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" |
16444a8a | 37 | |
6912896e SR |
38 | #define FTRACE_WARN_ON(cond) \ |
39 | do { \ | |
40 | if (WARN_ON(cond)) \ | |
41 | ftrace_kill(); \ | |
42 | } while (0) | |
43 | ||
44 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
45 | do { \ | |
46 | if (WARN_ON_ONCE(cond)) \ | |
47 | ftrace_kill(); \ | |
48 | } while (0) | |
49 | ||
8fc0c701 SR |
50 | /* hash bits for specific function selection */ |
51 | #define FTRACE_HASH_BITS 7 | |
52 | #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS) | |
53 | ||
4eebcc81 SR |
54 | /* ftrace_enabled is a method to turn ftrace on or off */ |
55 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 56 | static int last_ftrace_enabled; |
b0fc494f | 57 | |
60a7ecf4 SR |
58 | /* Quick disabling of function tracer. */ |
59 | int function_trace_stop; | |
60 | ||
4eebcc81 SR |
61 | /* |
62 | * ftrace_disabled is set when an anomaly is discovered. | |
63 | * ftrace_disabled is much stronger than ftrace_enabled. | |
64 | */ | |
65 | static int ftrace_disabled __read_mostly; | |
66 | ||
52baf119 | 67 | static DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 68 | |
16444a8a ACM |
69 | static struct ftrace_ops ftrace_list_end __read_mostly = |
70 | { | |
71 | .func = ftrace_stub, | |
72 | }; | |
73 | ||
74 | static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; | |
75 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; | |
60a7ecf4 | 76 | ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub; |
df4fc315 | 77 | ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; |
16444a8a | 78 | |
f2252935 | 79 | static void ftrace_list_func(unsigned long ip, unsigned long parent_ip) |
16444a8a ACM |
80 | { |
81 | struct ftrace_ops *op = ftrace_list; | |
82 | ||
83 | /* in case someone actually ports this to alpha! */ | |
84 | read_barrier_depends(); | |
85 | ||
86 | while (op != &ftrace_list_end) { | |
87 | /* silly alpha */ | |
88 | read_barrier_depends(); | |
89 | op->func(ip, parent_ip); | |
90 | op = op->next; | |
91 | }; | |
92 | } | |
93 | ||
df4fc315 SR |
94 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip) |
95 | { | |
0ef8cde5 | 96 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
97 | return; |
98 | ||
99 | ftrace_pid_function(ip, parent_ip); | |
100 | } | |
101 | ||
102 | static void set_ftrace_pid_function(ftrace_func_t func) | |
103 | { | |
104 | /* do not set ftrace_pid_function to itself! */ | |
105 | if (func != ftrace_pid_func) | |
106 | ftrace_pid_function = func; | |
107 | } | |
108 | ||
16444a8a | 109 | /** |
3d083395 | 110 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 111 | * |
3d083395 SR |
112 | * This NULLs the ftrace function and in essence stops |
113 | * tracing. There may be lag | |
16444a8a | 114 | */ |
3d083395 | 115 | void clear_ftrace_function(void) |
16444a8a | 116 | { |
3d083395 | 117 | ftrace_trace_function = ftrace_stub; |
60a7ecf4 | 118 | __ftrace_trace_function = ftrace_stub; |
df4fc315 | 119 | ftrace_pid_function = ftrace_stub; |
3d083395 SR |
120 | } |
121 | ||
60a7ecf4 SR |
122 | #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
123 | /* | |
124 | * For those archs that do not test ftrace_trace_stop in their | |
125 | * mcount call site, we need to do it from C. | |
126 | */ | |
127 | static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip) | |
128 | { | |
129 | if (function_trace_stop) | |
130 | return; | |
131 | ||
132 | __ftrace_trace_function(ip, parent_ip); | |
133 | } | |
134 | #endif | |
135 | ||
e309b41d | 136 | static int __register_ftrace_function(struct ftrace_ops *ops) |
3d083395 | 137 | { |
16444a8a ACM |
138 | ops->next = ftrace_list; |
139 | /* | |
140 | * We are entering ops into the ftrace_list but another | |
141 | * CPU might be walking that list. We need to make sure | |
142 | * the ops->next pointer is valid before another CPU sees | |
143 | * the ops pointer included into the ftrace_list. | |
144 | */ | |
145 | smp_wmb(); | |
146 | ftrace_list = ops; | |
3d083395 | 147 | |
b0fc494f | 148 | if (ftrace_enabled) { |
df4fc315 SR |
149 | ftrace_func_t func; |
150 | ||
151 | if (ops->next == &ftrace_list_end) | |
152 | func = ops->func; | |
153 | else | |
154 | func = ftrace_list_func; | |
155 | ||
978f3a45 | 156 | if (ftrace_pid_trace) { |
df4fc315 SR |
157 | set_ftrace_pid_function(func); |
158 | func = ftrace_pid_func; | |
159 | } | |
160 | ||
b0fc494f SR |
161 | /* |
162 | * For one func, simply call it directly. | |
163 | * For more than one func, call the chain. | |
164 | */ | |
60a7ecf4 | 165 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
df4fc315 | 166 | ftrace_trace_function = func; |
60a7ecf4 | 167 | #else |
df4fc315 | 168 | __ftrace_trace_function = func; |
60a7ecf4 SR |
169 | ftrace_trace_function = ftrace_test_stop_func; |
170 | #endif | |
b0fc494f | 171 | } |
3d083395 | 172 | |
16444a8a ACM |
173 | return 0; |
174 | } | |
175 | ||
e309b41d | 176 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 177 | { |
16444a8a | 178 | struct ftrace_ops **p; |
16444a8a ACM |
179 | |
180 | /* | |
3d083395 SR |
181 | * If we are removing the last function, then simply point |
182 | * to the ftrace_stub. | |
16444a8a ACM |
183 | */ |
184 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { | |
185 | ftrace_trace_function = ftrace_stub; | |
186 | ftrace_list = &ftrace_list_end; | |
e6ea44e9 | 187 | return 0; |
16444a8a ACM |
188 | } |
189 | ||
190 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) | |
191 | if (*p == ops) | |
192 | break; | |
193 | ||
e6ea44e9 SR |
194 | if (*p != ops) |
195 | return -1; | |
16444a8a ACM |
196 | |
197 | *p = (*p)->next; | |
198 | ||
b0fc494f SR |
199 | if (ftrace_enabled) { |
200 | /* If we only have one func left, then call that directly */ | |
df4fc315 SR |
201 | if (ftrace_list->next == &ftrace_list_end) { |
202 | ftrace_func_t func = ftrace_list->func; | |
203 | ||
978f3a45 | 204 | if (ftrace_pid_trace) { |
df4fc315 SR |
205 | set_ftrace_pid_function(func); |
206 | func = ftrace_pid_func; | |
207 | } | |
208 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
209 | ftrace_trace_function = func; | |
210 | #else | |
211 | __ftrace_trace_function = func; | |
212 | #endif | |
213 | } | |
b0fc494f | 214 | } |
16444a8a | 215 | |
e6ea44e9 | 216 | return 0; |
3d083395 SR |
217 | } |
218 | ||
df4fc315 SR |
219 | static void ftrace_update_pid_func(void) |
220 | { | |
221 | ftrace_func_t func; | |
222 | ||
df4fc315 | 223 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 224 | return; |
df4fc315 SR |
225 | |
226 | func = ftrace_trace_function; | |
227 | ||
978f3a45 | 228 | if (ftrace_pid_trace) { |
df4fc315 SR |
229 | set_ftrace_pid_function(func); |
230 | func = ftrace_pid_func; | |
231 | } else { | |
66eafebc LW |
232 | if (func == ftrace_pid_func) |
233 | func = ftrace_pid_function; | |
df4fc315 SR |
234 | } |
235 | ||
236 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
237 | ftrace_trace_function = func; | |
238 | #else | |
239 | __ftrace_trace_function = func; | |
240 | #endif | |
df4fc315 SR |
241 | } |
242 | ||
73d3fd96 IM |
243 | /* set when tracing only a pid */ |
244 | struct pid *ftrace_pid_trace; | |
245 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; | |
246 | ||
3d083395 | 247 | #ifdef CONFIG_DYNAMIC_FTRACE |
73d3fd96 | 248 | |
99ecdc43 | 249 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
cb7be3b2 | 250 | # error Dynamic ftrace depends on MCOUNT_RECORD |
99ecdc43 SR |
251 | #endif |
252 | ||
8fc0c701 SR |
253 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; |
254 | ||
b6887d79 | 255 | struct ftrace_func_probe { |
8fc0c701 | 256 | struct hlist_node node; |
b6887d79 | 257 | struct ftrace_probe_ops *ops; |
8fc0c701 SR |
258 | unsigned long flags; |
259 | unsigned long ip; | |
260 | void *data; | |
261 | struct rcu_head rcu; | |
262 | }; | |
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 AS |
311 | |
312 | #ifdef CONFIG_KPROBES | |
f17845e5 IM |
313 | |
314 | static int frozen_record_count; | |
315 | ||
ecea656d AS |
316 | static inline void freeze_record(struct dyn_ftrace *rec) |
317 | { | |
318 | if (!(rec->flags & FTRACE_FL_FROZEN)) { | |
319 | rec->flags |= FTRACE_FL_FROZEN; | |
320 | frozen_record_count++; | |
321 | } | |
322 | } | |
323 | ||
324 | static inline void unfreeze_record(struct dyn_ftrace *rec) | |
325 | { | |
326 | if (rec->flags & FTRACE_FL_FROZEN) { | |
327 | rec->flags &= ~FTRACE_FL_FROZEN; | |
328 | frozen_record_count--; | |
329 | } | |
330 | } | |
331 | ||
332 | static inline int record_frozen(struct dyn_ftrace *rec) | |
333 | { | |
334 | return rec->flags & FTRACE_FL_FROZEN; | |
335 | } | |
336 | #else | |
337 | # define freeze_record(rec) ({ 0; }) | |
338 | # define unfreeze_record(rec) ({ 0; }) | |
339 | # define record_frozen(rec) ({ 0; }) | |
340 | #endif /* CONFIG_KPROBES */ | |
341 | ||
e309b41d | 342 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
37ad5084 | 343 | { |
ee000b7f | 344 | rec->freelist = ftrace_free_records; |
37ad5084 SR |
345 | ftrace_free_records = rec; |
346 | rec->flags |= FTRACE_FL_FREE; | |
347 | } | |
348 | ||
fed1939c SR |
349 | void ftrace_release(void *start, unsigned long size) |
350 | { | |
351 | struct dyn_ftrace *rec; | |
352 | struct ftrace_page *pg; | |
353 | unsigned long s = (unsigned long)start; | |
354 | unsigned long e = s + size; | |
fed1939c | 355 | |
00fd61ae | 356 | if (ftrace_disabled || !start) |
fed1939c SR |
357 | return; |
358 | ||
52baf119 | 359 | mutex_lock(&ftrace_lock); |
265c831c | 360 | do_for_each_ftrace_rec(pg, rec) { |
2a4efa42 Z |
361 | if ((rec->ip >= s) && (rec->ip < e)) { |
362 | /* | |
363 | * rec->ip is changed in ftrace_free_rec() | |
364 | * It should not between s and e if record was freed. | |
365 | */ | |
366 | FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE); | |
265c831c | 367 | ftrace_free_rec(rec); |
2a4efa42 | 368 | } |
265c831c | 369 | } while_for_each_ftrace_rec(); |
52baf119 | 370 | mutex_unlock(&ftrace_lock); |
fed1939c SR |
371 | } |
372 | ||
e309b41d | 373 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 374 | { |
37ad5084 SR |
375 | struct dyn_ftrace *rec; |
376 | ||
377 | /* First check for freed records */ | |
378 | if (ftrace_free_records) { | |
379 | rec = ftrace_free_records; | |
380 | ||
37ad5084 | 381 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
6912896e | 382 | FTRACE_WARN_ON_ONCE(1); |
37ad5084 SR |
383 | ftrace_free_records = NULL; |
384 | return NULL; | |
385 | } | |
386 | ||
ee000b7f | 387 | ftrace_free_records = rec->freelist; |
37ad5084 SR |
388 | memset(rec, 0, sizeof(*rec)); |
389 | return rec; | |
390 | } | |
391 | ||
3c1720f0 | 392 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
08f5ac90 SR |
393 | if (!ftrace_pages->next) { |
394 | /* allocate another page */ | |
395 | ftrace_pages->next = | |
396 | (void *)get_zeroed_page(GFP_KERNEL); | |
397 | if (!ftrace_pages->next) | |
398 | return NULL; | |
399 | } | |
3c1720f0 SR |
400 | ftrace_pages = ftrace_pages->next; |
401 | } | |
402 | ||
403 | return &ftrace_pages->records[ftrace_pages->index++]; | |
404 | } | |
405 | ||
08f5ac90 | 406 | static struct dyn_ftrace * |
d61f82d0 | 407 | ftrace_record_ip(unsigned long ip) |
3d083395 | 408 | { |
08f5ac90 | 409 | struct dyn_ftrace *rec; |
3d083395 | 410 | |
f3c7ac40 | 411 | if (ftrace_disabled) |
08f5ac90 | 412 | return NULL; |
3d083395 | 413 | |
08f5ac90 SR |
414 | rec = ftrace_alloc_dyn_node(ip); |
415 | if (!rec) | |
416 | return NULL; | |
3d083395 | 417 | |
08f5ac90 | 418 | rec->ip = ip; |
ee000b7f | 419 | rec->newlist = ftrace_new_addrs; |
e94142a6 | 420 | ftrace_new_addrs = rec; |
3d083395 | 421 | |
08f5ac90 | 422 | return rec; |
3d083395 SR |
423 | } |
424 | ||
b17e8a37 SR |
425 | static void print_ip_ins(const char *fmt, unsigned char *p) |
426 | { | |
427 | int i; | |
428 | ||
429 | printk(KERN_CONT "%s", fmt); | |
430 | ||
431 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
432 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
433 | } | |
434 | ||
31e88909 | 435 | static void ftrace_bug(int failed, unsigned long ip) |
b17e8a37 SR |
436 | { |
437 | switch (failed) { | |
438 | case -EFAULT: | |
439 | FTRACE_WARN_ON_ONCE(1); | |
440 | pr_info("ftrace faulted on modifying "); | |
441 | print_ip_sym(ip); | |
442 | break; | |
443 | case -EINVAL: | |
444 | FTRACE_WARN_ON_ONCE(1); | |
445 | pr_info("ftrace failed to modify "); | |
446 | print_ip_sym(ip); | |
b17e8a37 | 447 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
448 | printk(KERN_CONT "\n"); |
449 | break; | |
450 | case -EPERM: | |
451 | FTRACE_WARN_ON_ONCE(1); | |
452 | pr_info("ftrace faulted on writing "); | |
453 | print_ip_sym(ip); | |
454 | break; | |
455 | default: | |
456 | FTRACE_WARN_ON_ONCE(1); | |
457 | pr_info("ftrace faulted on unknown error "); | |
458 | print_ip_sym(ip); | |
459 | } | |
460 | } | |
461 | ||
3c1720f0 | 462 | |
0eb96701 | 463 | static int |
31e88909 | 464 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) |
5072c59f | 465 | { |
e7d3737e | 466 | unsigned long ftrace_addr; |
6a24a244 | 467 | unsigned long ip, fl; |
e7d3737e | 468 | |
f0001207 | 469 | ftrace_addr = (unsigned long)FTRACE_ADDR; |
5072c59f SR |
470 | |
471 | ip = rec->ip; | |
472 | ||
982c350b SR |
473 | /* |
474 | * If this record is not to be traced and | |
475 | * it is not enabled then do nothing. | |
476 | * | |
477 | * If this record is not to be traced and | |
57794a9d | 478 | * it is enabled then disable it. |
982c350b SR |
479 | * |
480 | */ | |
481 | if (rec->flags & FTRACE_FL_NOTRACE) { | |
482 | if (rec->flags & FTRACE_FL_ENABLED) | |
483 | rec->flags &= ~FTRACE_FL_ENABLED; | |
484 | else | |
485 | return 0; | |
486 | ||
487 | } else if (ftrace_filtered && enable) { | |
5072c59f | 488 | /* |
982c350b | 489 | * Filtering is on: |
5072c59f | 490 | */ |
a4500b84 | 491 | |
982c350b | 492 | fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED); |
5072c59f | 493 | |
982c350b SR |
494 | /* Record is filtered and enabled, do nothing */ |
495 | if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) | |
0eb96701 | 496 | return 0; |
5072c59f | 497 | |
57794a9d | 498 | /* Record is not filtered or enabled, do nothing */ |
982c350b SR |
499 | if (!fl) |
500 | return 0; | |
501 | ||
502 | /* Record is not filtered but enabled, disable it */ | |
503 | if (fl == FTRACE_FL_ENABLED) | |
5072c59f | 504 | rec->flags &= ~FTRACE_FL_ENABLED; |
982c350b SR |
505 | else |
506 | /* Otherwise record is filtered but not enabled, enable it */ | |
5072c59f | 507 | rec->flags |= FTRACE_FL_ENABLED; |
5072c59f | 508 | } else { |
982c350b | 509 | /* Disable or not filtered */ |
5072c59f | 510 | |
41c52c0d | 511 | if (enable) { |
982c350b | 512 | /* if record is enabled, do nothing */ |
5072c59f | 513 | if (rec->flags & FTRACE_FL_ENABLED) |
0eb96701 | 514 | return 0; |
982c350b | 515 | |
5072c59f | 516 | rec->flags |= FTRACE_FL_ENABLED; |
982c350b | 517 | |
5072c59f | 518 | } else { |
982c350b | 519 | |
57794a9d | 520 | /* if record is not enabled, do nothing */ |
5072c59f | 521 | if (!(rec->flags & FTRACE_FL_ENABLED)) |
0eb96701 | 522 | return 0; |
982c350b | 523 | |
5072c59f SR |
524 | rec->flags &= ~FTRACE_FL_ENABLED; |
525 | } | |
526 | } | |
527 | ||
982c350b | 528 | if (rec->flags & FTRACE_FL_ENABLED) |
e7d3737e | 529 | return ftrace_make_call(rec, ftrace_addr); |
31e88909 | 530 | else |
e7d3737e | 531 | return ftrace_make_nop(NULL, rec, ftrace_addr); |
5072c59f SR |
532 | } |
533 | ||
e309b41d | 534 | static void ftrace_replace_code(int enable) |
3c1720f0 | 535 | { |
3c1720f0 SR |
536 | struct dyn_ftrace *rec; |
537 | struct ftrace_page *pg; | |
6a24a244 | 538 | int failed; |
3c1720f0 | 539 | |
265c831c SR |
540 | do_for_each_ftrace_rec(pg, rec) { |
541 | /* | |
fa9d13cf Z |
542 | * Skip over free records, records that have |
543 | * failed and not converted. | |
265c831c SR |
544 | */ |
545 | if (rec->flags & FTRACE_FL_FREE || | |
fa9d13cf | 546 | rec->flags & FTRACE_FL_FAILED || |
03303549 | 547 | !(rec->flags & FTRACE_FL_CONVERTED)) |
265c831c SR |
548 | continue; |
549 | ||
550 | /* ignore updates to this record's mcount site */ | |
551 | if (get_kprobe((void *)rec->ip)) { | |
552 | freeze_record(rec); | |
553 | continue; | |
554 | } else { | |
555 | unfreeze_record(rec); | |
556 | } | |
f22f9a89 | 557 | |
265c831c | 558 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 559 | if (failed) { |
265c831c SR |
560 | rec->flags |= FTRACE_FL_FAILED; |
561 | if ((system_state == SYSTEM_BOOTING) || | |
562 | !core_kernel_text(rec->ip)) { | |
563 | ftrace_free_rec(rec); | |
4377245a | 564 | } else { |
265c831c | 565 | ftrace_bug(failed, rec->ip); |
4377245a SR |
566 | /* Stop processing */ |
567 | return; | |
568 | } | |
3c1720f0 | 569 | } |
265c831c | 570 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
571 | } |
572 | ||
492a7ea5 | 573 | static int |
31e88909 | 574 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 SR |
575 | { |
576 | unsigned long ip; | |
593eb8a2 | 577 | int ret; |
3c1720f0 SR |
578 | |
579 | ip = rec->ip; | |
580 | ||
25aac9dc | 581 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 582 | if (ret) { |
31e88909 | 583 | ftrace_bug(ret, ip); |
3c1720f0 | 584 | rec->flags |= FTRACE_FL_FAILED; |
492a7ea5 | 585 | return 0; |
37ad5084 | 586 | } |
492a7ea5 | 587 | return 1; |
3c1720f0 SR |
588 | } |
589 | ||
000ab691 SR |
590 | /* |
591 | * archs can override this function if they must do something | |
592 | * before the modifying code is performed. | |
593 | */ | |
594 | int __weak ftrace_arch_code_modify_prepare(void) | |
595 | { | |
596 | return 0; | |
597 | } | |
598 | ||
599 | /* | |
600 | * archs can override this function if they must do something | |
601 | * after the modifying code is performed. | |
602 | */ | |
603 | int __weak ftrace_arch_code_modify_post_process(void) | |
604 | { | |
605 | return 0; | |
606 | } | |
607 | ||
e309b41d | 608 | static int __ftrace_modify_code(void *data) |
3d083395 | 609 | { |
d61f82d0 SR |
610 | int *command = data; |
611 | ||
a3583244 | 612 | if (*command & FTRACE_ENABLE_CALLS) |
d61f82d0 | 613 | ftrace_replace_code(1); |
a3583244 | 614 | else if (*command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
615 | ftrace_replace_code(0); |
616 | ||
617 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
618 | ftrace_update_ftrace_func(ftrace_trace_function); | |
619 | ||
5a45cfe1 SR |
620 | if (*command & FTRACE_START_FUNC_RET) |
621 | ftrace_enable_ftrace_graph_caller(); | |
622 | else if (*command & FTRACE_STOP_FUNC_RET) | |
623 | ftrace_disable_ftrace_graph_caller(); | |
624 | ||
d61f82d0 | 625 | return 0; |
3d083395 SR |
626 | } |
627 | ||
e309b41d | 628 | static void ftrace_run_update_code(int command) |
3d083395 | 629 | { |
000ab691 SR |
630 | int ret; |
631 | ||
632 | ret = ftrace_arch_code_modify_prepare(); | |
633 | FTRACE_WARN_ON(ret); | |
634 | if (ret) | |
635 | return; | |
636 | ||
784e2d76 | 637 | stop_machine(__ftrace_modify_code, &command, NULL); |
000ab691 SR |
638 | |
639 | ret = ftrace_arch_code_modify_post_process(); | |
640 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
641 | } |
642 | ||
d61f82d0 | 643 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 644 | static int ftrace_start_up; |
df4fc315 SR |
645 | |
646 | static void ftrace_startup_enable(int command) | |
647 | { | |
648 | if (saved_ftrace_func != ftrace_trace_function) { | |
649 | saved_ftrace_func = ftrace_trace_function; | |
650 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
651 | } | |
652 | ||
653 | if (!command || !ftrace_enabled) | |
654 | return; | |
655 | ||
656 | ftrace_run_update_code(command); | |
657 | } | |
d61f82d0 | 658 | |
5a45cfe1 | 659 | static void ftrace_startup(int command) |
3d083395 | 660 | { |
4eebcc81 SR |
661 | if (unlikely(ftrace_disabled)) |
662 | return; | |
663 | ||
60a7ecf4 | 664 | ftrace_start_up++; |
982c350b | 665 | command |= FTRACE_ENABLE_CALLS; |
d61f82d0 | 666 | |
df4fc315 | 667 | ftrace_startup_enable(command); |
3d083395 SR |
668 | } |
669 | ||
5a45cfe1 | 670 | static void ftrace_shutdown(int command) |
3d083395 | 671 | { |
4eebcc81 SR |
672 | if (unlikely(ftrace_disabled)) |
673 | return; | |
674 | ||
60a7ecf4 SR |
675 | ftrace_start_up--; |
676 | if (!ftrace_start_up) | |
d61f82d0 | 677 | command |= FTRACE_DISABLE_CALLS; |
3d083395 | 678 | |
d61f82d0 SR |
679 | if (saved_ftrace_func != ftrace_trace_function) { |
680 | saved_ftrace_func = ftrace_trace_function; | |
681 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
682 | } | |
3d083395 | 683 | |
d61f82d0 | 684 | if (!command || !ftrace_enabled) |
e6ea44e9 | 685 | return; |
d61f82d0 SR |
686 | |
687 | ftrace_run_update_code(command); | |
3d083395 SR |
688 | } |
689 | ||
e309b41d | 690 | static void ftrace_startup_sysctl(void) |
b0fc494f | 691 | { |
d61f82d0 SR |
692 | int command = FTRACE_ENABLE_MCOUNT; |
693 | ||
4eebcc81 SR |
694 | if (unlikely(ftrace_disabled)) |
695 | return; | |
696 | ||
d61f82d0 SR |
697 | /* Force update next time */ |
698 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
699 | /* ftrace_start_up is true if we want ftrace running */ |
700 | if (ftrace_start_up) | |
d61f82d0 SR |
701 | command |= FTRACE_ENABLE_CALLS; |
702 | ||
703 | ftrace_run_update_code(command); | |
b0fc494f SR |
704 | } |
705 | ||
e309b41d | 706 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 707 | { |
d61f82d0 SR |
708 | int command = FTRACE_DISABLE_MCOUNT; |
709 | ||
4eebcc81 SR |
710 | if (unlikely(ftrace_disabled)) |
711 | return; | |
712 | ||
60a7ecf4 SR |
713 | /* ftrace_start_up is true if ftrace is running */ |
714 | if (ftrace_start_up) | |
d61f82d0 SR |
715 | command |= FTRACE_DISABLE_CALLS; |
716 | ||
717 | ftrace_run_update_code(command); | |
b0fc494f SR |
718 | } |
719 | ||
3d083395 SR |
720 | static cycle_t ftrace_update_time; |
721 | static unsigned long ftrace_update_cnt; | |
722 | unsigned long ftrace_update_tot_cnt; | |
723 | ||
31e88909 | 724 | static int ftrace_update_code(struct module *mod) |
3d083395 | 725 | { |
e94142a6 | 726 | struct dyn_ftrace *p; |
f22f9a89 | 727 | cycle_t start, stop; |
3d083395 | 728 | |
750ed1a4 | 729 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
730 | ftrace_update_cnt = 0; |
731 | ||
e94142a6 | 732 | while (ftrace_new_addrs) { |
3d083395 | 733 | |
08f5ac90 SR |
734 | /* If something went wrong, bail without enabling anything */ |
735 | if (unlikely(ftrace_disabled)) | |
736 | return -1; | |
f22f9a89 | 737 | |
e94142a6 | 738 | p = ftrace_new_addrs; |
ee000b7f | 739 | ftrace_new_addrs = p->newlist; |
e94142a6 | 740 | p->flags = 0L; |
f22f9a89 | 741 | |
08f5ac90 | 742 | /* convert record (i.e, patch mcount-call with NOP) */ |
31e88909 | 743 | if (ftrace_code_disable(mod, p)) { |
08f5ac90 SR |
744 | p->flags |= FTRACE_FL_CONVERTED; |
745 | ftrace_update_cnt++; | |
746 | } else | |
747 | ftrace_free_rec(p); | |
3d083395 SR |
748 | } |
749 | ||
750ed1a4 | 750 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
751 | ftrace_update_time = stop - start; |
752 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
753 | ||
16444a8a ACM |
754 | return 0; |
755 | } | |
756 | ||
68bf21aa | 757 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
758 | { |
759 | struct ftrace_page *pg; | |
760 | int cnt; | |
761 | int i; | |
3c1720f0 SR |
762 | |
763 | /* allocate a few pages */ | |
764 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
765 | if (!ftrace_pages_start) | |
766 | return -1; | |
767 | ||
768 | /* | |
769 | * Allocate a few more pages. | |
770 | * | |
771 | * TODO: have some parser search vmlinux before | |
772 | * final linking to find all calls to ftrace. | |
773 | * Then we can: | |
774 | * a) know how many pages to allocate. | |
775 | * and/or | |
776 | * b) set up the table then. | |
777 | * | |
778 | * The dynamic code is still necessary for | |
779 | * modules. | |
780 | */ | |
781 | ||
782 | pg = ftrace_pages = ftrace_pages_start; | |
783 | ||
68bf21aa | 784 | cnt = num_to_init / ENTRIES_PER_PAGE; |
08f5ac90 | 785 | pr_info("ftrace: allocating %ld entries in %d pages\n", |
5821e1b7 | 786 | num_to_init, cnt + 1); |
3c1720f0 SR |
787 | |
788 | for (i = 0; i < cnt; i++) { | |
789 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
790 | ||
791 | /* If we fail, we'll try later anyway */ | |
792 | if (!pg->next) | |
793 | break; | |
794 | ||
795 | pg = pg->next; | |
796 | } | |
797 | ||
798 | return 0; | |
799 | } | |
800 | ||
5072c59f SR |
801 | enum { |
802 | FTRACE_ITER_FILTER = (1 << 0), | |
803 | FTRACE_ITER_CONT = (1 << 1), | |
41c52c0d | 804 | FTRACE_ITER_NOTRACE = (1 << 2), |
eb9a7bf0 | 805 | FTRACE_ITER_FAILURES = (1 << 3), |
0c75a3ed | 806 | FTRACE_ITER_PRINTALL = (1 << 4), |
8fc0c701 | 807 | FTRACE_ITER_HASH = (1 << 5), |
5072c59f SR |
808 | }; |
809 | ||
810 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
811 | ||
812 | struct ftrace_iterator { | |
5072c59f | 813 | struct ftrace_page *pg; |
8fc0c701 | 814 | int hidx; |
431aa3fb | 815 | int idx; |
5072c59f SR |
816 | unsigned flags; |
817 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
818 | unsigned buffer_idx; | |
819 | unsigned filtered; | |
820 | }; | |
821 | ||
8fc0c701 SR |
822 | static void * |
823 | t_hash_next(struct seq_file *m, void *v, loff_t *pos) | |
824 | { | |
825 | struct ftrace_iterator *iter = m->private; | |
826 | struct hlist_node *hnd = v; | |
827 | struct hlist_head *hhd; | |
828 | ||
829 | WARN_ON(!(iter->flags & FTRACE_ITER_HASH)); | |
830 | ||
831 | (*pos)++; | |
832 | ||
833 | retry: | |
834 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
835 | return NULL; | |
836 | ||
837 | hhd = &ftrace_func_hash[iter->hidx]; | |
838 | ||
839 | if (hlist_empty(hhd)) { | |
840 | iter->hidx++; | |
841 | hnd = NULL; | |
842 | goto retry; | |
843 | } | |
844 | ||
845 | if (!hnd) | |
846 | hnd = hhd->first; | |
847 | else { | |
848 | hnd = hnd->next; | |
849 | if (!hnd) { | |
850 | iter->hidx++; | |
851 | goto retry; | |
852 | } | |
853 | } | |
854 | ||
855 | return hnd; | |
856 | } | |
857 | ||
858 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
859 | { | |
860 | struct ftrace_iterator *iter = m->private; | |
861 | void *p = NULL; | |
862 | ||
863 | iter->flags |= FTRACE_ITER_HASH; | |
864 | ||
865 | return t_hash_next(m, p, pos); | |
866 | } | |
867 | ||
868 | static int t_hash_show(struct seq_file *m, void *v) | |
869 | { | |
b6887d79 | 870 | struct ftrace_func_probe *rec; |
8fc0c701 SR |
871 | struct hlist_node *hnd = v; |
872 | char str[KSYM_SYMBOL_LEN]; | |
873 | ||
b6887d79 | 874 | rec = hlist_entry(hnd, struct ftrace_func_probe, node); |
8fc0c701 | 875 | |
809dcf29 SR |
876 | if (rec->ops->print) |
877 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
878 | ||
8fc0c701 SR |
879 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
880 | seq_printf(m, "%s:", str); | |
881 | ||
882 | kallsyms_lookup((unsigned long)rec->ops->func, NULL, NULL, NULL, str); | |
883 | seq_printf(m, "%s", str); | |
884 | ||
885 | if (rec->data) | |
886 | seq_printf(m, ":%p", rec->data); | |
887 | seq_putc(m, '\n'); | |
888 | ||
889 | return 0; | |
890 | } | |
891 | ||
e309b41d | 892 | static void * |
5072c59f SR |
893 | t_next(struct seq_file *m, void *v, loff_t *pos) |
894 | { | |
895 | struct ftrace_iterator *iter = m->private; | |
896 | struct dyn_ftrace *rec = NULL; | |
897 | ||
8fc0c701 SR |
898 | if (iter->flags & FTRACE_ITER_HASH) |
899 | return t_hash_next(m, v, pos); | |
900 | ||
5072c59f SR |
901 | (*pos)++; |
902 | ||
0c75a3ed SR |
903 | if (iter->flags & FTRACE_ITER_PRINTALL) |
904 | return NULL; | |
905 | ||
5072c59f SR |
906 | retry: |
907 | if (iter->idx >= iter->pg->index) { | |
908 | if (iter->pg->next) { | |
909 | iter->pg = iter->pg->next; | |
910 | iter->idx = 0; | |
911 | goto retry; | |
50cdaf08 LW |
912 | } else { |
913 | iter->idx = -1; | |
5072c59f SR |
914 | } |
915 | } else { | |
916 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
917 | if ((rec->flags & FTRACE_FL_FREE) || |
918 | ||
919 | (!(iter->flags & FTRACE_ITER_FAILURES) && | |
eb9a7bf0 AS |
920 | (rec->flags & FTRACE_FL_FAILED)) || |
921 | ||
922 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
a9fdda33 | 923 | !(rec->flags & FTRACE_FL_FAILED)) || |
eb9a7bf0 | 924 | |
0183fb1c SR |
925 | ((iter->flags & FTRACE_ITER_FILTER) && |
926 | !(rec->flags & FTRACE_FL_FILTER)) || | |
927 | ||
41c52c0d SR |
928 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
929 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
930 | rec = NULL; |
931 | goto retry; | |
932 | } | |
933 | } | |
934 | ||
5072c59f SR |
935 | return rec; |
936 | } | |
937 | ||
938 | static void *t_start(struct seq_file *m, loff_t *pos) | |
939 | { | |
940 | struct ftrace_iterator *iter = m->private; | |
941 | void *p = NULL; | |
5072c59f | 942 | |
8fc0c701 | 943 | mutex_lock(&ftrace_lock); |
0c75a3ed SR |
944 | /* |
945 | * For set_ftrace_filter reading, if we have the filter | |
946 | * off, we can short cut and just print out that all | |
947 | * functions are enabled. | |
948 | */ | |
949 | if (iter->flags & FTRACE_ITER_FILTER && !ftrace_filtered) { | |
950 | if (*pos > 0) | |
8fc0c701 | 951 | return t_hash_start(m, pos); |
0c75a3ed SR |
952 | iter->flags |= FTRACE_ITER_PRINTALL; |
953 | (*pos)++; | |
954 | return iter; | |
955 | } | |
956 | ||
8fc0c701 SR |
957 | if (iter->flags & FTRACE_ITER_HASH) |
958 | return t_hash_start(m, pos); | |
959 | ||
50cdaf08 LW |
960 | if (*pos > 0) { |
961 | if (iter->idx < 0) | |
962 | return p; | |
963 | (*pos)--; | |
964 | iter->idx--; | |
965 | } | |
5821e1b7 | 966 | |
50cdaf08 | 967 | p = t_next(m, p, pos); |
5072c59f | 968 | |
8fc0c701 SR |
969 | if (!p) |
970 | return t_hash_start(m, pos); | |
971 | ||
5072c59f SR |
972 | return p; |
973 | } | |
974 | ||
975 | static void t_stop(struct seq_file *m, void *p) | |
976 | { | |
8fc0c701 | 977 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
978 | } |
979 | ||
980 | static int t_show(struct seq_file *m, void *v) | |
981 | { | |
0c75a3ed | 982 | struct ftrace_iterator *iter = m->private; |
5072c59f SR |
983 | struct dyn_ftrace *rec = v; |
984 | char str[KSYM_SYMBOL_LEN]; | |
985 | ||
8fc0c701 SR |
986 | if (iter->flags & FTRACE_ITER_HASH) |
987 | return t_hash_show(m, v); | |
988 | ||
0c75a3ed SR |
989 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
990 | seq_printf(m, "#### all functions enabled ####\n"); | |
991 | return 0; | |
992 | } | |
993 | ||
5072c59f SR |
994 | if (!rec) |
995 | return 0; | |
996 | ||
997 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
998 | ||
50cdaf08 | 999 | seq_printf(m, "%s\n", str); |
5072c59f SR |
1000 | |
1001 | return 0; | |
1002 | } | |
1003 | ||
1004 | static struct seq_operations show_ftrace_seq_ops = { | |
1005 | .start = t_start, | |
1006 | .next = t_next, | |
1007 | .stop = t_stop, | |
1008 | .show = t_show, | |
1009 | }; | |
1010 | ||
e309b41d | 1011 | static int |
5072c59f SR |
1012 | ftrace_avail_open(struct inode *inode, struct file *file) |
1013 | { | |
1014 | struct ftrace_iterator *iter; | |
1015 | int ret; | |
1016 | ||
4eebcc81 SR |
1017 | if (unlikely(ftrace_disabled)) |
1018 | return -ENODEV; | |
1019 | ||
5072c59f SR |
1020 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1021 | if (!iter) | |
1022 | return -ENOMEM; | |
1023 | ||
1024 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
1025 | |
1026 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1027 | if (!ret) { | |
1028 | struct seq_file *m = file->private_data; | |
4bf39a94 | 1029 | |
5072c59f | 1030 | m->private = iter; |
4bf39a94 | 1031 | } else { |
5072c59f | 1032 | kfree(iter); |
4bf39a94 | 1033 | } |
5072c59f SR |
1034 | |
1035 | return ret; | |
1036 | } | |
1037 | ||
1038 | int ftrace_avail_release(struct inode *inode, struct file *file) | |
1039 | { | |
1040 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1041 | struct ftrace_iterator *iter = m->private; | |
1042 | ||
1043 | seq_release(inode, file); | |
1044 | kfree(iter); | |
4bf39a94 | 1045 | |
5072c59f SR |
1046 | return 0; |
1047 | } | |
1048 | ||
eb9a7bf0 AS |
1049 | static int |
1050 | ftrace_failures_open(struct inode *inode, struct file *file) | |
1051 | { | |
1052 | int ret; | |
1053 | struct seq_file *m; | |
1054 | struct ftrace_iterator *iter; | |
1055 | ||
1056 | ret = ftrace_avail_open(inode, file); | |
1057 | if (!ret) { | |
1058 | m = (struct seq_file *)file->private_data; | |
1059 | iter = (struct ftrace_iterator *)m->private; | |
1060 | iter->flags = FTRACE_ITER_FAILURES; | |
1061 | } | |
1062 | ||
1063 | return ret; | |
1064 | } | |
1065 | ||
1066 | ||
41c52c0d | 1067 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
1068 | { |
1069 | struct ftrace_page *pg; | |
1070 | struct dyn_ftrace *rec; | |
41c52c0d | 1071 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f | 1072 | |
52baf119 | 1073 | mutex_lock(&ftrace_lock); |
41c52c0d SR |
1074 | if (enable) |
1075 | ftrace_filtered = 0; | |
265c831c SR |
1076 | do_for_each_ftrace_rec(pg, rec) { |
1077 | if (rec->flags & FTRACE_FL_FAILED) | |
1078 | continue; | |
1079 | rec->flags &= ~type; | |
1080 | } while_for_each_ftrace_rec(); | |
52baf119 | 1081 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1082 | } |
1083 | ||
e309b41d | 1084 | static int |
41c52c0d | 1085 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1086 | { |
1087 | struct ftrace_iterator *iter; | |
1088 | int ret = 0; | |
1089 | ||
4eebcc81 SR |
1090 | if (unlikely(ftrace_disabled)) |
1091 | return -ENODEV; | |
1092 | ||
5072c59f SR |
1093 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1094 | if (!iter) | |
1095 | return -ENOMEM; | |
1096 | ||
41c52c0d | 1097 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1098 | if ((file->f_mode & FMODE_WRITE) && |
1099 | !(file->f_flags & O_APPEND)) | |
41c52c0d | 1100 | ftrace_filter_reset(enable); |
5072c59f SR |
1101 | |
1102 | if (file->f_mode & FMODE_READ) { | |
1103 | iter->pg = ftrace_pages_start; | |
41c52c0d SR |
1104 | iter->flags = enable ? FTRACE_ITER_FILTER : |
1105 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
1106 | |
1107 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1108 | if (!ret) { | |
1109 | struct seq_file *m = file->private_data; | |
1110 | m->private = iter; | |
1111 | } else | |
1112 | kfree(iter); | |
1113 | } else | |
1114 | file->private_data = iter; | |
41c52c0d | 1115 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1116 | |
1117 | return ret; | |
1118 | } | |
1119 | ||
41c52c0d SR |
1120 | static int |
1121 | ftrace_filter_open(struct inode *inode, struct file *file) | |
1122 | { | |
1123 | return ftrace_regex_open(inode, file, 1); | |
1124 | } | |
1125 | ||
1126 | static int | |
1127 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
1128 | { | |
1129 | return ftrace_regex_open(inode, file, 0); | |
1130 | } | |
1131 | ||
e309b41d | 1132 | static loff_t |
41c52c0d | 1133 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
1134 | { |
1135 | loff_t ret; | |
1136 | ||
1137 | if (file->f_mode & FMODE_READ) | |
1138 | ret = seq_lseek(file, offset, origin); | |
1139 | else | |
1140 | file->f_pos = ret = 1; | |
1141 | ||
1142 | return ret; | |
1143 | } | |
1144 | ||
1145 | enum { | |
1146 | MATCH_FULL, | |
1147 | MATCH_FRONT_ONLY, | |
1148 | MATCH_MIDDLE_ONLY, | |
1149 | MATCH_END_ONLY, | |
1150 | }; | |
1151 | ||
9f4801e3 SR |
1152 | /* |
1153 | * (static function - no need for kernel doc) | |
1154 | * | |
1155 | * Pass in a buffer containing a glob and this function will | |
1156 | * set search to point to the search part of the buffer and | |
1157 | * return the type of search it is (see enum above). | |
1158 | * This does modify buff. | |
1159 | * | |
1160 | * Returns enum type. | |
1161 | * search returns the pointer to use for comparison. | |
1162 | * not returns 1 if buff started with a '!' | |
1163 | * 0 otherwise. | |
1164 | */ | |
1165 | static int | |
64e7c440 | 1166 | ftrace_setup_glob(char *buff, int len, char **search, int *not) |
5072c59f | 1167 | { |
5072c59f | 1168 | int type = MATCH_FULL; |
9f4801e3 | 1169 | int i; |
ea3a6d6d SR |
1170 | |
1171 | if (buff[0] == '!') { | |
9f4801e3 | 1172 | *not = 1; |
ea3a6d6d SR |
1173 | buff++; |
1174 | len--; | |
9f4801e3 SR |
1175 | } else |
1176 | *not = 0; | |
1177 | ||
1178 | *search = buff; | |
5072c59f SR |
1179 | |
1180 | for (i = 0; i < len; i++) { | |
1181 | if (buff[i] == '*') { | |
1182 | if (!i) { | |
9f4801e3 | 1183 | *search = buff + 1; |
5072c59f | 1184 | type = MATCH_END_ONLY; |
5072c59f | 1185 | } else { |
9f4801e3 | 1186 | if (type == MATCH_END_ONLY) |
5072c59f | 1187 | type = MATCH_MIDDLE_ONLY; |
9f4801e3 | 1188 | else |
5072c59f | 1189 | type = MATCH_FRONT_ONLY; |
5072c59f SR |
1190 | buff[i] = 0; |
1191 | break; | |
1192 | } | |
1193 | } | |
1194 | } | |
1195 | ||
9f4801e3 SR |
1196 | return type; |
1197 | } | |
1198 | ||
64e7c440 | 1199 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 1200 | { |
9f4801e3 SR |
1201 | int matched = 0; |
1202 | char *ptr; | |
1203 | ||
9f4801e3 SR |
1204 | switch (type) { |
1205 | case MATCH_FULL: | |
1206 | if (strcmp(str, regex) == 0) | |
1207 | matched = 1; | |
1208 | break; | |
1209 | case MATCH_FRONT_ONLY: | |
1210 | if (strncmp(str, regex, len) == 0) | |
1211 | matched = 1; | |
1212 | break; | |
1213 | case MATCH_MIDDLE_ONLY: | |
1214 | if (strstr(str, regex)) | |
1215 | matched = 1; | |
1216 | break; | |
1217 | case MATCH_END_ONLY: | |
1218 | ptr = strstr(str, regex); | |
1219 | if (ptr && (ptr[len] == 0)) | |
1220 | matched = 1; | |
1221 | break; | |
1222 | } | |
1223 | ||
1224 | return matched; | |
1225 | } | |
1226 | ||
64e7c440 SR |
1227 | static int |
1228 | ftrace_match_record(struct dyn_ftrace *rec, char *regex, int len, int type) | |
1229 | { | |
1230 | char str[KSYM_SYMBOL_LEN]; | |
1231 | ||
1232 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1233 | return ftrace_match(str, regex, len, type); | |
1234 | } | |
1235 | ||
9f4801e3 SR |
1236 | static void ftrace_match_records(char *buff, int len, int enable) |
1237 | { | |
6a24a244 | 1238 | unsigned int search_len; |
9f4801e3 SR |
1239 | struct ftrace_page *pg; |
1240 | struct dyn_ftrace *rec; | |
6a24a244 SR |
1241 | unsigned long flag; |
1242 | char *search; | |
9f4801e3 | 1243 | int type; |
9f4801e3 SR |
1244 | int not; |
1245 | ||
6a24a244 | 1246 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
9f4801e3 SR |
1247 | type = ftrace_setup_glob(buff, len, &search, ¬); |
1248 | ||
1249 | search_len = strlen(search); | |
1250 | ||
52baf119 | 1251 | mutex_lock(&ftrace_lock); |
265c831c | 1252 | do_for_each_ftrace_rec(pg, rec) { |
265c831c SR |
1253 | |
1254 | if (rec->flags & FTRACE_FL_FAILED) | |
1255 | continue; | |
9f4801e3 SR |
1256 | |
1257 | if (ftrace_match_record(rec, search, search_len, type)) { | |
265c831c SR |
1258 | if (not) |
1259 | rec->flags &= ~flag; | |
1260 | else | |
1261 | rec->flags |= flag; | |
1262 | } | |
e68746a2 SR |
1263 | /* |
1264 | * Only enable filtering if we have a function that | |
1265 | * is filtered on. | |
1266 | */ | |
1267 | if (enable && (rec->flags & FTRACE_FL_FILTER)) | |
1268 | ftrace_filtered = 1; | |
265c831c | 1269 | } while_for_each_ftrace_rec(); |
52baf119 | 1270 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1271 | } |
1272 | ||
64e7c440 SR |
1273 | static int |
1274 | ftrace_match_module_record(struct dyn_ftrace *rec, char *mod, | |
1275 | char *regex, int len, int type) | |
1276 | { | |
1277 | char str[KSYM_SYMBOL_LEN]; | |
1278 | char *modname; | |
1279 | ||
1280 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
1281 | ||
1282 | if (!modname || strcmp(modname, mod)) | |
1283 | return 0; | |
1284 | ||
1285 | /* blank search means to match all funcs in the mod */ | |
1286 | if (len) | |
1287 | return ftrace_match(str, regex, len, type); | |
1288 | else | |
1289 | return 1; | |
1290 | } | |
1291 | ||
1292 | static void ftrace_match_module_records(char *buff, char *mod, int enable) | |
1293 | { | |
6a24a244 | 1294 | unsigned search_len = 0; |
64e7c440 SR |
1295 | struct ftrace_page *pg; |
1296 | struct dyn_ftrace *rec; | |
1297 | int type = MATCH_FULL; | |
6a24a244 SR |
1298 | char *search = buff; |
1299 | unsigned long flag; | |
64e7c440 SR |
1300 | int not = 0; |
1301 | ||
6a24a244 SR |
1302 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
1303 | ||
64e7c440 SR |
1304 | /* blank or '*' mean the same */ |
1305 | if (strcmp(buff, "*") == 0) | |
1306 | buff[0] = 0; | |
1307 | ||
1308 | /* handle the case of 'dont filter this module' */ | |
1309 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
1310 | buff[0] = 0; | |
1311 | not = 1; | |
1312 | } | |
1313 | ||
1314 | if (strlen(buff)) { | |
1315 | type = ftrace_setup_glob(buff, strlen(buff), &search, ¬); | |
1316 | search_len = strlen(search); | |
1317 | } | |
1318 | ||
52baf119 | 1319 | mutex_lock(&ftrace_lock); |
64e7c440 SR |
1320 | do_for_each_ftrace_rec(pg, rec) { |
1321 | ||
1322 | if (rec->flags & FTRACE_FL_FAILED) | |
1323 | continue; | |
1324 | ||
1325 | if (ftrace_match_module_record(rec, mod, | |
1326 | search, search_len, type)) { | |
1327 | if (not) | |
1328 | rec->flags &= ~flag; | |
1329 | else | |
1330 | rec->flags |= flag; | |
1331 | } | |
e68746a2 SR |
1332 | if (enable && (rec->flags & FTRACE_FL_FILTER)) |
1333 | ftrace_filtered = 1; | |
64e7c440 SR |
1334 | |
1335 | } while_for_each_ftrace_rec(); | |
52baf119 | 1336 | mutex_unlock(&ftrace_lock); |
64e7c440 SR |
1337 | } |
1338 | ||
f6180773 SR |
1339 | /* |
1340 | * We register the module command as a template to show others how | |
1341 | * to register the a command as well. | |
1342 | */ | |
1343 | ||
1344 | static int | |
1345 | ftrace_mod_callback(char *func, char *cmd, char *param, int enable) | |
1346 | { | |
1347 | char *mod; | |
1348 | ||
1349 | /* | |
1350 | * cmd == 'mod' because we only registered this func | |
1351 | * for the 'mod' ftrace_func_command. | |
1352 | * But if you register one func with multiple commands, | |
1353 | * you can tell which command was used by the cmd | |
1354 | * parameter. | |
1355 | */ | |
1356 | ||
1357 | /* we must have a module name */ | |
1358 | if (!param) | |
1359 | return -EINVAL; | |
1360 | ||
1361 | mod = strsep(¶m, ":"); | |
1362 | if (!strlen(mod)) | |
1363 | return -EINVAL; | |
1364 | ||
1365 | ftrace_match_module_records(func, mod, enable); | |
1366 | return 0; | |
1367 | } | |
1368 | ||
1369 | static struct ftrace_func_command ftrace_mod_cmd = { | |
1370 | .name = "mod", | |
1371 | .func = ftrace_mod_callback, | |
1372 | }; | |
1373 | ||
1374 | static int __init ftrace_mod_cmd_init(void) | |
1375 | { | |
1376 | return register_ftrace_command(&ftrace_mod_cmd); | |
1377 | } | |
1378 | device_initcall(ftrace_mod_cmd_init); | |
1379 | ||
59df055f | 1380 | static void |
b6887d79 | 1381 | function_trace_probe_call(unsigned long ip, unsigned long parent_ip) |
59df055f | 1382 | { |
b6887d79 | 1383 | struct ftrace_func_probe *entry; |
59df055f SR |
1384 | struct hlist_head *hhd; |
1385 | struct hlist_node *n; | |
1386 | unsigned long key; | |
1387 | int resched; | |
1388 | ||
1389 | key = hash_long(ip, FTRACE_HASH_BITS); | |
1390 | ||
1391 | hhd = &ftrace_func_hash[key]; | |
1392 | ||
1393 | if (hlist_empty(hhd)) | |
1394 | return; | |
1395 | ||
1396 | /* | |
1397 | * Disable preemption for these calls to prevent a RCU grace | |
1398 | * period. This syncs the hash iteration and freeing of items | |
1399 | * on the hash. rcu_read_lock is too dangerous here. | |
1400 | */ | |
1401 | resched = ftrace_preempt_disable(); | |
1402 | hlist_for_each_entry_rcu(entry, n, hhd, node) { | |
1403 | if (entry->ip == ip) | |
1404 | entry->ops->func(ip, parent_ip, &entry->data); | |
1405 | } | |
1406 | ftrace_preempt_enable(resched); | |
1407 | } | |
1408 | ||
b6887d79 | 1409 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 1410 | { |
b6887d79 | 1411 | .func = function_trace_probe_call, |
59df055f SR |
1412 | }; |
1413 | ||
b6887d79 | 1414 | static int ftrace_probe_registered; |
59df055f | 1415 | |
b6887d79 | 1416 | static void __enable_ftrace_function_probe(void) |
59df055f SR |
1417 | { |
1418 | int i; | |
1419 | ||
b6887d79 | 1420 | if (ftrace_probe_registered) |
59df055f SR |
1421 | return; |
1422 | ||
1423 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1424 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1425 | if (hhd->first) | |
1426 | break; | |
1427 | } | |
1428 | /* Nothing registered? */ | |
1429 | if (i == FTRACE_FUNC_HASHSIZE) | |
1430 | return; | |
1431 | ||
b6887d79 | 1432 | __register_ftrace_function(&trace_probe_ops); |
59df055f | 1433 | ftrace_startup(0); |
b6887d79 | 1434 | ftrace_probe_registered = 1; |
59df055f SR |
1435 | } |
1436 | ||
b6887d79 | 1437 | static void __disable_ftrace_function_probe(void) |
59df055f SR |
1438 | { |
1439 | int i; | |
1440 | ||
b6887d79 | 1441 | if (!ftrace_probe_registered) |
59df055f SR |
1442 | return; |
1443 | ||
1444 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1445 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1446 | if (hhd->first) | |
1447 | return; | |
1448 | } | |
1449 | ||
1450 | /* no more funcs left */ | |
b6887d79 | 1451 | __unregister_ftrace_function(&trace_probe_ops); |
59df055f | 1452 | ftrace_shutdown(0); |
b6887d79 | 1453 | ftrace_probe_registered = 0; |
59df055f SR |
1454 | } |
1455 | ||
1456 | ||
1457 | static void ftrace_free_entry_rcu(struct rcu_head *rhp) | |
1458 | { | |
b6887d79 SR |
1459 | struct ftrace_func_probe *entry = |
1460 | container_of(rhp, struct ftrace_func_probe, rcu); | |
59df055f SR |
1461 | |
1462 | if (entry->ops->free) | |
1463 | entry->ops->free(&entry->data); | |
1464 | kfree(entry); | |
1465 | } | |
1466 | ||
1467 | ||
1468 | int | |
b6887d79 | 1469 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
1470 | void *data) |
1471 | { | |
b6887d79 | 1472 | struct ftrace_func_probe *entry; |
59df055f SR |
1473 | struct ftrace_page *pg; |
1474 | struct dyn_ftrace *rec; | |
59df055f | 1475 | int type, len, not; |
6a24a244 | 1476 | unsigned long key; |
59df055f SR |
1477 | int count = 0; |
1478 | char *search; | |
1479 | ||
1480 | type = ftrace_setup_glob(glob, strlen(glob), &search, ¬); | |
1481 | len = strlen(search); | |
1482 | ||
b6887d79 | 1483 | /* we do not support '!' for function probes */ |
59df055f SR |
1484 | if (WARN_ON(not)) |
1485 | return -EINVAL; | |
1486 | ||
1487 | mutex_lock(&ftrace_lock); | |
1488 | do_for_each_ftrace_rec(pg, rec) { | |
1489 | ||
1490 | if (rec->flags & FTRACE_FL_FAILED) | |
1491 | continue; | |
1492 | ||
1493 | if (!ftrace_match_record(rec, search, len, type)) | |
1494 | continue; | |
1495 | ||
1496 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1497 | if (!entry) { | |
b6887d79 | 1498 | /* If we did not process any, then return error */ |
59df055f SR |
1499 | if (!count) |
1500 | count = -ENOMEM; | |
1501 | goto out_unlock; | |
1502 | } | |
1503 | ||
1504 | count++; | |
1505 | ||
1506 | entry->data = data; | |
1507 | ||
1508 | /* | |
1509 | * The caller might want to do something special | |
1510 | * for each function we find. We call the callback | |
1511 | * to give the caller an opportunity to do so. | |
1512 | */ | |
1513 | if (ops->callback) { | |
1514 | if (ops->callback(rec->ip, &entry->data) < 0) { | |
1515 | /* caller does not like this func */ | |
1516 | kfree(entry); | |
1517 | continue; | |
1518 | } | |
1519 | } | |
1520 | ||
1521 | entry->ops = ops; | |
1522 | entry->ip = rec->ip; | |
1523 | ||
1524 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
1525 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
1526 | ||
1527 | } while_for_each_ftrace_rec(); | |
b6887d79 | 1528 | __enable_ftrace_function_probe(); |
59df055f SR |
1529 | |
1530 | out_unlock: | |
1531 | mutex_unlock(&ftrace_lock); | |
1532 | ||
1533 | return count; | |
1534 | } | |
1535 | ||
1536 | enum { | |
b6887d79 SR |
1537 | PROBE_TEST_FUNC = 1, |
1538 | PROBE_TEST_DATA = 2 | |
59df055f SR |
1539 | }; |
1540 | ||
1541 | static void | |
b6887d79 | 1542 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
1543 | void *data, int flags) |
1544 | { | |
b6887d79 | 1545 | struct ftrace_func_probe *entry; |
59df055f SR |
1546 | struct hlist_node *n, *tmp; |
1547 | char str[KSYM_SYMBOL_LEN]; | |
1548 | int type = MATCH_FULL; | |
1549 | int i, len = 0; | |
1550 | char *search; | |
1551 | ||
1552 | if (glob && (strcmp(glob, "*") || !strlen(glob))) | |
1553 | glob = NULL; | |
1554 | else { | |
1555 | int not; | |
1556 | ||
1557 | type = ftrace_setup_glob(glob, strlen(glob), &search, ¬); | |
1558 | len = strlen(search); | |
1559 | ||
b6887d79 | 1560 | /* we do not support '!' for function probes */ |
59df055f SR |
1561 | if (WARN_ON(not)) |
1562 | return; | |
1563 | } | |
1564 | ||
1565 | mutex_lock(&ftrace_lock); | |
1566 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1567 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1568 | ||
1569 | hlist_for_each_entry_safe(entry, n, tmp, hhd, node) { | |
1570 | ||
1571 | /* break up if statements for readability */ | |
b6887d79 | 1572 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
1573 | continue; |
1574 | ||
b6887d79 | 1575 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
1576 | continue; |
1577 | ||
1578 | /* do this last, since it is the most expensive */ | |
1579 | if (glob) { | |
1580 | kallsyms_lookup(entry->ip, NULL, NULL, | |
1581 | NULL, str); | |
1582 | if (!ftrace_match(str, glob, len, type)) | |
1583 | continue; | |
1584 | } | |
1585 | ||
1586 | hlist_del(&entry->node); | |
1587 | call_rcu(&entry->rcu, ftrace_free_entry_rcu); | |
1588 | } | |
1589 | } | |
b6887d79 | 1590 | __disable_ftrace_function_probe(); |
59df055f SR |
1591 | mutex_unlock(&ftrace_lock); |
1592 | } | |
1593 | ||
1594 | void | |
b6887d79 | 1595 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
1596 | void *data) |
1597 | { | |
b6887d79 SR |
1598 | __unregister_ftrace_function_probe(glob, ops, data, |
1599 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
1600 | } |
1601 | ||
1602 | void | |
b6887d79 | 1603 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 1604 | { |
b6887d79 | 1605 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
1606 | } |
1607 | ||
b6887d79 | 1608 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 1609 | { |
b6887d79 | 1610 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
1611 | } |
1612 | ||
f6180773 SR |
1613 | static LIST_HEAD(ftrace_commands); |
1614 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
1615 | ||
1616 | int register_ftrace_command(struct ftrace_func_command *cmd) | |
1617 | { | |
1618 | struct ftrace_func_command *p; | |
1619 | int ret = 0; | |
1620 | ||
1621 | mutex_lock(&ftrace_cmd_mutex); | |
1622 | list_for_each_entry(p, &ftrace_commands, list) { | |
1623 | if (strcmp(cmd->name, p->name) == 0) { | |
1624 | ret = -EBUSY; | |
1625 | goto out_unlock; | |
1626 | } | |
1627 | } | |
1628 | list_add(&cmd->list, &ftrace_commands); | |
1629 | out_unlock: | |
1630 | mutex_unlock(&ftrace_cmd_mutex); | |
1631 | ||
1632 | return ret; | |
1633 | } | |
1634 | ||
1635 | int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
1636 | { | |
1637 | struct ftrace_func_command *p, *n; | |
1638 | int ret = -ENODEV; | |
1639 | ||
1640 | mutex_lock(&ftrace_cmd_mutex); | |
1641 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
1642 | if (strcmp(cmd->name, p->name) == 0) { | |
1643 | ret = 0; | |
1644 | list_del_init(&p->list); | |
1645 | goto out_unlock; | |
1646 | } | |
1647 | } | |
1648 | out_unlock: | |
1649 | mutex_unlock(&ftrace_cmd_mutex); | |
1650 | ||
1651 | return ret; | |
1652 | } | |
1653 | ||
64e7c440 SR |
1654 | static int ftrace_process_regex(char *buff, int len, int enable) |
1655 | { | |
f6180773 | 1656 | char *func, *command, *next = buff; |
6a24a244 | 1657 | struct ftrace_func_command *p; |
f6180773 | 1658 | int ret = -EINVAL; |
64e7c440 SR |
1659 | |
1660 | func = strsep(&next, ":"); | |
1661 | ||
1662 | if (!next) { | |
1663 | ftrace_match_records(func, len, enable); | |
1664 | return 0; | |
1665 | } | |
1666 | ||
f6180773 | 1667 | /* command found */ |
64e7c440 SR |
1668 | |
1669 | command = strsep(&next, ":"); | |
1670 | ||
f6180773 SR |
1671 | mutex_lock(&ftrace_cmd_mutex); |
1672 | list_for_each_entry(p, &ftrace_commands, list) { | |
1673 | if (strcmp(p->name, command) == 0) { | |
1674 | ret = p->func(func, command, next, enable); | |
1675 | goto out_unlock; | |
1676 | } | |
64e7c440 | 1677 | } |
f6180773 SR |
1678 | out_unlock: |
1679 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 1680 | |
f6180773 | 1681 | return ret; |
64e7c440 SR |
1682 | } |
1683 | ||
e309b41d | 1684 | static ssize_t |
41c52c0d SR |
1685 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
1686 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
1687 | { |
1688 | struct ftrace_iterator *iter; | |
1689 | char ch; | |
1690 | size_t read = 0; | |
1691 | ssize_t ret; | |
1692 | ||
1693 | if (!cnt || cnt < 0) | |
1694 | return 0; | |
1695 | ||
41c52c0d | 1696 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1697 | |
1698 | if (file->f_mode & FMODE_READ) { | |
1699 | struct seq_file *m = file->private_data; | |
1700 | iter = m->private; | |
1701 | } else | |
1702 | iter = file->private_data; | |
1703 | ||
1704 | if (!*ppos) { | |
1705 | iter->flags &= ~FTRACE_ITER_CONT; | |
1706 | iter->buffer_idx = 0; | |
1707 | } | |
1708 | ||
1709 | ret = get_user(ch, ubuf++); | |
1710 | if (ret) | |
1711 | goto out; | |
1712 | read++; | |
1713 | cnt--; | |
1714 | ||
1715 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { | |
1716 | /* skip white space */ | |
1717 | while (cnt && isspace(ch)) { | |
1718 | ret = get_user(ch, ubuf++); | |
1719 | if (ret) | |
1720 | goto out; | |
1721 | read++; | |
1722 | cnt--; | |
1723 | } | |
1724 | ||
5072c59f SR |
1725 | if (isspace(ch)) { |
1726 | file->f_pos += read; | |
1727 | ret = read; | |
1728 | goto out; | |
1729 | } | |
1730 | ||
1731 | iter->buffer_idx = 0; | |
1732 | } | |
1733 | ||
1734 | while (cnt && !isspace(ch)) { | |
1735 | if (iter->buffer_idx < FTRACE_BUFF_MAX) | |
1736 | iter->buffer[iter->buffer_idx++] = ch; | |
1737 | else { | |
1738 | ret = -EINVAL; | |
1739 | goto out; | |
1740 | } | |
1741 | ret = get_user(ch, ubuf++); | |
1742 | if (ret) | |
1743 | goto out; | |
1744 | read++; | |
1745 | cnt--; | |
1746 | } | |
1747 | ||
1748 | if (isspace(ch)) { | |
1749 | iter->filtered++; | |
1750 | iter->buffer[iter->buffer_idx] = 0; | |
64e7c440 SR |
1751 | ret = ftrace_process_regex(iter->buffer, |
1752 | iter->buffer_idx, enable); | |
1753 | if (ret) | |
1754 | goto out; | |
5072c59f SR |
1755 | iter->buffer_idx = 0; |
1756 | } else | |
1757 | iter->flags |= FTRACE_ITER_CONT; | |
1758 | ||
1759 | ||
1760 | file->f_pos += read; | |
1761 | ||
1762 | ret = read; | |
1763 | out: | |
41c52c0d | 1764 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1765 | |
1766 | return ret; | |
1767 | } | |
1768 | ||
41c52c0d SR |
1769 | static ssize_t |
1770 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
1771 | size_t cnt, loff_t *ppos) | |
1772 | { | |
1773 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
1774 | } | |
1775 | ||
1776 | static ssize_t | |
1777 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
1778 | size_t cnt, loff_t *ppos) | |
1779 | { | |
1780 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
1781 | } | |
1782 | ||
1783 | static void | |
1784 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
1785 | { | |
1786 | if (unlikely(ftrace_disabled)) | |
1787 | return; | |
1788 | ||
1789 | mutex_lock(&ftrace_regex_lock); | |
1790 | if (reset) | |
1791 | ftrace_filter_reset(enable); | |
1792 | if (buf) | |
7f24b31b | 1793 | ftrace_match_records(buf, len, enable); |
41c52c0d SR |
1794 | mutex_unlock(&ftrace_regex_lock); |
1795 | } | |
1796 | ||
77a2b37d SR |
1797 | /** |
1798 | * ftrace_set_filter - set a function to filter on in ftrace | |
1799 | * @buf - the string that holds the function filter text. | |
1800 | * @len - the length of the string. | |
1801 | * @reset - non zero to reset all filters before applying this filter. | |
1802 | * | |
1803 | * Filters denote which functions should be enabled when tracing is enabled. | |
1804 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
1805 | */ | |
e309b41d | 1806 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 1807 | { |
41c52c0d SR |
1808 | ftrace_set_regex(buf, len, reset, 1); |
1809 | } | |
4eebcc81 | 1810 | |
41c52c0d SR |
1811 | /** |
1812 | * ftrace_set_notrace - set a function to not trace in ftrace | |
1813 | * @buf - the string that holds the function notrace text. | |
1814 | * @len - the length of the string. | |
1815 | * @reset - non zero to reset all filters before applying this filter. | |
1816 | * | |
1817 | * Notrace Filters denote which functions should not be enabled when tracing | |
1818 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
1819 | * for tracing. | |
1820 | */ | |
1821 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
1822 | { | |
1823 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
1824 | } |
1825 | ||
e309b41d | 1826 | static int |
41c52c0d | 1827 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1828 | { |
1829 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1830 | struct ftrace_iterator *iter; | |
1831 | ||
41c52c0d | 1832 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1833 | if (file->f_mode & FMODE_READ) { |
1834 | iter = m->private; | |
1835 | ||
1836 | seq_release(inode, file); | |
1837 | } else | |
1838 | iter = file->private_data; | |
1839 | ||
1840 | if (iter->buffer_idx) { | |
1841 | iter->filtered++; | |
1842 | iter->buffer[iter->buffer_idx] = 0; | |
7f24b31b | 1843 | ftrace_match_records(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1844 | } |
1845 | ||
e6ea44e9 | 1846 | mutex_lock(&ftrace_lock); |
ee02a2e5 | 1847 | if (ftrace_start_up && ftrace_enabled) |
5072c59f | 1848 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
e6ea44e9 | 1849 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1850 | |
1851 | kfree(iter); | |
41c52c0d | 1852 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1853 | return 0; |
1854 | } | |
1855 | ||
41c52c0d SR |
1856 | static int |
1857 | ftrace_filter_release(struct inode *inode, struct file *file) | |
1858 | { | |
1859 | return ftrace_regex_release(inode, file, 1); | |
1860 | } | |
1861 | ||
1862 | static int | |
1863 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
1864 | { | |
1865 | return ftrace_regex_release(inode, file, 0); | |
1866 | } | |
1867 | ||
5e2336a0 | 1868 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
1869 | .open = ftrace_avail_open, |
1870 | .read = seq_read, | |
1871 | .llseek = seq_lseek, | |
1872 | .release = ftrace_avail_release, | |
1873 | }; | |
1874 | ||
5e2336a0 | 1875 | static const struct file_operations ftrace_failures_fops = { |
eb9a7bf0 AS |
1876 | .open = ftrace_failures_open, |
1877 | .read = seq_read, | |
1878 | .llseek = seq_lseek, | |
1879 | .release = ftrace_avail_release, | |
1880 | }; | |
1881 | ||
5e2336a0 | 1882 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 1883 | .open = ftrace_filter_open, |
850a80cf | 1884 | .read = seq_read, |
5072c59f | 1885 | .write = ftrace_filter_write, |
41c52c0d | 1886 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
1887 | .release = ftrace_filter_release, |
1888 | }; | |
1889 | ||
5e2336a0 | 1890 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 1891 | .open = ftrace_notrace_open, |
850a80cf | 1892 | .read = seq_read, |
41c52c0d SR |
1893 | .write = ftrace_notrace_write, |
1894 | .llseek = ftrace_regex_lseek, | |
1895 | .release = ftrace_notrace_release, | |
1896 | }; | |
1897 | ||
ea4e2bc4 SR |
1898 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
1899 | ||
1900 | static DEFINE_MUTEX(graph_lock); | |
1901 | ||
1902 | int ftrace_graph_count; | |
1903 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; | |
1904 | ||
1905 | static void * | |
1906 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
1907 | { | |
1908 | unsigned long *array = m->private; | |
1909 | int index = *pos; | |
1910 | ||
1911 | (*pos)++; | |
1912 | ||
1913 | if (index >= ftrace_graph_count) | |
1914 | return NULL; | |
1915 | ||
1916 | return &array[index]; | |
1917 | } | |
1918 | ||
1919 | static void *g_start(struct seq_file *m, loff_t *pos) | |
1920 | { | |
1921 | void *p = NULL; | |
1922 | ||
1923 | mutex_lock(&graph_lock); | |
1924 | ||
f9349a8f FW |
1925 | /* Nothing, tell g_show to print all functions are enabled */ |
1926 | if (!ftrace_graph_count && !*pos) | |
1927 | return (void *)1; | |
1928 | ||
ea4e2bc4 SR |
1929 | p = g_next(m, p, pos); |
1930 | ||
1931 | return p; | |
1932 | } | |
1933 | ||
1934 | static void g_stop(struct seq_file *m, void *p) | |
1935 | { | |
1936 | mutex_unlock(&graph_lock); | |
1937 | } | |
1938 | ||
1939 | static int g_show(struct seq_file *m, void *v) | |
1940 | { | |
1941 | unsigned long *ptr = v; | |
1942 | char str[KSYM_SYMBOL_LEN]; | |
1943 | ||
1944 | if (!ptr) | |
1945 | return 0; | |
1946 | ||
f9349a8f FW |
1947 | if (ptr == (unsigned long *)1) { |
1948 | seq_printf(m, "#### all functions enabled ####\n"); | |
1949 | return 0; | |
1950 | } | |
1951 | ||
ea4e2bc4 SR |
1952 | kallsyms_lookup(*ptr, NULL, NULL, NULL, str); |
1953 | ||
1954 | seq_printf(m, "%s\n", str); | |
1955 | ||
1956 | return 0; | |
1957 | } | |
1958 | ||
1959 | static struct seq_operations ftrace_graph_seq_ops = { | |
1960 | .start = g_start, | |
1961 | .next = g_next, | |
1962 | .stop = g_stop, | |
1963 | .show = g_show, | |
1964 | }; | |
1965 | ||
1966 | static int | |
1967 | ftrace_graph_open(struct inode *inode, struct file *file) | |
1968 | { | |
1969 | int ret = 0; | |
1970 | ||
1971 | if (unlikely(ftrace_disabled)) | |
1972 | return -ENODEV; | |
1973 | ||
1974 | mutex_lock(&graph_lock); | |
1975 | if ((file->f_mode & FMODE_WRITE) && | |
1976 | !(file->f_flags & O_APPEND)) { | |
1977 | ftrace_graph_count = 0; | |
1978 | memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); | |
1979 | } | |
1980 | ||
1981 | if (file->f_mode & FMODE_READ) { | |
1982 | ret = seq_open(file, &ftrace_graph_seq_ops); | |
1983 | if (!ret) { | |
1984 | struct seq_file *m = file->private_data; | |
1985 | m->private = ftrace_graph_funcs; | |
1986 | } | |
1987 | } else | |
1988 | file->private_data = ftrace_graph_funcs; | |
1989 | mutex_unlock(&graph_lock); | |
1990 | ||
1991 | return ret; | |
1992 | } | |
1993 | ||
ea4e2bc4 | 1994 | static int |
f9349a8f | 1995 | ftrace_set_func(unsigned long *array, int *idx, char *buffer) |
ea4e2bc4 | 1996 | { |
ea4e2bc4 SR |
1997 | struct dyn_ftrace *rec; |
1998 | struct ftrace_page *pg; | |
f9349a8f | 1999 | int search_len; |
ea4e2bc4 | 2000 | int found = 0; |
f9349a8f FW |
2001 | int type, not; |
2002 | char *search; | |
2003 | bool exists; | |
2004 | int i; | |
ea4e2bc4 SR |
2005 | |
2006 | if (ftrace_disabled) | |
2007 | return -ENODEV; | |
2008 | ||
f9349a8f FW |
2009 | /* decode regex */ |
2010 | type = ftrace_setup_glob(buffer, strlen(buffer), &search, ¬); | |
2011 | if (not) | |
2012 | return -EINVAL; | |
2013 | ||
2014 | search_len = strlen(search); | |
2015 | ||
52baf119 | 2016 | mutex_lock(&ftrace_lock); |
265c831c SR |
2017 | do_for_each_ftrace_rec(pg, rec) { |
2018 | ||
f9349a8f FW |
2019 | if (*idx >= FTRACE_GRAPH_MAX_FUNCS) |
2020 | break; | |
2021 | ||
265c831c SR |
2022 | if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE)) |
2023 | continue; | |
2024 | ||
f9349a8f FW |
2025 | if (ftrace_match_record(rec, search, search_len, type)) { |
2026 | /* ensure it is not already in the array */ | |
2027 | exists = false; | |
2028 | for (i = 0; i < *idx; i++) | |
2029 | if (array[i] == rec->ip) { | |
2030 | exists = true; | |
265c831c SR |
2031 | break; |
2032 | } | |
f9349a8f FW |
2033 | if (!exists) { |
2034 | array[(*idx)++] = rec->ip; | |
2035 | found = 1; | |
2036 | } | |
ea4e2bc4 | 2037 | } |
265c831c | 2038 | } while_for_each_ftrace_rec(); |
f9349a8f | 2039 | |
52baf119 | 2040 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 SR |
2041 | |
2042 | return found ? 0 : -EINVAL; | |
2043 | } | |
2044 | ||
2045 | static ssize_t | |
2046 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
2047 | size_t cnt, loff_t *ppos) | |
2048 | { | |
2049 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
2050 | unsigned long *array; | |
2051 | size_t read = 0; | |
2052 | ssize_t ret; | |
2053 | int index = 0; | |
2054 | char ch; | |
2055 | ||
2056 | if (!cnt || cnt < 0) | |
2057 | return 0; | |
2058 | ||
2059 | mutex_lock(&graph_lock); | |
2060 | ||
2061 | if (ftrace_graph_count >= FTRACE_GRAPH_MAX_FUNCS) { | |
2062 | ret = -EBUSY; | |
2063 | goto out; | |
2064 | } | |
2065 | ||
2066 | if (file->f_mode & FMODE_READ) { | |
2067 | struct seq_file *m = file->private_data; | |
2068 | array = m->private; | |
2069 | } else | |
2070 | array = file->private_data; | |
2071 | ||
2072 | ret = get_user(ch, ubuf++); | |
2073 | if (ret) | |
2074 | goto out; | |
2075 | read++; | |
2076 | cnt--; | |
2077 | ||
2078 | /* skip white space */ | |
2079 | while (cnt && isspace(ch)) { | |
2080 | ret = get_user(ch, ubuf++); | |
2081 | if (ret) | |
2082 | goto out; | |
2083 | read++; | |
2084 | cnt--; | |
2085 | } | |
2086 | ||
2087 | if (isspace(ch)) { | |
2088 | *ppos += read; | |
2089 | ret = read; | |
2090 | goto out; | |
2091 | } | |
2092 | ||
2093 | while (cnt && !isspace(ch)) { | |
2094 | if (index < FTRACE_BUFF_MAX) | |
2095 | buffer[index++] = ch; | |
2096 | else { | |
2097 | ret = -EINVAL; | |
2098 | goto out; | |
2099 | } | |
2100 | ret = get_user(ch, ubuf++); | |
2101 | if (ret) | |
2102 | goto out; | |
2103 | read++; | |
2104 | cnt--; | |
2105 | } | |
2106 | buffer[index] = 0; | |
2107 | ||
f9349a8f FW |
2108 | /* we allow only one expression at a time */ |
2109 | ret = ftrace_set_func(array, &ftrace_graph_count, buffer); | |
ea4e2bc4 SR |
2110 | if (ret) |
2111 | goto out; | |
2112 | ||
ea4e2bc4 SR |
2113 | file->f_pos += read; |
2114 | ||
2115 | ret = read; | |
2116 | out: | |
2117 | mutex_unlock(&graph_lock); | |
2118 | ||
2119 | return ret; | |
2120 | } | |
2121 | ||
2122 | static const struct file_operations ftrace_graph_fops = { | |
2123 | .open = ftrace_graph_open, | |
850a80cf | 2124 | .read = seq_read, |
ea4e2bc4 SR |
2125 | .write = ftrace_graph_write, |
2126 | }; | |
2127 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2128 | ||
df4fc315 | 2129 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 2130 | { |
5072c59f SR |
2131 | struct dentry *entry; |
2132 | ||
5072c59f SR |
2133 | entry = debugfs_create_file("available_filter_functions", 0444, |
2134 | d_tracer, NULL, &ftrace_avail_fops); | |
2135 | if (!entry) | |
2136 | pr_warning("Could not create debugfs " | |
2137 | "'available_filter_functions' entry\n"); | |
2138 | ||
eb9a7bf0 AS |
2139 | entry = debugfs_create_file("failures", 0444, |
2140 | d_tracer, NULL, &ftrace_failures_fops); | |
2141 | if (!entry) | |
2142 | pr_warning("Could not create debugfs 'failures' entry\n"); | |
2143 | ||
5072c59f SR |
2144 | entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer, |
2145 | NULL, &ftrace_filter_fops); | |
2146 | if (!entry) | |
2147 | pr_warning("Could not create debugfs " | |
2148 | "'set_ftrace_filter' entry\n"); | |
41c52c0d SR |
2149 | |
2150 | entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer, | |
2151 | NULL, &ftrace_notrace_fops); | |
2152 | if (!entry) | |
2153 | pr_warning("Could not create debugfs " | |
2154 | "'set_ftrace_notrace' entry\n"); | |
ad90c0e3 | 2155 | |
ea4e2bc4 SR |
2156 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
2157 | entry = debugfs_create_file("set_graph_function", 0444, d_tracer, | |
2158 | NULL, | |
2159 | &ftrace_graph_fops); | |
2160 | if (!entry) | |
2161 | pr_warning("Could not create debugfs " | |
2162 | "'set_graph_function' entry\n"); | |
2163 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2164 | ||
5072c59f SR |
2165 | return 0; |
2166 | } | |
2167 | ||
31e88909 SR |
2168 | static int ftrace_convert_nops(struct module *mod, |
2169 | unsigned long *start, | |
68bf21aa SR |
2170 | unsigned long *end) |
2171 | { | |
2172 | unsigned long *p; | |
2173 | unsigned long addr; | |
2174 | unsigned long flags; | |
2175 | ||
e6ea44e9 | 2176 | mutex_lock(&ftrace_lock); |
68bf21aa SR |
2177 | p = start; |
2178 | while (p < end) { | |
2179 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
2180 | /* |
2181 | * Some architecture linkers will pad between | |
2182 | * the different mcount_loc sections of different | |
2183 | * object files to satisfy alignments. | |
2184 | * Skip any NULL pointers. | |
2185 | */ | |
2186 | if (!addr) | |
2187 | continue; | |
68bf21aa | 2188 | ftrace_record_ip(addr); |
68bf21aa SR |
2189 | } |
2190 | ||
08f5ac90 | 2191 | /* disable interrupts to prevent kstop machine */ |
68bf21aa | 2192 | local_irq_save(flags); |
31e88909 | 2193 | ftrace_update_code(mod); |
68bf21aa | 2194 | local_irq_restore(flags); |
e6ea44e9 | 2195 | mutex_unlock(&ftrace_lock); |
68bf21aa SR |
2196 | |
2197 | return 0; | |
2198 | } | |
2199 | ||
31e88909 SR |
2200 | void ftrace_init_module(struct module *mod, |
2201 | unsigned long *start, unsigned long *end) | |
90d595fe | 2202 | { |
00fd61ae | 2203 | if (ftrace_disabled || start == end) |
fed1939c | 2204 | return; |
31e88909 | 2205 | ftrace_convert_nops(mod, start, end); |
90d595fe SR |
2206 | } |
2207 | ||
68bf21aa SR |
2208 | extern unsigned long __start_mcount_loc[]; |
2209 | extern unsigned long __stop_mcount_loc[]; | |
2210 | ||
2211 | void __init ftrace_init(void) | |
2212 | { | |
2213 | unsigned long count, addr, flags; | |
2214 | int ret; | |
2215 | ||
2216 | /* Keep the ftrace pointer to the stub */ | |
2217 | addr = (unsigned long)ftrace_stub; | |
2218 | ||
2219 | local_irq_save(flags); | |
2220 | ftrace_dyn_arch_init(&addr); | |
2221 | local_irq_restore(flags); | |
2222 | ||
2223 | /* ftrace_dyn_arch_init places the return code in addr */ | |
2224 | if (addr) | |
2225 | goto failed; | |
2226 | ||
2227 | count = __stop_mcount_loc - __start_mcount_loc; | |
2228 | ||
2229 | ret = ftrace_dyn_table_alloc(count); | |
2230 | if (ret) | |
2231 | goto failed; | |
2232 | ||
2233 | last_ftrace_enabled = ftrace_enabled = 1; | |
2234 | ||
31e88909 SR |
2235 | ret = ftrace_convert_nops(NULL, |
2236 | __start_mcount_loc, | |
68bf21aa SR |
2237 | __stop_mcount_loc); |
2238 | ||
2239 | return; | |
2240 | failed: | |
2241 | ftrace_disabled = 1; | |
2242 | } | |
68bf21aa | 2243 | |
3d083395 | 2244 | #else |
0b6e4d56 FW |
2245 | |
2246 | static int __init ftrace_nodyn_init(void) | |
2247 | { | |
2248 | ftrace_enabled = 1; | |
2249 | return 0; | |
2250 | } | |
2251 | device_initcall(ftrace_nodyn_init); | |
2252 | ||
df4fc315 SR |
2253 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
2254 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 SR |
2255 | /* Keep as macros so we do not need to define the commands */ |
2256 | # define ftrace_startup(command) do { } while (0) | |
2257 | # define ftrace_shutdown(command) do { } while (0) | |
c7aafc54 IM |
2258 | # define ftrace_startup_sysctl() do { } while (0) |
2259 | # define ftrace_shutdown_sysctl() do { } while (0) | |
3d083395 SR |
2260 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
2261 | ||
df4fc315 SR |
2262 | static ssize_t |
2263 | ftrace_pid_read(struct file *file, char __user *ubuf, | |
2264 | size_t cnt, loff_t *ppos) | |
2265 | { | |
2266 | char buf[64]; | |
2267 | int r; | |
2268 | ||
e32d8956 SR |
2269 | if (ftrace_pid_trace == ftrace_swapper_pid) |
2270 | r = sprintf(buf, "swapper tasks\n"); | |
2271 | else if (ftrace_pid_trace) | |
cc59c9e8 | 2272 | r = sprintf(buf, "%u\n", pid_vnr(ftrace_pid_trace)); |
df4fc315 SR |
2273 | else |
2274 | r = sprintf(buf, "no pid\n"); | |
2275 | ||
2276 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
2277 | } | |
2278 | ||
e32d8956 | 2279 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
2280 | { |
2281 | struct task_struct *p; | |
e32d8956 | 2282 | int cpu; |
978f3a45 | 2283 | |
e32d8956 SR |
2284 | get_online_cpus(); |
2285 | for_each_online_cpu(cpu) { | |
2286 | p = idle_task(cpu); | |
978f3a45 | 2287 | clear_tsk_trace_trace(p); |
e32d8956 SR |
2288 | } |
2289 | put_online_cpus(); | |
2290 | } | |
978f3a45 | 2291 | |
e32d8956 SR |
2292 | static void set_ftrace_swapper(void) |
2293 | { | |
2294 | struct task_struct *p; | |
2295 | int cpu; | |
2296 | ||
2297 | get_online_cpus(); | |
2298 | for_each_online_cpu(cpu) { | |
2299 | p = idle_task(cpu); | |
2300 | set_tsk_trace_trace(p); | |
2301 | } | |
2302 | put_online_cpus(); | |
978f3a45 SR |
2303 | } |
2304 | ||
e32d8956 SR |
2305 | static void clear_ftrace_pid(struct pid *pid) |
2306 | { | |
2307 | struct task_struct *p; | |
2308 | ||
229c4ef8 | 2309 | rcu_read_lock(); |
e32d8956 SR |
2310 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2311 | clear_tsk_trace_trace(p); | |
2312 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
2313 | rcu_read_unlock(); |
2314 | ||
e32d8956 SR |
2315 | put_pid(pid); |
2316 | } | |
2317 | ||
2318 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
2319 | { |
2320 | struct task_struct *p; | |
2321 | ||
229c4ef8 | 2322 | rcu_read_lock(); |
978f3a45 SR |
2323 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2324 | set_tsk_trace_trace(p); | |
2325 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 2326 | rcu_read_unlock(); |
978f3a45 SR |
2327 | } |
2328 | ||
e32d8956 SR |
2329 | static void clear_ftrace_pid_task(struct pid **pid) |
2330 | { | |
2331 | if (*pid == ftrace_swapper_pid) | |
2332 | clear_ftrace_swapper(); | |
2333 | else | |
2334 | clear_ftrace_pid(*pid); | |
2335 | ||
2336 | *pid = NULL; | |
2337 | } | |
2338 | ||
2339 | static void set_ftrace_pid_task(struct pid *pid) | |
2340 | { | |
2341 | if (pid == ftrace_swapper_pid) | |
2342 | set_ftrace_swapper(); | |
2343 | else | |
2344 | set_ftrace_pid(pid); | |
2345 | } | |
2346 | ||
df4fc315 SR |
2347 | static ssize_t |
2348 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
2349 | size_t cnt, loff_t *ppos) | |
2350 | { | |
978f3a45 | 2351 | struct pid *pid; |
df4fc315 SR |
2352 | char buf[64]; |
2353 | long val; | |
2354 | int ret; | |
2355 | ||
2356 | if (cnt >= sizeof(buf)) | |
2357 | return -EINVAL; | |
2358 | ||
2359 | if (copy_from_user(&buf, ubuf, cnt)) | |
2360 | return -EFAULT; | |
2361 | ||
2362 | buf[cnt] = 0; | |
2363 | ||
2364 | ret = strict_strtol(buf, 10, &val); | |
2365 | if (ret < 0) | |
2366 | return ret; | |
2367 | ||
e6ea44e9 | 2368 | mutex_lock(&ftrace_lock); |
978f3a45 | 2369 | if (val < 0) { |
df4fc315 | 2370 | /* disable pid tracing */ |
978f3a45 | 2371 | if (!ftrace_pid_trace) |
df4fc315 | 2372 | goto out; |
978f3a45 SR |
2373 | |
2374 | clear_ftrace_pid_task(&ftrace_pid_trace); | |
df4fc315 SR |
2375 | |
2376 | } else { | |
e32d8956 SR |
2377 | /* swapper task is special */ |
2378 | if (!val) { | |
2379 | pid = ftrace_swapper_pid; | |
2380 | if (pid == ftrace_pid_trace) | |
2381 | goto out; | |
2382 | } else { | |
2383 | pid = find_get_pid(val); | |
df4fc315 | 2384 | |
e32d8956 SR |
2385 | if (pid == ftrace_pid_trace) { |
2386 | put_pid(pid); | |
2387 | goto out; | |
2388 | } | |
0ef8cde5 | 2389 | } |
0ef8cde5 | 2390 | |
978f3a45 SR |
2391 | if (ftrace_pid_trace) |
2392 | clear_ftrace_pid_task(&ftrace_pid_trace); | |
2393 | ||
2394 | if (!pid) | |
2395 | goto out; | |
2396 | ||
2397 | ftrace_pid_trace = pid; | |
2398 | ||
2399 | set_ftrace_pid_task(ftrace_pid_trace); | |
df4fc315 SR |
2400 | } |
2401 | ||
2402 | /* update the function call */ | |
2403 | ftrace_update_pid_func(); | |
2404 | ftrace_startup_enable(0); | |
2405 | ||
2406 | out: | |
e6ea44e9 | 2407 | mutex_unlock(&ftrace_lock); |
df4fc315 SR |
2408 | |
2409 | return cnt; | |
2410 | } | |
2411 | ||
5e2336a0 | 2412 | static const struct file_operations ftrace_pid_fops = { |
df4fc315 SR |
2413 | .read = ftrace_pid_read, |
2414 | .write = ftrace_pid_write, | |
2415 | }; | |
2416 | ||
2417 | static __init int ftrace_init_debugfs(void) | |
2418 | { | |
2419 | struct dentry *d_tracer; | |
2420 | struct dentry *entry; | |
2421 | ||
2422 | d_tracer = tracing_init_dentry(); | |
2423 | if (!d_tracer) | |
2424 | return 0; | |
2425 | ||
2426 | ftrace_init_dyn_debugfs(d_tracer); | |
2427 | ||
2428 | entry = debugfs_create_file("set_ftrace_pid", 0644, d_tracer, | |
2429 | NULL, &ftrace_pid_fops); | |
2430 | if (!entry) | |
2431 | pr_warning("Could not create debugfs " | |
2432 | "'set_ftrace_pid' entry\n"); | |
2433 | return 0; | |
2434 | } | |
df4fc315 SR |
2435 | fs_initcall(ftrace_init_debugfs); |
2436 | ||
a2bb6a3d | 2437 | /** |
81adbdc0 | 2438 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
2439 | * |
2440 | * This function should be used by panic code. It stops ftrace | |
2441 | * but in a not so nice way. If you need to simply kill ftrace | |
2442 | * from a non-atomic section, use ftrace_kill. | |
2443 | */ | |
81adbdc0 | 2444 | void ftrace_kill(void) |
a2bb6a3d SR |
2445 | { |
2446 | ftrace_disabled = 1; | |
2447 | ftrace_enabled = 0; | |
a2bb6a3d SR |
2448 | clear_ftrace_function(); |
2449 | } | |
2450 | ||
16444a8a | 2451 | /** |
3d083395 SR |
2452 | * register_ftrace_function - register a function for profiling |
2453 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 2454 | * |
3d083395 SR |
2455 | * Register a function to be called by all functions in the |
2456 | * kernel. | |
2457 | * | |
2458 | * Note: @ops->func and all the functions it calls must be labeled | |
2459 | * with "notrace", otherwise it will go into a | |
2460 | * recursive loop. | |
16444a8a | 2461 | */ |
3d083395 | 2462 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 2463 | { |
b0fc494f SR |
2464 | int ret; |
2465 | ||
4eebcc81 SR |
2466 | if (unlikely(ftrace_disabled)) |
2467 | return -1; | |
2468 | ||
e6ea44e9 | 2469 | mutex_lock(&ftrace_lock); |
e7d3737e | 2470 | |
b0fc494f | 2471 | ret = __register_ftrace_function(ops); |
5a45cfe1 | 2472 | ftrace_startup(0); |
b0fc494f | 2473 | |
e6ea44e9 | 2474 | mutex_unlock(&ftrace_lock); |
b0fc494f | 2475 | return ret; |
3d083395 SR |
2476 | } |
2477 | ||
2478 | /** | |
32632920 | 2479 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
2480 | * @ops - ops structure that holds the function to unregister |
2481 | * | |
2482 | * Unregister a function that was added to be called by ftrace profiling. | |
2483 | */ | |
2484 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
2485 | { | |
2486 | int ret; | |
2487 | ||
e6ea44e9 | 2488 | mutex_lock(&ftrace_lock); |
3d083395 | 2489 | ret = __unregister_ftrace_function(ops); |
5a45cfe1 | 2490 | ftrace_shutdown(0); |
e6ea44e9 | 2491 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
2492 | |
2493 | return ret; | |
2494 | } | |
2495 | ||
e309b41d | 2496 | int |
b0fc494f | 2497 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
5072c59f | 2498 | struct file *file, void __user *buffer, size_t *lenp, |
b0fc494f SR |
2499 | loff_t *ppos) |
2500 | { | |
2501 | int ret; | |
2502 | ||
4eebcc81 SR |
2503 | if (unlikely(ftrace_disabled)) |
2504 | return -ENODEV; | |
2505 | ||
e6ea44e9 | 2506 | mutex_lock(&ftrace_lock); |
b0fc494f | 2507 | |
5072c59f | 2508 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
b0fc494f SR |
2509 | |
2510 | if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) | |
2511 | goto out; | |
2512 | ||
2513 | last_ftrace_enabled = ftrace_enabled; | |
2514 | ||
2515 | if (ftrace_enabled) { | |
2516 | ||
2517 | ftrace_startup_sysctl(); | |
2518 | ||
2519 | /* we are starting ftrace again */ | |
2520 | if (ftrace_list != &ftrace_list_end) { | |
2521 | if (ftrace_list->next == &ftrace_list_end) | |
2522 | ftrace_trace_function = ftrace_list->func; | |
2523 | else | |
2524 | ftrace_trace_function = ftrace_list_func; | |
2525 | } | |
2526 | ||
2527 | } else { | |
2528 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
2529 | ftrace_trace_function = ftrace_stub; | |
2530 | ||
2531 | ftrace_shutdown_sysctl(); | |
2532 | } | |
2533 | ||
2534 | out: | |
e6ea44e9 | 2535 | mutex_unlock(&ftrace_lock); |
3d083395 | 2536 | return ret; |
16444a8a | 2537 | } |
f17845e5 | 2538 | |
fb52607a | 2539 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 2540 | |
287b6e68 | 2541 | static atomic_t ftrace_graph_active; |
4a2b8dda | 2542 | static struct notifier_block ftrace_suspend_notifier; |
e7d3737e | 2543 | |
e49dc19c SR |
2544 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
2545 | { | |
2546 | return 0; | |
2547 | } | |
2548 | ||
287b6e68 FW |
2549 | /* The callbacks that hook a function */ |
2550 | trace_func_graph_ret_t ftrace_graph_return = | |
2551 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 2552 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
2553 | |
2554 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
2555 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
2556 | { | |
2557 | int i; | |
2558 | int ret = 0; | |
2559 | unsigned long flags; | |
2560 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
2561 | struct task_struct *g, *t; | |
2562 | ||
2563 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
2564 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
2565 | * sizeof(struct ftrace_ret_stack), | |
2566 | GFP_KERNEL); | |
2567 | if (!ret_stack_list[i]) { | |
2568 | start = 0; | |
2569 | end = i; | |
2570 | ret = -ENOMEM; | |
2571 | goto free; | |
2572 | } | |
2573 | } | |
2574 | ||
2575 | read_lock_irqsave(&tasklist_lock, flags); | |
2576 | do_each_thread(g, t) { | |
2577 | if (start == end) { | |
2578 | ret = -EAGAIN; | |
2579 | goto unlock; | |
2580 | } | |
2581 | ||
2582 | if (t->ret_stack == NULL) { | |
f201ae23 | 2583 | t->curr_ret_stack = -1; |
48d68b20 FW |
2584 | /* Make sure IRQs see the -1 first: */ |
2585 | barrier(); | |
2586 | t->ret_stack = ret_stack_list[start++]; | |
380c4b14 | 2587 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 FW |
2588 | atomic_set(&t->trace_overrun, 0); |
2589 | } | |
2590 | } while_each_thread(g, t); | |
2591 | ||
2592 | unlock: | |
2593 | read_unlock_irqrestore(&tasklist_lock, flags); | |
2594 | free: | |
2595 | for (i = start; i < end; i++) | |
2596 | kfree(ret_stack_list[i]); | |
2597 | return ret; | |
2598 | } | |
2599 | ||
8aef2d28 SR |
2600 | static void |
2601 | ftrace_graph_probe_sched_switch(struct rq *__rq, struct task_struct *prev, | |
2602 | struct task_struct *next) | |
2603 | { | |
2604 | unsigned long long timestamp; | |
2605 | int index; | |
2606 | ||
be6f164a SR |
2607 | /* |
2608 | * Does the user want to count the time a function was asleep. | |
2609 | * If so, do not update the time stamps. | |
2610 | */ | |
2611 | if (trace_flags & TRACE_ITER_SLEEP_TIME) | |
2612 | return; | |
2613 | ||
8aef2d28 SR |
2614 | timestamp = trace_clock_local(); |
2615 | ||
2616 | prev->ftrace_timestamp = timestamp; | |
2617 | ||
2618 | /* only process tasks that we timestamped */ | |
2619 | if (!next->ftrace_timestamp) | |
2620 | return; | |
2621 | ||
2622 | /* | |
2623 | * Update all the counters in next to make up for the | |
2624 | * time next was sleeping. | |
2625 | */ | |
2626 | timestamp -= next->ftrace_timestamp; | |
2627 | ||
2628 | for (index = next->curr_ret_stack; index >= 0; index--) | |
2629 | next->ret_stack[index].calltime += timestamp; | |
2630 | } | |
2631 | ||
f201ae23 | 2632 | /* Allocate a return stack for each task */ |
fb52607a | 2633 | static int start_graph_tracing(void) |
f201ae23 FW |
2634 | { |
2635 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 2636 | int ret, cpu; |
f201ae23 FW |
2637 | |
2638 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
2639 | sizeof(struct ftrace_ret_stack *), | |
2640 | GFP_KERNEL); | |
2641 | ||
2642 | if (!ret_stack_list) | |
2643 | return -ENOMEM; | |
2644 | ||
5b058bcd FW |
2645 | /* The cpu_boot init_task->ret_stack will never be freed */ |
2646 | for_each_online_cpu(cpu) | |
2647 | ftrace_graph_init_task(idle_task(cpu)); | |
2648 | ||
f201ae23 FW |
2649 | do { |
2650 | ret = alloc_retstack_tasklist(ret_stack_list); | |
2651 | } while (ret == -EAGAIN); | |
2652 | ||
8aef2d28 SR |
2653 | if (!ret) { |
2654 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch); | |
2655 | if (ret) | |
2656 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
2657 | " probe to kernel_sched_switch\n"); | |
2658 | } | |
2659 | ||
f201ae23 FW |
2660 | kfree(ret_stack_list); |
2661 | return ret; | |
2662 | } | |
2663 | ||
4a2b8dda FW |
2664 | /* |
2665 | * Hibernation protection. | |
2666 | * The state of the current task is too much unstable during | |
2667 | * suspend/restore to disk. We want to protect against that. | |
2668 | */ | |
2669 | static int | |
2670 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
2671 | void *unused) | |
2672 | { | |
2673 | switch (state) { | |
2674 | case PM_HIBERNATION_PREPARE: | |
2675 | pause_graph_tracing(); | |
2676 | break; | |
2677 | ||
2678 | case PM_POST_HIBERNATION: | |
2679 | unpause_graph_tracing(); | |
2680 | break; | |
2681 | } | |
2682 | return NOTIFY_DONE; | |
2683 | } | |
2684 | ||
287b6e68 FW |
2685 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
2686 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 2687 | { |
e7d3737e FW |
2688 | int ret = 0; |
2689 | ||
e6ea44e9 | 2690 | mutex_lock(&ftrace_lock); |
e7d3737e | 2691 | |
05ce5818 SR |
2692 | /* we currently allow only one tracer registered at a time */ |
2693 | if (atomic_read(&ftrace_graph_active)) { | |
2694 | ret = -EBUSY; | |
2695 | goto out; | |
2696 | } | |
2697 | ||
4a2b8dda FW |
2698 | ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; |
2699 | register_pm_notifier(&ftrace_suspend_notifier); | |
2700 | ||
287b6e68 | 2701 | atomic_inc(&ftrace_graph_active); |
fb52607a | 2702 | ret = start_graph_tracing(); |
f201ae23 | 2703 | if (ret) { |
287b6e68 | 2704 | atomic_dec(&ftrace_graph_active); |
f201ae23 FW |
2705 | goto out; |
2706 | } | |
e53a6319 | 2707 | |
287b6e68 FW |
2708 | ftrace_graph_return = retfunc; |
2709 | ftrace_graph_entry = entryfunc; | |
e53a6319 | 2710 | |
5a45cfe1 | 2711 | ftrace_startup(FTRACE_START_FUNC_RET); |
e7d3737e FW |
2712 | |
2713 | out: | |
e6ea44e9 | 2714 | mutex_unlock(&ftrace_lock); |
e7d3737e | 2715 | return ret; |
15e6cb36 FW |
2716 | } |
2717 | ||
fb52607a | 2718 | void unregister_ftrace_graph(void) |
15e6cb36 | 2719 | { |
e6ea44e9 | 2720 | mutex_lock(&ftrace_lock); |
e7d3737e | 2721 | |
2aad1b76 SR |
2722 | if (!unlikely(atomic_read(&ftrace_graph_active))) |
2723 | goto out; | |
2724 | ||
287b6e68 | 2725 | atomic_dec(&ftrace_graph_active); |
8aef2d28 | 2726 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch); |
287b6e68 | 2727 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 2728 | ftrace_graph_entry = ftrace_graph_entry_stub; |
5a45cfe1 | 2729 | ftrace_shutdown(FTRACE_STOP_FUNC_RET); |
4a2b8dda | 2730 | unregister_pm_notifier(&ftrace_suspend_notifier); |
e7d3737e | 2731 | |
2aad1b76 | 2732 | out: |
e6ea44e9 | 2733 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 2734 | } |
f201ae23 FW |
2735 | |
2736 | /* Allocate a return stack for newly created task */ | |
fb52607a | 2737 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 2738 | { |
287b6e68 | 2739 | if (atomic_read(&ftrace_graph_active)) { |
f201ae23 FW |
2740 | t->ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH |
2741 | * sizeof(struct ftrace_ret_stack), | |
2742 | GFP_KERNEL); | |
2743 | if (!t->ret_stack) | |
2744 | return; | |
2745 | t->curr_ret_stack = -1; | |
380c4b14 | 2746 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 2747 | atomic_set(&t->trace_overrun, 0); |
8aef2d28 | 2748 | t->ftrace_timestamp = 0; |
f201ae23 FW |
2749 | } else |
2750 | t->ret_stack = NULL; | |
2751 | } | |
2752 | ||
fb52607a | 2753 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 2754 | { |
eae849ca FW |
2755 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
2756 | ||
f201ae23 | 2757 | t->ret_stack = NULL; |
eae849ca FW |
2758 | /* NULL must become visible to IRQs before we free it: */ |
2759 | barrier(); | |
2760 | ||
2761 | kfree(ret_stack); | |
f201ae23 | 2762 | } |
14a866c5 SR |
2763 | |
2764 | void ftrace_graph_stop(void) | |
2765 | { | |
2766 | ftrace_stop(); | |
2767 | } | |
15e6cb36 FW |
2768 | #endif |
2769 |