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> |
56d82e00 | 25 | #include <linux/module.h> |
2d8b820b | 26 | #include <linux/ftrace.h> |
b0fc494f | 27 | #include <linux/sysctl.h> |
5a0e3ad6 | 28 | #include <linux/slab.h> |
5072c59f | 29 | #include <linux/ctype.h> |
3d083395 | 30 | #include <linux/list.h> |
59df055f | 31 | #include <linux/hash.h> |
3f379b03 | 32 | #include <linux/rcupdate.h> |
3d083395 | 33 | |
ad8d75ff | 34 | #include <trace/events/sched.h> |
8aef2d28 | 35 | |
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 | |
bd38c0e6 | 85 | static struct ftrace_ops ftrace_list_end __read_mostly = { |
fb9fb015 | 86 | .func = ftrace_stub, |
16444a8a ACM |
87 | }; |
88 | ||
b848914c SR |
89 | static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end; |
90 | static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end; | |
16444a8a | 91 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
6331c28c | 92 | static ftrace_func_t __ftrace_trace_function_delay __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 | { |
b1cff0ad SR |
112 | struct ftrace_ops *op; |
113 | ||
114 | if (unlikely(trace_recursion_test(TRACE_GLOBAL_BIT))) | |
115 | return; | |
16444a8a | 116 | |
b1cff0ad SR |
117 | trace_recursion_set(TRACE_GLOBAL_BIT); |
118 | op = rcu_dereference_raw(ftrace_global_list); /*see above*/ | |
16444a8a | 119 | while (op != &ftrace_list_end) { |
16444a8a | 120 | op->func(ip, parent_ip); |
3f379b03 | 121 | op = rcu_dereference_raw(op->next); /*see above*/ |
16444a8a | 122 | }; |
b1cff0ad | 123 | trace_recursion_clear(TRACE_GLOBAL_BIT); |
16444a8a ACM |
124 | } |
125 | ||
df4fc315 SR |
126 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip) |
127 | { | |
0ef8cde5 | 128 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
129 | return; |
130 | ||
131 | ftrace_pid_function(ip, parent_ip); | |
132 | } | |
133 | ||
134 | static void set_ftrace_pid_function(ftrace_func_t func) | |
135 | { | |
136 | /* do not set ftrace_pid_function to itself! */ | |
137 | if (func != ftrace_pid_func) | |
138 | ftrace_pid_function = func; | |
139 | } | |
140 | ||
16444a8a | 141 | /** |
3d083395 | 142 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 143 | * |
3d083395 SR |
144 | * This NULLs the ftrace function and in essence stops |
145 | * tracing. There may be lag | |
16444a8a | 146 | */ |
3d083395 | 147 | void clear_ftrace_function(void) |
16444a8a | 148 | { |
3d083395 | 149 | ftrace_trace_function = ftrace_stub; |
60a7ecf4 | 150 | __ftrace_trace_function = ftrace_stub; |
6331c28c | 151 | __ftrace_trace_function_delay = ftrace_stub; |
df4fc315 | 152 | ftrace_pid_function = ftrace_stub; |
3d083395 SR |
153 | } |
154 | ||
60a7ecf4 SR |
155 | #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
156 | /* | |
157 | * For those archs that do not test ftrace_trace_stop in their | |
158 | * mcount call site, we need to do it from C. | |
159 | */ | |
160 | static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip) | |
161 | { | |
162 | if (function_trace_stop) | |
163 | return; | |
164 | ||
165 | __ftrace_trace_function(ip, parent_ip); | |
166 | } | |
167 | #endif | |
168 | ||
2b499381 | 169 | static void update_global_ops(void) |
491d0dcf SR |
170 | { |
171 | ftrace_func_t func; | |
172 | ||
173 | /* | |
174 | * If there's only one function registered, then call that | |
175 | * function directly. Otherwise, we need to iterate over the | |
176 | * registered callers. | |
177 | */ | |
b848914c SR |
178 | if (ftrace_global_list == &ftrace_list_end || |
179 | ftrace_global_list->next == &ftrace_list_end) | |
180 | func = ftrace_global_list->func; | |
491d0dcf | 181 | else |
b848914c | 182 | func = ftrace_global_list_func; |
491d0dcf SR |
183 | |
184 | /* If we filter on pids, update to use the pid function */ | |
185 | if (!list_empty(&ftrace_pids)) { | |
186 | set_ftrace_pid_function(func); | |
187 | func = ftrace_pid_func; | |
188 | } | |
2b499381 SR |
189 | |
190 | global_ops.func = func; | |
191 | } | |
192 | ||
193 | static void update_ftrace_function(void) | |
194 | { | |
195 | ftrace_func_t func; | |
196 | ||
197 | update_global_ops(); | |
198 | ||
cdbe61bf SR |
199 | /* |
200 | * If we are at the end of the list and this ops is | |
201 | * not dynamic, then have the mcount trampoline call | |
202 | * the function directly | |
203 | */ | |
b848914c | 204 | if (ftrace_ops_list == &ftrace_list_end || |
cdbe61bf SR |
205 | (ftrace_ops_list->next == &ftrace_list_end && |
206 | !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC))) | |
b848914c SR |
207 | func = ftrace_ops_list->func; |
208 | else | |
209 | func = ftrace_ops_list_func; | |
2b499381 | 210 | |
491d0dcf SR |
211 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
212 | ftrace_trace_function = func; | |
6331c28c SR |
213 | #else |
214 | #ifdef CONFIG_DYNAMIC_FTRACE | |
215 | /* do not update till all functions have been modified */ | |
216 | __ftrace_trace_function_delay = func; | |
491d0dcf SR |
217 | #else |
218 | __ftrace_trace_function = func; | |
6331c28c | 219 | #endif |
491d0dcf SR |
220 | ftrace_trace_function = ftrace_test_stop_func; |
221 | #endif | |
222 | } | |
223 | ||
2b499381 | 224 | static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
3d083395 | 225 | { |
2b499381 | 226 | ops->next = *list; |
16444a8a | 227 | /* |
b848914c | 228 | * We are entering ops into the list but another |
16444a8a ACM |
229 | * CPU might be walking that list. We need to make sure |
230 | * the ops->next pointer is valid before another CPU sees | |
b848914c | 231 | * the ops pointer included into the list. |
16444a8a | 232 | */ |
2b499381 | 233 | rcu_assign_pointer(*list, ops); |
16444a8a ACM |
234 | } |
235 | ||
2b499381 | 236 | static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
16444a8a | 237 | { |
16444a8a | 238 | struct ftrace_ops **p; |
16444a8a ACM |
239 | |
240 | /* | |
3d083395 SR |
241 | * If we are removing the last function, then simply point |
242 | * to the ftrace_stub. | |
16444a8a | 243 | */ |
2b499381 SR |
244 | if (*list == ops && ops->next == &ftrace_list_end) { |
245 | *list = &ftrace_list_end; | |
e6ea44e9 | 246 | return 0; |
16444a8a ACM |
247 | } |
248 | ||
2b499381 | 249 | for (p = list; *p != &ftrace_list_end; p = &(*p)->next) |
16444a8a ACM |
250 | if (*p == ops) |
251 | break; | |
252 | ||
e6ea44e9 SR |
253 | if (*p != ops) |
254 | return -1; | |
16444a8a ACM |
255 | |
256 | *p = (*p)->next; | |
2b499381 SR |
257 | return 0; |
258 | } | |
16444a8a | 259 | |
2b499381 SR |
260 | static int __register_ftrace_function(struct ftrace_ops *ops) |
261 | { | |
262 | if (ftrace_disabled) | |
263 | return -ENODEV; | |
264 | ||
265 | if (FTRACE_WARN_ON(ops == &global_ops)) | |
266 | return -EINVAL; | |
267 | ||
b848914c SR |
268 | if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) |
269 | return -EBUSY; | |
270 | ||
cdbe61bf SR |
271 | if (!core_kernel_data((unsigned long)ops)) |
272 | ops->flags |= FTRACE_OPS_FL_DYNAMIC; | |
273 | ||
b848914c SR |
274 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { |
275 | int first = ftrace_global_list == &ftrace_list_end; | |
276 | add_ftrace_ops(&ftrace_global_list, ops); | |
277 | ops->flags |= FTRACE_OPS_FL_ENABLED; | |
278 | if (first) | |
279 | add_ftrace_ops(&ftrace_ops_list, &global_ops); | |
280 | } else | |
281 | add_ftrace_ops(&ftrace_ops_list, ops); | |
282 | ||
2b499381 SR |
283 | if (ftrace_enabled) |
284 | update_ftrace_function(); | |
285 | ||
286 | return 0; | |
287 | } | |
288 | ||
289 | static int __unregister_ftrace_function(struct ftrace_ops *ops) | |
290 | { | |
291 | int ret; | |
292 | ||
293 | if (ftrace_disabled) | |
294 | return -ENODEV; | |
295 | ||
b848914c SR |
296 | if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) |
297 | return -EBUSY; | |
298 | ||
2b499381 SR |
299 | if (FTRACE_WARN_ON(ops == &global_ops)) |
300 | return -EINVAL; | |
301 | ||
b848914c SR |
302 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { |
303 | ret = remove_ftrace_ops(&ftrace_global_list, ops); | |
304 | if (!ret && ftrace_global_list == &ftrace_list_end) | |
305 | ret = remove_ftrace_ops(&ftrace_ops_list, &global_ops); | |
306 | if (!ret) | |
307 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; | |
308 | } else | |
309 | ret = remove_ftrace_ops(&ftrace_ops_list, ops); | |
310 | ||
2b499381 SR |
311 | if (ret < 0) |
312 | return ret; | |
b848914c | 313 | |
491d0dcf SR |
314 | if (ftrace_enabled) |
315 | update_ftrace_function(); | |
16444a8a | 316 | |
cdbe61bf SR |
317 | /* |
318 | * Dynamic ops may be freed, we must make sure that all | |
319 | * callers are done before leaving this function. | |
320 | */ | |
321 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) | |
322 | synchronize_sched(); | |
323 | ||
e6ea44e9 | 324 | return 0; |
3d083395 SR |
325 | } |
326 | ||
df4fc315 SR |
327 | static void ftrace_update_pid_func(void) |
328 | { | |
491d0dcf | 329 | /* Only do something if we are tracing something */ |
df4fc315 | 330 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 331 | return; |
df4fc315 | 332 | |
491d0dcf | 333 | update_ftrace_function(); |
df4fc315 SR |
334 | } |
335 | ||
493762fc SR |
336 | #ifdef CONFIG_FUNCTION_PROFILER |
337 | struct ftrace_profile { | |
338 | struct hlist_node node; | |
339 | unsigned long ip; | |
340 | unsigned long counter; | |
0706f1c4 SR |
341 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
342 | unsigned long long time; | |
e330b3bc | 343 | unsigned long long time_squared; |
0706f1c4 | 344 | #endif |
8fc0c701 SR |
345 | }; |
346 | ||
493762fc SR |
347 | struct ftrace_profile_page { |
348 | struct ftrace_profile_page *next; | |
349 | unsigned long index; | |
350 | struct ftrace_profile records[]; | |
d61f82d0 SR |
351 | }; |
352 | ||
cafb168a SR |
353 | struct ftrace_profile_stat { |
354 | atomic_t disabled; | |
355 | struct hlist_head *hash; | |
356 | struct ftrace_profile_page *pages; | |
357 | struct ftrace_profile_page *start; | |
358 | struct tracer_stat stat; | |
359 | }; | |
360 | ||
493762fc SR |
361 | #define PROFILE_RECORDS_SIZE \ |
362 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 363 | |
493762fc SR |
364 | #define PROFILES_PER_PAGE \ |
365 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 366 | |
fb9fb015 SR |
367 | static int ftrace_profile_bits __read_mostly; |
368 | static int ftrace_profile_enabled __read_mostly; | |
369 | ||
370 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
371 | static DEFINE_MUTEX(ftrace_profile_lock); |
372 | ||
cafb168a | 373 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc SR |
374 | |
375 | #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */ | |
376 | ||
bac429f0 SR |
377 | static void * |
378 | function_stat_next(void *v, int idx) | |
379 | { | |
493762fc SR |
380 | struct ftrace_profile *rec = v; |
381 | struct ftrace_profile_page *pg; | |
bac429f0 | 382 | |
493762fc | 383 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
384 | |
385 | again: | |
0296e425 LZ |
386 | if (idx != 0) |
387 | rec++; | |
388 | ||
bac429f0 SR |
389 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
390 | pg = pg->next; | |
391 | if (!pg) | |
392 | return NULL; | |
393 | rec = &pg->records[0]; | |
493762fc SR |
394 | if (!rec->counter) |
395 | goto again; | |
bac429f0 SR |
396 | } |
397 | ||
bac429f0 SR |
398 | return rec; |
399 | } | |
400 | ||
401 | static void *function_stat_start(struct tracer_stat *trace) | |
402 | { | |
cafb168a SR |
403 | struct ftrace_profile_stat *stat = |
404 | container_of(trace, struct ftrace_profile_stat, stat); | |
405 | ||
406 | if (!stat || !stat->start) | |
407 | return NULL; | |
408 | ||
409 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
410 | } |
411 | ||
0706f1c4 SR |
412 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
413 | /* function graph compares on total time */ | |
414 | static int function_stat_cmp(void *p1, void *p2) | |
415 | { | |
416 | struct ftrace_profile *a = p1; | |
417 | struct ftrace_profile *b = p2; | |
418 | ||
419 | if (a->time < b->time) | |
420 | return -1; | |
421 | if (a->time > b->time) | |
422 | return 1; | |
423 | else | |
424 | return 0; | |
425 | } | |
426 | #else | |
427 | /* not function graph compares against hits */ | |
bac429f0 SR |
428 | static int function_stat_cmp(void *p1, void *p2) |
429 | { | |
493762fc SR |
430 | struct ftrace_profile *a = p1; |
431 | struct ftrace_profile *b = p2; | |
bac429f0 SR |
432 | |
433 | if (a->counter < b->counter) | |
434 | return -1; | |
435 | if (a->counter > b->counter) | |
436 | return 1; | |
437 | else | |
438 | return 0; | |
439 | } | |
0706f1c4 | 440 | #endif |
bac429f0 SR |
441 | |
442 | static int function_stat_headers(struct seq_file *m) | |
443 | { | |
0706f1c4 | 444 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b | 445 | seq_printf(m, " Function " |
e330b3bc | 446 | "Hit Time Avg s^2\n" |
34886c8b | 447 | " -------- " |
e330b3bc | 448 | "--- ---- --- ---\n"); |
0706f1c4 | 449 | #else |
bac429f0 SR |
450 | seq_printf(m, " Function Hit\n" |
451 | " -------- ---\n"); | |
0706f1c4 | 452 | #endif |
bac429f0 SR |
453 | return 0; |
454 | } | |
455 | ||
456 | static int function_stat_show(struct seq_file *m, void *v) | |
457 | { | |
493762fc | 458 | struct ftrace_profile *rec = v; |
bac429f0 | 459 | char str[KSYM_SYMBOL_LEN]; |
3aaba20f | 460 | int ret = 0; |
0706f1c4 | 461 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
462 | static struct trace_seq s; |
463 | unsigned long long avg; | |
e330b3bc | 464 | unsigned long long stddev; |
0706f1c4 | 465 | #endif |
3aaba20f LZ |
466 | mutex_lock(&ftrace_profile_lock); |
467 | ||
468 | /* we raced with function_profile_reset() */ | |
469 | if (unlikely(rec->counter == 0)) { | |
470 | ret = -EBUSY; | |
471 | goto out; | |
472 | } | |
bac429f0 SR |
473 | |
474 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
0706f1c4 SR |
475 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
476 | ||
477 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
478 | seq_printf(m, " "); | |
34886c8b SR |
479 | avg = rec->time; |
480 | do_div(avg, rec->counter); | |
481 | ||
e330b3bc CD |
482 | /* Sample standard deviation (s^2) */ |
483 | if (rec->counter <= 1) | |
484 | stddev = 0; | |
485 | else { | |
486 | stddev = rec->time_squared - rec->counter * avg * avg; | |
487 | /* | |
488 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
489 | * trace_print_graph_duration will divide 1000 again. | |
490 | */ | |
491 | do_div(stddev, (rec->counter - 1) * 1000); | |
492 | } | |
493 | ||
34886c8b SR |
494 | trace_seq_init(&s); |
495 | trace_print_graph_duration(rec->time, &s); | |
496 | trace_seq_puts(&s, " "); | |
497 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
498 | trace_seq_puts(&s, " "); |
499 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 | 500 | trace_print_seq(m, &s); |
0706f1c4 SR |
501 | #endif |
502 | seq_putc(m, '\n'); | |
3aaba20f LZ |
503 | out: |
504 | mutex_unlock(&ftrace_profile_lock); | |
bac429f0 | 505 | |
3aaba20f | 506 | return ret; |
bac429f0 SR |
507 | } |
508 | ||
cafb168a | 509 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 510 | { |
493762fc | 511 | struct ftrace_profile_page *pg; |
bac429f0 | 512 | |
cafb168a | 513 | pg = stat->pages = stat->start; |
bac429f0 | 514 | |
493762fc SR |
515 | while (pg) { |
516 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
517 | pg->index = 0; | |
518 | pg = pg->next; | |
bac429f0 SR |
519 | } |
520 | ||
cafb168a | 521 | memset(stat->hash, 0, |
493762fc SR |
522 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
523 | } | |
bac429f0 | 524 | |
cafb168a | 525 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
526 | { |
527 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
528 | int functions; |
529 | int pages; | |
493762fc | 530 | int i; |
bac429f0 | 531 | |
493762fc | 532 | /* If we already allocated, do nothing */ |
cafb168a | 533 | if (stat->pages) |
493762fc | 534 | return 0; |
bac429f0 | 535 | |
cafb168a SR |
536 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
537 | if (!stat->pages) | |
493762fc | 538 | return -ENOMEM; |
bac429f0 | 539 | |
318e0a73 SR |
540 | #ifdef CONFIG_DYNAMIC_FTRACE |
541 | functions = ftrace_update_tot_cnt; | |
542 | #else | |
543 | /* | |
544 | * We do not know the number of functions that exist because | |
545 | * dynamic tracing is what counts them. With past experience | |
546 | * we have around 20K functions. That should be more than enough. | |
547 | * It is highly unlikely we will execute every function in | |
548 | * the kernel. | |
549 | */ | |
550 | functions = 20000; | |
551 | #endif | |
552 | ||
cafb168a | 553 | pg = stat->start = stat->pages; |
bac429f0 | 554 | |
318e0a73 SR |
555 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
556 | ||
557 | for (i = 0; i < pages; i++) { | |
493762fc | 558 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 559 | if (!pg->next) |
318e0a73 | 560 | goto out_free; |
493762fc SR |
561 | pg = pg->next; |
562 | } | |
563 | ||
564 | return 0; | |
318e0a73 SR |
565 | |
566 | out_free: | |
567 | pg = stat->start; | |
568 | while (pg) { | |
569 | unsigned long tmp = (unsigned long)pg; | |
570 | ||
571 | pg = pg->next; | |
572 | free_page(tmp); | |
573 | } | |
574 | ||
575 | free_page((unsigned long)stat->pages); | |
576 | stat->pages = NULL; | |
577 | stat->start = NULL; | |
578 | ||
579 | return -ENOMEM; | |
bac429f0 SR |
580 | } |
581 | ||
cafb168a | 582 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 583 | { |
cafb168a | 584 | struct ftrace_profile_stat *stat; |
493762fc | 585 | int size; |
bac429f0 | 586 | |
cafb168a SR |
587 | stat = &per_cpu(ftrace_profile_stats, cpu); |
588 | ||
589 | if (stat->hash) { | |
493762fc | 590 | /* If the profile is already created, simply reset it */ |
cafb168a | 591 | ftrace_profile_reset(stat); |
493762fc SR |
592 | return 0; |
593 | } | |
bac429f0 | 594 | |
493762fc SR |
595 | /* |
596 | * We are profiling all functions, but usually only a few thousand | |
597 | * functions are hit. We'll make a hash of 1024 items. | |
598 | */ | |
599 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 600 | |
cafb168a | 601 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
493762fc | 602 | |
cafb168a | 603 | if (!stat->hash) |
493762fc SR |
604 | return -ENOMEM; |
605 | ||
cafb168a SR |
606 | if (!ftrace_profile_bits) { |
607 | size--; | |
493762fc | 608 | |
cafb168a SR |
609 | for (; size; size >>= 1) |
610 | ftrace_profile_bits++; | |
611 | } | |
493762fc | 612 | |
318e0a73 | 613 | /* Preallocate the function profiling pages */ |
cafb168a SR |
614 | if (ftrace_profile_pages_init(stat) < 0) { |
615 | kfree(stat->hash); | |
616 | stat->hash = NULL; | |
493762fc SR |
617 | return -ENOMEM; |
618 | } | |
619 | ||
620 | return 0; | |
bac429f0 SR |
621 | } |
622 | ||
cafb168a SR |
623 | static int ftrace_profile_init(void) |
624 | { | |
625 | int cpu; | |
626 | int ret = 0; | |
627 | ||
628 | for_each_online_cpu(cpu) { | |
629 | ret = ftrace_profile_init_cpu(cpu); | |
630 | if (ret) | |
631 | break; | |
632 | } | |
633 | ||
634 | return ret; | |
635 | } | |
636 | ||
493762fc | 637 | /* interrupts must be disabled */ |
cafb168a SR |
638 | static struct ftrace_profile * |
639 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 640 | { |
493762fc | 641 | struct ftrace_profile *rec; |
bac429f0 SR |
642 | struct hlist_head *hhd; |
643 | struct hlist_node *n; | |
bac429f0 SR |
644 | unsigned long key; |
645 | ||
bac429f0 | 646 | key = hash_long(ip, ftrace_profile_bits); |
cafb168a | 647 | hhd = &stat->hash[key]; |
bac429f0 SR |
648 | |
649 | if (hlist_empty(hhd)) | |
650 | return NULL; | |
651 | ||
bac429f0 SR |
652 | hlist_for_each_entry_rcu(rec, n, hhd, node) { |
653 | if (rec->ip == ip) | |
493762fc SR |
654 | return rec; |
655 | } | |
656 | ||
657 | return NULL; | |
658 | } | |
659 | ||
cafb168a SR |
660 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
661 | struct ftrace_profile *rec) | |
493762fc SR |
662 | { |
663 | unsigned long key; | |
664 | ||
665 | key = hash_long(rec->ip, ftrace_profile_bits); | |
cafb168a | 666 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
667 | } |
668 | ||
318e0a73 SR |
669 | /* |
670 | * The memory is already allocated, this simply finds a new record to use. | |
671 | */ | |
493762fc | 672 | static struct ftrace_profile * |
318e0a73 | 673 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
674 | { |
675 | struct ftrace_profile *rec = NULL; | |
676 | ||
318e0a73 | 677 | /* prevent recursion (from NMIs) */ |
cafb168a | 678 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
679 | goto out; |
680 | ||
493762fc | 681 | /* |
318e0a73 SR |
682 | * Try to find the function again since an NMI |
683 | * could have added it | |
493762fc | 684 | */ |
cafb168a | 685 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 686 | if (rec) |
cafb168a | 687 | goto out; |
493762fc | 688 | |
cafb168a SR |
689 | if (stat->pages->index == PROFILES_PER_PAGE) { |
690 | if (!stat->pages->next) | |
691 | goto out; | |
692 | stat->pages = stat->pages->next; | |
bac429f0 | 693 | } |
493762fc | 694 | |
cafb168a | 695 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 696 | rec->ip = ip; |
cafb168a | 697 | ftrace_add_profile(stat, rec); |
493762fc | 698 | |
bac429f0 | 699 | out: |
cafb168a | 700 | atomic_dec(&stat->disabled); |
bac429f0 SR |
701 | |
702 | return rec; | |
703 | } | |
704 | ||
705 | static void | |
706 | function_profile_call(unsigned long ip, unsigned long parent_ip) | |
707 | { | |
cafb168a | 708 | struct ftrace_profile_stat *stat; |
493762fc | 709 | struct ftrace_profile *rec; |
bac429f0 SR |
710 | unsigned long flags; |
711 | ||
712 | if (!ftrace_profile_enabled) | |
713 | return; | |
714 | ||
715 | local_irq_save(flags); | |
cafb168a SR |
716 | |
717 | stat = &__get_cpu_var(ftrace_profile_stats); | |
0f6ce3de | 718 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
719 | goto out; |
720 | ||
721 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 722 | if (!rec) { |
318e0a73 | 723 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
724 | if (!rec) |
725 | goto out; | |
726 | } | |
bac429f0 SR |
727 | |
728 | rec->counter++; | |
729 | out: | |
730 | local_irq_restore(flags); | |
731 | } | |
732 | ||
0706f1c4 SR |
733 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
734 | static int profile_graph_entry(struct ftrace_graph_ent *trace) | |
735 | { | |
736 | function_profile_call(trace->func, 0); | |
737 | return 1; | |
738 | } | |
739 | ||
740 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
741 | { | |
cafb168a | 742 | struct ftrace_profile_stat *stat; |
a2a16d6a | 743 | unsigned long long calltime; |
0706f1c4 | 744 | struct ftrace_profile *rec; |
cafb168a | 745 | unsigned long flags; |
0706f1c4 SR |
746 | |
747 | local_irq_save(flags); | |
cafb168a | 748 | stat = &__get_cpu_var(ftrace_profile_stats); |
0f6ce3de | 749 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
750 | goto out; |
751 | ||
37e44bc5 SR |
752 | /* If the calltime was zero'd ignore it */ |
753 | if (!trace->calltime) | |
754 | goto out; | |
755 | ||
a2a16d6a SR |
756 | calltime = trace->rettime - trace->calltime; |
757 | ||
758 | if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) { | |
759 | int index; | |
760 | ||
761 | index = trace->depth; | |
762 | ||
763 | /* Append this call time to the parent time to subtract */ | |
764 | if (index) | |
765 | current->ret_stack[index - 1].subtime += calltime; | |
766 | ||
767 | if (current->ret_stack[index].subtime < calltime) | |
768 | calltime -= current->ret_stack[index].subtime; | |
769 | else | |
770 | calltime = 0; | |
771 | } | |
772 | ||
cafb168a | 773 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 774 | if (rec) { |
a2a16d6a | 775 | rec->time += calltime; |
e330b3bc CD |
776 | rec->time_squared += calltime * calltime; |
777 | } | |
a2a16d6a | 778 | |
cafb168a | 779 | out: |
0706f1c4 SR |
780 | local_irq_restore(flags); |
781 | } | |
782 | ||
783 | static int register_ftrace_profiler(void) | |
784 | { | |
785 | return register_ftrace_graph(&profile_graph_return, | |
786 | &profile_graph_entry); | |
787 | } | |
788 | ||
789 | static void unregister_ftrace_profiler(void) | |
790 | { | |
791 | unregister_ftrace_graph(); | |
792 | } | |
793 | #else | |
bd38c0e6 | 794 | static struct ftrace_ops ftrace_profile_ops __read_mostly = { |
fb9fb015 | 795 | .func = function_profile_call, |
bac429f0 SR |
796 | }; |
797 | ||
0706f1c4 SR |
798 | static int register_ftrace_profiler(void) |
799 | { | |
800 | return register_ftrace_function(&ftrace_profile_ops); | |
801 | } | |
802 | ||
803 | static void unregister_ftrace_profiler(void) | |
804 | { | |
805 | unregister_ftrace_function(&ftrace_profile_ops); | |
806 | } | |
807 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
808 | ||
bac429f0 SR |
809 | static ssize_t |
810 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
811 | size_t cnt, loff_t *ppos) | |
812 | { | |
813 | unsigned long val; | |
bac429f0 SR |
814 | int ret; |
815 | ||
22fe9b54 PH |
816 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
817 | if (ret) | |
bac429f0 SR |
818 | return ret; |
819 | ||
820 | val = !!val; | |
821 | ||
822 | mutex_lock(&ftrace_profile_lock); | |
823 | if (ftrace_profile_enabled ^ val) { | |
824 | if (val) { | |
493762fc SR |
825 | ret = ftrace_profile_init(); |
826 | if (ret < 0) { | |
827 | cnt = ret; | |
828 | goto out; | |
829 | } | |
830 | ||
0706f1c4 SR |
831 | ret = register_ftrace_profiler(); |
832 | if (ret < 0) { | |
833 | cnt = ret; | |
834 | goto out; | |
835 | } | |
bac429f0 SR |
836 | ftrace_profile_enabled = 1; |
837 | } else { | |
838 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
839 | /* |
840 | * unregister_ftrace_profiler calls stop_machine | |
841 | * so this acts like an synchronize_sched. | |
842 | */ | |
0706f1c4 | 843 | unregister_ftrace_profiler(); |
bac429f0 SR |
844 | } |
845 | } | |
493762fc | 846 | out: |
bac429f0 SR |
847 | mutex_unlock(&ftrace_profile_lock); |
848 | ||
cf8517cf | 849 | *ppos += cnt; |
bac429f0 SR |
850 | |
851 | return cnt; | |
852 | } | |
853 | ||
493762fc SR |
854 | static ssize_t |
855 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
856 | size_t cnt, loff_t *ppos) | |
857 | { | |
fb9fb015 | 858 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
859 | int r; |
860 | ||
861 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
862 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
863 | } | |
864 | ||
bac429f0 SR |
865 | static const struct file_operations ftrace_profile_fops = { |
866 | .open = tracing_open_generic, | |
867 | .read = ftrace_profile_read, | |
868 | .write = ftrace_profile_write, | |
6038f373 | 869 | .llseek = default_llseek, |
bac429f0 SR |
870 | }; |
871 | ||
cafb168a SR |
872 | /* used to initialize the real stat files */ |
873 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
874 | .name = "functions", |
875 | .stat_start = function_stat_start, | |
876 | .stat_next = function_stat_next, | |
877 | .stat_cmp = function_stat_cmp, | |
878 | .stat_headers = function_stat_headers, | |
879 | .stat_show = function_stat_show | |
cafb168a SR |
880 | }; |
881 | ||
6ab5d668 | 882 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 | 883 | { |
cafb168a | 884 | struct ftrace_profile_stat *stat; |
bac429f0 | 885 | struct dentry *entry; |
cafb168a | 886 | char *name; |
bac429f0 | 887 | int ret; |
cafb168a SR |
888 | int cpu; |
889 | ||
890 | for_each_possible_cpu(cpu) { | |
891 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
892 | ||
893 | /* allocate enough for function name + cpu number */ | |
894 | name = kmalloc(32, GFP_KERNEL); | |
895 | if (!name) { | |
896 | /* | |
897 | * The files created are permanent, if something happens | |
898 | * we still do not free memory. | |
899 | */ | |
cafb168a SR |
900 | WARN(1, |
901 | "Could not allocate stat file for cpu %d\n", | |
902 | cpu); | |
903 | return; | |
904 | } | |
905 | stat->stat = function_stats; | |
906 | snprintf(name, 32, "function%d", cpu); | |
907 | stat->stat.name = name; | |
908 | ret = register_stat_tracer(&stat->stat); | |
909 | if (ret) { | |
910 | WARN(1, | |
911 | "Could not register function stat for cpu %d\n", | |
912 | cpu); | |
913 | kfree(name); | |
914 | return; | |
915 | } | |
bac429f0 SR |
916 | } |
917 | ||
918 | entry = debugfs_create_file("function_profile_enabled", 0644, | |
919 | d_tracer, NULL, &ftrace_profile_fops); | |
920 | if (!entry) | |
921 | pr_warning("Could not create debugfs " | |
922 | "'function_profile_enabled' entry\n"); | |
923 | } | |
924 | ||
bac429f0 | 925 | #else /* CONFIG_FUNCTION_PROFILER */ |
6ab5d668 | 926 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 SR |
927 | { |
928 | } | |
bac429f0 SR |
929 | #endif /* CONFIG_FUNCTION_PROFILER */ |
930 | ||
493762fc SR |
931 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; |
932 | ||
933 | #ifdef CONFIG_DYNAMIC_FTRACE | |
934 | ||
935 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD | |
936 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
937 | #endif | |
938 | ||
939 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; | |
940 | ||
941 | struct ftrace_func_probe { | |
942 | struct hlist_node node; | |
943 | struct ftrace_probe_ops *ops; | |
944 | unsigned long flags; | |
945 | unsigned long ip; | |
946 | void *data; | |
947 | struct rcu_head rcu; | |
948 | }; | |
949 | ||
b448c4e3 SR |
950 | struct ftrace_func_entry { |
951 | struct hlist_node hlist; | |
952 | unsigned long ip; | |
953 | }; | |
954 | ||
955 | struct ftrace_hash { | |
956 | unsigned long size_bits; | |
957 | struct hlist_head *buckets; | |
958 | unsigned long count; | |
07fd5515 | 959 | struct rcu_head rcu; |
b448c4e3 SR |
960 | }; |
961 | ||
33dc9b12 SR |
962 | /* |
963 | * We make these constant because no one should touch them, | |
964 | * but they are used as the default "empty hash", to avoid allocating | |
965 | * it all the time. These are in a read only section such that if | |
966 | * anyone does try to modify it, it will cause an exception. | |
967 | */ | |
968 | static const struct hlist_head empty_buckets[1]; | |
969 | static const struct ftrace_hash empty_hash = { | |
970 | .buckets = (struct hlist_head *)empty_buckets, | |
1cf41dd7 | 971 | }; |
33dc9b12 | 972 | #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) |
493762fc | 973 | |
2b499381 | 974 | static struct ftrace_ops global_ops = { |
f45948e8 | 975 | .func = ftrace_stub, |
33dc9b12 SR |
976 | .notrace_hash = EMPTY_HASH, |
977 | .filter_hash = EMPTY_HASH, | |
f45948e8 SR |
978 | }; |
979 | ||
493762fc SR |
980 | static struct dyn_ftrace *ftrace_new_addrs; |
981 | ||
982 | static DEFINE_MUTEX(ftrace_regex_lock); | |
983 | ||
984 | struct ftrace_page { | |
985 | struct ftrace_page *next; | |
986 | int index; | |
987 | struct dyn_ftrace records[]; | |
988 | }; | |
989 | ||
990 | #define ENTRIES_PER_PAGE \ | |
991 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
992 | ||
993 | /* estimate from running different kernels */ | |
994 | #define NR_TO_INIT 10000 | |
995 | ||
996 | static struct ftrace_page *ftrace_pages_start; | |
997 | static struct ftrace_page *ftrace_pages; | |
998 | ||
b448c4e3 SR |
999 | static struct ftrace_func_entry * |
1000 | ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
1001 | { | |
1002 | unsigned long key; | |
1003 | struct ftrace_func_entry *entry; | |
1004 | struct hlist_head *hhd; | |
1005 | struct hlist_node *n; | |
1006 | ||
1007 | if (!hash->count) | |
1008 | return NULL; | |
1009 | ||
1010 | if (hash->size_bits > 0) | |
1011 | key = hash_long(ip, hash->size_bits); | |
1012 | else | |
1013 | key = 0; | |
1014 | ||
1015 | hhd = &hash->buckets[key]; | |
1016 | ||
1017 | hlist_for_each_entry_rcu(entry, n, hhd, hlist) { | |
1018 | if (entry->ip == ip) | |
1019 | return entry; | |
1020 | } | |
1021 | return NULL; | |
1022 | } | |
1023 | ||
33dc9b12 SR |
1024 | static void __add_hash_entry(struct ftrace_hash *hash, |
1025 | struct ftrace_func_entry *entry) | |
b448c4e3 | 1026 | { |
b448c4e3 SR |
1027 | struct hlist_head *hhd; |
1028 | unsigned long key; | |
1029 | ||
b448c4e3 | 1030 | if (hash->size_bits) |
33dc9b12 | 1031 | key = hash_long(entry->ip, hash->size_bits); |
b448c4e3 SR |
1032 | else |
1033 | key = 0; | |
1034 | ||
b448c4e3 SR |
1035 | hhd = &hash->buckets[key]; |
1036 | hlist_add_head(&entry->hlist, hhd); | |
1037 | hash->count++; | |
33dc9b12 SR |
1038 | } |
1039 | ||
1040 | static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip) | |
1041 | { | |
1042 | struct ftrace_func_entry *entry; | |
1043 | ||
1044 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1045 | if (!entry) | |
1046 | return -ENOMEM; | |
1047 | ||
1048 | entry->ip = ip; | |
1049 | __add_hash_entry(hash, entry); | |
b448c4e3 SR |
1050 | |
1051 | return 0; | |
1052 | } | |
1053 | ||
1054 | static void | |
33dc9b12 | 1055 | free_hash_entry(struct ftrace_hash *hash, |
b448c4e3 SR |
1056 | struct ftrace_func_entry *entry) |
1057 | { | |
1058 | hlist_del(&entry->hlist); | |
1059 | kfree(entry); | |
1060 | hash->count--; | |
1061 | } | |
1062 | ||
33dc9b12 SR |
1063 | static void |
1064 | remove_hash_entry(struct ftrace_hash *hash, | |
1065 | struct ftrace_func_entry *entry) | |
1066 | { | |
1067 | hlist_del(&entry->hlist); | |
1068 | hash->count--; | |
1069 | } | |
1070 | ||
b448c4e3 SR |
1071 | static void ftrace_hash_clear(struct ftrace_hash *hash) |
1072 | { | |
1073 | struct hlist_head *hhd; | |
1074 | struct hlist_node *tp, *tn; | |
1075 | struct ftrace_func_entry *entry; | |
1076 | int size = 1 << hash->size_bits; | |
1077 | int i; | |
1078 | ||
33dc9b12 SR |
1079 | if (!hash->count) |
1080 | return; | |
1081 | ||
b448c4e3 SR |
1082 | for (i = 0; i < size; i++) { |
1083 | hhd = &hash->buckets[i]; | |
1084 | hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist) | |
33dc9b12 | 1085 | free_hash_entry(hash, entry); |
b448c4e3 SR |
1086 | } |
1087 | FTRACE_WARN_ON(hash->count); | |
1088 | } | |
1089 | ||
33dc9b12 SR |
1090 | static void free_ftrace_hash(struct ftrace_hash *hash) |
1091 | { | |
1092 | if (!hash || hash == EMPTY_HASH) | |
1093 | return; | |
1094 | ftrace_hash_clear(hash); | |
1095 | kfree(hash->buckets); | |
1096 | kfree(hash); | |
1097 | } | |
1098 | ||
07fd5515 SR |
1099 | static void __free_ftrace_hash_rcu(struct rcu_head *rcu) |
1100 | { | |
1101 | struct ftrace_hash *hash; | |
1102 | ||
1103 | hash = container_of(rcu, struct ftrace_hash, rcu); | |
1104 | free_ftrace_hash(hash); | |
1105 | } | |
1106 | ||
1107 | static void free_ftrace_hash_rcu(struct ftrace_hash *hash) | |
1108 | { | |
1109 | if (!hash || hash == EMPTY_HASH) | |
1110 | return; | |
1111 | call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu); | |
1112 | } | |
1113 | ||
33dc9b12 SR |
1114 | static struct ftrace_hash *alloc_ftrace_hash(int size_bits) |
1115 | { | |
1116 | struct ftrace_hash *hash; | |
1117 | int size; | |
1118 | ||
1119 | hash = kzalloc(sizeof(*hash), GFP_KERNEL); | |
1120 | if (!hash) | |
1121 | return NULL; | |
1122 | ||
1123 | size = 1 << size_bits; | |
1124 | hash->buckets = kzalloc(sizeof(*hash->buckets) * size, GFP_KERNEL); | |
1125 | ||
1126 | if (!hash->buckets) { | |
1127 | kfree(hash); | |
1128 | return NULL; | |
1129 | } | |
1130 | ||
1131 | hash->size_bits = size_bits; | |
1132 | ||
1133 | return hash; | |
1134 | } | |
1135 | ||
1136 | static struct ftrace_hash * | |
1137 | alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) | |
1138 | { | |
1139 | struct ftrace_func_entry *entry; | |
1140 | struct ftrace_hash *new_hash; | |
1141 | struct hlist_node *tp; | |
1142 | int size; | |
1143 | int ret; | |
1144 | int i; | |
1145 | ||
1146 | new_hash = alloc_ftrace_hash(size_bits); | |
1147 | if (!new_hash) | |
1148 | return NULL; | |
1149 | ||
1150 | /* Empty hash? */ | |
1151 | if (!hash || !hash->count) | |
1152 | return new_hash; | |
1153 | ||
1154 | size = 1 << hash->size_bits; | |
1155 | for (i = 0; i < size; i++) { | |
1156 | hlist_for_each_entry(entry, tp, &hash->buckets[i], hlist) { | |
1157 | ret = add_hash_entry(new_hash, entry->ip); | |
1158 | if (ret < 0) | |
1159 | goto free_hash; | |
1160 | } | |
1161 | } | |
1162 | ||
1163 | FTRACE_WARN_ON(new_hash->count != hash->count); | |
1164 | ||
1165 | return new_hash; | |
1166 | ||
1167 | free_hash: | |
1168 | free_ftrace_hash(new_hash); | |
1169 | return NULL; | |
1170 | } | |
1171 | ||
41fb61c2 SR |
1172 | static void |
1173 | ftrace_hash_rec_disable(struct ftrace_ops *ops, int filter_hash); | |
1174 | static void | |
1175 | ftrace_hash_rec_enable(struct ftrace_ops *ops, int filter_hash); | |
1176 | ||
33dc9b12 | 1177 | static int |
41fb61c2 SR |
1178 | ftrace_hash_move(struct ftrace_ops *ops, int enable, |
1179 | struct ftrace_hash **dst, struct ftrace_hash *src) | |
33dc9b12 SR |
1180 | { |
1181 | struct ftrace_func_entry *entry; | |
1182 | struct hlist_node *tp, *tn; | |
1183 | struct hlist_head *hhd; | |
07fd5515 SR |
1184 | struct ftrace_hash *old_hash; |
1185 | struct ftrace_hash *new_hash; | |
33dc9b12 SR |
1186 | unsigned long key; |
1187 | int size = src->count; | |
1188 | int bits = 0; | |
41fb61c2 | 1189 | int ret; |
33dc9b12 SR |
1190 | int i; |
1191 | ||
41fb61c2 SR |
1192 | /* |
1193 | * Remove the current set, update the hash and add | |
1194 | * them back. | |
1195 | */ | |
1196 | ftrace_hash_rec_disable(ops, enable); | |
1197 | ||
33dc9b12 SR |
1198 | /* |
1199 | * If the new source is empty, just free dst and assign it | |
1200 | * the empty_hash. | |
1201 | */ | |
1202 | if (!src->count) { | |
07fd5515 SR |
1203 | free_ftrace_hash_rcu(*dst); |
1204 | rcu_assign_pointer(*dst, EMPTY_HASH); | |
d4d34b98 SR |
1205 | /* still need to update the function records */ |
1206 | ret = 0; | |
1207 | goto out; | |
33dc9b12 SR |
1208 | } |
1209 | ||
33dc9b12 SR |
1210 | /* |
1211 | * Make the hash size about 1/2 the # found | |
1212 | */ | |
1213 | for (size /= 2; size; size >>= 1) | |
1214 | bits++; | |
1215 | ||
1216 | /* Don't allocate too much */ | |
1217 | if (bits > FTRACE_HASH_MAX_BITS) | |
1218 | bits = FTRACE_HASH_MAX_BITS; | |
1219 | ||
41fb61c2 | 1220 | ret = -ENOMEM; |
07fd5515 SR |
1221 | new_hash = alloc_ftrace_hash(bits); |
1222 | if (!new_hash) | |
41fb61c2 | 1223 | goto out; |
33dc9b12 SR |
1224 | |
1225 | size = 1 << src->size_bits; | |
1226 | for (i = 0; i < size; i++) { | |
1227 | hhd = &src->buckets[i]; | |
1228 | hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist) { | |
1229 | if (bits > 0) | |
1230 | key = hash_long(entry->ip, bits); | |
1231 | else | |
1232 | key = 0; | |
1233 | remove_hash_entry(src, entry); | |
07fd5515 | 1234 | __add_hash_entry(new_hash, entry); |
33dc9b12 SR |
1235 | } |
1236 | } | |
1237 | ||
07fd5515 SR |
1238 | old_hash = *dst; |
1239 | rcu_assign_pointer(*dst, new_hash); | |
1240 | free_ftrace_hash_rcu(old_hash); | |
1241 | ||
41fb61c2 SR |
1242 | ret = 0; |
1243 | out: | |
1244 | /* | |
1245 | * Enable regardless of ret: | |
1246 | * On success, we enable the new hash. | |
1247 | * On failure, we re-enable the original hash. | |
1248 | */ | |
1249 | ftrace_hash_rec_enable(ops, enable); | |
1250 | ||
1251 | return ret; | |
33dc9b12 SR |
1252 | } |
1253 | ||
b848914c SR |
1254 | /* |
1255 | * Test the hashes for this ops to see if we want to call | |
1256 | * the ops->func or not. | |
1257 | * | |
1258 | * It's a match if the ip is in the ops->filter_hash or | |
1259 | * the filter_hash does not exist or is empty, | |
1260 | * AND | |
1261 | * the ip is not in the ops->notrace_hash. | |
cdbe61bf SR |
1262 | * |
1263 | * This needs to be called with preemption disabled as | |
1264 | * the hashes are freed with call_rcu_sched(). | |
b848914c SR |
1265 | */ |
1266 | static int | |
1267 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip) | |
1268 | { | |
1269 | struct ftrace_hash *filter_hash; | |
1270 | struct ftrace_hash *notrace_hash; | |
1271 | int ret; | |
1272 | ||
b848914c SR |
1273 | filter_hash = rcu_dereference_raw(ops->filter_hash); |
1274 | notrace_hash = rcu_dereference_raw(ops->notrace_hash); | |
1275 | ||
1276 | if ((!filter_hash || !filter_hash->count || | |
1277 | ftrace_lookup_ip(filter_hash, ip)) && | |
1278 | (!notrace_hash || !notrace_hash->count || | |
1279 | !ftrace_lookup_ip(notrace_hash, ip))) | |
1280 | ret = 1; | |
1281 | else | |
1282 | ret = 0; | |
b848914c SR |
1283 | |
1284 | return ret; | |
1285 | } | |
1286 | ||
493762fc SR |
1287 | /* |
1288 | * This is a double for. Do not use 'break' to break out of the loop, | |
1289 | * you must use a goto. | |
1290 | */ | |
1291 | #define do_for_each_ftrace_rec(pg, rec) \ | |
1292 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
1293 | int _____i; \ | |
1294 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
1295 | rec = &pg->records[_____i]; | |
1296 | ||
1297 | #define while_for_each_ftrace_rec() \ | |
1298 | } \ | |
1299 | } | |
1300 | ||
c88fd863 SR |
1301 | /** |
1302 | * ftrace_location - return true if the ip giving is a traced location | |
1303 | * @ip: the instruction pointer to check | |
1304 | * | |
1305 | * Returns 1 if @ip given is a pointer to a ftrace location. | |
1306 | * That is, the instruction that is either a NOP or call to | |
1307 | * the function tracer. It checks the ftrace internal tables to | |
1308 | * determine if the address belongs or not. | |
1309 | */ | |
1310 | int ftrace_location(unsigned long ip) | |
1311 | { | |
1312 | struct ftrace_page *pg; | |
1313 | struct dyn_ftrace *rec; | |
1314 | ||
1315 | do_for_each_ftrace_rec(pg, rec) { | |
1316 | if (rec->ip == ip) | |
1317 | return 1; | |
1318 | } while_for_each_ftrace_rec(); | |
1319 | ||
1320 | return 0; | |
1321 | } | |
1322 | ||
ed926f9b SR |
1323 | static void __ftrace_hash_rec_update(struct ftrace_ops *ops, |
1324 | int filter_hash, | |
1325 | bool inc) | |
1326 | { | |
1327 | struct ftrace_hash *hash; | |
1328 | struct ftrace_hash *other_hash; | |
1329 | struct ftrace_page *pg; | |
1330 | struct dyn_ftrace *rec; | |
1331 | int count = 0; | |
1332 | int all = 0; | |
1333 | ||
1334 | /* Only update if the ops has been registered */ | |
1335 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
1336 | return; | |
1337 | ||
1338 | /* | |
1339 | * In the filter_hash case: | |
1340 | * If the count is zero, we update all records. | |
1341 | * Otherwise we just update the items in the hash. | |
1342 | * | |
1343 | * In the notrace_hash case: | |
1344 | * We enable the update in the hash. | |
1345 | * As disabling notrace means enabling the tracing, | |
1346 | * and enabling notrace means disabling, the inc variable | |
1347 | * gets inversed. | |
1348 | */ | |
1349 | if (filter_hash) { | |
1350 | hash = ops->filter_hash; | |
1351 | other_hash = ops->notrace_hash; | |
b848914c | 1352 | if (!hash || !hash->count) |
ed926f9b SR |
1353 | all = 1; |
1354 | } else { | |
1355 | inc = !inc; | |
1356 | hash = ops->notrace_hash; | |
1357 | other_hash = ops->filter_hash; | |
1358 | /* | |
1359 | * If the notrace hash has no items, | |
1360 | * then there's nothing to do. | |
1361 | */ | |
b848914c | 1362 | if (hash && !hash->count) |
ed926f9b SR |
1363 | return; |
1364 | } | |
1365 | ||
1366 | do_for_each_ftrace_rec(pg, rec) { | |
1367 | int in_other_hash = 0; | |
1368 | int in_hash = 0; | |
1369 | int match = 0; | |
1370 | ||
1371 | if (all) { | |
1372 | /* | |
1373 | * Only the filter_hash affects all records. | |
1374 | * Update if the record is not in the notrace hash. | |
1375 | */ | |
b848914c | 1376 | if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) |
ed926f9b SR |
1377 | match = 1; |
1378 | } else { | |
b848914c SR |
1379 | in_hash = hash && !!ftrace_lookup_ip(hash, rec->ip); |
1380 | in_other_hash = other_hash && !!ftrace_lookup_ip(other_hash, rec->ip); | |
ed926f9b SR |
1381 | |
1382 | /* | |
1383 | * | |
1384 | */ | |
1385 | if (filter_hash && in_hash && !in_other_hash) | |
1386 | match = 1; | |
1387 | else if (!filter_hash && in_hash && | |
1388 | (in_other_hash || !other_hash->count)) | |
1389 | match = 1; | |
1390 | } | |
1391 | if (!match) | |
1392 | continue; | |
1393 | ||
1394 | if (inc) { | |
1395 | rec->flags++; | |
1396 | if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == FTRACE_REF_MAX)) | |
1397 | return; | |
1398 | } else { | |
1399 | if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == 0)) | |
1400 | return; | |
1401 | rec->flags--; | |
1402 | } | |
1403 | count++; | |
1404 | /* Shortcut, if we handled all records, we are done. */ | |
1405 | if (!all && count == hash->count) | |
1406 | return; | |
1407 | } while_for_each_ftrace_rec(); | |
1408 | } | |
1409 | ||
1410 | static void ftrace_hash_rec_disable(struct ftrace_ops *ops, | |
1411 | int filter_hash) | |
1412 | { | |
1413 | __ftrace_hash_rec_update(ops, filter_hash, 0); | |
1414 | } | |
1415 | ||
1416 | static void ftrace_hash_rec_enable(struct ftrace_ops *ops, | |
1417 | int filter_hash) | |
1418 | { | |
1419 | __ftrace_hash_rec_update(ops, filter_hash, 1); | |
1420 | } | |
1421 | ||
e309b41d | 1422 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 1423 | { |
3c1720f0 | 1424 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
08f5ac90 SR |
1425 | if (!ftrace_pages->next) { |
1426 | /* allocate another page */ | |
1427 | ftrace_pages->next = | |
1428 | (void *)get_zeroed_page(GFP_KERNEL); | |
1429 | if (!ftrace_pages->next) | |
1430 | return NULL; | |
1431 | } | |
3c1720f0 SR |
1432 | ftrace_pages = ftrace_pages->next; |
1433 | } | |
1434 | ||
1435 | return &ftrace_pages->records[ftrace_pages->index++]; | |
1436 | } | |
1437 | ||
08f5ac90 | 1438 | static struct dyn_ftrace * |
d61f82d0 | 1439 | ftrace_record_ip(unsigned long ip) |
3d083395 | 1440 | { |
08f5ac90 | 1441 | struct dyn_ftrace *rec; |
3d083395 | 1442 | |
f3c7ac40 | 1443 | if (ftrace_disabled) |
08f5ac90 | 1444 | return NULL; |
3d083395 | 1445 | |
08f5ac90 SR |
1446 | rec = ftrace_alloc_dyn_node(ip); |
1447 | if (!rec) | |
1448 | return NULL; | |
3d083395 | 1449 | |
08f5ac90 | 1450 | rec->ip = ip; |
ee000b7f | 1451 | rec->newlist = ftrace_new_addrs; |
e94142a6 | 1452 | ftrace_new_addrs = rec; |
3d083395 | 1453 | |
08f5ac90 | 1454 | return rec; |
3d083395 SR |
1455 | } |
1456 | ||
b17e8a37 SR |
1457 | static void print_ip_ins(const char *fmt, unsigned char *p) |
1458 | { | |
1459 | int i; | |
1460 | ||
1461 | printk(KERN_CONT "%s", fmt); | |
1462 | ||
1463 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
1464 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
1465 | } | |
1466 | ||
c88fd863 SR |
1467 | /** |
1468 | * ftrace_bug - report and shutdown function tracer | |
1469 | * @failed: The failed type (EFAULT, EINVAL, EPERM) | |
1470 | * @ip: The address that failed | |
1471 | * | |
1472 | * The arch code that enables or disables the function tracing | |
1473 | * can call ftrace_bug() when it has detected a problem in | |
1474 | * modifying the code. @failed should be one of either: | |
1475 | * EFAULT - if the problem happens on reading the @ip address | |
1476 | * EINVAL - if what is read at @ip is not what was expected | |
1477 | * EPERM - if the problem happens on writting to the @ip address | |
1478 | */ | |
1479 | void ftrace_bug(int failed, unsigned long ip) | |
b17e8a37 SR |
1480 | { |
1481 | switch (failed) { | |
1482 | case -EFAULT: | |
1483 | FTRACE_WARN_ON_ONCE(1); | |
1484 | pr_info("ftrace faulted on modifying "); | |
1485 | print_ip_sym(ip); | |
1486 | break; | |
1487 | case -EINVAL: | |
1488 | FTRACE_WARN_ON_ONCE(1); | |
1489 | pr_info("ftrace failed to modify "); | |
1490 | print_ip_sym(ip); | |
b17e8a37 | 1491 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
1492 | printk(KERN_CONT "\n"); |
1493 | break; | |
1494 | case -EPERM: | |
1495 | FTRACE_WARN_ON_ONCE(1); | |
1496 | pr_info("ftrace faulted on writing "); | |
1497 | print_ip_sym(ip); | |
1498 | break; | |
1499 | default: | |
1500 | FTRACE_WARN_ON_ONCE(1); | |
1501 | pr_info("ftrace faulted on unknown error "); | |
1502 | print_ip_sym(ip); | |
1503 | } | |
1504 | } | |
1505 | ||
3c1720f0 | 1506 | |
2cfa1978 MH |
1507 | /* Return 1 if the address range is reserved for ftrace */ |
1508 | int ftrace_text_reserved(void *start, void *end) | |
1509 | { | |
1510 | struct dyn_ftrace *rec; | |
1511 | struct ftrace_page *pg; | |
1512 | ||
1513 | do_for_each_ftrace_rec(pg, rec) { | |
1514 | if (rec->ip <= (unsigned long)end && | |
1515 | rec->ip + MCOUNT_INSN_SIZE > (unsigned long)start) | |
1516 | return 1; | |
1517 | } while_for_each_ftrace_rec(); | |
1518 | return 0; | |
1519 | } | |
1520 | ||
c88fd863 | 1521 | static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update) |
5072c59f | 1522 | { |
64fbcd16 | 1523 | unsigned long flag = 0UL; |
e7d3737e | 1524 | |
982c350b | 1525 | /* |
30fb6aa7 | 1526 | * If we are updating calls: |
982c350b | 1527 | * |
ed926f9b SR |
1528 | * If the record has a ref count, then we need to enable it |
1529 | * because someone is using it. | |
982c350b | 1530 | * |
ed926f9b SR |
1531 | * Otherwise we make sure its disabled. |
1532 | * | |
30fb6aa7 | 1533 | * If we are disabling calls, then disable all records that |
ed926f9b | 1534 | * are enabled. |
982c350b | 1535 | */ |
c88fd863 | 1536 | if (enable && (rec->flags & ~FTRACE_FL_MASK)) |
ed926f9b | 1537 | flag = FTRACE_FL_ENABLED; |
982c350b | 1538 | |
64fbcd16 XG |
1539 | /* If the state of this record hasn't changed, then do nothing */ |
1540 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
c88fd863 | 1541 | return FTRACE_UPDATE_IGNORE; |
982c350b | 1542 | |
64fbcd16 | 1543 | if (flag) { |
c88fd863 SR |
1544 | if (update) |
1545 | rec->flags |= FTRACE_FL_ENABLED; | |
1546 | return FTRACE_UPDATE_MAKE_CALL; | |
1547 | } | |
1548 | ||
1549 | if (update) | |
1550 | rec->flags &= ~FTRACE_FL_ENABLED; | |
1551 | ||
1552 | return FTRACE_UPDATE_MAKE_NOP; | |
1553 | } | |
1554 | ||
1555 | /** | |
1556 | * ftrace_update_record, set a record that now is tracing or not | |
1557 | * @rec: the record to update | |
1558 | * @enable: set to 1 if the record is tracing, zero to force disable | |
1559 | * | |
1560 | * The records that represent all functions that can be traced need | |
1561 | * to be updated when tracing has been enabled. | |
1562 | */ | |
1563 | int ftrace_update_record(struct dyn_ftrace *rec, int enable) | |
1564 | { | |
1565 | return ftrace_check_record(rec, enable, 1); | |
1566 | } | |
1567 | ||
1568 | /** | |
1569 | * ftrace_test_record, check if the record has been enabled or not | |
1570 | * @rec: the record to test | |
1571 | * @enable: set to 1 to check if enabled, 0 if it is disabled | |
1572 | * | |
1573 | * The arch code may need to test if a record is already set to | |
1574 | * tracing to determine how to modify the function code that it | |
1575 | * represents. | |
1576 | */ | |
1577 | int ftrace_test_record(struct dyn_ftrace *rec, int enable) | |
1578 | { | |
1579 | return ftrace_check_record(rec, enable, 0); | |
1580 | } | |
1581 | ||
1582 | static int | |
1583 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) | |
1584 | { | |
1585 | unsigned long ftrace_addr; | |
1586 | int ret; | |
1587 | ||
1588 | ftrace_addr = (unsigned long)FTRACE_ADDR; | |
1589 | ||
1590 | ret = ftrace_update_record(rec, enable); | |
1591 | ||
1592 | switch (ret) { | |
1593 | case FTRACE_UPDATE_IGNORE: | |
1594 | return 0; | |
1595 | ||
1596 | case FTRACE_UPDATE_MAKE_CALL: | |
64fbcd16 | 1597 | return ftrace_make_call(rec, ftrace_addr); |
c88fd863 SR |
1598 | |
1599 | case FTRACE_UPDATE_MAKE_NOP: | |
1600 | return ftrace_make_nop(NULL, rec, ftrace_addr); | |
5072c59f SR |
1601 | } |
1602 | ||
c88fd863 | 1603 | return -1; /* unknow ftrace bug */ |
5072c59f SR |
1604 | } |
1605 | ||
30fb6aa7 | 1606 | static void ftrace_replace_code(int update) |
3c1720f0 | 1607 | { |
3c1720f0 SR |
1608 | struct dyn_ftrace *rec; |
1609 | struct ftrace_page *pg; | |
6a24a244 | 1610 | int failed; |
3c1720f0 | 1611 | |
45a4a237 SR |
1612 | if (unlikely(ftrace_disabled)) |
1613 | return; | |
1614 | ||
265c831c | 1615 | do_for_each_ftrace_rec(pg, rec) { |
30fb6aa7 | 1616 | failed = __ftrace_replace_code(rec, update); |
fa9d13cf | 1617 | if (failed) { |
3279ba37 SR |
1618 | ftrace_bug(failed, rec->ip); |
1619 | /* Stop processing */ | |
1620 | return; | |
3c1720f0 | 1621 | } |
265c831c | 1622 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
1623 | } |
1624 | ||
c88fd863 SR |
1625 | struct ftrace_rec_iter { |
1626 | struct ftrace_page *pg; | |
1627 | int index; | |
1628 | }; | |
1629 | ||
1630 | /** | |
1631 | * ftrace_rec_iter_start, start up iterating over traced functions | |
1632 | * | |
1633 | * Returns an iterator handle that is used to iterate over all | |
1634 | * the records that represent address locations where functions | |
1635 | * are traced. | |
1636 | * | |
1637 | * May return NULL if no records are available. | |
1638 | */ | |
1639 | struct ftrace_rec_iter *ftrace_rec_iter_start(void) | |
1640 | { | |
1641 | /* | |
1642 | * We only use a single iterator. | |
1643 | * Protected by the ftrace_lock mutex. | |
1644 | */ | |
1645 | static struct ftrace_rec_iter ftrace_rec_iter; | |
1646 | struct ftrace_rec_iter *iter = &ftrace_rec_iter; | |
1647 | ||
1648 | iter->pg = ftrace_pages_start; | |
1649 | iter->index = 0; | |
1650 | ||
1651 | /* Could have empty pages */ | |
1652 | while (iter->pg && !iter->pg->index) | |
1653 | iter->pg = iter->pg->next; | |
1654 | ||
1655 | if (!iter->pg) | |
1656 | return NULL; | |
1657 | ||
1658 | return iter; | |
1659 | } | |
1660 | ||
1661 | /** | |
1662 | * ftrace_rec_iter_next, get the next record to process. | |
1663 | * @iter: The handle to the iterator. | |
1664 | * | |
1665 | * Returns the next iterator after the given iterator @iter. | |
1666 | */ | |
1667 | struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) | |
1668 | { | |
1669 | iter->index++; | |
1670 | ||
1671 | if (iter->index >= iter->pg->index) { | |
1672 | iter->pg = iter->pg->next; | |
1673 | iter->index = 0; | |
1674 | ||
1675 | /* Could have empty pages */ | |
1676 | while (iter->pg && !iter->pg->index) | |
1677 | iter->pg = iter->pg->next; | |
1678 | } | |
1679 | ||
1680 | if (!iter->pg) | |
1681 | return NULL; | |
1682 | ||
1683 | return iter; | |
1684 | } | |
1685 | ||
1686 | /** | |
1687 | * ftrace_rec_iter_record, get the record at the iterator location | |
1688 | * @iter: The current iterator location | |
1689 | * | |
1690 | * Returns the record that the current @iter is at. | |
1691 | */ | |
1692 | struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) | |
1693 | { | |
1694 | return &iter->pg->records[iter->index]; | |
1695 | } | |
1696 | ||
492a7ea5 | 1697 | static int |
31e88909 | 1698 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 SR |
1699 | { |
1700 | unsigned long ip; | |
593eb8a2 | 1701 | int ret; |
3c1720f0 SR |
1702 | |
1703 | ip = rec->ip; | |
1704 | ||
45a4a237 SR |
1705 | if (unlikely(ftrace_disabled)) |
1706 | return 0; | |
1707 | ||
25aac9dc | 1708 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 1709 | if (ret) { |
31e88909 | 1710 | ftrace_bug(ret, ip); |
492a7ea5 | 1711 | return 0; |
37ad5084 | 1712 | } |
492a7ea5 | 1713 | return 1; |
3c1720f0 SR |
1714 | } |
1715 | ||
000ab691 SR |
1716 | /* |
1717 | * archs can override this function if they must do something | |
1718 | * before the modifying code is performed. | |
1719 | */ | |
1720 | int __weak ftrace_arch_code_modify_prepare(void) | |
1721 | { | |
1722 | return 0; | |
1723 | } | |
1724 | ||
1725 | /* | |
1726 | * archs can override this function if they must do something | |
1727 | * after the modifying code is performed. | |
1728 | */ | |
1729 | int __weak ftrace_arch_code_modify_post_process(void) | |
1730 | { | |
1731 | return 0; | |
1732 | } | |
1733 | ||
e309b41d | 1734 | static int __ftrace_modify_code(void *data) |
3d083395 | 1735 | { |
d61f82d0 SR |
1736 | int *command = data; |
1737 | ||
30fb6aa7 | 1738 | if (*command & FTRACE_UPDATE_CALLS) |
d61f82d0 | 1739 | ftrace_replace_code(1); |
a3583244 | 1740 | else if (*command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
1741 | ftrace_replace_code(0); |
1742 | ||
1743 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
1744 | ftrace_update_ftrace_func(ftrace_trace_function); | |
1745 | ||
5a45cfe1 SR |
1746 | if (*command & FTRACE_START_FUNC_RET) |
1747 | ftrace_enable_ftrace_graph_caller(); | |
1748 | else if (*command & FTRACE_STOP_FUNC_RET) | |
1749 | ftrace_disable_ftrace_graph_caller(); | |
1750 | ||
d61f82d0 | 1751 | return 0; |
3d083395 SR |
1752 | } |
1753 | ||
c88fd863 SR |
1754 | /** |
1755 | * ftrace_run_stop_machine, go back to the stop machine method | |
1756 | * @command: The command to tell ftrace what to do | |
1757 | * | |
1758 | * If an arch needs to fall back to the stop machine method, the | |
1759 | * it can call this function. | |
1760 | */ | |
1761 | void ftrace_run_stop_machine(int command) | |
1762 | { | |
1763 | stop_machine(__ftrace_modify_code, &command, NULL); | |
1764 | } | |
1765 | ||
1766 | /** | |
1767 | * arch_ftrace_update_code, modify the code to trace or not trace | |
1768 | * @command: The command that needs to be done | |
1769 | * | |
1770 | * Archs can override this function if it does not need to | |
1771 | * run stop_machine() to modify code. | |
1772 | */ | |
1773 | void __weak arch_ftrace_update_code(int command) | |
1774 | { | |
1775 | ftrace_run_stop_machine(command); | |
1776 | } | |
1777 | ||
e309b41d | 1778 | static void ftrace_run_update_code(int command) |
3d083395 | 1779 | { |
000ab691 SR |
1780 | int ret; |
1781 | ||
1782 | ret = ftrace_arch_code_modify_prepare(); | |
1783 | FTRACE_WARN_ON(ret); | |
1784 | if (ret) | |
1785 | return; | |
c88fd863 SR |
1786 | /* |
1787 | * Do not call function tracer while we update the code. | |
1788 | * We are in stop machine. | |
1789 | */ | |
1790 | function_trace_stop++; | |
000ab691 | 1791 | |
c88fd863 SR |
1792 | /* |
1793 | * By default we use stop_machine() to modify the code. | |
1794 | * But archs can do what ever they want as long as it | |
1795 | * is safe. The stop_machine() is the safest, but also | |
1796 | * produces the most overhead. | |
1797 | */ | |
1798 | arch_ftrace_update_code(command); | |
1799 | ||
1800 | #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
1801 | /* | |
1802 | * For archs that call ftrace_test_stop_func(), we must | |
1803 | * wait till after we update all the function callers | |
1804 | * before we update the callback. This keeps different | |
1805 | * ops that record different functions from corrupting | |
1806 | * each other. | |
1807 | */ | |
1808 | __ftrace_trace_function = __ftrace_trace_function_delay; | |
1809 | #endif | |
1810 | function_trace_stop--; | |
000ab691 SR |
1811 | |
1812 | ret = ftrace_arch_code_modify_post_process(); | |
1813 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
1814 | } |
1815 | ||
d61f82d0 | 1816 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 1817 | static int ftrace_start_up; |
b848914c | 1818 | static int global_start_up; |
df4fc315 SR |
1819 | |
1820 | static void ftrace_startup_enable(int command) | |
1821 | { | |
1822 | if (saved_ftrace_func != ftrace_trace_function) { | |
1823 | saved_ftrace_func = ftrace_trace_function; | |
1824 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1825 | } | |
1826 | ||
1827 | if (!command || !ftrace_enabled) | |
1828 | return; | |
1829 | ||
1830 | ftrace_run_update_code(command); | |
1831 | } | |
d61f82d0 | 1832 | |
a1cd6173 | 1833 | static int ftrace_startup(struct ftrace_ops *ops, int command) |
3d083395 | 1834 | { |
b848914c SR |
1835 | bool hash_enable = true; |
1836 | ||
4eebcc81 | 1837 | if (unlikely(ftrace_disabled)) |
a1cd6173 | 1838 | return -ENODEV; |
4eebcc81 | 1839 | |
60a7ecf4 | 1840 | ftrace_start_up++; |
30fb6aa7 | 1841 | command |= FTRACE_UPDATE_CALLS; |
d61f82d0 | 1842 | |
b848914c SR |
1843 | /* ops marked global share the filter hashes */ |
1844 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { | |
1845 | ops = &global_ops; | |
1846 | /* Don't update hash if global is already set */ | |
1847 | if (global_start_up) | |
1848 | hash_enable = false; | |
1849 | global_start_up++; | |
1850 | } | |
1851 | ||
ed926f9b | 1852 | ops->flags |= FTRACE_OPS_FL_ENABLED; |
b848914c | 1853 | if (hash_enable) |
ed926f9b SR |
1854 | ftrace_hash_rec_enable(ops, 1); |
1855 | ||
df4fc315 | 1856 | ftrace_startup_enable(command); |
a1cd6173 SR |
1857 | |
1858 | return 0; | |
3d083395 SR |
1859 | } |
1860 | ||
bd69c30b | 1861 | static void ftrace_shutdown(struct ftrace_ops *ops, int command) |
3d083395 | 1862 | { |
b848914c SR |
1863 | bool hash_disable = true; |
1864 | ||
4eebcc81 SR |
1865 | if (unlikely(ftrace_disabled)) |
1866 | return; | |
1867 | ||
60a7ecf4 | 1868 | ftrace_start_up--; |
9ea1a153 FW |
1869 | /* |
1870 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
1871 | * critical but the ftrace_call callers may be never nopped again after | |
1872 | * further ftrace uses. | |
1873 | */ | |
1874 | WARN_ON_ONCE(ftrace_start_up < 0); | |
1875 | ||
b848914c SR |
1876 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { |
1877 | ops = &global_ops; | |
1878 | global_start_up--; | |
1879 | WARN_ON_ONCE(global_start_up < 0); | |
1880 | /* Don't update hash if global still has users */ | |
1881 | if (global_start_up) { | |
1882 | WARN_ON_ONCE(!ftrace_start_up); | |
1883 | hash_disable = false; | |
1884 | } | |
1885 | } | |
1886 | ||
1887 | if (hash_disable) | |
ed926f9b SR |
1888 | ftrace_hash_rec_disable(ops, 1); |
1889 | ||
b848914c | 1890 | if (ops != &global_ops || !global_start_up) |
ed926f9b | 1891 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
b848914c | 1892 | |
30fb6aa7 | 1893 | command |= FTRACE_UPDATE_CALLS; |
3d083395 | 1894 | |
d61f82d0 SR |
1895 | if (saved_ftrace_func != ftrace_trace_function) { |
1896 | saved_ftrace_func = ftrace_trace_function; | |
1897 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1898 | } | |
3d083395 | 1899 | |
d61f82d0 | 1900 | if (!command || !ftrace_enabled) |
e6ea44e9 | 1901 | return; |
d61f82d0 SR |
1902 | |
1903 | ftrace_run_update_code(command); | |
3d083395 SR |
1904 | } |
1905 | ||
e309b41d | 1906 | static void ftrace_startup_sysctl(void) |
b0fc494f | 1907 | { |
4eebcc81 SR |
1908 | if (unlikely(ftrace_disabled)) |
1909 | return; | |
1910 | ||
d61f82d0 SR |
1911 | /* Force update next time */ |
1912 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
1913 | /* ftrace_start_up is true if we want ftrace running */ |
1914 | if (ftrace_start_up) | |
30fb6aa7 | 1915 | ftrace_run_update_code(FTRACE_UPDATE_CALLS); |
b0fc494f SR |
1916 | } |
1917 | ||
e309b41d | 1918 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 1919 | { |
4eebcc81 SR |
1920 | if (unlikely(ftrace_disabled)) |
1921 | return; | |
1922 | ||
60a7ecf4 SR |
1923 | /* ftrace_start_up is true if ftrace is running */ |
1924 | if (ftrace_start_up) | |
79e406d7 | 1925 | ftrace_run_update_code(FTRACE_DISABLE_CALLS); |
b0fc494f SR |
1926 | } |
1927 | ||
3d083395 SR |
1928 | static cycle_t ftrace_update_time; |
1929 | static unsigned long ftrace_update_cnt; | |
1930 | unsigned long ftrace_update_tot_cnt; | |
1931 | ||
f7bc8b61 SR |
1932 | static int ops_traces_mod(struct ftrace_ops *ops) |
1933 | { | |
1934 | struct ftrace_hash *hash; | |
1935 | ||
1936 | hash = ops->filter_hash; | |
1937 | return !!(!hash || !hash->count); | |
1938 | } | |
1939 | ||
31e88909 | 1940 | static int ftrace_update_code(struct module *mod) |
3d083395 | 1941 | { |
e94142a6 | 1942 | struct dyn_ftrace *p; |
f22f9a89 | 1943 | cycle_t start, stop; |
f7bc8b61 SR |
1944 | unsigned long ref = 0; |
1945 | ||
1946 | /* | |
1947 | * When adding a module, we need to check if tracers are | |
1948 | * currently enabled and if they are set to trace all functions. | |
1949 | * If they are, we need to enable the module functions as well | |
1950 | * as update the reference counts for those function records. | |
1951 | */ | |
1952 | if (mod) { | |
1953 | struct ftrace_ops *ops; | |
1954 | ||
1955 | for (ops = ftrace_ops_list; | |
1956 | ops != &ftrace_list_end; ops = ops->next) { | |
1957 | if (ops->flags & FTRACE_OPS_FL_ENABLED && | |
1958 | ops_traces_mod(ops)) | |
1959 | ref++; | |
1960 | } | |
1961 | } | |
3d083395 | 1962 | |
750ed1a4 | 1963 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1964 | ftrace_update_cnt = 0; |
1965 | ||
e94142a6 | 1966 | while (ftrace_new_addrs) { |
3d083395 | 1967 | |
08f5ac90 SR |
1968 | /* If something went wrong, bail without enabling anything */ |
1969 | if (unlikely(ftrace_disabled)) | |
1970 | return -1; | |
f22f9a89 | 1971 | |
e94142a6 | 1972 | p = ftrace_new_addrs; |
ee000b7f | 1973 | ftrace_new_addrs = p->newlist; |
f7bc8b61 | 1974 | p->flags = ref; |
f22f9a89 | 1975 | |
5cb084bb | 1976 | /* |
25985edc | 1977 | * Do the initial record conversion from mcount jump |
5cb084bb JO |
1978 | * to the NOP instructions. |
1979 | */ | |
32082309 | 1980 | if (!ftrace_code_disable(mod, p)) |
d2c8c3ea | 1981 | break; |
5cb084bb | 1982 | |
5cb084bb JO |
1983 | ftrace_update_cnt++; |
1984 | ||
1985 | /* | |
1986 | * If the tracing is enabled, go ahead and enable the record. | |
1987 | * | |
1988 | * The reason not to enable the record immediatelly is the | |
1989 | * inherent check of ftrace_make_nop/ftrace_make_call for | |
1990 | * correct previous instructions. Making first the NOP | |
1991 | * conversion puts the module to the correct state, thus | |
1992 | * passing the ftrace_make_call check. | |
1993 | */ | |
f7bc8b61 | 1994 | if (ftrace_start_up && ref) { |
5cb084bb | 1995 | int failed = __ftrace_replace_code(p, 1); |
32082309 | 1996 | if (failed) |
5cb084bb | 1997 | ftrace_bug(failed, p->ip); |
5cb084bb | 1998 | } |
3d083395 SR |
1999 | } |
2000 | ||
750ed1a4 | 2001 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
2002 | ftrace_update_time = stop - start; |
2003 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
2004 | ||
16444a8a ACM |
2005 | return 0; |
2006 | } | |
2007 | ||
68bf21aa | 2008 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
2009 | { |
2010 | struct ftrace_page *pg; | |
2011 | int cnt; | |
2012 | int i; | |
3c1720f0 SR |
2013 | |
2014 | /* allocate a few pages */ | |
2015 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
2016 | if (!ftrace_pages_start) | |
2017 | return -1; | |
2018 | ||
2019 | /* | |
2020 | * Allocate a few more pages. | |
2021 | * | |
2022 | * TODO: have some parser search vmlinux before | |
2023 | * final linking to find all calls to ftrace. | |
2024 | * Then we can: | |
2025 | * a) know how many pages to allocate. | |
2026 | * and/or | |
2027 | * b) set up the table then. | |
2028 | * | |
2029 | * The dynamic code is still necessary for | |
2030 | * modules. | |
2031 | */ | |
2032 | ||
2033 | pg = ftrace_pages = ftrace_pages_start; | |
2034 | ||
68bf21aa | 2035 | cnt = num_to_init / ENTRIES_PER_PAGE; |
08f5ac90 | 2036 | pr_info("ftrace: allocating %ld entries in %d pages\n", |
5821e1b7 | 2037 | num_to_init, cnt + 1); |
3c1720f0 SR |
2038 | |
2039 | for (i = 0; i < cnt; i++) { | |
2040 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
2041 | ||
2042 | /* If we fail, we'll try later anyway */ | |
2043 | if (!pg->next) | |
2044 | break; | |
2045 | ||
2046 | pg = pg->next; | |
2047 | } | |
2048 | ||
2049 | return 0; | |
2050 | } | |
2051 | ||
5072c59f SR |
2052 | enum { |
2053 | FTRACE_ITER_FILTER = (1 << 0), | |
689fd8b6 | 2054 | FTRACE_ITER_NOTRACE = (1 << 1), |
3499e461 SR |
2055 | FTRACE_ITER_PRINTALL = (1 << 2), |
2056 | FTRACE_ITER_HASH = (1 << 3), | |
647bcd03 | 2057 | FTRACE_ITER_ENABLED = (1 << 4), |
5072c59f SR |
2058 | }; |
2059 | ||
2060 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
2061 | ||
2062 | struct ftrace_iterator { | |
98c4fd04 | 2063 | loff_t pos; |
4aeb6967 SR |
2064 | loff_t func_pos; |
2065 | struct ftrace_page *pg; | |
2066 | struct dyn_ftrace *func; | |
2067 | struct ftrace_func_probe *probe; | |
2068 | struct trace_parser parser; | |
1cf41dd7 | 2069 | struct ftrace_hash *hash; |
33dc9b12 | 2070 | struct ftrace_ops *ops; |
4aeb6967 SR |
2071 | int hidx; |
2072 | int idx; | |
2073 | unsigned flags; | |
5072c59f SR |
2074 | }; |
2075 | ||
8fc0c701 | 2076 | static void * |
4aeb6967 | 2077 | t_hash_next(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
2078 | { |
2079 | struct ftrace_iterator *iter = m->private; | |
4aeb6967 | 2080 | struct hlist_node *hnd = NULL; |
8fc0c701 SR |
2081 | struct hlist_head *hhd; |
2082 | ||
8fc0c701 | 2083 | (*pos)++; |
98c4fd04 | 2084 | iter->pos = *pos; |
8fc0c701 | 2085 | |
4aeb6967 SR |
2086 | if (iter->probe) |
2087 | hnd = &iter->probe->node; | |
8fc0c701 SR |
2088 | retry: |
2089 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
2090 | return NULL; | |
2091 | ||
2092 | hhd = &ftrace_func_hash[iter->hidx]; | |
2093 | ||
2094 | if (hlist_empty(hhd)) { | |
2095 | iter->hidx++; | |
2096 | hnd = NULL; | |
2097 | goto retry; | |
2098 | } | |
2099 | ||
2100 | if (!hnd) | |
2101 | hnd = hhd->first; | |
2102 | else { | |
2103 | hnd = hnd->next; | |
2104 | if (!hnd) { | |
2105 | iter->hidx++; | |
2106 | goto retry; | |
2107 | } | |
2108 | } | |
2109 | ||
4aeb6967 SR |
2110 | if (WARN_ON_ONCE(!hnd)) |
2111 | return NULL; | |
2112 | ||
2113 | iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node); | |
2114 | ||
2115 | return iter; | |
8fc0c701 SR |
2116 | } |
2117 | ||
2118 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
2119 | { | |
2120 | struct ftrace_iterator *iter = m->private; | |
2121 | void *p = NULL; | |
d82d6244 LZ |
2122 | loff_t l; |
2123 | ||
2bccfffd SR |
2124 | if (iter->func_pos > *pos) |
2125 | return NULL; | |
8fc0c701 | 2126 | |
d82d6244 | 2127 | iter->hidx = 0; |
2bccfffd | 2128 | for (l = 0; l <= (*pos - iter->func_pos); ) { |
4aeb6967 | 2129 | p = t_hash_next(m, &l); |
d82d6244 LZ |
2130 | if (!p) |
2131 | break; | |
2132 | } | |
4aeb6967 SR |
2133 | if (!p) |
2134 | return NULL; | |
2135 | ||
98c4fd04 SR |
2136 | /* Only set this if we have an item */ |
2137 | iter->flags |= FTRACE_ITER_HASH; | |
2138 | ||
4aeb6967 | 2139 | return iter; |
8fc0c701 SR |
2140 | } |
2141 | ||
4aeb6967 SR |
2142 | static int |
2143 | t_hash_show(struct seq_file *m, struct ftrace_iterator *iter) | |
8fc0c701 | 2144 | { |
b6887d79 | 2145 | struct ftrace_func_probe *rec; |
8fc0c701 | 2146 | |
4aeb6967 SR |
2147 | rec = iter->probe; |
2148 | if (WARN_ON_ONCE(!rec)) | |
2149 | return -EIO; | |
8fc0c701 | 2150 | |
809dcf29 SR |
2151 | if (rec->ops->print) |
2152 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
2153 | ||
b375a11a | 2154 | seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func); |
8fc0c701 SR |
2155 | |
2156 | if (rec->data) | |
2157 | seq_printf(m, ":%p", rec->data); | |
2158 | seq_putc(m, '\n'); | |
2159 | ||
2160 | return 0; | |
2161 | } | |
2162 | ||
e309b41d | 2163 | static void * |
5072c59f SR |
2164 | t_next(struct seq_file *m, void *v, loff_t *pos) |
2165 | { | |
2166 | struct ftrace_iterator *iter = m->private; | |
f45948e8 | 2167 | struct ftrace_ops *ops = &global_ops; |
5072c59f SR |
2168 | struct dyn_ftrace *rec = NULL; |
2169 | ||
45a4a237 SR |
2170 | if (unlikely(ftrace_disabled)) |
2171 | return NULL; | |
2172 | ||
8fc0c701 | 2173 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 2174 | return t_hash_next(m, pos); |
8fc0c701 | 2175 | |
5072c59f | 2176 | (*pos)++; |
1106b699 | 2177 | iter->pos = iter->func_pos = *pos; |
5072c59f | 2178 | |
0c75a3ed | 2179 | if (iter->flags & FTRACE_ITER_PRINTALL) |
57c072c7 | 2180 | return t_hash_start(m, pos); |
0c75a3ed | 2181 | |
5072c59f SR |
2182 | retry: |
2183 | if (iter->idx >= iter->pg->index) { | |
2184 | if (iter->pg->next) { | |
2185 | iter->pg = iter->pg->next; | |
2186 | iter->idx = 0; | |
2187 | goto retry; | |
2188 | } | |
2189 | } else { | |
2190 | rec = &iter->pg->records[iter->idx++]; | |
32082309 | 2191 | if (((iter->flags & FTRACE_ITER_FILTER) && |
f45948e8 | 2192 | !(ftrace_lookup_ip(ops->filter_hash, rec->ip))) || |
0183fb1c | 2193 | |
41c52c0d | 2194 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
647bcd03 SR |
2195 | !ftrace_lookup_ip(ops->notrace_hash, rec->ip)) || |
2196 | ||
2197 | ((iter->flags & FTRACE_ITER_ENABLED) && | |
2198 | !(rec->flags & ~FTRACE_FL_MASK))) { | |
2199 | ||
5072c59f SR |
2200 | rec = NULL; |
2201 | goto retry; | |
2202 | } | |
2203 | } | |
2204 | ||
4aeb6967 | 2205 | if (!rec) |
57c072c7 | 2206 | return t_hash_start(m, pos); |
4aeb6967 SR |
2207 | |
2208 | iter->func = rec; | |
2209 | ||
2210 | return iter; | |
5072c59f SR |
2211 | } |
2212 | ||
98c4fd04 SR |
2213 | static void reset_iter_read(struct ftrace_iterator *iter) |
2214 | { | |
2215 | iter->pos = 0; | |
2216 | iter->func_pos = 0; | |
2217 | iter->flags &= ~(FTRACE_ITER_PRINTALL & FTRACE_ITER_HASH); | |
5072c59f SR |
2218 | } |
2219 | ||
2220 | static void *t_start(struct seq_file *m, loff_t *pos) | |
2221 | { | |
2222 | struct ftrace_iterator *iter = m->private; | |
f45948e8 | 2223 | struct ftrace_ops *ops = &global_ops; |
5072c59f | 2224 | void *p = NULL; |
694ce0a5 | 2225 | loff_t l; |
5072c59f | 2226 | |
8fc0c701 | 2227 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
2228 | |
2229 | if (unlikely(ftrace_disabled)) | |
2230 | return NULL; | |
2231 | ||
98c4fd04 SR |
2232 | /* |
2233 | * If an lseek was done, then reset and start from beginning. | |
2234 | */ | |
2235 | if (*pos < iter->pos) | |
2236 | reset_iter_read(iter); | |
2237 | ||
0c75a3ed SR |
2238 | /* |
2239 | * For set_ftrace_filter reading, if we have the filter | |
2240 | * off, we can short cut and just print out that all | |
2241 | * functions are enabled. | |
2242 | */ | |
f45948e8 | 2243 | if (iter->flags & FTRACE_ITER_FILTER && !ops->filter_hash->count) { |
0c75a3ed | 2244 | if (*pos > 0) |
8fc0c701 | 2245 | return t_hash_start(m, pos); |
0c75a3ed | 2246 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 CW |
2247 | /* reset in case of seek/pread */ |
2248 | iter->flags &= ~FTRACE_ITER_HASH; | |
0c75a3ed SR |
2249 | return iter; |
2250 | } | |
2251 | ||
8fc0c701 SR |
2252 | if (iter->flags & FTRACE_ITER_HASH) |
2253 | return t_hash_start(m, pos); | |
2254 | ||
98c4fd04 SR |
2255 | /* |
2256 | * Unfortunately, we need to restart at ftrace_pages_start | |
2257 | * every time we let go of the ftrace_mutex. This is because | |
2258 | * those pointers can change without the lock. | |
2259 | */ | |
694ce0a5 LZ |
2260 | iter->pg = ftrace_pages_start; |
2261 | iter->idx = 0; | |
2262 | for (l = 0; l <= *pos; ) { | |
2263 | p = t_next(m, p, &l); | |
2264 | if (!p) | |
2265 | break; | |
50cdaf08 | 2266 | } |
5821e1b7 | 2267 | |
4aeb6967 SR |
2268 | if (!p) { |
2269 | if (iter->flags & FTRACE_ITER_FILTER) | |
2270 | return t_hash_start(m, pos); | |
8fc0c701 | 2271 | |
4aeb6967 SR |
2272 | return NULL; |
2273 | } | |
2274 | ||
2275 | return iter; | |
5072c59f SR |
2276 | } |
2277 | ||
2278 | static void t_stop(struct seq_file *m, void *p) | |
2279 | { | |
8fc0c701 | 2280 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
2281 | } |
2282 | ||
2283 | static int t_show(struct seq_file *m, void *v) | |
2284 | { | |
0c75a3ed | 2285 | struct ftrace_iterator *iter = m->private; |
4aeb6967 | 2286 | struct dyn_ftrace *rec; |
5072c59f | 2287 | |
8fc0c701 | 2288 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 2289 | return t_hash_show(m, iter); |
8fc0c701 | 2290 | |
0c75a3ed SR |
2291 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
2292 | seq_printf(m, "#### all functions enabled ####\n"); | |
2293 | return 0; | |
2294 | } | |
2295 | ||
4aeb6967 SR |
2296 | rec = iter->func; |
2297 | ||
5072c59f SR |
2298 | if (!rec) |
2299 | return 0; | |
2300 | ||
647bcd03 SR |
2301 | seq_printf(m, "%ps", (void *)rec->ip); |
2302 | if (iter->flags & FTRACE_ITER_ENABLED) | |
2303 | seq_printf(m, " (%ld)", | |
2304 | rec->flags & ~FTRACE_FL_MASK); | |
2305 | seq_printf(m, "\n"); | |
5072c59f SR |
2306 | |
2307 | return 0; | |
2308 | } | |
2309 | ||
88e9d34c | 2310 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
2311 | .start = t_start, |
2312 | .next = t_next, | |
2313 | .stop = t_stop, | |
2314 | .show = t_show, | |
2315 | }; | |
2316 | ||
e309b41d | 2317 | static int |
5072c59f SR |
2318 | ftrace_avail_open(struct inode *inode, struct file *file) |
2319 | { | |
2320 | struct ftrace_iterator *iter; | |
2321 | int ret; | |
2322 | ||
4eebcc81 SR |
2323 | if (unlikely(ftrace_disabled)) |
2324 | return -ENODEV; | |
2325 | ||
5072c59f SR |
2326 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
2327 | if (!iter) | |
2328 | return -ENOMEM; | |
2329 | ||
2330 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
2331 | |
2332 | ret = seq_open(file, &show_ftrace_seq_ops); | |
2333 | if (!ret) { | |
2334 | struct seq_file *m = file->private_data; | |
4bf39a94 | 2335 | |
5072c59f | 2336 | m->private = iter; |
4bf39a94 | 2337 | } else { |
5072c59f | 2338 | kfree(iter); |
4bf39a94 | 2339 | } |
5072c59f SR |
2340 | |
2341 | return ret; | |
2342 | } | |
2343 | ||
647bcd03 SR |
2344 | static int |
2345 | ftrace_enabled_open(struct inode *inode, struct file *file) | |
2346 | { | |
2347 | struct ftrace_iterator *iter; | |
2348 | int ret; | |
2349 | ||
2350 | if (unlikely(ftrace_disabled)) | |
2351 | return -ENODEV; | |
2352 | ||
2353 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); | |
2354 | if (!iter) | |
2355 | return -ENOMEM; | |
2356 | ||
2357 | iter->pg = ftrace_pages_start; | |
2358 | iter->flags = FTRACE_ITER_ENABLED; | |
2359 | ||
2360 | ret = seq_open(file, &show_ftrace_seq_ops); | |
2361 | if (!ret) { | |
2362 | struct seq_file *m = file->private_data; | |
2363 | ||
2364 | m->private = iter; | |
2365 | } else { | |
2366 | kfree(iter); | |
2367 | } | |
2368 | ||
2369 | return ret; | |
2370 | } | |
2371 | ||
1cf41dd7 | 2372 | static void ftrace_filter_reset(struct ftrace_hash *hash) |
5072c59f | 2373 | { |
52baf119 | 2374 | mutex_lock(&ftrace_lock); |
1cf41dd7 | 2375 | ftrace_hash_clear(hash); |
52baf119 | 2376 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
2377 | } |
2378 | ||
e309b41d | 2379 | static int |
f45948e8 | 2380 | ftrace_regex_open(struct ftrace_ops *ops, int flag, |
1cf41dd7 | 2381 | struct inode *inode, struct file *file) |
5072c59f SR |
2382 | { |
2383 | struct ftrace_iterator *iter; | |
f45948e8 | 2384 | struct ftrace_hash *hash; |
5072c59f SR |
2385 | int ret = 0; |
2386 | ||
4eebcc81 SR |
2387 | if (unlikely(ftrace_disabled)) |
2388 | return -ENODEV; | |
2389 | ||
5072c59f SR |
2390 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
2391 | if (!iter) | |
2392 | return -ENOMEM; | |
2393 | ||
689fd8b6 | 2394 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { |
2395 | kfree(iter); | |
2396 | return -ENOMEM; | |
2397 | } | |
2398 | ||
f45948e8 SR |
2399 | if (flag & FTRACE_ITER_NOTRACE) |
2400 | hash = ops->notrace_hash; | |
2401 | else | |
2402 | hash = ops->filter_hash; | |
2403 | ||
33dc9b12 SR |
2404 | iter->ops = ops; |
2405 | iter->flags = flag; | |
2406 | ||
2407 | if (file->f_mode & FMODE_WRITE) { | |
2408 | mutex_lock(&ftrace_lock); | |
2409 | iter->hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash); | |
2410 | mutex_unlock(&ftrace_lock); | |
2411 | ||
2412 | if (!iter->hash) { | |
2413 | trace_parser_put(&iter->parser); | |
2414 | kfree(iter); | |
2415 | return -ENOMEM; | |
2416 | } | |
2417 | } | |
1cf41dd7 | 2418 | |
41c52c0d | 2419 | mutex_lock(&ftrace_regex_lock); |
33dc9b12 | 2420 | |
5072c59f | 2421 | if ((file->f_mode & FMODE_WRITE) && |
8650ae32 | 2422 | (file->f_flags & O_TRUNC)) |
33dc9b12 | 2423 | ftrace_filter_reset(iter->hash); |
5072c59f SR |
2424 | |
2425 | if (file->f_mode & FMODE_READ) { | |
2426 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
2427 | |
2428 | ret = seq_open(file, &show_ftrace_seq_ops); | |
2429 | if (!ret) { | |
2430 | struct seq_file *m = file->private_data; | |
2431 | m->private = iter; | |
79fe249c | 2432 | } else { |
33dc9b12 SR |
2433 | /* Failed */ |
2434 | free_ftrace_hash(iter->hash); | |
79fe249c | 2435 | trace_parser_put(&iter->parser); |
5072c59f | 2436 | kfree(iter); |
79fe249c | 2437 | } |
5072c59f SR |
2438 | } else |
2439 | file->private_data = iter; | |
41c52c0d | 2440 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
2441 | |
2442 | return ret; | |
2443 | } | |
2444 | ||
41c52c0d SR |
2445 | static int |
2446 | ftrace_filter_open(struct inode *inode, struct file *file) | |
2447 | { | |
f45948e8 | 2448 | return ftrace_regex_open(&global_ops, FTRACE_ITER_FILTER, |
1cf41dd7 | 2449 | inode, file); |
41c52c0d SR |
2450 | } |
2451 | ||
2452 | static int | |
2453 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
2454 | { | |
f45948e8 | 2455 | return ftrace_regex_open(&global_ops, FTRACE_ITER_NOTRACE, |
1cf41dd7 | 2456 | inode, file); |
41c52c0d SR |
2457 | } |
2458 | ||
e309b41d | 2459 | static loff_t |
41c52c0d | 2460 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
2461 | { |
2462 | loff_t ret; | |
2463 | ||
2464 | if (file->f_mode & FMODE_READ) | |
2465 | ret = seq_lseek(file, offset, origin); | |
2466 | else | |
2467 | file->f_pos = ret = 1; | |
2468 | ||
2469 | return ret; | |
2470 | } | |
2471 | ||
64e7c440 | 2472 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 2473 | { |
9f4801e3 | 2474 | int matched = 0; |
751e9983 | 2475 | int slen; |
9f4801e3 | 2476 | |
9f4801e3 SR |
2477 | switch (type) { |
2478 | case MATCH_FULL: | |
2479 | if (strcmp(str, regex) == 0) | |
2480 | matched = 1; | |
2481 | break; | |
2482 | case MATCH_FRONT_ONLY: | |
2483 | if (strncmp(str, regex, len) == 0) | |
2484 | matched = 1; | |
2485 | break; | |
2486 | case MATCH_MIDDLE_ONLY: | |
2487 | if (strstr(str, regex)) | |
2488 | matched = 1; | |
2489 | break; | |
2490 | case MATCH_END_ONLY: | |
751e9983 LZ |
2491 | slen = strlen(str); |
2492 | if (slen >= len && memcmp(str + slen - len, regex, len) == 0) | |
9f4801e3 SR |
2493 | matched = 1; |
2494 | break; | |
2495 | } | |
2496 | ||
2497 | return matched; | |
2498 | } | |
2499 | ||
b448c4e3 | 2500 | static int |
1cf41dd7 | 2501 | enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not) |
996e87be | 2502 | { |
b448c4e3 | 2503 | struct ftrace_func_entry *entry; |
b448c4e3 SR |
2504 | int ret = 0; |
2505 | ||
1cf41dd7 SR |
2506 | entry = ftrace_lookup_ip(hash, rec->ip); |
2507 | if (not) { | |
2508 | /* Do nothing if it doesn't exist */ | |
2509 | if (!entry) | |
2510 | return 0; | |
b448c4e3 | 2511 | |
33dc9b12 | 2512 | free_hash_entry(hash, entry); |
1cf41dd7 SR |
2513 | } else { |
2514 | /* Do nothing if it exists */ | |
2515 | if (entry) | |
2516 | return 0; | |
b448c4e3 | 2517 | |
1cf41dd7 | 2518 | ret = add_hash_entry(hash, rec->ip); |
b448c4e3 SR |
2519 | } |
2520 | return ret; | |
996e87be SR |
2521 | } |
2522 | ||
64e7c440 | 2523 | static int |
b9df92d2 SR |
2524 | ftrace_match_record(struct dyn_ftrace *rec, char *mod, |
2525 | char *regex, int len, int type) | |
64e7c440 SR |
2526 | { |
2527 | char str[KSYM_SYMBOL_LEN]; | |
b9df92d2 SR |
2528 | char *modname; |
2529 | ||
2530 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
2531 | ||
2532 | if (mod) { | |
2533 | /* module lookup requires matching the module */ | |
2534 | if (!modname || strcmp(modname, mod)) | |
2535 | return 0; | |
2536 | ||
2537 | /* blank search means to match all funcs in the mod */ | |
2538 | if (!len) | |
2539 | return 1; | |
2540 | } | |
64e7c440 | 2541 | |
64e7c440 SR |
2542 | return ftrace_match(str, regex, len, type); |
2543 | } | |
2544 | ||
1cf41dd7 SR |
2545 | static int |
2546 | match_records(struct ftrace_hash *hash, char *buff, | |
2547 | int len, char *mod, int not) | |
9f4801e3 | 2548 | { |
b9df92d2 | 2549 | unsigned search_len = 0; |
9f4801e3 SR |
2550 | struct ftrace_page *pg; |
2551 | struct dyn_ftrace *rec; | |
b9df92d2 SR |
2552 | int type = MATCH_FULL; |
2553 | char *search = buff; | |
311d16da | 2554 | int found = 0; |
b448c4e3 | 2555 | int ret; |
9f4801e3 | 2556 | |
b9df92d2 SR |
2557 | if (len) { |
2558 | type = filter_parse_regex(buff, len, &search, ¬); | |
2559 | search_len = strlen(search); | |
2560 | } | |
9f4801e3 | 2561 | |
52baf119 | 2562 | mutex_lock(&ftrace_lock); |
265c831c | 2563 | |
b9df92d2 SR |
2564 | if (unlikely(ftrace_disabled)) |
2565 | goto out_unlock; | |
9f4801e3 | 2566 | |
265c831c | 2567 | do_for_each_ftrace_rec(pg, rec) { |
b9df92d2 | 2568 | if (ftrace_match_record(rec, mod, search, search_len, type)) { |
1cf41dd7 | 2569 | ret = enter_record(hash, rec, not); |
b448c4e3 SR |
2570 | if (ret < 0) { |
2571 | found = ret; | |
2572 | goto out_unlock; | |
2573 | } | |
311d16da | 2574 | found = 1; |
265c831c SR |
2575 | } |
2576 | } while_for_each_ftrace_rec(); | |
b9df92d2 | 2577 | out_unlock: |
52baf119 | 2578 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
2579 | |
2580 | return found; | |
5072c59f SR |
2581 | } |
2582 | ||
64e7c440 | 2583 | static int |
1cf41dd7 | 2584 | ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) |
64e7c440 | 2585 | { |
1cf41dd7 | 2586 | return match_records(hash, buff, len, NULL, 0); |
64e7c440 SR |
2587 | } |
2588 | ||
1cf41dd7 SR |
2589 | static int |
2590 | ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod) | |
64e7c440 | 2591 | { |
64e7c440 | 2592 | int not = 0; |
6a24a244 | 2593 | |
64e7c440 SR |
2594 | /* blank or '*' mean the same */ |
2595 | if (strcmp(buff, "*") == 0) | |
2596 | buff[0] = 0; | |
2597 | ||
2598 | /* handle the case of 'dont filter this module' */ | |
2599 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
2600 | buff[0] = 0; | |
2601 | not = 1; | |
2602 | } | |
2603 | ||
1cf41dd7 | 2604 | return match_records(hash, buff, strlen(buff), mod, not); |
64e7c440 SR |
2605 | } |
2606 | ||
f6180773 SR |
2607 | /* |
2608 | * We register the module command as a template to show others how | |
2609 | * to register the a command as well. | |
2610 | */ | |
2611 | ||
2612 | static int | |
43dd61c9 SR |
2613 | ftrace_mod_callback(struct ftrace_hash *hash, |
2614 | char *func, char *cmd, char *param, int enable) | |
f6180773 SR |
2615 | { |
2616 | char *mod; | |
b448c4e3 | 2617 | int ret = -EINVAL; |
f6180773 SR |
2618 | |
2619 | /* | |
2620 | * cmd == 'mod' because we only registered this func | |
2621 | * for the 'mod' ftrace_func_command. | |
2622 | * But if you register one func with multiple commands, | |
2623 | * you can tell which command was used by the cmd | |
2624 | * parameter. | |
2625 | */ | |
2626 | ||
2627 | /* we must have a module name */ | |
2628 | if (!param) | |
b448c4e3 | 2629 | return ret; |
f6180773 SR |
2630 | |
2631 | mod = strsep(¶m, ":"); | |
2632 | if (!strlen(mod)) | |
b448c4e3 | 2633 | return ret; |
f6180773 | 2634 | |
1cf41dd7 | 2635 | ret = ftrace_match_module_records(hash, func, mod); |
b448c4e3 SR |
2636 | if (!ret) |
2637 | ret = -EINVAL; | |
2638 | if (ret < 0) | |
2639 | return ret; | |
2640 | ||
2641 | return 0; | |
f6180773 SR |
2642 | } |
2643 | ||
2644 | static struct ftrace_func_command ftrace_mod_cmd = { | |
2645 | .name = "mod", | |
2646 | .func = ftrace_mod_callback, | |
2647 | }; | |
2648 | ||
2649 | static int __init ftrace_mod_cmd_init(void) | |
2650 | { | |
2651 | return register_ftrace_command(&ftrace_mod_cmd); | |
2652 | } | |
2653 | device_initcall(ftrace_mod_cmd_init); | |
2654 | ||
59df055f | 2655 | static void |
b6887d79 | 2656 | function_trace_probe_call(unsigned long ip, unsigned long parent_ip) |
59df055f | 2657 | { |
b6887d79 | 2658 | struct ftrace_func_probe *entry; |
59df055f SR |
2659 | struct hlist_head *hhd; |
2660 | struct hlist_node *n; | |
2661 | unsigned long key; | |
59df055f SR |
2662 | |
2663 | key = hash_long(ip, FTRACE_HASH_BITS); | |
2664 | ||
2665 | hhd = &ftrace_func_hash[key]; | |
2666 | ||
2667 | if (hlist_empty(hhd)) | |
2668 | return; | |
2669 | ||
2670 | /* | |
2671 | * Disable preemption for these calls to prevent a RCU grace | |
2672 | * period. This syncs the hash iteration and freeing of items | |
2673 | * on the hash. rcu_read_lock is too dangerous here. | |
2674 | */ | |
5168ae50 | 2675 | preempt_disable_notrace(); |
59df055f SR |
2676 | hlist_for_each_entry_rcu(entry, n, hhd, node) { |
2677 | if (entry->ip == ip) | |
2678 | entry->ops->func(ip, parent_ip, &entry->data); | |
2679 | } | |
5168ae50 | 2680 | preempt_enable_notrace(); |
59df055f SR |
2681 | } |
2682 | ||
b6887d79 | 2683 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 2684 | { |
fb9fb015 | 2685 | .func = function_trace_probe_call, |
59df055f SR |
2686 | }; |
2687 | ||
b6887d79 | 2688 | static int ftrace_probe_registered; |
59df055f | 2689 | |
b6887d79 | 2690 | static void __enable_ftrace_function_probe(void) |
59df055f | 2691 | { |
b848914c | 2692 | int ret; |
59df055f SR |
2693 | int i; |
2694 | ||
b6887d79 | 2695 | if (ftrace_probe_registered) |
59df055f SR |
2696 | return; |
2697 | ||
2698 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2699 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2700 | if (hhd->first) | |
2701 | break; | |
2702 | } | |
2703 | /* Nothing registered? */ | |
2704 | if (i == FTRACE_FUNC_HASHSIZE) | |
2705 | return; | |
2706 | ||
b848914c SR |
2707 | ret = __register_ftrace_function(&trace_probe_ops); |
2708 | if (!ret) | |
a1cd6173 | 2709 | ret = ftrace_startup(&trace_probe_ops, 0); |
b848914c | 2710 | |
b6887d79 | 2711 | ftrace_probe_registered = 1; |
59df055f SR |
2712 | } |
2713 | ||
b6887d79 | 2714 | static void __disable_ftrace_function_probe(void) |
59df055f | 2715 | { |
b848914c | 2716 | int ret; |
59df055f SR |
2717 | int i; |
2718 | ||
b6887d79 | 2719 | if (!ftrace_probe_registered) |
59df055f SR |
2720 | return; |
2721 | ||
2722 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2723 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2724 | if (hhd->first) | |
2725 | return; | |
2726 | } | |
2727 | ||
2728 | /* no more funcs left */ | |
b848914c SR |
2729 | ret = __unregister_ftrace_function(&trace_probe_ops); |
2730 | if (!ret) | |
2731 | ftrace_shutdown(&trace_probe_ops, 0); | |
2732 | ||
b6887d79 | 2733 | ftrace_probe_registered = 0; |
59df055f SR |
2734 | } |
2735 | ||
2736 | ||
2737 | static void ftrace_free_entry_rcu(struct rcu_head *rhp) | |
2738 | { | |
b6887d79 SR |
2739 | struct ftrace_func_probe *entry = |
2740 | container_of(rhp, struct ftrace_func_probe, rcu); | |
59df055f SR |
2741 | |
2742 | if (entry->ops->free) | |
2743 | entry->ops->free(&entry->data); | |
2744 | kfree(entry); | |
2745 | } | |
2746 | ||
2747 | ||
2748 | int | |
b6887d79 | 2749 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2750 | void *data) |
2751 | { | |
b6887d79 | 2752 | struct ftrace_func_probe *entry; |
59df055f SR |
2753 | struct ftrace_page *pg; |
2754 | struct dyn_ftrace *rec; | |
59df055f | 2755 | int type, len, not; |
6a24a244 | 2756 | unsigned long key; |
59df055f SR |
2757 | int count = 0; |
2758 | char *search; | |
2759 | ||
3f6fe06d | 2760 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
2761 | len = strlen(search); |
2762 | ||
b6887d79 | 2763 | /* we do not support '!' for function probes */ |
59df055f SR |
2764 | if (WARN_ON(not)) |
2765 | return -EINVAL; | |
2766 | ||
2767 | mutex_lock(&ftrace_lock); | |
59df055f | 2768 | |
45a4a237 SR |
2769 | if (unlikely(ftrace_disabled)) |
2770 | goto out_unlock; | |
59df055f | 2771 | |
45a4a237 | 2772 | do_for_each_ftrace_rec(pg, rec) { |
59df055f | 2773 | |
b9df92d2 | 2774 | if (!ftrace_match_record(rec, NULL, search, len, type)) |
59df055f SR |
2775 | continue; |
2776 | ||
2777 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
2778 | if (!entry) { | |
b6887d79 | 2779 | /* If we did not process any, then return error */ |
59df055f SR |
2780 | if (!count) |
2781 | count = -ENOMEM; | |
2782 | goto out_unlock; | |
2783 | } | |
2784 | ||
2785 | count++; | |
2786 | ||
2787 | entry->data = data; | |
2788 | ||
2789 | /* | |
2790 | * The caller might want to do something special | |
2791 | * for each function we find. We call the callback | |
2792 | * to give the caller an opportunity to do so. | |
2793 | */ | |
2794 | if (ops->callback) { | |
2795 | if (ops->callback(rec->ip, &entry->data) < 0) { | |
2796 | /* caller does not like this func */ | |
2797 | kfree(entry); | |
2798 | continue; | |
2799 | } | |
2800 | } | |
2801 | ||
2802 | entry->ops = ops; | |
2803 | entry->ip = rec->ip; | |
2804 | ||
2805 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
2806 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
2807 | ||
2808 | } while_for_each_ftrace_rec(); | |
b6887d79 | 2809 | __enable_ftrace_function_probe(); |
59df055f SR |
2810 | |
2811 | out_unlock: | |
2812 | mutex_unlock(&ftrace_lock); | |
2813 | ||
2814 | return count; | |
2815 | } | |
2816 | ||
2817 | enum { | |
b6887d79 SR |
2818 | PROBE_TEST_FUNC = 1, |
2819 | PROBE_TEST_DATA = 2 | |
59df055f SR |
2820 | }; |
2821 | ||
2822 | static void | |
b6887d79 | 2823 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2824 | void *data, int flags) |
2825 | { | |
b6887d79 | 2826 | struct ftrace_func_probe *entry; |
59df055f SR |
2827 | struct hlist_node *n, *tmp; |
2828 | char str[KSYM_SYMBOL_LEN]; | |
2829 | int type = MATCH_FULL; | |
2830 | int i, len = 0; | |
2831 | char *search; | |
2832 | ||
b36461da | 2833 | if (glob && (strcmp(glob, "*") == 0 || !strlen(glob))) |
59df055f | 2834 | glob = NULL; |
b36461da | 2835 | else if (glob) { |
59df055f SR |
2836 | int not; |
2837 | ||
3f6fe06d | 2838 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
2839 | len = strlen(search); |
2840 | ||
b6887d79 | 2841 | /* we do not support '!' for function probes */ |
59df055f SR |
2842 | if (WARN_ON(not)) |
2843 | return; | |
2844 | } | |
2845 | ||
2846 | mutex_lock(&ftrace_lock); | |
2847 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2848 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2849 | ||
2850 | hlist_for_each_entry_safe(entry, n, tmp, hhd, node) { | |
2851 | ||
2852 | /* break up if statements for readability */ | |
b6887d79 | 2853 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
2854 | continue; |
2855 | ||
b6887d79 | 2856 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
2857 | continue; |
2858 | ||
2859 | /* do this last, since it is the most expensive */ | |
2860 | if (glob) { | |
2861 | kallsyms_lookup(entry->ip, NULL, NULL, | |
2862 | NULL, str); | |
2863 | if (!ftrace_match(str, glob, len, type)) | |
2864 | continue; | |
2865 | } | |
2866 | ||
2867 | hlist_del(&entry->node); | |
2868 | call_rcu(&entry->rcu, ftrace_free_entry_rcu); | |
2869 | } | |
2870 | } | |
b6887d79 | 2871 | __disable_ftrace_function_probe(); |
59df055f SR |
2872 | mutex_unlock(&ftrace_lock); |
2873 | } | |
2874 | ||
2875 | void | |
b6887d79 | 2876 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2877 | void *data) |
2878 | { | |
b6887d79 SR |
2879 | __unregister_ftrace_function_probe(glob, ops, data, |
2880 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
2881 | } |
2882 | ||
2883 | void | |
b6887d79 | 2884 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 2885 | { |
b6887d79 | 2886 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
2887 | } |
2888 | ||
b6887d79 | 2889 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 2890 | { |
b6887d79 | 2891 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
2892 | } |
2893 | ||
f6180773 SR |
2894 | static LIST_HEAD(ftrace_commands); |
2895 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
2896 | ||
2897 | int register_ftrace_command(struct ftrace_func_command *cmd) | |
2898 | { | |
2899 | struct ftrace_func_command *p; | |
2900 | int ret = 0; | |
2901 | ||
2902 | mutex_lock(&ftrace_cmd_mutex); | |
2903 | list_for_each_entry(p, &ftrace_commands, list) { | |
2904 | if (strcmp(cmd->name, p->name) == 0) { | |
2905 | ret = -EBUSY; | |
2906 | goto out_unlock; | |
2907 | } | |
2908 | } | |
2909 | list_add(&cmd->list, &ftrace_commands); | |
2910 | out_unlock: | |
2911 | mutex_unlock(&ftrace_cmd_mutex); | |
2912 | ||
2913 | return ret; | |
2914 | } | |
2915 | ||
2916 | int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
2917 | { | |
2918 | struct ftrace_func_command *p, *n; | |
2919 | int ret = -ENODEV; | |
2920 | ||
2921 | mutex_lock(&ftrace_cmd_mutex); | |
2922 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
2923 | if (strcmp(cmd->name, p->name) == 0) { | |
2924 | ret = 0; | |
2925 | list_del_init(&p->list); | |
2926 | goto out_unlock; | |
2927 | } | |
2928 | } | |
2929 | out_unlock: | |
2930 | mutex_unlock(&ftrace_cmd_mutex); | |
2931 | ||
2932 | return ret; | |
2933 | } | |
2934 | ||
33dc9b12 SR |
2935 | static int ftrace_process_regex(struct ftrace_hash *hash, |
2936 | char *buff, int len, int enable) | |
64e7c440 | 2937 | { |
f6180773 | 2938 | char *func, *command, *next = buff; |
6a24a244 | 2939 | struct ftrace_func_command *p; |
0aff1c0c | 2940 | int ret = -EINVAL; |
64e7c440 SR |
2941 | |
2942 | func = strsep(&next, ":"); | |
2943 | ||
2944 | if (!next) { | |
1cf41dd7 | 2945 | ret = ftrace_match_records(hash, func, len); |
b448c4e3 SR |
2946 | if (!ret) |
2947 | ret = -EINVAL; | |
2948 | if (ret < 0) | |
2949 | return ret; | |
2950 | return 0; | |
64e7c440 SR |
2951 | } |
2952 | ||
f6180773 | 2953 | /* command found */ |
64e7c440 SR |
2954 | |
2955 | command = strsep(&next, ":"); | |
2956 | ||
f6180773 SR |
2957 | mutex_lock(&ftrace_cmd_mutex); |
2958 | list_for_each_entry(p, &ftrace_commands, list) { | |
2959 | if (strcmp(p->name, command) == 0) { | |
43dd61c9 | 2960 | ret = p->func(hash, func, command, next, enable); |
f6180773 SR |
2961 | goto out_unlock; |
2962 | } | |
64e7c440 | 2963 | } |
f6180773 SR |
2964 | out_unlock: |
2965 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 2966 | |
f6180773 | 2967 | return ret; |
64e7c440 SR |
2968 | } |
2969 | ||
e309b41d | 2970 | static ssize_t |
41c52c0d SR |
2971 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
2972 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
2973 | { |
2974 | struct ftrace_iterator *iter; | |
689fd8b6 | 2975 | struct trace_parser *parser; |
2976 | ssize_t ret, read; | |
5072c59f | 2977 | |
4ba7978e | 2978 | if (!cnt) |
5072c59f SR |
2979 | return 0; |
2980 | ||
41c52c0d | 2981 | mutex_lock(&ftrace_regex_lock); |
5072c59f | 2982 | |
45a4a237 SR |
2983 | ret = -ENODEV; |
2984 | if (unlikely(ftrace_disabled)) | |
2985 | goto out_unlock; | |
2986 | ||
5072c59f SR |
2987 | if (file->f_mode & FMODE_READ) { |
2988 | struct seq_file *m = file->private_data; | |
2989 | iter = m->private; | |
2990 | } else | |
2991 | iter = file->private_data; | |
2992 | ||
689fd8b6 | 2993 | parser = &iter->parser; |
2994 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 2995 | |
4ba7978e | 2996 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 2997 | !trace_parser_cont(parser)) { |
33dc9b12 | 2998 | ret = ftrace_process_regex(iter->hash, parser->buffer, |
689fd8b6 | 2999 | parser->idx, enable); |
313254a9 | 3000 | trace_parser_clear(parser); |
5072c59f | 3001 | if (ret) |
ed146b25 | 3002 | goto out_unlock; |
eda1e328 | 3003 | } |
5072c59f | 3004 | |
5072c59f | 3005 | ret = read; |
ed146b25 | 3006 | out_unlock: |
689fd8b6 | 3007 | mutex_unlock(&ftrace_regex_lock); |
ed146b25 | 3008 | |
5072c59f SR |
3009 | return ret; |
3010 | } | |
3011 | ||
41c52c0d SR |
3012 | static ssize_t |
3013 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
3014 | size_t cnt, loff_t *ppos) | |
3015 | { | |
3016 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
3017 | } | |
3018 | ||
3019 | static ssize_t | |
3020 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
3021 | size_t cnt, loff_t *ppos) | |
3022 | { | |
3023 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
3024 | } | |
3025 | ||
33dc9b12 | 3026 | static int |
f45948e8 SR |
3027 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, |
3028 | int reset, int enable) | |
41c52c0d | 3029 | { |
33dc9b12 | 3030 | struct ftrace_hash **orig_hash; |
f45948e8 | 3031 | struct ftrace_hash *hash; |
33dc9b12 | 3032 | int ret; |
f45948e8 | 3033 | |
936e074b SR |
3034 | /* All global ops uses the global ops filters */ |
3035 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) | |
3036 | ops = &global_ops; | |
3037 | ||
41c52c0d | 3038 | if (unlikely(ftrace_disabled)) |
33dc9b12 | 3039 | return -ENODEV; |
41c52c0d | 3040 | |
f45948e8 | 3041 | if (enable) |
33dc9b12 | 3042 | orig_hash = &ops->filter_hash; |
f45948e8 | 3043 | else |
33dc9b12 SR |
3044 | orig_hash = &ops->notrace_hash; |
3045 | ||
3046 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
3047 | if (!hash) | |
3048 | return -ENOMEM; | |
f45948e8 | 3049 | |
41c52c0d SR |
3050 | mutex_lock(&ftrace_regex_lock); |
3051 | if (reset) | |
1cf41dd7 | 3052 | ftrace_filter_reset(hash); |
41c52c0d | 3053 | if (buf) |
1cf41dd7 | 3054 | ftrace_match_records(hash, buf, len); |
33dc9b12 SR |
3055 | |
3056 | mutex_lock(&ftrace_lock); | |
41fb61c2 | 3057 | ret = ftrace_hash_move(ops, enable, orig_hash, hash); |
072126f4 SR |
3058 | if (!ret && ops->flags & FTRACE_OPS_FL_ENABLED |
3059 | && ftrace_enabled) | |
30fb6aa7 | 3060 | ftrace_run_update_code(FTRACE_UPDATE_CALLS); |
072126f4 | 3061 | |
33dc9b12 SR |
3062 | mutex_unlock(&ftrace_lock); |
3063 | ||
41c52c0d | 3064 | mutex_unlock(&ftrace_regex_lock); |
33dc9b12 SR |
3065 | |
3066 | free_ftrace_hash(hash); | |
3067 | return ret; | |
41c52c0d SR |
3068 | } |
3069 | ||
77a2b37d SR |
3070 | /** |
3071 | * ftrace_set_filter - set a function to filter on in ftrace | |
936e074b SR |
3072 | * @ops - the ops to set the filter with |
3073 | * @buf - the string that holds the function filter text. | |
3074 | * @len - the length of the string. | |
3075 | * @reset - non zero to reset all filters before applying this filter. | |
3076 | * | |
3077 | * Filters denote which functions should be enabled when tracing is enabled. | |
3078 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
3079 | */ | |
3080 | void ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, | |
3081 | int len, int reset) | |
3082 | { | |
3083 | ftrace_set_regex(ops, buf, len, reset, 1); | |
3084 | } | |
3085 | EXPORT_SYMBOL_GPL(ftrace_set_filter); | |
3086 | ||
3087 | /** | |
3088 | * ftrace_set_notrace - set a function to not trace in ftrace | |
3089 | * @ops - the ops to set the notrace filter with | |
3090 | * @buf - the string that holds the function notrace text. | |
3091 | * @len - the length of the string. | |
3092 | * @reset - non zero to reset all filters before applying this filter. | |
3093 | * | |
3094 | * Notrace Filters denote which functions should not be enabled when tracing | |
3095 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
3096 | * for tracing. | |
3097 | */ | |
3098 | void ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, | |
3099 | int len, int reset) | |
3100 | { | |
3101 | ftrace_set_regex(ops, buf, len, reset, 0); | |
3102 | } | |
3103 | EXPORT_SYMBOL_GPL(ftrace_set_notrace); | |
3104 | /** | |
3105 | * ftrace_set_filter - set a function to filter on in ftrace | |
3106 | * @ops - the ops to set the filter with | |
77a2b37d SR |
3107 | * @buf - the string that holds the function filter text. |
3108 | * @len - the length of the string. | |
3109 | * @reset - non zero to reset all filters before applying this filter. | |
3110 | * | |
3111 | * Filters denote which functions should be enabled when tracing is enabled. | |
3112 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
3113 | */ | |
936e074b | 3114 | void ftrace_set_global_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 3115 | { |
f45948e8 | 3116 | ftrace_set_regex(&global_ops, buf, len, reset, 1); |
41c52c0d | 3117 | } |
936e074b | 3118 | EXPORT_SYMBOL_GPL(ftrace_set_global_filter); |
4eebcc81 | 3119 | |
41c52c0d SR |
3120 | /** |
3121 | * ftrace_set_notrace - set a function to not trace in ftrace | |
936e074b | 3122 | * @ops - the ops to set the notrace filter with |
41c52c0d SR |
3123 | * @buf - the string that holds the function notrace text. |
3124 | * @len - the length of the string. | |
3125 | * @reset - non zero to reset all filters before applying this filter. | |
3126 | * | |
3127 | * Notrace Filters denote which functions should not be enabled when tracing | |
3128 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
3129 | * for tracing. | |
3130 | */ | |
936e074b | 3131 | void ftrace_set_global_notrace(unsigned char *buf, int len, int reset) |
41c52c0d | 3132 | { |
f45948e8 | 3133 | ftrace_set_regex(&global_ops, buf, len, reset, 0); |
77a2b37d | 3134 | } |
936e074b | 3135 | EXPORT_SYMBOL_GPL(ftrace_set_global_notrace); |
77a2b37d | 3136 | |
2af15d6a SR |
3137 | /* |
3138 | * command line interface to allow users to set filters on boot up. | |
3139 | */ | |
3140 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
3141 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
3142 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
3143 | ||
3144 | static int __init set_ftrace_notrace(char *str) | |
3145 | { | |
3146 | strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); | |
3147 | return 1; | |
3148 | } | |
3149 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
3150 | ||
3151 | static int __init set_ftrace_filter(char *str) | |
3152 | { | |
3153 | strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); | |
3154 | return 1; | |
3155 | } | |
3156 | __setup("ftrace_filter=", set_ftrace_filter); | |
3157 | ||
369bc18f | 3158 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 3159 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
801c29fd SR |
3160 | static int ftrace_set_func(unsigned long *array, int *idx, char *buffer); |
3161 | ||
369bc18f SA |
3162 | static int __init set_graph_function(char *str) |
3163 | { | |
06f43d66 | 3164 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
3165 | return 1; |
3166 | } | |
3167 | __setup("ftrace_graph_filter=", set_graph_function); | |
3168 | ||
3169 | static void __init set_ftrace_early_graph(char *buf) | |
3170 | { | |
3171 | int ret; | |
3172 | char *func; | |
3173 | ||
3174 | while (buf) { | |
3175 | func = strsep(&buf, ","); | |
3176 | /* we allow only one expression at a time */ | |
3177 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, | |
3178 | func); | |
3179 | if (ret) | |
3180 | printk(KERN_DEBUG "ftrace: function %s not " | |
3181 | "traceable\n", func); | |
3182 | } | |
3183 | } | |
3184 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
3185 | ||
f45948e8 SR |
3186 | static void __init |
3187 | set_ftrace_early_filter(struct ftrace_ops *ops, char *buf, int enable) | |
2af15d6a SR |
3188 | { |
3189 | char *func; | |
3190 | ||
3191 | while (buf) { | |
3192 | func = strsep(&buf, ","); | |
f45948e8 | 3193 | ftrace_set_regex(ops, func, strlen(func), 0, enable); |
2af15d6a SR |
3194 | } |
3195 | } | |
3196 | ||
3197 | static void __init set_ftrace_early_filters(void) | |
3198 | { | |
3199 | if (ftrace_filter_buf[0]) | |
f45948e8 | 3200 | set_ftrace_early_filter(&global_ops, ftrace_filter_buf, 1); |
2af15d6a | 3201 | if (ftrace_notrace_buf[0]) |
f45948e8 | 3202 | set_ftrace_early_filter(&global_ops, ftrace_notrace_buf, 0); |
369bc18f SA |
3203 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
3204 | if (ftrace_graph_buf[0]) | |
3205 | set_ftrace_early_graph(ftrace_graph_buf); | |
3206 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2af15d6a SR |
3207 | } |
3208 | ||
e309b41d | 3209 | static int |
1cf41dd7 | 3210 | ftrace_regex_release(struct inode *inode, struct file *file) |
5072c59f SR |
3211 | { |
3212 | struct seq_file *m = (struct seq_file *)file->private_data; | |
3213 | struct ftrace_iterator *iter; | |
33dc9b12 | 3214 | struct ftrace_hash **orig_hash; |
689fd8b6 | 3215 | struct trace_parser *parser; |
ed926f9b | 3216 | int filter_hash; |
33dc9b12 | 3217 | int ret; |
5072c59f | 3218 | |
41c52c0d | 3219 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
3220 | if (file->f_mode & FMODE_READ) { |
3221 | iter = m->private; | |
3222 | ||
3223 | seq_release(inode, file); | |
3224 | } else | |
3225 | iter = file->private_data; | |
3226 | ||
689fd8b6 | 3227 | parser = &iter->parser; |
3228 | if (trace_parser_loaded(parser)) { | |
3229 | parser->buffer[parser->idx] = 0; | |
1cf41dd7 | 3230 | ftrace_match_records(iter->hash, parser->buffer, parser->idx); |
5072c59f SR |
3231 | } |
3232 | ||
689fd8b6 | 3233 | trace_parser_put(parser); |
689fd8b6 | 3234 | |
058e297d | 3235 | if (file->f_mode & FMODE_WRITE) { |
ed926f9b SR |
3236 | filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); |
3237 | ||
3238 | if (filter_hash) | |
33dc9b12 | 3239 | orig_hash = &iter->ops->filter_hash; |
ed926f9b SR |
3240 | else |
3241 | orig_hash = &iter->ops->notrace_hash; | |
33dc9b12 | 3242 | |
058e297d | 3243 | mutex_lock(&ftrace_lock); |
41fb61c2 SR |
3244 | ret = ftrace_hash_move(iter->ops, filter_hash, |
3245 | orig_hash, iter->hash); | |
3246 | if (!ret && (iter->ops->flags & FTRACE_OPS_FL_ENABLED) | |
3247 | && ftrace_enabled) | |
30fb6aa7 | 3248 | ftrace_run_update_code(FTRACE_UPDATE_CALLS); |
41fb61c2 | 3249 | |
058e297d SR |
3250 | mutex_unlock(&ftrace_lock); |
3251 | } | |
33dc9b12 SR |
3252 | free_ftrace_hash(iter->hash); |
3253 | kfree(iter); | |
058e297d | 3254 | |
41c52c0d | 3255 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
3256 | return 0; |
3257 | } | |
3258 | ||
5e2336a0 | 3259 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
3260 | .open = ftrace_avail_open, |
3261 | .read = seq_read, | |
3262 | .llseek = seq_lseek, | |
3be04b47 | 3263 | .release = seq_release_private, |
5072c59f SR |
3264 | }; |
3265 | ||
647bcd03 SR |
3266 | static const struct file_operations ftrace_enabled_fops = { |
3267 | .open = ftrace_enabled_open, | |
3268 | .read = seq_read, | |
3269 | .llseek = seq_lseek, | |
3270 | .release = seq_release_private, | |
3271 | }; | |
3272 | ||
5e2336a0 | 3273 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 3274 | .open = ftrace_filter_open, |
850a80cf | 3275 | .read = seq_read, |
5072c59f | 3276 | .write = ftrace_filter_write, |
98c4fd04 | 3277 | .llseek = ftrace_regex_lseek, |
1cf41dd7 | 3278 | .release = ftrace_regex_release, |
5072c59f SR |
3279 | }; |
3280 | ||
5e2336a0 | 3281 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 3282 | .open = ftrace_notrace_open, |
850a80cf | 3283 | .read = seq_read, |
41c52c0d SR |
3284 | .write = ftrace_notrace_write, |
3285 | .llseek = ftrace_regex_lseek, | |
1cf41dd7 | 3286 | .release = ftrace_regex_release, |
41c52c0d SR |
3287 | }; |
3288 | ||
ea4e2bc4 SR |
3289 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
3290 | ||
3291 | static DEFINE_MUTEX(graph_lock); | |
3292 | ||
3293 | int ftrace_graph_count; | |
c7c6b1fe | 3294 | int ftrace_graph_filter_enabled; |
ea4e2bc4 SR |
3295 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
3296 | ||
3297 | static void * | |
85951842 | 3298 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 3299 | { |
85951842 | 3300 | if (*pos >= ftrace_graph_count) |
ea4e2bc4 | 3301 | return NULL; |
a4ec5e0c | 3302 | return &ftrace_graph_funcs[*pos]; |
85951842 | 3303 | } |
ea4e2bc4 | 3304 | |
85951842 LZ |
3305 | static void * |
3306 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
3307 | { | |
3308 | (*pos)++; | |
3309 | return __g_next(m, pos); | |
ea4e2bc4 SR |
3310 | } |
3311 | ||
3312 | static void *g_start(struct seq_file *m, loff_t *pos) | |
3313 | { | |
ea4e2bc4 SR |
3314 | mutex_lock(&graph_lock); |
3315 | ||
f9349a8f | 3316 | /* Nothing, tell g_show to print all functions are enabled */ |
c7c6b1fe | 3317 | if (!ftrace_graph_filter_enabled && !*pos) |
f9349a8f FW |
3318 | return (void *)1; |
3319 | ||
85951842 | 3320 | return __g_next(m, pos); |
ea4e2bc4 SR |
3321 | } |
3322 | ||
3323 | static void g_stop(struct seq_file *m, void *p) | |
3324 | { | |
3325 | mutex_unlock(&graph_lock); | |
3326 | } | |
3327 | ||
3328 | static int g_show(struct seq_file *m, void *v) | |
3329 | { | |
3330 | unsigned long *ptr = v; | |
ea4e2bc4 SR |
3331 | |
3332 | if (!ptr) | |
3333 | return 0; | |
3334 | ||
f9349a8f FW |
3335 | if (ptr == (unsigned long *)1) { |
3336 | seq_printf(m, "#### all functions enabled ####\n"); | |
3337 | return 0; | |
3338 | } | |
3339 | ||
b375a11a | 3340 | seq_printf(m, "%ps\n", (void *)*ptr); |
ea4e2bc4 SR |
3341 | |
3342 | return 0; | |
3343 | } | |
3344 | ||
88e9d34c | 3345 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
3346 | .start = g_start, |
3347 | .next = g_next, | |
3348 | .stop = g_stop, | |
3349 | .show = g_show, | |
3350 | }; | |
3351 | ||
3352 | static int | |
3353 | ftrace_graph_open(struct inode *inode, struct file *file) | |
3354 | { | |
3355 | int ret = 0; | |
3356 | ||
3357 | if (unlikely(ftrace_disabled)) | |
3358 | return -ENODEV; | |
3359 | ||
3360 | mutex_lock(&graph_lock); | |
3361 | if ((file->f_mode & FMODE_WRITE) && | |
8650ae32 | 3362 | (file->f_flags & O_TRUNC)) { |
c7c6b1fe | 3363 | ftrace_graph_filter_enabled = 0; |
ea4e2bc4 SR |
3364 | ftrace_graph_count = 0; |
3365 | memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); | |
3366 | } | |
a4ec5e0c | 3367 | mutex_unlock(&graph_lock); |
ea4e2bc4 | 3368 | |
a4ec5e0c | 3369 | if (file->f_mode & FMODE_READ) |
ea4e2bc4 | 3370 | ret = seq_open(file, &ftrace_graph_seq_ops); |
ea4e2bc4 SR |
3371 | |
3372 | return ret; | |
3373 | } | |
3374 | ||
87827111 LZ |
3375 | static int |
3376 | ftrace_graph_release(struct inode *inode, struct file *file) | |
3377 | { | |
3378 | if (file->f_mode & FMODE_READ) | |
3379 | seq_release(inode, file); | |
3380 | return 0; | |
3381 | } | |
3382 | ||
ea4e2bc4 | 3383 | static int |
f9349a8f | 3384 | ftrace_set_func(unsigned long *array, int *idx, char *buffer) |
ea4e2bc4 | 3385 | { |
ea4e2bc4 SR |
3386 | struct dyn_ftrace *rec; |
3387 | struct ftrace_page *pg; | |
f9349a8f | 3388 | int search_len; |
c7c6b1fe | 3389 | int fail = 1; |
f9349a8f FW |
3390 | int type, not; |
3391 | char *search; | |
3392 | bool exists; | |
3393 | int i; | |
ea4e2bc4 | 3394 | |
f9349a8f | 3395 | /* decode regex */ |
3f6fe06d | 3396 | type = filter_parse_regex(buffer, strlen(buffer), &search, ¬); |
c7c6b1fe LZ |
3397 | if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS) |
3398 | return -EBUSY; | |
f9349a8f FW |
3399 | |
3400 | search_len = strlen(search); | |
3401 | ||
52baf119 | 3402 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
3403 | |
3404 | if (unlikely(ftrace_disabled)) { | |
3405 | mutex_unlock(&ftrace_lock); | |
3406 | return -ENODEV; | |
3407 | } | |
3408 | ||
265c831c SR |
3409 | do_for_each_ftrace_rec(pg, rec) { |
3410 | ||
b9df92d2 | 3411 | if (ftrace_match_record(rec, NULL, search, search_len, type)) { |
c7c6b1fe | 3412 | /* if it is in the array */ |
f9349a8f | 3413 | exists = false; |
c7c6b1fe | 3414 | for (i = 0; i < *idx; i++) { |
f9349a8f FW |
3415 | if (array[i] == rec->ip) { |
3416 | exists = true; | |
265c831c SR |
3417 | break; |
3418 | } | |
c7c6b1fe LZ |
3419 | } |
3420 | ||
3421 | if (!not) { | |
3422 | fail = 0; | |
3423 | if (!exists) { | |
3424 | array[(*idx)++] = rec->ip; | |
3425 | if (*idx >= FTRACE_GRAPH_MAX_FUNCS) | |
3426 | goto out; | |
3427 | } | |
3428 | } else { | |
3429 | if (exists) { | |
3430 | array[i] = array[--(*idx)]; | |
3431 | array[*idx] = 0; | |
3432 | fail = 0; | |
3433 | } | |
3434 | } | |
ea4e2bc4 | 3435 | } |
265c831c | 3436 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 3437 | out: |
52baf119 | 3438 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 3439 | |
c7c6b1fe LZ |
3440 | if (fail) |
3441 | return -EINVAL; | |
3442 | ||
3443 | ftrace_graph_filter_enabled = 1; | |
3444 | return 0; | |
ea4e2bc4 SR |
3445 | } |
3446 | ||
3447 | static ssize_t | |
3448 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
3449 | size_t cnt, loff_t *ppos) | |
3450 | { | |
689fd8b6 | 3451 | struct trace_parser parser; |
4ba7978e | 3452 | ssize_t read, ret; |
ea4e2bc4 | 3453 | |
c7c6b1fe | 3454 | if (!cnt) |
ea4e2bc4 SR |
3455 | return 0; |
3456 | ||
3457 | mutex_lock(&graph_lock); | |
3458 | ||
689fd8b6 | 3459 | if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) { |
3460 | ret = -ENOMEM; | |
1eb90f13 | 3461 | goto out_unlock; |
ea4e2bc4 SR |
3462 | } |
3463 | ||
689fd8b6 | 3464 | read = trace_get_user(&parser, ubuf, cnt, ppos); |
ea4e2bc4 | 3465 | |
4ba7978e | 3466 | if (read >= 0 && trace_parser_loaded((&parser))) { |
689fd8b6 | 3467 | parser.buffer[parser.idx] = 0; |
3468 | ||
3469 | /* we allow only one expression at a time */ | |
a4ec5e0c | 3470 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, |
689fd8b6 | 3471 | parser.buffer); |
ea4e2bc4 | 3472 | if (ret) |
1eb90f13 | 3473 | goto out_free; |
ea4e2bc4 | 3474 | } |
ea4e2bc4 SR |
3475 | |
3476 | ret = read; | |
1eb90f13 LZ |
3477 | |
3478 | out_free: | |
689fd8b6 | 3479 | trace_parser_put(&parser); |
1eb90f13 | 3480 | out_unlock: |
ea4e2bc4 SR |
3481 | mutex_unlock(&graph_lock); |
3482 | ||
3483 | return ret; | |
3484 | } | |
3485 | ||
3486 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
3487 | .open = ftrace_graph_open, |
3488 | .read = seq_read, | |
3489 | .write = ftrace_graph_write, | |
3490 | .release = ftrace_graph_release, | |
6038f373 | 3491 | .llseek = seq_lseek, |
ea4e2bc4 SR |
3492 | }; |
3493 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
3494 | ||
df4fc315 | 3495 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 3496 | { |
5072c59f | 3497 | |
5452af66 FW |
3498 | trace_create_file("available_filter_functions", 0444, |
3499 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 3500 | |
647bcd03 SR |
3501 | trace_create_file("enabled_functions", 0444, |
3502 | d_tracer, NULL, &ftrace_enabled_fops); | |
3503 | ||
5452af66 FW |
3504 | trace_create_file("set_ftrace_filter", 0644, d_tracer, |
3505 | NULL, &ftrace_filter_fops); | |
41c52c0d | 3506 | |
5452af66 | 3507 | trace_create_file("set_ftrace_notrace", 0644, d_tracer, |
41c52c0d | 3508 | NULL, &ftrace_notrace_fops); |
ad90c0e3 | 3509 | |
ea4e2bc4 | 3510 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 3511 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
3512 | NULL, |
3513 | &ftrace_graph_fops); | |
ea4e2bc4 SR |
3514 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
3515 | ||
5072c59f SR |
3516 | return 0; |
3517 | } | |
3518 | ||
5cb084bb | 3519 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 3520 | unsigned long *start, |
68bf21aa SR |
3521 | unsigned long *end) |
3522 | { | |
3523 | unsigned long *p; | |
3524 | unsigned long addr; | |
4376cac6 | 3525 | unsigned long flags = 0; /* Shut up gcc */ |
68bf21aa | 3526 | |
e6ea44e9 | 3527 | mutex_lock(&ftrace_lock); |
32082309 SR |
3528 | /* |
3529 | * Core and each module needs their own pages, as | |
3530 | * modules will free them when they are removed. | |
3531 | * Force a new page to be allocated for modules. | |
3532 | */ | |
3533 | if (mod) { | |
3534 | if (!ftrace_pages) | |
3535 | return -ENOMEM; | |
3536 | ||
3537 | /* | |
3538 | * If the last page was full, it will be | |
3539 | * allocated anyway. | |
3540 | */ | |
3541 | if (ftrace_pages->index != ENTRIES_PER_PAGE) { | |
3542 | ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL); | |
3543 | if (!ftrace_pages->next) | |
3544 | return -ENOMEM; | |
3545 | ftrace_pages = ftrace_pages->next; | |
3546 | } | |
3547 | } | |
3548 | ||
68bf21aa SR |
3549 | p = start; |
3550 | while (p < end) { | |
3551 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
3552 | /* |
3553 | * Some architecture linkers will pad between | |
3554 | * the different mcount_loc sections of different | |
3555 | * object files to satisfy alignments. | |
3556 | * Skip any NULL pointers. | |
3557 | */ | |
3558 | if (!addr) | |
3559 | continue; | |
68bf21aa | 3560 | ftrace_record_ip(addr); |
68bf21aa SR |
3561 | } |
3562 | ||
a4f18ed1 | 3563 | /* |
4376cac6 SR |
3564 | * We only need to disable interrupts on start up |
3565 | * because we are modifying code that an interrupt | |
3566 | * may execute, and the modification is not atomic. | |
3567 | * But for modules, nothing runs the code we modify | |
3568 | * until we are finished with it, and there's no | |
3569 | * reason to cause large interrupt latencies while we do it. | |
a4f18ed1 | 3570 | */ |
4376cac6 SR |
3571 | if (!mod) |
3572 | local_irq_save(flags); | |
31e88909 | 3573 | ftrace_update_code(mod); |
4376cac6 SR |
3574 | if (!mod) |
3575 | local_irq_restore(flags); | |
e6ea44e9 | 3576 | mutex_unlock(&ftrace_lock); |
68bf21aa SR |
3577 | |
3578 | return 0; | |
3579 | } | |
3580 | ||
93eb677d | 3581 | #ifdef CONFIG_MODULES |
32082309 SR |
3582 | |
3583 | #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next) | |
3584 | ||
e7247a15 | 3585 | void ftrace_release_mod(struct module *mod) |
93eb677d SR |
3586 | { |
3587 | struct dyn_ftrace *rec; | |
32082309 | 3588 | struct ftrace_page **last_pg; |
93eb677d | 3589 | struct ftrace_page *pg; |
93eb677d | 3590 | |
45a4a237 SR |
3591 | mutex_lock(&ftrace_lock); |
3592 | ||
e7247a15 | 3593 | if (ftrace_disabled) |
45a4a237 | 3594 | goto out_unlock; |
93eb677d | 3595 | |
32082309 SR |
3596 | /* |
3597 | * Each module has its own ftrace_pages, remove | |
3598 | * them from the list. | |
3599 | */ | |
3600 | last_pg = &ftrace_pages_start; | |
3601 | for (pg = ftrace_pages_start; pg; pg = *last_pg) { | |
3602 | rec = &pg->records[0]; | |
e7247a15 | 3603 | if (within_module_core(rec->ip, mod)) { |
93eb677d | 3604 | /* |
32082309 SR |
3605 | * As core pages are first, the first |
3606 | * page should never be a module page. | |
93eb677d | 3607 | */ |
32082309 SR |
3608 | if (WARN_ON(pg == ftrace_pages_start)) |
3609 | goto out_unlock; | |
3610 | ||
3611 | /* Check if we are deleting the last page */ | |
3612 | if (pg == ftrace_pages) | |
3613 | ftrace_pages = next_to_ftrace_page(last_pg); | |
3614 | ||
3615 | *last_pg = pg->next; | |
3616 | free_page((unsigned long)pg); | |
3617 | } else | |
3618 | last_pg = &pg->next; | |
3619 | } | |
45a4a237 | 3620 | out_unlock: |
93eb677d SR |
3621 | mutex_unlock(&ftrace_lock); |
3622 | } | |
3623 | ||
3624 | static void ftrace_init_module(struct module *mod, | |
3625 | unsigned long *start, unsigned long *end) | |
90d595fe | 3626 | { |
00fd61ae | 3627 | if (ftrace_disabled || start == end) |
fed1939c | 3628 | return; |
5cb084bb | 3629 | ftrace_process_locs(mod, start, end); |
90d595fe SR |
3630 | } |
3631 | ||
93eb677d SR |
3632 | static int ftrace_module_notify(struct notifier_block *self, |
3633 | unsigned long val, void *data) | |
3634 | { | |
3635 | struct module *mod = data; | |
3636 | ||
3637 | switch (val) { | |
3638 | case MODULE_STATE_COMING: | |
3639 | ftrace_init_module(mod, mod->ftrace_callsites, | |
3640 | mod->ftrace_callsites + | |
3641 | mod->num_ftrace_callsites); | |
3642 | break; | |
3643 | case MODULE_STATE_GOING: | |
e7247a15 | 3644 | ftrace_release_mod(mod); |
93eb677d SR |
3645 | break; |
3646 | } | |
3647 | ||
3648 | return 0; | |
3649 | } | |
3650 | #else | |
3651 | static int ftrace_module_notify(struct notifier_block *self, | |
3652 | unsigned long val, void *data) | |
3653 | { | |
3654 | return 0; | |
3655 | } | |
3656 | #endif /* CONFIG_MODULES */ | |
3657 | ||
3658 | struct notifier_block ftrace_module_nb = { | |
3659 | .notifier_call = ftrace_module_notify, | |
3660 | .priority = 0, | |
3661 | }; | |
3662 | ||
68bf21aa SR |
3663 | extern unsigned long __start_mcount_loc[]; |
3664 | extern unsigned long __stop_mcount_loc[]; | |
3665 | ||
3666 | void __init ftrace_init(void) | |
3667 | { | |
3668 | unsigned long count, addr, flags; | |
3669 | int ret; | |
3670 | ||
3671 | /* Keep the ftrace pointer to the stub */ | |
3672 | addr = (unsigned long)ftrace_stub; | |
3673 | ||
3674 | local_irq_save(flags); | |
3675 | ftrace_dyn_arch_init(&addr); | |
3676 | local_irq_restore(flags); | |
3677 | ||
3678 | /* ftrace_dyn_arch_init places the return code in addr */ | |
3679 | if (addr) | |
3680 | goto failed; | |
3681 | ||
3682 | count = __stop_mcount_loc - __start_mcount_loc; | |
3683 | ||
3684 | ret = ftrace_dyn_table_alloc(count); | |
3685 | if (ret) | |
3686 | goto failed; | |
3687 | ||
3688 | last_ftrace_enabled = ftrace_enabled = 1; | |
3689 | ||
5cb084bb | 3690 | ret = ftrace_process_locs(NULL, |
31e88909 | 3691 | __start_mcount_loc, |
68bf21aa SR |
3692 | __stop_mcount_loc); |
3693 | ||
93eb677d | 3694 | ret = register_module_notifier(&ftrace_module_nb); |
24ed0c4b | 3695 | if (ret) |
93eb677d SR |
3696 | pr_warning("Failed to register trace ftrace module notifier\n"); |
3697 | ||
2af15d6a SR |
3698 | set_ftrace_early_filters(); |
3699 | ||
68bf21aa SR |
3700 | return; |
3701 | failed: | |
3702 | ftrace_disabled = 1; | |
3703 | } | |
68bf21aa | 3704 | |
3d083395 | 3705 | #else |
0b6e4d56 | 3706 | |
2b499381 | 3707 | static struct ftrace_ops global_ops = { |
bd69c30b SR |
3708 | .func = ftrace_stub, |
3709 | }; | |
3710 | ||
0b6e4d56 FW |
3711 | static int __init ftrace_nodyn_init(void) |
3712 | { | |
3713 | ftrace_enabled = 1; | |
3714 | return 0; | |
3715 | } | |
3716 | device_initcall(ftrace_nodyn_init); | |
3717 | ||
df4fc315 SR |
3718 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
3719 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 | 3720 | /* Keep as macros so we do not need to define the commands */ |
3b6cfdb1 SR |
3721 | # define ftrace_startup(ops, command) \ |
3722 | ({ \ | |
3723 | (ops)->flags |= FTRACE_OPS_FL_ENABLED; \ | |
3724 | 0; \ | |
3725 | }) | |
bd69c30b | 3726 | # define ftrace_shutdown(ops, command) do { } while (0) |
c7aafc54 IM |
3727 | # define ftrace_startup_sysctl() do { } while (0) |
3728 | # define ftrace_shutdown_sysctl() do { } while (0) | |
b848914c SR |
3729 | |
3730 | static inline int | |
3731 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip) | |
3732 | { | |
3733 | return 1; | |
3734 | } | |
3735 | ||
3d083395 SR |
3736 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
3737 | ||
b848914c SR |
3738 | static void |
3739 | ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip) | |
3740 | { | |
cdbe61bf | 3741 | struct ftrace_ops *op; |
b848914c | 3742 | |
b1cff0ad SR |
3743 | if (unlikely(trace_recursion_test(TRACE_INTERNAL_BIT))) |
3744 | return; | |
3745 | ||
3746 | trace_recursion_set(TRACE_INTERNAL_BIT); | |
cdbe61bf SR |
3747 | /* |
3748 | * Some of the ops may be dynamically allocated, | |
3749 | * they must be freed after a synchronize_sched(). | |
3750 | */ | |
3751 | preempt_disable_notrace(); | |
3752 | op = rcu_dereference_raw(ftrace_ops_list); | |
b848914c SR |
3753 | while (op != &ftrace_list_end) { |
3754 | if (ftrace_ops_test(op, ip)) | |
3755 | op->func(ip, parent_ip); | |
3756 | op = rcu_dereference_raw(op->next); | |
3757 | }; | |
cdbe61bf | 3758 | preempt_enable_notrace(); |
b1cff0ad | 3759 | trace_recursion_clear(TRACE_INTERNAL_BIT); |
b848914c SR |
3760 | } |
3761 | ||
e32d8956 | 3762 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
3763 | { |
3764 | struct task_struct *p; | |
e32d8956 | 3765 | int cpu; |
978f3a45 | 3766 | |
e32d8956 SR |
3767 | get_online_cpus(); |
3768 | for_each_online_cpu(cpu) { | |
3769 | p = idle_task(cpu); | |
978f3a45 | 3770 | clear_tsk_trace_trace(p); |
e32d8956 SR |
3771 | } |
3772 | put_online_cpus(); | |
3773 | } | |
978f3a45 | 3774 | |
e32d8956 SR |
3775 | static void set_ftrace_swapper(void) |
3776 | { | |
3777 | struct task_struct *p; | |
3778 | int cpu; | |
3779 | ||
3780 | get_online_cpus(); | |
3781 | for_each_online_cpu(cpu) { | |
3782 | p = idle_task(cpu); | |
3783 | set_tsk_trace_trace(p); | |
3784 | } | |
3785 | put_online_cpus(); | |
978f3a45 SR |
3786 | } |
3787 | ||
e32d8956 SR |
3788 | static void clear_ftrace_pid(struct pid *pid) |
3789 | { | |
3790 | struct task_struct *p; | |
3791 | ||
229c4ef8 | 3792 | rcu_read_lock(); |
e32d8956 SR |
3793 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
3794 | clear_tsk_trace_trace(p); | |
3795 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
3796 | rcu_read_unlock(); |
3797 | ||
e32d8956 SR |
3798 | put_pid(pid); |
3799 | } | |
3800 | ||
3801 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
3802 | { |
3803 | struct task_struct *p; | |
3804 | ||
229c4ef8 | 3805 | rcu_read_lock(); |
978f3a45 SR |
3806 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
3807 | set_tsk_trace_trace(p); | |
3808 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 3809 | rcu_read_unlock(); |
978f3a45 SR |
3810 | } |
3811 | ||
756d17ee | 3812 | static void clear_ftrace_pid_task(struct pid *pid) |
e32d8956 | 3813 | { |
756d17ee | 3814 | if (pid == ftrace_swapper_pid) |
e32d8956 SR |
3815 | clear_ftrace_swapper(); |
3816 | else | |
756d17ee | 3817 | clear_ftrace_pid(pid); |
e32d8956 SR |
3818 | } |
3819 | ||
3820 | static void set_ftrace_pid_task(struct pid *pid) | |
3821 | { | |
3822 | if (pid == ftrace_swapper_pid) | |
3823 | set_ftrace_swapper(); | |
3824 | else | |
3825 | set_ftrace_pid(pid); | |
3826 | } | |
3827 | ||
756d17ee | 3828 | static int ftrace_pid_add(int p) |
df4fc315 | 3829 | { |
978f3a45 | 3830 | struct pid *pid; |
756d17ee | 3831 | struct ftrace_pid *fpid; |
3832 | int ret = -EINVAL; | |
df4fc315 | 3833 | |
756d17ee | 3834 | mutex_lock(&ftrace_lock); |
df4fc315 | 3835 | |
756d17ee | 3836 | if (!p) |
3837 | pid = ftrace_swapper_pid; | |
3838 | else | |
3839 | pid = find_get_pid(p); | |
df4fc315 | 3840 | |
756d17ee | 3841 | if (!pid) |
3842 | goto out; | |
df4fc315 | 3843 | |
756d17ee | 3844 | ret = 0; |
df4fc315 | 3845 | |
756d17ee | 3846 | list_for_each_entry(fpid, &ftrace_pids, list) |
3847 | if (fpid->pid == pid) | |
3848 | goto out_put; | |
978f3a45 | 3849 | |
756d17ee | 3850 | ret = -ENOMEM; |
df4fc315 | 3851 | |
756d17ee | 3852 | fpid = kmalloc(sizeof(*fpid), GFP_KERNEL); |
3853 | if (!fpid) | |
3854 | goto out_put; | |
df4fc315 | 3855 | |
756d17ee | 3856 | list_add(&fpid->list, &ftrace_pids); |
3857 | fpid->pid = pid; | |
0ef8cde5 | 3858 | |
756d17ee | 3859 | set_ftrace_pid_task(pid); |
978f3a45 | 3860 | |
756d17ee | 3861 | ftrace_update_pid_func(); |
3862 | ftrace_startup_enable(0); | |
3863 | ||
3864 | mutex_unlock(&ftrace_lock); | |
3865 | return 0; | |
3866 | ||
3867 | out_put: | |
3868 | if (pid != ftrace_swapper_pid) | |
3869 | put_pid(pid); | |
978f3a45 | 3870 | |
756d17ee | 3871 | out: |
3872 | mutex_unlock(&ftrace_lock); | |
3873 | return ret; | |
3874 | } | |
3875 | ||
3876 | static void ftrace_pid_reset(void) | |
3877 | { | |
3878 | struct ftrace_pid *fpid, *safe; | |
978f3a45 | 3879 | |
756d17ee | 3880 | mutex_lock(&ftrace_lock); |
3881 | list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) { | |
3882 | struct pid *pid = fpid->pid; | |
3883 | ||
3884 | clear_ftrace_pid_task(pid); | |
3885 | ||
3886 | list_del(&fpid->list); | |
3887 | kfree(fpid); | |
df4fc315 SR |
3888 | } |
3889 | ||
df4fc315 SR |
3890 | ftrace_update_pid_func(); |
3891 | ftrace_startup_enable(0); | |
3892 | ||
e6ea44e9 | 3893 | mutex_unlock(&ftrace_lock); |
756d17ee | 3894 | } |
df4fc315 | 3895 | |
756d17ee | 3896 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
3897 | { | |
3898 | mutex_lock(&ftrace_lock); | |
3899 | ||
3900 | if (list_empty(&ftrace_pids) && (!*pos)) | |
3901 | return (void *) 1; | |
3902 | ||
3903 | return seq_list_start(&ftrace_pids, *pos); | |
3904 | } | |
3905 | ||
3906 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
3907 | { | |
3908 | if (v == (void *)1) | |
3909 | return NULL; | |
3910 | ||
3911 | return seq_list_next(v, &ftrace_pids, pos); | |
3912 | } | |
3913 | ||
3914 | static void fpid_stop(struct seq_file *m, void *p) | |
3915 | { | |
3916 | mutex_unlock(&ftrace_lock); | |
3917 | } | |
3918 | ||
3919 | static int fpid_show(struct seq_file *m, void *v) | |
3920 | { | |
3921 | const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list); | |
3922 | ||
3923 | if (v == (void *)1) { | |
3924 | seq_printf(m, "no pid\n"); | |
3925 | return 0; | |
3926 | } | |
3927 | ||
3928 | if (fpid->pid == ftrace_swapper_pid) | |
3929 | seq_printf(m, "swapper tasks\n"); | |
3930 | else | |
3931 | seq_printf(m, "%u\n", pid_vnr(fpid->pid)); | |
3932 | ||
3933 | return 0; | |
3934 | } | |
3935 | ||
3936 | static const struct seq_operations ftrace_pid_sops = { | |
3937 | .start = fpid_start, | |
3938 | .next = fpid_next, | |
3939 | .stop = fpid_stop, | |
3940 | .show = fpid_show, | |
3941 | }; | |
3942 | ||
3943 | static int | |
3944 | ftrace_pid_open(struct inode *inode, struct file *file) | |
3945 | { | |
3946 | int ret = 0; | |
3947 | ||
3948 | if ((file->f_mode & FMODE_WRITE) && | |
3949 | (file->f_flags & O_TRUNC)) | |
3950 | ftrace_pid_reset(); | |
3951 | ||
3952 | if (file->f_mode & FMODE_READ) | |
3953 | ret = seq_open(file, &ftrace_pid_sops); | |
3954 | ||
3955 | return ret; | |
3956 | } | |
3957 | ||
df4fc315 SR |
3958 | static ssize_t |
3959 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
3960 | size_t cnt, loff_t *ppos) | |
3961 | { | |
457dc928 | 3962 | char buf[64], *tmp; |
df4fc315 SR |
3963 | long val; |
3964 | int ret; | |
3965 | ||
3966 | if (cnt >= sizeof(buf)) | |
3967 | return -EINVAL; | |
3968 | ||
3969 | if (copy_from_user(&buf, ubuf, cnt)) | |
3970 | return -EFAULT; | |
3971 | ||
3972 | buf[cnt] = 0; | |
3973 | ||
756d17ee | 3974 | /* |
3975 | * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid" | |
3976 | * to clean the filter quietly. | |
3977 | */ | |
457dc928 IM |
3978 | tmp = strstrip(buf); |
3979 | if (strlen(tmp) == 0) | |
756d17ee | 3980 | return 1; |
3981 | ||
457dc928 | 3982 | ret = strict_strtol(tmp, 10, &val); |
df4fc315 SR |
3983 | if (ret < 0) |
3984 | return ret; | |
3985 | ||
756d17ee | 3986 | ret = ftrace_pid_add(val); |
df4fc315 | 3987 | |
756d17ee | 3988 | return ret ? ret : cnt; |
3989 | } | |
df4fc315 | 3990 | |
756d17ee | 3991 | static int |
3992 | ftrace_pid_release(struct inode *inode, struct file *file) | |
3993 | { | |
3994 | if (file->f_mode & FMODE_READ) | |
3995 | seq_release(inode, file); | |
df4fc315 | 3996 | |
756d17ee | 3997 | return 0; |
df4fc315 SR |
3998 | } |
3999 | ||
5e2336a0 | 4000 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 4001 | .open = ftrace_pid_open, |
4002 | .write = ftrace_pid_write, | |
4003 | .read = seq_read, | |
4004 | .llseek = seq_lseek, | |
4005 | .release = ftrace_pid_release, | |
df4fc315 SR |
4006 | }; |
4007 | ||
4008 | static __init int ftrace_init_debugfs(void) | |
4009 | { | |
4010 | struct dentry *d_tracer; | |
df4fc315 SR |
4011 | |
4012 | d_tracer = tracing_init_dentry(); | |
4013 | if (!d_tracer) | |
4014 | return 0; | |
4015 | ||
4016 | ftrace_init_dyn_debugfs(d_tracer); | |
4017 | ||
5452af66 FW |
4018 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
4019 | NULL, &ftrace_pid_fops); | |
493762fc SR |
4020 | |
4021 | ftrace_profile_debugfs(d_tracer); | |
4022 | ||
df4fc315 SR |
4023 | return 0; |
4024 | } | |
df4fc315 SR |
4025 | fs_initcall(ftrace_init_debugfs); |
4026 | ||
a2bb6a3d | 4027 | /** |
81adbdc0 | 4028 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
4029 | * |
4030 | * This function should be used by panic code. It stops ftrace | |
4031 | * but in a not so nice way. If you need to simply kill ftrace | |
4032 | * from a non-atomic section, use ftrace_kill. | |
4033 | */ | |
81adbdc0 | 4034 | void ftrace_kill(void) |
a2bb6a3d SR |
4035 | { |
4036 | ftrace_disabled = 1; | |
4037 | ftrace_enabled = 0; | |
a2bb6a3d SR |
4038 | clear_ftrace_function(); |
4039 | } | |
4040 | ||
e0a413f6 SR |
4041 | /** |
4042 | * Test if ftrace is dead or not. | |
4043 | */ | |
4044 | int ftrace_is_dead(void) | |
4045 | { | |
4046 | return ftrace_disabled; | |
4047 | } | |
4048 | ||
16444a8a | 4049 | /** |
3d083395 SR |
4050 | * register_ftrace_function - register a function for profiling |
4051 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 4052 | * |
3d083395 SR |
4053 | * Register a function to be called by all functions in the |
4054 | * kernel. | |
4055 | * | |
4056 | * Note: @ops->func and all the functions it calls must be labeled | |
4057 | * with "notrace", otherwise it will go into a | |
4058 | * recursive loop. | |
16444a8a | 4059 | */ |
3d083395 | 4060 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 4061 | { |
45a4a237 | 4062 | int ret = -1; |
4eebcc81 | 4063 | |
e6ea44e9 | 4064 | mutex_lock(&ftrace_lock); |
e7d3737e | 4065 | |
45a4a237 SR |
4066 | if (unlikely(ftrace_disabled)) |
4067 | goto out_unlock; | |
4068 | ||
b0fc494f | 4069 | ret = __register_ftrace_function(ops); |
b848914c | 4070 | if (!ret) |
a1cd6173 | 4071 | ret = ftrace_startup(ops, 0); |
b848914c | 4072 | |
b0fc494f | 4073 | |
45a4a237 | 4074 | out_unlock: |
e6ea44e9 | 4075 | mutex_unlock(&ftrace_lock); |
b0fc494f | 4076 | return ret; |
3d083395 | 4077 | } |
cdbe61bf | 4078 | EXPORT_SYMBOL_GPL(register_ftrace_function); |
3d083395 SR |
4079 | |
4080 | /** | |
32632920 | 4081 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
4082 | * @ops - ops structure that holds the function to unregister |
4083 | * | |
4084 | * Unregister a function that was added to be called by ftrace profiling. | |
4085 | */ | |
4086 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
4087 | { | |
4088 | int ret; | |
4089 | ||
e6ea44e9 | 4090 | mutex_lock(&ftrace_lock); |
3d083395 | 4091 | ret = __unregister_ftrace_function(ops); |
b848914c SR |
4092 | if (!ret) |
4093 | ftrace_shutdown(ops, 0); | |
e6ea44e9 | 4094 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
4095 | |
4096 | return ret; | |
4097 | } | |
cdbe61bf | 4098 | EXPORT_SYMBOL_GPL(unregister_ftrace_function); |
b0fc494f | 4099 | |
e309b41d | 4100 | int |
b0fc494f | 4101 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
8d65af78 | 4102 | void __user *buffer, size_t *lenp, |
b0fc494f SR |
4103 | loff_t *ppos) |
4104 | { | |
45a4a237 | 4105 | int ret = -ENODEV; |
4eebcc81 | 4106 | |
e6ea44e9 | 4107 | mutex_lock(&ftrace_lock); |
b0fc494f | 4108 | |
45a4a237 SR |
4109 | if (unlikely(ftrace_disabled)) |
4110 | goto out; | |
4111 | ||
4112 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
b0fc494f | 4113 | |
a32c7765 | 4114 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
4115 | goto out; |
4116 | ||
a32c7765 | 4117 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f SR |
4118 | |
4119 | if (ftrace_enabled) { | |
4120 | ||
4121 | ftrace_startup_sysctl(); | |
4122 | ||
4123 | /* we are starting ftrace again */ | |
b848914c SR |
4124 | if (ftrace_ops_list != &ftrace_list_end) { |
4125 | if (ftrace_ops_list->next == &ftrace_list_end) | |
4126 | ftrace_trace_function = ftrace_ops_list->func; | |
b0fc494f | 4127 | else |
b848914c | 4128 | ftrace_trace_function = ftrace_ops_list_func; |
b0fc494f SR |
4129 | } |
4130 | ||
4131 | } else { | |
4132 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
4133 | ftrace_trace_function = ftrace_stub; | |
4134 | ||
4135 | ftrace_shutdown_sysctl(); | |
4136 | } | |
4137 | ||
4138 | out: | |
e6ea44e9 | 4139 | mutex_unlock(&ftrace_lock); |
3d083395 | 4140 | return ret; |
16444a8a | 4141 | } |
f17845e5 | 4142 | |
fb52607a | 4143 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 4144 | |
597af815 | 4145 | static int ftrace_graph_active; |
4a2b8dda | 4146 | static struct notifier_block ftrace_suspend_notifier; |
e7d3737e | 4147 | |
e49dc19c SR |
4148 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
4149 | { | |
4150 | return 0; | |
4151 | } | |
4152 | ||
287b6e68 FW |
4153 | /* The callbacks that hook a function */ |
4154 | trace_func_graph_ret_t ftrace_graph_return = | |
4155 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 4156 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
4157 | |
4158 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
4159 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
4160 | { | |
4161 | int i; | |
4162 | int ret = 0; | |
4163 | unsigned long flags; | |
4164 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
4165 | struct task_struct *g, *t; | |
4166 | ||
4167 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
4168 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
4169 | * sizeof(struct ftrace_ret_stack), | |
4170 | GFP_KERNEL); | |
4171 | if (!ret_stack_list[i]) { | |
4172 | start = 0; | |
4173 | end = i; | |
4174 | ret = -ENOMEM; | |
4175 | goto free; | |
4176 | } | |
4177 | } | |
4178 | ||
4179 | read_lock_irqsave(&tasklist_lock, flags); | |
4180 | do_each_thread(g, t) { | |
4181 | if (start == end) { | |
4182 | ret = -EAGAIN; | |
4183 | goto unlock; | |
4184 | } | |
4185 | ||
4186 | if (t->ret_stack == NULL) { | |
380c4b14 | 4187 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 4188 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
4189 | t->curr_ret_stack = -1; |
4190 | /* Make sure the tasks see the -1 first: */ | |
4191 | smp_wmb(); | |
4192 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
4193 | } |
4194 | } while_each_thread(g, t); | |
4195 | ||
4196 | unlock: | |
4197 | read_unlock_irqrestore(&tasklist_lock, flags); | |
4198 | free: | |
4199 | for (i = start; i < end; i++) | |
4200 | kfree(ret_stack_list[i]); | |
4201 | return ret; | |
4202 | } | |
4203 | ||
8aef2d28 | 4204 | static void |
38516ab5 SR |
4205 | ftrace_graph_probe_sched_switch(void *ignore, |
4206 | struct task_struct *prev, struct task_struct *next) | |
8aef2d28 SR |
4207 | { |
4208 | unsigned long long timestamp; | |
4209 | int index; | |
4210 | ||
be6f164a SR |
4211 | /* |
4212 | * Does the user want to count the time a function was asleep. | |
4213 | * If so, do not update the time stamps. | |
4214 | */ | |
4215 | if (trace_flags & TRACE_ITER_SLEEP_TIME) | |
4216 | return; | |
4217 | ||
8aef2d28 SR |
4218 | timestamp = trace_clock_local(); |
4219 | ||
4220 | prev->ftrace_timestamp = timestamp; | |
4221 | ||
4222 | /* only process tasks that we timestamped */ | |
4223 | if (!next->ftrace_timestamp) | |
4224 | return; | |
4225 | ||
4226 | /* | |
4227 | * Update all the counters in next to make up for the | |
4228 | * time next was sleeping. | |
4229 | */ | |
4230 | timestamp -= next->ftrace_timestamp; | |
4231 | ||
4232 | for (index = next->curr_ret_stack; index >= 0; index--) | |
4233 | next->ret_stack[index].calltime += timestamp; | |
4234 | } | |
4235 | ||
f201ae23 | 4236 | /* Allocate a return stack for each task */ |
fb52607a | 4237 | static int start_graph_tracing(void) |
f201ae23 FW |
4238 | { |
4239 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 4240 | int ret, cpu; |
f201ae23 FW |
4241 | |
4242 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
4243 | sizeof(struct ftrace_ret_stack *), | |
4244 | GFP_KERNEL); | |
4245 | ||
4246 | if (!ret_stack_list) | |
4247 | return -ENOMEM; | |
4248 | ||
5b058bcd | 4249 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
4250 | for_each_online_cpu(cpu) { |
4251 | if (!idle_task(cpu)->ret_stack) | |
868baf07 | 4252 | ftrace_graph_init_idle_task(idle_task(cpu), cpu); |
179c498a | 4253 | } |
5b058bcd | 4254 | |
f201ae23 FW |
4255 | do { |
4256 | ret = alloc_retstack_tasklist(ret_stack_list); | |
4257 | } while (ret == -EAGAIN); | |
4258 | ||
8aef2d28 | 4259 | if (!ret) { |
38516ab5 | 4260 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
8aef2d28 SR |
4261 | if (ret) |
4262 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
4263 | " probe to kernel_sched_switch\n"); | |
4264 | } | |
4265 | ||
f201ae23 FW |
4266 | kfree(ret_stack_list); |
4267 | return ret; | |
4268 | } | |
4269 | ||
4a2b8dda FW |
4270 | /* |
4271 | * Hibernation protection. | |
4272 | * The state of the current task is too much unstable during | |
4273 | * suspend/restore to disk. We want to protect against that. | |
4274 | */ | |
4275 | static int | |
4276 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
4277 | void *unused) | |
4278 | { | |
4279 | switch (state) { | |
4280 | case PM_HIBERNATION_PREPARE: | |
4281 | pause_graph_tracing(); | |
4282 | break; | |
4283 | ||
4284 | case PM_POST_HIBERNATION: | |
4285 | unpause_graph_tracing(); | |
4286 | break; | |
4287 | } | |
4288 | return NOTIFY_DONE; | |
4289 | } | |
4290 | ||
287b6e68 FW |
4291 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
4292 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 4293 | { |
e7d3737e FW |
4294 | int ret = 0; |
4295 | ||
e6ea44e9 | 4296 | mutex_lock(&ftrace_lock); |
e7d3737e | 4297 | |
05ce5818 | 4298 | /* we currently allow only one tracer registered at a time */ |
597af815 | 4299 | if (ftrace_graph_active) { |
05ce5818 SR |
4300 | ret = -EBUSY; |
4301 | goto out; | |
4302 | } | |
4303 | ||
4a2b8dda FW |
4304 | ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; |
4305 | register_pm_notifier(&ftrace_suspend_notifier); | |
4306 | ||
597af815 | 4307 | ftrace_graph_active++; |
fb52607a | 4308 | ret = start_graph_tracing(); |
f201ae23 | 4309 | if (ret) { |
597af815 | 4310 | ftrace_graph_active--; |
f201ae23 FW |
4311 | goto out; |
4312 | } | |
e53a6319 | 4313 | |
287b6e68 FW |
4314 | ftrace_graph_return = retfunc; |
4315 | ftrace_graph_entry = entryfunc; | |
e53a6319 | 4316 | |
a1cd6173 | 4317 | ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET); |
e7d3737e FW |
4318 | |
4319 | out: | |
e6ea44e9 | 4320 | mutex_unlock(&ftrace_lock); |
e7d3737e | 4321 | return ret; |
15e6cb36 FW |
4322 | } |
4323 | ||
fb52607a | 4324 | void unregister_ftrace_graph(void) |
15e6cb36 | 4325 | { |
e6ea44e9 | 4326 | mutex_lock(&ftrace_lock); |
e7d3737e | 4327 | |
597af815 | 4328 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
4329 | goto out; |
4330 | ||
597af815 | 4331 | ftrace_graph_active--; |
287b6e68 | 4332 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 4333 | ftrace_graph_entry = ftrace_graph_entry_stub; |
bd69c30b | 4334 | ftrace_shutdown(&global_ops, FTRACE_STOP_FUNC_RET); |
4a2b8dda | 4335 | unregister_pm_notifier(&ftrace_suspend_notifier); |
38516ab5 | 4336 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
e7d3737e | 4337 | |
2aad1b76 | 4338 | out: |
e6ea44e9 | 4339 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 4340 | } |
f201ae23 | 4341 | |
868baf07 SR |
4342 | static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack); |
4343 | ||
4344 | static void | |
4345 | graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack) | |
4346 | { | |
4347 | atomic_set(&t->tracing_graph_pause, 0); | |
4348 | atomic_set(&t->trace_overrun, 0); | |
4349 | t->ftrace_timestamp = 0; | |
25985edc | 4350 | /* make curr_ret_stack visible before we add the ret_stack */ |
868baf07 SR |
4351 | smp_wmb(); |
4352 | t->ret_stack = ret_stack; | |
4353 | } | |
4354 | ||
4355 | /* | |
4356 | * Allocate a return stack for the idle task. May be the first | |
4357 | * time through, or it may be done by CPU hotplug online. | |
4358 | */ | |
4359 | void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) | |
4360 | { | |
4361 | t->curr_ret_stack = -1; | |
4362 | /* | |
4363 | * The idle task has no parent, it either has its own | |
4364 | * stack or no stack at all. | |
4365 | */ | |
4366 | if (t->ret_stack) | |
4367 | WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu)); | |
4368 | ||
4369 | if (ftrace_graph_active) { | |
4370 | struct ftrace_ret_stack *ret_stack; | |
4371 | ||
4372 | ret_stack = per_cpu(idle_ret_stack, cpu); | |
4373 | if (!ret_stack) { | |
4374 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
4375 | * sizeof(struct ftrace_ret_stack), | |
4376 | GFP_KERNEL); | |
4377 | if (!ret_stack) | |
4378 | return; | |
4379 | per_cpu(idle_ret_stack, cpu) = ret_stack; | |
4380 | } | |
4381 | graph_init_task(t, ret_stack); | |
4382 | } | |
4383 | } | |
4384 | ||
f201ae23 | 4385 | /* Allocate a return stack for newly created task */ |
fb52607a | 4386 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 4387 | { |
84047e36 SR |
4388 | /* Make sure we do not use the parent ret_stack */ |
4389 | t->ret_stack = NULL; | |
ea14eb71 | 4390 | t->curr_ret_stack = -1; |
84047e36 | 4391 | |
597af815 | 4392 | if (ftrace_graph_active) { |
82310a32 SR |
4393 | struct ftrace_ret_stack *ret_stack; |
4394 | ||
4395 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
4396 | * sizeof(struct ftrace_ret_stack), |
4397 | GFP_KERNEL); | |
82310a32 | 4398 | if (!ret_stack) |
f201ae23 | 4399 | return; |
868baf07 | 4400 | graph_init_task(t, ret_stack); |
84047e36 | 4401 | } |
f201ae23 FW |
4402 | } |
4403 | ||
fb52607a | 4404 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 4405 | { |
eae849ca FW |
4406 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
4407 | ||
f201ae23 | 4408 | t->ret_stack = NULL; |
eae849ca FW |
4409 | /* NULL must become visible to IRQs before we free it: */ |
4410 | barrier(); | |
4411 | ||
4412 | kfree(ret_stack); | |
f201ae23 | 4413 | } |
14a866c5 SR |
4414 | |
4415 | void ftrace_graph_stop(void) | |
4416 | { | |
4417 | ftrace_stop(); | |
4418 | } | |
15e6cb36 | 4419 | #endif |