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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> |
2d8b820b | 25 | #include <linux/ftrace.h> |
b0fc494f | 26 | #include <linux/sysctl.h> |
5a0e3ad6 | 27 | #include <linux/slab.h> |
5072c59f | 28 | #include <linux/ctype.h> |
3d083395 | 29 | #include <linux/list.h> |
59df055f | 30 | #include <linux/hash.h> |
3f379b03 | 31 | #include <linux/rcupdate.h> |
3d083395 | 32 | |
ad8d75ff | 33 | #include <trace/events/sched.h> |
8aef2d28 | 34 | |
395a59d0 | 35 | #include <asm/ftrace.h> |
2af15d6a | 36 | #include <asm/setup.h> |
395a59d0 | 37 | |
0706f1c4 | 38 | #include "trace_output.h" |
bac429f0 | 39 | #include "trace_stat.h" |
16444a8a | 40 | |
6912896e SR |
41 | #define FTRACE_WARN_ON(cond) \ |
42 | do { \ | |
43 | if (WARN_ON(cond)) \ | |
44 | ftrace_kill(); \ | |
45 | } while (0) | |
46 | ||
47 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
48 | do { \ | |
49 | if (WARN_ON_ONCE(cond)) \ | |
50 | ftrace_kill(); \ | |
51 | } while (0) | |
52 | ||
8fc0c701 SR |
53 | /* hash bits for specific function selection */ |
54 | #define FTRACE_HASH_BITS 7 | |
55 | #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS) | |
56 | ||
4eebcc81 SR |
57 | /* ftrace_enabled is a method to turn ftrace on or off */ |
58 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 59 | static int last_ftrace_enabled; |
b0fc494f | 60 | |
60a7ecf4 SR |
61 | /* Quick disabling of function tracer. */ |
62 | int function_trace_stop; | |
63 | ||
756d17ee | 64 | /* List for set_ftrace_pid's pids. */ |
65 | LIST_HEAD(ftrace_pids); | |
66 | struct ftrace_pid { | |
67 | struct list_head list; | |
68 | struct pid *pid; | |
69 | }; | |
70 | ||
4eebcc81 SR |
71 | /* |
72 | * ftrace_disabled is set when an anomaly is discovered. | |
73 | * ftrace_disabled is much stronger than ftrace_enabled. | |
74 | */ | |
75 | static int ftrace_disabled __read_mostly; | |
76 | ||
52baf119 | 77 | static DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 78 | |
16444a8a ACM |
79 | static struct ftrace_ops ftrace_list_end __read_mostly = |
80 | { | |
fb9fb015 | 81 | .func = ftrace_stub, |
16444a8a ACM |
82 | }; |
83 | ||
84 | static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; | |
85 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; | |
60a7ecf4 | 86 | ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub; |
df4fc315 | 87 | ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; |
16444a8a | 88 | |
3f379b03 PM |
89 | /* |
90 | * Traverse the ftrace_list, invoking all entries. The reason that we | |
91 | * can use rcu_dereference_raw() is that elements removed from this list | |
92 | * are simply leaked, so there is no need to interact with a grace-period | |
93 | * mechanism. The rcu_dereference_raw() calls are needed to handle | |
94 | * concurrent insertions into the ftrace_list. | |
95 | * | |
96 | * Silly Alpha and silly pointer-speculation compiler optimizations! | |
97 | */ | |
f2252935 | 98 | static void ftrace_list_func(unsigned long ip, unsigned long parent_ip) |
16444a8a | 99 | { |
3f379b03 | 100 | struct ftrace_ops *op = rcu_dereference_raw(ftrace_list); /*see above*/ |
16444a8a ACM |
101 | |
102 | while (op != &ftrace_list_end) { | |
16444a8a | 103 | op->func(ip, parent_ip); |
3f379b03 | 104 | op = rcu_dereference_raw(op->next); /*see above*/ |
16444a8a ACM |
105 | }; |
106 | } | |
107 | ||
df4fc315 SR |
108 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip) |
109 | { | |
0ef8cde5 | 110 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
111 | return; |
112 | ||
113 | ftrace_pid_function(ip, parent_ip); | |
114 | } | |
115 | ||
116 | static void set_ftrace_pid_function(ftrace_func_t func) | |
117 | { | |
118 | /* do not set ftrace_pid_function to itself! */ | |
119 | if (func != ftrace_pid_func) | |
120 | ftrace_pid_function = func; | |
121 | } | |
122 | ||
16444a8a | 123 | /** |
3d083395 | 124 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 125 | * |
3d083395 SR |
126 | * This NULLs the ftrace function and in essence stops |
127 | * tracing. There may be lag | |
16444a8a | 128 | */ |
3d083395 | 129 | void clear_ftrace_function(void) |
16444a8a | 130 | { |
3d083395 | 131 | ftrace_trace_function = ftrace_stub; |
60a7ecf4 | 132 | __ftrace_trace_function = ftrace_stub; |
df4fc315 | 133 | ftrace_pid_function = ftrace_stub; |
3d083395 SR |
134 | } |
135 | ||
60a7ecf4 SR |
136 | #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
137 | /* | |
138 | * For those archs that do not test ftrace_trace_stop in their | |
139 | * mcount call site, we need to do it from C. | |
140 | */ | |
141 | static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip) | |
142 | { | |
143 | if (function_trace_stop) | |
144 | return; | |
145 | ||
146 | __ftrace_trace_function(ip, parent_ip); | |
147 | } | |
148 | #endif | |
149 | ||
e309b41d | 150 | static int __register_ftrace_function(struct ftrace_ops *ops) |
3d083395 | 151 | { |
16444a8a ACM |
152 | ops->next = ftrace_list; |
153 | /* | |
154 | * We are entering ops into the ftrace_list but another | |
155 | * CPU might be walking that list. We need to make sure | |
156 | * the ops->next pointer is valid before another CPU sees | |
157 | * the ops pointer included into the ftrace_list. | |
158 | */ | |
3f379b03 | 159 | rcu_assign_pointer(ftrace_list, ops); |
3d083395 | 160 | |
b0fc494f | 161 | if (ftrace_enabled) { |
df4fc315 SR |
162 | ftrace_func_t func; |
163 | ||
164 | if (ops->next == &ftrace_list_end) | |
165 | func = ops->func; | |
166 | else | |
167 | func = ftrace_list_func; | |
168 | ||
756d17ee | 169 | if (!list_empty(&ftrace_pids)) { |
df4fc315 SR |
170 | set_ftrace_pid_function(func); |
171 | func = ftrace_pid_func; | |
172 | } | |
173 | ||
b0fc494f SR |
174 | /* |
175 | * For one func, simply call it directly. | |
176 | * For more than one func, call the chain. | |
177 | */ | |
60a7ecf4 | 178 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
df4fc315 | 179 | ftrace_trace_function = func; |
60a7ecf4 | 180 | #else |
df4fc315 | 181 | __ftrace_trace_function = func; |
60a7ecf4 SR |
182 | ftrace_trace_function = ftrace_test_stop_func; |
183 | #endif | |
b0fc494f | 184 | } |
3d083395 | 185 | |
16444a8a ACM |
186 | return 0; |
187 | } | |
188 | ||
e309b41d | 189 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 190 | { |
16444a8a | 191 | struct ftrace_ops **p; |
16444a8a ACM |
192 | |
193 | /* | |
3d083395 SR |
194 | * If we are removing the last function, then simply point |
195 | * to the ftrace_stub. | |
16444a8a ACM |
196 | */ |
197 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { | |
198 | ftrace_trace_function = ftrace_stub; | |
199 | ftrace_list = &ftrace_list_end; | |
e6ea44e9 | 200 | return 0; |
16444a8a ACM |
201 | } |
202 | ||
203 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) | |
204 | if (*p == ops) | |
205 | break; | |
206 | ||
e6ea44e9 SR |
207 | if (*p != ops) |
208 | return -1; | |
16444a8a ACM |
209 | |
210 | *p = (*p)->next; | |
211 | ||
b0fc494f SR |
212 | if (ftrace_enabled) { |
213 | /* If we only have one func left, then call that directly */ | |
df4fc315 SR |
214 | if (ftrace_list->next == &ftrace_list_end) { |
215 | ftrace_func_t func = ftrace_list->func; | |
216 | ||
756d17ee | 217 | if (!list_empty(&ftrace_pids)) { |
df4fc315 SR |
218 | set_ftrace_pid_function(func); |
219 | func = ftrace_pid_func; | |
220 | } | |
221 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
222 | ftrace_trace_function = func; | |
223 | #else | |
224 | __ftrace_trace_function = func; | |
225 | #endif | |
226 | } | |
b0fc494f | 227 | } |
16444a8a | 228 | |
e6ea44e9 | 229 | return 0; |
3d083395 SR |
230 | } |
231 | ||
df4fc315 SR |
232 | static void ftrace_update_pid_func(void) |
233 | { | |
234 | ftrace_func_t func; | |
235 | ||
df4fc315 | 236 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 237 | return; |
df4fc315 | 238 | |
33974093 | 239 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
df4fc315 | 240 | func = ftrace_trace_function; |
33974093 MF |
241 | #else |
242 | func = __ftrace_trace_function; | |
243 | #endif | |
df4fc315 | 244 | |
756d17ee | 245 | if (!list_empty(&ftrace_pids)) { |
df4fc315 SR |
246 | set_ftrace_pid_function(func); |
247 | func = ftrace_pid_func; | |
248 | } else { | |
66eafebc LW |
249 | if (func == ftrace_pid_func) |
250 | func = ftrace_pid_function; | |
df4fc315 SR |
251 | } |
252 | ||
253 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
254 | ftrace_trace_function = func; | |
255 | #else | |
256 | __ftrace_trace_function = func; | |
257 | #endif | |
df4fc315 SR |
258 | } |
259 | ||
493762fc SR |
260 | #ifdef CONFIG_FUNCTION_PROFILER |
261 | struct ftrace_profile { | |
262 | struct hlist_node node; | |
263 | unsigned long ip; | |
264 | unsigned long counter; | |
0706f1c4 SR |
265 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
266 | unsigned long long time; | |
e330b3bc | 267 | unsigned long long time_squared; |
0706f1c4 | 268 | #endif |
8fc0c701 SR |
269 | }; |
270 | ||
493762fc SR |
271 | struct ftrace_profile_page { |
272 | struct ftrace_profile_page *next; | |
273 | unsigned long index; | |
274 | struct ftrace_profile records[]; | |
d61f82d0 SR |
275 | }; |
276 | ||
cafb168a SR |
277 | struct ftrace_profile_stat { |
278 | atomic_t disabled; | |
279 | struct hlist_head *hash; | |
280 | struct ftrace_profile_page *pages; | |
281 | struct ftrace_profile_page *start; | |
282 | struct tracer_stat stat; | |
283 | }; | |
284 | ||
493762fc SR |
285 | #define PROFILE_RECORDS_SIZE \ |
286 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 287 | |
493762fc SR |
288 | #define PROFILES_PER_PAGE \ |
289 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 290 | |
fb9fb015 SR |
291 | static int ftrace_profile_bits __read_mostly; |
292 | static int ftrace_profile_enabled __read_mostly; | |
293 | ||
294 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
295 | static DEFINE_MUTEX(ftrace_profile_lock); |
296 | ||
cafb168a | 297 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc SR |
298 | |
299 | #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */ | |
300 | ||
bac429f0 SR |
301 | static void * |
302 | function_stat_next(void *v, int idx) | |
303 | { | |
493762fc SR |
304 | struct ftrace_profile *rec = v; |
305 | struct ftrace_profile_page *pg; | |
bac429f0 | 306 | |
493762fc | 307 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
308 | |
309 | again: | |
0296e425 LZ |
310 | if (idx != 0) |
311 | rec++; | |
312 | ||
bac429f0 SR |
313 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
314 | pg = pg->next; | |
315 | if (!pg) | |
316 | return NULL; | |
317 | rec = &pg->records[0]; | |
493762fc SR |
318 | if (!rec->counter) |
319 | goto again; | |
bac429f0 SR |
320 | } |
321 | ||
bac429f0 SR |
322 | return rec; |
323 | } | |
324 | ||
325 | static void *function_stat_start(struct tracer_stat *trace) | |
326 | { | |
cafb168a SR |
327 | struct ftrace_profile_stat *stat = |
328 | container_of(trace, struct ftrace_profile_stat, stat); | |
329 | ||
330 | if (!stat || !stat->start) | |
331 | return NULL; | |
332 | ||
333 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
334 | } |
335 | ||
0706f1c4 SR |
336 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
337 | /* function graph compares on total time */ | |
338 | static int function_stat_cmp(void *p1, void *p2) | |
339 | { | |
340 | struct ftrace_profile *a = p1; | |
341 | struct ftrace_profile *b = p2; | |
342 | ||
343 | if (a->time < b->time) | |
344 | return -1; | |
345 | if (a->time > b->time) | |
346 | return 1; | |
347 | else | |
348 | return 0; | |
349 | } | |
350 | #else | |
351 | /* not function graph compares against hits */ | |
bac429f0 SR |
352 | static int function_stat_cmp(void *p1, void *p2) |
353 | { | |
493762fc SR |
354 | struct ftrace_profile *a = p1; |
355 | struct ftrace_profile *b = p2; | |
bac429f0 SR |
356 | |
357 | if (a->counter < b->counter) | |
358 | return -1; | |
359 | if (a->counter > b->counter) | |
360 | return 1; | |
361 | else | |
362 | return 0; | |
363 | } | |
0706f1c4 | 364 | #endif |
bac429f0 SR |
365 | |
366 | static int function_stat_headers(struct seq_file *m) | |
367 | { | |
0706f1c4 | 368 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b | 369 | seq_printf(m, " Function " |
e330b3bc | 370 | "Hit Time Avg s^2\n" |
34886c8b | 371 | " -------- " |
e330b3bc | 372 | "--- ---- --- ---\n"); |
0706f1c4 | 373 | #else |
bac429f0 SR |
374 | seq_printf(m, " Function Hit\n" |
375 | " -------- ---\n"); | |
0706f1c4 | 376 | #endif |
bac429f0 SR |
377 | return 0; |
378 | } | |
379 | ||
380 | static int function_stat_show(struct seq_file *m, void *v) | |
381 | { | |
493762fc | 382 | struct ftrace_profile *rec = v; |
bac429f0 | 383 | char str[KSYM_SYMBOL_LEN]; |
3aaba20f | 384 | int ret = 0; |
0706f1c4 | 385 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
386 | static struct trace_seq s; |
387 | unsigned long long avg; | |
e330b3bc | 388 | unsigned long long stddev; |
0706f1c4 | 389 | #endif |
3aaba20f LZ |
390 | mutex_lock(&ftrace_profile_lock); |
391 | ||
392 | /* we raced with function_profile_reset() */ | |
393 | if (unlikely(rec->counter == 0)) { | |
394 | ret = -EBUSY; | |
395 | goto out; | |
396 | } | |
bac429f0 SR |
397 | |
398 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
0706f1c4 SR |
399 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
400 | ||
401 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
402 | seq_printf(m, " "); | |
34886c8b SR |
403 | avg = rec->time; |
404 | do_div(avg, rec->counter); | |
405 | ||
e330b3bc CD |
406 | /* Sample standard deviation (s^2) */ |
407 | if (rec->counter <= 1) | |
408 | stddev = 0; | |
409 | else { | |
410 | stddev = rec->time_squared - rec->counter * avg * avg; | |
411 | /* | |
412 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
413 | * trace_print_graph_duration will divide 1000 again. | |
414 | */ | |
415 | do_div(stddev, (rec->counter - 1) * 1000); | |
416 | } | |
417 | ||
34886c8b SR |
418 | trace_seq_init(&s); |
419 | trace_print_graph_duration(rec->time, &s); | |
420 | trace_seq_puts(&s, " "); | |
421 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
422 | trace_seq_puts(&s, " "); |
423 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 | 424 | trace_print_seq(m, &s); |
0706f1c4 SR |
425 | #endif |
426 | seq_putc(m, '\n'); | |
3aaba20f LZ |
427 | out: |
428 | mutex_unlock(&ftrace_profile_lock); | |
bac429f0 | 429 | |
3aaba20f | 430 | return ret; |
bac429f0 SR |
431 | } |
432 | ||
cafb168a | 433 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 434 | { |
493762fc | 435 | struct ftrace_profile_page *pg; |
bac429f0 | 436 | |
cafb168a | 437 | pg = stat->pages = stat->start; |
bac429f0 | 438 | |
493762fc SR |
439 | while (pg) { |
440 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
441 | pg->index = 0; | |
442 | pg = pg->next; | |
bac429f0 SR |
443 | } |
444 | ||
cafb168a | 445 | memset(stat->hash, 0, |
493762fc SR |
446 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
447 | } | |
bac429f0 | 448 | |
cafb168a | 449 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
450 | { |
451 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
452 | int functions; |
453 | int pages; | |
493762fc | 454 | int i; |
bac429f0 | 455 | |
493762fc | 456 | /* If we already allocated, do nothing */ |
cafb168a | 457 | if (stat->pages) |
493762fc | 458 | return 0; |
bac429f0 | 459 | |
cafb168a SR |
460 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
461 | if (!stat->pages) | |
493762fc | 462 | return -ENOMEM; |
bac429f0 | 463 | |
318e0a73 SR |
464 | #ifdef CONFIG_DYNAMIC_FTRACE |
465 | functions = ftrace_update_tot_cnt; | |
466 | #else | |
467 | /* | |
468 | * We do not know the number of functions that exist because | |
469 | * dynamic tracing is what counts them. With past experience | |
470 | * we have around 20K functions. That should be more than enough. | |
471 | * It is highly unlikely we will execute every function in | |
472 | * the kernel. | |
473 | */ | |
474 | functions = 20000; | |
475 | #endif | |
476 | ||
cafb168a | 477 | pg = stat->start = stat->pages; |
bac429f0 | 478 | |
318e0a73 SR |
479 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
480 | ||
481 | for (i = 0; i < pages; i++) { | |
493762fc | 482 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 483 | if (!pg->next) |
318e0a73 | 484 | goto out_free; |
493762fc SR |
485 | pg = pg->next; |
486 | } | |
487 | ||
488 | return 0; | |
318e0a73 SR |
489 | |
490 | out_free: | |
491 | pg = stat->start; | |
492 | while (pg) { | |
493 | unsigned long tmp = (unsigned long)pg; | |
494 | ||
495 | pg = pg->next; | |
496 | free_page(tmp); | |
497 | } | |
498 | ||
499 | free_page((unsigned long)stat->pages); | |
500 | stat->pages = NULL; | |
501 | stat->start = NULL; | |
502 | ||
503 | return -ENOMEM; | |
bac429f0 SR |
504 | } |
505 | ||
cafb168a | 506 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 507 | { |
cafb168a | 508 | struct ftrace_profile_stat *stat; |
493762fc | 509 | int size; |
bac429f0 | 510 | |
cafb168a SR |
511 | stat = &per_cpu(ftrace_profile_stats, cpu); |
512 | ||
513 | if (stat->hash) { | |
493762fc | 514 | /* If the profile is already created, simply reset it */ |
cafb168a | 515 | ftrace_profile_reset(stat); |
493762fc SR |
516 | return 0; |
517 | } | |
bac429f0 | 518 | |
493762fc SR |
519 | /* |
520 | * We are profiling all functions, but usually only a few thousand | |
521 | * functions are hit. We'll make a hash of 1024 items. | |
522 | */ | |
523 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 524 | |
cafb168a | 525 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
493762fc | 526 | |
cafb168a | 527 | if (!stat->hash) |
493762fc SR |
528 | return -ENOMEM; |
529 | ||
cafb168a SR |
530 | if (!ftrace_profile_bits) { |
531 | size--; | |
493762fc | 532 | |
cafb168a SR |
533 | for (; size; size >>= 1) |
534 | ftrace_profile_bits++; | |
535 | } | |
493762fc | 536 | |
318e0a73 | 537 | /* Preallocate the function profiling pages */ |
cafb168a SR |
538 | if (ftrace_profile_pages_init(stat) < 0) { |
539 | kfree(stat->hash); | |
540 | stat->hash = NULL; | |
493762fc SR |
541 | return -ENOMEM; |
542 | } | |
543 | ||
544 | return 0; | |
bac429f0 SR |
545 | } |
546 | ||
cafb168a SR |
547 | static int ftrace_profile_init(void) |
548 | { | |
549 | int cpu; | |
550 | int ret = 0; | |
551 | ||
552 | for_each_online_cpu(cpu) { | |
553 | ret = ftrace_profile_init_cpu(cpu); | |
554 | if (ret) | |
555 | break; | |
556 | } | |
557 | ||
558 | return ret; | |
559 | } | |
560 | ||
493762fc | 561 | /* interrupts must be disabled */ |
cafb168a SR |
562 | static struct ftrace_profile * |
563 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 564 | { |
493762fc | 565 | struct ftrace_profile *rec; |
bac429f0 SR |
566 | struct hlist_head *hhd; |
567 | struct hlist_node *n; | |
bac429f0 SR |
568 | unsigned long key; |
569 | ||
bac429f0 | 570 | key = hash_long(ip, ftrace_profile_bits); |
cafb168a | 571 | hhd = &stat->hash[key]; |
bac429f0 SR |
572 | |
573 | if (hlist_empty(hhd)) | |
574 | return NULL; | |
575 | ||
bac429f0 SR |
576 | hlist_for_each_entry_rcu(rec, n, hhd, node) { |
577 | if (rec->ip == ip) | |
493762fc SR |
578 | return rec; |
579 | } | |
580 | ||
581 | return NULL; | |
582 | } | |
583 | ||
cafb168a SR |
584 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
585 | struct ftrace_profile *rec) | |
493762fc SR |
586 | { |
587 | unsigned long key; | |
588 | ||
589 | key = hash_long(rec->ip, ftrace_profile_bits); | |
cafb168a | 590 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
591 | } |
592 | ||
318e0a73 SR |
593 | /* |
594 | * The memory is already allocated, this simply finds a new record to use. | |
595 | */ | |
493762fc | 596 | static struct ftrace_profile * |
318e0a73 | 597 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
598 | { |
599 | struct ftrace_profile *rec = NULL; | |
600 | ||
318e0a73 | 601 | /* prevent recursion (from NMIs) */ |
cafb168a | 602 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
603 | goto out; |
604 | ||
493762fc | 605 | /* |
318e0a73 SR |
606 | * Try to find the function again since an NMI |
607 | * could have added it | |
493762fc | 608 | */ |
cafb168a | 609 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 610 | if (rec) |
cafb168a | 611 | goto out; |
493762fc | 612 | |
cafb168a SR |
613 | if (stat->pages->index == PROFILES_PER_PAGE) { |
614 | if (!stat->pages->next) | |
615 | goto out; | |
616 | stat->pages = stat->pages->next; | |
bac429f0 | 617 | } |
493762fc | 618 | |
cafb168a | 619 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 620 | rec->ip = ip; |
cafb168a | 621 | ftrace_add_profile(stat, rec); |
493762fc | 622 | |
bac429f0 | 623 | out: |
cafb168a | 624 | atomic_dec(&stat->disabled); |
bac429f0 SR |
625 | |
626 | return rec; | |
627 | } | |
628 | ||
629 | static void | |
630 | function_profile_call(unsigned long ip, unsigned long parent_ip) | |
631 | { | |
cafb168a | 632 | struct ftrace_profile_stat *stat; |
493762fc | 633 | struct ftrace_profile *rec; |
bac429f0 SR |
634 | unsigned long flags; |
635 | ||
636 | if (!ftrace_profile_enabled) | |
637 | return; | |
638 | ||
639 | local_irq_save(flags); | |
cafb168a SR |
640 | |
641 | stat = &__get_cpu_var(ftrace_profile_stats); | |
0f6ce3de | 642 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
643 | goto out; |
644 | ||
645 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 646 | if (!rec) { |
318e0a73 | 647 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
648 | if (!rec) |
649 | goto out; | |
650 | } | |
bac429f0 SR |
651 | |
652 | rec->counter++; | |
653 | out: | |
654 | local_irq_restore(flags); | |
655 | } | |
656 | ||
0706f1c4 SR |
657 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
658 | static int profile_graph_entry(struct ftrace_graph_ent *trace) | |
659 | { | |
660 | function_profile_call(trace->func, 0); | |
661 | return 1; | |
662 | } | |
663 | ||
664 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
665 | { | |
cafb168a | 666 | struct ftrace_profile_stat *stat; |
a2a16d6a | 667 | unsigned long long calltime; |
0706f1c4 | 668 | struct ftrace_profile *rec; |
cafb168a | 669 | unsigned long flags; |
0706f1c4 SR |
670 | |
671 | local_irq_save(flags); | |
cafb168a | 672 | stat = &__get_cpu_var(ftrace_profile_stats); |
0f6ce3de | 673 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
674 | goto out; |
675 | ||
37e44bc5 SR |
676 | /* If the calltime was zero'd ignore it */ |
677 | if (!trace->calltime) | |
678 | goto out; | |
679 | ||
a2a16d6a SR |
680 | calltime = trace->rettime - trace->calltime; |
681 | ||
682 | if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) { | |
683 | int index; | |
684 | ||
685 | index = trace->depth; | |
686 | ||
687 | /* Append this call time to the parent time to subtract */ | |
688 | if (index) | |
689 | current->ret_stack[index - 1].subtime += calltime; | |
690 | ||
691 | if (current->ret_stack[index].subtime < calltime) | |
692 | calltime -= current->ret_stack[index].subtime; | |
693 | else | |
694 | calltime = 0; | |
695 | } | |
696 | ||
cafb168a | 697 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 698 | if (rec) { |
a2a16d6a | 699 | rec->time += calltime; |
e330b3bc CD |
700 | rec->time_squared += calltime * calltime; |
701 | } | |
a2a16d6a | 702 | |
cafb168a | 703 | out: |
0706f1c4 SR |
704 | local_irq_restore(flags); |
705 | } | |
706 | ||
707 | static int register_ftrace_profiler(void) | |
708 | { | |
709 | return register_ftrace_graph(&profile_graph_return, | |
710 | &profile_graph_entry); | |
711 | } | |
712 | ||
713 | static void unregister_ftrace_profiler(void) | |
714 | { | |
715 | unregister_ftrace_graph(); | |
716 | } | |
717 | #else | |
bac429f0 SR |
718 | static struct ftrace_ops ftrace_profile_ops __read_mostly = |
719 | { | |
fb9fb015 | 720 | .func = function_profile_call, |
bac429f0 SR |
721 | }; |
722 | ||
0706f1c4 SR |
723 | static int register_ftrace_profiler(void) |
724 | { | |
725 | return register_ftrace_function(&ftrace_profile_ops); | |
726 | } | |
727 | ||
728 | static void unregister_ftrace_profiler(void) | |
729 | { | |
730 | unregister_ftrace_function(&ftrace_profile_ops); | |
731 | } | |
732 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
733 | ||
bac429f0 SR |
734 | static ssize_t |
735 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
736 | size_t cnt, loff_t *ppos) | |
737 | { | |
738 | unsigned long val; | |
fb9fb015 | 739 | char buf[64]; /* big enough to hold a number */ |
bac429f0 SR |
740 | int ret; |
741 | ||
bac429f0 SR |
742 | if (cnt >= sizeof(buf)) |
743 | return -EINVAL; | |
744 | ||
745 | if (copy_from_user(&buf, ubuf, cnt)) | |
746 | return -EFAULT; | |
747 | ||
748 | buf[cnt] = 0; | |
749 | ||
750 | ret = strict_strtoul(buf, 10, &val); | |
751 | if (ret < 0) | |
752 | return ret; | |
753 | ||
754 | val = !!val; | |
755 | ||
756 | mutex_lock(&ftrace_profile_lock); | |
757 | if (ftrace_profile_enabled ^ val) { | |
758 | if (val) { | |
493762fc SR |
759 | ret = ftrace_profile_init(); |
760 | if (ret < 0) { | |
761 | cnt = ret; | |
762 | goto out; | |
763 | } | |
764 | ||
0706f1c4 SR |
765 | ret = register_ftrace_profiler(); |
766 | if (ret < 0) { | |
767 | cnt = ret; | |
768 | goto out; | |
769 | } | |
bac429f0 SR |
770 | ftrace_profile_enabled = 1; |
771 | } else { | |
772 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
773 | /* |
774 | * unregister_ftrace_profiler calls stop_machine | |
775 | * so this acts like an synchronize_sched. | |
776 | */ | |
0706f1c4 | 777 | unregister_ftrace_profiler(); |
bac429f0 SR |
778 | } |
779 | } | |
493762fc | 780 | out: |
bac429f0 SR |
781 | mutex_unlock(&ftrace_profile_lock); |
782 | ||
cf8517cf | 783 | *ppos += cnt; |
bac429f0 SR |
784 | |
785 | return cnt; | |
786 | } | |
787 | ||
493762fc SR |
788 | static ssize_t |
789 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
790 | size_t cnt, loff_t *ppos) | |
791 | { | |
fb9fb015 | 792 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
793 | int r; |
794 | ||
795 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
796 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
797 | } | |
798 | ||
bac429f0 SR |
799 | static const struct file_operations ftrace_profile_fops = { |
800 | .open = tracing_open_generic, | |
801 | .read = ftrace_profile_read, | |
802 | .write = ftrace_profile_write, | |
803 | }; | |
804 | ||
cafb168a SR |
805 | /* used to initialize the real stat files */ |
806 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
807 | .name = "functions", |
808 | .stat_start = function_stat_start, | |
809 | .stat_next = function_stat_next, | |
810 | .stat_cmp = function_stat_cmp, | |
811 | .stat_headers = function_stat_headers, | |
812 | .stat_show = function_stat_show | |
cafb168a SR |
813 | }; |
814 | ||
6ab5d668 | 815 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 | 816 | { |
cafb168a | 817 | struct ftrace_profile_stat *stat; |
bac429f0 | 818 | struct dentry *entry; |
cafb168a | 819 | char *name; |
bac429f0 | 820 | int ret; |
cafb168a SR |
821 | int cpu; |
822 | ||
823 | for_each_possible_cpu(cpu) { | |
824 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
825 | ||
826 | /* allocate enough for function name + cpu number */ | |
827 | name = kmalloc(32, GFP_KERNEL); | |
828 | if (!name) { | |
829 | /* | |
830 | * The files created are permanent, if something happens | |
831 | * we still do not free memory. | |
832 | */ | |
cafb168a SR |
833 | WARN(1, |
834 | "Could not allocate stat file for cpu %d\n", | |
835 | cpu); | |
836 | return; | |
837 | } | |
838 | stat->stat = function_stats; | |
839 | snprintf(name, 32, "function%d", cpu); | |
840 | stat->stat.name = name; | |
841 | ret = register_stat_tracer(&stat->stat); | |
842 | if (ret) { | |
843 | WARN(1, | |
844 | "Could not register function stat for cpu %d\n", | |
845 | cpu); | |
846 | kfree(name); | |
847 | return; | |
848 | } | |
bac429f0 SR |
849 | } |
850 | ||
851 | entry = debugfs_create_file("function_profile_enabled", 0644, | |
852 | d_tracer, NULL, &ftrace_profile_fops); | |
853 | if (!entry) | |
854 | pr_warning("Could not create debugfs " | |
855 | "'function_profile_enabled' entry\n"); | |
856 | } | |
857 | ||
bac429f0 | 858 | #else /* CONFIG_FUNCTION_PROFILER */ |
6ab5d668 | 859 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 SR |
860 | { |
861 | } | |
bac429f0 SR |
862 | #endif /* CONFIG_FUNCTION_PROFILER */ |
863 | ||
493762fc SR |
864 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; |
865 | ||
866 | #ifdef CONFIG_DYNAMIC_FTRACE | |
867 | ||
868 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD | |
869 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
870 | #endif | |
871 | ||
872 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; | |
873 | ||
874 | struct ftrace_func_probe { | |
875 | struct hlist_node node; | |
876 | struct ftrace_probe_ops *ops; | |
877 | unsigned long flags; | |
878 | unsigned long ip; | |
879 | void *data; | |
880 | struct rcu_head rcu; | |
881 | }; | |
882 | ||
883 | enum { | |
884 | FTRACE_ENABLE_CALLS = (1 << 0), | |
885 | FTRACE_DISABLE_CALLS = (1 << 1), | |
886 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
887 | FTRACE_ENABLE_MCOUNT = (1 << 3), | |
888 | FTRACE_DISABLE_MCOUNT = (1 << 4), | |
889 | FTRACE_START_FUNC_RET = (1 << 5), | |
890 | FTRACE_STOP_FUNC_RET = (1 << 6), | |
891 | }; | |
892 | ||
893 | static int ftrace_filtered; | |
894 | ||
895 | static struct dyn_ftrace *ftrace_new_addrs; | |
896 | ||
897 | static DEFINE_MUTEX(ftrace_regex_lock); | |
898 | ||
899 | struct ftrace_page { | |
900 | struct ftrace_page *next; | |
901 | int index; | |
902 | struct dyn_ftrace records[]; | |
903 | }; | |
904 | ||
905 | #define ENTRIES_PER_PAGE \ | |
906 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
907 | ||
908 | /* estimate from running different kernels */ | |
909 | #define NR_TO_INIT 10000 | |
910 | ||
911 | static struct ftrace_page *ftrace_pages_start; | |
912 | static struct ftrace_page *ftrace_pages; | |
913 | ||
914 | static struct dyn_ftrace *ftrace_free_records; | |
915 | ||
916 | /* | |
917 | * This is a double for. Do not use 'break' to break out of the loop, | |
918 | * you must use a goto. | |
919 | */ | |
920 | #define do_for_each_ftrace_rec(pg, rec) \ | |
921 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
922 | int _____i; \ | |
923 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
924 | rec = &pg->records[_____i]; | |
925 | ||
926 | #define while_for_each_ftrace_rec() \ | |
927 | } \ | |
928 | } | |
929 | ||
e309b41d | 930 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
37ad5084 | 931 | { |
ee000b7f | 932 | rec->freelist = ftrace_free_records; |
37ad5084 SR |
933 | ftrace_free_records = rec; |
934 | rec->flags |= FTRACE_FL_FREE; | |
935 | } | |
936 | ||
e309b41d | 937 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 938 | { |
37ad5084 SR |
939 | struct dyn_ftrace *rec; |
940 | ||
941 | /* First check for freed records */ | |
942 | if (ftrace_free_records) { | |
943 | rec = ftrace_free_records; | |
944 | ||
37ad5084 | 945 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
6912896e | 946 | FTRACE_WARN_ON_ONCE(1); |
37ad5084 SR |
947 | ftrace_free_records = NULL; |
948 | return NULL; | |
949 | } | |
950 | ||
ee000b7f | 951 | ftrace_free_records = rec->freelist; |
37ad5084 SR |
952 | memset(rec, 0, sizeof(*rec)); |
953 | return rec; | |
954 | } | |
955 | ||
3c1720f0 | 956 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
08f5ac90 SR |
957 | if (!ftrace_pages->next) { |
958 | /* allocate another page */ | |
959 | ftrace_pages->next = | |
960 | (void *)get_zeroed_page(GFP_KERNEL); | |
961 | if (!ftrace_pages->next) | |
962 | return NULL; | |
963 | } | |
3c1720f0 SR |
964 | ftrace_pages = ftrace_pages->next; |
965 | } | |
966 | ||
967 | return &ftrace_pages->records[ftrace_pages->index++]; | |
968 | } | |
969 | ||
08f5ac90 | 970 | static struct dyn_ftrace * |
d61f82d0 | 971 | ftrace_record_ip(unsigned long ip) |
3d083395 | 972 | { |
08f5ac90 | 973 | struct dyn_ftrace *rec; |
3d083395 | 974 | |
f3c7ac40 | 975 | if (ftrace_disabled) |
08f5ac90 | 976 | return NULL; |
3d083395 | 977 | |
08f5ac90 SR |
978 | rec = ftrace_alloc_dyn_node(ip); |
979 | if (!rec) | |
980 | return NULL; | |
3d083395 | 981 | |
08f5ac90 | 982 | rec->ip = ip; |
ee000b7f | 983 | rec->newlist = ftrace_new_addrs; |
e94142a6 | 984 | ftrace_new_addrs = rec; |
3d083395 | 985 | |
08f5ac90 | 986 | return rec; |
3d083395 SR |
987 | } |
988 | ||
b17e8a37 SR |
989 | static void print_ip_ins(const char *fmt, unsigned char *p) |
990 | { | |
991 | int i; | |
992 | ||
993 | printk(KERN_CONT "%s", fmt); | |
994 | ||
995 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
996 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
997 | } | |
998 | ||
31e88909 | 999 | static void ftrace_bug(int failed, unsigned long ip) |
b17e8a37 SR |
1000 | { |
1001 | switch (failed) { | |
1002 | case -EFAULT: | |
1003 | FTRACE_WARN_ON_ONCE(1); | |
1004 | pr_info("ftrace faulted on modifying "); | |
1005 | print_ip_sym(ip); | |
1006 | break; | |
1007 | case -EINVAL: | |
1008 | FTRACE_WARN_ON_ONCE(1); | |
1009 | pr_info("ftrace failed to modify "); | |
1010 | print_ip_sym(ip); | |
b17e8a37 | 1011 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
1012 | printk(KERN_CONT "\n"); |
1013 | break; | |
1014 | case -EPERM: | |
1015 | FTRACE_WARN_ON_ONCE(1); | |
1016 | pr_info("ftrace faulted on writing "); | |
1017 | print_ip_sym(ip); | |
1018 | break; | |
1019 | default: | |
1020 | FTRACE_WARN_ON_ONCE(1); | |
1021 | pr_info("ftrace faulted on unknown error "); | |
1022 | print_ip_sym(ip); | |
1023 | } | |
1024 | } | |
1025 | ||
3c1720f0 | 1026 | |
2cfa1978 MH |
1027 | /* Return 1 if the address range is reserved for ftrace */ |
1028 | int ftrace_text_reserved(void *start, void *end) | |
1029 | { | |
1030 | struct dyn_ftrace *rec; | |
1031 | struct ftrace_page *pg; | |
1032 | ||
1033 | do_for_each_ftrace_rec(pg, rec) { | |
1034 | if (rec->ip <= (unsigned long)end && | |
1035 | rec->ip + MCOUNT_INSN_SIZE > (unsigned long)start) | |
1036 | return 1; | |
1037 | } while_for_each_ftrace_rec(); | |
1038 | return 0; | |
1039 | } | |
1040 | ||
1041 | ||
0eb96701 | 1042 | static int |
31e88909 | 1043 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) |
5072c59f | 1044 | { |
e7d3737e | 1045 | unsigned long ftrace_addr; |
64fbcd16 | 1046 | unsigned long flag = 0UL; |
e7d3737e | 1047 | |
f0001207 | 1048 | ftrace_addr = (unsigned long)FTRACE_ADDR; |
5072c59f | 1049 | |
982c350b | 1050 | /* |
64fbcd16 XG |
1051 | * If this record is not to be traced or we want to disable it, |
1052 | * then disable it. | |
982c350b | 1053 | * |
64fbcd16 | 1054 | * If we want to enable it and filtering is off, then enable it. |
982c350b | 1055 | * |
64fbcd16 XG |
1056 | * If we want to enable it and filtering is on, enable it only if |
1057 | * it's filtered | |
982c350b | 1058 | */ |
64fbcd16 XG |
1059 | if (enable && !(rec->flags & FTRACE_FL_NOTRACE)) { |
1060 | if (!ftrace_filtered || (rec->flags & FTRACE_FL_FILTER)) | |
1061 | flag = FTRACE_FL_ENABLED; | |
1062 | } | |
982c350b | 1063 | |
64fbcd16 XG |
1064 | /* If the state of this record hasn't changed, then do nothing */ |
1065 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
1066 | return 0; | |
982c350b | 1067 | |
64fbcd16 XG |
1068 | if (flag) { |
1069 | rec->flags |= FTRACE_FL_ENABLED; | |
1070 | return ftrace_make_call(rec, ftrace_addr); | |
5072c59f SR |
1071 | } |
1072 | ||
64fbcd16 XG |
1073 | rec->flags &= ~FTRACE_FL_ENABLED; |
1074 | return ftrace_make_nop(NULL, rec, ftrace_addr); | |
5072c59f SR |
1075 | } |
1076 | ||
e309b41d | 1077 | static void ftrace_replace_code(int enable) |
3c1720f0 | 1078 | { |
3c1720f0 SR |
1079 | struct dyn_ftrace *rec; |
1080 | struct ftrace_page *pg; | |
6a24a244 | 1081 | int failed; |
3c1720f0 | 1082 | |
265c831c SR |
1083 | do_for_each_ftrace_rec(pg, rec) { |
1084 | /* | |
fa9d13cf Z |
1085 | * Skip over free records, records that have |
1086 | * failed and not converted. | |
265c831c SR |
1087 | */ |
1088 | if (rec->flags & FTRACE_FL_FREE || | |
fa9d13cf | 1089 | rec->flags & FTRACE_FL_FAILED || |
03303549 | 1090 | !(rec->flags & FTRACE_FL_CONVERTED)) |
265c831c SR |
1091 | continue; |
1092 | ||
265c831c | 1093 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 1094 | if (failed) { |
265c831c | 1095 | rec->flags |= FTRACE_FL_FAILED; |
3279ba37 SR |
1096 | ftrace_bug(failed, rec->ip); |
1097 | /* Stop processing */ | |
1098 | return; | |
3c1720f0 | 1099 | } |
265c831c | 1100 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
1101 | } |
1102 | ||
492a7ea5 | 1103 | static int |
31e88909 | 1104 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 SR |
1105 | { |
1106 | unsigned long ip; | |
593eb8a2 | 1107 | int ret; |
3c1720f0 SR |
1108 | |
1109 | ip = rec->ip; | |
1110 | ||
25aac9dc | 1111 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 1112 | if (ret) { |
31e88909 | 1113 | ftrace_bug(ret, ip); |
3c1720f0 | 1114 | rec->flags |= FTRACE_FL_FAILED; |
492a7ea5 | 1115 | return 0; |
37ad5084 | 1116 | } |
492a7ea5 | 1117 | return 1; |
3c1720f0 SR |
1118 | } |
1119 | ||
000ab691 SR |
1120 | /* |
1121 | * archs can override this function if they must do something | |
1122 | * before the modifying code is performed. | |
1123 | */ | |
1124 | int __weak ftrace_arch_code_modify_prepare(void) | |
1125 | { | |
1126 | return 0; | |
1127 | } | |
1128 | ||
1129 | /* | |
1130 | * archs can override this function if they must do something | |
1131 | * after the modifying code is performed. | |
1132 | */ | |
1133 | int __weak ftrace_arch_code_modify_post_process(void) | |
1134 | { | |
1135 | return 0; | |
1136 | } | |
1137 | ||
e309b41d | 1138 | static int __ftrace_modify_code(void *data) |
3d083395 | 1139 | { |
d61f82d0 SR |
1140 | int *command = data; |
1141 | ||
a3583244 | 1142 | if (*command & FTRACE_ENABLE_CALLS) |
d61f82d0 | 1143 | ftrace_replace_code(1); |
a3583244 | 1144 | else if (*command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
1145 | ftrace_replace_code(0); |
1146 | ||
1147 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
1148 | ftrace_update_ftrace_func(ftrace_trace_function); | |
1149 | ||
5a45cfe1 SR |
1150 | if (*command & FTRACE_START_FUNC_RET) |
1151 | ftrace_enable_ftrace_graph_caller(); | |
1152 | else if (*command & FTRACE_STOP_FUNC_RET) | |
1153 | ftrace_disable_ftrace_graph_caller(); | |
1154 | ||
d61f82d0 | 1155 | return 0; |
3d083395 SR |
1156 | } |
1157 | ||
e309b41d | 1158 | static void ftrace_run_update_code(int command) |
3d083395 | 1159 | { |
000ab691 SR |
1160 | int ret; |
1161 | ||
1162 | ret = ftrace_arch_code_modify_prepare(); | |
1163 | FTRACE_WARN_ON(ret); | |
1164 | if (ret) | |
1165 | return; | |
1166 | ||
784e2d76 | 1167 | stop_machine(__ftrace_modify_code, &command, NULL); |
000ab691 SR |
1168 | |
1169 | ret = ftrace_arch_code_modify_post_process(); | |
1170 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
1171 | } |
1172 | ||
d61f82d0 | 1173 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 1174 | static int ftrace_start_up; |
df4fc315 SR |
1175 | |
1176 | static void ftrace_startup_enable(int command) | |
1177 | { | |
1178 | if (saved_ftrace_func != ftrace_trace_function) { | |
1179 | saved_ftrace_func = ftrace_trace_function; | |
1180 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1181 | } | |
1182 | ||
1183 | if (!command || !ftrace_enabled) | |
1184 | return; | |
1185 | ||
1186 | ftrace_run_update_code(command); | |
1187 | } | |
d61f82d0 | 1188 | |
5a45cfe1 | 1189 | static void ftrace_startup(int command) |
3d083395 | 1190 | { |
4eebcc81 SR |
1191 | if (unlikely(ftrace_disabled)) |
1192 | return; | |
1193 | ||
60a7ecf4 | 1194 | ftrace_start_up++; |
982c350b | 1195 | command |= FTRACE_ENABLE_CALLS; |
d61f82d0 | 1196 | |
df4fc315 | 1197 | ftrace_startup_enable(command); |
3d083395 SR |
1198 | } |
1199 | ||
5a45cfe1 | 1200 | static void ftrace_shutdown(int command) |
3d083395 | 1201 | { |
4eebcc81 SR |
1202 | if (unlikely(ftrace_disabled)) |
1203 | return; | |
1204 | ||
60a7ecf4 | 1205 | ftrace_start_up--; |
9ea1a153 FW |
1206 | /* |
1207 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
1208 | * critical but the ftrace_call callers may be never nopped again after | |
1209 | * further ftrace uses. | |
1210 | */ | |
1211 | WARN_ON_ONCE(ftrace_start_up < 0); | |
1212 | ||
60a7ecf4 | 1213 | if (!ftrace_start_up) |
d61f82d0 | 1214 | command |= FTRACE_DISABLE_CALLS; |
3d083395 | 1215 | |
d61f82d0 SR |
1216 | if (saved_ftrace_func != ftrace_trace_function) { |
1217 | saved_ftrace_func = ftrace_trace_function; | |
1218 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1219 | } | |
3d083395 | 1220 | |
d61f82d0 | 1221 | if (!command || !ftrace_enabled) |
e6ea44e9 | 1222 | return; |
d61f82d0 SR |
1223 | |
1224 | ftrace_run_update_code(command); | |
3d083395 SR |
1225 | } |
1226 | ||
e309b41d | 1227 | static void ftrace_startup_sysctl(void) |
b0fc494f | 1228 | { |
d61f82d0 SR |
1229 | int command = FTRACE_ENABLE_MCOUNT; |
1230 | ||
4eebcc81 SR |
1231 | if (unlikely(ftrace_disabled)) |
1232 | return; | |
1233 | ||
d61f82d0 SR |
1234 | /* Force update next time */ |
1235 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
1236 | /* ftrace_start_up is true if we want ftrace running */ |
1237 | if (ftrace_start_up) | |
d61f82d0 SR |
1238 | command |= FTRACE_ENABLE_CALLS; |
1239 | ||
1240 | ftrace_run_update_code(command); | |
b0fc494f SR |
1241 | } |
1242 | ||
e309b41d | 1243 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 1244 | { |
d61f82d0 SR |
1245 | int command = FTRACE_DISABLE_MCOUNT; |
1246 | ||
4eebcc81 SR |
1247 | if (unlikely(ftrace_disabled)) |
1248 | return; | |
1249 | ||
60a7ecf4 SR |
1250 | /* ftrace_start_up is true if ftrace is running */ |
1251 | if (ftrace_start_up) | |
d61f82d0 SR |
1252 | command |= FTRACE_DISABLE_CALLS; |
1253 | ||
1254 | ftrace_run_update_code(command); | |
b0fc494f SR |
1255 | } |
1256 | ||
3d083395 SR |
1257 | static cycle_t ftrace_update_time; |
1258 | static unsigned long ftrace_update_cnt; | |
1259 | unsigned long ftrace_update_tot_cnt; | |
1260 | ||
31e88909 | 1261 | static int ftrace_update_code(struct module *mod) |
3d083395 | 1262 | { |
e94142a6 | 1263 | struct dyn_ftrace *p; |
f22f9a89 | 1264 | cycle_t start, stop; |
3d083395 | 1265 | |
750ed1a4 | 1266 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1267 | ftrace_update_cnt = 0; |
1268 | ||
e94142a6 | 1269 | while (ftrace_new_addrs) { |
3d083395 | 1270 | |
08f5ac90 SR |
1271 | /* If something went wrong, bail without enabling anything */ |
1272 | if (unlikely(ftrace_disabled)) | |
1273 | return -1; | |
f22f9a89 | 1274 | |
e94142a6 | 1275 | p = ftrace_new_addrs; |
ee000b7f | 1276 | ftrace_new_addrs = p->newlist; |
e94142a6 | 1277 | p->flags = 0L; |
f22f9a89 | 1278 | |
5cb084bb JO |
1279 | /* |
1280 | * Do the initial record convertion from mcount jump | |
1281 | * to the NOP instructions. | |
1282 | */ | |
1283 | if (!ftrace_code_disable(mod, p)) { | |
08f5ac90 | 1284 | ftrace_free_rec(p); |
5cb084bb JO |
1285 | continue; |
1286 | } | |
1287 | ||
1288 | p->flags |= FTRACE_FL_CONVERTED; | |
1289 | ftrace_update_cnt++; | |
1290 | ||
1291 | /* | |
1292 | * If the tracing is enabled, go ahead and enable the record. | |
1293 | * | |
1294 | * The reason not to enable the record immediatelly is the | |
1295 | * inherent check of ftrace_make_nop/ftrace_make_call for | |
1296 | * correct previous instructions. Making first the NOP | |
1297 | * conversion puts the module to the correct state, thus | |
1298 | * passing the ftrace_make_call check. | |
1299 | */ | |
1300 | if (ftrace_start_up) { | |
1301 | int failed = __ftrace_replace_code(p, 1); | |
1302 | if (failed) { | |
1303 | ftrace_bug(failed, p->ip); | |
1304 | ftrace_free_rec(p); | |
1305 | } | |
1306 | } | |
3d083395 SR |
1307 | } |
1308 | ||
750ed1a4 | 1309 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1310 | ftrace_update_time = stop - start; |
1311 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
1312 | ||
16444a8a ACM |
1313 | return 0; |
1314 | } | |
1315 | ||
68bf21aa | 1316 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
1317 | { |
1318 | struct ftrace_page *pg; | |
1319 | int cnt; | |
1320 | int i; | |
3c1720f0 SR |
1321 | |
1322 | /* allocate a few pages */ | |
1323 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
1324 | if (!ftrace_pages_start) | |
1325 | return -1; | |
1326 | ||
1327 | /* | |
1328 | * Allocate a few more pages. | |
1329 | * | |
1330 | * TODO: have some parser search vmlinux before | |
1331 | * final linking to find all calls to ftrace. | |
1332 | * Then we can: | |
1333 | * a) know how many pages to allocate. | |
1334 | * and/or | |
1335 | * b) set up the table then. | |
1336 | * | |
1337 | * The dynamic code is still necessary for | |
1338 | * modules. | |
1339 | */ | |
1340 | ||
1341 | pg = ftrace_pages = ftrace_pages_start; | |
1342 | ||
68bf21aa | 1343 | cnt = num_to_init / ENTRIES_PER_PAGE; |
08f5ac90 | 1344 | pr_info("ftrace: allocating %ld entries in %d pages\n", |
5821e1b7 | 1345 | num_to_init, cnt + 1); |
3c1720f0 SR |
1346 | |
1347 | for (i = 0; i < cnt; i++) { | |
1348 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
1349 | ||
1350 | /* If we fail, we'll try later anyway */ | |
1351 | if (!pg->next) | |
1352 | break; | |
1353 | ||
1354 | pg = pg->next; | |
1355 | } | |
1356 | ||
1357 | return 0; | |
1358 | } | |
1359 | ||
5072c59f SR |
1360 | enum { |
1361 | FTRACE_ITER_FILTER = (1 << 0), | |
689fd8b6 | 1362 | FTRACE_ITER_NOTRACE = (1 << 1), |
1363 | FTRACE_ITER_FAILURES = (1 << 2), | |
1364 | FTRACE_ITER_PRINTALL = (1 << 3), | |
1365 | FTRACE_ITER_HASH = (1 << 4), | |
5072c59f SR |
1366 | }; |
1367 | ||
1368 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
1369 | ||
1370 | struct ftrace_iterator { | |
4aeb6967 SR |
1371 | loff_t func_pos; |
1372 | struct ftrace_page *pg; | |
1373 | struct dyn_ftrace *func; | |
1374 | struct ftrace_func_probe *probe; | |
1375 | struct trace_parser parser; | |
1376 | int hidx; | |
1377 | int idx; | |
1378 | unsigned flags; | |
5072c59f SR |
1379 | }; |
1380 | ||
8fc0c701 | 1381 | static void * |
4aeb6967 | 1382 | t_hash_next(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
1383 | { |
1384 | struct ftrace_iterator *iter = m->private; | |
4aeb6967 | 1385 | struct hlist_node *hnd = NULL; |
8fc0c701 SR |
1386 | struct hlist_head *hhd; |
1387 | ||
1388 | WARN_ON(!(iter->flags & FTRACE_ITER_HASH)); | |
1389 | ||
1390 | (*pos)++; | |
1391 | ||
4aeb6967 SR |
1392 | if (iter->probe) |
1393 | hnd = &iter->probe->node; | |
8fc0c701 SR |
1394 | retry: |
1395 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
1396 | return NULL; | |
1397 | ||
1398 | hhd = &ftrace_func_hash[iter->hidx]; | |
1399 | ||
1400 | if (hlist_empty(hhd)) { | |
1401 | iter->hidx++; | |
1402 | hnd = NULL; | |
1403 | goto retry; | |
1404 | } | |
1405 | ||
1406 | if (!hnd) | |
1407 | hnd = hhd->first; | |
1408 | else { | |
1409 | hnd = hnd->next; | |
1410 | if (!hnd) { | |
1411 | iter->hidx++; | |
1412 | goto retry; | |
1413 | } | |
1414 | } | |
1415 | ||
4aeb6967 SR |
1416 | if (WARN_ON_ONCE(!hnd)) |
1417 | return NULL; | |
1418 | ||
1419 | iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node); | |
1420 | ||
1421 | return iter; | |
8fc0c701 SR |
1422 | } |
1423 | ||
1424 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
1425 | { | |
1426 | struct ftrace_iterator *iter = m->private; | |
1427 | void *p = NULL; | |
d82d6244 LZ |
1428 | loff_t l; |
1429 | ||
1430 | if (!(iter->flags & FTRACE_ITER_HASH)) | |
2bccfffd SR |
1431 | iter->func_pos = *pos; |
1432 | ||
1433 | if (iter->func_pos > *pos) | |
1434 | return NULL; | |
8fc0c701 SR |
1435 | |
1436 | iter->flags |= FTRACE_ITER_HASH; | |
1437 | ||
d82d6244 | 1438 | iter->hidx = 0; |
2bccfffd | 1439 | for (l = 0; l <= (*pos - iter->func_pos); ) { |
4aeb6967 | 1440 | p = t_hash_next(m, &l); |
d82d6244 LZ |
1441 | if (!p) |
1442 | break; | |
1443 | } | |
4aeb6967 SR |
1444 | if (!p) |
1445 | return NULL; | |
1446 | ||
1447 | return iter; | |
8fc0c701 SR |
1448 | } |
1449 | ||
4aeb6967 SR |
1450 | static int |
1451 | t_hash_show(struct seq_file *m, struct ftrace_iterator *iter) | |
8fc0c701 | 1452 | { |
b6887d79 | 1453 | struct ftrace_func_probe *rec; |
8fc0c701 | 1454 | |
4aeb6967 SR |
1455 | rec = iter->probe; |
1456 | if (WARN_ON_ONCE(!rec)) | |
1457 | return -EIO; | |
8fc0c701 | 1458 | |
809dcf29 SR |
1459 | if (rec->ops->print) |
1460 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
1461 | ||
b375a11a | 1462 | seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func); |
8fc0c701 SR |
1463 | |
1464 | if (rec->data) | |
1465 | seq_printf(m, ":%p", rec->data); | |
1466 | seq_putc(m, '\n'); | |
1467 | ||
1468 | return 0; | |
1469 | } | |
1470 | ||
e309b41d | 1471 | static void * |
5072c59f SR |
1472 | t_next(struct seq_file *m, void *v, loff_t *pos) |
1473 | { | |
1474 | struct ftrace_iterator *iter = m->private; | |
1475 | struct dyn_ftrace *rec = NULL; | |
1476 | ||
8fc0c701 | 1477 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 1478 | return t_hash_next(m, pos); |
8fc0c701 | 1479 | |
5072c59f SR |
1480 | (*pos)++; |
1481 | ||
0c75a3ed SR |
1482 | if (iter->flags & FTRACE_ITER_PRINTALL) |
1483 | return NULL; | |
1484 | ||
5072c59f SR |
1485 | retry: |
1486 | if (iter->idx >= iter->pg->index) { | |
1487 | if (iter->pg->next) { | |
1488 | iter->pg = iter->pg->next; | |
1489 | iter->idx = 0; | |
1490 | goto retry; | |
1491 | } | |
1492 | } else { | |
1493 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
1494 | if ((rec->flags & FTRACE_FL_FREE) || |
1495 | ||
1496 | (!(iter->flags & FTRACE_ITER_FAILURES) && | |
eb9a7bf0 AS |
1497 | (rec->flags & FTRACE_FL_FAILED)) || |
1498 | ||
1499 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
a9fdda33 | 1500 | !(rec->flags & FTRACE_FL_FAILED)) || |
eb9a7bf0 | 1501 | |
0183fb1c SR |
1502 | ((iter->flags & FTRACE_ITER_FILTER) && |
1503 | !(rec->flags & FTRACE_FL_FILTER)) || | |
1504 | ||
41c52c0d SR |
1505 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
1506 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
1507 | rec = NULL; |
1508 | goto retry; | |
1509 | } | |
1510 | } | |
1511 | ||
4aeb6967 SR |
1512 | if (!rec) |
1513 | return NULL; | |
1514 | ||
1515 | iter->func = rec; | |
1516 | ||
1517 | return iter; | |
5072c59f SR |
1518 | } |
1519 | ||
1520 | static void *t_start(struct seq_file *m, loff_t *pos) | |
1521 | { | |
1522 | struct ftrace_iterator *iter = m->private; | |
1523 | void *p = NULL; | |
694ce0a5 | 1524 | loff_t l; |
5072c59f | 1525 | |
8fc0c701 | 1526 | mutex_lock(&ftrace_lock); |
0c75a3ed SR |
1527 | /* |
1528 | * For set_ftrace_filter reading, if we have the filter | |
1529 | * off, we can short cut and just print out that all | |
1530 | * functions are enabled. | |
1531 | */ | |
1532 | if (iter->flags & FTRACE_ITER_FILTER && !ftrace_filtered) { | |
1533 | if (*pos > 0) | |
8fc0c701 | 1534 | return t_hash_start(m, pos); |
0c75a3ed | 1535 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 CW |
1536 | /* reset in case of seek/pread */ |
1537 | iter->flags &= ~FTRACE_ITER_HASH; | |
0c75a3ed SR |
1538 | return iter; |
1539 | } | |
1540 | ||
8fc0c701 SR |
1541 | if (iter->flags & FTRACE_ITER_HASH) |
1542 | return t_hash_start(m, pos); | |
1543 | ||
694ce0a5 LZ |
1544 | iter->pg = ftrace_pages_start; |
1545 | iter->idx = 0; | |
1546 | for (l = 0; l <= *pos; ) { | |
1547 | p = t_next(m, p, &l); | |
1548 | if (!p) | |
1549 | break; | |
50cdaf08 | 1550 | } |
5821e1b7 | 1551 | |
4aeb6967 SR |
1552 | if (!p) { |
1553 | if (iter->flags & FTRACE_ITER_FILTER) | |
1554 | return t_hash_start(m, pos); | |
8fc0c701 | 1555 | |
4aeb6967 SR |
1556 | return NULL; |
1557 | } | |
1558 | ||
1559 | return iter; | |
5072c59f SR |
1560 | } |
1561 | ||
1562 | static void t_stop(struct seq_file *m, void *p) | |
1563 | { | |
8fc0c701 | 1564 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1565 | } |
1566 | ||
1567 | static int t_show(struct seq_file *m, void *v) | |
1568 | { | |
0c75a3ed | 1569 | struct ftrace_iterator *iter = m->private; |
4aeb6967 | 1570 | struct dyn_ftrace *rec; |
5072c59f | 1571 | |
8fc0c701 | 1572 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 1573 | return t_hash_show(m, iter); |
8fc0c701 | 1574 | |
0c75a3ed SR |
1575 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
1576 | seq_printf(m, "#### all functions enabled ####\n"); | |
1577 | return 0; | |
1578 | } | |
1579 | ||
4aeb6967 SR |
1580 | rec = iter->func; |
1581 | ||
5072c59f SR |
1582 | if (!rec) |
1583 | return 0; | |
1584 | ||
b375a11a | 1585 | seq_printf(m, "%ps\n", (void *)rec->ip); |
5072c59f SR |
1586 | |
1587 | return 0; | |
1588 | } | |
1589 | ||
88e9d34c | 1590 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
1591 | .start = t_start, |
1592 | .next = t_next, | |
1593 | .stop = t_stop, | |
1594 | .show = t_show, | |
1595 | }; | |
1596 | ||
e309b41d | 1597 | static int |
5072c59f SR |
1598 | ftrace_avail_open(struct inode *inode, struct file *file) |
1599 | { | |
1600 | struct ftrace_iterator *iter; | |
1601 | int ret; | |
1602 | ||
4eebcc81 SR |
1603 | if (unlikely(ftrace_disabled)) |
1604 | return -ENODEV; | |
1605 | ||
5072c59f SR |
1606 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1607 | if (!iter) | |
1608 | return -ENOMEM; | |
1609 | ||
1610 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
1611 | |
1612 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1613 | if (!ret) { | |
1614 | struct seq_file *m = file->private_data; | |
4bf39a94 | 1615 | |
5072c59f | 1616 | m->private = iter; |
4bf39a94 | 1617 | } else { |
5072c59f | 1618 | kfree(iter); |
4bf39a94 | 1619 | } |
5072c59f SR |
1620 | |
1621 | return ret; | |
1622 | } | |
1623 | ||
eb9a7bf0 AS |
1624 | static int |
1625 | ftrace_failures_open(struct inode *inode, struct file *file) | |
1626 | { | |
1627 | int ret; | |
1628 | struct seq_file *m; | |
1629 | struct ftrace_iterator *iter; | |
1630 | ||
1631 | ret = ftrace_avail_open(inode, file); | |
1632 | if (!ret) { | |
1633 | m = (struct seq_file *)file->private_data; | |
1634 | iter = (struct ftrace_iterator *)m->private; | |
1635 | iter->flags = FTRACE_ITER_FAILURES; | |
1636 | } | |
1637 | ||
1638 | return ret; | |
1639 | } | |
1640 | ||
1641 | ||
41c52c0d | 1642 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
1643 | { |
1644 | struct ftrace_page *pg; | |
1645 | struct dyn_ftrace *rec; | |
41c52c0d | 1646 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f | 1647 | |
52baf119 | 1648 | mutex_lock(&ftrace_lock); |
41c52c0d SR |
1649 | if (enable) |
1650 | ftrace_filtered = 0; | |
265c831c SR |
1651 | do_for_each_ftrace_rec(pg, rec) { |
1652 | if (rec->flags & FTRACE_FL_FAILED) | |
1653 | continue; | |
1654 | rec->flags &= ~type; | |
1655 | } while_for_each_ftrace_rec(); | |
52baf119 | 1656 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1657 | } |
1658 | ||
e309b41d | 1659 | static int |
41c52c0d | 1660 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1661 | { |
1662 | struct ftrace_iterator *iter; | |
1663 | int ret = 0; | |
1664 | ||
4eebcc81 SR |
1665 | if (unlikely(ftrace_disabled)) |
1666 | return -ENODEV; | |
1667 | ||
5072c59f SR |
1668 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1669 | if (!iter) | |
1670 | return -ENOMEM; | |
1671 | ||
689fd8b6 | 1672 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { |
1673 | kfree(iter); | |
1674 | return -ENOMEM; | |
1675 | } | |
1676 | ||
41c52c0d | 1677 | mutex_lock(&ftrace_regex_lock); |
5072c59f | 1678 | if ((file->f_mode & FMODE_WRITE) && |
8650ae32 | 1679 | (file->f_flags & O_TRUNC)) |
41c52c0d | 1680 | ftrace_filter_reset(enable); |
5072c59f SR |
1681 | |
1682 | if (file->f_mode & FMODE_READ) { | |
1683 | iter->pg = ftrace_pages_start; | |
41c52c0d SR |
1684 | iter->flags = enable ? FTRACE_ITER_FILTER : |
1685 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
1686 | |
1687 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1688 | if (!ret) { | |
1689 | struct seq_file *m = file->private_data; | |
1690 | m->private = iter; | |
79fe249c LZ |
1691 | } else { |
1692 | trace_parser_put(&iter->parser); | |
5072c59f | 1693 | kfree(iter); |
79fe249c | 1694 | } |
5072c59f SR |
1695 | } else |
1696 | file->private_data = iter; | |
41c52c0d | 1697 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1698 | |
1699 | return ret; | |
1700 | } | |
1701 | ||
41c52c0d SR |
1702 | static int |
1703 | ftrace_filter_open(struct inode *inode, struct file *file) | |
1704 | { | |
1705 | return ftrace_regex_open(inode, file, 1); | |
1706 | } | |
1707 | ||
1708 | static int | |
1709 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
1710 | { | |
1711 | return ftrace_regex_open(inode, file, 0); | |
1712 | } | |
1713 | ||
e309b41d | 1714 | static loff_t |
41c52c0d | 1715 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
1716 | { |
1717 | loff_t ret; | |
1718 | ||
1719 | if (file->f_mode & FMODE_READ) | |
1720 | ret = seq_lseek(file, offset, origin); | |
1721 | else | |
1722 | file->f_pos = ret = 1; | |
1723 | ||
1724 | return ret; | |
1725 | } | |
1726 | ||
64e7c440 | 1727 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 1728 | { |
9f4801e3 | 1729 | int matched = 0; |
751e9983 | 1730 | int slen; |
9f4801e3 | 1731 | |
9f4801e3 SR |
1732 | switch (type) { |
1733 | case MATCH_FULL: | |
1734 | if (strcmp(str, regex) == 0) | |
1735 | matched = 1; | |
1736 | break; | |
1737 | case MATCH_FRONT_ONLY: | |
1738 | if (strncmp(str, regex, len) == 0) | |
1739 | matched = 1; | |
1740 | break; | |
1741 | case MATCH_MIDDLE_ONLY: | |
1742 | if (strstr(str, regex)) | |
1743 | matched = 1; | |
1744 | break; | |
1745 | case MATCH_END_ONLY: | |
751e9983 LZ |
1746 | slen = strlen(str); |
1747 | if (slen >= len && memcmp(str + slen - len, regex, len) == 0) | |
9f4801e3 SR |
1748 | matched = 1; |
1749 | break; | |
1750 | } | |
1751 | ||
1752 | return matched; | |
1753 | } | |
1754 | ||
64e7c440 SR |
1755 | static int |
1756 | ftrace_match_record(struct dyn_ftrace *rec, char *regex, int len, int type) | |
1757 | { | |
1758 | char str[KSYM_SYMBOL_LEN]; | |
1759 | ||
1760 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1761 | return ftrace_match(str, regex, len, type); | |
1762 | } | |
1763 | ||
311d16da | 1764 | static int ftrace_match_records(char *buff, int len, int enable) |
9f4801e3 | 1765 | { |
6a24a244 | 1766 | unsigned int search_len; |
9f4801e3 SR |
1767 | struct ftrace_page *pg; |
1768 | struct dyn_ftrace *rec; | |
6a24a244 SR |
1769 | unsigned long flag; |
1770 | char *search; | |
9f4801e3 | 1771 | int type; |
9f4801e3 | 1772 | int not; |
311d16da | 1773 | int found = 0; |
9f4801e3 | 1774 | |
6a24a244 | 1775 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
3f6fe06d | 1776 | type = filter_parse_regex(buff, len, &search, ¬); |
9f4801e3 SR |
1777 | |
1778 | search_len = strlen(search); | |
1779 | ||
52baf119 | 1780 | mutex_lock(&ftrace_lock); |
265c831c | 1781 | do_for_each_ftrace_rec(pg, rec) { |
265c831c SR |
1782 | |
1783 | if (rec->flags & FTRACE_FL_FAILED) | |
1784 | continue; | |
9f4801e3 SR |
1785 | |
1786 | if (ftrace_match_record(rec, search, search_len, type)) { | |
265c831c SR |
1787 | if (not) |
1788 | rec->flags &= ~flag; | |
1789 | else | |
1790 | rec->flags |= flag; | |
311d16da | 1791 | found = 1; |
265c831c | 1792 | } |
e68746a2 SR |
1793 | /* |
1794 | * Only enable filtering if we have a function that | |
1795 | * is filtered on. | |
1796 | */ | |
1797 | if (enable && (rec->flags & FTRACE_FL_FILTER)) | |
1798 | ftrace_filtered = 1; | |
265c831c | 1799 | } while_for_each_ftrace_rec(); |
52baf119 | 1800 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
1801 | |
1802 | return found; | |
5072c59f SR |
1803 | } |
1804 | ||
64e7c440 SR |
1805 | static int |
1806 | ftrace_match_module_record(struct dyn_ftrace *rec, char *mod, | |
1807 | char *regex, int len, int type) | |
1808 | { | |
1809 | char str[KSYM_SYMBOL_LEN]; | |
1810 | char *modname; | |
1811 | ||
1812 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
1813 | ||
1814 | if (!modname || strcmp(modname, mod)) | |
1815 | return 0; | |
1816 | ||
1817 | /* blank search means to match all funcs in the mod */ | |
1818 | if (len) | |
1819 | return ftrace_match(str, regex, len, type); | |
1820 | else | |
1821 | return 1; | |
1822 | } | |
1823 | ||
311d16da | 1824 | static int ftrace_match_module_records(char *buff, char *mod, int enable) |
64e7c440 | 1825 | { |
6a24a244 | 1826 | unsigned search_len = 0; |
64e7c440 SR |
1827 | struct ftrace_page *pg; |
1828 | struct dyn_ftrace *rec; | |
1829 | int type = MATCH_FULL; | |
6a24a244 SR |
1830 | char *search = buff; |
1831 | unsigned long flag; | |
64e7c440 | 1832 | int not = 0; |
311d16da | 1833 | int found = 0; |
64e7c440 | 1834 | |
6a24a244 SR |
1835 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
1836 | ||
64e7c440 SR |
1837 | /* blank or '*' mean the same */ |
1838 | if (strcmp(buff, "*") == 0) | |
1839 | buff[0] = 0; | |
1840 | ||
1841 | /* handle the case of 'dont filter this module' */ | |
1842 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
1843 | buff[0] = 0; | |
1844 | not = 1; | |
1845 | } | |
1846 | ||
1847 | if (strlen(buff)) { | |
3f6fe06d | 1848 | type = filter_parse_regex(buff, strlen(buff), &search, ¬); |
64e7c440 SR |
1849 | search_len = strlen(search); |
1850 | } | |
1851 | ||
52baf119 | 1852 | mutex_lock(&ftrace_lock); |
64e7c440 SR |
1853 | do_for_each_ftrace_rec(pg, rec) { |
1854 | ||
1855 | if (rec->flags & FTRACE_FL_FAILED) | |
1856 | continue; | |
1857 | ||
1858 | if (ftrace_match_module_record(rec, mod, | |
1859 | search, search_len, type)) { | |
1860 | if (not) | |
1861 | rec->flags &= ~flag; | |
1862 | else | |
1863 | rec->flags |= flag; | |
311d16da | 1864 | found = 1; |
64e7c440 | 1865 | } |
e68746a2 SR |
1866 | if (enable && (rec->flags & FTRACE_FL_FILTER)) |
1867 | ftrace_filtered = 1; | |
64e7c440 SR |
1868 | |
1869 | } while_for_each_ftrace_rec(); | |
52baf119 | 1870 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
1871 | |
1872 | return found; | |
64e7c440 SR |
1873 | } |
1874 | ||
f6180773 SR |
1875 | /* |
1876 | * We register the module command as a template to show others how | |
1877 | * to register the a command as well. | |
1878 | */ | |
1879 | ||
1880 | static int | |
1881 | ftrace_mod_callback(char *func, char *cmd, char *param, int enable) | |
1882 | { | |
1883 | char *mod; | |
1884 | ||
1885 | /* | |
1886 | * cmd == 'mod' because we only registered this func | |
1887 | * for the 'mod' ftrace_func_command. | |
1888 | * But if you register one func with multiple commands, | |
1889 | * you can tell which command was used by the cmd | |
1890 | * parameter. | |
1891 | */ | |
1892 | ||
1893 | /* we must have a module name */ | |
1894 | if (!param) | |
1895 | return -EINVAL; | |
1896 | ||
1897 | mod = strsep(¶m, ":"); | |
1898 | if (!strlen(mod)) | |
1899 | return -EINVAL; | |
1900 | ||
311d16da LZ |
1901 | if (ftrace_match_module_records(func, mod, enable)) |
1902 | return 0; | |
1903 | return -EINVAL; | |
f6180773 SR |
1904 | } |
1905 | ||
1906 | static struct ftrace_func_command ftrace_mod_cmd = { | |
1907 | .name = "mod", | |
1908 | .func = ftrace_mod_callback, | |
1909 | }; | |
1910 | ||
1911 | static int __init ftrace_mod_cmd_init(void) | |
1912 | { | |
1913 | return register_ftrace_command(&ftrace_mod_cmd); | |
1914 | } | |
1915 | device_initcall(ftrace_mod_cmd_init); | |
1916 | ||
59df055f | 1917 | static void |
b6887d79 | 1918 | function_trace_probe_call(unsigned long ip, unsigned long parent_ip) |
59df055f | 1919 | { |
b6887d79 | 1920 | struct ftrace_func_probe *entry; |
59df055f SR |
1921 | struct hlist_head *hhd; |
1922 | struct hlist_node *n; | |
1923 | unsigned long key; | |
59df055f SR |
1924 | |
1925 | key = hash_long(ip, FTRACE_HASH_BITS); | |
1926 | ||
1927 | hhd = &ftrace_func_hash[key]; | |
1928 | ||
1929 | if (hlist_empty(hhd)) | |
1930 | return; | |
1931 | ||
1932 | /* | |
1933 | * Disable preemption for these calls to prevent a RCU grace | |
1934 | * period. This syncs the hash iteration and freeing of items | |
1935 | * on the hash. rcu_read_lock is too dangerous here. | |
1936 | */ | |
5168ae50 | 1937 | preempt_disable_notrace(); |
59df055f SR |
1938 | hlist_for_each_entry_rcu(entry, n, hhd, node) { |
1939 | if (entry->ip == ip) | |
1940 | entry->ops->func(ip, parent_ip, &entry->data); | |
1941 | } | |
5168ae50 | 1942 | preempt_enable_notrace(); |
59df055f SR |
1943 | } |
1944 | ||
b6887d79 | 1945 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 1946 | { |
fb9fb015 | 1947 | .func = function_trace_probe_call, |
59df055f SR |
1948 | }; |
1949 | ||
b6887d79 | 1950 | static int ftrace_probe_registered; |
59df055f | 1951 | |
b6887d79 | 1952 | static void __enable_ftrace_function_probe(void) |
59df055f SR |
1953 | { |
1954 | int i; | |
1955 | ||
b6887d79 | 1956 | if (ftrace_probe_registered) |
59df055f SR |
1957 | return; |
1958 | ||
1959 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1960 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1961 | if (hhd->first) | |
1962 | break; | |
1963 | } | |
1964 | /* Nothing registered? */ | |
1965 | if (i == FTRACE_FUNC_HASHSIZE) | |
1966 | return; | |
1967 | ||
b6887d79 | 1968 | __register_ftrace_function(&trace_probe_ops); |
59df055f | 1969 | ftrace_startup(0); |
b6887d79 | 1970 | ftrace_probe_registered = 1; |
59df055f SR |
1971 | } |
1972 | ||
b6887d79 | 1973 | static void __disable_ftrace_function_probe(void) |
59df055f SR |
1974 | { |
1975 | int i; | |
1976 | ||
b6887d79 | 1977 | if (!ftrace_probe_registered) |
59df055f SR |
1978 | return; |
1979 | ||
1980 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1981 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1982 | if (hhd->first) | |
1983 | return; | |
1984 | } | |
1985 | ||
1986 | /* no more funcs left */ | |
b6887d79 | 1987 | __unregister_ftrace_function(&trace_probe_ops); |
59df055f | 1988 | ftrace_shutdown(0); |
b6887d79 | 1989 | ftrace_probe_registered = 0; |
59df055f SR |
1990 | } |
1991 | ||
1992 | ||
1993 | static void ftrace_free_entry_rcu(struct rcu_head *rhp) | |
1994 | { | |
b6887d79 SR |
1995 | struct ftrace_func_probe *entry = |
1996 | container_of(rhp, struct ftrace_func_probe, rcu); | |
59df055f SR |
1997 | |
1998 | if (entry->ops->free) | |
1999 | entry->ops->free(&entry->data); | |
2000 | kfree(entry); | |
2001 | } | |
2002 | ||
2003 | ||
2004 | int | |
b6887d79 | 2005 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2006 | void *data) |
2007 | { | |
b6887d79 | 2008 | struct ftrace_func_probe *entry; |
59df055f SR |
2009 | struct ftrace_page *pg; |
2010 | struct dyn_ftrace *rec; | |
59df055f | 2011 | int type, len, not; |
6a24a244 | 2012 | unsigned long key; |
59df055f SR |
2013 | int count = 0; |
2014 | char *search; | |
2015 | ||
3f6fe06d | 2016 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
2017 | len = strlen(search); |
2018 | ||
b6887d79 | 2019 | /* we do not support '!' for function probes */ |
59df055f SR |
2020 | if (WARN_ON(not)) |
2021 | return -EINVAL; | |
2022 | ||
2023 | mutex_lock(&ftrace_lock); | |
2024 | do_for_each_ftrace_rec(pg, rec) { | |
2025 | ||
2026 | if (rec->flags & FTRACE_FL_FAILED) | |
2027 | continue; | |
2028 | ||
2029 | if (!ftrace_match_record(rec, search, len, type)) | |
2030 | continue; | |
2031 | ||
2032 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
2033 | if (!entry) { | |
b6887d79 | 2034 | /* If we did not process any, then return error */ |
59df055f SR |
2035 | if (!count) |
2036 | count = -ENOMEM; | |
2037 | goto out_unlock; | |
2038 | } | |
2039 | ||
2040 | count++; | |
2041 | ||
2042 | entry->data = data; | |
2043 | ||
2044 | /* | |
2045 | * The caller might want to do something special | |
2046 | * for each function we find. We call the callback | |
2047 | * to give the caller an opportunity to do so. | |
2048 | */ | |
2049 | if (ops->callback) { | |
2050 | if (ops->callback(rec->ip, &entry->data) < 0) { | |
2051 | /* caller does not like this func */ | |
2052 | kfree(entry); | |
2053 | continue; | |
2054 | } | |
2055 | } | |
2056 | ||
2057 | entry->ops = ops; | |
2058 | entry->ip = rec->ip; | |
2059 | ||
2060 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
2061 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
2062 | ||
2063 | } while_for_each_ftrace_rec(); | |
b6887d79 | 2064 | __enable_ftrace_function_probe(); |
59df055f SR |
2065 | |
2066 | out_unlock: | |
2067 | mutex_unlock(&ftrace_lock); | |
2068 | ||
2069 | return count; | |
2070 | } | |
2071 | ||
2072 | enum { | |
b6887d79 SR |
2073 | PROBE_TEST_FUNC = 1, |
2074 | PROBE_TEST_DATA = 2 | |
59df055f SR |
2075 | }; |
2076 | ||
2077 | static void | |
b6887d79 | 2078 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2079 | void *data, int flags) |
2080 | { | |
b6887d79 | 2081 | struct ftrace_func_probe *entry; |
59df055f SR |
2082 | struct hlist_node *n, *tmp; |
2083 | char str[KSYM_SYMBOL_LEN]; | |
2084 | int type = MATCH_FULL; | |
2085 | int i, len = 0; | |
2086 | char *search; | |
2087 | ||
b36461da | 2088 | if (glob && (strcmp(glob, "*") == 0 || !strlen(glob))) |
59df055f | 2089 | glob = NULL; |
b36461da | 2090 | else if (glob) { |
59df055f SR |
2091 | int not; |
2092 | ||
3f6fe06d | 2093 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
2094 | len = strlen(search); |
2095 | ||
b6887d79 | 2096 | /* we do not support '!' for function probes */ |
59df055f SR |
2097 | if (WARN_ON(not)) |
2098 | return; | |
2099 | } | |
2100 | ||
2101 | mutex_lock(&ftrace_lock); | |
2102 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2103 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2104 | ||
2105 | hlist_for_each_entry_safe(entry, n, tmp, hhd, node) { | |
2106 | ||
2107 | /* break up if statements for readability */ | |
b6887d79 | 2108 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
2109 | continue; |
2110 | ||
b6887d79 | 2111 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
2112 | continue; |
2113 | ||
2114 | /* do this last, since it is the most expensive */ | |
2115 | if (glob) { | |
2116 | kallsyms_lookup(entry->ip, NULL, NULL, | |
2117 | NULL, str); | |
2118 | if (!ftrace_match(str, glob, len, type)) | |
2119 | continue; | |
2120 | } | |
2121 | ||
2122 | hlist_del(&entry->node); | |
2123 | call_rcu(&entry->rcu, ftrace_free_entry_rcu); | |
2124 | } | |
2125 | } | |
b6887d79 | 2126 | __disable_ftrace_function_probe(); |
59df055f SR |
2127 | mutex_unlock(&ftrace_lock); |
2128 | } | |
2129 | ||
2130 | void | |
b6887d79 | 2131 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2132 | void *data) |
2133 | { | |
b6887d79 SR |
2134 | __unregister_ftrace_function_probe(glob, ops, data, |
2135 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
2136 | } |
2137 | ||
2138 | void | |
b6887d79 | 2139 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 2140 | { |
b6887d79 | 2141 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
2142 | } |
2143 | ||
b6887d79 | 2144 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 2145 | { |
b6887d79 | 2146 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
2147 | } |
2148 | ||
f6180773 SR |
2149 | static LIST_HEAD(ftrace_commands); |
2150 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
2151 | ||
2152 | int register_ftrace_command(struct ftrace_func_command *cmd) | |
2153 | { | |
2154 | struct ftrace_func_command *p; | |
2155 | int ret = 0; | |
2156 | ||
2157 | mutex_lock(&ftrace_cmd_mutex); | |
2158 | list_for_each_entry(p, &ftrace_commands, list) { | |
2159 | if (strcmp(cmd->name, p->name) == 0) { | |
2160 | ret = -EBUSY; | |
2161 | goto out_unlock; | |
2162 | } | |
2163 | } | |
2164 | list_add(&cmd->list, &ftrace_commands); | |
2165 | out_unlock: | |
2166 | mutex_unlock(&ftrace_cmd_mutex); | |
2167 | ||
2168 | return ret; | |
2169 | } | |
2170 | ||
2171 | int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
2172 | { | |
2173 | struct ftrace_func_command *p, *n; | |
2174 | int ret = -ENODEV; | |
2175 | ||
2176 | mutex_lock(&ftrace_cmd_mutex); | |
2177 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
2178 | if (strcmp(cmd->name, p->name) == 0) { | |
2179 | ret = 0; | |
2180 | list_del_init(&p->list); | |
2181 | goto out_unlock; | |
2182 | } | |
2183 | } | |
2184 | out_unlock: | |
2185 | mutex_unlock(&ftrace_cmd_mutex); | |
2186 | ||
2187 | return ret; | |
2188 | } | |
2189 | ||
64e7c440 SR |
2190 | static int ftrace_process_regex(char *buff, int len, int enable) |
2191 | { | |
f6180773 | 2192 | char *func, *command, *next = buff; |
6a24a244 | 2193 | struct ftrace_func_command *p; |
f6180773 | 2194 | int ret = -EINVAL; |
64e7c440 SR |
2195 | |
2196 | func = strsep(&next, ":"); | |
2197 | ||
2198 | if (!next) { | |
311d16da LZ |
2199 | if (ftrace_match_records(func, len, enable)) |
2200 | return 0; | |
2201 | return ret; | |
64e7c440 SR |
2202 | } |
2203 | ||
f6180773 | 2204 | /* command found */ |
64e7c440 SR |
2205 | |
2206 | command = strsep(&next, ":"); | |
2207 | ||
f6180773 SR |
2208 | mutex_lock(&ftrace_cmd_mutex); |
2209 | list_for_each_entry(p, &ftrace_commands, list) { | |
2210 | if (strcmp(p->name, command) == 0) { | |
2211 | ret = p->func(func, command, next, enable); | |
2212 | goto out_unlock; | |
2213 | } | |
64e7c440 | 2214 | } |
f6180773 SR |
2215 | out_unlock: |
2216 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 2217 | |
f6180773 | 2218 | return ret; |
64e7c440 SR |
2219 | } |
2220 | ||
e309b41d | 2221 | static ssize_t |
41c52c0d SR |
2222 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
2223 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
2224 | { |
2225 | struct ftrace_iterator *iter; | |
689fd8b6 | 2226 | struct trace_parser *parser; |
2227 | ssize_t ret, read; | |
5072c59f | 2228 | |
4ba7978e | 2229 | if (!cnt) |
5072c59f SR |
2230 | return 0; |
2231 | ||
41c52c0d | 2232 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
2233 | |
2234 | if (file->f_mode & FMODE_READ) { | |
2235 | struct seq_file *m = file->private_data; | |
2236 | iter = m->private; | |
2237 | } else | |
2238 | iter = file->private_data; | |
2239 | ||
689fd8b6 | 2240 | parser = &iter->parser; |
2241 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 2242 | |
4ba7978e | 2243 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 2244 | !trace_parser_cont(parser)) { |
2245 | ret = ftrace_process_regex(parser->buffer, | |
2246 | parser->idx, enable); | |
313254a9 | 2247 | trace_parser_clear(parser); |
5072c59f | 2248 | if (ret) |
ed146b25 | 2249 | goto out_unlock; |
eda1e328 | 2250 | } |
5072c59f | 2251 | |
5072c59f | 2252 | ret = read; |
ed146b25 | 2253 | out_unlock: |
689fd8b6 | 2254 | mutex_unlock(&ftrace_regex_lock); |
ed146b25 | 2255 | |
5072c59f SR |
2256 | return ret; |
2257 | } | |
2258 | ||
41c52c0d SR |
2259 | static ssize_t |
2260 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
2261 | size_t cnt, loff_t *ppos) | |
2262 | { | |
2263 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
2264 | } | |
2265 | ||
2266 | static ssize_t | |
2267 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
2268 | size_t cnt, loff_t *ppos) | |
2269 | { | |
2270 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
2271 | } | |
2272 | ||
2273 | static void | |
2274 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
2275 | { | |
2276 | if (unlikely(ftrace_disabled)) | |
2277 | return; | |
2278 | ||
2279 | mutex_lock(&ftrace_regex_lock); | |
2280 | if (reset) | |
2281 | ftrace_filter_reset(enable); | |
2282 | if (buf) | |
7f24b31b | 2283 | ftrace_match_records(buf, len, enable); |
41c52c0d SR |
2284 | mutex_unlock(&ftrace_regex_lock); |
2285 | } | |
2286 | ||
77a2b37d SR |
2287 | /** |
2288 | * ftrace_set_filter - set a function to filter on in ftrace | |
2289 | * @buf - the string that holds the function filter text. | |
2290 | * @len - the length of the string. | |
2291 | * @reset - non zero to reset all filters before applying this filter. | |
2292 | * | |
2293 | * Filters denote which functions should be enabled when tracing is enabled. | |
2294 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
2295 | */ | |
e309b41d | 2296 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 2297 | { |
41c52c0d SR |
2298 | ftrace_set_regex(buf, len, reset, 1); |
2299 | } | |
4eebcc81 | 2300 | |
41c52c0d SR |
2301 | /** |
2302 | * ftrace_set_notrace - set a function to not trace in ftrace | |
2303 | * @buf - the string that holds the function notrace text. | |
2304 | * @len - the length of the string. | |
2305 | * @reset - non zero to reset all filters before applying this filter. | |
2306 | * | |
2307 | * Notrace Filters denote which functions should not be enabled when tracing | |
2308 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
2309 | * for tracing. | |
2310 | */ | |
2311 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
2312 | { | |
2313 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
2314 | } |
2315 | ||
2af15d6a SR |
2316 | /* |
2317 | * command line interface to allow users to set filters on boot up. | |
2318 | */ | |
2319 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
2320 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
2321 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
2322 | ||
2323 | static int __init set_ftrace_notrace(char *str) | |
2324 | { | |
2325 | strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); | |
2326 | return 1; | |
2327 | } | |
2328 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
2329 | ||
2330 | static int __init set_ftrace_filter(char *str) | |
2331 | { | |
2332 | strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); | |
2333 | return 1; | |
2334 | } | |
2335 | __setup("ftrace_filter=", set_ftrace_filter); | |
2336 | ||
369bc18f | 2337 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 2338 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
801c29fd SR |
2339 | static int ftrace_set_func(unsigned long *array, int *idx, char *buffer); |
2340 | ||
369bc18f SA |
2341 | static int __init set_graph_function(char *str) |
2342 | { | |
06f43d66 | 2343 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
2344 | return 1; |
2345 | } | |
2346 | __setup("ftrace_graph_filter=", set_graph_function); | |
2347 | ||
2348 | static void __init set_ftrace_early_graph(char *buf) | |
2349 | { | |
2350 | int ret; | |
2351 | char *func; | |
2352 | ||
2353 | while (buf) { | |
2354 | func = strsep(&buf, ","); | |
2355 | /* we allow only one expression at a time */ | |
2356 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, | |
2357 | func); | |
2358 | if (ret) | |
2359 | printk(KERN_DEBUG "ftrace: function %s not " | |
2360 | "traceable\n", func); | |
2361 | } | |
2362 | } | |
2363 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2364 | ||
2af15d6a SR |
2365 | static void __init set_ftrace_early_filter(char *buf, int enable) |
2366 | { | |
2367 | char *func; | |
2368 | ||
2369 | while (buf) { | |
2370 | func = strsep(&buf, ","); | |
2371 | ftrace_set_regex(func, strlen(func), 0, enable); | |
2372 | } | |
2373 | } | |
2374 | ||
2375 | static void __init set_ftrace_early_filters(void) | |
2376 | { | |
2377 | if (ftrace_filter_buf[0]) | |
2378 | set_ftrace_early_filter(ftrace_filter_buf, 1); | |
2379 | if (ftrace_notrace_buf[0]) | |
2380 | set_ftrace_early_filter(ftrace_notrace_buf, 0); | |
369bc18f SA |
2381 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
2382 | if (ftrace_graph_buf[0]) | |
2383 | set_ftrace_early_graph(ftrace_graph_buf); | |
2384 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2af15d6a SR |
2385 | } |
2386 | ||
e309b41d | 2387 | static int |
41c52c0d | 2388 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
2389 | { |
2390 | struct seq_file *m = (struct seq_file *)file->private_data; | |
2391 | struct ftrace_iterator *iter; | |
689fd8b6 | 2392 | struct trace_parser *parser; |
5072c59f | 2393 | |
41c52c0d | 2394 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
2395 | if (file->f_mode & FMODE_READ) { |
2396 | iter = m->private; | |
2397 | ||
2398 | seq_release(inode, file); | |
2399 | } else | |
2400 | iter = file->private_data; | |
2401 | ||
689fd8b6 | 2402 | parser = &iter->parser; |
2403 | if (trace_parser_loaded(parser)) { | |
2404 | parser->buffer[parser->idx] = 0; | |
2405 | ftrace_match_records(parser->buffer, parser->idx, enable); | |
5072c59f SR |
2406 | } |
2407 | ||
e6ea44e9 | 2408 | mutex_lock(&ftrace_lock); |
ee02a2e5 | 2409 | if (ftrace_start_up && ftrace_enabled) |
5072c59f | 2410 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
e6ea44e9 | 2411 | mutex_unlock(&ftrace_lock); |
5072c59f | 2412 | |
689fd8b6 | 2413 | trace_parser_put(parser); |
5072c59f | 2414 | kfree(iter); |
689fd8b6 | 2415 | |
41c52c0d | 2416 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
2417 | return 0; |
2418 | } | |
2419 | ||
41c52c0d SR |
2420 | static int |
2421 | ftrace_filter_release(struct inode *inode, struct file *file) | |
2422 | { | |
2423 | return ftrace_regex_release(inode, file, 1); | |
2424 | } | |
2425 | ||
2426 | static int | |
2427 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
2428 | { | |
2429 | return ftrace_regex_release(inode, file, 0); | |
2430 | } | |
2431 | ||
5e2336a0 | 2432 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
2433 | .open = ftrace_avail_open, |
2434 | .read = seq_read, | |
2435 | .llseek = seq_lseek, | |
3be04b47 | 2436 | .release = seq_release_private, |
5072c59f SR |
2437 | }; |
2438 | ||
5e2336a0 | 2439 | static const struct file_operations ftrace_failures_fops = { |
eb9a7bf0 AS |
2440 | .open = ftrace_failures_open, |
2441 | .read = seq_read, | |
2442 | .llseek = seq_lseek, | |
3be04b47 | 2443 | .release = seq_release_private, |
eb9a7bf0 AS |
2444 | }; |
2445 | ||
5e2336a0 | 2446 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 2447 | .open = ftrace_filter_open, |
850a80cf | 2448 | .read = seq_read, |
5072c59f | 2449 | .write = ftrace_filter_write, |
9c55cb12 | 2450 | .llseek = no_llseek, |
5072c59f SR |
2451 | .release = ftrace_filter_release, |
2452 | }; | |
2453 | ||
5e2336a0 | 2454 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 2455 | .open = ftrace_notrace_open, |
850a80cf | 2456 | .read = seq_read, |
41c52c0d SR |
2457 | .write = ftrace_notrace_write, |
2458 | .llseek = ftrace_regex_lseek, | |
2459 | .release = ftrace_notrace_release, | |
2460 | }; | |
2461 | ||
ea4e2bc4 SR |
2462 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
2463 | ||
2464 | static DEFINE_MUTEX(graph_lock); | |
2465 | ||
2466 | int ftrace_graph_count; | |
c7c6b1fe | 2467 | int ftrace_graph_filter_enabled; |
ea4e2bc4 SR |
2468 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
2469 | ||
2470 | static void * | |
85951842 | 2471 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 2472 | { |
85951842 | 2473 | if (*pos >= ftrace_graph_count) |
ea4e2bc4 | 2474 | return NULL; |
a4ec5e0c | 2475 | return &ftrace_graph_funcs[*pos]; |
85951842 | 2476 | } |
ea4e2bc4 | 2477 | |
85951842 LZ |
2478 | static void * |
2479 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
2480 | { | |
2481 | (*pos)++; | |
2482 | return __g_next(m, pos); | |
ea4e2bc4 SR |
2483 | } |
2484 | ||
2485 | static void *g_start(struct seq_file *m, loff_t *pos) | |
2486 | { | |
ea4e2bc4 SR |
2487 | mutex_lock(&graph_lock); |
2488 | ||
f9349a8f | 2489 | /* Nothing, tell g_show to print all functions are enabled */ |
c7c6b1fe | 2490 | if (!ftrace_graph_filter_enabled && !*pos) |
f9349a8f FW |
2491 | return (void *)1; |
2492 | ||
85951842 | 2493 | return __g_next(m, pos); |
ea4e2bc4 SR |
2494 | } |
2495 | ||
2496 | static void g_stop(struct seq_file *m, void *p) | |
2497 | { | |
2498 | mutex_unlock(&graph_lock); | |
2499 | } | |
2500 | ||
2501 | static int g_show(struct seq_file *m, void *v) | |
2502 | { | |
2503 | unsigned long *ptr = v; | |
ea4e2bc4 SR |
2504 | |
2505 | if (!ptr) | |
2506 | return 0; | |
2507 | ||
f9349a8f FW |
2508 | if (ptr == (unsigned long *)1) { |
2509 | seq_printf(m, "#### all functions enabled ####\n"); | |
2510 | return 0; | |
2511 | } | |
2512 | ||
b375a11a | 2513 | seq_printf(m, "%ps\n", (void *)*ptr); |
ea4e2bc4 SR |
2514 | |
2515 | return 0; | |
2516 | } | |
2517 | ||
88e9d34c | 2518 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
2519 | .start = g_start, |
2520 | .next = g_next, | |
2521 | .stop = g_stop, | |
2522 | .show = g_show, | |
2523 | }; | |
2524 | ||
2525 | static int | |
2526 | ftrace_graph_open(struct inode *inode, struct file *file) | |
2527 | { | |
2528 | int ret = 0; | |
2529 | ||
2530 | if (unlikely(ftrace_disabled)) | |
2531 | return -ENODEV; | |
2532 | ||
2533 | mutex_lock(&graph_lock); | |
2534 | if ((file->f_mode & FMODE_WRITE) && | |
8650ae32 | 2535 | (file->f_flags & O_TRUNC)) { |
c7c6b1fe | 2536 | ftrace_graph_filter_enabled = 0; |
ea4e2bc4 SR |
2537 | ftrace_graph_count = 0; |
2538 | memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); | |
2539 | } | |
a4ec5e0c | 2540 | mutex_unlock(&graph_lock); |
ea4e2bc4 | 2541 | |
a4ec5e0c | 2542 | if (file->f_mode & FMODE_READ) |
ea4e2bc4 | 2543 | ret = seq_open(file, &ftrace_graph_seq_ops); |
ea4e2bc4 SR |
2544 | |
2545 | return ret; | |
2546 | } | |
2547 | ||
87827111 LZ |
2548 | static int |
2549 | ftrace_graph_release(struct inode *inode, struct file *file) | |
2550 | { | |
2551 | if (file->f_mode & FMODE_READ) | |
2552 | seq_release(inode, file); | |
2553 | return 0; | |
2554 | } | |
2555 | ||
ea4e2bc4 | 2556 | static int |
f9349a8f | 2557 | ftrace_set_func(unsigned long *array, int *idx, char *buffer) |
ea4e2bc4 | 2558 | { |
ea4e2bc4 SR |
2559 | struct dyn_ftrace *rec; |
2560 | struct ftrace_page *pg; | |
f9349a8f | 2561 | int search_len; |
c7c6b1fe | 2562 | int fail = 1; |
f9349a8f FW |
2563 | int type, not; |
2564 | char *search; | |
2565 | bool exists; | |
2566 | int i; | |
ea4e2bc4 SR |
2567 | |
2568 | if (ftrace_disabled) | |
2569 | return -ENODEV; | |
2570 | ||
f9349a8f | 2571 | /* decode regex */ |
3f6fe06d | 2572 | type = filter_parse_regex(buffer, strlen(buffer), &search, ¬); |
c7c6b1fe LZ |
2573 | if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS) |
2574 | return -EBUSY; | |
f9349a8f FW |
2575 | |
2576 | search_len = strlen(search); | |
2577 | ||
52baf119 | 2578 | mutex_lock(&ftrace_lock); |
265c831c SR |
2579 | do_for_each_ftrace_rec(pg, rec) { |
2580 | ||
2581 | if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE)) | |
2582 | continue; | |
2583 | ||
f9349a8f | 2584 | if (ftrace_match_record(rec, search, search_len, type)) { |
c7c6b1fe | 2585 | /* if it is in the array */ |
f9349a8f | 2586 | exists = false; |
c7c6b1fe | 2587 | for (i = 0; i < *idx; i++) { |
f9349a8f FW |
2588 | if (array[i] == rec->ip) { |
2589 | exists = true; | |
265c831c SR |
2590 | break; |
2591 | } | |
c7c6b1fe LZ |
2592 | } |
2593 | ||
2594 | if (!not) { | |
2595 | fail = 0; | |
2596 | if (!exists) { | |
2597 | array[(*idx)++] = rec->ip; | |
2598 | if (*idx >= FTRACE_GRAPH_MAX_FUNCS) | |
2599 | goto out; | |
2600 | } | |
2601 | } else { | |
2602 | if (exists) { | |
2603 | array[i] = array[--(*idx)]; | |
2604 | array[*idx] = 0; | |
2605 | fail = 0; | |
2606 | } | |
2607 | } | |
ea4e2bc4 | 2608 | } |
265c831c | 2609 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 2610 | out: |
52baf119 | 2611 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 2612 | |
c7c6b1fe LZ |
2613 | if (fail) |
2614 | return -EINVAL; | |
2615 | ||
2616 | ftrace_graph_filter_enabled = 1; | |
2617 | return 0; | |
ea4e2bc4 SR |
2618 | } |
2619 | ||
2620 | static ssize_t | |
2621 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
2622 | size_t cnt, loff_t *ppos) | |
2623 | { | |
689fd8b6 | 2624 | struct trace_parser parser; |
4ba7978e | 2625 | ssize_t read, ret; |
ea4e2bc4 | 2626 | |
c7c6b1fe | 2627 | if (!cnt) |
ea4e2bc4 SR |
2628 | return 0; |
2629 | ||
2630 | mutex_lock(&graph_lock); | |
2631 | ||
689fd8b6 | 2632 | if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) { |
2633 | ret = -ENOMEM; | |
1eb90f13 | 2634 | goto out_unlock; |
ea4e2bc4 SR |
2635 | } |
2636 | ||
689fd8b6 | 2637 | read = trace_get_user(&parser, ubuf, cnt, ppos); |
ea4e2bc4 | 2638 | |
4ba7978e | 2639 | if (read >= 0 && trace_parser_loaded((&parser))) { |
689fd8b6 | 2640 | parser.buffer[parser.idx] = 0; |
2641 | ||
2642 | /* we allow only one expression at a time */ | |
a4ec5e0c | 2643 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, |
689fd8b6 | 2644 | parser.buffer); |
ea4e2bc4 | 2645 | if (ret) |
1eb90f13 | 2646 | goto out_free; |
ea4e2bc4 | 2647 | } |
ea4e2bc4 SR |
2648 | |
2649 | ret = read; | |
1eb90f13 LZ |
2650 | |
2651 | out_free: | |
689fd8b6 | 2652 | trace_parser_put(&parser); |
1eb90f13 | 2653 | out_unlock: |
ea4e2bc4 SR |
2654 | mutex_unlock(&graph_lock); |
2655 | ||
2656 | return ret; | |
2657 | } | |
2658 | ||
2659 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
2660 | .open = ftrace_graph_open, |
2661 | .read = seq_read, | |
2662 | .write = ftrace_graph_write, | |
2663 | .release = ftrace_graph_release, | |
ea4e2bc4 SR |
2664 | }; |
2665 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2666 | ||
df4fc315 | 2667 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 2668 | { |
5072c59f | 2669 | |
5452af66 FW |
2670 | trace_create_file("available_filter_functions", 0444, |
2671 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 2672 | |
5452af66 FW |
2673 | trace_create_file("failures", 0444, |
2674 | d_tracer, NULL, &ftrace_failures_fops); | |
eb9a7bf0 | 2675 | |
5452af66 FW |
2676 | trace_create_file("set_ftrace_filter", 0644, d_tracer, |
2677 | NULL, &ftrace_filter_fops); | |
41c52c0d | 2678 | |
5452af66 | 2679 | trace_create_file("set_ftrace_notrace", 0644, d_tracer, |
41c52c0d | 2680 | NULL, &ftrace_notrace_fops); |
ad90c0e3 | 2681 | |
ea4e2bc4 | 2682 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 2683 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
2684 | NULL, |
2685 | &ftrace_graph_fops); | |
ea4e2bc4 SR |
2686 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
2687 | ||
5072c59f SR |
2688 | return 0; |
2689 | } | |
2690 | ||
5cb084bb | 2691 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 2692 | unsigned long *start, |
68bf21aa SR |
2693 | unsigned long *end) |
2694 | { | |
2695 | unsigned long *p; | |
2696 | unsigned long addr; | |
2697 | unsigned long flags; | |
2698 | ||
e6ea44e9 | 2699 | mutex_lock(&ftrace_lock); |
68bf21aa SR |
2700 | p = start; |
2701 | while (p < end) { | |
2702 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
2703 | /* |
2704 | * Some architecture linkers will pad between | |
2705 | * the different mcount_loc sections of different | |
2706 | * object files to satisfy alignments. | |
2707 | * Skip any NULL pointers. | |
2708 | */ | |
2709 | if (!addr) | |
2710 | continue; | |
68bf21aa | 2711 | ftrace_record_ip(addr); |
68bf21aa SR |
2712 | } |
2713 | ||
08f5ac90 | 2714 | /* disable interrupts to prevent kstop machine */ |
68bf21aa | 2715 | local_irq_save(flags); |
31e88909 | 2716 | ftrace_update_code(mod); |
68bf21aa | 2717 | local_irq_restore(flags); |
e6ea44e9 | 2718 | mutex_unlock(&ftrace_lock); |
68bf21aa SR |
2719 | |
2720 | return 0; | |
2721 | } | |
2722 | ||
93eb677d | 2723 | #ifdef CONFIG_MODULES |
e7247a15 | 2724 | void ftrace_release_mod(struct module *mod) |
93eb677d SR |
2725 | { |
2726 | struct dyn_ftrace *rec; | |
2727 | struct ftrace_page *pg; | |
93eb677d | 2728 | |
e7247a15 | 2729 | if (ftrace_disabled) |
93eb677d SR |
2730 | return; |
2731 | ||
2732 | mutex_lock(&ftrace_lock); | |
2733 | do_for_each_ftrace_rec(pg, rec) { | |
e7247a15 | 2734 | if (within_module_core(rec->ip, mod)) { |
93eb677d SR |
2735 | /* |
2736 | * rec->ip is changed in ftrace_free_rec() | |
2737 | * It should not between s and e if record was freed. | |
2738 | */ | |
2739 | FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE); | |
2740 | ftrace_free_rec(rec); | |
2741 | } | |
2742 | } while_for_each_ftrace_rec(); | |
2743 | mutex_unlock(&ftrace_lock); | |
2744 | } | |
2745 | ||
2746 | static void ftrace_init_module(struct module *mod, | |
2747 | unsigned long *start, unsigned long *end) | |
90d595fe | 2748 | { |
00fd61ae | 2749 | if (ftrace_disabled || start == end) |
fed1939c | 2750 | return; |
5cb084bb | 2751 | ftrace_process_locs(mod, start, end); |
90d595fe SR |
2752 | } |
2753 | ||
93eb677d SR |
2754 | static int ftrace_module_notify(struct notifier_block *self, |
2755 | unsigned long val, void *data) | |
2756 | { | |
2757 | struct module *mod = data; | |
2758 | ||
2759 | switch (val) { | |
2760 | case MODULE_STATE_COMING: | |
2761 | ftrace_init_module(mod, mod->ftrace_callsites, | |
2762 | mod->ftrace_callsites + | |
2763 | mod->num_ftrace_callsites); | |
2764 | break; | |
2765 | case MODULE_STATE_GOING: | |
e7247a15 | 2766 | ftrace_release_mod(mod); |
93eb677d SR |
2767 | break; |
2768 | } | |
2769 | ||
2770 | return 0; | |
2771 | } | |
2772 | #else | |
2773 | static int ftrace_module_notify(struct notifier_block *self, | |
2774 | unsigned long val, void *data) | |
2775 | { | |
2776 | return 0; | |
2777 | } | |
2778 | #endif /* CONFIG_MODULES */ | |
2779 | ||
2780 | struct notifier_block ftrace_module_nb = { | |
2781 | .notifier_call = ftrace_module_notify, | |
2782 | .priority = 0, | |
2783 | }; | |
2784 | ||
68bf21aa SR |
2785 | extern unsigned long __start_mcount_loc[]; |
2786 | extern unsigned long __stop_mcount_loc[]; | |
2787 | ||
2788 | void __init ftrace_init(void) | |
2789 | { | |
2790 | unsigned long count, addr, flags; | |
2791 | int ret; | |
2792 | ||
2793 | /* Keep the ftrace pointer to the stub */ | |
2794 | addr = (unsigned long)ftrace_stub; | |
2795 | ||
2796 | local_irq_save(flags); | |
2797 | ftrace_dyn_arch_init(&addr); | |
2798 | local_irq_restore(flags); | |
2799 | ||
2800 | /* ftrace_dyn_arch_init places the return code in addr */ | |
2801 | if (addr) | |
2802 | goto failed; | |
2803 | ||
2804 | count = __stop_mcount_loc - __start_mcount_loc; | |
2805 | ||
2806 | ret = ftrace_dyn_table_alloc(count); | |
2807 | if (ret) | |
2808 | goto failed; | |
2809 | ||
2810 | last_ftrace_enabled = ftrace_enabled = 1; | |
2811 | ||
5cb084bb | 2812 | ret = ftrace_process_locs(NULL, |
31e88909 | 2813 | __start_mcount_loc, |
68bf21aa SR |
2814 | __stop_mcount_loc); |
2815 | ||
93eb677d | 2816 | ret = register_module_notifier(&ftrace_module_nb); |
24ed0c4b | 2817 | if (ret) |
93eb677d SR |
2818 | pr_warning("Failed to register trace ftrace module notifier\n"); |
2819 | ||
2af15d6a SR |
2820 | set_ftrace_early_filters(); |
2821 | ||
68bf21aa SR |
2822 | return; |
2823 | failed: | |
2824 | ftrace_disabled = 1; | |
2825 | } | |
68bf21aa | 2826 | |
3d083395 | 2827 | #else |
0b6e4d56 FW |
2828 | |
2829 | static int __init ftrace_nodyn_init(void) | |
2830 | { | |
2831 | ftrace_enabled = 1; | |
2832 | return 0; | |
2833 | } | |
2834 | device_initcall(ftrace_nodyn_init); | |
2835 | ||
df4fc315 SR |
2836 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
2837 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 SR |
2838 | /* Keep as macros so we do not need to define the commands */ |
2839 | # define ftrace_startup(command) do { } while (0) | |
2840 | # define ftrace_shutdown(command) do { } while (0) | |
c7aafc54 IM |
2841 | # define ftrace_startup_sysctl() do { } while (0) |
2842 | # define ftrace_shutdown_sysctl() do { } while (0) | |
3d083395 SR |
2843 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
2844 | ||
e32d8956 | 2845 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
2846 | { |
2847 | struct task_struct *p; | |
e32d8956 | 2848 | int cpu; |
978f3a45 | 2849 | |
e32d8956 SR |
2850 | get_online_cpus(); |
2851 | for_each_online_cpu(cpu) { | |
2852 | p = idle_task(cpu); | |
978f3a45 | 2853 | clear_tsk_trace_trace(p); |
e32d8956 SR |
2854 | } |
2855 | put_online_cpus(); | |
2856 | } | |
978f3a45 | 2857 | |
e32d8956 SR |
2858 | static void set_ftrace_swapper(void) |
2859 | { | |
2860 | struct task_struct *p; | |
2861 | int cpu; | |
2862 | ||
2863 | get_online_cpus(); | |
2864 | for_each_online_cpu(cpu) { | |
2865 | p = idle_task(cpu); | |
2866 | set_tsk_trace_trace(p); | |
2867 | } | |
2868 | put_online_cpus(); | |
978f3a45 SR |
2869 | } |
2870 | ||
e32d8956 SR |
2871 | static void clear_ftrace_pid(struct pid *pid) |
2872 | { | |
2873 | struct task_struct *p; | |
2874 | ||
229c4ef8 | 2875 | rcu_read_lock(); |
e32d8956 SR |
2876 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2877 | clear_tsk_trace_trace(p); | |
2878 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
2879 | rcu_read_unlock(); |
2880 | ||
e32d8956 SR |
2881 | put_pid(pid); |
2882 | } | |
2883 | ||
2884 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
2885 | { |
2886 | struct task_struct *p; | |
2887 | ||
229c4ef8 | 2888 | rcu_read_lock(); |
978f3a45 SR |
2889 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2890 | set_tsk_trace_trace(p); | |
2891 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 2892 | rcu_read_unlock(); |
978f3a45 SR |
2893 | } |
2894 | ||
756d17ee | 2895 | static void clear_ftrace_pid_task(struct pid *pid) |
e32d8956 | 2896 | { |
756d17ee | 2897 | if (pid == ftrace_swapper_pid) |
e32d8956 SR |
2898 | clear_ftrace_swapper(); |
2899 | else | |
756d17ee | 2900 | clear_ftrace_pid(pid); |
e32d8956 SR |
2901 | } |
2902 | ||
2903 | static void set_ftrace_pid_task(struct pid *pid) | |
2904 | { | |
2905 | if (pid == ftrace_swapper_pid) | |
2906 | set_ftrace_swapper(); | |
2907 | else | |
2908 | set_ftrace_pid(pid); | |
2909 | } | |
2910 | ||
756d17ee | 2911 | static int ftrace_pid_add(int p) |
df4fc315 | 2912 | { |
978f3a45 | 2913 | struct pid *pid; |
756d17ee | 2914 | struct ftrace_pid *fpid; |
2915 | int ret = -EINVAL; | |
df4fc315 | 2916 | |
756d17ee | 2917 | mutex_lock(&ftrace_lock); |
df4fc315 | 2918 | |
756d17ee | 2919 | if (!p) |
2920 | pid = ftrace_swapper_pid; | |
2921 | else | |
2922 | pid = find_get_pid(p); | |
df4fc315 | 2923 | |
756d17ee | 2924 | if (!pid) |
2925 | goto out; | |
df4fc315 | 2926 | |
756d17ee | 2927 | ret = 0; |
df4fc315 | 2928 | |
756d17ee | 2929 | list_for_each_entry(fpid, &ftrace_pids, list) |
2930 | if (fpid->pid == pid) | |
2931 | goto out_put; | |
978f3a45 | 2932 | |
756d17ee | 2933 | ret = -ENOMEM; |
df4fc315 | 2934 | |
756d17ee | 2935 | fpid = kmalloc(sizeof(*fpid), GFP_KERNEL); |
2936 | if (!fpid) | |
2937 | goto out_put; | |
df4fc315 | 2938 | |
756d17ee | 2939 | list_add(&fpid->list, &ftrace_pids); |
2940 | fpid->pid = pid; | |
0ef8cde5 | 2941 | |
756d17ee | 2942 | set_ftrace_pid_task(pid); |
978f3a45 | 2943 | |
756d17ee | 2944 | ftrace_update_pid_func(); |
2945 | ftrace_startup_enable(0); | |
2946 | ||
2947 | mutex_unlock(&ftrace_lock); | |
2948 | return 0; | |
2949 | ||
2950 | out_put: | |
2951 | if (pid != ftrace_swapper_pid) | |
2952 | put_pid(pid); | |
978f3a45 | 2953 | |
756d17ee | 2954 | out: |
2955 | mutex_unlock(&ftrace_lock); | |
2956 | return ret; | |
2957 | } | |
2958 | ||
2959 | static void ftrace_pid_reset(void) | |
2960 | { | |
2961 | struct ftrace_pid *fpid, *safe; | |
978f3a45 | 2962 | |
756d17ee | 2963 | mutex_lock(&ftrace_lock); |
2964 | list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) { | |
2965 | struct pid *pid = fpid->pid; | |
2966 | ||
2967 | clear_ftrace_pid_task(pid); | |
2968 | ||
2969 | list_del(&fpid->list); | |
2970 | kfree(fpid); | |
df4fc315 SR |
2971 | } |
2972 | ||
df4fc315 SR |
2973 | ftrace_update_pid_func(); |
2974 | ftrace_startup_enable(0); | |
2975 | ||
e6ea44e9 | 2976 | mutex_unlock(&ftrace_lock); |
756d17ee | 2977 | } |
df4fc315 | 2978 | |
756d17ee | 2979 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
2980 | { | |
2981 | mutex_lock(&ftrace_lock); | |
2982 | ||
2983 | if (list_empty(&ftrace_pids) && (!*pos)) | |
2984 | return (void *) 1; | |
2985 | ||
2986 | return seq_list_start(&ftrace_pids, *pos); | |
2987 | } | |
2988 | ||
2989 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
2990 | { | |
2991 | if (v == (void *)1) | |
2992 | return NULL; | |
2993 | ||
2994 | return seq_list_next(v, &ftrace_pids, pos); | |
2995 | } | |
2996 | ||
2997 | static void fpid_stop(struct seq_file *m, void *p) | |
2998 | { | |
2999 | mutex_unlock(&ftrace_lock); | |
3000 | } | |
3001 | ||
3002 | static int fpid_show(struct seq_file *m, void *v) | |
3003 | { | |
3004 | const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list); | |
3005 | ||
3006 | if (v == (void *)1) { | |
3007 | seq_printf(m, "no pid\n"); | |
3008 | return 0; | |
3009 | } | |
3010 | ||
3011 | if (fpid->pid == ftrace_swapper_pid) | |
3012 | seq_printf(m, "swapper tasks\n"); | |
3013 | else | |
3014 | seq_printf(m, "%u\n", pid_vnr(fpid->pid)); | |
3015 | ||
3016 | return 0; | |
3017 | } | |
3018 | ||
3019 | static const struct seq_operations ftrace_pid_sops = { | |
3020 | .start = fpid_start, | |
3021 | .next = fpid_next, | |
3022 | .stop = fpid_stop, | |
3023 | .show = fpid_show, | |
3024 | }; | |
3025 | ||
3026 | static int | |
3027 | ftrace_pid_open(struct inode *inode, struct file *file) | |
3028 | { | |
3029 | int ret = 0; | |
3030 | ||
3031 | if ((file->f_mode & FMODE_WRITE) && | |
3032 | (file->f_flags & O_TRUNC)) | |
3033 | ftrace_pid_reset(); | |
3034 | ||
3035 | if (file->f_mode & FMODE_READ) | |
3036 | ret = seq_open(file, &ftrace_pid_sops); | |
3037 | ||
3038 | return ret; | |
3039 | } | |
3040 | ||
df4fc315 SR |
3041 | static ssize_t |
3042 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
3043 | size_t cnt, loff_t *ppos) | |
3044 | { | |
457dc928 | 3045 | char buf[64], *tmp; |
df4fc315 SR |
3046 | long val; |
3047 | int ret; | |
3048 | ||
3049 | if (cnt >= sizeof(buf)) | |
3050 | return -EINVAL; | |
3051 | ||
3052 | if (copy_from_user(&buf, ubuf, cnt)) | |
3053 | return -EFAULT; | |
3054 | ||
3055 | buf[cnt] = 0; | |
3056 | ||
756d17ee | 3057 | /* |
3058 | * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid" | |
3059 | * to clean the filter quietly. | |
3060 | */ | |
457dc928 IM |
3061 | tmp = strstrip(buf); |
3062 | if (strlen(tmp) == 0) | |
756d17ee | 3063 | return 1; |
3064 | ||
457dc928 | 3065 | ret = strict_strtol(tmp, 10, &val); |
df4fc315 SR |
3066 | if (ret < 0) |
3067 | return ret; | |
3068 | ||
756d17ee | 3069 | ret = ftrace_pid_add(val); |
df4fc315 | 3070 | |
756d17ee | 3071 | return ret ? ret : cnt; |
3072 | } | |
df4fc315 | 3073 | |
756d17ee | 3074 | static int |
3075 | ftrace_pid_release(struct inode *inode, struct file *file) | |
3076 | { | |
3077 | if (file->f_mode & FMODE_READ) | |
3078 | seq_release(inode, file); | |
df4fc315 | 3079 | |
756d17ee | 3080 | return 0; |
df4fc315 SR |
3081 | } |
3082 | ||
5e2336a0 | 3083 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 3084 | .open = ftrace_pid_open, |
3085 | .write = ftrace_pid_write, | |
3086 | .read = seq_read, | |
3087 | .llseek = seq_lseek, | |
3088 | .release = ftrace_pid_release, | |
df4fc315 SR |
3089 | }; |
3090 | ||
3091 | static __init int ftrace_init_debugfs(void) | |
3092 | { | |
3093 | struct dentry *d_tracer; | |
df4fc315 SR |
3094 | |
3095 | d_tracer = tracing_init_dentry(); | |
3096 | if (!d_tracer) | |
3097 | return 0; | |
3098 | ||
3099 | ftrace_init_dyn_debugfs(d_tracer); | |
3100 | ||
5452af66 FW |
3101 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
3102 | NULL, &ftrace_pid_fops); | |
493762fc SR |
3103 | |
3104 | ftrace_profile_debugfs(d_tracer); | |
3105 | ||
df4fc315 SR |
3106 | return 0; |
3107 | } | |
df4fc315 SR |
3108 | fs_initcall(ftrace_init_debugfs); |
3109 | ||
a2bb6a3d | 3110 | /** |
81adbdc0 | 3111 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
3112 | * |
3113 | * This function should be used by panic code. It stops ftrace | |
3114 | * but in a not so nice way. If you need to simply kill ftrace | |
3115 | * from a non-atomic section, use ftrace_kill. | |
3116 | */ | |
81adbdc0 | 3117 | void ftrace_kill(void) |
a2bb6a3d SR |
3118 | { |
3119 | ftrace_disabled = 1; | |
3120 | ftrace_enabled = 0; | |
a2bb6a3d SR |
3121 | clear_ftrace_function(); |
3122 | } | |
3123 | ||
16444a8a | 3124 | /** |
3d083395 SR |
3125 | * register_ftrace_function - register a function for profiling |
3126 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 3127 | * |
3d083395 SR |
3128 | * Register a function to be called by all functions in the |
3129 | * kernel. | |
3130 | * | |
3131 | * Note: @ops->func and all the functions it calls must be labeled | |
3132 | * with "notrace", otherwise it will go into a | |
3133 | * recursive loop. | |
16444a8a | 3134 | */ |
3d083395 | 3135 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 3136 | { |
b0fc494f SR |
3137 | int ret; |
3138 | ||
4eebcc81 SR |
3139 | if (unlikely(ftrace_disabled)) |
3140 | return -1; | |
3141 | ||
e6ea44e9 | 3142 | mutex_lock(&ftrace_lock); |
e7d3737e | 3143 | |
b0fc494f | 3144 | ret = __register_ftrace_function(ops); |
5a45cfe1 | 3145 | ftrace_startup(0); |
b0fc494f | 3146 | |
e6ea44e9 | 3147 | mutex_unlock(&ftrace_lock); |
b0fc494f | 3148 | return ret; |
3d083395 SR |
3149 | } |
3150 | ||
3151 | /** | |
32632920 | 3152 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
3153 | * @ops - ops structure that holds the function to unregister |
3154 | * | |
3155 | * Unregister a function that was added to be called by ftrace profiling. | |
3156 | */ | |
3157 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
3158 | { | |
3159 | int ret; | |
3160 | ||
e6ea44e9 | 3161 | mutex_lock(&ftrace_lock); |
3d083395 | 3162 | ret = __unregister_ftrace_function(ops); |
5a45cfe1 | 3163 | ftrace_shutdown(0); |
e6ea44e9 | 3164 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
3165 | |
3166 | return ret; | |
3167 | } | |
3168 | ||
e309b41d | 3169 | int |
b0fc494f | 3170 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
8d65af78 | 3171 | void __user *buffer, size_t *lenp, |
b0fc494f SR |
3172 | loff_t *ppos) |
3173 | { | |
3174 | int ret; | |
3175 | ||
4eebcc81 SR |
3176 | if (unlikely(ftrace_disabled)) |
3177 | return -ENODEV; | |
3178 | ||
e6ea44e9 | 3179 | mutex_lock(&ftrace_lock); |
b0fc494f | 3180 | |
8d65af78 | 3181 | ret = proc_dointvec(table, write, buffer, lenp, ppos); |
b0fc494f | 3182 | |
a32c7765 | 3183 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
3184 | goto out; |
3185 | ||
a32c7765 | 3186 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f SR |
3187 | |
3188 | if (ftrace_enabled) { | |
3189 | ||
3190 | ftrace_startup_sysctl(); | |
3191 | ||
3192 | /* we are starting ftrace again */ | |
3193 | if (ftrace_list != &ftrace_list_end) { | |
3194 | if (ftrace_list->next == &ftrace_list_end) | |
3195 | ftrace_trace_function = ftrace_list->func; | |
3196 | else | |
3197 | ftrace_trace_function = ftrace_list_func; | |
3198 | } | |
3199 | ||
3200 | } else { | |
3201 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
3202 | ftrace_trace_function = ftrace_stub; | |
3203 | ||
3204 | ftrace_shutdown_sysctl(); | |
3205 | } | |
3206 | ||
3207 | out: | |
e6ea44e9 | 3208 | mutex_unlock(&ftrace_lock); |
3d083395 | 3209 | return ret; |
16444a8a | 3210 | } |
f17845e5 | 3211 | |
fb52607a | 3212 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 3213 | |
597af815 | 3214 | static int ftrace_graph_active; |
4a2b8dda | 3215 | static struct notifier_block ftrace_suspend_notifier; |
e7d3737e | 3216 | |
e49dc19c SR |
3217 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
3218 | { | |
3219 | return 0; | |
3220 | } | |
3221 | ||
287b6e68 FW |
3222 | /* The callbacks that hook a function */ |
3223 | trace_func_graph_ret_t ftrace_graph_return = | |
3224 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 3225 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
3226 | |
3227 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
3228 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
3229 | { | |
3230 | int i; | |
3231 | int ret = 0; | |
3232 | unsigned long flags; | |
3233 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
3234 | struct task_struct *g, *t; | |
3235 | ||
3236 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
3237 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
3238 | * sizeof(struct ftrace_ret_stack), | |
3239 | GFP_KERNEL); | |
3240 | if (!ret_stack_list[i]) { | |
3241 | start = 0; | |
3242 | end = i; | |
3243 | ret = -ENOMEM; | |
3244 | goto free; | |
3245 | } | |
3246 | } | |
3247 | ||
3248 | read_lock_irqsave(&tasklist_lock, flags); | |
3249 | do_each_thread(g, t) { | |
3250 | if (start == end) { | |
3251 | ret = -EAGAIN; | |
3252 | goto unlock; | |
3253 | } | |
3254 | ||
3255 | if (t->ret_stack == NULL) { | |
380c4b14 | 3256 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 3257 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
3258 | t->curr_ret_stack = -1; |
3259 | /* Make sure the tasks see the -1 first: */ | |
3260 | smp_wmb(); | |
3261 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
3262 | } |
3263 | } while_each_thread(g, t); | |
3264 | ||
3265 | unlock: | |
3266 | read_unlock_irqrestore(&tasklist_lock, flags); | |
3267 | free: | |
3268 | for (i = start; i < end; i++) | |
3269 | kfree(ret_stack_list[i]); | |
3270 | return ret; | |
3271 | } | |
3272 | ||
8aef2d28 | 3273 | static void |
38516ab5 SR |
3274 | ftrace_graph_probe_sched_switch(void *ignore, |
3275 | struct task_struct *prev, struct task_struct *next) | |
8aef2d28 SR |
3276 | { |
3277 | unsigned long long timestamp; | |
3278 | int index; | |
3279 | ||
be6f164a SR |
3280 | /* |
3281 | * Does the user want to count the time a function was asleep. | |
3282 | * If so, do not update the time stamps. | |
3283 | */ | |
3284 | if (trace_flags & TRACE_ITER_SLEEP_TIME) | |
3285 | return; | |
3286 | ||
8aef2d28 SR |
3287 | timestamp = trace_clock_local(); |
3288 | ||
3289 | prev->ftrace_timestamp = timestamp; | |
3290 | ||
3291 | /* only process tasks that we timestamped */ | |
3292 | if (!next->ftrace_timestamp) | |
3293 | return; | |
3294 | ||
3295 | /* | |
3296 | * Update all the counters in next to make up for the | |
3297 | * time next was sleeping. | |
3298 | */ | |
3299 | timestamp -= next->ftrace_timestamp; | |
3300 | ||
3301 | for (index = next->curr_ret_stack; index >= 0; index--) | |
3302 | next->ret_stack[index].calltime += timestamp; | |
3303 | } | |
3304 | ||
f201ae23 | 3305 | /* Allocate a return stack for each task */ |
fb52607a | 3306 | static int start_graph_tracing(void) |
f201ae23 FW |
3307 | { |
3308 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 3309 | int ret, cpu; |
f201ae23 FW |
3310 | |
3311 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
3312 | sizeof(struct ftrace_ret_stack *), | |
3313 | GFP_KERNEL); | |
3314 | ||
3315 | if (!ret_stack_list) | |
3316 | return -ENOMEM; | |
3317 | ||
5b058bcd | 3318 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
3319 | for_each_online_cpu(cpu) { |
3320 | if (!idle_task(cpu)->ret_stack) | |
3321 | ftrace_graph_init_task(idle_task(cpu)); | |
3322 | } | |
5b058bcd | 3323 | |
f201ae23 FW |
3324 | do { |
3325 | ret = alloc_retstack_tasklist(ret_stack_list); | |
3326 | } while (ret == -EAGAIN); | |
3327 | ||
8aef2d28 | 3328 | if (!ret) { |
38516ab5 | 3329 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
8aef2d28 SR |
3330 | if (ret) |
3331 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
3332 | " probe to kernel_sched_switch\n"); | |
3333 | } | |
3334 | ||
f201ae23 FW |
3335 | kfree(ret_stack_list); |
3336 | return ret; | |
3337 | } | |
3338 | ||
4a2b8dda FW |
3339 | /* |
3340 | * Hibernation protection. | |
3341 | * The state of the current task is too much unstable during | |
3342 | * suspend/restore to disk. We want to protect against that. | |
3343 | */ | |
3344 | static int | |
3345 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
3346 | void *unused) | |
3347 | { | |
3348 | switch (state) { | |
3349 | case PM_HIBERNATION_PREPARE: | |
3350 | pause_graph_tracing(); | |
3351 | break; | |
3352 | ||
3353 | case PM_POST_HIBERNATION: | |
3354 | unpause_graph_tracing(); | |
3355 | break; | |
3356 | } | |
3357 | return NOTIFY_DONE; | |
3358 | } | |
3359 | ||
287b6e68 FW |
3360 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
3361 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 3362 | { |
e7d3737e FW |
3363 | int ret = 0; |
3364 | ||
e6ea44e9 | 3365 | mutex_lock(&ftrace_lock); |
e7d3737e | 3366 | |
05ce5818 | 3367 | /* we currently allow only one tracer registered at a time */ |
597af815 | 3368 | if (ftrace_graph_active) { |
05ce5818 SR |
3369 | ret = -EBUSY; |
3370 | goto out; | |
3371 | } | |
3372 | ||
4a2b8dda FW |
3373 | ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; |
3374 | register_pm_notifier(&ftrace_suspend_notifier); | |
3375 | ||
597af815 | 3376 | ftrace_graph_active++; |
fb52607a | 3377 | ret = start_graph_tracing(); |
f201ae23 | 3378 | if (ret) { |
597af815 | 3379 | ftrace_graph_active--; |
f201ae23 FW |
3380 | goto out; |
3381 | } | |
e53a6319 | 3382 | |
287b6e68 FW |
3383 | ftrace_graph_return = retfunc; |
3384 | ftrace_graph_entry = entryfunc; | |
e53a6319 | 3385 | |
5a45cfe1 | 3386 | ftrace_startup(FTRACE_START_FUNC_RET); |
e7d3737e FW |
3387 | |
3388 | out: | |
e6ea44e9 | 3389 | mutex_unlock(&ftrace_lock); |
e7d3737e | 3390 | return ret; |
15e6cb36 FW |
3391 | } |
3392 | ||
fb52607a | 3393 | void unregister_ftrace_graph(void) |
15e6cb36 | 3394 | { |
e6ea44e9 | 3395 | mutex_lock(&ftrace_lock); |
e7d3737e | 3396 | |
597af815 | 3397 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
3398 | goto out; |
3399 | ||
597af815 | 3400 | ftrace_graph_active--; |
287b6e68 | 3401 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 3402 | ftrace_graph_entry = ftrace_graph_entry_stub; |
5a45cfe1 | 3403 | ftrace_shutdown(FTRACE_STOP_FUNC_RET); |
4a2b8dda | 3404 | unregister_pm_notifier(&ftrace_suspend_notifier); |
38516ab5 | 3405 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
e7d3737e | 3406 | |
2aad1b76 | 3407 | out: |
e6ea44e9 | 3408 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 3409 | } |
f201ae23 FW |
3410 | |
3411 | /* Allocate a return stack for newly created task */ | |
fb52607a | 3412 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 3413 | { |
84047e36 SR |
3414 | /* Make sure we do not use the parent ret_stack */ |
3415 | t->ret_stack = NULL; | |
ea14eb71 | 3416 | t->curr_ret_stack = -1; |
84047e36 | 3417 | |
597af815 | 3418 | if (ftrace_graph_active) { |
82310a32 SR |
3419 | struct ftrace_ret_stack *ret_stack; |
3420 | ||
3421 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
3422 | * sizeof(struct ftrace_ret_stack), |
3423 | GFP_KERNEL); | |
82310a32 | 3424 | if (!ret_stack) |
f201ae23 | 3425 | return; |
380c4b14 | 3426 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 3427 | atomic_set(&t->trace_overrun, 0); |
8aef2d28 | 3428 | t->ftrace_timestamp = 0; |
82310a32 SR |
3429 | /* make curr_ret_stack visable before we add the ret_stack */ |
3430 | smp_wmb(); | |
3431 | t->ret_stack = ret_stack; | |
84047e36 | 3432 | } |
f201ae23 FW |
3433 | } |
3434 | ||
fb52607a | 3435 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 3436 | { |
eae849ca FW |
3437 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
3438 | ||
f201ae23 | 3439 | t->ret_stack = NULL; |
eae849ca FW |
3440 | /* NULL must become visible to IRQs before we free it: */ |
3441 | barrier(); | |
3442 | ||
3443 | kfree(ret_stack); | |
f201ae23 | 3444 | } |
14a866c5 SR |
3445 | |
3446 | void ftrace_graph_stop(void) | |
3447 | { | |
3448 | ftrace_stop(); | |
3449 | } | |
15e6cb36 | 3450 | #endif |