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Commit | Line | Data |
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16444a8a ACM |
1 | /* |
2 | * Infrastructure for profiling code inserted by 'gcc -pg'. | |
3 | * | |
4 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> | |
5 | * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com> | |
6 | * | |
7 | * Originally ported from the -rt patch by: | |
8 | * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com> | |
9 | * | |
10 | * Based on code in the latency_tracer, that is: | |
11 | * | |
12 | * Copyright (C) 2004-2006 Ingo Molnar | |
13 | * Copyright (C) 2004 William Lee Irwin III | |
14 | */ | |
15 | ||
3d083395 SR |
16 | #include <linux/stop_machine.h> |
17 | #include <linux/clocksource.h> | |
18 | #include <linux/kallsyms.h> | |
5072c59f | 19 | #include <linux/seq_file.h> |
4a2b8dda | 20 | #include <linux/suspend.h> |
5072c59f | 21 | #include <linux/debugfs.h> |
3d083395 | 22 | #include <linux/hardirq.h> |
2d8b820b | 23 | #include <linux/kthread.h> |
5072c59f | 24 | #include <linux/uaccess.h> |
f22f9a89 | 25 | #include <linux/kprobes.h> |
2d8b820b | 26 | #include <linux/ftrace.h> |
b0fc494f | 27 | #include <linux/sysctl.h> |
5072c59f | 28 | #include <linux/ctype.h> |
3d083395 | 29 | #include <linux/list.h> |
59df055f | 30 | #include <linux/hash.h> |
3d083395 | 31 | |
8aef2d28 SR |
32 | #include <trace/sched.h> |
33 | ||
395a59d0 AS |
34 | #include <asm/ftrace.h> |
35 | ||
3d083395 | 36 | #include "trace.h" |
bac429f0 | 37 | #include "trace_stat.h" |
16444a8a | 38 | |
6912896e SR |
39 | #define FTRACE_WARN_ON(cond) \ |
40 | do { \ | |
41 | if (WARN_ON(cond)) \ | |
42 | ftrace_kill(); \ | |
43 | } while (0) | |
44 | ||
45 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
46 | do { \ | |
47 | if (WARN_ON_ONCE(cond)) \ | |
48 | ftrace_kill(); \ | |
49 | } while (0) | |
50 | ||
8fc0c701 SR |
51 | /* hash bits for specific function selection */ |
52 | #define FTRACE_HASH_BITS 7 | |
53 | #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS) | |
54 | ||
4eebcc81 SR |
55 | /* ftrace_enabled is a method to turn ftrace on or off */ |
56 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 57 | static int last_ftrace_enabled; |
b0fc494f | 58 | |
60a7ecf4 SR |
59 | /* Quick disabling of function tracer. */ |
60 | int function_trace_stop; | |
61 | ||
4eebcc81 SR |
62 | /* |
63 | * ftrace_disabled is set when an anomaly is discovered. | |
64 | * ftrace_disabled is much stronger than ftrace_enabled. | |
65 | */ | |
66 | static int ftrace_disabled __read_mostly; | |
67 | ||
52baf119 | 68 | static DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 69 | |
16444a8a ACM |
70 | static struct ftrace_ops ftrace_list_end __read_mostly = |
71 | { | |
72 | .func = ftrace_stub, | |
73 | }; | |
74 | ||
75 | static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; | |
76 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; | |
60a7ecf4 | 77 | ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub; |
df4fc315 | 78 | ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; |
16444a8a | 79 | |
f2252935 | 80 | static void ftrace_list_func(unsigned long ip, unsigned long parent_ip) |
16444a8a ACM |
81 | { |
82 | struct ftrace_ops *op = ftrace_list; | |
83 | ||
84 | /* in case someone actually ports this to alpha! */ | |
85 | read_barrier_depends(); | |
86 | ||
87 | while (op != &ftrace_list_end) { | |
88 | /* silly alpha */ | |
89 | read_barrier_depends(); | |
90 | op->func(ip, parent_ip); | |
91 | op = op->next; | |
92 | }; | |
93 | } | |
94 | ||
df4fc315 SR |
95 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip) |
96 | { | |
0ef8cde5 | 97 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
98 | return; |
99 | ||
100 | ftrace_pid_function(ip, parent_ip); | |
101 | } | |
102 | ||
103 | static void set_ftrace_pid_function(ftrace_func_t func) | |
104 | { | |
105 | /* do not set ftrace_pid_function to itself! */ | |
106 | if (func != ftrace_pid_func) | |
107 | ftrace_pid_function = func; | |
108 | } | |
109 | ||
16444a8a | 110 | /** |
3d083395 | 111 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 112 | * |
3d083395 SR |
113 | * This NULLs the ftrace function and in essence stops |
114 | * tracing. There may be lag | |
16444a8a | 115 | */ |
3d083395 | 116 | void clear_ftrace_function(void) |
16444a8a | 117 | { |
3d083395 | 118 | ftrace_trace_function = ftrace_stub; |
60a7ecf4 | 119 | __ftrace_trace_function = ftrace_stub; |
df4fc315 | 120 | ftrace_pid_function = ftrace_stub; |
3d083395 SR |
121 | } |
122 | ||
60a7ecf4 SR |
123 | #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
124 | /* | |
125 | * For those archs that do not test ftrace_trace_stop in their | |
126 | * mcount call site, we need to do it from C. | |
127 | */ | |
128 | static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip) | |
129 | { | |
130 | if (function_trace_stop) | |
131 | return; | |
132 | ||
133 | __ftrace_trace_function(ip, parent_ip); | |
134 | } | |
135 | #endif | |
136 | ||
e309b41d | 137 | static int __register_ftrace_function(struct ftrace_ops *ops) |
3d083395 | 138 | { |
16444a8a ACM |
139 | ops->next = ftrace_list; |
140 | /* | |
141 | * We are entering ops into the ftrace_list but another | |
142 | * CPU might be walking that list. We need to make sure | |
143 | * the ops->next pointer is valid before another CPU sees | |
144 | * the ops pointer included into the ftrace_list. | |
145 | */ | |
146 | smp_wmb(); | |
147 | ftrace_list = ops; | |
3d083395 | 148 | |
b0fc494f | 149 | if (ftrace_enabled) { |
df4fc315 SR |
150 | ftrace_func_t func; |
151 | ||
152 | if (ops->next == &ftrace_list_end) | |
153 | func = ops->func; | |
154 | else | |
155 | func = ftrace_list_func; | |
156 | ||
978f3a45 | 157 | if (ftrace_pid_trace) { |
df4fc315 SR |
158 | set_ftrace_pid_function(func); |
159 | func = ftrace_pid_func; | |
160 | } | |
161 | ||
b0fc494f SR |
162 | /* |
163 | * For one func, simply call it directly. | |
164 | * For more than one func, call the chain. | |
165 | */ | |
60a7ecf4 | 166 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
df4fc315 | 167 | ftrace_trace_function = func; |
60a7ecf4 | 168 | #else |
df4fc315 | 169 | __ftrace_trace_function = func; |
60a7ecf4 SR |
170 | ftrace_trace_function = ftrace_test_stop_func; |
171 | #endif | |
b0fc494f | 172 | } |
3d083395 | 173 | |
16444a8a ACM |
174 | return 0; |
175 | } | |
176 | ||
e309b41d | 177 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 178 | { |
16444a8a | 179 | struct ftrace_ops **p; |
16444a8a ACM |
180 | |
181 | /* | |
3d083395 SR |
182 | * If we are removing the last function, then simply point |
183 | * to the ftrace_stub. | |
16444a8a ACM |
184 | */ |
185 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { | |
186 | ftrace_trace_function = ftrace_stub; | |
187 | ftrace_list = &ftrace_list_end; | |
e6ea44e9 | 188 | return 0; |
16444a8a ACM |
189 | } |
190 | ||
191 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) | |
192 | if (*p == ops) | |
193 | break; | |
194 | ||
e6ea44e9 SR |
195 | if (*p != ops) |
196 | return -1; | |
16444a8a ACM |
197 | |
198 | *p = (*p)->next; | |
199 | ||
b0fc494f SR |
200 | if (ftrace_enabled) { |
201 | /* If we only have one func left, then call that directly */ | |
df4fc315 SR |
202 | if (ftrace_list->next == &ftrace_list_end) { |
203 | ftrace_func_t func = ftrace_list->func; | |
204 | ||
978f3a45 | 205 | if (ftrace_pid_trace) { |
df4fc315 SR |
206 | set_ftrace_pid_function(func); |
207 | func = ftrace_pid_func; | |
208 | } | |
209 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
210 | ftrace_trace_function = func; | |
211 | #else | |
212 | __ftrace_trace_function = func; | |
213 | #endif | |
214 | } | |
b0fc494f | 215 | } |
16444a8a | 216 | |
e6ea44e9 | 217 | return 0; |
3d083395 SR |
218 | } |
219 | ||
df4fc315 SR |
220 | static void ftrace_update_pid_func(void) |
221 | { | |
222 | ftrace_func_t func; | |
223 | ||
df4fc315 | 224 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 225 | return; |
df4fc315 SR |
226 | |
227 | func = ftrace_trace_function; | |
228 | ||
978f3a45 | 229 | if (ftrace_pid_trace) { |
df4fc315 SR |
230 | set_ftrace_pid_function(func); |
231 | func = ftrace_pid_func; | |
232 | } else { | |
66eafebc LW |
233 | if (func == ftrace_pid_func) |
234 | func = ftrace_pid_function; | |
df4fc315 SR |
235 | } |
236 | ||
237 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
238 | ftrace_trace_function = func; | |
239 | #else | |
240 | __ftrace_trace_function = func; | |
241 | #endif | |
df4fc315 SR |
242 | } |
243 | ||
73d3fd96 IM |
244 | /* set when tracing only a pid */ |
245 | struct pid *ftrace_pid_trace; | |
246 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; | |
247 | ||
3d083395 | 248 | #ifdef CONFIG_DYNAMIC_FTRACE |
73d3fd96 | 249 | |
99ecdc43 | 250 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
cb7be3b2 | 251 | # error Dynamic ftrace depends on MCOUNT_RECORD |
99ecdc43 SR |
252 | #endif |
253 | ||
8fc0c701 SR |
254 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; |
255 | ||
b6887d79 | 256 | struct ftrace_func_probe { |
8fc0c701 | 257 | struct hlist_node node; |
b6887d79 | 258 | struct ftrace_probe_ops *ops; |
8fc0c701 SR |
259 | unsigned long flags; |
260 | unsigned long ip; | |
261 | void *data; | |
262 | struct rcu_head rcu; | |
263 | }; | |
264 | ||
d61f82d0 SR |
265 | enum { |
266 | FTRACE_ENABLE_CALLS = (1 << 0), | |
267 | FTRACE_DISABLE_CALLS = (1 << 1), | |
268 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
269 | FTRACE_ENABLE_MCOUNT = (1 << 3), | |
270 | FTRACE_DISABLE_MCOUNT = (1 << 4), | |
5a45cfe1 SR |
271 | FTRACE_START_FUNC_RET = (1 << 5), |
272 | FTRACE_STOP_FUNC_RET = (1 << 6), | |
d61f82d0 SR |
273 | }; |
274 | ||
5072c59f SR |
275 | static int ftrace_filtered; |
276 | ||
e94142a6 | 277 | static struct dyn_ftrace *ftrace_new_addrs; |
3d083395 | 278 | |
41c52c0d | 279 | static DEFINE_MUTEX(ftrace_regex_lock); |
3d083395 | 280 | |
3c1720f0 SR |
281 | struct ftrace_page { |
282 | struct ftrace_page *next; | |
431aa3fb | 283 | int index; |
3c1720f0 | 284 | struct dyn_ftrace records[]; |
aa5e5cea | 285 | }; |
3c1720f0 SR |
286 | |
287 | #define ENTRIES_PER_PAGE \ | |
288 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
289 | ||
290 | /* estimate from running different kernels */ | |
291 | #define NR_TO_INIT 10000 | |
292 | ||
293 | static struct ftrace_page *ftrace_pages_start; | |
294 | static struct ftrace_page *ftrace_pages; | |
295 | ||
37ad5084 SR |
296 | static struct dyn_ftrace *ftrace_free_records; |
297 | ||
265c831c SR |
298 | /* |
299 | * This is a double for. Do not use 'break' to break out of the loop, | |
300 | * you must use a goto. | |
301 | */ | |
302 | #define do_for_each_ftrace_rec(pg, rec) \ | |
303 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
304 | int _____i; \ | |
305 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
306 | rec = &pg->records[_____i]; | |
307 | ||
308 | #define while_for_each_ftrace_rec() \ | |
309 | } \ | |
310 | } | |
ecea656d | 311 | |
bac429f0 SR |
312 | #ifdef CONFIG_FUNCTION_PROFILER |
313 | static struct hlist_head *ftrace_profile_hash; | |
314 | static int ftrace_profile_bits; | |
315 | static int ftrace_profile_enabled; | |
316 | static DEFINE_MUTEX(ftrace_profile_lock); | |
317 | ||
318 | static void * | |
319 | function_stat_next(void *v, int idx) | |
320 | { | |
321 | struct dyn_ftrace *rec = v; | |
322 | struct ftrace_page *pg; | |
323 | ||
324 | pg = (struct ftrace_page *)((unsigned long)rec & PAGE_MASK); | |
325 | ||
326 | again: | |
327 | rec++; | |
328 | if ((void *)rec >= (void *)&pg->records[pg->index]) { | |
329 | pg = pg->next; | |
330 | if (!pg) | |
331 | return NULL; | |
332 | rec = &pg->records[0]; | |
333 | } | |
334 | ||
335 | if (rec->flags & FTRACE_FL_FREE || | |
336 | rec->flags & FTRACE_FL_FAILED || | |
337 | !(rec->flags & FTRACE_FL_CONVERTED) || | |
338 | /* ignore non hit functions */ | |
339 | !rec->counter) | |
340 | goto again; | |
341 | ||
342 | return rec; | |
343 | } | |
344 | ||
345 | static void *function_stat_start(struct tracer_stat *trace) | |
346 | { | |
347 | return function_stat_next(&ftrace_pages_start->records[0], 0); | |
348 | } | |
349 | ||
350 | static int function_stat_cmp(void *p1, void *p2) | |
351 | { | |
352 | struct dyn_ftrace *a = p1; | |
353 | struct dyn_ftrace *b = p2; | |
354 | ||
355 | if (a->counter < b->counter) | |
356 | return -1; | |
357 | if (a->counter > b->counter) | |
358 | return 1; | |
359 | else | |
360 | return 0; | |
361 | } | |
362 | ||
363 | static int function_stat_headers(struct seq_file *m) | |
364 | { | |
365 | seq_printf(m, " Function Hit\n" | |
366 | " -------- ---\n"); | |
367 | return 0; | |
368 | } | |
369 | ||
370 | static int function_stat_show(struct seq_file *m, void *v) | |
371 | { | |
372 | struct dyn_ftrace *rec = v; | |
373 | char str[KSYM_SYMBOL_LEN]; | |
374 | ||
375 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
376 | ||
377 | seq_printf(m, " %-30.30s %10lu\n", str, rec->counter); | |
378 | return 0; | |
379 | } | |
380 | ||
381 | static struct tracer_stat function_stats = { | |
382 | .name = "functions", | |
383 | .stat_start = function_stat_start, | |
384 | .stat_next = function_stat_next, | |
385 | .stat_cmp = function_stat_cmp, | |
386 | .stat_headers = function_stat_headers, | |
387 | .stat_show = function_stat_show | |
388 | }; | |
389 | ||
390 | static void ftrace_profile_init(int nr_funcs) | |
391 | { | |
392 | unsigned long addr; | |
393 | int order; | |
394 | int size; | |
395 | ||
396 | /* | |
397 | * We are profiling all functions, lets make it 1/4th of the | |
398 | * number of functions that are in core kernel. So we have to | |
399 | * iterate 4 times. | |
400 | */ | |
401 | order = (sizeof(struct hlist_head) * nr_funcs) / 4; | |
402 | order = get_order(order); | |
403 | size = 1 << (PAGE_SHIFT + order); | |
404 | ||
405 | pr_info("Allocating %d KB for profiler hash\n", size >> 10); | |
406 | ||
407 | addr = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order); | |
408 | if (!addr) { | |
409 | pr_warning("Could not allocate function profiler hash\n"); | |
410 | return; | |
411 | } | |
412 | ||
413 | ftrace_profile_hash = (void *)addr; | |
414 | ||
415 | /* | |
416 | * struct hlist_head should be a pointer of 4 or 8 bytes. | |
417 | * And a simple bit manipulation can be done, but if for | |
418 | * some reason struct hlist_head is not a mulitple of 2, | |
419 | * then we play it safe, and simply count. This function | |
420 | * is done once at boot up, so it is not that critical in | |
421 | * performance. | |
422 | */ | |
423 | ||
424 | size--; | |
425 | size /= sizeof(struct hlist_head); | |
426 | ||
427 | for (; size; size >>= 1) | |
428 | ftrace_profile_bits++; | |
429 | ||
430 | pr_info("Function profiler has %d hash buckets\n", | |
431 | 1 << ftrace_profile_bits); | |
432 | ||
433 | return; | |
434 | } | |
435 | ||
436 | static ssize_t | |
437 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
438 | size_t cnt, loff_t *ppos) | |
439 | { | |
440 | char buf[64]; | |
441 | int r; | |
442 | ||
443 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
444 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
445 | } | |
446 | ||
447 | static void ftrace_profile_reset(void) | |
448 | { | |
449 | struct dyn_ftrace *rec; | |
450 | struct ftrace_page *pg; | |
451 | ||
452 | do_for_each_ftrace_rec(pg, rec) { | |
453 | rec->counter = 0; | |
454 | } while_for_each_ftrace_rec(); | |
455 | } | |
456 | ||
457 | static struct dyn_ftrace *ftrace_find_profiled_func(unsigned long ip) | |
458 | { | |
459 | struct dyn_ftrace *rec; | |
460 | struct hlist_head *hhd; | |
461 | struct hlist_node *n; | |
462 | unsigned long flags; | |
463 | unsigned long key; | |
464 | ||
465 | if (!ftrace_profile_hash) | |
466 | return NULL; | |
467 | ||
468 | key = hash_long(ip, ftrace_profile_bits); | |
469 | hhd = &ftrace_profile_hash[key]; | |
470 | ||
471 | if (hlist_empty(hhd)) | |
472 | return NULL; | |
473 | ||
474 | local_irq_save(flags); | |
475 | hlist_for_each_entry_rcu(rec, n, hhd, node) { | |
476 | if (rec->ip == ip) | |
477 | goto out; | |
478 | } | |
479 | rec = NULL; | |
480 | out: | |
481 | local_irq_restore(flags); | |
482 | ||
483 | return rec; | |
484 | } | |
485 | ||
486 | static void | |
487 | function_profile_call(unsigned long ip, unsigned long parent_ip) | |
488 | { | |
489 | struct dyn_ftrace *rec; | |
490 | unsigned long flags; | |
491 | ||
492 | if (!ftrace_profile_enabled) | |
493 | return; | |
494 | ||
495 | local_irq_save(flags); | |
496 | rec = ftrace_find_profiled_func(ip); | |
497 | if (!rec) | |
498 | goto out; | |
499 | ||
500 | rec->counter++; | |
501 | out: | |
502 | local_irq_restore(flags); | |
503 | } | |
504 | ||
505 | static struct ftrace_ops ftrace_profile_ops __read_mostly = | |
506 | { | |
507 | .func = function_profile_call, | |
508 | }; | |
509 | ||
510 | static ssize_t | |
511 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
512 | size_t cnt, loff_t *ppos) | |
513 | { | |
514 | unsigned long val; | |
515 | char buf[64]; | |
516 | int ret; | |
517 | ||
518 | if (!ftrace_profile_hash) { | |
519 | pr_info("Can not enable hash due to earlier problems\n"); | |
520 | return -ENODEV; | |
521 | } | |
522 | ||
523 | if (cnt >= sizeof(buf)) | |
524 | return -EINVAL; | |
525 | ||
526 | if (copy_from_user(&buf, ubuf, cnt)) | |
527 | return -EFAULT; | |
528 | ||
529 | buf[cnt] = 0; | |
530 | ||
531 | ret = strict_strtoul(buf, 10, &val); | |
532 | if (ret < 0) | |
533 | return ret; | |
534 | ||
535 | val = !!val; | |
536 | ||
537 | mutex_lock(&ftrace_profile_lock); | |
538 | if (ftrace_profile_enabled ^ val) { | |
539 | if (val) { | |
540 | ftrace_profile_reset(); | |
541 | register_ftrace_function(&ftrace_profile_ops); | |
542 | ftrace_profile_enabled = 1; | |
543 | } else { | |
544 | ftrace_profile_enabled = 0; | |
545 | unregister_ftrace_function(&ftrace_profile_ops); | |
546 | } | |
547 | } | |
548 | mutex_unlock(&ftrace_profile_lock); | |
549 | ||
550 | filp->f_pos += cnt; | |
551 | ||
552 | return cnt; | |
553 | } | |
554 | ||
555 | static const struct file_operations ftrace_profile_fops = { | |
556 | .open = tracing_open_generic, | |
557 | .read = ftrace_profile_read, | |
558 | .write = ftrace_profile_write, | |
559 | }; | |
560 | ||
561 | static void ftrace_profile_debugfs(struct dentry *d_tracer) | |
562 | { | |
563 | struct dentry *entry; | |
564 | int ret; | |
565 | ||
566 | ret = register_stat_tracer(&function_stats); | |
567 | if (ret) { | |
568 | pr_warning("Warning: could not register " | |
569 | "function stats\n"); | |
570 | return; | |
571 | } | |
572 | ||
573 | entry = debugfs_create_file("function_profile_enabled", 0644, | |
574 | d_tracer, NULL, &ftrace_profile_fops); | |
575 | if (!entry) | |
576 | pr_warning("Could not create debugfs " | |
577 | "'function_profile_enabled' entry\n"); | |
578 | } | |
579 | ||
580 | static void ftrace_add_profile(struct dyn_ftrace *rec) | |
581 | { | |
582 | unsigned long key; | |
583 | ||
584 | if (!ftrace_profile_hash) | |
585 | return; | |
586 | ||
587 | key = hash_long(rec->ip, ftrace_profile_bits); | |
588 | hlist_add_head_rcu(&rec->node, &ftrace_profile_hash[key]); | |
589 | } | |
590 | ||
591 | static void ftrace_profile_release(struct dyn_ftrace *rec) | |
592 | { | |
593 | mutex_lock(&ftrace_profile_lock); | |
594 | hlist_del(&rec->node); | |
595 | mutex_unlock(&ftrace_profile_lock); | |
596 | } | |
597 | ||
598 | #else /* CONFIG_FUNCTION_PROFILER */ | |
599 | static void ftrace_profile_init(int nr_funcs) | |
600 | { | |
601 | } | |
602 | static void ftrace_add_profile(struct dyn_ftrace *rec) | |
603 | { | |
604 | } | |
605 | static void ftrace_profile_debugfs(struct dentry *d_tracer) | |
606 | { | |
607 | } | |
608 | static void ftrace_profile_release(struct dyn_ftrace *rec) | |
609 | { | |
610 | } | |
611 | #endif /* CONFIG_FUNCTION_PROFILER */ | |
612 | ||
ecea656d | 613 | #ifdef CONFIG_KPROBES |
f17845e5 IM |
614 | |
615 | static int frozen_record_count; | |
616 | ||
ecea656d AS |
617 | static inline void freeze_record(struct dyn_ftrace *rec) |
618 | { | |
619 | if (!(rec->flags & FTRACE_FL_FROZEN)) { | |
620 | rec->flags |= FTRACE_FL_FROZEN; | |
621 | frozen_record_count++; | |
622 | } | |
623 | } | |
624 | ||
625 | static inline void unfreeze_record(struct dyn_ftrace *rec) | |
626 | { | |
627 | if (rec->flags & FTRACE_FL_FROZEN) { | |
628 | rec->flags &= ~FTRACE_FL_FROZEN; | |
629 | frozen_record_count--; | |
630 | } | |
631 | } | |
632 | ||
633 | static inline int record_frozen(struct dyn_ftrace *rec) | |
634 | { | |
635 | return rec->flags & FTRACE_FL_FROZEN; | |
636 | } | |
637 | #else | |
638 | # define freeze_record(rec) ({ 0; }) | |
639 | # define unfreeze_record(rec) ({ 0; }) | |
640 | # define record_frozen(rec) ({ 0; }) | |
641 | #endif /* CONFIG_KPROBES */ | |
642 | ||
e309b41d | 643 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
37ad5084 | 644 | { |
ee000b7f | 645 | rec->freelist = ftrace_free_records; |
37ad5084 SR |
646 | ftrace_free_records = rec; |
647 | rec->flags |= FTRACE_FL_FREE; | |
648 | } | |
649 | ||
fed1939c SR |
650 | void ftrace_release(void *start, unsigned long size) |
651 | { | |
652 | struct dyn_ftrace *rec; | |
653 | struct ftrace_page *pg; | |
654 | unsigned long s = (unsigned long)start; | |
655 | unsigned long e = s + size; | |
fed1939c | 656 | |
00fd61ae | 657 | if (ftrace_disabled || !start) |
fed1939c SR |
658 | return; |
659 | ||
52baf119 | 660 | mutex_lock(&ftrace_lock); |
265c831c | 661 | do_for_each_ftrace_rec(pg, rec) { |
b00f0b6d | 662 | if ((rec->ip >= s) && (rec->ip < e) && |
bac429f0 | 663 | !(rec->flags & FTRACE_FL_FREE)) { |
265c831c | 664 | ftrace_free_rec(rec); |
bac429f0 SR |
665 | ftrace_profile_release(rec); |
666 | } | |
265c831c | 667 | } while_for_each_ftrace_rec(); |
52baf119 | 668 | mutex_unlock(&ftrace_lock); |
fed1939c SR |
669 | } |
670 | ||
e309b41d | 671 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 672 | { |
37ad5084 SR |
673 | struct dyn_ftrace *rec; |
674 | ||
675 | /* First check for freed records */ | |
676 | if (ftrace_free_records) { | |
677 | rec = ftrace_free_records; | |
678 | ||
37ad5084 | 679 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
6912896e | 680 | FTRACE_WARN_ON_ONCE(1); |
37ad5084 SR |
681 | ftrace_free_records = NULL; |
682 | return NULL; | |
683 | } | |
684 | ||
ee000b7f | 685 | ftrace_free_records = rec->freelist; |
37ad5084 SR |
686 | memset(rec, 0, sizeof(*rec)); |
687 | return rec; | |
688 | } | |
689 | ||
3c1720f0 | 690 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
08f5ac90 SR |
691 | if (!ftrace_pages->next) { |
692 | /* allocate another page */ | |
693 | ftrace_pages->next = | |
694 | (void *)get_zeroed_page(GFP_KERNEL); | |
695 | if (!ftrace_pages->next) | |
696 | return NULL; | |
697 | } | |
3c1720f0 SR |
698 | ftrace_pages = ftrace_pages->next; |
699 | } | |
700 | ||
701 | return &ftrace_pages->records[ftrace_pages->index++]; | |
702 | } | |
703 | ||
08f5ac90 | 704 | static struct dyn_ftrace * |
d61f82d0 | 705 | ftrace_record_ip(unsigned long ip) |
3d083395 | 706 | { |
08f5ac90 | 707 | struct dyn_ftrace *rec; |
3d083395 | 708 | |
f3c7ac40 | 709 | if (ftrace_disabled) |
08f5ac90 | 710 | return NULL; |
3d083395 | 711 | |
08f5ac90 SR |
712 | rec = ftrace_alloc_dyn_node(ip); |
713 | if (!rec) | |
714 | return NULL; | |
3d083395 | 715 | |
08f5ac90 | 716 | rec->ip = ip; |
ee000b7f | 717 | rec->newlist = ftrace_new_addrs; |
e94142a6 | 718 | ftrace_new_addrs = rec; |
3d083395 | 719 | |
bac429f0 SR |
720 | ftrace_add_profile(rec); |
721 | ||
08f5ac90 | 722 | return rec; |
3d083395 SR |
723 | } |
724 | ||
b17e8a37 SR |
725 | static void print_ip_ins(const char *fmt, unsigned char *p) |
726 | { | |
727 | int i; | |
728 | ||
729 | printk(KERN_CONT "%s", fmt); | |
730 | ||
731 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
732 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
733 | } | |
734 | ||
31e88909 | 735 | static void ftrace_bug(int failed, unsigned long ip) |
b17e8a37 SR |
736 | { |
737 | switch (failed) { | |
738 | case -EFAULT: | |
739 | FTRACE_WARN_ON_ONCE(1); | |
740 | pr_info("ftrace faulted on modifying "); | |
741 | print_ip_sym(ip); | |
742 | break; | |
743 | case -EINVAL: | |
744 | FTRACE_WARN_ON_ONCE(1); | |
745 | pr_info("ftrace failed to modify "); | |
746 | print_ip_sym(ip); | |
b17e8a37 | 747 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
748 | printk(KERN_CONT "\n"); |
749 | break; | |
750 | case -EPERM: | |
751 | FTRACE_WARN_ON_ONCE(1); | |
752 | pr_info("ftrace faulted on writing "); | |
753 | print_ip_sym(ip); | |
754 | break; | |
755 | default: | |
756 | FTRACE_WARN_ON_ONCE(1); | |
757 | pr_info("ftrace faulted on unknown error "); | |
758 | print_ip_sym(ip); | |
759 | } | |
760 | } | |
761 | ||
3c1720f0 | 762 | |
0eb96701 | 763 | static int |
31e88909 | 764 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) |
5072c59f | 765 | { |
e7d3737e | 766 | unsigned long ftrace_addr; |
6a24a244 | 767 | unsigned long ip, fl; |
e7d3737e | 768 | |
f0001207 | 769 | ftrace_addr = (unsigned long)FTRACE_ADDR; |
5072c59f SR |
770 | |
771 | ip = rec->ip; | |
772 | ||
982c350b SR |
773 | /* |
774 | * If this record is not to be traced and | |
775 | * it is not enabled then do nothing. | |
776 | * | |
777 | * If this record is not to be traced and | |
57794a9d | 778 | * it is enabled then disable it. |
982c350b SR |
779 | * |
780 | */ | |
781 | if (rec->flags & FTRACE_FL_NOTRACE) { | |
782 | if (rec->flags & FTRACE_FL_ENABLED) | |
783 | rec->flags &= ~FTRACE_FL_ENABLED; | |
784 | else | |
785 | return 0; | |
786 | ||
787 | } else if (ftrace_filtered && enable) { | |
5072c59f | 788 | /* |
982c350b | 789 | * Filtering is on: |
5072c59f | 790 | */ |
a4500b84 | 791 | |
982c350b | 792 | fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED); |
5072c59f | 793 | |
982c350b SR |
794 | /* Record is filtered and enabled, do nothing */ |
795 | if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) | |
0eb96701 | 796 | return 0; |
5072c59f | 797 | |
57794a9d | 798 | /* Record is not filtered or enabled, do nothing */ |
982c350b SR |
799 | if (!fl) |
800 | return 0; | |
801 | ||
802 | /* Record is not filtered but enabled, disable it */ | |
803 | if (fl == FTRACE_FL_ENABLED) | |
5072c59f | 804 | rec->flags &= ~FTRACE_FL_ENABLED; |
982c350b SR |
805 | else |
806 | /* Otherwise record is filtered but not enabled, enable it */ | |
5072c59f | 807 | rec->flags |= FTRACE_FL_ENABLED; |
5072c59f | 808 | } else { |
982c350b | 809 | /* Disable or not filtered */ |
5072c59f | 810 | |
41c52c0d | 811 | if (enable) { |
982c350b | 812 | /* if record is enabled, do nothing */ |
5072c59f | 813 | if (rec->flags & FTRACE_FL_ENABLED) |
0eb96701 | 814 | return 0; |
982c350b | 815 | |
5072c59f | 816 | rec->flags |= FTRACE_FL_ENABLED; |
982c350b | 817 | |
5072c59f | 818 | } else { |
982c350b | 819 | |
57794a9d | 820 | /* if record is not enabled, do nothing */ |
5072c59f | 821 | if (!(rec->flags & FTRACE_FL_ENABLED)) |
0eb96701 | 822 | return 0; |
982c350b | 823 | |
5072c59f SR |
824 | rec->flags &= ~FTRACE_FL_ENABLED; |
825 | } | |
826 | } | |
827 | ||
982c350b | 828 | if (rec->flags & FTRACE_FL_ENABLED) |
e7d3737e | 829 | return ftrace_make_call(rec, ftrace_addr); |
31e88909 | 830 | else |
e7d3737e | 831 | return ftrace_make_nop(NULL, rec, ftrace_addr); |
5072c59f SR |
832 | } |
833 | ||
e309b41d | 834 | static void ftrace_replace_code(int enable) |
3c1720f0 | 835 | { |
3c1720f0 SR |
836 | struct dyn_ftrace *rec; |
837 | struct ftrace_page *pg; | |
6a24a244 | 838 | int failed; |
3c1720f0 | 839 | |
265c831c SR |
840 | do_for_each_ftrace_rec(pg, rec) { |
841 | /* | |
fa9d13cf Z |
842 | * Skip over free records, records that have |
843 | * failed and not converted. | |
265c831c SR |
844 | */ |
845 | if (rec->flags & FTRACE_FL_FREE || | |
fa9d13cf | 846 | rec->flags & FTRACE_FL_FAILED || |
03303549 | 847 | !(rec->flags & FTRACE_FL_CONVERTED)) |
265c831c SR |
848 | continue; |
849 | ||
850 | /* ignore updates to this record's mcount site */ | |
851 | if (get_kprobe((void *)rec->ip)) { | |
852 | freeze_record(rec); | |
853 | continue; | |
854 | } else { | |
855 | unfreeze_record(rec); | |
856 | } | |
f22f9a89 | 857 | |
265c831c | 858 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 859 | if (failed) { |
265c831c SR |
860 | rec->flags |= FTRACE_FL_FAILED; |
861 | if ((system_state == SYSTEM_BOOTING) || | |
862 | !core_kernel_text(rec->ip)) { | |
863 | ftrace_free_rec(rec); | |
4377245a | 864 | } else { |
265c831c | 865 | ftrace_bug(failed, rec->ip); |
4377245a SR |
866 | /* Stop processing */ |
867 | return; | |
868 | } | |
3c1720f0 | 869 | } |
265c831c | 870 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
871 | } |
872 | ||
492a7ea5 | 873 | static int |
31e88909 | 874 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 SR |
875 | { |
876 | unsigned long ip; | |
593eb8a2 | 877 | int ret; |
3c1720f0 SR |
878 | |
879 | ip = rec->ip; | |
880 | ||
25aac9dc | 881 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 882 | if (ret) { |
31e88909 | 883 | ftrace_bug(ret, ip); |
3c1720f0 | 884 | rec->flags |= FTRACE_FL_FAILED; |
492a7ea5 | 885 | return 0; |
37ad5084 | 886 | } |
492a7ea5 | 887 | return 1; |
3c1720f0 SR |
888 | } |
889 | ||
000ab691 SR |
890 | /* |
891 | * archs can override this function if they must do something | |
892 | * before the modifying code is performed. | |
893 | */ | |
894 | int __weak ftrace_arch_code_modify_prepare(void) | |
895 | { | |
896 | return 0; | |
897 | } | |
898 | ||
899 | /* | |
900 | * archs can override this function if they must do something | |
901 | * after the modifying code is performed. | |
902 | */ | |
903 | int __weak ftrace_arch_code_modify_post_process(void) | |
904 | { | |
905 | return 0; | |
906 | } | |
907 | ||
e309b41d | 908 | static int __ftrace_modify_code(void *data) |
3d083395 | 909 | { |
d61f82d0 SR |
910 | int *command = data; |
911 | ||
a3583244 | 912 | if (*command & FTRACE_ENABLE_CALLS) |
d61f82d0 | 913 | ftrace_replace_code(1); |
a3583244 | 914 | else if (*command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
915 | ftrace_replace_code(0); |
916 | ||
917 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
918 | ftrace_update_ftrace_func(ftrace_trace_function); | |
919 | ||
5a45cfe1 SR |
920 | if (*command & FTRACE_START_FUNC_RET) |
921 | ftrace_enable_ftrace_graph_caller(); | |
922 | else if (*command & FTRACE_STOP_FUNC_RET) | |
923 | ftrace_disable_ftrace_graph_caller(); | |
924 | ||
d61f82d0 | 925 | return 0; |
3d083395 SR |
926 | } |
927 | ||
e309b41d | 928 | static void ftrace_run_update_code(int command) |
3d083395 | 929 | { |
000ab691 SR |
930 | int ret; |
931 | ||
932 | ret = ftrace_arch_code_modify_prepare(); | |
933 | FTRACE_WARN_ON(ret); | |
934 | if (ret) | |
935 | return; | |
936 | ||
784e2d76 | 937 | stop_machine(__ftrace_modify_code, &command, NULL); |
000ab691 SR |
938 | |
939 | ret = ftrace_arch_code_modify_post_process(); | |
940 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
941 | } |
942 | ||
d61f82d0 | 943 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 944 | static int ftrace_start_up; |
df4fc315 SR |
945 | |
946 | static void ftrace_startup_enable(int command) | |
947 | { | |
948 | if (saved_ftrace_func != ftrace_trace_function) { | |
949 | saved_ftrace_func = ftrace_trace_function; | |
950 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
951 | } | |
952 | ||
953 | if (!command || !ftrace_enabled) | |
954 | return; | |
955 | ||
956 | ftrace_run_update_code(command); | |
957 | } | |
d61f82d0 | 958 | |
5a45cfe1 | 959 | static void ftrace_startup(int command) |
3d083395 | 960 | { |
4eebcc81 SR |
961 | if (unlikely(ftrace_disabled)) |
962 | return; | |
963 | ||
60a7ecf4 | 964 | ftrace_start_up++; |
982c350b | 965 | command |= FTRACE_ENABLE_CALLS; |
d61f82d0 | 966 | |
df4fc315 | 967 | ftrace_startup_enable(command); |
3d083395 SR |
968 | } |
969 | ||
5a45cfe1 | 970 | static void ftrace_shutdown(int command) |
3d083395 | 971 | { |
4eebcc81 SR |
972 | if (unlikely(ftrace_disabled)) |
973 | return; | |
974 | ||
60a7ecf4 SR |
975 | ftrace_start_up--; |
976 | if (!ftrace_start_up) | |
d61f82d0 | 977 | command |= FTRACE_DISABLE_CALLS; |
3d083395 | 978 | |
d61f82d0 SR |
979 | if (saved_ftrace_func != ftrace_trace_function) { |
980 | saved_ftrace_func = ftrace_trace_function; | |
981 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
982 | } | |
3d083395 | 983 | |
d61f82d0 | 984 | if (!command || !ftrace_enabled) |
e6ea44e9 | 985 | return; |
d61f82d0 SR |
986 | |
987 | ftrace_run_update_code(command); | |
3d083395 SR |
988 | } |
989 | ||
e309b41d | 990 | static void ftrace_startup_sysctl(void) |
b0fc494f | 991 | { |
d61f82d0 SR |
992 | int command = FTRACE_ENABLE_MCOUNT; |
993 | ||
4eebcc81 SR |
994 | if (unlikely(ftrace_disabled)) |
995 | return; | |
996 | ||
d61f82d0 SR |
997 | /* Force update next time */ |
998 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
999 | /* ftrace_start_up is true if we want ftrace running */ |
1000 | if (ftrace_start_up) | |
d61f82d0 SR |
1001 | command |= FTRACE_ENABLE_CALLS; |
1002 | ||
1003 | ftrace_run_update_code(command); | |
b0fc494f SR |
1004 | } |
1005 | ||
e309b41d | 1006 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 1007 | { |
d61f82d0 SR |
1008 | int command = FTRACE_DISABLE_MCOUNT; |
1009 | ||
4eebcc81 SR |
1010 | if (unlikely(ftrace_disabled)) |
1011 | return; | |
1012 | ||
60a7ecf4 SR |
1013 | /* ftrace_start_up is true if ftrace is running */ |
1014 | if (ftrace_start_up) | |
d61f82d0 SR |
1015 | command |= FTRACE_DISABLE_CALLS; |
1016 | ||
1017 | ftrace_run_update_code(command); | |
b0fc494f SR |
1018 | } |
1019 | ||
3d083395 SR |
1020 | static cycle_t ftrace_update_time; |
1021 | static unsigned long ftrace_update_cnt; | |
1022 | unsigned long ftrace_update_tot_cnt; | |
1023 | ||
31e88909 | 1024 | static int ftrace_update_code(struct module *mod) |
3d083395 | 1025 | { |
e94142a6 | 1026 | struct dyn_ftrace *p; |
f22f9a89 | 1027 | cycle_t start, stop; |
3d083395 | 1028 | |
750ed1a4 | 1029 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1030 | ftrace_update_cnt = 0; |
1031 | ||
e94142a6 | 1032 | while (ftrace_new_addrs) { |
3d083395 | 1033 | |
08f5ac90 SR |
1034 | /* If something went wrong, bail without enabling anything */ |
1035 | if (unlikely(ftrace_disabled)) | |
1036 | return -1; | |
f22f9a89 | 1037 | |
e94142a6 | 1038 | p = ftrace_new_addrs; |
ee000b7f | 1039 | ftrace_new_addrs = p->newlist; |
e94142a6 | 1040 | p->flags = 0L; |
f22f9a89 | 1041 | |
08f5ac90 | 1042 | /* convert record (i.e, patch mcount-call with NOP) */ |
31e88909 | 1043 | if (ftrace_code_disable(mod, p)) { |
08f5ac90 SR |
1044 | p->flags |= FTRACE_FL_CONVERTED; |
1045 | ftrace_update_cnt++; | |
1046 | } else | |
1047 | ftrace_free_rec(p); | |
3d083395 SR |
1048 | } |
1049 | ||
750ed1a4 | 1050 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
1051 | ftrace_update_time = stop - start; |
1052 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
1053 | ||
16444a8a ACM |
1054 | return 0; |
1055 | } | |
1056 | ||
68bf21aa | 1057 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
1058 | { |
1059 | struct ftrace_page *pg; | |
1060 | int cnt; | |
1061 | int i; | |
3c1720f0 SR |
1062 | |
1063 | /* allocate a few pages */ | |
1064 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
1065 | if (!ftrace_pages_start) | |
1066 | return -1; | |
1067 | ||
1068 | /* | |
1069 | * Allocate a few more pages. | |
1070 | * | |
1071 | * TODO: have some parser search vmlinux before | |
1072 | * final linking to find all calls to ftrace. | |
1073 | * Then we can: | |
1074 | * a) know how many pages to allocate. | |
1075 | * and/or | |
1076 | * b) set up the table then. | |
1077 | * | |
1078 | * The dynamic code is still necessary for | |
1079 | * modules. | |
1080 | */ | |
1081 | ||
1082 | pg = ftrace_pages = ftrace_pages_start; | |
1083 | ||
68bf21aa | 1084 | cnt = num_to_init / ENTRIES_PER_PAGE; |
08f5ac90 | 1085 | pr_info("ftrace: allocating %ld entries in %d pages\n", |
5821e1b7 | 1086 | num_to_init, cnt + 1); |
3c1720f0 SR |
1087 | |
1088 | for (i = 0; i < cnt; i++) { | |
1089 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
1090 | ||
1091 | /* If we fail, we'll try later anyway */ | |
1092 | if (!pg->next) | |
1093 | break; | |
1094 | ||
1095 | pg = pg->next; | |
1096 | } | |
1097 | ||
1098 | return 0; | |
1099 | } | |
1100 | ||
5072c59f SR |
1101 | enum { |
1102 | FTRACE_ITER_FILTER = (1 << 0), | |
1103 | FTRACE_ITER_CONT = (1 << 1), | |
41c52c0d | 1104 | FTRACE_ITER_NOTRACE = (1 << 2), |
eb9a7bf0 | 1105 | FTRACE_ITER_FAILURES = (1 << 3), |
0c75a3ed | 1106 | FTRACE_ITER_PRINTALL = (1 << 4), |
8fc0c701 | 1107 | FTRACE_ITER_HASH = (1 << 5), |
5072c59f SR |
1108 | }; |
1109 | ||
1110 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
1111 | ||
1112 | struct ftrace_iterator { | |
5072c59f | 1113 | struct ftrace_page *pg; |
8fc0c701 | 1114 | int hidx; |
431aa3fb | 1115 | int idx; |
5072c59f SR |
1116 | unsigned flags; |
1117 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
1118 | unsigned buffer_idx; | |
1119 | unsigned filtered; | |
1120 | }; | |
1121 | ||
8fc0c701 SR |
1122 | static void * |
1123 | t_hash_next(struct seq_file *m, void *v, loff_t *pos) | |
1124 | { | |
1125 | struct ftrace_iterator *iter = m->private; | |
1126 | struct hlist_node *hnd = v; | |
1127 | struct hlist_head *hhd; | |
1128 | ||
1129 | WARN_ON(!(iter->flags & FTRACE_ITER_HASH)); | |
1130 | ||
1131 | (*pos)++; | |
1132 | ||
1133 | retry: | |
1134 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
1135 | return NULL; | |
1136 | ||
1137 | hhd = &ftrace_func_hash[iter->hidx]; | |
1138 | ||
1139 | if (hlist_empty(hhd)) { | |
1140 | iter->hidx++; | |
1141 | hnd = NULL; | |
1142 | goto retry; | |
1143 | } | |
1144 | ||
1145 | if (!hnd) | |
1146 | hnd = hhd->first; | |
1147 | else { | |
1148 | hnd = hnd->next; | |
1149 | if (!hnd) { | |
1150 | iter->hidx++; | |
1151 | goto retry; | |
1152 | } | |
1153 | } | |
1154 | ||
1155 | return hnd; | |
1156 | } | |
1157 | ||
1158 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
1159 | { | |
1160 | struct ftrace_iterator *iter = m->private; | |
1161 | void *p = NULL; | |
1162 | ||
1163 | iter->flags |= FTRACE_ITER_HASH; | |
1164 | ||
1165 | return t_hash_next(m, p, pos); | |
1166 | } | |
1167 | ||
1168 | static int t_hash_show(struct seq_file *m, void *v) | |
1169 | { | |
b6887d79 | 1170 | struct ftrace_func_probe *rec; |
8fc0c701 SR |
1171 | struct hlist_node *hnd = v; |
1172 | char str[KSYM_SYMBOL_LEN]; | |
1173 | ||
b6887d79 | 1174 | rec = hlist_entry(hnd, struct ftrace_func_probe, node); |
8fc0c701 | 1175 | |
809dcf29 SR |
1176 | if (rec->ops->print) |
1177 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
1178 | ||
8fc0c701 SR |
1179 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
1180 | seq_printf(m, "%s:", str); | |
1181 | ||
1182 | kallsyms_lookup((unsigned long)rec->ops->func, NULL, NULL, NULL, str); | |
1183 | seq_printf(m, "%s", str); | |
1184 | ||
1185 | if (rec->data) | |
1186 | seq_printf(m, ":%p", rec->data); | |
1187 | seq_putc(m, '\n'); | |
1188 | ||
1189 | return 0; | |
1190 | } | |
1191 | ||
e309b41d | 1192 | static void * |
5072c59f SR |
1193 | t_next(struct seq_file *m, void *v, loff_t *pos) |
1194 | { | |
1195 | struct ftrace_iterator *iter = m->private; | |
1196 | struct dyn_ftrace *rec = NULL; | |
1197 | ||
8fc0c701 SR |
1198 | if (iter->flags & FTRACE_ITER_HASH) |
1199 | return t_hash_next(m, v, pos); | |
1200 | ||
5072c59f SR |
1201 | (*pos)++; |
1202 | ||
0c75a3ed SR |
1203 | if (iter->flags & FTRACE_ITER_PRINTALL) |
1204 | return NULL; | |
1205 | ||
5072c59f SR |
1206 | retry: |
1207 | if (iter->idx >= iter->pg->index) { | |
1208 | if (iter->pg->next) { | |
1209 | iter->pg = iter->pg->next; | |
1210 | iter->idx = 0; | |
1211 | goto retry; | |
50cdaf08 LW |
1212 | } else { |
1213 | iter->idx = -1; | |
5072c59f SR |
1214 | } |
1215 | } else { | |
1216 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
1217 | if ((rec->flags & FTRACE_FL_FREE) || |
1218 | ||
1219 | (!(iter->flags & FTRACE_ITER_FAILURES) && | |
eb9a7bf0 AS |
1220 | (rec->flags & FTRACE_FL_FAILED)) || |
1221 | ||
1222 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
a9fdda33 | 1223 | !(rec->flags & FTRACE_FL_FAILED)) || |
eb9a7bf0 | 1224 | |
0183fb1c SR |
1225 | ((iter->flags & FTRACE_ITER_FILTER) && |
1226 | !(rec->flags & FTRACE_FL_FILTER)) || | |
1227 | ||
41c52c0d SR |
1228 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
1229 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
1230 | rec = NULL; |
1231 | goto retry; | |
1232 | } | |
1233 | } | |
1234 | ||
5072c59f SR |
1235 | return rec; |
1236 | } | |
1237 | ||
1238 | static void *t_start(struct seq_file *m, loff_t *pos) | |
1239 | { | |
1240 | struct ftrace_iterator *iter = m->private; | |
1241 | void *p = NULL; | |
5072c59f | 1242 | |
8fc0c701 | 1243 | mutex_lock(&ftrace_lock); |
0c75a3ed SR |
1244 | /* |
1245 | * For set_ftrace_filter reading, if we have the filter | |
1246 | * off, we can short cut and just print out that all | |
1247 | * functions are enabled. | |
1248 | */ | |
1249 | if (iter->flags & FTRACE_ITER_FILTER && !ftrace_filtered) { | |
1250 | if (*pos > 0) | |
8fc0c701 | 1251 | return t_hash_start(m, pos); |
0c75a3ed SR |
1252 | iter->flags |= FTRACE_ITER_PRINTALL; |
1253 | (*pos)++; | |
1254 | return iter; | |
1255 | } | |
1256 | ||
8fc0c701 SR |
1257 | if (iter->flags & FTRACE_ITER_HASH) |
1258 | return t_hash_start(m, pos); | |
1259 | ||
50cdaf08 LW |
1260 | if (*pos > 0) { |
1261 | if (iter->idx < 0) | |
1262 | return p; | |
1263 | (*pos)--; | |
1264 | iter->idx--; | |
1265 | } | |
5821e1b7 | 1266 | |
50cdaf08 | 1267 | p = t_next(m, p, pos); |
5072c59f | 1268 | |
8fc0c701 SR |
1269 | if (!p) |
1270 | return t_hash_start(m, pos); | |
1271 | ||
5072c59f SR |
1272 | return p; |
1273 | } | |
1274 | ||
1275 | static void t_stop(struct seq_file *m, void *p) | |
1276 | { | |
8fc0c701 | 1277 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1278 | } |
1279 | ||
1280 | static int t_show(struct seq_file *m, void *v) | |
1281 | { | |
0c75a3ed | 1282 | struct ftrace_iterator *iter = m->private; |
5072c59f SR |
1283 | struct dyn_ftrace *rec = v; |
1284 | char str[KSYM_SYMBOL_LEN]; | |
1285 | ||
8fc0c701 SR |
1286 | if (iter->flags & FTRACE_ITER_HASH) |
1287 | return t_hash_show(m, v); | |
1288 | ||
0c75a3ed SR |
1289 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
1290 | seq_printf(m, "#### all functions enabled ####\n"); | |
1291 | return 0; | |
1292 | } | |
1293 | ||
5072c59f SR |
1294 | if (!rec) |
1295 | return 0; | |
1296 | ||
1297 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1298 | ||
50cdaf08 | 1299 | seq_printf(m, "%s\n", str); |
5072c59f SR |
1300 | |
1301 | return 0; | |
1302 | } | |
1303 | ||
1304 | static struct seq_operations show_ftrace_seq_ops = { | |
1305 | .start = t_start, | |
1306 | .next = t_next, | |
1307 | .stop = t_stop, | |
1308 | .show = t_show, | |
1309 | }; | |
1310 | ||
e309b41d | 1311 | static int |
5072c59f SR |
1312 | ftrace_avail_open(struct inode *inode, struct file *file) |
1313 | { | |
1314 | struct ftrace_iterator *iter; | |
1315 | int ret; | |
1316 | ||
4eebcc81 SR |
1317 | if (unlikely(ftrace_disabled)) |
1318 | return -ENODEV; | |
1319 | ||
5072c59f SR |
1320 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1321 | if (!iter) | |
1322 | return -ENOMEM; | |
1323 | ||
1324 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
1325 | |
1326 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1327 | if (!ret) { | |
1328 | struct seq_file *m = file->private_data; | |
4bf39a94 | 1329 | |
5072c59f | 1330 | m->private = iter; |
4bf39a94 | 1331 | } else { |
5072c59f | 1332 | kfree(iter); |
4bf39a94 | 1333 | } |
5072c59f SR |
1334 | |
1335 | return ret; | |
1336 | } | |
1337 | ||
1338 | int ftrace_avail_release(struct inode *inode, struct file *file) | |
1339 | { | |
1340 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1341 | struct ftrace_iterator *iter = m->private; | |
1342 | ||
1343 | seq_release(inode, file); | |
1344 | kfree(iter); | |
4bf39a94 | 1345 | |
5072c59f SR |
1346 | return 0; |
1347 | } | |
1348 | ||
eb9a7bf0 AS |
1349 | static int |
1350 | ftrace_failures_open(struct inode *inode, struct file *file) | |
1351 | { | |
1352 | int ret; | |
1353 | struct seq_file *m; | |
1354 | struct ftrace_iterator *iter; | |
1355 | ||
1356 | ret = ftrace_avail_open(inode, file); | |
1357 | if (!ret) { | |
1358 | m = (struct seq_file *)file->private_data; | |
1359 | iter = (struct ftrace_iterator *)m->private; | |
1360 | iter->flags = FTRACE_ITER_FAILURES; | |
1361 | } | |
1362 | ||
1363 | return ret; | |
1364 | } | |
1365 | ||
1366 | ||
41c52c0d | 1367 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
1368 | { |
1369 | struct ftrace_page *pg; | |
1370 | struct dyn_ftrace *rec; | |
41c52c0d | 1371 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f | 1372 | |
52baf119 | 1373 | mutex_lock(&ftrace_lock); |
41c52c0d SR |
1374 | if (enable) |
1375 | ftrace_filtered = 0; | |
265c831c SR |
1376 | do_for_each_ftrace_rec(pg, rec) { |
1377 | if (rec->flags & FTRACE_FL_FAILED) | |
1378 | continue; | |
1379 | rec->flags &= ~type; | |
1380 | } while_for_each_ftrace_rec(); | |
52baf119 | 1381 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1382 | } |
1383 | ||
e309b41d | 1384 | static int |
41c52c0d | 1385 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1386 | { |
1387 | struct ftrace_iterator *iter; | |
1388 | int ret = 0; | |
1389 | ||
4eebcc81 SR |
1390 | if (unlikely(ftrace_disabled)) |
1391 | return -ENODEV; | |
1392 | ||
5072c59f SR |
1393 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1394 | if (!iter) | |
1395 | return -ENOMEM; | |
1396 | ||
41c52c0d | 1397 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1398 | if ((file->f_mode & FMODE_WRITE) && |
1399 | !(file->f_flags & O_APPEND)) | |
41c52c0d | 1400 | ftrace_filter_reset(enable); |
5072c59f SR |
1401 | |
1402 | if (file->f_mode & FMODE_READ) { | |
1403 | iter->pg = ftrace_pages_start; | |
41c52c0d SR |
1404 | iter->flags = enable ? FTRACE_ITER_FILTER : |
1405 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
1406 | |
1407 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1408 | if (!ret) { | |
1409 | struct seq_file *m = file->private_data; | |
1410 | m->private = iter; | |
1411 | } else | |
1412 | kfree(iter); | |
1413 | } else | |
1414 | file->private_data = iter; | |
41c52c0d | 1415 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1416 | |
1417 | return ret; | |
1418 | } | |
1419 | ||
41c52c0d SR |
1420 | static int |
1421 | ftrace_filter_open(struct inode *inode, struct file *file) | |
1422 | { | |
1423 | return ftrace_regex_open(inode, file, 1); | |
1424 | } | |
1425 | ||
1426 | static int | |
1427 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
1428 | { | |
1429 | return ftrace_regex_open(inode, file, 0); | |
1430 | } | |
1431 | ||
e309b41d | 1432 | static loff_t |
41c52c0d | 1433 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
1434 | { |
1435 | loff_t ret; | |
1436 | ||
1437 | if (file->f_mode & FMODE_READ) | |
1438 | ret = seq_lseek(file, offset, origin); | |
1439 | else | |
1440 | file->f_pos = ret = 1; | |
1441 | ||
1442 | return ret; | |
1443 | } | |
1444 | ||
1445 | enum { | |
1446 | MATCH_FULL, | |
1447 | MATCH_FRONT_ONLY, | |
1448 | MATCH_MIDDLE_ONLY, | |
1449 | MATCH_END_ONLY, | |
1450 | }; | |
1451 | ||
9f4801e3 SR |
1452 | /* |
1453 | * (static function - no need for kernel doc) | |
1454 | * | |
1455 | * Pass in a buffer containing a glob and this function will | |
1456 | * set search to point to the search part of the buffer and | |
1457 | * return the type of search it is (see enum above). | |
1458 | * This does modify buff. | |
1459 | * | |
1460 | * Returns enum type. | |
1461 | * search returns the pointer to use for comparison. | |
1462 | * not returns 1 if buff started with a '!' | |
1463 | * 0 otherwise. | |
1464 | */ | |
1465 | static int | |
64e7c440 | 1466 | ftrace_setup_glob(char *buff, int len, char **search, int *not) |
5072c59f | 1467 | { |
5072c59f | 1468 | int type = MATCH_FULL; |
9f4801e3 | 1469 | int i; |
ea3a6d6d SR |
1470 | |
1471 | if (buff[0] == '!') { | |
9f4801e3 | 1472 | *not = 1; |
ea3a6d6d SR |
1473 | buff++; |
1474 | len--; | |
9f4801e3 SR |
1475 | } else |
1476 | *not = 0; | |
1477 | ||
1478 | *search = buff; | |
5072c59f SR |
1479 | |
1480 | for (i = 0; i < len; i++) { | |
1481 | if (buff[i] == '*') { | |
1482 | if (!i) { | |
9f4801e3 | 1483 | *search = buff + 1; |
5072c59f | 1484 | type = MATCH_END_ONLY; |
5072c59f | 1485 | } else { |
9f4801e3 | 1486 | if (type == MATCH_END_ONLY) |
5072c59f | 1487 | type = MATCH_MIDDLE_ONLY; |
9f4801e3 | 1488 | else |
5072c59f | 1489 | type = MATCH_FRONT_ONLY; |
5072c59f SR |
1490 | buff[i] = 0; |
1491 | break; | |
1492 | } | |
1493 | } | |
1494 | } | |
1495 | ||
9f4801e3 SR |
1496 | return type; |
1497 | } | |
1498 | ||
64e7c440 | 1499 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 1500 | { |
9f4801e3 SR |
1501 | int matched = 0; |
1502 | char *ptr; | |
1503 | ||
9f4801e3 SR |
1504 | switch (type) { |
1505 | case MATCH_FULL: | |
1506 | if (strcmp(str, regex) == 0) | |
1507 | matched = 1; | |
1508 | break; | |
1509 | case MATCH_FRONT_ONLY: | |
1510 | if (strncmp(str, regex, len) == 0) | |
1511 | matched = 1; | |
1512 | break; | |
1513 | case MATCH_MIDDLE_ONLY: | |
1514 | if (strstr(str, regex)) | |
1515 | matched = 1; | |
1516 | break; | |
1517 | case MATCH_END_ONLY: | |
1518 | ptr = strstr(str, regex); | |
1519 | if (ptr && (ptr[len] == 0)) | |
1520 | matched = 1; | |
1521 | break; | |
1522 | } | |
1523 | ||
1524 | return matched; | |
1525 | } | |
1526 | ||
64e7c440 SR |
1527 | static int |
1528 | ftrace_match_record(struct dyn_ftrace *rec, char *regex, int len, int type) | |
1529 | { | |
1530 | char str[KSYM_SYMBOL_LEN]; | |
1531 | ||
1532 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1533 | return ftrace_match(str, regex, len, type); | |
1534 | } | |
1535 | ||
9f4801e3 SR |
1536 | static void ftrace_match_records(char *buff, int len, int enable) |
1537 | { | |
6a24a244 | 1538 | unsigned int search_len; |
9f4801e3 SR |
1539 | struct ftrace_page *pg; |
1540 | struct dyn_ftrace *rec; | |
6a24a244 SR |
1541 | unsigned long flag; |
1542 | char *search; | |
9f4801e3 | 1543 | int type; |
9f4801e3 SR |
1544 | int not; |
1545 | ||
6a24a244 | 1546 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
9f4801e3 SR |
1547 | type = ftrace_setup_glob(buff, len, &search, ¬); |
1548 | ||
1549 | search_len = strlen(search); | |
1550 | ||
52baf119 | 1551 | mutex_lock(&ftrace_lock); |
265c831c | 1552 | do_for_each_ftrace_rec(pg, rec) { |
265c831c SR |
1553 | |
1554 | if (rec->flags & FTRACE_FL_FAILED) | |
1555 | continue; | |
9f4801e3 SR |
1556 | |
1557 | if (ftrace_match_record(rec, search, search_len, type)) { | |
265c831c SR |
1558 | if (not) |
1559 | rec->flags &= ~flag; | |
1560 | else | |
1561 | rec->flags |= flag; | |
1562 | } | |
e68746a2 SR |
1563 | /* |
1564 | * Only enable filtering if we have a function that | |
1565 | * is filtered on. | |
1566 | */ | |
1567 | if (enable && (rec->flags & FTRACE_FL_FILTER)) | |
1568 | ftrace_filtered = 1; | |
265c831c | 1569 | } while_for_each_ftrace_rec(); |
52baf119 | 1570 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1571 | } |
1572 | ||
64e7c440 SR |
1573 | static int |
1574 | ftrace_match_module_record(struct dyn_ftrace *rec, char *mod, | |
1575 | char *regex, int len, int type) | |
1576 | { | |
1577 | char str[KSYM_SYMBOL_LEN]; | |
1578 | char *modname; | |
1579 | ||
1580 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
1581 | ||
1582 | if (!modname || strcmp(modname, mod)) | |
1583 | return 0; | |
1584 | ||
1585 | /* blank search means to match all funcs in the mod */ | |
1586 | if (len) | |
1587 | return ftrace_match(str, regex, len, type); | |
1588 | else | |
1589 | return 1; | |
1590 | } | |
1591 | ||
1592 | static void ftrace_match_module_records(char *buff, char *mod, int enable) | |
1593 | { | |
6a24a244 | 1594 | unsigned search_len = 0; |
64e7c440 SR |
1595 | struct ftrace_page *pg; |
1596 | struct dyn_ftrace *rec; | |
1597 | int type = MATCH_FULL; | |
6a24a244 SR |
1598 | char *search = buff; |
1599 | unsigned long flag; | |
64e7c440 SR |
1600 | int not = 0; |
1601 | ||
6a24a244 SR |
1602 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
1603 | ||
64e7c440 SR |
1604 | /* blank or '*' mean the same */ |
1605 | if (strcmp(buff, "*") == 0) | |
1606 | buff[0] = 0; | |
1607 | ||
1608 | /* handle the case of 'dont filter this module' */ | |
1609 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
1610 | buff[0] = 0; | |
1611 | not = 1; | |
1612 | } | |
1613 | ||
1614 | if (strlen(buff)) { | |
1615 | type = ftrace_setup_glob(buff, strlen(buff), &search, ¬); | |
1616 | search_len = strlen(search); | |
1617 | } | |
1618 | ||
52baf119 | 1619 | mutex_lock(&ftrace_lock); |
64e7c440 SR |
1620 | do_for_each_ftrace_rec(pg, rec) { |
1621 | ||
1622 | if (rec->flags & FTRACE_FL_FAILED) | |
1623 | continue; | |
1624 | ||
1625 | if (ftrace_match_module_record(rec, mod, | |
1626 | search, search_len, type)) { | |
1627 | if (not) | |
1628 | rec->flags &= ~flag; | |
1629 | else | |
1630 | rec->flags |= flag; | |
1631 | } | |
e68746a2 SR |
1632 | if (enable && (rec->flags & FTRACE_FL_FILTER)) |
1633 | ftrace_filtered = 1; | |
64e7c440 SR |
1634 | |
1635 | } while_for_each_ftrace_rec(); | |
52baf119 | 1636 | mutex_unlock(&ftrace_lock); |
64e7c440 SR |
1637 | } |
1638 | ||
f6180773 SR |
1639 | /* |
1640 | * We register the module command as a template to show others how | |
1641 | * to register the a command as well. | |
1642 | */ | |
1643 | ||
1644 | static int | |
1645 | ftrace_mod_callback(char *func, char *cmd, char *param, int enable) | |
1646 | { | |
1647 | char *mod; | |
1648 | ||
1649 | /* | |
1650 | * cmd == 'mod' because we only registered this func | |
1651 | * for the 'mod' ftrace_func_command. | |
1652 | * But if you register one func with multiple commands, | |
1653 | * you can tell which command was used by the cmd | |
1654 | * parameter. | |
1655 | */ | |
1656 | ||
1657 | /* we must have a module name */ | |
1658 | if (!param) | |
1659 | return -EINVAL; | |
1660 | ||
1661 | mod = strsep(¶m, ":"); | |
1662 | if (!strlen(mod)) | |
1663 | return -EINVAL; | |
1664 | ||
1665 | ftrace_match_module_records(func, mod, enable); | |
1666 | return 0; | |
1667 | } | |
1668 | ||
1669 | static struct ftrace_func_command ftrace_mod_cmd = { | |
1670 | .name = "mod", | |
1671 | .func = ftrace_mod_callback, | |
1672 | }; | |
1673 | ||
1674 | static int __init ftrace_mod_cmd_init(void) | |
1675 | { | |
1676 | return register_ftrace_command(&ftrace_mod_cmd); | |
1677 | } | |
1678 | device_initcall(ftrace_mod_cmd_init); | |
1679 | ||
59df055f | 1680 | static void |
b6887d79 | 1681 | function_trace_probe_call(unsigned long ip, unsigned long parent_ip) |
59df055f | 1682 | { |
b6887d79 | 1683 | struct ftrace_func_probe *entry; |
59df055f SR |
1684 | struct hlist_head *hhd; |
1685 | struct hlist_node *n; | |
1686 | unsigned long key; | |
1687 | int resched; | |
1688 | ||
1689 | key = hash_long(ip, FTRACE_HASH_BITS); | |
1690 | ||
1691 | hhd = &ftrace_func_hash[key]; | |
1692 | ||
1693 | if (hlist_empty(hhd)) | |
1694 | return; | |
1695 | ||
1696 | /* | |
1697 | * Disable preemption for these calls to prevent a RCU grace | |
1698 | * period. This syncs the hash iteration and freeing of items | |
1699 | * on the hash. rcu_read_lock is too dangerous here. | |
1700 | */ | |
1701 | resched = ftrace_preempt_disable(); | |
1702 | hlist_for_each_entry_rcu(entry, n, hhd, node) { | |
1703 | if (entry->ip == ip) | |
1704 | entry->ops->func(ip, parent_ip, &entry->data); | |
1705 | } | |
1706 | ftrace_preempt_enable(resched); | |
1707 | } | |
1708 | ||
b6887d79 | 1709 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 1710 | { |
b6887d79 | 1711 | .func = function_trace_probe_call, |
59df055f SR |
1712 | }; |
1713 | ||
b6887d79 | 1714 | static int ftrace_probe_registered; |
59df055f | 1715 | |
b6887d79 | 1716 | static void __enable_ftrace_function_probe(void) |
59df055f SR |
1717 | { |
1718 | int i; | |
1719 | ||
b6887d79 | 1720 | if (ftrace_probe_registered) |
59df055f SR |
1721 | return; |
1722 | ||
1723 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1724 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1725 | if (hhd->first) | |
1726 | break; | |
1727 | } | |
1728 | /* Nothing registered? */ | |
1729 | if (i == FTRACE_FUNC_HASHSIZE) | |
1730 | return; | |
1731 | ||
b6887d79 | 1732 | __register_ftrace_function(&trace_probe_ops); |
59df055f | 1733 | ftrace_startup(0); |
b6887d79 | 1734 | ftrace_probe_registered = 1; |
59df055f SR |
1735 | } |
1736 | ||
b6887d79 | 1737 | static void __disable_ftrace_function_probe(void) |
59df055f SR |
1738 | { |
1739 | int i; | |
1740 | ||
b6887d79 | 1741 | if (!ftrace_probe_registered) |
59df055f SR |
1742 | return; |
1743 | ||
1744 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1745 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1746 | if (hhd->first) | |
1747 | return; | |
1748 | } | |
1749 | ||
1750 | /* no more funcs left */ | |
b6887d79 | 1751 | __unregister_ftrace_function(&trace_probe_ops); |
59df055f | 1752 | ftrace_shutdown(0); |
b6887d79 | 1753 | ftrace_probe_registered = 0; |
59df055f SR |
1754 | } |
1755 | ||
1756 | ||
1757 | static void ftrace_free_entry_rcu(struct rcu_head *rhp) | |
1758 | { | |
b6887d79 SR |
1759 | struct ftrace_func_probe *entry = |
1760 | container_of(rhp, struct ftrace_func_probe, rcu); | |
59df055f SR |
1761 | |
1762 | if (entry->ops->free) | |
1763 | entry->ops->free(&entry->data); | |
1764 | kfree(entry); | |
1765 | } | |
1766 | ||
1767 | ||
1768 | int | |
b6887d79 | 1769 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
1770 | void *data) |
1771 | { | |
b6887d79 | 1772 | struct ftrace_func_probe *entry; |
59df055f SR |
1773 | struct ftrace_page *pg; |
1774 | struct dyn_ftrace *rec; | |
59df055f | 1775 | int type, len, not; |
6a24a244 | 1776 | unsigned long key; |
59df055f SR |
1777 | int count = 0; |
1778 | char *search; | |
1779 | ||
1780 | type = ftrace_setup_glob(glob, strlen(glob), &search, ¬); | |
1781 | len = strlen(search); | |
1782 | ||
b6887d79 | 1783 | /* we do not support '!' for function probes */ |
59df055f SR |
1784 | if (WARN_ON(not)) |
1785 | return -EINVAL; | |
1786 | ||
1787 | mutex_lock(&ftrace_lock); | |
1788 | do_for_each_ftrace_rec(pg, rec) { | |
1789 | ||
1790 | if (rec->flags & FTRACE_FL_FAILED) | |
1791 | continue; | |
1792 | ||
1793 | if (!ftrace_match_record(rec, search, len, type)) | |
1794 | continue; | |
1795 | ||
1796 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1797 | if (!entry) { | |
b6887d79 | 1798 | /* If we did not process any, then return error */ |
59df055f SR |
1799 | if (!count) |
1800 | count = -ENOMEM; | |
1801 | goto out_unlock; | |
1802 | } | |
1803 | ||
1804 | count++; | |
1805 | ||
1806 | entry->data = data; | |
1807 | ||
1808 | /* | |
1809 | * The caller might want to do something special | |
1810 | * for each function we find. We call the callback | |
1811 | * to give the caller an opportunity to do so. | |
1812 | */ | |
1813 | if (ops->callback) { | |
1814 | if (ops->callback(rec->ip, &entry->data) < 0) { | |
1815 | /* caller does not like this func */ | |
1816 | kfree(entry); | |
1817 | continue; | |
1818 | } | |
1819 | } | |
1820 | ||
1821 | entry->ops = ops; | |
1822 | entry->ip = rec->ip; | |
1823 | ||
1824 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
1825 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
1826 | ||
1827 | } while_for_each_ftrace_rec(); | |
b6887d79 | 1828 | __enable_ftrace_function_probe(); |
59df055f SR |
1829 | |
1830 | out_unlock: | |
1831 | mutex_unlock(&ftrace_lock); | |
1832 | ||
1833 | return count; | |
1834 | } | |
1835 | ||
1836 | enum { | |
b6887d79 SR |
1837 | PROBE_TEST_FUNC = 1, |
1838 | PROBE_TEST_DATA = 2 | |
59df055f SR |
1839 | }; |
1840 | ||
1841 | static void | |
b6887d79 | 1842 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
1843 | void *data, int flags) |
1844 | { | |
b6887d79 | 1845 | struct ftrace_func_probe *entry; |
59df055f SR |
1846 | struct hlist_node *n, *tmp; |
1847 | char str[KSYM_SYMBOL_LEN]; | |
1848 | int type = MATCH_FULL; | |
1849 | int i, len = 0; | |
1850 | char *search; | |
1851 | ||
1852 | if (glob && (strcmp(glob, "*") || !strlen(glob))) | |
1853 | glob = NULL; | |
1854 | else { | |
1855 | int not; | |
1856 | ||
1857 | type = ftrace_setup_glob(glob, strlen(glob), &search, ¬); | |
1858 | len = strlen(search); | |
1859 | ||
b6887d79 | 1860 | /* we do not support '!' for function probes */ |
59df055f SR |
1861 | if (WARN_ON(not)) |
1862 | return; | |
1863 | } | |
1864 | ||
1865 | mutex_lock(&ftrace_lock); | |
1866 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1867 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1868 | ||
1869 | hlist_for_each_entry_safe(entry, n, tmp, hhd, node) { | |
1870 | ||
1871 | /* break up if statements for readability */ | |
b6887d79 | 1872 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
1873 | continue; |
1874 | ||
b6887d79 | 1875 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
1876 | continue; |
1877 | ||
1878 | /* do this last, since it is the most expensive */ | |
1879 | if (glob) { | |
1880 | kallsyms_lookup(entry->ip, NULL, NULL, | |
1881 | NULL, str); | |
1882 | if (!ftrace_match(str, glob, len, type)) | |
1883 | continue; | |
1884 | } | |
1885 | ||
1886 | hlist_del(&entry->node); | |
1887 | call_rcu(&entry->rcu, ftrace_free_entry_rcu); | |
1888 | } | |
1889 | } | |
b6887d79 | 1890 | __disable_ftrace_function_probe(); |
59df055f SR |
1891 | mutex_unlock(&ftrace_lock); |
1892 | } | |
1893 | ||
1894 | void | |
b6887d79 | 1895 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
1896 | void *data) |
1897 | { | |
b6887d79 SR |
1898 | __unregister_ftrace_function_probe(glob, ops, data, |
1899 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
1900 | } |
1901 | ||
1902 | void | |
b6887d79 | 1903 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 1904 | { |
b6887d79 | 1905 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
1906 | } |
1907 | ||
b6887d79 | 1908 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 1909 | { |
b6887d79 | 1910 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
1911 | } |
1912 | ||
f6180773 SR |
1913 | static LIST_HEAD(ftrace_commands); |
1914 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
1915 | ||
1916 | int register_ftrace_command(struct ftrace_func_command *cmd) | |
1917 | { | |
1918 | struct ftrace_func_command *p; | |
1919 | int ret = 0; | |
1920 | ||
1921 | mutex_lock(&ftrace_cmd_mutex); | |
1922 | list_for_each_entry(p, &ftrace_commands, list) { | |
1923 | if (strcmp(cmd->name, p->name) == 0) { | |
1924 | ret = -EBUSY; | |
1925 | goto out_unlock; | |
1926 | } | |
1927 | } | |
1928 | list_add(&cmd->list, &ftrace_commands); | |
1929 | out_unlock: | |
1930 | mutex_unlock(&ftrace_cmd_mutex); | |
1931 | ||
1932 | return ret; | |
1933 | } | |
1934 | ||
1935 | int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
1936 | { | |
1937 | struct ftrace_func_command *p, *n; | |
1938 | int ret = -ENODEV; | |
1939 | ||
1940 | mutex_lock(&ftrace_cmd_mutex); | |
1941 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
1942 | if (strcmp(cmd->name, p->name) == 0) { | |
1943 | ret = 0; | |
1944 | list_del_init(&p->list); | |
1945 | goto out_unlock; | |
1946 | } | |
1947 | } | |
1948 | out_unlock: | |
1949 | mutex_unlock(&ftrace_cmd_mutex); | |
1950 | ||
1951 | return ret; | |
1952 | } | |
1953 | ||
64e7c440 SR |
1954 | static int ftrace_process_regex(char *buff, int len, int enable) |
1955 | { | |
f6180773 | 1956 | char *func, *command, *next = buff; |
6a24a244 | 1957 | struct ftrace_func_command *p; |
f6180773 | 1958 | int ret = -EINVAL; |
64e7c440 SR |
1959 | |
1960 | func = strsep(&next, ":"); | |
1961 | ||
1962 | if (!next) { | |
1963 | ftrace_match_records(func, len, enable); | |
1964 | return 0; | |
1965 | } | |
1966 | ||
f6180773 | 1967 | /* command found */ |
64e7c440 SR |
1968 | |
1969 | command = strsep(&next, ":"); | |
1970 | ||
f6180773 SR |
1971 | mutex_lock(&ftrace_cmd_mutex); |
1972 | list_for_each_entry(p, &ftrace_commands, list) { | |
1973 | if (strcmp(p->name, command) == 0) { | |
1974 | ret = p->func(func, command, next, enable); | |
1975 | goto out_unlock; | |
1976 | } | |
64e7c440 | 1977 | } |
f6180773 SR |
1978 | out_unlock: |
1979 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 1980 | |
f6180773 | 1981 | return ret; |
64e7c440 SR |
1982 | } |
1983 | ||
e309b41d | 1984 | static ssize_t |
41c52c0d SR |
1985 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
1986 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
1987 | { |
1988 | struct ftrace_iterator *iter; | |
1989 | char ch; | |
1990 | size_t read = 0; | |
1991 | ssize_t ret; | |
1992 | ||
1993 | if (!cnt || cnt < 0) | |
1994 | return 0; | |
1995 | ||
41c52c0d | 1996 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1997 | |
1998 | if (file->f_mode & FMODE_READ) { | |
1999 | struct seq_file *m = file->private_data; | |
2000 | iter = m->private; | |
2001 | } else | |
2002 | iter = file->private_data; | |
2003 | ||
2004 | if (!*ppos) { | |
2005 | iter->flags &= ~FTRACE_ITER_CONT; | |
2006 | iter->buffer_idx = 0; | |
2007 | } | |
2008 | ||
2009 | ret = get_user(ch, ubuf++); | |
2010 | if (ret) | |
2011 | goto out; | |
2012 | read++; | |
2013 | cnt--; | |
2014 | ||
2015 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { | |
2016 | /* skip white space */ | |
2017 | while (cnt && isspace(ch)) { | |
2018 | ret = get_user(ch, ubuf++); | |
2019 | if (ret) | |
2020 | goto out; | |
2021 | read++; | |
2022 | cnt--; | |
2023 | } | |
2024 | ||
5072c59f SR |
2025 | if (isspace(ch)) { |
2026 | file->f_pos += read; | |
2027 | ret = read; | |
2028 | goto out; | |
2029 | } | |
2030 | ||
2031 | iter->buffer_idx = 0; | |
2032 | } | |
2033 | ||
2034 | while (cnt && !isspace(ch)) { | |
2035 | if (iter->buffer_idx < FTRACE_BUFF_MAX) | |
2036 | iter->buffer[iter->buffer_idx++] = ch; | |
2037 | else { | |
2038 | ret = -EINVAL; | |
2039 | goto out; | |
2040 | } | |
2041 | ret = get_user(ch, ubuf++); | |
2042 | if (ret) | |
2043 | goto out; | |
2044 | read++; | |
2045 | cnt--; | |
2046 | } | |
2047 | ||
2048 | if (isspace(ch)) { | |
2049 | iter->filtered++; | |
2050 | iter->buffer[iter->buffer_idx] = 0; | |
64e7c440 SR |
2051 | ret = ftrace_process_regex(iter->buffer, |
2052 | iter->buffer_idx, enable); | |
2053 | if (ret) | |
2054 | goto out; | |
5072c59f SR |
2055 | iter->buffer_idx = 0; |
2056 | } else | |
2057 | iter->flags |= FTRACE_ITER_CONT; | |
2058 | ||
2059 | ||
2060 | file->f_pos += read; | |
2061 | ||
2062 | ret = read; | |
2063 | out: | |
41c52c0d | 2064 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
2065 | |
2066 | return ret; | |
2067 | } | |
2068 | ||
41c52c0d SR |
2069 | static ssize_t |
2070 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
2071 | size_t cnt, loff_t *ppos) | |
2072 | { | |
2073 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
2074 | } | |
2075 | ||
2076 | static ssize_t | |
2077 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
2078 | size_t cnt, loff_t *ppos) | |
2079 | { | |
2080 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
2081 | } | |
2082 | ||
2083 | static void | |
2084 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
2085 | { | |
2086 | if (unlikely(ftrace_disabled)) | |
2087 | return; | |
2088 | ||
2089 | mutex_lock(&ftrace_regex_lock); | |
2090 | if (reset) | |
2091 | ftrace_filter_reset(enable); | |
2092 | if (buf) | |
7f24b31b | 2093 | ftrace_match_records(buf, len, enable); |
41c52c0d SR |
2094 | mutex_unlock(&ftrace_regex_lock); |
2095 | } | |
2096 | ||
77a2b37d SR |
2097 | /** |
2098 | * ftrace_set_filter - set a function to filter on in ftrace | |
2099 | * @buf - the string that holds the function filter text. | |
2100 | * @len - the length of the string. | |
2101 | * @reset - non zero to reset all filters before applying this filter. | |
2102 | * | |
2103 | * Filters denote which functions should be enabled when tracing is enabled. | |
2104 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
2105 | */ | |
e309b41d | 2106 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 2107 | { |
41c52c0d SR |
2108 | ftrace_set_regex(buf, len, reset, 1); |
2109 | } | |
4eebcc81 | 2110 | |
41c52c0d SR |
2111 | /** |
2112 | * ftrace_set_notrace - set a function to not trace in ftrace | |
2113 | * @buf - the string that holds the function notrace text. | |
2114 | * @len - the length of the string. | |
2115 | * @reset - non zero to reset all filters before applying this filter. | |
2116 | * | |
2117 | * Notrace Filters denote which functions should not be enabled when tracing | |
2118 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
2119 | * for tracing. | |
2120 | */ | |
2121 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
2122 | { | |
2123 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
2124 | } |
2125 | ||
e309b41d | 2126 | static int |
41c52c0d | 2127 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
2128 | { |
2129 | struct seq_file *m = (struct seq_file *)file->private_data; | |
2130 | struct ftrace_iterator *iter; | |
2131 | ||
41c52c0d | 2132 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
2133 | if (file->f_mode & FMODE_READ) { |
2134 | iter = m->private; | |
2135 | ||
2136 | seq_release(inode, file); | |
2137 | } else | |
2138 | iter = file->private_data; | |
2139 | ||
2140 | if (iter->buffer_idx) { | |
2141 | iter->filtered++; | |
2142 | iter->buffer[iter->buffer_idx] = 0; | |
7f24b31b | 2143 | ftrace_match_records(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
2144 | } |
2145 | ||
e6ea44e9 | 2146 | mutex_lock(&ftrace_lock); |
ee02a2e5 | 2147 | if (ftrace_start_up && ftrace_enabled) |
5072c59f | 2148 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
e6ea44e9 | 2149 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
2150 | |
2151 | kfree(iter); | |
41c52c0d | 2152 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
2153 | return 0; |
2154 | } | |
2155 | ||
41c52c0d SR |
2156 | static int |
2157 | ftrace_filter_release(struct inode *inode, struct file *file) | |
2158 | { | |
2159 | return ftrace_regex_release(inode, file, 1); | |
2160 | } | |
2161 | ||
2162 | static int | |
2163 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
2164 | { | |
2165 | return ftrace_regex_release(inode, file, 0); | |
2166 | } | |
2167 | ||
5e2336a0 | 2168 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
2169 | .open = ftrace_avail_open, |
2170 | .read = seq_read, | |
2171 | .llseek = seq_lseek, | |
2172 | .release = ftrace_avail_release, | |
2173 | }; | |
2174 | ||
5e2336a0 | 2175 | static const struct file_operations ftrace_failures_fops = { |
eb9a7bf0 AS |
2176 | .open = ftrace_failures_open, |
2177 | .read = seq_read, | |
2178 | .llseek = seq_lseek, | |
2179 | .release = ftrace_avail_release, | |
2180 | }; | |
2181 | ||
5e2336a0 | 2182 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 2183 | .open = ftrace_filter_open, |
850a80cf | 2184 | .read = seq_read, |
5072c59f | 2185 | .write = ftrace_filter_write, |
41c52c0d | 2186 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
2187 | .release = ftrace_filter_release, |
2188 | }; | |
2189 | ||
5e2336a0 | 2190 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 2191 | .open = ftrace_notrace_open, |
850a80cf | 2192 | .read = seq_read, |
41c52c0d SR |
2193 | .write = ftrace_notrace_write, |
2194 | .llseek = ftrace_regex_lseek, | |
2195 | .release = ftrace_notrace_release, | |
2196 | }; | |
2197 | ||
ea4e2bc4 SR |
2198 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
2199 | ||
2200 | static DEFINE_MUTEX(graph_lock); | |
2201 | ||
2202 | int ftrace_graph_count; | |
2203 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; | |
2204 | ||
2205 | static void * | |
2206 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
2207 | { | |
2208 | unsigned long *array = m->private; | |
2209 | int index = *pos; | |
2210 | ||
2211 | (*pos)++; | |
2212 | ||
2213 | if (index >= ftrace_graph_count) | |
2214 | return NULL; | |
2215 | ||
2216 | return &array[index]; | |
2217 | } | |
2218 | ||
2219 | static void *g_start(struct seq_file *m, loff_t *pos) | |
2220 | { | |
2221 | void *p = NULL; | |
2222 | ||
2223 | mutex_lock(&graph_lock); | |
2224 | ||
f9349a8f FW |
2225 | /* Nothing, tell g_show to print all functions are enabled */ |
2226 | if (!ftrace_graph_count && !*pos) | |
2227 | return (void *)1; | |
2228 | ||
ea4e2bc4 SR |
2229 | p = g_next(m, p, pos); |
2230 | ||
2231 | return p; | |
2232 | } | |
2233 | ||
2234 | static void g_stop(struct seq_file *m, void *p) | |
2235 | { | |
2236 | mutex_unlock(&graph_lock); | |
2237 | } | |
2238 | ||
2239 | static int g_show(struct seq_file *m, void *v) | |
2240 | { | |
2241 | unsigned long *ptr = v; | |
2242 | char str[KSYM_SYMBOL_LEN]; | |
2243 | ||
2244 | if (!ptr) | |
2245 | return 0; | |
2246 | ||
f9349a8f FW |
2247 | if (ptr == (unsigned long *)1) { |
2248 | seq_printf(m, "#### all functions enabled ####\n"); | |
2249 | return 0; | |
2250 | } | |
2251 | ||
ea4e2bc4 SR |
2252 | kallsyms_lookup(*ptr, NULL, NULL, NULL, str); |
2253 | ||
2254 | seq_printf(m, "%s\n", str); | |
2255 | ||
2256 | return 0; | |
2257 | } | |
2258 | ||
2259 | static struct seq_operations ftrace_graph_seq_ops = { | |
2260 | .start = g_start, | |
2261 | .next = g_next, | |
2262 | .stop = g_stop, | |
2263 | .show = g_show, | |
2264 | }; | |
2265 | ||
2266 | static int | |
2267 | ftrace_graph_open(struct inode *inode, struct file *file) | |
2268 | { | |
2269 | int ret = 0; | |
2270 | ||
2271 | if (unlikely(ftrace_disabled)) | |
2272 | return -ENODEV; | |
2273 | ||
2274 | mutex_lock(&graph_lock); | |
2275 | if ((file->f_mode & FMODE_WRITE) && | |
2276 | !(file->f_flags & O_APPEND)) { | |
2277 | ftrace_graph_count = 0; | |
2278 | memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); | |
2279 | } | |
2280 | ||
2281 | if (file->f_mode & FMODE_READ) { | |
2282 | ret = seq_open(file, &ftrace_graph_seq_ops); | |
2283 | if (!ret) { | |
2284 | struct seq_file *m = file->private_data; | |
2285 | m->private = ftrace_graph_funcs; | |
2286 | } | |
2287 | } else | |
2288 | file->private_data = ftrace_graph_funcs; | |
2289 | mutex_unlock(&graph_lock); | |
2290 | ||
2291 | return ret; | |
2292 | } | |
2293 | ||
ea4e2bc4 | 2294 | static int |
f9349a8f | 2295 | ftrace_set_func(unsigned long *array, int *idx, char *buffer) |
ea4e2bc4 | 2296 | { |
ea4e2bc4 SR |
2297 | struct dyn_ftrace *rec; |
2298 | struct ftrace_page *pg; | |
f9349a8f | 2299 | int search_len; |
ea4e2bc4 | 2300 | int found = 0; |
f9349a8f FW |
2301 | int type, not; |
2302 | char *search; | |
2303 | bool exists; | |
2304 | int i; | |
ea4e2bc4 SR |
2305 | |
2306 | if (ftrace_disabled) | |
2307 | return -ENODEV; | |
2308 | ||
f9349a8f FW |
2309 | /* decode regex */ |
2310 | type = ftrace_setup_glob(buffer, strlen(buffer), &search, ¬); | |
2311 | if (not) | |
2312 | return -EINVAL; | |
2313 | ||
2314 | search_len = strlen(search); | |
2315 | ||
52baf119 | 2316 | mutex_lock(&ftrace_lock); |
265c831c SR |
2317 | do_for_each_ftrace_rec(pg, rec) { |
2318 | ||
f9349a8f FW |
2319 | if (*idx >= FTRACE_GRAPH_MAX_FUNCS) |
2320 | break; | |
2321 | ||
265c831c SR |
2322 | if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE)) |
2323 | continue; | |
2324 | ||
f9349a8f FW |
2325 | if (ftrace_match_record(rec, search, search_len, type)) { |
2326 | /* ensure it is not already in the array */ | |
2327 | exists = false; | |
2328 | for (i = 0; i < *idx; i++) | |
2329 | if (array[i] == rec->ip) { | |
2330 | exists = true; | |
265c831c SR |
2331 | break; |
2332 | } | |
f9349a8f FW |
2333 | if (!exists) { |
2334 | array[(*idx)++] = rec->ip; | |
2335 | found = 1; | |
2336 | } | |
ea4e2bc4 | 2337 | } |
265c831c | 2338 | } while_for_each_ftrace_rec(); |
f9349a8f | 2339 | |
52baf119 | 2340 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 SR |
2341 | |
2342 | return found ? 0 : -EINVAL; | |
2343 | } | |
2344 | ||
2345 | static ssize_t | |
2346 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
2347 | size_t cnt, loff_t *ppos) | |
2348 | { | |
2349 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
2350 | unsigned long *array; | |
2351 | size_t read = 0; | |
2352 | ssize_t ret; | |
2353 | int index = 0; | |
2354 | char ch; | |
2355 | ||
2356 | if (!cnt || cnt < 0) | |
2357 | return 0; | |
2358 | ||
2359 | mutex_lock(&graph_lock); | |
2360 | ||
2361 | if (ftrace_graph_count >= FTRACE_GRAPH_MAX_FUNCS) { | |
2362 | ret = -EBUSY; | |
2363 | goto out; | |
2364 | } | |
2365 | ||
2366 | if (file->f_mode & FMODE_READ) { | |
2367 | struct seq_file *m = file->private_data; | |
2368 | array = m->private; | |
2369 | } else | |
2370 | array = file->private_data; | |
2371 | ||
2372 | ret = get_user(ch, ubuf++); | |
2373 | if (ret) | |
2374 | goto out; | |
2375 | read++; | |
2376 | cnt--; | |
2377 | ||
2378 | /* skip white space */ | |
2379 | while (cnt && isspace(ch)) { | |
2380 | ret = get_user(ch, ubuf++); | |
2381 | if (ret) | |
2382 | goto out; | |
2383 | read++; | |
2384 | cnt--; | |
2385 | } | |
2386 | ||
2387 | if (isspace(ch)) { | |
2388 | *ppos += read; | |
2389 | ret = read; | |
2390 | goto out; | |
2391 | } | |
2392 | ||
2393 | while (cnt && !isspace(ch)) { | |
2394 | if (index < FTRACE_BUFF_MAX) | |
2395 | buffer[index++] = ch; | |
2396 | else { | |
2397 | ret = -EINVAL; | |
2398 | goto out; | |
2399 | } | |
2400 | ret = get_user(ch, ubuf++); | |
2401 | if (ret) | |
2402 | goto out; | |
2403 | read++; | |
2404 | cnt--; | |
2405 | } | |
2406 | buffer[index] = 0; | |
2407 | ||
f9349a8f FW |
2408 | /* we allow only one expression at a time */ |
2409 | ret = ftrace_set_func(array, &ftrace_graph_count, buffer); | |
ea4e2bc4 SR |
2410 | if (ret) |
2411 | goto out; | |
2412 | ||
ea4e2bc4 SR |
2413 | file->f_pos += read; |
2414 | ||
2415 | ret = read; | |
2416 | out: | |
2417 | mutex_unlock(&graph_lock); | |
2418 | ||
2419 | return ret; | |
2420 | } | |
2421 | ||
2422 | static const struct file_operations ftrace_graph_fops = { | |
2423 | .open = ftrace_graph_open, | |
850a80cf | 2424 | .read = seq_read, |
ea4e2bc4 SR |
2425 | .write = ftrace_graph_write, |
2426 | }; | |
2427 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2428 | ||
df4fc315 | 2429 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 2430 | { |
5072c59f SR |
2431 | struct dentry *entry; |
2432 | ||
5072c59f SR |
2433 | entry = debugfs_create_file("available_filter_functions", 0444, |
2434 | d_tracer, NULL, &ftrace_avail_fops); | |
2435 | if (!entry) | |
2436 | pr_warning("Could not create debugfs " | |
2437 | "'available_filter_functions' entry\n"); | |
2438 | ||
eb9a7bf0 AS |
2439 | entry = debugfs_create_file("failures", 0444, |
2440 | d_tracer, NULL, &ftrace_failures_fops); | |
2441 | if (!entry) | |
2442 | pr_warning("Could not create debugfs 'failures' entry\n"); | |
2443 | ||
5072c59f SR |
2444 | entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer, |
2445 | NULL, &ftrace_filter_fops); | |
2446 | if (!entry) | |
2447 | pr_warning("Could not create debugfs " | |
2448 | "'set_ftrace_filter' entry\n"); | |
41c52c0d SR |
2449 | |
2450 | entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer, | |
2451 | NULL, &ftrace_notrace_fops); | |
2452 | if (!entry) | |
2453 | pr_warning("Could not create debugfs " | |
2454 | "'set_ftrace_notrace' entry\n"); | |
ad90c0e3 | 2455 | |
ea4e2bc4 SR |
2456 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
2457 | entry = debugfs_create_file("set_graph_function", 0444, d_tracer, | |
2458 | NULL, | |
2459 | &ftrace_graph_fops); | |
2460 | if (!entry) | |
2461 | pr_warning("Could not create debugfs " | |
2462 | "'set_graph_function' entry\n"); | |
2463 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2464 | ||
bac429f0 SR |
2465 | ftrace_profile_debugfs(d_tracer); |
2466 | ||
5072c59f SR |
2467 | return 0; |
2468 | } | |
2469 | ||
31e88909 SR |
2470 | static int ftrace_convert_nops(struct module *mod, |
2471 | unsigned long *start, | |
68bf21aa SR |
2472 | unsigned long *end) |
2473 | { | |
2474 | unsigned long *p; | |
2475 | unsigned long addr; | |
2476 | unsigned long flags; | |
2477 | ||
e6ea44e9 | 2478 | mutex_lock(&ftrace_lock); |
68bf21aa SR |
2479 | p = start; |
2480 | while (p < end) { | |
2481 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
2482 | /* |
2483 | * Some architecture linkers will pad between | |
2484 | * the different mcount_loc sections of different | |
2485 | * object files to satisfy alignments. | |
2486 | * Skip any NULL pointers. | |
2487 | */ | |
2488 | if (!addr) | |
2489 | continue; | |
68bf21aa | 2490 | ftrace_record_ip(addr); |
68bf21aa SR |
2491 | } |
2492 | ||
08f5ac90 | 2493 | /* disable interrupts to prevent kstop machine */ |
68bf21aa | 2494 | local_irq_save(flags); |
31e88909 | 2495 | ftrace_update_code(mod); |
68bf21aa | 2496 | local_irq_restore(flags); |
e6ea44e9 | 2497 | mutex_unlock(&ftrace_lock); |
68bf21aa SR |
2498 | |
2499 | return 0; | |
2500 | } | |
2501 | ||
31e88909 SR |
2502 | void ftrace_init_module(struct module *mod, |
2503 | unsigned long *start, unsigned long *end) | |
90d595fe | 2504 | { |
00fd61ae | 2505 | if (ftrace_disabled || start == end) |
fed1939c | 2506 | return; |
31e88909 | 2507 | ftrace_convert_nops(mod, start, end); |
90d595fe SR |
2508 | } |
2509 | ||
68bf21aa SR |
2510 | extern unsigned long __start_mcount_loc[]; |
2511 | extern unsigned long __stop_mcount_loc[]; | |
2512 | ||
2513 | void __init ftrace_init(void) | |
2514 | { | |
2515 | unsigned long count, addr, flags; | |
2516 | int ret; | |
2517 | ||
2518 | /* Keep the ftrace pointer to the stub */ | |
2519 | addr = (unsigned long)ftrace_stub; | |
2520 | ||
2521 | local_irq_save(flags); | |
2522 | ftrace_dyn_arch_init(&addr); | |
2523 | local_irq_restore(flags); | |
2524 | ||
2525 | /* ftrace_dyn_arch_init places the return code in addr */ | |
2526 | if (addr) | |
2527 | goto failed; | |
2528 | ||
2529 | count = __stop_mcount_loc - __start_mcount_loc; | |
2530 | ||
2531 | ret = ftrace_dyn_table_alloc(count); | |
2532 | if (ret) | |
2533 | goto failed; | |
2534 | ||
bac429f0 SR |
2535 | ftrace_profile_init(count); |
2536 | ||
68bf21aa SR |
2537 | last_ftrace_enabled = ftrace_enabled = 1; |
2538 | ||
31e88909 SR |
2539 | ret = ftrace_convert_nops(NULL, |
2540 | __start_mcount_loc, | |
68bf21aa SR |
2541 | __stop_mcount_loc); |
2542 | ||
2543 | return; | |
2544 | failed: | |
2545 | ftrace_disabled = 1; | |
2546 | } | |
68bf21aa | 2547 | |
3d083395 | 2548 | #else |
0b6e4d56 FW |
2549 | |
2550 | static int __init ftrace_nodyn_init(void) | |
2551 | { | |
2552 | ftrace_enabled = 1; | |
2553 | return 0; | |
2554 | } | |
2555 | device_initcall(ftrace_nodyn_init); | |
2556 | ||
df4fc315 SR |
2557 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
2558 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 SR |
2559 | /* Keep as macros so we do not need to define the commands */ |
2560 | # define ftrace_startup(command) do { } while (0) | |
2561 | # define ftrace_shutdown(command) do { } while (0) | |
c7aafc54 IM |
2562 | # define ftrace_startup_sysctl() do { } while (0) |
2563 | # define ftrace_shutdown_sysctl() do { } while (0) | |
3d083395 SR |
2564 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
2565 | ||
df4fc315 SR |
2566 | static ssize_t |
2567 | ftrace_pid_read(struct file *file, char __user *ubuf, | |
2568 | size_t cnt, loff_t *ppos) | |
2569 | { | |
2570 | char buf[64]; | |
2571 | int r; | |
2572 | ||
e32d8956 SR |
2573 | if (ftrace_pid_trace == ftrace_swapper_pid) |
2574 | r = sprintf(buf, "swapper tasks\n"); | |
2575 | else if (ftrace_pid_trace) | |
cc59c9e8 | 2576 | r = sprintf(buf, "%u\n", pid_vnr(ftrace_pid_trace)); |
df4fc315 SR |
2577 | else |
2578 | r = sprintf(buf, "no pid\n"); | |
2579 | ||
2580 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
2581 | } | |
2582 | ||
e32d8956 | 2583 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
2584 | { |
2585 | struct task_struct *p; | |
e32d8956 | 2586 | int cpu; |
978f3a45 | 2587 | |
e32d8956 SR |
2588 | get_online_cpus(); |
2589 | for_each_online_cpu(cpu) { | |
2590 | p = idle_task(cpu); | |
978f3a45 | 2591 | clear_tsk_trace_trace(p); |
e32d8956 SR |
2592 | } |
2593 | put_online_cpus(); | |
2594 | } | |
978f3a45 | 2595 | |
e32d8956 SR |
2596 | static void set_ftrace_swapper(void) |
2597 | { | |
2598 | struct task_struct *p; | |
2599 | int cpu; | |
2600 | ||
2601 | get_online_cpus(); | |
2602 | for_each_online_cpu(cpu) { | |
2603 | p = idle_task(cpu); | |
2604 | set_tsk_trace_trace(p); | |
2605 | } | |
2606 | put_online_cpus(); | |
978f3a45 SR |
2607 | } |
2608 | ||
e32d8956 SR |
2609 | static void clear_ftrace_pid(struct pid *pid) |
2610 | { | |
2611 | struct task_struct *p; | |
2612 | ||
229c4ef8 | 2613 | rcu_read_lock(); |
e32d8956 SR |
2614 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2615 | clear_tsk_trace_trace(p); | |
2616 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
2617 | rcu_read_unlock(); |
2618 | ||
e32d8956 SR |
2619 | put_pid(pid); |
2620 | } | |
2621 | ||
2622 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
2623 | { |
2624 | struct task_struct *p; | |
2625 | ||
229c4ef8 | 2626 | rcu_read_lock(); |
978f3a45 SR |
2627 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2628 | set_tsk_trace_trace(p); | |
2629 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 2630 | rcu_read_unlock(); |
978f3a45 SR |
2631 | } |
2632 | ||
e32d8956 SR |
2633 | static void clear_ftrace_pid_task(struct pid **pid) |
2634 | { | |
2635 | if (*pid == ftrace_swapper_pid) | |
2636 | clear_ftrace_swapper(); | |
2637 | else | |
2638 | clear_ftrace_pid(*pid); | |
2639 | ||
2640 | *pid = NULL; | |
2641 | } | |
2642 | ||
2643 | static void set_ftrace_pid_task(struct pid *pid) | |
2644 | { | |
2645 | if (pid == ftrace_swapper_pid) | |
2646 | set_ftrace_swapper(); | |
2647 | else | |
2648 | set_ftrace_pid(pid); | |
2649 | } | |
2650 | ||
df4fc315 SR |
2651 | static ssize_t |
2652 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
2653 | size_t cnt, loff_t *ppos) | |
2654 | { | |
978f3a45 | 2655 | struct pid *pid; |
df4fc315 SR |
2656 | char buf[64]; |
2657 | long val; | |
2658 | int ret; | |
2659 | ||
2660 | if (cnt >= sizeof(buf)) | |
2661 | return -EINVAL; | |
2662 | ||
2663 | if (copy_from_user(&buf, ubuf, cnt)) | |
2664 | return -EFAULT; | |
2665 | ||
2666 | buf[cnt] = 0; | |
2667 | ||
2668 | ret = strict_strtol(buf, 10, &val); | |
2669 | if (ret < 0) | |
2670 | return ret; | |
2671 | ||
e6ea44e9 | 2672 | mutex_lock(&ftrace_lock); |
978f3a45 | 2673 | if (val < 0) { |
df4fc315 | 2674 | /* disable pid tracing */ |
978f3a45 | 2675 | if (!ftrace_pid_trace) |
df4fc315 | 2676 | goto out; |
978f3a45 SR |
2677 | |
2678 | clear_ftrace_pid_task(&ftrace_pid_trace); | |
df4fc315 SR |
2679 | |
2680 | } else { | |
e32d8956 SR |
2681 | /* swapper task is special */ |
2682 | if (!val) { | |
2683 | pid = ftrace_swapper_pid; | |
2684 | if (pid == ftrace_pid_trace) | |
2685 | goto out; | |
2686 | } else { | |
2687 | pid = find_get_pid(val); | |
df4fc315 | 2688 | |
e32d8956 SR |
2689 | if (pid == ftrace_pid_trace) { |
2690 | put_pid(pid); | |
2691 | goto out; | |
2692 | } | |
0ef8cde5 | 2693 | } |
0ef8cde5 | 2694 | |
978f3a45 SR |
2695 | if (ftrace_pid_trace) |
2696 | clear_ftrace_pid_task(&ftrace_pid_trace); | |
2697 | ||
2698 | if (!pid) | |
2699 | goto out; | |
2700 | ||
2701 | ftrace_pid_trace = pid; | |
2702 | ||
2703 | set_ftrace_pid_task(ftrace_pid_trace); | |
df4fc315 SR |
2704 | } |
2705 | ||
2706 | /* update the function call */ | |
2707 | ftrace_update_pid_func(); | |
2708 | ftrace_startup_enable(0); | |
2709 | ||
2710 | out: | |
e6ea44e9 | 2711 | mutex_unlock(&ftrace_lock); |
df4fc315 SR |
2712 | |
2713 | return cnt; | |
2714 | } | |
2715 | ||
5e2336a0 | 2716 | static const struct file_operations ftrace_pid_fops = { |
df4fc315 SR |
2717 | .read = ftrace_pid_read, |
2718 | .write = ftrace_pid_write, | |
2719 | }; | |
2720 | ||
2721 | static __init int ftrace_init_debugfs(void) | |
2722 | { | |
2723 | struct dentry *d_tracer; | |
2724 | struct dentry *entry; | |
2725 | ||
2726 | d_tracer = tracing_init_dentry(); | |
2727 | if (!d_tracer) | |
2728 | return 0; | |
2729 | ||
2730 | ftrace_init_dyn_debugfs(d_tracer); | |
2731 | ||
2732 | entry = debugfs_create_file("set_ftrace_pid", 0644, d_tracer, | |
2733 | NULL, &ftrace_pid_fops); | |
2734 | if (!entry) | |
2735 | pr_warning("Could not create debugfs " | |
2736 | "'set_ftrace_pid' entry\n"); | |
2737 | return 0; | |
2738 | } | |
df4fc315 SR |
2739 | fs_initcall(ftrace_init_debugfs); |
2740 | ||
a2bb6a3d | 2741 | /** |
81adbdc0 | 2742 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
2743 | * |
2744 | * This function should be used by panic code. It stops ftrace | |
2745 | * but in a not so nice way. If you need to simply kill ftrace | |
2746 | * from a non-atomic section, use ftrace_kill. | |
2747 | */ | |
81adbdc0 | 2748 | void ftrace_kill(void) |
a2bb6a3d SR |
2749 | { |
2750 | ftrace_disabled = 1; | |
2751 | ftrace_enabled = 0; | |
a2bb6a3d SR |
2752 | clear_ftrace_function(); |
2753 | } | |
2754 | ||
16444a8a | 2755 | /** |
3d083395 SR |
2756 | * register_ftrace_function - register a function for profiling |
2757 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 2758 | * |
3d083395 SR |
2759 | * Register a function to be called by all functions in the |
2760 | * kernel. | |
2761 | * | |
2762 | * Note: @ops->func and all the functions it calls must be labeled | |
2763 | * with "notrace", otherwise it will go into a | |
2764 | * recursive loop. | |
16444a8a | 2765 | */ |
3d083395 | 2766 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 2767 | { |
b0fc494f SR |
2768 | int ret; |
2769 | ||
4eebcc81 SR |
2770 | if (unlikely(ftrace_disabled)) |
2771 | return -1; | |
2772 | ||
e6ea44e9 | 2773 | mutex_lock(&ftrace_lock); |
e7d3737e | 2774 | |
b0fc494f | 2775 | ret = __register_ftrace_function(ops); |
5a45cfe1 | 2776 | ftrace_startup(0); |
b0fc494f | 2777 | |
e6ea44e9 | 2778 | mutex_unlock(&ftrace_lock); |
b0fc494f | 2779 | return ret; |
3d083395 SR |
2780 | } |
2781 | ||
2782 | /** | |
32632920 | 2783 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
2784 | * @ops - ops structure that holds the function to unregister |
2785 | * | |
2786 | * Unregister a function that was added to be called by ftrace profiling. | |
2787 | */ | |
2788 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
2789 | { | |
2790 | int ret; | |
2791 | ||
e6ea44e9 | 2792 | mutex_lock(&ftrace_lock); |
3d083395 | 2793 | ret = __unregister_ftrace_function(ops); |
5a45cfe1 | 2794 | ftrace_shutdown(0); |
e6ea44e9 | 2795 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
2796 | |
2797 | return ret; | |
2798 | } | |
2799 | ||
e309b41d | 2800 | int |
b0fc494f | 2801 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
5072c59f | 2802 | struct file *file, void __user *buffer, size_t *lenp, |
b0fc494f SR |
2803 | loff_t *ppos) |
2804 | { | |
2805 | int ret; | |
2806 | ||
4eebcc81 SR |
2807 | if (unlikely(ftrace_disabled)) |
2808 | return -ENODEV; | |
2809 | ||
e6ea44e9 | 2810 | mutex_lock(&ftrace_lock); |
b0fc494f | 2811 | |
5072c59f | 2812 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
b0fc494f SR |
2813 | |
2814 | if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) | |
2815 | goto out; | |
2816 | ||
2817 | last_ftrace_enabled = ftrace_enabled; | |
2818 | ||
2819 | if (ftrace_enabled) { | |
2820 | ||
2821 | ftrace_startup_sysctl(); | |
2822 | ||
2823 | /* we are starting ftrace again */ | |
2824 | if (ftrace_list != &ftrace_list_end) { | |
2825 | if (ftrace_list->next == &ftrace_list_end) | |
2826 | ftrace_trace_function = ftrace_list->func; | |
2827 | else | |
2828 | ftrace_trace_function = ftrace_list_func; | |
2829 | } | |
2830 | ||
2831 | } else { | |
2832 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
2833 | ftrace_trace_function = ftrace_stub; | |
2834 | ||
2835 | ftrace_shutdown_sysctl(); | |
2836 | } | |
2837 | ||
2838 | out: | |
e6ea44e9 | 2839 | mutex_unlock(&ftrace_lock); |
3d083395 | 2840 | return ret; |
16444a8a | 2841 | } |
f17845e5 | 2842 | |
fb52607a | 2843 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 2844 | |
287b6e68 | 2845 | static atomic_t ftrace_graph_active; |
4a2b8dda | 2846 | static struct notifier_block ftrace_suspend_notifier; |
e7d3737e | 2847 | |
e49dc19c SR |
2848 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
2849 | { | |
2850 | return 0; | |
2851 | } | |
2852 | ||
287b6e68 FW |
2853 | /* The callbacks that hook a function */ |
2854 | trace_func_graph_ret_t ftrace_graph_return = | |
2855 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 2856 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
2857 | |
2858 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
2859 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
2860 | { | |
2861 | int i; | |
2862 | int ret = 0; | |
2863 | unsigned long flags; | |
2864 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
2865 | struct task_struct *g, *t; | |
2866 | ||
2867 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
2868 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
2869 | * sizeof(struct ftrace_ret_stack), | |
2870 | GFP_KERNEL); | |
2871 | if (!ret_stack_list[i]) { | |
2872 | start = 0; | |
2873 | end = i; | |
2874 | ret = -ENOMEM; | |
2875 | goto free; | |
2876 | } | |
2877 | } | |
2878 | ||
2879 | read_lock_irqsave(&tasklist_lock, flags); | |
2880 | do_each_thread(g, t) { | |
2881 | if (start == end) { | |
2882 | ret = -EAGAIN; | |
2883 | goto unlock; | |
2884 | } | |
2885 | ||
2886 | if (t->ret_stack == NULL) { | |
f201ae23 | 2887 | t->curr_ret_stack = -1; |
48d68b20 FW |
2888 | /* Make sure IRQs see the -1 first: */ |
2889 | barrier(); | |
2890 | t->ret_stack = ret_stack_list[start++]; | |
380c4b14 | 2891 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 FW |
2892 | atomic_set(&t->trace_overrun, 0); |
2893 | } | |
2894 | } while_each_thread(g, t); | |
2895 | ||
2896 | unlock: | |
2897 | read_unlock_irqrestore(&tasklist_lock, flags); | |
2898 | free: | |
2899 | for (i = start; i < end; i++) | |
2900 | kfree(ret_stack_list[i]); | |
2901 | return ret; | |
2902 | } | |
2903 | ||
8aef2d28 SR |
2904 | static void |
2905 | ftrace_graph_probe_sched_switch(struct rq *__rq, struct task_struct *prev, | |
2906 | struct task_struct *next) | |
2907 | { | |
2908 | unsigned long long timestamp; | |
2909 | int index; | |
2910 | ||
be6f164a SR |
2911 | /* |
2912 | * Does the user want to count the time a function was asleep. | |
2913 | * If so, do not update the time stamps. | |
2914 | */ | |
2915 | if (trace_flags & TRACE_ITER_SLEEP_TIME) | |
2916 | return; | |
2917 | ||
8aef2d28 SR |
2918 | timestamp = trace_clock_local(); |
2919 | ||
2920 | prev->ftrace_timestamp = timestamp; | |
2921 | ||
2922 | /* only process tasks that we timestamped */ | |
2923 | if (!next->ftrace_timestamp) | |
2924 | return; | |
2925 | ||
2926 | /* | |
2927 | * Update all the counters in next to make up for the | |
2928 | * time next was sleeping. | |
2929 | */ | |
2930 | timestamp -= next->ftrace_timestamp; | |
2931 | ||
2932 | for (index = next->curr_ret_stack; index >= 0; index--) | |
2933 | next->ret_stack[index].calltime += timestamp; | |
2934 | } | |
2935 | ||
f201ae23 | 2936 | /* Allocate a return stack for each task */ |
fb52607a | 2937 | static int start_graph_tracing(void) |
f201ae23 FW |
2938 | { |
2939 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 2940 | int ret, cpu; |
f201ae23 FW |
2941 | |
2942 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
2943 | sizeof(struct ftrace_ret_stack *), | |
2944 | GFP_KERNEL); | |
2945 | ||
2946 | if (!ret_stack_list) | |
2947 | return -ENOMEM; | |
2948 | ||
5b058bcd FW |
2949 | /* The cpu_boot init_task->ret_stack will never be freed */ |
2950 | for_each_online_cpu(cpu) | |
2951 | ftrace_graph_init_task(idle_task(cpu)); | |
2952 | ||
f201ae23 FW |
2953 | do { |
2954 | ret = alloc_retstack_tasklist(ret_stack_list); | |
2955 | } while (ret == -EAGAIN); | |
2956 | ||
8aef2d28 SR |
2957 | if (!ret) { |
2958 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch); | |
2959 | if (ret) | |
2960 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
2961 | " probe to kernel_sched_switch\n"); | |
2962 | } | |
2963 | ||
f201ae23 FW |
2964 | kfree(ret_stack_list); |
2965 | return ret; | |
2966 | } | |
2967 | ||
4a2b8dda FW |
2968 | /* |
2969 | * Hibernation protection. | |
2970 | * The state of the current task is too much unstable during | |
2971 | * suspend/restore to disk. We want to protect against that. | |
2972 | */ | |
2973 | static int | |
2974 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
2975 | void *unused) | |
2976 | { | |
2977 | switch (state) { | |
2978 | case PM_HIBERNATION_PREPARE: | |
2979 | pause_graph_tracing(); | |
2980 | break; | |
2981 | ||
2982 | case PM_POST_HIBERNATION: | |
2983 | unpause_graph_tracing(); | |
2984 | break; | |
2985 | } | |
2986 | return NOTIFY_DONE; | |
2987 | } | |
2988 | ||
287b6e68 FW |
2989 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
2990 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 2991 | { |
e7d3737e FW |
2992 | int ret = 0; |
2993 | ||
e6ea44e9 | 2994 | mutex_lock(&ftrace_lock); |
e7d3737e | 2995 | |
05ce5818 SR |
2996 | /* we currently allow only one tracer registered at a time */ |
2997 | if (atomic_read(&ftrace_graph_active)) { | |
2998 | ret = -EBUSY; | |
2999 | goto out; | |
3000 | } | |
3001 | ||
4a2b8dda FW |
3002 | ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; |
3003 | register_pm_notifier(&ftrace_suspend_notifier); | |
3004 | ||
287b6e68 | 3005 | atomic_inc(&ftrace_graph_active); |
fb52607a | 3006 | ret = start_graph_tracing(); |
f201ae23 | 3007 | if (ret) { |
287b6e68 | 3008 | atomic_dec(&ftrace_graph_active); |
f201ae23 FW |
3009 | goto out; |
3010 | } | |
e53a6319 | 3011 | |
287b6e68 FW |
3012 | ftrace_graph_return = retfunc; |
3013 | ftrace_graph_entry = entryfunc; | |
e53a6319 | 3014 | |
5a45cfe1 | 3015 | ftrace_startup(FTRACE_START_FUNC_RET); |
e7d3737e FW |
3016 | |
3017 | out: | |
e6ea44e9 | 3018 | mutex_unlock(&ftrace_lock); |
e7d3737e | 3019 | return ret; |
15e6cb36 FW |
3020 | } |
3021 | ||
fb52607a | 3022 | void unregister_ftrace_graph(void) |
15e6cb36 | 3023 | { |
e6ea44e9 | 3024 | mutex_lock(&ftrace_lock); |
e7d3737e | 3025 | |
287b6e68 | 3026 | atomic_dec(&ftrace_graph_active); |
8aef2d28 | 3027 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch); |
287b6e68 | 3028 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 3029 | ftrace_graph_entry = ftrace_graph_entry_stub; |
5a45cfe1 | 3030 | ftrace_shutdown(FTRACE_STOP_FUNC_RET); |
4a2b8dda | 3031 | unregister_pm_notifier(&ftrace_suspend_notifier); |
e7d3737e | 3032 | |
e6ea44e9 | 3033 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 3034 | } |
f201ae23 FW |
3035 | |
3036 | /* Allocate a return stack for newly created task */ | |
fb52607a | 3037 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 3038 | { |
287b6e68 | 3039 | if (atomic_read(&ftrace_graph_active)) { |
f201ae23 FW |
3040 | t->ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH |
3041 | * sizeof(struct ftrace_ret_stack), | |
3042 | GFP_KERNEL); | |
3043 | if (!t->ret_stack) | |
3044 | return; | |
3045 | t->curr_ret_stack = -1; | |
380c4b14 | 3046 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 3047 | atomic_set(&t->trace_overrun, 0); |
8aef2d28 | 3048 | t->ftrace_timestamp = 0; |
f201ae23 FW |
3049 | } else |
3050 | t->ret_stack = NULL; | |
3051 | } | |
3052 | ||
fb52607a | 3053 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 3054 | { |
eae849ca FW |
3055 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
3056 | ||
f201ae23 | 3057 | t->ret_stack = NULL; |
eae849ca FW |
3058 | /* NULL must become visible to IRQs before we free it: */ |
3059 | barrier(); | |
3060 | ||
3061 | kfree(ret_stack); | |
f201ae23 | 3062 | } |
14a866c5 SR |
3063 | |
3064 | void ftrace_graph_stop(void) | |
3065 | { | |
3066 | ftrace_stop(); | |
3067 | } | |
15e6cb36 FW |
3068 | #endif |
3069 |