Commit | Line | Data |
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16444a8a ACM |
1 | /* |
2 | * Infrastructure for profiling code inserted by 'gcc -pg'. | |
3 | * | |
4 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> | |
5 | * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com> | |
6 | * | |
7 | * Originally ported from the -rt patch by: | |
8 | * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com> | |
9 | * | |
10 | * Based on code in the latency_tracer, that is: | |
11 | * | |
12 | * Copyright (C) 2004-2006 Ingo Molnar | |
13 | * Copyright (C) 2004 William Lee Irwin III | |
14 | */ | |
15 | ||
3d083395 SR |
16 | #include <linux/stop_machine.h> |
17 | #include <linux/clocksource.h> | |
18 | #include <linux/kallsyms.h> | |
5072c59f SR |
19 | #include <linux/seq_file.h> |
20 | #include <linux/debugfs.h> | |
3d083395 | 21 | #include <linux/hardirq.h> |
2d8b820b | 22 | #include <linux/kthread.h> |
5072c59f | 23 | #include <linux/uaccess.h> |
f22f9a89 | 24 | #include <linux/kprobes.h> |
2d8b820b | 25 | #include <linux/ftrace.h> |
b0fc494f | 26 | #include <linux/sysctl.h> |
5072c59f | 27 | #include <linux/ctype.h> |
3d083395 SR |
28 | #include <linux/list.h> |
29 | ||
395a59d0 AS |
30 | #include <asm/ftrace.h> |
31 | ||
3d083395 | 32 | #include "trace.h" |
16444a8a | 33 | |
6912896e SR |
34 | #define FTRACE_WARN_ON(cond) \ |
35 | do { \ | |
36 | if (WARN_ON(cond)) \ | |
37 | ftrace_kill(); \ | |
38 | } while (0) | |
39 | ||
40 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
41 | do { \ | |
42 | if (WARN_ON_ONCE(cond)) \ | |
43 | ftrace_kill(); \ | |
44 | } while (0) | |
45 | ||
4eebcc81 SR |
46 | /* ftrace_enabled is a method to turn ftrace on or off */ |
47 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 48 | static int last_ftrace_enabled; |
b0fc494f | 49 | |
60a7ecf4 SR |
50 | /* Quick disabling of function tracer. */ |
51 | int function_trace_stop; | |
52 | ||
4eebcc81 SR |
53 | /* |
54 | * ftrace_disabled is set when an anomaly is discovered. | |
55 | * ftrace_disabled is much stronger than ftrace_enabled. | |
56 | */ | |
57 | static int ftrace_disabled __read_mostly; | |
58 | ||
3d083395 | 59 | static DEFINE_SPINLOCK(ftrace_lock); |
b0fc494f SR |
60 | static DEFINE_MUTEX(ftrace_sysctl_lock); |
61 | ||
16444a8a ACM |
62 | static struct ftrace_ops ftrace_list_end __read_mostly = |
63 | { | |
64 | .func = ftrace_stub, | |
65 | }; | |
66 | ||
67 | static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; | |
68 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; | |
60a7ecf4 | 69 | ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub; |
16444a8a | 70 | |
f2252935 | 71 | static void ftrace_list_func(unsigned long ip, unsigned long parent_ip) |
16444a8a ACM |
72 | { |
73 | struct ftrace_ops *op = ftrace_list; | |
74 | ||
75 | /* in case someone actually ports this to alpha! */ | |
76 | read_barrier_depends(); | |
77 | ||
78 | while (op != &ftrace_list_end) { | |
79 | /* silly alpha */ | |
80 | read_barrier_depends(); | |
81 | op->func(ip, parent_ip); | |
82 | op = op->next; | |
83 | }; | |
84 | } | |
85 | ||
86 | /** | |
3d083395 | 87 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 88 | * |
3d083395 SR |
89 | * This NULLs the ftrace function and in essence stops |
90 | * tracing. There may be lag | |
16444a8a | 91 | */ |
3d083395 | 92 | void clear_ftrace_function(void) |
16444a8a | 93 | { |
3d083395 | 94 | ftrace_trace_function = ftrace_stub; |
60a7ecf4 | 95 | __ftrace_trace_function = ftrace_stub; |
3d083395 SR |
96 | } |
97 | ||
60a7ecf4 SR |
98 | #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
99 | /* | |
100 | * For those archs that do not test ftrace_trace_stop in their | |
101 | * mcount call site, we need to do it from C. | |
102 | */ | |
103 | static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip) | |
104 | { | |
105 | if (function_trace_stop) | |
106 | return; | |
107 | ||
108 | __ftrace_trace_function(ip, parent_ip); | |
109 | } | |
110 | #endif | |
111 | ||
e309b41d | 112 | static int __register_ftrace_function(struct ftrace_ops *ops) |
3d083395 | 113 | { |
99ecdc43 | 114 | /* should not be called from interrupt context */ |
3d083395 | 115 | spin_lock(&ftrace_lock); |
16444a8a | 116 | |
16444a8a ACM |
117 | ops->next = ftrace_list; |
118 | /* | |
119 | * We are entering ops into the ftrace_list but another | |
120 | * CPU might be walking that list. We need to make sure | |
121 | * the ops->next pointer is valid before another CPU sees | |
122 | * the ops pointer included into the ftrace_list. | |
123 | */ | |
124 | smp_wmb(); | |
125 | ftrace_list = ops; | |
3d083395 | 126 | |
b0fc494f SR |
127 | if (ftrace_enabled) { |
128 | /* | |
129 | * For one func, simply call it directly. | |
130 | * For more than one func, call the chain. | |
131 | */ | |
60a7ecf4 | 132 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
b0fc494f SR |
133 | if (ops->next == &ftrace_list_end) |
134 | ftrace_trace_function = ops->func; | |
135 | else | |
136 | ftrace_trace_function = ftrace_list_func; | |
60a7ecf4 SR |
137 | #else |
138 | if (ops->next == &ftrace_list_end) | |
139 | __ftrace_trace_function = ops->func; | |
140 | else | |
141 | __ftrace_trace_function = ftrace_list_func; | |
142 | ftrace_trace_function = ftrace_test_stop_func; | |
143 | #endif | |
b0fc494f | 144 | } |
3d083395 SR |
145 | |
146 | spin_unlock(&ftrace_lock); | |
16444a8a ACM |
147 | |
148 | return 0; | |
149 | } | |
150 | ||
e309b41d | 151 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 152 | { |
16444a8a ACM |
153 | struct ftrace_ops **p; |
154 | int ret = 0; | |
155 | ||
99ecdc43 | 156 | /* should not be called from interrupt context */ |
3d083395 | 157 | spin_lock(&ftrace_lock); |
16444a8a ACM |
158 | |
159 | /* | |
3d083395 SR |
160 | * If we are removing the last function, then simply point |
161 | * to the ftrace_stub. | |
16444a8a ACM |
162 | */ |
163 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { | |
164 | ftrace_trace_function = ftrace_stub; | |
165 | ftrace_list = &ftrace_list_end; | |
166 | goto out; | |
167 | } | |
168 | ||
169 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) | |
170 | if (*p == ops) | |
171 | break; | |
172 | ||
173 | if (*p != ops) { | |
174 | ret = -1; | |
175 | goto out; | |
176 | } | |
177 | ||
178 | *p = (*p)->next; | |
179 | ||
b0fc494f SR |
180 | if (ftrace_enabled) { |
181 | /* If we only have one func left, then call that directly */ | |
182 | if (ftrace_list == &ftrace_list_end || | |
183 | ftrace_list->next == &ftrace_list_end) | |
184 | ftrace_trace_function = ftrace_list->func; | |
185 | } | |
16444a8a ACM |
186 | |
187 | out: | |
3d083395 SR |
188 | spin_unlock(&ftrace_lock); |
189 | ||
190 | return ret; | |
191 | } | |
192 | ||
193 | #ifdef CONFIG_DYNAMIC_FTRACE | |
99ecdc43 | 194 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
cb7be3b2 | 195 | # error Dynamic ftrace depends on MCOUNT_RECORD |
99ecdc43 SR |
196 | #endif |
197 | ||
71c67d58 SN |
198 | /* |
199 | * Since MCOUNT_ADDR may point to mcount itself, we do not want | |
200 | * to get it confused by reading a reference in the code as we | |
201 | * are parsing on objcopy output of text. Use a variable for | |
202 | * it instead. | |
203 | */ | |
204 | static unsigned long mcount_addr = MCOUNT_ADDR; | |
205 | ||
d61f82d0 SR |
206 | enum { |
207 | FTRACE_ENABLE_CALLS = (1 << 0), | |
208 | FTRACE_DISABLE_CALLS = (1 << 1), | |
209 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
210 | FTRACE_ENABLE_MCOUNT = (1 << 3), | |
211 | FTRACE_DISABLE_MCOUNT = (1 << 4), | |
212 | }; | |
213 | ||
5072c59f | 214 | static int ftrace_filtered; |
ecea656d | 215 | static int tracing_on; |
5072c59f | 216 | |
08f5ac90 | 217 | static LIST_HEAD(ftrace_new_addrs); |
3d083395 | 218 | |
41c52c0d | 219 | static DEFINE_MUTEX(ftrace_regex_lock); |
3d083395 | 220 | |
3c1720f0 SR |
221 | struct ftrace_page { |
222 | struct ftrace_page *next; | |
aa5e5cea | 223 | unsigned long index; |
3c1720f0 | 224 | struct dyn_ftrace records[]; |
aa5e5cea | 225 | }; |
3c1720f0 SR |
226 | |
227 | #define ENTRIES_PER_PAGE \ | |
228 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
229 | ||
230 | /* estimate from running different kernels */ | |
231 | #define NR_TO_INIT 10000 | |
232 | ||
233 | static struct ftrace_page *ftrace_pages_start; | |
234 | static struct ftrace_page *ftrace_pages; | |
235 | ||
37ad5084 SR |
236 | static struct dyn_ftrace *ftrace_free_records; |
237 | ||
ecea656d AS |
238 | |
239 | #ifdef CONFIG_KPROBES | |
f17845e5 IM |
240 | |
241 | static int frozen_record_count; | |
242 | ||
ecea656d AS |
243 | static inline void freeze_record(struct dyn_ftrace *rec) |
244 | { | |
245 | if (!(rec->flags & FTRACE_FL_FROZEN)) { | |
246 | rec->flags |= FTRACE_FL_FROZEN; | |
247 | frozen_record_count++; | |
248 | } | |
249 | } | |
250 | ||
251 | static inline void unfreeze_record(struct dyn_ftrace *rec) | |
252 | { | |
253 | if (rec->flags & FTRACE_FL_FROZEN) { | |
254 | rec->flags &= ~FTRACE_FL_FROZEN; | |
255 | frozen_record_count--; | |
256 | } | |
257 | } | |
258 | ||
259 | static inline int record_frozen(struct dyn_ftrace *rec) | |
260 | { | |
261 | return rec->flags & FTRACE_FL_FROZEN; | |
262 | } | |
263 | #else | |
264 | # define freeze_record(rec) ({ 0; }) | |
265 | # define unfreeze_record(rec) ({ 0; }) | |
266 | # define record_frozen(rec) ({ 0; }) | |
267 | #endif /* CONFIG_KPROBES */ | |
268 | ||
e309b41d | 269 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
37ad5084 | 270 | { |
37ad5084 SR |
271 | rec->ip = (unsigned long)ftrace_free_records; |
272 | ftrace_free_records = rec; | |
273 | rec->flags |= FTRACE_FL_FREE; | |
274 | } | |
275 | ||
fed1939c SR |
276 | void ftrace_release(void *start, unsigned long size) |
277 | { | |
278 | struct dyn_ftrace *rec; | |
279 | struct ftrace_page *pg; | |
280 | unsigned long s = (unsigned long)start; | |
281 | unsigned long e = s + size; | |
282 | int i; | |
283 | ||
00fd61ae | 284 | if (ftrace_disabled || !start) |
fed1939c SR |
285 | return; |
286 | ||
99ecdc43 | 287 | /* should not be called from interrupt context */ |
fed1939c SR |
288 | spin_lock(&ftrace_lock); |
289 | ||
290 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
291 | for (i = 0; i < pg->index; i++) { | |
292 | rec = &pg->records[i]; | |
293 | ||
294 | if ((rec->ip >= s) && (rec->ip < e)) | |
295 | ftrace_free_rec(rec); | |
296 | } | |
297 | } | |
298 | spin_unlock(&ftrace_lock); | |
fed1939c SR |
299 | } |
300 | ||
e309b41d | 301 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 302 | { |
37ad5084 SR |
303 | struct dyn_ftrace *rec; |
304 | ||
305 | /* First check for freed records */ | |
306 | if (ftrace_free_records) { | |
307 | rec = ftrace_free_records; | |
308 | ||
37ad5084 | 309 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
6912896e | 310 | FTRACE_WARN_ON_ONCE(1); |
37ad5084 SR |
311 | ftrace_free_records = NULL; |
312 | return NULL; | |
313 | } | |
314 | ||
315 | ftrace_free_records = (void *)rec->ip; | |
316 | memset(rec, 0, sizeof(*rec)); | |
317 | return rec; | |
318 | } | |
319 | ||
3c1720f0 | 320 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
08f5ac90 SR |
321 | if (!ftrace_pages->next) { |
322 | /* allocate another page */ | |
323 | ftrace_pages->next = | |
324 | (void *)get_zeroed_page(GFP_KERNEL); | |
325 | if (!ftrace_pages->next) | |
326 | return NULL; | |
327 | } | |
3c1720f0 SR |
328 | ftrace_pages = ftrace_pages->next; |
329 | } | |
330 | ||
331 | return &ftrace_pages->records[ftrace_pages->index++]; | |
332 | } | |
333 | ||
08f5ac90 | 334 | static struct dyn_ftrace * |
d61f82d0 | 335 | ftrace_record_ip(unsigned long ip) |
3d083395 | 336 | { |
08f5ac90 | 337 | struct dyn_ftrace *rec; |
3d083395 | 338 | |
4eebcc81 | 339 | if (!ftrace_enabled || ftrace_disabled) |
08f5ac90 | 340 | return NULL; |
3d083395 | 341 | |
08f5ac90 SR |
342 | rec = ftrace_alloc_dyn_node(ip); |
343 | if (!rec) | |
344 | return NULL; | |
3d083395 | 345 | |
08f5ac90 | 346 | rec->ip = ip; |
3d083395 | 347 | |
08f5ac90 | 348 | list_add(&rec->list, &ftrace_new_addrs); |
3d083395 | 349 | |
08f5ac90 | 350 | return rec; |
3d083395 SR |
351 | } |
352 | ||
caf8cdeb | 353 | #define FTRACE_ADDR ((long)(ftrace_caller)) |
3c1720f0 | 354 | |
0eb96701 | 355 | static int |
5072c59f SR |
356 | __ftrace_replace_code(struct dyn_ftrace *rec, |
357 | unsigned char *old, unsigned char *new, int enable) | |
358 | { | |
41c52c0d | 359 | unsigned long ip, fl; |
5072c59f SR |
360 | |
361 | ip = rec->ip; | |
362 | ||
363 | if (ftrace_filtered && enable) { | |
5072c59f SR |
364 | /* |
365 | * If filtering is on: | |
366 | * | |
367 | * If this record is set to be filtered and | |
368 | * is enabled then do nothing. | |
369 | * | |
370 | * If this record is set to be filtered and | |
371 | * it is not enabled, enable it. | |
372 | * | |
373 | * If this record is not set to be filtered | |
374 | * and it is not enabled do nothing. | |
375 | * | |
41c52c0d SR |
376 | * If this record is set not to trace then |
377 | * do nothing. | |
378 | * | |
a4500b84 AS |
379 | * If this record is set not to trace and |
380 | * it is enabled then disable it. | |
381 | * | |
5072c59f SR |
382 | * If this record is not set to be filtered and |
383 | * it is enabled, disable it. | |
384 | */ | |
a4500b84 AS |
385 | |
386 | fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE | | |
387 | FTRACE_FL_ENABLED); | |
5072c59f SR |
388 | |
389 | if ((fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) || | |
a4500b84 AS |
390 | (fl == (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE)) || |
391 | !fl || (fl == FTRACE_FL_NOTRACE)) | |
0eb96701 | 392 | return 0; |
5072c59f SR |
393 | |
394 | /* | |
395 | * If it is enabled disable it, | |
396 | * otherwise enable it! | |
397 | */ | |
a4500b84 | 398 | if (fl & FTRACE_FL_ENABLED) { |
5072c59f SR |
399 | /* swap new and old */ |
400 | new = old; | |
401 | old = ftrace_call_replace(ip, FTRACE_ADDR); | |
402 | rec->flags &= ~FTRACE_FL_ENABLED; | |
403 | } else { | |
404 | new = ftrace_call_replace(ip, FTRACE_ADDR); | |
405 | rec->flags |= FTRACE_FL_ENABLED; | |
406 | } | |
407 | } else { | |
408 | ||
41c52c0d SR |
409 | if (enable) { |
410 | /* | |
411 | * If this record is set not to trace and is | |
412 | * not enabled, do nothing. | |
413 | */ | |
414 | fl = rec->flags & (FTRACE_FL_NOTRACE | FTRACE_FL_ENABLED); | |
415 | if (fl == FTRACE_FL_NOTRACE) | |
0eb96701 | 416 | return 0; |
41c52c0d | 417 | |
5072c59f | 418 | new = ftrace_call_replace(ip, FTRACE_ADDR); |
41c52c0d | 419 | } else |
5072c59f SR |
420 | old = ftrace_call_replace(ip, FTRACE_ADDR); |
421 | ||
422 | if (enable) { | |
423 | if (rec->flags & FTRACE_FL_ENABLED) | |
0eb96701 | 424 | return 0; |
5072c59f SR |
425 | rec->flags |= FTRACE_FL_ENABLED; |
426 | } else { | |
427 | if (!(rec->flags & FTRACE_FL_ENABLED)) | |
0eb96701 | 428 | return 0; |
5072c59f SR |
429 | rec->flags &= ~FTRACE_FL_ENABLED; |
430 | } | |
431 | } | |
432 | ||
0eb96701 | 433 | return ftrace_modify_code(ip, old, new); |
5072c59f SR |
434 | } |
435 | ||
e309b41d | 436 | static void ftrace_replace_code(int enable) |
3c1720f0 | 437 | { |
0eb96701 | 438 | int i, failed; |
3c1720f0 SR |
439 | unsigned char *new = NULL, *old = NULL; |
440 | struct dyn_ftrace *rec; | |
441 | struct ftrace_page *pg; | |
3c1720f0 | 442 | |
5072c59f | 443 | if (enable) |
3c1720f0 SR |
444 | old = ftrace_nop_replace(); |
445 | else | |
446 | new = ftrace_nop_replace(); | |
447 | ||
448 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
449 | for (i = 0; i < pg->index; i++) { | |
450 | rec = &pg->records[i]; | |
451 | ||
452 | /* don't modify code that has already faulted */ | |
453 | if (rec->flags & FTRACE_FL_FAILED) | |
454 | continue; | |
455 | ||
f22f9a89 | 456 | /* ignore updates to this record's mcount site */ |
98a05ed4 AS |
457 | if (get_kprobe((void *)rec->ip)) { |
458 | freeze_record(rec); | |
f22f9a89 | 459 | continue; |
98a05ed4 AS |
460 | } else { |
461 | unfreeze_record(rec); | |
462 | } | |
f22f9a89 | 463 | |
0eb96701 AS |
464 | failed = __ftrace_replace_code(rec, old, new, enable); |
465 | if (failed && (rec->flags & FTRACE_FL_CONVERTED)) { | |
466 | rec->flags |= FTRACE_FL_FAILED; | |
467 | if ((system_state == SYSTEM_BOOTING) || | |
34078a5e | 468 | !core_kernel_text(rec->ip)) { |
0eb96701 AS |
469 | ftrace_free_rec(rec); |
470 | } | |
471 | } | |
3c1720f0 SR |
472 | } |
473 | } | |
474 | } | |
475 | ||
05736a42 SR |
476 | static void print_ip_ins(const char *fmt, unsigned char *p) |
477 | { | |
478 | int i; | |
479 | ||
480 | printk(KERN_CONT "%s", fmt); | |
481 | ||
482 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
483 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
484 | } | |
485 | ||
492a7ea5 | 486 | static int |
d61f82d0 | 487 | ftrace_code_disable(struct dyn_ftrace *rec) |
3c1720f0 SR |
488 | { |
489 | unsigned long ip; | |
490 | unsigned char *nop, *call; | |
593eb8a2 | 491 | int ret; |
3c1720f0 SR |
492 | |
493 | ip = rec->ip; | |
494 | ||
495 | nop = ftrace_nop_replace(); | |
3b47bfc1 | 496 | call = ftrace_call_replace(ip, mcount_addr); |
3c1720f0 | 497 | |
593eb8a2 SR |
498 | ret = ftrace_modify_code(ip, call, nop); |
499 | if (ret) { | |
500 | switch (ret) { | |
501 | case -EFAULT: | |
6912896e | 502 | FTRACE_WARN_ON_ONCE(1); |
05736a42 SR |
503 | pr_info("ftrace faulted on modifying "); |
504 | print_ip_sym(ip); | |
505 | break; | |
593eb8a2 | 506 | case -EINVAL: |
6912896e | 507 | FTRACE_WARN_ON_ONCE(1); |
05736a42 SR |
508 | pr_info("ftrace failed to modify "); |
509 | print_ip_sym(ip); | |
510 | print_ip_ins(" expected: ", call); | |
511 | print_ip_ins(" actual: ", (unsigned char *)ip); | |
512 | print_ip_ins(" replace: ", nop); | |
513 | printk(KERN_CONT "\n"); | |
514 | break; | |
593eb8a2 | 515 | case -EPERM: |
6912896e | 516 | FTRACE_WARN_ON_ONCE(1); |
593eb8a2 SR |
517 | pr_info("ftrace faulted on writing "); |
518 | print_ip_sym(ip); | |
519 | break; | |
520 | default: | |
6912896e | 521 | FTRACE_WARN_ON_ONCE(1); |
593eb8a2 SR |
522 | pr_info("ftrace faulted on unknown error "); |
523 | print_ip_sym(ip); | |
05736a42 SR |
524 | } |
525 | ||
3c1720f0 | 526 | rec->flags |= FTRACE_FL_FAILED; |
492a7ea5 | 527 | return 0; |
37ad5084 | 528 | } |
492a7ea5 | 529 | return 1; |
3c1720f0 SR |
530 | } |
531 | ||
e309b41d | 532 | static int __ftrace_modify_code(void *data) |
3d083395 | 533 | { |
d61f82d0 SR |
534 | int *command = data; |
535 | ||
ad90c0e3 | 536 | if (*command & FTRACE_ENABLE_CALLS) { |
d61f82d0 | 537 | ftrace_replace_code(1); |
ecea656d AS |
538 | tracing_on = 1; |
539 | } else if (*command & FTRACE_DISABLE_CALLS) { | |
d61f82d0 | 540 | ftrace_replace_code(0); |
ecea656d AS |
541 | tracing_on = 0; |
542 | } | |
d61f82d0 SR |
543 | |
544 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
545 | ftrace_update_ftrace_func(ftrace_trace_function); | |
546 | ||
d61f82d0 | 547 | return 0; |
3d083395 SR |
548 | } |
549 | ||
e309b41d | 550 | static void ftrace_run_update_code(int command) |
3d083395 | 551 | { |
784e2d76 | 552 | stop_machine(__ftrace_modify_code, &command, NULL); |
3d083395 SR |
553 | } |
554 | ||
d61f82d0 | 555 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 556 | static int ftrace_start_up; |
cb7be3b2 | 557 | static DEFINE_MUTEX(ftrace_start_lock); |
d61f82d0 | 558 | |
e309b41d | 559 | static void ftrace_startup(void) |
3d083395 | 560 | { |
d61f82d0 SR |
561 | int command = 0; |
562 | ||
4eebcc81 SR |
563 | if (unlikely(ftrace_disabled)) |
564 | return; | |
565 | ||
cb7be3b2 | 566 | mutex_lock(&ftrace_start_lock); |
60a7ecf4 SR |
567 | ftrace_start_up++; |
568 | if (ftrace_start_up == 1) | |
d61f82d0 SR |
569 | command |= FTRACE_ENABLE_CALLS; |
570 | ||
571 | if (saved_ftrace_func != ftrace_trace_function) { | |
572 | saved_ftrace_func = ftrace_trace_function; | |
573 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
574 | } | |
575 | ||
576 | if (!command || !ftrace_enabled) | |
3d083395 | 577 | goto out; |
3d083395 | 578 | |
d61f82d0 | 579 | ftrace_run_update_code(command); |
3d083395 | 580 | out: |
cb7be3b2 | 581 | mutex_unlock(&ftrace_start_lock); |
3d083395 SR |
582 | } |
583 | ||
e309b41d | 584 | static void ftrace_shutdown(void) |
3d083395 | 585 | { |
d61f82d0 SR |
586 | int command = 0; |
587 | ||
4eebcc81 SR |
588 | if (unlikely(ftrace_disabled)) |
589 | return; | |
590 | ||
cb7be3b2 | 591 | mutex_lock(&ftrace_start_lock); |
60a7ecf4 SR |
592 | ftrace_start_up--; |
593 | if (!ftrace_start_up) | |
d61f82d0 | 594 | command |= FTRACE_DISABLE_CALLS; |
3d083395 | 595 | |
d61f82d0 SR |
596 | if (saved_ftrace_func != ftrace_trace_function) { |
597 | saved_ftrace_func = ftrace_trace_function; | |
598 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
599 | } | |
3d083395 | 600 | |
d61f82d0 SR |
601 | if (!command || !ftrace_enabled) |
602 | goto out; | |
603 | ||
604 | ftrace_run_update_code(command); | |
3d083395 | 605 | out: |
cb7be3b2 | 606 | mutex_unlock(&ftrace_start_lock); |
3d083395 SR |
607 | } |
608 | ||
e309b41d | 609 | static void ftrace_startup_sysctl(void) |
b0fc494f | 610 | { |
d61f82d0 SR |
611 | int command = FTRACE_ENABLE_MCOUNT; |
612 | ||
4eebcc81 SR |
613 | if (unlikely(ftrace_disabled)) |
614 | return; | |
615 | ||
cb7be3b2 | 616 | mutex_lock(&ftrace_start_lock); |
d61f82d0 SR |
617 | /* Force update next time */ |
618 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
619 | /* ftrace_start_up is true if we want ftrace running */ |
620 | if (ftrace_start_up) | |
d61f82d0 SR |
621 | command |= FTRACE_ENABLE_CALLS; |
622 | ||
623 | ftrace_run_update_code(command); | |
cb7be3b2 | 624 | mutex_unlock(&ftrace_start_lock); |
b0fc494f SR |
625 | } |
626 | ||
e309b41d | 627 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 628 | { |
d61f82d0 SR |
629 | int command = FTRACE_DISABLE_MCOUNT; |
630 | ||
4eebcc81 SR |
631 | if (unlikely(ftrace_disabled)) |
632 | return; | |
633 | ||
cb7be3b2 | 634 | mutex_lock(&ftrace_start_lock); |
60a7ecf4 SR |
635 | /* ftrace_start_up is true if ftrace is running */ |
636 | if (ftrace_start_up) | |
d61f82d0 SR |
637 | command |= FTRACE_DISABLE_CALLS; |
638 | ||
639 | ftrace_run_update_code(command); | |
cb7be3b2 | 640 | mutex_unlock(&ftrace_start_lock); |
b0fc494f SR |
641 | } |
642 | ||
3d083395 SR |
643 | static cycle_t ftrace_update_time; |
644 | static unsigned long ftrace_update_cnt; | |
645 | unsigned long ftrace_update_tot_cnt; | |
646 | ||
08f5ac90 | 647 | static int ftrace_update_code(void) |
3d083395 | 648 | { |
08f5ac90 | 649 | struct dyn_ftrace *p, *t; |
f22f9a89 | 650 | cycle_t start, stop; |
3d083395 | 651 | |
750ed1a4 | 652 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
653 | ftrace_update_cnt = 0; |
654 | ||
08f5ac90 | 655 | list_for_each_entry_safe(p, t, &ftrace_new_addrs, list) { |
3d083395 | 656 | |
08f5ac90 SR |
657 | /* If something went wrong, bail without enabling anything */ |
658 | if (unlikely(ftrace_disabled)) | |
659 | return -1; | |
f22f9a89 | 660 | |
08f5ac90 | 661 | list_del_init(&p->list); |
f22f9a89 | 662 | |
08f5ac90 SR |
663 | /* convert record (i.e, patch mcount-call with NOP) */ |
664 | if (ftrace_code_disable(p)) { | |
665 | p->flags |= FTRACE_FL_CONVERTED; | |
666 | ftrace_update_cnt++; | |
667 | } else | |
668 | ftrace_free_rec(p); | |
3d083395 SR |
669 | } |
670 | ||
750ed1a4 | 671 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
672 | ftrace_update_time = stop - start; |
673 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
674 | ||
16444a8a ACM |
675 | return 0; |
676 | } | |
677 | ||
68bf21aa | 678 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
679 | { |
680 | struct ftrace_page *pg; | |
681 | int cnt; | |
682 | int i; | |
3c1720f0 SR |
683 | |
684 | /* allocate a few pages */ | |
685 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
686 | if (!ftrace_pages_start) | |
687 | return -1; | |
688 | ||
689 | /* | |
690 | * Allocate a few more pages. | |
691 | * | |
692 | * TODO: have some parser search vmlinux before | |
693 | * final linking to find all calls to ftrace. | |
694 | * Then we can: | |
695 | * a) know how many pages to allocate. | |
696 | * and/or | |
697 | * b) set up the table then. | |
698 | * | |
699 | * The dynamic code is still necessary for | |
700 | * modules. | |
701 | */ | |
702 | ||
703 | pg = ftrace_pages = ftrace_pages_start; | |
704 | ||
68bf21aa | 705 | cnt = num_to_init / ENTRIES_PER_PAGE; |
08f5ac90 | 706 | pr_info("ftrace: allocating %ld entries in %d pages\n", |
68bf21aa | 707 | num_to_init, cnt); |
3c1720f0 SR |
708 | |
709 | for (i = 0; i < cnt; i++) { | |
710 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
711 | ||
712 | /* If we fail, we'll try later anyway */ | |
713 | if (!pg->next) | |
714 | break; | |
715 | ||
716 | pg = pg->next; | |
717 | } | |
718 | ||
719 | return 0; | |
720 | } | |
721 | ||
5072c59f SR |
722 | enum { |
723 | FTRACE_ITER_FILTER = (1 << 0), | |
724 | FTRACE_ITER_CONT = (1 << 1), | |
41c52c0d | 725 | FTRACE_ITER_NOTRACE = (1 << 2), |
eb9a7bf0 | 726 | FTRACE_ITER_FAILURES = (1 << 3), |
5072c59f SR |
727 | }; |
728 | ||
729 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
730 | ||
731 | struct ftrace_iterator { | |
732 | loff_t pos; | |
733 | struct ftrace_page *pg; | |
734 | unsigned idx; | |
735 | unsigned flags; | |
736 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
737 | unsigned buffer_idx; | |
738 | unsigned filtered; | |
739 | }; | |
740 | ||
e309b41d | 741 | static void * |
5072c59f SR |
742 | t_next(struct seq_file *m, void *v, loff_t *pos) |
743 | { | |
744 | struct ftrace_iterator *iter = m->private; | |
745 | struct dyn_ftrace *rec = NULL; | |
746 | ||
747 | (*pos)++; | |
748 | ||
99ecdc43 SR |
749 | /* should not be called from interrupt context */ |
750 | spin_lock(&ftrace_lock); | |
5072c59f SR |
751 | retry: |
752 | if (iter->idx >= iter->pg->index) { | |
753 | if (iter->pg->next) { | |
754 | iter->pg = iter->pg->next; | |
755 | iter->idx = 0; | |
756 | goto retry; | |
757 | } | |
758 | } else { | |
759 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
760 | if ((rec->flags & FTRACE_FL_FREE) || |
761 | ||
762 | (!(iter->flags & FTRACE_ITER_FAILURES) && | |
eb9a7bf0 AS |
763 | (rec->flags & FTRACE_FL_FAILED)) || |
764 | ||
765 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
a9fdda33 | 766 | !(rec->flags & FTRACE_FL_FAILED)) || |
eb9a7bf0 | 767 | |
41c52c0d SR |
768 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
769 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
770 | rec = NULL; |
771 | goto retry; | |
772 | } | |
773 | } | |
99ecdc43 | 774 | spin_unlock(&ftrace_lock); |
5072c59f SR |
775 | |
776 | iter->pos = *pos; | |
777 | ||
778 | return rec; | |
779 | } | |
780 | ||
781 | static void *t_start(struct seq_file *m, loff_t *pos) | |
782 | { | |
783 | struct ftrace_iterator *iter = m->private; | |
784 | void *p = NULL; | |
785 | loff_t l = -1; | |
786 | ||
787 | if (*pos != iter->pos) { | |
788 | for (p = t_next(m, p, &l); p && l < *pos; p = t_next(m, p, &l)) | |
789 | ; | |
790 | } else { | |
791 | l = *pos; | |
792 | p = t_next(m, p, &l); | |
793 | } | |
794 | ||
795 | return p; | |
796 | } | |
797 | ||
798 | static void t_stop(struct seq_file *m, void *p) | |
799 | { | |
800 | } | |
801 | ||
802 | static int t_show(struct seq_file *m, void *v) | |
803 | { | |
804 | struct dyn_ftrace *rec = v; | |
805 | char str[KSYM_SYMBOL_LEN]; | |
806 | ||
807 | if (!rec) | |
808 | return 0; | |
809 | ||
810 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
811 | ||
812 | seq_printf(m, "%s\n", str); | |
813 | ||
814 | return 0; | |
815 | } | |
816 | ||
817 | static struct seq_operations show_ftrace_seq_ops = { | |
818 | .start = t_start, | |
819 | .next = t_next, | |
820 | .stop = t_stop, | |
821 | .show = t_show, | |
822 | }; | |
823 | ||
e309b41d | 824 | static int |
5072c59f SR |
825 | ftrace_avail_open(struct inode *inode, struct file *file) |
826 | { | |
827 | struct ftrace_iterator *iter; | |
828 | int ret; | |
829 | ||
4eebcc81 SR |
830 | if (unlikely(ftrace_disabled)) |
831 | return -ENODEV; | |
832 | ||
5072c59f SR |
833 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
834 | if (!iter) | |
835 | return -ENOMEM; | |
836 | ||
837 | iter->pg = ftrace_pages_start; | |
838 | iter->pos = -1; | |
839 | ||
840 | ret = seq_open(file, &show_ftrace_seq_ops); | |
841 | if (!ret) { | |
842 | struct seq_file *m = file->private_data; | |
4bf39a94 | 843 | |
5072c59f | 844 | m->private = iter; |
4bf39a94 | 845 | } else { |
5072c59f | 846 | kfree(iter); |
4bf39a94 | 847 | } |
5072c59f SR |
848 | |
849 | return ret; | |
850 | } | |
851 | ||
852 | int ftrace_avail_release(struct inode *inode, struct file *file) | |
853 | { | |
854 | struct seq_file *m = (struct seq_file *)file->private_data; | |
855 | struct ftrace_iterator *iter = m->private; | |
856 | ||
857 | seq_release(inode, file); | |
858 | kfree(iter); | |
4bf39a94 | 859 | |
5072c59f SR |
860 | return 0; |
861 | } | |
862 | ||
eb9a7bf0 AS |
863 | static int |
864 | ftrace_failures_open(struct inode *inode, struct file *file) | |
865 | { | |
866 | int ret; | |
867 | struct seq_file *m; | |
868 | struct ftrace_iterator *iter; | |
869 | ||
870 | ret = ftrace_avail_open(inode, file); | |
871 | if (!ret) { | |
872 | m = (struct seq_file *)file->private_data; | |
873 | iter = (struct ftrace_iterator *)m->private; | |
874 | iter->flags = FTRACE_ITER_FAILURES; | |
875 | } | |
876 | ||
877 | return ret; | |
878 | } | |
879 | ||
880 | ||
41c52c0d | 881 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
882 | { |
883 | struct ftrace_page *pg; | |
884 | struct dyn_ftrace *rec; | |
41c52c0d | 885 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f SR |
886 | unsigned i; |
887 | ||
99ecdc43 SR |
888 | /* should not be called from interrupt context */ |
889 | spin_lock(&ftrace_lock); | |
41c52c0d SR |
890 | if (enable) |
891 | ftrace_filtered = 0; | |
5072c59f SR |
892 | pg = ftrace_pages_start; |
893 | while (pg) { | |
894 | for (i = 0; i < pg->index; i++) { | |
895 | rec = &pg->records[i]; | |
896 | if (rec->flags & FTRACE_FL_FAILED) | |
897 | continue; | |
41c52c0d | 898 | rec->flags &= ~type; |
5072c59f SR |
899 | } |
900 | pg = pg->next; | |
901 | } | |
99ecdc43 | 902 | spin_unlock(&ftrace_lock); |
5072c59f SR |
903 | } |
904 | ||
e309b41d | 905 | static int |
41c52c0d | 906 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
907 | { |
908 | struct ftrace_iterator *iter; | |
909 | int ret = 0; | |
910 | ||
4eebcc81 SR |
911 | if (unlikely(ftrace_disabled)) |
912 | return -ENODEV; | |
913 | ||
5072c59f SR |
914 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
915 | if (!iter) | |
916 | return -ENOMEM; | |
917 | ||
41c52c0d | 918 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
919 | if ((file->f_mode & FMODE_WRITE) && |
920 | !(file->f_flags & O_APPEND)) | |
41c52c0d | 921 | ftrace_filter_reset(enable); |
5072c59f SR |
922 | |
923 | if (file->f_mode & FMODE_READ) { | |
924 | iter->pg = ftrace_pages_start; | |
925 | iter->pos = -1; | |
41c52c0d SR |
926 | iter->flags = enable ? FTRACE_ITER_FILTER : |
927 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
928 | |
929 | ret = seq_open(file, &show_ftrace_seq_ops); | |
930 | if (!ret) { | |
931 | struct seq_file *m = file->private_data; | |
932 | m->private = iter; | |
933 | } else | |
934 | kfree(iter); | |
935 | } else | |
936 | file->private_data = iter; | |
41c52c0d | 937 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
938 | |
939 | return ret; | |
940 | } | |
941 | ||
41c52c0d SR |
942 | static int |
943 | ftrace_filter_open(struct inode *inode, struct file *file) | |
944 | { | |
945 | return ftrace_regex_open(inode, file, 1); | |
946 | } | |
947 | ||
948 | static int | |
949 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
950 | { | |
951 | return ftrace_regex_open(inode, file, 0); | |
952 | } | |
953 | ||
e309b41d | 954 | static ssize_t |
41c52c0d | 955 | ftrace_regex_read(struct file *file, char __user *ubuf, |
5072c59f SR |
956 | size_t cnt, loff_t *ppos) |
957 | { | |
958 | if (file->f_mode & FMODE_READ) | |
959 | return seq_read(file, ubuf, cnt, ppos); | |
960 | else | |
961 | return -EPERM; | |
962 | } | |
963 | ||
e309b41d | 964 | static loff_t |
41c52c0d | 965 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
966 | { |
967 | loff_t ret; | |
968 | ||
969 | if (file->f_mode & FMODE_READ) | |
970 | ret = seq_lseek(file, offset, origin); | |
971 | else | |
972 | file->f_pos = ret = 1; | |
973 | ||
974 | return ret; | |
975 | } | |
976 | ||
977 | enum { | |
978 | MATCH_FULL, | |
979 | MATCH_FRONT_ONLY, | |
980 | MATCH_MIDDLE_ONLY, | |
981 | MATCH_END_ONLY, | |
982 | }; | |
983 | ||
e309b41d | 984 | static void |
41c52c0d | 985 | ftrace_match(unsigned char *buff, int len, int enable) |
5072c59f SR |
986 | { |
987 | char str[KSYM_SYMBOL_LEN]; | |
988 | char *search = NULL; | |
989 | struct ftrace_page *pg; | |
990 | struct dyn_ftrace *rec; | |
991 | int type = MATCH_FULL; | |
41c52c0d | 992 | unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f SR |
993 | unsigned i, match = 0, search_len = 0; |
994 | ||
995 | for (i = 0; i < len; i++) { | |
996 | if (buff[i] == '*') { | |
997 | if (!i) { | |
998 | search = buff + i + 1; | |
999 | type = MATCH_END_ONLY; | |
1000 | search_len = len - (i + 1); | |
1001 | } else { | |
1002 | if (type == MATCH_END_ONLY) { | |
1003 | type = MATCH_MIDDLE_ONLY; | |
1004 | } else { | |
1005 | match = i; | |
1006 | type = MATCH_FRONT_ONLY; | |
1007 | } | |
1008 | buff[i] = 0; | |
1009 | break; | |
1010 | } | |
1011 | } | |
1012 | } | |
1013 | ||
99ecdc43 SR |
1014 | /* should not be called from interrupt context */ |
1015 | spin_lock(&ftrace_lock); | |
41c52c0d SR |
1016 | if (enable) |
1017 | ftrace_filtered = 1; | |
5072c59f SR |
1018 | pg = ftrace_pages_start; |
1019 | while (pg) { | |
1020 | for (i = 0; i < pg->index; i++) { | |
1021 | int matched = 0; | |
1022 | char *ptr; | |
1023 | ||
1024 | rec = &pg->records[i]; | |
1025 | if (rec->flags & FTRACE_FL_FAILED) | |
1026 | continue; | |
1027 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1028 | switch (type) { | |
1029 | case MATCH_FULL: | |
1030 | if (strcmp(str, buff) == 0) | |
1031 | matched = 1; | |
1032 | break; | |
1033 | case MATCH_FRONT_ONLY: | |
1034 | if (memcmp(str, buff, match) == 0) | |
1035 | matched = 1; | |
1036 | break; | |
1037 | case MATCH_MIDDLE_ONLY: | |
1038 | if (strstr(str, search)) | |
1039 | matched = 1; | |
1040 | break; | |
1041 | case MATCH_END_ONLY: | |
1042 | ptr = strstr(str, search); | |
1043 | if (ptr && (ptr[search_len] == 0)) | |
1044 | matched = 1; | |
1045 | break; | |
1046 | } | |
1047 | if (matched) | |
41c52c0d | 1048 | rec->flags |= flag; |
5072c59f SR |
1049 | } |
1050 | pg = pg->next; | |
1051 | } | |
99ecdc43 | 1052 | spin_unlock(&ftrace_lock); |
5072c59f SR |
1053 | } |
1054 | ||
e309b41d | 1055 | static ssize_t |
41c52c0d SR |
1056 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
1057 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
1058 | { |
1059 | struct ftrace_iterator *iter; | |
1060 | char ch; | |
1061 | size_t read = 0; | |
1062 | ssize_t ret; | |
1063 | ||
1064 | if (!cnt || cnt < 0) | |
1065 | return 0; | |
1066 | ||
41c52c0d | 1067 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1068 | |
1069 | if (file->f_mode & FMODE_READ) { | |
1070 | struct seq_file *m = file->private_data; | |
1071 | iter = m->private; | |
1072 | } else | |
1073 | iter = file->private_data; | |
1074 | ||
1075 | if (!*ppos) { | |
1076 | iter->flags &= ~FTRACE_ITER_CONT; | |
1077 | iter->buffer_idx = 0; | |
1078 | } | |
1079 | ||
1080 | ret = get_user(ch, ubuf++); | |
1081 | if (ret) | |
1082 | goto out; | |
1083 | read++; | |
1084 | cnt--; | |
1085 | ||
1086 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { | |
1087 | /* skip white space */ | |
1088 | while (cnt && isspace(ch)) { | |
1089 | ret = get_user(ch, ubuf++); | |
1090 | if (ret) | |
1091 | goto out; | |
1092 | read++; | |
1093 | cnt--; | |
1094 | } | |
1095 | ||
5072c59f SR |
1096 | if (isspace(ch)) { |
1097 | file->f_pos += read; | |
1098 | ret = read; | |
1099 | goto out; | |
1100 | } | |
1101 | ||
1102 | iter->buffer_idx = 0; | |
1103 | } | |
1104 | ||
1105 | while (cnt && !isspace(ch)) { | |
1106 | if (iter->buffer_idx < FTRACE_BUFF_MAX) | |
1107 | iter->buffer[iter->buffer_idx++] = ch; | |
1108 | else { | |
1109 | ret = -EINVAL; | |
1110 | goto out; | |
1111 | } | |
1112 | ret = get_user(ch, ubuf++); | |
1113 | if (ret) | |
1114 | goto out; | |
1115 | read++; | |
1116 | cnt--; | |
1117 | } | |
1118 | ||
1119 | if (isspace(ch)) { | |
1120 | iter->filtered++; | |
1121 | iter->buffer[iter->buffer_idx] = 0; | |
41c52c0d | 1122 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1123 | iter->buffer_idx = 0; |
1124 | } else | |
1125 | iter->flags |= FTRACE_ITER_CONT; | |
1126 | ||
1127 | ||
1128 | file->f_pos += read; | |
1129 | ||
1130 | ret = read; | |
1131 | out: | |
41c52c0d | 1132 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1133 | |
1134 | return ret; | |
1135 | } | |
1136 | ||
41c52c0d SR |
1137 | static ssize_t |
1138 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
1139 | size_t cnt, loff_t *ppos) | |
1140 | { | |
1141 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
1142 | } | |
1143 | ||
1144 | static ssize_t | |
1145 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
1146 | size_t cnt, loff_t *ppos) | |
1147 | { | |
1148 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
1149 | } | |
1150 | ||
1151 | static void | |
1152 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
1153 | { | |
1154 | if (unlikely(ftrace_disabled)) | |
1155 | return; | |
1156 | ||
1157 | mutex_lock(&ftrace_regex_lock); | |
1158 | if (reset) | |
1159 | ftrace_filter_reset(enable); | |
1160 | if (buf) | |
1161 | ftrace_match(buf, len, enable); | |
1162 | mutex_unlock(&ftrace_regex_lock); | |
1163 | } | |
1164 | ||
77a2b37d SR |
1165 | /** |
1166 | * ftrace_set_filter - set a function to filter on in ftrace | |
1167 | * @buf - the string that holds the function filter text. | |
1168 | * @len - the length of the string. | |
1169 | * @reset - non zero to reset all filters before applying this filter. | |
1170 | * | |
1171 | * Filters denote which functions should be enabled when tracing is enabled. | |
1172 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
1173 | */ | |
e309b41d | 1174 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 1175 | { |
41c52c0d SR |
1176 | ftrace_set_regex(buf, len, reset, 1); |
1177 | } | |
4eebcc81 | 1178 | |
41c52c0d SR |
1179 | /** |
1180 | * ftrace_set_notrace - set a function to not trace in ftrace | |
1181 | * @buf - the string that holds the function notrace text. | |
1182 | * @len - the length of the string. | |
1183 | * @reset - non zero to reset all filters before applying this filter. | |
1184 | * | |
1185 | * Notrace Filters denote which functions should not be enabled when tracing | |
1186 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
1187 | * for tracing. | |
1188 | */ | |
1189 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
1190 | { | |
1191 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
1192 | } |
1193 | ||
e309b41d | 1194 | static int |
41c52c0d | 1195 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1196 | { |
1197 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1198 | struct ftrace_iterator *iter; | |
1199 | ||
41c52c0d | 1200 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1201 | if (file->f_mode & FMODE_READ) { |
1202 | iter = m->private; | |
1203 | ||
1204 | seq_release(inode, file); | |
1205 | } else | |
1206 | iter = file->private_data; | |
1207 | ||
1208 | if (iter->buffer_idx) { | |
1209 | iter->filtered++; | |
1210 | iter->buffer[iter->buffer_idx] = 0; | |
41c52c0d | 1211 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1212 | } |
1213 | ||
1214 | mutex_lock(&ftrace_sysctl_lock); | |
cb7be3b2 | 1215 | mutex_lock(&ftrace_start_lock); |
60a7ecf4 | 1216 | if (iter->filtered && ftrace_start_up && ftrace_enabled) |
5072c59f | 1217 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
cb7be3b2 | 1218 | mutex_unlock(&ftrace_start_lock); |
5072c59f SR |
1219 | mutex_unlock(&ftrace_sysctl_lock); |
1220 | ||
1221 | kfree(iter); | |
41c52c0d | 1222 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1223 | return 0; |
1224 | } | |
1225 | ||
41c52c0d SR |
1226 | static int |
1227 | ftrace_filter_release(struct inode *inode, struct file *file) | |
1228 | { | |
1229 | return ftrace_regex_release(inode, file, 1); | |
1230 | } | |
1231 | ||
1232 | static int | |
1233 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
1234 | { | |
1235 | return ftrace_regex_release(inode, file, 0); | |
1236 | } | |
1237 | ||
5072c59f SR |
1238 | static struct file_operations ftrace_avail_fops = { |
1239 | .open = ftrace_avail_open, | |
1240 | .read = seq_read, | |
1241 | .llseek = seq_lseek, | |
1242 | .release = ftrace_avail_release, | |
1243 | }; | |
1244 | ||
eb9a7bf0 AS |
1245 | static struct file_operations ftrace_failures_fops = { |
1246 | .open = ftrace_failures_open, | |
1247 | .read = seq_read, | |
1248 | .llseek = seq_lseek, | |
1249 | .release = ftrace_avail_release, | |
1250 | }; | |
1251 | ||
5072c59f SR |
1252 | static struct file_operations ftrace_filter_fops = { |
1253 | .open = ftrace_filter_open, | |
41c52c0d | 1254 | .read = ftrace_regex_read, |
5072c59f | 1255 | .write = ftrace_filter_write, |
41c52c0d | 1256 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
1257 | .release = ftrace_filter_release, |
1258 | }; | |
1259 | ||
41c52c0d SR |
1260 | static struct file_operations ftrace_notrace_fops = { |
1261 | .open = ftrace_notrace_open, | |
1262 | .read = ftrace_regex_read, | |
1263 | .write = ftrace_notrace_write, | |
1264 | .llseek = ftrace_regex_lseek, | |
1265 | .release = ftrace_notrace_release, | |
1266 | }; | |
1267 | ||
5072c59f SR |
1268 | static __init int ftrace_init_debugfs(void) |
1269 | { | |
1270 | struct dentry *d_tracer; | |
1271 | struct dentry *entry; | |
1272 | ||
1273 | d_tracer = tracing_init_dentry(); | |
1274 | ||
1275 | entry = debugfs_create_file("available_filter_functions", 0444, | |
1276 | d_tracer, NULL, &ftrace_avail_fops); | |
1277 | if (!entry) | |
1278 | pr_warning("Could not create debugfs " | |
1279 | "'available_filter_functions' entry\n"); | |
1280 | ||
eb9a7bf0 AS |
1281 | entry = debugfs_create_file("failures", 0444, |
1282 | d_tracer, NULL, &ftrace_failures_fops); | |
1283 | if (!entry) | |
1284 | pr_warning("Could not create debugfs 'failures' entry\n"); | |
1285 | ||
5072c59f SR |
1286 | entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer, |
1287 | NULL, &ftrace_filter_fops); | |
1288 | if (!entry) | |
1289 | pr_warning("Could not create debugfs " | |
1290 | "'set_ftrace_filter' entry\n"); | |
41c52c0d SR |
1291 | |
1292 | entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer, | |
1293 | NULL, &ftrace_notrace_fops); | |
1294 | if (!entry) | |
1295 | pr_warning("Could not create debugfs " | |
1296 | "'set_ftrace_notrace' entry\n"); | |
ad90c0e3 | 1297 | |
5072c59f SR |
1298 | return 0; |
1299 | } | |
1300 | ||
1301 | fs_initcall(ftrace_init_debugfs); | |
1302 | ||
68bf21aa SR |
1303 | static int ftrace_convert_nops(unsigned long *start, |
1304 | unsigned long *end) | |
1305 | { | |
1306 | unsigned long *p; | |
1307 | unsigned long addr; | |
1308 | unsigned long flags; | |
1309 | ||
08f5ac90 | 1310 | mutex_lock(&ftrace_start_lock); |
68bf21aa SR |
1311 | p = start; |
1312 | while (p < end) { | |
1313 | addr = ftrace_call_adjust(*p++); | |
1314 | ftrace_record_ip(addr); | |
68bf21aa SR |
1315 | } |
1316 | ||
08f5ac90 | 1317 | /* disable interrupts to prevent kstop machine */ |
68bf21aa | 1318 | local_irq_save(flags); |
08f5ac90 | 1319 | ftrace_update_code(); |
68bf21aa | 1320 | local_irq_restore(flags); |
08f5ac90 | 1321 | mutex_unlock(&ftrace_start_lock); |
68bf21aa SR |
1322 | |
1323 | return 0; | |
1324 | } | |
1325 | ||
90d595fe SR |
1326 | void ftrace_init_module(unsigned long *start, unsigned long *end) |
1327 | { | |
00fd61ae | 1328 | if (ftrace_disabled || start == end) |
fed1939c | 1329 | return; |
90d595fe SR |
1330 | ftrace_convert_nops(start, end); |
1331 | } | |
1332 | ||
68bf21aa SR |
1333 | extern unsigned long __start_mcount_loc[]; |
1334 | extern unsigned long __stop_mcount_loc[]; | |
1335 | ||
1336 | void __init ftrace_init(void) | |
1337 | { | |
1338 | unsigned long count, addr, flags; | |
1339 | int ret; | |
1340 | ||
1341 | /* Keep the ftrace pointer to the stub */ | |
1342 | addr = (unsigned long)ftrace_stub; | |
1343 | ||
1344 | local_irq_save(flags); | |
1345 | ftrace_dyn_arch_init(&addr); | |
1346 | local_irq_restore(flags); | |
1347 | ||
1348 | /* ftrace_dyn_arch_init places the return code in addr */ | |
1349 | if (addr) | |
1350 | goto failed; | |
1351 | ||
1352 | count = __stop_mcount_loc - __start_mcount_loc; | |
1353 | ||
1354 | ret = ftrace_dyn_table_alloc(count); | |
1355 | if (ret) | |
1356 | goto failed; | |
1357 | ||
1358 | last_ftrace_enabled = ftrace_enabled = 1; | |
1359 | ||
1360 | ret = ftrace_convert_nops(__start_mcount_loc, | |
1361 | __stop_mcount_loc); | |
1362 | ||
1363 | return; | |
1364 | failed: | |
1365 | ftrace_disabled = 1; | |
1366 | } | |
68bf21aa | 1367 | |
3d083395 | 1368 | #else |
0b6e4d56 FW |
1369 | |
1370 | static int __init ftrace_nodyn_init(void) | |
1371 | { | |
1372 | ftrace_enabled = 1; | |
1373 | return 0; | |
1374 | } | |
1375 | device_initcall(ftrace_nodyn_init); | |
1376 | ||
c7aafc54 IM |
1377 | # define ftrace_startup() do { } while (0) |
1378 | # define ftrace_shutdown() do { } while (0) | |
1379 | # define ftrace_startup_sysctl() do { } while (0) | |
1380 | # define ftrace_shutdown_sysctl() do { } while (0) | |
3d083395 SR |
1381 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
1382 | ||
a2bb6a3d | 1383 | /** |
81adbdc0 | 1384 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
1385 | * |
1386 | * This function should be used by panic code. It stops ftrace | |
1387 | * but in a not so nice way. If you need to simply kill ftrace | |
1388 | * from a non-atomic section, use ftrace_kill. | |
1389 | */ | |
81adbdc0 | 1390 | void ftrace_kill(void) |
a2bb6a3d SR |
1391 | { |
1392 | ftrace_disabled = 1; | |
1393 | ftrace_enabled = 0; | |
a2bb6a3d SR |
1394 | clear_ftrace_function(); |
1395 | } | |
1396 | ||
16444a8a | 1397 | /** |
3d083395 SR |
1398 | * register_ftrace_function - register a function for profiling |
1399 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 1400 | * |
3d083395 SR |
1401 | * Register a function to be called by all functions in the |
1402 | * kernel. | |
1403 | * | |
1404 | * Note: @ops->func and all the functions it calls must be labeled | |
1405 | * with "notrace", otherwise it will go into a | |
1406 | * recursive loop. | |
16444a8a | 1407 | */ |
3d083395 | 1408 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 1409 | { |
b0fc494f SR |
1410 | int ret; |
1411 | ||
4eebcc81 SR |
1412 | if (unlikely(ftrace_disabled)) |
1413 | return -1; | |
1414 | ||
b0fc494f | 1415 | mutex_lock(&ftrace_sysctl_lock); |
b0fc494f | 1416 | ret = __register_ftrace_function(ops); |
d61f82d0 | 1417 | ftrace_startup(); |
b0fc494f SR |
1418 | mutex_unlock(&ftrace_sysctl_lock); |
1419 | ||
1420 | return ret; | |
3d083395 SR |
1421 | } |
1422 | ||
1423 | /** | |
1424 | * unregister_ftrace_function - unresgister a function for profiling. | |
1425 | * @ops - ops structure that holds the function to unregister | |
1426 | * | |
1427 | * Unregister a function that was added to be called by ftrace profiling. | |
1428 | */ | |
1429 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
1430 | { | |
1431 | int ret; | |
1432 | ||
b0fc494f | 1433 | mutex_lock(&ftrace_sysctl_lock); |
3d083395 | 1434 | ret = __unregister_ftrace_function(ops); |
d61f82d0 | 1435 | ftrace_shutdown(); |
b0fc494f SR |
1436 | mutex_unlock(&ftrace_sysctl_lock); |
1437 | ||
1438 | return ret; | |
1439 | } | |
1440 | ||
e309b41d | 1441 | int |
b0fc494f | 1442 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
5072c59f | 1443 | struct file *file, void __user *buffer, size_t *lenp, |
b0fc494f SR |
1444 | loff_t *ppos) |
1445 | { | |
1446 | int ret; | |
1447 | ||
4eebcc81 SR |
1448 | if (unlikely(ftrace_disabled)) |
1449 | return -ENODEV; | |
1450 | ||
b0fc494f SR |
1451 | mutex_lock(&ftrace_sysctl_lock); |
1452 | ||
5072c59f | 1453 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
b0fc494f SR |
1454 | |
1455 | if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) | |
1456 | goto out; | |
1457 | ||
1458 | last_ftrace_enabled = ftrace_enabled; | |
1459 | ||
1460 | if (ftrace_enabled) { | |
1461 | ||
1462 | ftrace_startup_sysctl(); | |
1463 | ||
1464 | /* we are starting ftrace again */ | |
1465 | if (ftrace_list != &ftrace_list_end) { | |
1466 | if (ftrace_list->next == &ftrace_list_end) | |
1467 | ftrace_trace_function = ftrace_list->func; | |
1468 | else | |
1469 | ftrace_trace_function = ftrace_list_func; | |
1470 | } | |
1471 | ||
1472 | } else { | |
1473 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
1474 | ftrace_trace_function = ftrace_stub; | |
1475 | ||
1476 | ftrace_shutdown_sysctl(); | |
1477 | } | |
1478 | ||
1479 | out: | |
1480 | mutex_unlock(&ftrace_sysctl_lock); | |
3d083395 | 1481 | return ret; |
16444a8a | 1482 | } |
f17845e5 | 1483 |