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 SR |
29 | #include <linux/list.h> |
30 | ||
395a59d0 AS |
31 | #include <asm/ftrace.h> |
32 | ||
3d083395 | 33 | #include "trace.h" |
16444a8a | 34 | |
6912896e SR |
35 | #define FTRACE_WARN_ON(cond) \ |
36 | do { \ | |
37 | if (WARN_ON(cond)) \ | |
38 | ftrace_kill(); \ | |
39 | } while (0) | |
40 | ||
41 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
42 | do { \ | |
43 | if (WARN_ON_ONCE(cond)) \ | |
44 | ftrace_kill(); \ | |
45 | } while (0) | |
46 | ||
4eebcc81 SR |
47 | /* ftrace_enabled is a method to turn ftrace on or off */ |
48 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 49 | static int last_ftrace_enabled; |
b0fc494f | 50 | |
0ef8cde5 | 51 | /* set when tracing only a pid */ |
978f3a45 | 52 | struct pid *ftrace_pid_trace; |
21bbecda | 53 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; |
df4fc315 | 54 | |
60a7ecf4 SR |
55 | /* Quick disabling of function tracer. */ |
56 | int function_trace_stop; | |
57 | ||
4eebcc81 SR |
58 | /* |
59 | * ftrace_disabled is set when an anomaly is discovered. | |
60 | * ftrace_disabled is much stronger than ftrace_enabled. | |
61 | */ | |
62 | static int ftrace_disabled __read_mostly; | |
63 | ||
52baf119 | 64 | static DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 65 | static DEFINE_MUTEX(ftrace_sysctl_lock); |
df4fc315 | 66 | static DEFINE_MUTEX(ftrace_start_lock); |
b0fc494f | 67 | |
16444a8a ACM |
68 | static struct ftrace_ops ftrace_list_end __read_mostly = |
69 | { | |
70 | .func = ftrace_stub, | |
71 | }; | |
72 | ||
73 | static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; | |
74 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; | |
60a7ecf4 | 75 | ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub; |
df4fc315 | 76 | ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; |
16444a8a | 77 | |
f2252935 | 78 | static void ftrace_list_func(unsigned long ip, unsigned long parent_ip) |
16444a8a ACM |
79 | { |
80 | struct ftrace_ops *op = ftrace_list; | |
81 | ||
82 | /* in case someone actually ports this to alpha! */ | |
83 | read_barrier_depends(); | |
84 | ||
85 | while (op != &ftrace_list_end) { | |
86 | /* silly alpha */ | |
87 | read_barrier_depends(); | |
88 | op->func(ip, parent_ip); | |
89 | op = op->next; | |
90 | }; | |
91 | } | |
92 | ||
df4fc315 SR |
93 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip) |
94 | { | |
0ef8cde5 | 95 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
96 | return; |
97 | ||
98 | ftrace_pid_function(ip, parent_ip); | |
99 | } | |
100 | ||
101 | static void set_ftrace_pid_function(ftrace_func_t func) | |
102 | { | |
103 | /* do not set ftrace_pid_function to itself! */ | |
104 | if (func != ftrace_pid_func) | |
105 | ftrace_pid_function = func; | |
106 | } | |
107 | ||
16444a8a | 108 | /** |
3d083395 | 109 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 110 | * |
3d083395 SR |
111 | * This NULLs the ftrace function and in essence stops |
112 | * tracing. There may be lag | |
16444a8a | 113 | */ |
3d083395 | 114 | void clear_ftrace_function(void) |
16444a8a | 115 | { |
3d083395 | 116 | ftrace_trace_function = ftrace_stub; |
60a7ecf4 | 117 | __ftrace_trace_function = ftrace_stub; |
df4fc315 | 118 | ftrace_pid_function = ftrace_stub; |
3d083395 SR |
119 | } |
120 | ||
60a7ecf4 SR |
121 | #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
122 | /* | |
123 | * For those archs that do not test ftrace_trace_stop in their | |
124 | * mcount call site, we need to do it from C. | |
125 | */ | |
126 | static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip) | |
127 | { | |
128 | if (function_trace_stop) | |
129 | return; | |
130 | ||
131 | __ftrace_trace_function(ip, parent_ip); | |
132 | } | |
133 | #endif | |
134 | ||
e309b41d | 135 | static int __register_ftrace_function(struct ftrace_ops *ops) |
3d083395 | 136 | { |
52baf119 | 137 | mutex_lock(&ftrace_lock); |
16444a8a | 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 | |
52baf119 | 174 | mutex_unlock(&ftrace_lock); |
16444a8a ACM |
175 | |
176 | return 0; | |
177 | } | |
178 | ||
e309b41d | 179 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 180 | { |
16444a8a ACM |
181 | struct ftrace_ops **p; |
182 | int ret = 0; | |
183 | ||
52baf119 | 184 | mutex_lock(&ftrace_lock); |
16444a8a ACM |
185 | |
186 | /* | |
3d083395 SR |
187 | * If we are removing the last function, then simply point |
188 | * to the ftrace_stub. | |
16444a8a ACM |
189 | */ |
190 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { | |
191 | ftrace_trace_function = ftrace_stub; | |
192 | ftrace_list = &ftrace_list_end; | |
193 | goto out; | |
194 | } | |
195 | ||
196 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) | |
197 | if (*p == ops) | |
198 | break; | |
199 | ||
200 | if (*p != ops) { | |
201 | ret = -1; | |
202 | goto out; | |
203 | } | |
204 | ||
205 | *p = (*p)->next; | |
206 | ||
b0fc494f SR |
207 | if (ftrace_enabled) { |
208 | /* If we only have one func left, then call that directly */ | |
df4fc315 SR |
209 | if (ftrace_list->next == &ftrace_list_end) { |
210 | ftrace_func_t func = ftrace_list->func; | |
211 | ||
978f3a45 | 212 | if (ftrace_pid_trace) { |
df4fc315 SR |
213 | set_ftrace_pid_function(func); |
214 | func = ftrace_pid_func; | |
215 | } | |
216 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
217 | ftrace_trace_function = func; | |
218 | #else | |
219 | __ftrace_trace_function = func; | |
220 | #endif | |
221 | } | |
b0fc494f | 222 | } |
16444a8a ACM |
223 | |
224 | out: | |
52baf119 | 225 | mutex_unlock(&ftrace_lock); |
3d083395 SR |
226 | |
227 | return ret; | |
228 | } | |
229 | ||
df4fc315 SR |
230 | static void ftrace_update_pid_func(void) |
231 | { | |
232 | ftrace_func_t func; | |
233 | ||
52baf119 | 234 | mutex_lock(&ftrace_lock); |
df4fc315 SR |
235 | |
236 | if (ftrace_trace_function == ftrace_stub) | |
237 | goto out; | |
238 | ||
239 | func = ftrace_trace_function; | |
240 | ||
978f3a45 | 241 | if (ftrace_pid_trace) { |
df4fc315 SR |
242 | set_ftrace_pid_function(func); |
243 | func = ftrace_pid_func; | |
244 | } else { | |
66eafebc LW |
245 | if (func == ftrace_pid_func) |
246 | func = ftrace_pid_function; | |
df4fc315 SR |
247 | } |
248 | ||
249 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
250 | ftrace_trace_function = func; | |
251 | #else | |
252 | __ftrace_trace_function = func; | |
253 | #endif | |
254 | ||
255 | out: | |
52baf119 | 256 | mutex_unlock(&ftrace_lock); |
df4fc315 SR |
257 | } |
258 | ||
3d083395 | 259 | #ifdef CONFIG_DYNAMIC_FTRACE |
99ecdc43 | 260 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
cb7be3b2 | 261 | # error Dynamic ftrace depends on MCOUNT_RECORD |
99ecdc43 SR |
262 | #endif |
263 | ||
d61f82d0 SR |
264 | enum { |
265 | FTRACE_ENABLE_CALLS = (1 << 0), | |
266 | FTRACE_DISABLE_CALLS = (1 << 1), | |
267 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
268 | FTRACE_ENABLE_MCOUNT = (1 << 3), | |
269 | FTRACE_DISABLE_MCOUNT = (1 << 4), | |
5a45cfe1 SR |
270 | FTRACE_START_FUNC_RET = (1 << 5), |
271 | FTRACE_STOP_FUNC_RET = (1 << 6), | |
d61f82d0 SR |
272 | }; |
273 | ||
5072c59f SR |
274 | static int ftrace_filtered; |
275 | ||
08f5ac90 | 276 | static LIST_HEAD(ftrace_new_addrs); |
3d083395 | 277 | |
41c52c0d | 278 | static DEFINE_MUTEX(ftrace_regex_lock); |
3d083395 | 279 | |
3c1720f0 SR |
280 | struct ftrace_page { |
281 | struct ftrace_page *next; | |
431aa3fb | 282 | int index; |
3c1720f0 | 283 | struct dyn_ftrace records[]; |
aa5e5cea | 284 | }; |
3c1720f0 SR |
285 | |
286 | #define ENTRIES_PER_PAGE \ | |
287 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
288 | ||
289 | /* estimate from running different kernels */ | |
290 | #define NR_TO_INIT 10000 | |
291 | ||
292 | static struct ftrace_page *ftrace_pages_start; | |
293 | static struct ftrace_page *ftrace_pages; | |
294 | ||
37ad5084 SR |
295 | static struct dyn_ftrace *ftrace_free_records; |
296 | ||
265c831c SR |
297 | /* |
298 | * This is a double for. Do not use 'break' to break out of the loop, | |
299 | * you must use a goto. | |
300 | */ | |
301 | #define do_for_each_ftrace_rec(pg, rec) \ | |
302 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
303 | int _____i; \ | |
304 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
305 | rec = &pg->records[_____i]; | |
306 | ||
307 | #define while_for_each_ftrace_rec() \ | |
308 | } \ | |
309 | } | |
ecea656d AS |
310 | |
311 | #ifdef CONFIG_KPROBES | |
f17845e5 IM |
312 | |
313 | static int frozen_record_count; | |
314 | ||
ecea656d AS |
315 | static inline void freeze_record(struct dyn_ftrace *rec) |
316 | { | |
317 | if (!(rec->flags & FTRACE_FL_FROZEN)) { | |
318 | rec->flags |= FTRACE_FL_FROZEN; | |
319 | frozen_record_count++; | |
320 | } | |
321 | } | |
322 | ||
323 | static inline void unfreeze_record(struct dyn_ftrace *rec) | |
324 | { | |
325 | if (rec->flags & FTRACE_FL_FROZEN) { | |
326 | rec->flags &= ~FTRACE_FL_FROZEN; | |
327 | frozen_record_count--; | |
328 | } | |
329 | } | |
330 | ||
331 | static inline int record_frozen(struct dyn_ftrace *rec) | |
332 | { | |
333 | return rec->flags & FTRACE_FL_FROZEN; | |
334 | } | |
335 | #else | |
336 | # define freeze_record(rec) ({ 0; }) | |
337 | # define unfreeze_record(rec) ({ 0; }) | |
338 | # define record_frozen(rec) ({ 0; }) | |
339 | #endif /* CONFIG_KPROBES */ | |
340 | ||
e309b41d | 341 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
37ad5084 | 342 | { |
37ad5084 SR |
343 | rec->ip = (unsigned long)ftrace_free_records; |
344 | ftrace_free_records = rec; | |
345 | rec->flags |= FTRACE_FL_FREE; | |
346 | } | |
347 | ||
fed1939c SR |
348 | void ftrace_release(void *start, unsigned long size) |
349 | { | |
350 | struct dyn_ftrace *rec; | |
351 | struct ftrace_page *pg; | |
352 | unsigned long s = (unsigned long)start; | |
353 | unsigned long e = s + size; | |
fed1939c | 354 | |
00fd61ae | 355 | if (ftrace_disabled || !start) |
fed1939c SR |
356 | return; |
357 | ||
52baf119 | 358 | mutex_lock(&ftrace_lock); |
265c831c SR |
359 | do_for_each_ftrace_rec(pg, rec) { |
360 | if ((rec->ip >= s) && (rec->ip < e)) | |
361 | ftrace_free_rec(rec); | |
362 | } while_for_each_ftrace_rec(); | |
52baf119 | 363 | mutex_unlock(&ftrace_lock); |
fed1939c SR |
364 | } |
365 | ||
e309b41d | 366 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 367 | { |
37ad5084 SR |
368 | struct dyn_ftrace *rec; |
369 | ||
370 | /* First check for freed records */ | |
371 | if (ftrace_free_records) { | |
372 | rec = ftrace_free_records; | |
373 | ||
37ad5084 | 374 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
6912896e | 375 | FTRACE_WARN_ON_ONCE(1); |
37ad5084 SR |
376 | ftrace_free_records = NULL; |
377 | return NULL; | |
378 | } | |
379 | ||
380 | ftrace_free_records = (void *)rec->ip; | |
381 | memset(rec, 0, sizeof(*rec)); | |
382 | return rec; | |
383 | } | |
384 | ||
3c1720f0 | 385 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
08f5ac90 SR |
386 | if (!ftrace_pages->next) { |
387 | /* allocate another page */ | |
388 | ftrace_pages->next = | |
389 | (void *)get_zeroed_page(GFP_KERNEL); | |
390 | if (!ftrace_pages->next) | |
391 | return NULL; | |
392 | } | |
3c1720f0 SR |
393 | ftrace_pages = ftrace_pages->next; |
394 | } | |
395 | ||
396 | return &ftrace_pages->records[ftrace_pages->index++]; | |
397 | } | |
398 | ||
08f5ac90 | 399 | static struct dyn_ftrace * |
d61f82d0 | 400 | ftrace_record_ip(unsigned long ip) |
3d083395 | 401 | { |
08f5ac90 | 402 | struct dyn_ftrace *rec; |
3d083395 | 403 | |
f3c7ac40 | 404 | if (ftrace_disabled) |
08f5ac90 | 405 | return NULL; |
3d083395 | 406 | |
08f5ac90 SR |
407 | rec = ftrace_alloc_dyn_node(ip); |
408 | if (!rec) | |
409 | return NULL; | |
3d083395 | 410 | |
08f5ac90 | 411 | rec->ip = ip; |
3d083395 | 412 | |
08f5ac90 | 413 | list_add(&rec->list, &ftrace_new_addrs); |
3d083395 | 414 | |
08f5ac90 | 415 | return rec; |
3d083395 SR |
416 | } |
417 | ||
b17e8a37 SR |
418 | static void print_ip_ins(const char *fmt, unsigned char *p) |
419 | { | |
420 | int i; | |
421 | ||
422 | printk(KERN_CONT "%s", fmt); | |
423 | ||
424 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
425 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
426 | } | |
427 | ||
31e88909 | 428 | static void ftrace_bug(int failed, unsigned long ip) |
b17e8a37 SR |
429 | { |
430 | switch (failed) { | |
431 | case -EFAULT: | |
432 | FTRACE_WARN_ON_ONCE(1); | |
433 | pr_info("ftrace faulted on modifying "); | |
434 | print_ip_sym(ip); | |
435 | break; | |
436 | case -EINVAL: | |
437 | FTRACE_WARN_ON_ONCE(1); | |
438 | pr_info("ftrace failed to modify "); | |
439 | print_ip_sym(ip); | |
b17e8a37 | 440 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
441 | printk(KERN_CONT "\n"); |
442 | break; | |
443 | case -EPERM: | |
444 | FTRACE_WARN_ON_ONCE(1); | |
445 | pr_info("ftrace faulted on writing "); | |
446 | print_ip_sym(ip); | |
447 | break; | |
448 | default: | |
449 | FTRACE_WARN_ON_ONCE(1); | |
450 | pr_info("ftrace faulted on unknown error "); | |
451 | print_ip_sym(ip); | |
452 | } | |
453 | } | |
454 | ||
3c1720f0 | 455 | |
0eb96701 | 456 | static int |
31e88909 | 457 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) |
5072c59f | 458 | { |
41c52c0d | 459 | unsigned long ip, fl; |
e7d3737e FW |
460 | unsigned long ftrace_addr; |
461 | ||
f0001207 | 462 | ftrace_addr = (unsigned long)FTRACE_ADDR; |
5072c59f SR |
463 | |
464 | ip = rec->ip; | |
465 | ||
982c350b SR |
466 | /* |
467 | * If this record is not to be traced and | |
468 | * it is not enabled then do nothing. | |
469 | * | |
470 | * If this record is not to be traced and | |
57794a9d | 471 | * it is enabled then disable it. |
982c350b SR |
472 | * |
473 | */ | |
474 | if (rec->flags & FTRACE_FL_NOTRACE) { | |
475 | if (rec->flags & FTRACE_FL_ENABLED) | |
476 | rec->flags &= ~FTRACE_FL_ENABLED; | |
477 | else | |
478 | return 0; | |
479 | ||
480 | } else if (ftrace_filtered && enable) { | |
5072c59f | 481 | /* |
982c350b | 482 | * Filtering is on: |
5072c59f | 483 | */ |
a4500b84 | 484 | |
982c350b | 485 | fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED); |
5072c59f | 486 | |
982c350b SR |
487 | /* Record is filtered and enabled, do nothing */ |
488 | if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) | |
0eb96701 | 489 | return 0; |
5072c59f | 490 | |
57794a9d | 491 | /* Record is not filtered or enabled, do nothing */ |
982c350b SR |
492 | if (!fl) |
493 | return 0; | |
494 | ||
495 | /* Record is not filtered but enabled, disable it */ | |
496 | if (fl == FTRACE_FL_ENABLED) | |
5072c59f | 497 | rec->flags &= ~FTRACE_FL_ENABLED; |
982c350b SR |
498 | else |
499 | /* Otherwise record is filtered but not enabled, enable it */ | |
5072c59f | 500 | rec->flags |= FTRACE_FL_ENABLED; |
5072c59f | 501 | } else { |
982c350b | 502 | /* Disable or not filtered */ |
5072c59f | 503 | |
41c52c0d | 504 | if (enable) { |
982c350b | 505 | /* if record is enabled, do nothing */ |
5072c59f | 506 | if (rec->flags & FTRACE_FL_ENABLED) |
0eb96701 | 507 | return 0; |
982c350b | 508 | |
5072c59f | 509 | rec->flags |= FTRACE_FL_ENABLED; |
982c350b | 510 | |
5072c59f | 511 | } else { |
982c350b | 512 | |
57794a9d | 513 | /* if record is not enabled, do nothing */ |
5072c59f | 514 | if (!(rec->flags & FTRACE_FL_ENABLED)) |
0eb96701 | 515 | return 0; |
982c350b | 516 | |
5072c59f SR |
517 | rec->flags &= ~FTRACE_FL_ENABLED; |
518 | } | |
519 | } | |
520 | ||
982c350b | 521 | if (rec->flags & FTRACE_FL_ENABLED) |
e7d3737e | 522 | return ftrace_make_call(rec, ftrace_addr); |
31e88909 | 523 | else |
e7d3737e | 524 | return ftrace_make_nop(NULL, rec, ftrace_addr); |
5072c59f SR |
525 | } |
526 | ||
e309b41d | 527 | static void ftrace_replace_code(int enable) |
3c1720f0 | 528 | { |
265c831c | 529 | int failed; |
3c1720f0 SR |
530 | struct dyn_ftrace *rec; |
531 | struct ftrace_page *pg; | |
3c1720f0 | 532 | |
265c831c SR |
533 | do_for_each_ftrace_rec(pg, rec) { |
534 | /* | |
535 | * Skip over free records and records that have | |
536 | * failed. | |
537 | */ | |
538 | if (rec->flags & FTRACE_FL_FREE || | |
539 | rec->flags & FTRACE_FL_FAILED) | |
540 | continue; | |
541 | ||
542 | /* ignore updates to this record's mcount site */ | |
543 | if (get_kprobe((void *)rec->ip)) { | |
544 | freeze_record(rec); | |
545 | continue; | |
546 | } else { | |
547 | unfreeze_record(rec); | |
548 | } | |
f22f9a89 | 549 | |
265c831c SR |
550 | failed = __ftrace_replace_code(rec, enable); |
551 | if (failed && (rec->flags & FTRACE_FL_CONVERTED)) { | |
552 | rec->flags |= FTRACE_FL_FAILED; | |
553 | if ((system_state == SYSTEM_BOOTING) || | |
554 | !core_kernel_text(rec->ip)) { | |
555 | ftrace_free_rec(rec); | |
556 | } else | |
557 | ftrace_bug(failed, rec->ip); | |
3c1720f0 | 558 | } |
265c831c | 559 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
560 | } |
561 | ||
492a7ea5 | 562 | static int |
31e88909 | 563 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 SR |
564 | { |
565 | unsigned long ip; | |
593eb8a2 | 566 | int ret; |
3c1720f0 SR |
567 | |
568 | ip = rec->ip; | |
569 | ||
25aac9dc | 570 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 571 | if (ret) { |
31e88909 | 572 | ftrace_bug(ret, ip); |
3c1720f0 | 573 | rec->flags |= FTRACE_FL_FAILED; |
492a7ea5 | 574 | return 0; |
37ad5084 | 575 | } |
492a7ea5 | 576 | return 1; |
3c1720f0 SR |
577 | } |
578 | ||
e309b41d | 579 | static int __ftrace_modify_code(void *data) |
3d083395 | 580 | { |
d61f82d0 SR |
581 | int *command = data; |
582 | ||
a3583244 | 583 | if (*command & FTRACE_ENABLE_CALLS) |
d61f82d0 | 584 | ftrace_replace_code(1); |
a3583244 | 585 | else if (*command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
586 | ftrace_replace_code(0); |
587 | ||
588 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
589 | ftrace_update_ftrace_func(ftrace_trace_function); | |
590 | ||
5a45cfe1 SR |
591 | if (*command & FTRACE_START_FUNC_RET) |
592 | ftrace_enable_ftrace_graph_caller(); | |
593 | else if (*command & FTRACE_STOP_FUNC_RET) | |
594 | ftrace_disable_ftrace_graph_caller(); | |
595 | ||
d61f82d0 | 596 | return 0; |
3d083395 SR |
597 | } |
598 | ||
e309b41d | 599 | static void ftrace_run_update_code(int command) |
3d083395 | 600 | { |
784e2d76 | 601 | stop_machine(__ftrace_modify_code, &command, NULL); |
3d083395 SR |
602 | } |
603 | ||
d61f82d0 | 604 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 605 | static int ftrace_start_up; |
df4fc315 SR |
606 | |
607 | static void ftrace_startup_enable(int command) | |
608 | { | |
609 | if (saved_ftrace_func != ftrace_trace_function) { | |
610 | saved_ftrace_func = ftrace_trace_function; | |
611 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
612 | } | |
613 | ||
614 | if (!command || !ftrace_enabled) | |
615 | return; | |
616 | ||
617 | ftrace_run_update_code(command); | |
618 | } | |
d61f82d0 | 619 | |
5a45cfe1 | 620 | static void ftrace_startup(int command) |
3d083395 | 621 | { |
4eebcc81 SR |
622 | if (unlikely(ftrace_disabled)) |
623 | return; | |
624 | ||
cb7be3b2 | 625 | mutex_lock(&ftrace_start_lock); |
60a7ecf4 | 626 | ftrace_start_up++; |
982c350b | 627 | command |= FTRACE_ENABLE_CALLS; |
d61f82d0 | 628 | |
df4fc315 | 629 | ftrace_startup_enable(command); |
3d083395 | 630 | |
cb7be3b2 | 631 | mutex_unlock(&ftrace_start_lock); |
3d083395 SR |
632 | } |
633 | ||
5a45cfe1 | 634 | static void ftrace_shutdown(int command) |
3d083395 | 635 | { |
4eebcc81 SR |
636 | if (unlikely(ftrace_disabled)) |
637 | return; | |
638 | ||
cb7be3b2 | 639 | mutex_lock(&ftrace_start_lock); |
60a7ecf4 SR |
640 | ftrace_start_up--; |
641 | if (!ftrace_start_up) | |
d61f82d0 | 642 | command |= FTRACE_DISABLE_CALLS; |
3d083395 | 643 | |
d61f82d0 SR |
644 | if (saved_ftrace_func != ftrace_trace_function) { |
645 | saved_ftrace_func = ftrace_trace_function; | |
646 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
647 | } | |
3d083395 | 648 | |
d61f82d0 SR |
649 | if (!command || !ftrace_enabled) |
650 | goto out; | |
651 | ||
652 | ftrace_run_update_code(command); | |
3d083395 | 653 | out: |
cb7be3b2 | 654 | mutex_unlock(&ftrace_start_lock); |
3d083395 SR |
655 | } |
656 | ||
e309b41d | 657 | static void ftrace_startup_sysctl(void) |
b0fc494f | 658 | { |
d61f82d0 SR |
659 | int command = FTRACE_ENABLE_MCOUNT; |
660 | ||
4eebcc81 SR |
661 | if (unlikely(ftrace_disabled)) |
662 | return; | |
663 | ||
cb7be3b2 | 664 | mutex_lock(&ftrace_start_lock); |
d61f82d0 SR |
665 | /* Force update next time */ |
666 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
667 | /* ftrace_start_up is true if we want ftrace running */ |
668 | if (ftrace_start_up) | |
d61f82d0 SR |
669 | command |= FTRACE_ENABLE_CALLS; |
670 | ||
671 | ftrace_run_update_code(command); | |
cb7be3b2 | 672 | mutex_unlock(&ftrace_start_lock); |
b0fc494f SR |
673 | } |
674 | ||
e309b41d | 675 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 676 | { |
d61f82d0 SR |
677 | int command = FTRACE_DISABLE_MCOUNT; |
678 | ||
4eebcc81 SR |
679 | if (unlikely(ftrace_disabled)) |
680 | return; | |
681 | ||
cb7be3b2 | 682 | mutex_lock(&ftrace_start_lock); |
60a7ecf4 SR |
683 | /* ftrace_start_up is true if ftrace is running */ |
684 | if (ftrace_start_up) | |
d61f82d0 SR |
685 | command |= FTRACE_DISABLE_CALLS; |
686 | ||
687 | ftrace_run_update_code(command); | |
cb7be3b2 | 688 | mutex_unlock(&ftrace_start_lock); |
b0fc494f SR |
689 | } |
690 | ||
3d083395 SR |
691 | static cycle_t ftrace_update_time; |
692 | static unsigned long ftrace_update_cnt; | |
693 | unsigned long ftrace_update_tot_cnt; | |
694 | ||
31e88909 | 695 | static int ftrace_update_code(struct module *mod) |
3d083395 | 696 | { |
08f5ac90 | 697 | struct dyn_ftrace *p, *t; |
f22f9a89 | 698 | cycle_t start, stop; |
3d083395 | 699 | |
750ed1a4 | 700 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
701 | ftrace_update_cnt = 0; |
702 | ||
08f5ac90 | 703 | list_for_each_entry_safe(p, t, &ftrace_new_addrs, list) { |
3d083395 | 704 | |
08f5ac90 SR |
705 | /* If something went wrong, bail without enabling anything */ |
706 | if (unlikely(ftrace_disabled)) | |
707 | return -1; | |
f22f9a89 | 708 | |
08f5ac90 | 709 | list_del_init(&p->list); |
f22f9a89 | 710 | |
08f5ac90 | 711 | /* convert record (i.e, patch mcount-call with NOP) */ |
31e88909 | 712 | if (ftrace_code_disable(mod, p)) { |
08f5ac90 SR |
713 | p->flags |= FTRACE_FL_CONVERTED; |
714 | ftrace_update_cnt++; | |
715 | } else | |
716 | ftrace_free_rec(p); | |
3d083395 SR |
717 | } |
718 | ||
750ed1a4 | 719 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
720 | ftrace_update_time = stop - start; |
721 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
722 | ||
16444a8a ACM |
723 | return 0; |
724 | } | |
725 | ||
68bf21aa | 726 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
727 | { |
728 | struct ftrace_page *pg; | |
729 | int cnt; | |
730 | int i; | |
3c1720f0 SR |
731 | |
732 | /* allocate a few pages */ | |
733 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
734 | if (!ftrace_pages_start) | |
735 | return -1; | |
736 | ||
737 | /* | |
738 | * Allocate a few more pages. | |
739 | * | |
740 | * TODO: have some parser search vmlinux before | |
741 | * final linking to find all calls to ftrace. | |
742 | * Then we can: | |
743 | * a) know how many pages to allocate. | |
744 | * and/or | |
745 | * b) set up the table then. | |
746 | * | |
747 | * The dynamic code is still necessary for | |
748 | * modules. | |
749 | */ | |
750 | ||
751 | pg = ftrace_pages = ftrace_pages_start; | |
752 | ||
68bf21aa | 753 | cnt = num_to_init / ENTRIES_PER_PAGE; |
08f5ac90 | 754 | pr_info("ftrace: allocating %ld entries in %d pages\n", |
5821e1b7 | 755 | num_to_init, cnt + 1); |
3c1720f0 SR |
756 | |
757 | for (i = 0; i < cnt; i++) { | |
758 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
759 | ||
760 | /* If we fail, we'll try later anyway */ | |
761 | if (!pg->next) | |
762 | break; | |
763 | ||
764 | pg = pg->next; | |
765 | } | |
766 | ||
767 | return 0; | |
768 | } | |
769 | ||
5072c59f SR |
770 | enum { |
771 | FTRACE_ITER_FILTER = (1 << 0), | |
772 | FTRACE_ITER_CONT = (1 << 1), | |
41c52c0d | 773 | FTRACE_ITER_NOTRACE = (1 << 2), |
eb9a7bf0 | 774 | FTRACE_ITER_FAILURES = (1 << 3), |
0c75a3ed | 775 | FTRACE_ITER_PRINTALL = (1 << 4), |
5072c59f SR |
776 | }; |
777 | ||
778 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
779 | ||
780 | struct ftrace_iterator { | |
5072c59f | 781 | struct ftrace_page *pg; |
431aa3fb | 782 | int idx; |
5072c59f SR |
783 | unsigned flags; |
784 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
785 | unsigned buffer_idx; | |
786 | unsigned filtered; | |
787 | }; | |
788 | ||
e309b41d | 789 | static void * |
5072c59f SR |
790 | t_next(struct seq_file *m, void *v, loff_t *pos) |
791 | { | |
792 | struct ftrace_iterator *iter = m->private; | |
793 | struct dyn_ftrace *rec = NULL; | |
794 | ||
795 | (*pos)++; | |
796 | ||
0c75a3ed SR |
797 | if (iter->flags & FTRACE_ITER_PRINTALL) |
798 | return NULL; | |
799 | ||
52baf119 | 800 | mutex_lock(&ftrace_lock); |
5072c59f SR |
801 | retry: |
802 | if (iter->idx >= iter->pg->index) { | |
803 | if (iter->pg->next) { | |
804 | iter->pg = iter->pg->next; | |
805 | iter->idx = 0; | |
806 | goto retry; | |
50cdaf08 LW |
807 | } else { |
808 | iter->idx = -1; | |
5072c59f SR |
809 | } |
810 | } else { | |
811 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
812 | if ((rec->flags & FTRACE_FL_FREE) || |
813 | ||
814 | (!(iter->flags & FTRACE_ITER_FAILURES) && | |
eb9a7bf0 AS |
815 | (rec->flags & FTRACE_FL_FAILED)) || |
816 | ||
817 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
a9fdda33 | 818 | !(rec->flags & FTRACE_FL_FAILED)) || |
eb9a7bf0 | 819 | |
0183fb1c SR |
820 | ((iter->flags & FTRACE_ITER_FILTER) && |
821 | !(rec->flags & FTRACE_FL_FILTER)) || | |
822 | ||
41c52c0d SR |
823 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
824 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
825 | rec = NULL; |
826 | goto retry; | |
827 | } | |
828 | } | |
52baf119 | 829 | mutex_unlock(&ftrace_lock); |
5072c59f | 830 | |
5072c59f SR |
831 | return rec; |
832 | } | |
833 | ||
834 | static void *t_start(struct seq_file *m, loff_t *pos) | |
835 | { | |
836 | struct ftrace_iterator *iter = m->private; | |
837 | void *p = NULL; | |
5072c59f | 838 | |
0c75a3ed SR |
839 | /* |
840 | * For set_ftrace_filter reading, if we have the filter | |
841 | * off, we can short cut and just print out that all | |
842 | * functions are enabled. | |
843 | */ | |
844 | if (iter->flags & FTRACE_ITER_FILTER && !ftrace_filtered) { | |
845 | if (*pos > 0) | |
846 | return NULL; | |
847 | iter->flags |= FTRACE_ITER_PRINTALL; | |
848 | (*pos)++; | |
849 | return iter; | |
850 | } | |
851 | ||
50cdaf08 LW |
852 | if (*pos > 0) { |
853 | if (iter->idx < 0) | |
854 | return p; | |
855 | (*pos)--; | |
856 | iter->idx--; | |
857 | } | |
5821e1b7 | 858 | |
50cdaf08 | 859 | p = t_next(m, p, pos); |
5072c59f SR |
860 | |
861 | return p; | |
862 | } | |
863 | ||
864 | static void t_stop(struct seq_file *m, void *p) | |
865 | { | |
866 | } | |
867 | ||
868 | static int t_show(struct seq_file *m, void *v) | |
869 | { | |
0c75a3ed | 870 | struct ftrace_iterator *iter = m->private; |
5072c59f SR |
871 | struct dyn_ftrace *rec = v; |
872 | char str[KSYM_SYMBOL_LEN]; | |
873 | ||
0c75a3ed SR |
874 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
875 | seq_printf(m, "#### all functions enabled ####\n"); | |
876 | return 0; | |
877 | } | |
878 | ||
5072c59f SR |
879 | if (!rec) |
880 | return 0; | |
881 | ||
882 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
883 | ||
50cdaf08 | 884 | seq_printf(m, "%s\n", str); |
5072c59f SR |
885 | |
886 | return 0; | |
887 | } | |
888 | ||
889 | static struct seq_operations show_ftrace_seq_ops = { | |
890 | .start = t_start, | |
891 | .next = t_next, | |
892 | .stop = t_stop, | |
893 | .show = t_show, | |
894 | }; | |
895 | ||
e309b41d | 896 | static int |
5072c59f SR |
897 | ftrace_avail_open(struct inode *inode, struct file *file) |
898 | { | |
899 | struct ftrace_iterator *iter; | |
900 | int ret; | |
901 | ||
4eebcc81 SR |
902 | if (unlikely(ftrace_disabled)) |
903 | return -ENODEV; | |
904 | ||
5072c59f SR |
905 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
906 | if (!iter) | |
907 | return -ENOMEM; | |
908 | ||
909 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
910 | |
911 | ret = seq_open(file, &show_ftrace_seq_ops); | |
912 | if (!ret) { | |
913 | struct seq_file *m = file->private_data; | |
4bf39a94 | 914 | |
5072c59f | 915 | m->private = iter; |
4bf39a94 | 916 | } else { |
5072c59f | 917 | kfree(iter); |
4bf39a94 | 918 | } |
5072c59f SR |
919 | |
920 | return ret; | |
921 | } | |
922 | ||
923 | int ftrace_avail_release(struct inode *inode, struct file *file) | |
924 | { | |
925 | struct seq_file *m = (struct seq_file *)file->private_data; | |
926 | struct ftrace_iterator *iter = m->private; | |
927 | ||
928 | seq_release(inode, file); | |
929 | kfree(iter); | |
4bf39a94 | 930 | |
5072c59f SR |
931 | return 0; |
932 | } | |
933 | ||
eb9a7bf0 AS |
934 | static int |
935 | ftrace_failures_open(struct inode *inode, struct file *file) | |
936 | { | |
937 | int ret; | |
938 | struct seq_file *m; | |
939 | struct ftrace_iterator *iter; | |
940 | ||
941 | ret = ftrace_avail_open(inode, file); | |
942 | if (!ret) { | |
943 | m = (struct seq_file *)file->private_data; | |
944 | iter = (struct ftrace_iterator *)m->private; | |
945 | iter->flags = FTRACE_ITER_FAILURES; | |
946 | } | |
947 | ||
948 | return ret; | |
949 | } | |
950 | ||
951 | ||
41c52c0d | 952 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
953 | { |
954 | struct ftrace_page *pg; | |
955 | struct dyn_ftrace *rec; | |
41c52c0d | 956 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f | 957 | |
52baf119 | 958 | mutex_lock(&ftrace_lock); |
41c52c0d SR |
959 | if (enable) |
960 | ftrace_filtered = 0; | |
265c831c SR |
961 | do_for_each_ftrace_rec(pg, rec) { |
962 | if (rec->flags & FTRACE_FL_FAILED) | |
963 | continue; | |
964 | rec->flags &= ~type; | |
965 | } while_for_each_ftrace_rec(); | |
52baf119 | 966 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
967 | } |
968 | ||
e309b41d | 969 | static int |
41c52c0d | 970 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
971 | { |
972 | struct ftrace_iterator *iter; | |
973 | int ret = 0; | |
974 | ||
4eebcc81 SR |
975 | if (unlikely(ftrace_disabled)) |
976 | return -ENODEV; | |
977 | ||
5072c59f SR |
978 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
979 | if (!iter) | |
980 | return -ENOMEM; | |
981 | ||
41c52c0d | 982 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
983 | if ((file->f_mode & FMODE_WRITE) && |
984 | !(file->f_flags & O_APPEND)) | |
41c52c0d | 985 | ftrace_filter_reset(enable); |
5072c59f SR |
986 | |
987 | if (file->f_mode & FMODE_READ) { | |
988 | iter->pg = ftrace_pages_start; | |
41c52c0d SR |
989 | iter->flags = enable ? FTRACE_ITER_FILTER : |
990 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
991 | |
992 | ret = seq_open(file, &show_ftrace_seq_ops); | |
993 | if (!ret) { | |
994 | struct seq_file *m = file->private_data; | |
995 | m->private = iter; | |
996 | } else | |
997 | kfree(iter); | |
998 | } else | |
999 | file->private_data = iter; | |
41c52c0d | 1000 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1001 | |
1002 | return ret; | |
1003 | } | |
1004 | ||
41c52c0d SR |
1005 | static int |
1006 | ftrace_filter_open(struct inode *inode, struct file *file) | |
1007 | { | |
1008 | return ftrace_regex_open(inode, file, 1); | |
1009 | } | |
1010 | ||
1011 | static int | |
1012 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
1013 | { | |
1014 | return ftrace_regex_open(inode, file, 0); | |
1015 | } | |
1016 | ||
e309b41d | 1017 | static ssize_t |
41c52c0d | 1018 | ftrace_regex_read(struct file *file, char __user *ubuf, |
5072c59f SR |
1019 | size_t cnt, loff_t *ppos) |
1020 | { | |
1021 | if (file->f_mode & FMODE_READ) | |
1022 | return seq_read(file, ubuf, cnt, ppos); | |
1023 | else | |
1024 | return -EPERM; | |
1025 | } | |
1026 | ||
e309b41d | 1027 | static loff_t |
41c52c0d | 1028 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
1029 | { |
1030 | loff_t ret; | |
1031 | ||
1032 | if (file->f_mode & FMODE_READ) | |
1033 | ret = seq_lseek(file, offset, origin); | |
1034 | else | |
1035 | file->f_pos = ret = 1; | |
1036 | ||
1037 | return ret; | |
1038 | } | |
1039 | ||
1040 | enum { | |
1041 | MATCH_FULL, | |
1042 | MATCH_FRONT_ONLY, | |
1043 | MATCH_MIDDLE_ONLY, | |
1044 | MATCH_END_ONLY, | |
1045 | }; | |
1046 | ||
9f4801e3 SR |
1047 | /* |
1048 | * (static function - no need for kernel doc) | |
1049 | * | |
1050 | * Pass in a buffer containing a glob and this function will | |
1051 | * set search to point to the search part of the buffer and | |
1052 | * return the type of search it is (see enum above). | |
1053 | * This does modify buff. | |
1054 | * | |
1055 | * Returns enum type. | |
1056 | * search returns the pointer to use for comparison. | |
1057 | * not returns 1 if buff started with a '!' | |
1058 | * 0 otherwise. | |
1059 | */ | |
1060 | static int | |
64e7c440 | 1061 | ftrace_setup_glob(char *buff, int len, char **search, int *not) |
5072c59f | 1062 | { |
5072c59f | 1063 | int type = MATCH_FULL; |
9f4801e3 | 1064 | int i; |
ea3a6d6d SR |
1065 | |
1066 | if (buff[0] == '!') { | |
9f4801e3 | 1067 | *not = 1; |
ea3a6d6d SR |
1068 | buff++; |
1069 | len--; | |
9f4801e3 SR |
1070 | } else |
1071 | *not = 0; | |
1072 | ||
1073 | *search = buff; | |
5072c59f SR |
1074 | |
1075 | for (i = 0; i < len; i++) { | |
1076 | if (buff[i] == '*') { | |
1077 | if (!i) { | |
9f4801e3 | 1078 | *search = buff + 1; |
5072c59f | 1079 | type = MATCH_END_ONLY; |
5072c59f | 1080 | } else { |
9f4801e3 | 1081 | if (type == MATCH_END_ONLY) |
5072c59f | 1082 | type = MATCH_MIDDLE_ONLY; |
9f4801e3 | 1083 | else |
5072c59f | 1084 | type = MATCH_FRONT_ONLY; |
5072c59f SR |
1085 | buff[i] = 0; |
1086 | break; | |
1087 | } | |
1088 | } | |
1089 | } | |
1090 | ||
9f4801e3 SR |
1091 | return type; |
1092 | } | |
1093 | ||
64e7c440 | 1094 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 1095 | { |
9f4801e3 SR |
1096 | int matched = 0; |
1097 | char *ptr; | |
1098 | ||
9f4801e3 SR |
1099 | switch (type) { |
1100 | case MATCH_FULL: | |
1101 | if (strcmp(str, regex) == 0) | |
1102 | matched = 1; | |
1103 | break; | |
1104 | case MATCH_FRONT_ONLY: | |
1105 | if (strncmp(str, regex, len) == 0) | |
1106 | matched = 1; | |
1107 | break; | |
1108 | case MATCH_MIDDLE_ONLY: | |
1109 | if (strstr(str, regex)) | |
1110 | matched = 1; | |
1111 | break; | |
1112 | case MATCH_END_ONLY: | |
1113 | ptr = strstr(str, regex); | |
1114 | if (ptr && (ptr[len] == 0)) | |
1115 | matched = 1; | |
1116 | break; | |
1117 | } | |
1118 | ||
1119 | return matched; | |
1120 | } | |
1121 | ||
64e7c440 SR |
1122 | static int |
1123 | ftrace_match_record(struct dyn_ftrace *rec, char *regex, int len, int type) | |
1124 | { | |
1125 | char str[KSYM_SYMBOL_LEN]; | |
1126 | ||
1127 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1128 | return ftrace_match(str, regex, len, type); | |
1129 | } | |
1130 | ||
9f4801e3 SR |
1131 | static void ftrace_match_records(char *buff, int len, int enable) |
1132 | { | |
1133 | char *search; | |
1134 | struct ftrace_page *pg; | |
1135 | struct dyn_ftrace *rec; | |
1136 | int type; | |
1137 | unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; | |
1138 | unsigned search_len; | |
1139 | int not; | |
1140 | ||
1141 | type = ftrace_setup_glob(buff, len, &search, ¬); | |
1142 | ||
1143 | search_len = strlen(search); | |
1144 | ||
52baf119 | 1145 | mutex_lock(&ftrace_lock); |
265c831c | 1146 | do_for_each_ftrace_rec(pg, rec) { |
265c831c SR |
1147 | |
1148 | if (rec->flags & FTRACE_FL_FAILED) | |
1149 | continue; | |
9f4801e3 SR |
1150 | |
1151 | if (ftrace_match_record(rec, search, search_len, type)) { | |
265c831c SR |
1152 | if (not) |
1153 | rec->flags &= ~flag; | |
1154 | else | |
1155 | rec->flags |= flag; | |
1156 | } | |
e68746a2 SR |
1157 | /* |
1158 | * Only enable filtering if we have a function that | |
1159 | * is filtered on. | |
1160 | */ | |
1161 | if (enable && (rec->flags & FTRACE_FL_FILTER)) | |
1162 | ftrace_filtered = 1; | |
265c831c | 1163 | } while_for_each_ftrace_rec(); |
52baf119 | 1164 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1165 | } |
1166 | ||
64e7c440 SR |
1167 | static int |
1168 | ftrace_match_module_record(struct dyn_ftrace *rec, char *mod, | |
1169 | char *regex, int len, int type) | |
1170 | { | |
1171 | char str[KSYM_SYMBOL_LEN]; | |
1172 | char *modname; | |
1173 | ||
1174 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
1175 | ||
1176 | if (!modname || strcmp(modname, mod)) | |
1177 | return 0; | |
1178 | ||
1179 | /* blank search means to match all funcs in the mod */ | |
1180 | if (len) | |
1181 | return ftrace_match(str, regex, len, type); | |
1182 | else | |
1183 | return 1; | |
1184 | } | |
1185 | ||
1186 | static void ftrace_match_module_records(char *buff, char *mod, int enable) | |
1187 | { | |
1188 | char *search = buff; | |
1189 | struct ftrace_page *pg; | |
1190 | struct dyn_ftrace *rec; | |
1191 | int type = MATCH_FULL; | |
1192 | unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; | |
1193 | unsigned search_len = 0; | |
1194 | int not = 0; | |
1195 | ||
1196 | /* blank or '*' mean the same */ | |
1197 | if (strcmp(buff, "*") == 0) | |
1198 | buff[0] = 0; | |
1199 | ||
1200 | /* handle the case of 'dont filter this module' */ | |
1201 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
1202 | buff[0] = 0; | |
1203 | not = 1; | |
1204 | } | |
1205 | ||
1206 | if (strlen(buff)) { | |
1207 | type = ftrace_setup_glob(buff, strlen(buff), &search, ¬); | |
1208 | search_len = strlen(search); | |
1209 | } | |
1210 | ||
52baf119 | 1211 | mutex_lock(&ftrace_lock); |
64e7c440 SR |
1212 | do_for_each_ftrace_rec(pg, rec) { |
1213 | ||
1214 | if (rec->flags & FTRACE_FL_FAILED) | |
1215 | continue; | |
1216 | ||
1217 | if (ftrace_match_module_record(rec, mod, | |
1218 | search, search_len, type)) { | |
1219 | if (not) | |
1220 | rec->flags &= ~flag; | |
1221 | else | |
1222 | rec->flags |= flag; | |
1223 | } | |
e68746a2 SR |
1224 | if (enable && (rec->flags & FTRACE_FL_FILTER)) |
1225 | ftrace_filtered = 1; | |
64e7c440 SR |
1226 | |
1227 | } while_for_each_ftrace_rec(); | |
52baf119 | 1228 | mutex_unlock(&ftrace_lock); |
64e7c440 SR |
1229 | } |
1230 | ||
f6180773 SR |
1231 | /* |
1232 | * We register the module command as a template to show others how | |
1233 | * to register the a command as well. | |
1234 | */ | |
1235 | ||
1236 | static int | |
1237 | ftrace_mod_callback(char *func, char *cmd, char *param, int enable) | |
1238 | { | |
1239 | char *mod; | |
1240 | ||
1241 | /* | |
1242 | * cmd == 'mod' because we only registered this func | |
1243 | * for the 'mod' ftrace_func_command. | |
1244 | * But if you register one func with multiple commands, | |
1245 | * you can tell which command was used by the cmd | |
1246 | * parameter. | |
1247 | */ | |
1248 | ||
1249 | /* we must have a module name */ | |
1250 | if (!param) | |
1251 | return -EINVAL; | |
1252 | ||
1253 | mod = strsep(¶m, ":"); | |
1254 | if (!strlen(mod)) | |
1255 | return -EINVAL; | |
1256 | ||
1257 | ftrace_match_module_records(func, mod, enable); | |
1258 | return 0; | |
1259 | } | |
1260 | ||
1261 | static struct ftrace_func_command ftrace_mod_cmd = { | |
1262 | .name = "mod", | |
1263 | .func = ftrace_mod_callback, | |
1264 | }; | |
1265 | ||
1266 | static int __init ftrace_mod_cmd_init(void) | |
1267 | { | |
1268 | return register_ftrace_command(&ftrace_mod_cmd); | |
1269 | } | |
1270 | device_initcall(ftrace_mod_cmd_init); | |
1271 | ||
1272 | static LIST_HEAD(ftrace_commands); | |
1273 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
1274 | ||
1275 | int register_ftrace_command(struct ftrace_func_command *cmd) | |
1276 | { | |
1277 | struct ftrace_func_command *p; | |
1278 | int ret = 0; | |
1279 | ||
1280 | mutex_lock(&ftrace_cmd_mutex); | |
1281 | list_for_each_entry(p, &ftrace_commands, list) { | |
1282 | if (strcmp(cmd->name, p->name) == 0) { | |
1283 | ret = -EBUSY; | |
1284 | goto out_unlock; | |
1285 | } | |
1286 | } | |
1287 | list_add(&cmd->list, &ftrace_commands); | |
1288 | out_unlock: | |
1289 | mutex_unlock(&ftrace_cmd_mutex); | |
1290 | ||
1291 | return ret; | |
1292 | } | |
1293 | ||
1294 | int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
1295 | { | |
1296 | struct ftrace_func_command *p, *n; | |
1297 | int ret = -ENODEV; | |
1298 | ||
1299 | mutex_lock(&ftrace_cmd_mutex); | |
1300 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
1301 | if (strcmp(cmd->name, p->name) == 0) { | |
1302 | ret = 0; | |
1303 | list_del_init(&p->list); | |
1304 | goto out_unlock; | |
1305 | } | |
1306 | } | |
1307 | out_unlock: | |
1308 | mutex_unlock(&ftrace_cmd_mutex); | |
1309 | ||
1310 | return ret; | |
1311 | } | |
1312 | ||
64e7c440 SR |
1313 | static int ftrace_process_regex(char *buff, int len, int enable) |
1314 | { | |
f6180773 SR |
1315 | struct ftrace_func_command *p; |
1316 | char *func, *command, *next = buff; | |
1317 | int ret = -EINVAL; | |
64e7c440 SR |
1318 | |
1319 | func = strsep(&next, ":"); | |
1320 | ||
1321 | if (!next) { | |
1322 | ftrace_match_records(func, len, enable); | |
1323 | return 0; | |
1324 | } | |
1325 | ||
f6180773 | 1326 | /* command found */ |
64e7c440 SR |
1327 | |
1328 | command = strsep(&next, ":"); | |
1329 | ||
f6180773 SR |
1330 | mutex_lock(&ftrace_cmd_mutex); |
1331 | list_for_each_entry(p, &ftrace_commands, list) { | |
1332 | if (strcmp(p->name, command) == 0) { | |
1333 | ret = p->func(func, command, next, enable); | |
1334 | goto out_unlock; | |
1335 | } | |
64e7c440 | 1336 | } |
f6180773 SR |
1337 | out_unlock: |
1338 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 1339 | |
f6180773 | 1340 | return ret; |
64e7c440 SR |
1341 | } |
1342 | ||
e309b41d | 1343 | static ssize_t |
41c52c0d SR |
1344 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
1345 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
1346 | { |
1347 | struct ftrace_iterator *iter; | |
1348 | char ch; | |
1349 | size_t read = 0; | |
1350 | ssize_t ret; | |
1351 | ||
1352 | if (!cnt || cnt < 0) | |
1353 | return 0; | |
1354 | ||
41c52c0d | 1355 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1356 | |
1357 | if (file->f_mode & FMODE_READ) { | |
1358 | struct seq_file *m = file->private_data; | |
1359 | iter = m->private; | |
1360 | } else | |
1361 | iter = file->private_data; | |
1362 | ||
1363 | if (!*ppos) { | |
1364 | iter->flags &= ~FTRACE_ITER_CONT; | |
1365 | iter->buffer_idx = 0; | |
1366 | } | |
1367 | ||
1368 | ret = get_user(ch, ubuf++); | |
1369 | if (ret) | |
1370 | goto out; | |
1371 | read++; | |
1372 | cnt--; | |
1373 | ||
1374 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { | |
1375 | /* skip white space */ | |
1376 | while (cnt && isspace(ch)) { | |
1377 | ret = get_user(ch, ubuf++); | |
1378 | if (ret) | |
1379 | goto out; | |
1380 | read++; | |
1381 | cnt--; | |
1382 | } | |
1383 | ||
5072c59f SR |
1384 | if (isspace(ch)) { |
1385 | file->f_pos += read; | |
1386 | ret = read; | |
1387 | goto out; | |
1388 | } | |
1389 | ||
1390 | iter->buffer_idx = 0; | |
1391 | } | |
1392 | ||
1393 | while (cnt && !isspace(ch)) { | |
1394 | if (iter->buffer_idx < FTRACE_BUFF_MAX) | |
1395 | iter->buffer[iter->buffer_idx++] = ch; | |
1396 | else { | |
1397 | ret = -EINVAL; | |
1398 | goto out; | |
1399 | } | |
1400 | ret = get_user(ch, ubuf++); | |
1401 | if (ret) | |
1402 | goto out; | |
1403 | read++; | |
1404 | cnt--; | |
1405 | } | |
1406 | ||
1407 | if (isspace(ch)) { | |
1408 | iter->filtered++; | |
1409 | iter->buffer[iter->buffer_idx] = 0; | |
64e7c440 SR |
1410 | ret = ftrace_process_regex(iter->buffer, |
1411 | iter->buffer_idx, enable); | |
1412 | if (ret) | |
1413 | goto out; | |
5072c59f SR |
1414 | iter->buffer_idx = 0; |
1415 | } else | |
1416 | iter->flags |= FTRACE_ITER_CONT; | |
1417 | ||
1418 | ||
1419 | file->f_pos += read; | |
1420 | ||
1421 | ret = read; | |
1422 | out: | |
41c52c0d | 1423 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1424 | |
1425 | return ret; | |
1426 | } | |
1427 | ||
41c52c0d SR |
1428 | static ssize_t |
1429 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
1430 | size_t cnt, loff_t *ppos) | |
1431 | { | |
1432 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
1433 | } | |
1434 | ||
1435 | static ssize_t | |
1436 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
1437 | size_t cnt, loff_t *ppos) | |
1438 | { | |
1439 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
1440 | } | |
1441 | ||
1442 | static void | |
1443 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
1444 | { | |
1445 | if (unlikely(ftrace_disabled)) | |
1446 | return; | |
1447 | ||
1448 | mutex_lock(&ftrace_regex_lock); | |
1449 | if (reset) | |
1450 | ftrace_filter_reset(enable); | |
1451 | if (buf) | |
7f24b31b | 1452 | ftrace_match_records(buf, len, enable); |
41c52c0d SR |
1453 | mutex_unlock(&ftrace_regex_lock); |
1454 | } | |
1455 | ||
77a2b37d SR |
1456 | /** |
1457 | * ftrace_set_filter - set a function to filter on in ftrace | |
1458 | * @buf - the string that holds the function filter text. | |
1459 | * @len - the length of the string. | |
1460 | * @reset - non zero to reset all filters before applying this filter. | |
1461 | * | |
1462 | * Filters denote which functions should be enabled when tracing is enabled. | |
1463 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
1464 | */ | |
e309b41d | 1465 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 1466 | { |
41c52c0d SR |
1467 | ftrace_set_regex(buf, len, reset, 1); |
1468 | } | |
4eebcc81 | 1469 | |
41c52c0d SR |
1470 | /** |
1471 | * ftrace_set_notrace - set a function to not trace in ftrace | |
1472 | * @buf - the string that holds the function notrace text. | |
1473 | * @len - the length of the string. | |
1474 | * @reset - non zero to reset all filters before applying this filter. | |
1475 | * | |
1476 | * Notrace Filters denote which functions should not be enabled when tracing | |
1477 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
1478 | * for tracing. | |
1479 | */ | |
1480 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
1481 | { | |
1482 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
1483 | } |
1484 | ||
e309b41d | 1485 | static int |
41c52c0d | 1486 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1487 | { |
1488 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1489 | struct ftrace_iterator *iter; | |
1490 | ||
41c52c0d | 1491 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1492 | if (file->f_mode & FMODE_READ) { |
1493 | iter = m->private; | |
1494 | ||
1495 | seq_release(inode, file); | |
1496 | } else | |
1497 | iter = file->private_data; | |
1498 | ||
1499 | if (iter->buffer_idx) { | |
1500 | iter->filtered++; | |
1501 | iter->buffer[iter->buffer_idx] = 0; | |
7f24b31b | 1502 | ftrace_match_records(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1503 | } |
1504 | ||
1505 | mutex_lock(&ftrace_sysctl_lock); | |
cb7be3b2 | 1506 | mutex_lock(&ftrace_start_lock); |
ee02a2e5 | 1507 | if (ftrace_start_up && ftrace_enabled) |
5072c59f | 1508 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
cb7be3b2 | 1509 | mutex_unlock(&ftrace_start_lock); |
5072c59f SR |
1510 | mutex_unlock(&ftrace_sysctl_lock); |
1511 | ||
1512 | kfree(iter); | |
41c52c0d | 1513 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1514 | return 0; |
1515 | } | |
1516 | ||
41c52c0d SR |
1517 | static int |
1518 | ftrace_filter_release(struct inode *inode, struct file *file) | |
1519 | { | |
1520 | return ftrace_regex_release(inode, file, 1); | |
1521 | } | |
1522 | ||
1523 | static int | |
1524 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
1525 | { | |
1526 | return ftrace_regex_release(inode, file, 0); | |
1527 | } | |
1528 | ||
5072c59f SR |
1529 | static struct file_operations ftrace_avail_fops = { |
1530 | .open = ftrace_avail_open, | |
1531 | .read = seq_read, | |
1532 | .llseek = seq_lseek, | |
1533 | .release = ftrace_avail_release, | |
1534 | }; | |
1535 | ||
eb9a7bf0 AS |
1536 | static struct file_operations ftrace_failures_fops = { |
1537 | .open = ftrace_failures_open, | |
1538 | .read = seq_read, | |
1539 | .llseek = seq_lseek, | |
1540 | .release = ftrace_avail_release, | |
1541 | }; | |
1542 | ||
5072c59f SR |
1543 | static struct file_operations ftrace_filter_fops = { |
1544 | .open = ftrace_filter_open, | |
41c52c0d | 1545 | .read = ftrace_regex_read, |
5072c59f | 1546 | .write = ftrace_filter_write, |
41c52c0d | 1547 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
1548 | .release = ftrace_filter_release, |
1549 | }; | |
1550 | ||
41c52c0d SR |
1551 | static struct file_operations ftrace_notrace_fops = { |
1552 | .open = ftrace_notrace_open, | |
1553 | .read = ftrace_regex_read, | |
1554 | .write = ftrace_notrace_write, | |
1555 | .llseek = ftrace_regex_lseek, | |
1556 | .release = ftrace_notrace_release, | |
1557 | }; | |
1558 | ||
ea4e2bc4 SR |
1559 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
1560 | ||
1561 | static DEFINE_MUTEX(graph_lock); | |
1562 | ||
1563 | int ftrace_graph_count; | |
1564 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; | |
1565 | ||
1566 | static void * | |
1567 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
1568 | { | |
1569 | unsigned long *array = m->private; | |
1570 | int index = *pos; | |
1571 | ||
1572 | (*pos)++; | |
1573 | ||
1574 | if (index >= ftrace_graph_count) | |
1575 | return NULL; | |
1576 | ||
1577 | return &array[index]; | |
1578 | } | |
1579 | ||
1580 | static void *g_start(struct seq_file *m, loff_t *pos) | |
1581 | { | |
1582 | void *p = NULL; | |
1583 | ||
1584 | mutex_lock(&graph_lock); | |
1585 | ||
1586 | p = g_next(m, p, pos); | |
1587 | ||
1588 | return p; | |
1589 | } | |
1590 | ||
1591 | static void g_stop(struct seq_file *m, void *p) | |
1592 | { | |
1593 | mutex_unlock(&graph_lock); | |
1594 | } | |
1595 | ||
1596 | static int g_show(struct seq_file *m, void *v) | |
1597 | { | |
1598 | unsigned long *ptr = v; | |
1599 | char str[KSYM_SYMBOL_LEN]; | |
1600 | ||
1601 | if (!ptr) | |
1602 | return 0; | |
1603 | ||
1604 | kallsyms_lookup(*ptr, NULL, NULL, NULL, str); | |
1605 | ||
1606 | seq_printf(m, "%s\n", str); | |
1607 | ||
1608 | return 0; | |
1609 | } | |
1610 | ||
1611 | static struct seq_operations ftrace_graph_seq_ops = { | |
1612 | .start = g_start, | |
1613 | .next = g_next, | |
1614 | .stop = g_stop, | |
1615 | .show = g_show, | |
1616 | }; | |
1617 | ||
1618 | static int | |
1619 | ftrace_graph_open(struct inode *inode, struct file *file) | |
1620 | { | |
1621 | int ret = 0; | |
1622 | ||
1623 | if (unlikely(ftrace_disabled)) | |
1624 | return -ENODEV; | |
1625 | ||
1626 | mutex_lock(&graph_lock); | |
1627 | if ((file->f_mode & FMODE_WRITE) && | |
1628 | !(file->f_flags & O_APPEND)) { | |
1629 | ftrace_graph_count = 0; | |
1630 | memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); | |
1631 | } | |
1632 | ||
1633 | if (file->f_mode & FMODE_READ) { | |
1634 | ret = seq_open(file, &ftrace_graph_seq_ops); | |
1635 | if (!ret) { | |
1636 | struct seq_file *m = file->private_data; | |
1637 | m->private = ftrace_graph_funcs; | |
1638 | } | |
1639 | } else | |
1640 | file->private_data = ftrace_graph_funcs; | |
1641 | mutex_unlock(&graph_lock); | |
1642 | ||
1643 | return ret; | |
1644 | } | |
1645 | ||
1646 | static ssize_t | |
1647 | ftrace_graph_read(struct file *file, char __user *ubuf, | |
1648 | size_t cnt, loff_t *ppos) | |
1649 | { | |
1650 | if (file->f_mode & FMODE_READ) | |
1651 | return seq_read(file, ubuf, cnt, ppos); | |
1652 | else | |
1653 | return -EPERM; | |
1654 | } | |
1655 | ||
1656 | static int | |
1657 | ftrace_set_func(unsigned long *array, int idx, char *buffer) | |
1658 | { | |
1659 | char str[KSYM_SYMBOL_LEN]; | |
1660 | struct dyn_ftrace *rec; | |
1661 | struct ftrace_page *pg; | |
1662 | int found = 0; | |
265c831c | 1663 | int j; |
ea4e2bc4 SR |
1664 | |
1665 | if (ftrace_disabled) | |
1666 | return -ENODEV; | |
1667 | ||
52baf119 | 1668 | mutex_lock(&ftrace_lock); |
265c831c SR |
1669 | do_for_each_ftrace_rec(pg, rec) { |
1670 | ||
1671 | if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE)) | |
1672 | continue; | |
1673 | ||
1674 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1675 | if (strcmp(str, buffer) == 0) { | |
1676 | /* Return 1 if we add it to the array */ | |
1677 | found = 1; | |
1678 | for (j = 0; j < idx; j++) | |
1679 | if (array[j] == rec->ip) { | |
1680 | found = 0; | |
1681 | break; | |
1682 | } | |
1683 | if (found) | |
1684 | array[idx] = rec->ip; | |
1685 | goto out; | |
ea4e2bc4 | 1686 | } |
265c831c SR |
1687 | } while_for_each_ftrace_rec(); |
1688 | out: | |
52baf119 | 1689 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 SR |
1690 | |
1691 | return found ? 0 : -EINVAL; | |
1692 | } | |
1693 | ||
1694 | static ssize_t | |
1695 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
1696 | size_t cnt, loff_t *ppos) | |
1697 | { | |
1698 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
1699 | unsigned long *array; | |
1700 | size_t read = 0; | |
1701 | ssize_t ret; | |
1702 | int index = 0; | |
1703 | char ch; | |
1704 | ||
1705 | if (!cnt || cnt < 0) | |
1706 | return 0; | |
1707 | ||
1708 | mutex_lock(&graph_lock); | |
1709 | ||
1710 | if (ftrace_graph_count >= FTRACE_GRAPH_MAX_FUNCS) { | |
1711 | ret = -EBUSY; | |
1712 | goto out; | |
1713 | } | |
1714 | ||
1715 | if (file->f_mode & FMODE_READ) { | |
1716 | struct seq_file *m = file->private_data; | |
1717 | array = m->private; | |
1718 | } else | |
1719 | array = file->private_data; | |
1720 | ||
1721 | ret = get_user(ch, ubuf++); | |
1722 | if (ret) | |
1723 | goto out; | |
1724 | read++; | |
1725 | cnt--; | |
1726 | ||
1727 | /* skip white space */ | |
1728 | while (cnt && isspace(ch)) { | |
1729 | ret = get_user(ch, ubuf++); | |
1730 | if (ret) | |
1731 | goto out; | |
1732 | read++; | |
1733 | cnt--; | |
1734 | } | |
1735 | ||
1736 | if (isspace(ch)) { | |
1737 | *ppos += read; | |
1738 | ret = read; | |
1739 | goto out; | |
1740 | } | |
1741 | ||
1742 | while (cnt && !isspace(ch)) { | |
1743 | if (index < FTRACE_BUFF_MAX) | |
1744 | buffer[index++] = ch; | |
1745 | else { | |
1746 | ret = -EINVAL; | |
1747 | goto out; | |
1748 | } | |
1749 | ret = get_user(ch, ubuf++); | |
1750 | if (ret) | |
1751 | goto out; | |
1752 | read++; | |
1753 | cnt--; | |
1754 | } | |
1755 | buffer[index] = 0; | |
1756 | ||
1757 | /* we allow only one at a time */ | |
1758 | ret = ftrace_set_func(array, ftrace_graph_count, buffer); | |
1759 | if (ret) | |
1760 | goto out; | |
1761 | ||
1762 | ftrace_graph_count++; | |
1763 | ||
1764 | file->f_pos += read; | |
1765 | ||
1766 | ret = read; | |
1767 | out: | |
1768 | mutex_unlock(&graph_lock); | |
1769 | ||
1770 | return ret; | |
1771 | } | |
1772 | ||
1773 | static const struct file_operations ftrace_graph_fops = { | |
1774 | .open = ftrace_graph_open, | |
1775 | .read = ftrace_graph_read, | |
1776 | .write = ftrace_graph_write, | |
1777 | }; | |
1778 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
1779 | ||
df4fc315 | 1780 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 1781 | { |
5072c59f SR |
1782 | struct dentry *entry; |
1783 | ||
5072c59f SR |
1784 | entry = debugfs_create_file("available_filter_functions", 0444, |
1785 | d_tracer, NULL, &ftrace_avail_fops); | |
1786 | if (!entry) | |
1787 | pr_warning("Could not create debugfs " | |
1788 | "'available_filter_functions' entry\n"); | |
1789 | ||
eb9a7bf0 AS |
1790 | entry = debugfs_create_file("failures", 0444, |
1791 | d_tracer, NULL, &ftrace_failures_fops); | |
1792 | if (!entry) | |
1793 | pr_warning("Could not create debugfs 'failures' entry\n"); | |
1794 | ||
5072c59f SR |
1795 | entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer, |
1796 | NULL, &ftrace_filter_fops); | |
1797 | if (!entry) | |
1798 | pr_warning("Could not create debugfs " | |
1799 | "'set_ftrace_filter' entry\n"); | |
41c52c0d SR |
1800 | |
1801 | entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer, | |
1802 | NULL, &ftrace_notrace_fops); | |
1803 | if (!entry) | |
1804 | pr_warning("Could not create debugfs " | |
1805 | "'set_ftrace_notrace' entry\n"); | |
ad90c0e3 | 1806 | |
ea4e2bc4 SR |
1807 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
1808 | entry = debugfs_create_file("set_graph_function", 0444, d_tracer, | |
1809 | NULL, | |
1810 | &ftrace_graph_fops); | |
1811 | if (!entry) | |
1812 | pr_warning("Could not create debugfs " | |
1813 | "'set_graph_function' entry\n"); | |
1814 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
1815 | ||
5072c59f SR |
1816 | return 0; |
1817 | } | |
1818 | ||
31e88909 SR |
1819 | static int ftrace_convert_nops(struct module *mod, |
1820 | unsigned long *start, | |
68bf21aa SR |
1821 | unsigned long *end) |
1822 | { | |
1823 | unsigned long *p; | |
1824 | unsigned long addr; | |
1825 | unsigned long flags; | |
1826 | ||
08f5ac90 | 1827 | mutex_lock(&ftrace_start_lock); |
68bf21aa SR |
1828 | p = start; |
1829 | while (p < end) { | |
1830 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
1831 | /* |
1832 | * Some architecture linkers will pad between | |
1833 | * the different mcount_loc sections of different | |
1834 | * object files to satisfy alignments. | |
1835 | * Skip any NULL pointers. | |
1836 | */ | |
1837 | if (!addr) | |
1838 | continue; | |
68bf21aa | 1839 | ftrace_record_ip(addr); |
68bf21aa SR |
1840 | } |
1841 | ||
08f5ac90 | 1842 | /* disable interrupts to prevent kstop machine */ |
68bf21aa | 1843 | local_irq_save(flags); |
31e88909 | 1844 | ftrace_update_code(mod); |
68bf21aa | 1845 | local_irq_restore(flags); |
08f5ac90 | 1846 | mutex_unlock(&ftrace_start_lock); |
68bf21aa SR |
1847 | |
1848 | return 0; | |
1849 | } | |
1850 | ||
31e88909 SR |
1851 | void ftrace_init_module(struct module *mod, |
1852 | unsigned long *start, unsigned long *end) | |
90d595fe | 1853 | { |
00fd61ae | 1854 | if (ftrace_disabled || start == end) |
fed1939c | 1855 | return; |
31e88909 | 1856 | ftrace_convert_nops(mod, start, end); |
90d595fe SR |
1857 | } |
1858 | ||
68bf21aa SR |
1859 | extern unsigned long __start_mcount_loc[]; |
1860 | extern unsigned long __stop_mcount_loc[]; | |
1861 | ||
1862 | void __init ftrace_init(void) | |
1863 | { | |
1864 | unsigned long count, addr, flags; | |
1865 | int ret; | |
1866 | ||
1867 | /* Keep the ftrace pointer to the stub */ | |
1868 | addr = (unsigned long)ftrace_stub; | |
1869 | ||
1870 | local_irq_save(flags); | |
1871 | ftrace_dyn_arch_init(&addr); | |
1872 | local_irq_restore(flags); | |
1873 | ||
1874 | /* ftrace_dyn_arch_init places the return code in addr */ | |
1875 | if (addr) | |
1876 | goto failed; | |
1877 | ||
1878 | count = __stop_mcount_loc - __start_mcount_loc; | |
1879 | ||
1880 | ret = ftrace_dyn_table_alloc(count); | |
1881 | if (ret) | |
1882 | goto failed; | |
1883 | ||
1884 | last_ftrace_enabled = ftrace_enabled = 1; | |
1885 | ||
31e88909 SR |
1886 | ret = ftrace_convert_nops(NULL, |
1887 | __start_mcount_loc, | |
68bf21aa SR |
1888 | __stop_mcount_loc); |
1889 | ||
1890 | return; | |
1891 | failed: | |
1892 | ftrace_disabled = 1; | |
1893 | } | |
68bf21aa | 1894 | |
3d083395 | 1895 | #else |
0b6e4d56 FW |
1896 | |
1897 | static int __init ftrace_nodyn_init(void) | |
1898 | { | |
1899 | ftrace_enabled = 1; | |
1900 | return 0; | |
1901 | } | |
1902 | device_initcall(ftrace_nodyn_init); | |
1903 | ||
df4fc315 SR |
1904 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
1905 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 SR |
1906 | /* Keep as macros so we do not need to define the commands */ |
1907 | # define ftrace_startup(command) do { } while (0) | |
1908 | # define ftrace_shutdown(command) do { } while (0) | |
c7aafc54 IM |
1909 | # define ftrace_startup_sysctl() do { } while (0) |
1910 | # define ftrace_shutdown_sysctl() do { } while (0) | |
3d083395 SR |
1911 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
1912 | ||
df4fc315 SR |
1913 | static ssize_t |
1914 | ftrace_pid_read(struct file *file, char __user *ubuf, | |
1915 | size_t cnt, loff_t *ppos) | |
1916 | { | |
1917 | char buf[64]; | |
1918 | int r; | |
1919 | ||
e32d8956 SR |
1920 | if (ftrace_pid_trace == ftrace_swapper_pid) |
1921 | r = sprintf(buf, "swapper tasks\n"); | |
1922 | else if (ftrace_pid_trace) | |
978f3a45 | 1923 | r = sprintf(buf, "%u\n", pid_nr(ftrace_pid_trace)); |
df4fc315 SR |
1924 | else |
1925 | r = sprintf(buf, "no pid\n"); | |
1926 | ||
1927 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
1928 | } | |
1929 | ||
e32d8956 | 1930 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
1931 | { |
1932 | struct task_struct *p; | |
e32d8956 | 1933 | int cpu; |
978f3a45 | 1934 | |
e32d8956 SR |
1935 | get_online_cpus(); |
1936 | for_each_online_cpu(cpu) { | |
1937 | p = idle_task(cpu); | |
978f3a45 | 1938 | clear_tsk_trace_trace(p); |
e32d8956 SR |
1939 | } |
1940 | put_online_cpus(); | |
1941 | } | |
978f3a45 | 1942 | |
e32d8956 SR |
1943 | static void set_ftrace_swapper(void) |
1944 | { | |
1945 | struct task_struct *p; | |
1946 | int cpu; | |
1947 | ||
1948 | get_online_cpus(); | |
1949 | for_each_online_cpu(cpu) { | |
1950 | p = idle_task(cpu); | |
1951 | set_tsk_trace_trace(p); | |
1952 | } | |
1953 | put_online_cpus(); | |
978f3a45 SR |
1954 | } |
1955 | ||
e32d8956 SR |
1956 | static void clear_ftrace_pid(struct pid *pid) |
1957 | { | |
1958 | struct task_struct *p; | |
1959 | ||
229c4ef8 | 1960 | rcu_read_lock(); |
e32d8956 SR |
1961 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
1962 | clear_tsk_trace_trace(p); | |
1963 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
1964 | rcu_read_unlock(); |
1965 | ||
e32d8956 SR |
1966 | put_pid(pid); |
1967 | } | |
1968 | ||
1969 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
1970 | { |
1971 | struct task_struct *p; | |
1972 | ||
229c4ef8 | 1973 | rcu_read_lock(); |
978f3a45 SR |
1974 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
1975 | set_tsk_trace_trace(p); | |
1976 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 1977 | rcu_read_unlock(); |
978f3a45 SR |
1978 | } |
1979 | ||
e32d8956 SR |
1980 | static void clear_ftrace_pid_task(struct pid **pid) |
1981 | { | |
1982 | if (*pid == ftrace_swapper_pid) | |
1983 | clear_ftrace_swapper(); | |
1984 | else | |
1985 | clear_ftrace_pid(*pid); | |
1986 | ||
1987 | *pid = NULL; | |
1988 | } | |
1989 | ||
1990 | static void set_ftrace_pid_task(struct pid *pid) | |
1991 | { | |
1992 | if (pid == ftrace_swapper_pid) | |
1993 | set_ftrace_swapper(); | |
1994 | else | |
1995 | set_ftrace_pid(pid); | |
1996 | } | |
1997 | ||
df4fc315 SR |
1998 | static ssize_t |
1999 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
2000 | size_t cnt, loff_t *ppos) | |
2001 | { | |
978f3a45 | 2002 | struct pid *pid; |
df4fc315 SR |
2003 | char buf[64]; |
2004 | long val; | |
2005 | int ret; | |
2006 | ||
2007 | if (cnt >= sizeof(buf)) | |
2008 | return -EINVAL; | |
2009 | ||
2010 | if (copy_from_user(&buf, ubuf, cnt)) | |
2011 | return -EFAULT; | |
2012 | ||
2013 | buf[cnt] = 0; | |
2014 | ||
2015 | ret = strict_strtol(buf, 10, &val); | |
2016 | if (ret < 0) | |
2017 | return ret; | |
2018 | ||
2019 | mutex_lock(&ftrace_start_lock); | |
978f3a45 | 2020 | if (val < 0) { |
df4fc315 | 2021 | /* disable pid tracing */ |
978f3a45 | 2022 | if (!ftrace_pid_trace) |
df4fc315 | 2023 | goto out; |
978f3a45 SR |
2024 | |
2025 | clear_ftrace_pid_task(&ftrace_pid_trace); | |
df4fc315 SR |
2026 | |
2027 | } else { | |
e32d8956 SR |
2028 | /* swapper task is special */ |
2029 | if (!val) { | |
2030 | pid = ftrace_swapper_pid; | |
2031 | if (pid == ftrace_pid_trace) | |
2032 | goto out; | |
2033 | } else { | |
2034 | pid = find_get_pid(val); | |
df4fc315 | 2035 | |
e32d8956 SR |
2036 | if (pid == ftrace_pid_trace) { |
2037 | put_pid(pid); | |
2038 | goto out; | |
2039 | } | |
0ef8cde5 | 2040 | } |
0ef8cde5 | 2041 | |
978f3a45 SR |
2042 | if (ftrace_pid_trace) |
2043 | clear_ftrace_pid_task(&ftrace_pid_trace); | |
2044 | ||
2045 | if (!pid) | |
2046 | goto out; | |
2047 | ||
2048 | ftrace_pid_trace = pid; | |
2049 | ||
2050 | set_ftrace_pid_task(ftrace_pid_trace); | |
df4fc315 SR |
2051 | } |
2052 | ||
2053 | /* update the function call */ | |
2054 | ftrace_update_pid_func(); | |
2055 | ftrace_startup_enable(0); | |
2056 | ||
2057 | out: | |
2058 | mutex_unlock(&ftrace_start_lock); | |
2059 | ||
2060 | return cnt; | |
2061 | } | |
2062 | ||
2063 | static struct file_operations ftrace_pid_fops = { | |
2064 | .read = ftrace_pid_read, | |
2065 | .write = ftrace_pid_write, | |
2066 | }; | |
2067 | ||
2068 | static __init int ftrace_init_debugfs(void) | |
2069 | { | |
2070 | struct dentry *d_tracer; | |
2071 | struct dentry *entry; | |
2072 | ||
2073 | d_tracer = tracing_init_dentry(); | |
2074 | if (!d_tracer) | |
2075 | return 0; | |
2076 | ||
2077 | ftrace_init_dyn_debugfs(d_tracer); | |
2078 | ||
2079 | entry = debugfs_create_file("set_ftrace_pid", 0644, d_tracer, | |
2080 | NULL, &ftrace_pid_fops); | |
2081 | if (!entry) | |
2082 | pr_warning("Could not create debugfs " | |
2083 | "'set_ftrace_pid' entry\n"); | |
2084 | return 0; | |
2085 | } | |
2086 | ||
2087 | fs_initcall(ftrace_init_debugfs); | |
2088 | ||
a2bb6a3d | 2089 | /** |
81adbdc0 | 2090 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
2091 | * |
2092 | * This function should be used by panic code. It stops ftrace | |
2093 | * but in a not so nice way. If you need to simply kill ftrace | |
2094 | * from a non-atomic section, use ftrace_kill. | |
2095 | */ | |
81adbdc0 | 2096 | void ftrace_kill(void) |
a2bb6a3d SR |
2097 | { |
2098 | ftrace_disabled = 1; | |
2099 | ftrace_enabled = 0; | |
a2bb6a3d SR |
2100 | clear_ftrace_function(); |
2101 | } | |
2102 | ||
16444a8a | 2103 | /** |
3d083395 SR |
2104 | * register_ftrace_function - register a function for profiling |
2105 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 2106 | * |
3d083395 SR |
2107 | * Register a function to be called by all functions in the |
2108 | * kernel. | |
2109 | * | |
2110 | * Note: @ops->func and all the functions it calls must be labeled | |
2111 | * with "notrace", otherwise it will go into a | |
2112 | * recursive loop. | |
16444a8a | 2113 | */ |
3d083395 | 2114 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 2115 | { |
b0fc494f SR |
2116 | int ret; |
2117 | ||
4eebcc81 SR |
2118 | if (unlikely(ftrace_disabled)) |
2119 | return -1; | |
2120 | ||
b0fc494f | 2121 | mutex_lock(&ftrace_sysctl_lock); |
e7d3737e | 2122 | |
b0fc494f | 2123 | ret = __register_ftrace_function(ops); |
5a45cfe1 | 2124 | ftrace_startup(0); |
b0fc494f | 2125 | |
e7d3737e | 2126 | mutex_unlock(&ftrace_sysctl_lock); |
b0fc494f | 2127 | return ret; |
3d083395 SR |
2128 | } |
2129 | ||
2130 | /** | |
32632920 | 2131 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
2132 | * @ops - ops structure that holds the function to unregister |
2133 | * | |
2134 | * Unregister a function that was added to be called by ftrace profiling. | |
2135 | */ | |
2136 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
2137 | { | |
2138 | int ret; | |
2139 | ||
b0fc494f | 2140 | mutex_lock(&ftrace_sysctl_lock); |
3d083395 | 2141 | ret = __unregister_ftrace_function(ops); |
5a45cfe1 | 2142 | ftrace_shutdown(0); |
b0fc494f SR |
2143 | mutex_unlock(&ftrace_sysctl_lock); |
2144 | ||
2145 | return ret; | |
2146 | } | |
2147 | ||
e309b41d | 2148 | int |
b0fc494f | 2149 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
5072c59f | 2150 | struct file *file, void __user *buffer, size_t *lenp, |
b0fc494f SR |
2151 | loff_t *ppos) |
2152 | { | |
2153 | int ret; | |
2154 | ||
4eebcc81 SR |
2155 | if (unlikely(ftrace_disabled)) |
2156 | return -ENODEV; | |
2157 | ||
b0fc494f SR |
2158 | mutex_lock(&ftrace_sysctl_lock); |
2159 | ||
5072c59f | 2160 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
b0fc494f SR |
2161 | |
2162 | if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) | |
2163 | goto out; | |
2164 | ||
2165 | last_ftrace_enabled = ftrace_enabled; | |
2166 | ||
2167 | if (ftrace_enabled) { | |
2168 | ||
2169 | ftrace_startup_sysctl(); | |
2170 | ||
2171 | /* we are starting ftrace again */ | |
2172 | if (ftrace_list != &ftrace_list_end) { | |
2173 | if (ftrace_list->next == &ftrace_list_end) | |
2174 | ftrace_trace_function = ftrace_list->func; | |
2175 | else | |
2176 | ftrace_trace_function = ftrace_list_func; | |
2177 | } | |
2178 | ||
2179 | } else { | |
2180 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
2181 | ftrace_trace_function = ftrace_stub; | |
2182 | ||
2183 | ftrace_shutdown_sysctl(); | |
2184 | } | |
2185 | ||
2186 | out: | |
2187 | mutex_unlock(&ftrace_sysctl_lock); | |
3d083395 | 2188 | return ret; |
16444a8a | 2189 | } |
f17845e5 | 2190 | |
fb52607a | 2191 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 2192 | |
287b6e68 | 2193 | static atomic_t ftrace_graph_active; |
4a2b8dda | 2194 | static struct notifier_block ftrace_suspend_notifier; |
e7d3737e | 2195 | |
e49dc19c SR |
2196 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
2197 | { | |
2198 | return 0; | |
2199 | } | |
2200 | ||
287b6e68 FW |
2201 | /* The callbacks that hook a function */ |
2202 | trace_func_graph_ret_t ftrace_graph_return = | |
2203 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 2204 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
2205 | |
2206 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
2207 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
2208 | { | |
2209 | int i; | |
2210 | int ret = 0; | |
2211 | unsigned long flags; | |
2212 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
2213 | struct task_struct *g, *t; | |
2214 | ||
2215 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
2216 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
2217 | * sizeof(struct ftrace_ret_stack), | |
2218 | GFP_KERNEL); | |
2219 | if (!ret_stack_list[i]) { | |
2220 | start = 0; | |
2221 | end = i; | |
2222 | ret = -ENOMEM; | |
2223 | goto free; | |
2224 | } | |
2225 | } | |
2226 | ||
2227 | read_lock_irqsave(&tasklist_lock, flags); | |
2228 | do_each_thread(g, t) { | |
2229 | if (start == end) { | |
2230 | ret = -EAGAIN; | |
2231 | goto unlock; | |
2232 | } | |
2233 | ||
2234 | if (t->ret_stack == NULL) { | |
f201ae23 | 2235 | t->curr_ret_stack = -1; |
48d68b20 FW |
2236 | /* Make sure IRQs see the -1 first: */ |
2237 | barrier(); | |
2238 | t->ret_stack = ret_stack_list[start++]; | |
380c4b14 | 2239 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 FW |
2240 | atomic_set(&t->trace_overrun, 0); |
2241 | } | |
2242 | } while_each_thread(g, t); | |
2243 | ||
2244 | unlock: | |
2245 | read_unlock_irqrestore(&tasklist_lock, flags); | |
2246 | free: | |
2247 | for (i = start; i < end; i++) | |
2248 | kfree(ret_stack_list[i]); | |
2249 | return ret; | |
2250 | } | |
2251 | ||
2252 | /* Allocate a return stack for each task */ | |
fb52607a | 2253 | static int start_graph_tracing(void) |
f201ae23 FW |
2254 | { |
2255 | struct ftrace_ret_stack **ret_stack_list; | |
2256 | int ret; | |
2257 | ||
2258 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
2259 | sizeof(struct ftrace_ret_stack *), | |
2260 | GFP_KERNEL); | |
2261 | ||
2262 | if (!ret_stack_list) | |
2263 | return -ENOMEM; | |
2264 | ||
2265 | do { | |
2266 | ret = alloc_retstack_tasklist(ret_stack_list); | |
2267 | } while (ret == -EAGAIN); | |
2268 | ||
2269 | kfree(ret_stack_list); | |
2270 | return ret; | |
2271 | } | |
2272 | ||
4a2b8dda FW |
2273 | /* |
2274 | * Hibernation protection. | |
2275 | * The state of the current task is too much unstable during | |
2276 | * suspend/restore to disk. We want to protect against that. | |
2277 | */ | |
2278 | static int | |
2279 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
2280 | void *unused) | |
2281 | { | |
2282 | switch (state) { | |
2283 | case PM_HIBERNATION_PREPARE: | |
2284 | pause_graph_tracing(); | |
2285 | break; | |
2286 | ||
2287 | case PM_POST_HIBERNATION: | |
2288 | unpause_graph_tracing(); | |
2289 | break; | |
2290 | } | |
2291 | return NOTIFY_DONE; | |
2292 | } | |
2293 | ||
287b6e68 FW |
2294 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
2295 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 2296 | { |
e7d3737e FW |
2297 | int ret = 0; |
2298 | ||
2299 | mutex_lock(&ftrace_sysctl_lock); | |
2300 | ||
4a2b8dda FW |
2301 | ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; |
2302 | register_pm_notifier(&ftrace_suspend_notifier); | |
2303 | ||
287b6e68 | 2304 | atomic_inc(&ftrace_graph_active); |
fb52607a | 2305 | ret = start_graph_tracing(); |
f201ae23 | 2306 | if (ret) { |
287b6e68 | 2307 | atomic_dec(&ftrace_graph_active); |
f201ae23 FW |
2308 | goto out; |
2309 | } | |
e53a6319 | 2310 | |
287b6e68 FW |
2311 | ftrace_graph_return = retfunc; |
2312 | ftrace_graph_entry = entryfunc; | |
e53a6319 | 2313 | |
5a45cfe1 | 2314 | ftrace_startup(FTRACE_START_FUNC_RET); |
e7d3737e FW |
2315 | |
2316 | out: | |
2317 | mutex_unlock(&ftrace_sysctl_lock); | |
2318 | return ret; | |
15e6cb36 FW |
2319 | } |
2320 | ||
fb52607a | 2321 | void unregister_ftrace_graph(void) |
15e6cb36 | 2322 | { |
e7d3737e FW |
2323 | mutex_lock(&ftrace_sysctl_lock); |
2324 | ||
287b6e68 FW |
2325 | atomic_dec(&ftrace_graph_active); |
2326 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 2327 | ftrace_graph_entry = ftrace_graph_entry_stub; |
5a45cfe1 | 2328 | ftrace_shutdown(FTRACE_STOP_FUNC_RET); |
4a2b8dda | 2329 | unregister_pm_notifier(&ftrace_suspend_notifier); |
e7d3737e FW |
2330 | |
2331 | mutex_unlock(&ftrace_sysctl_lock); | |
15e6cb36 | 2332 | } |
f201ae23 FW |
2333 | |
2334 | /* Allocate a return stack for newly created task */ | |
fb52607a | 2335 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 2336 | { |
287b6e68 | 2337 | if (atomic_read(&ftrace_graph_active)) { |
f201ae23 FW |
2338 | t->ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH |
2339 | * sizeof(struct ftrace_ret_stack), | |
2340 | GFP_KERNEL); | |
2341 | if (!t->ret_stack) | |
2342 | return; | |
2343 | t->curr_ret_stack = -1; | |
380c4b14 | 2344 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 FW |
2345 | atomic_set(&t->trace_overrun, 0); |
2346 | } else | |
2347 | t->ret_stack = NULL; | |
2348 | } | |
2349 | ||
fb52607a | 2350 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 2351 | { |
eae849ca FW |
2352 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
2353 | ||
f201ae23 | 2354 | t->ret_stack = NULL; |
eae849ca FW |
2355 | /* NULL must become visible to IRQs before we free it: */ |
2356 | barrier(); | |
2357 | ||
2358 | kfree(ret_stack); | |
f201ae23 | 2359 | } |
14a866c5 SR |
2360 | |
2361 | void ftrace_graph_stop(void) | |
2362 | { | |
2363 | ftrace_stop(); | |
2364 | } | |
15e6cb36 FW |
2365 | #endif |
2366 |