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 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 | 328 | __ftrace_replace_code(struct dyn_ftrace *rec, |
32464779 | 329 | unsigned char *nop, int enable) |
5072c59f | 330 | { |
41c52c0d | 331 | unsigned long ip, fl; |
32464779 | 332 | unsigned char *call, *old, *new; |
5072c59f SR |
333 | |
334 | ip = rec->ip; | |
335 | ||
32464779 SR |
336 | /* |
337 | * If this record is not to be traced and | |
338 | * it is not enabled then do nothing. | |
339 | * | |
340 | * If this record is not to be traced and | |
341 | * it is enabled then disabled it. | |
342 | * | |
343 | */ | |
344 | if (rec->flags & FTRACE_FL_NOTRACE) { | |
345 | if (rec->flags & FTRACE_FL_ENABLED) | |
346 | rec->flags &= ~FTRACE_FL_ENABLED; | |
347 | else | |
348 | return 0; | |
349 | ||
350 | } else if (ftrace_filtered && enable) { | |
5072c59f | 351 | /* |
32464779 | 352 | * Filtering is on: |
5072c59f | 353 | */ |
a4500b84 | 354 | |
32464779 | 355 | fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED); |
5072c59f | 356 | |
32464779 SR |
357 | /* Record is filtered and enabled, do nothing */ |
358 | if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) | |
0eb96701 | 359 | return 0; |
5072c59f | 360 | |
32464779 SR |
361 | /* Record is not filtered and is not enabled do nothing */ |
362 | if (!fl) | |
363 | return 0; | |
364 | ||
365 | /* Record is not filtered but enabled, disable it */ | |
366 | if (fl == FTRACE_FL_ENABLED) | |
5072c59f | 367 | rec->flags &= ~FTRACE_FL_ENABLED; |
32464779 SR |
368 | else |
369 | /* Otherwise record is filtered but not enabled, enable it */ | |
5072c59f | 370 | rec->flags |= FTRACE_FL_ENABLED; |
5072c59f | 371 | } else { |
32464779 | 372 | /* Disable or not filtered */ |
5072c59f | 373 | |
41c52c0d | 374 | if (enable) { |
32464779 | 375 | /* if record is enabled, do nothing */ |
5072c59f | 376 | if (rec->flags & FTRACE_FL_ENABLED) |
0eb96701 | 377 | return 0; |
32464779 | 378 | |
5072c59f | 379 | rec->flags |= FTRACE_FL_ENABLED; |
32464779 | 380 | |
5072c59f | 381 | } else { |
32464779 SR |
382 | |
383 | /* if record is not enabled do nothing */ | |
5072c59f | 384 | if (!(rec->flags & FTRACE_FL_ENABLED)) |
0eb96701 | 385 | return 0; |
32464779 | 386 | |
5072c59f SR |
387 | rec->flags &= ~FTRACE_FL_ENABLED; |
388 | } | |
389 | } | |
390 | ||
32464779 SR |
391 | call = ftrace_call_replace(ip, FTRACE_ADDR); |
392 | ||
393 | if (rec->flags & FTRACE_FL_ENABLED) { | |
394 | old = nop; | |
395 | new = call; | |
396 | } else { | |
397 | old = call; | |
398 | new = nop; | |
399 | } | |
400 | ||
0eb96701 | 401 | return ftrace_modify_code(ip, old, new); |
5072c59f SR |
402 | } |
403 | ||
e309b41d | 404 | static void ftrace_replace_code(int enable) |
3c1720f0 | 405 | { |
0eb96701 | 406 | int i, failed; |
32464779 | 407 | unsigned char *nop = NULL; |
3c1720f0 SR |
408 | struct dyn_ftrace *rec; |
409 | struct ftrace_page *pg; | |
3c1720f0 | 410 | |
32464779 | 411 | nop = ftrace_nop_replace(); |
3c1720f0 SR |
412 | |
413 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
414 | for (i = 0; i < pg->index; i++) { | |
415 | rec = &pg->records[i]; | |
416 | ||
417 | /* don't modify code that has already faulted */ | |
418 | if (rec->flags & FTRACE_FL_FAILED) | |
419 | continue; | |
420 | ||
f22f9a89 | 421 | /* ignore updates to this record's mcount site */ |
98a05ed4 AS |
422 | if (get_kprobe((void *)rec->ip)) { |
423 | freeze_record(rec); | |
f22f9a89 | 424 | continue; |
98a05ed4 AS |
425 | } else { |
426 | unfreeze_record(rec); | |
427 | } | |
f22f9a89 | 428 | |
32464779 | 429 | failed = __ftrace_replace_code(rec, nop, enable); |
0eb96701 AS |
430 | if (failed && (rec->flags & FTRACE_FL_CONVERTED)) { |
431 | rec->flags |= FTRACE_FL_FAILED; | |
432 | if ((system_state == SYSTEM_BOOTING) || | |
34078a5e | 433 | !core_kernel_text(rec->ip)) { |
0eb96701 AS |
434 | ftrace_free_rec(rec); |
435 | } | |
436 | } | |
3c1720f0 SR |
437 | } |
438 | } | |
439 | } | |
440 | ||
05736a42 SR |
441 | static void print_ip_ins(const char *fmt, unsigned char *p) |
442 | { | |
443 | int i; | |
444 | ||
445 | printk(KERN_CONT "%s", fmt); | |
446 | ||
447 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
448 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
449 | } | |
450 | ||
492a7ea5 | 451 | static int |
d61f82d0 | 452 | ftrace_code_disable(struct dyn_ftrace *rec) |
3c1720f0 SR |
453 | { |
454 | unsigned long ip; | |
455 | unsigned char *nop, *call; | |
593eb8a2 | 456 | int ret; |
3c1720f0 SR |
457 | |
458 | ip = rec->ip; | |
459 | ||
460 | nop = ftrace_nop_replace(); | |
3b47bfc1 | 461 | call = ftrace_call_replace(ip, mcount_addr); |
3c1720f0 | 462 | |
593eb8a2 SR |
463 | ret = ftrace_modify_code(ip, call, nop); |
464 | if (ret) { | |
465 | switch (ret) { | |
466 | case -EFAULT: | |
6912896e | 467 | FTRACE_WARN_ON_ONCE(1); |
05736a42 SR |
468 | pr_info("ftrace faulted on modifying "); |
469 | print_ip_sym(ip); | |
470 | break; | |
593eb8a2 | 471 | case -EINVAL: |
6912896e | 472 | FTRACE_WARN_ON_ONCE(1); |
05736a42 SR |
473 | pr_info("ftrace failed to modify "); |
474 | print_ip_sym(ip); | |
475 | print_ip_ins(" expected: ", call); | |
476 | print_ip_ins(" actual: ", (unsigned char *)ip); | |
477 | print_ip_ins(" replace: ", nop); | |
478 | printk(KERN_CONT "\n"); | |
479 | break; | |
593eb8a2 | 480 | case -EPERM: |
6912896e | 481 | FTRACE_WARN_ON_ONCE(1); |
593eb8a2 SR |
482 | pr_info("ftrace faulted on writing "); |
483 | print_ip_sym(ip); | |
484 | break; | |
485 | default: | |
6912896e | 486 | FTRACE_WARN_ON_ONCE(1); |
593eb8a2 SR |
487 | pr_info("ftrace faulted on unknown error "); |
488 | print_ip_sym(ip); | |
05736a42 SR |
489 | } |
490 | ||
3c1720f0 | 491 | rec->flags |= FTRACE_FL_FAILED; |
492a7ea5 | 492 | return 0; |
37ad5084 | 493 | } |
492a7ea5 | 494 | return 1; |
3c1720f0 SR |
495 | } |
496 | ||
e309b41d | 497 | static int __ftrace_modify_code(void *data) |
3d083395 | 498 | { |
d61f82d0 SR |
499 | int *command = data; |
500 | ||
a3583244 | 501 | if (*command & FTRACE_ENABLE_CALLS) |
d61f82d0 | 502 | ftrace_replace_code(1); |
a3583244 | 503 | else if (*command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
504 | ftrace_replace_code(0); |
505 | ||
506 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
507 | ftrace_update_ftrace_func(ftrace_trace_function); | |
508 | ||
d61f82d0 | 509 | return 0; |
3d083395 SR |
510 | } |
511 | ||
e309b41d | 512 | static void ftrace_run_update_code(int command) |
3d083395 | 513 | { |
784e2d76 | 514 | stop_machine(__ftrace_modify_code, &command, NULL); |
3d083395 SR |
515 | } |
516 | ||
d61f82d0 | 517 | static ftrace_func_t saved_ftrace_func; |
cb7be3b2 SR |
518 | static int ftrace_start; |
519 | static DEFINE_MUTEX(ftrace_start_lock); | |
d61f82d0 | 520 | |
e309b41d | 521 | static void ftrace_startup(void) |
3d083395 | 522 | { |
d61f82d0 SR |
523 | int command = 0; |
524 | ||
4eebcc81 SR |
525 | if (unlikely(ftrace_disabled)) |
526 | return; | |
527 | ||
cb7be3b2 SR |
528 | mutex_lock(&ftrace_start_lock); |
529 | ftrace_start++; | |
32464779 | 530 | command |= FTRACE_ENABLE_CALLS; |
d61f82d0 SR |
531 | |
532 | if (saved_ftrace_func != ftrace_trace_function) { | |
533 | saved_ftrace_func = ftrace_trace_function; | |
534 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
535 | } | |
536 | ||
537 | if (!command || !ftrace_enabled) | |
3d083395 | 538 | goto out; |
3d083395 | 539 | |
d61f82d0 | 540 | ftrace_run_update_code(command); |
3d083395 | 541 | out: |
cb7be3b2 | 542 | mutex_unlock(&ftrace_start_lock); |
3d083395 SR |
543 | } |
544 | ||
e309b41d | 545 | static void ftrace_shutdown(void) |
3d083395 | 546 | { |
d61f82d0 SR |
547 | int command = 0; |
548 | ||
4eebcc81 SR |
549 | if (unlikely(ftrace_disabled)) |
550 | return; | |
551 | ||
cb7be3b2 SR |
552 | mutex_lock(&ftrace_start_lock); |
553 | ftrace_start--; | |
554 | if (!ftrace_start) | |
d61f82d0 | 555 | command |= FTRACE_DISABLE_CALLS; |
3d083395 | 556 | |
d61f82d0 SR |
557 | if (saved_ftrace_func != ftrace_trace_function) { |
558 | saved_ftrace_func = ftrace_trace_function; | |
559 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
560 | } | |
3d083395 | 561 | |
d61f82d0 SR |
562 | if (!command || !ftrace_enabled) |
563 | goto out; | |
564 | ||
565 | ftrace_run_update_code(command); | |
3d083395 | 566 | out: |
cb7be3b2 | 567 | mutex_unlock(&ftrace_start_lock); |
3d083395 SR |
568 | } |
569 | ||
e309b41d | 570 | static void ftrace_startup_sysctl(void) |
b0fc494f | 571 | { |
d61f82d0 SR |
572 | int command = FTRACE_ENABLE_MCOUNT; |
573 | ||
4eebcc81 SR |
574 | if (unlikely(ftrace_disabled)) |
575 | return; | |
576 | ||
cb7be3b2 | 577 | mutex_lock(&ftrace_start_lock); |
d61f82d0 SR |
578 | /* Force update next time */ |
579 | saved_ftrace_func = NULL; | |
cb7be3b2 SR |
580 | /* ftrace_start is true if we want ftrace running */ |
581 | if (ftrace_start) | |
d61f82d0 SR |
582 | command |= FTRACE_ENABLE_CALLS; |
583 | ||
584 | ftrace_run_update_code(command); | |
cb7be3b2 | 585 | mutex_unlock(&ftrace_start_lock); |
b0fc494f SR |
586 | } |
587 | ||
e309b41d | 588 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 589 | { |
d61f82d0 SR |
590 | int command = FTRACE_DISABLE_MCOUNT; |
591 | ||
4eebcc81 SR |
592 | if (unlikely(ftrace_disabled)) |
593 | return; | |
594 | ||
cb7be3b2 SR |
595 | mutex_lock(&ftrace_start_lock); |
596 | /* ftrace_start is true if ftrace is running */ | |
597 | if (ftrace_start) | |
d61f82d0 SR |
598 | command |= FTRACE_DISABLE_CALLS; |
599 | ||
600 | ftrace_run_update_code(command); | |
cb7be3b2 | 601 | mutex_unlock(&ftrace_start_lock); |
b0fc494f SR |
602 | } |
603 | ||
3d083395 SR |
604 | static cycle_t ftrace_update_time; |
605 | static unsigned long ftrace_update_cnt; | |
606 | unsigned long ftrace_update_tot_cnt; | |
607 | ||
08f5ac90 | 608 | static int ftrace_update_code(void) |
3d083395 | 609 | { |
08f5ac90 | 610 | struct dyn_ftrace *p, *t; |
f22f9a89 | 611 | cycle_t start, stop; |
3d083395 | 612 | |
750ed1a4 | 613 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
614 | ftrace_update_cnt = 0; |
615 | ||
08f5ac90 | 616 | list_for_each_entry_safe(p, t, &ftrace_new_addrs, list) { |
3d083395 | 617 | |
08f5ac90 SR |
618 | /* If something went wrong, bail without enabling anything */ |
619 | if (unlikely(ftrace_disabled)) | |
620 | return -1; | |
f22f9a89 | 621 | |
08f5ac90 | 622 | list_del_init(&p->list); |
f22f9a89 | 623 | |
08f5ac90 SR |
624 | /* convert record (i.e, patch mcount-call with NOP) */ |
625 | if (ftrace_code_disable(p)) { | |
626 | p->flags |= FTRACE_FL_CONVERTED; | |
627 | ftrace_update_cnt++; | |
628 | } else | |
629 | ftrace_free_rec(p); | |
3d083395 SR |
630 | } |
631 | ||
750ed1a4 | 632 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
633 | ftrace_update_time = stop - start; |
634 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
635 | ||
16444a8a ACM |
636 | return 0; |
637 | } | |
638 | ||
68bf21aa | 639 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
640 | { |
641 | struct ftrace_page *pg; | |
642 | int cnt; | |
643 | int i; | |
3c1720f0 SR |
644 | |
645 | /* allocate a few pages */ | |
646 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
647 | if (!ftrace_pages_start) | |
648 | return -1; | |
649 | ||
650 | /* | |
651 | * Allocate a few more pages. | |
652 | * | |
653 | * TODO: have some parser search vmlinux before | |
654 | * final linking to find all calls to ftrace. | |
655 | * Then we can: | |
656 | * a) know how many pages to allocate. | |
657 | * and/or | |
658 | * b) set up the table then. | |
659 | * | |
660 | * The dynamic code is still necessary for | |
661 | * modules. | |
662 | */ | |
663 | ||
664 | pg = ftrace_pages = ftrace_pages_start; | |
665 | ||
68bf21aa | 666 | cnt = num_to_init / ENTRIES_PER_PAGE; |
08f5ac90 | 667 | pr_info("ftrace: allocating %ld entries in %d pages\n", |
5821e1b7 | 668 | num_to_init, cnt + 1); |
3c1720f0 SR |
669 | |
670 | for (i = 0; i < cnt; i++) { | |
671 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
672 | ||
673 | /* If we fail, we'll try later anyway */ | |
674 | if (!pg->next) | |
675 | break; | |
676 | ||
677 | pg = pg->next; | |
678 | } | |
679 | ||
680 | return 0; | |
681 | } | |
682 | ||
5072c59f SR |
683 | enum { |
684 | FTRACE_ITER_FILTER = (1 << 0), | |
685 | FTRACE_ITER_CONT = (1 << 1), | |
41c52c0d | 686 | FTRACE_ITER_NOTRACE = (1 << 2), |
eb9a7bf0 | 687 | FTRACE_ITER_FAILURES = (1 << 3), |
5072c59f SR |
688 | }; |
689 | ||
690 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
691 | ||
692 | struct ftrace_iterator { | |
693 | loff_t pos; | |
694 | struct ftrace_page *pg; | |
695 | unsigned idx; | |
696 | unsigned flags; | |
697 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
698 | unsigned buffer_idx; | |
699 | unsigned filtered; | |
700 | }; | |
701 | ||
e309b41d | 702 | static void * |
5072c59f SR |
703 | t_next(struct seq_file *m, void *v, loff_t *pos) |
704 | { | |
705 | struct ftrace_iterator *iter = m->private; | |
706 | struct dyn_ftrace *rec = NULL; | |
707 | ||
708 | (*pos)++; | |
709 | ||
99ecdc43 SR |
710 | /* should not be called from interrupt context */ |
711 | spin_lock(&ftrace_lock); | |
5072c59f SR |
712 | retry: |
713 | if (iter->idx >= iter->pg->index) { | |
714 | if (iter->pg->next) { | |
715 | iter->pg = iter->pg->next; | |
716 | iter->idx = 0; | |
717 | goto retry; | |
718 | } | |
719 | } else { | |
720 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
721 | if ((rec->flags & FTRACE_FL_FREE) || |
722 | ||
723 | (!(iter->flags & FTRACE_ITER_FAILURES) && | |
eb9a7bf0 AS |
724 | (rec->flags & FTRACE_FL_FAILED)) || |
725 | ||
726 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
a9fdda33 | 727 | !(rec->flags & FTRACE_FL_FAILED)) || |
eb9a7bf0 | 728 | |
f10ed36e SR |
729 | ((iter->flags & FTRACE_ITER_FILTER) && |
730 | !(rec->flags & FTRACE_FL_FILTER)) || | |
731 | ||
41c52c0d SR |
732 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
733 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
734 | rec = NULL; |
735 | goto retry; | |
736 | } | |
737 | } | |
99ecdc43 | 738 | spin_unlock(&ftrace_lock); |
5072c59f SR |
739 | |
740 | iter->pos = *pos; | |
741 | ||
742 | return rec; | |
743 | } | |
744 | ||
745 | static void *t_start(struct seq_file *m, loff_t *pos) | |
746 | { | |
747 | struct ftrace_iterator *iter = m->private; | |
748 | void *p = NULL; | |
749 | loff_t l = -1; | |
750 | ||
5821e1b7 | 751 | if (*pos > iter->pos) |
752 | *pos = iter->pos; | |
753 | ||
754 | l = *pos; | |
755 | p = t_next(m, p, &l); | |
5072c59f SR |
756 | |
757 | return p; | |
758 | } | |
759 | ||
760 | static void t_stop(struct seq_file *m, void *p) | |
761 | { | |
762 | } | |
763 | ||
764 | static int t_show(struct seq_file *m, void *v) | |
765 | { | |
5821e1b7 | 766 | struct ftrace_iterator *iter = m->private; |
5072c59f SR |
767 | struct dyn_ftrace *rec = v; |
768 | char str[KSYM_SYMBOL_LEN]; | |
5821e1b7 | 769 | int ret = 0; |
5072c59f SR |
770 | |
771 | if (!rec) | |
772 | return 0; | |
773 | ||
774 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
775 | ||
5821e1b7 | 776 | ret = seq_printf(m, "%s\n", str); |
777 | if (ret < 0) { | |
778 | iter->pos--; | |
779 | iter->idx--; | |
780 | } | |
5072c59f SR |
781 | |
782 | return 0; | |
783 | } | |
784 | ||
785 | static struct seq_operations show_ftrace_seq_ops = { | |
786 | .start = t_start, | |
787 | .next = t_next, | |
788 | .stop = t_stop, | |
789 | .show = t_show, | |
790 | }; | |
791 | ||
e309b41d | 792 | static int |
5072c59f SR |
793 | ftrace_avail_open(struct inode *inode, struct file *file) |
794 | { | |
795 | struct ftrace_iterator *iter; | |
796 | int ret; | |
797 | ||
4eebcc81 SR |
798 | if (unlikely(ftrace_disabled)) |
799 | return -ENODEV; | |
800 | ||
5072c59f SR |
801 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
802 | if (!iter) | |
803 | return -ENOMEM; | |
804 | ||
805 | iter->pg = ftrace_pages_start; | |
5821e1b7 | 806 | iter->pos = 0; |
5072c59f SR |
807 | |
808 | ret = seq_open(file, &show_ftrace_seq_ops); | |
809 | if (!ret) { | |
810 | struct seq_file *m = file->private_data; | |
4bf39a94 | 811 | |
5072c59f | 812 | m->private = iter; |
4bf39a94 | 813 | } else { |
5072c59f | 814 | kfree(iter); |
4bf39a94 | 815 | } |
5072c59f SR |
816 | |
817 | return ret; | |
818 | } | |
819 | ||
820 | int ftrace_avail_release(struct inode *inode, struct file *file) | |
821 | { | |
822 | struct seq_file *m = (struct seq_file *)file->private_data; | |
823 | struct ftrace_iterator *iter = m->private; | |
824 | ||
825 | seq_release(inode, file); | |
826 | kfree(iter); | |
4bf39a94 | 827 | |
5072c59f SR |
828 | return 0; |
829 | } | |
830 | ||
eb9a7bf0 AS |
831 | static int |
832 | ftrace_failures_open(struct inode *inode, struct file *file) | |
833 | { | |
834 | int ret; | |
835 | struct seq_file *m; | |
836 | struct ftrace_iterator *iter; | |
837 | ||
838 | ret = ftrace_avail_open(inode, file); | |
839 | if (!ret) { | |
840 | m = (struct seq_file *)file->private_data; | |
841 | iter = (struct ftrace_iterator *)m->private; | |
842 | iter->flags = FTRACE_ITER_FAILURES; | |
843 | } | |
844 | ||
845 | return ret; | |
846 | } | |
847 | ||
848 | ||
41c52c0d | 849 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
850 | { |
851 | struct ftrace_page *pg; | |
852 | struct dyn_ftrace *rec; | |
41c52c0d | 853 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f SR |
854 | unsigned i; |
855 | ||
99ecdc43 SR |
856 | /* should not be called from interrupt context */ |
857 | spin_lock(&ftrace_lock); | |
41c52c0d SR |
858 | if (enable) |
859 | ftrace_filtered = 0; | |
5072c59f SR |
860 | pg = ftrace_pages_start; |
861 | while (pg) { | |
862 | for (i = 0; i < pg->index; i++) { | |
863 | rec = &pg->records[i]; | |
864 | if (rec->flags & FTRACE_FL_FAILED) | |
865 | continue; | |
41c52c0d | 866 | rec->flags &= ~type; |
5072c59f SR |
867 | } |
868 | pg = pg->next; | |
869 | } | |
99ecdc43 | 870 | spin_unlock(&ftrace_lock); |
5072c59f SR |
871 | } |
872 | ||
e309b41d | 873 | static int |
41c52c0d | 874 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
875 | { |
876 | struct ftrace_iterator *iter; | |
877 | int ret = 0; | |
878 | ||
4eebcc81 SR |
879 | if (unlikely(ftrace_disabled)) |
880 | return -ENODEV; | |
881 | ||
5072c59f SR |
882 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
883 | if (!iter) | |
884 | return -ENOMEM; | |
885 | ||
41c52c0d | 886 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
887 | if ((file->f_mode & FMODE_WRITE) && |
888 | !(file->f_flags & O_APPEND)) | |
41c52c0d | 889 | ftrace_filter_reset(enable); |
5072c59f SR |
890 | |
891 | if (file->f_mode & FMODE_READ) { | |
892 | iter->pg = ftrace_pages_start; | |
5821e1b7 | 893 | iter->pos = 0; |
41c52c0d SR |
894 | iter->flags = enable ? FTRACE_ITER_FILTER : |
895 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
896 | |
897 | ret = seq_open(file, &show_ftrace_seq_ops); | |
898 | if (!ret) { | |
899 | struct seq_file *m = file->private_data; | |
900 | m->private = iter; | |
901 | } else | |
902 | kfree(iter); | |
903 | } else | |
904 | file->private_data = iter; | |
41c52c0d | 905 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
906 | |
907 | return ret; | |
908 | } | |
909 | ||
41c52c0d SR |
910 | static int |
911 | ftrace_filter_open(struct inode *inode, struct file *file) | |
912 | { | |
913 | return ftrace_regex_open(inode, file, 1); | |
914 | } | |
915 | ||
916 | static int | |
917 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
918 | { | |
919 | return ftrace_regex_open(inode, file, 0); | |
920 | } | |
921 | ||
e309b41d | 922 | static ssize_t |
41c52c0d | 923 | ftrace_regex_read(struct file *file, char __user *ubuf, |
5072c59f SR |
924 | size_t cnt, loff_t *ppos) |
925 | { | |
926 | if (file->f_mode & FMODE_READ) | |
927 | return seq_read(file, ubuf, cnt, ppos); | |
928 | else | |
929 | return -EPERM; | |
930 | } | |
931 | ||
e309b41d | 932 | static loff_t |
41c52c0d | 933 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
934 | { |
935 | loff_t ret; | |
936 | ||
937 | if (file->f_mode & FMODE_READ) | |
938 | ret = seq_lseek(file, offset, origin); | |
939 | else | |
940 | file->f_pos = ret = 1; | |
941 | ||
942 | return ret; | |
943 | } | |
944 | ||
945 | enum { | |
946 | MATCH_FULL, | |
947 | MATCH_FRONT_ONLY, | |
948 | MATCH_MIDDLE_ONLY, | |
949 | MATCH_END_ONLY, | |
950 | }; | |
951 | ||
e309b41d | 952 | static void |
41c52c0d | 953 | ftrace_match(unsigned char *buff, int len, int enable) |
5072c59f SR |
954 | { |
955 | char str[KSYM_SYMBOL_LEN]; | |
956 | char *search = NULL; | |
957 | struct ftrace_page *pg; | |
958 | struct dyn_ftrace *rec; | |
959 | int type = MATCH_FULL; | |
41c52c0d | 960 | unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f SR |
961 | unsigned i, match = 0, search_len = 0; |
962 | ||
963 | for (i = 0; i < len; i++) { | |
964 | if (buff[i] == '*') { | |
965 | if (!i) { | |
966 | search = buff + i + 1; | |
967 | type = MATCH_END_ONLY; | |
968 | search_len = len - (i + 1); | |
969 | } else { | |
970 | if (type == MATCH_END_ONLY) { | |
971 | type = MATCH_MIDDLE_ONLY; | |
972 | } else { | |
973 | match = i; | |
974 | type = MATCH_FRONT_ONLY; | |
975 | } | |
976 | buff[i] = 0; | |
977 | break; | |
978 | } | |
979 | } | |
980 | } | |
981 | ||
99ecdc43 SR |
982 | /* should not be called from interrupt context */ |
983 | spin_lock(&ftrace_lock); | |
41c52c0d SR |
984 | if (enable) |
985 | ftrace_filtered = 1; | |
5072c59f SR |
986 | pg = ftrace_pages_start; |
987 | while (pg) { | |
988 | for (i = 0; i < pg->index; i++) { | |
989 | int matched = 0; | |
990 | char *ptr; | |
991 | ||
992 | rec = &pg->records[i]; | |
993 | if (rec->flags & FTRACE_FL_FAILED) | |
994 | continue; | |
995 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
996 | switch (type) { | |
997 | case MATCH_FULL: | |
998 | if (strcmp(str, buff) == 0) | |
999 | matched = 1; | |
1000 | break; | |
1001 | case MATCH_FRONT_ONLY: | |
1002 | if (memcmp(str, buff, match) == 0) | |
1003 | matched = 1; | |
1004 | break; | |
1005 | case MATCH_MIDDLE_ONLY: | |
1006 | if (strstr(str, search)) | |
1007 | matched = 1; | |
1008 | break; | |
1009 | case MATCH_END_ONLY: | |
1010 | ptr = strstr(str, search); | |
1011 | if (ptr && (ptr[search_len] == 0)) | |
1012 | matched = 1; | |
1013 | break; | |
1014 | } | |
1015 | if (matched) | |
41c52c0d | 1016 | rec->flags |= flag; |
5072c59f SR |
1017 | } |
1018 | pg = pg->next; | |
1019 | } | |
99ecdc43 | 1020 | spin_unlock(&ftrace_lock); |
5072c59f SR |
1021 | } |
1022 | ||
e309b41d | 1023 | static ssize_t |
41c52c0d SR |
1024 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
1025 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
1026 | { |
1027 | struct ftrace_iterator *iter; | |
1028 | char ch; | |
1029 | size_t read = 0; | |
1030 | ssize_t ret; | |
1031 | ||
1032 | if (!cnt || cnt < 0) | |
1033 | return 0; | |
1034 | ||
41c52c0d | 1035 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1036 | |
1037 | if (file->f_mode & FMODE_READ) { | |
1038 | struct seq_file *m = file->private_data; | |
1039 | iter = m->private; | |
1040 | } else | |
1041 | iter = file->private_data; | |
1042 | ||
1043 | if (!*ppos) { | |
1044 | iter->flags &= ~FTRACE_ITER_CONT; | |
1045 | iter->buffer_idx = 0; | |
1046 | } | |
1047 | ||
1048 | ret = get_user(ch, ubuf++); | |
1049 | if (ret) | |
1050 | goto out; | |
1051 | read++; | |
1052 | cnt--; | |
1053 | ||
1054 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { | |
1055 | /* skip white space */ | |
1056 | while (cnt && isspace(ch)) { | |
1057 | ret = get_user(ch, ubuf++); | |
1058 | if (ret) | |
1059 | goto out; | |
1060 | read++; | |
1061 | cnt--; | |
1062 | } | |
1063 | ||
5072c59f SR |
1064 | if (isspace(ch)) { |
1065 | file->f_pos += read; | |
1066 | ret = read; | |
1067 | goto out; | |
1068 | } | |
1069 | ||
1070 | iter->buffer_idx = 0; | |
1071 | } | |
1072 | ||
1073 | while (cnt && !isspace(ch)) { | |
1074 | if (iter->buffer_idx < FTRACE_BUFF_MAX) | |
1075 | iter->buffer[iter->buffer_idx++] = ch; | |
1076 | else { | |
1077 | ret = -EINVAL; | |
1078 | goto out; | |
1079 | } | |
1080 | ret = get_user(ch, ubuf++); | |
1081 | if (ret) | |
1082 | goto out; | |
1083 | read++; | |
1084 | cnt--; | |
1085 | } | |
1086 | ||
1087 | if (isspace(ch)) { | |
1088 | iter->filtered++; | |
1089 | iter->buffer[iter->buffer_idx] = 0; | |
41c52c0d | 1090 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1091 | iter->buffer_idx = 0; |
1092 | } else | |
1093 | iter->flags |= FTRACE_ITER_CONT; | |
1094 | ||
1095 | ||
1096 | file->f_pos += read; | |
1097 | ||
1098 | ret = read; | |
1099 | out: | |
41c52c0d | 1100 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1101 | |
1102 | return ret; | |
1103 | } | |
1104 | ||
41c52c0d SR |
1105 | static ssize_t |
1106 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
1107 | size_t cnt, loff_t *ppos) | |
1108 | { | |
1109 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
1110 | } | |
1111 | ||
1112 | static ssize_t | |
1113 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
1114 | size_t cnt, loff_t *ppos) | |
1115 | { | |
1116 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
1117 | } | |
1118 | ||
1119 | static void | |
1120 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
1121 | { | |
1122 | if (unlikely(ftrace_disabled)) | |
1123 | return; | |
1124 | ||
1125 | mutex_lock(&ftrace_regex_lock); | |
1126 | if (reset) | |
1127 | ftrace_filter_reset(enable); | |
1128 | if (buf) | |
1129 | ftrace_match(buf, len, enable); | |
1130 | mutex_unlock(&ftrace_regex_lock); | |
1131 | } | |
1132 | ||
77a2b37d SR |
1133 | /** |
1134 | * ftrace_set_filter - set a function to filter on in ftrace | |
1135 | * @buf - the string that holds the function filter text. | |
1136 | * @len - the length of the string. | |
1137 | * @reset - non zero to reset all filters before applying this filter. | |
1138 | * | |
1139 | * Filters denote which functions should be enabled when tracing is enabled. | |
1140 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
1141 | */ | |
e309b41d | 1142 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 1143 | { |
41c52c0d SR |
1144 | ftrace_set_regex(buf, len, reset, 1); |
1145 | } | |
4eebcc81 | 1146 | |
41c52c0d SR |
1147 | /** |
1148 | * ftrace_set_notrace - set a function to not trace in ftrace | |
1149 | * @buf - the string that holds the function notrace text. | |
1150 | * @len - the length of the string. | |
1151 | * @reset - non zero to reset all filters before applying this filter. | |
1152 | * | |
1153 | * Notrace Filters denote which functions should not be enabled when tracing | |
1154 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
1155 | * for tracing. | |
1156 | */ | |
1157 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
1158 | { | |
1159 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
1160 | } |
1161 | ||
e309b41d | 1162 | static int |
41c52c0d | 1163 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1164 | { |
1165 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1166 | struct ftrace_iterator *iter; | |
1167 | ||
41c52c0d | 1168 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1169 | if (file->f_mode & FMODE_READ) { |
1170 | iter = m->private; | |
1171 | ||
1172 | seq_release(inode, file); | |
1173 | } else | |
1174 | iter = file->private_data; | |
1175 | ||
1176 | if (iter->buffer_idx) { | |
1177 | iter->filtered++; | |
1178 | iter->buffer[iter->buffer_idx] = 0; | |
41c52c0d | 1179 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1180 | } |
1181 | ||
1182 | mutex_lock(&ftrace_sysctl_lock); | |
cb7be3b2 | 1183 | mutex_lock(&ftrace_start_lock); |
82043278 | 1184 | if (ftrace_start && ftrace_enabled) |
5072c59f | 1185 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
cb7be3b2 | 1186 | mutex_unlock(&ftrace_start_lock); |
5072c59f SR |
1187 | mutex_unlock(&ftrace_sysctl_lock); |
1188 | ||
1189 | kfree(iter); | |
41c52c0d | 1190 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1191 | return 0; |
1192 | } | |
1193 | ||
41c52c0d SR |
1194 | static int |
1195 | ftrace_filter_release(struct inode *inode, struct file *file) | |
1196 | { | |
1197 | return ftrace_regex_release(inode, file, 1); | |
1198 | } | |
1199 | ||
1200 | static int | |
1201 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
1202 | { | |
1203 | return ftrace_regex_release(inode, file, 0); | |
1204 | } | |
1205 | ||
5072c59f SR |
1206 | static struct file_operations ftrace_avail_fops = { |
1207 | .open = ftrace_avail_open, | |
1208 | .read = seq_read, | |
1209 | .llseek = seq_lseek, | |
1210 | .release = ftrace_avail_release, | |
1211 | }; | |
1212 | ||
eb9a7bf0 AS |
1213 | static struct file_operations ftrace_failures_fops = { |
1214 | .open = ftrace_failures_open, | |
1215 | .read = seq_read, | |
1216 | .llseek = seq_lseek, | |
1217 | .release = ftrace_avail_release, | |
1218 | }; | |
1219 | ||
5072c59f SR |
1220 | static struct file_operations ftrace_filter_fops = { |
1221 | .open = ftrace_filter_open, | |
41c52c0d | 1222 | .read = ftrace_regex_read, |
5072c59f | 1223 | .write = ftrace_filter_write, |
41c52c0d | 1224 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
1225 | .release = ftrace_filter_release, |
1226 | }; | |
1227 | ||
41c52c0d SR |
1228 | static struct file_operations ftrace_notrace_fops = { |
1229 | .open = ftrace_notrace_open, | |
1230 | .read = ftrace_regex_read, | |
1231 | .write = ftrace_notrace_write, | |
1232 | .llseek = ftrace_regex_lseek, | |
1233 | .release = ftrace_notrace_release, | |
1234 | }; | |
1235 | ||
5072c59f SR |
1236 | static __init int ftrace_init_debugfs(void) |
1237 | { | |
1238 | struct dentry *d_tracer; | |
1239 | struct dentry *entry; | |
1240 | ||
1241 | d_tracer = tracing_init_dentry(); | |
1242 | ||
1243 | entry = debugfs_create_file("available_filter_functions", 0444, | |
1244 | d_tracer, NULL, &ftrace_avail_fops); | |
1245 | if (!entry) | |
1246 | pr_warning("Could not create debugfs " | |
1247 | "'available_filter_functions' entry\n"); | |
1248 | ||
eb9a7bf0 AS |
1249 | entry = debugfs_create_file("failures", 0444, |
1250 | d_tracer, NULL, &ftrace_failures_fops); | |
1251 | if (!entry) | |
1252 | pr_warning("Could not create debugfs 'failures' entry\n"); | |
1253 | ||
5072c59f SR |
1254 | entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer, |
1255 | NULL, &ftrace_filter_fops); | |
1256 | if (!entry) | |
1257 | pr_warning("Could not create debugfs " | |
1258 | "'set_ftrace_filter' entry\n"); | |
41c52c0d SR |
1259 | |
1260 | entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer, | |
1261 | NULL, &ftrace_notrace_fops); | |
1262 | if (!entry) | |
1263 | pr_warning("Could not create debugfs " | |
1264 | "'set_ftrace_notrace' entry\n"); | |
ad90c0e3 | 1265 | |
5072c59f SR |
1266 | return 0; |
1267 | } | |
1268 | ||
1269 | fs_initcall(ftrace_init_debugfs); | |
1270 | ||
68bf21aa SR |
1271 | static int ftrace_convert_nops(unsigned long *start, |
1272 | unsigned long *end) | |
1273 | { | |
1274 | unsigned long *p; | |
1275 | unsigned long addr; | |
1276 | unsigned long flags; | |
1277 | ||
08f5ac90 | 1278 | mutex_lock(&ftrace_start_lock); |
68bf21aa SR |
1279 | p = start; |
1280 | while (p < end) { | |
1281 | addr = ftrace_call_adjust(*p++); | |
1282 | ftrace_record_ip(addr); | |
68bf21aa SR |
1283 | } |
1284 | ||
08f5ac90 | 1285 | /* disable interrupts to prevent kstop machine */ |
68bf21aa | 1286 | local_irq_save(flags); |
08f5ac90 | 1287 | ftrace_update_code(); |
68bf21aa | 1288 | local_irq_restore(flags); |
08f5ac90 | 1289 | mutex_unlock(&ftrace_start_lock); |
68bf21aa SR |
1290 | |
1291 | return 0; | |
1292 | } | |
1293 | ||
90d595fe SR |
1294 | void ftrace_init_module(unsigned long *start, unsigned long *end) |
1295 | { | |
00fd61ae | 1296 | if (ftrace_disabled || start == end) |
fed1939c | 1297 | return; |
90d595fe SR |
1298 | ftrace_convert_nops(start, end); |
1299 | } | |
1300 | ||
68bf21aa SR |
1301 | extern unsigned long __start_mcount_loc[]; |
1302 | extern unsigned long __stop_mcount_loc[]; | |
1303 | ||
1304 | void __init ftrace_init(void) | |
1305 | { | |
1306 | unsigned long count, addr, flags; | |
1307 | int ret; | |
1308 | ||
1309 | /* Keep the ftrace pointer to the stub */ | |
1310 | addr = (unsigned long)ftrace_stub; | |
1311 | ||
1312 | local_irq_save(flags); | |
1313 | ftrace_dyn_arch_init(&addr); | |
1314 | local_irq_restore(flags); | |
1315 | ||
1316 | /* ftrace_dyn_arch_init places the return code in addr */ | |
1317 | if (addr) | |
1318 | goto failed; | |
1319 | ||
1320 | count = __stop_mcount_loc - __start_mcount_loc; | |
1321 | ||
1322 | ret = ftrace_dyn_table_alloc(count); | |
1323 | if (ret) | |
1324 | goto failed; | |
1325 | ||
1326 | last_ftrace_enabled = ftrace_enabled = 1; | |
1327 | ||
1328 | ret = ftrace_convert_nops(__start_mcount_loc, | |
1329 | __stop_mcount_loc); | |
1330 | ||
1331 | return; | |
1332 | failed: | |
1333 | ftrace_disabled = 1; | |
1334 | } | |
68bf21aa | 1335 | |
3d083395 | 1336 | #else |
0b6e4d56 FW |
1337 | |
1338 | static int __init ftrace_nodyn_init(void) | |
1339 | { | |
1340 | ftrace_enabled = 1; | |
1341 | return 0; | |
1342 | } | |
1343 | device_initcall(ftrace_nodyn_init); | |
1344 | ||
c7aafc54 IM |
1345 | # define ftrace_startup() do { } while (0) |
1346 | # define ftrace_shutdown() do { } while (0) | |
1347 | # define ftrace_startup_sysctl() do { } while (0) | |
1348 | # define ftrace_shutdown_sysctl() do { } while (0) | |
3d083395 SR |
1349 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
1350 | ||
a2bb6a3d | 1351 | /** |
81adbdc0 | 1352 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
1353 | * |
1354 | * This function should be used by panic code. It stops ftrace | |
1355 | * but in a not so nice way. If you need to simply kill ftrace | |
1356 | * from a non-atomic section, use ftrace_kill. | |
1357 | */ | |
81adbdc0 | 1358 | void ftrace_kill(void) |
a2bb6a3d SR |
1359 | { |
1360 | ftrace_disabled = 1; | |
1361 | ftrace_enabled = 0; | |
a2bb6a3d SR |
1362 | clear_ftrace_function(); |
1363 | } | |
1364 | ||
16444a8a | 1365 | /** |
3d083395 SR |
1366 | * register_ftrace_function - register a function for profiling |
1367 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 1368 | * |
3d083395 SR |
1369 | * Register a function to be called by all functions in the |
1370 | * kernel. | |
1371 | * | |
1372 | * Note: @ops->func and all the functions it calls must be labeled | |
1373 | * with "notrace", otherwise it will go into a | |
1374 | * recursive loop. | |
16444a8a | 1375 | */ |
3d083395 | 1376 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 1377 | { |
b0fc494f SR |
1378 | int ret; |
1379 | ||
4eebcc81 SR |
1380 | if (unlikely(ftrace_disabled)) |
1381 | return -1; | |
1382 | ||
b0fc494f | 1383 | mutex_lock(&ftrace_sysctl_lock); |
b0fc494f | 1384 | ret = __register_ftrace_function(ops); |
d61f82d0 | 1385 | ftrace_startup(); |
b0fc494f SR |
1386 | mutex_unlock(&ftrace_sysctl_lock); |
1387 | ||
1388 | return ret; | |
3d083395 SR |
1389 | } |
1390 | ||
1391 | /** | |
1392 | * unregister_ftrace_function - unresgister a function for profiling. | |
1393 | * @ops - ops structure that holds the function to unregister | |
1394 | * | |
1395 | * Unregister a function that was added to be called by ftrace profiling. | |
1396 | */ | |
1397 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
1398 | { | |
1399 | int ret; | |
1400 | ||
b0fc494f | 1401 | mutex_lock(&ftrace_sysctl_lock); |
3d083395 | 1402 | ret = __unregister_ftrace_function(ops); |
d61f82d0 | 1403 | ftrace_shutdown(); |
b0fc494f SR |
1404 | mutex_unlock(&ftrace_sysctl_lock); |
1405 | ||
1406 | return ret; | |
1407 | } | |
1408 | ||
e309b41d | 1409 | int |
b0fc494f | 1410 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
5072c59f | 1411 | struct file *file, void __user *buffer, size_t *lenp, |
b0fc494f SR |
1412 | loff_t *ppos) |
1413 | { | |
1414 | int ret; | |
1415 | ||
4eebcc81 SR |
1416 | if (unlikely(ftrace_disabled)) |
1417 | return -ENODEV; | |
1418 | ||
b0fc494f SR |
1419 | mutex_lock(&ftrace_sysctl_lock); |
1420 | ||
5072c59f | 1421 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
b0fc494f SR |
1422 | |
1423 | if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) | |
1424 | goto out; | |
1425 | ||
1426 | last_ftrace_enabled = ftrace_enabled; | |
1427 | ||
1428 | if (ftrace_enabled) { | |
1429 | ||
1430 | ftrace_startup_sysctl(); | |
1431 | ||
1432 | /* we are starting ftrace again */ | |
1433 | if (ftrace_list != &ftrace_list_end) { | |
1434 | if (ftrace_list->next == &ftrace_list_end) | |
1435 | ftrace_trace_function = ftrace_list->func; | |
1436 | else | |
1437 | ftrace_trace_function = ftrace_list_func; | |
1438 | } | |
1439 | ||
1440 | } else { | |
1441 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
1442 | ftrace_trace_function = ftrace_stub; | |
1443 | ||
1444 | ftrace_shutdown_sysctl(); | |
1445 | } | |
1446 | ||
1447 | out: | |
1448 | mutex_unlock(&ftrace_sysctl_lock); | |
3d083395 | 1449 | return ret; |
16444a8a | 1450 | } |
f17845e5 | 1451 |