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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 SR |
19 | #include <linux/seq_file.h> |
20 | #include <linux/debugfs.h> | |
3d083395 | 21 | #include <linux/hardirq.h> |
2d8b820b | 22 | #include <linux/kthread.h> |
5072c59f | 23 | #include <linux/uaccess.h> |
f22f9a89 | 24 | #include <linux/kprobes.h> |
2d8b820b | 25 | #include <linux/ftrace.h> |
b0fc494f | 26 | #include <linux/sysctl.h> |
5072c59f | 27 | #include <linux/ctype.h> |
3d083395 SR |
28 | #include <linux/list.h> |
29 | ||
395a59d0 AS |
30 | #include <asm/ftrace.h> |
31 | ||
3d083395 | 32 | #include "trace.h" |
16444a8a | 33 | |
6912896e SR |
34 | #define FTRACE_WARN_ON(cond) \ |
35 | do { \ | |
36 | if (WARN_ON(cond)) \ | |
37 | ftrace_kill(); \ | |
38 | } while (0) | |
39 | ||
40 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
41 | do { \ | |
42 | if (WARN_ON_ONCE(cond)) \ | |
43 | ftrace_kill(); \ | |
44 | } while (0) | |
45 | ||
4eebcc81 SR |
46 | /* ftrace_enabled is a method to turn ftrace on or off */ |
47 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 48 | static int last_ftrace_enabled; |
b0fc494f | 49 | |
4eebcc81 SR |
50 | /* |
51 | * ftrace_disabled is set when an anomaly is discovered. | |
52 | * ftrace_disabled is much stronger than ftrace_enabled. | |
53 | */ | |
54 | static int ftrace_disabled __read_mostly; | |
55 | ||
3d083395 | 56 | static DEFINE_SPINLOCK(ftrace_lock); |
b0fc494f SR |
57 | static DEFINE_MUTEX(ftrace_sysctl_lock); |
58 | ||
16444a8a ACM |
59 | static struct ftrace_ops ftrace_list_end __read_mostly = |
60 | { | |
61 | .func = ftrace_stub, | |
62 | }; | |
63 | ||
64 | static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; | |
65 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; | |
66 | ||
f2252935 | 67 | static void ftrace_list_func(unsigned long ip, unsigned long parent_ip) |
16444a8a ACM |
68 | { |
69 | struct ftrace_ops *op = ftrace_list; | |
70 | ||
71 | /* in case someone actually ports this to alpha! */ | |
72 | read_barrier_depends(); | |
73 | ||
74 | while (op != &ftrace_list_end) { | |
75 | /* silly alpha */ | |
76 | read_barrier_depends(); | |
77 | op->func(ip, parent_ip); | |
78 | op = op->next; | |
79 | }; | |
80 | } | |
81 | ||
82 | /** | |
3d083395 | 83 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 84 | * |
3d083395 SR |
85 | * This NULLs the ftrace function and in essence stops |
86 | * tracing. There may be lag | |
16444a8a | 87 | */ |
3d083395 | 88 | void clear_ftrace_function(void) |
16444a8a | 89 | { |
3d083395 SR |
90 | ftrace_trace_function = ftrace_stub; |
91 | } | |
92 | ||
e309b41d | 93 | static int __register_ftrace_function(struct ftrace_ops *ops) |
3d083395 | 94 | { |
99ecdc43 | 95 | /* should not be called from interrupt context */ |
3d083395 | 96 | spin_lock(&ftrace_lock); |
16444a8a | 97 | |
16444a8a ACM |
98 | ops->next = ftrace_list; |
99 | /* | |
100 | * We are entering ops into the ftrace_list but another | |
101 | * CPU might be walking that list. We need to make sure | |
102 | * the ops->next pointer is valid before another CPU sees | |
103 | * the ops pointer included into the ftrace_list. | |
104 | */ | |
105 | smp_wmb(); | |
106 | ftrace_list = ops; | |
3d083395 | 107 | |
b0fc494f SR |
108 | if (ftrace_enabled) { |
109 | /* | |
110 | * For one func, simply call it directly. | |
111 | * For more than one func, call the chain. | |
112 | */ | |
113 | if (ops->next == &ftrace_list_end) | |
114 | ftrace_trace_function = ops->func; | |
115 | else | |
116 | ftrace_trace_function = ftrace_list_func; | |
117 | } | |
3d083395 SR |
118 | |
119 | spin_unlock(&ftrace_lock); | |
16444a8a ACM |
120 | |
121 | return 0; | |
122 | } | |
123 | ||
e309b41d | 124 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 125 | { |
16444a8a ACM |
126 | struct ftrace_ops **p; |
127 | int ret = 0; | |
128 | ||
99ecdc43 | 129 | /* should not be called from interrupt context */ |
3d083395 | 130 | spin_lock(&ftrace_lock); |
16444a8a ACM |
131 | |
132 | /* | |
3d083395 SR |
133 | * If we are removing the last function, then simply point |
134 | * to the ftrace_stub. | |
16444a8a ACM |
135 | */ |
136 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { | |
137 | ftrace_trace_function = ftrace_stub; | |
138 | ftrace_list = &ftrace_list_end; | |
139 | goto out; | |
140 | } | |
141 | ||
142 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) | |
143 | if (*p == ops) | |
144 | break; | |
145 | ||
146 | if (*p != ops) { | |
147 | ret = -1; | |
148 | goto out; | |
149 | } | |
150 | ||
151 | *p = (*p)->next; | |
152 | ||
b0fc494f SR |
153 | if (ftrace_enabled) { |
154 | /* If we only have one func left, then call that directly */ | |
155 | if (ftrace_list == &ftrace_list_end || | |
156 | ftrace_list->next == &ftrace_list_end) | |
157 | ftrace_trace_function = ftrace_list->func; | |
158 | } | |
16444a8a ACM |
159 | |
160 | out: | |
3d083395 SR |
161 | spin_unlock(&ftrace_lock); |
162 | ||
163 | return ret; | |
164 | } | |
165 | ||
166 | #ifdef CONFIG_DYNAMIC_FTRACE | |
99ecdc43 | 167 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
cb7be3b2 | 168 | # error Dynamic ftrace depends on MCOUNT_RECORD |
99ecdc43 SR |
169 | #endif |
170 | ||
71c67d58 SN |
171 | /* |
172 | * Since MCOUNT_ADDR may point to mcount itself, we do not want | |
173 | * to get it confused by reading a reference in the code as we | |
174 | * are parsing on objcopy output of text. Use a variable for | |
175 | * it instead. | |
176 | */ | |
177 | static unsigned long mcount_addr = MCOUNT_ADDR; | |
178 | ||
d61f82d0 SR |
179 | enum { |
180 | FTRACE_ENABLE_CALLS = (1 << 0), | |
181 | FTRACE_DISABLE_CALLS = (1 << 1), | |
182 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
183 | FTRACE_ENABLE_MCOUNT = (1 << 3), | |
184 | FTRACE_DISABLE_MCOUNT = (1 << 4), | |
185 | }; | |
186 | ||
5072c59f SR |
187 | static int ftrace_filtered; |
188 | ||
08f5ac90 | 189 | static LIST_HEAD(ftrace_new_addrs); |
3d083395 | 190 | |
41c52c0d | 191 | static DEFINE_MUTEX(ftrace_regex_lock); |
3d083395 | 192 | |
3c1720f0 SR |
193 | struct ftrace_page { |
194 | struct ftrace_page *next; | |
aa5e5cea | 195 | unsigned long index; |
3c1720f0 | 196 | struct dyn_ftrace records[]; |
aa5e5cea | 197 | }; |
3c1720f0 SR |
198 | |
199 | #define ENTRIES_PER_PAGE \ | |
200 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
201 | ||
202 | /* estimate from running different kernels */ | |
203 | #define NR_TO_INIT 10000 | |
204 | ||
205 | static struct ftrace_page *ftrace_pages_start; | |
206 | static struct ftrace_page *ftrace_pages; | |
207 | ||
37ad5084 SR |
208 | static struct dyn_ftrace *ftrace_free_records; |
209 | ||
ecea656d AS |
210 | |
211 | #ifdef CONFIG_KPROBES | |
f17845e5 IM |
212 | |
213 | static int frozen_record_count; | |
214 | ||
ecea656d AS |
215 | static inline void freeze_record(struct dyn_ftrace *rec) |
216 | { | |
217 | if (!(rec->flags & FTRACE_FL_FROZEN)) { | |
218 | rec->flags |= FTRACE_FL_FROZEN; | |
219 | frozen_record_count++; | |
220 | } | |
221 | } | |
222 | ||
223 | static inline void unfreeze_record(struct dyn_ftrace *rec) | |
224 | { | |
225 | if (rec->flags & FTRACE_FL_FROZEN) { | |
226 | rec->flags &= ~FTRACE_FL_FROZEN; | |
227 | frozen_record_count--; | |
228 | } | |
229 | } | |
230 | ||
231 | static inline int record_frozen(struct dyn_ftrace *rec) | |
232 | { | |
233 | return rec->flags & FTRACE_FL_FROZEN; | |
234 | } | |
235 | #else | |
236 | # define freeze_record(rec) ({ 0; }) | |
237 | # define unfreeze_record(rec) ({ 0; }) | |
238 | # define record_frozen(rec) ({ 0; }) | |
239 | #endif /* CONFIG_KPROBES */ | |
240 | ||
e309b41d | 241 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
37ad5084 | 242 | { |
37ad5084 SR |
243 | rec->ip = (unsigned long)ftrace_free_records; |
244 | ftrace_free_records = rec; | |
245 | rec->flags |= FTRACE_FL_FREE; | |
246 | } | |
247 | ||
fed1939c SR |
248 | void ftrace_release(void *start, unsigned long size) |
249 | { | |
250 | struct dyn_ftrace *rec; | |
251 | struct ftrace_page *pg; | |
252 | unsigned long s = (unsigned long)start; | |
253 | unsigned long e = s + size; | |
254 | int i; | |
255 | ||
00fd61ae | 256 | if (ftrace_disabled || !start) |
fed1939c SR |
257 | return; |
258 | ||
99ecdc43 | 259 | /* should not be called from interrupt context */ |
fed1939c SR |
260 | spin_lock(&ftrace_lock); |
261 | ||
262 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
263 | for (i = 0; i < pg->index; i++) { | |
264 | rec = &pg->records[i]; | |
265 | ||
266 | if ((rec->ip >= s) && (rec->ip < e)) | |
267 | ftrace_free_rec(rec); | |
268 | } | |
269 | } | |
270 | spin_unlock(&ftrace_lock); | |
fed1939c SR |
271 | } |
272 | ||
e309b41d | 273 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 274 | { |
37ad5084 SR |
275 | struct dyn_ftrace *rec; |
276 | ||
277 | /* First check for freed records */ | |
278 | if (ftrace_free_records) { | |
279 | rec = ftrace_free_records; | |
280 | ||
37ad5084 | 281 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
6912896e | 282 | FTRACE_WARN_ON_ONCE(1); |
37ad5084 SR |
283 | ftrace_free_records = NULL; |
284 | return NULL; | |
285 | } | |
286 | ||
287 | ftrace_free_records = (void *)rec->ip; | |
288 | memset(rec, 0, sizeof(*rec)); | |
289 | return rec; | |
290 | } | |
291 | ||
3c1720f0 | 292 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
08f5ac90 SR |
293 | if (!ftrace_pages->next) { |
294 | /* allocate another page */ | |
295 | ftrace_pages->next = | |
296 | (void *)get_zeroed_page(GFP_KERNEL); | |
297 | if (!ftrace_pages->next) | |
298 | return NULL; | |
299 | } | |
3c1720f0 SR |
300 | ftrace_pages = ftrace_pages->next; |
301 | } | |
302 | ||
303 | return &ftrace_pages->records[ftrace_pages->index++]; | |
304 | } | |
305 | ||
08f5ac90 | 306 | static struct dyn_ftrace * |
d61f82d0 | 307 | ftrace_record_ip(unsigned long ip) |
3d083395 | 308 | { |
08f5ac90 | 309 | struct dyn_ftrace *rec; |
3d083395 | 310 | |
4eebcc81 | 311 | if (!ftrace_enabled || ftrace_disabled) |
08f5ac90 | 312 | return NULL; |
3d083395 | 313 | |
08f5ac90 SR |
314 | rec = ftrace_alloc_dyn_node(ip); |
315 | if (!rec) | |
316 | return NULL; | |
3d083395 | 317 | |
08f5ac90 | 318 | rec->ip = ip; |
3d083395 | 319 | |
08f5ac90 | 320 | list_add(&rec->list, &ftrace_new_addrs); |
3d083395 | 321 | |
08f5ac90 | 322 | return rec; |
3d083395 SR |
323 | } |
324 | ||
caf8cdeb | 325 | #define FTRACE_ADDR ((long)(ftrace_caller)) |
3c1720f0 | 326 | |
0eb96701 | 327 | static int |
5072c59f SR |
328 | __ftrace_replace_code(struct dyn_ftrace *rec, |
329 | unsigned char *old, unsigned char *new, int enable) | |
330 | { | |
41c52c0d | 331 | unsigned long ip, fl; |
5072c59f SR |
332 | |
333 | ip = rec->ip; | |
334 | ||
335 | if (ftrace_filtered && enable) { | |
5072c59f SR |
336 | /* |
337 | * If filtering is on: | |
338 | * | |
339 | * If this record is set to be filtered and | |
340 | * is enabled then do nothing. | |
341 | * | |
342 | * If this record is set to be filtered and | |
343 | * it is not enabled, enable it. | |
344 | * | |
345 | * If this record is not set to be filtered | |
346 | * and it is not enabled do nothing. | |
347 | * | |
41c52c0d SR |
348 | * If this record is set not to trace then |
349 | * do nothing. | |
350 | * | |
a4500b84 AS |
351 | * If this record is set not to trace and |
352 | * it is enabled then disable it. | |
353 | * | |
5072c59f SR |
354 | * If this record is not set to be filtered and |
355 | * it is enabled, disable it. | |
356 | */ | |
a4500b84 AS |
357 | |
358 | fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE | | |
359 | FTRACE_FL_ENABLED); | |
5072c59f SR |
360 | |
361 | if ((fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) || | |
a4500b84 AS |
362 | (fl == (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE)) || |
363 | !fl || (fl == FTRACE_FL_NOTRACE)) | |
0eb96701 | 364 | return 0; |
5072c59f SR |
365 | |
366 | /* | |
367 | * If it is enabled disable it, | |
368 | * otherwise enable it! | |
369 | */ | |
a4500b84 | 370 | if (fl & FTRACE_FL_ENABLED) { |
5072c59f SR |
371 | /* swap new and old */ |
372 | new = old; | |
373 | old = ftrace_call_replace(ip, FTRACE_ADDR); | |
374 | rec->flags &= ~FTRACE_FL_ENABLED; | |
375 | } else { | |
376 | new = ftrace_call_replace(ip, FTRACE_ADDR); | |
377 | rec->flags |= FTRACE_FL_ENABLED; | |
378 | } | |
379 | } else { | |
380 | ||
41c52c0d SR |
381 | if (enable) { |
382 | /* | |
383 | * If this record is set not to trace and is | |
384 | * not enabled, do nothing. | |
385 | */ | |
386 | fl = rec->flags & (FTRACE_FL_NOTRACE | FTRACE_FL_ENABLED); | |
387 | if (fl == FTRACE_FL_NOTRACE) | |
0eb96701 | 388 | return 0; |
41c52c0d | 389 | |
5072c59f | 390 | new = ftrace_call_replace(ip, FTRACE_ADDR); |
41c52c0d | 391 | } else |
5072c59f SR |
392 | old = ftrace_call_replace(ip, FTRACE_ADDR); |
393 | ||
394 | if (enable) { | |
395 | if (rec->flags & FTRACE_FL_ENABLED) | |
0eb96701 | 396 | return 0; |
5072c59f SR |
397 | rec->flags |= FTRACE_FL_ENABLED; |
398 | } else { | |
399 | if (!(rec->flags & FTRACE_FL_ENABLED)) | |
0eb96701 | 400 | return 0; |
5072c59f SR |
401 | rec->flags &= ~FTRACE_FL_ENABLED; |
402 | } | |
403 | } | |
404 | ||
0eb96701 | 405 | return ftrace_modify_code(ip, old, new); |
5072c59f SR |
406 | } |
407 | ||
e309b41d | 408 | static void ftrace_replace_code(int enable) |
3c1720f0 | 409 | { |
0eb96701 | 410 | int i, failed; |
3c1720f0 SR |
411 | unsigned char *new = NULL, *old = NULL; |
412 | struct dyn_ftrace *rec; | |
413 | struct ftrace_page *pg; | |
3c1720f0 | 414 | |
5072c59f | 415 | if (enable) |
3c1720f0 SR |
416 | old = ftrace_nop_replace(); |
417 | else | |
418 | new = ftrace_nop_replace(); | |
419 | ||
420 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
421 | for (i = 0; i < pg->index; i++) { | |
422 | rec = &pg->records[i]; | |
423 | ||
424 | /* don't modify code that has already faulted */ | |
425 | if (rec->flags & FTRACE_FL_FAILED) | |
426 | continue; | |
427 | ||
f22f9a89 | 428 | /* ignore updates to this record's mcount site */ |
98a05ed4 AS |
429 | if (get_kprobe((void *)rec->ip)) { |
430 | freeze_record(rec); | |
f22f9a89 | 431 | continue; |
98a05ed4 AS |
432 | } else { |
433 | unfreeze_record(rec); | |
434 | } | |
f22f9a89 | 435 | |
0eb96701 AS |
436 | failed = __ftrace_replace_code(rec, old, new, enable); |
437 | if (failed && (rec->flags & FTRACE_FL_CONVERTED)) { | |
438 | rec->flags |= FTRACE_FL_FAILED; | |
439 | if ((system_state == SYSTEM_BOOTING) || | |
34078a5e | 440 | !core_kernel_text(rec->ip)) { |
0eb96701 AS |
441 | ftrace_free_rec(rec); |
442 | } | |
443 | } | |
3c1720f0 SR |
444 | } |
445 | } | |
446 | } | |
447 | ||
05736a42 SR |
448 | static void print_ip_ins(const char *fmt, unsigned char *p) |
449 | { | |
450 | int i; | |
451 | ||
452 | printk(KERN_CONT "%s", fmt); | |
453 | ||
454 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
455 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
456 | } | |
457 | ||
492a7ea5 | 458 | static int |
d61f82d0 | 459 | ftrace_code_disable(struct dyn_ftrace *rec) |
3c1720f0 SR |
460 | { |
461 | unsigned long ip; | |
462 | unsigned char *nop, *call; | |
593eb8a2 | 463 | int ret; |
3c1720f0 SR |
464 | |
465 | ip = rec->ip; | |
466 | ||
467 | nop = ftrace_nop_replace(); | |
3b47bfc1 | 468 | call = ftrace_call_replace(ip, mcount_addr); |
3c1720f0 | 469 | |
593eb8a2 SR |
470 | ret = ftrace_modify_code(ip, call, nop); |
471 | if (ret) { | |
472 | switch (ret) { | |
473 | case -EFAULT: | |
6912896e | 474 | FTRACE_WARN_ON_ONCE(1); |
05736a42 SR |
475 | pr_info("ftrace faulted on modifying "); |
476 | print_ip_sym(ip); | |
477 | break; | |
593eb8a2 | 478 | case -EINVAL: |
6912896e | 479 | FTRACE_WARN_ON_ONCE(1); |
05736a42 SR |
480 | pr_info("ftrace failed to modify "); |
481 | print_ip_sym(ip); | |
482 | print_ip_ins(" expected: ", call); | |
483 | print_ip_ins(" actual: ", (unsigned char *)ip); | |
484 | print_ip_ins(" replace: ", nop); | |
485 | printk(KERN_CONT "\n"); | |
486 | break; | |
593eb8a2 | 487 | case -EPERM: |
6912896e | 488 | FTRACE_WARN_ON_ONCE(1); |
593eb8a2 SR |
489 | pr_info("ftrace faulted on writing "); |
490 | print_ip_sym(ip); | |
491 | break; | |
492 | default: | |
6912896e | 493 | FTRACE_WARN_ON_ONCE(1); |
593eb8a2 SR |
494 | pr_info("ftrace faulted on unknown error "); |
495 | print_ip_sym(ip); | |
05736a42 SR |
496 | } |
497 | ||
3c1720f0 | 498 | rec->flags |= FTRACE_FL_FAILED; |
492a7ea5 | 499 | return 0; |
37ad5084 | 500 | } |
492a7ea5 | 501 | return 1; |
3c1720f0 SR |
502 | } |
503 | ||
e309b41d | 504 | static int __ftrace_modify_code(void *data) |
3d083395 | 505 | { |
d61f82d0 SR |
506 | int *command = data; |
507 | ||
a3583244 | 508 | if (*command & FTRACE_ENABLE_CALLS) |
d61f82d0 | 509 | ftrace_replace_code(1); |
a3583244 | 510 | else if (*command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
511 | ftrace_replace_code(0); |
512 | ||
513 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
514 | ftrace_update_ftrace_func(ftrace_trace_function); | |
515 | ||
d61f82d0 | 516 | return 0; |
3d083395 SR |
517 | } |
518 | ||
e309b41d | 519 | static void ftrace_run_update_code(int command) |
3d083395 | 520 | { |
784e2d76 | 521 | stop_machine(__ftrace_modify_code, &command, NULL); |
3d083395 SR |
522 | } |
523 | ||
d61f82d0 | 524 | static ftrace_func_t saved_ftrace_func; |
cb7be3b2 SR |
525 | static int ftrace_start; |
526 | static DEFINE_MUTEX(ftrace_start_lock); | |
d61f82d0 | 527 | |
e309b41d | 528 | static void ftrace_startup(void) |
3d083395 | 529 | { |
d61f82d0 SR |
530 | int command = 0; |
531 | ||
4eebcc81 SR |
532 | if (unlikely(ftrace_disabled)) |
533 | return; | |
534 | ||
cb7be3b2 SR |
535 | mutex_lock(&ftrace_start_lock); |
536 | ftrace_start++; | |
537 | if (ftrace_start == 1) | |
d61f82d0 SR |
538 | command |= FTRACE_ENABLE_CALLS; |
539 | ||
540 | if (saved_ftrace_func != ftrace_trace_function) { | |
541 | saved_ftrace_func = ftrace_trace_function; | |
542 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
543 | } | |
544 | ||
545 | if (!command || !ftrace_enabled) | |
3d083395 | 546 | goto out; |
3d083395 | 547 | |
d61f82d0 | 548 | ftrace_run_update_code(command); |
3d083395 | 549 | out: |
cb7be3b2 | 550 | mutex_unlock(&ftrace_start_lock); |
3d083395 SR |
551 | } |
552 | ||
e309b41d | 553 | static void ftrace_shutdown(void) |
3d083395 | 554 | { |
d61f82d0 SR |
555 | int command = 0; |
556 | ||
4eebcc81 SR |
557 | if (unlikely(ftrace_disabled)) |
558 | return; | |
559 | ||
cb7be3b2 SR |
560 | mutex_lock(&ftrace_start_lock); |
561 | ftrace_start--; | |
562 | if (!ftrace_start) | |
d61f82d0 | 563 | command |= FTRACE_DISABLE_CALLS; |
3d083395 | 564 | |
d61f82d0 SR |
565 | if (saved_ftrace_func != ftrace_trace_function) { |
566 | saved_ftrace_func = ftrace_trace_function; | |
567 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
568 | } | |
3d083395 | 569 | |
d61f82d0 SR |
570 | if (!command || !ftrace_enabled) |
571 | goto out; | |
572 | ||
573 | ftrace_run_update_code(command); | |
3d083395 | 574 | out: |
cb7be3b2 | 575 | mutex_unlock(&ftrace_start_lock); |
3d083395 SR |
576 | } |
577 | ||
e309b41d | 578 | static void ftrace_startup_sysctl(void) |
b0fc494f | 579 | { |
d61f82d0 SR |
580 | int command = FTRACE_ENABLE_MCOUNT; |
581 | ||
4eebcc81 SR |
582 | if (unlikely(ftrace_disabled)) |
583 | return; | |
584 | ||
cb7be3b2 | 585 | mutex_lock(&ftrace_start_lock); |
d61f82d0 SR |
586 | /* Force update next time */ |
587 | saved_ftrace_func = NULL; | |
cb7be3b2 SR |
588 | /* ftrace_start is true if we want ftrace running */ |
589 | if (ftrace_start) | |
d61f82d0 SR |
590 | command |= FTRACE_ENABLE_CALLS; |
591 | ||
592 | ftrace_run_update_code(command); | |
cb7be3b2 | 593 | mutex_unlock(&ftrace_start_lock); |
b0fc494f SR |
594 | } |
595 | ||
e309b41d | 596 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 597 | { |
d61f82d0 SR |
598 | int command = FTRACE_DISABLE_MCOUNT; |
599 | ||
4eebcc81 SR |
600 | if (unlikely(ftrace_disabled)) |
601 | return; | |
602 | ||
cb7be3b2 SR |
603 | mutex_lock(&ftrace_start_lock); |
604 | /* ftrace_start is true if ftrace is running */ | |
605 | if (ftrace_start) | |
d61f82d0 SR |
606 | command |= FTRACE_DISABLE_CALLS; |
607 | ||
608 | ftrace_run_update_code(command); | |
cb7be3b2 | 609 | mutex_unlock(&ftrace_start_lock); |
b0fc494f SR |
610 | } |
611 | ||
3d083395 SR |
612 | static cycle_t ftrace_update_time; |
613 | static unsigned long ftrace_update_cnt; | |
614 | unsigned long ftrace_update_tot_cnt; | |
615 | ||
08f5ac90 | 616 | static int ftrace_update_code(void) |
3d083395 | 617 | { |
08f5ac90 | 618 | struct dyn_ftrace *p, *t; |
f22f9a89 | 619 | cycle_t start, stop; |
3d083395 | 620 | |
750ed1a4 | 621 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
622 | ftrace_update_cnt = 0; |
623 | ||
08f5ac90 | 624 | list_for_each_entry_safe(p, t, &ftrace_new_addrs, list) { |
3d083395 | 625 | |
08f5ac90 SR |
626 | /* If something went wrong, bail without enabling anything */ |
627 | if (unlikely(ftrace_disabled)) | |
628 | return -1; | |
f22f9a89 | 629 | |
08f5ac90 | 630 | list_del_init(&p->list); |
f22f9a89 | 631 | |
08f5ac90 SR |
632 | /* convert record (i.e, patch mcount-call with NOP) */ |
633 | if (ftrace_code_disable(p)) { | |
634 | p->flags |= FTRACE_FL_CONVERTED; | |
635 | ftrace_update_cnt++; | |
636 | } else | |
637 | ftrace_free_rec(p); | |
3d083395 SR |
638 | } |
639 | ||
750ed1a4 | 640 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
641 | ftrace_update_time = stop - start; |
642 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
643 | ||
16444a8a ACM |
644 | return 0; |
645 | } | |
646 | ||
68bf21aa | 647 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
648 | { |
649 | struct ftrace_page *pg; | |
650 | int cnt; | |
651 | int i; | |
3c1720f0 SR |
652 | |
653 | /* allocate a few pages */ | |
654 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
655 | if (!ftrace_pages_start) | |
656 | return -1; | |
657 | ||
658 | /* | |
659 | * Allocate a few more pages. | |
660 | * | |
661 | * TODO: have some parser search vmlinux before | |
662 | * final linking to find all calls to ftrace. | |
663 | * Then we can: | |
664 | * a) know how many pages to allocate. | |
665 | * and/or | |
666 | * b) set up the table then. | |
667 | * | |
668 | * The dynamic code is still necessary for | |
669 | * modules. | |
670 | */ | |
671 | ||
672 | pg = ftrace_pages = ftrace_pages_start; | |
673 | ||
68bf21aa | 674 | cnt = num_to_init / ENTRIES_PER_PAGE; |
08f5ac90 | 675 | pr_info("ftrace: allocating %ld entries in %d pages\n", |
68bf21aa | 676 | num_to_init, cnt); |
3c1720f0 SR |
677 | |
678 | for (i = 0; i < cnt; i++) { | |
679 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
680 | ||
681 | /* If we fail, we'll try later anyway */ | |
682 | if (!pg->next) | |
683 | break; | |
684 | ||
685 | pg = pg->next; | |
686 | } | |
687 | ||
688 | return 0; | |
689 | } | |
690 | ||
5072c59f SR |
691 | enum { |
692 | FTRACE_ITER_FILTER = (1 << 0), | |
693 | FTRACE_ITER_CONT = (1 << 1), | |
41c52c0d | 694 | FTRACE_ITER_NOTRACE = (1 << 2), |
eb9a7bf0 | 695 | FTRACE_ITER_FAILURES = (1 << 3), |
5072c59f SR |
696 | }; |
697 | ||
698 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
699 | ||
700 | struct ftrace_iterator { | |
701 | loff_t pos; | |
702 | struct ftrace_page *pg; | |
703 | unsigned idx; | |
704 | unsigned flags; | |
705 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
706 | unsigned buffer_idx; | |
707 | unsigned filtered; | |
708 | }; | |
709 | ||
e309b41d | 710 | static void * |
5072c59f SR |
711 | t_next(struct seq_file *m, void *v, loff_t *pos) |
712 | { | |
713 | struct ftrace_iterator *iter = m->private; | |
714 | struct dyn_ftrace *rec = NULL; | |
715 | ||
716 | (*pos)++; | |
717 | ||
99ecdc43 SR |
718 | /* should not be called from interrupt context */ |
719 | spin_lock(&ftrace_lock); | |
5072c59f SR |
720 | retry: |
721 | if (iter->idx >= iter->pg->index) { | |
722 | if (iter->pg->next) { | |
723 | iter->pg = iter->pg->next; | |
724 | iter->idx = 0; | |
725 | goto retry; | |
726 | } | |
727 | } else { | |
728 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
729 | if ((rec->flags & FTRACE_FL_FREE) || |
730 | ||
731 | (!(iter->flags & FTRACE_ITER_FAILURES) && | |
eb9a7bf0 AS |
732 | (rec->flags & FTRACE_FL_FAILED)) || |
733 | ||
734 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
a9fdda33 | 735 | !(rec->flags & FTRACE_FL_FAILED)) || |
eb9a7bf0 | 736 | |
41c52c0d SR |
737 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
738 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
739 | rec = NULL; |
740 | goto retry; | |
741 | } | |
742 | } | |
99ecdc43 | 743 | spin_unlock(&ftrace_lock); |
5072c59f SR |
744 | |
745 | iter->pos = *pos; | |
746 | ||
747 | return rec; | |
748 | } | |
749 | ||
750 | static void *t_start(struct seq_file *m, loff_t *pos) | |
751 | { | |
752 | struct ftrace_iterator *iter = m->private; | |
753 | void *p = NULL; | |
754 | loff_t l = -1; | |
755 | ||
756 | if (*pos != iter->pos) { | |
757 | for (p = t_next(m, p, &l); p && l < *pos; p = t_next(m, p, &l)) | |
758 | ; | |
759 | } else { | |
760 | l = *pos; | |
761 | p = t_next(m, p, &l); | |
762 | } | |
763 | ||
764 | return p; | |
765 | } | |
766 | ||
767 | static void t_stop(struct seq_file *m, void *p) | |
768 | { | |
769 | } | |
770 | ||
771 | static int t_show(struct seq_file *m, void *v) | |
772 | { | |
773 | struct dyn_ftrace *rec = v; | |
774 | char str[KSYM_SYMBOL_LEN]; | |
775 | ||
776 | if (!rec) | |
777 | return 0; | |
778 | ||
779 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
780 | ||
781 | seq_printf(m, "%s\n", str); | |
782 | ||
783 | return 0; | |
784 | } | |
785 | ||
786 | static struct seq_operations show_ftrace_seq_ops = { | |
787 | .start = t_start, | |
788 | .next = t_next, | |
789 | .stop = t_stop, | |
790 | .show = t_show, | |
791 | }; | |
792 | ||
e309b41d | 793 | static int |
5072c59f SR |
794 | ftrace_avail_open(struct inode *inode, struct file *file) |
795 | { | |
796 | struct ftrace_iterator *iter; | |
797 | int ret; | |
798 | ||
4eebcc81 SR |
799 | if (unlikely(ftrace_disabled)) |
800 | return -ENODEV; | |
801 | ||
5072c59f SR |
802 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
803 | if (!iter) | |
804 | return -ENOMEM; | |
805 | ||
806 | iter->pg = ftrace_pages_start; | |
807 | iter->pos = -1; | |
808 | ||
809 | ret = seq_open(file, &show_ftrace_seq_ops); | |
810 | if (!ret) { | |
811 | struct seq_file *m = file->private_data; | |
4bf39a94 | 812 | |
5072c59f | 813 | m->private = iter; |
4bf39a94 | 814 | } else { |
5072c59f | 815 | kfree(iter); |
4bf39a94 | 816 | } |
5072c59f SR |
817 | |
818 | return ret; | |
819 | } | |
820 | ||
821 | int ftrace_avail_release(struct inode *inode, struct file *file) | |
822 | { | |
823 | struct seq_file *m = (struct seq_file *)file->private_data; | |
824 | struct ftrace_iterator *iter = m->private; | |
825 | ||
826 | seq_release(inode, file); | |
827 | kfree(iter); | |
4bf39a94 | 828 | |
5072c59f SR |
829 | return 0; |
830 | } | |
831 | ||
eb9a7bf0 AS |
832 | static int |
833 | ftrace_failures_open(struct inode *inode, struct file *file) | |
834 | { | |
835 | int ret; | |
836 | struct seq_file *m; | |
837 | struct ftrace_iterator *iter; | |
838 | ||
839 | ret = ftrace_avail_open(inode, file); | |
840 | if (!ret) { | |
841 | m = (struct seq_file *)file->private_data; | |
842 | iter = (struct ftrace_iterator *)m->private; | |
843 | iter->flags = FTRACE_ITER_FAILURES; | |
844 | } | |
845 | ||
846 | return ret; | |
847 | } | |
848 | ||
849 | ||
41c52c0d | 850 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
851 | { |
852 | struct ftrace_page *pg; | |
853 | struct dyn_ftrace *rec; | |
41c52c0d | 854 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f SR |
855 | unsigned i; |
856 | ||
99ecdc43 SR |
857 | /* should not be called from interrupt context */ |
858 | spin_lock(&ftrace_lock); | |
41c52c0d SR |
859 | if (enable) |
860 | ftrace_filtered = 0; | |
5072c59f SR |
861 | pg = ftrace_pages_start; |
862 | while (pg) { | |
863 | for (i = 0; i < pg->index; i++) { | |
864 | rec = &pg->records[i]; | |
865 | if (rec->flags & FTRACE_FL_FAILED) | |
866 | continue; | |
41c52c0d | 867 | rec->flags &= ~type; |
5072c59f SR |
868 | } |
869 | pg = pg->next; | |
870 | } | |
99ecdc43 | 871 | spin_unlock(&ftrace_lock); |
5072c59f SR |
872 | } |
873 | ||
e309b41d | 874 | static int |
41c52c0d | 875 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
876 | { |
877 | struct ftrace_iterator *iter; | |
878 | int ret = 0; | |
879 | ||
4eebcc81 SR |
880 | if (unlikely(ftrace_disabled)) |
881 | return -ENODEV; | |
882 | ||
5072c59f SR |
883 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
884 | if (!iter) | |
885 | return -ENOMEM; | |
886 | ||
41c52c0d | 887 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
888 | if ((file->f_mode & FMODE_WRITE) && |
889 | !(file->f_flags & O_APPEND)) | |
41c52c0d | 890 | ftrace_filter_reset(enable); |
5072c59f SR |
891 | |
892 | if (file->f_mode & FMODE_READ) { | |
893 | iter->pg = ftrace_pages_start; | |
894 | iter->pos = -1; | |
41c52c0d SR |
895 | iter->flags = enable ? FTRACE_ITER_FILTER : |
896 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
897 | |
898 | ret = seq_open(file, &show_ftrace_seq_ops); | |
899 | if (!ret) { | |
900 | struct seq_file *m = file->private_data; | |
901 | m->private = iter; | |
902 | } else | |
903 | kfree(iter); | |
904 | } else | |
905 | file->private_data = iter; | |
41c52c0d | 906 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
907 | |
908 | return ret; | |
909 | } | |
910 | ||
41c52c0d SR |
911 | static int |
912 | ftrace_filter_open(struct inode *inode, struct file *file) | |
913 | { | |
914 | return ftrace_regex_open(inode, file, 1); | |
915 | } | |
916 | ||
917 | static int | |
918 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
919 | { | |
920 | return ftrace_regex_open(inode, file, 0); | |
921 | } | |
922 | ||
e309b41d | 923 | static ssize_t |
41c52c0d | 924 | ftrace_regex_read(struct file *file, char __user *ubuf, |
5072c59f SR |
925 | size_t cnt, loff_t *ppos) |
926 | { | |
927 | if (file->f_mode & FMODE_READ) | |
928 | return seq_read(file, ubuf, cnt, ppos); | |
929 | else | |
930 | return -EPERM; | |
931 | } | |
932 | ||
e309b41d | 933 | static loff_t |
41c52c0d | 934 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
935 | { |
936 | loff_t ret; | |
937 | ||
938 | if (file->f_mode & FMODE_READ) | |
939 | ret = seq_lseek(file, offset, origin); | |
940 | else | |
941 | file->f_pos = ret = 1; | |
942 | ||
943 | return ret; | |
944 | } | |
945 | ||
946 | enum { | |
947 | MATCH_FULL, | |
948 | MATCH_FRONT_ONLY, | |
949 | MATCH_MIDDLE_ONLY, | |
950 | MATCH_END_ONLY, | |
951 | }; | |
952 | ||
e309b41d | 953 | static void |
41c52c0d | 954 | ftrace_match(unsigned char *buff, int len, int enable) |
5072c59f SR |
955 | { |
956 | char str[KSYM_SYMBOL_LEN]; | |
957 | char *search = NULL; | |
958 | struct ftrace_page *pg; | |
959 | struct dyn_ftrace *rec; | |
960 | int type = MATCH_FULL; | |
41c52c0d | 961 | unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f SR |
962 | unsigned i, match = 0, search_len = 0; |
963 | ||
964 | for (i = 0; i < len; i++) { | |
965 | if (buff[i] == '*') { | |
966 | if (!i) { | |
967 | search = buff + i + 1; | |
968 | type = MATCH_END_ONLY; | |
969 | search_len = len - (i + 1); | |
970 | } else { | |
971 | if (type == MATCH_END_ONLY) { | |
972 | type = MATCH_MIDDLE_ONLY; | |
973 | } else { | |
974 | match = i; | |
975 | type = MATCH_FRONT_ONLY; | |
976 | } | |
977 | buff[i] = 0; | |
978 | break; | |
979 | } | |
980 | } | |
981 | } | |
982 | ||
99ecdc43 SR |
983 | /* should not be called from interrupt context */ |
984 | spin_lock(&ftrace_lock); | |
41c52c0d SR |
985 | if (enable) |
986 | ftrace_filtered = 1; | |
5072c59f SR |
987 | pg = ftrace_pages_start; |
988 | while (pg) { | |
989 | for (i = 0; i < pg->index; i++) { | |
990 | int matched = 0; | |
991 | char *ptr; | |
992 | ||
993 | rec = &pg->records[i]; | |
994 | if (rec->flags & FTRACE_FL_FAILED) | |
995 | continue; | |
996 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
997 | switch (type) { | |
998 | case MATCH_FULL: | |
999 | if (strcmp(str, buff) == 0) | |
1000 | matched = 1; | |
1001 | break; | |
1002 | case MATCH_FRONT_ONLY: | |
1003 | if (memcmp(str, buff, match) == 0) | |
1004 | matched = 1; | |
1005 | break; | |
1006 | case MATCH_MIDDLE_ONLY: | |
1007 | if (strstr(str, search)) | |
1008 | matched = 1; | |
1009 | break; | |
1010 | case MATCH_END_ONLY: | |
1011 | ptr = strstr(str, search); | |
1012 | if (ptr && (ptr[search_len] == 0)) | |
1013 | matched = 1; | |
1014 | break; | |
1015 | } | |
1016 | if (matched) | |
41c52c0d | 1017 | rec->flags |= flag; |
5072c59f SR |
1018 | } |
1019 | pg = pg->next; | |
1020 | } | |
99ecdc43 | 1021 | spin_unlock(&ftrace_lock); |
5072c59f SR |
1022 | } |
1023 | ||
e309b41d | 1024 | static ssize_t |
41c52c0d SR |
1025 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
1026 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
1027 | { |
1028 | struct ftrace_iterator *iter; | |
1029 | char ch; | |
1030 | size_t read = 0; | |
1031 | ssize_t ret; | |
1032 | ||
1033 | if (!cnt || cnt < 0) | |
1034 | return 0; | |
1035 | ||
41c52c0d | 1036 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1037 | |
1038 | if (file->f_mode & FMODE_READ) { | |
1039 | struct seq_file *m = file->private_data; | |
1040 | iter = m->private; | |
1041 | } else | |
1042 | iter = file->private_data; | |
1043 | ||
1044 | if (!*ppos) { | |
1045 | iter->flags &= ~FTRACE_ITER_CONT; | |
1046 | iter->buffer_idx = 0; | |
1047 | } | |
1048 | ||
1049 | ret = get_user(ch, ubuf++); | |
1050 | if (ret) | |
1051 | goto out; | |
1052 | read++; | |
1053 | cnt--; | |
1054 | ||
1055 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { | |
1056 | /* skip white space */ | |
1057 | while (cnt && isspace(ch)) { | |
1058 | ret = get_user(ch, ubuf++); | |
1059 | if (ret) | |
1060 | goto out; | |
1061 | read++; | |
1062 | cnt--; | |
1063 | } | |
1064 | ||
5072c59f SR |
1065 | if (isspace(ch)) { |
1066 | file->f_pos += read; | |
1067 | ret = read; | |
1068 | goto out; | |
1069 | } | |
1070 | ||
1071 | iter->buffer_idx = 0; | |
1072 | } | |
1073 | ||
1074 | while (cnt && !isspace(ch)) { | |
1075 | if (iter->buffer_idx < FTRACE_BUFF_MAX) | |
1076 | iter->buffer[iter->buffer_idx++] = ch; | |
1077 | else { | |
1078 | ret = -EINVAL; | |
1079 | goto out; | |
1080 | } | |
1081 | ret = get_user(ch, ubuf++); | |
1082 | if (ret) | |
1083 | goto out; | |
1084 | read++; | |
1085 | cnt--; | |
1086 | } | |
1087 | ||
1088 | if (isspace(ch)) { | |
1089 | iter->filtered++; | |
1090 | iter->buffer[iter->buffer_idx] = 0; | |
41c52c0d | 1091 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1092 | iter->buffer_idx = 0; |
1093 | } else | |
1094 | iter->flags |= FTRACE_ITER_CONT; | |
1095 | ||
1096 | ||
1097 | file->f_pos += read; | |
1098 | ||
1099 | ret = read; | |
1100 | out: | |
41c52c0d | 1101 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1102 | |
1103 | return ret; | |
1104 | } | |
1105 | ||
41c52c0d SR |
1106 | static ssize_t |
1107 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
1108 | size_t cnt, loff_t *ppos) | |
1109 | { | |
1110 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
1111 | } | |
1112 | ||
1113 | static ssize_t | |
1114 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
1115 | size_t cnt, loff_t *ppos) | |
1116 | { | |
1117 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
1118 | } | |
1119 | ||
1120 | static void | |
1121 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
1122 | { | |
1123 | if (unlikely(ftrace_disabled)) | |
1124 | return; | |
1125 | ||
1126 | mutex_lock(&ftrace_regex_lock); | |
1127 | if (reset) | |
1128 | ftrace_filter_reset(enable); | |
1129 | if (buf) | |
1130 | ftrace_match(buf, len, enable); | |
1131 | mutex_unlock(&ftrace_regex_lock); | |
1132 | } | |
1133 | ||
77a2b37d SR |
1134 | /** |
1135 | * ftrace_set_filter - set a function to filter on in ftrace | |
1136 | * @buf - the string that holds the function filter text. | |
1137 | * @len - the length of the string. | |
1138 | * @reset - non zero to reset all filters before applying this filter. | |
1139 | * | |
1140 | * Filters denote which functions should be enabled when tracing is enabled. | |
1141 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
1142 | */ | |
e309b41d | 1143 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 1144 | { |
41c52c0d SR |
1145 | ftrace_set_regex(buf, len, reset, 1); |
1146 | } | |
4eebcc81 | 1147 | |
41c52c0d SR |
1148 | /** |
1149 | * ftrace_set_notrace - set a function to not trace in ftrace | |
1150 | * @buf - the string that holds the function notrace text. | |
1151 | * @len - the length of the string. | |
1152 | * @reset - non zero to reset all filters before applying this filter. | |
1153 | * | |
1154 | * Notrace Filters denote which functions should not be enabled when tracing | |
1155 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
1156 | * for tracing. | |
1157 | */ | |
1158 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
1159 | { | |
1160 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
1161 | } |
1162 | ||
e309b41d | 1163 | static int |
41c52c0d | 1164 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1165 | { |
1166 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1167 | struct ftrace_iterator *iter; | |
1168 | ||
41c52c0d | 1169 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1170 | if (file->f_mode & FMODE_READ) { |
1171 | iter = m->private; | |
1172 | ||
1173 | seq_release(inode, file); | |
1174 | } else | |
1175 | iter = file->private_data; | |
1176 | ||
1177 | if (iter->buffer_idx) { | |
1178 | iter->filtered++; | |
1179 | iter->buffer[iter->buffer_idx] = 0; | |
41c52c0d | 1180 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1181 | } |
1182 | ||
1183 | mutex_lock(&ftrace_sysctl_lock); | |
cb7be3b2 SR |
1184 | mutex_lock(&ftrace_start_lock); |
1185 | if (iter->filtered && ftrace_start && ftrace_enabled) | |
5072c59f | 1186 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
cb7be3b2 | 1187 | mutex_unlock(&ftrace_start_lock); |
5072c59f SR |
1188 | mutex_unlock(&ftrace_sysctl_lock); |
1189 | ||
1190 | kfree(iter); | |
41c52c0d | 1191 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1192 | return 0; |
1193 | } | |
1194 | ||
41c52c0d SR |
1195 | static int |
1196 | ftrace_filter_release(struct inode *inode, struct file *file) | |
1197 | { | |
1198 | return ftrace_regex_release(inode, file, 1); | |
1199 | } | |
1200 | ||
1201 | static int | |
1202 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
1203 | { | |
1204 | return ftrace_regex_release(inode, file, 0); | |
1205 | } | |
1206 | ||
5072c59f SR |
1207 | static struct file_operations ftrace_avail_fops = { |
1208 | .open = ftrace_avail_open, | |
1209 | .read = seq_read, | |
1210 | .llseek = seq_lseek, | |
1211 | .release = ftrace_avail_release, | |
1212 | }; | |
1213 | ||
eb9a7bf0 AS |
1214 | static struct file_operations ftrace_failures_fops = { |
1215 | .open = ftrace_failures_open, | |
1216 | .read = seq_read, | |
1217 | .llseek = seq_lseek, | |
1218 | .release = ftrace_avail_release, | |
1219 | }; | |
1220 | ||
5072c59f SR |
1221 | static struct file_operations ftrace_filter_fops = { |
1222 | .open = ftrace_filter_open, | |
41c52c0d | 1223 | .read = ftrace_regex_read, |
5072c59f | 1224 | .write = ftrace_filter_write, |
41c52c0d | 1225 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
1226 | .release = ftrace_filter_release, |
1227 | }; | |
1228 | ||
41c52c0d SR |
1229 | static struct file_operations ftrace_notrace_fops = { |
1230 | .open = ftrace_notrace_open, | |
1231 | .read = ftrace_regex_read, | |
1232 | .write = ftrace_notrace_write, | |
1233 | .llseek = ftrace_regex_lseek, | |
1234 | .release = ftrace_notrace_release, | |
1235 | }; | |
1236 | ||
5072c59f SR |
1237 | static __init int ftrace_init_debugfs(void) |
1238 | { | |
1239 | struct dentry *d_tracer; | |
1240 | struct dentry *entry; | |
1241 | ||
1242 | d_tracer = tracing_init_dentry(); | |
1243 | ||
1244 | entry = debugfs_create_file("available_filter_functions", 0444, | |
1245 | d_tracer, NULL, &ftrace_avail_fops); | |
1246 | if (!entry) | |
1247 | pr_warning("Could not create debugfs " | |
1248 | "'available_filter_functions' entry\n"); | |
1249 | ||
eb9a7bf0 AS |
1250 | entry = debugfs_create_file("failures", 0444, |
1251 | d_tracer, NULL, &ftrace_failures_fops); | |
1252 | if (!entry) | |
1253 | pr_warning("Could not create debugfs 'failures' entry\n"); | |
1254 | ||
5072c59f SR |
1255 | entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer, |
1256 | NULL, &ftrace_filter_fops); | |
1257 | if (!entry) | |
1258 | pr_warning("Could not create debugfs " | |
1259 | "'set_ftrace_filter' entry\n"); | |
41c52c0d SR |
1260 | |
1261 | entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer, | |
1262 | NULL, &ftrace_notrace_fops); | |
1263 | if (!entry) | |
1264 | pr_warning("Could not create debugfs " | |
1265 | "'set_ftrace_notrace' entry\n"); | |
ad90c0e3 | 1266 | |
5072c59f SR |
1267 | return 0; |
1268 | } | |
1269 | ||
1270 | fs_initcall(ftrace_init_debugfs); | |
1271 | ||
68bf21aa SR |
1272 | static int ftrace_convert_nops(unsigned long *start, |
1273 | unsigned long *end) | |
1274 | { | |
1275 | unsigned long *p; | |
1276 | unsigned long addr; | |
1277 | unsigned long flags; | |
1278 | ||
08f5ac90 | 1279 | mutex_lock(&ftrace_start_lock); |
68bf21aa SR |
1280 | p = start; |
1281 | while (p < end) { | |
1282 | addr = ftrace_call_adjust(*p++); | |
1283 | ftrace_record_ip(addr); | |
68bf21aa SR |
1284 | } |
1285 | ||
08f5ac90 | 1286 | /* disable interrupts to prevent kstop machine */ |
68bf21aa | 1287 | local_irq_save(flags); |
08f5ac90 | 1288 | ftrace_update_code(); |
68bf21aa | 1289 | local_irq_restore(flags); |
08f5ac90 | 1290 | mutex_unlock(&ftrace_start_lock); |
68bf21aa SR |
1291 | |
1292 | return 0; | |
1293 | } | |
1294 | ||
90d595fe SR |
1295 | void ftrace_init_module(unsigned long *start, unsigned long *end) |
1296 | { | |
00fd61ae | 1297 | if (ftrace_disabled || start == end) |
fed1939c | 1298 | return; |
90d595fe SR |
1299 | ftrace_convert_nops(start, end); |
1300 | } | |
1301 | ||
68bf21aa SR |
1302 | extern unsigned long __start_mcount_loc[]; |
1303 | extern unsigned long __stop_mcount_loc[]; | |
1304 | ||
1305 | void __init ftrace_init(void) | |
1306 | { | |
1307 | unsigned long count, addr, flags; | |
1308 | int ret; | |
1309 | ||
1310 | /* Keep the ftrace pointer to the stub */ | |
1311 | addr = (unsigned long)ftrace_stub; | |
1312 | ||
1313 | local_irq_save(flags); | |
1314 | ftrace_dyn_arch_init(&addr); | |
1315 | local_irq_restore(flags); | |
1316 | ||
1317 | /* ftrace_dyn_arch_init places the return code in addr */ | |
1318 | if (addr) | |
1319 | goto failed; | |
1320 | ||
1321 | count = __stop_mcount_loc - __start_mcount_loc; | |
1322 | ||
1323 | ret = ftrace_dyn_table_alloc(count); | |
1324 | if (ret) | |
1325 | goto failed; | |
1326 | ||
1327 | last_ftrace_enabled = ftrace_enabled = 1; | |
1328 | ||
1329 | ret = ftrace_convert_nops(__start_mcount_loc, | |
1330 | __stop_mcount_loc); | |
1331 | ||
1332 | return; | |
1333 | failed: | |
1334 | ftrace_disabled = 1; | |
1335 | } | |
68bf21aa | 1336 | |
3d083395 | 1337 | #else |
0b6e4d56 FW |
1338 | |
1339 | static int __init ftrace_nodyn_init(void) | |
1340 | { | |
1341 | ftrace_enabled = 1; | |
1342 | return 0; | |
1343 | } | |
1344 | device_initcall(ftrace_nodyn_init); | |
1345 | ||
c7aafc54 IM |
1346 | # define ftrace_startup() do { } while (0) |
1347 | # define ftrace_shutdown() do { } while (0) | |
1348 | # define ftrace_startup_sysctl() do { } while (0) | |
1349 | # define ftrace_shutdown_sysctl() do { } while (0) | |
3d083395 SR |
1350 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
1351 | ||
a2bb6a3d | 1352 | /** |
81adbdc0 | 1353 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
1354 | * |
1355 | * This function should be used by panic code. It stops ftrace | |
1356 | * but in a not so nice way. If you need to simply kill ftrace | |
1357 | * from a non-atomic section, use ftrace_kill. | |
1358 | */ | |
81adbdc0 | 1359 | void ftrace_kill(void) |
a2bb6a3d SR |
1360 | { |
1361 | ftrace_disabled = 1; | |
1362 | ftrace_enabled = 0; | |
a2bb6a3d SR |
1363 | clear_ftrace_function(); |
1364 | } | |
1365 | ||
16444a8a | 1366 | /** |
3d083395 SR |
1367 | * register_ftrace_function - register a function for profiling |
1368 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 1369 | * |
3d083395 SR |
1370 | * Register a function to be called by all functions in the |
1371 | * kernel. | |
1372 | * | |
1373 | * Note: @ops->func and all the functions it calls must be labeled | |
1374 | * with "notrace", otherwise it will go into a | |
1375 | * recursive loop. | |
16444a8a | 1376 | */ |
3d083395 | 1377 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 1378 | { |
b0fc494f SR |
1379 | int ret; |
1380 | ||
4eebcc81 SR |
1381 | if (unlikely(ftrace_disabled)) |
1382 | return -1; | |
1383 | ||
b0fc494f | 1384 | mutex_lock(&ftrace_sysctl_lock); |
b0fc494f | 1385 | ret = __register_ftrace_function(ops); |
d61f82d0 | 1386 | ftrace_startup(); |
b0fc494f SR |
1387 | mutex_unlock(&ftrace_sysctl_lock); |
1388 | ||
1389 | return ret; | |
3d083395 SR |
1390 | } |
1391 | ||
1392 | /** | |
1393 | * unregister_ftrace_function - unresgister a function for profiling. | |
1394 | * @ops - ops structure that holds the function to unregister | |
1395 | * | |
1396 | * Unregister a function that was added to be called by ftrace profiling. | |
1397 | */ | |
1398 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
1399 | { | |
1400 | int ret; | |
1401 | ||
b0fc494f | 1402 | mutex_lock(&ftrace_sysctl_lock); |
3d083395 | 1403 | ret = __unregister_ftrace_function(ops); |
d61f82d0 | 1404 | ftrace_shutdown(); |
b0fc494f SR |
1405 | mutex_unlock(&ftrace_sysctl_lock); |
1406 | ||
1407 | return ret; | |
1408 | } | |
1409 | ||
e309b41d | 1410 | int |
b0fc494f | 1411 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
5072c59f | 1412 | struct file *file, void __user *buffer, size_t *lenp, |
b0fc494f SR |
1413 | loff_t *ppos) |
1414 | { | |
1415 | int ret; | |
1416 | ||
4eebcc81 SR |
1417 | if (unlikely(ftrace_disabled)) |
1418 | return -ENODEV; | |
1419 | ||
b0fc494f SR |
1420 | mutex_lock(&ftrace_sysctl_lock); |
1421 | ||
5072c59f | 1422 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
b0fc494f SR |
1423 | |
1424 | if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) | |
1425 | goto out; | |
1426 | ||
1427 | last_ftrace_enabled = ftrace_enabled; | |
1428 | ||
1429 | if (ftrace_enabled) { | |
1430 | ||
1431 | ftrace_startup_sysctl(); | |
1432 | ||
1433 | /* we are starting ftrace again */ | |
1434 | if (ftrace_list != &ftrace_list_end) { | |
1435 | if (ftrace_list->next == &ftrace_list_end) | |
1436 | ftrace_trace_function = ftrace_list->func; | |
1437 | else | |
1438 | ftrace_trace_function = ftrace_list_func; | |
1439 | } | |
1440 | ||
1441 | } else { | |
1442 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
1443 | ftrace_trace_function = ftrace_stub; | |
1444 | ||
1445 | ftrace_shutdown_sysctl(); | |
1446 | } | |
1447 | ||
1448 | out: | |
1449 | mutex_unlock(&ftrace_sysctl_lock); | |
3d083395 | 1450 | return ret; |
16444a8a | 1451 | } |
f17845e5 | 1452 |