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 | 41 | #define FTRACE_WARN_ON(cond) \ |
0778d9ad SR |
42 | ({ \ |
43 | int ___r = cond; \ | |
44 | if (WARN_ON(___r)) \ | |
6912896e | 45 | ftrace_kill(); \ |
0778d9ad SR |
46 | ___r; \ |
47 | }) | |
6912896e SR |
48 | |
49 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
0778d9ad SR |
50 | ({ \ |
51 | int ___r = cond; \ | |
52 | if (WARN_ON_ONCE(___r)) \ | |
6912896e | 53 | ftrace_kill(); \ |
0778d9ad SR |
54 | ___r; \ |
55 | }) | |
6912896e | 56 | |
8fc0c701 SR |
57 | /* hash bits for specific function selection */ |
58 | #define FTRACE_HASH_BITS 7 | |
59 | #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS) | |
33dc9b12 SR |
60 | #define FTRACE_HASH_DEFAULT_BITS 10 |
61 | #define FTRACE_HASH_MAX_BITS 12 | |
8fc0c701 | 62 | |
4eebcc81 SR |
63 | /* ftrace_enabled is a method to turn ftrace on or off */ |
64 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 65 | static int last_ftrace_enabled; |
b0fc494f | 66 | |
60a7ecf4 SR |
67 | /* Quick disabling of function tracer. */ |
68 | int function_trace_stop; | |
69 | ||
756d17ee | 70 | /* List for set_ftrace_pid's pids. */ |
71 | LIST_HEAD(ftrace_pids); | |
72 | struct ftrace_pid { | |
73 | struct list_head list; | |
74 | struct pid *pid; | |
75 | }; | |
76 | ||
4eebcc81 SR |
77 | /* |
78 | * ftrace_disabled is set when an anomaly is discovered. | |
79 | * ftrace_disabled is much stronger than ftrace_enabled. | |
80 | */ | |
81 | static int ftrace_disabled __read_mostly; | |
82 | ||
52baf119 | 83 | static DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 84 | |
16444a8a ACM |
85 | static struct ftrace_ops ftrace_list_end __read_mostly = |
86 | { | |
fb9fb015 | 87 | .func = ftrace_stub, |
16444a8a ACM |
88 | }; |
89 | ||
b848914c SR |
90 | static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end; |
91 | static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end; | |
16444a8a | 92 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
60a7ecf4 | 93 | ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub; |
df4fc315 | 94 | ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; |
2b499381 | 95 | static struct ftrace_ops global_ops; |
16444a8a | 96 | |
b848914c SR |
97 | static void |
98 | ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip); | |
99 | ||
3f379b03 | 100 | /* |
b848914c | 101 | * Traverse the ftrace_global_list, invoking all entries. The reason that we |
3f379b03 PM |
102 | * can use rcu_dereference_raw() is that elements removed from this list |
103 | * are simply leaked, so there is no need to interact with a grace-period | |
104 | * mechanism. The rcu_dereference_raw() calls are needed to handle | |
b848914c | 105 | * concurrent insertions into the ftrace_global_list. |
3f379b03 PM |
106 | * |
107 | * Silly Alpha and silly pointer-speculation compiler optimizations! | |
108 | */ | |
b848914c SR |
109 | static void ftrace_global_list_func(unsigned long ip, |
110 | unsigned long parent_ip) | |
16444a8a | 111 | { |
b848914c | 112 | struct ftrace_ops *op = rcu_dereference_raw(ftrace_global_list); /*see above*/ |
16444a8a ACM |
113 | |
114 | while (op != &ftrace_list_end) { | |
16444a8a | 115 | op->func(ip, parent_ip); |
3f379b03 | 116 | op = rcu_dereference_raw(op->next); /*see above*/ |
16444a8a ACM |
117 | }; |
118 | } | |
119 | ||
df4fc315 SR |
120 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip) |
121 | { | |
0ef8cde5 | 122 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
123 | return; |
124 | ||
125 | ftrace_pid_function(ip, parent_ip); | |
126 | } | |
127 | ||
128 | static void set_ftrace_pid_function(ftrace_func_t func) | |
129 | { | |
130 | /* do not set ftrace_pid_function to itself! */ | |
131 | if (func != ftrace_pid_func) | |
132 | ftrace_pid_function = func; | |
133 | } | |
134 | ||
16444a8a | 135 | /** |
3d083395 | 136 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 137 | * |
3d083395 SR |
138 | * This NULLs the ftrace function and in essence stops |
139 | * tracing. There may be lag | |
16444a8a | 140 | */ |
3d083395 | 141 | void clear_ftrace_function(void) |
16444a8a | 142 | { |
3d083395 | 143 | ftrace_trace_function = ftrace_stub; |
60a7ecf4 | 144 | __ftrace_trace_function = ftrace_stub; |
df4fc315 | 145 | ftrace_pid_function = ftrace_stub; |
3d083395 SR |
146 | } |
147 | ||
60a7ecf4 SR |
148 | #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
149 | /* | |
150 | * For those archs that do not test ftrace_trace_stop in their | |
151 | * mcount call site, we need to do it from C. | |
152 | */ | |
153 | static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip) | |
154 | { | |
155 | if (function_trace_stop) | |
156 | return; | |
157 | ||
158 | __ftrace_trace_function(ip, parent_ip); | |
159 | } | |
160 | #endif | |
161 | ||
2b499381 | 162 | static void update_global_ops(void) |
491d0dcf SR |
163 | { |
164 | ftrace_func_t func; | |
165 | ||
166 | /* | |
167 | * If there's only one function registered, then call that | |
168 | * function directly. Otherwise, we need to iterate over the | |
169 | * registered callers. | |
170 | */ | |
b848914c SR |
171 | if (ftrace_global_list == &ftrace_list_end || |
172 | ftrace_global_list->next == &ftrace_list_end) | |
173 | func = ftrace_global_list->func; | |
491d0dcf | 174 | else |
b848914c | 175 | func = ftrace_global_list_func; |
491d0dcf SR |
176 | |
177 | /* If we filter on pids, update to use the pid function */ | |
178 | if (!list_empty(&ftrace_pids)) { | |
179 | set_ftrace_pid_function(func); | |
180 | func = ftrace_pid_func; | |
181 | } | |
2b499381 SR |
182 | |
183 | global_ops.func = func; | |
184 | } | |
185 | ||
186 | static void update_ftrace_function(void) | |
187 | { | |
188 | ftrace_func_t func; | |
189 | ||
190 | update_global_ops(); | |
191 | ||
b848914c SR |
192 | if (ftrace_ops_list == &ftrace_list_end || |
193 | ftrace_ops_list->next == &ftrace_list_end) | |
194 | func = ftrace_ops_list->func; | |
195 | else | |
196 | func = ftrace_ops_list_func; | |
2b499381 | 197 | |
491d0dcf SR |
198 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
199 | ftrace_trace_function = func; | |
200 | #else | |
201 | __ftrace_trace_function = func; | |
202 | ftrace_trace_function = ftrace_test_stop_func; | |
203 | #endif | |
204 | } | |
205 | ||
2b499381 | 206 | static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
3d083395 | 207 | { |
2b499381 | 208 | ops->next = *list; |
16444a8a | 209 | /* |
b848914c | 210 | * We are entering ops into the list but another |
16444a8a ACM |
211 | * CPU might be walking that list. We need to make sure |
212 | * the ops->next pointer is valid before another CPU sees | |
b848914c | 213 | * the ops pointer included into the list. |
16444a8a | 214 | */ |
2b499381 | 215 | rcu_assign_pointer(*list, ops); |
16444a8a ACM |
216 | } |
217 | ||
2b499381 | 218 | static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
16444a8a | 219 | { |
16444a8a | 220 | struct ftrace_ops **p; |
16444a8a ACM |
221 | |
222 | /* | |
3d083395 SR |
223 | * If we are removing the last function, then simply point |
224 | * to the ftrace_stub. | |
16444a8a | 225 | */ |
2b499381 SR |
226 | if (*list == ops && ops->next == &ftrace_list_end) { |
227 | *list = &ftrace_list_end; | |
e6ea44e9 | 228 | return 0; |
16444a8a ACM |
229 | } |
230 | ||
2b499381 | 231 | for (p = list; *p != &ftrace_list_end; p = &(*p)->next) |
16444a8a ACM |
232 | if (*p == ops) |
233 | break; | |
234 | ||
e6ea44e9 SR |
235 | if (*p != ops) |
236 | return -1; | |
16444a8a ACM |
237 | |
238 | *p = (*p)->next; | |
2b499381 SR |
239 | return 0; |
240 | } | |
16444a8a | 241 | |
2b499381 SR |
242 | static int __register_ftrace_function(struct ftrace_ops *ops) |
243 | { | |
244 | if (ftrace_disabled) | |
245 | return -ENODEV; | |
246 | ||
247 | if (FTRACE_WARN_ON(ops == &global_ops)) | |
248 | return -EINVAL; | |
249 | ||
b848914c SR |
250 | if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) |
251 | return -EBUSY; | |
252 | ||
253 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { | |
254 | int first = ftrace_global_list == &ftrace_list_end; | |
255 | add_ftrace_ops(&ftrace_global_list, ops); | |
256 | ops->flags |= FTRACE_OPS_FL_ENABLED; | |
257 | if (first) | |
258 | add_ftrace_ops(&ftrace_ops_list, &global_ops); | |
259 | } else | |
260 | add_ftrace_ops(&ftrace_ops_list, ops); | |
261 | ||
2b499381 SR |
262 | if (ftrace_enabled) |
263 | update_ftrace_function(); | |
264 | ||
265 | return 0; | |
266 | } | |
267 | ||
268 | static int __unregister_ftrace_function(struct ftrace_ops *ops) | |
269 | { | |
270 | int ret; | |
271 | ||
272 | if (ftrace_disabled) | |
273 | return -ENODEV; | |
274 | ||
b848914c SR |
275 | if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) |
276 | return -EBUSY; | |
277 | ||
2b499381 SR |
278 | if (FTRACE_WARN_ON(ops == &global_ops)) |
279 | return -EINVAL; | |
280 | ||
b848914c SR |
281 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { |
282 | ret = remove_ftrace_ops(&ftrace_global_list, ops); | |
283 | if (!ret && ftrace_global_list == &ftrace_list_end) | |
284 | ret = remove_ftrace_ops(&ftrace_ops_list, &global_ops); | |
285 | if (!ret) | |
286 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; | |
287 | } else | |
288 | ret = remove_ftrace_ops(&ftrace_ops_list, ops); | |
289 | ||
2b499381 SR |
290 | if (ret < 0) |
291 | return ret; | |
b848914c | 292 | |
491d0dcf SR |
293 | if (ftrace_enabled) |
294 | update_ftrace_function(); | |
16444a8a | 295 | |
e6ea44e9 | 296 | return 0; |
3d083395 SR |
297 | } |
298 | ||
df4fc315 SR |
299 | static void ftrace_update_pid_func(void) |
300 | { | |
491d0dcf | 301 | /* Only do something if we are tracing something */ |
df4fc315 | 302 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 303 | return; |
df4fc315 | 304 | |
491d0dcf | 305 | update_ftrace_function(); |
df4fc315 SR |
306 | } |
307 | ||
493762fc SR |
308 | #ifdef CONFIG_FUNCTION_PROFILER |
309 | struct ftrace_profile { | |
310 | struct hlist_node node; | |
311 | unsigned long ip; | |
312 | unsigned long counter; | |
0706f1c4 SR |
313 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
314 | unsigned long long time; | |
e330b3bc | 315 | unsigned long long time_squared; |
0706f1c4 | 316 | #endif |
8fc0c701 SR |
317 | }; |
318 | ||
493762fc SR |
319 | struct ftrace_profile_page { |
320 | struct ftrace_profile_page *next; | |
321 | unsigned long index; | |
322 | struct ftrace_profile records[]; | |
d61f82d0 SR |
323 | }; |
324 | ||
cafb168a SR |
325 | struct ftrace_profile_stat { |
326 | atomic_t disabled; | |
327 | struct hlist_head *hash; | |
328 | struct ftrace_profile_page *pages; | |
329 | struct ftrace_profile_page *start; | |
330 | struct tracer_stat stat; | |
331 | }; | |
332 | ||
493762fc SR |
333 | #define PROFILE_RECORDS_SIZE \ |
334 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 335 | |
493762fc SR |
336 | #define PROFILES_PER_PAGE \ |
337 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 338 | |
fb9fb015 SR |
339 | static int ftrace_profile_bits __read_mostly; |
340 | static int ftrace_profile_enabled __read_mostly; | |
341 | ||
342 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
343 | static DEFINE_MUTEX(ftrace_profile_lock); |
344 | ||
cafb168a | 345 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc SR |
346 | |
347 | #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */ | |
348 | ||
bac429f0 SR |
349 | static void * |
350 | function_stat_next(void *v, int idx) | |
351 | { | |
493762fc SR |
352 | struct ftrace_profile *rec = v; |
353 | struct ftrace_profile_page *pg; | |
bac429f0 | 354 | |
493762fc | 355 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
356 | |
357 | again: | |
0296e425 LZ |
358 | if (idx != 0) |
359 | rec++; | |
360 | ||
bac429f0 SR |
361 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
362 | pg = pg->next; | |
363 | if (!pg) | |
364 | return NULL; | |
365 | rec = &pg->records[0]; | |
493762fc SR |
366 | if (!rec->counter) |
367 | goto again; | |
bac429f0 SR |
368 | } |
369 | ||
bac429f0 SR |
370 | return rec; |
371 | } | |
372 | ||
373 | static void *function_stat_start(struct tracer_stat *trace) | |
374 | { | |
cafb168a SR |
375 | struct ftrace_profile_stat *stat = |
376 | container_of(trace, struct ftrace_profile_stat, stat); | |
377 | ||
378 | if (!stat || !stat->start) | |
379 | return NULL; | |
380 | ||
381 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
382 | } |
383 | ||
0706f1c4 SR |
384 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
385 | /* function graph compares on total time */ | |
386 | static int function_stat_cmp(void *p1, void *p2) | |
387 | { | |
388 | struct ftrace_profile *a = p1; | |
389 | struct ftrace_profile *b = p2; | |
390 | ||
391 | if (a->time < b->time) | |
392 | return -1; | |
393 | if (a->time > b->time) | |
394 | return 1; | |
395 | else | |
396 | return 0; | |
397 | } | |
398 | #else | |
399 | /* not function graph compares against hits */ | |
bac429f0 SR |
400 | static int function_stat_cmp(void *p1, void *p2) |
401 | { | |
493762fc SR |
402 | struct ftrace_profile *a = p1; |
403 | struct ftrace_profile *b = p2; | |
bac429f0 SR |
404 | |
405 | if (a->counter < b->counter) | |
406 | return -1; | |
407 | if (a->counter > b->counter) | |
408 | return 1; | |
409 | else | |
410 | return 0; | |
411 | } | |
0706f1c4 | 412 | #endif |
bac429f0 SR |
413 | |
414 | static int function_stat_headers(struct seq_file *m) | |
415 | { | |
0706f1c4 | 416 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b | 417 | seq_printf(m, " Function " |
e330b3bc | 418 | "Hit Time Avg s^2\n" |
34886c8b | 419 | " -------- " |
e330b3bc | 420 | "--- ---- --- ---\n"); |
0706f1c4 | 421 | #else |
bac429f0 SR |
422 | seq_printf(m, " Function Hit\n" |
423 | " -------- ---\n"); | |
0706f1c4 | 424 | #endif |
bac429f0 SR |
425 | return 0; |
426 | } | |
427 | ||
428 | static int function_stat_show(struct seq_file *m, void *v) | |
429 | { | |
493762fc | 430 | struct ftrace_profile *rec = v; |
bac429f0 | 431 | char str[KSYM_SYMBOL_LEN]; |
3aaba20f | 432 | int ret = 0; |
0706f1c4 | 433 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
434 | static struct trace_seq s; |
435 | unsigned long long avg; | |
e330b3bc | 436 | unsigned long long stddev; |
0706f1c4 | 437 | #endif |
3aaba20f LZ |
438 | mutex_lock(&ftrace_profile_lock); |
439 | ||
440 | /* we raced with function_profile_reset() */ | |
441 | if (unlikely(rec->counter == 0)) { | |
442 | ret = -EBUSY; | |
443 | goto out; | |
444 | } | |
bac429f0 SR |
445 | |
446 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
0706f1c4 SR |
447 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
448 | ||
449 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
450 | seq_printf(m, " "); | |
34886c8b SR |
451 | avg = rec->time; |
452 | do_div(avg, rec->counter); | |
453 | ||
e330b3bc CD |
454 | /* Sample standard deviation (s^2) */ |
455 | if (rec->counter <= 1) | |
456 | stddev = 0; | |
457 | else { | |
458 | stddev = rec->time_squared - rec->counter * avg * avg; | |
459 | /* | |
460 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
461 | * trace_print_graph_duration will divide 1000 again. | |
462 | */ | |
463 | do_div(stddev, (rec->counter - 1) * 1000); | |
464 | } | |
465 | ||
34886c8b SR |
466 | trace_seq_init(&s); |
467 | trace_print_graph_duration(rec->time, &s); | |
468 | trace_seq_puts(&s, " "); | |
469 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
470 | trace_seq_puts(&s, " "); |
471 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 | 472 | trace_print_seq(m, &s); |
0706f1c4 SR |
473 | #endif |
474 | seq_putc(m, '\n'); | |
3aaba20f LZ |
475 | out: |
476 | mutex_unlock(&ftrace_profile_lock); | |
bac429f0 | 477 | |
3aaba20f | 478 | return ret; |
bac429f0 SR |
479 | } |
480 | ||
cafb168a | 481 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 482 | { |
493762fc | 483 | struct ftrace_profile_page *pg; |
bac429f0 | 484 | |
cafb168a | 485 | pg = stat->pages = stat->start; |
bac429f0 | 486 | |
493762fc SR |
487 | while (pg) { |
488 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
489 | pg->index = 0; | |
490 | pg = pg->next; | |
bac429f0 SR |
491 | } |
492 | ||
cafb168a | 493 | memset(stat->hash, 0, |
493762fc SR |
494 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
495 | } | |
bac429f0 | 496 | |
cafb168a | 497 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
498 | { |
499 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
500 | int functions; |
501 | int pages; | |
493762fc | 502 | int i; |
bac429f0 | 503 | |
493762fc | 504 | /* If we already allocated, do nothing */ |
cafb168a | 505 | if (stat->pages) |
493762fc | 506 | return 0; |
bac429f0 | 507 | |
cafb168a SR |
508 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
509 | if (!stat->pages) | |
493762fc | 510 | return -ENOMEM; |
bac429f0 | 511 | |
318e0a73 SR |
512 | #ifdef CONFIG_DYNAMIC_FTRACE |
513 | functions = ftrace_update_tot_cnt; | |
514 | #else | |
515 | /* | |
516 | * We do not know the number of functions that exist because | |
517 | * dynamic tracing is what counts them. With past experience | |
518 | * we have around 20K functions. That should be more than enough. | |
519 | * It is highly unlikely we will execute every function in | |
520 | * the kernel. | |
521 | */ | |
522 | functions = 20000; | |
523 | #endif | |
524 | ||
cafb168a | 525 | pg = stat->start = stat->pages; |
bac429f0 | 526 | |
318e0a73 SR |
527 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
528 | ||
529 | for (i = 0; i < pages; i++) { | |
493762fc | 530 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 531 | if (!pg->next) |
318e0a73 | 532 | goto out_free; |
493762fc SR |
533 | pg = pg->next; |
534 | } | |
535 | ||
536 | return 0; | |
318e0a73 SR |
537 | |
538 | out_free: | |
539 | pg = stat->start; | |
540 | while (pg) { | |
541 | unsigned long tmp = (unsigned long)pg; | |
542 | ||
543 | pg = pg->next; | |
544 | free_page(tmp); | |
545 | } | |
546 | ||
547 | free_page((unsigned long)stat->pages); | |
548 | stat->pages = NULL; | |
549 | stat->start = NULL; | |
550 | ||
551 | return -ENOMEM; | |
bac429f0 SR |
552 | } |
553 | ||
cafb168a | 554 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 555 | { |
cafb168a | 556 | struct ftrace_profile_stat *stat; |
493762fc | 557 | int size; |
bac429f0 | 558 | |
cafb168a SR |
559 | stat = &per_cpu(ftrace_profile_stats, cpu); |
560 | ||
561 | if (stat->hash) { | |
493762fc | 562 | /* If the profile is already created, simply reset it */ |
cafb168a | 563 | ftrace_profile_reset(stat); |
493762fc SR |
564 | return 0; |
565 | } | |
bac429f0 | 566 | |
493762fc SR |
567 | /* |
568 | * We are profiling all functions, but usually only a few thousand | |
569 | * functions are hit. We'll make a hash of 1024 items. | |
570 | */ | |
571 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 572 | |
cafb168a | 573 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
493762fc | 574 | |
cafb168a | 575 | if (!stat->hash) |
493762fc SR |
576 | return -ENOMEM; |
577 | ||
cafb168a SR |
578 | if (!ftrace_profile_bits) { |
579 | size--; | |
493762fc | 580 | |
cafb168a SR |
581 | for (; size; size >>= 1) |
582 | ftrace_profile_bits++; | |
583 | } | |
493762fc | 584 | |
318e0a73 | 585 | /* Preallocate the function profiling pages */ |
cafb168a SR |
586 | if (ftrace_profile_pages_init(stat) < 0) { |
587 | kfree(stat->hash); | |
588 | stat->hash = NULL; | |
493762fc SR |
589 | return -ENOMEM; |
590 | } | |
591 | ||
592 | return 0; | |
bac429f0 SR |
593 | } |
594 | ||
cafb168a SR |
595 | static int ftrace_profile_init(void) |
596 | { | |
597 | int cpu; | |
598 | int ret = 0; | |
599 | ||
600 | for_each_online_cpu(cpu) { | |
601 | ret = ftrace_profile_init_cpu(cpu); | |
602 | if (ret) | |
603 | break; | |
604 | } | |
605 | ||
606 | return ret; | |
607 | } | |
608 | ||
493762fc | 609 | /* interrupts must be disabled */ |
cafb168a SR |
610 | static struct ftrace_profile * |
611 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 612 | { |
493762fc | 613 | struct ftrace_profile *rec; |
bac429f0 SR |
614 | struct hlist_head *hhd; |
615 | struct hlist_node *n; | |
bac429f0 SR |
616 | unsigned long key; |
617 | ||
bac429f0 | 618 | key = hash_long(ip, ftrace_profile_bits); |
cafb168a | 619 | hhd = &stat->hash[key]; |
bac429f0 SR |
620 | |
621 | if (hlist_empty(hhd)) | |
622 | return NULL; | |
623 | ||
bac429f0 SR |
624 | hlist_for_each_entry_rcu(rec, n, hhd, node) { |
625 | if (rec->ip == ip) | |
493762fc SR |
626 | return rec; |
627 | } | |
628 | ||
629 | return NULL; | |
630 | } | |
631 | ||
cafb168a SR |
632 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
633 | struct ftrace_profile *rec) | |
493762fc SR |
634 | { |
635 | unsigned long key; | |
636 | ||
637 | key = hash_long(rec->ip, ftrace_profile_bits); | |
cafb168a | 638 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
639 | } |
640 | ||
318e0a73 SR |
641 | /* |
642 | * The memory is already allocated, this simply finds a new record to use. | |
643 | */ | |
493762fc | 644 | static struct ftrace_profile * |
318e0a73 | 645 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
646 | { |
647 | struct ftrace_profile *rec = NULL; | |
648 | ||
318e0a73 | 649 | /* prevent recursion (from NMIs) */ |
cafb168a | 650 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
651 | goto out; |
652 | ||
493762fc | 653 | /* |
318e0a73 SR |
654 | * Try to find the function again since an NMI |
655 | * could have added it | |
493762fc | 656 | */ |
cafb168a | 657 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 658 | if (rec) |
cafb168a | 659 | goto out; |
493762fc | 660 | |
cafb168a SR |
661 | if (stat->pages->index == PROFILES_PER_PAGE) { |
662 | if (!stat->pages->next) | |
663 | goto out; | |
664 | stat->pages = stat->pages->next; | |
bac429f0 | 665 | } |
493762fc | 666 | |
cafb168a | 667 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 668 | rec->ip = ip; |
cafb168a | 669 | ftrace_add_profile(stat, rec); |
493762fc | 670 | |
bac429f0 | 671 | out: |
cafb168a | 672 | atomic_dec(&stat->disabled); |
bac429f0 SR |
673 | |
674 | return rec; | |
675 | } | |
676 | ||
677 | static void | |
678 | function_profile_call(unsigned long ip, unsigned long parent_ip) | |
679 | { | |
cafb168a | 680 | struct ftrace_profile_stat *stat; |
493762fc | 681 | struct ftrace_profile *rec; |
bac429f0 SR |
682 | unsigned long flags; |
683 | ||
684 | if (!ftrace_profile_enabled) | |
685 | return; | |
686 | ||
687 | local_irq_save(flags); | |
cafb168a SR |
688 | |
689 | stat = &__get_cpu_var(ftrace_profile_stats); | |
0f6ce3de | 690 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
691 | goto out; |
692 | ||
693 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 694 | if (!rec) { |
318e0a73 | 695 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
696 | if (!rec) |
697 | goto out; | |
698 | } | |
bac429f0 SR |
699 | |
700 | rec->counter++; | |
701 | out: | |
702 | local_irq_restore(flags); | |
703 | } | |
704 | ||
0706f1c4 SR |
705 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
706 | static int profile_graph_entry(struct ftrace_graph_ent *trace) | |
707 | { | |
708 | function_profile_call(trace->func, 0); | |
709 | return 1; | |
710 | } | |
711 | ||
712 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
713 | { | |
cafb168a | 714 | struct ftrace_profile_stat *stat; |
a2a16d6a | 715 | unsigned long long calltime; |
0706f1c4 | 716 | struct ftrace_profile *rec; |
cafb168a | 717 | unsigned long flags; |
0706f1c4 SR |
718 | |
719 | local_irq_save(flags); | |
cafb168a | 720 | stat = &__get_cpu_var(ftrace_profile_stats); |
0f6ce3de | 721 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
722 | goto out; |
723 | ||
37e44bc5 SR |
724 | /* If the calltime was zero'd ignore it */ |
725 | if (!trace->calltime) | |
726 | goto out; | |
727 | ||
a2a16d6a SR |
728 | calltime = trace->rettime - trace->calltime; |
729 | ||
730 | if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) { | |
731 | int index; | |
732 | ||
733 | index = trace->depth; | |
734 | ||
735 | /* Append this call time to the parent time to subtract */ | |
736 | if (index) | |
737 | current->ret_stack[index - 1].subtime += calltime; | |
738 | ||
739 | if (current->ret_stack[index].subtime < calltime) | |
740 | calltime -= current->ret_stack[index].subtime; | |
741 | else | |
742 | calltime = 0; | |
743 | } | |
744 | ||
cafb168a | 745 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 746 | if (rec) { |
a2a16d6a | 747 | rec->time += calltime; |
e330b3bc CD |
748 | rec->time_squared += calltime * calltime; |
749 | } | |
a2a16d6a | 750 | |
cafb168a | 751 | out: |
0706f1c4 SR |
752 | local_irq_restore(flags); |
753 | } | |
754 | ||
755 | static int register_ftrace_profiler(void) | |
756 | { | |
757 | return register_ftrace_graph(&profile_graph_return, | |
758 | &profile_graph_entry); | |
759 | } | |
760 | ||
761 | static void unregister_ftrace_profiler(void) | |
762 | { | |
763 | unregister_ftrace_graph(); | |
764 | } | |
765 | #else | |
bac429f0 SR |
766 | static struct ftrace_ops ftrace_profile_ops __read_mostly = |
767 | { | |
fb9fb015 | 768 | .func = function_profile_call, |
bac429f0 SR |
769 | }; |
770 | ||
0706f1c4 SR |
771 | static int register_ftrace_profiler(void) |
772 | { | |
773 | return register_ftrace_function(&ftrace_profile_ops); | |
774 | } | |
775 | ||
776 | static void unregister_ftrace_profiler(void) | |
777 | { | |
778 | unregister_ftrace_function(&ftrace_profile_ops); | |
779 | } | |
780 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
781 | ||
bac429f0 SR |
782 | static ssize_t |
783 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
784 | size_t cnt, loff_t *ppos) | |
785 | { | |
786 | unsigned long val; | |
fb9fb015 | 787 | char buf[64]; /* big enough to hold a number */ |
bac429f0 SR |
788 | int ret; |
789 | ||
bac429f0 SR |
790 | if (cnt >= sizeof(buf)) |
791 | return -EINVAL; | |
792 | ||
793 | if (copy_from_user(&buf, ubuf, cnt)) | |
794 | return -EFAULT; | |
795 | ||
796 | buf[cnt] = 0; | |
797 | ||
798 | ret = strict_strtoul(buf, 10, &val); | |
799 | if (ret < 0) | |
800 | return ret; | |
801 | ||
802 | val = !!val; | |
803 | ||
804 | mutex_lock(&ftrace_profile_lock); | |
805 | if (ftrace_profile_enabled ^ val) { | |
806 | if (val) { | |
493762fc SR |
807 | ret = ftrace_profile_init(); |
808 | if (ret < 0) { | |
809 | cnt = ret; | |
810 | goto out; | |
811 | } | |
812 | ||
0706f1c4 SR |
813 | ret = register_ftrace_profiler(); |
814 | if (ret < 0) { | |
815 | cnt = ret; | |
816 | goto out; | |
817 | } | |
bac429f0 SR |
818 | ftrace_profile_enabled = 1; |
819 | } else { | |
820 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
821 | /* |
822 | * unregister_ftrace_profiler calls stop_machine | |
823 | * so this acts like an synchronize_sched. | |
824 | */ | |
0706f1c4 | 825 | unregister_ftrace_profiler(); |
bac429f0 SR |
826 | } |
827 | } | |
493762fc | 828 | out: |
bac429f0 SR |
829 | mutex_unlock(&ftrace_profile_lock); |
830 | ||
cf8517cf | 831 | *ppos += cnt; |
bac429f0 SR |
832 | |
833 | return cnt; | |
834 | } | |
835 | ||
493762fc SR |
836 | static ssize_t |
837 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
838 | size_t cnt, loff_t *ppos) | |
839 | { | |
fb9fb015 | 840 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
841 | int r; |
842 | ||
843 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
844 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
845 | } | |
846 | ||
bac429f0 SR |
847 | static const struct file_operations ftrace_profile_fops = { |
848 | .open = tracing_open_generic, | |
849 | .read = ftrace_profile_read, | |
850 | .write = ftrace_profile_write, | |
6038f373 | 851 | .llseek = default_llseek, |
bac429f0 SR |
852 | }; |
853 | ||
cafb168a SR |
854 | /* used to initialize the real stat files */ |
855 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
856 | .name = "functions", |
857 | .stat_start = function_stat_start, | |
858 | .stat_next = function_stat_next, | |
859 | .stat_cmp = function_stat_cmp, | |
860 | .stat_headers = function_stat_headers, | |
861 | .stat_show = function_stat_show | |
cafb168a SR |
862 | }; |
863 | ||
6ab5d668 | 864 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 | 865 | { |
cafb168a | 866 | struct ftrace_profile_stat *stat; |
bac429f0 | 867 | struct dentry *entry; |
cafb168a | 868 | char *name; |
bac429f0 | 869 | int ret; |
cafb168a SR |
870 | int cpu; |
871 | ||
872 | for_each_possible_cpu(cpu) { | |
873 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
874 | ||
875 | /* allocate enough for function name + cpu number */ | |
876 | name = kmalloc(32, GFP_KERNEL); | |
877 | if (!name) { | |
878 | /* | |
879 | * The files created are permanent, if something happens | |
880 | * we still do not free memory. | |
881 | */ | |
cafb168a SR |
882 | WARN(1, |
883 | "Could not allocate stat file for cpu %d\n", | |
884 | cpu); | |
885 | return; | |
886 | } | |
887 | stat->stat = function_stats; | |
888 | snprintf(name, 32, "function%d", cpu); | |
889 | stat->stat.name = name; | |
890 | ret = register_stat_tracer(&stat->stat); | |
891 | if (ret) { | |
892 | WARN(1, | |
893 | "Could not register function stat for cpu %d\n", | |
894 | cpu); | |
895 | kfree(name); | |
896 | return; | |
897 | } | |
bac429f0 SR |
898 | } |
899 | ||
900 | entry = debugfs_create_file("function_profile_enabled", 0644, | |
901 | d_tracer, NULL, &ftrace_profile_fops); | |
902 | if (!entry) | |
903 | pr_warning("Could not create debugfs " | |
904 | "'function_profile_enabled' entry\n"); | |
905 | } | |
906 | ||
bac429f0 | 907 | #else /* CONFIG_FUNCTION_PROFILER */ |
6ab5d668 | 908 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 SR |
909 | { |
910 | } | |
bac429f0 SR |
911 | #endif /* CONFIG_FUNCTION_PROFILER */ |
912 | ||
493762fc SR |
913 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; |
914 | ||
915 | #ifdef CONFIG_DYNAMIC_FTRACE | |
916 | ||
917 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD | |
918 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
919 | #endif | |
920 | ||
921 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; | |
922 | ||
923 | struct ftrace_func_probe { | |
924 | struct hlist_node node; | |
925 | struct ftrace_probe_ops *ops; | |
926 | unsigned long flags; | |
927 | unsigned long ip; | |
928 | void *data; | |
929 | struct rcu_head rcu; | |
930 | }; | |
931 | ||
932 | enum { | |
933 | FTRACE_ENABLE_CALLS = (1 << 0), | |
934 | FTRACE_DISABLE_CALLS = (1 << 1), | |
935 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
79e406d7 SR |
936 | FTRACE_START_FUNC_RET = (1 << 3), |
937 | FTRACE_STOP_FUNC_RET = (1 << 4), | |
493762fc | 938 | }; |
b448c4e3 SR |
939 | struct ftrace_func_entry { |
940 | struct hlist_node hlist; | |
941 | unsigned long ip; | |
942 | }; | |
943 | ||
944 | struct ftrace_hash { | |
945 | unsigned long size_bits; | |
946 | struct hlist_head *buckets; | |
947 | unsigned long count; | |
07fd5515 | 948 | struct rcu_head rcu; |
b448c4e3 SR |
949 | }; |
950 | ||
33dc9b12 SR |
951 | /* |
952 | * We make these constant because no one should touch them, | |
953 | * but they are used as the default "empty hash", to avoid allocating | |
954 | * it all the time. These are in a read only section such that if | |
955 | * anyone does try to modify it, it will cause an exception. | |
956 | */ | |
957 | static const struct hlist_head empty_buckets[1]; | |
958 | static const struct ftrace_hash empty_hash = { | |
959 | .buckets = (struct hlist_head *)empty_buckets, | |
1cf41dd7 | 960 | }; |
33dc9b12 | 961 | #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) |
493762fc | 962 | |
2b499381 | 963 | static struct ftrace_ops global_ops = { |
f45948e8 | 964 | .func = ftrace_stub, |
33dc9b12 SR |
965 | .notrace_hash = EMPTY_HASH, |
966 | .filter_hash = EMPTY_HASH, | |
f45948e8 SR |
967 | }; |
968 | ||
493762fc SR |
969 | static struct dyn_ftrace *ftrace_new_addrs; |
970 | ||
971 | static DEFINE_MUTEX(ftrace_regex_lock); | |
972 | ||
973 | struct ftrace_page { | |
974 | struct ftrace_page *next; | |
975 | int index; | |
976 | struct dyn_ftrace records[]; | |
977 | }; | |
978 | ||
979 | #define ENTRIES_PER_PAGE \ | |
980 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
981 | ||
982 | /* estimate from running different kernels */ | |
983 | #define NR_TO_INIT 10000 | |
984 | ||
985 | static struct ftrace_page *ftrace_pages_start; | |
986 | static struct ftrace_page *ftrace_pages; | |
987 | ||
988 | static struct dyn_ftrace *ftrace_free_records; | |
989 | ||
b448c4e3 SR |
990 | static struct ftrace_func_entry * |
991 | ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
992 | { | |
993 | unsigned long key; | |
994 | struct ftrace_func_entry *entry; | |
995 | struct hlist_head *hhd; | |
996 | struct hlist_node *n; | |
997 | ||
998 | if (!hash->count) | |
999 | return NULL; | |
1000 | ||
1001 | if (hash->size_bits > 0) | |
1002 | key = hash_long(ip, hash->size_bits); | |
1003 | else | |
1004 | key = 0; | |
1005 | ||
1006 | hhd = &hash->buckets[key]; | |
1007 | ||
1008 | hlist_for_each_entry_rcu(entry, n, hhd, hlist) { | |
1009 | if (entry->ip == ip) | |
1010 | return entry; | |
1011 | } | |
1012 | return NULL; | |
1013 | } | |
1014 | ||
33dc9b12 SR |
1015 | static void __add_hash_entry(struct ftrace_hash *hash, |
1016 | struct ftrace_func_entry *entry) | |
b448c4e3 | 1017 | { |
b448c4e3 SR |
1018 | struct hlist_head *hhd; |
1019 | unsigned long key; | |
1020 | ||
b448c4e3 | 1021 | if (hash->size_bits) |
33dc9b12 | 1022 | key = hash_long(entry->ip, hash->size_bits); |
b448c4e3 SR |
1023 | else |
1024 | key = 0; | |
1025 | ||
b448c4e3 SR |
1026 | hhd = &hash->buckets[key]; |
1027 | hlist_add_head(&entry->hlist, hhd); | |
1028 | hash->count++; | |
33dc9b12 SR |
1029 | } |
1030 | ||
1031 | static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip) | |
1032 | { | |
1033 | struct ftrace_func_entry *entry; | |
1034 | ||
1035 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1036 | if (!entry) | |
1037 | return -ENOMEM; | |
1038 | ||
1039 | entry->ip = ip; | |
1040 | __add_hash_entry(hash, entry); | |
b448c4e3 SR |
1041 | |
1042 | return 0; | |
1043 | } | |
1044 | ||
1045 | static void | |
33dc9b12 | 1046 | free_hash_entry(struct ftrace_hash *hash, |
b448c4e3 SR |
1047 | struct ftrace_func_entry *entry) |
1048 | { | |
1049 | hlist_del(&entry->hlist); | |
1050 | kfree(entry); | |
1051 | hash->count--; | |
1052 | } | |
1053 | ||
33dc9b12 SR |
1054 | static void |
1055 | remove_hash_entry(struct ftrace_hash *hash, | |
1056 | struct ftrace_func_entry *entry) | |
1057 | { | |
1058 | hlist_del(&entry->hlist); | |
1059 | hash->count--; | |
1060 | } | |
1061 | ||
b448c4e3 SR |
1062 | static void ftrace_hash_clear(struct ftrace_hash *hash) |
1063 | { | |
1064 | struct hlist_head *hhd; | |
1065 | struct hlist_node *tp, *tn; | |
1066 | struct ftrace_func_entry *entry; | |
1067 | int size = 1 << hash->size_bits; | |
1068 | int i; | |
1069 | ||
33dc9b12 SR |
1070 | if (!hash->count) |
1071 | return; | |
1072 | ||
b448c4e3 SR |
1073 | for (i = 0; i < size; i++) { |
1074 | hhd = &hash->buckets[i]; | |
1075 | hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist) | |
33dc9b12 | 1076 | free_hash_entry(hash, entry); |
b448c4e3 SR |
1077 | } |
1078 | FTRACE_WARN_ON(hash->count); | |
1079 | } | |
1080 | ||
33dc9b12 SR |
1081 | static void free_ftrace_hash(struct ftrace_hash *hash) |
1082 | { | |
1083 | if (!hash || hash == EMPTY_HASH) | |
1084 | return; | |
1085 | ftrace_hash_clear(hash); | |
1086 | kfree(hash->buckets); | |
1087 | kfree(hash); | |
1088 | } | |
1089 | ||
07fd5515 SR |
1090 | static void __free_ftrace_hash_rcu(struct rcu_head *rcu) |
1091 | { | |
1092 | struct ftrace_hash *hash; | |
1093 | ||
1094 | hash = container_of(rcu, struct ftrace_hash, rcu); | |
1095 | free_ftrace_hash(hash); | |
1096 | } | |
1097 | ||
1098 | static void free_ftrace_hash_rcu(struct ftrace_hash *hash) | |
1099 | { | |
1100 | if (!hash || hash == EMPTY_HASH) | |
1101 | return; | |
1102 | call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu); | |
1103 | } | |
1104 | ||
33dc9b12 SR |
1105 | static struct ftrace_hash *alloc_ftrace_hash(int size_bits) |
1106 | { | |
1107 | struct ftrace_hash *hash; | |
1108 | int size; | |
1109 | ||
1110 | hash = kzalloc(sizeof(*hash), GFP_KERNEL); | |
1111 | if (!hash) | |
1112 | return NULL; | |
1113 | ||
1114 | size = 1 << size_bits; | |
1115 | hash->buckets = kzalloc(sizeof(*hash->buckets) * size, GFP_KERNEL); | |
1116 | ||
1117 | if (!hash->buckets) { | |
1118 | kfree(hash); | |
1119 | return NULL; | |
1120 | } | |
1121 | ||
1122 | hash->size_bits = size_bits; | |
1123 | ||
1124 | return hash; | |
1125 | } | |
1126 | ||
1127 | static struct ftrace_hash * | |
1128 | alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) | |
1129 | { | |
1130 | struct ftrace_func_entry *entry; | |
1131 | struct ftrace_hash *new_hash; | |
1132 | struct hlist_node *tp; | |
1133 | int size; | |
1134 | int ret; | |
1135 | int i; | |
1136 | ||
1137 | new_hash = alloc_ftrace_hash(size_bits); | |
1138 | if (!new_hash) | |
1139 | return NULL; | |
1140 | ||
1141 | /* Empty hash? */ | |
1142 | if (!hash || !hash->count) | |
1143 | return new_hash; | |
1144 | ||
1145 | size = 1 << hash->size_bits; | |
1146 | for (i = 0; i < size; i++) { | |
1147 | hlist_for_each_entry(entry, tp, &hash->buckets[i], hlist) { | |
1148 | ret = add_hash_entry(new_hash, entry->ip); | |
1149 | if (ret < 0) | |
1150 | goto free_hash; | |
1151 | } | |
1152 | } | |
1153 | ||
1154 | FTRACE_WARN_ON(new_hash->count != hash->count); | |
1155 | ||
1156 | return new_hash; | |
1157 | ||
1158 | free_hash: | |
1159 | free_ftrace_hash(new_hash); | |
1160 | return NULL; | |
1161 | } | |
1162 | ||
1163 | static int | |
1164 | ftrace_hash_move(struct ftrace_hash **dst, struct ftrace_hash *src) | |
1165 | { | |
1166 | struct ftrace_func_entry *entry; | |
1167 | struct hlist_node *tp, *tn; | |
1168 | struct hlist_head *hhd; | |
07fd5515 SR |
1169 | struct ftrace_hash *old_hash; |
1170 | struct ftrace_hash *new_hash; | |
33dc9b12 SR |
1171 | unsigned long key; |
1172 | int size = src->count; | |
1173 | int bits = 0; | |
1174 | int i; | |
1175 | ||
1176 | /* | |
1177 | * If the new source is empty, just free dst and assign it | |
1178 | * the empty_hash. | |
1179 | */ | |
1180 | if (!src->count) { | |
07fd5515 SR |
1181 | free_ftrace_hash_rcu(*dst); |
1182 | rcu_assign_pointer(*dst, EMPTY_HASH); | |
33dc9b12 SR |
1183 | return 0; |
1184 | } | |
1185 | ||
33dc9b12 SR |
1186 | /* |
1187 | * Make the hash size about 1/2 the # found | |
1188 | */ | |
1189 | for (size /= 2; size; size >>= 1) | |
1190 | bits++; | |
1191 | ||
1192 | /* Don't allocate too much */ | |
1193 | if (bits > FTRACE_HASH_MAX_BITS) | |
1194 | bits = FTRACE_HASH_MAX_BITS; | |
1195 | ||
07fd5515 SR |
1196 | new_hash = alloc_ftrace_hash(bits); |
1197 | if (!new_hash) | |
1198 | return -ENOMEM; | |
33dc9b12 SR |
1199 | |
1200 | size = 1 << src->size_bits; | |
1201 | for (i = 0; i < size; i++) { | |
1202 | hhd = &src->buckets[i]; | |
1203 | hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist) { | |
1204 | if (bits > 0) | |
1205 | key = hash_long(entry->ip, bits); | |
1206 | else | |
1207 | key = 0; | |
1208 | remove_hash_entry(src, entry); | |
07fd5515 | 1209 | __add_hash_entry(new_hash, entry); |
33dc9b12 SR |
1210 | } |
1211 | } | |
1212 | ||
07fd5515 SR |
1213 | old_hash = *dst; |
1214 | rcu_assign_pointer(*dst, new_hash); | |
1215 | free_ftrace_hash_rcu(old_hash); | |
1216 | ||
33dc9b12 SR |
1217 | return 0; |
1218 | } | |
1219 | ||
b848914c SR |
1220 | /* |
1221 | * Test the hashes for this ops to see if we want to call | |
1222 | * the ops->func or not. | |
1223 | * | |
1224 | * It's a match if the ip is in the ops->filter_hash or | |
1225 | * the filter_hash does not exist or is empty, | |
1226 | * AND | |
1227 | * the ip is not in the ops->notrace_hash. | |
1228 | */ | |
1229 | static int | |
1230 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip) | |
1231 | { | |
1232 | struct ftrace_hash *filter_hash; | |
1233 | struct ftrace_hash *notrace_hash; | |
1234 | int ret; | |
1235 | ||
1236 | /* The hashes are freed with call_rcu_sched() */ | |
1237 | preempt_disable_notrace(); | |
1238 | ||
1239 | filter_hash = rcu_dereference_raw(ops->filter_hash); | |
1240 | notrace_hash = rcu_dereference_raw(ops->notrace_hash); | |
1241 | ||
1242 | if ((!filter_hash || !filter_hash->count || | |
1243 | ftrace_lookup_ip(filter_hash, ip)) && | |
1244 | (!notrace_hash || !notrace_hash->count || | |
1245 | !ftrace_lookup_ip(notrace_hash, ip))) | |
1246 | ret = 1; | |
1247 | else | |
1248 | ret = 0; | |
1249 | preempt_enable_notrace(); | |
1250 | ||
1251 | return ret; | |
1252 | } | |
1253 | ||
493762fc SR |
1254 | /* |
1255 | * This is a double for. Do not use 'break' to break out of the loop, | |
1256 | * you must use a goto. | |
1257 | */ | |
1258 | #define do_for_each_ftrace_rec(pg, rec) \ | |
1259 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
1260 | int _____i; \ | |
1261 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
1262 | rec = &pg->records[_____i]; | |
1263 | ||
1264 | #define while_for_each_ftrace_rec() \ | |
1265 | } \ | |
1266 | } | |
1267 | ||
ed926f9b SR |
1268 | static void __ftrace_hash_rec_update(struct ftrace_ops *ops, |
1269 | int filter_hash, | |
1270 | bool inc) | |
1271 | { | |
1272 | struct ftrace_hash *hash; | |
1273 | struct ftrace_hash *other_hash; | |
1274 | struct ftrace_page *pg; | |
1275 | struct dyn_ftrace *rec; | |
1276 | int count = 0; | |
1277 | int all = 0; | |
1278 | ||
1279 | /* Only update if the ops has been registered */ | |
1280 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
1281 | return; | |
1282 | ||
1283 | /* | |
1284 | * In the filter_hash case: | |
1285 | * If the count is zero, we update all records. | |
1286 | * Otherwise we just update the items in the hash. | |
1287 | * | |
1288 | * In the notrace_hash case: | |
1289 | * We enable the update in the hash. | |
1290 | * As disabling notrace means enabling the tracing, | |
1291 | * and enabling notrace means disabling, the inc variable | |
1292 | * gets inversed. | |
1293 | */ | |
1294 | if (filter_hash) { | |
1295 | hash = ops->filter_hash; | |
1296 | other_hash = ops->notrace_hash; | |
b848914c | 1297 | if (!hash || !hash->count) |
ed926f9b SR |
1298 | all = 1; |
1299 | } else { | |
1300 | inc = !inc; | |
1301 | hash = ops->notrace_hash; | |
1302 | other_hash = ops->filter_hash; | |
1303 | /* | |
1304 | * If the notrace hash has no items, | |
1305 | * then there's nothing to do. | |
1306 | */ | |
b848914c | 1307 | if (hash && !hash->count) |
ed926f9b SR |
1308 | return; |
1309 | } | |
1310 | ||
1311 | do_for_each_ftrace_rec(pg, rec) { | |
1312 | int in_other_hash = 0; | |
1313 | int in_hash = 0; | |
1314 | int match = 0; | |
1315 | ||
1316 | if (all) { | |
1317 | /* | |
1318 | * Only the filter_hash affects all records. | |
1319 | * Update if the record is not in the notrace hash. | |
1320 | */ | |
b848914c | 1321 | if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) |
ed926f9b SR |
1322 | match = 1; |
1323 | } else { | |
b848914c SR |
1324 | in_hash = hash && !!ftrace_lookup_ip(hash, rec->ip); |
1325 | in_other_hash = other_hash && !!ftrace_lookup_ip(other_hash, rec->ip); | |
ed926f9b SR |
1326 | |
1327 | /* | |
1328 | * | |
1329 | */ | |
1330 | if (filter_hash && in_hash && !in_other_hash) | |
1331 | match = 1; | |
1332 | else if (!filter_hash && in_hash && | |
1333 | (in_other_hash || !other_hash->count)) | |
1334 | match = 1; | |
1335 | } | |
1336 | if (!match) | |
1337 | continue; | |
1338 | ||
1339 | if (inc) { | |
1340 | rec->flags++; | |
1341 | if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == FTRACE_REF_MAX)) | |
1342 | return; | |
1343 | } else { | |
1344 | if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == 0)) | |
1345 | return; | |
1346 | rec->flags--; | |
1347 | } | |
1348 | count++; | |
1349 | /* Shortcut, if we handled all records, we are done. */ | |
1350 | if (!all && count == hash->count) | |
1351 | return; | |
1352 | } while_for_each_ftrace_rec(); | |
1353 | } | |
1354 | ||
1355 | static void ftrace_hash_rec_disable(struct ftrace_ops *ops, | |
1356 | int filter_hash) | |
1357 | { | |
1358 | __ftrace_hash_rec_update(ops, filter_hash, 0); | |
1359 | } | |
1360 | ||
1361 | static void ftrace_hash_rec_enable(struct ftrace_ops *ops, | |
1362 | int filter_hash) | |
1363 | { | |
1364 | __ftrace_hash_rec_update(ops, filter_hash, 1); | |
1365 | } | |
1366 | ||
e309b41d | 1367 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
37ad5084 | 1368 | { |
ee000b7f | 1369 | rec->freelist = ftrace_free_records; |
37ad5084 SR |
1370 | ftrace_free_records = rec; |
1371 | rec->flags |= FTRACE_FL_FREE; | |
1372 | } | |
1373 | ||
e309b41d | 1374 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 1375 | { |
37ad5084 SR |
1376 | struct dyn_ftrace *rec; |
1377 | ||
1378 | /* First check for freed records */ | |
1379 | if (ftrace_free_records) { | |
1380 | rec = ftrace_free_records; | |
1381 | ||
37ad5084 | 1382 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
6912896e | 1383 | FTRACE_WARN_ON_ONCE(1); |
37ad5084 SR |
1384 | ftrace_free_records = NULL; |
1385 | return NULL; | |
1386 | } | |
1387 | ||
ee000b7f | 1388 | ftrace_free_records = rec->freelist; |
37ad5084 SR |
1389 | memset(rec, 0, sizeof(*rec)); |
1390 | return rec; | |
1391 | } | |
1392 | ||
3c1720f0 | 1393 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
08f5ac90 SR |
1394 | if (!ftrace_pages->next) { |
1395 | /* allocate another page */ | |
1396 | ftrace_pages->next = | |
1397 | (void *)get_zeroed_page(GFP_KERNEL); | |
1398 | if (!ftrace_pages->next) | |
1399 | return NULL; | |
1400 | } | |
3c1720f0 SR |
1401 | ftrace_pages = ftrace_pages->next; |
1402 | } | |
1403 | ||
1404 | return &ftrace_pages->records[ftrace_pages->index++]; | |
1405 | } | |
1406 | ||
08f5ac90 | 1407 | static struct dyn_ftrace * |
d61f82d0 | 1408 | ftrace_record_ip(unsigned long ip) |
3d083395 | 1409 | { |
08f5ac90 | 1410 | struct dyn_ftrace *rec; |
3d083395 | 1411 | |
f3c7ac40 | 1412 | if (ftrace_disabled) |
08f5ac90 | 1413 | return NULL; |
3d083395 | 1414 | |
08f5ac90 SR |
1415 | rec = ftrace_alloc_dyn_node(ip); |
1416 | if (!rec) | |
1417 | return NULL; | |
3d083395 | 1418 | |
08f5ac90 | 1419 | rec->ip = ip; |
ee000b7f | 1420 | rec->newlist = ftrace_new_addrs; |
e94142a6 | 1421 | ftrace_new_addrs = rec; |
3d083395 | 1422 | |
08f5ac90 | 1423 | return rec; |
3d083395 SR |
1424 | } |
1425 | ||
b17e8a37 SR |
1426 | static void print_ip_ins(const char *fmt, unsigned char *p) |
1427 | { | |
1428 | int i; | |
1429 | ||
1430 | printk(KERN_CONT "%s", fmt); | |
1431 | ||
1432 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
1433 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
1434 | } | |
1435 | ||
31e88909 | 1436 | static void ftrace_bug(int failed, unsigned long ip) |
b17e8a37 SR |
1437 | { |
1438 | switch (failed) { | |
1439 | case -EFAULT: | |
1440 | FTRACE_WARN_ON_ONCE(1); | |
1441 | pr_info("ftrace faulted on modifying "); | |
1442 | print_ip_sym(ip); | |
1443 | break; | |
1444 | case -EINVAL: | |
1445 | FTRACE_WARN_ON_ONCE(1); | |
1446 | pr_info("ftrace failed to modify "); | |
1447 | print_ip_sym(ip); | |
b17e8a37 | 1448 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
1449 | printk(KERN_CONT "\n"); |
1450 | break; | |
1451 | case -EPERM: | |
1452 | FTRACE_WARN_ON_ONCE(1); | |
1453 | pr_info("ftrace faulted on writing "); | |
1454 | print_ip_sym(ip); | |
1455 | break; | |
1456 | default: | |
1457 | FTRACE_WARN_ON_ONCE(1); | |
1458 | pr_info("ftrace faulted on unknown error "); | |
1459 | print_ip_sym(ip); | |
1460 | } | |
1461 | } | |
1462 | ||
3c1720f0 | 1463 | |
2cfa1978 MH |
1464 | /* Return 1 if the address range is reserved for ftrace */ |
1465 | int ftrace_text_reserved(void *start, void *end) | |
1466 | { | |
1467 | struct dyn_ftrace *rec; | |
1468 | struct ftrace_page *pg; | |
1469 | ||
1470 | do_for_each_ftrace_rec(pg, rec) { | |
1471 | if (rec->ip <= (unsigned long)end && | |
1472 | rec->ip + MCOUNT_INSN_SIZE > (unsigned long)start) | |
1473 | return 1; | |
1474 | } while_for_each_ftrace_rec(); | |
1475 | return 0; | |
1476 | } | |
1477 | ||
1478 | ||
0eb96701 | 1479 | static int |
31e88909 | 1480 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) |
5072c59f | 1481 | { |
e7d3737e | 1482 | unsigned long ftrace_addr; |
64fbcd16 | 1483 | unsigned long flag = 0UL; |
e7d3737e | 1484 | |
f0001207 | 1485 | ftrace_addr = (unsigned long)FTRACE_ADDR; |
5072c59f | 1486 | |
982c350b | 1487 | /* |
ed926f9b | 1488 | * If we are enabling tracing: |
982c350b | 1489 | * |
ed926f9b SR |
1490 | * If the record has a ref count, then we need to enable it |
1491 | * because someone is using it. | |
982c350b | 1492 | * |
ed926f9b SR |
1493 | * Otherwise we make sure its disabled. |
1494 | * | |
1495 | * If we are disabling tracing, then disable all records that | |
1496 | * are enabled. | |
982c350b | 1497 | */ |
ed926f9b SR |
1498 | if (enable && (rec->flags & ~FTRACE_FL_MASK)) |
1499 | flag = FTRACE_FL_ENABLED; | |
982c350b | 1500 | |
64fbcd16 XG |
1501 | /* If the state of this record hasn't changed, then do nothing */ |
1502 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
1503 | return 0; | |
982c350b | 1504 | |
64fbcd16 XG |
1505 | if (flag) { |
1506 | rec->flags |= FTRACE_FL_ENABLED; | |
1507 | return ftrace_make_call(rec, ftrace_addr); | |
5072c59f SR |
1508 | } |
1509 | ||
64fbcd16 XG |
1510 | rec->flags &= ~FTRACE_FL_ENABLED; |
1511 | return ftrace_make_nop(NULL, rec, ftrace_addr); | |
5072c59f SR |
1512 | } |
1513 | ||
e309b41d | 1514 | static void ftrace_replace_code(int enable) |
3c1720f0 | 1515 | { |
3c1720f0 SR |
1516 | struct dyn_ftrace *rec; |
1517 | struct ftrace_page *pg; | |
6a24a244 | 1518 | int failed; |
3c1720f0 | 1519 | |
45a4a237 SR |
1520 | if (unlikely(ftrace_disabled)) |
1521 | return; | |
1522 | ||
265c831c | 1523 | do_for_each_ftrace_rec(pg, rec) { |
d2c8c3ea SR |
1524 | /* Skip over free records */ |
1525 | if (rec->flags & FTRACE_FL_FREE) | |
265c831c SR |
1526 | continue; |
1527 | ||
265c831c | 1528 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 1529 | if (failed) { |
3279ba37 SR |
1530 | ftrace_bug(failed, rec->ip); |
1531 | /* Stop processing */ | |
1532 | return; | |
3c1720f0 | 1533 | } |
265c831c | 1534 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
1535 | } |
1536 | ||
492a7ea5 | 1537 | static int |
31e88909 | 1538 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 SR |
1539 | { |
1540 | unsigned long ip; | |
593eb8a2 | 1541 | int ret; |
3c1720f0 SR |
1542 | |
1543 | ip = rec->ip; | |
1544 | ||
45a4a237 SR |
1545 | if (unlikely(ftrace_disabled)) |
1546 | return 0; | |
1547 | ||
25aac9dc | 1548 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 1549 | if (ret) { |
31e88909 | 1550 | ftrace_bug(ret, ip); |
492a7ea5 | 1551 | return 0; |
37ad5084 | 1552 | } |
492a7ea5 | 1553 | return 1; |
3c1720f0 SR |
1554 | } |
1555 | ||
000ab691 SR |
1556 | /* |
1557 | * archs can override this function if they must do something | |
1558 | * before the modifying code is performed. | |
1559 | */ | |
1560 | int __weak ftrace_arch_code_modify_prepare(void) | |
1561 | { | |
1562 | return 0; | |
1563 | } | |
1564 | ||
1565 | /* | |
1566 | * archs can override this function if they must do something | |
1567 | * after the modifying code is performed. | |
1568 | */ | |
1569 | int __weak ftrace_arch_code_modify_post_process(void) | |
1570 | { | |
1571 | return 0; | |
1572 | } | |
1573 | ||
e309b41d | 1574 | static int __ftrace_modify_code(void *data) |
3d083395 | 1575 | { |
d61f82d0 SR |
1576 | int *command = data; |
1577 | ||
a3583244 | 1578 | if (*command & FTRACE_ENABLE_CALLS) |
d61f82d0 | 1579 | ftrace_replace_code(1); |
a3583244 | 1580 | else if (*command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
1581 | ftrace_replace_code(0); |
1582 | ||
1583 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
1584 | ftrace_update_ftrace_func(ftrace_trace_function); | |
1585 | ||
5a45cfe1 SR |
1586 | if (*command & FTRACE_START_FUNC_RET) |
1587 | ftrace_enable_ftrace_graph_caller(); | |
1588 | else if (*command & FTRACE_STOP_FUNC_RET) | |
1589 | ftrace_disable_ftrace_graph_caller(); | |
1590 | ||
d61f82d0 | 1591 | return 0; |
3d083395 SR |
1592 | } |
1593 | ||
e309b41d | 1594 | static void ftrace_run_update_code(int command) |
3d083395 | 1595 | { |
000ab691 SR |
1596 | int ret; |
1597 | ||
1598 | ret = ftrace_arch_code_modify_prepare(); | |
1599 | FTRACE_WARN_ON(ret); | |
1600 | if (ret) | |
1601 | return; | |
1602 | ||
784e2d76 | 1603 | stop_machine(__ftrace_modify_code, &command, NULL); |
000ab691 SR |
1604 | |
1605 | ret = ftrace_arch_code_modify_post_process(); | |
1606 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
1607 | } |
1608 | ||
d61f82d0 | 1609 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 1610 | static int ftrace_start_up; |
b848914c | 1611 | static int global_start_up; |
df4fc315 SR |
1612 | |
1613 | static void ftrace_startup_enable(int command) | |
1614 | { | |
1615 | if (saved_ftrace_func != ftrace_trace_function) { | |
1616 | saved_ftrace_func = ftrace_trace_function; | |
1617 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1618 | } | |
1619 | ||
1620 | if (!command || !ftrace_enabled) | |
1621 | return; | |
1622 | ||
1623 | ftrace_run_update_code(command); | |
1624 | } | |
d61f82d0 | 1625 | |
bd69c30b | 1626 | static void ftrace_startup(struct ftrace_ops *ops, int command) |
3d083395 | 1627 | { |
b848914c SR |
1628 | bool hash_enable = true; |
1629 | ||
4eebcc81 SR |
1630 | if (unlikely(ftrace_disabled)) |
1631 | return; | |
1632 | ||
60a7ecf4 | 1633 | ftrace_start_up++; |
982c350b | 1634 | command |= FTRACE_ENABLE_CALLS; |
d61f82d0 | 1635 | |
b848914c SR |
1636 | /* ops marked global share the filter hashes */ |
1637 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { | |
1638 | ops = &global_ops; | |
1639 | /* Don't update hash if global is already set */ | |
1640 | if (global_start_up) | |
1641 | hash_enable = false; | |
1642 | global_start_up++; | |
1643 | } | |
1644 | ||
ed926f9b | 1645 | ops->flags |= FTRACE_OPS_FL_ENABLED; |
b848914c | 1646 | if (hash_enable) |
ed926f9b SR |
1647 | ftrace_hash_rec_enable(ops, 1); |
1648 | ||
df4fc315 | 1649 | ftrace_startup_enable(command); |
3d083395 SR |
1650 | } |
1651 | ||
bd69c30b | 1652 | static void ftrace_shutdown(struct ftrace_ops *ops, int command) |
3d083395 | 1653 | { |
b848914c SR |
1654 | bool hash_disable = true; |
1655 | ||
4eebcc81 SR |
1656 | if (unlikely(ftrace_disabled)) |
1657 | return; | |
1658 | ||
60a7ecf4 | 1659 | ftrace_start_up--; |
9ea1a153 FW |
1660 | /* |
1661 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
1662 | * critical but the ftrace_call callers may be never nopped again after | |
1663 | * further ftrace uses. | |
1664 | */ | |
1665 | WARN_ON_ONCE(ftrace_start_up < 0); | |
1666 | ||
b848914c SR |
1667 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { |
1668 | ops = &global_ops; | |
1669 | global_start_up--; | |
1670 | WARN_ON_ONCE(global_start_up < 0); | |
1671 | /* Don't update hash if global still has users */ | |
1672 | if (global_start_up) { | |
1673 | WARN_ON_ONCE(!ftrace_start_up); | |
1674 | hash_disable = false; | |
1675 | } | |
1676 | } | |
1677 | ||
1678 | if (hash_disable) | |
ed926f9b SR |
1679 | ftrace_hash_rec_disable(ops, 1); |
1680 | ||
b848914c | 1681 | if (ops != &global_ops || !global_start_up) |
ed926f9b | 1682 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
b848914c SR |
1683 | |
1684 | if (!ftrace_start_up) | |
1685 | command |= FTRACE_DISABLE_CALLS; | |
3d083395 | 1686 | |
d61f82d0 SR |
1687 | if (saved_ftrace_func != ftrace_trace_function) { |
1688 | saved_ftrace_func = ftrace_trace_function; | |
1689 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1690 | } | |
3d083395 | 1691 | |
d61f82d0 | 1692 | if (!command || !ftrace_enabled) |
e6ea44e9 | 1693 | return; |
d61f82d0 SR |
1694 | |
1695 | ftrace_run_update_code(command); | |
3d083395 SR |
1696 | } |
1697 | ||
e309b41d | 1698 | static void ftrace_startup_sysctl(void) |
b0fc494f | 1699 | { |
4eebcc81 SR |
1700 | if (unlikely(ftrace_disabled)) |
1701 | return; | |
1702 | ||
d61f82d0 SR |
1703 | /* Force update next time */ |
1704 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
1705 | /* ftrace_start_up is true if we want ftrace running */ |
1706 | if (ftrace_start_up) | |
79e406d7 | 1707 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
b0fc494f SR |
1708 | } |
1709 | ||
e309b41d | 1710 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 1711 | { |
4eebcc81 SR |
1712 | if (unlikely(ftrace_disabled)) |
1713 | return; | |
1714 | ||
60a7ecf4 SR |
1715 | /* ftrace_start_up is true if ftrace is running */ |
1716 | if (ftrace_start_up) | |
79e406d7 | 1717 | ftrace_run_update_code(FTRACE_DISABLE_CALLS); |
b0fc494f SR |
1718 | } |
1719 | ||
3d083395 SR |
1720 | static cycle_t ftrace_update_time; |
1721 | static unsigned long ftrace_update_cnt; | |
1722 | unsigned long ftrace_update_tot_cnt; | |
1723 | ||
31e88909 | 1724 | static int ftrace_update_code(struct module *mod) |
3d083395 | 1725 | { |
e94142a6 | 1726 | struct dyn_ftrace *p; |
f22f9a89 | 1727 | cycle_t start, stop; |
3d083395 | 1728 | |
750ed1a4 | 1729 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1730 | ftrace_update_cnt = 0; |
1731 | ||
e94142a6 | 1732 | while (ftrace_new_addrs) { |
3d083395 | 1733 | |
08f5ac90 SR |
1734 | /* If something went wrong, bail without enabling anything */ |
1735 | if (unlikely(ftrace_disabled)) | |
1736 | return -1; | |
f22f9a89 | 1737 | |
e94142a6 | 1738 | p = ftrace_new_addrs; |
ee000b7f | 1739 | ftrace_new_addrs = p->newlist; |
e94142a6 | 1740 | p->flags = 0L; |
f22f9a89 | 1741 | |
5cb084bb | 1742 | /* |
25985edc | 1743 | * Do the initial record conversion from mcount jump |
5cb084bb JO |
1744 | * to the NOP instructions. |
1745 | */ | |
1746 | if (!ftrace_code_disable(mod, p)) { | |
08f5ac90 | 1747 | ftrace_free_rec(p); |
d2c8c3ea SR |
1748 | /* Game over */ |
1749 | break; | |
5cb084bb JO |
1750 | } |
1751 | ||
5cb084bb JO |
1752 | ftrace_update_cnt++; |
1753 | ||
1754 | /* | |
1755 | * If the tracing is enabled, go ahead and enable the record. | |
1756 | * | |
1757 | * The reason not to enable the record immediatelly is the | |
1758 | * inherent check of ftrace_make_nop/ftrace_make_call for | |
1759 | * correct previous instructions. Making first the NOP | |
1760 | * conversion puts the module to the correct state, thus | |
1761 | * passing the ftrace_make_call check. | |
1762 | */ | |
1763 | if (ftrace_start_up) { | |
1764 | int failed = __ftrace_replace_code(p, 1); | |
1765 | if (failed) { | |
1766 | ftrace_bug(failed, p->ip); | |
1767 | ftrace_free_rec(p); | |
1768 | } | |
1769 | } | |
3d083395 SR |
1770 | } |
1771 | ||
750ed1a4 | 1772 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1773 | ftrace_update_time = stop - start; |
1774 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
1775 | ||
16444a8a ACM |
1776 | return 0; |
1777 | } | |
1778 | ||
68bf21aa | 1779 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
1780 | { |
1781 | struct ftrace_page *pg; | |
1782 | int cnt; | |
1783 | int i; | |
3c1720f0 SR |
1784 | |
1785 | /* allocate a few pages */ | |
1786 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
1787 | if (!ftrace_pages_start) | |
1788 | return -1; | |
1789 | ||
1790 | /* | |
1791 | * Allocate a few more pages. | |
1792 | * | |
1793 | * TODO: have some parser search vmlinux before | |
1794 | * final linking to find all calls to ftrace. | |
1795 | * Then we can: | |
1796 | * a) know how many pages to allocate. | |
1797 | * and/or | |
1798 | * b) set up the table then. | |
1799 | * | |
1800 | * The dynamic code is still necessary for | |
1801 | * modules. | |
1802 | */ | |
1803 | ||
1804 | pg = ftrace_pages = ftrace_pages_start; | |
1805 | ||
68bf21aa | 1806 | cnt = num_to_init / ENTRIES_PER_PAGE; |
08f5ac90 | 1807 | pr_info("ftrace: allocating %ld entries in %d pages\n", |
5821e1b7 | 1808 | num_to_init, cnt + 1); |
3c1720f0 SR |
1809 | |
1810 | for (i = 0; i < cnt; i++) { | |
1811 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
1812 | ||
1813 | /* If we fail, we'll try later anyway */ | |
1814 | if (!pg->next) | |
1815 | break; | |
1816 | ||
1817 | pg = pg->next; | |
1818 | } | |
1819 | ||
1820 | return 0; | |
1821 | } | |
1822 | ||
5072c59f SR |
1823 | enum { |
1824 | FTRACE_ITER_FILTER = (1 << 0), | |
689fd8b6 | 1825 | FTRACE_ITER_NOTRACE = (1 << 1), |
3499e461 SR |
1826 | FTRACE_ITER_PRINTALL = (1 << 2), |
1827 | FTRACE_ITER_HASH = (1 << 3), | |
647bcd03 | 1828 | FTRACE_ITER_ENABLED = (1 << 4), |
5072c59f SR |
1829 | }; |
1830 | ||
1831 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
1832 | ||
1833 | struct ftrace_iterator { | |
98c4fd04 | 1834 | loff_t pos; |
4aeb6967 SR |
1835 | loff_t func_pos; |
1836 | struct ftrace_page *pg; | |
1837 | struct dyn_ftrace *func; | |
1838 | struct ftrace_func_probe *probe; | |
1839 | struct trace_parser parser; | |
1cf41dd7 | 1840 | struct ftrace_hash *hash; |
33dc9b12 | 1841 | struct ftrace_ops *ops; |
4aeb6967 SR |
1842 | int hidx; |
1843 | int idx; | |
1844 | unsigned flags; | |
5072c59f SR |
1845 | }; |
1846 | ||
8fc0c701 | 1847 | static void * |
4aeb6967 | 1848 | t_hash_next(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
1849 | { |
1850 | struct ftrace_iterator *iter = m->private; | |
4aeb6967 | 1851 | struct hlist_node *hnd = NULL; |
8fc0c701 SR |
1852 | struct hlist_head *hhd; |
1853 | ||
8fc0c701 | 1854 | (*pos)++; |
98c4fd04 | 1855 | iter->pos = *pos; |
8fc0c701 | 1856 | |
4aeb6967 SR |
1857 | if (iter->probe) |
1858 | hnd = &iter->probe->node; | |
8fc0c701 SR |
1859 | retry: |
1860 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
1861 | return NULL; | |
1862 | ||
1863 | hhd = &ftrace_func_hash[iter->hidx]; | |
1864 | ||
1865 | if (hlist_empty(hhd)) { | |
1866 | iter->hidx++; | |
1867 | hnd = NULL; | |
1868 | goto retry; | |
1869 | } | |
1870 | ||
1871 | if (!hnd) | |
1872 | hnd = hhd->first; | |
1873 | else { | |
1874 | hnd = hnd->next; | |
1875 | if (!hnd) { | |
1876 | iter->hidx++; | |
1877 | goto retry; | |
1878 | } | |
1879 | } | |
1880 | ||
4aeb6967 SR |
1881 | if (WARN_ON_ONCE(!hnd)) |
1882 | return NULL; | |
1883 | ||
1884 | iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node); | |
1885 | ||
1886 | return iter; | |
8fc0c701 SR |
1887 | } |
1888 | ||
1889 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
1890 | { | |
1891 | struct ftrace_iterator *iter = m->private; | |
1892 | void *p = NULL; | |
d82d6244 LZ |
1893 | loff_t l; |
1894 | ||
2bccfffd SR |
1895 | if (iter->func_pos > *pos) |
1896 | return NULL; | |
8fc0c701 | 1897 | |
d82d6244 | 1898 | iter->hidx = 0; |
2bccfffd | 1899 | for (l = 0; l <= (*pos - iter->func_pos); ) { |
4aeb6967 | 1900 | p = t_hash_next(m, &l); |
d82d6244 LZ |
1901 | if (!p) |
1902 | break; | |
1903 | } | |
4aeb6967 SR |
1904 | if (!p) |
1905 | return NULL; | |
1906 | ||
98c4fd04 SR |
1907 | /* Only set this if we have an item */ |
1908 | iter->flags |= FTRACE_ITER_HASH; | |
1909 | ||
4aeb6967 | 1910 | return iter; |
8fc0c701 SR |
1911 | } |
1912 | ||
4aeb6967 SR |
1913 | static int |
1914 | t_hash_show(struct seq_file *m, struct ftrace_iterator *iter) | |
8fc0c701 | 1915 | { |
b6887d79 | 1916 | struct ftrace_func_probe *rec; |
8fc0c701 | 1917 | |
4aeb6967 SR |
1918 | rec = iter->probe; |
1919 | if (WARN_ON_ONCE(!rec)) | |
1920 | return -EIO; | |
8fc0c701 | 1921 | |
809dcf29 SR |
1922 | if (rec->ops->print) |
1923 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
1924 | ||
b375a11a | 1925 | seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func); |
8fc0c701 SR |
1926 | |
1927 | if (rec->data) | |
1928 | seq_printf(m, ":%p", rec->data); | |
1929 | seq_putc(m, '\n'); | |
1930 | ||
1931 | return 0; | |
1932 | } | |
1933 | ||
e309b41d | 1934 | static void * |
5072c59f SR |
1935 | t_next(struct seq_file *m, void *v, loff_t *pos) |
1936 | { | |
1937 | struct ftrace_iterator *iter = m->private; | |
f45948e8 | 1938 | struct ftrace_ops *ops = &global_ops; |
5072c59f SR |
1939 | struct dyn_ftrace *rec = NULL; |
1940 | ||
45a4a237 SR |
1941 | if (unlikely(ftrace_disabled)) |
1942 | return NULL; | |
1943 | ||
8fc0c701 | 1944 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 1945 | return t_hash_next(m, pos); |
8fc0c701 | 1946 | |
5072c59f | 1947 | (*pos)++; |
1106b699 | 1948 | iter->pos = iter->func_pos = *pos; |
5072c59f | 1949 | |
0c75a3ed | 1950 | if (iter->flags & FTRACE_ITER_PRINTALL) |
57c072c7 | 1951 | return t_hash_start(m, pos); |
0c75a3ed | 1952 | |
5072c59f SR |
1953 | retry: |
1954 | if (iter->idx >= iter->pg->index) { | |
1955 | if (iter->pg->next) { | |
1956 | iter->pg = iter->pg->next; | |
1957 | iter->idx = 0; | |
1958 | goto retry; | |
1959 | } | |
1960 | } else { | |
1961 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
1962 | if ((rec->flags & FTRACE_FL_FREE) || |
1963 | ||
0183fb1c | 1964 | ((iter->flags & FTRACE_ITER_FILTER) && |
f45948e8 | 1965 | !(ftrace_lookup_ip(ops->filter_hash, rec->ip))) || |
0183fb1c | 1966 | |
41c52c0d | 1967 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
647bcd03 SR |
1968 | !ftrace_lookup_ip(ops->notrace_hash, rec->ip)) || |
1969 | ||
1970 | ((iter->flags & FTRACE_ITER_ENABLED) && | |
1971 | !(rec->flags & ~FTRACE_FL_MASK))) { | |
1972 | ||
5072c59f SR |
1973 | rec = NULL; |
1974 | goto retry; | |
1975 | } | |
1976 | } | |
1977 | ||
4aeb6967 | 1978 | if (!rec) |
57c072c7 | 1979 | return t_hash_start(m, pos); |
4aeb6967 SR |
1980 | |
1981 | iter->func = rec; | |
1982 | ||
1983 | return iter; | |
5072c59f SR |
1984 | } |
1985 | ||
98c4fd04 SR |
1986 | static void reset_iter_read(struct ftrace_iterator *iter) |
1987 | { | |
1988 | iter->pos = 0; | |
1989 | iter->func_pos = 0; | |
1990 | iter->flags &= ~(FTRACE_ITER_PRINTALL & FTRACE_ITER_HASH); | |
5072c59f SR |
1991 | } |
1992 | ||
1993 | static void *t_start(struct seq_file *m, loff_t *pos) | |
1994 | { | |
1995 | struct ftrace_iterator *iter = m->private; | |
f45948e8 | 1996 | struct ftrace_ops *ops = &global_ops; |
5072c59f | 1997 | void *p = NULL; |
694ce0a5 | 1998 | loff_t l; |
5072c59f | 1999 | |
8fc0c701 | 2000 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
2001 | |
2002 | if (unlikely(ftrace_disabled)) | |
2003 | return NULL; | |
2004 | ||
98c4fd04 SR |
2005 | /* |
2006 | * If an lseek was done, then reset and start from beginning. | |
2007 | */ | |
2008 | if (*pos < iter->pos) | |
2009 | reset_iter_read(iter); | |
2010 | ||
0c75a3ed SR |
2011 | /* |
2012 | * For set_ftrace_filter reading, if we have the filter | |
2013 | * off, we can short cut and just print out that all | |
2014 | * functions are enabled. | |
2015 | */ | |
f45948e8 | 2016 | if (iter->flags & FTRACE_ITER_FILTER && !ops->filter_hash->count) { |
0c75a3ed | 2017 | if (*pos > 0) |
8fc0c701 | 2018 | return t_hash_start(m, pos); |
0c75a3ed | 2019 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 CW |
2020 | /* reset in case of seek/pread */ |
2021 | iter->flags &= ~FTRACE_ITER_HASH; | |
0c75a3ed SR |
2022 | return iter; |
2023 | } | |
2024 | ||
8fc0c701 SR |
2025 | if (iter->flags & FTRACE_ITER_HASH) |
2026 | return t_hash_start(m, pos); | |
2027 | ||
98c4fd04 SR |
2028 | /* |
2029 | * Unfortunately, we need to restart at ftrace_pages_start | |
2030 | * every time we let go of the ftrace_mutex. This is because | |
2031 | * those pointers can change without the lock. | |
2032 | */ | |
694ce0a5 LZ |
2033 | iter->pg = ftrace_pages_start; |
2034 | iter->idx = 0; | |
2035 | for (l = 0; l <= *pos; ) { | |
2036 | p = t_next(m, p, &l); | |
2037 | if (!p) | |
2038 | break; | |
50cdaf08 | 2039 | } |
5821e1b7 | 2040 | |
4aeb6967 SR |
2041 | if (!p) { |
2042 | if (iter->flags & FTRACE_ITER_FILTER) | |
2043 | return t_hash_start(m, pos); | |
8fc0c701 | 2044 | |
4aeb6967 SR |
2045 | return NULL; |
2046 | } | |
2047 | ||
2048 | return iter; | |
5072c59f SR |
2049 | } |
2050 | ||
2051 | static void t_stop(struct seq_file *m, void *p) | |
2052 | { | |
8fc0c701 | 2053 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
2054 | } |
2055 | ||
2056 | static int t_show(struct seq_file *m, void *v) | |
2057 | { | |
0c75a3ed | 2058 | struct ftrace_iterator *iter = m->private; |
4aeb6967 | 2059 | struct dyn_ftrace *rec; |
5072c59f | 2060 | |
8fc0c701 | 2061 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 2062 | return t_hash_show(m, iter); |
8fc0c701 | 2063 | |
0c75a3ed SR |
2064 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
2065 | seq_printf(m, "#### all functions enabled ####\n"); | |
2066 | return 0; | |
2067 | } | |
2068 | ||
4aeb6967 SR |
2069 | rec = iter->func; |
2070 | ||
5072c59f SR |
2071 | if (!rec) |
2072 | return 0; | |
2073 | ||
647bcd03 SR |
2074 | seq_printf(m, "%ps", (void *)rec->ip); |
2075 | if (iter->flags & FTRACE_ITER_ENABLED) | |
2076 | seq_printf(m, " (%ld)", | |
2077 | rec->flags & ~FTRACE_FL_MASK); | |
2078 | seq_printf(m, "\n"); | |
5072c59f SR |
2079 | |
2080 | return 0; | |
2081 | } | |
2082 | ||
88e9d34c | 2083 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
2084 | .start = t_start, |
2085 | .next = t_next, | |
2086 | .stop = t_stop, | |
2087 | .show = t_show, | |
2088 | }; | |
2089 | ||
e309b41d | 2090 | static int |
5072c59f SR |
2091 | ftrace_avail_open(struct inode *inode, struct file *file) |
2092 | { | |
2093 | struct ftrace_iterator *iter; | |
2094 | int ret; | |
2095 | ||
4eebcc81 SR |
2096 | if (unlikely(ftrace_disabled)) |
2097 | return -ENODEV; | |
2098 | ||
5072c59f SR |
2099 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
2100 | if (!iter) | |
2101 | return -ENOMEM; | |
2102 | ||
2103 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
2104 | |
2105 | ret = seq_open(file, &show_ftrace_seq_ops); | |
2106 | if (!ret) { | |
2107 | struct seq_file *m = file->private_data; | |
4bf39a94 | 2108 | |
5072c59f | 2109 | m->private = iter; |
4bf39a94 | 2110 | } else { |
5072c59f | 2111 | kfree(iter); |
4bf39a94 | 2112 | } |
5072c59f SR |
2113 | |
2114 | return ret; | |
2115 | } | |
2116 | ||
647bcd03 SR |
2117 | static int |
2118 | ftrace_enabled_open(struct inode *inode, struct file *file) | |
2119 | { | |
2120 | struct ftrace_iterator *iter; | |
2121 | int ret; | |
2122 | ||
2123 | if (unlikely(ftrace_disabled)) | |
2124 | return -ENODEV; | |
2125 | ||
2126 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); | |
2127 | if (!iter) | |
2128 | return -ENOMEM; | |
2129 | ||
2130 | iter->pg = ftrace_pages_start; | |
2131 | iter->flags = FTRACE_ITER_ENABLED; | |
2132 | ||
2133 | ret = seq_open(file, &show_ftrace_seq_ops); | |
2134 | if (!ret) { | |
2135 | struct seq_file *m = file->private_data; | |
2136 | ||
2137 | m->private = iter; | |
2138 | } else { | |
2139 | kfree(iter); | |
2140 | } | |
2141 | ||
2142 | return ret; | |
2143 | } | |
2144 | ||
1cf41dd7 | 2145 | static void ftrace_filter_reset(struct ftrace_hash *hash) |
5072c59f | 2146 | { |
52baf119 | 2147 | mutex_lock(&ftrace_lock); |
1cf41dd7 | 2148 | ftrace_hash_clear(hash); |
52baf119 | 2149 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
2150 | } |
2151 | ||
e309b41d | 2152 | static int |
f45948e8 | 2153 | ftrace_regex_open(struct ftrace_ops *ops, int flag, |
1cf41dd7 | 2154 | struct inode *inode, struct file *file) |
5072c59f SR |
2155 | { |
2156 | struct ftrace_iterator *iter; | |
f45948e8 | 2157 | struct ftrace_hash *hash; |
5072c59f SR |
2158 | int ret = 0; |
2159 | ||
4eebcc81 SR |
2160 | if (unlikely(ftrace_disabled)) |
2161 | return -ENODEV; | |
2162 | ||
5072c59f SR |
2163 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
2164 | if (!iter) | |
2165 | return -ENOMEM; | |
2166 | ||
689fd8b6 | 2167 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { |
2168 | kfree(iter); | |
2169 | return -ENOMEM; | |
2170 | } | |
2171 | ||
f45948e8 SR |
2172 | if (flag & FTRACE_ITER_NOTRACE) |
2173 | hash = ops->notrace_hash; | |
2174 | else | |
2175 | hash = ops->filter_hash; | |
2176 | ||
33dc9b12 SR |
2177 | iter->ops = ops; |
2178 | iter->flags = flag; | |
2179 | ||
2180 | if (file->f_mode & FMODE_WRITE) { | |
2181 | mutex_lock(&ftrace_lock); | |
2182 | iter->hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash); | |
2183 | mutex_unlock(&ftrace_lock); | |
2184 | ||
2185 | if (!iter->hash) { | |
2186 | trace_parser_put(&iter->parser); | |
2187 | kfree(iter); | |
2188 | return -ENOMEM; | |
2189 | } | |
2190 | } | |
1cf41dd7 | 2191 | |
41c52c0d | 2192 | mutex_lock(&ftrace_regex_lock); |
33dc9b12 | 2193 | |
5072c59f | 2194 | if ((file->f_mode & FMODE_WRITE) && |
8650ae32 | 2195 | (file->f_flags & O_TRUNC)) |
33dc9b12 | 2196 | ftrace_filter_reset(iter->hash); |
5072c59f SR |
2197 | |
2198 | if (file->f_mode & FMODE_READ) { | |
2199 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
2200 | |
2201 | ret = seq_open(file, &show_ftrace_seq_ops); | |
2202 | if (!ret) { | |
2203 | struct seq_file *m = file->private_data; | |
2204 | m->private = iter; | |
79fe249c | 2205 | } else { |
33dc9b12 SR |
2206 | /* Failed */ |
2207 | free_ftrace_hash(iter->hash); | |
79fe249c | 2208 | trace_parser_put(&iter->parser); |
5072c59f | 2209 | kfree(iter); |
79fe249c | 2210 | } |
5072c59f SR |
2211 | } else |
2212 | file->private_data = iter; | |
41c52c0d | 2213 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
2214 | |
2215 | return ret; | |
2216 | } | |
2217 | ||
41c52c0d SR |
2218 | static int |
2219 | ftrace_filter_open(struct inode *inode, struct file *file) | |
2220 | { | |
f45948e8 | 2221 | return ftrace_regex_open(&global_ops, FTRACE_ITER_FILTER, |
1cf41dd7 | 2222 | inode, file); |
41c52c0d SR |
2223 | } |
2224 | ||
2225 | static int | |
2226 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
2227 | { | |
f45948e8 | 2228 | return ftrace_regex_open(&global_ops, FTRACE_ITER_NOTRACE, |
1cf41dd7 | 2229 | inode, file); |
41c52c0d SR |
2230 | } |
2231 | ||
e309b41d | 2232 | static loff_t |
41c52c0d | 2233 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
2234 | { |
2235 | loff_t ret; | |
2236 | ||
2237 | if (file->f_mode & FMODE_READ) | |
2238 | ret = seq_lseek(file, offset, origin); | |
2239 | else | |
2240 | file->f_pos = ret = 1; | |
2241 | ||
2242 | return ret; | |
2243 | } | |
2244 | ||
64e7c440 | 2245 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 2246 | { |
9f4801e3 | 2247 | int matched = 0; |
751e9983 | 2248 | int slen; |
9f4801e3 | 2249 | |
9f4801e3 SR |
2250 | switch (type) { |
2251 | case MATCH_FULL: | |
2252 | if (strcmp(str, regex) == 0) | |
2253 | matched = 1; | |
2254 | break; | |
2255 | case MATCH_FRONT_ONLY: | |
2256 | if (strncmp(str, regex, len) == 0) | |
2257 | matched = 1; | |
2258 | break; | |
2259 | case MATCH_MIDDLE_ONLY: | |
2260 | if (strstr(str, regex)) | |
2261 | matched = 1; | |
2262 | break; | |
2263 | case MATCH_END_ONLY: | |
751e9983 LZ |
2264 | slen = strlen(str); |
2265 | if (slen >= len && memcmp(str + slen - len, regex, len) == 0) | |
9f4801e3 SR |
2266 | matched = 1; |
2267 | break; | |
2268 | } | |
2269 | ||
2270 | return matched; | |
2271 | } | |
2272 | ||
b448c4e3 | 2273 | static int |
1cf41dd7 | 2274 | enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not) |
996e87be | 2275 | { |
b448c4e3 | 2276 | struct ftrace_func_entry *entry; |
b448c4e3 SR |
2277 | int ret = 0; |
2278 | ||
1cf41dd7 SR |
2279 | entry = ftrace_lookup_ip(hash, rec->ip); |
2280 | if (not) { | |
2281 | /* Do nothing if it doesn't exist */ | |
2282 | if (!entry) | |
2283 | return 0; | |
b448c4e3 | 2284 | |
33dc9b12 | 2285 | free_hash_entry(hash, entry); |
1cf41dd7 SR |
2286 | } else { |
2287 | /* Do nothing if it exists */ | |
2288 | if (entry) | |
2289 | return 0; | |
b448c4e3 | 2290 | |
1cf41dd7 | 2291 | ret = add_hash_entry(hash, rec->ip); |
b448c4e3 SR |
2292 | } |
2293 | return ret; | |
996e87be SR |
2294 | } |
2295 | ||
64e7c440 | 2296 | static int |
b9df92d2 SR |
2297 | ftrace_match_record(struct dyn_ftrace *rec, char *mod, |
2298 | char *regex, int len, int type) | |
64e7c440 SR |
2299 | { |
2300 | char str[KSYM_SYMBOL_LEN]; | |
b9df92d2 SR |
2301 | char *modname; |
2302 | ||
2303 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
2304 | ||
2305 | if (mod) { | |
2306 | /* module lookup requires matching the module */ | |
2307 | if (!modname || strcmp(modname, mod)) | |
2308 | return 0; | |
2309 | ||
2310 | /* blank search means to match all funcs in the mod */ | |
2311 | if (!len) | |
2312 | return 1; | |
2313 | } | |
64e7c440 | 2314 | |
64e7c440 SR |
2315 | return ftrace_match(str, regex, len, type); |
2316 | } | |
2317 | ||
1cf41dd7 SR |
2318 | static int |
2319 | match_records(struct ftrace_hash *hash, char *buff, | |
2320 | int len, char *mod, int not) | |
9f4801e3 | 2321 | { |
b9df92d2 | 2322 | unsigned search_len = 0; |
9f4801e3 SR |
2323 | struct ftrace_page *pg; |
2324 | struct dyn_ftrace *rec; | |
b9df92d2 SR |
2325 | int type = MATCH_FULL; |
2326 | char *search = buff; | |
311d16da | 2327 | int found = 0; |
b448c4e3 | 2328 | int ret; |
9f4801e3 | 2329 | |
b9df92d2 SR |
2330 | if (len) { |
2331 | type = filter_parse_regex(buff, len, &search, ¬); | |
2332 | search_len = strlen(search); | |
2333 | } | |
9f4801e3 | 2334 | |
52baf119 | 2335 | mutex_lock(&ftrace_lock); |
265c831c | 2336 | |
b9df92d2 SR |
2337 | if (unlikely(ftrace_disabled)) |
2338 | goto out_unlock; | |
9f4801e3 | 2339 | |
265c831c | 2340 | do_for_each_ftrace_rec(pg, rec) { |
265c831c | 2341 | |
b9df92d2 | 2342 | if (ftrace_match_record(rec, mod, search, search_len, type)) { |
1cf41dd7 | 2343 | ret = enter_record(hash, rec, not); |
b448c4e3 SR |
2344 | if (ret < 0) { |
2345 | found = ret; | |
2346 | goto out_unlock; | |
2347 | } | |
311d16da | 2348 | found = 1; |
265c831c SR |
2349 | } |
2350 | } while_for_each_ftrace_rec(); | |
b9df92d2 | 2351 | out_unlock: |
52baf119 | 2352 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
2353 | |
2354 | return found; | |
5072c59f SR |
2355 | } |
2356 | ||
64e7c440 | 2357 | static int |
1cf41dd7 | 2358 | ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) |
64e7c440 | 2359 | { |
1cf41dd7 | 2360 | return match_records(hash, buff, len, NULL, 0); |
64e7c440 SR |
2361 | } |
2362 | ||
1cf41dd7 SR |
2363 | static int |
2364 | ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod) | |
64e7c440 | 2365 | { |
64e7c440 | 2366 | int not = 0; |
6a24a244 | 2367 | |
64e7c440 SR |
2368 | /* blank or '*' mean the same */ |
2369 | if (strcmp(buff, "*") == 0) | |
2370 | buff[0] = 0; | |
2371 | ||
2372 | /* handle the case of 'dont filter this module' */ | |
2373 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
2374 | buff[0] = 0; | |
2375 | not = 1; | |
2376 | } | |
2377 | ||
1cf41dd7 | 2378 | return match_records(hash, buff, strlen(buff), mod, not); |
64e7c440 SR |
2379 | } |
2380 | ||
f6180773 SR |
2381 | /* |
2382 | * We register the module command as a template to show others how | |
2383 | * to register the a command as well. | |
2384 | */ | |
2385 | ||
2386 | static int | |
2387 | ftrace_mod_callback(char *func, char *cmd, char *param, int enable) | |
2388 | { | |
f45948e8 | 2389 | struct ftrace_ops *ops = &global_ops; |
1cf41dd7 | 2390 | struct ftrace_hash *hash; |
f6180773 | 2391 | char *mod; |
b448c4e3 | 2392 | int ret = -EINVAL; |
f6180773 SR |
2393 | |
2394 | /* | |
2395 | * cmd == 'mod' because we only registered this func | |
2396 | * for the 'mod' ftrace_func_command. | |
2397 | * But if you register one func with multiple commands, | |
2398 | * you can tell which command was used by the cmd | |
2399 | * parameter. | |
2400 | */ | |
2401 | ||
2402 | /* we must have a module name */ | |
2403 | if (!param) | |
b448c4e3 | 2404 | return ret; |
f6180773 SR |
2405 | |
2406 | mod = strsep(¶m, ":"); | |
2407 | if (!strlen(mod)) | |
b448c4e3 | 2408 | return ret; |
f6180773 | 2409 | |
1cf41dd7 | 2410 | if (enable) |
f45948e8 | 2411 | hash = ops->filter_hash; |
1cf41dd7 | 2412 | else |
f45948e8 | 2413 | hash = ops->notrace_hash; |
1cf41dd7 SR |
2414 | |
2415 | ret = ftrace_match_module_records(hash, func, mod); | |
b448c4e3 SR |
2416 | if (!ret) |
2417 | ret = -EINVAL; | |
2418 | if (ret < 0) | |
2419 | return ret; | |
2420 | ||
2421 | return 0; | |
f6180773 SR |
2422 | } |
2423 | ||
2424 | static struct ftrace_func_command ftrace_mod_cmd = { | |
2425 | .name = "mod", | |
2426 | .func = ftrace_mod_callback, | |
2427 | }; | |
2428 | ||
2429 | static int __init ftrace_mod_cmd_init(void) | |
2430 | { | |
2431 | return register_ftrace_command(&ftrace_mod_cmd); | |
2432 | } | |
2433 | device_initcall(ftrace_mod_cmd_init); | |
2434 | ||
59df055f | 2435 | static void |
b6887d79 | 2436 | function_trace_probe_call(unsigned long ip, unsigned long parent_ip) |
59df055f | 2437 | { |
b6887d79 | 2438 | struct ftrace_func_probe *entry; |
59df055f SR |
2439 | struct hlist_head *hhd; |
2440 | struct hlist_node *n; | |
2441 | unsigned long key; | |
59df055f SR |
2442 | |
2443 | key = hash_long(ip, FTRACE_HASH_BITS); | |
2444 | ||
2445 | hhd = &ftrace_func_hash[key]; | |
2446 | ||
2447 | if (hlist_empty(hhd)) | |
2448 | return; | |
2449 | ||
2450 | /* | |
2451 | * Disable preemption for these calls to prevent a RCU grace | |
2452 | * period. This syncs the hash iteration and freeing of items | |
2453 | * on the hash. rcu_read_lock is too dangerous here. | |
2454 | */ | |
5168ae50 | 2455 | preempt_disable_notrace(); |
59df055f SR |
2456 | hlist_for_each_entry_rcu(entry, n, hhd, node) { |
2457 | if (entry->ip == ip) | |
2458 | entry->ops->func(ip, parent_ip, &entry->data); | |
2459 | } | |
5168ae50 | 2460 | preempt_enable_notrace(); |
59df055f SR |
2461 | } |
2462 | ||
b6887d79 | 2463 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 2464 | { |
fb9fb015 | 2465 | .func = function_trace_probe_call, |
59df055f SR |
2466 | }; |
2467 | ||
b6887d79 | 2468 | static int ftrace_probe_registered; |
59df055f | 2469 | |
b6887d79 | 2470 | static void __enable_ftrace_function_probe(void) |
59df055f | 2471 | { |
b848914c | 2472 | int ret; |
59df055f SR |
2473 | int i; |
2474 | ||
b6887d79 | 2475 | if (ftrace_probe_registered) |
59df055f SR |
2476 | return; |
2477 | ||
2478 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2479 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2480 | if (hhd->first) | |
2481 | break; | |
2482 | } | |
2483 | /* Nothing registered? */ | |
2484 | if (i == FTRACE_FUNC_HASHSIZE) | |
2485 | return; | |
2486 | ||
b848914c SR |
2487 | ret = __register_ftrace_function(&trace_probe_ops); |
2488 | if (!ret) | |
2489 | ftrace_startup(&trace_probe_ops, 0); | |
2490 | ||
b6887d79 | 2491 | ftrace_probe_registered = 1; |
59df055f SR |
2492 | } |
2493 | ||
b6887d79 | 2494 | static void __disable_ftrace_function_probe(void) |
59df055f | 2495 | { |
b848914c | 2496 | int ret; |
59df055f SR |
2497 | int i; |
2498 | ||
b6887d79 | 2499 | if (!ftrace_probe_registered) |
59df055f SR |
2500 | return; |
2501 | ||
2502 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2503 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2504 | if (hhd->first) | |
2505 | return; | |
2506 | } | |
2507 | ||
2508 | /* no more funcs left */ | |
b848914c SR |
2509 | ret = __unregister_ftrace_function(&trace_probe_ops); |
2510 | if (!ret) | |
2511 | ftrace_shutdown(&trace_probe_ops, 0); | |
2512 | ||
b6887d79 | 2513 | ftrace_probe_registered = 0; |
59df055f SR |
2514 | } |
2515 | ||
2516 | ||
2517 | static void ftrace_free_entry_rcu(struct rcu_head *rhp) | |
2518 | { | |
b6887d79 SR |
2519 | struct ftrace_func_probe *entry = |
2520 | container_of(rhp, struct ftrace_func_probe, rcu); | |
59df055f SR |
2521 | |
2522 | if (entry->ops->free) | |
2523 | entry->ops->free(&entry->data); | |
2524 | kfree(entry); | |
2525 | } | |
2526 | ||
2527 | ||
2528 | int | |
b6887d79 | 2529 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2530 | void *data) |
2531 | { | |
b6887d79 | 2532 | struct ftrace_func_probe *entry; |
59df055f SR |
2533 | struct ftrace_page *pg; |
2534 | struct dyn_ftrace *rec; | |
59df055f | 2535 | int type, len, not; |
6a24a244 | 2536 | unsigned long key; |
59df055f SR |
2537 | int count = 0; |
2538 | char *search; | |
2539 | ||
3f6fe06d | 2540 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
2541 | len = strlen(search); |
2542 | ||
b6887d79 | 2543 | /* we do not support '!' for function probes */ |
59df055f SR |
2544 | if (WARN_ON(not)) |
2545 | return -EINVAL; | |
2546 | ||
2547 | mutex_lock(&ftrace_lock); | |
59df055f | 2548 | |
45a4a237 SR |
2549 | if (unlikely(ftrace_disabled)) |
2550 | goto out_unlock; | |
59df055f | 2551 | |
45a4a237 | 2552 | do_for_each_ftrace_rec(pg, rec) { |
59df055f | 2553 | |
b9df92d2 | 2554 | if (!ftrace_match_record(rec, NULL, search, len, type)) |
59df055f SR |
2555 | continue; |
2556 | ||
2557 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
2558 | if (!entry) { | |
b6887d79 | 2559 | /* If we did not process any, then return error */ |
59df055f SR |
2560 | if (!count) |
2561 | count = -ENOMEM; | |
2562 | goto out_unlock; | |
2563 | } | |
2564 | ||
2565 | count++; | |
2566 | ||
2567 | entry->data = data; | |
2568 | ||
2569 | /* | |
2570 | * The caller might want to do something special | |
2571 | * for each function we find. We call the callback | |
2572 | * to give the caller an opportunity to do so. | |
2573 | */ | |
2574 | if (ops->callback) { | |
2575 | if (ops->callback(rec->ip, &entry->data) < 0) { | |
2576 | /* caller does not like this func */ | |
2577 | kfree(entry); | |
2578 | continue; | |
2579 | } | |
2580 | } | |
2581 | ||
2582 | entry->ops = ops; | |
2583 | entry->ip = rec->ip; | |
2584 | ||
2585 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
2586 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
2587 | ||
2588 | } while_for_each_ftrace_rec(); | |
b6887d79 | 2589 | __enable_ftrace_function_probe(); |
59df055f SR |
2590 | |
2591 | out_unlock: | |
2592 | mutex_unlock(&ftrace_lock); | |
2593 | ||
2594 | return count; | |
2595 | } | |
2596 | ||
2597 | enum { | |
b6887d79 SR |
2598 | PROBE_TEST_FUNC = 1, |
2599 | PROBE_TEST_DATA = 2 | |
59df055f SR |
2600 | }; |
2601 | ||
2602 | static void | |
b6887d79 | 2603 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2604 | void *data, int flags) |
2605 | { | |
b6887d79 | 2606 | struct ftrace_func_probe *entry; |
59df055f SR |
2607 | struct hlist_node *n, *tmp; |
2608 | char str[KSYM_SYMBOL_LEN]; | |
2609 | int type = MATCH_FULL; | |
2610 | int i, len = 0; | |
2611 | char *search; | |
2612 | ||
b36461da | 2613 | if (glob && (strcmp(glob, "*") == 0 || !strlen(glob))) |
59df055f | 2614 | glob = NULL; |
b36461da | 2615 | else if (glob) { |
59df055f SR |
2616 | int not; |
2617 | ||
3f6fe06d | 2618 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
2619 | len = strlen(search); |
2620 | ||
b6887d79 | 2621 | /* we do not support '!' for function probes */ |
59df055f SR |
2622 | if (WARN_ON(not)) |
2623 | return; | |
2624 | } | |
2625 | ||
2626 | mutex_lock(&ftrace_lock); | |
2627 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2628 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2629 | ||
2630 | hlist_for_each_entry_safe(entry, n, tmp, hhd, node) { | |
2631 | ||
2632 | /* break up if statements for readability */ | |
b6887d79 | 2633 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
2634 | continue; |
2635 | ||
b6887d79 | 2636 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
2637 | continue; |
2638 | ||
2639 | /* do this last, since it is the most expensive */ | |
2640 | if (glob) { | |
2641 | kallsyms_lookup(entry->ip, NULL, NULL, | |
2642 | NULL, str); | |
2643 | if (!ftrace_match(str, glob, len, type)) | |
2644 | continue; | |
2645 | } | |
2646 | ||
2647 | hlist_del(&entry->node); | |
2648 | call_rcu(&entry->rcu, ftrace_free_entry_rcu); | |
2649 | } | |
2650 | } | |
b6887d79 | 2651 | __disable_ftrace_function_probe(); |
59df055f SR |
2652 | mutex_unlock(&ftrace_lock); |
2653 | } | |
2654 | ||
2655 | void | |
b6887d79 | 2656 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2657 | void *data) |
2658 | { | |
b6887d79 SR |
2659 | __unregister_ftrace_function_probe(glob, ops, data, |
2660 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
2661 | } |
2662 | ||
2663 | void | |
b6887d79 | 2664 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 2665 | { |
b6887d79 | 2666 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
2667 | } |
2668 | ||
b6887d79 | 2669 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 2670 | { |
b6887d79 | 2671 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
2672 | } |
2673 | ||
f6180773 SR |
2674 | static LIST_HEAD(ftrace_commands); |
2675 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
2676 | ||
2677 | int register_ftrace_command(struct ftrace_func_command *cmd) | |
2678 | { | |
2679 | struct ftrace_func_command *p; | |
2680 | int ret = 0; | |
2681 | ||
2682 | mutex_lock(&ftrace_cmd_mutex); | |
2683 | list_for_each_entry(p, &ftrace_commands, list) { | |
2684 | if (strcmp(cmd->name, p->name) == 0) { | |
2685 | ret = -EBUSY; | |
2686 | goto out_unlock; | |
2687 | } | |
2688 | } | |
2689 | list_add(&cmd->list, &ftrace_commands); | |
2690 | out_unlock: | |
2691 | mutex_unlock(&ftrace_cmd_mutex); | |
2692 | ||
2693 | return ret; | |
2694 | } | |
2695 | ||
2696 | int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
2697 | { | |
2698 | struct ftrace_func_command *p, *n; | |
2699 | int ret = -ENODEV; | |
2700 | ||
2701 | mutex_lock(&ftrace_cmd_mutex); | |
2702 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
2703 | if (strcmp(cmd->name, p->name) == 0) { | |
2704 | ret = 0; | |
2705 | list_del_init(&p->list); | |
2706 | goto out_unlock; | |
2707 | } | |
2708 | } | |
2709 | out_unlock: | |
2710 | mutex_unlock(&ftrace_cmd_mutex); | |
2711 | ||
2712 | return ret; | |
2713 | } | |
2714 | ||
33dc9b12 SR |
2715 | static int ftrace_process_regex(struct ftrace_hash *hash, |
2716 | char *buff, int len, int enable) | |
64e7c440 | 2717 | { |
f6180773 | 2718 | char *func, *command, *next = buff; |
6a24a244 | 2719 | struct ftrace_func_command *p; |
b448c4e3 | 2720 | int ret; |
64e7c440 SR |
2721 | |
2722 | func = strsep(&next, ":"); | |
2723 | ||
2724 | if (!next) { | |
1cf41dd7 | 2725 | ret = ftrace_match_records(hash, func, len); |
b448c4e3 SR |
2726 | if (!ret) |
2727 | ret = -EINVAL; | |
2728 | if (ret < 0) | |
2729 | return ret; | |
2730 | return 0; | |
64e7c440 SR |
2731 | } |
2732 | ||
f6180773 | 2733 | /* command found */ |
64e7c440 SR |
2734 | |
2735 | command = strsep(&next, ":"); | |
2736 | ||
f6180773 SR |
2737 | mutex_lock(&ftrace_cmd_mutex); |
2738 | list_for_each_entry(p, &ftrace_commands, list) { | |
2739 | if (strcmp(p->name, command) == 0) { | |
2740 | ret = p->func(func, command, next, enable); | |
2741 | goto out_unlock; | |
2742 | } | |
64e7c440 | 2743 | } |
f6180773 SR |
2744 | out_unlock: |
2745 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 2746 | |
f6180773 | 2747 | return ret; |
64e7c440 SR |
2748 | } |
2749 | ||
e309b41d | 2750 | static ssize_t |
41c52c0d SR |
2751 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
2752 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
2753 | { |
2754 | struct ftrace_iterator *iter; | |
689fd8b6 | 2755 | struct trace_parser *parser; |
2756 | ssize_t ret, read; | |
5072c59f | 2757 | |
4ba7978e | 2758 | if (!cnt) |
5072c59f SR |
2759 | return 0; |
2760 | ||
41c52c0d | 2761 | mutex_lock(&ftrace_regex_lock); |
5072c59f | 2762 | |
45a4a237 SR |
2763 | ret = -ENODEV; |
2764 | if (unlikely(ftrace_disabled)) | |
2765 | goto out_unlock; | |
2766 | ||
5072c59f SR |
2767 | if (file->f_mode & FMODE_READ) { |
2768 | struct seq_file *m = file->private_data; | |
2769 | iter = m->private; | |
2770 | } else | |
2771 | iter = file->private_data; | |
2772 | ||
689fd8b6 | 2773 | parser = &iter->parser; |
2774 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 2775 | |
4ba7978e | 2776 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 2777 | !trace_parser_cont(parser)) { |
33dc9b12 | 2778 | ret = ftrace_process_regex(iter->hash, parser->buffer, |
689fd8b6 | 2779 | parser->idx, enable); |
313254a9 | 2780 | trace_parser_clear(parser); |
5072c59f | 2781 | if (ret) |
ed146b25 | 2782 | goto out_unlock; |
eda1e328 | 2783 | } |
5072c59f | 2784 | |
5072c59f | 2785 | ret = read; |
ed146b25 | 2786 | out_unlock: |
689fd8b6 | 2787 | mutex_unlock(&ftrace_regex_lock); |
ed146b25 | 2788 | |
5072c59f SR |
2789 | return ret; |
2790 | } | |
2791 | ||
41c52c0d SR |
2792 | static ssize_t |
2793 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
2794 | size_t cnt, loff_t *ppos) | |
2795 | { | |
2796 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
2797 | } | |
2798 | ||
2799 | static ssize_t | |
2800 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
2801 | size_t cnt, loff_t *ppos) | |
2802 | { | |
2803 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
2804 | } | |
2805 | ||
33dc9b12 | 2806 | static int |
f45948e8 SR |
2807 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, |
2808 | int reset, int enable) | |
41c52c0d | 2809 | { |
33dc9b12 | 2810 | struct ftrace_hash **orig_hash; |
f45948e8 | 2811 | struct ftrace_hash *hash; |
33dc9b12 | 2812 | int ret; |
f45948e8 | 2813 | |
41c52c0d | 2814 | if (unlikely(ftrace_disabled)) |
33dc9b12 | 2815 | return -ENODEV; |
41c52c0d | 2816 | |
f45948e8 | 2817 | if (enable) |
33dc9b12 | 2818 | orig_hash = &ops->filter_hash; |
f45948e8 | 2819 | else |
33dc9b12 SR |
2820 | orig_hash = &ops->notrace_hash; |
2821 | ||
2822 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
2823 | if (!hash) | |
2824 | return -ENOMEM; | |
f45948e8 | 2825 | |
41c52c0d SR |
2826 | mutex_lock(&ftrace_regex_lock); |
2827 | if (reset) | |
1cf41dd7 | 2828 | ftrace_filter_reset(hash); |
41c52c0d | 2829 | if (buf) |
1cf41dd7 | 2830 | ftrace_match_records(hash, buf, len); |
33dc9b12 SR |
2831 | |
2832 | mutex_lock(&ftrace_lock); | |
2833 | ret = ftrace_hash_move(orig_hash, hash); | |
2834 | mutex_unlock(&ftrace_lock); | |
2835 | ||
41c52c0d | 2836 | mutex_unlock(&ftrace_regex_lock); |
33dc9b12 SR |
2837 | |
2838 | free_ftrace_hash(hash); | |
2839 | return ret; | |
41c52c0d SR |
2840 | } |
2841 | ||
77a2b37d SR |
2842 | /** |
2843 | * ftrace_set_filter - set a function to filter on in ftrace | |
2844 | * @buf - the string that holds the function filter text. | |
2845 | * @len - the length of the string. | |
2846 | * @reset - non zero to reset all filters before applying this filter. | |
2847 | * | |
2848 | * Filters denote which functions should be enabled when tracing is enabled. | |
2849 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
2850 | */ | |
e309b41d | 2851 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 2852 | { |
f45948e8 | 2853 | ftrace_set_regex(&global_ops, buf, len, reset, 1); |
41c52c0d | 2854 | } |
4eebcc81 | 2855 | |
41c52c0d SR |
2856 | /** |
2857 | * ftrace_set_notrace - set a function to not trace in ftrace | |
2858 | * @buf - the string that holds the function notrace text. | |
2859 | * @len - the length of the string. | |
2860 | * @reset - non zero to reset all filters before applying this filter. | |
2861 | * | |
2862 | * Notrace Filters denote which functions should not be enabled when tracing | |
2863 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
2864 | * for tracing. | |
2865 | */ | |
2866 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
2867 | { | |
f45948e8 | 2868 | ftrace_set_regex(&global_ops, buf, len, reset, 0); |
77a2b37d SR |
2869 | } |
2870 | ||
2af15d6a SR |
2871 | /* |
2872 | * command line interface to allow users to set filters on boot up. | |
2873 | */ | |
2874 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
2875 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
2876 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
2877 | ||
2878 | static int __init set_ftrace_notrace(char *str) | |
2879 | { | |
2880 | strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); | |
2881 | return 1; | |
2882 | } | |
2883 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
2884 | ||
2885 | static int __init set_ftrace_filter(char *str) | |
2886 | { | |
2887 | strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); | |
2888 | return 1; | |
2889 | } | |
2890 | __setup("ftrace_filter=", set_ftrace_filter); | |
2891 | ||
369bc18f | 2892 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 2893 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
801c29fd SR |
2894 | static int ftrace_set_func(unsigned long *array, int *idx, char *buffer); |
2895 | ||
369bc18f SA |
2896 | static int __init set_graph_function(char *str) |
2897 | { | |
06f43d66 | 2898 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
2899 | return 1; |
2900 | } | |
2901 | __setup("ftrace_graph_filter=", set_graph_function); | |
2902 | ||
2903 | static void __init set_ftrace_early_graph(char *buf) | |
2904 | { | |
2905 | int ret; | |
2906 | char *func; | |
2907 | ||
2908 | while (buf) { | |
2909 | func = strsep(&buf, ","); | |
2910 | /* we allow only one expression at a time */ | |
2911 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, | |
2912 | func); | |
2913 | if (ret) | |
2914 | printk(KERN_DEBUG "ftrace: function %s not " | |
2915 | "traceable\n", func); | |
2916 | } | |
2917 | } | |
2918 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2919 | ||
f45948e8 SR |
2920 | static void __init |
2921 | set_ftrace_early_filter(struct ftrace_ops *ops, char *buf, int enable) | |
2af15d6a SR |
2922 | { |
2923 | char *func; | |
2924 | ||
2925 | while (buf) { | |
2926 | func = strsep(&buf, ","); | |
f45948e8 | 2927 | ftrace_set_regex(ops, func, strlen(func), 0, enable); |
2af15d6a SR |
2928 | } |
2929 | } | |
2930 | ||
2931 | static void __init set_ftrace_early_filters(void) | |
2932 | { | |
2933 | if (ftrace_filter_buf[0]) | |
f45948e8 | 2934 | set_ftrace_early_filter(&global_ops, ftrace_filter_buf, 1); |
2af15d6a | 2935 | if (ftrace_notrace_buf[0]) |
f45948e8 | 2936 | set_ftrace_early_filter(&global_ops, ftrace_notrace_buf, 0); |
369bc18f SA |
2937 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
2938 | if (ftrace_graph_buf[0]) | |
2939 | set_ftrace_early_graph(ftrace_graph_buf); | |
2940 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2af15d6a SR |
2941 | } |
2942 | ||
e309b41d | 2943 | static int |
1cf41dd7 | 2944 | ftrace_regex_release(struct inode *inode, struct file *file) |
5072c59f SR |
2945 | { |
2946 | struct seq_file *m = (struct seq_file *)file->private_data; | |
2947 | struct ftrace_iterator *iter; | |
33dc9b12 | 2948 | struct ftrace_hash **orig_hash; |
689fd8b6 | 2949 | struct trace_parser *parser; |
ed926f9b | 2950 | int filter_hash; |
33dc9b12 | 2951 | int ret; |
5072c59f | 2952 | |
41c52c0d | 2953 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
2954 | if (file->f_mode & FMODE_READ) { |
2955 | iter = m->private; | |
2956 | ||
2957 | seq_release(inode, file); | |
2958 | } else | |
2959 | iter = file->private_data; | |
2960 | ||
689fd8b6 | 2961 | parser = &iter->parser; |
2962 | if (trace_parser_loaded(parser)) { | |
2963 | parser->buffer[parser->idx] = 0; | |
1cf41dd7 | 2964 | ftrace_match_records(iter->hash, parser->buffer, parser->idx); |
5072c59f SR |
2965 | } |
2966 | ||
689fd8b6 | 2967 | trace_parser_put(parser); |
689fd8b6 | 2968 | |
058e297d | 2969 | if (file->f_mode & FMODE_WRITE) { |
ed926f9b SR |
2970 | filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); |
2971 | ||
2972 | if (filter_hash) | |
33dc9b12 | 2973 | orig_hash = &iter->ops->filter_hash; |
ed926f9b SR |
2974 | else |
2975 | orig_hash = &iter->ops->notrace_hash; | |
33dc9b12 | 2976 | |
058e297d | 2977 | mutex_lock(&ftrace_lock); |
ed926f9b SR |
2978 | /* |
2979 | * Remove the current set, update the hash and add | |
2980 | * them back. | |
2981 | */ | |
2982 | ftrace_hash_rec_disable(iter->ops, filter_hash); | |
33dc9b12 | 2983 | ret = ftrace_hash_move(orig_hash, iter->hash); |
ed926f9b SR |
2984 | if (!ret) { |
2985 | ftrace_hash_rec_enable(iter->ops, filter_hash); | |
2986 | if (iter->ops->flags & FTRACE_OPS_FL_ENABLED | |
2987 | && ftrace_enabled) | |
2988 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); | |
2989 | } | |
058e297d SR |
2990 | mutex_unlock(&ftrace_lock); |
2991 | } | |
33dc9b12 SR |
2992 | free_ftrace_hash(iter->hash); |
2993 | kfree(iter); | |
058e297d | 2994 | |
41c52c0d | 2995 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
2996 | return 0; |
2997 | } | |
2998 | ||
5e2336a0 | 2999 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
3000 | .open = ftrace_avail_open, |
3001 | .read = seq_read, | |
3002 | .llseek = seq_lseek, | |
3be04b47 | 3003 | .release = seq_release_private, |
5072c59f SR |
3004 | }; |
3005 | ||
647bcd03 SR |
3006 | static const struct file_operations ftrace_enabled_fops = { |
3007 | .open = ftrace_enabled_open, | |
3008 | .read = seq_read, | |
3009 | .llseek = seq_lseek, | |
3010 | .release = seq_release_private, | |
3011 | }; | |
3012 | ||
5e2336a0 | 3013 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 3014 | .open = ftrace_filter_open, |
850a80cf | 3015 | .read = seq_read, |
5072c59f | 3016 | .write = ftrace_filter_write, |
98c4fd04 | 3017 | .llseek = ftrace_regex_lseek, |
1cf41dd7 | 3018 | .release = ftrace_regex_release, |
5072c59f SR |
3019 | }; |
3020 | ||
5e2336a0 | 3021 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 3022 | .open = ftrace_notrace_open, |
850a80cf | 3023 | .read = seq_read, |
41c52c0d SR |
3024 | .write = ftrace_notrace_write, |
3025 | .llseek = ftrace_regex_lseek, | |
1cf41dd7 | 3026 | .release = ftrace_regex_release, |
41c52c0d SR |
3027 | }; |
3028 | ||
ea4e2bc4 SR |
3029 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
3030 | ||
3031 | static DEFINE_MUTEX(graph_lock); | |
3032 | ||
3033 | int ftrace_graph_count; | |
c7c6b1fe | 3034 | int ftrace_graph_filter_enabled; |
ea4e2bc4 SR |
3035 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
3036 | ||
3037 | static void * | |
85951842 | 3038 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 3039 | { |
85951842 | 3040 | if (*pos >= ftrace_graph_count) |
ea4e2bc4 | 3041 | return NULL; |
a4ec5e0c | 3042 | return &ftrace_graph_funcs[*pos]; |
85951842 | 3043 | } |
ea4e2bc4 | 3044 | |
85951842 LZ |
3045 | static void * |
3046 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
3047 | { | |
3048 | (*pos)++; | |
3049 | return __g_next(m, pos); | |
ea4e2bc4 SR |
3050 | } |
3051 | ||
3052 | static void *g_start(struct seq_file *m, loff_t *pos) | |
3053 | { | |
ea4e2bc4 SR |
3054 | mutex_lock(&graph_lock); |
3055 | ||
f9349a8f | 3056 | /* Nothing, tell g_show to print all functions are enabled */ |
c7c6b1fe | 3057 | if (!ftrace_graph_filter_enabled && !*pos) |
f9349a8f FW |
3058 | return (void *)1; |
3059 | ||
85951842 | 3060 | return __g_next(m, pos); |
ea4e2bc4 SR |
3061 | } |
3062 | ||
3063 | static void g_stop(struct seq_file *m, void *p) | |
3064 | { | |
3065 | mutex_unlock(&graph_lock); | |
3066 | } | |
3067 | ||
3068 | static int g_show(struct seq_file *m, void *v) | |
3069 | { | |
3070 | unsigned long *ptr = v; | |
ea4e2bc4 SR |
3071 | |
3072 | if (!ptr) | |
3073 | return 0; | |
3074 | ||
f9349a8f FW |
3075 | if (ptr == (unsigned long *)1) { |
3076 | seq_printf(m, "#### all functions enabled ####\n"); | |
3077 | return 0; | |
3078 | } | |
3079 | ||
b375a11a | 3080 | seq_printf(m, "%ps\n", (void *)*ptr); |
ea4e2bc4 SR |
3081 | |
3082 | return 0; | |
3083 | } | |
3084 | ||
88e9d34c | 3085 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
3086 | .start = g_start, |
3087 | .next = g_next, | |
3088 | .stop = g_stop, | |
3089 | .show = g_show, | |
3090 | }; | |
3091 | ||
3092 | static int | |
3093 | ftrace_graph_open(struct inode *inode, struct file *file) | |
3094 | { | |
3095 | int ret = 0; | |
3096 | ||
3097 | if (unlikely(ftrace_disabled)) | |
3098 | return -ENODEV; | |
3099 | ||
3100 | mutex_lock(&graph_lock); | |
3101 | if ((file->f_mode & FMODE_WRITE) && | |
8650ae32 | 3102 | (file->f_flags & O_TRUNC)) { |
c7c6b1fe | 3103 | ftrace_graph_filter_enabled = 0; |
ea4e2bc4 SR |
3104 | ftrace_graph_count = 0; |
3105 | memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); | |
3106 | } | |
a4ec5e0c | 3107 | mutex_unlock(&graph_lock); |
ea4e2bc4 | 3108 | |
a4ec5e0c | 3109 | if (file->f_mode & FMODE_READ) |
ea4e2bc4 | 3110 | ret = seq_open(file, &ftrace_graph_seq_ops); |
ea4e2bc4 SR |
3111 | |
3112 | return ret; | |
3113 | } | |
3114 | ||
87827111 LZ |
3115 | static int |
3116 | ftrace_graph_release(struct inode *inode, struct file *file) | |
3117 | { | |
3118 | if (file->f_mode & FMODE_READ) | |
3119 | seq_release(inode, file); | |
3120 | return 0; | |
3121 | } | |
3122 | ||
ea4e2bc4 | 3123 | static int |
f9349a8f | 3124 | ftrace_set_func(unsigned long *array, int *idx, char *buffer) |
ea4e2bc4 | 3125 | { |
ea4e2bc4 SR |
3126 | struct dyn_ftrace *rec; |
3127 | struct ftrace_page *pg; | |
f9349a8f | 3128 | int search_len; |
c7c6b1fe | 3129 | int fail = 1; |
f9349a8f FW |
3130 | int type, not; |
3131 | char *search; | |
3132 | bool exists; | |
3133 | int i; | |
ea4e2bc4 | 3134 | |
f9349a8f | 3135 | /* decode regex */ |
3f6fe06d | 3136 | type = filter_parse_regex(buffer, strlen(buffer), &search, ¬); |
c7c6b1fe LZ |
3137 | if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS) |
3138 | return -EBUSY; | |
f9349a8f FW |
3139 | |
3140 | search_len = strlen(search); | |
3141 | ||
52baf119 | 3142 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
3143 | |
3144 | if (unlikely(ftrace_disabled)) { | |
3145 | mutex_unlock(&ftrace_lock); | |
3146 | return -ENODEV; | |
3147 | } | |
3148 | ||
265c831c SR |
3149 | do_for_each_ftrace_rec(pg, rec) { |
3150 | ||
45a4a237 | 3151 | if (rec->flags & FTRACE_FL_FREE) |
265c831c SR |
3152 | continue; |
3153 | ||
b9df92d2 | 3154 | if (ftrace_match_record(rec, NULL, search, search_len, type)) { |
c7c6b1fe | 3155 | /* if it is in the array */ |
f9349a8f | 3156 | exists = false; |
c7c6b1fe | 3157 | for (i = 0; i < *idx; i++) { |
f9349a8f FW |
3158 | if (array[i] == rec->ip) { |
3159 | exists = true; | |
265c831c SR |
3160 | break; |
3161 | } | |
c7c6b1fe LZ |
3162 | } |
3163 | ||
3164 | if (!not) { | |
3165 | fail = 0; | |
3166 | if (!exists) { | |
3167 | array[(*idx)++] = rec->ip; | |
3168 | if (*idx >= FTRACE_GRAPH_MAX_FUNCS) | |
3169 | goto out; | |
3170 | } | |
3171 | } else { | |
3172 | if (exists) { | |
3173 | array[i] = array[--(*idx)]; | |
3174 | array[*idx] = 0; | |
3175 | fail = 0; | |
3176 | } | |
3177 | } | |
ea4e2bc4 | 3178 | } |
265c831c | 3179 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 3180 | out: |
52baf119 | 3181 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 3182 | |
c7c6b1fe LZ |
3183 | if (fail) |
3184 | return -EINVAL; | |
3185 | ||
3186 | ftrace_graph_filter_enabled = 1; | |
3187 | return 0; | |
ea4e2bc4 SR |
3188 | } |
3189 | ||
3190 | static ssize_t | |
3191 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
3192 | size_t cnt, loff_t *ppos) | |
3193 | { | |
689fd8b6 | 3194 | struct trace_parser parser; |
4ba7978e | 3195 | ssize_t read, ret; |
ea4e2bc4 | 3196 | |
c7c6b1fe | 3197 | if (!cnt) |
ea4e2bc4 SR |
3198 | return 0; |
3199 | ||
3200 | mutex_lock(&graph_lock); | |
3201 | ||
689fd8b6 | 3202 | if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) { |
3203 | ret = -ENOMEM; | |
1eb90f13 | 3204 | goto out_unlock; |
ea4e2bc4 SR |
3205 | } |
3206 | ||
689fd8b6 | 3207 | read = trace_get_user(&parser, ubuf, cnt, ppos); |
ea4e2bc4 | 3208 | |
4ba7978e | 3209 | if (read >= 0 && trace_parser_loaded((&parser))) { |
689fd8b6 | 3210 | parser.buffer[parser.idx] = 0; |
3211 | ||
3212 | /* we allow only one expression at a time */ | |
a4ec5e0c | 3213 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, |
689fd8b6 | 3214 | parser.buffer); |
ea4e2bc4 | 3215 | if (ret) |
1eb90f13 | 3216 | goto out_free; |
ea4e2bc4 | 3217 | } |
ea4e2bc4 SR |
3218 | |
3219 | ret = read; | |
1eb90f13 LZ |
3220 | |
3221 | out_free: | |
689fd8b6 | 3222 | trace_parser_put(&parser); |
1eb90f13 | 3223 | out_unlock: |
ea4e2bc4 SR |
3224 | mutex_unlock(&graph_lock); |
3225 | ||
3226 | return ret; | |
3227 | } | |
3228 | ||
3229 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
3230 | .open = ftrace_graph_open, |
3231 | .read = seq_read, | |
3232 | .write = ftrace_graph_write, | |
3233 | .release = ftrace_graph_release, | |
6038f373 | 3234 | .llseek = seq_lseek, |
ea4e2bc4 SR |
3235 | }; |
3236 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
3237 | ||
df4fc315 | 3238 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 3239 | { |
5072c59f | 3240 | |
5452af66 FW |
3241 | trace_create_file("available_filter_functions", 0444, |
3242 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 3243 | |
647bcd03 SR |
3244 | trace_create_file("enabled_functions", 0444, |
3245 | d_tracer, NULL, &ftrace_enabled_fops); | |
3246 | ||
5452af66 FW |
3247 | trace_create_file("set_ftrace_filter", 0644, d_tracer, |
3248 | NULL, &ftrace_filter_fops); | |
41c52c0d | 3249 | |
5452af66 | 3250 | trace_create_file("set_ftrace_notrace", 0644, d_tracer, |
41c52c0d | 3251 | NULL, &ftrace_notrace_fops); |
ad90c0e3 | 3252 | |
ea4e2bc4 | 3253 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 3254 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
3255 | NULL, |
3256 | &ftrace_graph_fops); | |
ea4e2bc4 SR |
3257 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
3258 | ||
5072c59f SR |
3259 | return 0; |
3260 | } | |
3261 | ||
5cb084bb | 3262 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 3263 | unsigned long *start, |
68bf21aa SR |
3264 | unsigned long *end) |
3265 | { | |
3266 | unsigned long *p; | |
3267 | unsigned long addr; | |
68bf21aa | 3268 | |
e6ea44e9 | 3269 | mutex_lock(&ftrace_lock); |
68bf21aa SR |
3270 | p = start; |
3271 | while (p < end) { | |
3272 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
3273 | /* |
3274 | * Some architecture linkers will pad between | |
3275 | * the different mcount_loc sections of different | |
3276 | * object files to satisfy alignments. | |
3277 | * Skip any NULL pointers. | |
3278 | */ | |
3279 | if (!addr) | |
3280 | continue; | |
68bf21aa | 3281 | ftrace_record_ip(addr); |
68bf21aa SR |
3282 | } |
3283 | ||
31e88909 | 3284 | ftrace_update_code(mod); |
e6ea44e9 | 3285 | mutex_unlock(&ftrace_lock); |
68bf21aa SR |
3286 | |
3287 | return 0; | |
3288 | } | |
3289 | ||
93eb677d | 3290 | #ifdef CONFIG_MODULES |
e7247a15 | 3291 | void ftrace_release_mod(struct module *mod) |
93eb677d SR |
3292 | { |
3293 | struct dyn_ftrace *rec; | |
3294 | struct ftrace_page *pg; | |
93eb677d | 3295 | |
45a4a237 SR |
3296 | mutex_lock(&ftrace_lock); |
3297 | ||
e7247a15 | 3298 | if (ftrace_disabled) |
45a4a237 | 3299 | goto out_unlock; |
93eb677d | 3300 | |
93eb677d | 3301 | do_for_each_ftrace_rec(pg, rec) { |
e7247a15 | 3302 | if (within_module_core(rec->ip, mod)) { |
93eb677d SR |
3303 | /* |
3304 | * rec->ip is changed in ftrace_free_rec() | |
3305 | * It should not between s and e if record was freed. | |
3306 | */ | |
3307 | FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE); | |
3308 | ftrace_free_rec(rec); | |
3309 | } | |
3310 | } while_for_each_ftrace_rec(); | |
45a4a237 | 3311 | out_unlock: |
93eb677d SR |
3312 | mutex_unlock(&ftrace_lock); |
3313 | } | |
3314 | ||
3315 | static void ftrace_init_module(struct module *mod, | |
3316 | unsigned long *start, unsigned long *end) | |
90d595fe | 3317 | { |
00fd61ae | 3318 | if (ftrace_disabled || start == end) |
fed1939c | 3319 | return; |
5cb084bb | 3320 | ftrace_process_locs(mod, start, end); |
90d595fe SR |
3321 | } |
3322 | ||
93eb677d SR |
3323 | static int ftrace_module_notify(struct notifier_block *self, |
3324 | unsigned long val, void *data) | |
3325 | { | |
3326 | struct module *mod = data; | |
3327 | ||
3328 | switch (val) { | |
3329 | case MODULE_STATE_COMING: | |
3330 | ftrace_init_module(mod, mod->ftrace_callsites, | |
3331 | mod->ftrace_callsites + | |
3332 | mod->num_ftrace_callsites); | |
3333 | break; | |
3334 | case MODULE_STATE_GOING: | |
e7247a15 | 3335 | ftrace_release_mod(mod); |
93eb677d SR |
3336 | break; |
3337 | } | |
3338 | ||
3339 | return 0; | |
3340 | } | |
3341 | #else | |
3342 | static int ftrace_module_notify(struct notifier_block *self, | |
3343 | unsigned long val, void *data) | |
3344 | { | |
3345 | return 0; | |
3346 | } | |
3347 | #endif /* CONFIG_MODULES */ | |
3348 | ||
3349 | struct notifier_block ftrace_module_nb = { | |
3350 | .notifier_call = ftrace_module_notify, | |
3351 | .priority = 0, | |
3352 | }; | |
3353 | ||
68bf21aa SR |
3354 | extern unsigned long __start_mcount_loc[]; |
3355 | extern unsigned long __stop_mcount_loc[]; | |
3356 | ||
3357 | void __init ftrace_init(void) | |
3358 | { | |
3359 | unsigned long count, addr, flags; | |
3360 | int ret; | |
3361 | ||
3362 | /* Keep the ftrace pointer to the stub */ | |
3363 | addr = (unsigned long)ftrace_stub; | |
3364 | ||
3365 | local_irq_save(flags); | |
3366 | ftrace_dyn_arch_init(&addr); | |
3367 | local_irq_restore(flags); | |
3368 | ||
3369 | /* ftrace_dyn_arch_init places the return code in addr */ | |
3370 | if (addr) | |
3371 | goto failed; | |
3372 | ||
3373 | count = __stop_mcount_loc - __start_mcount_loc; | |
3374 | ||
3375 | ret = ftrace_dyn_table_alloc(count); | |
3376 | if (ret) | |
3377 | goto failed; | |
3378 | ||
3379 | last_ftrace_enabled = ftrace_enabled = 1; | |
3380 | ||
5cb084bb | 3381 | ret = ftrace_process_locs(NULL, |
31e88909 | 3382 | __start_mcount_loc, |
68bf21aa SR |
3383 | __stop_mcount_loc); |
3384 | ||
93eb677d | 3385 | ret = register_module_notifier(&ftrace_module_nb); |
24ed0c4b | 3386 | if (ret) |
93eb677d SR |
3387 | pr_warning("Failed to register trace ftrace module notifier\n"); |
3388 | ||
2af15d6a SR |
3389 | set_ftrace_early_filters(); |
3390 | ||
68bf21aa SR |
3391 | return; |
3392 | failed: | |
3393 | ftrace_disabled = 1; | |
3394 | } | |
68bf21aa | 3395 | |
3d083395 | 3396 | #else |
0b6e4d56 | 3397 | |
2b499381 | 3398 | static struct ftrace_ops global_ops = { |
bd69c30b SR |
3399 | .func = ftrace_stub, |
3400 | }; | |
3401 | ||
0b6e4d56 FW |
3402 | static int __init ftrace_nodyn_init(void) |
3403 | { | |
3404 | ftrace_enabled = 1; | |
3405 | return 0; | |
3406 | } | |
3407 | device_initcall(ftrace_nodyn_init); | |
3408 | ||
df4fc315 SR |
3409 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
3410 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 | 3411 | /* Keep as macros so we do not need to define the commands */ |
bd69c30b SR |
3412 | # define ftrace_startup(ops, command) do { } while (0) |
3413 | # define ftrace_shutdown(ops, command) do { } while (0) | |
c7aafc54 IM |
3414 | # define ftrace_startup_sysctl() do { } while (0) |
3415 | # define ftrace_shutdown_sysctl() do { } while (0) | |
b848914c SR |
3416 | |
3417 | static inline int | |
3418 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip) | |
3419 | { | |
3420 | return 1; | |
3421 | } | |
3422 | ||
3d083395 SR |
3423 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
3424 | ||
b848914c SR |
3425 | static void |
3426 | ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip) | |
3427 | { | |
3428 | /* see comment above ftrace_global_list_func */ | |
3429 | struct ftrace_ops *op = rcu_dereference_raw(ftrace_ops_list); | |
3430 | ||
3431 | while (op != &ftrace_list_end) { | |
3432 | if (ftrace_ops_test(op, ip)) | |
3433 | op->func(ip, parent_ip); | |
3434 | op = rcu_dereference_raw(op->next); | |
3435 | }; | |
3436 | } | |
3437 | ||
e32d8956 | 3438 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
3439 | { |
3440 | struct task_struct *p; | |
e32d8956 | 3441 | int cpu; |
978f3a45 | 3442 | |
e32d8956 SR |
3443 | get_online_cpus(); |
3444 | for_each_online_cpu(cpu) { | |
3445 | p = idle_task(cpu); | |
978f3a45 | 3446 | clear_tsk_trace_trace(p); |
e32d8956 SR |
3447 | } |
3448 | put_online_cpus(); | |
3449 | } | |
978f3a45 | 3450 | |
e32d8956 SR |
3451 | static void set_ftrace_swapper(void) |
3452 | { | |
3453 | struct task_struct *p; | |
3454 | int cpu; | |
3455 | ||
3456 | get_online_cpus(); | |
3457 | for_each_online_cpu(cpu) { | |
3458 | p = idle_task(cpu); | |
3459 | set_tsk_trace_trace(p); | |
3460 | } | |
3461 | put_online_cpus(); | |
978f3a45 SR |
3462 | } |
3463 | ||
e32d8956 SR |
3464 | static void clear_ftrace_pid(struct pid *pid) |
3465 | { | |
3466 | struct task_struct *p; | |
3467 | ||
229c4ef8 | 3468 | rcu_read_lock(); |
e32d8956 SR |
3469 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
3470 | clear_tsk_trace_trace(p); | |
3471 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
3472 | rcu_read_unlock(); |
3473 | ||
e32d8956 SR |
3474 | put_pid(pid); |
3475 | } | |
3476 | ||
3477 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
3478 | { |
3479 | struct task_struct *p; | |
3480 | ||
229c4ef8 | 3481 | rcu_read_lock(); |
978f3a45 SR |
3482 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
3483 | set_tsk_trace_trace(p); | |
3484 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 3485 | rcu_read_unlock(); |
978f3a45 SR |
3486 | } |
3487 | ||
756d17ee | 3488 | static void clear_ftrace_pid_task(struct pid *pid) |
e32d8956 | 3489 | { |
756d17ee | 3490 | if (pid == ftrace_swapper_pid) |
e32d8956 SR |
3491 | clear_ftrace_swapper(); |
3492 | else | |
756d17ee | 3493 | clear_ftrace_pid(pid); |
e32d8956 SR |
3494 | } |
3495 | ||
3496 | static void set_ftrace_pid_task(struct pid *pid) | |
3497 | { | |
3498 | if (pid == ftrace_swapper_pid) | |
3499 | set_ftrace_swapper(); | |
3500 | else | |
3501 | set_ftrace_pid(pid); | |
3502 | } | |
3503 | ||
756d17ee | 3504 | static int ftrace_pid_add(int p) |
df4fc315 | 3505 | { |
978f3a45 | 3506 | struct pid *pid; |
756d17ee | 3507 | struct ftrace_pid *fpid; |
3508 | int ret = -EINVAL; | |
df4fc315 | 3509 | |
756d17ee | 3510 | mutex_lock(&ftrace_lock); |
df4fc315 | 3511 | |
756d17ee | 3512 | if (!p) |
3513 | pid = ftrace_swapper_pid; | |
3514 | else | |
3515 | pid = find_get_pid(p); | |
df4fc315 | 3516 | |
756d17ee | 3517 | if (!pid) |
3518 | goto out; | |
df4fc315 | 3519 | |
756d17ee | 3520 | ret = 0; |
df4fc315 | 3521 | |
756d17ee | 3522 | list_for_each_entry(fpid, &ftrace_pids, list) |
3523 | if (fpid->pid == pid) | |
3524 | goto out_put; | |
978f3a45 | 3525 | |
756d17ee | 3526 | ret = -ENOMEM; |
df4fc315 | 3527 | |
756d17ee | 3528 | fpid = kmalloc(sizeof(*fpid), GFP_KERNEL); |
3529 | if (!fpid) | |
3530 | goto out_put; | |
df4fc315 | 3531 | |
756d17ee | 3532 | list_add(&fpid->list, &ftrace_pids); |
3533 | fpid->pid = pid; | |
0ef8cde5 | 3534 | |
756d17ee | 3535 | set_ftrace_pid_task(pid); |
978f3a45 | 3536 | |
756d17ee | 3537 | ftrace_update_pid_func(); |
3538 | ftrace_startup_enable(0); | |
3539 | ||
3540 | mutex_unlock(&ftrace_lock); | |
3541 | return 0; | |
3542 | ||
3543 | out_put: | |
3544 | if (pid != ftrace_swapper_pid) | |
3545 | put_pid(pid); | |
978f3a45 | 3546 | |
756d17ee | 3547 | out: |
3548 | mutex_unlock(&ftrace_lock); | |
3549 | return ret; | |
3550 | } | |
3551 | ||
3552 | static void ftrace_pid_reset(void) | |
3553 | { | |
3554 | struct ftrace_pid *fpid, *safe; | |
978f3a45 | 3555 | |
756d17ee | 3556 | mutex_lock(&ftrace_lock); |
3557 | list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) { | |
3558 | struct pid *pid = fpid->pid; | |
3559 | ||
3560 | clear_ftrace_pid_task(pid); | |
3561 | ||
3562 | list_del(&fpid->list); | |
3563 | kfree(fpid); | |
df4fc315 SR |
3564 | } |
3565 | ||
df4fc315 SR |
3566 | ftrace_update_pid_func(); |
3567 | ftrace_startup_enable(0); | |
3568 | ||
e6ea44e9 | 3569 | mutex_unlock(&ftrace_lock); |
756d17ee | 3570 | } |
df4fc315 | 3571 | |
756d17ee | 3572 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
3573 | { | |
3574 | mutex_lock(&ftrace_lock); | |
3575 | ||
3576 | if (list_empty(&ftrace_pids) && (!*pos)) | |
3577 | return (void *) 1; | |
3578 | ||
3579 | return seq_list_start(&ftrace_pids, *pos); | |
3580 | } | |
3581 | ||
3582 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
3583 | { | |
3584 | if (v == (void *)1) | |
3585 | return NULL; | |
3586 | ||
3587 | return seq_list_next(v, &ftrace_pids, pos); | |
3588 | } | |
3589 | ||
3590 | static void fpid_stop(struct seq_file *m, void *p) | |
3591 | { | |
3592 | mutex_unlock(&ftrace_lock); | |
3593 | } | |
3594 | ||
3595 | static int fpid_show(struct seq_file *m, void *v) | |
3596 | { | |
3597 | const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list); | |
3598 | ||
3599 | if (v == (void *)1) { | |
3600 | seq_printf(m, "no pid\n"); | |
3601 | return 0; | |
3602 | } | |
3603 | ||
3604 | if (fpid->pid == ftrace_swapper_pid) | |
3605 | seq_printf(m, "swapper tasks\n"); | |
3606 | else | |
3607 | seq_printf(m, "%u\n", pid_vnr(fpid->pid)); | |
3608 | ||
3609 | return 0; | |
3610 | } | |
3611 | ||
3612 | static const struct seq_operations ftrace_pid_sops = { | |
3613 | .start = fpid_start, | |
3614 | .next = fpid_next, | |
3615 | .stop = fpid_stop, | |
3616 | .show = fpid_show, | |
3617 | }; | |
3618 | ||
3619 | static int | |
3620 | ftrace_pid_open(struct inode *inode, struct file *file) | |
3621 | { | |
3622 | int ret = 0; | |
3623 | ||
3624 | if ((file->f_mode & FMODE_WRITE) && | |
3625 | (file->f_flags & O_TRUNC)) | |
3626 | ftrace_pid_reset(); | |
3627 | ||
3628 | if (file->f_mode & FMODE_READ) | |
3629 | ret = seq_open(file, &ftrace_pid_sops); | |
3630 | ||
3631 | return ret; | |
3632 | } | |
3633 | ||
df4fc315 SR |
3634 | static ssize_t |
3635 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
3636 | size_t cnt, loff_t *ppos) | |
3637 | { | |
457dc928 | 3638 | char buf[64], *tmp; |
df4fc315 SR |
3639 | long val; |
3640 | int ret; | |
3641 | ||
3642 | if (cnt >= sizeof(buf)) | |
3643 | return -EINVAL; | |
3644 | ||
3645 | if (copy_from_user(&buf, ubuf, cnt)) | |
3646 | return -EFAULT; | |
3647 | ||
3648 | buf[cnt] = 0; | |
3649 | ||
756d17ee | 3650 | /* |
3651 | * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid" | |
3652 | * to clean the filter quietly. | |
3653 | */ | |
457dc928 IM |
3654 | tmp = strstrip(buf); |
3655 | if (strlen(tmp) == 0) | |
756d17ee | 3656 | return 1; |
3657 | ||
457dc928 | 3658 | ret = strict_strtol(tmp, 10, &val); |
df4fc315 SR |
3659 | if (ret < 0) |
3660 | return ret; | |
3661 | ||
756d17ee | 3662 | ret = ftrace_pid_add(val); |
df4fc315 | 3663 | |
756d17ee | 3664 | return ret ? ret : cnt; |
3665 | } | |
df4fc315 | 3666 | |
756d17ee | 3667 | static int |
3668 | ftrace_pid_release(struct inode *inode, struct file *file) | |
3669 | { | |
3670 | if (file->f_mode & FMODE_READ) | |
3671 | seq_release(inode, file); | |
df4fc315 | 3672 | |
756d17ee | 3673 | return 0; |
df4fc315 SR |
3674 | } |
3675 | ||
5e2336a0 | 3676 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 3677 | .open = ftrace_pid_open, |
3678 | .write = ftrace_pid_write, | |
3679 | .read = seq_read, | |
3680 | .llseek = seq_lseek, | |
3681 | .release = ftrace_pid_release, | |
df4fc315 SR |
3682 | }; |
3683 | ||
3684 | static __init int ftrace_init_debugfs(void) | |
3685 | { | |
3686 | struct dentry *d_tracer; | |
df4fc315 SR |
3687 | |
3688 | d_tracer = tracing_init_dentry(); | |
3689 | if (!d_tracer) | |
3690 | return 0; | |
3691 | ||
3692 | ftrace_init_dyn_debugfs(d_tracer); | |
3693 | ||
5452af66 FW |
3694 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
3695 | NULL, &ftrace_pid_fops); | |
493762fc SR |
3696 | |
3697 | ftrace_profile_debugfs(d_tracer); | |
3698 | ||
df4fc315 SR |
3699 | return 0; |
3700 | } | |
df4fc315 SR |
3701 | fs_initcall(ftrace_init_debugfs); |
3702 | ||
a2bb6a3d | 3703 | /** |
81adbdc0 | 3704 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
3705 | * |
3706 | * This function should be used by panic code. It stops ftrace | |
3707 | * but in a not so nice way. If you need to simply kill ftrace | |
3708 | * from a non-atomic section, use ftrace_kill. | |
3709 | */ | |
81adbdc0 | 3710 | void ftrace_kill(void) |
a2bb6a3d SR |
3711 | { |
3712 | ftrace_disabled = 1; | |
3713 | ftrace_enabled = 0; | |
a2bb6a3d SR |
3714 | clear_ftrace_function(); |
3715 | } | |
3716 | ||
16444a8a | 3717 | /** |
3d083395 SR |
3718 | * register_ftrace_function - register a function for profiling |
3719 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 3720 | * |
3d083395 SR |
3721 | * Register a function to be called by all functions in the |
3722 | * kernel. | |
3723 | * | |
3724 | * Note: @ops->func and all the functions it calls must be labeled | |
3725 | * with "notrace", otherwise it will go into a | |
3726 | * recursive loop. | |
16444a8a | 3727 | */ |
3d083395 | 3728 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 3729 | { |
45a4a237 | 3730 | int ret = -1; |
4eebcc81 | 3731 | |
e6ea44e9 | 3732 | mutex_lock(&ftrace_lock); |
e7d3737e | 3733 | |
45a4a237 SR |
3734 | if (unlikely(ftrace_disabled)) |
3735 | goto out_unlock; | |
3736 | ||
b0fc494f | 3737 | ret = __register_ftrace_function(ops); |
b848914c SR |
3738 | if (!ret) |
3739 | ftrace_startup(ops, 0); | |
3740 | ||
b0fc494f | 3741 | |
45a4a237 | 3742 | out_unlock: |
e6ea44e9 | 3743 | mutex_unlock(&ftrace_lock); |
b0fc494f | 3744 | return ret; |
3d083395 SR |
3745 | } |
3746 | ||
3747 | /** | |
32632920 | 3748 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
3749 | * @ops - ops structure that holds the function to unregister |
3750 | * | |
3751 | * Unregister a function that was added to be called by ftrace profiling. | |
3752 | */ | |
3753 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
3754 | { | |
3755 | int ret; | |
3756 | ||
e6ea44e9 | 3757 | mutex_lock(&ftrace_lock); |
3d083395 | 3758 | ret = __unregister_ftrace_function(ops); |
b848914c SR |
3759 | if (!ret) |
3760 | ftrace_shutdown(ops, 0); | |
e6ea44e9 | 3761 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
3762 | |
3763 | return ret; | |
3764 | } | |
3765 | ||
e309b41d | 3766 | int |
b0fc494f | 3767 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
8d65af78 | 3768 | void __user *buffer, size_t *lenp, |
b0fc494f SR |
3769 | loff_t *ppos) |
3770 | { | |
45a4a237 | 3771 | int ret = -ENODEV; |
4eebcc81 | 3772 | |
e6ea44e9 | 3773 | mutex_lock(&ftrace_lock); |
b0fc494f | 3774 | |
45a4a237 SR |
3775 | if (unlikely(ftrace_disabled)) |
3776 | goto out; | |
3777 | ||
3778 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
b0fc494f | 3779 | |
a32c7765 | 3780 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
3781 | goto out; |
3782 | ||
a32c7765 | 3783 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f SR |
3784 | |
3785 | if (ftrace_enabled) { | |
3786 | ||
3787 | ftrace_startup_sysctl(); | |
3788 | ||
3789 | /* we are starting ftrace again */ | |
b848914c SR |
3790 | if (ftrace_ops_list != &ftrace_list_end) { |
3791 | if (ftrace_ops_list->next == &ftrace_list_end) | |
3792 | ftrace_trace_function = ftrace_ops_list->func; | |
b0fc494f | 3793 | else |
b848914c | 3794 | ftrace_trace_function = ftrace_ops_list_func; |
b0fc494f SR |
3795 | } |
3796 | ||
3797 | } else { | |
3798 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
3799 | ftrace_trace_function = ftrace_stub; | |
3800 | ||
3801 | ftrace_shutdown_sysctl(); | |
3802 | } | |
3803 | ||
3804 | out: | |
e6ea44e9 | 3805 | mutex_unlock(&ftrace_lock); |
3d083395 | 3806 | return ret; |
16444a8a | 3807 | } |
f17845e5 | 3808 | |
fb52607a | 3809 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 3810 | |
597af815 | 3811 | static int ftrace_graph_active; |
4a2b8dda | 3812 | static struct notifier_block ftrace_suspend_notifier; |
e7d3737e | 3813 | |
e49dc19c SR |
3814 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
3815 | { | |
3816 | return 0; | |
3817 | } | |
3818 | ||
287b6e68 FW |
3819 | /* The callbacks that hook a function */ |
3820 | trace_func_graph_ret_t ftrace_graph_return = | |
3821 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 3822 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
3823 | |
3824 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
3825 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
3826 | { | |
3827 | int i; | |
3828 | int ret = 0; | |
3829 | unsigned long flags; | |
3830 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
3831 | struct task_struct *g, *t; | |
3832 | ||
3833 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
3834 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
3835 | * sizeof(struct ftrace_ret_stack), | |
3836 | GFP_KERNEL); | |
3837 | if (!ret_stack_list[i]) { | |
3838 | start = 0; | |
3839 | end = i; | |
3840 | ret = -ENOMEM; | |
3841 | goto free; | |
3842 | } | |
3843 | } | |
3844 | ||
3845 | read_lock_irqsave(&tasklist_lock, flags); | |
3846 | do_each_thread(g, t) { | |
3847 | if (start == end) { | |
3848 | ret = -EAGAIN; | |
3849 | goto unlock; | |
3850 | } | |
3851 | ||
3852 | if (t->ret_stack == NULL) { | |
380c4b14 | 3853 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 3854 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
3855 | t->curr_ret_stack = -1; |
3856 | /* Make sure the tasks see the -1 first: */ | |
3857 | smp_wmb(); | |
3858 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
3859 | } |
3860 | } while_each_thread(g, t); | |
3861 | ||
3862 | unlock: | |
3863 | read_unlock_irqrestore(&tasklist_lock, flags); | |
3864 | free: | |
3865 | for (i = start; i < end; i++) | |
3866 | kfree(ret_stack_list[i]); | |
3867 | return ret; | |
3868 | } | |
3869 | ||
8aef2d28 | 3870 | static void |
38516ab5 SR |
3871 | ftrace_graph_probe_sched_switch(void *ignore, |
3872 | struct task_struct *prev, struct task_struct *next) | |
8aef2d28 SR |
3873 | { |
3874 | unsigned long long timestamp; | |
3875 | int index; | |
3876 | ||
be6f164a SR |
3877 | /* |
3878 | * Does the user want to count the time a function was asleep. | |
3879 | * If so, do not update the time stamps. | |
3880 | */ | |
3881 | if (trace_flags & TRACE_ITER_SLEEP_TIME) | |
3882 | return; | |
3883 | ||
8aef2d28 SR |
3884 | timestamp = trace_clock_local(); |
3885 | ||
3886 | prev->ftrace_timestamp = timestamp; | |
3887 | ||
3888 | /* only process tasks that we timestamped */ | |
3889 | if (!next->ftrace_timestamp) | |
3890 | return; | |
3891 | ||
3892 | /* | |
3893 | * Update all the counters in next to make up for the | |
3894 | * time next was sleeping. | |
3895 | */ | |
3896 | timestamp -= next->ftrace_timestamp; | |
3897 | ||
3898 | for (index = next->curr_ret_stack; index >= 0; index--) | |
3899 | next->ret_stack[index].calltime += timestamp; | |
3900 | } | |
3901 | ||
f201ae23 | 3902 | /* Allocate a return stack for each task */ |
fb52607a | 3903 | static int start_graph_tracing(void) |
f201ae23 FW |
3904 | { |
3905 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 3906 | int ret, cpu; |
f201ae23 FW |
3907 | |
3908 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
3909 | sizeof(struct ftrace_ret_stack *), | |
3910 | GFP_KERNEL); | |
3911 | ||
3912 | if (!ret_stack_list) | |
3913 | return -ENOMEM; | |
3914 | ||
5b058bcd | 3915 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
3916 | for_each_online_cpu(cpu) { |
3917 | if (!idle_task(cpu)->ret_stack) | |
868baf07 | 3918 | ftrace_graph_init_idle_task(idle_task(cpu), cpu); |
179c498a | 3919 | } |
5b058bcd | 3920 | |
f201ae23 FW |
3921 | do { |
3922 | ret = alloc_retstack_tasklist(ret_stack_list); | |
3923 | } while (ret == -EAGAIN); | |
3924 | ||
8aef2d28 | 3925 | if (!ret) { |
38516ab5 | 3926 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
8aef2d28 SR |
3927 | if (ret) |
3928 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
3929 | " probe to kernel_sched_switch\n"); | |
3930 | } | |
3931 | ||
f201ae23 FW |
3932 | kfree(ret_stack_list); |
3933 | return ret; | |
3934 | } | |
3935 | ||
4a2b8dda FW |
3936 | /* |
3937 | * Hibernation protection. | |
3938 | * The state of the current task is too much unstable during | |
3939 | * suspend/restore to disk. We want to protect against that. | |
3940 | */ | |
3941 | static int | |
3942 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
3943 | void *unused) | |
3944 | { | |
3945 | switch (state) { | |
3946 | case PM_HIBERNATION_PREPARE: | |
3947 | pause_graph_tracing(); | |
3948 | break; | |
3949 | ||
3950 | case PM_POST_HIBERNATION: | |
3951 | unpause_graph_tracing(); | |
3952 | break; | |
3953 | } | |
3954 | return NOTIFY_DONE; | |
3955 | } | |
3956 | ||
287b6e68 FW |
3957 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
3958 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 3959 | { |
e7d3737e FW |
3960 | int ret = 0; |
3961 | ||
e6ea44e9 | 3962 | mutex_lock(&ftrace_lock); |
e7d3737e | 3963 | |
05ce5818 | 3964 | /* we currently allow only one tracer registered at a time */ |
597af815 | 3965 | if (ftrace_graph_active) { |
05ce5818 SR |
3966 | ret = -EBUSY; |
3967 | goto out; | |
3968 | } | |
3969 | ||
4a2b8dda FW |
3970 | ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; |
3971 | register_pm_notifier(&ftrace_suspend_notifier); | |
3972 | ||
597af815 | 3973 | ftrace_graph_active++; |
fb52607a | 3974 | ret = start_graph_tracing(); |
f201ae23 | 3975 | if (ret) { |
597af815 | 3976 | ftrace_graph_active--; |
f201ae23 FW |
3977 | goto out; |
3978 | } | |
e53a6319 | 3979 | |
287b6e68 FW |
3980 | ftrace_graph_return = retfunc; |
3981 | ftrace_graph_entry = entryfunc; | |
e53a6319 | 3982 | |
bd69c30b | 3983 | ftrace_startup(&global_ops, FTRACE_START_FUNC_RET); |
e7d3737e FW |
3984 | |
3985 | out: | |
e6ea44e9 | 3986 | mutex_unlock(&ftrace_lock); |
e7d3737e | 3987 | return ret; |
15e6cb36 FW |
3988 | } |
3989 | ||
fb52607a | 3990 | void unregister_ftrace_graph(void) |
15e6cb36 | 3991 | { |
e6ea44e9 | 3992 | mutex_lock(&ftrace_lock); |
e7d3737e | 3993 | |
597af815 | 3994 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
3995 | goto out; |
3996 | ||
597af815 | 3997 | ftrace_graph_active--; |
287b6e68 | 3998 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 3999 | ftrace_graph_entry = ftrace_graph_entry_stub; |
bd69c30b | 4000 | ftrace_shutdown(&global_ops, FTRACE_STOP_FUNC_RET); |
4a2b8dda | 4001 | unregister_pm_notifier(&ftrace_suspend_notifier); |
38516ab5 | 4002 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
e7d3737e | 4003 | |
2aad1b76 | 4004 | out: |
e6ea44e9 | 4005 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 4006 | } |
f201ae23 | 4007 | |
868baf07 SR |
4008 | static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack); |
4009 | ||
4010 | static void | |
4011 | graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack) | |
4012 | { | |
4013 | atomic_set(&t->tracing_graph_pause, 0); | |
4014 | atomic_set(&t->trace_overrun, 0); | |
4015 | t->ftrace_timestamp = 0; | |
25985edc | 4016 | /* make curr_ret_stack visible before we add the ret_stack */ |
868baf07 SR |
4017 | smp_wmb(); |
4018 | t->ret_stack = ret_stack; | |
4019 | } | |
4020 | ||
4021 | /* | |
4022 | * Allocate a return stack for the idle task. May be the first | |
4023 | * time through, or it may be done by CPU hotplug online. | |
4024 | */ | |
4025 | void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) | |
4026 | { | |
4027 | t->curr_ret_stack = -1; | |
4028 | /* | |
4029 | * The idle task has no parent, it either has its own | |
4030 | * stack or no stack at all. | |
4031 | */ | |
4032 | if (t->ret_stack) | |
4033 | WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu)); | |
4034 | ||
4035 | if (ftrace_graph_active) { | |
4036 | struct ftrace_ret_stack *ret_stack; | |
4037 | ||
4038 | ret_stack = per_cpu(idle_ret_stack, cpu); | |
4039 | if (!ret_stack) { | |
4040 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
4041 | * sizeof(struct ftrace_ret_stack), | |
4042 | GFP_KERNEL); | |
4043 | if (!ret_stack) | |
4044 | return; | |
4045 | per_cpu(idle_ret_stack, cpu) = ret_stack; | |
4046 | } | |
4047 | graph_init_task(t, ret_stack); | |
4048 | } | |
4049 | } | |
4050 | ||
f201ae23 | 4051 | /* Allocate a return stack for newly created task */ |
fb52607a | 4052 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 4053 | { |
84047e36 SR |
4054 | /* Make sure we do not use the parent ret_stack */ |
4055 | t->ret_stack = NULL; | |
ea14eb71 | 4056 | t->curr_ret_stack = -1; |
84047e36 | 4057 | |
597af815 | 4058 | if (ftrace_graph_active) { |
82310a32 SR |
4059 | struct ftrace_ret_stack *ret_stack; |
4060 | ||
4061 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
4062 | * sizeof(struct ftrace_ret_stack), |
4063 | GFP_KERNEL); | |
82310a32 | 4064 | if (!ret_stack) |
f201ae23 | 4065 | return; |
868baf07 | 4066 | graph_init_task(t, ret_stack); |
84047e36 | 4067 | } |
f201ae23 FW |
4068 | } |
4069 | ||
fb52607a | 4070 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 4071 | { |
eae849ca FW |
4072 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
4073 | ||
f201ae23 | 4074 | t->ret_stack = NULL; |
eae849ca FW |
4075 | /* NULL must become visible to IRQs before we free it: */ |
4076 | barrier(); | |
4077 | ||
4078 | kfree(ret_stack); | |
f201ae23 | 4079 | } |
14a866c5 SR |
4080 | |
4081 | void ftrace_graph_stop(void) | |
4082 | { | |
4083 | ftrace_stop(); | |
4084 | } | |
15e6cb36 | 4085 | #endif |