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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, | |
6038f373 | 803 | .llseek = default_llseek, |
bac429f0 SR |
804 | }; |
805 | ||
cafb168a SR |
806 | /* used to initialize the real stat files */ |
807 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
808 | .name = "functions", |
809 | .stat_start = function_stat_start, | |
810 | .stat_next = function_stat_next, | |
811 | .stat_cmp = function_stat_cmp, | |
812 | .stat_headers = function_stat_headers, | |
813 | .stat_show = function_stat_show | |
cafb168a SR |
814 | }; |
815 | ||
6ab5d668 | 816 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 | 817 | { |
cafb168a | 818 | struct ftrace_profile_stat *stat; |
bac429f0 | 819 | struct dentry *entry; |
cafb168a | 820 | char *name; |
bac429f0 | 821 | int ret; |
cafb168a SR |
822 | int cpu; |
823 | ||
824 | for_each_possible_cpu(cpu) { | |
825 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
826 | ||
827 | /* allocate enough for function name + cpu number */ | |
828 | name = kmalloc(32, GFP_KERNEL); | |
829 | if (!name) { | |
830 | /* | |
831 | * The files created are permanent, if something happens | |
832 | * we still do not free memory. | |
833 | */ | |
cafb168a SR |
834 | WARN(1, |
835 | "Could not allocate stat file for cpu %d\n", | |
836 | cpu); | |
837 | return; | |
838 | } | |
839 | stat->stat = function_stats; | |
840 | snprintf(name, 32, "function%d", cpu); | |
841 | stat->stat.name = name; | |
842 | ret = register_stat_tracer(&stat->stat); | |
843 | if (ret) { | |
844 | WARN(1, | |
845 | "Could not register function stat for cpu %d\n", | |
846 | cpu); | |
847 | kfree(name); | |
848 | return; | |
849 | } | |
bac429f0 SR |
850 | } |
851 | ||
852 | entry = debugfs_create_file("function_profile_enabled", 0644, | |
853 | d_tracer, NULL, &ftrace_profile_fops); | |
854 | if (!entry) | |
855 | pr_warning("Could not create debugfs " | |
856 | "'function_profile_enabled' entry\n"); | |
857 | } | |
858 | ||
bac429f0 | 859 | #else /* CONFIG_FUNCTION_PROFILER */ |
6ab5d668 | 860 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 SR |
861 | { |
862 | } | |
bac429f0 SR |
863 | #endif /* CONFIG_FUNCTION_PROFILER */ |
864 | ||
493762fc SR |
865 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; |
866 | ||
867 | #ifdef CONFIG_DYNAMIC_FTRACE | |
868 | ||
869 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD | |
870 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
871 | #endif | |
872 | ||
873 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; | |
874 | ||
875 | struct ftrace_func_probe { | |
876 | struct hlist_node node; | |
877 | struct ftrace_probe_ops *ops; | |
878 | unsigned long flags; | |
879 | unsigned long ip; | |
880 | void *data; | |
881 | struct rcu_head rcu; | |
882 | }; | |
883 | ||
884 | enum { | |
885 | FTRACE_ENABLE_CALLS = (1 << 0), | |
886 | FTRACE_DISABLE_CALLS = (1 << 1), | |
887 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
79e406d7 SR |
888 | FTRACE_START_FUNC_RET = (1 << 3), |
889 | FTRACE_STOP_FUNC_RET = (1 << 4), | |
493762fc SR |
890 | }; |
891 | ||
892 | static int ftrace_filtered; | |
893 | ||
894 | static struct dyn_ftrace *ftrace_new_addrs; | |
895 | ||
896 | static DEFINE_MUTEX(ftrace_regex_lock); | |
897 | ||
898 | struct ftrace_page { | |
899 | struct ftrace_page *next; | |
900 | int index; | |
901 | struct dyn_ftrace records[]; | |
902 | }; | |
903 | ||
904 | #define ENTRIES_PER_PAGE \ | |
905 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
906 | ||
907 | /* estimate from running different kernels */ | |
908 | #define NR_TO_INIT 10000 | |
909 | ||
910 | static struct ftrace_page *ftrace_pages_start; | |
911 | static struct ftrace_page *ftrace_pages; | |
912 | ||
913 | static struct dyn_ftrace *ftrace_free_records; | |
914 | ||
915 | /* | |
916 | * This is a double for. Do not use 'break' to break out of the loop, | |
917 | * you must use a goto. | |
918 | */ | |
919 | #define do_for_each_ftrace_rec(pg, rec) \ | |
920 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
921 | int _____i; \ | |
922 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
923 | rec = &pg->records[_____i]; | |
924 | ||
925 | #define while_for_each_ftrace_rec() \ | |
926 | } \ | |
927 | } | |
928 | ||
e309b41d | 929 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
37ad5084 | 930 | { |
ee000b7f | 931 | rec->freelist = ftrace_free_records; |
37ad5084 SR |
932 | ftrace_free_records = rec; |
933 | rec->flags |= FTRACE_FL_FREE; | |
934 | } | |
935 | ||
e309b41d | 936 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 937 | { |
37ad5084 SR |
938 | struct dyn_ftrace *rec; |
939 | ||
940 | /* First check for freed records */ | |
941 | if (ftrace_free_records) { | |
942 | rec = ftrace_free_records; | |
943 | ||
37ad5084 | 944 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
6912896e | 945 | FTRACE_WARN_ON_ONCE(1); |
37ad5084 SR |
946 | ftrace_free_records = NULL; |
947 | return NULL; | |
948 | } | |
949 | ||
ee000b7f | 950 | ftrace_free_records = rec->freelist; |
37ad5084 SR |
951 | memset(rec, 0, sizeof(*rec)); |
952 | return rec; | |
953 | } | |
954 | ||
3c1720f0 | 955 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
08f5ac90 SR |
956 | if (!ftrace_pages->next) { |
957 | /* allocate another page */ | |
958 | ftrace_pages->next = | |
959 | (void *)get_zeroed_page(GFP_KERNEL); | |
960 | if (!ftrace_pages->next) | |
961 | return NULL; | |
962 | } | |
3c1720f0 SR |
963 | ftrace_pages = ftrace_pages->next; |
964 | } | |
965 | ||
966 | return &ftrace_pages->records[ftrace_pages->index++]; | |
967 | } | |
968 | ||
08f5ac90 | 969 | static struct dyn_ftrace * |
d61f82d0 | 970 | ftrace_record_ip(unsigned long ip) |
3d083395 | 971 | { |
08f5ac90 | 972 | struct dyn_ftrace *rec; |
3d083395 | 973 | |
f3c7ac40 | 974 | if (ftrace_disabled) |
08f5ac90 | 975 | return NULL; |
3d083395 | 976 | |
08f5ac90 SR |
977 | rec = ftrace_alloc_dyn_node(ip); |
978 | if (!rec) | |
979 | return NULL; | |
3d083395 | 980 | |
08f5ac90 | 981 | rec->ip = ip; |
ee000b7f | 982 | rec->newlist = ftrace_new_addrs; |
e94142a6 | 983 | ftrace_new_addrs = rec; |
3d083395 | 984 | |
08f5ac90 | 985 | return rec; |
3d083395 SR |
986 | } |
987 | ||
b17e8a37 SR |
988 | static void print_ip_ins(const char *fmt, unsigned char *p) |
989 | { | |
990 | int i; | |
991 | ||
992 | printk(KERN_CONT "%s", fmt); | |
993 | ||
994 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
995 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
996 | } | |
997 | ||
31e88909 | 998 | static void ftrace_bug(int failed, unsigned long ip) |
b17e8a37 SR |
999 | { |
1000 | switch (failed) { | |
1001 | case -EFAULT: | |
1002 | FTRACE_WARN_ON_ONCE(1); | |
1003 | pr_info("ftrace faulted on modifying "); | |
1004 | print_ip_sym(ip); | |
1005 | break; | |
1006 | case -EINVAL: | |
1007 | FTRACE_WARN_ON_ONCE(1); | |
1008 | pr_info("ftrace failed to modify "); | |
1009 | print_ip_sym(ip); | |
b17e8a37 | 1010 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
1011 | printk(KERN_CONT "\n"); |
1012 | break; | |
1013 | case -EPERM: | |
1014 | FTRACE_WARN_ON_ONCE(1); | |
1015 | pr_info("ftrace faulted on writing "); | |
1016 | print_ip_sym(ip); | |
1017 | break; | |
1018 | default: | |
1019 | FTRACE_WARN_ON_ONCE(1); | |
1020 | pr_info("ftrace faulted on unknown error "); | |
1021 | print_ip_sym(ip); | |
1022 | } | |
1023 | } | |
1024 | ||
3c1720f0 | 1025 | |
2cfa1978 MH |
1026 | /* Return 1 if the address range is reserved for ftrace */ |
1027 | int ftrace_text_reserved(void *start, void *end) | |
1028 | { | |
1029 | struct dyn_ftrace *rec; | |
1030 | struct ftrace_page *pg; | |
1031 | ||
1032 | do_for_each_ftrace_rec(pg, rec) { | |
1033 | if (rec->ip <= (unsigned long)end && | |
1034 | rec->ip + MCOUNT_INSN_SIZE > (unsigned long)start) | |
1035 | return 1; | |
1036 | } while_for_each_ftrace_rec(); | |
1037 | return 0; | |
1038 | } | |
1039 | ||
1040 | ||
0eb96701 | 1041 | static int |
31e88909 | 1042 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) |
5072c59f | 1043 | { |
e7d3737e | 1044 | unsigned long ftrace_addr; |
64fbcd16 | 1045 | unsigned long flag = 0UL; |
e7d3737e | 1046 | |
f0001207 | 1047 | ftrace_addr = (unsigned long)FTRACE_ADDR; |
5072c59f | 1048 | |
982c350b | 1049 | /* |
64fbcd16 XG |
1050 | * If this record is not to be traced or we want to disable it, |
1051 | * then disable it. | |
982c350b | 1052 | * |
64fbcd16 | 1053 | * If we want to enable it and filtering is off, then enable it. |
982c350b | 1054 | * |
64fbcd16 XG |
1055 | * If we want to enable it and filtering is on, enable it only if |
1056 | * it's filtered | |
982c350b | 1057 | */ |
64fbcd16 XG |
1058 | if (enable && !(rec->flags & FTRACE_FL_NOTRACE)) { |
1059 | if (!ftrace_filtered || (rec->flags & FTRACE_FL_FILTER)) | |
1060 | flag = FTRACE_FL_ENABLED; | |
1061 | } | |
982c350b | 1062 | |
64fbcd16 XG |
1063 | /* If the state of this record hasn't changed, then do nothing */ |
1064 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
1065 | return 0; | |
982c350b | 1066 | |
64fbcd16 XG |
1067 | if (flag) { |
1068 | rec->flags |= FTRACE_FL_ENABLED; | |
1069 | return ftrace_make_call(rec, ftrace_addr); | |
5072c59f SR |
1070 | } |
1071 | ||
64fbcd16 XG |
1072 | rec->flags &= ~FTRACE_FL_ENABLED; |
1073 | return ftrace_make_nop(NULL, rec, ftrace_addr); | |
5072c59f SR |
1074 | } |
1075 | ||
e309b41d | 1076 | static void ftrace_replace_code(int enable) |
3c1720f0 | 1077 | { |
3c1720f0 SR |
1078 | struct dyn_ftrace *rec; |
1079 | struct ftrace_page *pg; | |
6a24a244 | 1080 | int failed; |
3c1720f0 | 1081 | |
265c831c SR |
1082 | do_for_each_ftrace_rec(pg, rec) { |
1083 | /* | |
fa9d13cf Z |
1084 | * Skip over free records, records that have |
1085 | * failed and not converted. | |
265c831c SR |
1086 | */ |
1087 | if (rec->flags & FTRACE_FL_FREE || | |
fa9d13cf | 1088 | rec->flags & FTRACE_FL_FAILED || |
03303549 | 1089 | !(rec->flags & FTRACE_FL_CONVERTED)) |
265c831c SR |
1090 | continue; |
1091 | ||
265c831c | 1092 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 1093 | if (failed) { |
265c831c | 1094 | rec->flags |= FTRACE_FL_FAILED; |
3279ba37 SR |
1095 | ftrace_bug(failed, rec->ip); |
1096 | /* Stop processing */ | |
1097 | return; | |
3c1720f0 | 1098 | } |
265c831c | 1099 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
1100 | } |
1101 | ||
492a7ea5 | 1102 | static int |
31e88909 | 1103 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 SR |
1104 | { |
1105 | unsigned long ip; | |
593eb8a2 | 1106 | int ret; |
3c1720f0 SR |
1107 | |
1108 | ip = rec->ip; | |
1109 | ||
25aac9dc | 1110 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 1111 | if (ret) { |
31e88909 | 1112 | ftrace_bug(ret, ip); |
3c1720f0 | 1113 | rec->flags |= FTRACE_FL_FAILED; |
492a7ea5 | 1114 | return 0; |
37ad5084 | 1115 | } |
492a7ea5 | 1116 | return 1; |
3c1720f0 SR |
1117 | } |
1118 | ||
000ab691 SR |
1119 | /* |
1120 | * archs can override this function if they must do something | |
1121 | * before the modifying code is performed. | |
1122 | */ | |
1123 | int __weak ftrace_arch_code_modify_prepare(void) | |
1124 | { | |
1125 | return 0; | |
1126 | } | |
1127 | ||
1128 | /* | |
1129 | * archs can override this function if they must do something | |
1130 | * after the modifying code is performed. | |
1131 | */ | |
1132 | int __weak ftrace_arch_code_modify_post_process(void) | |
1133 | { | |
1134 | return 0; | |
1135 | } | |
1136 | ||
e309b41d | 1137 | static int __ftrace_modify_code(void *data) |
3d083395 | 1138 | { |
d61f82d0 SR |
1139 | int *command = data; |
1140 | ||
a3583244 | 1141 | if (*command & FTRACE_ENABLE_CALLS) |
d61f82d0 | 1142 | ftrace_replace_code(1); |
a3583244 | 1143 | else if (*command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
1144 | ftrace_replace_code(0); |
1145 | ||
1146 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
1147 | ftrace_update_ftrace_func(ftrace_trace_function); | |
1148 | ||
5a45cfe1 SR |
1149 | if (*command & FTRACE_START_FUNC_RET) |
1150 | ftrace_enable_ftrace_graph_caller(); | |
1151 | else if (*command & FTRACE_STOP_FUNC_RET) | |
1152 | ftrace_disable_ftrace_graph_caller(); | |
1153 | ||
d61f82d0 | 1154 | return 0; |
3d083395 SR |
1155 | } |
1156 | ||
e309b41d | 1157 | static void ftrace_run_update_code(int command) |
3d083395 | 1158 | { |
000ab691 SR |
1159 | int ret; |
1160 | ||
1161 | ret = ftrace_arch_code_modify_prepare(); | |
1162 | FTRACE_WARN_ON(ret); | |
1163 | if (ret) | |
1164 | return; | |
1165 | ||
784e2d76 | 1166 | stop_machine(__ftrace_modify_code, &command, NULL); |
000ab691 SR |
1167 | |
1168 | ret = ftrace_arch_code_modify_post_process(); | |
1169 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
1170 | } |
1171 | ||
d61f82d0 | 1172 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 1173 | static int ftrace_start_up; |
df4fc315 SR |
1174 | |
1175 | static void ftrace_startup_enable(int command) | |
1176 | { | |
1177 | if (saved_ftrace_func != ftrace_trace_function) { | |
1178 | saved_ftrace_func = ftrace_trace_function; | |
1179 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1180 | } | |
1181 | ||
1182 | if (!command || !ftrace_enabled) | |
1183 | return; | |
1184 | ||
1185 | ftrace_run_update_code(command); | |
1186 | } | |
d61f82d0 | 1187 | |
5a45cfe1 | 1188 | static void ftrace_startup(int command) |
3d083395 | 1189 | { |
4eebcc81 SR |
1190 | if (unlikely(ftrace_disabled)) |
1191 | return; | |
1192 | ||
60a7ecf4 | 1193 | ftrace_start_up++; |
982c350b | 1194 | command |= FTRACE_ENABLE_CALLS; |
d61f82d0 | 1195 | |
df4fc315 | 1196 | ftrace_startup_enable(command); |
3d083395 SR |
1197 | } |
1198 | ||
5a45cfe1 | 1199 | static void ftrace_shutdown(int command) |
3d083395 | 1200 | { |
4eebcc81 SR |
1201 | if (unlikely(ftrace_disabled)) |
1202 | return; | |
1203 | ||
60a7ecf4 | 1204 | ftrace_start_up--; |
9ea1a153 FW |
1205 | /* |
1206 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
1207 | * critical but the ftrace_call callers may be never nopped again after | |
1208 | * further ftrace uses. | |
1209 | */ | |
1210 | WARN_ON_ONCE(ftrace_start_up < 0); | |
1211 | ||
60a7ecf4 | 1212 | if (!ftrace_start_up) |
d61f82d0 | 1213 | command |= FTRACE_DISABLE_CALLS; |
3d083395 | 1214 | |
d61f82d0 SR |
1215 | if (saved_ftrace_func != ftrace_trace_function) { |
1216 | saved_ftrace_func = ftrace_trace_function; | |
1217 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
1218 | } | |
3d083395 | 1219 | |
d61f82d0 | 1220 | if (!command || !ftrace_enabled) |
e6ea44e9 | 1221 | return; |
d61f82d0 SR |
1222 | |
1223 | ftrace_run_update_code(command); | |
3d083395 SR |
1224 | } |
1225 | ||
e309b41d | 1226 | static void ftrace_startup_sysctl(void) |
b0fc494f | 1227 | { |
4eebcc81 SR |
1228 | if (unlikely(ftrace_disabled)) |
1229 | return; | |
1230 | ||
d61f82d0 SR |
1231 | /* Force update next time */ |
1232 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
1233 | /* ftrace_start_up is true if we want ftrace running */ |
1234 | if (ftrace_start_up) | |
79e406d7 | 1235 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
b0fc494f SR |
1236 | } |
1237 | ||
e309b41d | 1238 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 1239 | { |
4eebcc81 SR |
1240 | if (unlikely(ftrace_disabled)) |
1241 | return; | |
1242 | ||
60a7ecf4 SR |
1243 | /* ftrace_start_up is true if ftrace is running */ |
1244 | if (ftrace_start_up) | |
79e406d7 | 1245 | ftrace_run_update_code(FTRACE_DISABLE_CALLS); |
b0fc494f SR |
1246 | } |
1247 | ||
3d083395 SR |
1248 | static cycle_t ftrace_update_time; |
1249 | static unsigned long ftrace_update_cnt; | |
1250 | unsigned long ftrace_update_tot_cnt; | |
1251 | ||
31e88909 | 1252 | static int ftrace_update_code(struct module *mod) |
3d083395 | 1253 | { |
e94142a6 | 1254 | struct dyn_ftrace *p; |
f22f9a89 | 1255 | cycle_t start, stop; |
3d083395 | 1256 | |
750ed1a4 | 1257 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1258 | ftrace_update_cnt = 0; |
1259 | ||
e94142a6 | 1260 | while (ftrace_new_addrs) { |
3d083395 | 1261 | |
08f5ac90 SR |
1262 | /* If something went wrong, bail without enabling anything */ |
1263 | if (unlikely(ftrace_disabled)) | |
1264 | return -1; | |
f22f9a89 | 1265 | |
e94142a6 | 1266 | p = ftrace_new_addrs; |
ee000b7f | 1267 | ftrace_new_addrs = p->newlist; |
e94142a6 | 1268 | p->flags = 0L; |
f22f9a89 | 1269 | |
5cb084bb | 1270 | /* |
25985edc | 1271 | * Do the initial record conversion from mcount jump |
5cb084bb JO |
1272 | * to the NOP instructions. |
1273 | */ | |
1274 | if (!ftrace_code_disable(mod, p)) { | |
08f5ac90 | 1275 | ftrace_free_rec(p); |
5cb084bb JO |
1276 | continue; |
1277 | } | |
1278 | ||
1279 | p->flags |= FTRACE_FL_CONVERTED; | |
1280 | ftrace_update_cnt++; | |
1281 | ||
1282 | /* | |
1283 | * If the tracing is enabled, go ahead and enable the record. | |
1284 | * | |
1285 | * The reason not to enable the record immediatelly is the | |
1286 | * inherent check of ftrace_make_nop/ftrace_make_call for | |
1287 | * correct previous instructions. Making first the NOP | |
1288 | * conversion puts the module to the correct state, thus | |
1289 | * passing the ftrace_make_call check. | |
1290 | */ | |
1291 | if (ftrace_start_up) { | |
1292 | int failed = __ftrace_replace_code(p, 1); | |
1293 | if (failed) { | |
1294 | ftrace_bug(failed, p->ip); | |
1295 | ftrace_free_rec(p); | |
1296 | } | |
1297 | } | |
3d083395 SR |
1298 | } |
1299 | ||
750ed1a4 | 1300 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1301 | ftrace_update_time = stop - start; |
1302 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
1303 | ||
16444a8a ACM |
1304 | return 0; |
1305 | } | |
1306 | ||
68bf21aa | 1307 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
1308 | { |
1309 | struct ftrace_page *pg; | |
1310 | int cnt; | |
1311 | int i; | |
3c1720f0 SR |
1312 | |
1313 | /* allocate a few pages */ | |
1314 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
1315 | if (!ftrace_pages_start) | |
1316 | return -1; | |
1317 | ||
1318 | /* | |
1319 | * Allocate a few more pages. | |
1320 | * | |
1321 | * TODO: have some parser search vmlinux before | |
1322 | * final linking to find all calls to ftrace. | |
1323 | * Then we can: | |
1324 | * a) know how many pages to allocate. | |
1325 | * and/or | |
1326 | * b) set up the table then. | |
1327 | * | |
1328 | * The dynamic code is still necessary for | |
1329 | * modules. | |
1330 | */ | |
1331 | ||
1332 | pg = ftrace_pages = ftrace_pages_start; | |
1333 | ||
68bf21aa | 1334 | cnt = num_to_init / ENTRIES_PER_PAGE; |
08f5ac90 | 1335 | pr_info("ftrace: allocating %ld entries in %d pages\n", |
5821e1b7 | 1336 | num_to_init, cnt + 1); |
3c1720f0 SR |
1337 | |
1338 | for (i = 0; i < cnt; i++) { | |
1339 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
1340 | ||
1341 | /* If we fail, we'll try later anyway */ | |
1342 | if (!pg->next) | |
1343 | break; | |
1344 | ||
1345 | pg = pg->next; | |
1346 | } | |
1347 | ||
1348 | return 0; | |
1349 | } | |
1350 | ||
5072c59f SR |
1351 | enum { |
1352 | FTRACE_ITER_FILTER = (1 << 0), | |
689fd8b6 | 1353 | FTRACE_ITER_NOTRACE = (1 << 1), |
1354 | FTRACE_ITER_FAILURES = (1 << 2), | |
1355 | FTRACE_ITER_PRINTALL = (1 << 3), | |
1356 | FTRACE_ITER_HASH = (1 << 4), | |
5072c59f SR |
1357 | }; |
1358 | ||
1359 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
1360 | ||
1361 | struct ftrace_iterator { | |
98c4fd04 | 1362 | loff_t pos; |
4aeb6967 SR |
1363 | loff_t func_pos; |
1364 | struct ftrace_page *pg; | |
1365 | struct dyn_ftrace *func; | |
1366 | struct ftrace_func_probe *probe; | |
1367 | struct trace_parser parser; | |
1368 | int hidx; | |
1369 | int idx; | |
1370 | unsigned flags; | |
5072c59f SR |
1371 | }; |
1372 | ||
8fc0c701 | 1373 | static void * |
4aeb6967 | 1374 | t_hash_next(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
1375 | { |
1376 | struct ftrace_iterator *iter = m->private; | |
4aeb6967 | 1377 | struct hlist_node *hnd = NULL; |
8fc0c701 SR |
1378 | struct hlist_head *hhd; |
1379 | ||
8fc0c701 | 1380 | (*pos)++; |
98c4fd04 | 1381 | iter->pos = *pos; |
8fc0c701 | 1382 | |
4aeb6967 SR |
1383 | if (iter->probe) |
1384 | hnd = &iter->probe->node; | |
8fc0c701 SR |
1385 | retry: |
1386 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
1387 | return NULL; | |
1388 | ||
1389 | hhd = &ftrace_func_hash[iter->hidx]; | |
1390 | ||
1391 | if (hlist_empty(hhd)) { | |
1392 | iter->hidx++; | |
1393 | hnd = NULL; | |
1394 | goto retry; | |
1395 | } | |
1396 | ||
1397 | if (!hnd) | |
1398 | hnd = hhd->first; | |
1399 | else { | |
1400 | hnd = hnd->next; | |
1401 | if (!hnd) { | |
1402 | iter->hidx++; | |
1403 | goto retry; | |
1404 | } | |
1405 | } | |
1406 | ||
4aeb6967 SR |
1407 | if (WARN_ON_ONCE(!hnd)) |
1408 | return NULL; | |
1409 | ||
1410 | iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node); | |
1411 | ||
1412 | return iter; | |
8fc0c701 SR |
1413 | } |
1414 | ||
1415 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
1416 | { | |
1417 | struct ftrace_iterator *iter = m->private; | |
1418 | void *p = NULL; | |
d82d6244 LZ |
1419 | loff_t l; |
1420 | ||
2bccfffd SR |
1421 | if (iter->func_pos > *pos) |
1422 | return NULL; | |
8fc0c701 | 1423 | |
d82d6244 | 1424 | iter->hidx = 0; |
2bccfffd | 1425 | for (l = 0; l <= (*pos - iter->func_pos); ) { |
4aeb6967 | 1426 | p = t_hash_next(m, &l); |
d82d6244 LZ |
1427 | if (!p) |
1428 | break; | |
1429 | } | |
4aeb6967 SR |
1430 | if (!p) |
1431 | return NULL; | |
1432 | ||
98c4fd04 SR |
1433 | /* Only set this if we have an item */ |
1434 | iter->flags |= FTRACE_ITER_HASH; | |
1435 | ||
4aeb6967 | 1436 | return iter; |
8fc0c701 SR |
1437 | } |
1438 | ||
4aeb6967 SR |
1439 | static int |
1440 | t_hash_show(struct seq_file *m, struct ftrace_iterator *iter) | |
8fc0c701 | 1441 | { |
b6887d79 | 1442 | struct ftrace_func_probe *rec; |
8fc0c701 | 1443 | |
4aeb6967 SR |
1444 | rec = iter->probe; |
1445 | if (WARN_ON_ONCE(!rec)) | |
1446 | return -EIO; | |
8fc0c701 | 1447 | |
809dcf29 SR |
1448 | if (rec->ops->print) |
1449 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
1450 | ||
b375a11a | 1451 | seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func); |
8fc0c701 SR |
1452 | |
1453 | if (rec->data) | |
1454 | seq_printf(m, ":%p", rec->data); | |
1455 | seq_putc(m, '\n'); | |
1456 | ||
1457 | return 0; | |
1458 | } | |
1459 | ||
e309b41d | 1460 | static void * |
5072c59f SR |
1461 | t_next(struct seq_file *m, void *v, loff_t *pos) |
1462 | { | |
1463 | struct ftrace_iterator *iter = m->private; | |
1464 | struct dyn_ftrace *rec = NULL; | |
1465 | ||
8fc0c701 | 1466 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 1467 | return t_hash_next(m, pos); |
8fc0c701 | 1468 | |
5072c59f | 1469 | (*pos)++; |
1106b699 | 1470 | iter->pos = iter->func_pos = *pos; |
5072c59f | 1471 | |
0c75a3ed | 1472 | if (iter->flags & FTRACE_ITER_PRINTALL) |
57c072c7 | 1473 | return t_hash_start(m, pos); |
0c75a3ed | 1474 | |
5072c59f SR |
1475 | retry: |
1476 | if (iter->idx >= iter->pg->index) { | |
1477 | if (iter->pg->next) { | |
1478 | iter->pg = iter->pg->next; | |
1479 | iter->idx = 0; | |
1480 | goto retry; | |
1481 | } | |
1482 | } else { | |
1483 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
1484 | if ((rec->flags & FTRACE_FL_FREE) || |
1485 | ||
1486 | (!(iter->flags & FTRACE_ITER_FAILURES) && | |
eb9a7bf0 AS |
1487 | (rec->flags & FTRACE_FL_FAILED)) || |
1488 | ||
1489 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
a9fdda33 | 1490 | !(rec->flags & FTRACE_FL_FAILED)) || |
eb9a7bf0 | 1491 | |
0183fb1c SR |
1492 | ((iter->flags & FTRACE_ITER_FILTER) && |
1493 | !(rec->flags & FTRACE_FL_FILTER)) || | |
1494 | ||
41c52c0d SR |
1495 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
1496 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
1497 | rec = NULL; |
1498 | goto retry; | |
1499 | } | |
1500 | } | |
1501 | ||
4aeb6967 | 1502 | if (!rec) |
57c072c7 | 1503 | return t_hash_start(m, pos); |
4aeb6967 SR |
1504 | |
1505 | iter->func = rec; | |
1506 | ||
1507 | return iter; | |
5072c59f SR |
1508 | } |
1509 | ||
98c4fd04 SR |
1510 | static void reset_iter_read(struct ftrace_iterator *iter) |
1511 | { | |
1512 | iter->pos = 0; | |
1513 | iter->func_pos = 0; | |
1514 | iter->flags &= ~(FTRACE_ITER_PRINTALL & FTRACE_ITER_HASH); | |
5072c59f SR |
1515 | } |
1516 | ||
1517 | static void *t_start(struct seq_file *m, loff_t *pos) | |
1518 | { | |
1519 | struct ftrace_iterator *iter = m->private; | |
1520 | void *p = NULL; | |
694ce0a5 | 1521 | loff_t l; |
5072c59f | 1522 | |
8fc0c701 | 1523 | mutex_lock(&ftrace_lock); |
98c4fd04 SR |
1524 | /* |
1525 | * If an lseek was done, then reset and start from beginning. | |
1526 | */ | |
1527 | if (*pos < iter->pos) | |
1528 | reset_iter_read(iter); | |
1529 | ||
0c75a3ed SR |
1530 | /* |
1531 | * For set_ftrace_filter reading, if we have the filter | |
1532 | * off, we can short cut and just print out that all | |
1533 | * functions are enabled. | |
1534 | */ | |
1535 | if (iter->flags & FTRACE_ITER_FILTER && !ftrace_filtered) { | |
1536 | if (*pos > 0) | |
8fc0c701 | 1537 | return t_hash_start(m, pos); |
0c75a3ed | 1538 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 CW |
1539 | /* reset in case of seek/pread */ |
1540 | iter->flags &= ~FTRACE_ITER_HASH; | |
0c75a3ed SR |
1541 | return iter; |
1542 | } | |
1543 | ||
8fc0c701 SR |
1544 | if (iter->flags & FTRACE_ITER_HASH) |
1545 | return t_hash_start(m, pos); | |
1546 | ||
98c4fd04 SR |
1547 | /* |
1548 | * Unfortunately, we need to restart at ftrace_pages_start | |
1549 | * every time we let go of the ftrace_mutex. This is because | |
1550 | * those pointers can change without the lock. | |
1551 | */ | |
694ce0a5 LZ |
1552 | iter->pg = ftrace_pages_start; |
1553 | iter->idx = 0; | |
1554 | for (l = 0; l <= *pos; ) { | |
1555 | p = t_next(m, p, &l); | |
1556 | if (!p) | |
1557 | break; | |
50cdaf08 | 1558 | } |
5821e1b7 | 1559 | |
4aeb6967 SR |
1560 | if (!p) { |
1561 | if (iter->flags & FTRACE_ITER_FILTER) | |
1562 | return t_hash_start(m, pos); | |
8fc0c701 | 1563 | |
4aeb6967 SR |
1564 | return NULL; |
1565 | } | |
1566 | ||
1567 | return iter; | |
5072c59f SR |
1568 | } |
1569 | ||
1570 | static void t_stop(struct seq_file *m, void *p) | |
1571 | { | |
8fc0c701 | 1572 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1573 | } |
1574 | ||
1575 | static int t_show(struct seq_file *m, void *v) | |
1576 | { | |
0c75a3ed | 1577 | struct ftrace_iterator *iter = m->private; |
4aeb6967 | 1578 | struct dyn_ftrace *rec; |
5072c59f | 1579 | |
8fc0c701 | 1580 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 1581 | return t_hash_show(m, iter); |
8fc0c701 | 1582 | |
0c75a3ed SR |
1583 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
1584 | seq_printf(m, "#### all functions enabled ####\n"); | |
1585 | return 0; | |
1586 | } | |
1587 | ||
4aeb6967 SR |
1588 | rec = iter->func; |
1589 | ||
5072c59f SR |
1590 | if (!rec) |
1591 | return 0; | |
1592 | ||
b375a11a | 1593 | seq_printf(m, "%ps\n", (void *)rec->ip); |
5072c59f SR |
1594 | |
1595 | return 0; | |
1596 | } | |
1597 | ||
88e9d34c | 1598 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
1599 | .start = t_start, |
1600 | .next = t_next, | |
1601 | .stop = t_stop, | |
1602 | .show = t_show, | |
1603 | }; | |
1604 | ||
e309b41d | 1605 | static int |
5072c59f SR |
1606 | ftrace_avail_open(struct inode *inode, struct file *file) |
1607 | { | |
1608 | struct ftrace_iterator *iter; | |
1609 | int ret; | |
1610 | ||
4eebcc81 SR |
1611 | if (unlikely(ftrace_disabled)) |
1612 | return -ENODEV; | |
1613 | ||
5072c59f SR |
1614 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1615 | if (!iter) | |
1616 | return -ENOMEM; | |
1617 | ||
1618 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
1619 | |
1620 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1621 | if (!ret) { | |
1622 | struct seq_file *m = file->private_data; | |
4bf39a94 | 1623 | |
5072c59f | 1624 | m->private = iter; |
4bf39a94 | 1625 | } else { |
5072c59f | 1626 | kfree(iter); |
4bf39a94 | 1627 | } |
5072c59f SR |
1628 | |
1629 | return ret; | |
1630 | } | |
1631 | ||
eb9a7bf0 AS |
1632 | static int |
1633 | ftrace_failures_open(struct inode *inode, struct file *file) | |
1634 | { | |
1635 | int ret; | |
1636 | struct seq_file *m; | |
1637 | struct ftrace_iterator *iter; | |
1638 | ||
1639 | ret = ftrace_avail_open(inode, file); | |
1640 | if (!ret) { | |
907f2784 | 1641 | m = file->private_data; |
1642 | iter = m->private; | |
eb9a7bf0 AS |
1643 | iter->flags = FTRACE_ITER_FAILURES; |
1644 | } | |
1645 | ||
1646 | return ret; | |
1647 | } | |
1648 | ||
1649 | ||
41c52c0d | 1650 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
1651 | { |
1652 | struct ftrace_page *pg; | |
1653 | struct dyn_ftrace *rec; | |
41c52c0d | 1654 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f | 1655 | |
52baf119 | 1656 | mutex_lock(&ftrace_lock); |
41c52c0d SR |
1657 | if (enable) |
1658 | ftrace_filtered = 0; | |
265c831c SR |
1659 | do_for_each_ftrace_rec(pg, rec) { |
1660 | if (rec->flags & FTRACE_FL_FAILED) | |
1661 | continue; | |
1662 | rec->flags &= ~type; | |
1663 | } while_for_each_ftrace_rec(); | |
52baf119 | 1664 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1665 | } |
1666 | ||
e309b41d | 1667 | static int |
41c52c0d | 1668 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1669 | { |
1670 | struct ftrace_iterator *iter; | |
1671 | int ret = 0; | |
1672 | ||
4eebcc81 SR |
1673 | if (unlikely(ftrace_disabled)) |
1674 | return -ENODEV; | |
1675 | ||
5072c59f SR |
1676 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1677 | if (!iter) | |
1678 | return -ENOMEM; | |
1679 | ||
689fd8b6 | 1680 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { |
1681 | kfree(iter); | |
1682 | return -ENOMEM; | |
1683 | } | |
1684 | ||
41c52c0d | 1685 | mutex_lock(&ftrace_regex_lock); |
5072c59f | 1686 | if ((file->f_mode & FMODE_WRITE) && |
8650ae32 | 1687 | (file->f_flags & O_TRUNC)) |
41c52c0d | 1688 | ftrace_filter_reset(enable); |
5072c59f SR |
1689 | |
1690 | if (file->f_mode & FMODE_READ) { | |
1691 | iter->pg = ftrace_pages_start; | |
41c52c0d SR |
1692 | iter->flags = enable ? FTRACE_ITER_FILTER : |
1693 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
1694 | |
1695 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1696 | if (!ret) { | |
1697 | struct seq_file *m = file->private_data; | |
1698 | m->private = iter; | |
79fe249c LZ |
1699 | } else { |
1700 | trace_parser_put(&iter->parser); | |
5072c59f | 1701 | kfree(iter); |
79fe249c | 1702 | } |
5072c59f SR |
1703 | } else |
1704 | file->private_data = iter; | |
41c52c0d | 1705 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1706 | |
1707 | return ret; | |
1708 | } | |
1709 | ||
41c52c0d SR |
1710 | static int |
1711 | ftrace_filter_open(struct inode *inode, struct file *file) | |
1712 | { | |
1713 | return ftrace_regex_open(inode, file, 1); | |
1714 | } | |
1715 | ||
1716 | static int | |
1717 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
1718 | { | |
1719 | return ftrace_regex_open(inode, file, 0); | |
1720 | } | |
1721 | ||
e309b41d | 1722 | static loff_t |
41c52c0d | 1723 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
1724 | { |
1725 | loff_t ret; | |
1726 | ||
1727 | if (file->f_mode & FMODE_READ) | |
1728 | ret = seq_lseek(file, offset, origin); | |
1729 | else | |
1730 | file->f_pos = ret = 1; | |
1731 | ||
1732 | return ret; | |
1733 | } | |
1734 | ||
64e7c440 | 1735 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 1736 | { |
9f4801e3 | 1737 | int matched = 0; |
751e9983 | 1738 | int slen; |
9f4801e3 | 1739 | |
9f4801e3 SR |
1740 | switch (type) { |
1741 | case MATCH_FULL: | |
1742 | if (strcmp(str, regex) == 0) | |
1743 | matched = 1; | |
1744 | break; | |
1745 | case MATCH_FRONT_ONLY: | |
1746 | if (strncmp(str, regex, len) == 0) | |
1747 | matched = 1; | |
1748 | break; | |
1749 | case MATCH_MIDDLE_ONLY: | |
1750 | if (strstr(str, regex)) | |
1751 | matched = 1; | |
1752 | break; | |
1753 | case MATCH_END_ONLY: | |
751e9983 LZ |
1754 | slen = strlen(str); |
1755 | if (slen >= len && memcmp(str + slen - len, regex, len) == 0) | |
9f4801e3 SR |
1756 | matched = 1; |
1757 | break; | |
1758 | } | |
1759 | ||
1760 | return matched; | |
1761 | } | |
1762 | ||
64e7c440 SR |
1763 | static int |
1764 | ftrace_match_record(struct dyn_ftrace *rec, char *regex, int len, int type) | |
1765 | { | |
1766 | char str[KSYM_SYMBOL_LEN]; | |
1767 | ||
1768 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1769 | return ftrace_match(str, regex, len, type); | |
1770 | } | |
1771 | ||
311d16da | 1772 | static int ftrace_match_records(char *buff, int len, int enable) |
9f4801e3 | 1773 | { |
6a24a244 | 1774 | unsigned int search_len; |
9f4801e3 SR |
1775 | struct ftrace_page *pg; |
1776 | struct dyn_ftrace *rec; | |
6a24a244 SR |
1777 | unsigned long flag; |
1778 | char *search; | |
9f4801e3 | 1779 | int type; |
9f4801e3 | 1780 | int not; |
311d16da | 1781 | int found = 0; |
9f4801e3 | 1782 | |
6a24a244 | 1783 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
3f6fe06d | 1784 | type = filter_parse_regex(buff, len, &search, ¬); |
9f4801e3 SR |
1785 | |
1786 | search_len = strlen(search); | |
1787 | ||
52baf119 | 1788 | mutex_lock(&ftrace_lock); |
265c831c | 1789 | do_for_each_ftrace_rec(pg, rec) { |
265c831c SR |
1790 | |
1791 | if (rec->flags & FTRACE_FL_FAILED) | |
1792 | continue; | |
9f4801e3 SR |
1793 | |
1794 | if (ftrace_match_record(rec, search, search_len, type)) { | |
265c831c SR |
1795 | if (not) |
1796 | rec->flags &= ~flag; | |
1797 | else | |
1798 | rec->flags |= flag; | |
311d16da | 1799 | found = 1; |
265c831c | 1800 | } |
e68746a2 SR |
1801 | /* |
1802 | * Only enable filtering if we have a function that | |
1803 | * is filtered on. | |
1804 | */ | |
1805 | if (enable && (rec->flags & FTRACE_FL_FILTER)) | |
1806 | ftrace_filtered = 1; | |
265c831c | 1807 | } while_for_each_ftrace_rec(); |
52baf119 | 1808 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
1809 | |
1810 | return found; | |
5072c59f SR |
1811 | } |
1812 | ||
64e7c440 SR |
1813 | static int |
1814 | ftrace_match_module_record(struct dyn_ftrace *rec, char *mod, | |
1815 | char *regex, int len, int type) | |
1816 | { | |
1817 | char str[KSYM_SYMBOL_LEN]; | |
1818 | char *modname; | |
1819 | ||
1820 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
1821 | ||
1822 | if (!modname || strcmp(modname, mod)) | |
1823 | return 0; | |
1824 | ||
1825 | /* blank search means to match all funcs in the mod */ | |
1826 | if (len) | |
1827 | return ftrace_match(str, regex, len, type); | |
1828 | else | |
1829 | return 1; | |
1830 | } | |
1831 | ||
311d16da | 1832 | static int ftrace_match_module_records(char *buff, char *mod, int enable) |
64e7c440 | 1833 | { |
6a24a244 | 1834 | unsigned search_len = 0; |
64e7c440 SR |
1835 | struct ftrace_page *pg; |
1836 | struct dyn_ftrace *rec; | |
1837 | int type = MATCH_FULL; | |
6a24a244 SR |
1838 | char *search = buff; |
1839 | unsigned long flag; | |
64e7c440 | 1840 | int not = 0; |
311d16da | 1841 | int found = 0; |
64e7c440 | 1842 | |
6a24a244 SR |
1843 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
1844 | ||
64e7c440 SR |
1845 | /* blank or '*' mean the same */ |
1846 | if (strcmp(buff, "*") == 0) | |
1847 | buff[0] = 0; | |
1848 | ||
1849 | /* handle the case of 'dont filter this module' */ | |
1850 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
1851 | buff[0] = 0; | |
1852 | not = 1; | |
1853 | } | |
1854 | ||
1855 | if (strlen(buff)) { | |
3f6fe06d | 1856 | type = filter_parse_regex(buff, strlen(buff), &search, ¬); |
64e7c440 SR |
1857 | search_len = strlen(search); |
1858 | } | |
1859 | ||
52baf119 | 1860 | mutex_lock(&ftrace_lock); |
64e7c440 SR |
1861 | do_for_each_ftrace_rec(pg, rec) { |
1862 | ||
1863 | if (rec->flags & FTRACE_FL_FAILED) | |
1864 | continue; | |
1865 | ||
1866 | if (ftrace_match_module_record(rec, mod, | |
1867 | search, search_len, type)) { | |
1868 | if (not) | |
1869 | rec->flags &= ~flag; | |
1870 | else | |
1871 | rec->flags |= flag; | |
311d16da | 1872 | found = 1; |
64e7c440 | 1873 | } |
e68746a2 SR |
1874 | if (enable && (rec->flags & FTRACE_FL_FILTER)) |
1875 | ftrace_filtered = 1; | |
64e7c440 SR |
1876 | |
1877 | } while_for_each_ftrace_rec(); | |
52baf119 | 1878 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
1879 | |
1880 | return found; | |
64e7c440 SR |
1881 | } |
1882 | ||
f6180773 SR |
1883 | /* |
1884 | * We register the module command as a template to show others how | |
1885 | * to register the a command as well. | |
1886 | */ | |
1887 | ||
1888 | static int | |
1889 | ftrace_mod_callback(char *func, char *cmd, char *param, int enable) | |
1890 | { | |
1891 | char *mod; | |
1892 | ||
1893 | /* | |
1894 | * cmd == 'mod' because we only registered this func | |
1895 | * for the 'mod' ftrace_func_command. | |
1896 | * But if you register one func with multiple commands, | |
1897 | * you can tell which command was used by the cmd | |
1898 | * parameter. | |
1899 | */ | |
1900 | ||
1901 | /* we must have a module name */ | |
1902 | if (!param) | |
1903 | return -EINVAL; | |
1904 | ||
1905 | mod = strsep(¶m, ":"); | |
1906 | if (!strlen(mod)) | |
1907 | return -EINVAL; | |
1908 | ||
311d16da LZ |
1909 | if (ftrace_match_module_records(func, mod, enable)) |
1910 | return 0; | |
1911 | return -EINVAL; | |
f6180773 SR |
1912 | } |
1913 | ||
1914 | static struct ftrace_func_command ftrace_mod_cmd = { | |
1915 | .name = "mod", | |
1916 | .func = ftrace_mod_callback, | |
1917 | }; | |
1918 | ||
1919 | static int __init ftrace_mod_cmd_init(void) | |
1920 | { | |
1921 | return register_ftrace_command(&ftrace_mod_cmd); | |
1922 | } | |
1923 | device_initcall(ftrace_mod_cmd_init); | |
1924 | ||
59df055f | 1925 | static void |
b6887d79 | 1926 | function_trace_probe_call(unsigned long ip, unsigned long parent_ip) |
59df055f | 1927 | { |
b6887d79 | 1928 | struct ftrace_func_probe *entry; |
59df055f SR |
1929 | struct hlist_head *hhd; |
1930 | struct hlist_node *n; | |
1931 | unsigned long key; | |
59df055f SR |
1932 | |
1933 | key = hash_long(ip, FTRACE_HASH_BITS); | |
1934 | ||
1935 | hhd = &ftrace_func_hash[key]; | |
1936 | ||
1937 | if (hlist_empty(hhd)) | |
1938 | return; | |
1939 | ||
1940 | /* | |
1941 | * Disable preemption for these calls to prevent a RCU grace | |
1942 | * period. This syncs the hash iteration and freeing of items | |
1943 | * on the hash. rcu_read_lock is too dangerous here. | |
1944 | */ | |
5168ae50 | 1945 | preempt_disable_notrace(); |
59df055f SR |
1946 | hlist_for_each_entry_rcu(entry, n, hhd, node) { |
1947 | if (entry->ip == ip) | |
1948 | entry->ops->func(ip, parent_ip, &entry->data); | |
1949 | } | |
5168ae50 | 1950 | preempt_enable_notrace(); |
59df055f SR |
1951 | } |
1952 | ||
b6887d79 | 1953 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 1954 | { |
fb9fb015 | 1955 | .func = function_trace_probe_call, |
59df055f SR |
1956 | }; |
1957 | ||
b6887d79 | 1958 | static int ftrace_probe_registered; |
59df055f | 1959 | |
b6887d79 | 1960 | static void __enable_ftrace_function_probe(void) |
59df055f SR |
1961 | { |
1962 | int i; | |
1963 | ||
b6887d79 | 1964 | if (ftrace_probe_registered) |
59df055f SR |
1965 | return; |
1966 | ||
1967 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1968 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1969 | if (hhd->first) | |
1970 | break; | |
1971 | } | |
1972 | /* Nothing registered? */ | |
1973 | if (i == FTRACE_FUNC_HASHSIZE) | |
1974 | return; | |
1975 | ||
b6887d79 | 1976 | __register_ftrace_function(&trace_probe_ops); |
59df055f | 1977 | ftrace_startup(0); |
b6887d79 | 1978 | ftrace_probe_registered = 1; |
59df055f SR |
1979 | } |
1980 | ||
b6887d79 | 1981 | static void __disable_ftrace_function_probe(void) |
59df055f SR |
1982 | { |
1983 | int i; | |
1984 | ||
b6887d79 | 1985 | if (!ftrace_probe_registered) |
59df055f SR |
1986 | return; |
1987 | ||
1988 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1989 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1990 | if (hhd->first) | |
1991 | return; | |
1992 | } | |
1993 | ||
1994 | /* no more funcs left */ | |
b6887d79 | 1995 | __unregister_ftrace_function(&trace_probe_ops); |
59df055f | 1996 | ftrace_shutdown(0); |
b6887d79 | 1997 | ftrace_probe_registered = 0; |
59df055f SR |
1998 | } |
1999 | ||
2000 | ||
2001 | static void ftrace_free_entry_rcu(struct rcu_head *rhp) | |
2002 | { | |
b6887d79 SR |
2003 | struct ftrace_func_probe *entry = |
2004 | container_of(rhp, struct ftrace_func_probe, rcu); | |
59df055f SR |
2005 | |
2006 | if (entry->ops->free) | |
2007 | entry->ops->free(&entry->data); | |
2008 | kfree(entry); | |
2009 | } | |
2010 | ||
2011 | ||
2012 | int | |
b6887d79 | 2013 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2014 | void *data) |
2015 | { | |
b6887d79 | 2016 | struct ftrace_func_probe *entry; |
59df055f SR |
2017 | struct ftrace_page *pg; |
2018 | struct dyn_ftrace *rec; | |
59df055f | 2019 | int type, len, not; |
6a24a244 | 2020 | unsigned long key; |
59df055f SR |
2021 | int count = 0; |
2022 | char *search; | |
2023 | ||
3f6fe06d | 2024 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
2025 | len = strlen(search); |
2026 | ||
b6887d79 | 2027 | /* we do not support '!' for function probes */ |
59df055f SR |
2028 | if (WARN_ON(not)) |
2029 | return -EINVAL; | |
2030 | ||
2031 | mutex_lock(&ftrace_lock); | |
2032 | do_for_each_ftrace_rec(pg, rec) { | |
2033 | ||
2034 | if (rec->flags & FTRACE_FL_FAILED) | |
2035 | continue; | |
2036 | ||
2037 | if (!ftrace_match_record(rec, search, len, type)) | |
2038 | continue; | |
2039 | ||
2040 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
2041 | if (!entry) { | |
b6887d79 | 2042 | /* If we did not process any, then return error */ |
59df055f SR |
2043 | if (!count) |
2044 | count = -ENOMEM; | |
2045 | goto out_unlock; | |
2046 | } | |
2047 | ||
2048 | count++; | |
2049 | ||
2050 | entry->data = data; | |
2051 | ||
2052 | /* | |
2053 | * The caller might want to do something special | |
2054 | * for each function we find. We call the callback | |
2055 | * to give the caller an opportunity to do so. | |
2056 | */ | |
2057 | if (ops->callback) { | |
2058 | if (ops->callback(rec->ip, &entry->data) < 0) { | |
2059 | /* caller does not like this func */ | |
2060 | kfree(entry); | |
2061 | continue; | |
2062 | } | |
2063 | } | |
2064 | ||
2065 | entry->ops = ops; | |
2066 | entry->ip = rec->ip; | |
2067 | ||
2068 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
2069 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
2070 | ||
2071 | } while_for_each_ftrace_rec(); | |
b6887d79 | 2072 | __enable_ftrace_function_probe(); |
59df055f SR |
2073 | |
2074 | out_unlock: | |
2075 | mutex_unlock(&ftrace_lock); | |
2076 | ||
2077 | return count; | |
2078 | } | |
2079 | ||
2080 | enum { | |
b6887d79 SR |
2081 | PROBE_TEST_FUNC = 1, |
2082 | PROBE_TEST_DATA = 2 | |
59df055f SR |
2083 | }; |
2084 | ||
2085 | static void | |
b6887d79 | 2086 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2087 | void *data, int flags) |
2088 | { | |
b6887d79 | 2089 | struct ftrace_func_probe *entry; |
59df055f SR |
2090 | struct hlist_node *n, *tmp; |
2091 | char str[KSYM_SYMBOL_LEN]; | |
2092 | int type = MATCH_FULL; | |
2093 | int i, len = 0; | |
2094 | char *search; | |
2095 | ||
b36461da | 2096 | if (glob && (strcmp(glob, "*") == 0 || !strlen(glob))) |
59df055f | 2097 | glob = NULL; |
b36461da | 2098 | else if (glob) { |
59df055f SR |
2099 | int not; |
2100 | ||
3f6fe06d | 2101 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
2102 | len = strlen(search); |
2103 | ||
b6887d79 | 2104 | /* we do not support '!' for function probes */ |
59df055f SR |
2105 | if (WARN_ON(not)) |
2106 | return; | |
2107 | } | |
2108 | ||
2109 | mutex_lock(&ftrace_lock); | |
2110 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2111 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2112 | ||
2113 | hlist_for_each_entry_safe(entry, n, tmp, hhd, node) { | |
2114 | ||
2115 | /* break up if statements for readability */ | |
b6887d79 | 2116 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
2117 | continue; |
2118 | ||
b6887d79 | 2119 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
2120 | continue; |
2121 | ||
2122 | /* do this last, since it is the most expensive */ | |
2123 | if (glob) { | |
2124 | kallsyms_lookup(entry->ip, NULL, NULL, | |
2125 | NULL, str); | |
2126 | if (!ftrace_match(str, glob, len, type)) | |
2127 | continue; | |
2128 | } | |
2129 | ||
2130 | hlist_del(&entry->node); | |
2131 | call_rcu(&entry->rcu, ftrace_free_entry_rcu); | |
2132 | } | |
2133 | } | |
b6887d79 | 2134 | __disable_ftrace_function_probe(); |
59df055f SR |
2135 | mutex_unlock(&ftrace_lock); |
2136 | } | |
2137 | ||
2138 | void | |
b6887d79 | 2139 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2140 | void *data) |
2141 | { | |
b6887d79 SR |
2142 | __unregister_ftrace_function_probe(glob, ops, data, |
2143 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
2144 | } |
2145 | ||
2146 | void | |
b6887d79 | 2147 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 2148 | { |
b6887d79 | 2149 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
2150 | } |
2151 | ||
b6887d79 | 2152 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 2153 | { |
b6887d79 | 2154 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
2155 | } |
2156 | ||
f6180773 SR |
2157 | static LIST_HEAD(ftrace_commands); |
2158 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
2159 | ||
2160 | int register_ftrace_command(struct ftrace_func_command *cmd) | |
2161 | { | |
2162 | struct ftrace_func_command *p; | |
2163 | int ret = 0; | |
2164 | ||
2165 | mutex_lock(&ftrace_cmd_mutex); | |
2166 | list_for_each_entry(p, &ftrace_commands, list) { | |
2167 | if (strcmp(cmd->name, p->name) == 0) { | |
2168 | ret = -EBUSY; | |
2169 | goto out_unlock; | |
2170 | } | |
2171 | } | |
2172 | list_add(&cmd->list, &ftrace_commands); | |
2173 | out_unlock: | |
2174 | mutex_unlock(&ftrace_cmd_mutex); | |
2175 | ||
2176 | return ret; | |
2177 | } | |
2178 | ||
2179 | int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
2180 | { | |
2181 | struct ftrace_func_command *p, *n; | |
2182 | int ret = -ENODEV; | |
2183 | ||
2184 | mutex_lock(&ftrace_cmd_mutex); | |
2185 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
2186 | if (strcmp(cmd->name, p->name) == 0) { | |
2187 | ret = 0; | |
2188 | list_del_init(&p->list); | |
2189 | goto out_unlock; | |
2190 | } | |
2191 | } | |
2192 | out_unlock: | |
2193 | mutex_unlock(&ftrace_cmd_mutex); | |
2194 | ||
2195 | return ret; | |
2196 | } | |
2197 | ||
64e7c440 SR |
2198 | static int ftrace_process_regex(char *buff, int len, int enable) |
2199 | { | |
f6180773 | 2200 | char *func, *command, *next = buff; |
6a24a244 | 2201 | struct ftrace_func_command *p; |
f6180773 | 2202 | int ret = -EINVAL; |
64e7c440 SR |
2203 | |
2204 | func = strsep(&next, ":"); | |
2205 | ||
2206 | if (!next) { | |
311d16da LZ |
2207 | if (ftrace_match_records(func, len, enable)) |
2208 | return 0; | |
2209 | return ret; | |
64e7c440 SR |
2210 | } |
2211 | ||
f6180773 | 2212 | /* command found */ |
64e7c440 SR |
2213 | |
2214 | command = strsep(&next, ":"); | |
2215 | ||
f6180773 SR |
2216 | mutex_lock(&ftrace_cmd_mutex); |
2217 | list_for_each_entry(p, &ftrace_commands, list) { | |
2218 | if (strcmp(p->name, command) == 0) { | |
2219 | ret = p->func(func, command, next, enable); | |
2220 | goto out_unlock; | |
2221 | } | |
64e7c440 | 2222 | } |
f6180773 SR |
2223 | out_unlock: |
2224 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 2225 | |
f6180773 | 2226 | return ret; |
64e7c440 SR |
2227 | } |
2228 | ||
e309b41d | 2229 | static ssize_t |
41c52c0d SR |
2230 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
2231 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
2232 | { |
2233 | struct ftrace_iterator *iter; | |
689fd8b6 | 2234 | struct trace_parser *parser; |
2235 | ssize_t ret, read; | |
5072c59f | 2236 | |
4ba7978e | 2237 | if (!cnt) |
5072c59f SR |
2238 | return 0; |
2239 | ||
41c52c0d | 2240 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
2241 | |
2242 | if (file->f_mode & FMODE_READ) { | |
2243 | struct seq_file *m = file->private_data; | |
2244 | iter = m->private; | |
2245 | } else | |
2246 | iter = file->private_data; | |
2247 | ||
689fd8b6 | 2248 | parser = &iter->parser; |
2249 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 2250 | |
4ba7978e | 2251 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 2252 | !trace_parser_cont(parser)) { |
2253 | ret = ftrace_process_regex(parser->buffer, | |
2254 | parser->idx, enable); | |
313254a9 | 2255 | trace_parser_clear(parser); |
5072c59f | 2256 | if (ret) |
ed146b25 | 2257 | goto out_unlock; |
eda1e328 | 2258 | } |
5072c59f | 2259 | |
5072c59f | 2260 | ret = read; |
ed146b25 | 2261 | out_unlock: |
689fd8b6 | 2262 | mutex_unlock(&ftrace_regex_lock); |
ed146b25 | 2263 | |
5072c59f SR |
2264 | return ret; |
2265 | } | |
2266 | ||
41c52c0d SR |
2267 | static ssize_t |
2268 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
2269 | size_t cnt, loff_t *ppos) | |
2270 | { | |
2271 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
2272 | } | |
2273 | ||
2274 | static ssize_t | |
2275 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
2276 | size_t cnt, loff_t *ppos) | |
2277 | { | |
2278 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
2279 | } | |
2280 | ||
2281 | static void | |
2282 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
2283 | { | |
2284 | if (unlikely(ftrace_disabled)) | |
2285 | return; | |
2286 | ||
2287 | mutex_lock(&ftrace_regex_lock); | |
2288 | if (reset) | |
2289 | ftrace_filter_reset(enable); | |
2290 | if (buf) | |
7f24b31b | 2291 | ftrace_match_records(buf, len, enable); |
41c52c0d SR |
2292 | mutex_unlock(&ftrace_regex_lock); |
2293 | } | |
2294 | ||
77a2b37d SR |
2295 | /** |
2296 | * ftrace_set_filter - set a function to filter on in ftrace | |
2297 | * @buf - the string that holds the function filter text. | |
2298 | * @len - the length of the string. | |
2299 | * @reset - non zero to reset all filters before applying this filter. | |
2300 | * | |
2301 | * Filters denote which functions should be enabled when tracing is enabled. | |
2302 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
2303 | */ | |
e309b41d | 2304 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 2305 | { |
41c52c0d SR |
2306 | ftrace_set_regex(buf, len, reset, 1); |
2307 | } | |
4eebcc81 | 2308 | |
41c52c0d SR |
2309 | /** |
2310 | * ftrace_set_notrace - set a function to not trace in ftrace | |
2311 | * @buf - the string that holds the function notrace text. | |
2312 | * @len - the length of the string. | |
2313 | * @reset - non zero to reset all filters before applying this filter. | |
2314 | * | |
2315 | * Notrace Filters denote which functions should not be enabled when tracing | |
2316 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
2317 | * for tracing. | |
2318 | */ | |
2319 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
2320 | { | |
2321 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
2322 | } |
2323 | ||
2af15d6a SR |
2324 | /* |
2325 | * command line interface to allow users to set filters on boot up. | |
2326 | */ | |
2327 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
2328 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
2329 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
2330 | ||
2331 | static int __init set_ftrace_notrace(char *str) | |
2332 | { | |
2333 | strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); | |
2334 | return 1; | |
2335 | } | |
2336 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
2337 | ||
2338 | static int __init set_ftrace_filter(char *str) | |
2339 | { | |
2340 | strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); | |
2341 | return 1; | |
2342 | } | |
2343 | __setup("ftrace_filter=", set_ftrace_filter); | |
2344 | ||
369bc18f | 2345 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 2346 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
801c29fd SR |
2347 | static int ftrace_set_func(unsigned long *array, int *idx, char *buffer); |
2348 | ||
369bc18f SA |
2349 | static int __init set_graph_function(char *str) |
2350 | { | |
06f43d66 | 2351 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
2352 | return 1; |
2353 | } | |
2354 | __setup("ftrace_graph_filter=", set_graph_function); | |
2355 | ||
2356 | static void __init set_ftrace_early_graph(char *buf) | |
2357 | { | |
2358 | int ret; | |
2359 | char *func; | |
2360 | ||
2361 | while (buf) { | |
2362 | func = strsep(&buf, ","); | |
2363 | /* we allow only one expression at a time */ | |
2364 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, | |
2365 | func); | |
2366 | if (ret) | |
2367 | printk(KERN_DEBUG "ftrace: function %s not " | |
2368 | "traceable\n", func); | |
2369 | } | |
2370 | } | |
2371 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2372 | ||
2af15d6a SR |
2373 | static void __init set_ftrace_early_filter(char *buf, int enable) |
2374 | { | |
2375 | char *func; | |
2376 | ||
2377 | while (buf) { | |
2378 | func = strsep(&buf, ","); | |
2379 | ftrace_set_regex(func, strlen(func), 0, enable); | |
2380 | } | |
2381 | } | |
2382 | ||
2383 | static void __init set_ftrace_early_filters(void) | |
2384 | { | |
2385 | if (ftrace_filter_buf[0]) | |
2386 | set_ftrace_early_filter(ftrace_filter_buf, 1); | |
2387 | if (ftrace_notrace_buf[0]) | |
2388 | set_ftrace_early_filter(ftrace_notrace_buf, 0); | |
369bc18f SA |
2389 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
2390 | if (ftrace_graph_buf[0]) | |
2391 | set_ftrace_early_graph(ftrace_graph_buf); | |
2392 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2af15d6a SR |
2393 | } |
2394 | ||
e309b41d | 2395 | static int |
41c52c0d | 2396 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
2397 | { |
2398 | struct seq_file *m = (struct seq_file *)file->private_data; | |
2399 | struct ftrace_iterator *iter; | |
689fd8b6 | 2400 | struct trace_parser *parser; |
5072c59f | 2401 | |
41c52c0d | 2402 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
2403 | if (file->f_mode & FMODE_READ) { |
2404 | iter = m->private; | |
2405 | ||
2406 | seq_release(inode, file); | |
2407 | } else | |
2408 | iter = file->private_data; | |
2409 | ||
689fd8b6 | 2410 | parser = &iter->parser; |
2411 | if (trace_parser_loaded(parser)) { | |
2412 | parser->buffer[parser->idx] = 0; | |
2413 | ftrace_match_records(parser->buffer, parser->idx, enable); | |
5072c59f SR |
2414 | } |
2415 | ||
e6ea44e9 | 2416 | mutex_lock(&ftrace_lock); |
ee02a2e5 | 2417 | if (ftrace_start_up && ftrace_enabled) |
5072c59f | 2418 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
e6ea44e9 | 2419 | mutex_unlock(&ftrace_lock); |
5072c59f | 2420 | |
689fd8b6 | 2421 | trace_parser_put(parser); |
5072c59f | 2422 | kfree(iter); |
689fd8b6 | 2423 | |
41c52c0d | 2424 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
2425 | return 0; |
2426 | } | |
2427 | ||
41c52c0d SR |
2428 | static int |
2429 | ftrace_filter_release(struct inode *inode, struct file *file) | |
2430 | { | |
2431 | return ftrace_regex_release(inode, file, 1); | |
2432 | } | |
2433 | ||
2434 | static int | |
2435 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
2436 | { | |
2437 | return ftrace_regex_release(inode, file, 0); | |
2438 | } | |
2439 | ||
5e2336a0 | 2440 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
2441 | .open = ftrace_avail_open, |
2442 | .read = seq_read, | |
2443 | .llseek = seq_lseek, | |
3be04b47 | 2444 | .release = seq_release_private, |
5072c59f SR |
2445 | }; |
2446 | ||
5e2336a0 | 2447 | static const struct file_operations ftrace_failures_fops = { |
eb9a7bf0 AS |
2448 | .open = ftrace_failures_open, |
2449 | .read = seq_read, | |
2450 | .llseek = seq_lseek, | |
3be04b47 | 2451 | .release = seq_release_private, |
eb9a7bf0 AS |
2452 | }; |
2453 | ||
5e2336a0 | 2454 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 2455 | .open = ftrace_filter_open, |
850a80cf | 2456 | .read = seq_read, |
5072c59f | 2457 | .write = ftrace_filter_write, |
98c4fd04 | 2458 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
2459 | .release = ftrace_filter_release, |
2460 | }; | |
2461 | ||
5e2336a0 | 2462 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 2463 | .open = ftrace_notrace_open, |
850a80cf | 2464 | .read = seq_read, |
41c52c0d SR |
2465 | .write = ftrace_notrace_write, |
2466 | .llseek = ftrace_regex_lseek, | |
2467 | .release = ftrace_notrace_release, | |
2468 | }; | |
2469 | ||
ea4e2bc4 SR |
2470 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
2471 | ||
2472 | static DEFINE_MUTEX(graph_lock); | |
2473 | ||
2474 | int ftrace_graph_count; | |
c7c6b1fe | 2475 | int ftrace_graph_filter_enabled; |
ea4e2bc4 SR |
2476 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
2477 | ||
2478 | static void * | |
85951842 | 2479 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 2480 | { |
85951842 | 2481 | if (*pos >= ftrace_graph_count) |
ea4e2bc4 | 2482 | return NULL; |
a4ec5e0c | 2483 | return &ftrace_graph_funcs[*pos]; |
85951842 | 2484 | } |
ea4e2bc4 | 2485 | |
85951842 LZ |
2486 | static void * |
2487 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
2488 | { | |
2489 | (*pos)++; | |
2490 | return __g_next(m, pos); | |
ea4e2bc4 SR |
2491 | } |
2492 | ||
2493 | static void *g_start(struct seq_file *m, loff_t *pos) | |
2494 | { | |
ea4e2bc4 SR |
2495 | mutex_lock(&graph_lock); |
2496 | ||
f9349a8f | 2497 | /* Nothing, tell g_show to print all functions are enabled */ |
c7c6b1fe | 2498 | if (!ftrace_graph_filter_enabled && !*pos) |
f9349a8f FW |
2499 | return (void *)1; |
2500 | ||
85951842 | 2501 | return __g_next(m, pos); |
ea4e2bc4 SR |
2502 | } |
2503 | ||
2504 | static void g_stop(struct seq_file *m, void *p) | |
2505 | { | |
2506 | mutex_unlock(&graph_lock); | |
2507 | } | |
2508 | ||
2509 | static int g_show(struct seq_file *m, void *v) | |
2510 | { | |
2511 | unsigned long *ptr = v; | |
ea4e2bc4 SR |
2512 | |
2513 | if (!ptr) | |
2514 | return 0; | |
2515 | ||
f9349a8f FW |
2516 | if (ptr == (unsigned long *)1) { |
2517 | seq_printf(m, "#### all functions enabled ####\n"); | |
2518 | return 0; | |
2519 | } | |
2520 | ||
b375a11a | 2521 | seq_printf(m, "%ps\n", (void *)*ptr); |
ea4e2bc4 SR |
2522 | |
2523 | return 0; | |
2524 | } | |
2525 | ||
88e9d34c | 2526 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
2527 | .start = g_start, |
2528 | .next = g_next, | |
2529 | .stop = g_stop, | |
2530 | .show = g_show, | |
2531 | }; | |
2532 | ||
2533 | static int | |
2534 | ftrace_graph_open(struct inode *inode, struct file *file) | |
2535 | { | |
2536 | int ret = 0; | |
2537 | ||
2538 | if (unlikely(ftrace_disabled)) | |
2539 | return -ENODEV; | |
2540 | ||
2541 | mutex_lock(&graph_lock); | |
2542 | if ((file->f_mode & FMODE_WRITE) && | |
8650ae32 | 2543 | (file->f_flags & O_TRUNC)) { |
c7c6b1fe | 2544 | ftrace_graph_filter_enabled = 0; |
ea4e2bc4 SR |
2545 | ftrace_graph_count = 0; |
2546 | memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); | |
2547 | } | |
a4ec5e0c | 2548 | mutex_unlock(&graph_lock); |
ea4e2bc4 | 2549 | |
a4ec5e0c | 2550 | if (file->f_mode & FMODE_READ) |
ea4e2bc4 | 2551 | ret = seq_open(file, &ftrace_graph_seq_ops); |
ea4e2bc4 SR |
2552 | |
2553 | return ret; | |
2554 | } | |
2555 | ||
87827111 LZ |
2556 | static int |
2557 | ftrace_graph_release(struct inode *inode, struct file *file) | |
2558 | { | |
2559 | if (file->f_mode & FMODE_READ) | |
2560 | seq_release(inode, file); | |
2561 | return 0; | |
2562 | } | |
2563 | ||
ea4e2bc4 | 2564 | static int |
f9349a8f | 2565 | ftrace_set_func(unsigned long *array, int *idx, char *buffer) |
ea4e2bc4 | 2566 | { |
ea4e2bc4 SR |
2567 | struct dyn_ftrace *rec; |
2568 | struct ftrace_page *pg; | |
f9349a8f | 2569 | int search_len; |
c7c6b1fe | 2570 | int fail = 1; |
f9349a8f FW |
2571 | int type, not; |
2572 | char *search; | |
2573 | bool exists; | |
2574 | int i; | |
ea4e2bc4 SR |
2575 | |
2576 | if (ftrace_disabled) | |
2577 | return -ENODEV; | |
2578 | ||
f9349a8f | 2579 | /* decode regex */ |
3f6fe06d | 2580 | type = filter_parse_regex(buffer, strlen(buffer), &search, ¬); |
c7c6b1fe LZ |
2581 | if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS) |
2582 | return -EBUSY; | |
f9349a8f FW |
2583 | |
2584 | search_len = strlen(search); | |
2585 | ||
52baf119 | 2586 | mutex_lock(&ftrace_lock); |
265c831c SR |
2587 | do_for_each_ftrace_rec(pg, rec) { |
2588 | ||
2589 | if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE)) | |
2590 | continue; | |
2591 | ||
f9349a8f | 2592 | if (ftrace_match_record(rec, search, search_len, type)) { |
c7c6b1fe | 2593 | /* if it is in the array */ |
f9349a8f | 2594 | exists = false; |
c7c6b1fe | 2595 | for (i = 0; i < *idx; i++) { |
f9349a8f FW |
2596 | if (array[i] == rec->ip) { |
2597 | exists = true; | |
265c831c SR |
2598 | break; |
2599 | } | |
c7c6b1fe LZ |
2600 | } |
2601 | ||
2602 | if (!not) { | |
2603 | fail = 0; | |
2604 | if (!exists) { | |
2605 | array[(*idx)++] = rec->ip; | |
2606 | if (*idx >= FTRACE_GRAPH_MAX_FUNCS) | |
2607 | goto out; | |
2608 | } | |
2609 | } else { | |
2610 | if (exists) { | |
2611 | array[i] = array[--(*idx)]; | |
2612 | array[*idx] = 0; | |
2613 | fail = 0; | |
2614 | } | |
2615 | } | |
ea4e2bc4 | 2616 | } |
265c831c | 2617 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 2618 | out: |
52baf119 | 2619 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 2620 | |
c7c6b1fe LZ |
2621 | if (fail) |
2622 | return -EINVAL; | |
2623 | ||
2624 | ftrace_graph_filter_enabled = 1; | |
2625 | return 0; | |
ea4e2bc4 SR |
2626 | } |
2627 | ||
2628 | static ssize_t | |
2629 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
2630 | size_t cnt, loff_t *ppos) | |
2631 | { | |
689fd8b6 | 2632 | struct trace_parser parser; |
4ba7978e | 2633 | ssize_t read, ret; |
ea4e2bc4 | 2634 | |
c7c6b1fe | 2635 | if (!cnt) |
ea4e2bc4 SR |
2636 | return 0; |
2637 | ||
2638 | mutex_lock(&graph_lock); | |
2639 | ||
689fd8b6 | 2640 | if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) { |
2641 | ret = -ENOMEM; | |
1eb90f13 | 2642 | goto out_unlock; |
ea4e2bc4 SR |
2643 | } |
2644 | ||
689fd8b6 | 2645 | read = trace_get_user(&parser, ubuf, cnt, ppos); |
ea4e2bc4 | 2646 | |
4ba7978e | 2647 | if (read >= 0 && trace_parser_loaded((&parser))) { |
689fd8b6 | 2648 | parser.buffer[parser.idx] = 0; |
2649 | ||
2650 | /* we allow only one expression at a time */ | |
a4ec5e0c | 2651 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, |
689fd8b6 | 2652 | parser.buffer); |
ea4e2bc4 | 2653 | if (ret) |
1eb90f13 | 2654 | goto out_free; |
ea4e2bc4 | 2655 | } |
ea4e2bc4 SR |
2656 | |
2657 | ret = read; | |
1eb90f13 LZ |
2658 | |
2659 | out_free: | |
689fd8b6 | 2660 | trace_parser_put(&parser); |
1eb90f13 | 2661 | out_unlock: |
ea4e2bc4 SR |
2662 | mutex_unlock(&graph_lock); |
2663 | ||
2664 | return ret; | |
2665 | } | |
2666 | ||
2667 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
2668 | .open = ftrace_graph_open, |
2669 | .read = seq_read, | |
2670 | .write = ftrace_graph_write, | |
2671 | .release = ftrace_graph_release, | |
6038f373 | 2672 | .llseek = seq_lseek, |
ea4e2bc4 SR |
2673 | }; |
2674 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2675 | ||
df4fc315 | 2676 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 2677 | { |
5072c59f | 2678 | |
5452af66 FW |
2679 | trace_create_file("available_filter_functions", 0444, |
2680 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 2681 | |
5452af66 FW |
2682 | trace_create_file("failures", 0444, |
2683 | d_tracer, NULL, &ftrace_failures_fops); | |
eb9a7bf0 | 2684 | |
5452af66 FW |
2685 | trace_create_file("set_ftrace_filter", 0644, d_tracer, |
2686 | NULL, &ftrace_filter_fops); | |
41c52c0d | 2687 | |
5452af66 | 2688 | trace_create_file("set_ftrace_notrace", 0644, d_tracer, |
41c52c0d | 2689 | NULL, &ftrace_notrace_fops); |
ad90c0e3 | 2690 | |
ea4e2bc4 | 2691 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 2692 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
2693 | NULL, |
2694 | &ftrace_graph_fops); | |
ea4e2bc4 SR |
2695 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
2696 | ||
5072c59f SR |
2697 | return 0; |
2698 | } | |
2699 | ||
5cb084bb | 2700 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 2701 | unsigned long *start, |
68bf21aa SR |
2702 | unsigned long *end) |
2703 | { | |
2704 | unsigned long *p; | |
2705 | unsigned long addr; | |
2706 | unsigned long flags; | |
2707 | ||
e6ea44e9 | 2708 | mutex_lock(&ftrace_lock); |
68bf21aa SR |
2709 | p = start; |
2710 | while (p < end) { | |
2711 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
2712 | /* |
2713 | * Some architecture linkers will pad between | |
2714 | * the different mcount_loc sections of different | |
2715 | * object files to satisfy alignments. | |
2716 | * Skip any NULL pointers. | |
2717 | */ | |
2718 | if (!addr) | |
2719 | continue; | |
68bf21aa | 2720 | ftrace_record_ip(addr); |
68bf21aa SR |
2721 | } |
2722 | ||
08f5ac90 | 2723 | /* disable interrupts to prevent kstop machine */ |
68bf21aa | 2724 | local_irq_save(flags); |
31e88909 | 2725 | ftrace_update_code(mod); |
68bf21aa | 2726 | local_irq_restore(flags); |
e6ea44e9 | 2727 | mutex_unlock(&ftrace_lock); |
68bf21aa SR |
2728 | |
2729 | return 0; | |
2730 | } | |
2731 | ||
93eb677d | 2732 | #ifdef CONFIG_MODULES |
e7247a15 | 2733 | void ftrace_release_mod(struct module *mod) |
93eb677d SR |
2734 | { |
2735 | struct dyn_ftrace *rec; | |
2736 | struct ftrace_page *pg; | |
93eb677d | 2737 | |
e7247a15 | 2738 | if (ftrace_disabled) |
93eb677d SR |
2739 | return; |
2740 | ||
2741 | mutex_lock(&ftrace_lock); | |
2742 | do_for_each_ftrace_rec(pg, rec) { | |
e7247a15 | 2743 | if (within_module_core(rec->ip, mod)) { |
93eb677d SR |
2744 | /* |
2745 | * rec->ip is changed in ftrace_free_rec() | |
2746 | * It should not between s and e if record was freed. | |
2747 | */ | |
2748 | FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE); | |
2749 | ftrace_free_rec(rec); | |
2750 | } | |
2751 | } while_for_each_ftrace_rec(); | |
2752 | mutex_unlock(&ftrace_lock); | |
2753 | } | |
2754 | ||
2755 | static void ftrace_init_module(struct module *mod, | |
2756 | unsigned long *start, unsigned long *end) | |
90d595fe | 2757 | { |
00fd61ae | 2758 | if (ftrace_disabled || start == end) |
fed1939c | 2759 | return; |
5cb084bb | 2760 | ftrace_process_locs(mod, start, end); |
90d595fe SR |
2761 | } |
2762 | ||
93eb677d SR |
2763 | static int ftrace_module_notify(struct notifier_block *self, |
2764 | unsigned long val, void *data) | |
2765 | { | |
2766 | struct module *mod = data; | |
2767 | ||
2768 | switch (val) { | |
2769 | case MODULE_STATE_COMING: | |
2770 | ftrace_init_module(mod, mod->ftrace_callsites, | |
2771 | mod->ftrace_callsites + | |
2772 | mod->num_ftrace_callsites); | |
2773 | break; | |
2774 | case MODULE_STATE_GOING: | |
e7247a15 | 2775 | ftrace_release_mod(mod); |
93eb677d SR |
2776 | break; |
2777 | } | |
2778 | ||
2779 | return 0; | |
2780 | } | |
2781 | #else | |
2782 | static int ftrace_module_notify(struct notifier_block *self, | |
2783 | unsigned long val, void *data) | |
2784 | { | |
2785 | return 0; | |
2786 | } | |
2787 | #endif /* CONFIG_MODULES */ | |
2788 | ||
2789 | struct notifier_block ftrace_module_nb = { | |
2790 | .notifier_call = ftrace_module_notify, | |
2791 | .priority = 0, | |
2792 | }; | |
2793 | ||
68bf21aa SR |
2794 | extern unsigned long __start_mcount_loc[]; |
2795 | extern unsigned long __stop_mcount_loc[]; | |
2796 | ||
2797 | void __init ftrace_init(void) | |
2798 | { | |
2799 | unsigned long count, addr, flags; | |
2800 | int ret; | |
2801 | ||
2802 | /* Keep the ftrace pointer to the stub */ | |
2803 | addr = (unsigned long)ftrace_stub; | |
2804 | ||
2805 | local_irq_save(flags); | |
2806 | ftrace_dyn_arch_init(&addr); | |
2807 | local_irq_restore(flags); | |
2808 | ||
2809 | /* ftrace_dyn_arch_init places the return code in addr */ | |
2810 | if (addr) | |
2811 | goto failed; | |
2812 | ||
2813 | count = __stop_mcount_loc - __start_mcount_loc; | |
2814 | ||
2815 | ret = ftrace_dyn_table_alloc(count); | |
2816 | if (ret) | |
2817 | goto failed; | |
2818 | ||
2819 | last_ftrace_enabled = ftrace_enabled = 1; | |
2820 | ||
5cb084bb | 2821 | ret = ftrace_process_locs(NULL, |
31e88909 | 2822 | __start_mcount_loc, |
68bf21aa SR |
2823 | __stop_mcount_loc); |
2824 | ||
93eb677d | 2825 | ret = register_module_notifier(&ftrace_module_nb); |
24ed0c4b | 2826 | if (ret) |
93eb677d SR |
2827 | pr_warning("Failed to register trace ftrace module notifier\n"); |
2828 | ||
2af15d6a SR |
2829 | set_ftrace_early_filters(); |
2830 | ||
68bf21aa SR |
2831 | return; |
2832 | failed: | |
2833 | ftrace_disabled = 1; | |
2834 | } | |
68bf21aa | 2835 | |
3d083395 | 2836 | #else |
0b6e4d56 FW |
2837 | |
2838 | static int __init ftrace_nodyn_init(void) | |
2839 | { | |
2840 | ftrace_enabled = 1; | |
2841 | return 0; | |
2842 | } | |
2843 | device_initcall(ftrace_nodyn_init); | |
2844 | ||
df4fc315 SR |
2845 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
2846 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 SR |
2847 | /* Keep as macros so we do not need to define the commands */ |
2848 | # define ftrace_startup(command) do { } while (0) | |
2849 | # define ftrace_shutdown(command) do { } while (0) | |
c7aafc54 IM |
2850 | # define ftrace_startup_sysctl() do { } while (0) |
2851 | # define ftrace_shutdown_sysctl() do { } while (0) | |
3d083395 SR |
2852 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
2853 | ||
e32d8956 | 2854 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
2855 | { |
2856 | struct task_struct *p; | |
e32d8956 | 2857 | int cpu; |
978f3a45 | 2858 | |
e32d8956 SR |
2859 | get_online_cpus(); |
2860 | for_each_online_cpu(cpu) { | |
2861 | p = idle_task(cpu); | |
978f3a45 | 2862 | clear_tsk_trace_trace(p); |
e32d8956 SR |
2863 | } |
2864 | put_online_cpus(); | |
2865 | } | |
978f3a45 | 2866 | |
e32d8956 SR |
2867 | static void set_ftrace_swapper(void) |
2868 | { | |
2869 | struct task_struct *p; | |
2870 | int cpu; | |
2871 | ||
2872 | get_online_cpus(); | |
2873 | for_each_online_cpu(cpu) { | |
2874 | p = idle_task(cpu); | |
2875 | set_tsk_trace_trace(p); | |
2876 | } | |
2877 | put_online_cpus(); | |
978f3a45 SR |
2878 | } |
2879 | ||
e32d8956 SR |
2880 | static void clear_ftrace_pid(struct pid *pid) |
2881 | { | |
2882 | struct task_struct *p; | |
2883 | ||
229c4ef8 | 2884 | rcu_read_lock(); |
e32d8956 SR |
2885 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2886 | clear_tsk_trace_trace(p); | |
2887 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
2888 | rcu_read_unlock(); |
2889 | ||
e32d8956 SR |
2890 | put_pid(pid); |
2891 | } | |
2892 | ||
2893 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
2894 | { |
2895 | struct task_struct *p; | |
2896 | ||
229c4ef8 | 2897 | rcu_read_lock(); |
978f3a45 SR |
2898 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2899 | set_tsk_trace_trace(p); | |
2900 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 2901 | rcu_read_unlock(); |
978f3a45 SR |
2902 | } |
2903 | ||
756d17ee | 2904 | static void clear_ftrace_pid_task(struct pid *pid) |
e32d8956 | 2905 | { |
756d17ee | 2906 | if (pid == ftrace_swapper_pid) |
e32d8956 SR |
2907 | clear_ftrace_swapper(); |
2908 | else | |
756d17ee | 2909 | clear_ftrace_pid(pid); |
e32d8956 SR |
2910 | } |
2911 | ||
2912 | static void set_ftrace_pid_task(struct pid *pid) | |
2913 | { | |
2914 | if (pid == ftrace_swapper_pid) | |
2915 | set_ftrace_swapper(); | |
2916 | else | |
2917 | set_ftrace_pid(pid); | |
2918 | } | |
2919 | ||
756d17ee | 2920 | static int ftrace_pid_add(int p) |
df4fc315 | 2921 | { |
978f3a45 | 2922 | struct pid *pid; |
756d17ee | 2923 | struct ftrace_pid *fpid; |
2924 | int ret = -EINVAL; | |
df4fc315 | 2925 | |
756d17ee | 2926 | mutex_lock(&ftrace_lock); |
df4fc315 | 2927 | |
756d17ee | 2928 | if (!p) |
2929 | pid = ftrace_swapper_pid; | |
2930 | else | |
2931 | pid = find_get_pid(p); | |
df4fc315 | 2932 | |
756d17ee | 2933 | if (!pid) |
2934 | goto out; | |
df4fc315 | 2935 | |
756d17ee | 2936 | ret = 0; |
df4fc315 | 2937 | |
756d17ee | 2938 | list_for_each_entry(fpid, &ftrace_pids, list) |
2939 | if (fpid->pid == pid) | |
2940 | goto out_put; | |
978f3a45 | 2941 | |
756d17ee | 2942 | ret = -ENOMEM; |
df4fc315 | 2943 | |
756d17ee | 2944 | fpid = kmalloc(sizeof(*fpid), GFP_KERNEL); |
2945 | if (!fpid) | |
2946 | goto out_put; | |
df4fc315 | 2947 | |
756d17ee | 2948 | list_add(&fpid->list, &ftrace_pids); |
2949 | fpid->pid = pid; | |
0ef8cde5 | 2950 | |
756d17ee | 2951 | set_ftrace_pid_task(pid); |
978f3a45 | 2952 | |
756d17ee | 2953 | ftrace_update_pid_func(); |
2954 | ftrace_startup_enable(0); | |
2955 | ||
2956 | mutex_unlock(&ftrace_lock); | |
2957 | return 0; | |
2958 | ||
2959 | out_put: | |
2960 | if (pid != ftrace_swapper_pid) | |
2961 | put_pid(pid); | |
978f3a45 | 2962 | |
756d17ee | 2963 | out: |
2964 | mutex_unlock(&ftrace_lock); | |
2965 | return ret; | |
2966 | } | |
2967 | ||
2968 | static void ftrace_pid_reset(void) | |
2969 | { | |
2970 | struct ftrace_pid *fpid, *safe; | |
978f3a45 | 2971 | |
756d17ee | 2972 | mutex_lock(&ftrace_lock); |
2973 | list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) { | |
2974 | struct pid *pid = fpid->pid; | |
2975 | ||
2976 | clear_ftrace_pid_task(pid); | |
2977 | ||
2978 | list_del(&fpid->list); | |
2979 | kfree(fpid); | |
df4fc315 SR |
2980 | } |
2981 | ||
df4fc315 SR |
2982 | ftrace_update_pid_func(); |
2983 | ftrace_startup_enable(0); | |
2984 | ||
e6ea44e9 | 2985 | mutex_unlock(&ftrace_lock); |
756d17ee | 2986 | } |
df4fc315 | 2987 | |
756d17ee | 2988 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
2989 | { | |
2990 | mutex_lock(&ftrace_lock); | |
2991 | ||
2992 | if (list_empty(&ftrace_pids) && (!*pos)) | |
2993 | return (void *) 1; | |
2994 | ||
2995 | return seq_list_start(&ftrace_pids, *pos); | |
2996 | } | |
2997 | ||
2998 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
2999 | { | |
3000 | if (v == (void *)1) | |
3001 | return NULL; | |
3002 | ||
3003 | return seq_list_next(v, &ftrace_pids, pos); | |
3004 | } | |
3005 | ||
3006 | static void fpid_stop(struct seq_file *m, void *p) | |
3007 | { | |
3008 | mutex_unlock(&ftrace_lock); | |
3009 | } | |
3010 | ||
3011 | static int fpid_show(struct seq_file *m, void *v) | |
3012 | { | |
3013 | const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list); | |
3014 | ||
3015 | if (v == (void *)1) { | |
3016 | seq_printf(m, "no pid\n"); | |
3017 | return 0; | |
3018 | } | |
3019 | ||
3020 | if (fpid->pid == ftrace_swapper_pid) | |
3021 | seq_printf(m, "swapper tasks\n"); | |
3022 | else | |
3023 | seq_printf(m, "%u\n", pid_vnr(fpid->pid)); | |
3024 | ||
3025 | return 0; | |
3026 | } | |
3027 | ||
3028 | static const struct seq_operations ftrace_pid_sops = { | |
3029 | .start = fpid_start, | |
3030 | .next = fpid_next, | |
3031 | .stop = fpid_stop, | |
3032 | .show = fpid_show, | |
3033 | }; | |
3034 | ||
3035 | static int | |
3036 | ftrace_pid_open(struct inode *inode, struct file *file) | |
3037 | { | |
3038 | int ret = 0; | |
3039 | ||
3040 | if ((file->f_mode & FMODE_WRITE) && | |
3041 | (file->f_flags & O_TRUNC)) | |
3042 | ftrace_pid_reset(); | |
3043 | ||
3044 | if (file->f_mode & FMODE_READ) | |
3045 | ret = seq_open(file, &ftrace_pid_sops); | |
3046 | ||
3047 | return ret; | |
3048 | } | |
3049 | ||
df4fc315 SR |
3050 | static ssize_t |
3051 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
3052 | size_t cnt, loff_t *ppos) | |
3053 | { | |
457dc928 | 3054 | char buf[64], *tmp; |
df4fc315 SR |
3055 | long val; |
3056 | int ret; | |
3057 | ||
3058 | if (cnt >= sizeof(buf)) | |
3059 | return -EINVAL; | |
3060 | ||
3061 | if (copy_from_user(&buf, ubuf, cnt)) | |
3062 | return -EFAULT; | |
3063 | ||
3064 | buf[cnt] = 0; | |
3065 | ||
756d17ee | 3066 | /* |
3067 | * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid" | |
3068 | * to clean the filter quietly. | |
3069 | */ | |
457dc928 IM |
3070 | tmp = strstrip(buf); |
3071 | if (strlen(tmp) == 0) | |
756d17ee | 3072 | return 1; |
3073 | ||
457dc928 | 3074 | ret = strict_strtol(tmp, 10, &val); |
df4fc315 SR |
3075 | if (ret < 0) |
3076 | return ret; | |
3077 | ||
756d17ee | 3078 | ret = ftrace_pid_add(val); |
df4fc315 | 3079 | |
756d17ee | 3080 | return ret ? ret : cnt; |
3081 | } | |
df4fc315 | 3082 | |
756d17ee | 3083 | static int |
3084 | ftrace_pid_release(struct inode *inode, struct file *file) | |
3085 | { | |
3086 | if (file->f_mode & FMODE_READ) | |
3087 | seq_release(inode, file); | |
df4fc315 | 3088 | |
756d17ee | 3089 | return 0; |
df4fc315 SR |
3090 | } |
3091 | ||
5e2336a0 | 3092 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 3093 | .open = ftrace_pid_open, |
3094 | .write = ftrace_pid_write, | |
3095 | .read = seq_read, | |
3096 | .llseek = seq_lseek, | |
3097 | .release = ftrace_pid_release, | |
df4fc315 SR |
3098 | }; |
3099 | ||
3100 | static __init int ftrace_init_debugfs(void) | |
3101 | { | |
3102 | struct dentry *d_tracer; | |
df4fc315 SR |
3103 | |
3104 | d_tracer = tracing_init_dentry(); | |
3105 | if (!d_tracer) | |
3106 | return 0; | |
3107 | ||
3108 | ftrace_init_dyn_debugfs(d_tracer); | |
3109 | ||
5452af66 FW |
3110 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
3111 | NULL, &ftrace_pid_fops); | |
493762fc SR |
3112 | |
3113 | ftrace_profile_debugfs(d_tracer); | |
3114 | ||
df4fc315 SR |
3115 | return 0; |
3116 | } | |
df4fc315 SR |
3117 | fs_initcall(ftrace_init_debugfs); |
3118 | ||
a2bb6a3d | 3119 | /** |
81adbdc0 | 3120 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
3121 | * |
3122 | * This function should be used by panic code. It stops ftrace | |
3123 | * but in a not so nice way. If you need to simply kill ftrace | |
3124 | * from a non-atomic section, use ftrace_kill. | |
3125 | */ | |
81adbdc0 | 3126 | void ftrace_kill(void) |
a2bb6a3d SR |
3127 | { |
3128 | ftrace_disabled = 1; | |
3129 | ftrace_enabled = 0; | |
a2bb6a3d SR |
3130 | clear_ftrace_function(); |
3131 | } | |
3132 | ||
16444a8a | 3133 | /** |
3d083395 SR |
3134 | * register_ftrace_function - register a function for profiling |
3135 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 3136 | * |
3d083395 SR |
3137 | * Register a function to be called by all functions in the |
3138 | * kernel. | |
3139 | * | |
3140 | * Note: @ops->func and all the functions it calls must be labeled | |
3141 | * with "notrace", otherwise it will go into a | |
3142 | * recursive loop. | |
16444a8a | 3143 | */ |
3d083395 | 3144 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 3145 | { |
b0fc494f SR |
3146 | int ret; |
3147 | ||
4eebcc81 SR |
3148 | if (unlikely(ftrace_disabled)) |
3149 | return -1; | |
3150 | ||
e6ea44e9 | 3151 | mutex_lock(&ftrace_lock); |
e7d3737e | 3152 | |
b0fc494f | 3153 | ret = __register_ftrace_function(ops); |
5a45cfe1 | 3154 | ftrace_startup(0); |
b0fc494f | 3155 | |
e6ea44e9 | 3156 | mutex_unlock(&ftrace_lock); |
b0fc494f | 3157 | return ret; |
3d083395 SR |
3158 | } |
3159 | ||
3160 | /** | |
32632920 | 3161 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
3162 | * @ops - ops structure that holds the function to unregister |
3163 | * | |
3164 | * Unregister a function that was added to be called by ftrace profiling. | |
3165 | */ | |
3166 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
3167 | { | |
3168 | int ret; | |
3169 | ||
e6ea44e9 | 3170 | mutex_lock(&ftrace_lock); |
3d083395 | 3171 | ret = __unregister_ftrace_function(ops); |
5a45cfe1 | 3172 | ftrace_shutdown(0); |
e6ea44e9 | 3173 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
3174 | |
3175 | return ret; | |
3176 | } | |
3177 | ||
e309b41d | 3178 | int |
b0fc494f | 3179 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
8d65af78 | 3180 | void __user *buffer, size_t *lenp, |
b0fc494f SR |
3181 | loff_t *ppos) |
3182 | { | |
3183 | int ret; | |
3184 | ||
4eebcc81 SR |
3185 | if (unlikely(ftrace_disabled)) |
3186 | return -ENODEV; | |
3187 | ||
e6ea44e9 | 3188 | mutex_lock(&ftrace_lock); |
b0fc494f | 3189 | |
8d65af78 | 3190 | ret = proc_dointvec(table, write, buffer, lenp, ppos); |
b0fc494f | 3191 | |
a32c7765 | 3192 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
3193 | goto out; |
3194 | ||
a32c7765 | 3195 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f SR |
3196 | |
3197 | if (ftrace_enabled) { | |
3198 | ||
3199 | ftrace_startup_sysctl(); | |
3200 | ||
3201 | /* we are starting ftrace again */ | |
3202 | if (ftrace_list != &ftrace_list_end) { | |
3203 | if (ftrace_list->next == &ftrace_list_end) | |
3204 | ftrace_trace_function = ftrace_list->func; | |
3205 | else | |
3206 | ftrace_trace_function = ftrace_list_func; | |
3207 | } | |
3208 | ||
3209 | } else { | |
3210 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
3211 | ftrace_trace_function = ftrace_stub; | |
3212 | ||
3213 | ftrace_shutdown_sysctl(); | |
3214 | } | |
3215 | ||
3216 | out: | |
e6ea44e9 | 3217 | mutex_unlock(&ftrace_lock); |
3d083395 | 3218 | return ret; |
16444a8a | 3219 | } |
f17845e5 | 3220 | |
fb52607a | 3221 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 3222 | |
597af815 | 3223 | static int ftrace_graph_active; |
4a2b8dda | 3224 | static struct notifier_block ftrace_suspend_notifier; |
e7d3737e | 3225 | |
e49dc19c SR |
3226 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
3227 | { | |
3228 | return 0; | |
3229 | } | |
3230 | ||
287b6e68 FW |
3231 | /* The callbacks that hook a function */ |
3232 | trace_func_graph_ret_t ftrace_graph_return = | |
3233 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 3234 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
3235 | |
3236 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
3237 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
3238 | { | |
3239 | int i; | |
3240 | int ret = 0; | |
3241 | unsigned long flags; | |
3242 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
3243 | struct task_struct *g, *t; | |
3244 | ||
3245 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
3246 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
3247 | * sizeof(struct ftrace_ret_stack), | |
3248 | GFP_KERNEL); | |
3249 | if (!ret_stack_list[i]) { | |
3250 | start = 0; | |
3251 | end = i; | |
3252 | ret = -ENOMEM; | |
3253 | goto free; | |
3254 | } | |
3255 | } | |
3256 | ||
3257 | read_lock_irqsave(&tasklist_lock, flags); | |
3258 | do_each_thread(g, t) { | |
3259 | if (start == end) { | |
3260 | ret = -EAGAIN; | |
3261 | goto unlock; | |
3262 | } | |
3263 | ||
3264 | if (t->ret_stack == NULL) { | |
380c4b14 | 3265 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 3266 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
3267 | t->curr_ret_stack = -1; |
3268 | /* Make sure the tasks see the -1 first: */ | |
3269 | smp_wmb(); | |
3270 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
3271 | } |
3272 | } while_each_thread(g, t); | |
3273 | ||
3274 | unlock: | |
3275 | read_unlock_irqrestore(&tasklist_lock, flags); | |
3276 | free: | |
3277 | for (i = start; i < end; i++) | |
3278 | kfree(ret_stack_list[i]); | |
3279 | return ret; | |
3280 | } | |
3281 | ||
8aef2d28 | 3282 | static void |
38516ab5 SR |
3283 | ftrace_graph_probe_sched_switch(void *ignore, |
3284 | struct task_struct *prev, struct task_struct *next) | |
8aef2d28 SR |
3285 | { |
3286 | unsigned long long timestamp; | |
3287 | int index; | |
3288 | ||
be6f164a SR |
3289 | /* |
3290 | * Does the user want to count the time a function was asleep. | |
3291 | * If so, do not update the time stamps. | |
3292 | */ | |
3293 | if (trace_flags & TRACE_ITER_SLEEP_TIME) | |
3294 | return; | |
3295 | ||
8aef2d28 SR |
3296 | timestamp = trace_clock_local(); |
3297 | ||
3298 | prev->ftrace_timestamp = timestamp; | |
3299 | ||
3300 | /* only process tasks that we timestamped */ | |
3301 | if (!next->ftrace_timestamp) | |
3302 | return; | |
3303 | ||
3304 | /* | |
3305 | * Update all the counters in next to make up for the | |
3306 | * time next was sleeping. | |
3307 | */ | |
3308 | timestamp -= next->ftrace_timestamp; | |
3309 | ||
3310 | for (index = next->curr_ret_stack; index >= 0; index--) | |
3311 | next->ret_stack[index].calltime += timestamp; | |
3312 | } | |
3313 | ||
f201ae23 | 3314 | /* Allocate a return stack for each task */ |
fb52607a | 3315 | static int start_graph_tracing(void) |
f201ae23 FW |
3316 | { |
3317 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 3318 | int ret, cpu; |
f201ae23 FW |
3319 | |
3320 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
3321 | sizeof(struct ftrace_ret_stack *), | |
3322 | GFP_KERNEL); | |
3323 | ||
3324 | if (!ret_stack_list) | |
3325 | return -ENOMEM; | |
3326 | ||
5b058bcd | 3327 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
3328 | for_each_online_cpu(cpu) { |
3329 | if (!idle_task(cpu)->ret_stack) | |
868baf07 | 3330 | ftrace_graph_init_idle_task(idle_task(cpu), cpu); |
179c498a | 3331 | } |
5b058bcd | 3332 | |
f201ae23 FW |
3333 | do { |
3334 | ret = alloc_retstack_tasklist(ret_stack_list); | |
3335 | } while (ret == -EAGAIN); | |
3336 | ||
8aef2d28 | 3337 | if (!ret) { |
38516ab5 | 3338 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
8aef2d28 SR |
3339 | if (ret) |
3340 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
3341 | " probe to kernel_sched_switch\n"); | |
3342 | } | |
3343 | ||
f201ae23 FW |
3344 | kfree(ret_stack_list); |
3345 | return ret; | |
3346 | } | |
3347 | ||
4a2b8dda FW |
3348 | /* |
3349 | * Hibernation protection. | |
3350 | * The state of the current task is too much unstable during | |
3351 | * suspend/restore to disk. We want to protect against that. | |
3352 | */ | |
3353 | static int | |
3354 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
3355 | void *unused) | |
3356 | { | |
3357 | switch (state) { | |
3358 | case PM_HIBERNATION_PREPARE: | |
3359 | pause_graph_tracing(); | |
3360 | break; | |
3361 | ||
3362 | case PM_POST_HIBERNATION: | |
3363 | unpause_graph_tracing(); | |
3364 | break; | |
3365 | } | |
3366 | return NOTIFY_DONE; | |
3367 | } | |
3368 | ||
287b6e68 FW |
3369 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
3370 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 3371 | { |
e7d3737e FW |
3372 | int ret = 0; |
3373 | ||
e6ea44e9 | 3374 | mutex_lock(&ftrace_lock); |
e7d3737e | 3375 | |
05ce5818 | 3376 | /* we currently allow only one tracer registered at a time */ |
597af815 | 3377 | if (ftrace_graph_active) { |
05ce5818 SR |
3378 | ret = -EBUSY; |
3379 | goto out; | |
3380 | } | |
3381 | ||
4a2b8dda FW |
3382 | ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; |
3383 | register_pm_notifier(&ftrace_suspend_notifier); | |
3384 | ||
597af815 | 3385 | ftrace_graph_active++; |
fb52607a | 3386 | ret = start_graph_tracing(); |
f201ae23 | 3387 | if (ret) { |
597af815 | 3388 | ftrace_graph_active--; |
f201ae23 FW |
3389 | goto out; |
3390 | } | |
e53a6319 | 3391 | |
287b6e68 FW |
3392 | ftrace_graph_return = retfunc; |
3393 | ftrace_graph_entry = entryfunc; | |
e53a6319 | 3394 | |
5a45cfe1 | 3395 | ftrace_startup(FTRACE_START_FUNC_RET); |
e7d3737e FW |
3396 | |
3397 | out: | |
e6ea44e9 | 3398 | mutex_unlock(&ftrace_lock); |
e7d3737e | 3399 | return ret; |
15e6cb36 FW |
3400 | } |
3401 | ||
fb52607a | 3402 | void unregister_ftrace_graph(void) |
15e6cb36 | 3403 | { |
e6ea44e9 | 3404 | mutex_lock(&ftrace_lock); |
e7d3737e | 3405 | |
597af815 | 3406 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
3407 | goto out; |
3408 | ||
597af815 | 3409 | ftrace_graph_active--; |
287b6e68 | 3410 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 3411 | ftrace_graph_entry = ftrace_graph_entry_stub; |
5a45cfe1 | 3412 | ftrace_shutdown(FTRACE_STOP_FUNC_RET); |
4a2b8dda | 3413 | unregister_pm_notifier(&ftrace_suspend_notifier); |
38516ab5 | 3414 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
e7d3737e | 3415 | |
2aad1b76 | 3416 | out: |
e6ea44e9 | 3417 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 3418 | } |
f201ae23 | 3419 | |
868baf07 SR |
3420 | static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack); |
3421 | ||
3422 | static void | |
3423 | graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack) | |
3424 | { | |
3425 | atomic_set(&t->tracing_graph_pause, 0); | |
3426 | atomic_set(&t->trace_overrun, 0); | |
3427 | t->ftrace_timestamp = 0; | |
25985edc | 3428 | /* make curr_ret_stack visible before we add the ret_stack */ |
868baf07 SR |
3429 | smp_wmb(); |
3430 | t->ret_stack = ret_stack; | |
3431 | } | |
3432 | ||
3433 | /* | |
3434 | * Allocate a return stack for the idle task. May be the first | |
3435 | * time through, or it may be done by CPU hotplug online. | |
3436 | */ | |
3437 | void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) | |
3438 | { | |
3439 | t->curr_ret_stack = -1; | |
3440 | /* | |
3441 | * The idle task has no parent, it either has its own | |
3442 | * stack or no stack at all. | |
3443 | */ | |
3444 | if (t->ret_stack) | |
3445 | WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu)); | |
3446 | ||
3447 | if (ftrace_graph_active) { | |
3448 | struct ftrace_ret_stack *ret_stack; | |
3449 | ||
3450 | ret_stack = per_cpu(idle_ret_stack, cpu); | |
3451 | if (!ret_stack) { | |
3452 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
3453 | * sizeof(struct ftrace_ret_stack), | |
3454 | GFP_KERNEL); | |
3455 | if (!ret_stack) | |
3456 | return; | |
3457 | per_cpu(idle_ret_stack, cpu) = ret_stack; | |
3458 | } | |
3459 | graph_init_task(t, ret_stack); | |
3460 | } | |
3461 | } | |
3462 | ||
f201ae23 | 3463 | /* Allocate a return stack for newly created task */ |
fb52607a | 3464 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 3465 | { |
84047e36 SR |
3466 | /* Make sure we do not use the parent ret_stack */ |
3467 | t->ret_stack = NULL; | |
ea14eb71 | 3468 | t->curr_ret_stack = -1; |
84047e36 | 3469 | |
597af815 | 3470 | if (ftrace_graph_active) { |
82310a32 SR |
3471 | struct ftrace_ret_stack *ret_stack; |
3472 | ||
3473 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
3474 | * sizeof(struct ftrace_ret_stack), |
3475 | GFP_KERNEL); | |
82310a32 | 3476 | if (!ret_stack) |
f201ae23 | 3477 | return; |
868baf07 | 3478 | graph_init_task(t, ret_stack); |
84047e36 | 3479 | } |
f201ae23 FW |
3480 | } |
3481 | ||
fb52607a | 3482 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 3483 | { |
eae849ca FW |
3484 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
3485 | ||
f201ae23 | 3486 | t->ret_stack = NULL; |
eae849ca FW |
3487 | /* NULL must become visible to IRQs before we free it: */ |
3488 | barrier(); | |
3489 | ||
3490 | kfree(ret_stack); | |
f201ae23 | 3491 | } |
14a866c5 SR |
3492 | |
3493 | void ftrace_graph_stop(void) | |
3494 | { | |
3495 | ftrace_stop(); | |
3496 | } | |
15e6cb36 | 3497 | #endif |