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