0c | 2512 | mutex_unlock(&graph_lock); |
ea4e2bc4 | 2513 | |
a4ec5e0c | 2514 | if (file->f_mode & FMODE_READ) |
ea4e2bc4 | 2515 | ret = seq_open(file, &ftrace_graph_seq_ops); |
ea4e2bc4 SR |
2516 | |
2517 | return ret; | |
2518 | } | |
2519 | ||
87827111 LZ |
2520 | static int |
2521 | ftrace_graph_release(struct inode *inode, struct file *file) | |
2522 | { | |
2523 | if (file->f_mode & FMODE_READ) | |
2524 | seq_release(inode, file); | |
2525 | return 0; | |
2526 | } | |
2527 | ||
ea4e2bc4 | 2528 | static int |
f9349a8f | 2529 | ftrace_set_func(unsigned long *array, int *idx, char *buffer) |
ea4e2bc4 | 2530 | { |
ea4e2bc4 SR |
2531 | struct dyn_ftrace *rec; |
2532 | struct ftrace_page *pg; | |
f9349a8f | 2533 | int search_len; |
c7c6b1fe | 2534 | int fail = 1; |
f9349a8f FW |
2535 | int type, not; |
2536 | char *search; | |
2537 | bool exists; | |
2538 | int i; | |
ea4e2bc4 SR |
2539 | |
2540 | if (ftrace_disabled) | |
2541 | return -ENODEV; | |
2542 | ||
f9349a8f | 2543 | /* decode regex */ |
3f6fe06d | 2544 | type = filter_parse_regex(buffer, strlen(buffer), &search, ¬); |
c7c6b1fe LZ |
2545 | if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS) |
2546 | return -EBUSY; | |
f9349a8f FW |
2547 | |
2548 | search_len = strlen(search); | |
2549 | ||
52baf119 | 2550 | mutex_lock(&ftrace_lock); |
265c831c SR |
2551 | do_for_each_ftrace_rec(pg, rec) { |
2552 | ||
2553 | if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE)) | |
2554 | continue; | |
2555 | ||
f9349a8f | 2556 | if (ftrace_match_record(rec, search, search_len, type)) { |
c7c6b1fe | 2557 | /* if it is in the array */ |
f9349a8f | 2558 | exists = false; |
c7c6b1fe | 2559 | for (i = 0; i < *idx; i++) { |
f9349a8f FW |
2560 | if (array[i] == rec->ip) { |
2561 | exists = true; | |
265c831c SR |
2562 | break; |
2563 | } | |
c7c6b1fe LZ |
2564 | } |
2565 | ||
2566 | if (!not) { | |
2567 | fail = 0; | |
2568 | if (!exists) { | |
2569 | array[(*idx)++] = rec->ip; | |
2570 | if (*idx >= FTRACE_GRAPH_MAX_FUNCS) | |
2571 | goto out; | |
2572 | } | |
2573 | } else { | |
2574 | if (exists) { | |
2575 | array[i] = array[--(*idx)]; | |
2576 | array[*idx] = 0; | |
2577 | fail = 0; | |
2578 | } | |
2579 | } | |
ea4e2bc4 | 2580 | } |
265c831c | 2581 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 2582 | out: |
52baf119 | 2583 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 2584 | |
c7c6b1fe LZ |
2585 | if (fail) |
2586 | return -EINVAL; | |
2587 | ||
2588 | ftrace_graph_filter_enabled = 1; | |
2589 | return 0; | |
ea4e2bc4 SR |
2590 | } |
2591 | ||
2592 | static ssize_t | |
2593 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
2594 | size_t cnt, loff_t *ppos) | |
2595 | { | |
689fd8b6 | 2596 | struct trace_parser parser; |
4ba7978e | 2597 | ssize_t read, ret; |
ea4e2bc4 | 2598 | |
c7c6b1fe | 2599 | if (!cnt) |
ea4e2bc4 SR |
2600 | return 0; |
2601 | ||
2602 | mutex_lock(&graph_lock); | |
2603 | ||
689fd8b6 | 2604 | if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) { |
2605 | ret = -ENOMEM; | |
1eb90f13 | 2606 | goto out_unlock; |
ea4e2bc4 SR |
2607 | } |
2608 | ||
689fd8b6 | 2609 | read = trace_get_user(&parser, ubuf, cnt, ppos); |
ea4e2bc4 | 2610 | |
4ba7978e | 2611 | if (read >= 0 && trace_parser_loaded((&parser))) { |
689fd8b6 | 2612 | parser.buffer[parser.idx] = 0; |
2613 | ||
2614 | /* we allow only one expression at a time */ | |
a4ec5e0c | 2615 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, |
689fd8b6 | 2616 | parser.buffer); |
ea4e2bc4 | 2617 | if (ret) |
1eb90f13 | 2618 | goto out_free; |
ea4e2bc4 | 2619 | } |
ea4e2bc4 SR |
2620 | |
2621 | ret = read; | |
1eb90f13 LZ |
2622 | |
2623 | out_free: | |
689fd8b6 | 2624 | trace_parser_put(&parser); |
1eb90f13 | 2625 | out_unlock: |
ea4e2bc4 SR |
2626 | mutex_unlock(&graph_lock); |
2627 | ||
2628 | return ret; | |
2629 | } | |
2630 | ||
2631 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
2632 | .open = ftrace_graph_open, |
2633 | .read = seq_read, | |
2634 | .write = ftrace_graph_write, | |
2635 | .release = ftrace_graph_release, | |
6038f373 | 2636 | .llseek = seq_lseek, |
ea4e2bc4 SR |
2637 | }; |
2638 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2639 | ||
df4fc315 | 2640 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 2641 | { |
5072c59f | 2642 | |
5452af66 FW |
2643 | trace_create_file("available_filter_functions", 0444, |
2644 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 2645 | |
5452af66 FW |
2646 | trace_create_file("failures", 0444, |
2647 | d_tracer, NULL, &ftrace_failures_fops); | |
eb9a7bf0 | 2648 | |
5452af66 FW |
2649 | trace_create_file("set_ftrace_filter", 0644, d_tracer, |
2650 | NULL, &ftrace_filter_fops); | |
41c52c0d | 2651 | |
5452af66 | 2652 | trace_create_file("set_ftrace_notrace", 0644, d_tracer, |
41c52c0d | 2653 | NULL, &ftrace_notrace_fops); |
ad90c0e3 | 2654 | |
ea4e2bc4 | 2655 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 2656 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
2657 | NULL, |
2658 | &ftrace_graph_fops); | |
ea4e2bc4 SR |
2659 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
2660 | ||
5072c59f SR |
2661 | return 0; |
2662 | } | |
2663 | ||
5cb084bb | 2664 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 2665 | unsigned long *start, |
68bf21aa SR |
2666 | unsigned long *end) |
2667 | { | |
2668 | unsigned long *p; | |
2669 | unsigned long addr; | |
2670 | unsigned long flags; | |
2671 | ||
e6ea44e9 | 2672 | mutex_lock(&ftrace_lock); |
68bf21aa SR |
2673 | p = start; |
2674 | while (p < end) { | |
2675 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
2676 | /* |
2677 | * Some architecture linkers will pad between | |
2678 | * the different mcount_loc sections of different | |
2679 | * object files to satisfy alignments. | |
2680 | * Skip any NULL pointers. | |
2681 | */ | |
2682 | if (!addr) | |
2683 | continue; | |
68bf21aa | 2684 | ftrace_record_ip(addr); |
68bf21aa SR |
2685 | } |
2686 | ||
08f5ac90 | 2687 | /* disable interrupts to prevent kstop machine */ |
68bf21aa | 2688 | local_irq_save(flags); |
31e88909 | 2689 | ftrace_update_code(mod); |
68bf21aa | 2690 | local_irq_restore(flags); |
e6ea44e9 | 2691 | mutex_unlock(&ftrace_lock); |
68bf21aa SR |
2692 | |
2693 | return 0; | |
2694 | } | |
2695 | ||
93eb677d | 2696 | #ifdef CONFIG_MODULES |
e7247a15 | 2697 | void ftrace_release_mod(struct module *mod) |
93eb677d SR |
2698 | { |
2699 | struct dyn_ftrace *rec; | |
2700 | struct ftrace_page *pg; | |
93eb677d | 2701 | |
e7247a15 | 2702 | if (ftrace_disabled) |
93eb677d SR |
2703 | return; |
2704 | ||
2705 | mutex_lock(&ftrace_lock); | |
2706 | do_for_each_ftrace_rec(pg, rec) { | |
e7247a15 | 2707 | if (within_module_core(rec->ip, mod)) { |
93eb677d SR |
2708 | /* |
2709 | * rec->ip is changed in ftrace_free_rec() | |
2710 | * It should not between s and e if record was freed. | |
2711 | */ | |
2712 | FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE); | |
2713 | ftrace_free_rec(rec); | |
2714 | } | |
2715 | } while_for_each_ftrace_rec(); | |
2716 | mutex_unlock(&ftrace_lock); | |
2717 | } | |
2718 | ||
2719 | static void ftrace_init_module(struct module *mod, | |
2720 | unsigned long *start, unsigned long *end) | |
90d595fe | 2721 | { |
00fd61ae | 2722 | if (ftrace_disabled || start == end) |
fed1939c | 2723 | return; |
5cb084bb | 2724 | ftrace_process_locs(mod, start, end); |
90d595fe SR |
2725 | } |
2726 | ||
93eb677d SR |
2727 | static int ftrace_module_notify(struct notifier_block *self, |
2728 | unsigned long val, void *data) | |
2729 | { | |
2730 | struct module *mod = data; | |
2731 | ||
2732 | switch (val) { | |
2733 | case MODULE_STATE_COMING: | |
2734 | ftrace_init_module(mod, mod->ftrace_callsites, | |
2735 | mod->ftrace_callsites + | |
2736 | mod->num_ftrace_callsites); | |
2737 | break; | |
2738 | case MODULE_STATE_GOING: | |
e7247a15 | 2739 | ftrace_release_mod(mod); |
93eb677d SR |
2740 | break; |
2741 | } | |
2742 | ||
2743 | return 0; | |
2744 | } | |
2745 | #else | |
2746 | static int ftrace_module_notify(struct notifier_block *self, | |
2747 | unsigned long val, void *data) | |
2748 | { | |
2749 | return 0; | |
2750 | } | |
2751 | #endif /* CONFIG_MODULES */ | |
2752 | ||
2753 | struct notifier_block ftrace_module_nb = { | |
2754 | .notifier_call = ftrace_module_notify, | |
2755 | .priority = 0, | |
2756 | }; | |
2757 | ||
68bf21aa SR |
2758 | extern unsigned long __start_mcount_loc[]; |
2759 | extern unsigned long __stop_mcount_loc[]; | |
2760 | ||
2761 | void __init ftrace_init(void) | |
2762 | { | |
2763 | unsigned long count, addr, flags; | |
2764 | int ret; | |
2765 | ||
2766 | /* Keep the ftrace pointer to the stub */ | |
2767 | addr = (unsigned long)ftrace_stub; | |
2768 | ||
2769 | local_irq_save(flags); | |
2770 | ftrace_dyn_arch_init(&addr); | |
2771 | local_irq_restore(flags); | |
2772 | ||
2773 | /* ftrace_dyn_arch_init places the return code in addr */ | |
2774 | if (addr) | |
2775 | goto failed; | |
2776 | ||
2777 | count = __stop_mcount_loc - __start_mcount_loc; | |
2778 | ||
2779 | ret = ftrace_dyn_table_alloc(count); | |
2780 | if (ret) | |
2781 | goto failed; | |
2782 | ||
2783 | last_ftrace_enabled = ftrace_enabled = 1; | |
2784 | ||
5cb084bb | 2785 | ret = ftrace_process_locs(NULL, |
31e88909 | 2786 | __start_mcount_loc, |
68bf21aa SR |
2787 | __stop_mcount_loc); |
2788 | ||
93eb677d | 2789 | ret = register_module_notifier(&ftrace_module_nb); |
24ed0c4b | 2790 | if (ret) |
93eb677d SR |
2791 | pr_warning("Failed to register trace ftrace module notifier\n"); |
2792 | ||
2af15d6a SR |
2793 | set_ftrace_early_filters(); |
2794 | ||
68bf21aa SR |
2795 | return; |
2796 | failed: | |
2797 | ftrace_disabled = 1; | |
2798 | } | |
68bf21aa | 2799 | |
3d083395 | 2800 | #else |
0b6e4d56 FW |
2801 | |
2802 | static int __init ftrace_nodyn_init(void) | |
2803 | { | |
2804 | ftrace_enabled = 1; | |
2805 | return 0; | |
2806 | } | |
2807 | device_initcall(ftrace_nodyn_init); | |
2808 | ||
df4fc315 SR |
2809 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
2810 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 SR |
2811 | /* Keep as macros so we do not need to define the commands */ |
2812 | # define ftrace_startup(command) do { } while (0) | |
2813 | # define ftrace_shutdown(command) do { } while (0) | |
c7aafc54 IM |
2814 | # define ftrace_startup_sysctl() do { } while (0) |
2815 | # define ftrace_shutdown_sysctl() do { } while (0) | |
3d083395 SR |
2816 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
2817 | ||
e32d8956 | 2818 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
2819 | { |
2820 | struct task_struct *p; | |
e32d8956 | 2821 | int cpu; |
978f3a45 | 2822 | |
e32d8956 SR |
2823 | get_online_cpus(); |
2824 | for_each_online_cpu(cpu) { | |
2825 | p = idle_task(cpu); | |
978f3a45 | 2826 | clear_tsk_trace_trace(p); |
e32d8956 SR |
2827 | } |
2828 | put_online_cpus(); | |
2829 | } | |
978f3a45 | 2830 | |
e32d8956 SR |
2831 | static void set_ftrace_swapper(void) |
2832 | { | |
2833 | struct task_struct *p; | |
2834 | int cpu; | |
2835 | ||
2836 | get_online_cpus(); | |
2837 | for_each_online_cpu(cpu) { | |
2838 | p = idle_task(cpu); | |
2839 | set_tsk_trace_trace(p); | |
2840 | } | |
2841 | put_online_cpus(); | |
978f3a45 SR |
2842 | } |
2843 | ||
e32d8956 SR |
2844 | static void clear_ftrace_pid(struct pid *pid) |
2845 | { | |
2846 | struct task_struct *p; | |
2847 | ||
229c4ef8 | 2848 | rcu_read_lock(); |
e32d8956 SR |
2849 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2850 | clear_tsk_trace_trace(p); | |
2851 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
2852 | rcu_read_unlock(); |
2853 | ||
e32d8956 SR |
2854 | put_pid(pid); |
2855 | } | |
2856 | ||
2857 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
2858 | { |
2859 | struct task_struct *p; | |
2860 | ||
229c4ef8 | 2861 | rcu_read_lock(); |
978f3a45 SR |
2862 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2863 | set_tsk_trace_trace(p); | |
2864 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 2865 | rcu_read_unlock(); |
978f3a45 SR |
2866 | } |
2867 | ||
756d17ee | 2868 | static void clear_ftrace_pid_task(struct pid *pid) |
e32d8956 | 2869 | { |
756d17ee | 2870 | if (pid == ftrace_swapper_pid) |
e32d8956 SR |
2871 | clear_ftrace_swapper(); |
2872 | else | |
756d17ee | 2873 | clear_ftrace_pid(pid); |
e32d8956 SR |
2874 | } |
2875 | ||
2876 | static void set_ftrace_pid_task(struct pid *pid) | |
2877 | { | |
2878 | if (pid == ftrace_swapper_pid) | |
2879 | set_ftrace_swapper(); | |
2880 | else | |
2881 | set_ftrace_pid(pid); | |
2882 | } | |
2883 | ||
756d17ee | 2884 | static int ftrace_pid_add(int p) |
df4fc315 | 2885 | { |
978f3a45 | 2886 | struct pid *pid; |
756d17ee | 2887 | struct ftrace_pid *fpid; |
2888 | int ret = -EINVAL; | |
df4fc315 | 2889 | |
756d17ee | 2890 | mutex_lock(&ftrace_lock); |
df4fc315 | 2891 | |
756d17ee | 2892 | if (!p) |
2893 | pid = ftrace_swapper_pid; | |
2894 | else | |
2895 | pid = find_get_pid(p); | |
df4fc315 | 2896 | |
756d17ee | 2897 | if (!pid) |
2898 | goto out; | |
df4fc315 | 2899 | |
756d17ee | 2900 | ret = 0; |
df4fc315 | 2901 | |
756d17ee | 2902 | list_for_each_entry(fpid, &ftrace_pids, list) |
2903 | if (fpid->pid == pid) | |
2904 | goto out_put; | |
978f3a45 | 2905 | |
756d17ee | 2906 | ret = -ENOMEM; |
df4fc315 | 2907 | |
756d17ee | 2908 | fpid = kmalloc(sizeof(*fpid), GFP_KERNEL); |
2909 | if (!fpid) | |
2910 | goto out_put; | |
df4fc315 | 2911 | |
756d17ee | 2912 | list_add(&fpid->list, &ftrace_pids); |
2913 | fpid->pid = pid; | |
0ef8cde5 | 2914 | |
756d17ee | 2915 | set_ftrace_pid_task(pid); |
978f3a45 | 2916 | |
756d17ee | 2917 | ftrace_update_pid_func(); |
2918 | ftrace_startup_enable(0); | |
2919 | ||
2920 | mutex_unlock(&ftrace_lock); | |
2921 | return 0; | |
2922 | ||
2923 | out_put: | |
2924 | if (pid != ftrace_swapper_pid) | |
2925 | put_pid(pid); | |
978f3a45 | 2926 | |
756d17ee | 2927 | out: |
2928 | mutex_unlock(&ftrace_lock); | |
2929 | return ret; | |
2930 | } | |
2931 | ||
2932 | static void ftrace_pid_reset(void) | |
2933 | { | |
2934 | struct ftrace_pid *fpid, *safe; | |
978f3a45 | 2935 | |
756d17ee | 2936 | mutex_lock(&ftrace_lock); |
2937 | list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) { | |
2938 | struct pid *pid = fpid->pid; | |
2939 | ||
2940 | clear_ftrace_pid_task(pid); | |
2941 | ||
2942 | list_del(&fpid->list); | |
2943 | kfree(fpid); | |
df4fc315 SR |
2944 | } |
2945 | ||
df4fc315 SR |
2946 | ftrace_update_pid_func(); |
2947 | ftrace_startup_enable(0); | |
2948 | ||
e6ea44e9 | 2949 | mutex_unlock(&ftrace_lock); |
756d17ee | 2950 | } |
df4fc315 | 2951 | |
756d17ee | 2952 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
2953 | { | |
2954 | mutex_lock(&ftrace_lock); | |
2955 | ||
2956 | if (list_empty(&ftrace_pids) && (!*pos)) | |
2957 | return (void *) 1; | |
2958 | ||
2959 | return seq_list_start(&ftrace_pids, *pos); | |
2960 | } | |
2961 | ||
2962 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
2963 | { | |
2964 | if (v == (void *)1) | |
2965 | return NULL; | |
2966 | ||
2967 | return seq_list_next(v, &ftrace_pids, pos); | |
2968 | } | |
2969 | ||
2970 | static void fpid_stop(struct seq_file *m, void *p) | |
2971 | { | |
2972 | mutex_unlock(&ftrace_lock); | |
2973 | } | |
2974 | ||
2975 | static int fpid_show(struct seq_file *m, void *v) | |
2976 | { | |
2977 | const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list); | |
2978 | ||
2979 | if (v == (void *)1) { | |
2980 | seq_printf(m, "no pid\n"); | |
2981 | return 0; | |
2982 | } | |
2983 | ||
2984 | if (fpid->pid == ftrace_swapper_pid) | |
2985 | seq_printf(m, "swapper tasks\n"); | |
2986 | else | |
2987 | seq_printf(m, "%u\n", pid_vnr(fpid->pid)); | |
2988 | ||
2989 | return 0; | |
2990 | } | |
2991 | ||
2992 | static const struct seq_operations ftrace_pid_sops = { | |
2993 | .start = fpid_start, | |
2994 | .next = fpid_next, | |
2995 | .stop = fpid_stop, | |
2996 | .show = fpid_show, | |
2997 | }; | |
2998 | ||
2999 | static int | |
3000 | ftrace_pid_open(struct inode *inode, struct file *file) | |
3001 | { | |
3002 | int ret = 0; | |
3003 | ||
3004 | if ((file->f_mode & FMODE_WRITE) && | |
3005 | (file->f_flags & O_TRUNC)) | |
3006 | ftrace_pid_reset(); | |
3007 | ||
3008 | if (file->f_mode & FMODE_READ) | |
3009 | ret = seq_open(file, &ftrace_pid_sops); | |
3010 | ||
3011 | return ret; | |
3012 | } | |
3013 | ||
df4fc315 SR |
3014 | static ssize_t |
3015 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
3016 | size_t cnt, loff_t *ppos) | |
3017 | { | |
457dc928 | 3018 | char buf[64], *tmp; |
df4fc315 SR |
3019 | long val; |
3020 | int ret; | |
3021 | ||
3022 | if (cnt >= sizeof(buf)) | |
3023 | return -EINVAL; | |
3024 | ||
3025 | if (copy_from_user(&buf, ubuf, cnt)) | |
3026 | return -EFAULT; | |
3027 | ||
3028 | buf[cnt] = 0; | |
3029 | ||
756d17ee | 3030 | /* |
3031 | * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid" | |
3032 | * to clean the filter quietly. | |
3033 | */ | |
457dc928 IM |
3034 | tmp = strstrip(buf); |
3035 | if (strlen(tmp) == 0) | |
756d17ee | 3036 | return 1; |
3037 | ||
457dc928 | 3038 | ret = strict_strtol(tmp, 10, &val); |
df4fc315 SR |
3039 | if (ret < 0) |
3040 | return ret; | |
3041 | ||
756d17ee | 3042 | ret = ftrace_pid_add(val); |
df4fc315 | 3043 | |
756d17ee | 3044 | return ret ? ret : cnt; |
3045 | } | |
df4fc315 | 3046 | |
756d17ee | 3047 | static int |
3048 | ftrace_pid_release(struct inode *inode, struct file *file) | |
3049 | { | |
3050 | if (file->f_mode & FMODE_READ) | |
3051 | seq_release(inode, file); | |
df4fc315 | 3052 | |
756d17ee | 3053 | return 0; |
df4fc315 SR |
3054 | } |
3055 | ||
5e2336a0 | 3056 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 3057 | .open = ftrace_pid_open, |
3058 | .write = ftrace_pid_write, | |
3059 | .read = seq_read, | |
3060 | .llseek = seq_lseek, | |
3061 | .release = ftrace_pid_release, | |
df4fc315 SR |
3062 | }; |
3063 | ||
3064 | static __init int ftrace_init_debugfs(void) | |
3065 | { | |
3066 | struct dentry *d_tracer; | |
df4fc315 SR |
3067 | |
3068 | d_tracer = tracing_init_dentry(); | |
3069 | if (!d_tracer) | |
3070 | return 0; | |
3071 | ||
3072 | ftrace_init_dyn_debugfs(d_tracer); | |
3073 | ||
5452af66 FW |
3074 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
3075 | NULL, &ftrace_pid_fops); | |
493762fc SR |
3076 | |
3077 | ftrace_profile_debugfs(d_tracer); | |
3078 | ||
df4fc315 SR |
3079 | return 0; |
3080 | } | |
df4fc315 SR |
3081 | fs_initcall(ftrace_init_debugfs); |
3082 | ||
a2bb6a3d | 3083 | /** |
81adbdc0 | 3084 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
3085 | * |
3086 | * This function should be used by panic code. It stops ftrace | |
3087 | * but in a not so nice way. If you need to simply kill ftrace | |
3088 | * from a non-atomic section, use ftrace_kill. | |
3089 | */ | |
81adbdc0 | 3090 | void ftrace_kill(void) |
a2bb6a3d SR |
3091 | { |
3092 | ftrace_disabled = 1; | |
3093 | ftrace_enabled = 0; | |
a2bb6a3d SR |
3094 | clear_ftrace_function(); |
3095 | } | |
3096 | ||
16444a8a | 3097 | /** |
3d083395 SR |
3098 | * register_ftrace_function - register a function for profiling |
3099 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 3100 | * |
3d083395 SR |
3101 | * Register a function to be called by all functions in the |
3102 | * kernel. | |
3103 | * | |
3104 | * Note: @ops->func and all the functions it calls must be labeled | |
3105 | * with "notrace", otherwise it will go into a | |
3106 | * recursive loop. | |
16444a8a | 3107 | */ |
3d083395 | 3108 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 3109 | { |
b0fc494f SR |
3110 | int ret; |
3111 | ||
4eebcc81 SR |
3112 | if (unlikely(ftrace_disabled)) |
3113 | return -1; | |
3114 | ||
e6ea44e9 | 3115 | mutex_lock(&ftrace_lock); |
e7d3737e | 3116 | |
b0fc494f | 3117 | ret = __register_ftrace_function(ops); |
5a45cfe1 | 3118 | ftrace_startup(0); |
b0fc494f | 3119 | |
e6ea44e9 | 3120 | mutex_unlock(&ftrace_lock); |
b0fc494f | 3121 | return ret; |
3d083395 SR |
3122 | } |
3123 | ||
3124 | /** | |
32632920 | 3125 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
3126 | * @ops - ops structure that holds the function to unregister |
3127 | * | |
3128 | * Unregister a function that was added to be called by ftrace profiling. | |
3129 | */ | |
3130 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
3131 | { | |
3132 | int ret; | |
3133 | ||
e6ea44e9 | 3134 | mutex_lock(&ftrace_lock); |
3d083395 | 3135 | ret = __unregister_ftrace_function(ops); |
5a45cfe1 | 3136 | ftrace_shutdown(0); |
e6ea44e9 | 3137 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
3138 | |
3139 | return ret; | |
3140 | } | |
3141 | ||
e309b41d | 3142 | int |
b0fc494f | 3143 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
8d65af78 | 3144 | void __user *buffer, size_t *lenp, |
b0fc494f SR |
3145 | loff_t *ppos) |
3146 | { | |
3147 | int ret; | |
3148 | ||
4eebcc81 SR |
3149 | if (unlikely(ftrace_disabled)) |
3150 | return -ENODEV; | |
3151 | ||
e6ea44e9 | 3152 | mutex_lock(&ftrace_lock); |
b0fc494f | 3153 | |
8d65af78 | 3154 | ret = proc_dointvec(table, write, buffer, lenp, ppos); |
b0fc494f | 3155 | |
a32c7765 | 3156 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
3157 | goto out; |
3158 | ||
a32c7765 | 3159 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f SR |
3160 | |
3161 | if (ftrace_enabled) { | |
3162 | ||
3163 | ftrace_startup_sysctl(); | |
3164 | ||
3165 | /* we are starting ftrace again */ | |
3166 | if (ftrace_list != &ftrace_list_end) { | |
3167 | if (ftrace_list->next == &ftrace_list_end) | |
3168 | ftrace_trace_function = ftrace_list->func; | |
3169 | else | |
3170 | ftrace_trace_function = ftrace_list_func; | |
3171 | } | |
3172 | ||
3173 | } else { | |
3174 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
3175 | ftrace_trace_function = ftrace_stub; | |
3176 | ||
3177 | ftrace_shutdown_sysctl(); | |
3178 | } | |
3179 | ||
3180 | out: | |
e6ea44e9 | 3181 | mutex_unlock(&ftrace_lock); |
3d083395 | 3182 | return ret; |
16444a8a | 3183 | } |
f17845e5 | 3184 | |
fb52607a | 3185 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 3186 | |
597af815 | 3187 | static int ftrace_graph_active; |
4a2b8dda | 3188 | static struct notifier_block ftrace_suspend_notifier; |
e7d3737e | 3189 | |
e49dc19c SR |
3190 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
3191 | { | |
3192 | return 0; | |
3193 | } | |
3194 | ||
287b6e68 FW |
3195 | /* The callbacks that hook a function */ |
3196 | trace_func_graph_ret_t ftrace_graph_return = | |
3197 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 3198 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
3199 | |
3200 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
3201 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
3202 | { | |
3203 | int i; | |
3204 | int ret = 0; | |
3205 | unsigned long flags; | |
3206 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
3207 | struct task_struct *g, *t; | |
3208 | ||
3209 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
3210 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
3211 | * sizeof(struct ftrace_ret_stack), | |
3212 | GFP_KERNEL); | |
3213 | if (!ret_stack_list[i]) { | |
3214 | start = 0; | |
3215 | end = i; | |
3216 | ret = -ENOMEM; | |
3217 | goto free; | |
3218 | } | |
3219 | } | |
3220 | ||
3221 | read_lock_irqsave(&tasklist_lock, flags); | |
3222 | do_each_thread(g, t) { | |
3223 | if (start == end) { | |
3224 | ret = -EAGAIN; | |
3225 | goto unlock; | |
3226 | } | |
3227 | ||
3228 | if (t->ret_stack == NULL) { | |
380c4b14 | 3229 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 3230 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
3231 | t->curr_ret_stack = -1; |
3232 | /* Make sure the tasks see the -1 first: */ | |
3233 | smp_wmb(); | |
3234 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
3235 | } |
3236 | } while_each_thread(g, t); | |
3237 | ||
3238 | unlock: | |
3239 | read_unlock_irqrestore(&tasklist_lock, flags); | |
3240 | free: | |
3241 | for (i = start; i < end; i++) | |
3242 | kfree(ret_stack_list[i]); | |
3243 | return ret; | |
3244 | } | |
3245 | ||
8aef2d28 | 3246 | static void |
38516ab5 SR |
3247 | ftrace_graph_probe_sched_switch(void *ignore, |
3248 | struct task_struct *prev, struct task_struct *next) | |
8aef2d28 SR |
3249 | { |
3250 | unsigned long long timestamp; | |
3251 | int index; | |
3252 | ||
be6f164a SR |
3253 | /* |
3254 | * Does the user want to count the time a function was asleep. | |
3255 | * If so, do not update the time stamps. | |
3256 | */ | |
3257 | if (trace_flags & TRACE_ITER_SLEEP_TIME) | |
3258 | return; | |
3259 | ||
8aef2d28 SR |
3260 | timestamp = trace_clock_local(); |
3261 | ||
3262 | prev->ftrace_timestamp = timestamp; | |
3263 | ||
3264 | /* only process tasks that we timestamped */ | |
3265 | if (!next->ftrace_timestamp) | |
3266 | return; | |
3267 | ||
3268 | /* | |
3269 | * Update all the counters in next to make up for the | |
3270 | * time next was sleeping. | |
3271 | */ | |
3272 | timestamp -= next->ftrace_timestamp; | |
3273 | ||
3274 | for (index = next->curr_ret_stack; index >= 0; index--) | |
3275 | next->ret_stack[index].calltime += timestamp; | |
3276 | } | |
3277 | ||
f201ae23 | 3278 | /* Allocate a return stack for each task */ |
fb52607a | 3279 | static int start_graph_tracing(void) |
f201ae23 FW |
3280 | { |
3281 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 3282 | int ret, cpu; |
f201ae23 FW |
3283 | |
3284 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
3285 | sizeof(struct ftrace_ret_stack *), | |
3286 | GFP_KERNEL); | |
3287 | ||
3288 | if (!ret_stack_list) | |
3289 | return -ENOMEM; | |
3290 | ||
5b058bcd | 3291 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
3292 | for_each_online_cpu(cpu) { |
3293 | if (!idle_task(cpu)->ret_stack) | |
3294 | ftrace_graph_init_task(idle_task(cpu)); | |
3295 | } | |
5b058bcd | 3296 | |
f201ae23 FW |
3297 | do { |
3298 | ret = alloc_retstack_tasklist(ret_stack_list); | |
3299 | } while (ret == -EAGAIN); | |
3300 | ||
8aef2d28 | 3301 | if (!ret) { |
38516ab5 | 3302 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
8aef2d28 SR |
3303 | if (ret) |
3304 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
3305 | " probe to kernel_sched_switch\n"); | |
3306 | } | |
3307 | ||
f201ae23 FW |
3308 | kfree(ret_stack_list); |
3309 | return ret; | |
3310 | } | |
3311 | ||
4a2b8dda FW |
3312 | /* |
3313 | * Hibernation protection. | |
3314 | * The state of the current task is too much unstable during | |
3315 | * suspend/restore to disk. We want to protect against that. | |
3316 | */ | |
3317 | static int | |
3318 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
3319 | void *unused) | |
3320 | { | |
3321 | switch (state) { | |
3322 | case PM_HIBERNATION_PREPARE: | |
3323 | pause_graph_tracing(); | |
3324 | break; | |
3325 | ||
3326 | case PM_POST_HIBERNATION: | |
3327 | unpause_graph_tracing(); | |
3328 | break; | |
3329 | } | |
3330 | return NOTIFY_DONE; | |
3331 | } | |
3332 | ||
287b6e68 FW |
3333 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
3334 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 3335 | { |
e7d3737e FW |
3336 | int ret = 0; |
3337 | ||
e6ea44e9 | 3338 | mutex_lock(&ftrace_lock); |
e7d3737e | 3339 | |
05ce5818 | 3340 | /* we currently allow only one tracer registered at a time */ |
597af815 | 3341 | if (ftrace_graph_active) { |
05ce5818 SR |
3342 | ret = -EBUSY; |
3343 | goto out; | |
3344 | } | |
3345 | ||
4a2b8dda FW |
3346 | ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; |
3347 | register_pm_notifier(&ftrace_suspend_notifier); | |
3348 | ||
597af815 | 3349 | ftrace_graph_active++; |
fb52607a | 3350 | ret = start_graph_tracing(); |
f201ae23 | 3351 | if (ret) { |
597af815 | 3352 | ftrace_graph_active--; |
f201ae23 FW |
3353 | goto out; |
3354 | } | |
e53a6319 | 3355 | |
287b6e68 FW |
3356 | ftrace_graph_return = retfunc; |
3357 | ftrace_graph_entry = entryfunc; | |
e53a6319 | 3358 | |
5a45cfe1 | 3359 | ftrace_startup(FTRACE_START_FUNC_RET); |
e7d3737e FW |
3360 | |
3361 | out: | |
e6ea44e9 | 3362 | mutex_unlock(&ftrace_lock); |
e7d3737e | 3363 | return ret; |
15e6cb36 FW |
3364 | } |
3365 | ||
fb52607a | 3366 | void unregister_ftrace_graph(void) |
15e6cb36 | 3367 | { |
e6ea44e9 | 3368 | mutex_lock(&ftrace_lock); |
e7d3737e | 3369 | |
597af815 | 3370 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
3371 | goto out; |
3372 | ||
597af815 | 3373 | ftrace_graph_active--; |
287b6e68 | 3374 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 3375 | ftrace_graph_entry = ftrace_graph_entry_stub; |
5a45cfe1 | 3376 | ftrace_shutdown(FTRACE_STOP_FUNC_RET); |
4a2b8dda | 3377 | unregister_pm_notifier(&ftrace_suspend_notifier); |
38516ab5 | 3378 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
e7d3737e | 3379 | |
2aad1b76 | 3380 | out: |
e6ea44e9 | 3381 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 3382 | } |
f201ae23 FW |
3383 | |
3384 | /* Allocate a return stack for newly created task */ | |
fb52607a | 3385 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 3386 | { |
84047e36 SR |
3387 | /* Make sure we do not use the parent ret_stack */ |
3388 | t->ret_stack = NULL; | |
ea14eb71 | 3389 | t->curr_ret_stack = -1; |
84047e36 | 3390 | |
597af815 | 3391 | if (ftrace_graph_active) { |
82310a32 SR |
3392 | struct ftrace_ret_stack *ret_stack; |
3393 | ||
3394 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
3395 | * sizeof(struct ftrace_ret_stack), |
3396 | GFP_KERNEL); | |
82310a32 | 3397 | if (!ret_stack) |
f201ae23 | 3398 | return; |
380c4b14 | 3399 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 3400 | atomic_set(&t->trace_overrun, 0); |
8aef2d28 | 3401 | t->ftrace_timestamp = 0; |
82310a32 SR |
3402 | /* make curr_ret_stack visable before we add the ret_stack */ |
3403 | smp_wmb(); | |
3404 | t->ret_stack = ret_stack; | |
84047e36 | 3405 | } |
f201ae23 FW |
3406 | } |
3407 | ||
fb52607a | 3408 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 3409 | { |
eae849ca FW |
3410 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
3411 | ||
f201ae23 | 3412 | t->ret_stack = NULL; |
eae849ca FW |
3413 | /* NULL must become visible to IRQs before we free it: */ |
3414 | barrier(); | |
3415 | ||
3416 | kfree(ret_stack); | |
f201ae23 | 3417 | } |
14a866c5 SR |
3418 | |
3419 | void ftrace_graph_stop(void) | |
3420 | { | |
3421 | ftrace_stop(); | |
3422 | } | |
15e6cb36 | 3423 | #endif |