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Commit | Line | Data |
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16444a8a ACM |
1 | /* |
2 | * Infrastructure for profiling code inserted by 'gcc -pg'. | |
3 | * | |
4 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> | |
5 | * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com> | |
6 | * | |
7 | * Originally ported from the -rt patch by: | |
8 | * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com> | |
9 | * | |
10 | * Based on code in the latency_tracer, that is: | |
11 | * | |
12 | * Copyright (C) 2004-2006 Ingo Molnar | |
13 | * Copyright (C) 2004 William Lee Irwin III | |
14 | */ | |
15 | ||
3d083395 SR |
16 | #include <linux/stop_machine.h> |
17 | #include <linux/clocksource.h> | |
18 | #include <linux/kallsyms.h> | |
5072c59f | 19 | #include <linux/seq_file.h> |
4a2b8dda | 20 | #include <linux/suspend.h> |
5072c59f | 21 | #include <linux/debugfs.h> |
3d083395 | 22 | #include <linux/hardirq.h> |
2d8b820b | 23 | #include <linux/kthread.h> |
5072c59f | 24 | #include <linux/uaccess.h> |
56d82e00 | 25 | #include <linux/module.h> |
2d8b820b | 26 | #include <linux/ftrace.h> |
b0fc494f | 27 | #include <linux/sysctl.h> |
5a0e3ad6 | 28 | #include <linux/slab.h> |
5072c59f | 29 | #include <linux/ctype.h> |
68950619 | 30 | #include <linux/sort.h> |
3d083395 | 31 | #include <linux/list.h> |
59df055f | 32 | #include <linux/hash.h> |
3f379b03 | 33 | #include <linux/rcupdate.h> |
3d083395 | 34 | |
ad8d75ff | 35 | #include <trace/events/sched.h> |
8aef2d28 | 36 | |
2af15d6a | 37 | #include <asm/setup.h> |
395a59d0 | 38 | |
0706f1c4 | 39 | #include "trace_output.h" |
bac429f0 | 40 | #include "trace_stat.h" |
16444a8a | 41 | |
6912896e | 42 | #define FTRACE_WARN_ON(cond) \ |
0778d9ad SR |
43 | ({ \ |
44 | int ___r = cond; \ | |
45 | if (WARN_ON(___r)) \ | |
6912896e | 46 | ftrace_kill(); \ |
0778d9ad SR |
47 | ___r; \ |
48 | }) | |
6912896e SR |
49 | |
50 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
0778d9ad SR |
51 | ({ \ |
52 | int ___r = cond; \ | |
53 | if (WARN_ON_ONCE(___r)) \ | |
6912896e | 54 | ftrace_kill(); \ |
0778d9ad SR |
55 | ___r; \ |
56 | }) | |
6912896e | 57 | |
8fc0c701 SR |
58 | /* hash bits for specific function selection */ |
59 | #define FTRACE_HASH_BITS 7 | |
60 | #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS) | |
33dc9b12 SR |
61 | #define FTRACE_HASH_DEFAULT_BITS 10 |
62 | #define FTRACE_HASH_MAX_BITS 12 | |
8fc0c701 | 63 | |
4eebcc81 SR |
64 | /* ftrace_enabled is a method to turn ftrace on or off */ |
65 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 66 | static int last_ftrace_enabled; |
b0fc494f | 67 | |
60a7ecf4 SR |
68 | /* Quick disabling of function tracer. */ |
69 | int function_trace_stop; | |
70 | ||
756d17ee | 71 | /* List for set_ftrace_pid's pids. */ |
72 | LIST_HEAD(ftrace_pids); | |
73 | struct ftrace_pid { | |
74 | struct list_head list; | |
75 | struct pid *pid; | |
76 | }; | |
77 | ||
4eebcc81 SR |
78 | /* |
79 | * ftrace_disabled is set when an anomaly is discovered. | |
80 | * ftrace_disabled is much stronger than ftrace_enabled. | |
81 | */ | |
82 | static int ftrace_disabled __read_mostly; | |
83 | ||
52baf119 | 84 | static DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 85 | |
bd38c0e6 | 86 | static struct ftrace_ops ftrace_list_end __read_mostly = { |
fb9fb015 | 87 | .func = ftrace_stub, |
16444a8a ACM |
88 | }; |
89 | ||
b848914c SR |
90 | static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end; |
91 | static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end; | |
16444a8a | 92 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
6331c28c | 93 | static ftrace_func_t __ftrace_trace_function_delay __read_mostly = ftrace_stub; |
60a7ecf4 | 94 | ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub; |
df4fc315 | 95 | ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; |
2b499381 | 96 | static struct ftrace_ops global_ops; |
16444a8a | 97 | |
b848914c SR |
98 | static void |
99 | ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip); | |
100 | ||
3f379b03 | 101 | /* |
b848914c | 102 | * Traverse the ftrace_global_list, invoking all entries. The reason that we |
3f379b03 PM |
103 | * can use rcu_dereference_raw() is that elements removed from this list |
104 | * are simply leaked, so there is no need to interact with a grace-period | |
105 | * mechanism. The rcu_dereference_raw() calls are needed to handle | |
b848914c | 106 | * concurrent insertions into the ftrace_global_list. |
3f379b03 PM |
107 | * |
108 | * Silly Alpha and silly pointer-speculation compiler optimizations! | |
109 | */ | |
b848914c SR |
110 | static void ftrace_global_list_func(unsigned long ip, |
111 | unsigned long parent_ip) | |
16444a8a | 112 | { |
b1cff0ad SR |
113 | struct ftrace_ops *op; |
114 | ||
115 | if (unlikely(trace_recursion_test(TRACE_GLOBAL_BIT))) | |
116 | return; | |
16444a8a | 117 | |
b1cff0ad SR |
118 | trace_recursion_set(TRACE_GLOBAL_BIT); |
119 | op = rcu_dereference_raw(ftrace_global_list); /*see above*/ | |
16444a8a | 120 | while (op != &ftrace_list_end) { |
16444a8a | 121 | op->func(ip, parent_ip); |
3f379b03 | 122 | op = rcu_dereference_raw(op->next); /*see above*/ |
16444a8a | 123 | }; |
b1cff0ad | 124 | trace_recursion_clear(TRACE_GLOBAL_BIT); |
16444a8a ACM |
125 | } |
126 | ||
df4fc315 SR |
127 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip) |
128 | { | |
0ef8cde5 | 129 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
130 | return; |
131 | ||
132 | ftrace_pid_function(ip, parent_ip); | |
133 | } | |
134 | ||
135 | static void set_ftrace_pid_function(ftrace_func_t func) | |
136 | { | |
137 | /* do not set ftrace_pid_function to itself! */ | |
138 | if (func != ftrace_pid_func) | |
139 | ftrace_pid_function = func; | |
140 | } | |
141 | ||
16444a8a | 142 | /** |
3d083395 | 143 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 144 | * |
3d083395 SR |
145 | * This NULLs the ftrace function and in essence stops |
146 | * tracing. There may be lag | |
16444a8a | 147 | */ |
3d083395 | 148 | void clear_ftrace_function(void) |
16444a8a | 149 | { |
3d083395 | 150 | ftrace_trace_function = ftrace_stub; |
60a7ecf4 | 151 | __ftrace_trace_function = ftrace_stub; |
6331c28c | 152 | __ftrace_trace_function_delay = ftrace_stub; |
df4fc315 | 153 | ftrace_pid_function = ftrace_stub; |
3d083395 SR |
154 | } |
155 | ||
60a7ecf4 SR |
156 | #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
157 | /* | |
158 | * For those archs that do not test ftrace_trace_stop in their | |
159 | * mcount call site, we need to do it from C. | |
160 | */ | |
161 | static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip) | |
162 | { | |
163 | if (function_trace_stop) | |
164 | return; | |
165 | ||
166 | __ftrace_trace_function(ip, parent_ip); | |
167 | } | |
168 | #endif | |
169 | ||
2b499381 | 170 | static void update_global_ops(void) |
491d0dcf SR |
171 | { |
172 | ftrace_func_t func; | |
173 | ||
174 | /* | |
175 | * If there's only one function registered, then call that | |
176 | * function directly. Otherwise, we need to iterate over the | |
177 | * registered callers. | |
178 | */ | |
b848914c SR |
179 | if (ftrace_global_list == &ftrace_list_end || |
180 | ftrace_global_list->next == &ftrace_list_end) | |
181 | func = ftrace_global_list->func; | |
491d0dcf | 182 | else |
b848914c | 183 | func = ftrace_global_list_func; |
491d0dcf SR |
184 | |
185 | /* If we filter on pids, update to use the pid function */ | |
186 | if (!list_empty(&ftrace_pids)) { | |
187 | set_ftrace_pid_function(func); | |
188 | func = ftrace_pid_func; | |
189 | } | |
2b499381 SR |
190 | |
191 | global_ops.func = func; | |
192 | } | |
193 | ||
194 | static void update_ftrace_function(void) | |
195 | { | |
196 | ftrace_func_t func; | |
197 | ||
198 | update_global_ops(); | |
199 | ||
cdbe61bf SR |
200 | /* |
201 | * If we are at the end of the list and this ops is | |
202 | * not dynamic, then have the mcount trampoline call | |
203 | * the function directly | |
204 | */ | |
b848914c | 205 | if (ftrace_ops_list == &ftrace_list_end || |
cdbe61bf SR |
206 | (ftrace_ops_list->next == &ftrace_list_end && |
207 | !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC))) | |
b848914c SR |
208 | func = ftrace_ops_list->func; |
209 | else | |
210 | func = ftrace_ops_list_func; | |
2b499381 | 211 | |
491d0dcf SR |
212 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
213 | ftrace_trace_function = func; | |
6331c28c SR |
214 | #else |
215 | #ifdef CONFIG_DYNAMIC_FTRACE | |
216 | /* do not update till all functions have been modified */ | |
217 | __ftrace_trace_function_delay = func; | |
491d0dcf SR |
218 | #else |
219 | __ftrace_trace_function = func; | |
6331c28c | 220 | #endif |
491d0dcf SR |
221 | ftrace_trace_function = ftrace_test_stop_func; |
222 | #endif | |
223 | } | |
224 | ||
2b499381 | 225 | static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
3d083395 | 226 | { |
2b499381 | 227 | ops->next = *list; |
16444a8a | 228 | /* |
b848914c | 229 | * We are entering ops into the list but another |
16444a8a ACM |
230 | * CPU might be walking that list. We need to make sure |
231 | * the ops->next pointer is valid before another CPU sees | |
b848914c | 232 | * the ops pointer included into the list. |
16444a8a | 233 | */ |
2b499381 | 234 | rcu_assign_pointer(*list, ops); |
16444a8a ACM |
235 | } |
236 | ||
2b499381 | 237 | static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
16444a8a | 238 | { |
16444a8a | 239 | struct ftrace_ops **p; |
16444a8a ACM |
240 | |
241 | /* | |
3d083395 SR |
242 | * If we are removing the last function, then simply point |
243 | * to the ftrace_stub. | |
16444a8a | 244 | */ |
2b499381 SR |
245 | if (*list == ops && ops->next == &ftrace_list_end) { |
246 | *list = &ftrace_list_end; | |
e6ea44e9 | 247 | return 0; |
16444a8a ACM |
248 | } |
249 | ||
2b499381 | 250 | for (p = list; *p != &ftrace_list_end; p = &(*p)->next) |
16444a8a ACM |
251 | if (*p == ops) |
252 | break; | |
253 | ||
e6ea44e9 SR |
254 | if (*p != ops) |
255 | return -1; | |
16444a8a ACM |
256 | |
257 | *p = (*p)->next; | |
2b499381 SR |
258 | return 0; |
259 | } | |
16444a8a | 260 | |
2b499381 SR |
261 | static int __register_ftrace_function(struct ftrace_ops *ops) |
262 | { | |
263 | if (ftrace_disabled) | |
264 | return -ENODEV; | |
265 | ||
266 | if (FTRACE_WARN_ON(ops == &global_ops)) | |
267 | return -EINVAL; | |
268 | ||
b848914c SR |
269 | if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) |
270 | return -EBUSY; | |
271 | ||
cdbe61bf SR |
272 | if (!core_kernel_data((unsigned long)ops)) |
273 | ops->flags |= FTRACE_OPS_FL_DYNAMIC; | |
274 | ||
b848914c SR |
275 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { |
276 | int first = ftrace_global_list == &ftrace_list_end; | |
277 | add_ftrace_ops(&ftrace_global_list, ops); | |
278 | ops->flags |= FTRACE_OPS_FL_ENABLED; | |
279 | if (first) | |
280 | add_ftrace_ops(&ftrace_ops_list, &global_ops); | |
281 | } else | |
282 | add_ftrace_ops(&ftrace_ops_list, ops); | |
283 | ||
2b499381 SR |
284 | if (ftrace_enabled) |
285 | update_ftrace_function(); | |
286 | ||
287 | return 0; | |
288 | } | |
289 | ||
290 | static int __unregister_ftrace_function(struct ftrace_ops *ops) | |
291 | { | |
292 | int ret; | |
293 | ||
294 | if (ftrace_disabled) | |
295 | return -ENODEV; | |
296 | ||
b848914c SR |
297 | if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) |
298 | return -EBUSY; | |
299 | ||
2b499381 SR |
300 | if (FTRACE_WARN_ON(ops == &global_ops)) |
301 | return -EINVAL; | |
302 | ||
b848914c SR |
303 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { |
304 | ret = remove_ftrace_ops(&ftrace_global_list, ops); | |
305 | if (!ret && ftrace_global_list == &ftrace_list_end) | |
306 | ret = remove_ftrace_ops(&ftrace_ops_list, &global_ops); | |
307 | if (!ret) | |
308 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; | |
309 | } else | |
310 | ret = remove_ftrace_ops(&ftrace_ops_list, ops); | |
311 | ||
2b499381 SR |
312 | if (ret < 0) |
313 | return ret; | |
b848914c | 314 | |
491d0dcf SR |
315 | if (ftrace_enabled) |
316 | update_ftrace_function(); | |
16444a8a | 317 | |
cdbe61bf SR |
318 | /* |
319 | * Dynamic ops may be freed, we must make sure that all | |
320 | * callers are done before leaving this function. | |
321 | */ | |
322 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) | |
323 | synchronize_sched(); | |
324 | ||
e6ea44e9 | 325 | return 0; |
3d083395 SR |
326 | } |
327 | ||
df4fc315 SR |
328 | static void ftrace_update_pid_func(void) |
329 | { | |
491d0dcf | 330 | /* Only do something if we are tracing something */ |
df4fc315 | 331 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 332 | return; |
df4fc315 | 333 | |
491d0dcf | 334 | update_ftrace_function(); |
df4fc315 SR |
335 | } |
336 | ||
493762fc SR |
337 | #ifdef CONFIG_FUNCTION_PROFILER |
338 | struct ftrace_profile { | |
339 | struct hlist_node node; | |
340 | unsigned long ip; | |
341 | unsigned long counter; | |
0706f1c4 SR |
342 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
343 | unsigned long long time; | |
e330b3bc | 344 | unsigned long long time_squared; |
0706f1c4 | 345 | #endif |
8fc0c701 SR |
346 | }; |
347 | ||
493762fc SR |
348 | struct ftrace_profile_page { |
349 | struct ftrace_profile_page *next; | |
350 | unsigned long index; | |
351 | struct ftrace_profile records[]; | |
d61f82d0 SR |
352 | }; |
353 | ||
cafb168a SR |
354 | struct ftrace_profile_stat { |
355 | atomic_t disabled; | |
356 | struct hlist_head *hash; | |
357 | struct ftrace_profile_page *pages; | |
358 | struct ftrace_profile_page *start; | |
359 | struct tracer_stat stat; | |
360 | }; | |
361 | ||
493762fc SR |
362 | #define PROFILE_RECORDS_SIZE \ |
363 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 364 | |
493762fc SR |
365 | #define PROFILES_PER_PAGE \ |
366 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 367 | |
fb9fb015 SR |
368 | static int ftrace_profile_bits __read_mostly; |
369 | static int ftrace_profile_enabled __read_mostly; | |
370 | ||
371 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
372 | static DEFINE_MUTEX(ftrace_profile_lock); |
373 | ||
cafb168a | 374 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc SR |
375 | |
376 | #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */ | |
377 | ||
bac429f0 SR |
378 | static void * |
379 | function_stat_next(void *v, int idx) | |
380 | { | |
493762fc SR |
381 | struct ftrace_profile *rec = v; |
382 | struct ftrace_profile_page *pg; | |
bac429f0 | 383 | |
493762fc | 384 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
385 | |
386 | again: | |
0296e425 LZ |
387 | if (idx != 0) |
388 | rec++; | |
389 | ||
bac429f0 SR |
390 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
391 | pg = pg->next; | |
392 | if (!pg) | |
393 | return NULL; | |
394 | rec = &pg->records[0]; | |
493762fc SR |
395 | if (!rec->counter) |
396 | goto again; | |
bac429f0 SR |
397 | } |
398 | ||
bac429f0 SR |
399 | return rec; |
400 | } | |
401 | ||
402 | static void *function_stat_start(struct tracer_stat *trace) | |
403 | { | |
cafb168a SR |
404 | struct ftrace_profile_stat *stat = |
405 | container_of(trace, struct ftrace_profile_stat, stat); | |
406 | ||
407 | if (!stat || !stat->start) | |
408 | return NULL; | |
409 | ||
410 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
411 | } |
412 | ||
0706f1c4 SR |
413 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
414 | /* function graph compares on total time */ | |
415 | static int function_stat_cmp(void *p1, void *p2) | |
416 | { | |
417 | struct ftrace_profile *a = p1; | |
418 | struct ftrace_profile *b = p2; | |
419 | ||
420 | if (a->time < b->time) | |
421 | return -1; | |
422 | if (a->time > b->time) | |
423 | return 1; | |
424 | else | |
425 | return 0; | |
426 | } | |
427 | #else | |
428 | /* not function graph compares against hits */ | |
bac429f0 SR |
429 | static int function_stat_cmp(void *p1, void *p2) |
430 | { | |
493762fc SR |
431 | struct ftrace_profile *a = p1; |
432 | struct ftrace_profile *b = p2; | |
bac429f0 SR |
433 | |
434 | if (a->counter < b->counter) | |
435 | return -1; | |
436 | if (a->counter > b->counter) | |
437 | return 1; | |
438 | else | |
439 | return 0; | |
440 | } | |
0706f1c4 | 441 | #endif |
bac429f0 SR |
442 | |
443 | static int function_stat_headers(struct seq_file *m) | |
444 | { | |
0706f1c4 | 445 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b | 446 | seq_printf(m, " Function " |
e330b3bc | 447 | "Hit Time Avg s^2\n" |
34886c8b | 448 | " -------- " |
e330b3bc | 449 | "--- ---- --- ---\n"); |
0706f1c4 | 450 | #else |
bac429f0 SR |
451 | seq_printf(m, " Function Hit\n" |
452 | " -------- ---\n"); | |
0706f1c4 | 453 | #endif |
bac429f0 SR |
454 | return 0; |
455 | } | |
456 | ||
457 | static int function_stat_show(struct seq_file *m, void *v) | |
458 | { | |
493762fc | 459 | struct ftrace_profile *rec = v; |
bac429f0 | 460 | char str[KSYM_SYMBOL_LEN]; |
3aaba20f | 461 | int ret = 0; |
0706f1c4 | 462 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
463 | static struct trace_seq s; |
464 | unsigned long long avg; | |
e330b3bc | 465 | unsigned long long stddev; |
0706f1c4 | 466 | #endif |
3aaba20f LZ |
467 | mutex_lock(&ftrace_profile_lock); |
468 | ||
469 | /* we raced with function_profile_reset() */ | |
470 | if (unlikely(rec->counter == 0)) { | |
471 | ret = -EBUSY; | |
472 | goto out; | |
473 | } | |
bac429f0 SR |
474 | |
475 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
0706f1c4 SR |
476 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
477 | ||
478 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
479 | seq_printf(m, " "); | |
34886c8b SR |
480 | avg = rec->time; |
481 | do_div(avg, rec->counter); | |
482 | ||
e330b3bc CD |
483 | /* Sample standard deviation (s^2) */ |
484 | if (rec->counter <= 1) | |
485 | stddev = 0; | |
486 | else { | |
487 | stddev = rec->time_squared - rec->counter * avg * avg; | |
488 | /* | |
489 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
490 | * trace_print_graph_duration will divide 1000 again. | |
491 | */ | |
492 | do_div(stddev, (rec->counter - 1) * 1000); | |
493 | } | |
494 | ||
34886c8b SR |
495 | trace_seq_init(&s); |
496 | trace_print_graph_duration(rec->time, &s); | |
497 | trace_seq_puts(&s, " "); | |
498 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
499 | trace_seq_puts(&s, " "); |
500 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 | 501 | trace_print_seq(m, &s); |
0706f1c4 SR |
502 | #endif |
503 | seq_putc(m, '\n'); | |
3aaba20f LZ |
504 | out: |
505 | mutex_unlock(&ftrace_profile_lock); | |
bac429f0 | 506 | |
3aaba20f | 507 | return ret; |
bac429f0 SR |
508 | } |
509 | ||
cafb168a | 510 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 511 | { |
493762fc | 512 | struct ftrace_profile_page *pg; |
bac429f0 | 513 | |
cafb168a | 514 | pg = stat->pages = stat->start; |
bac429f0 | 515 | |
493762fc SR |
516 | while (pg) { |
517 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
518 | pg->index = 0; | |
519 | pg = pg->next; | |
bac429f0 SR |
520 | } |
521 | ||
cafb168a | 522 | memset(stat->hash, 0, |
493762fc SR |
523 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
524 | } | |
bac429f0 | 525 | |
cafb168a | 526 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
527 | { |
528 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
529 | int functions; |
530 | int pages; | |
493762fc | 531 | int i; |
bac429f0 | 532 | |
493762fc | 533 | /* If we already allocated, do nothing */ |
cafb168a | 534 | if (stat->pages) |
493762fc | 535 | return 0; |
bac429f0 | 536 | |
cafb168a SR |
537 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
538 | if (!stat->pages) | |
493762fc | 539 | return -ENOMEM; |
bac429f0 | 540 | |
318e0a73 SR |
541 | #ifdef CONFIG_DYNAMIC_FTRACE |
542 | functions = ftrace_update_tot_cnt; | |
543 | #else | |
544 | /* | |
545 | * We do not know the number of functions that exist because | |
546 | * dynamic tracing is what counts them. With past experience | |
547 | * we have around 20K functions. That should be more than enough. | |
548 | * It is highly unlikely we will execute every function in | |
549 | * the kernel. | |
550 | */ | |
551 | functions = 20000; | |
552 | #endif | |
553 | ||
cafb168a | 554 | pg = stat->start = stat->pages; |
bac429f0 | 555 | |
318e0a73 SR |
556 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
557 | ||
558 | for (i = 0; i < pages; i++) { | |
493762fc | 559 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 560 | if (!pg->next) |
318e0a73 | 561 | goto out_free; |
493762fc SR |
562 | pg = pg->next; |
563 | } | |
564 | ||
565 | return 0; | |
318e0a73 SR |
566 | |
567 | out_free: | |
568 | pg = stat->start; | |
569 | while (pg) { | |
570 | unsigned long tmp = (unsigned long)pg; | |
571 | ||
572 | pg = pg->next; | |
573 | free_page(tmp); | |
574 | } | |
575 | ||
576 | free_page((unsigned long)stat->pages); | |
577 | stat->pages = NULL; | |
578 | stat->start = NULL; | |
579 | ||
580 | return -ENOMEM; | |
bac429f0 SR |
581 | } |
582 | ||
cafb168a | 583 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 584 | { |
cafb168a | 585 | struct ftrace_profile_stat *stat; |
493762fc | 586 | int size; |
bac429f0 | 587 | |
cafb168a SR |
588 | stat = &per_cpu(ftrace_profile_stats, cpu); |
589 | ||
590 | if (stat->hash) { | |
493762fc | 591 | /* If the profile is already created, simply reset it */ |
cafb168a | 592 | ftrace_profile_reset(stat); |
493762fc SR |
593 | return 0; |
594 | } | |
bac429f0 | 595 | |
493762fc SR |
596 | /* |
597 | * We are profiling all functions, but usually only a few thousand | |
598 | * functions are hit. We'll make a hash of 1024 items. | |
599 | */ | |
600 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 601 | |
cafb168a | 602 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
493762fc | 603 | |
cafb168a | 604 | if (!stat->hash) |
493762fc SR |
605 | return -ENOMEM; |
606 | ||
cafb168a SR |
607 | if (!ftrace_profile_bits) { |
608 | size--; | |
493762fc | 609 | |
cafb168a SR |
610 | for (; size; size >>= 1) |
611 | ftrace_profile_bits++; | |
612 | } | |
493762fc | 613 | |
318e0a73 | 614 | /* Preallocate the function profiling pages */ |
cafb168a SR |
615 | if (ftrace_profile_pages_init(stat) < 0) { |
616 | kfree(stat->hash); | |
617 | stat->hash = NULL; | |
493762fc SR |
618 | return -ENOMEM; |
619 | } | |
620 | ||
621 | return 0; | |
bac429f0 SR |
622 | } |
623 | ||
cafb168a SR |
624 | static int ftrace_profile_init(void) |
625 | { | |
626 | int cpu; | |
627 | int ret = 0; | |
628 | ||
629 | for_each_online_cpu(cpu) { | |
630 | ret = ftrace_profile_init_cpu(cpu); | |
631 | if (ret) | |
632 | break; | |
633 | } | |
634 | ||
635 | return ret; | |
636 | } | |
637 | ||
493762fc | 638 | /* interrupts must be disabled */ |
cafb168a SR |
639 | static struct ftrace_profile * |
640 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 641 | { |
493762fc | 642 | struct ftrace_profile *rec; |
bac429f0 SR |
643 | struct hlist_head *hhd; |
644 | struct hlist_node *n; | |
bac429f0 SR |
645 | unsigned long key; |
646 | ||
bac429f0 | 647 | key = hash_long(ip, ftrace_profile_bits); |
cafb168a | 648 | hhd = &stat->hash[key]; |
bac429f0 SR |
649 | |
650 | if (hlist_empty(hhd)) | |
651 | return NULL; | |
652 | ||
bac429f0 SR |
653 | hlist_for_each_entry_rcu(rec, n, hhd, node) { |
654 | if (rec->ip == ip) | |
493762fc SR |
655 | return rec; |
656 | } | |
657 | ||
658 | return NULL; | |
659 | } | |
660 | ||
cafb168a SR |
661 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
662 | struct ftrace_profile *rec) | |
493762fc SR |
663 | { |
664 | unsigned long key; | |
665 | ||
666 | key = hash_long(rec->ip, ftrace_profile_bits); | |
cafb168a | 667 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
668 | } |
669 | ||
318e0a73 SR |
670 | /* |
671 | * The memory is already allocated, this simply finds a new record to use. | |
672 | */ | |
493762fc | 673 | static struct ftrace_profile * |
318e0a73 | 674 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
675 | { |
676 | struct ftrace_profile *rec = NULL; | |
677 | ||
318e0a73 | 678 | /* prevent recursion (from NMIs) */ |
cafb168a | 679 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
680 | goto out; |
681 | ||
493762fc | 682 | /* |
318e0a73 SR |
683 | * Try to find the function again since an NMI |
684 | * could have added it | |
493762fc | 685 | */ |
cafb168a | 686 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 687 | if (rec) |
cafb168a | 688 | goto out; |
493762fc | 689 | |
cafb168a SR |
690 | if (stat->pages->index == PROFILES_PER_PAGE) { |
691 | if (!stat->pages->next) | |
692 | goto out; | |
693 | stat->pages = stat->pages->next; | |
bac429f0 | 694 | } |
493762fc | 695 | |
cafb168a | 696 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 697 | rec->ip = ip; |
cafb168a | 698 | ftrace_add_profile(stat, rec); |
493762fc | 699 | |
bac429f0 | 700 | out: |
cafb168a | 701 | atomic_dec(&stat->disabled); |
bac429f0 SR |
702 | |
703 | return rec; | |
704 | } | |
705 | ||
706 | static void | |
707 | function_profile_call(unsigned long ip, unsigned long parent_ip) | |
708 | { | |
cafb168a | 709 | struct ftrace_profile_stat *stat; |
493762fc | 710 | struct ftrace_profile *rec; |
bac429f0 SR |
711 | unsigned long flags; |
712 | ||
713 | if (!ftrace_profile_enabled) | |
714 | return; | |
715 | ||
716 | local_irq_save(flags); | |
cafb168a SR |
717 | |
718 | stat = &__get_cpu_var(ftrace_profile_stats); | |
0f6ce3de | 719 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
720 | goto out; |
721 | ||
722 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 723 | if (!rec) { |
318e0a73 | 724 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
725 | if (!rec) |
726 | goto out; | |
727 | } | |
bac429f0 SR |
728 | |
729 | rec->counter++; | |
730 | out: | |
731 | local_irq_restore(flags); | |
732 | } | |
733 | ||
0706f1c4 SR |
734 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
735 | static int profile_graph_entry(struct ftrace_graph_ent *trace) | |
736 | { | |
737 | function_profile_call(trace->func, 0); | |
738 | return 1; | |
739 | } | |
740 | ||
741 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
742 | { | |
cafb168a | 743 | struct ftrace_profile_stat *stat; |
a2a16d6a | 744 | unsigned long long calltime; |
0706f1c4 | 745 | struct ftrace_profile *rec; |
cafb168a | 746 | unsigned long flags; |
0706f1c4 SR |
747 | |
748 | local_irq_save(flags); | |
cafb168a | 749 | stat = &__get_cpu_var(ftrace_profile_stats); |
0f6ce3de | 750 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
751 | goto out; |
752 | ||
37e44bc5 SR |
753 | /* If the calltime was zero'd ignore it */ |
754 | if (!trace->calltime) | |
755 | goto out; | |
756 | ||
a2a16d6a SR |
757 | calltime = trace->rettime - trace->calltime; |
758 | ||
759 | if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) { | |
760 | int index; | |
761 | ||
762 | index = trace->depth; | |
763 | ||
764 | /* Append this call time to the parent time to subtract */ | |
765 | if (index) | |
766 | current->ret_stack[index - 1].subtime += calltime; | |
767 | ||
768 | if (current->ret_stack[index].subtime < calltime) | |
769 | calltime -= current->ret_stack[index].subtime; | |
770 | else | |
771 | calltime = 0; | |
772 | } | |
773 | ||
cafb168a | 774 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 775 | if (rec) { |
a2a16d6a | 776 | rec->time += calltime; |
e330b3bc CD |
777 | rec->time_squared += calltime * calltime; |
778 | } | |
a2a16d6a | 779 | |
cafb168a | 780 | out: |
0706f1c4 SR |
781 | local_irq_restore(flags); |
782 | } | |
783 | ||
784 | static int register_ftrace_profiler(void) | |
785 | { | |
786 | return register_ftrace_graph(&profile_graph_return, | |
787 | &profile_graph_entry); | |
788 | } | |
789 | ||
790 | static void unregister_ftrace_profiler(void) | |
791 | { | |
792 | unregister_ftrace_graph(); | |
793 | } | |
794 | #else | |
bd38c0e6 | 795 | static struct ftrace_ops ftrace_profile_ops __read_mostly = { |
fb9fb015 | 796 | .func = function_profile_call, |
bac429f0 SR |
797 | }; |
798 | ||
0706f1c4 SR |
799 | static int register_ftrace_profiler(void) |
800 | { | |
801 | return register_ftrace_function(&ftrace_profile_ops); | |
802 | } | |
803 | ||
804 | static void unregister_ftrace_profiler(void) | |
805 | { | |
806 | unregister_ftrace_function(&ftrace_profile_ops); | |
807 | } | |
808 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
809 | ||
bac429f0 SR |
810 | static ssize_t |
811 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
812 | size_t cnt, loff_t *ppos) | |
813 | { | |
814 | unsigned long val; | |
bac429f0 SR |
815 | int ret; |
816 | ||
22fe9b54 PH |
817 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
818 | if (ret) | |
bac429f0 SR |
819 | return ret; |
820 | ||
821 | val = !!val; | |
822 | ||
823 | mutex_lock(&ftrace_profile_lock); | |
824 | if (ftrace_profile_enabled ^ val) { | |
825 | if (val) { | |
493762fc SR |
826 | ret = ftrace_profile_init(); |
827 | if (ret < 0) { | |
828 | cnt = ret; | |
829 | goto out; | |
830 | } | |
831 | ||
0706f1c4 SR |
832 | ret = register_ftrace_profiler(); |
833 | if (ret < 0) { | |
834 | cnt = ret; | |
835 | goto out; | |
836 | } | |
bac429f0 SR |
837 | ftrace_profile_enabled = 1; |
838 | } else { | |
839 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
840 | /* |
841 | * unregister_ftrace_profiler calls stop_machine | |
842 | * so this acts like an synchronize_sched. | |
843 | */ | |
0706f1c4 | 844 | unregister_ftrace_profiler(); |
bac429f0 SR |
845 | } |
846 | } | |
493762fc | 847 | out: |
bac429f0 SR |
848 | mutex_unlock(&ftrace_profile_lock); |
849 | ||
cf8517cf | 850 | *ppos += cnt; |
bac429f0 SR |
851 | |
852 | return cnt; | |
853 | } | |
854 | ||
493762fc SR |
855 | static ssize_t |
856 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
857 | size_t cnt, loff_t *ppos) | |
858 | { | |
fb9fb015 | 859 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
860 | int r; |
861 | ||
862 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
863 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
864 | } | |
865 | ||
bac429f0 SR |
866 | static const struct file_operations ftrace_profile_fops = { |
867 | .open = tracing_open_generic, | |
868 | .read = ftrace_profile_read, | |
869 | .write = ftrace_profile_write, | |
6038f373 | 870 | .llseek = default_llseek, |
bac429f0 SR |
871 | }; |
872 | ||
cafb168a SR |
873 | /* used to initialize the real stat files */ |
874 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
875 | .name = "functions", |
876 | .stat_start = function_stat_start, | |
877 | .stat_next = function_stat_next, | |
878 | .stat_cmp = function_stat_cmp, | |
879 | .stat_headers = function_stat_headers, | |
880 | .stat_show = function_stat_show | |
cafb168a SR |
881 | }; |
882 | ||
6ab5d668 | 883 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 | 884 | { |
cafb168a | 885 | struct ftrace_profile_stat *stat; |
bac429f0 | 886 | struct dentry *entry; |
cafb168a | 887 | char *name; |
bac429f0 | 888 | int ret; |
cafb168a SR |
889 | int cpu; |
890 | ||
891 | for_each_possible_cpu(cpu) { | |
892 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
893 | ||
894 | /* allocate enough for function name + cpu number */ | |
895 | name = kmalloc(32, GFP_KERNEL); | |
896 | if (!name) { | |
897 | /* | |
898 | * The files created are permanent, if something happens | |
899 | * we still do not free memory. | |
900 | */ | |
cafb168a SR |
901 | WARN(1, |
902 | "Could not allocate stat file for cpu %d\n", | |
903 | cpu); | |
904 | return; | |
905 | } | |
906 | stat->stat = function_stats; | |
907 | snprintf(name, 32, "function%d", cpu); | |
908 | stat->stat.name = name; | |
909 | ret = register_stat_tracer(&stat->stat); | |
910 | if (ret) { | |
911 | WARN(1, | |
912 | "Could not register function stat for cpu %d\n", | |
913 | cpu); | |
914 | kfree(name); | |
915 | return; | |
916 | } | |
bac429f0 SR |
917 | } |
918 | ||
919 | entry = debugfs_create_file("function_profile_enabled", 0644, | |
920 | d_tracer, NULL, &ftrace_profile_fops); | |
921 | if (!entry) | |
922 | pr_warning("Could not create debugfs " | |
923 | "'function_profile_enabled' entry\n"); | |
924 | } | |
925 | ||
bac429f0 | 926 | #else /* CONFIG_FUNCTION_PROFILER */ |
6ab5d668 | 927 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 SR |
928 | { |
929 | } | |
bac429f0 SR |
930 | #endif /* CONFIG_FUNCTION_PROFILER */ |
931 | ||
493762fc SR |
932 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; |
933 | ||
934 | #ifdef CONFIG_DYNAMIC_FTRACE | |
935 | ||
936 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD | |
937 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
938 | #endif | |
939 | ||
940 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; | |
941 | ||
942 | struct ftrace_func_probe { | |
943 | struct hlist_node node; | |
944 | struct ftrace_probe_ops *ops; | |
945 | unsigned long flags; | |
946 | unsigned long ip; | |
947 | void *data; | |
948 | struct rcu_head rcu; | |
949 | }; | |
950 | ||
b448c4e3 SR |
951 | struct ftrace_func_entry { |
952 | struct hlist_node hlist; | |
953 | unsigned long ip; | |
954 | }; | |
955 | ||
956 | struct ftrace_hash { | |
957 | unsigned long size_bits; | |
958 | struct hlist_head *buckets; | |
959 | unsigned long count; | |
07fd5515 | 960 | struct rcu_head rcu; |
b448c4e3 SR |
961 | }; |
962 | ||
33dc9b12 SR |
963 | /* |
964 | * We make these constant because no one should touch them, | |
965 | * but they are used as the default "empty hash", to avoid allocating | |
966 | * it all the time. These are in a read only section such that if | |
967 | * anyone does try to modify it, it will cause an exception. | |
968 | */ | |
969 | static const struct hlist_head empty_buckets[1]; | |
970 | static const struct ftrace_hash empty_hash = { | |
971 | .buckets = (struct hlist_head *)empty_buckets, | |
1cf41dd7 | 972 | }; |
33dc9b12 | 973 | #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) |
493762fc | 974 | |
2b499381 | 975 | static struct ftrace_ops global_ops = { |
f45948e8 | 976 | .func = ftrace_stub, |
33dc9b12 SR |
977 | .notrace_hash = EMPTY_HASH, |
978 | .filter_hash = EMPTY_HASH, | |
f45948e8 SR |
979 | }; |
980 | ||
493762fc SR |
981 | static DEFINE_MUTEX(ftrace_regex_lock); |
982 | ||
983 | struct ftrace_page { | |
984 | struct ftrace_page *next; | |
a7900875 | 985 | struct dyn_ftrace *records; |
493762fc | 986 | int index; |
a7900875 | 987 | int size; |
493762fc SR |
988 | }; |
989 | ||
85ae32ae SR |
990 | static struct ftrace_page *ftrace_new_pgs; |
991 | ||
a7900875 SR |
992 | #define ENTRY_SIZE sizeof(struct dyn_ftrace) |
993 | #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE) | |
493762fc SR |
994 | |
995 | /* estimate from running different kernels */ | |
996 | #define NR_TO_INIT 10000 | |
997 | ||
998 | static struct ftrace_page *ftrace_pages_start; | |
999 | static struct ftrace_page *ftrace_pages; | |
1000 | ||
b448c4e3 SR |
1001 | static struct ftrace_func_entry * |
1002 | ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
1003 | { | |
1004 | unsigned long key; | |
1005 | struct ftrace_func_entry *entry; | |
1006 | struct hlist_head *hhd; | |
1007 | struct hlist_node *n; | |
1008 | ||
1009 | if (!hash->count) | |
1010 | return NULL; | |
1011 | ||
1012 | if (hash->size_bits > 0) | |
1013 | key = hash_long(ip, hash->size_bits); | |
1014 | else | |
1015 | key = 0; | |
1016 | ||
1017 | hhd = &hash->buckets[key]; | |
1018 | ||
1019 | hlist_for_each_entry_rcu(entry, n, hhd, hlist) { | |
1020 | if (entry->ip == ip) | |
1021 | return entry; | |
1022 | } | |
1023 | return NULL; | |
1024 | } | |
1025 | ||
33dc9b12 SR |
1026 | static void __add_hash_entry(struct ftrace_hash *hash, |
1027 | struct ftrace_func_entry *entry) | |
b448c4e3 | 1028 | { |
b448c4e3 SR |
1029 | struct hlist_head *hhd; |
1030 | unsigned long key; | |
1031 | ||
b448c4e3 | 1032 | if (hash->size_bits) |
33dc9b12 | 1033 | key = hash_long(entry->ip, hash->size_bits); |
b448c4e3 SR |
1034 | else |
1035 | key = 0; | |
1036 | ||
b448c4e3 SR |
1037 | hhd = &hash->buckets[key]; |
1038 | hlist_add_head(&entry->hlist, hhd); | |
1039 | hash->count++; | |
33dc9b12 SR |
1040 | } |
1041 | ||
1042 | static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip) | |
1043 | { | |
1044 | struct ftrace_func_entry *entry; | |
1045 | ||
1046 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1047 | if (!entry) | |
1048 | return -ENOMEM; | |
1049 | ||
1050 | entry->ip = ip; | |
1051 | __add_hash_entry(hash, entry); | |
b448c4e3 SR |
1052 | |
1053 | return 0; | |
1054 | } | |
1055 | ||
1056 | static void | |
33dc9b12 | 1057 | free_hash_entry(struct ftrace_hash *hash, |
b448c4e3 SR |
1058 | struct ftrace_func_entry *entry) |
1059 | { | |
1060 | hlist_del(&entry->hlist); | |
1061 | kfree(entry); | |
1062 | hash->count--; | |
1063 | } | |
1064 | ||
33dc9b12 SR |
1065 | static void |
1066 | remove_hash_entry(struct ftrace_hash *hash, | |
1067 | struct ftrace_func_entry *entry) | |
1068 | { | |
1069 | hlist_del(&entry->hlist); | |
1070 | hash->count--; | |
1071 | } | |
1072 | ||
b448c4e3 SR |
1073 | static void ftrace_hash_clear(struct ftrace_hash *hash) |
1074 | { | |
1075 | struct hlist_head *hhd; | |
1076 | struct hlist_node *tp, *tn; | |
1077 | struct ftrace_func_entry *entry; | |
1078 | int size = 1 << hash->size_bits; | |
1079 | int i; | |
1080 | ||
33dc9b12 SR |
1081 | if (!hash->count) |
1082 | return; | |
1083 | ||
b448c4e3 SR |
1084 | for (i = 0; i < size; i++) { |
1085 | hhd = &hash->buckets[i]; | |
1086 | hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist) | |
33dc9b12 | 1087 | free_hash_entry(hash, entry); |
b448c4e3 SR |
1088 | } |
1089 | FTRACE_WARN_ON(hash->count); | |
1090 | } | |
1091 | ||
33dc9b12 SR |
1092 | static void free_ftrace_hash(struct ftrace_hash *hash) |
1093 | { | |
1094 | if (!hash || hash == EMPTY_HASH) | |
1095 | return; | |
1096 | ftrace_hash_clear(hash); | |
1097 | kfree(hash->buckets); | |
1098 | kfree(hash); | |
1099 | } | |
1100 | ||
07fd5515 SR |
1101 | static void __free_ftrace_hash_rcu(struct rcu_head *rcu) |
1102 | { | |
1103 | struct ftrace_hash *hash; | |
1104 | ||
1105 | hash = container_of(rcu, struct ftrace_hash, rcu); | |
1106 | free_ftrace_hash(hash); | |
1107 | } | |
1108 | ||
1109 | static void free_ftrace_hash_rcu(struct ftrace_hash *hash) | |
1110 | { | |
1111 | if (!hash || hash == EMPTY_HASH) | |
1112 | return; | |
1113 | call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu); | |
1114 | } | |
1115 | ||
33dc9b12 SR |
1116 | static struct ftrace_hash *alloc_ftrace_hash(int size_bits) |
1117 | { | |
1118 | struct ftrace_hash *hash; | |
1119 | int size; | |
1120 | ||
1121 | hash = kzalloc(sizeof(*hash), GFP_KERNEL); | |
1122 | if (!hash) | |
1123 | return NULL; | |
1124 | ||
1125 | size = 1 << size_bits; | |
1126 | hash->buckets = kzalloc(sizeof(*hash->buckets) * size, GFP_KERNEL); | |
1127 | ||
1128 | if (!hash->buckets) { | |
1129 | kfree(hash); | |
1130 | return NULL; | |
1131 | } | |
1132 | ||
1133 | hash->size_bits = size_bits; | |
1134 | ||
1135 | return hash; | |
1136 | } | |
1137 | ||
1138 | static struct ftrace_hash * | |
1139 | alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) | |
1140 | { | |
1141 | struct ftrace_func_entry *entry; | |
1142 | struct ftrace_hash *new_hash; | |
1143 | struct hlist_node *tp; | |
1144 | int size; | |
1145 | int ret; | |
1146 | int i; | |
1147 | ||
1148 | new_hash = alloc_ftrace_hash(size_bits); | |
1149 | if (!new_hash) | |
1150 | return NULL; | |
1151 | ||
1152 | /* Empty hash? */ | |
1153 | if (!hash || !hash->count) | |
1154 | return new_hash; | |
1155 | ||
1156 | size = 1 << hash->size_bits; | |
1157 | for (i = 0; i < size; i++) { | |
1158 | hlist_for_each_entry(entry, tp, &hash->buckets[i], hlist) { | |
1159 | ret = add_hash_entry(new_hash, entry->ip); | |
1160 | if (ret < 0) | |
1161 | goto free_hash; | |
1162 | } | |
1163 | } | |
1164 | ||
1165 | FTRACE_WARN_ON(new_hash->count != hash->count); | |
1166 | ||
1167 | return new_hash; | |
1168 | ||
1169 | free_hash: | |
1170 | free_ftrace_hash(new_hash); | |
1171 | return NULL; | |
1172 | } | |
1173 | ||
41fb61c2 SR |
1174 | static void |
1175 | ftrace_hash_rec_disable(struct ftrace_ops *ops, int filter_hash); | |
1176 | static void | |
1177 | ftrace_hash_rec_enable(struct ftrace_ops *ops, int filter_hash); | |
1178 | ||
33dc9b12 | 1179 | static int |
41fb61c2 SR |
1180 | ftrace_hash_move(struct ftrace_ops *ops, int enable, |
1181 | struct ftrace_hash **dst, struct ftrace_hash *src) | |
33dc9b12 SR |
1182 | { |
1183 | struct ftrace_func_entry *entry; | |
1184 | struct hlist_node *tp, *tn; | |
1185 | struct hlist_head *hhd; | |
07fd5515 SR |
1186 | struct ftrace_hash *old_hash; |
1187 | struct ftrace_hash *new_hash; | |
33dc9b12 SR |
1188 | unsigned long key; |
1189 | int size = src->count; | |
1190 | int bits = 0; | |
41fb61c2 | 1191 | int ret; |
33dc9b12 SR |
1192 | int i; |
1193 | ||
41fb61c2 SR |
1194 | /* |
1195 | * Remove the current set, update the hash and add | |
1196 | * them back. | |
1197 | */ | |
1198 | ftrace_hash_rec_disable(ops, enable); | |
1199 | ||
33dc9b12 SR |
1200 | /* |
1201 | * If the new source is empty, just free dst and assign it | |
1202 | * the empty_hash. | |
1203 | */ | |
1204 | if (!src->count) { | |
07fd5515 SR |
1205 | free_ftrace_hash_rcu(*dst); |
1206 | rcu_assign_pointer(*dst, EMPTY_HASH); | |
d4d34b98 SR |
1207 | /* still need to update the function records */ |
1208 | ret = 0; | |
1209 | goto out; | |
33dc9b12 SR |
1210 | } |
1211 | ||
33dc9b12 SR |
1212 | /* |
1213 | * Make the hash size about 1/2 the # found | |
1214 | */ | |
1215 | for (size /= 2; size; size >>= 1) | |
1216 | bits++; | |
1217 | ||
1218 | /* Don't allocate too much */ | |
1219 | if (bits > FTRACE_HASH_MAX_BITS) | |
1220 | bits = FTRACE_HASH_MAX_BITS; | |
1221 | ||
41fb61c2 | 1222 | ret = -ENOMEM; |
07fd5515 SR |
1223 | new_hash = alloc_ftrace_hash(bits); |
1224 | if (!new_hash) | |
41fb61c2 | 1225 | goto out; |
33dc9b12 SR |
1226 | |
1227 | size = 1 << src->size_bits; | |
1228 | for (i = 0; i < size; i++) { | |
1229 | hhd = &src->buckets[i]; | |
1230 | hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist) { | |
1231 | if (bits > 0) | |
1232 | key = hash_long(entry->ip, bits); | |
1233 | else | |
1234 | key = 0; | |
1235 | remove_hash_entry(src, entry); | |
07fd5515 | 1236 | __add_hash_entry(new_hash, entry); |
33dc9b12 SR |
1237 | } |
1238 | } | |
1239 | ||
07fd5515 SR |
1240 | old_hash = *dst; |
1241 | rcu_assign_pointer(*dst, new_hash); | |
1242 | free_ftrace_hash_rcu(old_hash); | |
1243 | ||
41fb61c2 SR |
1244 | ret = 0; |
1245 | out: | |
1246 | /* | |
1247 | * Enable regardless of ret: | |
1248 | * On success, we enable the new hash. | |
1249 | * On failure, we re-enable the original hash. | |
1250 | */ | |
1251 | ftrace_hash_rec_enable(ops, enable); | |
1252 | ||
1253 | return ret; | |
33dc9b12 SR |
1254 | } |
1255 | ||
b848914c SR |
1256 | /* |
1257 | * Test the hashes for this ops to see if we want to call | |
1258 | * the ops->func or not. | |
1259 | * | |
1260 | * It's a match if the ip is in the ops->filter_hash or | |
1261 | * the filter_hash does not exist or is empty, | |
1262 | * AND | |
1263 | * the ip is not in the ops->notrace_hash. | |
cdbe61bf SR |
1264 | * |
1265 | * This needs to be called with preemption disabled as | |
1266 | * the hashes are freed with call_rcu_sched(). | |
b848914c SR |
1267 | */ |
1268 | static int | |
1269 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip) | |
1270 | { | |
1271 | struct ftrace_hash *filter_hash; | |
1272 | struct ftrace_hash *notrace_hash; | |
1273 | int ret; | |
1274 | ||
b848914c SR |
1275 | filter_hash = rcu_dereference_raw(ops->filter_hash); |
1276 | notrace_hash = rcu_dereference_raw(ops->notrace_hash); | |
1277 | ||
1278 | if ((!filter_hash || !filter_hash->count || | |
1279 | ftrace_lookup_ip(filter_hash, ip)) && | |
1280 | (!notrace_hash || !notrace_hash->count || | |
1281 | !ftrace_lookup_ip(notrace_hash, ip))) | |
1282 | ret = 1; | |
1283 | else | |
1284 | ret = 0; | |
b848914c SR |
1285 | |
1286 | return ret; | |
1287 | } | |
1288 | ||
493762fc SR |
1289 | /* |
1290 | * This is a double for. Do not use 'break' to break out of the loop, | |
1291 | * you must use a goto. | |
1292 | */ | |
1293 | #define do_for_each_ftrace_rec(pg, rec) \ | |
1294 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
1295 | int _____i; \ | |
1296 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
1297 | rec = &pg->records[_____i]; | |
1298 | ||
1299 | #define while_for_each_ftrace_rec() \ | |
1300 | } \ | |
1301 | } | |
1302 | ||
c88fd863 SR |
1303 | /** |
1304 | * ftrace_location - return true if the ip giving is a traced location | |
1305 | * @ip: the instruction pointer to check | |
1306 | * | |
1307 | * Returns 1 if @ip given is a pointer to a ftrace location. | |
1308 | * That is, the instruction that is either a NOP or call to | |
1309 | * the function tracer. It checks the ftrace internal tables to | |
1310 | * determine if the address belongs or not. | |
1311 | */ | |
1312 | int ftrace_location(unsigned long ip) | |
1313 | { | |
1314 | struct ftrace_page *pg; | |
1315 | struct dyn_ftrace *rec; | |
1316 | ||
1317 | do_for_each_ftrace_rec(pg, rec) { | |
1318 | if (rec->ip == ip) | |
1319 | return 1; | |
1320 | } while_for_each_ftrace_rec(); | |
1321 | ||
1322 | return 0; | |
1323 | } | |
1324 | ||
ed926f9b SR |
1325 | static void __ftrace_hash_rec_update(struct ftrace_ops *ops, |
1326 | int filter_hash, | |
1327 | bool inc) | |
1328 | { | |
1329 | struct ftrace_hash *hash; | |
1330 | struct ftrace_hash *other_hash; | |
1331 | struct ftrace_page *pg; | |
1332 | struct dyn_ftrace *rec; | |
1333 | int count = 0; | |
1334 | int all = 0; | |
1335 | ||
1336 | /* Only update if the ops has been registered */ | |
1337 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
1338 | return; | |
1339 | ||
1340 | /* | |
1341 | * In the filter_hash case: | |
1342 | * If the count is zero, we update all records. | |
1343 | * Otherwise we just update the items in the hash. | |
1344 | * | |
1345 | * In the notrace_hash case: | |
1346 | * We enable the update in the hash. | |
1347 | * As disabling notrace means enabling the tracing, | |
1348 | * and enabling notrace means disabling, the inc variable | |
1349 | * gets inversed. | |
1350 | */ | |
1351 | if (filter_hash) { | |
1352 | hash = ops->filter_hash; | |
1353 | other_hash = ops->notrace_hash; | |
b848914c | 1354 | if (!hash || !hash->count) |
ed926f9b SR |
1355 | all = 1; |
1356 | } else { | |
1357 | inc = !inc; | |
1358 | hash = ops->notrace_hash; | |
1359 | other_hash = ops->filter_hash; | |
1360 | /* | |
1361 | * If the notrace hash has no items, | |
1362 | * then there's nothing to do. | |
1363 | */ | |
b848914c | 1364 | if (hash && !hash->count) |
ed926f9b SR |
1365 | return; |
1366 | } | |
1367 | ||
1368 | do_for_each_ftrace_rec(pg, rec) { | |
1369 | int in_other_hash = 0; | |
1370 | int in_hash = 0; | |
1371 | int match = 0; | |
1372 | ||
1373 | if (all) { | |
1374 | /* | |
1375 | * Only the filter_hash affects all records. | |
1376 | * Update if the record is not in the notrace hash. | |
1377 | */ | |
b848914c | 1378 | if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) |
ed926f9b SR |
1379 | match = 1; |
1380 | } else { | |
b848914c SR |
1381 | in_hash = hash && !!ftrace_lookup_ip(hash, rec->ip); |
1382 | in_other_hash = other_hash && !!ftrace_lookup_ip(other_hash, rec->ip); | |
ed926f9b SR |
1383 | |
1384 | /* | |
1385 | * | |
1386 | */ | |
1387 | if (filter_hash && in_hash && !in_other_hash) | |
1388 | match = 1; | |
1389 | else if (!filter_hash && in_hash && | |
1390 | (in_other_hash || !other_hash->count)) | |
1391 | match = 1; | |
1392 | } | |
1393 | if (!match) | |
1394 | continue; | |
1395 | ||
1396 | if (inc) { | |
1397 | rec->flags++; | |
1398 | if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == FTRACE_REF_MAX)) | |
1399 | return; | |
1400 | } else { | |
1401 | if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == 0)) | |
1402 | return; | |
1403 | rec->flags--; | |
1404 | } | |
1405 | count++; | |
1406 | /* Shortcut, if we handled all records, we are done. */ | |
1407 | if (!all && count == hash->count) | |
1408 | return; | |
1409 | } while_for_each_ftrace_rec(); | |
1410 | } | |
1411 | ||
1412 | static void ftrace_hash_rec_disable(struct ftrace_ops *ops, | |
1413 | int filter_hash) | |
1414 | { | |
1415 | __ftrace_hash_rec_update(ops, filter_hash, 0); | |
1416 | } | |
1417 | ||
1418 | static void ftrace_hash_rec_enable(struct ftrace_ops *ops, | |
1419 | int filter_hash) | |
1420 | { | |
1421 | __ftrace_hash_rec_update(ops, filter_hash, 1); | |
1422 | } | |
1423 | ||
e309b41d | 1424 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 1425 | { |
a7900875 SR |
1426 | if (ftrace_pages->index == ftrace_pages->size) { |
1427 | /* We should have allocated enough */ | |
1428 | if (WARN_ON(!ftrace_pages->next)) | |
1429 | return NULL; | |
3c1720f0 SR |
1430 | ftrace_pages = ftrace_pages->next; |
1431 | } | |
1432 | ||
1433 | return &ftrace_pages->records[ftrace_pages->index++]; | |
1434 | } | |
1435 | ||
08f5ac90 | 1436 | static struct dyn_ftrace * |
d61f82d0 | 1437 | ftrace_record_ip(unsigned long ip) |
3d083395 | 1438 | { |
08f5ac90 | 1439 | struct dyn_ftrace *rec; |
3d083395 | 1440 | |
f3c7ac40 | 1441 | if (ftrace_disabled) |
08f5ac90 | 1442 | return NULL; |
3d083395 | 1443 | |
08f5ac90 SR |
1444 | rec = ftrace_alloc_dyn_node(ip); |
1445 | if (!rec) | |
1446 | return NULL; | |
3d083395 | 1447 | |
08f5ac90 | 1448 | rec->ip = ip; |
3d083395 | 1449 | |
08f5ac90 | 1450 | return rec; |
3d083395 SR |
1451 | } |
1452 | ||
b17e8a37 SR |
1453 | static void print_ip_ins(const char *fmt, unsigned char *p) |
1454 | { | |
1455 | int i; | |
1456 | ||
1457 | printk(KERN_CONT "%s", fmt); | |
1458 | ||
1459 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
1460 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
1461 | } | |
1462 | ||
c88fd863 SR |
1463 | /** |
1464 | * ftrace_bug - report and shutdown function tracer | |
1465 | * @failed: The failed type (EFAULT, EINVAL, EPERM) | |
1466 | * @ip: The address that failed | |
1467 | * | |
1468 | * The arch code that enables or disables the function tracing | |
1469 | * can call ftrace_bug() when it has detected a problem in | |
1470 | * modifying the code. @failed should be one of either: | |
1471 | * EFAULT - if the problem happens on reading the @ip address | |
1472 | * EINVAL - if what is read at @ip is not what was expected | |
1473 | * EPERM - if the problem happens on writting to the @ip address | |
1474 | */ | |
1475 | void ftrace_bug(int failed, unsigned long ip) | |
b17e8a37 SR |
1476 | { |
1477 | switch (failed) { | |
1478 | case -EFAULT: | |
1479 | FTRACE_WARN_ON_ONCE(1); | |
1480 | pr_info("ftrace faulted on modifying "); | |
1481 | print_ip_sym(ip); | |
1482 | break; | |
1483 | case -EINVAL: | |
1484 | FTRACE_WARN_ON_ONCE(1); | |
1485 | pr_info("ftrace failed to modify "); | |
1486 | print_ip_sym(ip); | |
b17e8a37 | 1487 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
1488 | printk(KERN_CONT "\n"); |
1489 | break; | |
1490 | case -EPERM: | |
1491 | FTRACE_WARN_ON_ONCE(1); | |
1492 | pr_info("ftrace faulted on writing "); | |
1493 | print_ip_sym(ip); | |
1494 | break; | |
1495 | default: | |
1496 | FTRACE_WARN_ON_ONCE(1); | |
1497 | pr_info("ftrace faulted on unknown error "); | |
1498 | print_ip_sym(ip); | |
1499 | } | |
1500 | } | |
1501 | ||
3c1720f0 | 1502 | |
2cfa1978 MH |
1503 | /* Return 1 if the address range is reserved for ftrace */ |
1504 | int ftrace_text_reserved(void *start, void *end) | |
1505 | { | |
1506 | struct dyn_ftrace *rec; | |
1507 | struct ftrace_page *pg; | |
1508 | ||
1509 | do_for_each_ftrace_rec(pg, rec) { | |
1510 | if (rec->ip <= (unsigned long)end && | |
1511 | rec->ip + MCOUNT_INSN_SIZE > (unsigned long)start) | |
1512 | return 1; | |
1513 | } while_for_each_ftrace_rec(); | |
1514 | return 0; | |
1515 | } | |
1516 | ||
c88fd863 | 1517 | static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update) |
5072c59f | 1518 | { |
64fbcd16 | 1519 | unsigned long flag = 0UL; |
e7d3737e | 1520 | |
982c350b | 1521 | /* |
30fb6aa7 | 1522 | * If we are updating calls: |
982c350b | 1523 | * |
ed926f9b SR |
1524 | * If the record has a ref count, then we need to enable it |
1525 | * because someone is using it. | |
982c350b | 1526 | * |
ed926f9b SR |
1527 | * Otherwise we make sure its disabled. |
1528 | * | |
30fb6aa7 | 1529 | * If we are disabling calls, then disable all records that |
ed926f9b | 1530 | * are enabled. |
982c350b | 1531 | */ |
c88fd863 | 1532 | if (enable && (rec->flags & ~FTRACE_FL_MASK)) |
ed926f9b | 1533 | flag = FTRACE_FL_ENABLED; |
982c350b | 1534 | |
64fbcd16 XG |
1535 | /* If the state of this record hasn't changed, then do nothing */ |
1536 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
c88fd863 | 1537 | return FTRACE_UPDATE_IGNORE; |
982c350b | 1538 | |
64fbcd16 | 1539 | if (flag) { |
c88fd863 SR |
1540 | if (update) |
1541 | rec->flags |= FTRACE_FL_ENABLED; | |
1542 | return FTRACE_UPDATE_MAKE_CALL; | |
1543 | } | |
1544 | ||
1545 | if (update) | |
1546 | rec->flags &= ~FTRACE_FL_ENABLED; | |
1547 | ||
1548 | return FTRACE_UPDATE_MAKE_NOP; | |
1549 | } | |
1550 | ||
1551 | /** | |
1552 | * ftrace_update_record, set a record that now is tracing or not | |
1553 | * @rec: the record to update | |
1554 | * @enable: set to 1 if the record is tracing, zero to force disable | |
1555 | * | |
1556 | * The records that represent all functions that can be traced need | |
1557 | * to be updated when tracing has been enabled. | |
1558 | */ | |
1559 | int ftrace_update_record(struct dyn_ftrace *rec, int enable) | |
1560 | { | |
1561 | return ftrace_check_record(rec, enable, 1); | |
1562 | } | |
1563 | ||
1564 | /** | |
1565 | * ftrace_test_record, check if the record has been enabled or not | |
1566 | * @rec: the record to test | |
1567 | * @enable: set to 1 to check if enabled, 0 if it is disabled | |
1568 | * | |
1569 | * The arch code may need to test if a record is already set to | |
1570 | * tracing to determine how to modify the function code that it | |
1571 | * represents. | |
1572 | */ | |
1573 | int ftrace_test_record(struct dyn_ftrace *rec, int enable) | |
1574 | { | |
1575 | return ftrace_check_record(rec, enable, 0); | |
1576 | } | |
1577 | ||
1578 | static int | |
1579 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) | |
1580 | { | |
1581 | unsigned long ftrace_addr; | |
1582 | int ret; | |
1583 | ||
1584 | ftrace_addr = (unsigned long)FTRACE_ADDR; | |
1585 | ||
1586 | ret = ftrace_update_record(rec, enable); | |
1587 | ||
1588 | switch (ret) { | |
1589 | case FTRACE_UPDATE_IGNORE: | |
1590 | return 0; | |
1591 | ||
1592 | case FTRACE_UPDATE_MAKE_CALL: | |
64fbcd16 | 1593 | return ftrace_make_call(rec, ftrace_addr); |
c88fd863 SR |
1594 | |
1595 | case FTRACE_UPDATE_MAKE_NOP: | |
1596 | return ftrace_make_nop(NULL, rec, ftrace_addr); | |
5072c59f SR |
1597 | } |
1598 | ||
c88fd863 | 1599 | return -1; /* unknow ftrace bug */ |
5072c59f SR |
1600 | } |
1601 | ||
30fb6aa7 | 1602 | static void ftrace_replace_code(int update) |
3c1720f0 | 1603 | { |
3c1720f0 SR |
1604 | struct dyn_ftrace *rec; |
1605 | struct ftrace_page *pg; | |
6a24a244 | 1606 | int failed; |
3c1720f0 | 1607 | |
45a4a237 SR |
1608 | if (unlikely(ftrace_disabled)) |
1609 | return; | |
1610 | ||
265c831c | 1611 | do_for_each_ftrace_rec(pg, rec) { |
30fb6aa7 | 1612 | failed = __ftrace_replace_code(rec, update); |
fa9d13cf | 1613 | if (failed) { |
3279ba37 SR |
1614 | ftrace_bug(failed, rec->ip); |
1615 | /* Stop processing */ | |
1616 | return; | |
3c1720f0 | 1617 | } |
265c831c | 1618 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
1619 | } |
1620 | ||
c88fd863 SR |
1621 | struct ftrace_rec_iter { |
1622 | struct ftrace_page *pg; | |
1623 | int index; | |
1624 | }; | |
1625 | ||
1626 | /** | |
1627 | * ftrace_rec_iter_start, start up iterating over traced functions | |
1628 | * | |
1629 | * Returns an iterator handle that is used to iterate over all | |
1630 | * the records that represent address locations where functions | |
1631 | * are traced. | |
1632 | * | |
1633 | * May return NULL if no records are available. | |
1634 | */ | |
1635 | struct ftrace_rec_iter *ftrace_rec_iter_start(void) | |
1636 | { | |
1637 | /* | |
1638 | * We only use a single iterator. | |
1639 | * Protected by the ftrace_lock mutex. | |
1640 | */ | |
1641 | static struct ftrace_rec_iter ftrace_rec_iter; | |
1642 | struct ftrace_rec_iter *iter = &ftrace_rec_iter; | |
1643 | ||
1644 | iter->pg = ftrace_pages_start; | |
1645 | iter->index = 0; | |
1646 | ||
1647 | /* Could have empty pages */ | |
1648 | while (iter->pg && !iter->pg->index) | |
1649 | iter->pg = iter->pg->next; | |
1650 | ||
1651 | if (!iter->pg) | |
1652 | return NULL; | |
1653 | ||
1654 | return iter; | |
1655 | } | |
1656 | ||
1657 | /** | |
1658 | * ftrace_rec_iter_next, get the next record to process. | |
1659 | * @iter: The handle to the iterator. | |
1660 | * | |
1661 | * Returns the next iterator after the given iterator @iter. | |
1662 | */ | |
1663 | struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) | |
1664 | { | |
1665 | iter->index++; | |
1666 | ||
1667 | if (iter->index >= iter->pg->index) { | |
1668 | iter->pg = iter->pg->next; | |
1669 | iter->index = 0; | |
1670 | ||
1671 | /* Could have empty pages */ | |
1672 | while (iter->pg && !iter->pg->index) | |
1673 | iter->pg = iter->pg->next; | |
1674 | } | |
1675 | ||
1676 | if (!iter->pg) | |
1677 | return NULL; | |
1678 | ||
1679 | return iter; | |
1680 | } | |
1681 | ||
1682 | /** | |
1683 | * ftrace_rec_iter_record, get the record at the iterator location | |
1684 | * @iter: The current iterator location | |
1685 | * | |
1686 | * Returns the record that the current @iter is at. | |
1687 | */ | |
1688 | struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) | |
1689 | { | |
1690 | return &iter->pg->records[iter->index]; | |
1691 | } | |
1692 | ||
492a7ea5 | 1693 | static int |
31e88909 | 1694 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 SR |
1695 | { |
1696 | unsigned long ip; | |
593eb8a2 | 1697 | int ret; |
3c1720f0 SR |
1698 | |
1699 | ip = rec->ip; | |
1700 | ||
45a4a237 SR |
1701 | if (unlikely(ftrace_disabled)) |
1702 | return 0; | |
1703 | ||
25aac9dc | 1704 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 1705 | if (ret) { |
31e88909 | 1706 | ftrace_bug(ret, ip); |
492a7ea5 | 1707 | return 0; |
37ad5084 | 1708 | } |
492a7ea5 | 1709 | return 1; |
3c1720f0 SR |
1710 | } |
1711 | ||
000ab691 SR |
1712 | /* |
1713 | * archs can override this function if they must do something | |
1714 | * before the modifying code is performed. | |
1715 | */ | |
1716 | int __weak ftrace_arch_code_modify_prepare(void) | |
1717 | { | |
1718 | return 0; | |
1719 | } | |
1720 | ||
1721 | /* | |
1722 | * archs can override this function if they must do something | |
1723 | * after the modifying code is performed. | |
1724 | */ | |
1725 | int __weak ftrace_arch_code_modify_post_process(void) | |
1726 | { | |
1727 | return 0; | |
1728 | } | |
1729 | ||
e309b41d | 1730 | static int __ftrace_modify_code(void *data) |
3d083395 | 1731 | { |
d61f82d0 SR |
1732 | int *command = data; |
1733 | ||
30fb6aa7 | 1734 | if (*command & FTRACE_UPDATE_CALLS) |
d61f82d0 | 1735 | ftrace_replace_code(1); |
a3583244 | 1736 | else if (*command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
1737 | ftrace_replace_code(0); |
1738 | ||
1739 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
1740 | ftrace_update_ftrace_func(ftrace_trace_function); | |
1741 | ||
5a45cfe1 SR |
1742 | if (*command & FTRACE_START_FUNC_RET) |
1743 | ftrace_enable_ftrace_graph_caller(); | |
1744 | else if (*command & FTRACE_STOP_FUNC_RET) | |
1745 | ftrace_disable_ftrace_graph_caller(); | |
1746 | ||
d61f82d0 | 1747 | return 0; |
3d083395 SR |
1748 | } |
1749 | ||
c88fd863 SR |
1750 | /** |
1751 | * ftrace_run_stop_machine, go back to the stop machine method | |
1752 | * @command: The command to tell ftrace what to do | |
1753 | * | |
1754 | * If an arch needs to fall back to the stop machine method, the | |
1755 | * it can call this function. | |
1756 | */ | |
1757 | void ftrace_run_stop_machine(int command) | |
1758 | { | |
1759 | stop_machine(__ftrace_modify_code, &command, NULL); | |
1760 | } | |
1761 | ||
1762 | /** | |
1763 | * arch_ftrace_update_code, modify the code to trace or not trace | |
1764 | * @command: The command that needs to be done | |
1765 | * | |
1766 | * Archs can override this function if it does not need to | |
1767 | * run stop_machine() to modify code. | |
1768 | */ | |
1769 | void __weak arch_ftrace_update_code(int command) | |
1770 | { | |
1771 | ftrace_run_stop_machine(command); | |
1772 | } | |
1773 | ||
e309b41d | 1774 | static void ftrace_run_update_code(int command) |
3d083395 | 1775 | { |
000ab691 SR |
1776 | int ret; |
1777 | ||
1778 | ret = ftrace_arch_code_modify_prepare(); | |
1779 | FTRACE_WARN_ON(ret); | |
1780 | if (ret) | |
1781 | return; | |
c88fd863 SR |
1782 | /* |
1783 | * Do not call function tracer while we update the code. | |
1784 | * We are in stop machine. | |
1785 | */ | |
1786 | function_trace_stop++; | |
000ab691 | 1787 | |
c88fd863 SR |
1788 | /* |
1789 | * By default we use stop_machine() to modify the code. | |
1790 | * But archs can do what ever they want as long as it | |
1791 | * is safe. The stop_machine() is the safest, but also | |
1792 | * produces the most overhead. | |
1793 | */ | |
1794 | arch_ftrace_update_code(command); | |
1795 | ||
1796 | #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
1797 | /* | |
1798 | * For archs that call ftrace_test_stop_func(), we must | |
1799 | * wait till after we update all the function callers | |
1800 | * before we update the callback. This keeps different | |
1801 | * ops that record different functions from corrupting | |
1802 | * each other. | |
1803 | */ | |
1804 | __ftrace_trace_function = __ftrace_trace_function_delay; | |
1805 | #endif | |
1806 | function_trace_stop--; | |
000ab691 SR |
1807 | |
1808 | ret = ftrace_arch_code_modify_post_process(); | |
1809 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
1810 | } |
1811 | ||
d61f82d0 | 1812 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 1813 | static int ftrace_start_up; |
b848914c | 1814 | static int global_start_up; |
df4fc315 SR |
1815 | |
1816 | static void ftrace_startup_enable(int command) | |
1817 | { | |
1818 | if (saved_ftrace_func != ftrace_trace_function) { | |
1819 | saved_ftrace_func = ftrace_trace_function; | |
1820 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1821 | } | |
1822 | ||
1823 | if (!command || !ftrace_enabled) | |
1824 | return; | |
1825 | ||
1826 | ftrace_run_update_code(command); | |
1827 | } | |
d61f82d0 | 1828 | |
a1cd6173 | 1829 | static int ftrace_startup(struct ftrace_ops *ops, int command) |
3d083395 | 1830 | { |
b848914c SR |
1831 | bool hash_enable = true; |
1832 | ||
4eebcc81 | 1833 | if (unlikely(ftrace_disabled)) |
a1cd6173 | 1834 | return -ENODEV; |
4eebcc81 | 1835 | |
60a7ecf4 | 1836 | ftrace_start_up++; |
30fb6aa7 | 1837 | command |= FTRACE_UPDATE_CALLS; |
d61f82d0 | 1838 | |
b848914c SR |
1839 | /* ops marked global share the filter hashes */ |
1840 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { | |
1841 | ops = &global_ops; | |
1842 | /* Don't update hash if global is already set */ | |
1843 | if (global_start_up) | |
1844 | hash_enable = false; | |
1845 | global_start_up++; | |
1846 | } | |
1847 | ||
ed926f9b | 1848 | ops->flags |= FTRACE_OPS_FL_ENABLED; |
b848914c | 1849 | if (hash_enable) |
ed926f9b SR |
1850 | ftrace_hash_rec_enable(ops, 1); |
1851 | ||
df4fc315 | 1852 | ftrace_startup_enable(command); |
a1cd6173 SR |
1853 | |
1854 | return 0; | |
3d083395 SR |
1855 | } |
1856 | ||
bd69c30b | 1857 | static void ftrace_shutdown(struct ftrace_ops *ops, int command) |
3d083395 | 1858 | { |
b848914c SR |
1859 | bool hash_disable = true; |
1860 | ||
4eebcc81 SR |
1861 | if (unlikely(ftrace_disabled)) |
1862 | return; | |
1863 | ||
60a7ecf4 | 1864 | ftrace_start_up--; |
9ea1a153 FW |
1865 | /* |
1866 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
1867 | * critical but the ftrace_call callers may be never nopped again after | |
1868 | * further ftrace uses. | |
1869 | */ | |
1870 | WARN_ON_ONCE(ftrace_start_up < 0); | |
1871 | ||
b848914c SR |
1872 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { |
1873 | ops = &global_ops; | |
1874 | global_start_up--; | |
1875 | WARN_ON_ONCE(global_start_up < 0); | |
1876 | /* Don't update hash if global still has users */ | |
1877 | if (global_start_up) { | |
1878 | WARN_ON_ONCE(!ftrace_start_up); | |
1879 | hash_disable = false; | |
1880 | } | |
1881 | } | |
1882 | ||
1883 | if (hash_disable) | |
ed926f9b SR |
1884 | ftrace_hash_rec_disable(ops, 1); |
1885 | ||
b848914c | 1886 | if (ops != &global_ops || !global_start_up) |
ed926f9b | 1887 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
b848914c | 1888 | |
30fb6aa7 | 1889 | command |= FTRACE_UPDATE_CALLS; |
3d083395 | 1890 | |
d61f82d0 SR |
1891 | if (saved_ftrace_func != ftrace_trace_function) { |
1892 | saved_ftrace_func = ftrace_trace_function; | |
1893 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1894 | } | |
3d083395 | 1895 | |
d61f82d0 | 1896 | if (!command || !ftrace_enabled) |
e6ea44e9 | 1897 | return; |
d61f82d0 SR |
1898 | |
1899 | ftrace_run_update_code(command); | |
3d083395 SR |
1900 | } |
1901 | ||
e309b41d | 1902 | static void ftrace_startup_sysctl(void) |
b0fc494f | 1903 | { |
4eebcc81 SR |
1904 | if (unlikely(ftrace_disabled)) |
1905 | return; | |
1906 | ||
d61f82d0 SR |
1907 | /* Force update next time */ |
1908 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
1909 | /* ftrace_start_up is true if we want ftrace running */ |
1910 | if (ftrace_start_up) | |
30fb6aa7 | 1911 | ftrace_run_update_code(FTRACE_UPDATE_CALLS); |
b0fc494f SR |
1912 | } |
1913 | ||
e309b41d | 1914 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 1915 | { |
4eebcc81 SR |
1916 | if (unlikely(ftrace_disabled)) |
1917 | return; | |
1918 | ||
60a7ecf4 SR |
1919 | /* ftrace_start_up is true if ftrace is running */ |
1920 | if (ftrace_start_up) | |
79e406d7 | 1921 | ftrace_run_update_code(FTRACE_DISABLE_CALLS); |
b0fc494f SR |
1922 | } |
1923 | ||
3d083395 SR |
1924 | static cycle_t ftrace_update_time; |
1925 | static unsigned long ftrace_update_cnt; | |
1926 | unsigned long ftrace_update_tot_cnt; | |
1927 | ||
f7bc8b61 SR |
1928 | static int ops_traces_mod(struct ftrace_ops *ops) |
1929 | { | |
1930 | struct ftrace_hash *hash; | |
1931 | ||
1932 | hash = ops->filter_hash; | |
1933 | return !!(!hash || !hash->count); | |
1934 | } | |
1935 | ||
31e88909 | 1936 | static int ftrace_update_code(struct module *mod) |
3d083395 | 1937 | { |
85ae32ae | 1938 | struct ftrace_page *pg; |
e94142a6 | 1939 | struct dyn_ftrace *p; |
f22f9a89 | 1940 | cycle_t start, stop; |
f7bc8b61 | 1941 | unsigned long ref = 0; |
85ae32ae | 1942 | int i; |
f7bc8b61 SR |
1943 | |
1944 | /* | |
1945 | * When adding a module, we need to check if tracers are | |
1946 | * currently enabled and if they are set to trace all functions. | |
1947 | * If they are, we need to enable the module functions as well | |
1948 | * as update the reference counts for those function records. | |
1949 | */ | |
1950 | if (mod) { | |
1951 | struct ftrace_ops *ops; | |
1952 | ||
1953 | for (ops = ftrace_ops_list; | |
1954 | ops != &ftrace_list_end; ops = ops->next) { | |
1955 | if (ops->flags & FTRACE_OPS_FL_ENABLED && | |
1956 | ops_traces_mod(ops)) | |
1957 | ref++; | |
1958 | } | |
1959 | } | |
3d083395 | 1960 | |
750ed1a4 | 1961 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1962 | ftrace_update_cnt = 0; |
1963 | ||
85ae32ae | 1964 | for (pg = ftrace_new_pgs; pg; pg = pg->next) { |
3d083395 | 1965 | |
85ae32ae SR |
1966 | for (i = 0; i < pg->index; i++) { |
1967 | /* If something went wrong, bail without enabling anything */ | |
1968 | if (unlikely(ftrace_disabled)) | |
1969 | return -1; | |
f22f9a89 | 1970 | |
85ae32ae SR |
1971 | p = &pg->records[i]; |
1972 | p->flags = ref; | |
f22f9a89 | 1973 | |
85ae32ae SR |
1974 | /* |
1975 | * Do the initial record conversion from mcount jump | |
1976 | * to the NOP instructions. | |
1977 | */ | |
1978 | if (!ftrace_code_disable(mod, p)) | |
1979 | break; | |
5cb084bb | 1980 | |
85ae32ae | 1981 | ftrace_update_cnt++; |
5cb084bb | 1982 | |
85ae32ae SR |
1983 | /* |
1984 | * If the tracing is enabled, go ahead and enable the record. | |
1985 | * | |
1986 | * The reason not to enable the record immediatelly is the | |
1987 | * inherent check of ftrace_make_nop/ftrace_make_call for | |
1988 | * correct previous instructions. Making first the NOP | |
1989 | * conversion puts the module to the correct state, thus | |
1990 | * passing the ftrace_make_call check. | |
1991 | */ | |
1992 | if (ftrace_start_up && ref) { | |
1993 | int failed = __ftrace_replace_code(p, 1); | |
1994 | if (failed) | |
1995 | ftrace_bug(failed, p->ip); | |
1996 | } | |
5cb084bb | 1997 | } |
3d083395 SR |
1998 | } |
1999 | ||
85ae32ae SR |
2000 | ftrace_new_pgs = NULL; |
2001 | ||
750ed1a4 | 2002 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
2003 | ftrace_update_time = stop - start; |
2004 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
2005 | ||
16444a8a ACM |
2006 | return 0; |
2007 | } | |
2008 | ||
a7900875 | 2009 | static int ftrace_allocate_records(struct ftrace_page *pg, int count) |
3c1720f0 | 2010 | { |
a7900875 | 2011 | int order; |
3c1720f0 | 2012 | int cnt; |
3c1720f0 | 2013 | |
a7900875 SR |
2014 | if (WARN_ON(!count)) |
2015 | return -EINVAL; | |
2016 | ||
2017 | order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE)); | |
3c1720f0 SR |
2018 | |
2019 | /* | |
a7900875 SR |
2020 | * We want to fill as much as possible. No more than a page |
2021 | * may be empty. | |
3c1720f0 | 2022 | */ |
a7900875 SR |
2023 | while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE) |
2024 | order--; | |
3c1720f0 | 2025 | |
a7900875 SR |
2026 | again: |
2027 | pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); | |
3c1720f0 | 2028 | |
a7900875 SR |
2029 | if (!pg->records) { |
2030 | /* if we can't allocate this size, try something smaller */ | |
2031 | if (!order) | |
2032 | return -ENOMEM; | |
2033 | order >>= 1; | |
2034 | goto again; | |
2035 | } | |
3c1720f0 | 2036 | |
a7900875 SR |
2037 | cnt = (PAGE_SIZE << order) / ENTRY_SIZE; |
2038 | pg->size = cnt; | |
3c1720f0 | 2039 | |
a7900875 SR |
2040 | if (cnt > count) |
2041 | cnt = count; | |
2042 | ||
2043 | return cnt; | |
2044 | } | |
2045 | ||
2046 | static struct ftrace_page * | |
2047 | ftrace_allocate_pages(unsigned long num_to_init) | |
2048 | { | |
2049 | struct ftrace_page *start_pg; | |
2050 | struct ftrace_page *pg; | |
2051 | int order; | |
2052 | int cnt; | |
2053 | ||
2054 | if (!num_to_init) | |
2055 | return 0; | |
2056 | ||
2057 | start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL); | |
2058 | if (!pg) | |
2059 | return NULL; | |
2060 | ||
2061 | /* | |
2062 | * Try to allocate as much as possible in one continues | |
2063 | * location that fills in all of the space. We want to | |
2064 | * waste as little space as possible. | |
2065 | */ | |
2066 | for (;;) { | |
2067 | cnt = ftrace_allocate_records(pg, num_to_init); | |
2068 | if (cnt < 0) | |
2069 | goto free_pages; | |
2070 | ||
2071 | num_to_init -= cnt; | |
2072 | if (!num_to_init) | |
3c1720f0 SR |
2073 | break; |
2074 | ||
a7900875 SR |
2075 | pg->next = kzalloc(sizeof(*pg), GFP_KERNEL); |
2076 | if (!pg->next) | |
2077 | goto free_pages; | |
2078 | ||
3c1720f0 SR |
2079 | pg = pg->next; |
2080 | } | |
2081 | ||
a7900875 SR |
2082 | return start_pg; |
2083 | ||
2084 | free_pages: | |
2085 | while (start_pg) { | |
2086 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); | |
2087 | free_pages((unsigned long)pg->records, order); | |
2088 | start_pg = pg->next; | |
2089 | kfree(pg); | |
2090 | pg = start_pg; | |
2091 | } | |
2092 | pr_info("ftrace: FAILED to allocate memory for functions\n"); | |
2093 | return NULL; | |
2094 | } | |
2095 | ||
2096 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) | |
2097 | { | |
2098 | int cnt; | |
2099 | ||
2100 | if (!num_to_init) { | |
2101 | pr_info("ftrace: No functions to be traced?\n"); | |
2102 | return -1; | |
2103 | } | |
2104 | ||
2105 | cnt = num_to_init / ENTRIES_PER_PAGE; | |
2106 | pr_info("ftrace: allocating %ld entries in %d pages\n", | |
2107 | num_to_init, cnt + 1); | |
2108 | ||
3c1720f0 SR |
2109 | return 0; |
2110 | } | |
2111 | ||
5072c59f SR |
2112 | enum { |
2113 | FTRACE_ITER_FILTER = (1 << 0), | |
689fd8b6 | 2114 | FTRACE_ITER_NOTRACE = (1 << 1), |
3499e461 SR |
2115 | FTRACE_ITER_PRINTALL = (1 << 2), |
2116 | FTRACE_ITER_HASH = (1 << 3), | |
647bcd03 | 2117 | FTRACE_ITER_ENABLED = (1 << 4), |
5072c59f SR |
2118 | }; |
2119 | ||
2120 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
2121 | ||
2122 | struct ftrace_iterator { | |
98c4fd04 | 2123 | loff_t pos; |
4aeb6967 SR |
2124 | loff_t func_pos; |
2125 | struct ftrace_page *pg; | |
2126 | struct dyn_ftrace *func; | |
2127 | struct ftrace_func_probe *probe; | |
2128 | struct trace_parser parser; | |
1cf41dd7 | 2129 | struct ftrace_hash *hash; |
33dc9b12 | 2130 | struct ftrace_ops *ops; |
4aeb6967 SR |
2131 | int hidx; |
2132 | int idx; | |
2133 | unsigned flags; | |
5072c59f SR |
2134 | }; |
2135 | ||
8fc0c701 | 2136 | static void * |
4aeb6967 | 2137 | t_hash_next(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
2138 | { |
2139 | struct ftrace_iterator *iter = m->private; | |
4aeb6967 | 2140 | struct hlist_node *hnd = NULL; |
8fc0c701 SR |
2141 | struct hlist_head *hhd; |
2142 | ||
8fc0c701 | 2143 | (*pos)++; |
98c4fd04 | 2144 | iter->pos = *pos; |
8fc0c701 | 2145 | |
4aeb6967 SR |
2146 | if (iter->probe) |
2147 | hnd = &iter->probe->node; | |
8fc0c701 SR |
2148 | retry: |
2149 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
2150 | return NULL; | |
2151 | ||
2152 | hhd = &ftrace_func_hash[iter->hidx]; | |
2153 | ||
2154 | if (hlist_empty(hhd)) { | |
2155 | iter->hidx++; | |
2156 | hnd = NULL; | |
2157 | goto retry; | |
2158 | } | |
2159 | ||
2160 | if (!hnd) | |
2161 | hnd = hhd->first; | |
2162 | else { | |
2163 | hnd = hnd->next; | |
2164 | if (!hnd) { | |
2165 | iter->hidx++; | |
2166 | goto retry; | |
2167 | } | |
2168 | } | |
2169 | ||
4aeb6967 SR |
2170 | if (WARN_ON_ONCE(!hnd)) |
2171 | return NULL; | |
2172 | ||
2173 | iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node); | |
2174 | ||
2175 | return iter; | |
8fc0c701 SR |
2176 | } |
2177 | ||
2178 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
2179 | { | |
2180 | struct ftrace_iterator *iter = m->private; | |
2181 | void *p = NULL; | |
d82d6244 LZ |
2182 | loff_t l; |
2183 | ||
2bccfffd SR |
2184 | if (iter->func_pos > *pos) |
2185 | return NULL; | |
8fc0c701 | 2186 | |
d82d6244 | 2187 | iter->hidx = 0; |
2bccfffd | 2188 | for (l = 0; l <= (*pos - iter->func_pos); ) { |
4aeb6967 | 2189 | p = t_hash_next(m, &l); |
d82d6244 LZ |
2190 | if (!p) |
2191 | break; | |
2192 | } | |
4aeb6967 SR |
2193 | if (!p) |
2194 | return NULL; | |
2195 | ||
98c4fd04 SR |
2196 | /* Only set this if we have an item */ |
2197 | iter->flags |= FTRACE_ITER_HASH; | |
2198 | ||
4aeb6967 | 2199 | return iter; |
8fc0c701 SR |
2200 | } |
2201 | ||
4aeb6967 SR |
2202 | static int |
2203 | t_hash_show(struct seq_file *m, struct ftrace_iterator *iter) | |
8fc0c701 | 2204 | { |
b6887d79 | 2205 | struct ftrace_func_probe *rec; |
8fc0c701 | 2206 | |
4aeb6967 SR |
2207 | rec = iter->probe; |
2208 | if (WARN_ON_ONCE(!rec)) | |
2209 | return -EIO; | |
8fc0c701 | 2210 | |
809dcf29 SR |
2211 | if (rec->ops->print) |
2212 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
2213 | ||
b375a11a | 2214 | seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func); |
8fc0c701 SR |
2215 | |
2216 | if (rec->data) | |
2217 | seq_printf(m, ":%p", rec->data); | |
2218 | seq_putc(m, '\n'); | |
2219 | ||
2220 | return 0; | |
2221 | } | |
2222 | ||
e309b41d | 2223 | static void * |
5072c59f SR |
2224 | t_next(struct seq_file *m, void *v, loff_t *pos) |
2225 | { | |
2226 | struct ftrace_iterator *iter = m->private; | |
f45948e8 | 2227 | struct ftrace_ops *ops = &global_ops; |
5072c59f SR |
2228 | struct dyn_ftrace *rec = NULL; |
2229 | ||
45a4a237 SR |
2230 | if (unlikely(ftrace_disabled)) |
2231 | return NULL; | |
2232 | ||
8fc0c701 | 2233 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 2234 | return t_hash_next(m, pos); |
8fc0c701 | 2235 | |
5072c59f | 2236 | (*pos)++; |
1106b699 | 2237 | iter->pos = iter->func_pos = *pos; |
5072c59f | 2238 | |
0c75a3ed | 2239 | if (iter->flags & FTRACE_ITER_PRINTALL) |
57c072c7 | 2240 | return t_hash_start(m, pos); |
0c75a3ed | 2241 | |
5072c59f SR |
2242 | retry: |
2243 | if (iter->idx >= iter->pg->index) { | |
2244 | if (iter->pg->next) { | |
2245 | iter->pg = iter->pg->next; | |
2246 | iter->idx = 0; | |
2247 | goto retry; | |
2248 | } | |
2249 | } else { | |
2250 | rec = &iter->pg->records[iter->idx++]; | |
32082309 | 2251 | if (((iter->flags & FTRACE_ITER_FILTER) && |
f45948e8 | 2252 | !(ftrace_lookup_ip(ops->filter_hash, rec->ip))) || |
0183fb1c | 2253 | |
41c52c0d | 2254 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
647bcd03 SR |
2255 | !ftrace_lookup_ip(ops->notrace_hash, rec->ip)) || |
2256 | ||
2257 | ((iter->flags & FTRACE_ITER_ENABLED) && | |
2258 | !(rec->flags & ~FTRACE_FL_MASK))) { | |
2259 | ||
5072c59f SR |
2260 | rec = NULL; |
2261 | goto retry; | |
2262 | } | |
2263 | } | |
2264 | ||
4aeb6967 | 2265 | if (!rec) |
57c072c7 | 2266 | return t_hash_start(m, pos); |
4aeb6967 SR |
2267 | |
2268 | iter->func = rec; | |
2269 | ||
2270 | return iter; | |
5072c59f SR |
2271 | } |
2272 | ||
98c4fd04 SR |
2273 | static void reset_iter_read(struct ftrace_iterator *iter) |
2274 | { | |
2275 | iter->pos = 0; | |
2276 | iter->func_pos = 0; | |
2277 | iter->flags &= ~(FTRACE_ITER_PRINTALL & FTRACE_ITER_HASH); | |
5072c59f SR |
2278 | } |
2279 | ||
2280 | static void *t_start(struct seq_file *m, loff_t *pos) | |
2281 | { | |
2282 | struct ftrace_iterator *iter = m->private; | |
f45948e8 | 2283 | struct ftrace_ops *ops = &global_ops; |
5072c59f | 2284 | void *p = NULL; |
694ce0a5 | 2285 | loff_t l; |
5072c59f | 2286 | |
8fc0c701 | 2287 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
2288 | |
2289 | if (unlikely(ftrace_disabled)) | |
2290 | return NULL; | |
2291 | ||
98c4fd04 SR |
2292 | /* |
2293 | * If an lseek was done, then reset and start from beginning. | |
2294 | */ | |
2295 | if (*pos < iter->pos) | |
2296 | reset_iter_read(iter); | |
2297 | ||
0c75a3ed SR |
2298 | /* |
2299 | * For set_ftrace_filter reading, if we have the filter | |
2300 | * off, we can short cut and just print out that all | |
2301 | * functions are enabled. | |
2302 | */ | |
f45948e8 | 2303 | if (iter->flags & FTRACE_ITER_FILTER && !ops->filter_hash->count) { |
0c75a3ed | 2304 | if (*pos > 0) |
8fc0c701 | 2305 | return t_hash_start(m, pos); |
0c75a3ed | 2306 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 CW |
2307 | /* reset in case of seek/pread */ |
2308 | iter->flags &= ~FTRACE_ITER_HASH; | |
0c75a3ed SR |
2309 | return iter; |
2310 | } | |
2311 | ||
8fc0c701 SR |
2312 | if (iter->flags & FTRACE_ITER_HASH) |
2313 | return t_hash_start(m, pos); | |
2314 | ||
98c4fd04 SR |
2315 | /* |
2316 | * Unfortunately, we need to restart at ftrace_pages_start | |
2317 | * every time we let go of the ftrace_mutex. This is because | |
2318 | * those pointers can change without the lock. | |
2319 | */ | |
694ce0a5 LZ |
2320 | iter->pg = ftrace_pages_start; |
2321 | iter->idx = 0; | |
2322 | for (l = 0; l <= *pos; ) { | |
2323 | p = t_next(m, p, &l); | |
2324 | if (!p) | |
2325 | break; | |
50cdaf08 | 2326 | } |
5821e1b7 | 2327 | |
4aeb6967 SR |
2328 | if (!p) { |
2329 | if (iter->flags & FTRACE_ITER_FILTER) | |
2330 | return t_hash_start(m, pos); | |
8fc0c701 | 2331 | |
4aeb6967 SR |
2332 | return NULL; |
2333 | } | |
2334 | ||
2335 | return iter; | |
5072c59f SR |
2336 | } |
2337 | ||
2338 | static void t_stop(struct seq_file *m, void *p) | |
2339 | { | |
8fc0c701 | 2340 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
2341 | } |
2342 | ||
2343 | static int t_show(struct seq_file *m, void *v) | |
2344 | { | |
0c75a3ed | 2345 | struct ftrace_iterator *iter = m->private; |
4aeb6967 | 2346 | struct dyn_ftrace *rec; |
5072c59f | 2347 | |
8fc0c701 | 2348 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 2349 | return t_hash_show(m, iter); |
8fc0c701 | 2350 | |
0c75a3ed SR |
2351 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
2352 | seq_printf(m, "#### all functions enabled ####\n"); | |
2353 | return 0; | |
2354 | } | |
2355 | ||
4aeb6967 SR |
2356 | rec = iter->func; |
2357 | ||
5072c59f SR |
2358 | if (!rec) |
2359 | return 0; | |
2360 | ||
647bcd03 SR |
2361 | seq_printf(m, "%ps", (void *)rec->ip); |
2362 | if (iter->flags & FTRACE_ITER_ENABLED) | |
2363 | seq_printf(m, " (%ld)", | |
2364 | rec->flags & ~FTRACE_FL_MASK); | |
2365 | seq_printf(m, "\n"); | |
5072c59f SR |
2366 | |
2367 | return 0; | |
2368 | } | |
2369 | ||
88e9d34c | 2370 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
2371 | .start = t_start, |
2372 | .next = t_next, | |
2373 | .stop = t_stop, | |
2374 | .show = t_show, | |
2375 | }; | |
2376 | ||
e309b41d | 2377 | static int |
5072c59f SR |
2378 | ftrace_avail_open(struct inode *inode, struct file *file) |
2379 | { | |
2380 | struct ftrace_iterator *iter; | |
2381 | int ret; | |
2382 | ||
4eebcc81 SR |
2383 | if (unlikely(ftrace_disabled)) |
2384 | return -ENODEV; | |
2385 | ||
5072c59f SR |
2386 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
2387 | if (!iter) | |
2388 | return -ENOMEM; | |
2389 | ||
2390 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
2391 | |
2392 | ret = seq_open(file, &show_ftrace_seq_ops); | |
2393 | if (!ret) { | |
2394 | struct seq_file *m = file->private_data; | |
4bf39a94 | 2395 | |
5072c59f | 2396 | m->private = iter; |
4bf39a94 | 2397 | } else { |
5072c59f | 2398 | kfree(iter); |
4bf39a94 | 2399 | } |
5072c59f SR |
2400 | |
2401 | return ret; | |
2402 | } | |
2403 | ||
647bcd03 SR |
2404 | static int |
2405 | ftrace_enabled_open(struct inode *inode, struct file *file) | |
2406 | { | |
2407 | struct ftrace_iterator *iter; | |
2408 | int ret; | |
2409 | ||
2410 | if (unlikely(ftrace_disabled)) | |
2411 | return -ENODEV; | |
2412 | ||
2413 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); | |
2414 | if (!iter) | |
2415 | return -ENOMEM; | |
2416 | ||
2417 | iter->pg = ftrace_pages_start; | |
2418 | iter->flags = FTRACE_ITER_ENABLED; | |
2419 | ||
2420 | ret = seq_open(file, &show_ftrace_seq_ops); | |
2421 | if (!ret) { | |
2422 | struct seq_file *m = file->private_data; | |
2423 | ||
2424 | m->private = iter; | |
2425 | } else { | |
2426 | kfree(iter); | |
2427 | } | |
2428 | ||
2429 | return ret; | |
2430 | } | |
2431 | ||
1cf41dd7 | 2432 | static void ftrace_filter_reset(struct ftrace_hash *hash) |
5072c59f | 2433 | { |
52baf119 | 2434 | mutex_lock(&ftrace_lock); |
1cf41dd7 | 2435 | ftrace_hash_clear(hash); |
52baf119 | 2436 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
2437 | } |
2438 | ||
e309b41d | 2439 | static int |
f45948e8 | 2440 | ftrace_regex_open(struct ftrace_ops *ops, int flag, |
1cf41dd7 | 2441 | struct inode *inode, struct file *file) |
5072c59f SR |
2442 | { |
2443 | struct ftrace_iterator *iter; | |
f45948e8 | 2444 | struct ftrace_hash *hash; |
5072c59f SR |
2445 | int ret = 0; |
2446 | ||
4eebcc81 SR |
2447 | if (unlikely(ftrace_disabled)) |
2448 | return -ENODEV; | |
2449 | ||
5072c59f SR |
2450 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
2451 | if (!iter) | |
2452 | return -ENOMEM; | |
2453 | ||
689fd8b6 | 2454 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { |
2455 | kfree(iter); | |
2456 | return -ENOMEM; | |
2457 | } | |
2458 | ||
f45948e8 SR |
2459 | if (flag & FTRACE_ITER_NOTRACE) |
2460 | hash = ops->notrace_hash; | |
2461 | else | |
2462 | hash = ops->filter_hash; | |
2463 | ||
33dc9b12 SR |
2464 | iter->ops = ops; |
2465 | iter->flags = flag; | |
2466 | ||
2467 | if (file->f_mode & FMODE_WRITE) { | |
2468 | mutex_lock(&ftrace_lock); | |
2469 | iter->hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash); | |
2470 | mutex_unlock(&ftrace_lock); | |
2471 | ||
2472 | if (!iter->hash) { | |
2473 | trace_parser_put(&iter->parser); | |
2474 | kfree(iter); | |
2475 | return -ENOMEM; | |
2476 | } | |
2477 | } | |
1cf41dd7 | 2478 | |
41c52c0d | 2479 | mutex_lock(&ftrace_regex_lock); |
33dc9b12 | 2480 | |
5072c59f | 2481 | if ((file->f_mode & FMODE_WRITE) && |
8650ae32 | 2482 | (file->f_flags & O_TRUNC)) |
33dc9b12 | 2483 | ftrace_filter_reset(iter->hash); |
5072c59f SR |
2484 | |
2485 | if (file->f_mode & FMODE_READ) { | |
2486 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
2487 | |
2488 | ret = seq_open(file, &show_ftrace_seq_ops); | |
2489 | if (!ret) { | |
2490 | struct seq_file *m = file->private_data; | |
2491 | m->private = iter; | |
79fe249c | 2492 | } else { |
33dc9b12 SR |
2493 | /* Failed */ |
2494 | free_ftrace_hash(iter->hash); | |
79fe249c | 2495 | trace_parser_put(&iter->parser); |
5072c59f | 2496 | kfree(iter); |
79fe249c | 2497 | } |
5072c59f SR |
2498 | } else |
2499 | file->private_data = iter; | |
41c52c0d | 2500 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
2501 | |
2502 | return ret; | |
2503 | } | |
2504 | ||
41c52c0d SR |
2505 | static int |
2506 | ftrace_filter_open(struct inode *inode, struct file *file) | |
2507 | { | |
f45948e8 | 2508 | return ftrace_regex_open(&global_ops, FTRACE_ITER_FILTER, |
1cf41dd7 | 2509 | inode, file); |
41c52c0d SR |
2510 | } |
2511 | ||
2512 | static int | |
2513 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
2514 | { | |
f45948e8 | 2515 | return ftrace_regex_open(&global_ops, FTRACE_ITER_NOTRACE, |
1cf41dd7 | 2516 | inode, file); |
41c52c0d SR |
2517 | } |
2518 | ||
e309b41d | 2519 | static loff_t |
41c52c0d | 2520 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
2521 | { |
2522 | loff_t ret; | |
2523 | ||
2524 | if (file->f_mode & FMODE_READ) | |
2525 | ret = seq_lseek(file, offset, origin); | |
2526 | else | |
2527 | file->f_pos = ret = 1; | |
2528 | ||
2529 | return ret; | |
2530 | } | |
2531 | ||
64e7c440 | 2532 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 2533 | { |
9f4801e3 | 2534 | int matched = 0; |
751e9983 | 2535 | int slen; |
9f4801e3 | 2536 | |
9f4801e3 SR |
2537 | switch (type) { |
2538 | case MATCH_FULL: | |
2539 | if (strcmp(str, regex) == 0) | |
2540 | matched = 1; | |
2541 | break; | |
2542 | case MATCH_FRONT_ONLY: | |
2543 | if (strncmp(str, regex, len) == 0) | |
2544 | matched = 1; | |
2545 | break; | |
2546 | case MATCH_MIDDLE_ONLY: | |
2547 | if (strstr(str, regex)) | |
2548 | matched = 1; | |
2549 | break; | |
2550 | case MATCH_END_ONLY: | |
751e9983 LZ |
2551 | slen = strlen(str); |
2552 | if (slen >= len && memcmp(str + slen - len, regex, len) == 0) | |
9f4801e3 SR |
2553 | matched = 1; |
2554 | break; | |
2555 | } | |
2556 | ||
2557 | return matched; | |
2558 | } | |
2559 | ||
b448c4e3 | 2560 | static int |
1cf41dd7 | 2561 | enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not) |
996e87be | 2562 | { |
b448c4e3 | 2563 | struct ftrace_func_entry *entry; |
b448c4e3 SR |
2564 | int ret = 0; |
2565 | ||
1cf41dd7 SR |
2566 | entry = ftrace_lookup_ip(hash, rec->ip); |
2567 | if (not) { | |
2568 | /* Do nothing if it doesn't exist */ | |
2569 | if (!entry) | |
2570 | return 0; | |
b448c4e3 | 2571 | |
33dc9b12 | 2572 | free_hash_entry(hash, entry); |
1cf41dd7 SR |
2573 | } else { |
2574 | /* Do nothing if it exists */ | |
2575 | if (entry) | |
2576 | return 0; | |
b448c4e3 | 2577 | |
1cf41dd7 | 2578 | ret = add_hash_entry(hash, rec->ip); |
b448c4e3 SR |
2579 | } |
2580 | return ret; | |
996e87be SR |
2581 | } |
2582 | ||
64e7c440 | 2583 | static int |
b9df92d2 SR |
2584 | ftrace_match_record(struct dyn_ftrace *rec, char *mod, |
2585 | char *regex, int len, int type) | |
64e7c440 SR |
2586 | { |
2587 | char str[KSYM_SYMBOL_LEN]; | |
b9df92d2 SR |
2588 | char *modname; |
2589 | ||
2590 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
2591 | ||
2592 | if (mod) { | |
2593 | /* module lookup requires matching the module */ | |
2594 | if (!modname || strcmp(modname, mod)) | |
2595 | return 0; | |
2596 | ||
2597 | /* blank search means to match all funcs in the mod */ | |
2598 | if (!len) | |
2599 | return 1; | |
2600 | } | |
64e7c440 | 2601 | |
64e7c440 SR |
2602 | return ftrace_match(str, regex, len, type); |
2603 | } | |
2604 | ||
1cf41dd7 SR |
2605 | static int |
2606 | match_records(struct ftrace_hash *hash, char *buff, | |
2607 | int len, char *mod, int not) | |
9f4801e3 | 2608 | { |
b9df92d2 | 2609 | unsigned search_len = 0; |
9f4801e3 SR |
2610 | struct ftrace_page *pg; |
2611 | struct dyn_ftrace *rec; | |
b9df92d2 SR |
2612 | int type = MATCH_FULL; |
2613 | char *search = buff; | |
311d16da | 2614 | int found = 0; |
b448c4e3 | 2615 | int ret; |
9f4801e3 | 2616 | |
b9df92d2 SR |
2617 | if (len) { |
2618 | type = filter_parse_regex(buff, len, &search, ¬); | |
2619 | search_len = strlen(search); | |
2620 | } | |
9f4801e3 | 2621 | |
52baf119 | 2622 | mutex_lock(&ftrace_lock); |
265c831c | 2623 | |
b9df92d2 SR |
2624 | if (unlikely(ftrace_disabled)) |
2625 | goto out_unlock; | |
9f4801e3 | 2626 | |
265c831c | 2627 | do_for_each_ftrace_rec(pg, rec) { |
b9df92d2 | 2628 | if (ftrace_match_record(rec, mod, search, search_len, type)) { |
1cf41dd7 | 2629 | ret = enter_record(hash, rec, not); |
b448c4e3 SR |
2630 | if (ret < 0) { |
2631 | found = ret; | |
2632 | goto out_unlock; | |
2633 | } | |
311d16da | 2634 | found = 1; |
265c831c SR |
2635 | } |
2636 | } while_for_each_ftrace_rec(); | |
b9df92d2 | 2637 | out_unlock: |
52baf119 | 2638 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
2639 | |
2640 | return found; | |
5072c59f SR |
2641 | } |
2642 | ||
64e7c440 | 2643 | static int |
1cf41dd7 | 2644 | ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) |
64e7c440 | 2645 | { |
1cf41dd7 | 2646 | return match_records(hash, buff, len, NULL, 0); |
64e7c440 SR |
2647 | } |
2648 | ||
1cf41dd7 SR |
2649 | static int |
2650 | ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod) | |
64e7c440 | 2651 | { |
64e7c440 | 2652 | int not = 0; |
6a24a244 | 2653 | |
64e7c440 SR |
2654 | /* blank or '*' mean the same */ |
2655 | if (strcmp(buff, "*") == 0) | |
2656 | buff[0] = 0; | |
2657 | ||
2658 | /* handle the case of 'dont filter this module' */ | |
2659 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
2660 | buff[0] = 0; | |
2661 | not = 1; | |
2662 | } | |
2663 | ||
1cf41dd7 | 2664 | return match_records(hash, buff, strlen(buff), mod, not); |
64e7c440 SR |
2665 | } |
2666 | ||
f6180773 SR |
2667 | /* |
2668 | * We register the module command as a template to show others how | |
2669 | * to register the a command as well. | |
2670 | */ | |
2671 | ||
2672 | static int | |
43dd61c9 SR |
2673 | ftrace_mod_callback(struct ftrace_hash *hash, |
2674 | char *func, char *cmd, char *param, int enable) | |
f6180773 SR |
2675 | { |
2676 | char *mod; | |
b448c4e3 | 2677 | int ret = -EINVAL; |
f6180773 SR |
2678 | |
2679 | /* | |
2680 | * cmd == 'mod' because we only registered this func | |
2681 | * for the 'mod' ftrace_func_command. | |
2682 | * But if you register one func with multiple commands, | |
2683 | * you can tell which command was used by the cmd | |
2684 | * parameter. | |
2685 | */ | |
2686 | ||
2687 | /* we must have a module name */ | |
2688 | if (!param) | |
b448c4e3 | 2689 | return ret; |
f6180773 SR |
2690 | |
2691 | mod = strsep(¶m, ":"); | |
2692 | if (!strlen(mod)) | |
b448c4e3 | 2693 | return ret; |
f6180773 | 2694 | |
1cf41dd7 | 2695 | ret = ftrace_match_module_records(hash, func, mod); |
b448c4e3 SR |
2696 | if (!ret) |
2697 | ret = -EINVAL; | |
2698 | if (ret < 0) | |
2699 | return ret; | |
2700 | ||
2701 | return 0; | |
f6180773 SR |
2702 | } |
2703 | ||
2704 | static struct ftrace_func_command ftrace_mod_cmd = { | |
2705 | .name = "mod", | |
2706 | .func = ftrace_mod_callback, | |
2707 | }; | |
2708 | ||
2709 | static int __init ftrace_mod_cmd_init(void) | |
2710 | { | |
2711 | return register_ftrace_command(&ftrace_mod_cmd); | |
2712 | } | |
2713 | device_initcall(ftrace_mod_cmd_init); | |
2714 | ||
59df055f | 2715 | static void |
b6887d79 | 2716 | function_trace_probe_call(unsigned long ip, unsigned long parent_ip) |
59df055f | 2717 | { |
b6887d79 | 2718 | struct ftrace_func_probe *entry; |
59df055f SR |
2719 | struct hlist_head *hhd; |
2720 | struct hlist_node *n; | |
2721 | unsigned long key; | |
59df055f SR |
2722 | |
2723 | key = hash_long(ip, FTRACE_HASH_BITS); | |
2724 | ||
2725 | hhd = &ftrace_func_hash[key]; | |
2726 | ||
2727 | if (hlist_empty(hhd)) | |
2728 | return; | |
2729 | ||
2730 | /* | |
2731 | * Disable preemption for these calls to prevent a RCU grace | |
2732 | * period. This syncs the hash iteration and freeing of items | |
2733 | * on the hash. rcu_read_lock is too dangerous here. | |
2734 | */ | |
5168ae50 | 2735 | preempt_disable_notrace(); |
59df055f SR |
2736 | hlist_for_each_entry_rcu(entry, n, hhd, node) { |
2737 | if (entry->ip == ip) | |
2738 | entry->ops->func(ip, parent_ip, &entry->data); | |
2739 | } | |
5168ae50 | 2740 | preempt_enable_notrace(); |
59df055f SR |
2741 | } |
2742 | ||
b6887d79 | 2743 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 2744 | { |
fb9fb015 | 2745 | .func = function_trace_probe_call, |
59df055f SR |
2746 | }; |
2747 | ||
b6887d79 | 2748 | static int ftrace_probe_registered; |
59df055f | 2749 | |
b6887d79 | 2750 | static void __enable_ftrace_function_probe(void) |
59df055f | 2751 | { |
b848914c | 2752 | int ret; |
59df055f SR |
2753 | int i; |
2754 | ||
b6887d79 | 2755 | if (ftrace_probe_registered) |
59df055f SR |
2756 | return; |
2757 | ||
2758 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2759 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2760 | if (hhd->first) | |
2761 | break; | |
2762 | } | |
2763 | /* Nothing registered? */ | |
2764 | if (i == FTRACE_FUNC_HASHSIZE) | |
2765 | return; | |
2766 | ||
b848914c SR |
2767 | ret = __register_ftrace_function(&trace_probe_ops); |
2768 | if (!ret) | |
a1cd6173 | 2769 | ret = ftrace_startup(&trace_probe_ops, 0); |
b848914c | 2770 | |
b6887d79 | 2771 | ftrace_probe_registered = 1; |
59df055f SR |
2772 | } |
2773 | ||
b6887d79 | 2774 | static void __disable_ftrace_function_probe(void) |
59df055f | 2775 | { |
b848914c | 2776 | int ret; |
59df055f SR |
2777 | int i; |
2778 | ||
b6887d79 | 2779 | if (!ftrace_probe_registered) |
59df055f SR |
2780 | return; |
2781 | ||
2782 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2783 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2784 | if (hhd->first) | |
2785 | return; | |
2786 | } | |
2787 | ||
2788 | /* no more funcs left */ | |
b848914c SR |
2789 | ret = __unregister_ftrace_function(&trace_probe_ops); |
2790 | if (!ret) | |
2791 | ftrace_shutdown(&trace_probe_ops, 0); | |
2792 | ||
b6887d79 | 2793 | ftrace_probe_registered = 0; |
59df055f SR |
2794 | } |
2795 | ||
2796 | ||
2797 | static void ftrace_free_entry_rcu(struct rcu_head *rhp) | |
2798 | { | |
b6887d79 SR |
2799 | struct ftrace_func_probe *entry = |
2800 | container_of(rhp, struct ftrace_func_probe, rcu); | |
59df055f SR |
2801 | |
2802 | if (entry->ops->free) | |
2803 | entry->ops->free(&entry->data); | |
2804 | kfree(entry); | |
2805 | } | |
2806 | ||
2807 | ||
2808 | int | |
b6887d79 | 2809 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2810 | void *data) |
2811 | { | |
b6887d79 | 2812 | struct ftrace_func_probe *entry; |
59df055f SR |
2813 | struct ftrace_page *pg; |
2814 | struct dyn_ftrace *rec; | |
59df055f | 2815 | int type, len, not; |
6a24a244 | 2816 | unsigned long key; |
59df055f SR |
2817 | int count = 0; |
2818 | char *search; | |
2819 | ||
3f6fe06d | 2820 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
2821 | len = strlen(search); |
2822 | ||
b6887d79 | 2823 | /* we do not support '!' for function probes */ |
59df055f SR |
2824 | if (WARN_ON(not)) |
2825 | return -EINVAL; | |
2826 | ||
2827 | mutex_lock(&ftrace_lock); | |
59df055f | 2828 | |
45a4a237 SR |
2829 | if (unlikely(ftrace_disabled)) |
2830 | goto out_unlock; | |
59df055f | 2831 | |
45a4a237 | 2832 | do_for_each_ftrace_rec(pg, rec) { |
59df055f | 2833 | |
b9df92d2 | 2834 | if (!ftrace_match_record(rec, NULL, search, len, type)) |
59df055f SR |
2835 | continue; |
2836 | ||
2837 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
2838 | if (!entry) { | |
b6887d79 | 2839 | /* If we did not process any, then return error */ |
59df055f SR |
2840 | if (!count) |
2841 | count = -ENOMEM; | |
2842 | goto out_unlock; | |
2843 | } | |
2844 | ||
2845 | count++; | |
2846 | ||
2847 | entry->data = data; | |
2848 | ||
2849 | /* | |
2850 | * The caller might want to do something special | |
2851 | * for each function we find. We call the callback | |
2852 | * to give the caller an opportunity to do so. | |
2853 | */ | |
2854 | if (ops->callback) { | |
2855 | if (ops->callback(rec->ip, &entry->data) < 0) { | |
2856 | /* caller does not like this func */ | |
2857 | kfree(entry); | |
2858 | continue; | |
2859 | } | |
2860 | } | |
2861 | ||
2862 | entry->ops = ops; | |
2863 | entry->ip = rec->ip; | |
2864 | ||
2865 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
2866 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
2867 | ||
2868 | } while_for_each_ftrace_rec(); | |
b6887d79 | 2869 | __enable_ftrace_function_probe(); |
59df055f SR |
2870 | |
2871 | out_unlock: | |
2872 | mutex_unlock(&ftrace_lock); | |
2873 | ||
2874 | return count; | |
2875 | } | |
2876 | ||
2877 | enum { | |
b6887d79 SR |
2878 | PROBE_TEST_FUNC = 1, |
2879 | PROBE_TEST_DATA = 2 | |
59df055f SR |
2880 | }; |
2881 | ||
2882 | static void | |
b6887d79 | 2883 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2884 | void *data, int flags) |
2885 | { | |
b6887d79 | 2886 | struct ftrace_func_probe *entry; |
59df055f SR |
2887 | struct hlist_node *n, *tmp; |
2888 | char str[KSYM_SYMBOL_LEN]; | |
2889 | int type = MATCH_FULL; | |
2890 | int i, len = 0; | |
2891 | char *search; | |
2892 | ||
b36461da | 2893 | if (glob && (strcmp(glob, "*") == 0 || !strlen(glob))) |
59df055f | 2894 | glob = NULL; |
b36461da | 2895 | else if (glob) { |
59df055f SR |
2896 | int not; |
2897 | ||
3f6fe06d | 2898 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
2899 | len = strlen(search); |
2900 | ||
b6887d79 | 2901 | /* we do not support '!' for function probes */ |
59df055f SR |
2902 | if (WARN_ON(not)) |
2903 | return; | |
2904 | } | |
2905 | ||
2906 | mutex_lock(&ftrace_lock); | |
2907 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2908 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2909 | ||
2910 | hlist_for_each_entry_safe(entry, n, tmp, hhd, node) { | |
2911 | ||
2912 | /* break up if statements for readability */ | |
b6887d79 | 2913 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
2914 | continue; |
2915 | ||
b6887d79 | 2916 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
2917 | continue; |
2918 | ||
2919 | /* do this last, since it is the most expensive */ | |
2920 | if (glob) { | |
2921 | kallsyms_lookup(entry->ip, NULL, NULL, | |
2922 | NULL, str); | |
2923 | if (!ftrace_match(str, glob, len, type)) | |
2924 | continue; | |
2925 | } | |
2926 | ||
2927 | hlist_del(&entry->node); | |
2928 | call_rcu(&entry->rcu, ftrace_free_entry_rcu); | |
2929 | } | |
2930 | } | |
b6887d79 | 2931 | __disable_ftrace_function_probe(); |
59df055f SR |
2932 | mutex_unlock(&ftrace_lock); |
2933 | } | |
2934 | ||
2935 | void | |
b6887d79 | 2936 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2937 | void *data) |
2938 | { | |
b6887d79 SR |
2939 | __unregister_ftrace_function_probe(glob, ops, data, |
2940 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
2941 | } |
2942 | ||
2943 | void | |
b6887d79 | 2944 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 2945 | { |
b6887d79 | 2946 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
2947 | } |
2948 | ||
b6887d79 | 2949 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 2950 | { |
b6887d79 | 2951 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
2952 | } |
2953 | ||
f6180773 SR |
2954 | static LIST_HEAD(ftrace_commands); |
2955 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
2956 | ||
2957 | int register_ftrace_command(struct ftrace_func_command *cmd) | |
2958 | { | |
2959 | struct ftrace_func_command *p; | |
2960 | int ret = 0; | |
2961 | ||
2962 | mutex_lock(&ftrace_cmd_mutex); | |
2963 | list_for_each_entry(p, &ftrace_commands, list) { | |
2964 | if (strcmp(cmd->name, p->name) == 0) { | |
2965 | ret = -EBUSY; | |
2966 | goto out_unlock; | |
2967 | } | |
2968 | } | |
2969 | list_add(&cmd->list, &ftrace_commands); | |
2970 | out_unlock: | |
2971 | mutex_unlock(&ftrace_cmd_mutex); | |
2972 | ||
2973 | return ret; | |
2974 | } | |
2975 | ||
2976 | int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
2977 | { | |
2978 | struct ftrace_func_command *p, *n; | |
2979 | int ret = -ENODEV; | |
2980 | ||
2981 | mutex_lock(&ftrace_cmd_mutex); | |
2982 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
2983 | if (strcmp(cmd->name, p->name) == 0) { | |
2984 | ret = 0; | |
2985 | list_del_init(&p->list); | |
2986 | goto out_unlock; | |
2987 | } | |
2988 | } | |
2989 | out_unlock: | |
2990 | mutex_unlock(&ftrace_cmd_mutex); | |
2991 | ||
2992 | return ret; | |
2993 | } | |
2994 | ||
33dc9b12 SR |
2995 | static int ftrace_process_regex(struct ftrace_hash *hash, |
2996 | char *buff, int len, int enable) | |
64e7c440 | 2997 | { |
f6180773 | 2998 | char *func, *command, *next = buff; |
6a24a244 | 2999 | struct ftrace_func_command *p; |
0aff1c0c | 3000 | int ret = -EINVAL; |
64e7c440 SR |
3001 | |
3002 | func = strsep(&next, ":"); | |
3003 | ||
3004 | if (!next) { | |
1cf41dd7 | 3005 | ret = ftrace_match_records(hash, func, len); |
b448c4e3 SR |
3006 | if (!ret) |
3007 | ret = -EINVAL; | |
3008 | if (ret < 0) | |
3009 | return ret; | |
3010 | return 0; | |
64e7c440 SR |
3011 | } |
3012 | ||
f6180773 | 3013 | /* command found */ |
64e7c440 SR |
3014 | |
3015 | command = strsep(&next, ":"); | |
3016 | ||
f6180773 SR |
3017 | mutex_lock(&ftrace_cmd_mutex); |
3018 | list_for_each_entry(p, &ftrace_commands, list) { | |
3019 | if (strcmp(p->name, command) == 0) { | |
43dd61c9 | 3020 | ret = p->func(hash, func, command, next, enable); |
f6180773 SR |
3021 | goto out_unlock; |
3022 | } | |
64e7c440 | 3023 | } |
f6180773 SR |
3024 | out_unlock: |
3025 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 3026 | |
f6180773 | 3027 | return ret; |
64e7c440 SR |
3028 | } |
3029 | ||
e309b41d | 3030 | static ssize_t |
41c52c0d SR |
3031 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
3032 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
3033 | { |
3034 | struct ftrace_iterator *iter; | |
689fd8b6 | 3035 | struct trace_parser *parser; |
3036 | ssize_t ret, read; | |
5072c59f | 3037 | |
4ba7978e | 3038 | if (!cnt) |
5072c59f SR |
3039 | return 0; |
3040 | ||
41c52c0d | 3041 | mutex_lock(&ftrace_regex_lock); |
5072c59f | 3042 | |
45a4a237 SR |
3043 | ret = -ENODEV; |
3044 | if (unlikely(ftrace_disabled)) | |
3045 | goto out_unlock; | |
3046 | ||
5072c59f SR |
3047 | if (file->f_mode & FMODE_READ) { |
3048 | struct seq_file *m = file->private_data; | |
3049 | iter = m->private; | |
3050 | } else | |
3051 | iter = file->private_data; | |
3052 | ||
689fd8b6 | 3053 | parser = &iter->parser; |
3054 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 3055 | |
4ba7978e | 3056 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 3057 | !trace_parser_cont(parser)) { |
33dc9b12 | 3058 | ret = ftrace_process_regex(iter->hash, parser->buffer, |
689fd8b6 | 3059 | parser->idx, enable); |
313254a9 | 3060 | trace_parser_clear(parser); |
5072c59f | 3061 | if (ret) |
ed146b25 | 3062 | goto out_unlock; |
eda1e328 | 3063 | } |
5072c59f | 3064 | |
5072c59f | 3065 | ret = read; |
ed146b25 | 3066 | out_unlock: |
689fd8b6 | 3067 | mutex_unlock(&ftrace_regex_lock); |
ed146b25 | 3068 | |
5072c59f SR |
3069 | return ret; |
3070 | } | |
3071 | ||
41c52c0d SR |
3072 | static ssize_t |
3073 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
3074 | size_t cnt, loff_t *ppos) | |
3075 | { | |
3076 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
3077 | } | |
3078 | ||
3079 | static ssize_t | |
3080 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
3081 | size_t cnt, loff_t *ppos) | |
3082 | { | |
3083 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
3084 | } | |
3085 | ||
33dc9b12 | 3086 | static int |
f45948e8 SR |
3087 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, |
3088 | int reset, int enable) | |
41c52c0d | 3089 | { |
33dc9b12 | 3090 | struct ftrace_hash **orig_hash; |
f45948e8 | 3091 | struct ftrace_hash *hash; |
33dc9b12 | 3092 | int ret; |
f45948e8 | 3093 | |
936e074b SR |
3094 | /* All global ops uses the global ops filters */ |
3095 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) | |
3096 | ops = &global_ops; | |
3097 | ||
41c52c0d | 3098 | if (unlikely(ftrace_disabled)) |
33dc9b12 | 3099 | return -ENODEV; |
41c52c0d | 3100 | |
f45948e8 | 3101 | if (enable) |
33dc9b12 | 3102 | orig_hash = &ops->filter_hash; |
f45948e8 | 3103 | else |
33dc9b12 SR |
3104 | orig_hash = &ops->notrace_hash; |
3105 | ||
3106 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
3107 | if (!hash) | |
3108 | return -ENOMEM; | |
f45948e8 | 3109 | |
41c52c0d SR |
3110 | mutex_lock(&ftrace_regex_lock); |
3111 | if (reset) | |
1cf41dd7 | 3112 | ftrace_filter_reset(hash); |
41c52c0d | 3113 | if (buf) |
1cf41dd7 | 3114 | ftrace_match_records(hash, buf, len); |
33dc9b12 SR |
3115 | |
3116 | mutex_lock(&ftrace_lock); | |
41fb61c2 | 3117 | ret = ftrace_hash_move(ops, enable, orig_hash, hash); |
072126f4 SR |
3118 | if (!ret && ops->flags & FTRACE_OPS_FL_ENABLED |
3119 | && ftrace_enabled) | |
30fb6aa7 | 3120 | ftrace_run_update_code(FTRACE_UPDATE_CALLS); |
072126f4 | 3121 | |
33dc9b12 SR |
3122 | mutex_unlock(&ftrace_lock); |
3123 | ||
41c52c0d | 3124 | mutex_unlock(&ftrace_regex_lock); |
33dc9b12 SR |
3125 | |
3126 | free_ftrace_hash(hash); | |
3127 | return ret; | |
41c52c0d SR |
3128 | } |
3129 | ||
77a2b37d SR |
3130 | /** |
3131 | * ftrace_set_filter - set a function to filter on in ftrace | |
936e074b SR |
3132 | * @ops - the ops to set the filter with |
3133 | * @buf - the string that holds the function filter text. | |
3134 | * @len - the length of the string. | |
3135 | * @reset - non zero to reset all filters before applying this filter. | |
3136 | * | |
3137 | * Filters denote which functions should be enabled when tracing is enabled. | |
3138 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
3139 | */ | |
3140 | void ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, | |
3141 | int len, int reset) | |
3142 | { | |
3143 | ftrace_set_regex(ops, buf, len, reset, 1); | |
3144 | } | |
3145 | EXPORT_SYMBOL_GPL(ftrace_set_filter); | |
3146 | ||
3147 | /** | |
3148 | * ftrace_set_notrace - set a function to not trace in ftrace | |
3149 | * @ops - the ops to set the notrace filter with | |
3150 | * @buf - the string that holds the function notrace text. | |
3151 | * @len - the length of the string. | |
3152 | * @reset - non zero to reset all filters before applying this filter. | |
3153 | * | |
3154 | * Notrace Filters denote which functions should not be enabled when tracing | |
3155 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
3156 | * for tracing. | |
3157 | */ | |
3158 | void ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, | |
3159 | int len, int reset) | |
3160 | { | |
3161 | ftrace_set_regex(ops, buf, len, reset, 0); | |
3162 | } | |
3163 | EXPORT_SYMBOL_GPL(ftrace_set_notrace); | |
3164 | /** | |
3165 | * ftrace_set_filter - set a function to filter on in ftrace | |
3166 | * @ops - the ops to set the filter with | |
77a2b37d SR |
3167 | * @buf - the string that holds the function filter text. |
3168 | * @len - the length of the string. | |
3169 | * @reset - non zero to reset all filters before applying this filter. | |
3170 | * | |
3171 | * Filters denote which functions should be enabled when tracing is enabled. | |
3172 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
3173 | */ | |
936e074b | 3174 | void ftrace_set_global_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 3175 | { |
f45948e8 | 3176 | ftrace_set_regex(&global_ops, buf, len, reset, 1); |
41c52c0d | 3177 | } |
936e074b | 3178 | EXPORT_SYMBOL_GPL(ftrace_set_global_filter); |
4eebcc81 | 3179 | |
41c52c0d SR |
3180 | /** |
3181 | * ftrace_set_notrace - set a function to not trace in ftrace | |
936e074b | 3182 | * @ops - the ops to set the notrace filter with |
41c52c0d SR |
3183 | * @buf - the string that holds the function notrace text. |
3184 | * @len - the length of the string. | |
3185 | * @reset - non zero to reset all filters before applying this filter. | |
3186 | * | |
3187 | * Notrace Filters denote which functions should not be enabled when tracing | |
3188 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
3189 | * for tracing. | |
3190 | */ | |
936e074b | 3191 | void ftrace_set_global_notrace(unsigned char *buf, int len, int reset) |
41c52c0d | 3192 | { |
f45948e8 | 3193 | ftrace_set_regex(&global_ops, buf, len, reset, 0); |
77a2b37d | 3194 | } |
936e074b | 3195 | EXPORT_SYMBOL_GPL(ftrace_set_global_notrace); |
77a2b37d | 3196 | |
2af15d6a SR |
3197 | /* |
3198 | * command line interface to allow users to set filters on boot up. | |
3199 | */ | |
3200 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
3201 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
3202 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
3203 | ||
3204 | static int __init set_ftrace_notrace(char *str) | |
3205 | { | |
3206 | strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); | |
3207 | return 1; | |
3208 | } | |
3209 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
3210 | ||
3211 | static int __init set_ftrace_filter(char *str) | |
3212 | { | |
3213 | strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); | |
3214 | return 1; | |
3215 | } | |
3216 | __setup("ftrace_filter=", set_ftrace_filter); | |
3217 | ||
369bc18f | 3218 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 3219 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
801c29fd SR |
3220 | static int ftrace_set_func(unsigned long *array, int *idx, char *buffer); |
3221 | ||
369bc18f SA |
3222 | static int __init set_graph_function(char *str) |
3223 | { | |
06f43d66 | 3224 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
3225 | return 1; |
3226 | } | |
3227 | __setup("ftrace_graph_filter=", set_graph_function); | |
3228 | ||
3229 | static void __init set_ftrace_early_graph(char *buf) | |
3230 | { | |
3231 | int ret; | |
3232 | char *func; | |
3233 | ||
3234 | while (buf) { | |
3235 | func = strsep(&buf, ","); | |
3236 | /* we allow only one expression at a time */ | |
3237 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, | |
3238 | func); | |
3239 | if (ret) | |
3240 | printk(KERN_DEBUG "ftrace: function %s not " | |
3241 | "traceable\n", func); | |
3242 | } | |
3243 | } | |
3244 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
3245 | ||
f45948e8 SR |
3246 | static void __init |
3247 | set_ftrace_early_filter(struct ftrace_ops *ops, char *buf, int enable) | |
2af15d6a SR |
3248 | { |
3249 | char *func; | |
3250 | ||
3251 | while (buf) { | |
3252 | func = strsep(&buf, ","); | |
f45948e8 | 3253 | ftrace_set_regex(ops, func, strlen(func), 0, enable); |
2af15d6a SR |
3254 | } |
3255 | } | |
3256 | ||
3257 | static void __init set_ftrace_early_filters(void) | |
3258 | { | |
3259 | if (ftrace_filter_buf[0]) | |
f45948e8 | 3260 | set_ftrace_early_filter(&global_ops, ftrace_filter_buf, 1); |
2af15d6a | 3261 | if (ftrace_notrace_buf[0]) |
f45948e8 | 3262 | set_ftrace_early_filter(&global_ops, ftrace_notrace_buf, 0); |
369bc18f SA |
3263 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
3264 | if (ftrace_graph_buf[0]) | |
3265 | set_ftrace_early_graph(ftrace_graph_buf); | |
3266 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2af15d6a SR |
3267 | } |
3268 | ||
e309b41d | 3269 | static int |
1cf41dd7 | 3270 | ftrace_regex_release(struct inode *inode, struct file *file) |
5072c59f SR |
3271 | { |
3272 | struct seq_file *m = (struct seq_file *)file->private_data; | |
3273 | struct ftrace_iterator *iter; | |
33dc9b12 | 3274 | struct ftrace_hash **orig_hash; |
689fd8b6 | 3275 | struct trace_parser *parser; |
ed926f9b | 3276 | int filter_hash; |
33dc9b12 | 3277 | int ret; |
5072c59f | 3278 | |
41c52c0d | 3279 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
3280 | if (file->f_mode & FMODE_READ) { |
3281 | iter = m->private; | |
3282 | ||
3283 | seq_release(inode, file); | |
3284 | } else | |
3285 | iter = file->private_data; | |
3286 | ||
689fd8b6 | 3287 | parser = &iter->parser; |
3288 | if (trace_parser_loaded(parser)) { | |
3289 | parser->buffer[parser->idx] = 0; | |
1cf41dd7 | 3290 | ftrace_match_records(iter->hash, parser->buffer, parser->idx); |
5072c59f SR |
3291 | } |
3292 | ||
689fd8b6 | 3293 | trace_parser_put(parser); |
689fd8b6 | 3294 | |
058e297d | 3295 | if (file->f_mode & FMODE_WRITE) { |
ed926f9b SR |
3296 | filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); |
3297 | ||
3298 | if (filter_hash) | |
33dc9b12 | 3299 | orig_hash = &iter->ops->filter_hash; |
ed926f9b SR |
3300 | else |
3301 | orig_hash = &iter->ops->notrace_hash; | |
33dc9b12 | 3302 | |
058e297d | 3303 | mutex_lock(&ftrace_lock); |
41fb61c2 SR |
3304 | ret = ftrace_hash_move(iter->ops, filter_hash, |
3305 | orig_hash, iter->hash); | |
3306 | if (!ret && (iter->ops->flags & FTRACE_OPS_FL_ENABLED) | |
3307 | && ftrace_enabled) | |
30fb6aa7 | 3308 | ftrace_run_update_code(FTRACE_UPDATE_CALLS); |
41fb61c2 | 3309 | |
058e297d SR |
3310 | mutex_unlock(&ftrace_lock); |
3311 | } | |
33dc9b12 SR |
3312 | free_ftrace_hash(iter->hash); |
3313 | kfree(iter); | |
058e297d | 3314 | |
41c52c0d | 3315 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
3316 | return 0; |
3317 | } | |
3318 | ||
5e2336a0 | 3319 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
3320 | .open = ftrace_avail_open, |
3321 | .read = seq_read, | |
3322 | .llseek = seq_lseek, | |
3be04b47 | 3323 | .release = seq_release_private, |
5072c59f SR |
3324 | }; |
3325 | ||
647bcd03 SR |
3326 | static const struct file_operations ftrace_enabled_fops = { |
3327 | .open = ftrace_enabled_open, | |
3328 | .read = seq_read, | |
3329 | .llseek = seq_lseek, | |
3330 | .release = seq_release_private, | |
3331 | }; | |
3332 | ||
5e2336a0 | 3333 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 3334 | .open = ftrace_filter_open, |
850a80cf | 3335 | .read = seq_read, |
5072c59f | 3336 | .write = ftrace_filter_write, |
98c4fd04 | 3337 | .llseek = ftrace_regex_lseek, |
1cf41dd7 | 3338 | .release = ftrace_regex_release, |
5072c59f SR |
3339 | }; |
3340 | ||
5e2336a0 | 3341 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 3342 | .open = ftrace_notrace_open, |
850a80cf | 3343 | .read = seq_read, |
41c52c0d SR |
3344 | .write = ftrace_notrace_write, |
3345 | .llseek = ftrace_regex_lseek, | |
1cf41dd7 | 3346 | .release = ftrace_regex_release, |
41c52c0d SR |
3347 | }; |
3348 | ||
ea4e2bc4 SR |
3349 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
3350 | ||
3351 | static DEFINE_MUTEX(graph_lock); | |
3352 | ||
3353 | int ftrace_graph_count; | |
c7c6b1fe | 3354 | int ftrace_graph_filter_enabled; |
ea4e2bc4 SR |
3355 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
3356 | ||
3357 | static void * | |
85951842 | 3358 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 3359 | { |
85951842 | 3360 | if (*pos >= ftrace_graph_count) |
ea4e2bc4 | 3361 | return NULL; |
a4ec5e0c | 3362 | return &ftrace_graph_funcs[*pos]; |
85951842 | 3363 | } |
ea4e2bc4 | 3364 | |
85951842 LZ |
3365 | static void * |
3366 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
3367 | { | |
3368 | (*pos)++; | |
3369 | return __g_next(m, pos); | |
ea4e2bc4 SR |
3370 | } |
3371 | ||
3372 | static void *g_start(struct seq_file *m, loff_t *pos) | |
3373 | { | |
ea4e2bc4 SR |
3374 | mutex_lock(&graph_lock); |
3375 | ||
f9349a8f | 3376 | /* Nothing, tell g_show to print all functions are enabled */ |
c7c6b1fe | 3377 | if (!ftrace_graph_filter_enabled && !*pos) |
f9349a8f FW |
3378 | return (void *)1; |
3379 | ||
85951842 | 3380 | return __g_next(m, pos); |
ea4e2bc4 SR |
3381 | } |
3382 | ||
3383 | static void g_stop(struct seq_file *m, void *p) | |
3384 | { | |
3385 | mutex_unlock(&graph_lock); | |
3386 | } | |
3387 | ||
3388 | static int g_show(struct seq_file *m, void *v) | |
3389 | { | |
3390 | unsigned long *ptr = v; | |
ea4e2bc4 SR |
3391 | |
3392 | if (!ptr) | |
3393 | return 0; | |
3394 | ||
f9349a8f FW |
3395 | if (ptr == (unsigned long *)1) { |
3396 | seq_printf(m, "#### all functions enabled ####\n"); | |
3397 | return 0; | |
3398 | } | |
3399 | ||
b375a11a | 3400 | seq_printf(m, "%ps\n", (void *)*ptr); |
ea4e2bc4 SR |
3401 | |
3402 | return 0; | |
3403 | } | |
3404 | ||
88e9d34c | 3405 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
3406 | .start = g_start, |
3407 | .next = g_next, | |
3408 | .stop = g_stop, | |
3409 | .show = g_show, | |
3410 | }; | |
3411 | ||
3412 | static int | |
3413 | ftrace_graph_open(struct inode *inode, struct file *file) | |
3414 | { | |
3415 | int ret = 0; | |
3416 | ||
3417 | if (unlikely(ftrace_disabled)) | |
3418 | return -ENODEV; | |
3419 | ||
3420 | mutex_lock(&graph_lock); | |
3421 | if ((file->f_mode & FMODE_WRITE) && | |
8650ae32 | 3422 | (file->f_flags & O_TRUNC)) { |
c7c6b1fe | 3423 | ftrace_graph_filter_enabled = 0; |
ea4e2bc4 SR |
3424 | ftrace_graph_count = 0; |
3425 | memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); | |
3426 | } | |
a4ec5e0c | 3427 | mutex_unlock(&graph_lock); |
ea4e2bc4 | 3428 | |
a4ec5e0c | 3429 | if (file->f_mode & FMODE_READ) |
ea4e2bc4 | 3430 | ret = seq_open(file, &ftrace_graph_seq_ops); |
ea4e2bc4 SR |
3431 | |
3432 | return ret; | |
3433 | } | |
3434 | ||
87827111 LZ |
3435 | static int |
3436 | ftrace_graph_release(struct inode *inode, struct file *file) | |
3437 | { | |
3438 | if (file->f_mode & FMODE_READ) | |
3439 | seq_release(inode, file); | |
3440 | return 0; | |
3441 | } | |
3442 | ||
ea4e2bc4 | 3443 | static int |
f9349a8f | 3444 | ftrace_set_func(unsigned long *array, int *idx, char *buffer) |
ea4e2bc4 | 3445 | { |
ea4e2bc4 SR |
3446 | struct dyn_ftrace *rec; |
3447 | struct ftrace_page *pg; | |
f9349a8f | 3448 | int search_len; |
c7c6b1fe | 3449 | int fail = 1; |
f9349a8f FW |
3450 | int type, not; |
3451 | char *search; | |
3452 | bool exists; | |
3453 | int i; | |
ea4e2bc4 | 3454 | |
f9349a8f | 3455 | /* decode regex */ |
3f6fe06d | 3456 | type = filter_parse_regex(buffer, strlen(buffer), &search, ¬); |
c7c6b1fe LZ |
3457 | if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS) |
3458 | return -EBUSY; | |
f9349a8f FW |
3459 | |
3460 | search_len = strlen(search); | |
3461 | ||
52baf119 | 3462 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
3463 | |
3464 | if (unlikely(ftrace_disabled)) { | |
3465 | mutex_unlock(&ftrace_lock); | |
3466 | return -ENODEV; | |
3467 | } | |
3468 | ||
265c831c SR |
3469 | do_for_each_ftrace_rec(pg, rec) { |
3470 | ||
b9df92d2 | 3471 | if (ftrace_match_record(rec, NULL, search, search_len, type)) { |
c7c6b1fe | 3472 | /* if it is in the array */ |
f9349a8f | 3473 | exists = false; |
c7c6b1fe | 3474 | for (i = 0; i < *idx; i++) { |
f9349a8f FW |
3475 | if (array[i] == rec->ip) { |
3476 | exists = true; | |
265c831c SR |
3477 | break; |
3478 | } | |
c7c6b1fe LZ |
3479 | } |
3480 | ||
3481 | if (!not) { | |
3482 | fail = 0; | |
3483 | if (!exists) { | |
3484 | array[(*idx)++] = rec->ip; | |
3485 | if (*idx >= FTRACE_GRAPH_MAX_FUNCS) | |
3486 | goto out; | |
3487 | } | |
3488 | } else { | |
3489 | if (exists) { | |
3490 | array[i] = array[--(*idx)]; | |
3491 | array[*idx] = 0; | |
3492 | fail = 0; | |
3493 | } | |
3494 | } | |
ea4e2bc4 | 3495 | } |
265c831c | 3496 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 3497 | out: |
52baf119 | 3498 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 3499 | |
c7c6b1fe LZ |
3500 | if (fail) |
3501 | return -EINVAL; | |
3502 | ||
3503 | ftrace_graph_filter_enabled = 1; | |
3504 | return 0; | |
ea4e2bc4 SR |
3505 | } |
3506 | ||
3507 | static ssize_t | |
3508 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
3509 | size_t cnt, loff_t *ppos) | |
3510 | { | |
689fd8b6 | 3511 | struct trace_parser parser; |
4ba7978e | 3512 | ssize_t read, ret; |
ea4e2bc4 | 3513 | |
c7c6b1fe | 3514 | if (!cnt) |
ea4e2bc4 SR |
3515 | return 0; |
3516 | ||
3517 | mutex_lock(&graph_lock); | |
3518 | ||
689fd8b6 | 3519 | if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) { |
3520 | ret = -ENOMEM; | |
1eb90f13 | 3521 | goto out_unlock; |
ea4e2bc4 SR |
3522 | } |
3523 | ||
689fd8b6 | 3524 | read = trace_get_user(&parser, ubuf, cnt, ppos); |
ea4e2bc4 | 3525 | |
4ba7978e | 3526 | if (read >= 0 && trace_parser_loaded((&parser))) { |
689fd8b6 | 3527 | parser.buffer[parser.idx] = 0; |
3528 | ||
3529 | /* we allow only one expression at a time */ | |
a4ec5e0c | 3530 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, |
689fd8b6 | 3531 | parser.buffer); |
ea4e2bc4 | 3532 | if (ret) |
1eb90f13 | 3533 | goto out_free; |
ea4e2bc4 | 3534 | } |
ea4e2bc4 SR |
3535 | |
3536 | ret = read; | |
1eb90f13 LZ |
3537 | |
3538 | out_free: | |
689fd8b6 | 3539 | trace_parser_put(&parser); |
1eb90f13 | 3540 | out_unlock: |
ea4e2bc4 SR |
3541 | mutex_unlock(&graph_lock); |
3542 | ||
3543 | return ret; | |
3544 | } | |
3545 | ||
3546 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
3547 | .open = ftrace_graph_open, |
3548 | .read = seq_read, | |
3549 | .write = ftrace_graph_write, | |
3550 | .release = ftrace_graph_release, | |
6038f373 | 3551 | .llseek = seq_lseek, |
ea4e2bc4 SR |
3552 | }; |
3553 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
3554 | ||
df4fc315 | 3555 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 3556 | { |
5072c59f | 3557 | |
5452af66 FW |
3558 | trace_create_file("available_filter_functions", 0444, |
3559 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 3560 | |
647bcd03 SR |
3561 | trace_create_file("enabled_functions", 0444, |
3562 | d_tracer, NULL, &ftrace_enabled_fops); | |
3563 | ||
5452af66 FW |
3564 | trace_create_file("set_ftrace_filter", 0644, d_tracer, |
3565 | NULL, &ftrace_filter_fops); | |
41c52c0d | 3566 | |
5452af66 | 3567 | trace_create_file("set_ftrace_notrace", 0644, d_tracer, |
41c52c0d | 3568 | NULL, &ftrace_notrace_fops); |
ad90c0e3 | 3569 | |
ea4e2bc4 | 3570 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 3571 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
3572 | NULL, |
3573 | &ftrace_graph_fops); | |
ea4e2bc4 SR |
3574 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
3575 | ||
5072c59f SR |
3576 | return 0; |
3577 | } | |
3578 | ||
68950619 SR |
3579 | static void ftrace_swap_recs(void *a, void *b, int size) |
3580 | { | |
3581 | struct dyn_ftrace *reca = a; | |
3582 | struct dyn_ftrace *recb = b; | |
3583 | struct dyn_ftrace t; | |
3584 | ||
3585 | t = *reca; | |
3586 | *reca = *recb; | |
3587 | *recb = t; | |
3588 | } | |
3589 | ||
3590 | static int ftrace_cmp_recs(const void *a, const void *b) | |
3591 | { | |
3592 | const struct dyn_ftrace *reca = a; | |
3593 | const struct dyn_ftrace *recb = b; | |
3594 | ||
3595 | if (reca->ip > recb->ip) | |
3596 | return 1; | |
3597 | if (reca->ip < recb->ip) | |
3598 | return -1; | |
3599 | return 0; | |
3600 | } | |
3601 | ||
5cb084bb | 3602 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 3603 | unsigned long *start, |
68bf21aa SR |
3604 | unsigned long *end) |
3605 | { | |
a7900875 SR |
3606 | struct ftrace_page *pg; |
3607 | unsigned long count; | |
68bf21aa SR |
3608 | unsigned long *p; |
3609 | unsigned long addr; | |
4376cac6 | 3610 | unsigned long flags = 0; /* Shut up gcc */ |
a7900875 SR |
3611 | int ret = -ENOMEM; |
3612 | ||
3613 | count = end - start; | |
3614 | ||
3615 | if (!count) | |
3616 | return 0; | |
3617 | ||
3618 | pg = ftrace_allocate_pages(count); | |
3619 | if (!pg) | |
3620 | return -ENOMEM; | |
68bf21aa | 3621 | |
e6ea44e9 | 3622 | mutex_lock(&ftrace_lock); |
a7900875 | 3623 | |
32082309 SR |
3624 | /* |
3625 | * Core and each module needs their own pages, as | |
3626 | * modules will free them when they are removed. | |
3627 | * Force a new page to be allocated for modules. | |
3628 | */ | |
a7900875 SR |
3629 | if (!mod) { |
3630 | WARN_ON(ftrace_pages || ftrace_pages_start); | |
3631 | /* First initialization */ | |
3632 | ftrace_pages = ftrace_pages_start = pg; | |
3633 | } else { | |
32082309 | 3634 | if (!ftrace_pages) |
a7900875 | 3635 | goto out; |
32082309 | 3636 | |
a7900875 SR |
3637 | if (WARN_ON(ftrace_pages->next)) { |
3638 | /* Hmm, we have free pages? */ | |
3639 | while (ftrace_pages->next) | |
3640 | ftrace_pages = ftrace_pages->next; | |
32082309 | 3641 | } |
a7900875 SR |
3642 | |
3643 | ftrace_pages->next = pg; | |
3644 | ftrace_pages = pg; | |
32082309 SR |
3645 | } |
3646 | ||
68bf21aa SR |
3647 | p = start; |
3648 | while (p < end) { | |
3649 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
3650 | /* |
3651 | * Some architecture linkers will pad between | |
3652 | * the different mcount_loc sections of different | |
3653 | * object files to satisfy alignments. | |
3654 | * Skip any NULL pointers. | |
3655 | */ | |
3656 | if (!addr) | |
3657 | continue; | |
a7900875 SR |
3658 | if (!ftrace_record_ip(addr)) |
3659 | break; | |
68bf21aa SR |
3660 | } |
3661 | ||
85ae32ae SR |
3662 | /* These new locations need to be initialized */ |
3663 | ftrace_new_pgs = pg; | |
3664 | ||
68950619 SR |
3665 | /* Make each individual set of pages sorted by ips */ |
3666 | for (; pg; pg = pg->next) | |
3667 | sort(pg->records, pg->index, sizeof(struct dyn_ftrace), | |
3668 | ftrace_cmp_recs, ftrace_swap_recs); | |
3669 | ||
a4f18ed1 | 3670 | /* |
4376cac6 SR |
3671 | * We only need to disable interrupts on start up |
3672 | * because we are modifying code that an interrupt | |
3673 | * may execute, and the modification is not atomic. | |
3674 | * But for modules, nothing runs the code we modify | |
3675 | * until we are finished with it, and there's no | |
3676 | * reason to cause large interrupt latencies while we do it. | |
a4f18ed1 | 3677 | */ |
4376cac6 SR |
3678 | if (!mod) |
3679 | local_irq_save(flags); | |
31e88909 | 3680 | ftrace_update_code(mod); |
4376cac6 SR |
3681 | if (!mod) |
3682 | local_irq_restore(flags); | |
a7900875 SR |
3683 | ret = 0; |
3684 | out: | |
e6ea44e9 | 3685 | mutex_unlock(&ftrace_lock); |
68bf21aa | 3686 | |
a7900875 | 3687 | return ret; |
68bf21aa SR |
3688 | } |
3689 | ||
93eb677d | 3690 | #ifdef CONFIG_MODULES |
32082309 SR |
3691 | |
3692 | #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next) | |
3693 | ||
e7247a15 | 3694 | void ftrace_release_mod(struct module *mod) |
93eb677d SR |
3695 | { |
3696 | struct dyn_ftrace *rec; | |
32082309 | 3697 | struct ftrace_page **last_pg; |
93eb677d | 3698 | struct ftrace_page *pg; |
a7900875 | 3699 | int order; |
93eb677d | 3700 | |
45a4a237 SR |
3701 | mutex_lock(&ftrace_lock); |
3702 | ||
e7247a15 | 3703 | if (ftrace_disabled) |
45a4a237 | 3704 | goto out_unlock; |
93eb677d | 3705 | |
32082309 SR |
3706 | /* |
3707 | * Each module has its own ftrace_pages, remove | |
3708 | * them from the list. | |
3709 | */ | |
3710 | last_pg = &ftrace_pages_start; | |
3711 | for (pg = ftrace_pages_start; pg; pg = *last_pg) { | |
3712 | rec = &pg->records[0]; | |
e7247a15 | 3713 | if (within_module_core(rec->ip, mod)) { |
93eb677d | 3714 | /* |
32082309 SR |
3715 | * As core pages are first, the first |
3716 | * page should never be a module page. | |
93eb677d | 3717 | */ |
32082309 SR |
3718 | if (WARN_ON(pg == ftrace_pages_start)) |
3719 | goto out_unlock; | |
3720 | ||
3721 | /* Check if we are deleting the last page */ | |
3722 | if (pg == ftrace_pages) | |
3723 | ftrace_pages = next_to_ftrace_page(last_pg); | |
3724 | ||
3725 | *last_pg = pg->next; | |
a7900875 SR |
3726 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
3727 | free_pages((unsigned long)pg->records, order); | |
3728 | kfree(pg); | |
32082309 SR |
3729 | } else |
3730 | last_pg = &pg->next; | |
3731 | } | |
45a4a237 | 3732 | out_unlock: |
93eb677d SR |
3733 | mutex_unlock(&ftrace_lock); |
3734 | } | |
3735 | ||
3736 | static void ftrace_init_module(struct module *mod, | |
3737 | unsigned long *start, unsigned long *end) | |
90d595fe | 3738 | { |
00fd61ae | 3739 | if (ftrace_disabled || start == end) |
fed1939c | 3740 | return; |
5cb084bb | 3741 | ftrace_process_locs(mod, start, end); |
90d595fe SR |
3742 | } |
3743 | ||
93eb677d SR |
3744 | static int ftrace_module_notify(struct notifier_block *self, |
3745 | unsigned long val, void *data) | |
3746 | { | |
3747 | struct module *mod = data; | |
3748 | ||
3749 | switch (val) { | |
3750 | case MODULE_STATE_COMING: | |
3751 | ftrace_init_module(mod, mod->ftrace_callsites, | |
3752 | mod->ftrace_callsites + | |
3753 | mod->num_ftrace_callsites); | |
3754 | break; | |
3755 | case MODULE_STATE_GOING: | |
e7247a15 | 3756 | ftrace_release_mod(mod); |
93eb677d SR |
3757 | break; |
3758 | } | |
3759 | ||
3760 | return 0; | |
3761 | } | |
3762 | #else | |
3763 | static int ftrace_module_notify(struct notifier_block *self, | |
3764 | unsigned long val, void *data) | |
3765 | { | |
3766 | return 0; | |
3767 | } | |
3768 | #endif /* CONFIG_MODULES */ | |
3769 | ||
3770 | struct notifier_block ftrace_module_nb = { | |
3771 | .notifier_call = ftrace_module_notify, | |
3772 | .priority = 0, | |
3773 | }; | |
3774 | ||
68bf21aa SR |
3775 | extern unsigned long __start_mcount_loc[]; |
3776 | extern unsigned long __stop_mcount_loc[]; | |
3777 | ||
3778 | void __init ftrace_init(void) | |
3779 | { | |
3780 | unsigned long count, addr, flags; | |
3781 | int ret; | |
3782 | ||
3783 | /* Keep the ftrace pointer to the stub */ | |
3784 | addr = (unsigned long)ftrace_stub; | |
3785 | ||
3786 | local_irq_save(flags); | |
3787 | ftrace_dyn_arch_init(&addr); | |
3788 | local_irq_restore(flags); | |
3789 | ||
3790 | /* ftrace_dyn_arch_init places the return code in addr */ | |
3791 | if (addr) | |
3792 | goto failed; | |
3793 | ||
3794 | count = __stop_mcount_loc - __start_mcount_loc; | |
3795 | ||
3796 | ret = ftrace_dyn_table_alloc(count); | |
3797 | if (ret) | |
3798 | goto failed; | |
3799 | ||
3800 | last_ftrace_enabled = ftrace_enabled = 1; | |
3801 | ||
5cb084bb | 3802 | ret = ftrace_process_locs(NULL, |
31e88909 | 3803 | __start_mcount_loc, |
68bf21aa SR |
3804 | __stop_mcount_loc); |
3805 | ||
93eb677d | 3806 | ret = register_module_notifier(&ftrace_module_nb); |
24ed0c4b | 3807 | if (ret) |
93eb677d SR |
3808 | pr_warning("Failed to register trace ftrace module notifier\n"); |
3809 | ||
2af15d6a SR |
3810 | set_ftrace_early_filters(); |
3811 | ||
68bf21aa SR |
3812 | return; |
3813 | failed: | |
3814 | ftrace_disabled = 1; | |
3815 | } | |
68bf21aa | 3816 | |
3d083395 | 3817 | #else |
0b6e4d56 | 3818 | |
2b499381 | 3819 | static struct ftrace_ops global_ops = { |
bd69c30b SR |
3820 | .func = ftrace_stub, |
3821 | }; | |
3822 | ||
0b6e4d56 FW |
3823 | static int __init ftrace_nodyn_init(void) |
3824 | { | |
3825 | ftrace_enabled = 1; | |
3826 | return 0; | |
3827 | } | |
3828 | device_initcall(ftrace_nodyn_init); | |
3829 | ||
df4fc315 SR |
3830 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
3831 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 | 3832 | /* Keep as macros so we do not need to define the commands */ |
3b6cfdb1 SR |
3833 | # define ftrace_startup(ops, command) \ |
3834 | ({ \ | |
3835 | (ops)->flags |= FTRACE_OPS_FL_ENABLED; \ | |
3836 | 0; \ | |
3837 | }) | |
bd69c30b | 3838 | # define ftrace_shutdown(ops, command) do { } while (0) |
c7aafc54 IM |
3839 | # define ftrace_startup_sysctl() do { } while (0) |
3840 | # define ftrace_shutdown_sysctl() do { } while (0) | |
b848914c SR |
3841 | |
3842 | static inline int | |
3843 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip) | |
3844 | { | |
3845 | return 1; | |
3846 | } | |
3847 | ||
3d083395 SR |
3848 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
3849 | ||
b848914c SR |
3850 | static void |
3851 | ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip) | |
3852 | { | |
cdbe61bf | 3853 | struct ftrace_ops *op; |
b848914c | 3854 | |
b1cff0ad SR |
3855 | if (unlikely(trace_recursion_test(TRACE_INTERNAL_BIT))) |
3856 | return; | |
3857 | ||
3858 | trace_recursion_set(TRACE_INTERNAL_BIT); | |
cdbe61bf SR |
3859 | /* |
3860 | * Some of the ops may be dynamically allocated, | |
3861 | * they must be freed after a synchronize_sched(). | |
3862 | */ | |
3863 | preempt_disable_notrace(); | |
3864 | op = rcu_dereference_raw(ftrace_ops_list); | |
b848914c SR |
3865 | while (op != &ftrace_list_end) { |
3866 | if (ftrace_ops_test(op, ip)) | |
3867 | op->func(ip, parent_ip); | |
3868 | op = rcu_dereference_raw(op->next); | |
3869 | }; | |
cdbe61bf | 3870 | preempt_enable_notrace(); |
b1cff0ad | 3871 | trace_recursion_clear(TRACE_INTERNAL_BIT); |
b848914c SR |
3872 | } |
3873 | ||
e32d8956 | 3874 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
3875 | { |
3876 | struct task_struct *p; | |
e32d8956 | 3877 | int cpu; |
978f3a45 | 3878 | |
e32d8956 SR |
3879 | get_online_cpus(); |
3880 | for_each_online_cpu(cpu) { | |
3881 | p = idle_task(cpu); | |
978f3a45 | 3882 | clear_tsk_trace_trace(p); |
e32d8956 SR |
3883 | } |
3884 | put_online_cpus(); | |
3885 | } | |
978f3a45 | 3886 | |
e32d8956 SR |
3887 | static void set_ftrace_swapper(void) |
3888 | { | |
3889 | struct task_struct *p; | |
3890 | int cpu; | |
3891 | ||
3892 | get_online_cpus(); | |
3893 | for_each_online_cpu(cpu) { | |
3894 | p = idle_task(cpu); | |
3895 | set_tsk_trace_trace(p); | |
3896 | } | |
3897 | put_online_cpus(); | |
978f3a45 SR |
3898 | } |
3899 | ||
e32d8956 SR |
3900 | static void clear_ftrace_pid(struct pid *pid) |
3901 | { | |
3902 | struct task_struct *p; | |
3903 | ||
229c4ef8 | 3904 | rcu_read_lock(); |
e32d8956 SR |
3905 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
3906 | clear_tsk_trace_trace(p); | |
3907 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
3908 | rcu_read_unlock(); |
3909 | ||
e32d8956 SR |
3910 | put_pid(pid); |
3911 | } | |
3912 | ||
3913 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
3914 | { |
3915 | struct task_struct *p; | |
3916 | ||
229c4ef8 | 3917 | rcu_read_lock(); |
978f3a45 SR |
3918 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
3919 | set_tsk_trace_trace(p); | |
3920 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 3921 | rcu_read_unlock(); |
978f3a45 SR |
3922 | } |
3923 | ||
756d17ee | 3924 | static void clear_ftrace_pid_task(struct pid *pid) |
e32d8956 | 3925 | { |
756d17ee | 3926 | if (pid == ftrace_swapper_pid) |
e32d8956 SR |
3927 | clear_ftrace_swapper(); |
3928 | else | |
756d17ee | 3929 | clear_ftrace_pid(pid); |
e32d8956 SR |
3930 | } |
3931 | ||
3932 | static void set_ftrace_pid_task(struct pid *pid) | |
3933 | { | |
3934 | if (pid == ftrace_swapper_pid) | |
3935 | set_ftrace_swapper(); | |
3936 | else | |
3937 | set_ftrace_pid(pid); | |
3938 | } | |
3939 | ||
756d17ee | 3940 | static int ftrace_pid_add(int p) |
df4fc315 | 3941 | { |
978f3a45 | 3942 | struct pid *pid; |
756d17ee | 3943 | struct ftrace_pid *fpid; |
3944 | int ret = -EINVAL; | |
df4fc315 | 3945 | |
756d17ee | 3946 | mutex_lock(&ftrace_lock); |
df4fc315 | 3947 | |
756d17ee | 3948 | if (!p) |
3949 | pid = ftrace_swapper_pid; | |
3950 | else | |
3951 | pid = find_get_pid(p); | |
df4fc315 | 3952 | |
756d17ee | 3953 | if (!pid) |
3954 | goto out; | |
df4fc315 | 3955 | |
756d17ee | 3956 | ret = 0; |
df4fc315 | 3957 | |
756d17ee | 3958 | list_for_each_entry(fpid, &ftrace_pids, list) |
3959 | if (fpid->pid == pid) | |
3960 | goto out_put; | |
978f3a45 | 3961 | |
756d17ee | 3962 | ret = -ENOMEM; |
df4fc315 | 3963 | |
756d17ee | 3964 | fpid = kmalloc(sizeof(*fpid), GFP_KERNEL); |
3965 | if (!fpid) | |
3966 | goto out_put; | |
df4fc315 | 3967 | |
756d17ee | 3968 | list_add(&fpid->list, &ftrace_pids); |
3969 | fpid->pid = pid; | |
0ef8cde5 | 3970 | |
756d17ee | 3971 | set_ftrace_pid_task(pid); |
978f3a45 | 3972 | |
756d17ee | 3973 | ftrace_update_pid_func(); |
3974 | ftrace_startup_enable(0); | |
3975 | ||
3976 | mutex_unlock(&ftrace_lock); | |
3977 | return 0; | |
3978 | ||
3979 | out_put: | |
3980 | if (pid != ftrace_swapper_pid) | |
3981 | put_pid(pid); | |
978f3a45 | 3982 | |
756d17ee | 3983 | out: |
3984 | mutex_unlock(&ftrace_lock); | |
3985 | return ret; | |
3986 | } | |
3987 | ||
3988 | static void ftrace_pid_reset(void) | |
3989 | { | |
3990 | struct ftrace_pid *fpid, *safe; | |
978f3a45 | 3991 | |
756d17ee | 3992 | mutex_lock(&ftrace_lock); |
3993 | list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) { | |
3994 | struct pid *pid = fpid->pid; | |
3995 | ||
3996 | clear_ftrace_pid_task(pid); | |
3997 | ||
3998 | list_del(&fpid->list); | |
3999 | kfree(fpid); | |
df4fc315 SR |
4000 | } |
4001 | ||
df4fc315 SR |
4002 | ftrace_update_pid_func(); |
4003 | ftrace_startup_enable(0); | |
4004 | ||
e6ea44e9 | 4005 | mutex_unlock(&ftrace_lock); |
756d17ee | 4006 | } |
df4fc315 | 4007 | |
756d17ee | 4008 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
4009 | { | |
4010 | mutex_lock(&ftrace_lock); | |
4011 | ||
4012 | if (list_empty(&ftrace_pids) && (!*pos)) | |
4013 | return (void *) 1; | |
4014 | ||
4015 | return seq_list_start(&ftrace_pids, *pos); | |
4016 | } | |
4017 | ||
4018 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
4019 | { | |
4020 | if (v == (void *)1) | |
4021 | return NULL; | |
4022 | ||
4023 | return seq_list_next(v, &ftrace_pids, pos); | |
4024 | } | |
4025 | ||
4026 | static void fpid_stop(struct seq_file *m, void *p) | |
4027 | { | |
4028 | mutex_unlock(&ftrace_lock); | |
4029 | } | |
4030 | ||
4031 | static int fpid_show(struct seq_file *m, void *v) | |
4032 | { | |
4033 | const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list); | |
4034 | ||
4035 | if (v == (void *)1) { | |
4036 | seq_printf(m, "no pid\n"); | |
4037 | return 0; | |
4038 | } | |
4039 | ||
4040 | if (fpid->pid == ftrace_swapper_pid) | |
4041 | seq_printf(m, "swapper tasks\n"); | |
4042 | else | |
4043 | seq_printf(m, "%u\n", pid_vnr(fpid->pid)); | |
4044 | ||
4045 | return 0; | |
4046 | } | |
4047 | ||
4048 | static const struct seq_operations ftrace_pid_sops = { | |
4049 | .start = fpid_start, | |
4050 | .next = fpid_next, | |
4051 | .stop = fpid_stop, | |
4052 | .show = fpid_show, | |
4053 | }; | |
4054 | ||
4055 | static int | |
4056 | ftrace_pid_open(struct inode *inode, struct file *file) | |
4057 | { | |
4058 | int ret = 0; | |
4059 | ||
4060 | if ((file->f_mode & FMODE_WRITE) && | |
4061 | (file->f_flags & O_TRUNC)) | |
4062 | ftrace_pid_reset(); | |
4063 | ||
4064 | if (file->f_mode & FMODE_READ) | |
4065 | ret = seq_open(file, &ftrace_pid_sops); | |
4066 | ||
4067 | return ret; | |
4068 | } | |
4069 | ||
df4fc315 SR |
4070 | static ssize_t |
4071 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
4072 | size_t cnt, loff_t *ppos) | |
4073 | { | |
457dc928 | 4074 | char buf[64], *tmp; |
df4fc315 SR |
4075 | long val; |
4076 | int ret; | |
4077 | ||
4078 | if (cnt >= sizeof(buf)) | |
4079 | return -EINVAL; | |
4080 | ||
4081 | if (copy_from_user(&buf, ubuf, cnt)) | |
4082 | return -EFAULT; | |
4083 | ||
4084 | buf[cnt] = 0; | |
4085 | ||
756d17ee | 4086 | /* |
4087 | * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid" | |
4088 | * to clean the filter quietly. | |
4089 | */ | |
457dc928 IM |
4090 | tmp = strstrip(buf); |
4091 | if (strlen(tmp) == 0) | |
756d17ee | 4092 | return 1; |
4093 | ||
457dc928 | 4094 | ret = strict_strtol(tmp, 10, &val); |
df4fc315 SR |
4095 | if (ret < 0) |
4096 | return ret; | |
4097 | ||
756d17ee | 4098 | ret = ftrace_pid_add(val); |
df4fc315 | 4099 | |
756d17ee | 4100 | return ret ? ret : cnt; |
4101 | } | |
df4fc315 | 4102 | |
756d17ee | 4103 | static int |
4104 | ftrace_pid_release(struct inode *inode, struct file *file) | |
4105 | { | |
4106 | if (file->f_mode & FMODE_READ) | |
4107 | seq_release(inode, file); | |
df4fc315 | 4108 | |
756d17ee | 4109 | return 0; |
df4fc315 SR |
4110 | } |
4111 | ||
5e2336a0 | 4112 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 4113 | .open = ftrace_pid_open, |
4114 | .write = ftrace_pid_write, | |
4115 | .read = seq_read, | |
4116 | .llseek = seq_lseek, | |
4117 | .release = ftrace_pid_release, | |
df4fc315 SR |
4118 | }; |
4119 | ||
4120 | static __init int ftrace_init_debugfs(void) | |
4121 | { | |
4122 | struct dentry *d_tracer; | |
df4fc315 SR |
4123 | |
4124 | d_tracer = tracing_init_dentry(); | |
4125 | if (!d_tracer) | |
4126 | return 0; | |
4127 | ||
4128 | ftrace_init_dyn_debugfs(d_tracer); | |
4129 | ||
5452af66 FW |
4130 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
4131 | NULL, &ftrace_pid_fops); | |
493762fc SR |
4132 | |
4133 | ftrace_profile_debugfs(d_tracer); | |
4134 | ||
df4fc315 SR |
4135 | return 0; |
4136 | } | |
df4fc315 SR |
4137 | fs_initcall(ftrace_init_debugfs); |
4138 | ||
a2bb6a3d | 4139 | /** |
81adbdc0 | 4140 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
4141 | * |
4142 | * This function should be used by panic code. It stops ftrace | |
4143 | * but in a not so nice way. If you need to simply kill ftrace | |
4144 | * from a non-atomic section, use ftrace_kill. | |
4145 | */ | |
81adbdc0 | 4146 | void ftrace_kill(void) |
a2bb6a3d SR |
4147 | { |
4148 | ftrace_disabled = 1; | |
4149 | ftrace_enabled = 0; | |
a2bb6a3d SR |
4150 | clear_ftrace_function(); |
4151 | } | |
4152 | ||
e0a413f6 SR |
4153 | /** |
4154 | * Test if ftrace is dead or not. | |
4155 | */ | |
4156 | int ftrace_is_dead(void) | |
4157 | { | |
4158 | return ftrace_disabled; | |
4159 | } | |
4160 | ||
16444a8a | 4161 | /** |
3d083395 SR |
4162 | * register_ftrace_function - register a function for profiling |
4163 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 4164 | * |
3d083395 SR |
4165 | * Register a function to be called by all functions in the |
4166 | * kernel. | |
4167 | * | |
4168 | * Note: @ops->func and all the functions it calls must be labeled | |
4169 | * with "notrace", otherwise it will go into a | |
4170 | * recursive loop. | |
16444a8a | 4171 | */ |
3d083395 | 4172 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 4173 | { |
45a4a237 | 4174 | int ret = -1; |
4eebcc81 | 4175 | |
e6ea44e9 | 4176 | mutex_lock(&ftrace_lock); |
e7d3737e | 4177 | |
45a4a237 SR |
4178 | if (unlikely(ftrace_disabled)) |
4179 | goto out_unlock; | |
4180 | ||
b0fc494f | 4181 | ret = __register_ftrace_function(ops); |
b848914c | 4182 | if (!ret) |
a1cd6173 | 4183 | ret = ftrace_startup(ops, 0); |
b848914c | 4184 | |
b0fc494f | 4185 | |
45a4a237 | 4186 | out_unlock: |
e6ea44e9 | 4187 | mutex_unlock(&ftrace_lock); |
b0fc494f | 4188 | return ret; |
3d083395 | 4189 | } |
cdbe61bf | 4190 | EXPORT_SYMBOL_GPL(register_ftrace_function); |
3d083395 SR |
4191 | |
4192 | /** | |
32632920 | 4193 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
4194 | * @ops - ops structure that holds the function to unregister |
4195 | * | |
4196 | * Unregister a function that was added to be called by ftrace profiling. | |
4197 | */ | |
4198 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
4199 | { | |
4200 | int ret; | |
4201 | ||
e6ea44e9 | 4202 | mutex_lock(&ftrace_lock); |
3d083395 | 4203 | ret = __unregister_ftrace_function(ops); |
b848914c SR |
4204 | if (!ret) |
4205 | ftrace_shutdown(ops, 0); | |
e6ea44e9 | 4206 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
4207 | |
4208 | return ret; | |
4209 | } | |
cdbe61bf | 4210 | EXPORT_SYMBOL_GPL(unregister_ftrace_function); |
b0fc494f | 4211 | |
e309b41d | 4212 | int |
b0fc494f | 4213 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
8d65af78 | 4214 | void __user *buffer, size_t *lenp, |
b0fc494f SR |
4215 | loff_t *ppos) |
4216 | { | |
45a4a237 | 4217 | int ret = -ENODEV; |
4eebcc81 | 4218 | |
e6ea44e9 | 4219 | mutex_lock(&ftrace_lock); |
b0fc494f | 4220 | |
45a4a237 SR |
4221 | if (unlikely(ftrace_disabled)) |
4222 | goto out; | |
4223 | ||
4224 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
b0fc494f | 4225 | |
a32c7765 | 4226 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
4227 | goto out; |
4228 | ||
a32c7765 | 4229 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f SR |
4230 | |
4231 | if (ftrace_enabled) { | |
4232 | ||
4233 | ftrace_startup_sysctl(); | |
4234 | ||
4235 | /* we are starting ftrace again */ | |
b848914c SR |
4236 | if (ftrace_ops_list != &ftrace_list_end) { |
4237 | if (ftrace_ops_list->next == &ftrace_list_end) | |
4238 | ftrace_trace_function = ftrace_ops_list->func; | |
b0fc494f | 4239 | else |
b848914c | 4240 | ftrace_trace_function = ftrace_ops_list_func; |
b0fc494f SR |
4241 | } |
4242 | ||
4243 | } else { | |
4244 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
4245 | ftrace_trace_function = ftrace_stub; | |
4246 | ||
4247 | ftrace_shutdown_sysctl(); | |
4248 | } | |
4249 | ||
4250 | out: | |
e6ea44e9 | 4251 | mutex_unlock(&ftrace_lock); |
3d083395 | 4252 | return ret; |
16444a8a | 4253 | } |
f17845e5 | 4254 | |
fb52607a | 4255 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 4256 | |
597af815 | 4257 | static int ftrace_graph_active; |
4a2b8dda | 4258 | static struct notifier_block ftrace_suspend_notifier; |
e7d3737e | 4259 | |
e49dc19c SR |
4260 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
4261 | { | |
4262 | return 0; | |
4263 | } | |
4264 | ||
287b6e68 FW |
4265 | /* The callbacks that hook a function */ |
4266 | trace_func_graph_ret_t ftrace_graph_return = | |
4267 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 4268 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
4269 | |
4270 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
4271 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
4272 | { | |
4273 | int i; | |
4274 | int ret = 0; | |
4275 | unsigned long flags; | |
4276 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
4277 | struct task_struct *g, *t; | |
4278 | ||
4279 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
4280 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
4281 | * sizeof(struct ftrace_ret_stack), | |
4282 | GFP_KERNEL); | |
4283 | if (!ret_stack_list[i]) { | |
4284 | start = 0; | |
4285 | end = i; | |
4286 | ret = -ENOMEM; | |
4287 | goto free; | |
4288 | } | |
4289 | } | |
4290 | ||
4291 | read_lock_irqsave(&tasklist_lock, flags); | |
4292 | do_each_thread(g, t) { | |
4293 | if (start == end) { | |
4294 | ret = -EAGAIN; | |
4295 | goto unlock; | |
4296 | } | |
4297 | ||
4298 | if (t->ret_stack == NULL) { | |
380c4b14 | 4299 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 4300 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
4301 | t->curr_ret_stack = -1; |
4302 | /* Make sure the tasks see the -1 first: */ | |
4303 | smp_wmb(); | |
4304 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
4305 | } |
4306 | } while_each_thread(g, t); | |
4307 | ||
4308 | unlock: | |
4309 | read_unlock_irqrestore(&tasklist_lock, flags); | |
4310 | free: | |
4311 | for (i = start; i < end; i++) | |
4312 | kfree(ret_stack_list[i]); | |
4313 | return ret; | |
4314 | } | |
4315 | ||
8aef2d28 | 4316 | static void |
38516ab5 SR |
4317 | ftrace_graph_probe_sched_switch(void *ignore, |
4318 | struct task_struct *prev, struct task_struct *next) | |
8aef2d28 SR |
4319 | { |
4320 | unsigned long long timestamp; | |
4321 | int index; | |
4322 | ||
be6f164a SR |
4323 | /* |
4324 | * Does the user want to count the time a function was asleep. | |
4325 | * If so, do not update the time stamps. | |
4326 | */ | |
4327 | if (trace_flags & TRACE_ITER_SLEEP_TIME) | |
4328 | return; | |
4329 | ||
8aef2d28 SR |
4330 | timestamp = trace_clock_local(); |
4331 | ||
4332 | prev->ftrace_timestamp = timestamp; | |
4333 | ||
4334 | /* only process tasks that we timestamped */ | |
4335 | if (!next->ftrace_timestamp) | |
4336 | return; | |
4337 | ||
4338 | /* | |
4339 | * Update all the counters in next to make up for the | |
4340 | * time next was sleeping. | |
4341 | */ | |
4342 | timestamp -= next->ftrace_timestamp; | |
4343 | ||
4344 | for (index = next->curr_ret_stack; index >= 0; index--) | |
4345 | next->ret_stack[index].calltime += timestamp; | |
4346 | } | |
4347 | ||
f201ae23 | 4348 | /* Allocate a return stack for each task */ |
fb52607a | 4349 | static int start_graph_tracing(void) |
f201ae23 FW |
4350 | { |
4351 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 4352 | int ret, cpu; |
f201ae23 FW |
4353 | |
4354 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
4355 | sizeof(struct ftrace_ret_stack *), | |
4356 | GFP_KERNEL); | |
4357 | ||
4358 | if (!ret_stack_list) | |
4359 | return -ENOMEM; | |
4360 | ||
5b058bcd | 4361 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
4362 | for_each_online_cpu(cpu) { |
4363 | if (!idle_task(cpu)->ret_stack) | |
868baf07 | 4364 | ftrace_graph_init_idle_task(idle_task(cpu), cpu); |
179c498a | 4365 | } |
5b058bcd | 4366 | |
f201ae23 FW |
4367 | do { |
4368 | ret = alloc_retstack_tasklist(ret_stack_list); | |
4369 | } while (ret == -EAGAIN); | |
4370 | ||
8aef2d28 | 4371 | if (!ret) { |
38516ab5 | 4372 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
8aef2d28 SR |
4373 | if (ret) |
4374 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
4375 | " probe to kernel_sched_switch\n"); | |
4376 | } | |
4377 | ||
f201ae23 FW |
4378 | kfree(ret_stack_list); |
4379 | return ret; | |
4380 | } | |
4381 | ||
4a2b8dda FW |
4382 | /* |
4383 | * Hibernation protection. | |
4384 | * The state of the current task is too much unstable during | |
4385 | * suspend/restore to disk. We want to protect against that. | |
4386 | */ | |
4387 | static int | |
4388 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
4389 | void *unused) | |
4390 | { | |
4391 | switch (state) { | |
4392 | case PM_HIBERNATION_PREPARE: | |
4393 | pause_graph_tracing(); | |
4394 | break; | |
4395 | ||
4396 | case PM_POST_HIBERNATION: | |
4397 | unpause_graph_tracing(); | |
4398 | break; | |
4399 | } | |
4400 | return NOTIFY_DONE; | |
4401 | } | |
4402 | ||
287b6e68 FW |
4403 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
4404 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 4405 | { |
e7d3737e FW |
4406 | int ret = 0; |
4407 | ||
e6ea44e9 | 4408 | mutex_lock(&ftrace_lock); |
e7d3737e | 4409 | |
05ce5818 | 4410 | /* we currently allow only one tracer registered at a time */ |
597af815 | 4411 | if (ftrace_graph_active) { |
05ce5818 SR |
4412 | ret = -EBUSY; |
4413 | goto out; | |
4414 | } | |
4415 | ||
4a2b8dda FW |
4416 | ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; |
4417 | register_pm_notifier(&ftrace_suspend_notifier); | |
4418 | ||
597af815 | 4419 | ftrace_graph_active++; |
fb52607a | 4420 | ret = start_graph_tracing(); |
f201ae23 | 4421 | if (ret) { |
597af815 | 4422 | ftrace_graph_active--; |
f201ae23 FW |
4423 | goto out; |
4424 | } | |
e53a6319 | 4425 | |
287b6e68 FW |
4426 | ftrace_graph_return = retfunc; |
4427 | ftrace_graph_entry = entryfunc; | |
e53a6319 | 4428 | |
a1cd6173 | 4429 | ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET); |
e7d3737e FW |
4430 | |
4431 | out: | |
e6ea44e9 | 4432 | mutex_unlock(&ftrace_lock); |
e7d3737e | 4433 | return ret; |
15e6cb36 FW |
4434 | } |
4435 | ||
fb52607a | 4436 | void unregister_ftrace_graph(void) |
15e6cb36 | 4437 | { |
e6ea44e9 | 4438 | mutex_lock(&ftrace_lock); |
e7d3737e | 4439 | |
597af815 | 4440 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
4441 | goto out; |
4442 | ||
597af815 | 4443 | ftrace_graph_active--; |
287b6e68 | 4444 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 4445 | ftrace_graph_entry = ftrace_graph_entry_stub; |
bd69c30b | 4446 | ftrace_shutdown(&global_ops, FTRACE_STOP_FUNC_RET); |
4a2b8dda | 4447 | unregister_pm_notifier(&ftrace_suspend_notifier); |
38516ab5 | 4448 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
e7d3737e | 4449 | |
2aad1b76 | 4450 | out: |
e6ea44e9 | 4451 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 4452 | } |
f201ae23 | 4453 | |
868baf07 SR |
4454 | static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack); |
4455 | ||
4456 | static void | |
4457 | graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack) | |
4458 | { | |
4459 | atomic_set(&t->tracing_graph_pause, 0); | |
4460 | atomic_set(&t->trace_overrun, 0); | |
4461 | t->ftrace_timestamp = 0; | |
25985edc | 4462 | /* make curr_ret_stack visible before we add the ret_stack */ |
868baf07 SR |
4463 | smp_wmb(); |
4464 | t->ret_stack = ret_stack; | |
4465 | } | |
4466 | ||
4467 | /* | |
4468 | * Allocate a return stack for the idle task. May be the first | |
4469 | * time through, or it may be done by CPU hotplug online. | |
4470 | */ | |
4471 | void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) | |
4472 | { | |
4473 | t->curr_ret_stack = -1; | |
4474 | /* | |
4475 | * The idle task has no parent, it either has its own | |
4476 | * stack or no stack at all. | |
4477 | */ | |
4478 | if (t->ret_stack) | |
4479 | WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu)); | |
4480 | ||
4481 | if (ftrace_graph_active) { | |
4482 | struct ftrace_ret_stack *ret_stack; | |
4483 | ||
4484 | ret_stack = per_cpu(idle_ret_stack, cpu); | |
4485 | if (!ret_stack) { | |
4486 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
4487 | * sizeof(struct ftrace_ret_stack), | |
4488 | GFP_KERNEL); | |
4489 | if (!ret_stack) | |
4490 | return; | |
4491 | per_cpu(idle_ret_stack, cpu) = ret_stack; | |
4492 | } | |
4493 | graph_init_task(t, ret_stack); | |
4494 | } | |
4495 | } | |
4496 | ||
f201ae23 | 4497 | /* Allocate a return stack for newly created task */ |
fb52607a | 4498 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 4499 | { |
84047e36 SR |
4500 | /* Make sure we do not use the parent ret_stack */ |
4501 | t->ret_stack = NULL; | |
ea14eb71 | 4502 | t->curr_ret_stack = -1; |
84047e36 | 4503 | |
597af815 | 4504 | if (ftrace_graph_active) { |
82310a32 SR |
4505 | struct ftrace_ret_stack *ret_stack; |
4506 | ||
4507 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
4508 | * sizeof(struct ftrace_ret_stack), |
4509 | GFP_KERNEL); | |
82310a32 | 4510 | if (!ret_stack) |
f201ae23 | 4511 | return; |
868baf07 | 4512 | graph_init_task(t, ret_stack); |
84047e36 | 4513 | } |
f201ae23 FW |
4514 | } |
4515 | ||
fb52607a | 4516 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 4517 | { |
eae849ca FW |
4518 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
4519 | ||
f201ae23 | 4520 | t->ret_stack = NULL; |
eae849ca FW |
4521 | /* NULL must become visible to IRQs before we free it: */ |
4522 | barrier(); | |
4523 | ||
4524 | kfree(ret_stack); | |
f201ae23 | 4525 | } |
14a866c5 SR |
4526 | |
4527 | void ftrace_graph_stop(void) | |
4528 | { | |
4529 | ftrace_stop(); | |
4530 | } | |
15e6cb36 | 4531 | #endif |