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 */ | |
b3535c63 | 182 | if (ftrace_list->next == &ftrace_list_end) |
b0fc494f SR |
183 | ftrace_trace_function = ftrace_list->func; |
184 | } | |
16444a8a ACM |
185 | |
186 | out: | |
3d083395 SR |
187 | spin_unlock(&ftrace_lock); |
188 | ||
189 | return ret; | |
190 | } | |
191 | ||
192 | #ifdef CONFIG_DYNAMIC_FTRACE | |
99ecdc43 | 193 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
cb7be3b2 | 194 | # error Dynamic ftrace depends on MCOUNT_RECORD |
99ecdc43 SR |
195 | #endif |
196 | ||
71c67d58 SN |
197 | /* |
198 | * Since MCOUNT_ADDR may point to mcount itself, we do not want | |
199 | * to get it confused by reading a reference in the code as we | |
200 | * are parsing on objcopy output of text. Use a variable for | |
201 | * it instead. | |
202 | */ | |
203 | static unsigned long mcount_addr = MCOUNT_ADDR; | |
204 | ||
d61f82d0 SR |
205 | enum { |
206 | FTRACE_ENABLE_CALLS = (1 << 0), | |
207 | FTRACE_DISABLE_CALLS = (1 << 1), | |
208 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
209 | FTRACE_ENABLE_MCOUNT = (1 << 3), | |
210 | FTRACE_DISABLE_MCOUNT = (1 << 4), | |
211 | }; | |
212 | ||
5072c59f SR |
213 | static int ftrace_filtered; |
214 | ||
08f5ac90 | 215 | static LIST_HEAD(ftrace_new_addrs); |
3d083395 | 216 | |
41c52c0d | 217 | static DEFINE_MUTEX(ftrace_regex_lock); |
3d083395 | 218 | |
3c1720f0 SR |
219 | struct ftrace_page { |
220 | struct ftrace_page *next; | |
aa5e5cea | 221 | unsigned long index; |
3c1720f0 | 222 | struct dyn_ftrace records[]; |
aa5e5cea | 223 | }; |
3c1720f0 SR |
224 | |
225 | #define ENTRIES_PER_PAGE \ | |
226 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
227 | ||
228 | /* estimate from running different kernels */ | |
229 | #define NR_TO_INIT 10000 | |
230 | ||
231 | static struct ftrace_page *ftrace_pages_start; | |
232 | static struct ftrace_page *ftrace_pages; | |
233 | ||
37ad5084 SR |
234 | static struct dyn_ftrace *ftrace_free_records; |
235 | ||
ecea656d AS |
236 | |
237 | #ifdef CONFIG_KPROBES | |
f17845e5 IM |
238 | |
239 | static int frozen_record_count; | |
240 | ||
ecea656d AS |
241 | static inline void freeze_record(struct dyn_ftrace *rec) |
242 | { | |
243 | if (!(rec->flags & FTRACE_FL_FROZEN)) { | |
244 | rec->flags |= FTRACE_FL_FROZEN; | |
245 | frozen_record_count++; | |
246 | } | |
247 | } | |
248 | ||
249 | static inline void unfreeze_record(struct dyn_ftrace *rec) | |
250 | { | |
251 | if (rec->flags & FTRACE_FL_FROZEN) { | |
252 | rec->flags &= ~FTRACE_FL_FROZEN; | |
253 | frozen_record_count--; | |
254 | } | |
255 | } | |
256 | ||
257 | static inline int record_frozen(struct dyn_ftrace *rec) | |
258 | { | |
259 | return rec->flags & FTRACE_FL_FROZEN; | |
260 | } | |
261 | #else | |
262 | # define freeze_record(rec) ({ 0; }) | |
263 | # define unfreeze_record(rec) ({ 0; }) | |
264 | # define record_frozen(rec) ({ 0; }) | |
265 | #endif /* CONFIG_KPROBES */ | |
266 | ||
e309b41d | 267 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
37ad5084 | 268 | { |
37ad5084 SR |
269 | rec->ip = (unsigned long)ftrace_free_records; |
270 | ftrace_free_records = rec; | |
271 | rec->flags |= FTRACE_FL_FREE; | |
272 | } | |
273 | ||
fed1939c SR |
274 | void ftrace_release(void *start, unsigned long size) |
275 | { | |
276 | struct dyn_ftrace *rec; | |
277 | struct ftrace_page *pg; | |
278 | unsigned long s = (unsigned long)start; | |
279 | unsigned long e = s + size; | |
280 | int i; | |
281 | ||
00fd61ae | 282 | if (ftrace_disabled || !start) |
fed1939c SR |
283 | return; |
284 | ||
99ecdc43 | 285 | /* should not be called from interrupt context */ |
fed1939c SR |
286 | spin_lock(&ftrace_lock); |
287 | ||
288 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
289 | for (i = 0; i < pg->index; i++) { | |
290 | rec = &pg->records[i]; | |
291 | ||
292 | if ((rec->ip >= s) && (rec->ip < e)) | |
293 | ftrace_free_rec(rec); | |
294 | } | |
295 | } | |
296 | spin_unlock(&ftrace_lock); | |
fed1939c SR |
297 | } |
298 | ||
e309b41d | 299 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 300 | { |
37ad5084 SR |
301 | struct dyn_ftrace *rec; |
302 | ||
303 | /* First check for freed records */ | |
304 | if (ftrace_free_records) { | |
305 | rec = ftrace_free_records; | |
306 | ||
37ad5084 | 307 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
6912896e | 308 | FTRACE_WARN_ON_ONCE(1); |
37ad5084 SR |
309 | ftrace_free_records = NULL; |
310 | return NULL; | |
311 | } | |
312 | ||
313 | ftrace_free_records = (void *)rec->ip; | |
314 | memset(rec, 0, sizeof(*rec)); | |
315 | return rec; | |
316 | } | |
317 | ||
3c1720f0 | 318 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
08f5ac90 SR |
319 | if (!ftrace_pages->next) { |
320 | /* allocate another page */ | |
321 | ftrace_pages->next = | |
322 | (void *)get_zeroed_page(GFP_KERNEL); | |
323 | if (!ftrace_pages->next) | |
324 | return NULL; | |
325 | } | |
3c1720f0 SR |
326 | ftrace_pages = ftrace_pages->next; |
327 | } | |
328 | ||
329 | return &ftrace_pages->records[ftrace_pages->index++]; | |
330 | } | |
331 | ||
08f5ac90 | 332 | static struct dyn_ftrace * |
d61f82d0 | 333 | ftrace_record_ip(unsigned long ip) |
3d083395 | 334 | { |
08f5ac90 | 335 | struct dyn_ftrace *rec; |
3d083395 | 336 | |
f3c7ac40 | 337 | if (ftrace_disabled) |
08f5ac90 | 338 | return NULL; |
3d083395 | 339 | |
08f5ac90 SR |
340 | rec = ftrace_alloc_dyn_node(ip); |
341 | if (!rec) | |
342 | return NULL; | |
3d083395 | 343 | |
08f5ac90 | 344 | rec->ip = ip; |
3d083395 | 345 | |
08f5ac90 | 346 | list_add(&rec->list, &ftrace_new_addrs); |
3d083395 | 347 | |
08f5ac90 | 348 | return rec; |
3d083395 SR |
349 | } |
350 | ||
caf8cdeb | 351 | #define FTRACE_ADDR ((long)(ftrace_caller)) |
3c1720f0 | 352 | |
0eb96701 | 353 | static int |
5072c59f SR |
354 | __ftrace_replace_code(struct dyn_ftrace *rec, |
355 | unsigned char *old, unsigned char *new, int enable) | |
356 | { | |
41c52c0d | 357 | unsigned long ip, fl; |
5072c59f SR |
358 | |
359 | ip = rec->ip; | |
360 | ||
361 | if (ftrace_filtered && enable) { | |
5072c59f SR |
362 | /* |
363 | * If filtering is on: | |
364 | * | |
365 | * If this record is set to be filtered and | |
366 | * is enabled then do nothing. | |
367 | * | |
368 | * If this record is set to be filtered and | |
369 | * it is not enabled, enable it. | |
370 | * | |
371 | * If this record is not set to be filtered | |
372 | * and it is not enabled do nothing. | |
373 | * | |
41c52c0d SR |
374 | * If this record is set not to trace then |
375 | * do nothing. | |
376 | * | |
a4500b84 AS |
377 | * If this record is set not to trace and |
378 | * it is enabled then disable it. | |
379 | * | |
5072c59f SR |
380 | * If this record is not set to be filtered and |
381 | * it is enabled, disable it. | |
382 | */ | |
a4500b84 AS |
383 | |
384 | fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE | | |
385 | FTRACE_FL_ENABLED); | |
5072c59f SR |
386 | |
387 | if ((fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) || | |
a4500b84 AS |
388 | (fl == (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE)) || |
389 | !fl || (fl == FTRACE_FL_NOTRACE)) | |
0eb96701 | 390 | return 0; |
5072c59f SR |
391 | |
392 | /* | |
393 | * If it is enabled disable it, | |
394 | * otherwise enable it! | |
395 | */ | |
a4500b84 | 396 | if (fl & FTRACE_FL_ENABLED) { |
5072c59f SR |
397 | /* swap new and old */ |
398 | new = old; | |
399 | old = ftrace_call_replace(ip, FTRACE_ADDR); | |
400 | rec->flags &= ~FTRACE_FL_ENABLED; | |
401 | } else { | |
402 | new = ftrace_call_replace(ip, FTRACE_ADDR); | |
403 | rec->flags |= FTRACE_FL_ENABLED; | |
404 | } | |
405 | } else { | |
406 | ||
41c52c0d SR |
407 | if (enable) { |
408 | /* | |
409 | * If this record is set not to trace and is | |
410 | * not enabled, do nothing. | |
411 | */ | |
412 | fl = rec->flags & (FTRACE_FL_NOTRACE | FTRACE_FL_ENABLED); | |
413 | if (fl == FTRACE_FL_NOTRACE) | |
0eb96701 | 414 | return 0; |
41c52c0d | 415 | |
5072c59f | 416 | new = ftrace_call_replace(ip, FTRACE_ADDR); |
41c52c0d | 417 | } else |
5072c59f SR |
418 | old = ftrace_call_replace(ip, FTRACE_ADDR); |
419 | ||
420 | if (enable) { | |
421 | if (rec->flags & FTRACE_FL_ENABLED) | |
0eb96701 | 422 | return 0; |
5072c59f SR |
423 | rec->flags |= FTRACE_FL_ENABLED; |
424 | } else { | |
425 | if (!(rec->flags & FTRACE_FL_ENABLED)) | |
0eb96701 | 426 | return 0; |
5072c59f SR |
427 | rec->flags &= ~FTRACE_FL_ENABLED; |
428 | } | |
429 | } | |
430 | ||
0eb96701 | 431 | return ftrace_modify_code(ip, old, new); |
5072c59f SR |
432 | } |
433 | ||
e309b41d | 434 | static void ftrace_replace_code(int enable) |
3c1720f0 | 435 | { |
0eb96701 | 436 | int i, failed; |
3c1720f0 SR |
437 | unsigned char *new = NULL, *old = NULL; |
438 | struct dyn_ftrace *rec; | |
439 | struct ftrace_page *pg; | |
3c1720f0 | 440 | |
5072c59f | 441 | if (enable) |
3c1720f0 SR |
442 | old = ftrace_nop_replace(); |
443 | else | |
444 | new = ftrace_nop_replace(); | |
445 | ||
446 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
447 | for (i = 0; i < pg->index; i++) { | |
448 | rec = &pg->records[i]; | |
449 | ||
450 | /* don't modify code that has already faulted */ | |
451 | if (rec->flags & FTRACE_FL_FAILED) | |
452 | continue; | |
453 | ||
f22f9a89 | 454 | /* ignore updates to this record's mcount site */ |
98a05ed4 AS |
455 | if (get_kprobe((void *)rec->ip)) { |
456 | freeze_record(rec); | |
f22f9a89 | 457 | continue; |
98a05ed4 AS |
458 | } else { |
459 | unfreeze_record(rec); | |
460 | } | |
f22f9a89 | 461 | |
0eb96701 AS |
462 | failed = __ftrace_replace_code(rec, old, new, enable); |
463 | if (failed && (rec->flags & FTRACE_FL_CONVERTED)) { | |
464 | rec->flags |= FTRACE_FL_FAILED; | |
465 | if ((system_state == SYSTEM_BOOTING) || | |
34078a5e | 466 | !core_kernel_text(rec->ip)) { |
0eb96701 AS |
467 | ftrace_free_rec(rec); |
468 | } | |
469 | } | |
3c1720f0 SR |
470 | } |
471 | } | |
472 | } | |
473 | ||
05736a42 SR |
474 | static void print_ip_ins(const char *fmt, unsigned char *p) |
475 | { | |
476 | int i; | |
477 | ||
478 | printk(KERN_CONT "%s", fmt); | |
479 | ||
480 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
481 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
482 | } | |
483 | ||
492a7ea5 | 484 | static int |
d61f82d0 | 485 | ftrace_code_disable(struct dyn_ftrace *rec) |
3c1720f0 SR |
486 | { |
487 | unsigned long ip; | |
488 | unsigned char *nop, *call; | |
593eb8a2 | 489 | int ret; |
3c1720f0 SR |
490 | |
491 | ip = rec->ip; | |
492 | ||
493 | nop = ftrace_nop_replace(); | |
3b47bfc1 | 494 | call = ftrace_call_replace(ip, mcount_addr); |
3c1720f0 | 495 | |
593eb8a2 SR |
496 | ret = ftrace_modify_code(ip, call, nop); |
497 | if (ret) { | |
498 | switch (ret) { | |
499 | case -EFAULT: | |
6912896e | 500 | FTRACE_WARN_ON_ONCE(1); |
05736a42 SR |
501 | pr_info("ftrace faulted on modifying "); |
502 | print_ip_sym(ip); | |
503 | break; | |
593eb8a2 | 504 | case -EINVAL: |
6912896e | 505 | FTRACE_WARN_ON_ONCE(1); |
05736a42 SR |
506 | pr_info("ftrace failed to modify "); |
507 | print_ip_sym(ip); | |
508 | print_ip_ins(" expected: ", call); | |
509 | print_ip_ins(" actual: ", (unsigned char *)ip); | |
510 | print_ip_ins(" replace: ", nop); | |
511 | printk(KERN_CONT "\n"); | |
512 | break; | |
593eb8a2 | 513 | case -EPERM: |
6912896e | 514 | FTRACE_WARN_ON_ONCE(1); |
593eb8a2 SR |
515 | pr_info("ftrace faulted on writing "); |
516 | print_ip_sym(ip); | |
517 | break; | |
518 | default: | |
6912896e | 519 | FTRACE_WARN_ON_ONCE(1); |
593eb8a2 SR |
520 | pr_info("ftrace faulted on unknown error "); |
521 | print_ip_sym(ip); | |
05736a42 SR |
522 | } |
523 | ||
3c1720f0 | 524 | rec->flags |= FTRACE_FL_FAILED; |
492a7ea5 | 525 | return 0; |
37ad5084 | 526 | } |
492a7ea5 | 527 | return 1; |
3c1720f0 SR |
528 | } |
529 | ||
e309b41d | 530 | static int __ftrace_modify_code(void *data) |
3d083395 | 531 | { |
d61f82d0 SR |
532 | int *command = data; |
533 | ||
a3583244 | 534 | if (*command & FTRACE_ENABLE_CALLS) |
d61f82d0 | 535 | ftrace_replace_code(1); |
a3583244 | 536 | else if (*command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
537 | ftrace_replace_code(0); |
538 | ||
539 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
540 | ftrace_update_ftrace_func(ftrace_trace_function); | |
541 | ||
d61f82d0 | 542 | return 0; |
3d083395 SR |
543 | } |
544 | ||
e309b41d | 545 | static void ftrace_run_update_code(int command) |
3d083395 | 546 | { |
784e2d76 | 547 | stop_machine(__ftrace_modify_code, &command, NULL); |
3d083395 SR |
548 | } |
549 | ||
d61f82d0 | 550 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 551 | static int ftrace_start_up; |
cb7be3b2 | 552 | static DEFINE_MUTEX(ftrace_start_lock); |
d61f82d0 | 553 | |
e309b41d | 554 | static void ftrace_startup(void) |
3d083395 | 555 | { |
d61f82d0 SR |
556 | int command = 0; |
557 | ||
4eebcc81 SR |
558 | if (unlikely(ftrace_disabled)) |
559 | return; | |
560 | ||
cb7be3b2 | 561 | mutex_lock(&ftrace_start_lock); |
60a7ecf4 SR |
562 | ftrace_start_up++; |
563 | if (ftrace_start_up == 1) | |
d61f82d0 SR |
564 | command |= FTRACE_ENABLE_CALLS; |
565 | ||
566 | if (saved_ftrace_func != ftrace_trace_function) { | |
567 | saved_ftrace_func = ftrace_trace_function; | |
568 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
569 | } | |
570 | ||
571 | if (!command || !ftrace_enabled) | |
3d083395 | 572 | goto out; |
3d083395 | 573 | |
d61f82d0 | 574 | ftrace_run_update_code(command); |
3d083395 | 575 | out: |
cb7be3b2 | 576 | mutex_unlock(&ftrace_start_lock); |
3d083395 SR |
577 | } |
578 | ||
e309b41d | 579 | static void ftrace_shutdown(void) |
3d083395 | 580 | { |
d61f82d0 SR |
581 | int command = 0; |
582 | ||
4eebcc81 SR |
583 | if (unlikely(ftrace_disabled)) |
584 | return; | |
585 | ||
cb7be3b2 | 586 | mutex_lock(&ftrace_start_lock); |
60a7ecf4 SR |
587 | ftrace_start_up--; |
588 | if (!ftrace_start_up) | |
d61f82d0 | 589 | command |= FTRACE_DISABLE_CALLS; |
3d083395 | 590 | |
d61f82d0 SR |
591 | if (saved_ftrace_func != ftrace_trace_function) { |
592 | saved_ftrace_func = ftrace_trace_function; | |
593 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
594 | } | |
3d083395 | 595 | |
d61f82d0 SR |
596 | if (!command || !ftrace_enabled) |
597 | goto out; | |
598 | ||
599 | ftrace_run_update_code(command); | |
3d083395 | 600 | out: |
cb7be3b2 | 601 | mutex_unlock(&ftrace_start_lock); |
3d083395 SR |
602 | } |
603 | ||
e309b41d | 604 | static void ftrace_startup_sysctl(void) |
b0fc494f | 605 | { |
d61f82d0 SR |
606 | int command = FTRACE_ENABLE_MCOUNT; |
607 | ||
4eebcc81 SR |
608 | if (unlikely(ftrace_disabled)) |
609 | return; | |
610 | ||
cb7be3b2 | 611 | mutex_lock(&ftrace_start_lock); |
d61f82d0 SR |
612 | /* Force update next time */ |
613 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
614 | /* ftrace_start_up is true if we want ftrace running */ |
615 | if (ftrace_start_up) | |
d61f82d0 SR |
616 | command |= FTRACE_ENABLE_CALLS; |
617 | ||
618 | ftrace_run_update_code(command); | |
cb7be3b2 | 619 | mutex_unlock(&ftrace_start_lock); |
b0fc494f SR |
620 | } |
621 | ||
e309b41d | 622 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 623 | { |
d61f82d0 SR |
624 | int command = FTRACE_DISABLE_MCOUNT; |
625 | ||
4eebcc81 SR |
626 | if (unlikely(ftrace_disabled)) |
627 | return; | |
628 | ||
cb7be3b2 | 629 | mutex_lock(&ftrace_start_lock); |
60a7ecf4 SR |
630 | /* ftrace_start_up is true if ftrace is running */ |
631 | if (ftrace_start_up) | |
d61f82d0 SR |
632 | command |= FTRACE_DISABLE_CALLS; |
633 | ||
634 | ftrace_run_update_code(command); | |
cb7be3b2 | 635 | mutex_unlock(&ftrace_start_lock); |
b0fc494f SR |
636 | } |
637 | ||
3d083395 SR |
638 | static cycle_t ftrace_update_time; |
639 | static unsigned long ftrace_update_cnt; | |
640 | unsigned long ftrace_update_tot_cnt; | |
641 | ||
08f5ac90 | 642 | static int ftrace_update_code(void) |
3d083395 | 643 | { |
08f5ac90 | 644 | struct dyn_ftrace *p, *t; |
f22f9a89 | 645 | cycle_t start, stop; |
3d083395 | 646 | |
750ed1a4 | 647 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
648 | ftrace_update_cnt = 0; |
649 | ||
08f5ac90 | 650 | list_for_each_entry_safe(p, t, &ftrace_new_addrs, list) { |
3d083395 | 651 | |
08f5ac90 SR |
652 | /* If something went wrong, bail without enabling anything */ |
653 | if (unlikely(ftrace_disabled)) | |
654 | return -1; | |
f22f9a89 | 655 | |
08f5ac90 | 656 | list_del_init(&p->list); |
f22f9a89 | 657 | |
08f5ac90 SR |
658 | /* convert record (i.e, patch mcount-call with NOP) */ |
659 | if (ftrace_code_disable(p)) { | |
660 | p->flags |= FTRACE_FL_CONVERTED; | |
661 | ftrace_update_cnt++; | |
662 | } else | |
663 | ftrace_free_rec(p); | |
3d083395 SR |
664 | } |
665 | ||
750ed1a4 | 666 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
667 | ftrace_update_time = stop - start; |
668 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
669 | ||
16444a8a ACM |
670 | return 0; |
671 | } | |
672 | ||
68bf21aa | 673 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
674 | { |
675 | struct ftrace_page *pg; | |
676 | int cnt; | |
677 | int i; | |
3c1720f0 SR |
678 | |
679 | /* allocate a few pages */ | |
680 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
681 | if (!ftrace_pages_start) | |
682 | return -1; | |
683 | ||
684 | /* | |
685 | * Allocate a few more pages. | |
686 | * | |
687 | * TODO: have some parser search vmlinux before | |
688 | * final linking to find all calls to ftrace. | |
689 | * Then we can: | |
690 | * a) know how many pages to allocate. | |
691 | * and/or | |
692 | * b) set up the table then. | |
693 | * | |
694 | * The dynamic code is still necessary for | |
695 | * modules. | |
696 | */ | |
697 | ||
698 | pg = ftrace_pages = ftrace_pages_start; | |
699 | ||
68bf21aa | 700 | cnt = num_to_init / ENTRIES_PER_PAGE; |
08f5ac90 | 701 | pr_info("ftrace: allocating %ld entries in %d pages\n", |
68bf21aa | 702 | num_to_init, cnt); |
3c1720f0 SR |
703 | |
704 | for (i = 0; i < cnt; i++) { | |
705 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
706 | ||
707 | /* If we fail, we'll try later anyway */ | |
708 | if (!pg->next) | |
709 | break; | |
710 | ||
711 | pg = pg->next; | |
712 | } | |
713 | ||
714 | return 0; | |
715 | } | |
716 | ||
5072c59f SR |
717 | enum { |
718 | FTRACE_ITER_FILTER = (1 << 0), | |
719 | FTRACE_ITER_CONT = (1 << 1), | |
41c52c0d | 720 | FTRACE_ITER_NOTRACE = (1 << 2), |
eb9a7bf0 | 721 | FTRACE_ITER_FAILURES = (1 << 3), |
5072c59f SR |
722 | }; |
723 | ||
724 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
725 | ||
726 | struct ftrace_iterator { | |
727 | loff_t pos; | |
728 | struct ftrace_page *pg; | |
729 | unsigned idx; | |
730 | unsigned flags; | |
731 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
732 | unsigned buffer_idx; | |
733 | unsigned filtered; | |
734 | }; | |
735 | ||
e309b41d | 736 | static void * |
5072c59f SR |
737 | t_next(struct seq_file *m, void *v, loff_t *pos) |
738 | { | |
739 | struct ftrace_iterator *iter = m->private; | |
740 | struct dyn_ftrace *rec = NULL; | |
741 | ||
742 | (*pos)++; | |
743 | ||
99ecdc43 SR |
744 | /* should not be called from interrupt context */ |
745 | spin_lock(&ftrace_lock); | |
5072c59f SR |
746 | retry: |
747 | if (iter->idx >= iter->pg->index) { | |
748 | if (iter->pg->next) { | |
749 | iter->pg = iter->pg->next; | |
750 | iter->idx = 0; | |
751 | goto retry; | |
752 | } | |
753 | } else { | |
754 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
755 | if ((rec->flags & FTRACE_FL_FREE) || |
756 | ||
757 | (!(iter->flags & FTRACE_ITER_FAILURES) && | |
eb9a7bf0 AS |
758 | (rec->flags & FTRACE_FL_FAILED)) || |
759 | ||
760 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
a9fdda33 | 761 | !(rec->flags & FTRACE_FL_FAILED)) || |
eb9a7bf0 | 762 | |
0183fb1c SR |
763 | ((iter->flags & FTRACE_ITER_FILTER) && |
764 | !(rec->flags & FTRACE_FL_FILTER)) || | |
765 | ||
41c52c0d SR |
766 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
767 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
768 | rec = NULL; |
769 | goto retry; | |
770 | } | |
771 | } | |
99ecdc43 | 772 | spin_unlock(&ftrace_lock); |
5072c59f SR |
773 | |
774 | iter->pos = *pos; | |
775 | ||
776 | return rec; | |
777 | } | |
778 | ||
779 | static void *t_start(struct seq_file *m, loff_t *pos) | |
780 | { | |
781 | struct ftrace_iterator *iter = m->private; | |
782 | void *p = NULL; | |
783 | loff_t l = -1; | |
784 | ||
785 | if (*pos != iter->pos) { | |
786 | for (p = t_next(m, p, &l); p && l < *pos; p = t_next(m, p, &l)) | |
787 | ; | |
788 | } else { | |
789 | l = *pos; | |
790 | p = t_next(m, p, &l); | |
791 | } | |
792 | ||
793 | return p; | |
794 | } | |
795 | ||
796 | static void t_stop(struct seq_file *m, void *p) | |
797 | { | |
798 | } | |
799 | ||
800 | static int t_show(struct seq_file *m, void *v) | |
801 | { | |
802 | struct dyn_ftrace *rec = v; | |
803 | char str[KSYM_SYMBOL_LEN]; | |
804 | ||
805 | if (!rec) | |
806 | return 0; | |
807 | ||
808 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
809 | ||
810 | seq_printf(m, "%s\n", str); | |
811 | ||
812 | return 0; | |
813 | } | |
814 | ||
815 | static struct seq_operations show_ftrace_seq_ops = { | |
816 | .start = t_start, | |
817 | .next = t_next, | |
818 | .stop = t_stop, | |
819 | .show = t_show, | |
820 | }; | |
821 | ||
e309b41d | 822 | static int |
5072c59f SR |
823 | ftrace_avail_open(struct inode *inode, struct file *file) |
824 | { | |
825 | struct ftrace_iterator *iter; | |
826 | int ret; | |
827 | ||
4eebcc81 SR |
828 | if (unlikely(ftrace_disabled)) |
829 | return -ENODEV; | |
830 | ||
5072c59f SR |
831 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
832 | if (!iter) | |
833 | return -ENOMEM; | |
834 | ||
835 | iter->pg = ftrace_pages_start; | |
836 | iter->pos = -1; | |
837 | ||
838 | ret = seq_open(file, &show_ftrace_seq_ops); | |
839 | if (!ret) { | |
840 | struct seq_file *m = file->private_data; | |
4bf39a94 | 841 | |
5072c59f | 842 | m->private = iter; |
4bf39a94 | 843 | } else { |
5072c59f | 844 | kfree(iter); |
4bf39a94 | 845 | } |
5072c59f SR |
846 | |
847 | return ret; | |
848 | } | |
849 | ||
850 | int ftrace_avail_release(struct inode *inode, struct file *file) | |
851 | { | |
852 | struct seq_file *m = (struct seq_file *)file->private_data; | |
853 | struct ftrace_iterator *iter = m->private; | |
854 | ||
855 | seq_release(inode, file); | |
856 | kfree(iter); | |
4bf39a94 | 857 | |
5072c59f SR |
858 | return 0; |
859 | } | |
860 | ||
eb9a7bf0 AS |
861 | static int |
862 | ftrace_failures_open(struct inode *inode, struct file *file) | |
863 | { | |
864 | int ret; | |
865 | struct seq_file *m; | |
866 | struct ftrace_iterator *iter; | |
867 | ||
868 | ret = ftrace_avail_open(inode, file); | |
869 | if (!ret) { | |
870 | m = (struct seq_file *)file->private_data; | |
871 | iter = (struct ftrace_iterator *)m->private; | |
872 | iter->flags = FTRACE_ITER_FAILURES; | |
873 | } | |
874 | ||
875 | return ret; | |
876 | } | |
877 | ||
878 | ||
41c52c0d | 879 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
880 | { |
881 | struct ftrace_page *pg; | |
882 | struct dyn_ftrace *rec; | |
41c52c0d | 883 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f SR |
884 | unsigned i; |
885 | ||
99ecdc43 SR |
886 | /* should not be called from interrupt context */ |
887 | spin_lock(&ftrace_lock); | |
41c52c0d SR |
888 | if (enable) |
889 | ftrace_filtered = 0; | |
5072c59f SR |
890 | pg = ftrace_pages_start; |
891 | while (pg) { | |
892 | for (i = 0; i < pg->index; i++) { | |
893 | rec = &pg->records[i]; | |
894 | if (rec->flags & FTRACE_FL_FAILED) | |
895 | continue; | |
41c52c0d | 896 | rec->flags &= ~type; |
5072c59f SR |
897 | } |
898 | pg = pg->next; | |
899 | } | |
99ecdc43 | 900 | spin_unlock(&ftrace_lock); |
5072c59f SR |
901 | } |
902 | ||
e309b41d | 903 | static int |
41c52c0d | 904 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
905 | { |
906 | struct ftrace_iterator *iter; | |
907 | int ret = 0; | |
908 | ||
4eebcc81 SR |
909 | if (unlikely(ftrace_disabled)) |
910 | return -ENODEV; | |
911 | ||
5072c59f SR |
912 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
913 | if (!iter) | |
914 | return -ENOMEM; | |
915 | ||
41c52c0d | 916 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
917 | if ((file->f_mode & FMODE_WRITE) && |
918 | !(file->f_flags & O_APPEND)) | |
41c52c0d | 919 | ftrace_filter_reset(enable); |
5072c59f SR |
920 | |
921 | if (file->f_mode & FMODE_READ) { | |
922 | iter->pg = ftrace_pages_start; | |
923 | iter->pos = -1; | |
41c52c0d SR |
924 | iter->flags = enable ? FTRACE_ITER_FILTER : |
925 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
926 | |
927 | ret = seq_open(file, &show_ftrace_seq_ops); | |
928 | if (!ret) { | |
929 | struct seq_file *m = file->private_data; | |
930 | m->private = iter; | |
931 | } else | |
932 | kfree(iter); | |
933 | } else | |
934 | file->private_data = iter; | |
41c52c0d | 935 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
936 | |
937 | return ret; | |
938 | } | |
939 | ||
41c52c0d SR |
940 | static int |
941 | ftrace_filter_open(struct inode *inode, struct file *file) | |
942 | { | |
943 | return ftrace_regex_open(inode, file, 1); | |
944 | } | |
945 | ||
946 | static int | |
947 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
948 | { | |
949 | return ftrace_regex_open(inode, file, 0); | |
950 | } | |
951 | ||
e309b41d | 952 | static ssize_t |
41c52c0d | 953 | ftrace_regex_read(struct file *file, char __user *ubuf, |
5072c59f SR |
954 | size_t cnt, loff_t *ppos) |
955 | { | |
956 | if (file->f_mode & FMODE_READ) | |
957 | return seq_read(file, ubuf, cnt, ppos); | |
958 | else | |
959 | return -EPERM; | |
960 | } | |
961 | ||
e309b41d | 962 | static loff_t |
41c52c0d | 963 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
964 | { |
965 | loff_t ret; | |
966 | ||
967 | if (file->f_mode & FMODE_READ) | |
968 | ret = seq_lseek(file, offset, origin); | |
969 | else | |
970 | file->f_pos = ret = 1; | |
971 | ||
972 | return ret; | |
973 | } | |
974 | ||
975 | enum { | |
976 | MATCH_FULL, | |
977 | MATCH_FRONT_ONLY, | |
978 | MATCH_MIDDLE_ONLY, | |
979 | MATCH_END_ONLY, | |
980 | }; | |
981 | ||
e309b41d | 982 | static void |
41c52c0d | 983 | ftrace_match(unsigned char *buff, int len, int enable) |
5072c59f SR |
984 | { |
985 | char str[KSYM_SYMBOL_LEN]; | |
986 | char *search = NULL; | |
987 | struct ftrace_page *pg; | |
988 | struct dyn_ftrace *rec; | |
989 | int type = MATCH_FULL; | |
41c52c0d | 990 | unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f SR |
991 | unsigned i, match = 0, search_len = 0; |
992 | ||
993 | for (i = 0; i < len; i++) { | |
994 | if (buff[i] == '*') { | |
995 | if (!i) { | |
996 | search = buff + i + 1; | |
997 | type = MATCH_END_ONLY; | |
998 | search_len = len - (i + 1); | |
999 | } else { | |
1000 | if (type == MATCH_END_ONLY) { | |
1001 | type = MATCH_MIDDLE_ONLY; | |
1002 | } else { | |
1003 | match = i; | |
1004 | type = MATCH_FRONT_ONLY; | |
1005 | } | |
1006 | buff[i] = 0; | |
1007 | break; | |
1008 | } | |
1009 | } | |
1010 | } | |
1011 | ||
99ecdc43 SR |
1012 | /* should not be called from interrupt context */ |
1013 | spin_lock(&ftrace_lock); | |
41c52c0d SR |
1014 | if (enable) |
1015 | ftrace_filtered = 1; | |
5072c59f SR |
1016 | pg = ftrace_pages_start; |
1017 | while (pg) { | |
1018 | for (i = 0; i < pg->index; i++) { | |
1019 | int matched = 0; | |
1020 | char *ptr; | |
1021 | ||
1022 | rec = &pg->records[i]; | |
1023 | if (rec->flags & FTRACE_FL_FAILED) | |
1024 | continue; | |
1025 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1026 | switch (type) { | |
1027 | case MATCH_FULL: | |
1028 | if (strcmp(str, buff) == 0) | |
1029 | matched = 1; | |
1030 | break; | |
1031 | case MATCH_FRONT_ONLY: | |
1032 | if (memcmp(str, buff, match) == 0) | |
1033 | matched = 1; | |
1034 | break; | |
1035 | case MATCH_MIDDLE_ONLY: | |
1036 | if (strstr(str, search)) | |
1037 | matched = 1; | |
1038 | break; | |
1039 | case MATCH_END_ONLY: | |
1040 | ptr = strstr(str, search); | |
1041 | if (ptr && (ptr[search_len] == 0)) | |
1042 | matched = 1; | |
1043 | break; | |
1044 | } | |
1045 | if (matched) | |
41c52c0d | 1046 | rec->flags |= flag; |
5072c59f SR |
1047 | } |
1048 | pg = pg->next; | |
1049 | } | |
99ecdc43 | 1050 | spin_unlock(&ftrace_lock); |
5072c59f SR |
1051 | } |
1052 | ||
e309b41d | 1053 | static ssize_t |
41c52c0d SR |
1054 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
1055 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
1056 | { |
1057 | struct ftrace_iterator *iter; | |
1058 | char ch; | |
1059 | size_t read = 0; | |
1060 | ssize_t ret; | |
1061 | ||
1062 | if (!cnt || cnt < 0) | |
1063 | return 0; | |
1064 | ||
41c52c0d | 1065 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1066 | |
1067 | if (file->f_mode & FMODE_READ) { | |
1068 | struct seq_file *m = file->private_data; | |
1069 | iter = m->private; | |
1070 | } else | |
1071 | iter = file->private_data; | |
1072 | ||
1073 | if (!*ppos) { | |
1074 | iter->flags &= ~FTRACE_ITER_CONT; | |
1075 | iter->buffer_idx = 0; | |
1076 | } | |
1077 | ||
1078 | ret = get_user(ch, ubuf++); | |
1079 | if (ret) | |
1080 | goto out; | |
1081 | read++; | |
1082 | cnt--; | |
1083 | ||
1084 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { | |
1085 | /* skip white space */ | |
1086 | while (cnt && isspace(ch)) { | |
1087 | ret = get_user(ch, ubuf++); | |
1088 | if (ret) | |
1089 | goto out; | |
1090 | read++; | |
1091 | cnt--; | |
1092 | } | |
1093 | ||
5072c59f SR |
1094 | if (isspace(ch)) { |
1095 | file->f_pos += read; | |
1096 | ret = read; | |
1097 | goto out; | |
1098 | } | |
1099 | ||
1100 | iter->buffer_idx = 0; | |
1101 | } | |
1102 | ||
1103 | while (cnt && !isspace(ch)) { | |
1104 | if (iter->buffer_idx < FTRACE_BUFF_MAX) | |
1105 | iter->buffer[iter->buffer_idx++] = ch; | |
1106 | else { | |
1107 | ret = -EINVAL; | |
1108 | goto out; | |
1109 | } | |
1110 | ret = get_user(ch, ubuf++); | |
1111 | if (ret) | |
1112 | goto out; | |
1113 | read++; | |
1114 | cnt--; | |
1115 | } | |
1116 | ||
1117 | if (isspace(ch)) { | |
1118 | iter->filtered++; | |
1119 | iter->buffer[iter->buffer_idx] = 0; | |
41c52c0d | 1120 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1121 | iter->buffer_idx = 0; |
1122 | } else | |
1123 | iter->flags |= FTRACE_ITER_CONT; | |
1124 | ||
1125 | ||
1126 | file->f_pos += read; | |
1127 | ||
1128 | ret = read; | |
1129 | out: | |
41c52c0d | 1130 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1131 | |
1132 | return ret; | |
1133 | } | |
1134 | ||
41c52c0d SR |
1135 | static ssize_t |
1136 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
1137 | size_t cnt, loff_t *ppos) | |
1138 | { | |
1139 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
1140 | } | |
1141 | ||
1142 | static ssize_t | |
1143 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
1144 | size_t cnt, loff_t *ppos) | |
1145 | { | |
1146 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
1147 | } | |
1148 | ||
1149 | static void | |
1150 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
1151 | { | |
1152 | if (unlikely(ftrace_disabled)) | |
1153 | return; | |
1154 | ||
1155 | mutex_lock(&ftrace_regex_lock); | |
1156 | if (reset) | |
1157 | ftrace_filter_reset(enable); | |
1158 | if (buf) | |
1159 | ftrace_match(buf, len, enable); | |
1160 | mutex_unlock(&ftrace_regex_lock); | |
1161 | } | |
1162 | ||
77a2b37d SR |
1163 | /** |
1164 | * ftrace_set_filter - set a function to filter on in ftrace | |
1165 | * @buf - the string that holds the function filter text. | |
1166 | * @len - the length of the string. | |
1167 | * @reset - non zero to reset all filters before applying this filter. | |
1168 | * | |
1169 | * Filters denote which functions should be enabled when tracing is enabled. | |
1170 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
1171 | */ | |
e309b41d | 1172 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 1173 | { |
41c52c0d SR |
1174 | ftrace_set_regex(buf, len, reset, 1); |
1175 | } | |
4eebcc81 | 1176 | |
41c52c0d SR |
1177 | /** |
1178 | * ftrace_set_notrace - set a function to not trace in ftrace | |
1179 | * @buf - the string that holds the function notrace text. | |
1180 | * @len - the length of the string. | |
1181 | * @reset - non zero to reset all filters before applying this filter. | |
1182 | * | |
1183 | * Notrace Filters denote which functions should not be enabled when tracing | |
1184 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
1185 | * for tracing. | |
1186 | */ | |
1187 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
1188 | { | |
1189 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
1190 | } |
1191 | ||
e309b41d | 1192 | static int |
41c52c0d | 1193 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1194 | { |
1195 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1196 | struct ftrace_iterator *iter; | |
1197 | ||
41c52c0d | 1198 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1199 | if (file->f_mode & FMODE_READ) { |
1200 | iter = m->private; | |
1201 | ||
1202 | seq_release(inode, file); | |
1203 | } else | |
1204 | iter = file->private_data; | |
1205 | ||
1206 | if (iter->buffer_idx) { | |
1207 | iter->filtered++; | |
1208 | iter->buffer[iter->buffer_idx] = 0; | |
41c52c0d | 1209 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1210 | } |
1211 | ||
1212 | mutex_lock(&ftrace_sysctl_lock); | |
cb7be3b2 | 1213 | mutex_lock(&ftrace_start_lock); |
60a7ecf4 | 1214 | if (iter->filtered && ftrace_start_up && ftrace_enabled) |
5072c59f | 1215 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
cb7be3b2 | 1216 | mutex_unlock(&ftrace_start_lock); |
5072c59f SR |
1217 | mutex_unlock(&ftrace_sysctl_lock); |
1218 | ||
1219 | kfree(iter); | |
41c52c0d | 1220 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1221 | return 0; |
1222 | } | |
1223 | ||
41c52c0d SR |
1224 | static int |
1225 | ftrace_filter_release(struct inode *inode, struct file *file) | |
1226 | { | |
1227 | return ftrace_regex_release(inode, file, 1); | |
1228 | } | |
1229 | ||
1230 | static int | |
1231 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
1232 | { | |
1233 | return ftrace_regex_release(inode, file, 0); | |
1234 | } | |
1235 | ||
5072c59f SR |
1236 | static struct file_operations ftrace_avail_fops = { |
1237 | .open = ftrace_avail_open, | |
1238 | .read = seq_read, | |
1239 | .llseek = seq_lseek, | |
1240 | .release = ftrace_avail_release, | |
1241 | }; | |
1242 | ||
eb9a7bf0 AS |
1243 | static struct file_operations ftrace_failures_fops = { |
1244 | .open = ftrace_failures_open, | |
1245 | .read = seq_read, | |
1246 | .llseek = seq_lseek, | |
1247 | .release = ftrace_avail_release, | |
1248 | }; | |
1249 | ||
5072c59f SR |
1250 | static struct file_operations ftrace_filter_fops = { |
1251 | .open = ftrace_filter_open, | |
41c52c0d | 1252 | .read = ftrace_regex_read, |
5072c59f | 1253 | .write = ftrace_filter_write, |
41c52c0d | 1254 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
1255 | .release = ftrace_filter_release, |
1256 | }; | |
1257 | ||
41c52c0d SR |
1258 | static struct file_operations ftrace_notrace_fops = { |
1259 | .open = ftrace_notrace_open, | |
1260 | .read = ftrace_regex_read, | |
1261 | .write = ftrace_notrace_write, | |
1262 | .llseek = ftrace_regex_lseek, | |
1263 | .release = ftrace_notrace_release, | |
1264 | }; | |
1265 | ||
5072c59f SR |
1266 | static __init int ftrace_init_debugfs(void) |
1267 | { | |
1268 | struct dentry *d_tracer; | |
1269 | struct dentry *entry; | |
1270 | ||
1271 | d_tracer = tracing_init_dentry(); | |
1272 | ||
1273 | entry = debugfs_create_file("available_filter_functions", 0444, | |
1274 | d_tracer, NULL, &ftrace_avail_fops); | |
1275 | if (!entry) | |
1276 | pr_warning("Could not create debugfs " | |
1277 | "'available_filter_functions' entry\n"); | |
1278 | ||
eb9a7bf0 AS |
1279 | entry = debugfs_create_file("failures", 0444, |
1280 | d_tracer, NULL, &ftrace_failures_fops); | |
1281 | if (!entry) | |
1282 | pr_warning("Could not create debugfs 'failures' entry\n"); | |
1283 | ||
5072c59f SR |
1284 | entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer, |
1285 | NULL, &ftrace_filter_fops); | |
1286 | if (!entry) | |
1287 | pr_warning("Could not create debugfs " | |
1288 | "'set_ftrace_filter' entry\n"); | |
41c52c0d SR |
1289 | |
1290 | entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer, | |
1291 | NULL, &ftrace_notrace_fops); | |
1292 | if (!entry) | |
1293 | pr_warning("Could not create debugfs " | |
1294 | "'set_ftrace_notrace' entry\n"); | |
ad90c0e3 | 1295 | |
5072c59f SR |
1296 | return 0; |
1297 | } | |
1298 | ||
1299 | fs_initcall(ftrace_init_debugfs); | |
1300 | ||
68bf21aa SR |
1301 | static int ftrace_convert_nops(unsigned long *start, |
1302 | unsigned long *end) | |
1303 | { | |
1304 | unsigned long *p; | |
1305 | unsigned long addr; | |
1306 | unsigned long flags; | |
1307 | ||
08f5ac90 | 1308 | mutex_lock(&ftrace_start_lock); |
68bf21aa SR |
1309 | p = start; |
1310 | while (p < end) { | |
1311 | addr = ftrace_call_adjust(*p++); | |
1312 | ftrace_record_ip(addr); | |
68bf21aa SR |
1313 | } |
1314 | ||
08f5ac90 | 1315 | /* disable interrupts to prevent kstop machine */ |
68bf21aa | 1316 | local_irq_save(flags); |
08f5ac90 | 1317 | ftrace_update_code(); |
68bf21aa | 1318 | local_irq_restore(flags); |
08f5ac90 | 1319 | mutex_unlock(&ftrace_start_lock); |
68bf21aa SR |
1320 | |
1321 | return 0; | |
1322 | } | |
1323 | ||
90d595fe SR |
1324 | void ftrace_init_module(unsigned long *start, unsigned long *end) |
1325 | { | |
00fd61ae | 1326 | if (ftrace_disabled || start == end) |
fed1939c | 1327 | return; |
90d595fe SR |
1328 | ftrace_convert_nops(start, end); |
1329 | } | |
1330 | ||
68bf21aa SR |
1331 | extern unsigned long __start_mcount_loc[]; |
1332 | extern unsigned long __stop_mcount_loc[]; | |
1333 | ||
1334 | void __init ftrace_init(void) | |
1335 | { | |
1336 | unsigned long count, addr, flags; | |
1337 | int ret; | |
1338 | ||
1339 | /* Keep the ftrace pointer to the stub */ | |
1340 | addr = (unsigned long)ftrace_stub; | |
1341 | ||
1342 | local_irq_save(flags); | |
1343 | ftrace_dyn_arch_init(&addr); | |
1344 | local_irq_restore(flags); | |
1345 | ||
1346 | /* ftrace_dyn_arch_init places the return code in addr */ | |
1347 | if (addr) | |
1348 | goto failed; | |
1349 | ||
1350 | count = __stop_mcount_loc - __start_mcount_loc; | |
1351 | ||
1352 | ret = ftrace_dyn_table_alloc(count); | |
1353 | if (ret) | |
1354 | goto failed; | |
1355 | ||
1356 | last_ftrace_enabled = ftrace_enabled = 1; | |
1357 | ||
1358 | ret = ftrace_convert_nops(__start_mcount_loc, | |
1359 | __stop_mcount_loc); | |
1360 | ||
1361 | return; | |
1362 | failed: | |
1363 | ftrace_disabled = 1; | |
1364 | } | |
68bf21aa | 1365 | |
3d083395 | 1366 | #else |
0b6e4d56 FW |
1367 | |
1368 | static int __init ftrace_nodyn_init(void) | |
1369 | { | |
1370 | ftrace_enabled = 1; | |
1371 | return 0; | |
1372 | } | |
1373 | device_initcall(ftrace_nodyn_init); | |
1374 | ||
c7aafc54 IM |
1375 | # define ftrace_startup() do { } while (0) |
1376 | # define ftrace_shutdown() do { } while (0) | |
1377 | # define ftrace_startup_sysctl() do { } while (0) | |
1378 | # define ftrace_shutdown_sysctl() do { } while (0) | |
3d083395 SR |
1379 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
1380 | ||
a2bb6a3d | 1381 | /** |
81adbdc0 | 1382 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
1383 | * |
1384 | * This function should be used by panic code. It stops ftrace | |
1385 | * but in a not so nice way. If you need to simply kill ftrace | |
1386 | * from a non-atomic section, use ftrace_kill. | |
1387 | */ | |
81adbdc0 | 1388 | void ftrace_kill(void) |
a2bb6a3d SR |
1389 | { |
1390 | ftrace_disabled = 1; | |
1391 | ftrace_enabled = 0; | |
a2bb6a3d SR |
1392 | clear_ftrace_function(); |
1393 | } | |
1394 | ||
16444a8a | 1395 | /** |
3d083395 SR |
1396 | * register_ftrace_function - register a function for profiling |
1397 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 1398 | * |
3d083395 SR |
1399 | * Register a function to be called by all functions in the |
1400 | * kernel. | |
1401 | * | |
1402 | * Note: @ops->func and all the functions it calls must be labeled | |
1403 | * with "notrace", otherwise it will go into a | |
1404 | * recursive loop. | |
16444a8a | 1405 | */ |
3d083395 | 1406 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 1407 | { |
b0fc494f SR |
1408 | int ret; |
1409 | ||
4eebcc81 SR |
1410 | if (unlikely(ftrace_disabled)) |
1411 | return -1; | |
1412 | ||
b0fc494f | 1413 | mutex_lock(&ftrace_sysctl_lock); |
b0fc494f | 1414 | ret = __register_ftrace_function(ops); |
d61f82d0 | 1415 | ftrace_startup(); |
b0fc494f SR |
1416 | mutex_unlock(&ftrace_sysctl_lock); |
1417 | ||
1418 | return ret; | |
3d083395 SR |
1419 | } |
1420 | ||
1421 | /** | |
1422 | * unregister_ftrace_function - unresgister a function for profiling. | |
1423 | * @ops - ops structure that holds the function to unregister | |
1424 | * | |
1425 | * Unregister a function that was added to be called by ftrace profiling. | |
1426 | */ | |
1427 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
1428 | { | |
1429 | int ret; | |
1430 | ||
b0fc494f | 1431 | mutex_lock(&ftrace_sysctl_lock); |
3d083395 | 1432 | ret = __unregister_ftrace_function(ops); |
d61f82d0 | 1433 | ftrace_shutdown(); |
b0fc494f SR |
1434 | mutex_unlock(&ftrace_sysctl_lock); |
1435 | ||
1436 | return ret; | |
1437 | } | |
1438 | ||
e309b41d | 1439 | int |
b0fc494f | 1440 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
5072c59f | 1441 | struct file *file, void __user *buffer, size_t *lenp, |
b0fc494f SR |
1442 | loff_t *ppos) |
1443 | { | |
1444 | int ret; | |
1445 | ||
4eebcc81 SR |
1446 | if (unlikely(ftrace_disabled)) |
1447 | return -ENODEV; | |
1448 | ||
b0fc494f SR |
1449 | mutex_lock(&ftrace_sysctl_lock); |
1450 | ||
5072c59f | 1451 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
b0fc494f SR |
1452 | |
1453 | if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) | |
1454 | goto out; | |
1455 | ||
1456 | last_ftrace_enabled = ftrace_enabled; | |
1457 | ||
1458 | if (ftrace_enabled) { | |
1459 | ||
1460 | ftrace_startup_sysctl(); | |
1461 | ||
1462 | /* we are starting ftrace again */ | |
1463 | if (ftrace_list != &ftrace_list_end) { | |
1464 | if (ftrace_list->next == &ftrace_list_end) | |
1465 | ftrace_trace_function = ftrace_list->func; | |
1466 | else | |
1467 | ftrace_trace_function = ftrace_list_func; | |
1468 | } | |
1469 | ||
1470 | } else { | |
1471 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
1472 | ftrace_trace_function = ftrace_stub; | |
1473 | ||
1474 | ftrace_shutdown_sysctl(); | |
1475 | } | |
1476 | ||
1477 | out: | |
1478 | mutex_unlock(&ftrace_sysctl_lock); | |
3d083395 | 1479 | return ret; |
16444a8a | 1480 | } |
f17845e5 | 1481 | |
15e6cb36 FW |
1482 | #ifdef CONFIG_FUNCTION_RET_TRACER |
1483 | trace_function_return_t ftrace_function_return = | |
1484 | (trace_function_return_t)ftrace_stub; | |
1485 | void register_ftrace_return(trace_function_return_t func) | |
1486 | { | |
1487 | ftrace_function_return = func; | |
1488 | } | |
1489 | ||
1490 | void unregister_ftrace_return(void) | |
1491 | { | |
1492 | ftrace_function_return = (trace_function_return_t)ftrace_stub; | |
1493 | } | |
1494 | #endif | |
1495 | ||
1496 | ||
1497 |