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> |
5855fead | 25 | #include <linux/bsearch.h> |
56d82e00 | 26 | #include <linux/module.h> |
2d8b820b | 27 | #include <linux/ftrace.h> |
b0fc494f | 28 | #include <linux/sysctl.h> |
5a0e3ad6 | 29 | #include <linux/slab.h> |
5072c59f | 30 | #include <linux/ctype.h> |
68950619 | 31 | #include <linux/sort.h> |
3d083395 | 32 | #include <linux/list.h> |
59df055f | 33 | #include <linux/hash.h> |
3f379b03 | 34 | #include <linux/rcupdate.h> |
3d083395 | 35 | |
ad8d75ff | 36 | #include <trace/events/sched.h> |
8aef2d28 | 37 | |
2af15d6a | 38 | #include <asm/setup.h> |
395a59d0 | 39 | |
0706f1c4 | 40 | #include "trace_output.h" |
bac429f0 | 41 | #include "trace_stat.h" |
16444a8a | 42 | |
6912896e | 43 | #define FTRACE_WARN_ON(cond) \ |
0778d9ad SR |
44 | ({ \ |
45 | int ___r = cond; \ | |
46 | if (WARN_ON(___r)) \ | |
6912896e | 47 | ftrace_kill(); \ |
0778d9ad SR |
48 | ___r; \ |
49 | }) | |
6912896e SR |
50 | |
51 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
0778d9ad SR |
52 | ({ \ |
53 | int ___r = cond; \ | |
54 | if (WARN_ON_ONCE(___r)) \ | |
6912896e | 55 | ftrace_kill(); \ |
0778d9ad SR |
56 | ___r; \ |
57 | }) | |
6912896e | 58 | |
8fc0c701 SR |
59 | /* hash bits for specific function selection */ |
60 | #define FTRACE_HASH_BITS 7 | |
61 | #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS) | |
33dc9b12 SR |
62 | #define FTRACE_HASH_DEFAULT_BITS 10 |
63 | #define FTRACE_HASH_MAX_BITS 12 | |
8fc0c701 | 64 | |
e248491a JO |
65 | #define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_CONTROL) |
66 | ||
4eebcc81 SR |
67 | /* ftrace_enabled is a method to turn ftrace on or off */ |
68 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 69 | static int last_ftrace_enabled; |
b0fc494f | 70 | |
60a7ecf4 SR |
71 | /* Quick disabling of function tracer. */ |
72 | int function_trace_stop; | |
73 | ||
756d17ee | 74 | /* List for set_ftrace_pid's pids. */ |
75 | LIST_HEAD(ftrace_pids); | |
76 | struct ftrace_pid { | |
77 | struct list_head list; | |
78 | struct pid *pid; | |
79 | }; | |
80 | ||
4eebcc81 SR |
81 | /* |
82 | * ftrace_disabled is set when an anomaly is discovered. | |
83 | * ftrace_disabled is much stronger than ftrace_enabled. | |
84 | */ | |
85 | static int ftrace_disabled __read_mostly; | |
86 | ||
52baf119 | 87 | static DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 88 | |
bd38c0e6 | 89 | static struct ftrace_ops ftrace_list_end __read_mostly = { |
fb9fb015 | 90 | .func = ftrace_stub, |
16444a8a ACM |
91 | }; |
92 | ||
b848914c | 93 | static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end; |
e248491a | 94 | static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end; |
b848914c | 95 | static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end; |
16444a8a | 96 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
6331c28c | 97 | static ftrace_func_t __ftrace_trace_function_delay __read_mostly = ftrace_stub; |
60a7ecf4 | 98 | ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub; |
df4fc315 | 99 | ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; |
2b499381 | 100 | static struct ftrace_ops global_ops; |
e248491a | 101 | static struct ftrace_ops control_ops; |
16444a8a | 102 | |
b848914c SR |
103 | static void |
104 | ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip); | |
105 | ||
3f379b03 | 106 | /* |
b848914c | 107 | * Traverse the ftrace_global_list, invoking all entries. The reason that we |
3f379b03 PM |
108 | * can use rcu_dereference_raw() is that elements removed from this list |
109 | * are simply leaked, so there is no need to interact with a grace-period | |
110 | * mechanism. The rcu_dereference_raw() calls are needed to handle | |
b848914c | 111 | * concurrent insertions into the ftrace_global_list. |
3f379b03 PM |
112 | * |
113 | * Silly Alpha and silly pointer-speculation compiler optimizations! | |
114 | */ | |
b848914c SR |
115 | static void ftrace_global_list_func(unsigned long ip, |
116 | unsigned long parent_ip) | |
16444a8a | 117 | { |
b1cff0ad SR |
118 | struct ftrace_ops *op; |
119 | ||
120 | if (unlikely(trace_recursion_test(TRACE_GLOBAL_BIT))) | |
121 | return; | |
16444a8a | 122 | |
b1cff0ad SR |
123 | trace_recursion_set(TRACE_GLOBAL_BIT); |
124 | op = rcu_dereference_raw(ftrace_global_list); /*see above*/ | |
16444a8a | 125 | while (op != &ftrace_list_end) { |
16444a8a | 126 | op->func(ip, parent_ip); |
3f379b03 | 127 | op = rcu_dereference_raw(op->next); /*see above*/ |
16444a8a | 128 | }; |
b1cff0ad | 129 | trace_recursion_clear(TRACE_GLOBAL_BIT); |
16444a8a ACM |
130 | } |
131 | ||
df4fc315 SR |
132 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip) |
133 | { | |
0ef8cde5 | 134 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
135 | return; |
136 | ||
137 | ftrace_pid_function(ip, parent_ip); | |
138 | } | |
139 | ||
140 | static void set_ftrace_pid_function(ftrace_func_t func) | |
141 | { | |
142 | /* do not set ftrace_pid_function to itself! */ | |
143 | if (func != ftrace_pid_func) | |
144 | ftrace_pid_function = func; | |
145 | } | |
146 | ||
16444a8a | 147 | /** |
3d083395 | 148 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 149 | * |
3d083395 SR |
150 | * This NULLs the ftrace function and in essence stops |
151 | * tracing. There may be lag | |
16444a8a | 152 | */ |
3d083395 | 153 | void clear_ftrace_function(void) |
16444a8a | 154 | { |
3d083395 | 155 | ftrace_trace_function = ftrace_stub; |
60a7ecf4 | 156 | __ftrace_trace_function = ftrace_stub; |
6331c28c | 157 | __ftrace_trace_function_delay = ftrace_stub; |
df4fc315 | 158 | ftrace_pid_function = ftrace_stub; |
3d083395 SR |
159 | } |
160 | ||
60a7ecf4 SR |
161 | #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
162 | /* | |
163 | * For those archs that do not test ftrace_trace_stop in their | |
164 | * mcount call site, we need to do it from C. | |
165 | */ | |
166 | static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip) | |
167 | { | |
168 | if (function_trace_stop) | |
169 | return; | |
170 | ||
171 | __ftrace_trace_function(ip, parent_ip); | |
172 | } | |
173 | #endif | |
174 | ||
e248491a JO |
175 | static void control_ops_disable_all(struct ftrace_ops *ops) |
176 | { | |
177 | int cpu; | |
178 | ||
179 | for_each_possible_cpu(cpu) | |
180 | *per_cpu_ptr(ops->disabled, cpu) = 1; | |
181 | } | |
182 | ||
183 | static int control_ops_alloc(struct ftrace_ops *ops) | |
184 | { | |
185 | int __percpu *disabled; | |
186 | ||
187 | disabled = alloc_percpu(int); | |
188 | if (!disabled) | |
189 | return -ENOMEM; | |
190 | ||
191 | ops->disabled = disabled; | |
192 | control_ops_disable_all(ops); | |
193 | return 0; | |
194 | } | |
195 | ||
196 | static void control_ops_free(struct ftrace_ops *ops) | |
197 | { | |
198 | free_percpu(ops->disabled); | |
199 | } | |
200 | ||
2b499381 | 201 | static void update_global_ops(void) |
491d0dcf SR |
202 | { |
203 | ftrace_func_t func; | |
204 | ||
205 | /* | |
206 | * If there's only one function registered, then call that | |
207 | * function directly. Otherwise, we need to iterate over the | |
208 | * registered callers. | |
209 | */ | |
b848914c SR |
210 | if (ftrace_global_list == &ftrace_list_end || |
211 | ftrace_global_list->next == &ftrace_list_end) | |
212 | func = ftrace_global_list->func; | |
491d0dcf | 213 | else |
b848914c | 214 | func = ftrace_global_list_func; |
491d0dcf SR |
215 | |
216 | /* If we filter on pids, update to use the pid function */ | |
217 | if (!list_empty(&ftrace_pids)) { | |
218 | set_ftrace_pid_function(func); | |
219 | func = ftrace_pid_func; | |
220 | } | |
2b499381 SR |
221 | |
222 | global_ops.func = func; | |
223 | } | |
224 | ||
225 | static void update_ftrace_function(void) | |
226 | { | |
227 | ftrace_func_t func; | |
228 | ||
229 | update_global_ops(); | |
230 | ||
cdbe61bf SR |
231 | /* |
232 | * If we are at the end of the list and this ops is | |
233 | * not dynamic, then have the mcount trampoline call | |
234 | * the function directly | |
235 | */ | |
b848914c | 236 | if (ftrace_ops_list == &ftrace_list_end || |
cdbe61bf SR |
237 | (ftrace_ops_list->next == &ftrace_list_end && |
238 | !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC))) | |
b848914c SR |
239 | func = ftrace_ops_list->func; |
240 | else | |
241 | func = ftrace_ops_list_func; | |
2b499381 | 242 | |
491d0dcf SR |
243 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
244 | ftrace_trace_function = func; | |
6331c28c SR |
245 | #else |
246 | #ifdef CONFIG_DYNAMIC_FTRACE | |
247 | /* do not update till all functions have been modified */ | |
248 | __ftrace_trace_function_delay = func; | |
491d0dcf SR |
249 | #else |
250 | __ftrace_trace_function = func; | |
6331c28c | 251 | #endif |
db6544e0 RB |
252 | ftrace_trace_function = |
253 | (func == ftrace_stub) ? func : ftrace_test_stop_func; | |
491d0dcf SR |
254 | #endif |
255 | } | |
256 | ||
2b499381 | 257 | static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
3d083395 | 258 | { |
2b499381 | 259 | ops->next = *list; |
16444a8a | 260 | /* |
b848914c | 261 | * We are entering ops into the list but another |
16444a8a ACM |
262 | * CPU might be walking that list. We need to make sure |
263 | * the ops->next pointer is valid before another CPU sees | |
b848914c | 264 | * the ops pointer included into the list. |
16444a8a | 265 | */ |
2b499381 | 266 | rcu_assign_pointer(*list, ops); |
16444a8a ACM |
267 | } |
268 | ||
2b499381 | 269 | static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
16444a8a | 270 | { |
16444a8a | 271 | struct ftrace_ops **p; |
16444a8a ACM |
272 | |
273 | /* | |
3d083395 SR |
274 | * If we are removing the last function, then simply point |
275 | * to the ftrace_stub. | |
16444a8a | 276 | */ |
2b499381 SR |
277 | if (*list == ops && ops->next == &ftrace_list_end) { |
278 | *list = &ftrace_list_end; | |
e6ea44e9 | 279 | return 0; |
16444a8a ACM |
280 | } |
281 | ||
2b499381 | 282 | for (p = list; *p != &ftrace_list_end; p = &(*p)->next) |
16444a8a ACM |
283 | if (*p == ops) |
284 | break; | |
285 | ||
e6ea44e9 SR |
286 | if (*p != ops) |
287 | return -1; | |
16444a8a ACM |
288 | |
289 | *p = (*p)->next; | |
2b499381 SR |
290 | return 0; |
291 | } | |
16444a8a | 292 | |
e248491a JO |
293 | static void add_ftrace_list_ops(struct ftrace_ops **list, |
294 | struct ftrace_ops *main_ops, | |
295 | struct ftrace_ops *ops) | |
296 | { | |
297 | int first = *list == &ftrace_list_end; | |
298 | add_ftrace_ops(list, ops); | |
299 | if (first) | |
300 | add_ftrace_ops(&ftrace_ops_list, main_ops); | |
301 | } | |
302 | ||
303 | static int remove_ftrace_list_ops(struct ftrace_ops **list, | |
304 | struct ftrace_ops *main_ops, | |
305 | struct ftrace_ops *ops) | |
306 | { | |
307 | int ret = remove_ftrace_ops(list, ops); | |
308 | if (!ret && *list == &ftrace_list_end) | |
309 | ret = remove_ftrace_ops(&ftrace_ops_list, main_ops); | |
310 | return ret; | |
311 | } | |
312 | ||
2b499381 SR |
313 | static int __register_ftrace_function(struct ftrace_ops *ops) |
314 | { | |
315 | if (ftrace_disabled) | |
316 | return -ENODEV; | |
317 | ||
318 | if (FTRACE_WARN_ON(ops == &global_ops)) | |
319 | return -EINVAL; | |
320 | ||
b848914c SR |
321 | if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) |
322 | return -EBUSY; | |
323 | ||
e248491a JO |
324 | /* We don't support both control and global flags set. */ |
325 | if ((ops->flags & FL_GLOBAL_CONTROL_MASK) == FL_GLOBAL_CONTROL_MASK) | |
326 | return -EINVAL; | |
327 | ||
cdbe61bf SR |
328 | if (!core_kernel_data((unsigned long)ops)) |
329 | ops->flags |= FTRACE_OPS_FL_DYNAMIC; | |
330 | ||
b848914c | 331 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { |
e248491a | 332 | add_ftrace_list_ops(&ftrace_global_list, &global_ops, ops); |
b848914c | 333 | ops->flags |= FTRACE_OPS_FL_ENABLED; |
e248491a JO |
334 | } else if (ops->flags & FTRACE_OPS_FL_CONTROL) { |
335 | if (control_ops_alloc(ops)) | |
336 | return -ENOMEM; | |
337 | add_ftrace_list_ops(&ftrace_control_list, &control_ops, ops); | |
b848914c SR |
338 | } else |
339 | add_ftrace_ops(&ftrace_ops_list, ops); | |
340 | ||
2b499381 SR |
341 | if (ftrace_enabled) |
342 | update_ftrace_function(); | |
343 | ||
344 | return 0; | |
345 | } | |
346 | ||
347 | static int __unregister_ftrace_function(struct ftrace_ops *ops) | |
348 | { | |
349 | int ret; | |
350 | ||
351 | if (ftrace_disabled) | |
352 | return -ENODEV; | |
353 | ||
b848914c SR |
354 | if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) |
355 | return -EBUSY; | |
356 | ||
2b499381 SR |
357 | if (FTRACE_WARN_ON(ops == &global_ops)) |
358 | return -EINVAL; | |
359 | ||
b848914c | 360 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { |
e248491a JO |
361 | ret = remove_ftrace_list_ops(&ftrace_global_list, |
362 | &global_ops, ops); | |
b848914c SR |
363 | if (!ret) |
364 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; | |
e248491a JO |
365 | } else if (ops->flags & FTRACE_OPS_FL_CONTROL) { |
366 | ret = remove_ftrace_list_ops(&ftrace_control_list, | |
367 | &control_ops, ops); | |
368 | if (!ret) { | |
369 | /* | |
370 | * The ftrace_ops is now removed from the list, | |
371 | * so there'll be no new users. We must ensure | |
372 | * all current users are done before we free | |
373 | * the control data. | |
374 | */ | |
375 | synchronize_sched(); | |
376 | control_ops_free(ops); | |
377 | } | |
b848914c SR |
378 | } else |
379 | ret = remove_ftrace_ops(&ftrace_ops_list, ops); | |
380 | ||
2b499381 SR |
381 | if (ret < 0) |
382 | return ret; | |
b848914c | 383 | |
491d0dcf SR |
384 | if (ftrace_enabled) |
385 | update_ftrace_function(); | |
16444a8a | 386 | |
cdbe61bf SR |
387 | /* |
388 | * Dynamic ops may be freed, we must make sure that all | |
389 | * callers are done before leaving this function. | |
390 | */ | |
391 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) | |
392 | synchronize_sched(); | |
393 | ||
e6ea44e9 | 394 | return 0; |
3d083395 SR |
395 | } |
396 | ||
df4fc315 SR |
397 | static void ftrace_update_pid_func(void) |
398 | { | |
491d0dcf | 399 | /* Only do something if we are tracing something */ |
df4fc315 | 400 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 401 | return; |
df4fc315 | 402 | |
491d0dcf | 403 | update_ftrace_function(); |
df4fc315 SR |
404 | } |
405 | ||
493762fc SR |
406 | #ifdef CONFIG_FUNCTION_PROFILER |
407 | struct ftrace_profile { | |
408 | struct hlist_node node; | |
409 | unsigned long ip; | |
410 | unsigned long counter; | |
0706f1c4 SR |
411 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
412 | unsigned long long time; | |
e330b3bc | 413 | unsigned long long time_squared; |
0706f1c4 | 414 | #endif |
8fc0c701 SR |
415 | }; |
416 | ||
493762fc SR |
417 | struct ftrace_profile_page { |
418 | struct ftrace_profile_page *next; | |
419 | unsigned long index; | |
420 | struct ftrace_profile records[]; | |
d61f82d0 SR |
421 | }; |
422 | ||
cafb168a SR |
423 | struct ftrace_profile_stat { |
424 | atomic_t disabled; | |
425 | struct hlist_head *hash; | |
426 | struct ftrace_profile_page *pages; | |
427 | struct ftrace_profile_page *start; | |
428 | struct tracer_stat stat; | |
429 | }; | |
430 | ||
493762fc SR |
431 | #define PROFILE_RECORDS_SIZE \ |
432 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 433 | |
493762fc SR |
434 | #define PROFILES_PER_PAGE \ |
435 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 436 | |
fb9fb015 SR |
437 | static int ftrace_profile_bits __read_mostly; |
438 | static int ftrace_profile_enabled __read_mostly; | |
439 | ||
440 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
441 | static DEFINE_MUTEX(ftrace_profile_lock); |
442 | ||
cafb168a | 443 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc SR |
444 | |
445 | #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */ | |
446 | ||
bac429f0 SR |
447 | static void * |
448 | function_stat_next(void *v, int idx) | |
449 | { | |
493762fc SR |
450 | struct ftrace_profile *rec = v; |
451 | struct ftrace_profile_page *pg; | |
bac429f0 | 452 | |
493762fc | 453 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
454 | |
455 | again: | |
0296e425 LZ |
456 | if (idx != 0) |
457 | rec++; | |
458 | ||
bac429f0 SR |
459 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
460 | pg = pg->next; | |
461 | if (!pg) | |
462 | return NULL; | |
463 | rec = &pg->records[0]; | |
493762fc SR |
464 | if (!rec->counter) |
465 | goto again; | |
bac429f0 SR |
466 | } |
467 | ||
bac429f0 SR |
468 | return rec; |
469 | } | |
470 | ||
471 | static void *function_stat_start(struct tracer_stat *trace) | |
472 | { | |
cafb168a SR |
473 | struct ftrace_profile_stat *stat = |
474 | container_of(trace, struct ftrace_profile_stat, stat); | |
475 | ||
476 | if (!stat || !stat->start) | |
477 | return NULL; | |
478 | ||
479 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
480 | } |
481 | ||
0706f1c4 SR |
482 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
483 | /* function graph compares on total time */ | |
484 | static int function_stat_cmp(void *p1, void *p2) | |
485 | { | |
486 | struct ftrace_profile *a = p1; | |
487 | struct ftrace_profile *b = p2; | |
488 | ||
489 | if (a->time < b->time) | |
490 | return -1; | |
491 | if (a->time > b->time) | |
492 | return 1; | |
493 | else | |
494 | return 0; | |
495 | } | |
496 | #else | |
497 | /* not function graph compares against hits */ | |
bac429f0 SR |
498 | static int function_stat_cmp(void *p1, void *p2) |
499 | { | |
493762fc SR |
500 | struct ftrace_profile *a = p1; |
501 | struct ftrace_profile *b = p2; | |
bac429f0 SR |
502 | |
503 | if (a->counter < b->counter) | |
504 | return -1; | |
505 | if (a->counter > b->counter) | |
506 | return 1; | |
507 | else | |
508 | return 0; | |
509 | } | |
0706f1c4 | 510 | #endif |
bac429f0 SR |
511 | |
512 | static int function_stat_headers(struct seq_file *m) | |
513 | { | |
0706f1c4 | 514 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b | 515 | seq_printf(m, " Function " |
e330b3bc | 516 | "Hit Time Avg s^2\n" |
34886c8b | 517 | " -------- " |
e330b3bc | 518 | "--- ---- --- ---\n"); |
0706f1c4 | 519 | #else |
bac429f0 SR |
520 | seq_printf(m, " Function Hit\n" |
521 | " -------- ---\n"); | |
0706f1c4 | 522 | #endif |
bac429f0 SR |
523 | return 0; |
524 | } | |
525 | ||
526 | static int function_stat_show(struct seq_file *m, void *v) | |
527 | { | |
493762fc | 528 | struct ftrace_profile *rec = v; |
bac429f0 | 529 | char str[KSYM_SYMBOL_LEN]; |
3aaba20f | 530 | int ret = 0; |
0706f1c4 | 531 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
532 | static struct trace_seq s; |
533 | unsigned long long avg; | |
e330b3bc | 534 | unsigned long long stddev; |
0706f1c4 | 535 | #endif |
3aaba20f LZ |
536 | mutex_lock(&ftrace_profile_lock); |
537 | ||
538 | /* we raced with function_profile_reset() */ | |
539 | if (unlikely(rec->counter == 0)) { | |
540 | ret = -EBUSY; | |
541 | goto out; | |
542 | } | |
bac429f0 SR |
543 | |
544 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
0706f1c4 SR |
545 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
546 | ||
547 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
548 | seq_printf(m, " "); | |
34886c8b SR |
549 | avg = rec->time; |
550 | do_div(avg, rec->counter); | |
551 | ||
e330b3bc CD |
552 | /* Sample standard deviation (s^2) */ |
553 | if (rec->counter <= 1) | |
554 | stddev = 0; | |
555 | else { | |
556 | stddev = rec->time_squared - rec->counter * avg * avg; | |
557 | /* | |
558 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
559 | * trace_print_graph_duration will divide 1000 again. | |
560 | */ | |
561 | do_div(stddev, (rec->counter - 1) * 1000); | |
562 | } | |
563 | ||
34886c8b SR |
564 | trace_seq_init(&s); |
565 | trace_print_graph_duration(rec->time, &s); | |
566 | trace_seq_puts(&s, " "); | |
567 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
568 | trace_seq_puts(&s, " "); |
569 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 | 570 | trace_print_seq(m, &s); |
0706f1c4 SR |
571 | #endif |
572 | seq_putc(m, '\n'); | |
3aaba20f LZ |
573 | out: |
574 | mutex_unlock(&ftrace_profile_lock); | |
bac429f0 | 575 | |
3aaba20f | 576 | return ret; |
bac429f0 SR |
577 | } |
578 | ||
cafb168a | 579 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 580 | { |
493762fc | 581 | struct ftrace_profile_page *pg; |
bac429f0 | 582 | |
cafb168a | 583 | pg = stat->pages = stat->start; |
bac429f0 | 584 | |
493762fc SR |
585 | while (pg) { |
586 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
587 | pg->index = 0; | |
588 | pg = pg->next; | |
bac429f0 SR |
589 | } |
590 | ||
cafb168a | 591 | memset(stat->hash, 0, |
493762fc SR |
592 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
593 | } | |
bac429f0 | 594 | |
cafb168a | 595 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
596 | { |
597 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
598 | int functions; |
599 | int pages; | |
493762fc | 600 | int i; |
bac429f0 | 601 | |
493762fc | 602 | /* If we already allocated, do nothing */ |
cafb168a | 603 | if (stat->pages) |
493762fc | 604 | return 0; |
bac429f0 | 605 | |
cafb168a SR |
606 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
607 | if (!stat->pages) | |
493762fc | 608 | return -ENOMEM; |
bac429f0 | 609 | |
318e0a73 SR |
610 | #ifdef CONFIG_DYNAMIC_FTRACE |
611 | functions = ftrace_update_tot_cnt; | |
612 | #else | |
613 | /* | |
614 | * We do not know the number of functions that exist because | |
615 | * dynamic tracing is what counts them. With past experience | |
616 | * we have around 20K functions. That should be more than enough. | |
617 | * It is highly unlikely we will execute every function in | |
618 | * the kernel. | |
619 | */ | |
620 | functions = 20000; | |
621 | #endif | |
622 | ||
cafb168a | 623 | pg = stat->start = stat->pages; |
bac429f0 | 624 | |
318e0a73 SR |
625 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
626 | ||
627 | for (i = 0; i < pages; i++) { | |
493762fc | 628 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 629 | if (!pg->next) |
318e0a73 | 630 | goto out_free; |
493762fc SR |
631 | pg = pg->next; |
632 | } | |
633 | ||
634 | return 0; | |
318e0a73 SR |
635 | |
636 | out_free: | |
637 | pg = stat->start; | |
638 | while (pg) { | |
639 | unsigned long tmp = (unsigned long)pg; | |
640 | ||
641 | pg = pg->next; | |
642 | free_page(tmp); | |
643 | } | |
644 | ||
645 | free_page((unsigned long)stat->pages); | |
646 | stat->pages = NULL; | |
647 | stat->start = NULL; | |
648 | ||
649 | return -ENOMEM; | |
bac429f0 SR |
650 | } |
651 | ||
cafb168a | 652 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 653 | { |
cafb168a | 654 | struct ftrace_profile_stat *stat; |
493762fc | 655 | int size; |
bac429f0 | 656 | |
cafb168a SR |
657 | stat = &per_cpu(ftrace_profile_stats, cpu); |
658 | ||
659 | if (stat->hash) { | |
493762fc | 660 | /* If the profile is already created, simply reset it */ |
cafb168a | 661 | ftrace_profile_reset(stat); |
493762fc SR |
662 | return 0; |
663 | } | |
bac429f0 | 664 | |
493762fc SR |
665 | /* |
666 | * We are profiling all functions, but usually only a few thousand | |
667 | * functions are hit. We'll make a hash of 1024 items. | |
668 | */ | |
669 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 670 | |
cafb168a | 671 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
493762fc | 672 | |
cafb168a | 673 | if (!stat->hash) |
493762fc SR |
674 | return -ENOMEM; |
675 | ||
cafb168a SR |
676 | if (!ftrace_profile_bits) { |
677 | size--; | |
493762fc | 678 | |
cafb168a SR |
679 | for (; size; size >>= 1) |
680 | ftrace_profile_bits++; | |
681 | } | |
493762fc | 682 | |
318e0a73 | 683 | /* Preallocate the function profiling pages */ |
cafb168a SR |
684 | if (ftrace_profile_pages_init(stat) < 0) { |
685 | kfree(stat->hash); | |
686 | stat->hash = NULL; | |
493762fc SR |
687 | return -ENOMEM; |
688 | } | |
689 | ||
690 | return 0; | |
bac429f0 SR |
691 | } |
692 | ||
cafb168a SR |
693 | static int ftrace_profile_init(void) |
694 | { | |
695 | int cpu; | |
696 | int ret = 0; | |
697 | ||
698 | for_each_online_cpu(cpu) { | |
699 | ret = ftrace_profile_init_cpu(cpu); | |
700 | if (ret) | |
701 | break; | |
702 | } | |
703 | ||
704 | return ret; | |
705 | } | |
706 | ||
493762fc | 707 | /* interrupts must be disabled */ |
cafb168a SR |
708 | static struct ftrace_profile * |
709 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 710 | { |
493762fc | 711 | struct ftrace_profile *rec; |
bac429f0 SR |
712 | struct hlist_head *hhd; |
713 | struct hlist_node *n; | |
bac429f0 SR |
714 | unsigned long key; |
715 | ||
bac429f0 | 716 | key = hash_long(ip, ftrace_profile_bits); |
cafb168a | 717 | hhd = &stat->hash[key]; |
bac429f0 SR |
718 | |
719 | if (hlist_empty(hhd)) | |
720 | return NULL; | |
721 | ||
bac429f0 SR |
722 | hlist_for_each_entry_rcu(rec, n, hhd, node) { |
723 | if (rec->ip == ip) | |
493762fc SR |
724 | return rec; |
725 | } | |
726 | ||
727 | return NULL; | |
728 | } | |
729 | ||
cafb168a SR |
730 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
731 | struct ftrace_profile *rec) | |
493762fc SR |
732 | { |
733 | unsigned long key; | |
734 | ||
735 | key = hash_long(rec->ip, ftrace_profile_bits); | |
cafb168a | 736 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
737 | } |
738 | ||
318e0a73 SR |
739 | /* |
740 | * The memory is already allocated, this simply finds a new record to use. | |
741 | */ | |
493762fc | 742 | static struct ftrace_profile * |
318e0a73 | 743 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
744 | { |
745 | struct ftrace_profile *rec = NULL; | |
746 | ||
318e0a73 | 747 | /* prevent recursion (from NMIs) */ |
cafb168a | 748 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
749 | goto out; |
750 | ||
493762fc | 751 | /* |
318e0a73 SR |
752 | * Try to find the function again since an NMI |
753 | * could have added it | |
493762fc | 754 | */ |
cafb168a | 755 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 756 | if (rec) |
cafb168a | 757 | goto out; |
493762fc | 758 | |
cafb168a SR |
759 | if (stat->pages->index == PROFILES_PER_PAGE) { |
760 | if (!stat->pages->next) | |
761 | goto out; | |
762 | stat->pages = stat->pages->next; | |
bac429f0 | 763 | } |
493762fc | 764 | |
cafb168a | 765 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 766 | rec->ip = ip; |
cafb168a | 767 | ftrace_add_profile(stat, rec); |
493762fc | 768 | |
bac429f0 | 769 | out: |
cafb168a | 770 | atomic_dec(&stat->disabled); |
bac429f0 SR |
771 | |
772 | return rec; | |
773 | } | |
774 | ||
775 | static void | |
776 | function_profile_call(unsigned long ip, unsigned long parent_ip) | |
777 | { | |
cafb168a | 778 | struct ftrace_profile_stat *stat; |
493762fc | 779 | struct ftrace_profile *rec; |
bac429f0 SR |
780 | unsigned long flags; |
781 | ||
782 | if (!ftrace_profile_enabled) | |
783 | return; | |
784 | ||
785 | local_irq_save(flags); | |
cafb168a SR |
786 | |
787 | stat = &__get_cpu_var(ftrace_profile_stats); | |
0f6ce3de | 788 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
789 | goto out; |
790 | ||
791 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 792 | if (!rec) { |
318e0a73 | 793 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
794 | if (!rec) |
795 | goto out; | |
796 | } | |
bac429f0 SR |
797 | |
798 | rec->counter++; | |
799 | out: | |
800 | local_irq_restore(flags); | |
801 | } | |
802 | ||
0706f1c4 SR |
803 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
804 | static int profile_graph_entry(struct ftrace_graph_ent *trace) | |
805 | { | |
806 | function_profile_call(trace->func, 0); | |
807 | return 1; | |
808 | } | |
809 | ||
810 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
811 | { | |
cafb168a | 812 | struct ftrace_profile_stat *stat; |
a2a16d6a | 813 | unsigned long long calltime; |
0706f1c4 | 814 | struct ftrace_profile *rec; |
cafb168a | 815 | unsigned long flags; |
0706f1c4 SR |
816 | |
817 | local_irq_save(flags); | |
cafb168a | 818 | stat = &__get_cpu_var(ftrace_profile_stats); |
0f6ce3de | 819 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
820 | goto out; |
821 | ||
37e44bc5 SR |
822 | /* If the calltime was zero'd ignore it */ |
823 | if (!trace->calltime) | |
824 | goto out; | |
825 | ||
a2a16d6a SR |
826 | calltime = trace->rettime - trace->calltime; |
827 | ||
828 | if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) { | |
829 | int index; | |
830 | ||
831 | index = trace->depth; | |
832 | ||
833 | /* Append this call time to the parent time to subtract */ | |
834 | if (index) | |
835 | current->ret_stack[index - 1].subtime += calltime; | |
836 | ||
837 | if (current->ret_stack[index].subtime < calltime) | |
838 | calltime -= current->ret_stack[index].subtime; | |
839 | else | |
840 | calltime = 0; | |
841 | } | |
842 | ||
cafb168a | 843 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 844 | if (rec) { |
a2a16d6a | 845 | rec->time += calltime; |
e330b3bc CD |
846 | rec->time_squared += calltime * calltime; |
847 | } | |
a2a16d6a | 848 | |
cafb168a | 849 | out: |
0706f1c4 SR |
850 | local_irq_restore(flags); |
851 | } | |
852 | ||
853 | static int register_ftrace_profiler(void) | |
854 | { | |
855 | return register_ftrace_graph(&profile_graph_return, | |
856 | &profile_graph_entry); | |
857 | } | |
858 | ||
859 | static void unregister_ftrace_profiler(void) | |
860 | { | |
861 | unregister_ftrace_graph(); | |
862 | } | |
863 | #else | |
bd38c0e6 | 864 | static struct ftrace_ops ftrace_profile_ops __read_mostly = { |
fb9fb015 | 865 | .func = function_profile_call, |
bac429f0 SR |
866 | }; |
867 | ||
0706f1c4 SR |
868 | static int register_ftrace_profiler(void) |
869 | { | |
870 | return register_ftrace_function(&ftrace_profile_ops); | |
871 | } | |
872 | ||
873 | static void unregister_ftrace_profiler(void) | |
874 | { | |
875 | unregister_ftrace_function(&ftrace_profile_ops); | |
876 | } | |
877 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
878 | ||
bac429f0 SR |
879 | static ssize_t |
880 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
881 | size_t cnt, loff_t *ppos) | |
882 | { | |
883 | unsigned long val; | |
bac429f0 SR |
884 | int ret; |
885 | ||
22fe9b54 PH |
886 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
887 | if (ret) | |
bac429f0 SR |
888 | return ret; |
889 | ||
890 | val = !!val; | |
891 | ||
892 | mutex_lock(&ftrace_profile_lock); | |
893 | if (ftrace_profile_enabled ^ val) { | |
894 | if (val) { | |
493762fc SR |
895 | ret = ftrace_profile_init(); |
896 | if (ret < 0) { | |
897 | cnt = ret; | |
898 | goto out; | |
899 | } | |
900 | ||
0706f1c4 SR |
901 | ret = register_ftrace_profiler(); |
902 | if (ret < 0) { | |
903 | cnt = ret; | |
904 | goto out; | |
905 | } | |
bac429f0 SR |
906 | ftrace_profile_enabled = 1; |
907 | } else { | |
908 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
909 | /* |
910 | * unregister_ftrace_profiler calls stop_machine | |
911 | * so this acts like an synchronize_sched. | |
912 | */ | |
0706f1c4 | 913 | unregister_ftrace_profiler(); |
bac429f0 SR |
914 | } |
915 | } | |
493762fc | 916 | out: |
bac429f0 SR |
917 | mutex_unlock(&ftrace_profile_lock); |
918 | ||
cf8517cf | 919 | *ppos += cnt; |
bac429f0 SR |
920 | |
921 | return cnt; | |
922 | } | |
923 | ||
493762fc SR |
924 | static ssize_t |
925 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
926 | size_t cnt, loff_t *ppos) | |
927 | { | |
fb9fb015 | 928 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
929 | int r; |
930 | ||
931 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
932 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
933 | } | |
934 | ||
bac429f0 SR |
935 | static const struct file_operations ftrace_profile_fops = { |
936 | .open = tracing_open_generic, | |
937 | .read = ftrace_profile_read, | |
938 | .write = ftrace_profile_write, | |
6038f373 | 939 | .llseek = default_llseek, |
bac429f0 SR |
940 | }; |
941 | ||
cafb168a SR |
942 | /* used to initialize the real stat files */ |
943 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
944 | .name = "functions", |
945 | .stat_start = function_stat_start, | |
946 | .stat_next = function_stat_next, | |
947 | .stat_cmp = function_stat_cmp, | |
948 | .stat_headers = function_stat_headers, | |
949 | .stat_show = function_stat_show | |
cafb168a SR |
950 | }; |
951 | ||
6ab5d668 | 952 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 | 953 | { |
cafb168a | 954 | struct ftrace_profile_stat *stat; |
bac429f0 | 955 | struct dentry *entry; |
cafb168a | 956 | char *name; |
bac429f0 | 957 | int ret; |
cafb168a SR |
958 | int cpu; |
959 | ||
960 | for_each_possible_cpu(cpu) { | |
961 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
962 | ||
963 | /* allocate enough for function name + cpu number */ | |
964 | name = kmalloc(32, GFP_KERNEL); | |
965 | if (!name) { | |
966 | /* | |
967 | * The files created are permanent, if something happens | |
968 | * we still do not free memory. | |
969 | */ | |
cafb168a SR |
970 | WARN(1, |
971 | "Could not allocate stat file for cpu %d\n", | |
972 | cpu); | |
973 | return; | |
974 | } | |
975 | stat->stat = function_stats; | |
976 | snprintf(name, 32, "function%d", cpu); | |
977 | stat->stat.name = name; | |
978 | ret = register_stat_tracer(&stat->stat); | |
979 | if (ret) { | |
980 | WARN(1, | |
981 | "Could not register function stat for cpu %d\n", | |
982 | cpu); | |
983 | kfree(name); | |
984 | return; | |
985 | } | |
bac429f0 SR |
986 | } |
987 | ||
988 | entry = debugfs_create_file("function_profile_enabled", 0644, | |
989 | d_tracer, NULL, &ftrace_profile_fops); | |
990 | if (!entry) | |
991 | pr_warning("Could not create debugfs " | |
992 | "'function_profile_enabled' entry\n"); | |
993 | } | |
994 | ||
bac429f0 | 995 | #else /* CONFIG_FUNCTION_PROFILER */ |
6ab5d668 | 996 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 SR |
997 | { |
998 | } | |
bac429f0 SR |
999 | #endif /* CONFIG_FUNCTION_PROFILER */ |
1000 | ||
493762fc SR |
1001 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; |
1002 | ||
1003 | #ifdef CONFIG_DYNAMIC_FTRACE | |
1004 | ||
1005 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD | |
1006 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
1007 | #endif | |
1008 | ||
1009 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; | |
1010 | ||
1011 | struct ftrace_func_probe { | |
1012 | struct hlist_node node; | |
1013 | struct ftrace_probe_ops *ops; | |
1014 | unsigned long flags; | |
1015 | unsigned long ip; | |
1016 | void *data; | |
1017 | struct rcu_head rcu; | |
1018 | }; | |
1019 | ||
b448c4e3 SR |
1020 | struct ftrace_func_entry { |
1021 | struct hlist_node hlist; | |
1022 | unsigned long ip; | |
1023 | }; | |
1024 | ||
1025 | struct ftrace_hash { | |
1026 | unsigned long size_bits; | |
1027 | struct hlist_head *buckets; | |
1028 | unsigned long count; | |
07fd5515 | 1029 | struct rcu_head rcu; |
b448c4e3 SR |
1030 | }; |
1031 | ||
33dc9b12 SR |
1032 | /* |
1033 | * We make these constant because no one should touch them, | |
1034 | * but they are used as the default "empty hash", to avoid allocating | |
1035 | * it all the time. These are in a read only section such that if | |
1036 | * anyone does try to modify it, it will cause an exception. | |
1037 | */ | |
1038 | static const struct hlist_head empty_buckets[1]; | |
1039 | static const struct ftrace_hash empty_hash = { | |
1040 | .buckets = (struct hlist_head *)empty_buckets, | |
1cf41dd7 | 1041 | }; |
33dc9b12 | 1042 | #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) |
493762fc | 1043 | |
2b499381 | 1044 | static struct ftrace_ops global_ops = { |
f45948e8 | 1045 | .func = ftrace_stub, |
33dc9b12 SR |
1046 | .notrace_hash = EMPTY_HASH, |
1047 | .filter_hash = EMPTY_HASH, | |
f45948e8 SR |
1048 | }; |
1049 | ||
493762fc SR |
1050 | static DEFINE_MUTEX(ftrace_regex_lock); |
1051 | ||
1052 | struct ftrace_page { | |
1053 | struct ftrace_page *next; | |
a7900875 | 1054 | struct dyn_ftrace *records; |
493762fc | 1055 | int index; |
a7900875 | 1056 | int size; |
493762fc SR |
1057 | }; |
1058 | ||
85ae32ae SR |
1059 | static struct ftrace_page *ftrace_new_pgs; |
1060 | ||
a7900875 SR |
1061 | #define ENTRY_SIZE sizeof(struct dyn_ftrace) |
1062 | #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE) | |
493762fc SR |
1063 | |
1064 | /* estimate from running different kernels */ | |
1065 | #define NR_TO_INIT 10000 | |
1066 | ||
1067 | static struct ftrace_page *ftrace_pages_start; | |
1068 | static struct ftrace_page *ftrace_pages; | |
1069 | ||
06a51d93 SR |
1070 | static bool ftrace_hash_empty(struct ftrace_hash *hash) |
1071 | { | |
1072 | return !hash || !hash->count; | |
1073 | } | |
1074 | ||
b448c4e3 SR |
1075 | static struct ftrace_func_entry * |
1076 | ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
1077 | { | |
1078 | unsigned long key; | |
1079 | struct ftrace_func_entry *entry; | |
1080 | struct hlist_head *hhd; | |
1081 | struct hlist_node *n; | |
1082 | ||
06a51d93 | 1083 | if (ftrace_hash_empty(hash)) |
b448c4e3 SR |
1084 | return NULL; |
1085 | ||
1086 | if (hash->size_bits > 0) | |
1087 | key = hash_long(ip, hash->size_bits); | |
1088 | else | |
1089 | key = 0; | |
1090 | ||
1091 | hhd = &hash->buckets[key]; | |
1092 | ||
1093 | hlist_for_each_entry_rcu(entry, n, hhd, hlist) { | |
1094 | if (entry->ip == ip) | |
1095 | return entry; | |
1096 | } | |
1097 | return NULL; | |
1098 | } | |
1099 | ||
33dc9b12 SR |
1100 | static void __add_hash_entry(struct ftrace_hash *hash, |
1101 | struct ftrace_func_entry *entry) | |
b448c4e3 | 1102 | { |
b448c4e3 SR |
1103 | struct hlist_head *hhd; |
1104 | unsigned long key; | |
1105 | ||
b448c4e3 | 1106 | if (hash->size_bits) |
33dc9b12 | 1107 | key = hash_long(entry->ip, hash->size_bits); |
b448c4e3 SR |
1108 | else |
1109 | key = 0; | |
1110 | ||
b448c4e3 SR |
1111 | hhd = &hash->buckets[key]; |
1112 | hlist_add_head(&entry->hlist, hhd); | |
1113 | hash->count++; | |
33dc9b12 SR |
1114 | } |
1115 | ||
1116 | static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip) | |
1117 | { | |
1118 | struct ftrace_func_entry *entry; | |
1119 | ||
1120 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1121 | if (!entry) | |
1122 | return -ENOMEM; | |
1123 | ||
1124 | entry->ip = ip; | |
1125 | __add_hash_entry(hash, entry); | |
b448c4e3 SR |
1126 | |
1127 | return 0; | |
1128 | } | |
1129 | ||
1130 | static void | |
33dc9b12 | 1131 | free_hash_entry(struct ftrace_hash *hash, |
b448c4e3 SR |
1132 | struct ftrace_func_entry *entry) |
1133 | { | |
1134 | hlist_del(&entry->hlist); | |
1135 | kfree(entry); | |
1136 | hash->count--; | |
1137 | } | |
1138 | ||
33dc9b12 SR |
1139 | static void |
1140 | remove_hash_entry(struct ftrace_hash *hash, | |
1141 | struct ftrace_func_entry *entry) | |
1142 | { | |
1143 | hlist_del(&entry->hlist); | |
1144 | hash->count--; | |
1145 | } | |
1146 | ||
b448c4e3 SR |
1147 | static void ftrace_hash_clear(struct ftrace_hash *hash) |
1148 | { | |
1149 | struct hlist_head *hhd; | |
1150 | struct hlist_node *tp, *tn; | |
1151 | struct ftrace_func_entry *entry; | |
1152 | int size = 1 << hash->size_bits; | |
1153 | int i; | |
1154 | ||
33dc9b12 SR |
1155 | if (!hash->count) |
1156 | return; | |
1157 | ||
b448c4e3 SR |
1158 | for (i = 0; i < size; i++) { |
1159 | hhd = &hash->buckets[i]; | |
1160 | hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist) | |
33dc9b12 | 1161 | free_hash_entry(hash, entry); |
b448c4e3 SR |
1162 | } |
1163 | FTRACE_WARN_ON(hash->count); | |
1164 | } | |
1165 | ||
33dc9b12 SR |
1166 | static void free_ftrace_hash(struct ftrace_hash *hash) |
1167 | { | |
1168 | if (!hash || hash == EMPTY_HASH) | |
1169 | return; | |
1170 | ftrace_hash_clear(hash); | |
1171 | kfree(hash->buckets); | |
1172 | kfree(hash); | |
1173 | } | |
1174 | ||
07fd5515 SR |
1175 | static void __free_ftrace_hash_rcu(struct rcu_head *rcu) |
1176 | { | |
1177 | struct ftrace_hash *hash; | |
1178 | ||
1179 | hash = container_of(rcu, struct ftrace_hash, rcu); | |
1180 | free_ftrace_hash(hash); | |
1181 | } | |
1182 | ||
1183 | static void free_ftrace_hash_rcu(struct ftrace_hash *hash) | |
1184 | { | |
1185 | if (!hash || hash == EMPTY_HASH) | |
1186 | return; | |
1187 | call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu); | |
1188 | } | |
1189 | ||
5500fa51 JO |
1190 | void ftrace_free_filter(struct ftrace_ops *ops) |
1191 | { | |
1192 | free_ftrace_hash(ops->filter_hash); | |
1193 | free_ftrace_hash(ops->notrace_hash); | |
1194 | } | |
1195 | ||
33dc9b12 SR |
1196 | static struct ftrace_hash *alloc_ftrace_hash(int size_bits) |
1197 | { | |
1198 | struct ftrace_hash *hash; | |
1199 | int size; | |
1200 | ||
1201 | hash = kzalloc(sizeof(*hash), GFP_KERNEL); | |
1202 | if (!hash) | |
1203 | return NULL; | |
1204 | ||
1205 | size = 1 << size_bits; | |
47b0edcb | 1206 | hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL); |
33dc9b12 SR |
1207 | |
1208 | if (!hash->buckets) { | |
1209 | kfree(hash); | |
1210 | return NULL; | |
1211 | } | |
1212 | ||
1213 | hash->size_bits = size_bits; | |
1214 | ||
1215 | return hash; | |
1216 | } | |
1217 | ||
1218 | static struct ftrace_hash * | |
1219 | alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) | |
1220 | { | |
1221 | struct ftrace_func_entry *entry; | |
1222 | struct ftrace_hash *new_hash; | |
1223 | struct hlist_node *tp; | |
1224 | int size; | |
1225 | int ret; | |
1226 | int i; | |
1227 | ||
1228 | new_hash = alloc_ftrace_hash(size_bits); | |
1229 | if (!new_hash) | |
1230 | return NULL; | |
1231 | ||
1232 | /* Empty hash? */ | |
06a51d93 | 1233 | if (ftrace_hash_empty(hash)) |
33dc9b12 SR |
1234 | return new_hash; |
1235 | ||
1236 | size = 1 << hash->size_bits; | |
1237 | for (i = 0; i < size; i++) { | |
1238 | hlist_for_each_entry(entry, tp, &hash->buckets[i], hlist) { | |
1239 | ret = add_hash_entry(new_hash, entry->ip); | |
1240 | if (ret < 0) | |
1241 | goto free_hash; | |
1242 | } | |
1243 | } | |
1244 | ||
1245 | FTRACE_WARN_ON(new_hash->count != hash->count); | |
1246 | ||
1247 | return new_hash; | |
1248 | ||
1249 | free_hash: | |
1250 | free_ftrace_hash(new_hash); | |
1251 | return NULL; | |
1252 | } | |
1253 | ||
41fb61c2 SR |
1254 | static void |
1255 | ftrace_hash_rec_disable(struct ftrace_ops *ops, int filter_hash); | |
1256 | static void | |
1257 | ftrace_hash_rec_enable(struct ftrace_ops *ops, int filter_hash); | |
1258 | ||
33dc9b12 | 1259 | static int |
41fb61c2 SR |
1260 | ftrace_hash_move(struct ftrace_ops *ops, int enable, |
1261 | struct ftrace_hash **dst, struct ftrace_hash *src) | |
33dc9b12 SR |
1262 | { |
1263 | struct ftrace_func_entry *entry; | |
1264 | struct hlist_node *tp, *tn; | |
1265 | struct hlist_head *hhd; | |
07fd5515 SR |
1266 | struct ftrace_hash *old_hash; |
1267 | struct ftrace_hash *new_hash; | |
33dc9b12 SR |
1268 | unsigned long key; |
1269 | int size = src->count; | |
1270 | int bits = 0; | |
41fb61c2 | 1271 | int ret; |
33dc9b12 SR |
1272 | int i; |
1273 | ||
41fb61c2 SR |
1274 | /* |
1275 | * Remove the current set, update the hash and add | |
1276 | * them back. | |
1277 | */ | |
1278 | ftrace_hash_rec_disable(ops, enable); | |
1279 | ||
33dc9b12 SR |
1280 | /* |
1281 | * If the new source is empty, just free dst and assign it | |
1282 | * the empty_hash. | |
1283 | */ | |
1284 | if (!src->count) { | |
07fd5515 SR |
1285 | free_ftrace_hash_rcu(*dst); |
1286 | rcu_assign_pointer(*dst, EMPTY_HASH); | |
d4d34b98 SR |
1287 | /* still need to update the function records */ |
1288 | ret = 0; | |
1289 | goto out; | |
33dc9b12 SR |
1290 | } |
1291 | ||
33dc9b12 SR |
1292 | /* |
1293 | * Make the hash size about 1/2 the # found | |
1294 | */ | |
1295 | for (size /= 2; size; size >>= 1) | |
1296 | bits++; | |
1297 | ||
1298 | /* Don't allocate too much */ | |
1299 | if (bits > FTRACE_HASH_MAX_BITS) | |
1300 | bits = FTRACE_HASH_MAX_BITS; | |
1301 | ||
41fb61c2 | 1302 | ret = -ENOMEM; |
07fd5515 SR |
1303 | new_hash = alloc_ftrace_hash(bits); |
1304 | if (!new_hash) | |
41fb61c2 | 1305 | goto out; |
33dc9b12 SR |
1306 | |
1307 | size = 1 << src->size_bits; | |
1308 | for (i = 0; i < size; i++) { | |
1309 | hhd = &src->buckets[i]; | |
1310 | hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist) { | |
1311 | if (bits > 0) | |
1312 | key = hash_long(entry->ip, bits); | |
1313 | else | |
1314 | key = 0; | |
1315 | remove_hash_entry(src, entry); | |
07fd5515 | 1316 | __add_hash_entry(new_hash, entry); |
33dc9b12 SR |
1317 | } |
1318 | } | |
1319 | ||
07fd5515 SR |
1320 | old_hash = *dst; |
1321 | rcu_assign_pointer(*dst, new_hash); | |
1322 | free_ftrace_hash_rcu(old_hash); | |
1323 | ||
41fb61c2 SR |
1324 | ret = 0; |
1325 | out: | |
1326 | /* | |
1327 | * Enable regardless of ret: | |
1328 | * On success, we enable the new hash. | |
1329 | * On failure, we re-enable the original hash. | |
1330 | */ | |
1331 | ftrace_hash_rec_enable(ops, enable); | |
1332 | ||
1333 | return ret; | |
33dc9b12 SR |
1334 | } |
1335 | ||
b848914c SR |
1336 | /* |
1337 | * Test the hashes for this ops to see if we want to call | |
1338 | * the ops->func or not. | |
1339 | * | |
1340 | * It's a match if the ip is in the ops->filter_hash or | |
1341 | * the filter_hash does not exist or is empty, | |
1342 | * AND | |
1343 | * the ip is not in the ops->notrace_hash. | |
cdbe61bf SR |
1344 | * |
1345 | * This needs to be called with preemption disabled as | |
1346 | * the hashes are freed with call_rcu_sched(). | |
b848914c SR |
1347 | */ |
1348 | static int | |
1349 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip) | |
1350 | { | |
1351 | struct ftrace_hash *filter_hash; | |
1352 | struct ftrace_hash *notrace_hash; | |
1353 | int ret; | |
1354 | ||
b848914c SR |
1355 | filter_hash = rcu_dereference_raw(ops->filter_hash); |
1356 | notrace_hash = rcu_dereference_raw(ops->notrace_hash); | |
1357 | ||
06a51d93 | 1358 | if ((ftrace_hash_empty(filter_hash) || |
b848914c | 1359 | ftrace_lookup_ip(filter_hash, ip)) && |
06a51d93 | 1360 | (ftrace_hash_empty(notrace_hash) || |
b848914c SR |
1361 | !ftrace_lookup_ip(notrace_hash, ip))) |
1362 | ret = 1; | |
1363 | else | |
1364 | ret = 0; | |
b848914c SR |
1365 | |
1366 | return ret; | |
1367 | } | |
1368 | ||
493762fc SR |
1369 | /* |
1370 | * This is a double for. Do not use 'break' to break out of the loop, | |
1371 | * you must use a goto. | |
1372 | */ | |
1373 | #define do_for_each_ftrace_rec(pg, rec) \ | |
1374 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
1375 | int _____i; \ | |
1376 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
1377 | rec = &pg->records[_____i]; | |
1378 | ||
1379 | #define while_for_each_ftrace_rec() \ | |
1380 | } \ | |
1381 | } | |
1382 | ||
5855fead SR |
1383 | |
1384 | static int ftrace_cmp_recs(const void *a, const void *b) | |
1385 | { | |
a650e02a SR |
1386 | const struct dyn_ftrace *key = a; |
1387 | const struct dyn_ftrace *rec = b; | |
5855fead | 1388 | |
a650e02a | 1389 | if (key->flags < rec->ip) |
5855fead | 1390 | return -1; |
a650e02a SR |
1391 | if (key->ip >= rec->ip + MCOUNT_INSN_SIZE) |
1392 | return 1; | |
5855fead SR |
1393 | return 0; |
1394 | } | |
1395 | ||
a650e02a | 1396 | static int ftrace_location_range(unsigned long start, unsigned long end) |
c88fd863 SR |
1397 | { |
1398 | struct ftrace_page *pg; | |
1399 | struct dyn_ftrace *rec; | |
5855fead | 1400 | struct dyn_ftrace key; |
c88fd863 | 1401 | |
a650e02a SR |
1402 | key.ip = start; |
1403 | key.flags = end; /* overload flags, as it is unsigned long */ | |
5855fead SR |
1404 | |
1405 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
a650e02a SR |
1406 | if (end < pg->records[0].ip || |
1407 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) | |
9644302e | 1408 | continue; |
5855fead SR |
1409 | rec = bsearch(&key, pg->records, pg->index, |
1410 | sizeof(struct dyn_ftrace), | |
1411 | ftrace_cmp_recs); | |
1412 | if (rec) | |
c88fd863 | 1413 | return 1; |
5855fead | 1414 | } |
c88fd863 SR |
1415 | |
1416 | return 0; | |
1417 | } | |
1418 | ||
a650e02a SR |
1419 | /** |
1420 | * ftrace_location - return true if the ip giving is a traced location | |
1421 | * @ip: the instruction pointer to check | |
1422 | * | |
1423 | * Returns 1 if @ip given is a pointer to a ftrace location. | |
1424 | * That is, the instruction that is either a NOP or call to | |
1425 | * the function tracer. It checks the ftrace internal tables to | |
1426 | * determine if the address belongs or not. | |
1427 | */ | |
1428 | int ftrace_location(unsigned long ip) | |
1429 | { | |
1430 | return ftrace_location_range(ip, ip); | |
1431 | } | |
1432 | ||
1433 | /** | |
1434 | * ftrace_text_reserved - return true if range contains an ftrace location | |
1435 | * @start: start of range to search | |
1436 | * @end: end of range to search (inclusive). @end points to the last byte to check. | |
1437 | * | |
1438 | * Returns 1 if @start and @end contains a ftrace location. | |
1439 | * That is, the instruction that is either a NOP or call to | |
1440 | * the function tracer. It checks the ftrace internal tables to | |
1441 | * determine if the address belongs or not. | |
1442 | */ | |
1443 | int ftrace_text_reserved(void *start, void *end) | |
1444 | { | |
1445 | return ftrace_location_range((unsigned long)start, | |
1446 | (unsigned long)end); | |
1447 | } | |
1448 | ||
ed926f9b SR |
1449 | static void __ftrace_hash_rec_update(struct ftrace_ops *ops, |
1450 | int filter_hash, | |
1451 | bool inc) | |
1452 | { | |
1453 | struct ftrace_hash *hash; | |
1454 | struct ftrace_hash *other_hash; | |
1455 | struct ftrace_page *pg; | |
1456 | struct dyn_ftrace *rec; | |
1457 | int count = 0; | |
1458 | int all = 0; | |
1459 | ||
1460 | /* Only update if the ops has been registered */ | |
1461 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
1462 | return; | |
1463 | ||
1464 | /* | |
1465 | * In the filter_hash case: | |
1466 | * If the count is zero, we update all records. | |
1467 | * Otherwise we just update the items in the hash. | |
1468 | * | |
1469 | * In the notrace_hash case: | |
1470 | * We enable the update in the hash. | |
1471 | * As disabling notrace means enabling the tracing, | |
1472 | * and enabling notrace means disabling, the inc variable | |
1473 | * gets inversed. | |
1474 | */ | |
1475 | if (filter_hash) { | |
1476 | hash = ops->filter_hash; | |
1477 | other_hash = ops->notrace_hash; | |
06a51d93 | 1478 | if (ftrace_hash_empty(hash)) |
ed926f9b SR |
1479 | all = 1; |
1480 | } else { | |
1481 | inc = !inc; | |
1482 | hash = ops->notrace_hash; | |
1483 | other_hash = ops->filter_hash; | |
1484 | /* | |
1485 | * If the notrace hash has no items, | |
1486 | * then there's nothing to do. | |
1487 | */ | |
06a51d93 | 1488 | if (ftrace_hash_empty(hash)) |
ed926f9b SR |
1489 | return; |
1490 | } | |
1491 | ||
1492 | do_for_each_ftrace_rec(pg, rec) { | |
1493 | int in_other_hash = 0; | |
1494 | int in_hash = 0; | |
1495 | int match = 0; | |
1496 | ||
1497 | if (all) { | |
1498 | /* | |
1499 | * Only the filter_hash affects all records. | |
1500 | * Update if the record is not in the notrace hash. | |
1501 | */ | |
b848914c | 1502 | if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) |
ed926f9b SR |
1503 | match = 1; |
1504 | } else { | |
06a51d93 SR |
1505 | in_hash = !!ftrace_lookup_ip(hash, rec->ip); |
1506 | in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip); | |
ed926f9b SR |
1507 | |
1508 | /* | |
1509 | * | |
1510 | */ | |
1511 | if (filter_hash && in_hash && !in_other_hash) | |
1512 | match = 1; | |
1513 | else if (!filter_hash && in_hash && | |
06a51d93 | 1514 | (in_other_hash || ftrace_hash_empty(other_hash))) |
ed926f9b SR |
1515 | match = 1; |
1516 | } | |
1517 | if (!match) | |
1518 | continue; | |
1519 | ||
1520 | if (inc) { | |
1521 | rec->flags++; | |
1522 | if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == FTRACE_REF_MAX)) | |
1523 | return; | |
1524 | } else { | |
1525 | if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == 0)) | |
1526 | return; | |
1527 | rec->flags--; | |
1528 | } | |
1529 | count++; | |
1530 | /* Shortcut, if we handled all records, we are done. */ | |
1531 | if (!all && count == hash->count) | |
1532 | return; | |
1533 | } while_for_each_ftrace_rec(); | |
1534 | } | |
1535 | ||
1536 | static void ftrace_hash_rec_disable(struct ftrace_ops *ops, | |
1537 | int filter_hash) | |
1538 | { | |
1539 | __ftrace_hash_rec_update(ops, filter_hash, 0); | |
1540 | } | |
1541 | ||
1542 | static void ftrace_hash_rec_enable(struct ftrace_ops *ops, | |
1543 | int filter_hash) | |
1544 | { | |
1545 | __ftrace_hash_rec_update(ops, filter_hash, 1); | |
1546 | } | |
1547 | ||
b17e8a37 SR |
1548 | static void print_ip_ins(const char *fmt, unsigned char *p) |
1549 | { | |
1550 | int i; | |
1551 | ||
1552 | printk(KERN_CONT "%s", fmt); | |
1553 | ||
1554 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
1555 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
1556 | } | |
1557 | ||
c88fd863 SR |
1558 | /** |
1559 | * ftrace_bug - report and shutdown function tracer | |
1560 | * @failed: The failed type (EFAULT, EINVAL, EPERM) | |
1561 | * @ip: The address that failed | |
1562 | * | |
1563 | * The arch code that enables or disables the function tracing | |
1564 | * can call ftrace_bug() when it has detected a problem in | |
1565 | * modifying the code. @failed should be one of either: | |
1566 | * EFAULT - if the problem happens on reading the @ip address | |
1567 | * EINVAL - if what is read at @ip is not what was expected | |
1568 | * EPERM - if the problem happens on writting to the @ip address | |
1569 | */ | |
1570 | void ftrace_bug(int failed, unsigned long ip) | |
b17e8a37 SR |
1571 | { |
1572 | switch (failed) { | |
1573 | case -EFAULT: | |
1574 | FTRACE_WARN_ON_ONCE(1); | |
1575 | pr_info("ftrace faulted on modifying "); | |
1576 | print_ip_sym(ip); | |
1577 | break; | |
1578 | case -EINVAL: | |
1579 | FTRACE_WARN_ON_ONCE(1); | |
1580 | pr_info("ftrace failed to modify "); | |
1581 | print_ip_sym(ip); | |
b17e8a37 | 1582 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
1583 | printk(KERN_CONT "\n"); |
1584 | break; | |
1585 | case -EPERM: | |
1586 | FTRACE_WARN_ON_ONCE(1); | |
1587 | pr_info("ftrace faulted on writing "); | |
1588 | print_ip_sym(ip); | |
1589 | break; | |
1590 | default: | |
1591 | FTRACE_WARN_ON_ONCE(1); | |
1592 | pr_info("ftrace faulted on unknown error "); | |
1593 | print_ip_sym(ip); | |
1594 | } | |
1595 | } | |
1596 | ||
c88fd863 | 1597 | static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update) |
5072c59f | 1598 | { |
64fbcd16 | 1599 | unsigned long flag = 0UL; |
e7d3737e | 1600 | |
982c350b | 1601 | /* |
30fb6aa7 | 1602 | * If we are updating calls: |
982c350b | 1603 | * |
ed926f9b SR |
1604 | * If the record has a ref count, then we need to enable it |
1605 | * because someone is using it. | |
982c350b | 1606 | * |
ed926f9b SR |
1607 | * Otherwise we make sure its disabled. |
1608 | * | |
30fb6aa7 | 1609 | * If we are disabling calls, then disable all records that |
ed926f9b | 1610 | * are enabled. |
982c350b | 1611 | */ |
c88fd863 | 1612 | if (enable && (rec->flags & ~FTRACE_FL_MASK)) |
ed926f9b | 1613 | flag = FTRACE_FL_ENABLED; |
982c350b | 1614 | |
64fbcd16 XG |
1615 | /* If the state of this record hasn't changed, then do nothing */ |
1616 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
c88fd863 | 1617 | return FTRACE_UPDATE_IGNORE; |
982c350b | 1618 | |
64fbcd16 | 1619 | if (flag) { |
c88fd863 SR |
1620 | if (update) |
1621 | rec->flags |= FTRACE_FL_ENABLED; | |
1622 | return FTRACE_UPDATE_MAKE_CALL; | |
1623 | } | |
1624 | ||
1625 | if (update) | |
1626 | rec->flags &= ~FTRACE_FL_ENABLED; | |
1627 | ||
1628 | return FTRACE_UPDATE_MAKE_NOP; | |
1629 | } | |
1630 | ||
1631 | /** | |
1632 | * ftrace_update_record, set a record that now is tracing or not | |
1633 | * @rec: the record to update | |
1634 | * @enable: set to 1 if the record is tracing, zero to force disable | |
1635 | * | |
1636 | * The records that represent all functions that can be traced need | |
1637 | * to be updated when tracing has been enabled. | |
1638 | */ | |
1639 | int ftrace_update_record(struct dyn_ftrace *rec, int enable) | |
1640 | { | |
1641 | return ftrace_check_record(rec, enable, 1); | |
1642 | } | |
1643 | ||
1644 | /** | |
1645 | * ftrace_test_record, check if the record has been enabled or not | |
1646 | * @rec: the record to test | |
1647 | * @enable: set to 1 to check if enabled, 0 if it is disabled | |
1648 | * | |
1649 | * The arch code may need to test if a record is already set to | |
1650 | * tracing to determine how to modify the function code that it | |
1651 | * represents. | |
1652 | */ | |
1653 | int ftrace_test_record(struct dyn_ftrace *rec, int enable) | |
1654 | { | |
1655 | return ftrace_check_record(rec, enable, 0); | |
1656 | } | |
1657 | ||
1658 | static int | |
1659 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) | |
1660 | { | |
1661 | unsigned long ftrace_addr; | |
1662 | int ret; | |
1663 | ||
1664 | ftrace_addr = (unsigned long)FTRACE_ADDR; | |
1665 | ||
1666 | ret = ftrace_update_record(rec, enable); | |
1667 | ||
1668 | switch (ret) { | |
1669 | case FTRACE_UPDATE_IGNORE: | |
1670 | return 0; | |
1671 | ||
1672 | case FTRACE_UPDATE_MAKE_CALL: | |
64fbcd16 | 1673 | return ftrace_make_call(rec, ftrace_addr); |
c88fd863 SR |
1674 | |
1675 | case FTRACE_UPDATE_MAKE_NOP: | |
1676 | return ftrace_make_nop(NULL, rec, ftrace_addr); | |
5072c59f SR |
1677 | } |
1678 | ||
c88fd863 | 1679 | return -1; /* unknow ftrace bug */ |
5072c59f SR |
1680 | } |
1681 | ||
30fb6aa7 | 1682 | static void ftrace_replace_code(int update) |
3c1720f0 | 1683 | { |
3c1720f0 SR |
1684 | struct dyn_ftrace *rec; |
1685 | struct ftrace_page *pg; | |
6a24a244 | 1686 | int failed; |
3c1720f0 | 1687 | |
45a4a237 SR |
1688 | if (unlikely(ftrace_disabled)) |
1689 | return; | |
1690 | ||
265c831c | 1691 | do_for_each_ftrace_rec(pg, rec) { |
30fb6aa7 | 1692 | failed = __ftrace_replace_code(rec, update); |
fa9d13cf | 1693 | if (failed) { |
3279ba37 SR |
1694 | ftrace_bug(failed, rec->ip); |
1695 | /* Stop processing */ | |
1696 | return; | |
3c1720f0 | 1697 | } |
265c831c | 1698 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
1699 | } |
1700 | ||
c88fd863 SR |
1701 | struct ftrace_rec_iter { |
1702 | struct ftrace_page *pg; | |
1703 | int index; | |
1704 | }; | |
1705 | ||
1706 | /** | |
1707 | * ftrace_rec_iter_start, start up iterating over traced functions | |
1708 | * | |
1709 | * Returns an iterator handle that is used to iterate over all | |
1710 | * the records that represent address locations where functions | |
1711 | * are traced. | |
1712 | * | |
1713 | * May return NULL if no records are available. | |
1714 | */ | |
1715 | struct ftrace_rec_iter *ftrace_rec_iter_start(void) | |
1716 | { | |
1717 | /* | |
1718 | * We only use a single iterator. | |
1719 | * Protected by the ftrace_lock mutex. | |
1720 | */ | |
1721 | static struct ftrace_rec_iter ftrace_rec_iter; | |
1722 | struct ftrace_rec_iter *iter = &ftrace_rec_iter; | |
1723 | ||
1724 | iter->pg = ftrace_pages_start; | |
1725 | iter->index = 0; | |
1726 | ||
1727 | /* Could have empty pages */ | |
1728 | while (iter->pg && !iter->pg->index) | |
1729 | iter->pg = iter->pg->next; | |
1730 | ||
1731 | if (!iter->pg) | |
1732 | return NULL; | |
1733 | ||
1734 | return iter; | |
1735 | } | |
1736 | ||
1737 | /** | |
1738 | * ftrace_rec_iter_next, get the next record to process. | |
1739 | * @iter: The handle to the iterator. | |
1740 | * | |
1741 | * Returns the next iterator after the given iterator @iter. | |
1742 | */ | |
1743 | struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) | |
1744 | { | |
1745 | iter->index++; | |
1746 | ||
1747 | if (iter->index >= iter->pg->index) { | |
1748 | iter->pg = iter->pg->next; | |
1749 | iter->index = 0; | |
1750 | ||
1751 | /* Could have empty pages */ | |
1752 | while (iter->pg && !iter->pg->index) | |
1753 | iter->pg = iter->pg->next; | |
1754 | } | |
1755 | ||
1756 | if (!iter->pg) | |
1757 | return NULL; | |
1758 | ||
1759 | return iter; | |
1760 | } | |
1761 | ||
1762 | /** | |
1763 | * ftrace_rec_iter_record, get the record at the iterator location | |
1764 | * @iter: The current iterator location | |
1765 | * | |
1766 | * Returns the record that the current @iter is at. | |
1767 | */ | |
1768 | struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) | |
1769 | { | |
1770 | return &iter->pg->records[iter->index]; | |
1771 | } | |
1772 | ||
492a7ea5 | 1773 | static int |
31e88909 | 1774 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 SR |
1775 | { |
1776 | unsigned long ip; | |
593eb8a2 | 1777 | int ret; |
3c1720f0 SR |
1778 | |
1779 | ip = rec->ip; | |
1780 | ||
45a4a237 SR |
1781 | if (unlikely(ftrace_disabled)) |
1782 | return 0; | |
1783 | ||
25aac9dc | 1784 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 1785 | if (ret) { |
31e88909 | 1786 | ftrace_bug(ret, ip); |
492a7ea5 | 1787 | return 0; |
37ad5084 | 1788 | } |
492a7ea5 | 1789 | return 1; |
3c1720f0 SR |
1790 | } |
1791 | ||
000ab691 SR |
1792 | /* |
1793 | * archs can override this function if they must do something | |
1794 | * before the modifying code is performed. | |
1795 | */ | |
1796 | int __weak ftrace_arch_code_modify_prepare(void) | |
1797 | { | |
1798 | return 0; | |
1799 | } | |
1800 | ||
1801 | /* | |
1802 | * archs can override this function if they must do something | |
1803 | * after the modifying code is performed. | |
1804 | */ | |
1805 | int __weak ftrace_arch_code_modify_post_process(void) | |
1806 | { | |
1807 | return 0; | |
1808 | } | |
1809 | ||
e309b41d | 1810 | static int __ftrace_modify_code(void *data) |
3d083395 | 1811 | { |
d61f82d0 SR |
1812 | int *command = data; |
1813 | ||
30fb6aa7 | 1814 | if (*command & FTRACE_UPDATE_CALLS) |
d61f82d0 | 1815 | ftrace_replace_code(1); |
a3583244 | 1816 | else if (*command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
1817 | ftrace_replace_code(0); |
1818 | ||
1819 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
1820 | ftrace_update_ftrace_func(ftrace_trace_function); | |
1821 | ||
5a45cfe1 SR |
1822 | if (*command & FTRACE_START_FUNC_RET) |
1823 | ftrace_enable_ftrace_graph_caller(); | |
1824 | else if (*command & FTRACE_STOP_FUNC_RET) | |
1825 | ftrace_disable_ftrace_graph_caller(); | |
1826 | ||
d61f82d0 | 1827 | return 0; |
3d083395 SR |
1828 | } |
1829 | ||
c88fd863 SR |
1830 | /** |
1831 | * ftrace_run_stop_machine, go back to the stop machine method | |
1832 | * @command: The command to tell ftrace what to do | |
1833 | * | |
1834 | * If an arch needs to fall back to the stop machine method, the | |
1835 | * it can call this function. | |
1836 | */ | |
1837 | void ftrace_run_stop_machine(int command) | |
1838 | { | |
1839 | stop_machine(__ftrace_modify_code, &command, NULL); | |
1840 | } | |
1841 | ||
1842 | /** | |
1843 | * arch_ftrace_update_code, modify the code to trace or not trace | |
1844 | * @command: The command that needs to be done | |
1845 | * | |
1846 | * Archs can override this function if it does not need to | |
1847 | * run stop_machine() to modify code. | |
1848 | */ | |
1849 | void __weak arch_ftrace_update_code(int command) | |
1850 | { | |
1851 | ftrace_run_stop_machine(command); | |
1852 | } | |
1853 | ||
e309b41d | 1854 | static void ftrace_run_update_code(int command) |
3d083395 | 1855 | { |
000ab691 SR |
1856 | int ret; |
1857 | ||
1858 | ret = ftrace_arch_code_modify_prepare(); | |
1859 | FTRACE_WARN_ON(ret); | |
1860 | if (ret) | |
1861 | return; | |
c88fd863 SR |
1862 | /* |
1863 | * Do not call function tracer while we update the code. | |
1864 | * We are in stop machine. | |
1865 | */ | |
1866 | function_trace_stop++; | |
000ab691 | 1867 | |
c88fd863 SR |
1868 | /* |
1869 | * By default we use stop_machine() to modify the code. | |
1870 | * But archs can do what ever they want as long as it | |
1871 | * is safe. The stop_machine() is the safest, but also | |
1872 | * produces the most overhead. | |
1873 | */ | |
1874 | arch_ftrace_update_code(command); | |
1875 | ||
1876 | #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
1877 | /* | |
1878 | * For archs that call ftrace_test_stop_func(), we must | |
1879 | * wait till after we update all the function callers | |
1880 | * before we update the callback. This keeps different | |
1881 | * ops that record different functions from corrupting | |
1882 | * each other. | |
1883 | */ | |
1884 | __ftrace_trace_function = __ftrace_trace_function_delay; | |
1885 | #endif | |
1886 | function_trace_stop--; | |
000ab691 SR |
1887 | |
1888 | ret = ftrace_arch_code_modify_post_process(); | |
1889 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
1890 | } |
1891 | ||
d61f82d0 | 1892 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 1893 | static int ftrace_start_up; |
b848914c | 1894 | static int global_start_up; |
df4fc315 SR |
1895 | |
1896 | static void ftrace_startup_enable(int command) | |
1897 | { | |
1898 | if (saved_ftrace_func != ftrace_trace_function) { | |
1899 | saved_ftrace_func = ftrace_trace_function; | |
1900 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1901 | } | |
1902 | ||
1903 | if (!command || !ftrace_enabled) | |
1904 | return; | |
1905 | ||
1906 | ftrace_run_update_code(command); | |
1907 | } | |
d61f82d0 | 1908 | |
a1cd6173 | 1909 | static int ftrace_startup(struct ftrace_ops *ops, int command) |
3d083395 | 1910 | { |
b848914c SR |
1911 | bool hash_enable = true; |
1912 | ||
4eebcc81 | 1913 | if (unlikely(ftrace_disabled)) |
a1cd6173 | 1914 | return -ENODEV; |
4eebcc81 | 1915 | |
60a7ecf4 | 1916 | ftrace_start_up++; |
30fb6aa7 | 1917 | command |= FTRACE_UPDATE_CALLS; |
d61f82d0 | 1918 | |
b848914c SR |
1919 | /* ops marked global share the filter hashes */ |
1920 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { | |
1921 | ops = &global_ops; | |
1922 | /* Don't update hash if global is already set */ | |
1923 | if (global_start_up) | |
1924 | hash_enable = false; | |
1925 | global_start_up++; | |
1926 | } | |
1927 | ||
ed926f9b | 1928 | ops->flags |= FTRACE_OPS_FL_ENABLED; |
b848914c | 1929 | if (hash_enable) |
ed926f9b SR |
1930 | ftrace_hash_rec_enable(ops, 1); |
1931 | ||
df4fc315 | 1932 | ftrace_startup_enable(command); |
a1cd6173 SR |
1933 | |
1934 | return 0; | |
3d083395 SR |
1935 | } |
1936 | ||
bd69c30b | 1937 | static void ftrace_shutdown(struct ftrace_ops *ops, int command) |
3d083395 | 1938 | { |
b848914c SR |
1939 | bool hash_disable = true; |
1940 | ||
4eebcc81 SR |
1941 | if (unlikely(ftrace_disabled)) |
1942 | return; | |
1943 | ||
60a7ecf4 | 1944 | ftrace_start_up--; |
9ea1a153 FW |
1945 | /* |
1946 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
1947 | * critical but the ftrace_call callers may be never nopped again after | |
1948 | * further ftrace uses. | |
1949 | */ | |
1950 | WARN_ON_ONCE(ftrace_start_up < 0); | |
1951 | ||
b848914c SR |
1952 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { |
1953 | ops = &global_ops; | |
1954 | global_start_up--; | |
1955 | WARN_ON_ONCE(global_start_up < 0); | |
1956 | /* Don't update hash if global still has users */ | |
1957 | if (global_start_up) { | |
1958 | WARN_ON_ONCE(!ftrace_start_up); | |
1959 | hash_disable = false; | |
1960 | } | |
1961 | } | |
1962 | ||
1963 | if (hash_disable) | |
ed926f9b SR |
1964 | ftrace_hash_rec_disable(ops, 1); |
1965 | ||
b848914c | 1966 | if (ops != &global_ops || !global_start_up) |
ed926f9b | 1967 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
b848914c | 1968 | |
30fb6aa7 | 1969 | command |= FTRACE_UPDATE_CALLS; |
3d083395 | 1970 | |
d61f82d0 SR |
1971 | if (saved_ftrace_func != ftrace_trace_function) { |
1972 | saved_ftrace_func = ftrace_trace_function; | |
1973 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1974 | } | |
3d083395 | 1975 | |
d61f82d0 | 1976 | if (!command || !ftrace_enabled) |
e6ea44e9 | 1977 | return; |
d61f82d0 SR |
1978 | |
1979 | ftrace_run_update_code(command); | |
3d083395 SR |
1980 | } |
1981 | ||
e309b41d | 1982 | static void ftrace_startup_sysctl(void) |
b0fc494f | 1983 | { |
4eebcc81 SR |
1984 | if (unlikely(ftrace_disabled)) |
1985 | return; | |
1986 | ||
d61f82d0 SR |
1987 | /* Force update next time */ |
1988 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
1989 | /* ftrace_start_up is true if we want ftrace running */ |
1990 | if (ftrace_start_up) | |
30fb6aa7 | 1991 | ftrace_run_update_code(FTRACE_UPDATE_CALLS); |
b0fc494f SR |
1992 | } |
1993 | ||
e309b41d | 1994 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 1995 | { |
4eebcc81 SR |
1996 | if (unlikely(ftrace_disabled)) |
1997 | return; | |
1998 | ||
60a7ecf4 SR |
1999 | /* ftrace_start_up is true if ftrace is running */ |
2000 | if (ftrace_start_up) | |
79e406d7 | 2001 | ftrace_run_update_code(FTRACE_DISABLE_CALLS); |
b0fc494f SR |
2002 | } |
2003 | ||
3d083395 SR |
2004 | static cycle_t ftrace_update_time; |
2005 | static unsigned long ftrace_update_cnt; | |
2006 | unsigned long ftrace_update_tot_cnt; | |
2007 | ||
f7bc8b61 SR |
2008 | static int ops_traces_mod(struct ftrace_ops *ops) |
2009 | { | |
2010 | struct ftrace_hash *hash; | |
2011 | ||
2012 | hash = ops->filter_hash; | |
06a51d93 | 2013 | return ftrace_hash_empty(hash); |
f7bc8b61 SR |
2014 | } |
2015 | ||
31e88909 | 2016 | static int ftrace_update_code(struct module *mod) |
3d083395 | 2017 | { |
85ae32ae | 2018 | struct ftrace_page *pg; |
e94142a6 | 2019 | struct dyn_ftrace *p; |
f22f9a89 | 2020 | cycle_t start, stop; |
f7bc8b61 | 2021 | unsigned long ref = 0; |
85ae32ae | 2022 | int i; |
f7bc8b61 SR |
2023 | |
2024 | /* | |
2025 | * When adding a module, we need to check if tracers are | |
2026 | * currently enabled and if they are set to trace all functions. | |
2027 | * If they are, we need to enable the module functions as well | |
2028 | * as update the reference counts for those function records. | |
2029 | */ | |
2030 | if (mod) { | |
2031 | struct ftrace_ops *ops; | |
2032 | ||
2033 | for (ops = ftrace_ops_list; | |
2034 | ops != &ftrace_list_end; ops = ops->next) { | |
2035 | if (ops->flags & FTRACE_OPS_FL_ENABLED && | |
2036 | ops_traces_mod(ops)) | |
2037 | ref++; | |
2038 | } | |
2039 | } | |
3d083395 | 2040 | |
750ed1a4 | 2041 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
2042 | ftrace_update_cnt = 0; |
2043 | ||
85ae32ae | 2044 | for (pg = ftrace_new_pgs; pg; pg = pg->next) { |
3d083395 | 2045 | |
85ae32ae SR |
2046 | for (i = 0; i < pg->index; i++) { |
2047 | /* If something went wrong, bail without enabling anything */ | |
2048 | if (unlikely(ftrace_disabled)) | |
2049 | return -1; | |
f22f9a89 | 2050 | |
85ae32ae SR |
2051 | p = &pg->records[i]; |
2052 | p->flags = ref; | |
f22f9a89 | 2053 | |
85ae32ae SR |
2054 | /* |
2055 | * Do the initial record conversion from mcount jump | |
2056 | * to the NOP instructions. | |
2057 | */ | |
2058 | if (!ftrace_code_disable(mod, p)) | |
2059 | break; | |
5cb084bb | 2060 | |
85ae32ae | 2061 | ftrace_update_cnt++; |
5cb084bb | 2062 | |
85ae32ae SR |
2063 | /* |
2064 | * If the tracing is enabled, go ahead and enable the record. | |
2065 | * | |
2066 | * The reason not to enable the record immediatelly is the | |
2067 | * inherent check of ftrace_make_nop/ftrace_make_call for | |
2068 | * correct previous instructions. Making first the NOP | |
2069 | * conversion puts the module to the correct state, thus | |
2070 | * passing the ftrace_make_call check. | |
2071 | */ | |
2072 | if (ftrace_start_up && ref) { | |
2073 | int failed = __ftrace_replace_code(p, 1); | |
2074 | if (failed) | |
2075 | ftrace_bug(failed, p->ip); | |
2076 | } | |
5cb084bb | 2077 | } |
3d083395 SR |
2078 | } |
2079 | ||
85ae32ae SR |
2080 | ftrace_new_pgs = NULL; |
2081 | ||
750ed1a4 | 2082 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
2083 | ftrace_update_time = stop - start; |
2084 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
2085 | ||
16444a8a ACM |
2086 | return 0; |
2087 | } | |
2088 | ||
a7900875 | 2089 | static int ftrace_allocate_records(struct ftrace_page *pg, int count) |
3c1720f0 | 2090 | { |
a7900875 | 2091 | int order; |
3c1720f0 | 2092 | int cnt; |
3c1720f0 | 2093 | |
a7900875 SR |
2094 | if (WARN_ON(!count)) |
2095 | return -EINVAL; | |
2096 | ||
2097 | order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE)); | |
3c1720f0 SR |
2098 | |
2099 | /* | |
a7900875 SR |
2100 | * We want to fill as much as possible. No more than a page |
2101 | * may be empty. | |
3c1720f0 | 2102 | */ |
a7900875 SR |
2103 | while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE) |
2104 | order--; | |
3c1720f0 | 2105 | |
a7900875 SR |
2106 | again: |
2107 | pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); | |
3c1720f0 | 2108 | |
a7900875 SR |
2109 | if (!pg->records) { |
2110 | /* if we can't allocate this size, try something smaller */ | |
2111 | if (!order) | |
2112 | return -ENOMEM; | |
2113 | order >>= 1; | |
2114 | goto again; | |
2115 | } | |
3c1720f0 | 2116 | |
a7900875 SR |
2117 | cnt = (PAGE_SIZE << order) / ENTRY_SIZE; |
2118 | pg->size = cnt; | |
3c1720f0 | 2119 | |
a7900875 SR |
2120 | if (cnt > count) |
2121 | cnt = count; | |
2122 | ||
2123 | return cnt; | |
2124 | } | |
2125 | ||
2126 | static struct ftrace_page * | |
2127 | ftrace_allocate_pages(unsigned long num_to_init) | |
2128 | { | |
2129 | struct ftrace_page *start_pg; | |
2130 | struct ftrace_page *pg; | |
2131 | int order; | |
2132 | int cnt; | |
2133 | ||
2134 | if (!num_to_init) | |
2135 | return 0; | |
2136 | ||
2137 | start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL); | |
2138 | if (!pg) | |
2139 | return NULL; | |
2140 | ||
2141 | /* | |
2142 | * Try to allocate as much as possible in one continues | |
2143 | * location that fills in all of the space. We want to | |
2144 | * waste as little space as possible. | |
2145 | */ | |
2146 | for (;;) { | |
2147 | cnt = ftrace_allocate_records(pg, num_to_init); | |
2148 | if (cnt < 0) | |
2149 | goto free_pages; | |
2150 | ||
2151 | num_to_init -= cnt; | |
2152 | if (!num_to_init) | |
3c1720f0 SR |
2153 | break; |
2154 | ||
a7900875 SR |
2155 | pg->next = kzalloc(sizeof(*pg), GFP_KERNEL); |
2156 | if (!pg->next) | |
2157 | goto free_pages; | |
2158 | ||
3c1720f0 SR |
2159 | pg = pg->next; |
2160 | } | |
2161 | ||
a7900875 SR |
2162 | return start_pg; |
2163 | ||
2164 | free_pages: | |
2165 | while (start_pg) { | |
2166 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); | |
2167 | free_pages((unsigned long)pg->records, order); | |
2168 | start_pg = pg->next; | |
2169 | kfree(pg); | |
2170 | pg = start_pg; | |
2171 | } | |
2172 | pr_info("ftrace: FAILED to allocate memory for functions\n"); | |
2173 | return NULL; | |
2174 | } | |
2175 | ||
2176 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) | |
2177 | { | |
2178 | int cnt; | |
2179 | ||
2180 | if (!num_to_init) { | |
2181 | pr_info("ftrace: No functions to be traced?\n"); | |
2182 | return -1; | |
2183 | } | |
2184 | ||
2185 | cnt = num_to_init / ENTRIES_PER_PAGE; | |
2186 | pr_info("ftrace: allocating %ld entries in %d pages\n", | |
2187 | num_to_init, cnt + 1); | |
2188 | ||
3c1720f0 SR |
2189 | return 0; |
2190 | } | |
2191 | ||
5072c59f SR |
2192 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
2193 | ||
2194 | struct ftrace_iterator { | |
98c4fd04 | 2195 | loff_t pos; |
4aeb6967 SR |
2196 | loff_t func_pos; |
2197 | struct ftrace_page *pg; | |
2198 | struct dyn_ftrace *func; | |
2199 | struct ftrace_func_probe *probe; | |
2200 | struct trace_parser parser; | |
1cf41dd7 | 2201 | struct ftrace_hash *hash; |
33dc9b12 | 2202 | struct ftrace_ops *ops; |
4aeb6967 SR |
2203 | int hidx; |
2204 | int idx; | |
2205 | unsigned flags; | |
5072c59f SR |
2206 | }; |
2207 | ||
8fc0c701 | 2208 | static void * |
4aeb6967 | 2209 | t_hash_next(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
2210 | { |
2211 | struct ftrace_iterator *iter = m->private; | |
4aeb6967 | 2212 | struct hlist_node *hnd = NULL; |
8fc0c701 SR |
2213 | struct hlist_head *hhd; |
2214 | ||
8fc0c701 | 2215 | (*pos)++; |
98c4fd04 | 2216 | iter->pos = *pos; |
8fc0c701 | 2217 | |
4aeb6967 SR |
2218 | if (iter->probe) |
2219 | hnd = &iter->probe->node; | |
8fc0c701 SR |
2220 | retry: |
2221 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
2222 | return NULL; | |
2223 | ||
2224 | hhd = &ftrace_func_hash[iter->hidx]; | |
2225 | ||
2226 | if (hlist_empty(hhd)) { | |
2227 | iter->hidx++; | |
2228 | hnd = NULL; | |
2229 | goto retry; | |
2230 | } | |
2231 | ||
2232 | if (!hnd) | |
2233 | hnd = hhd->first; | |
2234 | else { | |
2235 | hnd = hnd->next; | |
2236 | if (!hnd) { | |
2237 | iter->hidx++; | |
2238 | goto retry; | |
2239 | } | |
2240 | } | |
2241 | ||
4aeb6967 SR |
2242 | if (WARN_ON_ONCE(!hnd)) |
2243 | return NULL; | |
2244 | ||
2245 | iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node); | |
2246 | ||
2247 | return iter; | |
8fc0c701 SR |
2248 | } |
2249 | ||
2250 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
2251 | { | |
2252 | struct ftrace_iterator *iter = m->private; | |
2253 | void *p = NULL; | |
d82d6244 LZ |
2254 | loff_t l; |
2255 | ||
69a3083c SR |
2256 | if (!(iter->flags & FTRACE_ITER_DO_HASH)) |
2257 | return NULL; | |
2258 | ||
2bccfffd SR |
2259 | if (iter->func_pos > *pos) |
2260 | return NULL; | |
8fc0c701 | 2261 | |
d82d6244 | 2262 | iter->hidx = 0; |
2bccfffd | 2263 | for (l = 0; l <= (*pos - iter->func_pos); ) { |
4aeb6967 | 2264 | p = t_hash_next(m, &l); |
d82d6244 LZ |
2265 | if (!p) |
2266 | break; | |
2267 | } | |
4aeb6967 SR |
2268 | if (!p) |
2269 | return NULL; | |
2270 | ||
98c4fd04 SR |
2271 | /* Only set this if we have an item */ |
2272 | iter->flags |= FTRACE_ITER_HASH; | |
2273 | ||
4aeb6967 | 2274 | return iter; |
8fc0c701 SR |
2275 | } |
2276 | ||
4aeb6967 SR |
2277 | static int |
2278 | t_hash_show(struct seq_file *m, struct ftrace_iterator *iter) | |
8fc0c701 | 2279 | { |
b6887d79 | 2280 | struct ftrace_func_probe *rec; |
8fc0c701 | 2281 | |
4aeb6967 SR |
2282 | rec = iter->probe; |
2283 | if (WARN_ON_ONCE(!rec)) | |
2284 | return -EIO; | |
8fc0c701 | 2285 | |
809dcf29 SR |
2286 | if (rec->ops->print) |
2287 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
2288 | ||
b375a11a | 2289 | seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func); |
8fc0c701 SR |
2290 | |
2291 | if (rec->data) | |
2292 | seq_printf(m, ":%p", rec->data); | |
2293 | seq_putc(m, '\n'); | |
2294 | ||
2295 | return 0; | |
2296 | } | |
2297 | ||
e309b41d | 2298 | static void * |
5072c59f SR |
2299 | t_next(struct seq_file *m, void *v, loff_t *pos) |
2300 | { | |
2301 | struct ftrace_iterator *iter = m->private; | |
fc13cb0c | 2302 | struct ftrace_ops *ops = iter->ops; |
5072c59f SR |
2303 | struct dyn_ftrace *rec = NULL; |
2304 | ||
45a4a237 SR |
2305 | if (unlikely(ftrace_disabled)) |
2306 | return NULL; | |
2307 | ||
8fc0c701 | 2308 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 2309 | return t_hash_next(m, pos); |
8fc0c701 | 2310 | |
5072c59f | 2311 | (*pos)++; |
1106b699 | 2312 | iter->pos = iter->func_pos = *pos; |
5072c59f | 2313 | |
0c75a3ed | 2314 | if (iter->flags & FTRACE_ITER_PRINTALL) |
57c072c7 | 2315 | return t_hash_start(m, pos); |
0c75a3ed | 2316 | |
5072c59f SR |
2317 | retry: |
2318 | if (iter->idx >= iter->pg->index) { | |
2319 | if (iter->pg->next) { | |
2320 | iter->pg = iter->pg->next; | |
2321 | iter->idx = 0; | |
2322 | goto retry; | |
2323 | } | |
2324 | } else { | |
2325 | rec = &iter->pg->records[iter->idx++]; | |
32082309 | 2326 | if (((iter->flags & FTRACE_ITER_FILTER) && |
f45948e8 | 2327 | !(ftrace_lookup_ip(ops->filter_hash, rec->ip))) || |
0183fb1c | 2328 | |
41c52c0d | 2329 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
647bcd03 SR |
2330 | !ftrace_lookup_ip(ops->notrace_hash, rec->ip)) || |
2331 | ||
2332 | ((iter->flags & FTRACE_ITER_ENABLED) && | |
2333 | !(rec->flags & ~FTRACE_FL_MASK))) { | |
2334 | ||
5072c59f SR |
2335 | rec = NULL; |
2336 | goto retry; | |
2337 | } | |
2338 | } | |
2339 | ||
4aeb6967 | 2340 | if (!rec) |
57c072c7 | 2341 | return t_hash_start(m, pos); |
4aeb6967 SR |
2342 | |
2343 | iter->func = rec; | |
2344 | ||
2345 | return iter; | |
5072c59f SR |
2346 | } |
2347 | ||
98c4fd04 SR |
2348 | static void reset_iter_read(struct ftrace_iterator *iter) |
2349 | { | |
2350 | iter->pos = 0; | |
2351 | iter->func_pos = 0; | |
2352 | iter->flags &= ~(FTRACE_ITER_PRINTALL & FTRACE_ITER_HASH); | |
5072c59f SR |
2353 | } |
2354 | ||
2355 | static void *t_start(struct seq_file *m, loff_t *pos) | |
2356 | { | |
2357 | struct ftrace_iterator *iter = m->private; | |
fc13cb0c | 2358 | struct ftrace_ops *ops = iter->ops; |
5072c59f | 2359 | void *p = NULL; |
694ce0a5 | 2360 | loff_t l; |
5072c59f | 2361 | |
8fc0c701 | 2362 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
2363 | |
2364 | if (unlikely(ftrace_disabled)) | |
2365 | return NULL; | |
2366 | ||
98c4fd04 SR |
2367 | /* |
2368 | * If an lseek was done, then reset and start from beginning. | |
2369 | */ | |
2370 | if (*pos < iter->pos) | |
2371 | reset_iter_read(iter); | |
2372 | ||
0c75a3ed SR |
2373 | /* |
2374 | * For set_ftrace_filter reading, if we have the filter | |
2375 | * off, we can short cut and just print out that all | |
2376 | * functions are enabled. | |
2377 | */ | |
06a51d93 SR |
2378 | if (iter->flags & FTRACE_ITER_FILTER && |
2379 | ftrace_hash_empty(ops->filter_hash)) { | |
0c75a3ed | 2380 | if (*pos > 0) |
8fc0c701 | 2381 | return t_hash_start(m, pos); |
0c75a3ed | 2382 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 CW |
2383 | /* reset in case of seek/pread */ |
2384 | iter->flags &= ~FTRACE_ITER_HASH; | |
0c75a3ed SR |
2385 | return iter; |
2386 | } | |
2387 | ||
8fc0c701 SR |
2388 | if (iter->flags & FTRACE_ITER_HASH) |
2389 | return t_hash_start(m, pos); | |
2390 | ||
98c4fd04 SR |
2391 | /* |
2392 | * Unfortunately, we need to restart at ftrace_pages_start | |
2393 | * every time we let go of the ftrace_mutex. This is because | |
2394 | * those pointers can change without the lock. | |
2395 | */ | |
694ce0a5 LZ |
2396 | iter->pg = ftrace_pages_start; |
2397 | iter->idx = 0; | |
2398 | for (l = 0; l <= *pos; ) { | |
2399 | p = t_next(m, p, &l); | |
2400 | if (!p) | |
2401 | break; | |
50cdaf08 | 2402 | } |
5821e1b7 | 2403 | |
69a3083c SR |
2404 | if (!p) |
2405 | return t_hash_start(m, pos); | |
4aeb6967 SR |
2406 | |
2407 | return iter; | |
5072c59f SR |
2408 | } |
2409 | ||
2410 | static void t_stop(struct seq_file *m, void *p) | |
2411 | { | |
8fc0c701 | 2412 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
2413 | } |
2414 | ||
2415 | static int t_show(struct seq_file *m, void *v) | |
2416 | { | |
0c75a3ed | 2417 | struct ftrace_iterator *iter = m->private; |
4aeb6967 | 2418 | struct dyn_ftrace *rec; |
5072c59f | 2419 | |
8fc0c701 | 2420 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 2421 | return t_hash_show(m, iter); |
8fc0c701 | 2422 | |
0c75a3ed SR |
2423 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
2424 | seq_printf(m, "#### all functions enabled ####\n"); | |
2425 | return 0; | |
2426 | } | |
2427 | ||
4aeb6967 SR |
2428 | rec = iter->func; |
2429 | ||
5072c59f SR |
2430 | if (!rec) |
2431 | return 0; | |
2432 | ||
647bcd03 SR |
2433 | seq_printf(m, "%ps", (void *)rec->ip); |
2434 | if (iter->flags & FTRACE_ITER_ENABLED) | |
2435 | seq_printf(m, " (%ld)", | |
2436 | rec->flags & ~FTRACE_FL_MASK); | |
2437 | seq_printf(m, "\n"); | |
5072c59f SR |
2438 | |
2439 | return 0; | |
2440 | } | |
2441 | ||
88e9d34c | 2442 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
2443 | .start = t_start, |
2444 | .next = t_next, | |
2445 | .stop = t_stop, | |
2446 | .show = t_show, | |
2447 | }; | |
2448 | ||
e309b41d | 2449 | static int |
5072c59f SR |
2450 | ftrace_avail_open(struct inode *inode, struct file *file) |
2451 | { | |
2452 | struct ftrace_iterator *iter; | |
5072c59f | 2453 | |
4eebcc81 SR |
2454 | if (unlikely(ftrace_disabled)) |
2455 | return -ENODEV; | |
2456 | ||
50e18b94 JO |
2457 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
2458 | if (iter) { | |
2459 | iter->pg = ftrace_pages_start; | |
2460 | iter->ops = &global_ops; | |
4bf39a94 | 2461 | } |
5072c59f | 2462 | |
50e18b94 | 2463 | return iter ? 0 : -ENOMEM; |
5072c59f SR |
2464 | } |
2465 | ||
647bcd03 SR |
2466 | static int |
2467 | ftrace_enabled_open(struct inode *inode, struct file *file) | |
2468 | { | |
2469 | struct ftrace_iterator *iter; | |
647bcd03 SR |
2470 | |
2471 | if (unlikely(ftrace_disabled)) | |
2472 | return -ENODEV; | |
2473 | ||
50e18b94 JO |
2474 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
2475 | if (iter) { | |
2476 | iter->pg = ftrace_pages_start; | |
2477 | iter->flags = FTRACE_ITER_ENABLED; | |
2478 | iter->ops = &global_ops; | |
647bcd03 SR |
2479 | } |
2480 | ||
50e18b94 | 2481 | return iter ? 0 : -ENOMEM; |
647bcd03 SR |
2482 | } |
2483 | ||
1cf41dd7 | 2484 | static void ftrace_filter_reset(struct ftrace_hash *hash) |
5072c59f | 2485 | { |
52baf119 | 2486 | mutex_lock(&ftrace_lock); |
1cf41dd7 | 2487 | ftrace_hash_clear(hash); |
52baf119 | 2488 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
2489 | } |
2490 | ||
fc13cb0c SR |
2491 | /** |
2492 | * ftrace_regex_open - initialize function tracer filter files | |
2493 | * @ops: The ftrace_ops that hold the hash filters | |
2494 | * @flag: The type of filter to process | |
2495 | * @inode: The inode, usually passed in to your open routine | |
2496 | * @file: The file, usually passed in to your open routine | |
2497 | * | |
2498 | * ftrace_regex_open() initializes the filter files for the | |
2499 | * @ops. Depending on @flag it may process the filter hash or | |
2500 | * the notrace hash of @ops. With this called from the open | |
2501 | * routine, you can use ftrace_filter_write() for the write | |
2502 | * routine if @flag has FTRACE_ITER_FILTER set, or | |
2503 | * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set. | |
2504 | * ftrace_regex_lseek() should be used as the lseek routine, and | |
2505 | * release must call ftrace_regex_release(). | |
2506 | */ | |
2507 | int | |
f45948e8 | 2508 | ftrace_regex_open(struct ftrace_ops *ops, int flag, |
1cf41dd7 | 2509 | struct inode *inode, struct file *file) |
5072c59f SR |
2510 | { |
2511 | struct ftrace_iterator *iter; | |
f45948e8 | 2512 | struct ftrace_hash *hash; |
5072c59f SR |
2513 | int ret = 0; |
2514 | ||
4eebcc81 SR |
2515 | if (unlikely(ftrace_disabled)) |
2516 | return -ENODEV; | |
2517 | ||
5072c59f SR |
2518 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
2519 | if (!iter) | |
2520 | return -ENOMEM; | |
2521 | ||
689fd8b6 | 2522 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { |
2523 | kfree(iter); | |
2524 | return -ENOMEM; | |
2525 | } | |
2526 | ||
f45948e8 SR |
2527 | if (flag & FTRACE_ITER_NOTRACE) |
2528 | hash = ops->notrace_hash; | |
2529 | else | |
2530 | hash = ops->filter_hash; | |
2531 | ||
33dc9b12 SR |
2532 | iter->ops = ops; |
2533 | iter->flags = flag; | |
2534 | ||
2535 | if (file->f_mode & FMODE_WRITE) { | |
2536 | mutex_lock(&ftrace_lock); | |
2537 | iter->hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash); | |
2538 | mutex_unlock(&ftrace_lock); | |
2539 | ||
2540 | if (!iter->hash) { | |
2541 | trace_parser_put(&iter->parser); | |
2542 | kfree(iter); | |
2543 | return -ENOMEM; | |
2544 | } | |
2545 | } | |
1cf41dd7 | 2546 | |
41c52c0d | 2547 | mutex_lock(&ftrace_regex_lock); |
33dc9b12 | 2548 | |
5072c59f | 2549 | if ((file->f_mode & FMODE_WRITE) && |
8650ae32 | 2550 | (file->f_flags & O_TRUNC)) |
33dc9b12 | 2551 | ftrace_filter_reset(iter->hash); |
5072c59f SR |
2552 | |
2553 | if (file->f_mode & FMODE_READ) { | |
2554 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
2555 | |
2556 | ret = seq_open(file, &show_ftrace_seq_ops); | |
2557 | if (!ret) { | |
2558 | struct seq_file *m = file->private_data; | |
2559 | m->private = iter; | |
79fe249c | 2560 | } else { |
33dc9b12 SR |
2561 | /* Failed */ |
2562 | free_ftrace_hash(iter->hash); | |
79fe249c | 2563 | trace_parser_put(&iter->parser); |
5072c59f | 2564 | kfree(iter); |
79fe249c | 2565 | } |
5072c59f SR |
2566 | } else |
2567 | file->private_data = iter; | |
41c52c0d | 2568 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
2569 | |
2570 | return ret; | |
2571 | } | |
2572 | ||
41c52c0d SR |
2573 | static int |
2574 | ftrace_filter_open(struct inode *inode, struct file *file) | |
2575 | { | |
69a3083c SR |
2576 | return ftrace_regex_open(&global_ops, |
2577 | FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH, | |
2578 | inode, file); | |
41c52c0d SR |
2579 | } |
2580 | ||
2581 | static int | |
2582 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
2583 | { | |
f45948e8 | 2584 | return ftrace_regex_open(&global_ops, FTRACE_ITER_NOTRACE, |
1cf41dd7 | 2585 | inode, file); |
41c52c0d SR |
2586 | } |
2587 | ||
fc13cb0c | 2588 | loff_t |
41c52c0d | 2589 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
2590 | { |
2591 | loff_t ret; | |
2592 | ||
2593 | if (file->f_mode & FMODE_READ) | |
2594 | ret = seq_lseek(file, offset, origin); | |
2595 | else | |
2596 | file->f_pos = ret = 1; | |
2597 | ||
2598 | return ret; | |
2599 | } | |
2600 | ||
64e7c440 | 2601 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 2602 | { |
9f4801e3 | 2603 | int matched = 0; |
751e9983 | 2604 | int slen; |
9f4801e3 | 2605 | |
9f4801e3 SR |
2606 | switch (type) { |
2607 | case MATCH_FULL: | |
2608 | if (strcmp(str, regex) == 0) | |
2609 | matched = 1; | |
2610 | break; | |
2611 | case MATCH_FRONT_ONLY: | |
2612 | if (strncmp(str, regex, len) == 0) | |
2613 | matched = 1; | |
2614 | break; | |
2615 | case MATCH_MIDDLE_ONLY: | |
2616 | if (strstr(str, regex)) | |
2617 | matched = 1; | |
2618 | break; | |
2619 | case MATCH_END_ONLY: | |
751e9983 LZ |
2620 | slen = strlen(str); |
2621 | if (slen >= len && memcmp(str + slen - len, regex, len) == 0) | |
9f4801e3 SR |
2622 | matched = 1; |
2623 | break; | |
2624 | } | |
2625 | ||
2626 | return matched; | |
2627 | } | |
2628 | ||
b448c4e3 | 2629 | static int |
1cf41dd7 | 2630 | enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not) |
996e87be | 2631 | { |
b448c4e3 | 2632 | struct ftrace_func_entry *entry; |
b448c4e3 SR |
2633 | int ret = 0; |
2634 | ||
1cf41dd7 SR |
2635 | entry = ftrace_lookup_ip(hash, rec->ip); |
2636 | if (not) { | |
2637 | /* Do nothing if it doesn't exist */ | |
2638 | if (!entry) | |
2639 | return 0; | |
b448c4e3 | 2640 | |
33dc9b12 | 2641 | free_hash_entry(hash, entry); |
1cf41dd7 SR |
2642 | } else { |
2643 | /* Do nothing if it exists */ | |
2644 | if (entry) | |
2645 | return 0; | |
b448c4e3 | 2646 | |
1cf41dd7 | 2647 | ret = add_hash_entry(hash, rec->ip); |
b448c4e3 SR |
2648 | } |
2649 | return ret; | |
996e87be SR |
2650 | } |
2651 | ||
64e7c440 | 2652 | static int |
b9df92d2 SR |
2653 | ftrace_match_record(struct dyn_ftrace *rec, char *mod, |
2654 | char *regex, int len, int type) | |
64e7c440 SR |
2655 | { |
2656 | char str[KSYM_SYMBOL_LEN]; | |
b9df92d2 SR |
2657 | char *modname; |
2658 | ||
2659 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
2660 | ||
2661 | if (mod) { | |
2662 | /* module lookup requires matching the module */ | |
2663 | if (!modname || strcmp(modname, mod)) | |
2664 | return 0; | |
2665 | ||
2666 | /* blank search means to match all funcs in the mod */ | |
2667 | if (!len) | |
2668 | return 1; | |
2669 | } | |
64e7c440 | 2670 | |
64e7c440 SR |
2671 | return ftrace_match(str, regex, len, type); |
2672 | } | |
2673 | ||
1cf41dd7 SR |
2674 | static int |
2675 | match_records(struct ftrace_hash *hash, char *buff, | |
2676 | int len, char *mod, int not) | |
9f4801e3 | 2677 | { |
b9df92d2 | 2678 | unsigned search_len = 0; |
9f4801e3 SR |
2679 | struct ftrace_page *pg; |
2680 | struct dyn_ftrace *rec; | |
b9df92d2 SR |
2681 | int type = MATCH_FULL; |
2682 | char *search = buff; | |
311d16da | 2683 | int found = 0; |
b448c4e3 | 2684 | int ret; |
9f4801e3 | 2685 | |
b9df92d2 SR |
2686 | if (len) { |
2687 | type = filter_parse_regex(buff, len, &search, ¬); | |
2688 | search_len = strlen(search); | |
2689 | } | |
9f4801e3 | 2690 | |
52baf119 | 2691 | mutex_lock(&ftrace_lock); |
265c831c | 2692 | |
b9df92d2 SR |
2693 | if (unlikely(ftrace_disabled)) |
2694 | goto out_unlock; | |
9f4801e3 | 2695 | |
265c831c | 2696 | do_for_each_ftrace_rec(pg, rec) { |
b9df92d2 | 2697 | if (ftrace_match_record(rec, mod, search, search_len, type)) { |
1cf41dd7 | 2698 | ret = enter_record(hash, rec, not); |
b448c4e3 SR |
2699 | if (ret < 0) { |
2700 | found = ret; | |
2701 | goto out_unlock; | |
2702 | } | |
311d16da | 2703 | found = 1; |
265c831c SR |
2704 | } |
2705 | } while_for_each_ftrace_rec(); | |
b9df92d2 | 2706 | out_unlock: |
52baf119 | 2707 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
2708 | |
2709 | return found; | |
5072c59f SR |
2710 | } |
2711 | ||
64e7c440 | 2712 | static int |
1cf41dd7 | 2713 | ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) |
64e7c440 | 2714 | { |
1cf41dd7 | 2715 | return match_records(hash, buff, len, NULL, 0); |
64e7c440 SR |
2716 | } |
2717 | ||
1cf41dd7 SR |
2718 | static int |
2719 | ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod) | |
64e7c440 | 2720 | { |
64e7c440 | 2721 | int not = 0; |
6a24a244 | 2722 | |
64e7c440 SR |
2723 | /* blank or '*' mean the same */ |
2724 | if (strcmp(buff, "*") == 0) | |
2725 | buff[0] = 0; | |
2726 | ||
2727 | /* handle the case of 'dont filter this module' */ | |
2728 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
2729 | buff[0] = 0; | |
2730 | not = 1; | |
2731 | } | |
2732 | ||
1cf41dd7 | 2733 | return match_records(hash, buff, strlen(buff), mod, not); |
64e7c440 SR |
2734 | } |
2735 | ||
f6180773 SR |
2736 | /* |
2737 | * We register the module command as a template to show others how | |
2738 | * to register the a command as well. | |
2739 | */ | |
2740 | ||
2741 | static int | |
43dd61c9 SR |
2742 | ftrace_mod_callback(struct ftrace_hash *hash, |
2743 | char *func, char *cmd, char *param, int enable) | |
f6180773 SR |
2744 | { |
2745 | char *mod; | |
b448c4e3 | 2746 | int ret = -EINVAL; |
f6180773 SR |
2747 | |
2748 | /* | |
2749 | * cmd == 'mod' because we only registered this func | |
2750 | * for the 'mod' ftrace_func_command. | |
2751 | * But if you register one func with multiple commands, | |
2752 | * you can tell which command was used by the cmd | |
2753 | * parameter. | |
2754 | */ | |
2755 | ||
2756 | /* we must have a module name */ | |
2757 | if (!param) | |
b448c4e3 | 2758 | return ret; |
f6180773 SR |
2759 | |
2760 | mod = strsep(¶m, ":"); | |
2761 | if (!strlen(mod)) | |
b448c4e3 | 2762 | return ret; |
f6180773 | 2763 | |
1cf41dd7 | 2764 | ret = ftrace_match_module_records(hash, func, mod); |
b448c4e3 SR |
2765 | if (!ret) |
2766 | ret = -EINVAL; | |
2767 | if (ret < 0) | |
2768 | return ret; | |
2769 | ||
2770 | return 0; | |
f6180773 SR |
2771 | } |
2772 | ||
2773 | static struct ftrace_func_command ftrace_mod_cmd = { | |
2774 | .name = "mod", | |
2775 | .func = ftrace_mod_callback, | |
2776 | }; | |
2777 | ||
2778 | static int __init ftrace_mod_cmd_init(void) | |
2779 | { | |
2780 | return register_ftrace_command(&ftrace_mod_cmd); | |
2781 | } | |
2782 | device_initcall(ftrace_mod_cmd_init); | |
2783 | ||
59df055f | 2784 | static void |
b6887d79 | 2785 | function_trace_probe_call(unsigned long ip, unsigned long parent_ip) |
59df055f | 2786 | { |
b6887d79 | 2787 | struct ftrace_func_probe *entry; |
59df055f SR |
2788 | struct hlist_head *hhd; |
2789 | struct hlist_node *n; | |
2790 | unsigned long key; | |
59df055f SR |
2791 | |
2792 | key = hash_long(ip, FTRACE_HASH_BITS); | |
2793 | ||
2794 | hhd = &ftrace_func_hash[key]; | |
2795 | ||
2796 | if (hlist_empty(hhd)) | |
2797 | return; | |
2798 | ||
2799 | /* | |
2800 | * Disable preemption for these calls to prevent a RCU grace | |
2801 | * period. This syncs the hash iteration and freeing of items | |
2802 | * on the hash. rcu_read_lock is too dangerous here. | |
2803 | */ | |
5168ae50 | 2804 | preempt_disable_notrace(); |
59df055f SR |
2805 | hlist_for_each_entry_rcu(entry, n, hhd, node) { |
2806 | if (entry->ip == ip) | |
2807 | entry->ops->func(ip, parent_ip, &entry->data); | |
2808 | } | |
5168ae50 | 2809 | preempt_enable_notrace(); |
59df055f SR |
2810 | } |
2811 | ||
b6887d79 | 2812 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 2813 | { |
fb9fb015 | 2814 | .func = function_trace_probe_call, |
59df055f SR |
2815 | }; |
2816 | ||
b6887d79 | 2817 | static int ftrace_probe_registered; |
59df055f | 2818 | |
b6887d79 | 2819 | static void __enable_ftrace_function_probe(void) |
59df055f | 2820 | { |
b848914c | 2821 | int ret; |
59df055f SR |
2822 | int i; |
2823 | ||
b6887d79 | 2824 | if (ftrace_probe_registered) |
59df055f SR |
2825 | return; |
2826 | ||
2827 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2828 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2829 | if (hhd->first) | |
2830 | break; | |
2831 | } | |
2832 | /* Nothing registered? */ | |
2833 | if (i == FTRACE_FUNC_HASHSIZE) | |
2834 | return; | |
2835 | ||
b848914c SR |
2836 | ret = __register_ftrace_function(&trace_probe_ops); |
2837 | if (!ret) | |
a1cd6173 | 2838 | ret = ftrace_startup(&trace_probe_ops, 0); |
b848914c | 2839 | |
b6887d79 | 2840 | ftrace_probe_registered = 1; |
59df055f SR |
2841 | } |
2842 | ||
b6887d79 | 2843 | static void __disable_ftrace_function_probe(void) |
59df055f | 2844 | { |
b848914c | 2845 | int ret; |
59df055f SR |
2846 | int i; |
2847 | ||
b6887d79 | 2848 | if (!ftrace_probe_registered) |
59df055f SR |
2849 | return; |
2850 | ||
2851 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2852 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2853 | if (hhd->first) | |
2854 | return; | |
2855 | } | |
2856 | ||
2857 | /* no more funcs left */ | |
b848914c SR |
2858 | ret = __unregister_ftrace_function(&trace_probe_ops); |
2859 | if (!ret) | |
2860 | ftrace_shutdown(&trace_probe_ops, 0); | |
2861 | ||
b6887d79 | 2862 | ftrace_probe_registered = 0; |
59df055f SR |
2863 | } |
2864 | ||
2865 | ||
2866 | static void ftrace_free_entry_rcu(struct rcu_head *rhp) | |
2867 | { | |
b6887d79 SR |
2868 | struct ftrace_func_probe *entry = |
2869 | container_of(rhp, struct ftrace_func_probe, rcu); | |
59df055f SR |
2870 | |
2871 | if (entry->ops->free) | |
2872 | entry->ops->free(&entry->data); | |
2873 | kfree(entry); | |
2874 | } | |
2875 | ||
2876 | ||
2877 | int | |
b6887d79 | 2878 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2879 | void *data) |
2880 | { | |
b6887d79 | 2881 | struct ftrace_func_probe *entry; |
59df055f SR |
2882 | struct ftrace_page *pg; |
2883 | struct dyn_ftrace *rec; | |
59df055f | 2884 | int type, len, not; |
6a24a244 | 2885 | unsigned long key; |
59df055f SR |
2886 | int count = 0; |
2887 | char *search; | |
2888 | ||
3f6fe06d | 2889 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
2890 | len = strlen(search); |
2891 | ||
b6887d79 | 2892 | /* we do not support '!' for function probes */ |
59df055f SR |
2893 | if (WARN_ON(not)) |
2894 | return -EINVAL; | |
2895 | ||
2896 | mutex_lock(&ftrace_lock); | |
59df055f | 2897 | |
45a4a237 SR |
2898 | if (unlikely(ftrace_disabled)) |
2899 | goto out_unlock; | |
59df055f | 2900 | |
45a4a237 | 2901 | do_for_each_ftrace_rec(pg, rec) { |
59df055f | 2902 | |
b9df92d2 | 2903 | if (!ftrace_match_record(rec, NULL, search, len, type)) |
59df055f SR |
2904 | continue; |
2905 | ||
2906 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
2907 | if (!entry) { | |
b6887d79 | 2908 | /* If we did not process any, then return error */ |
59df055f SR |
2909 | if (!count) |
2910 | count = -ENOMEM; | |
2911 | goto out_unlock; | |
2912 | } | |
2913 | ||
2914 | count++; | |
2915 | ||
2916 | entry->data = data; | |
2917 | ||
2918 | /* | |
2919 | * The caller might want to do something special | |
2920 | * for each function we find. We call the callback | |
2921 | * to give the caller an opportunity to do so. | |
2922 | */ | |
2923 | if (ops->callback) { | |
2924 | if (ops->callback(rec->ip, &entry->data) < 0) { | |
2925 | /* caller does not like this func */ | |
2926 | kfree(entry); | |
2927 | continue; | |
2928 | } | |
2929 | } | |
2930 | ||
2931 | entry->ops = ops; | |
2932 | entry->ip = rec->ip; | |
2933 | ||
2934 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
2935 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
2936 | ||
2937 | } while_for_each_ftrace_rec(); | |
b6887d79 | 2938 | __enable_ftrace_function_probe(); |
59df055f SR |
2939 | |
2940 | out_unlock: | |
2941 | mutex_unlock(&ftrace_lock); | |
2942 | ||
2943 | return count; | |
2944 | } | |
2945 | ||
2946 | enum { | |
b6887d79 SR |
2947 | PROBE_TEST_FUNC = 1, |
2948 | PROBE_TEST_DATA = 2 | |
59df055f SR |
2949 | }; |
2950 | ||
2951 | static void | |
b6887d79 | 2952 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2953 | void *data, int flags) |
2954 | { | |
b6887d79 | 2955 | struct ftrace_func_probe *entry; |
59df055f SR |
2956 | struct hlist_node *n, *tmp; |
2957 | char str[KSYM_SYMBOL_LEN]; | |
2958 | int type = MATCH_FULL; | |
2959 | int i, len = 0; | |
2960 | char *search; | |
2961 | ||
b36461da | 2962 | if (glob && (strcmp(glob, "*") == 0 || !strlen(glob))) |
59df055f | 2963 | glob = NULL; |
b36461da | 2964 | else if (glob) { |
59df055f SR |
2965 | int not; |
2966 | ||
3f6fe06d | 2967 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
2968 | len = strlen(search); |
2969 | ||
b6887d79 | 2970 | /* we do not support '!' for function probes */ |
59df055f SR |
2971 | if (WARN_ON(not)) |
2972 | return; | |
2973 | } | |
2974 | ||
2975 | mutex_lock(&ftrace_lock); | |
2976 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2977 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2978 | ||
2979 | hlist_for_each_entry_safe(entry, n, tmp, hhd, node) { | |
2980 | ||
2981 | /* break up if statements for readability */ | |
b6887d79 | 2982 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
2983 | continue; |
2984 | ||
b6887d79 | 2985 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
2986 | continue; |
2987 | ||
2988 | /* do this last, since it is the most expensive */ | |
2989 | if (glob) { | |
2990 | kallsyms_lookup(entry->ip, NULL, NULL, | |
2991 | NULL, str); | |
2992 | if (!ftrace_match(str, glob, len, type)) | |
2993 | continue; | |
2994 | } | |
2995 | ||
2996 | hlist_del(&entry->node); | |
2997 | call_rcu(&entry->rcu, ftrace_free_entry_rcu); | |
2998 | } | |
2999 | } | |
b6887d79 | 3000 | __disable_ftrace_function_probe(); |
59df055f SR |
3001 | mutex_unlock(&ftrace_lock); |
3002 | } | |
3003 | ||
3004 | void | |
b6887d79 | 3005 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3006 | void *data) |
3007 | { | |
b6887d79 SR |
3008 | __unregister_ftrace_function_probe(glob, ops, data, |
3009 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
3010 | } |
3011 | ||
3012 | void | |
b6887d79 | 3013 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 3014 | { |
b6887d79 | 3015 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
3016 | } |
3017 | ||
b6887d79 | 3018 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 3019 | { |
b6887d79 | 3020 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
3021 | } |
3022 | ||
f6180773 SR |
3023 | static LIST_HEAD(ftrace_commands); |
3024 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
3025 | ||
3026 | int register_ftrace_command(struct ftrace_func_command *cmd) | |
3027 | { | |
3028 | struct ftrace_func_command *p; | |
3029 | int ret = 0; | |
3030 | ||
3031 | mutex_lock(&ftrace_cmd_mutex); | |
3032 | list_for_each_entry(p, &ftrace_commands, list) { | |
3033 | if (strcmp(cmd->name, p->name) == 0) { | |
3034 | ret = -EBUSY; | |
3035 | goto out_unlock; | |
3036 | } | |
3037 | } | |
3038 | list_add(&cmd->list, &ftrace_commands); | |
3039 | out_unlock: | |
3040 | mutex_unlock(&ftrace_cmd_mutex); | |
3041 | ||
3042 | return ret; | |
3043 | } | |
3044 | ||
3045 | int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
3046 | { | |
3047 | struct ftrace_func_command *p, *n; | |
3048 | int ret = -ENODEV; | |
3049 | ||
3050 | mutex_lock(&ftrace_cmd_mutex); | |
3051 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
3052 | if (strcmp(cmd->name, p->name) == 0) { | |
3053 | ret = 0; | |
3054 | list_del_init(&p->list); | |
3055 | goto out_unlock; | |
3056 | } | |
3057 | } | |
3058 | out_unlock: | |
3059 | mutex_unlock(&ftrace_cmd_mutex); | |
3060 | ||
3061 | return ret; | |
3062 | } | |
3063 | ||
33dc9b12 SR |
3064 | static int ftrace_process_regex(struct ftrace_hash *hash, |
3065 | char *buff, int len, int enable) | |
64e7c440 | 3066 | { |
f6180773 | 3067 | char *func, *command, *next = buff; |
6a24a244 | 3068 | struct ftrace_func_command *p; |
0aff1c0c | 3069 | int ret = -EINVAL; |
64e7c440 SR |
3070 | |
3071 | func = strsep(&next, ":"); | |
3072 | ||
3073 | if (!next) { | |
1cf41dd7 | 3074 | ret = ftrace_match_records(hash, func, len); |
b448c4e3 SR |
3075 | if (!ret) |
3076 | ret = -EINVAL; | |
3077 | if (ret < 0) | |
3078 | return ret; | |
3079 | return 0; | |
64e7c440 SR |
3080 | } |
3081 | ||
f6180773 | 3082 | /* command found */ |
64e7c440 SR |
3083 | |
3084 | command = strsep(&next, ":"); | |
3085 | ||
f6180773 SR |
3086 | mutex_lock(&ftrace_cmd_mutex); |
3087 | list_for_each_entry(p, &ftrace_commands, list) { | |
3088 | if (strcmp(p->name, command) == 0) { | |
43dd61c9 | 3089 | ret = p->func(hash, func, command, next, enable); |
f6180773 SR |
3090 | goto out_unlock; |
3091 | } | |
64e7c440 | 3092 | } |
f6180773 SR |
3093 | out_unlock: |
3094 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 3095 | |
f6180773 | 3096 | return ret; |
64e7c440 SR |
3097 | } |
3098 | ||
e309b41d | 3099 | static ssize_t |
41c52c0d SR |
3100 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
3101 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
3102 | { |
3103 | struct ftrace_iterator *iter; | |
689fd8b6 | 3104 | struct trace_parser *parser; |
3105 | ssize_t ret, read; | |
5072c59f | 3106 | |
4ba7978e | 3107 | if (!cnt) |
5072c59f SR |
3108 | return 0; |
3109 | ||
41c52c0d | 3110 | mutex_lock(&ftrace_regex_lock); |
5072c59f | 3111 | |
45a4a237 SR |
3112 | ret = -ENODEV; |
3113 | if (unlikely(ftrace_disabled)) | |
3114 | goto out_unlock; | |
3115 | ||
5072c59f SR |
3116 | if (file->f_mode & FMODE_READ) { |
3117 | struct seq_file *m = file->private_data; | |
3118 | iter = m->private; | |
3119 | } else | |
3120 | iter = file->private_data; | |
3121 | ||
689fd8b6 | 3122 | parser = &iter->parser; |
3123 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 3124 | |
4ba7978e | 3125 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 3126 | !trace_parser_cont(parser)) { |
33dc9b12 | 3127 | ret = ftrace_process_regex(iter->hash, parser->buffer, |
689fd8b6 | 3128 | parser->idx, enable); |
313254a9 | 3129 | trace_parser_clear(parser); |
5072c59f | 3130 | if (ret) |
ed146b25 | 3131 | goto out_unlock; |
eda1e328 | 3132 | } |
5072c59f | 3133 | |
5072c59f | 3134 | ret = read; |
ed146b25 | 3135 | out_unlock: |
689fd8b6 | 3136 | mutex_unlock(&ftrace_regex_lock); |
ed146b25 | 3137 | |
5072c59f SR |
3138 | return ret; |
3139 | } | |
3140 | ||
fc13cb0c | 3141 | ssize_t |
41c52c0d SR |
3142 | ftrace_filter_write(struct file *file, const char __user *ubuf, |
3143 | size_t cnt, loff_t *ppos) | |
3144 | { | |
3145 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
3146 | } | |
3147 | ||
fc13cb0c | 3148 | ssize_t |
41c52c0d SR |
3149 | ftrace_notrace_write(struct file *file, const char __user *ubuf, |
3150 | size_t cnt, loff_t *ppos) | |
3151 | { | |
3152 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
3153 | } | |
3154 | ||
33dc9b12 | 3155 | static int |
f45948e8 SR |
3156 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, |
3157 | int reset, int enable) | |
41c52c0d | 3158 | { |
33dc9b12 | 3159 | struct ftrace_hash **orig_hash; |
f45948e8 | 3160 | struct ftrace_hash *hash; |
33dc9b12 | 3161 | int ret; |
f45948e8 | 3162 | |
936e074b SR |
3163 | /* All global ops uses the global ops filters */ |
3164 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) | |
3165 | ops = &global_ops; | |
3166 | ||
41c52c0d | 3167 | if (unlikely(ftrace_disabled)) |
33dc9b12 | 3168 | return -ENODEV; |
41c52c0d | 3169 | |
f45948e8 | 3170 | if (enable) |
33dc9b12 | 3171 | orig_hash = &ops->filter_hash; |
f45948e8 | 3172 | else |
33dc9b12 SR |
3173 | orig_hash = &ops->notrace_hash; |
3174 | ||
3175 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
3176 | if (!hash) | |
3177 | return -ENOMEM; | |
f45948e8 | 3178 | |
41c52c0d SR |
3179 | mutex_lock(&ftrace_regex_lock); |
3180 | if (reset) | |
1cf41dd7 | 3181 | ftrace_filter_reset(hash); |
ac483c44 JO |
3182 | if (buf && !ftrace_match_records(hash, buf, len)) { |
3183 | ret = -EINVAL; | |
3184 | goto out_regex_unlock; | |
3185 | } | |
33dc9b12 SR |
3186 | |
3187 | mutex_lock(&ftrace_lock); | |
41fb61c2 | 3188 | ret = ftrace_hash_move(ops, enable, orig_hash, hash); |
072126f4 SR |
3189 | if (!ret && ops->flags & FTRACE_OPS_FL_ENABLED |
3190 | && ftrace_enabled) | |
30fb6aa7 | 3191 | ftrace_run_update_code(FTRACE_UPDATE_CALLS); |
072126f4 | 3192 | |
33dc9b12 SR |
3193 | mutex_unlock(&ftrace_lock); |
3194 | ||
ac483c44 | 3195 | out_regex_unlock: |
41c52c0d | 3196 | mutex_unlock(&ftrace_regex_lock); |
33dc9b12 SR |
3197 | |
3198 | free_ftrace_hash(hash); | |
3199 | return ret; | |
41c52c0d SR |
3200 | } |
3201 | ||
77a2b37d SR |
3202 | /** |
3203 | * ftrace_set_filter - set a function to filter on in ftrace | |
936e074b SR |
3204 | * @ops - the ops to set the filter with |
3205 | * @buf - the string that holds the function filter text. | |
3206 | * @len - the length of the string. | |
3207 | * @reset - non zero to reset all filters before applying this filter. | |
3208 | * | |
3209 | * Filters denote which functions should be enabled when tracing is enabled. | |
3210 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
3211 | */ | |
ac483c44 | 3212 | int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
3213 | int len, int reset) |
3214 | { | |
ac483c44 | 3215 | return ftrace_set_regex(ops, buf, len, reset, 1); |
936e074b SR |
3216 | } |
3217 | EXPORT_SYMBOL_GPL(ftrace_set_filter); | |
3218 | ||
3219 | /** | |
3220 | * ftrace_set_notrace - set a function to not trace in ftrace | |
3221 | * @ops - the ops to set the notrace filter with | |
3222 | * @buf - the string that holds the function notrace text. | |
3223 | * @len - the length of the string. | |
3224 | * @reset - non zero to reset all filters before applying this filter. | |
3225 | * | |
3226 | * Notrace Filters denote which functions should not be enabled when tracing | |
3227 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
3228 | * for tracing. | |
3229 | */ | |
ac483c44 | 3230 | int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
3231 | int len, int reset) |
3232 | { | |
ac483c44 | 3233 | return ftrace_set_regex(ops, buf, len, reset, 0); |
936e074b SR |
3234 | } |
3235 | EXPORT_SYMBOL_GPL(ftrace_set_notrace); | |
3236 | /** | |
3237 | * ftrace_set_filter - set a function to filter on in ftrace | |
3238 | * @ops - the ops to set the filter with | |
77a2b37d SR |
3239 | * @buf - the string that holds the function filter text. |
3240 | * @len - the length of the string. | |
3241 | * @reset - non zero to reset all filters before applying this filter. | |
3242 | * | |
3243 | * Filters denote which functions should be enabled when tracing is enabled. | |
3244 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
3245 | */ | |
936e074b | 3246 | void ftrace_set_global_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 3247 | { |
f45948e8 | 3248 | ftrace_set_regex(&global_ops, buf, len, reset, 1); |
41c52c0d | 3249 | } |
936e074b | 3250 | EXPORT_SYMBOL_GPL(ftrace_set_global_filter); |
4eebcc81 | 3251 | |
41c52c0d SR |
3252 | /** |
3253 | * ftrace_set_notrace - set a function to not trace in ftrace | |
936e074b | 3254 | * @ops - the ops to set the notrace filter with |
41c52c0d SR |
3255 | * @buf - the string that holds the function notrace text. |
3256 | * @len - the length of the string. | |
3257 | * @reset - non zero to reset all filters before applying this filter. | |
3258 | * | |
3259 | * Notrace Filters denote which functions should not be enabled when tracing | |
3260 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
3261 | * for tracing. | |
3262 | */ | |
936e074b | 3263 | void ftrace_set_global_notrace(unsigned char *buf, int len, int reset) |
41c52c0d | 3264 | { |
f45948e8 | 3265 | ftrace_set_regex(&global_ops, buf, len, reset, 0); |
77a2b37d | 3266 | } |
936e074b | 3267 | EXPORT_SYMBOL_GPL(ftrace_set_global_notrace); |
77a2b37d | 3268 | |
2af15d6a SR |
3269 | /* |
3270 | * command line interface to allow users to set filters on boot up. | |
3271 | */ | |
3272 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
3273 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
3274 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
3275 | ||
3276 | static int __init set_ftrace_notrace(char *str) | |
3277 | { | |
3278 | strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); | |
3279 | return 1; | |
3280 | } | |
3281 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
3282 | ||
3283 | static int __init set_ftrace_filter(char *str) | |
3284 | { | |
3285 | strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); | |
3286 | return 1; | |
3287 | } | |
3288 | __setup("ftrace_filter=", set_ftrace_filter); | |
3289 | ||
369bc18f | 3290 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 3291 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
801c29fd SR |
3292 | static int ftrace_set_func(unsigned long *array, int *idx, char *buffer); |
3293 | ||
369bc18f SA |
3294 | static int __init set_graph_function(char *str) |
3295 | { | |
06f43d66 | 3296 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
3297 | return 1; |
3298 | } | |
3299 | __setup("ftrace_graph_filter=", set_graph_function); | |
3300 | ||
3301 | static void __init set_ftrace_early_graph(char *buf) | |
3302 | { | |
3303 | int ret; | |
3304 | char *func; | |
3305 | ||
3306 | while (buf) { | |
3307 | func = strsep(&buf, ","); | |
3308 | /* we allow only one expression at a time */ | |
3309 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, | |
3310 | func); | |
3311 | if (ret) | |
3312 | printk(KERN_DEBUG "ftrace: function %s not " | |
3313 | "traceable\n", func); | |
3314 | } | |
3315 | } | |
3316 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
3317 | ||
2a85a37f SR |
3318 | void __init |
3319 | ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable) | |
2af15d6a SR |
3320 | { |
3321 | char *func; | |
3322 | ||
3323 | while (buf) { | |
3324 | func = strsep(&buf, ","); | |
f45948e8 | 3325 | ftrace_set_regex(ops, func, strlen(func), 0, enable); |
2af15d6a SR |
3326 | } |
3327 | } | |
3328 | ||
3329 | static void __init set_ftrace_early_filters(void) | |
3330 | { | |
3331 | if (ftrace_filter_buf[0]) | |
2a85a37f | 3332 | ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1); |
2af15d6a | 3333 | if (ftrace_notrace_buf[0]) |
2a85a37f | 3334 | ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0); |
369bc18f SA |
3335 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
3336 | if (ftrace_graph_buf[0]) | |
3337 | set_ftrace_early_graph(ftrace_graph_buf); | |
3338 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2af15d6a SR |
3339 | } |
3340 | ||
fc13cb0c | 3341 | int ftrace_regex_release(struct inode *inode, struct file *file) |
5072c59f SR |
3342 | { |
3343 | struct seq_file *m = (struct seq_file *)file->private_data; | |
3344 | struct ftrace_iterator *iter; | |
33dc9b12 | 3345 | struct ftrace_hash **orig_hash; |
689fd8b6 | 3346 | struct trace_parser *parser; |
ed926f9b | 3347 | int filter_hash; |
33dc9b12 | 3348 | int ret; |
5072c59f | 3349 | |
41c52c0d | 3350 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
3351 | if (file->f_mode & FMODE_READ) { |
3352 | iter = m->private; | |
3353 | ||
3354 | seq_release(inode, file); | |
3355 | } else | |
3356 | iter = file->private_data; | |
3357 | ||
689fd8b6 | 3358 | parser = &iter->parser; |
3359 | if (trace_parser_loaded(parser)) { | |
3360 | parser->buffer[parser->idx] = 0; | |
1cf41dd7 | 3361 | ftrace_match_records(iter->hash, parser->buffer, parser->idx); |
5072c59f SR |
3362 | } |
3363 | ||
689fd8b6 | 3364 | trace_parser_put(parser); |
689fd8b6 | 3365 | |
058e297d | 3366 | if (file->f_mode & FMODE_WRITE) { |
ed926f9b SR |
3367 | filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); |
3368 | ||
3369 | if (filter_hash) | |
33dc9b12 | 3370 | orig_hash = &iter->ops->filter_hash; |
ed926f9b SR |
3371 | else |
3372 | orig_hash = &iter->ops->notrace_hash; | |
33dc9b12 | 3373 | |
058e297d | 3374 | mutex_lock(&ftrace_lock); |
41fb61c2 SR |
3375 | ret = ftrace_hash_move(iter->ops, filter_hash, |
3376 | orig_hash, iter->hash); | |
3377 | if (!ret && (iter->ops->flags & FTRACE_OPS_FL_ENABLED) | |
3378 | && ftrace_enabled) | |
30fb6aa7 | 3379 | ftrace_run_update_code(FTRACE_UPDATE_CALLS); |
41fb61c2 | 3380 | |
058e297d SR |
3381 | mutex_unlock(&ftrace_lock); |
3382 | } | |
33dc9b12 SR |
3383 | free_ftrace_hash(iter->hash); |
3384 | kfree(iter); | |
058e297d | 3385 | |
41c52c0d | 3386 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
3387 | return 0; |
3388 | } | |
3389 | ||
5e2336a0 | 3390 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
3391 | .open = ftrace_avail_open, |
3392 | .read = seq_read, | |
3393 | .llseek = seq_lseek, | |
3be04b47 | 3394 | .release = seq_release_private, |
5072c59f SR |
3395 | }; |
3396 | ||
647bcd03 SR |
3397 | static const struct file_operations ftrace_enabled_fops = { |
3398 | .open = ftrace_enabled_open, | |
3399 | .read = seq_read, | |
3400 | .llseek = seq_lseek, | |
3401 | .release = seq_release_private, | |
3402 | }; | |
3403 | ||
5e2336a0 | 3404 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 3405 | .open = ftrace_filter_open, |
850a80cf | 3406 | .read = seq_read, |
5072c59f | 3407 | .write = ftrace_filter_write, |
98c4fd04 | 3408 | .llseek = ftrace_regex_lseek, |
1cf41dd7 | 3409 | .release = ftrace_regex_release, |
5072c59f SR |
3410 | }; |
3411 | ||
5e2336a0 | 3412 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 3413 | .open = ftrace_notrace_open, |
850a80cf | 3414 | .read = seq_read, |
41c52c0d SR |
3415 | .write = ftrace_notrace_write, |
3416 | .llseek = ftrace_regex_lseek, | |
1cf41dd7 | 3417 | .release = ftrace_regex_release, |
41c52c0d SR |
3418 | }; |
3419 | ||
ea4e2bc4 SR |
3420 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
3421 | ||
3422 | static DEFINE_MUTEX(graph_lock); | |
3423 | ||
3424 | int ftrace_graph_count; | |
c7c6b1fe | 3425 | int ftrace_graph_filter_enabled; |
ea4e2bc4 SR |
3426 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
3427 | ||
3428 | static void * | |
85951842 | 3429 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 3430 | { |
85951842 | 3431 | if (*pos >= ftrace_graph_count) |
ea4e2bc4 | 3432 | return NULL; |
a4ec5e0c | 3433 | return &ftrace_graph_funcs[*pos]; |
85951842 | 3434 | } |
ea4e2bc4 | 3435 | |
85951842 LZ |
3436 | static void * |
3437 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
3438 | { | |
3439 | (*pos)++; | |
3440 | return __g_next(m, pos); | |
ea4e2bc4 SR |
3441 | } |
3442 | ||
3443 | static void *g_start(struct seq_file *m, loff_t *pos) | |
3444 | { | |
ea4e2bc4 SR |
3445 | mutex_lock(&graph_lock); |
3446 | ||
f9349a8f | 3447 | /* Nothing, tell g_show to print all functions are enabled */ |
c7c6b1fe | 3448 | if (!ftrace_graph_filter_enabled && !*pos) |
f9349a8f FW |
3449 | return (void *)1; |
3450 | ||
85951842 | 3451 | return __g_next(m, pos); |
ea4e2bc4 SR |
3452 | } |
3453 | ||
3454 | static void g_stop(struct seq_file *m, void *p) | |
3455 | { | |
3456 | mutex_unlock(&graph_lock); | |
3457 | } | |
3458 | ||
3459 | static int g_show(struct seq_file *m, void *v) | |
3460 | { | |
3461 | unsigned long *ptr = v; | |
ea4e2bc4 SR |
3462 | |
3463 | if (!ptr) | |
3464 | return 0; | |
3465 | ||
f9349a8f FW |
3466 | if (ptr == (unsigned long *)1) { |
3467 | seq_printf(m, "#### all functions enabled ####\n"); | |
3468 | return 0; | |
3469 | } | |
3470 | ||
b375a11a | 3471 | seq_printf(m, "%ps\n", (void *)*ptr); |
ea4e2bc4 SR |
3472 | |
3473 | return 0; | |
3474 | } | |
3475 | ||
88e9d34c | 3476 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
3477 | .start = g_start, |
3478 | .next = g_next, | |
3479 | .stop = g_stop, | |
3480 | .show = g_show, | |
3481 | }; | |
3482 | ||
3483 | static int | |
3484 | ftrace_graph_open(struct inode *inode, struct file *file) | |
3485 | { | |
3486 | int ret = 0; | |
3487 | ||
3488 | if (unlikely(ftrace_disabled)) | |
3489 | return -ENODEV; | |
3490 | ||
3491 | mutex_lock(&graph_lock); | |
3492 | if ((file->f_mode & FMODE_WRITE) && | |
8650ae32 | 3493 | (file->f_flags & O_TRUNC)) { |
c7c6b1fe | 3494 | ftrace_graph_filter_enabled = 0; |
ea4e2bc4 SR |
3495 | ftrace_graph_count = 0; |
3496 | memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); | |
3497 | } | |
a4ec5e0c | 3498 | mutex_unlock(&graph_lock); |
ea4e2bc4 | 3499 | |
a4ec5e0c | 3500 | if (file->f_mode & FMODE_READ) |
ea4e2bc4 | 3501 | ret = seq_open(file, &ftrace_graph_seq_ops); |
ea4e2bc4 SR |
3502 | |
3503 | return ret; | |
3504 | } | |
3505 | ||
87827111 LZ |
3506 | static int |
3507 | ftrace_graph_release(struct inode *inode, struct file *file) | |
3508 | { | |
3509 | if (file->f_mode & FMODE_READ) | |
3510 | seq_release(inode, file); | |
3511 | return 0; | |
3512 | } | |
3513 | ||
ea4e2bc4 | 3514 | static int |
f9349a8f | 3515 | ftrace_set_func(unsigned long *array, int *idx, char *buffer) |
ea4e2bc4 | 3516 | { |
ea4e2bc4 SR |
3517 | struct dyn_ftrace *rec; |
3518 | struct ftrace_page *pg; | |
f9349a8f | 3519 | int search_len; |
c7c6b1fe | 3520 | int fail = 1; |
f9349a8f FW |
3521 | int type, not; |
3522 | char *search; | |
3523 | bool exists; | |
3524 | int i; | |
ea4e2bc4 | 3525 | |
f9349a8f | 3526 | /* decode regex */ |
3f6fe06d | 3527 | type = filter_parse_regex(buffer, strlen(buffer), &search, ¬); |
c7c6b1fe LZ |
3528 | if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS) |
3529 | return -EBUSY; | |
f9349a8f FW |
3530 | |
3531 | search_len = strlen(search); | |
3532 | ||
52baf119 | 3533 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
3534 | |
3535 | if (unlikely(ftrace_disabled)) { | |
3536 | mutex_unlock(&ftrace_lock); | |
3537 | return -ENODEV; | |
3538 | } | |
3539 | ||
265c831c SR |
3540 | do_for_each_ftrace_rec(pg, rec) { |
3541 | ||
b9df92d2 | 3542 | if (ftrace_match_record(rec, NULL, search, search_len, type)) { |
c7c6b1fe | 3543 | /* if it is in the array */ |
f9349a8f | 3544 | exists = false; |
c7c6b1fe | 3545 | for (i = 0; i < *idx; i++) { |
f9349a8f FW |
3546 | if (array[i] == rec->ip) { |
3547 | exists = true; | |
265c831c SR |
3548 | break; |
3549 | } | |
c7c6b1fe LZ |
3550 | } |
3551 | ||
3552 | if (!not) { | |
3553 | fail = 0; | |
3554 | if (!exists) { | |
3555 | array[(*idx)++] = rec->ip; | |
3556 | if (*idx >= FTRACE_GRAPH_MAX_FUNCS) | |
3557 | goto out; | |
3558 | } | |
3559 | } else { | |
3560 | if (exists) { | |
3561 | array[i] = array[--(*idx)]; | |
3562 | array[*idx] = 0; | |
3563 | fail = 0; | |
3564 | } | |
3565 | } | |
ea4e2bc4 | 3566 | } |
265c831c | 3567 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 3568 | out: |
52baf119 | 3569 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 3570 | |
c7c6b1fe LZ |
3571 | if (fail) |
3572 | return -EINVAL; | |
3573 | ||
3574 | ftrace_graph_filter_enabled = 1; | |
3575 | return 0; | |
ea4e2bc4 SR |
3576 | } |
3577 | ||
3578 | static ssize_t | |
3579 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
3580 | size_t cnt, loff_t *ppos) | |
3581 | { | |
689fd8b6 | 3582 | struct trace_parser parser; |
4ba7978e | 3583 | ssize_t read, ret; |
ea4e2bc4 | 3584 | |
c7c6b1fe | 3585 | if (!cnt) |
ea4e2bc4 SR |
3586 | return 0; |
3587 | ||
3588 | mutex_lock(&graph_lock); | |
3589 | ||
689fd8b6 | 3590 | if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) { |
3591 | ret = -ENOMEM; | |
1eb90f13 | 3592 | goto out_unlock; |
ea4e2bc4 SR |
3593 | } |
3594 | ||
689fd8b6 | 3595 | read = trace_get_user(&parser, ubuf, cnt, ppos); |
ea4e2bc4 | 3596 | |
4ba7978e | 3597 | if (read >= 0 && trace_parser_loaded((&parser))) { |
689fd8b6 | 3598 | parser.buffer[parser.idx] = 0; |
3599 | ||
3600 | /* we allow only one expression at a time */ | |
a4ec5e0c | 3601 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, |
689fd8b6 | 3602 | parser.buffer); |
ea4e2bc4 | 3603 | if (ret) |
1eb90f13 | 3604 | goto out_free; |
ea4e2bc4 | 3605 | } |
ea4e2bc4 SR |
3606 | |
3607 | ret = read; | |
1eb90f13 LZ |
3608 | |
3609 | out_free: | |
689fd8b6 | 3610 | trace_parser_put(&parser); |
1eb90f13 | 3611 | out_unlock: |
ea4e2bc4 SR |
3612 | mutex_unlock(&graph_lock); |
3613 | ||
3614 | return ret; | |
3615 | } | |
3616 | ||
3617 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
3618 | .open = ftrace_graph_open, |
3619 | .read = seq_read, | |
3620 | .write = ftrace_graph_write, | |
3621 | .release = ftrace_graph_release, | |
6038f373 | 3622 | .llseek = seq_lseek, |
ea4e2bc4 SR |
3623 | }; |
3624 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
3625 | ||
df4fc315 | 3626 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 3627 | { |
5072c59f | 3628 | |
5452af66 FW |
3629 | trace_create_file("available_filter_functions", 0444, |
3630 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 3631 | |
647bcd03 SR |
3632 | trace_create_file("enabled_functions", 0444, |
3633 | d_tracer, NULL, &ftrace_enabled_fops); | |
3634 | ||
5452af66 FW |
3635 | trace_create_file("set_ftrace_filter", 0644, d_tracer, |
3636 | NULL, &ftrace_filter_fops); | |
41c52c0d | 3637 | |
5452af66 | 3638 | trace_create_file("set_ftrace_notrace", 0644, d_tracer, |
41c52c0d | 3639 | NULL, &ftrace_notrace_fops); |
ad90c0e3 | 3640 | |
ea4e2bc4 | 3641 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 3642 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
3643 | NULL, |
3644 | &ftrace_graph_fops); | |
ea4e2bc4 SR |
3645 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
3646 | ||
5072c59f SR |
3647 | return 0; |
3648 | } | |
3649 | ||
9fd49328 | 3650 | static int ftrace_cmp_ips(const void *a, const void *b) |
68950619 | 3651 | { |
9fd49328 SR |
3652 | const unsigned long *ipa = a; |
3653 | const unsigned long *ipb = b; | |
68950619 | 3654 | |
9fd49328 SR |
3655 | if (*ipa > *ipb) |
3656 | return 1; | |
3657 | if (*ipa < *ipb) | |
3658 | return -1; | |
3659 | return 0; | |
3660 | } | |
3661 | ||
3662 | static void ftrace_swap_ips(void *a, void *b, int size) | |
3663 | { | |
3664 | unsigned long *ipa = a; | |
3665 | unsigned long *ipb = b; | |
3666 | unsigned long t; | |
3667 | ||
3668 | t = *ipa; | |
3669 | *ipa = *ipb; | |
3670 | *ipb = t; | |
68950619 SR |
3671 | } |
3672 | ||
5cb084bb | 3673 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 3674 | unsigned long *start, |
68bf21aa SR |
3675 | unsigned long *end) |
3676 | { | |
706c81f8 | 3677 | struct ftrace_page *start_pg; |
a7900875 | 3678 | struct ftrace_page *pg; |
706c81f8 | 3679 | struct dyn_ftrace *rec; |
a7900875 | 3680 | unsigned long count; |
68bf21aa SR |
3681 | unsigned long *p; |
3682 | unsigned long addr; | |
4376cac6 | 3683 | unsigned long flags = 0; /* Shut up gcc */ |
a7900875 SR |
3684 | int ret = -ENOMEM; |
3685 | ||
3686 | count = end - start; | |
3687 | ||
3688 | if (!count) | |
3689 | return 0; | |
3690 | ||
9fd49328 SR |
3691 | sort(start, count, sizeof(*start), |
3692 | ftrace_cmp_ips, ftrace_swap_ips); | |
3693 | ||
706c81f8 SR |
3694 | start_pg = ftrace_allocate_pages(count); |
3695 | if (!start_pg) | |
a7900875 | 3696 | return -ENOMEM; |
68bf21aa | 3697 | |
e6ea44e9 | 3698 | mutex_lock(&ftrace_lock); |
a7900875 | 3699 | |
32082309 SR |
3700 | /* |
3701 | * Core and each module needs their own pages, as | |
3702 | * modules will free them when they are removed. | |
3703 | * Force a new page to be allocated for modules. | |
3704 | */ | |
a7900875 SR |
3705 | if (!mod) { |
3706 | WARN_ON(ftrace_pages || ftrace_pages_start); | |
3707 | /* First initialization */ | |
706c81f8 | 3708 | ftrace_pages = ftrace_pages_start = start_pg; |
a7900875 | 3709 | } else { |
32082309 | 3710 | if (!ftrace_pages) |
a7900875 | 3711 | goto out; |
32082309 | 3712 | |
a7900875 SR |
3713 | if (WARN_ON(ftrace_pages->next)) { |
3714 | /* Hmm, we have free pages? */ | |
3715 | while (ftrace_pages->next) | |
3716 | ftrace_pages = ftrace_pages->next; | |
32082309 | 3717 | } |
a7900875 | 3718 | |
706c81f8 | 3719 | ftrace_pages->next = start_pg; |
32082309 SR |
3720 | } |
3721 | ||
68bf21aa | 3722 | p = start; |
706c81f8 | 3723 | pg = start_pg; |
68bf21aa SR |
3724 | while (p < end) { |
3725 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
3726 | /* |
3727 | * Some architecture linkers will pad between | |
3728 | * the different mcount_loc sections of different | |
3729 | * object files to satisfy alignments. | |
3730 | * Skip any NULL pointers. | |
3731 | */ | |
3732 | if (!addr) | |
3733 | continue; | |
706c81f8 SR |
3734 | |
3735 | if (pg->index == pg->size) { | |
3736 | /* We should have allocated enough */ | |
3737 | if (WARN_ON(!pg->next)) | |
3738 | break; | |
3739 | pg = pg->next; | |
3740 | } | |
3741 | ||
3742 | rec = &pg->records[pg->index++]; | |
3743 | rec->ip = addr; | |
68bf21aa SR |
3744 | } |
3745 | ||
706c81f8 SR |
3746 | /* We should have used all pages */ |
3747 | WARN_ON(pg->next); | |
3748 | ||
3749 | /* Assign the last page to ftrace_pages */ | |
3750 | ftrace_pages = pg; | |
3751 | ||
85ae32ae | 3752 | /* These new locations need to be initialized */ |
706c81f8 | 3753 | ftrace_new_pgs = start_pg; |
85ae32ae | 3754 | |
a4f18ed1 | 3755 | /* |
4376cac6 SR |
3756 | * We only need to disable interrupts on start up |
3757 | * because we are modifying code that an interrupt | |
3758 | * may execute, and the modification is not atomic. | |
3759 | * But for modules, nothing runs the code we modify | |
3760 | * until we are finished with it, and there's no | |
3761 | * reason to cause large interrupt latencies while we do it. | |
a4f18ed1 | 3762 | */ |
4376cac6 SR |
3763 | if (!mod) |
3764 | local_irq_save(flags); | |
31e88909 | 3765 | ftrace_update_code(mod); |
4376cac6 SR |
3766 | if (!mod) |
3767 | local_irq_restore(flags); | |
a7900875 SR |
3768 | ret = 0; |
3769 | out: | |
e6ea44e9 | 3770 | mutex_unlock(&ftrace_lock); |
68bf21aa | 3771 | |
a7900875 | 3772 | return ret; |
68bf21aa SR |
3773 | } |
3774 | ||
93eb677d | 3775 | #ifdef CONFIG_MODULES |
32082309 SR |
3776 | |
3777 | #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next) | |
3778 | ||
e7247a15 | 3779 | void ftrace_release_mod(struct module *mod) |
93eb677d SR |
3780 | { |
3781 | struct dyn_ftrace *rec; | |
32082309 | 3782 | struct ftrace_page **last_pg; |
93eb677d | 3783 | struct ftrace_page *pg; |
a7900875 | 3784 | int order; |
93eb677d | 3785 | |
45a4a237 SR |
3786 | mutex_lock(&ftrace_lock); |
3787 | ||
e7247a15 | 3788 | if (ftrace_disabled) |
45a4a237 | 3789 | goto out_unlock; |
93eb677d | 3790 | |
32082309 SR |
3791 | /* |
3792 | * Each module has its own ftrace_pages, remove | |
3793 | * them from the list. | |
3794 | */ | |
3795 | last_pg = &ftrace_pages_start; | |
3796 | for (pg = ftrace_pages_start; pg; pg = *last_pg) { | |
3797 | rec = &pg->records[0]; | |
e7247a15 | 3798 | if (within_module_core(rec->ip, mod)) { |
93eb677d | 3799 | /* |
32082309 SR |
3800 | * As core pages are first, the first |
3801 | * page should never be a module page. | |
93eb677d | 3802 | */ |
32082309 SR |
3803 | if (WARN_ON(pg == ftrace_pages_start)) |
3804 | goto out_unlock; | |
3805 | ||
3806 | /* Check if we are deleting the last page */ | |
3807 | if (pg == ftrace_pages) | |
3808 | ftrace_pages = next_to_ftrace_page(last_pg); | |
3809 | ||
3810 | *last_pg = pg->next; | |
a7900875 SR |
3811 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
3812 | free_pages((unsigned long)pg->records, order); | |
3813 | kfree(pg); | |
32082309 SR |
3814 | } else |
3815 | last_pg = &pg->next; | |
3816 | } | |
45a4a237 | 3817 | out_unlock: |
93eb677d SR |
3818 | mutex_unlock(&ftrace_lock); |
3819 | } | |
3820 | ||
3821 | static void ftrace_init_module(struct module *mod, | |
3822 | unsigned long *start, unsigned long *end) | |
90d595fe | 3823 | { |
00fd61ae | 3824 | if (ftrace_disabled || start == end) |
fed1939c | 3825 | return; |
5cb084bb | 3826 | ftrace_process_locs(mod, start, end); |
90d595fe SR |
3827 | } |
3828 | ||
93eb677d SR |
3829 | static int ftrace_module_notify(struct notifier_block *self, |
3830 | unsigned long val, void *data) | |
3831 | { | |
3832 | struct module *mod = data; | |
3833 | ||
3834 | switch (val) { | |
3835 | case MODULE_STATE_COMING: | |
3836 | ftrace_init_module(mod, mod->ftrace_callsites, | |
3837 | mod->ftrace_callsites + | |
3838 | mod->num_ftrace_callsites); | |
3839 | break; | |
3840 | case MODULE_STATE_GOING: | |
e7247a15 | 3841 | ftrace_release_mod(mod); |
93eb677d SR |
3842 | break; |
3843 | } | |
3844 | ||
3845 | return 0; | |
3846 | } | |
3847 | #else | |
3848 | static int ftrace_module_notify(struct notifier_block *self, | |
3849 | unsigned long val, void *data) | |
3850 | { | |
3851 | return 0; | |
3852 | } | |
3853 | #endif /* CONFIG_MODULES */ | |
3854 | ||
3855 | struct notifier_block ftrace_module_nb = { | |
3856 | .notifier_call = ftrace_module_notify, | |
3857 | .priority = 0, | |
3858 | }; | |
3859 | ||
68bf21aa SR |
3860 | extern unsigned long __start_mcount_loc[]; |
3861 | extern unsigned long __stop_mcount_loc[]; | |
3862 | ||
3863 | void __init ftrace_init(void) | |
3864 | { | |
3865 | unsigned long count, addr, flags; | |
3866 | int ret; | |
3867 | ||
3868 | /* Keep the ftrace pointer to the stub */ | |
3869 | addr = (unsigned long)ftrace_stub; | |
3870 | ||
3871 | local_irq_save(flags); | |
3872 | ftrace_dyn_arch_init(&addr); | |
3873 | local_irq_restore(flags); | |
3874 | ||
3875 | /* ftrace_dyn_arch_init places the return code in addr */ | |
3876 | if (addr) | |
3877 | goto failed; | |
3878 | ||
3879 | count = __stop_mcount_loc - __start_mcount_loc; | |
3880 | ||
3881 | ret = ftrace_dyn_table_alloc(count); | |
3882 | if (ret) | |
3883 | goto failed; | |
3884 | ||
3885 | last_ftrace_enabled = ftrace_enabled = 1; | |
3886 | ||
5cb084bb | 3887 | ret = ftrace_process_locs(NULL, |
31e88909 | 3888 | __start_mcount_loc, |
68bf21aa SR |
3889 | __stop_mcount_loc); |
3890 | ||
93eb677d | 3891 | ret = register_module_notifier(&ftrace_module_nb); |
24ed0c4b | 3892 | if (ret) |
93eb677d SR |
3893 | pr_warning("Failed to register trace ftrace module notifier\n"); |
3894 | ||
2af15d6a SR |
3895 | set_ftrace_early_filters(); |
3896 | ||
68bf21aa SR |
3897 | return; |
3898 | failed: | |
3899 | ftrace_disabled = 1; | |
3900 | } | |
68bf21aa | 3901 | |
3d083395 | 3902 | #else |
0b6e4d56 | 3903 | |
2b499381 | 3904 | static struct ftrace_ops global_ops = { |
bd69c30b SR |
3905 | .func = ftrace_stub, |
3906 | }; | |
3907 | ||
0b6e4d56 FW |
3908 | static int __init ftrace_nodyn_init(void) |
3909 | { | |
3910 | ftrace_enabled = 1; | |
3911 | return 0; | |
3912 | } | |
3913 | device_initcall(ftrace_nodyn_init); | |
3914 | ||
df4fc315 SR |
3915 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
3916 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 | 3917 | /* Keep as macros so we do not need to define the commands */ |
3b6cfdb1 SR |
3918 | # define ftrace_startup(ops, command) \ |
3919 | ({ \ | |
3920 | (ops)->flags |= FTRACE_OPS_FL_ENABLED; \ | |
3921 | 0; \ | |
3922 | }) | |
bd69c30b | 3923 | # define ftrace_shutdown(ops, command) do { } while (0) |
c7aafc54 IM |
3924 | # define ftrace_startup_sysctl() do { } while (0) |
3925 | # define ftrace_shutdown_sysctl() do { } while (0) | |
b848914c SR |
3926 | |
3927 | static inline int | |
3928 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip) | |
3929 | { | |
3930 | return 1; | |
3931 | } | |
3932 | ||
3d083395 SR |
3933 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
3934 | ||
e248491a JO |
3935 | static void |
3936 | ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip) | |
3937 | { | |
3938 | struct ftrace_ops *op; | |
3939 | ||
3940 | if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT))) | |
3941 | return; | |
3942 | ||
3943 | /* | |
3944 | * Some of the ops may be dynamically allocated, | |
3945 | * they must be freed after a synchronize_sched(). | |
3946 | */ | |
3947 | preempt_disable_notrace(); | |
3948 | trace_recursion_set(TRACE_CONTROL_BIT); | |
3949 | op = rcu_dereference_raw(ftrace_control_list); | |
3950 | while (op != &ftrace_list_end) { | |
3951 | if (!ftrace_function_local_disabled(op) && | |
3952 | ftrace_ops_test(op, ip)) | |
3953 | op->func(ip, parent_ip); | |
3954 | ||
3955 | op = rcu_dereference_raw(op->next); | |
3956 | }; | |
3957 | trace_recursion_clear(TRACE_CONTROL_BIT); | |
3958 | preempt_enable_notrace(); | |
3959 | } | |
3960 | ||
3961 | static struct ftrace_ops control_ops = { | |
3962 | .func = ftrace_ops_control_func, | |
3963 | }; | |
3964 | ||
b848914c SR |
3965 | static void |
3966 | ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip) | |
3967 | { | |
cdbe61bf | 3968 | struct ftrace_ops *op; |
b848914c | 3969 | |
b1cff0ad SR |
3970 | if (unlikely(trace_recursion_test(TRACE_INTERNAL_BIT))) |
3971 | return; | |
3972 | ||
3973 | trace_recursion_set(TRACE_INTERNAL_BIT); | |
cdbe61bf SR |
3974 | /* |
3975 | * Some of the ops may be dynamically allocated, | |
3976 | * they must be freed after a synchronize_sched(). | |
3977 | */ | |
3978 | preempt_disable_notrace(); | |
3979 | op = rcu_dereference_raw(ftrace_ops_list); | |
b848914c SR |
3980 | while (op != &ftrace_list_end) { |
3981 | if (ftrace_ops_test(op, ip)) | |
3982 | op->func(ip, parent_ip); | |
3983 | op = rcu_dereference_raw(op->next); | |
3984 | }; | |
cdbe61bf | 3985 | preempt_enable_notrace(); |
b1cff0ad | 3986 | trace_recursion_clear(TRACE_INTERNAL_BIT); |
b848914c SR |
3987 | } |
3988 | ||
e32d8956 | 3989 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
3990 | { |
3991 | struct task_struct *p; | |
e32d8956 | 3992 | int cpu; |
978f3a45 | 3993 | |
e32d8956 SR |
3994 | get_online_cpus(); |
3995 | for_each_online_cpu(cpu) { | |
3996 | p = idle_task(cpu); | |
978f3a45 | 3997 | clear_tsk_trace_trace(p); |
e32d8956 SR |
3998 | } |
3999 | put_online_cpus(); | |
4000 | } | |
978f3a45 | 4001 | |
e32d8956 SR |
4002 | static void set_ftrace_swapper(void) |
4003 | { | |
4004 | struct task_struct *p; | |
4005 | int cpu; | |
4006 | ||
4007 | get_online_cpus(); | |
4008 | for_each_online_cpu(cpu) { | |
4009 | p = idle_task(cpu); | |
4010 | set_tsk_trace_trace(p); | |
4011 | } | |
4012 | put_online_cpus(); | |
978f3a45 SR |
4013 | } |
4014 | ||
e32d8956 SR |
4015 | static void clear_ftrace_pid(struct pid *pid) |
4016 | { | |
4017 | struct task_struct *p; | |
4018 | ||
229c4ef8 | 4019 | rcu_read_lock(); |
e32d8956 SR |
4020 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
4021 | clear_tsk_trace_trace(p); | |
4022 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
4023 | rcu_read_unlock(); |
4024 | ||
e32d8956 SR |
4025 | put_pid(pid); |
4026 | } | |
4027 | ||
4028 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
4029 | { |
4030 | struct task_struct *p; | |
4031 | ||
229c4ef8 | 4032 | rcu_read_lock(); |
978f3a45 SR |
4033 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
4034 | set_tsk_trace_trace(p); | |
4035 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 4036 | rcu_read_unlock(); |
978f3a45 SR |
4037 | } |
4038 | ||
756d17ee | 4039 | static void clear_ftrace_pid_task(struct pid *pid) |
e32d8956 | 4040 | { |
756d17ee | 4041 | if (pid == ftrace_swapper_pid) |
e32d8956 SR |
4042 | clear_ftrace_swapper(); |
4043 | else | |
756d17ee | 4044 | clear_ftrace_pid(pid); |
e32d8956 SR |
4045 | } |
4046 | ||
4047 | static void set_ftrace_pid_task(struct pid *pid) | |
4048 | { | |
4049 | if (pid == ftrace_swapper_pid) | |
4050 | set_ftrace_swapper(); | |
4051 | else | |
4052 | set_ftrace_pid(pid); | |
4053 | } | |
4054 | ||
756d17ee | 4055 | static int ftrace_pid_add(int p) |
df4fc315 | 4056 | { |
978f3a45 | 4057 | struct pid *pid; |
756d17ee | 4058 | struct ftrace_pid *fpid; |
4059 | int ret = -EINVAL; | |
df4fc315 | 4060 | |
756d17ee | 4061 | mutex_lock(&ftrace_lock); |
df4fc315 | 4062 | |
756d17ee | 4063 | if (!p) |
4064 | pid = ftrace_swapper_pid; | |
4065 | else | |
4066 | pid = find_get_pid(p); | |
df4fc315 | 4067 | |
756d17ee | 4068 | if (!pid) |
4069 | goto out; | |
df4fc315 | 4070 | |
756d17ee | 4071 | ret = 0; |
df4fc315 | 4072 | |
756d17ee | 4073 | list_for_each_entry(fpid, &ftrace_pids, list) |
4074 | if (fpid->pid == pid) | |
4075 | goto out_put; | |
978f3a45 | 4076 | |
756d17ee | 4077 | ret = -ENOMEM; |
df4fc315 | 4078 | |
756d17ee | 4079 | fpid = kmalloc(sizeof(*fpid), GFP_KERNEL); |
4080 | if (!fpid) | |
4081 | goto out_put; | |
df4fc315 | 4082 | |
756d17ee | 4083 | list_add(&fpid->list, &ftrace_pids); |
4084 | fpid->pid = pid; | |
0ef8cde5 | 4085 | |
756d17ee | 4086 | set_ftrace_pid_task(pid); |
978f3a45 | 4087 | |
756d17ee | 4088 | ftrace_update_pid_func(); |
4089 | ftrace_startup_enable(0); | |
4090 | ||
4091 | mutex_unlock(&ftrace_lock); | |
4092 | return 0; | |
4093 | ||
4094 | out_put: | |
4095 | if (pid != ftrace_swapper_pid) | |
4096 | put_pid(pid); | |
978f3a45 | 4097 | |
756d17ee | 4098 | out: |
4099 | mutex_unlock(&ftrace_lock); | |
4100 | return ret; | |
4101 | } | |
4102 | ||
4103 | static void ftrace_pid_reset(void) | |
4104 | { | |
4105 | struct ftrace_pid *fpid, *safe; | |
978f3a45 | 4106 | |
756d17ee | 4107 | mutex_lock(&ftrace_lock); |
4108 | list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) { | |
4109 | struct pid *pid = fpid->pid; | |
4110 | ||
4111 | clear_ftrace_pid_task(pid); | |
4112 | ||
4113 | list_del(&fpid->list); | |
4114 | kfree(fpid); | |
df4fc315 SR |
4115 | } |
4116 | ||
df4fc315 SR |
4117 | ftrace_update_pid_func(); |
4118 | ftrace_startup_enable(0); | |
4119 | ||
e6ea44e9 | 4120 | mutex_unlock(&ftrace_lock); |
756d17ee | 4121 | } |
df4fc315 | 4122 | |
756d17ee | 4123 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
4124 | { | |
4125 | mutex_lock(&ftrace_lock); | |
4126 | ||
4127 | if (list_empty(&ftrace_pids) && (!*pos)) | |
4128 | return (void *) 1; | |
4129 | ||
4130 | return seq_list_start(&ftrace_pids, *pos); | |
4131 | } | |
4132 | ||
4133 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
4134 | { | |
4135 | if (v == (void *)1) | |
4136 | return NULL; | |
4137 | ||
4138 | return seq_list_next(v, &ftrace_pids, pos); | |
4139 | } | |
4140 | ||
4141 | static void fpid_stop(struct seq_file *m, void *p) | |
4142 | { | |
4143 | mutex_unlock(&ftrace_lock); | |
4144 | } | |
4145 | ||
4146 | static int fpid_show(struct seq_file *m, void *v) | |
4147 | { | |
4148 | const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list); | |
4149 | ||
4150 | if (v == (void *)1) { | |
4151 | seq_printf(m, "no pid\n"); | |
4152 | return 0; | |
4153 | } | |
4154 | ||
4155 | if (fpid->pid == ftrace_swapper_pid) | |
4156 | seq_printf(m, "swapper tasks\n"); | |
4157 | else | |
4158 | seq_printf(m, "%u\n", pid_vnr(fpid->pid)); | |
4159 | ||
4160 | return 0; | |
4161 | } | |
4162 | ||
4163 | static const struct seq_operations ftrace_pid_sops = { | |
4164 | .start = fpid_start, | |
4165 | .next = fpid_next, | |
4166 | .stop = fpid_stop, | |
4167 | .show = fpid_show, | |
4168 | }; | |
4169 | ||
4170 | static int | |
4171 | ftrace_pid_open(struct inode *inode, struct file *file) | |
4172 | { | |
4173 | int ret = 0; | |
4174 | ||
4175 | if ((file->f_mode & FMODE_WRITE) && | |
4176 | (file->f_flags & O_TRUNC)) | |
4177 | ftrace_pid_reset(); | |
4178 | ||
4179 | if (file->f_mode & FMODE_READ) | |
4180 | ret = seq_open(file, &ftrace_pid_sops); | |
4181 | ||
4182 | return ret; | |
4183 | } | |
4184 | ||
df4fc315 SR |
4185 | static ssize_t |
4186 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
4187 | size_t cnt, loff_t *ppos) | |
4188 | { | |
457dc928 | 4189 | char buf[64], *tmp; |
df4fc315 SR |
4190 | long val; |
4191 | int ret; | |
4192 | ||
4193 | if (cnt >= sizeof(buf)) | |
4194 | return -EINVAL; | |
4195 | ||
4196 | if (copy_from_user(&buf, ubuf, cnt)) | |
4197 | return -EFAULT; | |
4198 | ||
4199 | buf[cnt] = 0; | |
4200 | ||
756d17ee | 4201 | /* |
4202 | * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid" | |
4203 | * to clean the filter quietly. | |
4204 | */ | |
457dc928 IM |
4205 | tmp = strstrip(buf); |
4206 | if (strlen(tmp) == 0) | |
756d17ee | 4207 | return 1; |
4208 | ||
457dc928 | 4209 | ret = strict_strtol(tmp, 10, &val); |
df4fc315 SR |
4210 | if (ret < 0) |
4211 | return ret; | |
4212 | ||
756d17ee | 4213 | ret = ftrace_pid_add(val); |
df4fc315 | 4214 | |
756d17ee | 4215 | return ret ? ret : cnt; |
4216 | } | |
df4fc315 | 4217 | |
756d17ee | 4218 | static int |
4219 | ftrace_pid_release(struct inode *inode, struct file *file) | |
4220 | { | |
4221 | if (file->f_mode & FMODE_READ) | |
4222 | seq_release(inode, file); | |
df4fc315 | 4223 | |
756d17ee | 4224 | return 0; |
df4fc315 SR |
4225 | } |
4226 | ||
5e2336a0 | 4227 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 4228 | .open = ftrace_pid_open, |
4229 | .write = ftrace_pid_write, | |
4230 | .read = seq_read, | |
4231 | .llseek = seq_lseek, | |
4232 | .release = ftrace_pid_release, | |
df4fc315 SR |
4233 | }; |
4234 | ||
4235 | static __init int ftrace_init_debugfs(void) | |
4236 | { | |
4237 | struct dentry *d_tracer; | |
df4fc315 SR |
4238 | |
4239 | d_tracer = tracing_init_dentry(); | |
4240 | if (!d_tracer) | |
4241 | return 0; | |
4242 | ||
4243 | ftrace_init_dyn_debugfs(d_tracer); | |
4244 | ||
5452af66 FW |
4245 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
4246 | NULL, &ftrace_pid_fops); | |
493762fc SR |
4247 | |
4248 | ftrace_profile_debugfs(d_tracer); | |
4249 | ||
df4fc315 SR |
4250 | return 0; |
4251 | } | |
df4fc315 SR |
4252 | fs_initcall(ftrace_init_debugfs); |
4253 | ||
a2bb6a3d | 4254 | /** |
81adbdc0 | 4255 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
4256 | * |
4257 | * This function should be used by panic code. It stops ftrace | |
4258 | * but in a not so nice way. If you need to simply kill ftrace | |
4259 | * from a non-atomic section, use ftrace_kill. | |
4260 | */ | |
81adbdc0 | 4261 | void ftrace_kill(void) |
a2bb6a3d SR |
4262 | { |
4263 | ftrace_disabled = 1; | |
4264 | ftrace_enabled = 0; | |
a2bb6a3d SR |
4265 | clear_ftrace_function(); |
4266 | } | |
4267 | ||
e0a413f6 SR |
4268 | /** |
4269 | * Test if ftrace is dead or not. | |
4270 | */ | |
4271 | int ftrace_is_dead(void) | |
4272 | { | |
4273 | return ftrace_disabled; | |
4274 | } | |
4275 | ||
16444a8a | 4276 | /** |
3d083395 SR |
4277 | * register_ftrace_function - register a function for profiling |
4278 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 4279 | * |
3d083395 SR |
4280 | * Register a function to be called by all functions in the |
4281 | * kernel. | |
4282 | * | |
4283 | * Note: @ops->func and all the functions it calls must be labeled | |
4284 | * with "notrace", otherwise it will go into a | |
4285 | * recursive loop. | |
16444a8a | 4286 | */ |
3d083395 | 4287 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 4288 | { |
45a4a237 | 4289 | int ret = -1; |
4eebcc81 | 4290 | |
e6ea44e9 | 4291 | mutex_lock(&ftrace_lock); |
e7d3737e | 4292 | |
45a4a237 SR |
4293 | if (unlikely(ftrace_disabled)) |
4294 | goto out_unlock; | |
4295 | ||
b0fc494f | 4296 | ret = __register_ftrace_function(ops); |
b848914c | 4297 | if (!ret) |
a1cd6173 | 4298 | ret = ftrace_startup(ops, 0); |
b848914c | 4299 | |
b0fc494f | 4300 | |
45a4a237 | 4301 | out_unlock: |
e6ea44e9 | 4302 | mutex_unlock(&ftrace_lock); |
b0fc494f | 4303 | return ret; |
3d083395 | 4304 | } |
cdbe61bf | 4305 | EXPORT_SYMBOL_GPL(register_ftrace_function); |
3d083395 SR |
4306 | |
4307 | /** | |
32632920 | 4308 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
4309 | * @ops - ops structure that holds the function to unregister |
4310 | * | |
4311 | * Unregister a function that was added to be called by ftrace profiling. | |
4312 | */ | |
4313 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
4314 | { | |
4315 | int ret; | |
4316 | ||
e6ea44e9 | 4317 | mutex_lock(&ftrace_lock); |
3d083395 | 4318 | ret = __unregister_ftrace_function(ops); |
b848914c SR |
4319 | if (!ret) |
4320 | ftrace_shutdown(ops, 0); | |
e6ea44e9 | 4321 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
4322 | |
4323 | return ret; | |
4324 | } | |
cdbe61bf | 4325 | EXPORT_SYMBOL_GPL(unregister_ftrace_function); |
b0fc494f | 4326 | |
e309b41d | 4327 | int |
b0fc494f | 4328 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
8d65af78 | 4329 | void __user *buffer, size_t *lenp, |
b0fc494f SR |
4330 | loff_t *ppos) |
4331 | { | |
45a4a237 | 4332 | int ret = -ENODEV; |
4eebcc81 | 4333 | |
e6ea44e9 | 4334 | mutex_lock(&ftrace_lock); |
b0fc494f | 4335 | |
45a4a237 SR |
4336 | if (unlikely(ftrace_disabled)) |
4337 | goto out; | |
4338 | ||
4339 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
b0fc494f | 4340 | |
a32c7765 | 4341 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
4342 | goto out; |
4343 | ||
a32c7765 | 4344 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f SR |
4345 | |
4346 | if (ftrace_enabled) { | |
4347 | ||
4348 | ftrace_startup_sysctl(); | |
4349 | ||
4350 | /* we are starting ftrace again */ | |
b848914c SR |
4351 | if (ftrace_ops_list != &ftrace_list_end) { |
4352 | if (ftrace_ops_list->next == &ftrace_list_end) | |
4353 | ftrace_trace_function = ftrace_ops_list->func; | |
b0fc494f | 4354 | else |
b848914c | 4355 | ftrace_trace_function = ftrace_ops_list_func; |
b0fc494f SR |
4356 | } |
4357 | ||
4358 | } else { | |
4359 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
4360 | ftrace_trace_function = ftrace_stub; | |
4361 | ||
4362 | ftrace_shutdown_sysctl(); | |
4363 | } | |
4364 | ||
4365 | out: | |
e6ea44e9 | 4366 | mutex_unlock(&ftrace_lock); |
3d083395 | 4367 | return ret; |
16444a8a | 4368 | } |
f17845e5 | 4369 | |
fb52607a | 4370 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 4371 | |
597af815 | 4372 | static int ftrace_graph_active; |
4a2b8dda | 4373 | static struct notifier_block ftrace_suspend_notifier; |
e7d3737e | 4374 | |
e49dc19c SR |
4375 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
4376 | { | |
4377 | return 0; | |
4378 | } | |
4379 | ||
287b6e68 FW |
4380 | /* The callbacks that hook a function */ |
4381 | trace_func_graph_ret_t ftrace_graph_return = | |
4382 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 4383 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
4384 | |
4385 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
4386 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
4387 | { | |
4388 | int i; | |
4389 | int ret = 0; | |
4390 | unsigned long flags; | |
4391 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
4392 | struct task_struct *g, *t; | |
4393 | ||
4394 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
4395 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
4396 | * sizeof(struct ftrace_ret_stack), | |
4397 | GFP_KERNEL); | |
4398 | if (!ret_stack_list[i]) { | |
4399 | start = 0; | |
4400 | end = i; | |
4401 | ret = -ENOMEM; | |
4402 | goto free; | |
4403 | } | |
4404 | } | |
4405 | ||
4406 | read_lock_irqsave(&tasklist_lock, flags); | |
4407 | do_each_thread(g, t) { | |
4408 | if (start == end) { | |
4409 | ret = -EAGAIN; | |
4410 | goto unlock; | |
4411 | } | |
4412 | ||
4413 | if (t->ret_stack == NULL) { | |
380c4b14 | 4414 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 4415 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
4416 | t->curr_ret_stack = -1; |
4417 | /* Make sure the tasks see the -1 first: */ | |
4418 | smp_wmb(); | |
4419 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
4420 | } |
4421 | } while_each_thread(g, t); | |
4422 | ||
4423 | unlock: | |
4424 | read_unlock_irqrestore(&tasklist_lock, flags); | |
4425 | free: | |
4426 | for (i = start; i < end; i++) | |
4427 | kfree(ret_stack_list[i]); | |
4428 | return ret; | |
4429 | } | |
4430 | ||
8aef2d28 | 4431 | static void |
38516ab5 SR |
4432 | ftrace_graph_probe_sched_switch(void *ignore, |
4433 | struct task_struct *prev, struct task_struct *next) | |
8aef2d28 SR |
4434 | { |
4435 | unsigned long long timestamp; | |
4436 | int index; | |
4437 | ||
be6f164a SR |
4438 | /* |
4439 | * Does the user want to count the time a function was asleep. | |
4440 | * If so, do not update the time stamps. | |
4441 | */ | |
4442 | if (trace_flags & TRACE_ITER_SLEEP_TIME) | |
4443 | return; | |
4444 | ||
8aef2d28 SR |
4445 | timestamp = trace_clock_local(); |
4446 | ||
4447 | prev->ftrace_timestamp = timestamp; | |
4448 | ||
4449 | /* only process tasks that we timestamped */ | |
4450 | if (!next->ftrace_timestamp) | |
4451 | return; | |
4452 | ||
4453 | /* | |
4454 | * Update all the counters in next to make up for the | |
4455 | * time next was sleeping. | |
4456 | */ | |
4457 | timestamp -= next->ftrace_timestamp; | |
4458 | ||
4459 | for (index = next->curr_ret_stack; index >= 0; index--) | |
4460 | next->ret_stack[index].calltime += timestamp; | |
4461 | } | |
4462 | ||
f201ae23 | 4463 | /* Allocate a return stack for each task */ |
fb52607a | 4464 | static int start_graph_tracing(void) |
f201ae23 FW |
4465 | { |
4466 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 4467 | int ret, cpu; |
f201ae23 FW |
4468 | |
4469 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
4470 | sizeof(struct ftrace_ret_stack *), | |
4471 | GFP_KERNEL); | |
4472 | ||
4473 | if (!ret_stack_list) | |
4474 | return -ENOMEM; | |
4475 | ||
5b058bcd | 4476 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
4477 | for_each_online_cpu(cpu) { |
4478 | if (!idle_task(cpu)->ret_stack) | |
868baf07 | 4479 | ftrace_graph_init_idle_task(idle_task(cpu), cpu); |
179c498a | 4480 | } |
5b058bcd | 4481 | |
f201ae23 FW |
4482 | do { |
4483 | ret = alloc_retstack_tasklist(ret_stack_list); | |
4484 | } while (ret == -EAGAIN); | |
4485 | ||
8aef2d28 | 4486 | if (!ret) { |
38516ab5 | 4487 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
8aef2d28 SR |
4488 | if (ret) |
4489 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
4490 | " probe to kernel_sched_switch\n"); | |
4491 | } | |
4492 | ||
f201ae23 FW |
4493 | kfree(ret_stack_list); |
4494 | return ret; | |
4495 | } | |
4496 | ||
4a2b8dda FW |
4497 | /* |
4498 | * Hibernation protection. | |
4499 | * The state of the current task is too much unstable during | |
4500 | * suspend/restore to disk. We want to protect against that. | |
4501 | */ | |
4502 | static int | |
4503 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
4504 | void *unused) | |
4505 | { | |
4506 | switch (state) { | |
4507 | case PM_HIBERNATION_PREPARE: | |
4508 | pause_graph_tracing(); | |
4509 | break; | |
4510 | ||
4511 | case PM_POST_HIBERNATION: | |
4512 | unpause_graph_tracing(); | |
4513 | break; | |
4514 | } | |
4515 | return NOTIFY_DONE; | |
4516 | } | |
4517 | ||
287b6e68 FW |
4518 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
4519 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 4520 | { |
e7d3737e FW |
4521 | int ret = 0; |
4522 | ||
e6ea44e9 | 4523 | mutex_lock(&ftrace_lock); |
e7d3737e | 4524 | |
05ce5818 | 4525 | /* we currently allow only one tracer registered at a time */ |
597af815 | 4526 | if (ftrace_graph_active) { |
05ce5818 SR |
4527 | ret = -EBUSY; |
4528 | goto out; | |
4529 | } | |
4530 | ||
4a2b8dda FW |
4531 | ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; |
4532 | register_pm_notifier(&ftrace_suspend_notifier); | |
4533 | ||
597af815 | 4534 | ftrace_graph_active++; |
fb52607a | 4535 | ret = start_graph_tracing(); |
f201ae23 | 4536 | if (ret) { |
597af815 | 4537 | ftrace_graph_active--; |
f201ae23 FW |
4538 | goto out; |
4539 | } | |
e53a6319 | 4540 | |
287b6e68 FW |
4541 | ftrace_graph_return = retfunc; |
4542 | ftrace_graph_entry = entryfunc; | |
e53a6319 | 4543 | |
a1cd6173 | 4544 | ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET); |
e7d3737e FW |
4545 | |
4546 | out: | |
e6ea44e9 | 4547 | mutex_unlock(&ftrace_lock); |
e7d3737e | 4548 | return ret; |
15e6cb36 FW |
4549 | } |
4550 | ||
fb52607a | 4551 | void unregister_ftrace_graph(void) |
15e6cb36 | 4552 | { |
e6ea44e9 | 4553 | mutex_lock(&ftrace_lock); |
e7d3737e | 4554 | |
597af815 | 4555 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
4556 | goto out; |
4557 | ||
597af815 | 4558 | ftrace_graph_active--; |
287b6e68 | 4559 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 4560 | ftrace_graph_entry = ftrace_graph_entry_stub; |
bd69c30b | 4561 | ftrace_shutdown(&global_ops, FTRACE_STOP_FUNC_RET); |
4a2b8dda | 4562 | unregister_pm_notifier(&ftrace_suspend_notifier); |
38516ab5 | 4563 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
e7d3737e | 4564 | |
2aad1b76 | 4565 | out: |
e6ea44e9 | 4566 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 4567 | } |
f201ae23 | 4568 | |
868baf07 SR |
4569 | static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack); |
4570 | ||
4571 | static void | |
4572 | graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack) | |
4573 | { | |
4574 | atomic_set(&t->tracing_graph_pause, 0); | |
4575 | atomic_set(&t->trace_overrun, 0); | |
4576 | t->ftrace_timestamp = 0; | |
25985edc | 4577 | /* make curr_ret_stack visible before we add the ret_stack */ |
868baf07 SR |
4578 | smp_wmb(); |
4579 | t->ret_stack = ret_stack; | |
4580 | } | |
4581 | ||
4582 | /* | |
4583 | * Allocate a return stack for the idle task. May be the first | |
4584 | * time through, or it may be done by CPU hotplug online. | |
4585 | */ | |
4586 | void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) | |
4587 | { | |
4588 | t->curr_ret_stack = -1; | |
4589 | /* | |
4590 | * The idle task has no parent, it either has its own | |
4591 | * stack or no stack at all. | |
4592 | */ | |
4593 | if (t->ret_stack) | |
4594 | WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu)); | |
4595 | ||
4596 | if (ftrace_graph_active) { | |
4597 | struct ftrace_ret_stack *ret_stack; | |
4598 | ||
4599 | ret_stack = per_cpu(idle_ret_stack, cpu); | |
4600 | if (!ret_stack) { | |
4601 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
4602 | * sizeof(struct ftrace_ret_stack), | |
4603 | GFP_KERNEL); | |
4604 | if (!ret_stack) | |
4605 | return; | |
4606 | per_cpu(idle_ret_stack, cpu) = ret_stack; | |
4607 | } | |
4608 | graph_init_task(t, ret_stack); | |
4609 | } | |
4610 | } | |
4611 | ||
f201ae23 | 4612 | /* Allocate a return stack for newly created task */ |
fb52607a | 4613 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 4614 | { |
84047e36 SR |
4615 | /* Make sure we do not use the parent ret_stack */ |
4616 | t->ret_stack = NULL; | |
ea14eb71 | 4617 | t->curr_ret_stack = -1; |
84047e36 | 4618 | |
597af815 | 4619 | if (ftrace_graph_active) { |
82310a32 SR |
4620 | struct ftrace_ret_stack *ret_stack; |
4621 | ||
4622 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
4623 | * sizeof(struct ftrace_ret_stack), |
4624 | GFP_KERNEL); | |
82310a32 | 4625 | if (!ret_stack) |
f201ae23 | 4626 | return; |
868baf07 | 4627 | graph_init_task(t, ret_stack); |
84047e36 | 4628 | } |
f201ae23 FW |
4629 | } |
4630 | ||
fb52607a | 4631 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 4632 | { |
eae849ca FW |
4633 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
4634 | ||
f201ae23 | 4635 | t->ret_stack = NULL; |
eae849ca FW |
4636 | /* NULL must become visible to IRQs before we free it: */ |
4637 | barrier(); | |
4638 | ||
4639 | kfree(ret_stack); | |
f201ae23 | 4640 | } |
14a866c5 SR |
4641 | |
4642 | void ftrace_graph_stop(void) | |
4643 | { | |
4644 | ftrace_stop(); | |
4645 | } | |
15e6cb36 | 4646 | #endif |