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Commit | Line | Data |
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16444a8a ACM |
1 | /* |
2 | * Infrastructure for profiling code inserted by 'gcc -pg'. | |
3 | * | |
4 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> | |
5 | * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com> | |
6 | * | |
7 | * Originally ported from the -rt patch by: | |
8 | * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com> | |
9 | * | |
10 | * Based on code in the latency_tracer, that is: | |
11 | * | |
12 | * Copyright (C) 2004-2006 Ingo Molnar | |
13 | * Copyright (C) 2004 William Lee Irwin III | |
14 | */ | |
15 | ||
3d083395 SR |
16 | #include <linux/stop_machine.h> |
17 | #include <linux/clocksource.h> | |
18 | #include <linux/kallsyms.h> | |
5072c59f SR |
19 | #include <linux/seq_file.h> |
20 | #include <linux/debugfs.h> | |
3d083395 | 21 | #include <linux/hardirq.h> |
2d8b820b | 22 | #include <linux/kthread.h> |
5072c59f | 23 | #include <linux/uaccess.h> |
f22f9a89 | 24 | #include <linux/kprobes.h> |
2d8b820b | 25 | #include <linux/ftrace.h> |
b0fc494f | 26 | #include <linux/sysctl.h> |
5072c59f | 27 | #include <linux/ctype.h> |
3d083395 SR |
28 | #include <linux/list.h> |
29 | ||
395a59d0 AS |
30 | #include <asm/ftrace.h> |
31 | ||
3d083395 | 32 | #include "trace.h" |
16444a8a | 33 | |
6912896e SR |
34 | #define FTRACE_WARN_ON(cond) \ |
35 | do { \ | |
36 | if (WARN_ON(cond)) \ | |
37 | ftrace_kill(); \ | |
38 | } while (0) | |
39 | ||
40 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
41 | do { \ | |
42 | if (WARN_ON_ONCE(cond)) \ | |
43 | ftrace_kill(); \ | |
44 | } while (0) | |
45 | ||
4eebcc81 SR |
46 | /* ftrace_enabled is a method to turn ftrace on or off */ |
47 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 48 | static int last_ftrace_enabled; |
b0fc494f | 49 | |
df4fc315 SR |
50 | /* ftrace_pid_trace >= 0 will only trace threads with this pid */ |
51 | static int ftrace_pid_trace = -1; | |
52 | ||
60a7ecf4 SR |
53 | /* Quick disabling of function tracer. */ |
54 | int function_trace_stop; | |
55 | ||
e7d3737e FW |
56 | /* By default, current tracing type is normal tracing. */ |
57 | enum ftrace_tracing_type_t ftrace_tracing_type = FTRACE_TYPE_ENTER; | |
58 | ||
4eebcc81 SR |
59 | /* |
60 | * ftrace_disabled is set when an anomaly is discovered. | |
61 | * ftrace_disabled is much stronger than ftrace_enabled. | |
62 | */ | |
63 | static int ftrace_disabled __read_mostly; | |
64 | ||
3d083395 | 65 | static DEFINE_SPINLOCK(ftrace_lock); |
b0fc494f | 66 | static DEFINE_MUTEX(ftrace_sysctl_lock); |
df4fc315 | 67 | static DEFINE_MUTEX(ftrace_start_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 | { | |
96 | if (current->pid != ftrace_pid_trace) | |
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 | { |
99ecdc43 | 138 | /* should not be called from interrupt context */ |
3d083395 | 139 | spin_lock(&ftrace_lock); |
16444a8a | 140 | |
16444a8a ACM |
141 | ops->next = ftrace_list; |
142 | /* | |
143 | * We are entering ops into the ftrace_list but another | |
144 | * CPU might be walking that list. We need to make sure | |
145 | * the ops->next pointer is valid before another CPU sees | |
146 | * the ops pointer included into the ftrace_list. | |
147 | */ | |
148 | smp_wmb(); | |
149 | ftrace_list = ops; | |
3d083395 | 150 | |
b0fc494f | 151 | if (ftrace_enabled) { |
df4fc315 SR |
152 | ftrace_func_t func; |
153 | ||
154 | if (ops->next == &ftrace_list_end) | |
155 | func = ops->func; | |
156 | else | |
157 | func = ftrace_list_func; | |
158 | ||
159 | if (ftrace_pid_trace >= 0) { | |
160 | set_ftrace_pid_function(func); | |
161 | func = ftrace_pid_func; | |
162 | } | |
163 | ||
b0fc494f SR |
164 | /* |
165 | * For one func, simply call it directly. | |
166 | * For more than one func, call the chain. | |
167 | */ | |
60a7ecf4 | 168 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
df4fc315 | 169 | ftrace_trace_function = func; |
60a7ecf4 | 170 | #else |
df4fc315 | 171 | __ftrace_trace_function = func; |
60a7ecf4 SR |
172 | ftrace_trace_function = ftrace_test_stop_func; |
173 | #endif | |
b0fc494f | 174 | } |
3d083395 SR |
175 | |
176 | spin_unlock(&ftrace_lock); | |
16444a8a ACM |
177 | |
178 | return 0; | |
179 | } | |
180 | ||
e309b41d | 181 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 182 | { |
16444a8a ACM |
183 | struct ftrace_ops **p; |
184 | int ret = 0; | |
185 | ||
99ecdc43 | 186 | /* should not be called from interrupt context */ |
3d083395 | 187 | spin_lock(&ftrace_lock); |
16444a8a ACM |
188 | |
189 | /* | |
3d083395 SR |
190 | * If we are removing the last function, then simply point |
191 | * to the ftrace_stub. | |
16444a8a ACM |
192 | */ |
193 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { | |
194 | ftrace_trace_function = ftrace_stub; | |
195 | ftrace_list = &ftrace_list_end; | |
196 | goto out; | |
197 | } | |
198 | ||
199 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) | |
200 | if (*p == ops) | |
201 | break; | |
202 | ||
203 | if (*p != ops) { | |
204 | ret = -1; | |
205 | goto out; | |
206 | } | |
207 | ||
208 | *p = (*p)->next; | |
209 | ||
b0fc494f SR |
210 | if (ftrace_enabled) { |
211 | /* If we only have one func left, then call that directly */ | |
df4fc315 SR |
212 | if (ftrace_list->next == &ftrace_list_end) { |
213 | ftrace_func_t func = ftrace_list->func; | |
214 | ||
215 | if (ftrace_pid_trace >= 0) { | |
216 | set_ftrace_pid_function(func); | |
217 | func = ftrace_pid_func; | |
218 | } | |
219 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
220 | ftrace_trace_function = func; | |
221 | #else | |
222 | __ftrace_trace_function = func; | |
223 | #endif | |
224 | } | |
b0fc494f | 225 | } |
16444a8a ACM |
226 | |
227 | out: | |
3d083395 SR |
228 | spin_unlock(&ftrace_lock); |
229 | ||
230 | return ret; | |
231 | } | |
232 | ||
df4fc315 SR |
233 | static void ftrace_update_pid_func(void) |
234 | { | |
235 | ftrace_func_t func; | |
236 | ||
237 | /* should not be called from interrupt context */ | |
238 | spin_lock(&ftrace_lock); | |
239 | ||
240 | if (ftrace_trace_function == ftrace_stub) | |
241 | goto out; | |
242 | ||
243 | func = ftrace_trace_function; | |
244 | ||
245 | if (ftrace_pid_trace >= 0) { | |
246 | set_ftrace_pid_function(func); | |
247 | func = ftrace_pid_func; | |
248 | } else { | |
249 | if (func != ftrace_pid_func) | |
250 | goto out; | |
251 | ||
252 | set_ftrace_pid_function(func); | |
253 | } | |
254 | ||
255 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
256 | ftrace_trace_function = func; | |
257 | #else | |
258 | __ftrace_trace_function = func; | |
259 | #endif | |
260 | ||
261 | out: | |
262 | spin_unlock(&ftrace_lock); | |
263 | } | |
264 | ||
3d083395 | 265 | #ifdef CONFIG_DYNAMIC_FTRACE |
99ecdc43 | 266 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
cb7be3b2 | 267 | # error Dynamic ftrace depends on MCOUNT_RECORD |
99ecdc43 SR |
268 | #endif |
269 | ||
71c67d58 SN |
270 | /* |
271 | * Since MCOUNT_ADDR may point to mcount itself, we do not want | |
272 | * to get it confused by reading a reference in the code as we | |
273 | * are parsing on objcopy output of text. Use a variable for | |
274 | * it instead. | |
275 | */ | |
276 | static unsigned long mcount_addr = MCOUNT_ADDR; | |
277 | ||
d61f82d0 SR |
278 | enum { |
279 | FTRACE_ENABLE_CALLS = (1 << 0), | |
280 | FTRACE_DISABLE_CALLS = (1 << 1), | |
281 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
282 | FTRACE_ENABLE_MCOUNT = (1 << 3), | |
283 | FTRACE_DISABLE_MCOUNT = (1 << 4), | |
5a45cfe1 SR |
284 | FTRACE_START_FUNC_RET = (1 << 5), |
285 | FTRACE_STOP_FUNC_RET = (1 << 6), | |
d61f82d0 SR |
286 | }; |
287 | ||
5072c59f SR |
288 | static int ftrace_filtered; |
289 | ||
08f5ac90 | 290 | static LIST_HEAD(ftrace_new_addrs); |
3d083395 | 291 | |
41c52c0d | 292 | static DEFINE_MUTEX(ftrace_regex_lock); |
3d083395 | 293 | |
3c1720f0 SR |
294 | struct ftrace_page { |
295 | struct ftrace_page *next; | |
aa5e5cea | 296 | unsigned long index; |
3c1720f0 | 297 | struct dyn_ftrace records[]; |
aa5e5cea | 298 | }; |
3c1720f0 SR |
299 | |
300 | #define ENTRIES_PER_PAGE \ | |
301 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
302 | ||
303 | /* estimate from running different kernels */ | |
304 | #define NR_TO_INIT 10000 | |
305 | ||
306 | static struct ftrace_page *ftrace_pages_start; | |
307 | static struct ftrace_page *ftrace_pages; | |
308 | ||
37ad5084 SR |
309 | static struct dyn_ftrace *ftrace_free_records; |
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 | { |
37ad5084 SR |
344 | rec->ip = (unsigned long)ftrace_free_records; |
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; | |
355 | int i; | |
356 | ||
00fd61ae | 357 | if (ftrace_disabled || !start) |
fed1939c SR |
358 | return; |
359 | ||
99ecdc43 | 360 | /* should not be called from interrupt context */ |
fed1939c SR |
361 | spin_lock(&ftrace_lock); |
362 | ||
363 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
364 | for (i = 0; i < pg->index; i++) { | |
365 | rec = &pg->records[i]; | |
366 | ||
367 | if ((rec->ip >= s) && (rec->ip < e)) | |
368 | ftrace_free_rec(rec); | |
369 | } | |
370 | } | |
371 | spin_unlock(&ftrace_lock); | |
fed1939c SR |
372 | } |
373 | ||
e309b41d | 374 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 375 | { |
37ad5084 SR |
376 | struct dyn_ftrace *rec; |
377 | ||
378 | /* First check for freed records */ | |
379 | if (ftrace_free_records) { | |
380 | rec = ftrace_free_records; | |
381 | ||
37ad5084 | 382 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
6912896e | 383 | FTRACE_WARN_ON_ONCE(1); |
37ad5084 SR |
384 | ftrace_free_records = NULL; |
385 | return NULL; | |
386 | } | |
387 | ||
388 | ftrace_free_records = (void *)rec->ip; | |
389 | memset(rec, 0, sizeof(*rec)); | |
390 | return rec; | |
391 | } | |
392 | ||
3c1720f0 | 393 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
08f5ac90 SR |
394 | if (!ftrace_pages->next) { |
395 | /* allocate another page */ | |
396 | ftrace_pages->next = | |
397 | (void *)get_zeroed_page(GFP_KERNEL); | |
398 | if (!ftrace_pages->next) | |
399 | return NULL; | |
400 | } | |
3c1720f0 SR |
401 | ftrace_pages = ftrace_pages->next; |
402 | } | |
403 | ||
404 | return &ftrace_pages->records[ftrace_pages->index++]; | |
405 | } | |
406 | ||
08f5ac90 | 407 | static struct dyn_ftrace * |
d61f82d0 | 408 | ftrace_record_ip(unsigned long ip) |
3d083395 | 409 | { |
08f5ac90 | 410 | struct dyn_ftrace *rec; |
3d083395 | 411 | |
f3c7ac40 | 412 | if (ftrace_disabled) |
08f5ac90 | 413 | return NULL; |
3d083395 | 414 | |
08f5ac90 SR |
415 | rec = ftrace_alloc_dyn_node(ip); |
416 | if (!rec) | |
417 | return NULL; | |
3d083395 | 418 | |
08f5ac90 | 419 | rec->ip = ip; |
3d083395 | 420 | |
08f5ac90 | 421 | list_add(&rec->list, &ftrace_new_addrs); |
3d083395 | 422 | |
08f5ac90 | 423 | return rec; |
3d083395 SR |
424 | } |
425 | ||
b17e8a37 SR |
426 | static void print_ip_ins(const char *fmt, unsigned char *p) |
427 | { | |
428 | int i; | |
429 | ||
430 | printk(KERN_CONT "%s", fmt); | |
431 | ||
432 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
433 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
434 | } | |
435 | ||
31e88909 | 436 | static void ftrace_bug(int failed, unsigned long ip) |
b17e8a37 SR |
437 | { |
438 | switch (failed) { | |
439 | case -EFAULT: | |
440 | FTRACE_WARN_ON_ONCE(1); | |
441 | pr_info("ftrace faulted on modifying "); | |
442 | print_ip_sym(ip); | |
443 | break; | |
444 | case -EINVAL: | |
445 | FTRACE_WARN_ON_ONCE(1); | |
446 | pr_info("ftrace failed to modify "); | |
447 | print_ip_sym(ip); | |
b17e8a37 | 448 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
449 | printk(KERN_CONT "\n"); |
450 | break; | |
451 | case -EPERM: | |
452 | FTRACE_WARN_ON_ONCE(1); | |
453 | pr_info("ftrace faulted on writing "); | |
454 | print_ip_sym(ip); | |
455 | break; | |
456 | default: | |
457 | FTRACE_WARN_ON_ONCE(1); | |
458 | pr_info("ftrace faulted on unknown error "); | |
459 | print_ip_sym(ip); | |
460 | } | |
461 | } | |
462 | ||
3c1720f0 | 463 | |
0eb96701 | 464 | static int |
31e88909 | 465 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) |
5072c59f | 466 | { |
41c52c0d | 467 | unsigned long ip, fl; |
e7d3737e FW |
468 | unsigned long ftrace_addr; |
469 | ||
e7d3737e | 470 | ftrace_addr = (unsigned long)ftrace_caller; |
5072c59f SR |
471 | |
472 | ip = rec->ip; | |
473 | ||
982c350b SR |
474 | /* |
475 | * If this record is not to be traced and | |
476 | * it is not enabled then do nothing. | |
477 | * | |
478 | * If this record is not to be traced and | |
479 | * it is enabled then disabled it. | |
480 | * | |
481 | */ | |
482 | if (rec->flags & FTRACE_FL_NOTRACE) { | |
483 | if (rec->flags & FTRACE_FL_ENABLED) | |
484 | rec->flags &= ~FTRACE_FL_ENABLED; | |
485 | else | |
486 | return 0; | |
487 | ||
488 | } else if (ftrace_filtered && enable) { | |
5072c59f | 489 | /* |
982c350b | 490 | * Filtering is on: |
5072c59f | 491 | */ |
a4500b84 | 492 | |
982c350b | 493 | fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED); |
5072c59f | 494 | |
982c350b SR |
495 | /* Record is filtered and enabled, do nothing */ |
496 | if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) | |
0eb96701 | 497 | return 0; |
5072c59f | 498 | |
982c350b SR |
499 | /* Record is not filtered and is not enabled do nothing */ |
500 | if (!fl) | |
501 | return 0; | |
502 | ||
503 | /* Record is not filtered but enabled, disable it */ | |
504 | if (fl == FTRACE_FL_ENABLED) | |
5072c59f | 505 | rec->flags &= ~FTRACE_FL_ENABLED; |
982c350b SR |
506 | else |
507 | /* Otherwise record is filtered but not enabled, enable it */ | |
5072c59f | 508 | rec->flags |= FTRACE_FL_ENABLED; |
5072c59f | 509 | } else { |
982c350b | 510 | /* Disable or not filtered */ |
5072c59f | 511 | |
41c52c0d | 512 | if (enable) { |
982c350b | 513 | /* if record is enabled, do nothing */ |
5072c59f | 514 | if (rec->flags & FTRACE_FL_ENABLED) |
0eb96701 | 515 | return 0; |
982c350b | 516 | |
5072c59f | 517 | rec->flags |= FTRACE_FL_ENABLED; |
982c350b | 518 | |
5072c59f | 519 | } else { |
982c350b SR |
520 | |
521 | /* if record is not enabled do nothing */ | |
5072c59f | 522 | if (!(rec->flags & FTRACE_FL_ENABLED)) |
0eb96701 | 523 | return 0; |
982c350b | 524 | |
5072c59f SR |
525 | rec->flags &= ~FTRACE_FL_ENABLED; |
526 | } | |
527 | } | |
528 | ||
982c350b | 529 | if (rec->flags & FTRACE_FL_ENABLED) |
e7d3737e | 530 | return ftrace_make_call(rec, ftrace_addr); |
31e88909 | 531 | else |
e7d3737e | 532 | return ftrace_make_nop(NULL, rec, ftrace_addr); |
5072c59f SR |
533 | } |
534 | ||
e309b41d | 535 | static void ftrace_replace_code(int enable) |
3c1720f0 | 536 | { |
0eb96701 | 537 | int i, failed; |
3c1720f0 SR |
538 | struct dyn_ftrace *rec; |
539 | struct ftrace_page *pg; | |
3c1720f0 | 540 | |
3c1720f0 SR |
541 | for (pg = ftrace_pages_start; pg; pg = pg->next) { |
542 | for (i = 0; i < pg->index; i++) { | |
543 | rec = &pg->records[i]; | |
544 | ||
918c1154 SR |
545 | /* |
546 | * Skip over free records and records that have | |
547 | * failed. | |
548 | */ | |
549 | if (rec->flags & FTRACE_FL_FREE || | |
550 | rec->flags & FTRACE_FL_FAILED) | |
3c1720f0 SR |
551 | continue; |
552 | ||
f22f9a89 | 553 | /* ignore updates to this record's mcount site */ |
98a05ed4 AS |
554 | if (get_kprobe((void *)rec->ip)) { |
555 | freeze_record(rec); | |
f22f9a89 | 556 | continue; |
98a05ed4 AS |
557 | } else { |
558 | unfreeze_record(rec); | |
559 | } | |
f22f9a89 | 560 | |
31e88909 | 561 | failed = __ftrace_replace_code(rec, enable); |
0eb96701 AS |
562 | if (failed && (rec->flags & FTRACE_FL_CONVERTED)) { |
563 | rec->flags |= FTRACE_FL_FAILED; | |
564 | if ((system_state == SYSTEM_BOOTING) || | |
34078a5e | 565 | !core_kernel_text(rec->ip)) { |
0eb96701 | 566 | ftrace_free_rec(rec); |
b17e8a37 | 567 | } else |
31e88909 | 568 | ftrace_bug(failed, rec->ip); |
0eb96701 | 569 | } |
3c1720f0 SR |
570 | } |
571 | } | |
572 | } | |
573 | ||
492a7ea5 | 574 | static int |
31e88909 | 575 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 SR |
576 | { |
577 | unsigned long ip; | |
593eb8a2 | 578 | int ret; |
3c1720f0 SR |
579 | |
580 | ip = rec->ip; | |
581 | ||
31e88909 | 582 | ret = ftrace_make_nop(mod, rec, mcount_addr); |
593eb8a2 | 583 | if (ret) { |
31e88909 | 584 | ftrace_bug(ret, ip); |
3c1720f0 | 585 | rec->flags |= FTRACE_FL_FAILED; |
492a7ea5 | 586 | return 0; |
37ad5084 | 587 | } |
492a7ea5 | 588 | return 1; |
3c1720f0 SR |
589 | } |
590 | ||
e309b41d | 591 | static int __ftrace_modify_code(void *data) |
3d083395 | 592 | { |
d61f82d0 SR |
593 | int *command = data; |
594 | ||
a3583244 | 595 | if (*command & FTRACE_ENABLE_CALLS) |
d61f82d0 | 596 | ftrace_replace_code(1); |
a3583244 | 597 | else if (*command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
598 | ftrace_replace_code(0); |
599 | ||
600 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
601 | ftrace_update_ftrace_func(ftrace_trace_function); | |
602 | ||
5a45cfe1 SR |
603 | if (*command & FTRACE_START_FUNC_RET) |
604 | ftrace_enable_ftrace_graph_caller(); | |
605 | else if (*command & FTRACE_STOP_FUNC_RET) | |
606 | ftrace_disable_ftrace_graph_caller(); | |
607 | ||
d61f82d0 | 608 | return 0; |
3d083395 SR |
609 | } |
610 | ||
e309b41d | 611 | static void ftrace_run_update_code(int command) |
3d083395 | 612 | { |
784e2d76 | 613 | stop_machine(__ftrace_modify_code, &command, NULL); |
3d083395 SR |
614 | } |
615 | ||
d61f82d0 | 616 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 617 | static int ftrace_start_up; |
df4fc315 SR |
618 | |
619 | static void ftrace_startup_enable(int command) | |
620 | { | |
621 | if (saved_ftrace_func != ftrace_trace_function) { | |
622 | saved_ftrace_func = ftrace_trace_function; | |
623 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
624 | } | |
625 | ||
626 | if (!command || !ftrace_enabled) | |
627 | return; | |
628 | ||
629 | ftrace_run_update_code(command); | |
630 | } | |
d61f82d0 | 631 | |
5a45cfe1 | 632 | static void ftrace_startup(int command) |
3d083395 | 633 | { |
4eebcc81 SR |
634 | if (unlikely(ftrace_disabled)) |
635 | return; | |
636 | ||
cb7be3b2 | 637 | mutex_lock(&ftrace_start_lock); |
60a7ecf4 | 638 | ftrace_start_up++; |
982c350b | 639 | command |= FTRACE_ENABLE_CALLS; |
d61f82d0 | 640 | |
df4fc315 | 641 | ftrace_startup_enable(command); |
3d083395 | 642 | |
cb7be3b2 | 643 | mutex_unlock(&ftrace_start_lock); |
3d083395 SR |
644 | } |
645 | ||
5a45cfe1 | 646 | static void ftrace_shutdown(int command) |
3d083395 | 647 | { |
4eebcc81 SR |
648 | if (unlikely(ftrace_disabled)) |
649 | return; | |
650 | ||
cb7be3b2 | 651 | mutex_lock(&ftrace_start_lock); |
60a7ecf4 SR |
652 | ftrace_start_up--; |
653 | if (!ftrace_start_up) | |
d61f82d0 | 654 | command |= FTRACE_DISABLE_CALLS; |
3d083395 | 655 | |
d61f82d0 SR |
656 | if (saved_ftrace_func != ftrace_trace_function) { |
657 | saved_ftrace_func = ftrace_trace_function; | |
658 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
659 | } | |
3d083395 | 660 | |
d61f82d0 SR |
661 | if (!command || !ftrace_enabled) |
662 | goto out; | |
663 | ||
664 | ftrace_run_update_code(command); | |
3d083395 | 665 | out: |
cb7be3b2 | 666 | mutex_unlock(&ftrace_start_lock); |
3d083395 SR |
667 | } |
668 | ||
e309b41d | 669 | static void ftrace_startup_sysctl(void) |
b0fc494f | 670 | { |
d61f82d0 SR |
671 | int command = FTRACE_ENABLE_MCOUNT; |
672 | ||
4eebcc81 SR |
673 | if (unlikely(ftrace_disabled)) |
674 | return; | |
675 | ||
cb7be3b2 | 676 | mutex_lock(&ftrace_start_lock); |
d61f82d0 SR |
677 | /* Force update next time */ |
678 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
679 | /* ftrace_start_up is true if we want ftrace running */ |
680 | if (ftrace_start_up) | |
d61f82d0 SR |
681 | command |= FTRACE_ENABLE_CALLS; |
682 | ||
683 | ftrace_run_update_code(command); | |
cb7be3b2 | 684 | mutex_unlock(&ftrace_start_lock); |
b0fc494f SR |
685 | } |
686 | ||
e309b41d | 687 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 688 | { |
d61f82d0 SR |
689 | int command = FTRACE_DISABLE_MCOUNT; |
690 | ||
4eebcc81 SR |
691 | if (unlikely(ftrace_disabled)) |
692 | return; | |
693 | ||
cb7be3b2 | 694 | mutex_lock(&ftrace_start_lock); |
60a7ecf4 SR |
695 | /* ftrace_start_up is true if ftrace is running */ |
696 | if (ftrace_start_up) | |
d61f82d0 SR |
697 | command |= FTRACE_DISABLE_CALLS; |
698 | ||
699 | ftrace_run_update_code(command); | |
cb7be3b2 | 700 | mutex_unlock(&ftrace_start_lock); |
b0fc494f SR |
701 | } |
702 | ||
3d083395 SR |
703 | static cycle_t ftrace_update_time; |
704 | static unsigned long ftrace_update_cnt; | |
705 | unsigned long ftrace_update_tot_cnt; | |
706 | ||
31e88909 | 707 | static int ftrace_update_code(struct module *mod) |
3d083395 | 708 | { |
08f5ac90 | 709 | struct dyn_ftrace *p, *t; |
f22f9a89 | 710 | cycle_t start, stop; |
3d083395 | 711 | |
750ed1a4 | 712 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
713 | ftrace_update_cnt = 0; |
714 | ||
08f5ac90 | 715 | list_for_each_entry_safe(p, t, &ftrace_new_addrs, list) { |
3d083395 | 716 | |
08f5ac90 SR |
717 | /* If something went wrong, bail without enabling anything */ |
718 | if (unlikely(ftrace_disabled)) | |
719 | return -1; | |
f22f9a89 | 720 | |
08f5ac90 | 721 | list_del_init(&p->list); |
f22f9a89 | 722 | |
08f5ac90 | 723 | /* convert record (i.e, patch mcount-call with NOP) */ |
31e88909 | 724 | if (ftrace_code_disable(mod, p)) { |
08f5ac90 SR |
725 | p->flags |= FTRACE_FL_CONVERTED; |
726 | ftrace_update_cnt++; | |
727 | } else | |
728 | ftrace_free_rec(p); | |
3d083395 SR |
729 | } |
730 | ||
750ed1a4 | 731 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
732 | ftrace_update_time = stop - start; |
733 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
734 | ||
16444a8a ACM |
735 | return 0; |
736 | } | |
737 | ||
68bf21aa | 738 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
739 | { |
740 | struct ftrace_page *pg; | |
741 | int cnt; | |
742 | int i; | |
3c1720f0 SR |
743 | |
744 | /* allocate a few pages */ | |
745 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
746 | if (!ftrace_pages_start) | |
747 | return -1; | |
748 | ||
749 | /* | |
750 | * Allocate a few more pages. | |
751 | * | |
752 | * TODO: have some parser search vmlinux before | |
753 | * final linking to find all calls to ftrace. | |
754 | * Then we can: | |
755 | * a) know how many pages to allocate. | |
756 | * and/or | |
757 | * b) set up the table then. | |
758 | * | |
759 | * The dynamic code is still necessary for | |
760 | * modules. | |
761 | */ | |
762 | ||
763 | pg = ftrace_pages = ftrace_pages_start; | |
764 | ||
68bf21aa | 765 | cnt = num_to_init / ENTRIES_PER_PAGE; |
08f5ac90 | 766 | pr_info("ftrace: allocating %ld entries in %d pages\n", |
5821e1b7 | 767 | num_to_init, cnt + 1); |
3c1720f0 SR |
768 | |
769 | for (i = 0; i < cnt; i++) { | |
770 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
771 | ||
772 | /* If we fail, we'll try later anyway */ | |
773 | if (!pg->next) | |
774 | break; | |
775 | ||
776 | pg = pg->next; | |
777 | } | |
778 | ||
779 | return 0; | |
780 | } | |
781 | ||
5072c59f SR |
782 | enum { |
783 | FTRACE_ITER_FILTER = (1 << 0), | |
784 | FTRACE_ITER_CONT = (1 << 1), | |
41c52c0d | 785 | FTRACE_ITER_NOTRACE = (1 << 2), |
eb9a7bf0 | 786 | FTRACE_ITER_FAILURES = (1 << 3), |
5072c59f SR |
787 | }; |
788 | ||
789 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
790 | ||
791 | struct ftrace_iterator { | |
792 | loff_t pos; | |
793 | struct ftrace_page *pg; | |
794 | unsigned idx; | |
795 | unsigned flags; | |
796 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
797 | unsigned buffer_idx; | |
798 | unsigned filtered; | |
799 | }; | |
800 | ||
e309b41d | 801 | static void * |
5072c59f SR |
802 | t_next(struct seq_file *m, void *v, loff_t *pos) |
803 | { | |
804 | struct ftrace_iterator *iter = m->private; | |
805 | struct dyn_ftrace *rec = NULL; | |
806 | ||
807 | (*pos)++; | |
808 | ||
99ecdc43 SR |
809 | /* should not be called from interrupt context */ |
810 | spin_lock(&ftrace_lock); | |
5072c59f SR |
811 | retry: |
812 | if (iter->idx >= iter->pg->index) { | |
813 | if (iter->pg->next) { | |
814 | iter->pg = iter->pg->next; | |
815 | iter->idx = 0; | |
816 | goto retry; | |
817 | } | |
818 | } else { | |
819 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
820 | if ((rec->flags & FTRACE_FL_FREE) || |
821 | ||
822 | (!(iter->flags & FTRACE_ITER_FAILURES) && | |
eb9a7bf0 AS |
823 | (rec->flags & FTRACE_FL_FAILED)) || |
824 | ||
825 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
a9fdda33 | 826 | !(rec->flags & FTRACE_FL_FAILED)) || |
eb9a7bf0 | 827 | |
0183fb1c SR |
828 | ((iter->flags & FTRACE_ITER_FILTER) && |
829 | !(rec->flags & FTRACE_FL_FILTER)) || | |
830 | ||
41c52c0d SR |
831 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
832 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
833 | rec = NULL; |
834 | goto retry; | |
835 | } | |
836 | } | |
99ecdc43 | 837 | spin_unlock(&ftrace_lock); |
5072c59f SR |
838 | |
839 | iter->pos = *pos; | |
840 | ||
841 | return rec; | |
842 | } | |
843 | ||
844 | static void *t_start(struct seq_file *m, loff_t *pos) | |
845 | { | |
846 | struct ftrace_iterator *iter = m->private; | |
847 | void *p = NULL; | |
848 | loff_t l = -1; | |
849 | ||
5821e1b7 | 850 | if (*pos > iter->pos) |
851 | *pos = iter->pos; | |
852 | ||
853 | l = *pos; | |
854 | p = t_next(m, p, &l); | |
5072c59f SR |
855 | |
856 | return p; | |
857 | } | |
858 | ||
859 | static void t_stop(struct seq_file *m, void *p) | |
860 | { | |
861 | } | |
862 | ||
863 | static int t_show(struct seq_file *m, void *v) | |
864 | { | |
5821e1b7 | 865 | struct ftrace_iterator *iter = m->private; |
5072c59f SR |
866 | struct dyn_ftrace *rec = v; |
867 | char str[KSYM_SYMBOL_LEN]; | |
5821e1b7 | 868 | int ret = 0; |
5072c59f SR |
869 | |
870 | if (!rec) | |
871 | return 0; | |
872 | ||
873 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
874 | ||
5821e1b7 | 875 | ret = seq_printf(m, "%s\n", str); |
876 | if (ret < 0) { | |
877 | iter->pos--; | |
878 | iter->idx--; | |
879 | } | |
5072c59f SR |
880 | |
881 | return 0; | |
882 | } | |
883 | ||
884 | static struct seq_operations show_ftrace_seq_ops = { | |
885 | .start = t_start, | |
886 | .next = t_next, | |
887 | .stop = t_stop, | |
888 | .show = t_show, | |
889 | }; | |
890 | ||
e309b41d | 891 | static int |
5072c59f SR |
892 | ftrace_avail_open(struct inode *inode, struct file *file) |
893 | { | |
894 | struct ftrace_iterator *iter; | |
895 | int ret; | |
896 | ||
4eebcc81 SR |
897 | if (unlikely(ftrace_disabled)) |
898 | return -ENODEV; | |
899 | ||
5072c59f SR |
900 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
901 | if (!iter) | |
902 | return -ENOMEM; | |
903 | ||
904 | iter->pg = ftrace_pages_start; | |
5821e1b7 | 905 | iter->pos = 0; |
5072c59f SR |
906 | |
907 | ret = seq_open(file, &show_ftrace_seq_ops); | |
908 | if (!ret) { | |
909 | struct seq_file *m = file->private_data; | |
4bf39a94 | 910 | |
5072c59f | 911 | m->private = iter; |
4bf39a94 | 912 | } else { |
5072c59f | 913 | kfree(iter); |
4bf39a94 | 914 | } |
5072c59f SR |
915 | |
916 | return ret; | |
917 | } | |
918 | ||
919 | int ftrace_avail_release(struct inode *inode, struct file *file) | |
920 | { | |
921 | struct seq_file *m = (struct seq_file *)file->private_data; | |
922 | struct ftrace_iterator *iter = m->private; | |
923 | ||
924 | seq_release(inode, file); | |
925 | kfree(iter); | |
4bf39a94 | 926 | |
5072c59f SR |
927 | return 0; |
928 | } | |
929 | ||
eb9a7bf0 AS |
930 | static int |
931 | ftrace_failures_open(struct inode *inode, struct file *file) | |
932 | { | |
933 | int ret; | |
934 | struct seq_file *m; | |
935 | struct ftrace_iterator *iter; | |
936 | ||
937 | ret = ftrace_avail_open(inode, file); | |
938 | if (!ret) { | |
939 | m = (struct seq_file *)file->private_data; | |
940 | iter = (struct ftrace_iterator *)m->private; | |
941 | iter->flags = FTRACE_ITER_FAILURES; | |
942 | } | |
943 | ||
944 | return ret; | |
945 | } | |
946 | ||
947 | ||
41c52c0d | 948 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
949 | { |
950 | struct ftrace_page *pg; | |
951 | struct dyn_ftrace *rec; | |
41c52c0d | 952 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f SR |
953 | unsigned i; |
954 | ||
99ecdc43 SR |
955 | /* should not be called from interrupt context */ |
956 | spin_lock(&ftrace_lock); | |
41c52c0d SR |
957 | if (enable) |
958 | ftrace_filtered = 0; | |
5072c59f SR |
959 | pg = ftrace_pages_start; |
960 | while (pg) { | |
961 | for (i = 0; i < pg->index; i++) { | |
962 | rec = &pg->records[i]; | |
963 | if (rec->flags & FTRACE_FL_FAILED) | |
964 | continue; | |
41c52c0d | 965 | rec->flags &= ~type; |
5072c59f SR |
966 | } |
967 | pg = pg->next; | |
968 | } | |
99ecdc43 | 969 | spin_unlock(&ftrace_lock); |
5072c59f SR |
970 | } |
971 | ||
e309b41d | 972 | static int |
41c52c0d | 973 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
974 | { |
975 | struct ftrace_iterator *iter; | |
976 | int ret = 0; | |
977 | ||
4eebcc81 SR |
978 | if (unlikely(ftrace_disabled)) |
979 | return -ENODEV; | |
980 | ||
5072c59f SR |
981 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
982 | if (!iter) | |
983 | return -ENOMEM; | |
984 | ||
41c52c0d | 985 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
986 | if ((file->f_mode & FMODE_WRITE) && |
987 | !(file->f_flags & O_APPEND)) | |
41c52c0d | 988 | ftrace_filter_reset(enable); |
5072c59f SR |
989 | |
990 | if (file->f_mode & FMODE_READ) { | |
991 | iter->pg = ftrace_pages_start; | |
5821e1b7 | 992 | iter->pos = 0; |
41c52c0d SR |
993 | iter->flags = enable ? FTRACE_ITER_FILTER : |
994 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
995 | |
996 | ret = seq_open(file, &show_ftrace_seq_ops); | |
997 | if (!ret) { | |
998 | struct seq_file *m = file->private_data; | |
999 | m->private = iter; | |
1000 | } else | |
1001 | kfree(iter); | |
1002 | } else | |
1003 | file->private_data = iter; | |
41c52c0d | 1004 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1005 | |
1006 | return ret; | |
1007 | } | |
1008 | ||
41c52c0d SR |
1009 | static int |
1010 | ftrace_filter_open(struct inode *inode, struct file *file) | |
1011 | { | |
1012 | return ftrace_regex_open(inode, file, 1); | |
1013 | } | |
1014 | ||
1015 | static int | |
1016 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
1017 | { | |
1018 | return ftrace_regex_open(inode, file, 0); | |
1019 | } | |
1020 | ||
e309b41d | 1021 | static ssize_t |
41c52c0d | 1022 | ftrace_regex_read(struct file *file, char __user *ubuf, |
5072c59f SR |
1023 | size_t cnt, loff_t *ppos) |
1024 | { | |
1025 | if (file->f_mode & FMODE_READ) | |
1026 | return seq_read(file, ubuf, cnt, ppos); | |
1027 | else | |
1028 | return -EPERM; | |
1029 | } | |
1030 | ||
e309b41d | 1031 | static loff_t |
41c52c0d | 1032 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
1033 | { |
1034 | loff_t ret; | |
1035 | ||
1036 | if (file->f_mode & FMODE_READ) | |
1037 | ret = seq_lseek(file, offset, origin); | |
1038 | else | |
1039 | file->f_pos = ret = 1; | |
1040 | ||
1041 | return ret; | |
1042 | } | |
1043 | ||
1044 | enum { | |
1045 | MATCH_FULL, | |
1046 | MATCH_FRONT_ONLY, | |
1047 | MATCH_MIDDLE_ONLY, | |
1048 | MATCH_END_ONLY, | |
1049 | }; | |
1050 | ||
e309b41d | 1051 | static void |
41c52c0d | 1052 | ftrace_match(unsigned char *buff, int len, int enable) |
5072c59f SR |
1053 | { |
1054 | char str[KSYM_SYMBOL_LEN]; | |
1055 | char *search = NULL; | |
1056 | struct ftrace_page *pg; | |
1057 | struct dyn_ftrace *rec; | |
1058 | int type = MATCH_FULL; | |
41c52c0d | 1059 | unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f SR |
1060 | unsigned i, match = 0, search_len = 0; |
1061 | ||
1062 | for (i = 0; i < len; i++) { | |
1063 | if (buff[i] == '*') { | |
1064 | if (!i) { | |
1065 | search = buff + i + 1; | |
1066 | type = MATCH_END_ONLY; | |
1067 | search_len = len - (i + 1); | |
1068 | } else { | |
1069 | if (type == MATCH_END_ONLY) { | |
1070 | type = MATCH_MIDDLE_ONLY; | |
1071 | } else { | |
1072 | match = i; | |
1073 | type = MATCH_FRONT_ONLY; | |
1074 | } | |
1075 | buff[i] = 0; | |
1076 | break; | |
1077 | } | |
1078 | } | |
1079 | } | |
1080 | ||
99ecdc43 SR |
1081 | /* should not be called from interrupt context */ |
1082 | spin_lock(&ftrace_lock); | |
41c52c0d SR |
1083 | if (enable) |
1084 | ftrace_filtered = 1; | |
5072c59f SR |
1085 | pg = ftrace_pages_start; |
1086 | while (pg) { | |
1087 | for (i = 0; i < pg->index; i++) { | |
1088 | int matched = 0; | |
1089 | char *ptr; | |
1090 | ||
1091 | rec = &pg->records[i]; | |
1092 | if (rec->flags & FTRACE_FL_FAILED) | |
1093 | continue; | |
1094 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1095 | switch (type) { | |
1096 | case MATCH_FULL: | |
1097 | if (strcmp(str, buff) == 0) | |
1098 | matched = 1; | |
1099 | break; | |
1100 | case MATCH_FRONT_ONLY: | |
1101 | if (memcmp(str, buff, match) == 0) | |
1102 | matched = 1; | |
1103 | break; | |
1104 | case MATCH_MIDDLE_ONLY: | |
1105 | if (strstr(str, search)) | |
1106 | matched = 1; | |
1107 | break; | |
1108 | case MATCH_END_ONLY: | |
1109 | ptr = strstr(str, search); | |
1110 | if (ptr && (ptr[search_len] == 0)) | |
1111 | matched = 1; | |
1112 | break; | |
1113 | } | |
1114 | if (matched) | |
41c52c0d | 1115 | rec->flags |= flag; |
5072c59f SR |
1116 | } |
1117 | pg = pg->next; | |
1118 | } | |
99ecdc43 | 1119 | spin_unlock(&ftrace_lock); |
5072c59f SR |
1120 | } |
1121 | ||
e309b41d | 1122 | static ssize_t |
41c52c0d SR |
1123 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
1124 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
1125 | { |
1126 | struct ftrace_iterator *iter; | |
1127 | char ch; | |
1128 | size_t read = 0; | |
1129 | ssize_t ret; | |
1130 | ||
1131 | if (!cnt || cnt < 0) | |
1132 | return 0; | |
1133 | ||
41c52c0d | 1134 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1135 | |
1136 | if (file->f_mode & FMODE_READ) { | |
1137 | struct seq_file *m = file->private_data; | |
1138 | iter = m->private; | |
1139 | } else | |
1140 | iter = file->private_data; | |
1141 | ||
1142 | if (!*ppos) { | |
1143 | iter->flags &= ~FTRACE_ITER_CONT; | |
1144 | iter->buffer_idx = 0; | |
1145 | } | |
1146 | ||
1147 | ret = get_user(ch, ubuf++); | |
1148 | if (ret) | |
1149 | goto out; | |
1150 | read++; | |
1151 | cnt--; | |
1152 | ||
1153 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { | |
1154 | /* skip white space */ | |
1155 | while (cnt && isspace(ch)) { | |
1156 | ret = get_user(ch, ubuf++); | |
1157 | if (ret) | |
1158 | goto out; | |
1159 | read++; | |
1160 | cnt--; | |
1161 | } | |
1162 | ||
5072c59f SR |
1163 | if (isspace(ch)) { |
1164 | file->f_pos += read; | |
1165 | ret = read; | |
1166 | goto out; | |
1167 | } | |
1168 | ||
1169 | iter->buffer_idx = 0; | |
1170 | } | |
1171 | ||
1172 | while (cnt && !isspace(ch)) { | |
1173 | if (iter->buffer_idx < FTRACE_BUFF_MAX) | |
1174 | iter->buffer[iter->buffer_idx++] = ch; | |
1175 | else { | |
1176 | ret = -EINVAL; | |
1177 | goto out; | |
1178 | } | |
1179 | ret = get_user(ch, ubuf++); | |
1180 | if (ret) | |
1181 | goto out; | |
1182 | read++; | |
1183 | cnt--; | |
1184 | } | |
1185 | ||
1186 | if (isspace(ch)) { | |
1187 | iter->filtered++; | |
1188 | iter->buffer[iter->buffer_idx] = 0; | |
41c52c0d | 1189 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1190 | iter->buffer_idx = 0; |
1191 | } else | |
1192 | iter->flags |= FTRACE_ITER_CONT; | |
1193 | ||
1194 | ||
1195 | file->f_pos += read; | |
1196 | ||
1197 | ret = read; | |
1198 | out: | |
41c52c0d | 1199 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1200 | |
1201 | return ret; | |
1202 | } | |
1203 | ||
41c52c0d SR |
1204 | static ssize_t |
1205 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
1206 | size_t cnt, loff_t *ppos) | |
1207 | { | |
1208 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
1209 | } | |
1210 | ||
1211 | static ssize_t | |
1212 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
1213 | size_t cnt, loff_t *ppos) | |
1214 | { | |
1215 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
1216 | } | |
1217 | ||
1218 | static void | |
1219 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
1220 | { | |
1221 | if (unlikely(ftrace_disabled)) | |
1222 | return; | |
1223 | ||
1224 | mutex_lock(&ftrace_regex_lock); | |
1225 | if (reset) | |
1226 | ftrace_filter_reset(enable); | |
1227 | if (buf) | |
1228 | ftrace_match(buf, len, enable); | |
1229 | mutex_unlock(&ftrace_regex_lock); | |
1230 | } | |
1231 | ||
77a2b37d SR |
1232 | /** |
1233 | * ftrace_set_filter - set a function to filter on in ftrace | |
1234 | * @buf - the string that holds the function filter text. | |
1235 | * @len - the length of the string. | |
1236 | * @reset - non zero to reset all filters before applying this filter. | |
1237 | * | |
1238 | * Filters denote which functions should be enabled when tracing is enabled. | |
1239 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
1240 | */ | |
e309b41d | 1241 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 1242 | { |
41c52c0d SR |
1243 | ftrace_set_regex(buf, len, reset, 1); |
1244 | } | |
4eebcc81 | 1245 | |
41c52c0d SR |
1246 | /** |
1247 | * ftrace_set_notrace - set a function to not trace in ftrace | |
1248 | * @buf - the string that holds the function notrace text. | |
1249 | * @len - the length of the string. | |
1250 | * @reset - non zero to reset all filters before applying this filter. | |
1251 | * | |
1252 | * Notrace Filters denote which functions should not be enabled when tracing | |
1253 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
1254 | * for tracing. | |
1255 | */ | |
1256 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
1257 | { | |
1258 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
1259 | } |
1260 | ||
e309b41d | 1261 | static int |
41c52c0d | 1262 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1263 | { |
1264 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1265 | struct ftrace_iterator *iter; | |
1266 | ||
41c52c0d | 1267 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1268 | if (file->f_mode & FMODE_READ) { |
1269 | iter = m->private; | |
1270 | ||
1271 | seq_release(inode, file); | |
1272 | } else | |
1273 | iter = file->private_data; | |
1274 | ||
1275 | if (iter->buffer_idx) { | |
1276 | iter->filtered++; | |
1277 | iter->buffer[iter->buffer_idx] = 0; | |
41c52c0d | 1278 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1279 | } |
1280 | ||
1281 | mutex_lock(&ftrace_sysctl_lock); | |
cb7be3b2 | 1282 | mutex_lock(&ftrace_start_lock); |
ee02a2e5 | 1283 | if (ftrace_start_up && ftrace_enabled) |
5072c59f | 1284 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
cb7be3b2 | 1285 | mutex_unlock(&ftrace_start_lock); |
5072c59f SR |
1286 | mutex_unlock(&ftrace_sysctl_lock); |
1287 | ||
1288 | kfree(iter); | |
41c52c0d | 1289 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1290 | return 0; |
1291 | } | |
1292 | ||
41c52c0d SR |
1293 | static int |
1294 | ftrace_filter_release(struct inode *inode, struct file *file) | |
1295 | { | |
1296 | return ftrace_regex_release(inode, file, 1); | |
1297 | } | |
1298 | ||
1299 | static int | |
1300 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
1301 | { | |
1302 | return ftrace_regex_release(inode, file, 0); | |
1303 | } | |
1304 | ||
5072c59f SR |
1305 | static struct file_operations ftrace_avail_fops = { |
1306 | .open = ftrace_avail_open, | |
1307 | .read = seq_read, | |
1308 | .llseek = seq_lseek, | |
1309 | .release = ftrace_avail_release, | |
1310 | }; | |
1311 | ||
eb9a7bf0 AS |
1312 | static struct file_operations ftrace_failures_fops = { |
1313 | .open = ftrace_failures_open, | |
1314 | .read = seq_read, | |
1315 | .llseek = seq_lseek, | |
1316 | .release = ftrace_avail_release, | |
1317 | }; | |
1318 | ||
5072c59f SR |
1319 | static struct file_operations ftrace_filter_fops = { |
1320 | .open = ftrace_filter_open, | |
41c52c0d | 1321 | .read = ftrace_regex_read, |
5072c59f | 1322 | .write = ftrace_filter_write, |
41c52c0d | 1323 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
1324 | .release = ftrace_filter_release, |
1325 | }; | |
1326 | ||
41c52c0d SR |
1327 | static struct file_operations ftrace_notrace_fops = { |
1328 | .open = ftrace_notrace_open, | |
1329 | .read = ftrace_regex_read, | |
1330 | .write = ftrace_notrace_write, | |
1331 | .llseek = ftrace_regex_lseek, | |
1332 | .release = ftrace_notrace_release, | |
1333 | }; | |
1334 | ||
df4fc315 | 1335 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 1336 | { |
5072c59f SR |
1337 | struct dentry *entry; |
1338 | ||
5072c59f SR |
1339 | entry = debugfs_create_file("available_filter_functions", 0444, |
1340 | d_tracer, NULL, &ftrace_avail_fops); | |
1341 | if (!entry) | |
1342 | pr_warning("Could not create debugfs " | |
1343 | "'available_filter_functions' entry\n"); | |
1344 | ||
eb9a7bf0 AS |
1345 | entry = debugfs_create_file("failures", 0444, |
1346 | d_tracer, NULL, &ftrace_failures_fops); | |
1347 | if (!entry) | |
1348 | pr_warning("Could not create debugfs 'failures' entry\n"); | |
1349 | ||
5072c59f SR |
1350 | entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer, |
1351 | NULL, &ftrace_filter_fops); | |
1352 | if (!entry) | |
1353 | pr_warning("Could not create debugfs " | |
1354 | "'set_ftrace_filter' entry\n"); | |
41c52c0d SR |
1355 | |
1356 | entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer, | |
1357 | NULL, &ftrace_notrace_fops); | |
1358 | if (!entry) | |
1359 | pr_warning("Could not create debugfs " | |
1360 | "'set_ftrace_notrace' entry\n"); | |
ad90c0e3 | 1361 | |
5072c59f SR |
1362 | return 0; |
1363 | } | |
1364 | ||
31e88909 SR |
1365 | static int ftrace_convert_nops(struct module *mod, |
1366 | unsigned long *start, | |
68bf21aa SR |
1367 | unsigned long *end) |
1368 | { | |
1369 | unsigned long *p; | |
1370 | unsigned long addr; | |
1371 | unsigned long flags; | |
1372 | ||
08f5ac90 | 1373 | mutex_lock(&ftrace_start_lock); |
68bf21aa SR |
1374 | p = start; |
1375 | while (p < end) { | |
1376 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
1377 | /* |
1378 | * Some architecture linkers will pad between | |
1379 | * the different mcount_loc sections of different | |
1380 | * object files to satisfy alignments. | |
1381 | * Skip any NULL pointers. | |
1382 | */ | |
1383 | if (!addr) | |
1384 | continue; | |
68bf21aa | 1385 | ftrace_record_ip(addr); |
68bf21aa SR |
1386 | } |
1387 | ||
08f5ac90 | 1388 | /* disable interrupts to prevent kstop machine */ |
68bf21aa | 1389 | local_irq_save(flags); |
31e88909 | 1390 | ftrace_update_code(mod); |
68bf21aa | 1391 | local_irq_restore(flags); |
08f5ac90 | 1392 | mutex_unlock(&ftrace_start_lock); |
68bf21aa SR |
1393 | |
1394 | return 0; | |
1395 | } | |
1396 | ||
31e88909 SR |
1397 | void ftrace_init_module(struct module *mod, |
1398 | unsigned long *start, unsigned long *end) | |
90d595fe | 1399 | { |
00fd61ae | 1400 | if (ftrace_disabled || start == end) |
fed1939c | 1401 | return; |
31e88909 | 1402 | ftrace_convert_nops(mod, start, end); |
90d595fe SR |
1403 | } |
1404 | ||
68bf21aa SR |
1405 | extern unsigned long __start_mcount_loc[]; |
1406 | extern unsigned long __stop_mcount_loc[]; | |
1407 | ||
1408 | void __init ftrace_init(void) | |
1409 | { | |
1410 | unsigned long count, addr, flags; | |
1411 | int ret; | |
1412 | ||
1413 | /* Keep the ftrace pointer to the stub */ | |
1414 | addr = (unsigned long)ftrace_stub; | |
1415 | ||
1416 | local_irq_save(flags); | |
1417 | ftrace_dyn_arch_init(&addr); | |
1418 | local_irq_restore(flags); | |
1419 | ||
1420 | /* ftrace_dyn_arch_init places the return code in addr */ | |
1421 | if (addr) | |
1422 | goto failed; | |
1423 | ||
1424 | count = __stop_mcount_loc - __start_mcount_loc; | |
1425 | ||
1426 | ret = ftrace_dyn_table_alloc(count); | |
1427 | if (ret) | |
1428 | goto failed; | |
1429 | ||
1430 | last_ftrace_enabled = ftrace_enabled = 1; | |
1431 | ||
31e88909 SR |
1432 | ret = ftrace_convert_nops(NULL, |
1433 | __start_mcount_loc, | |
68bf21aa SR |
1434 | __stop_mcount_loc); |
1435 | ||
1436 | return; | |
1437 | failed: | |
1438 | ftrace_disabled = 1; | |
1439 | } | |
68bf21aa | 1440 | |
3d083395 | 1441 | #else |
0b6e4d56 FW |
1442 | |
1443 | static int __init ftrace_nodyn_init(void) | |
1444 | { | |
1445 | ftrace_enabled = 1; | |
1446 | return 0; | |
1447 | } | |
1448 | device_initcall(ftrace_nodyn_init); | |
1449 | ||
df4fc315 SR |
1450 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
1451 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 SR |
1452 | /* Keep as macros so we do not need to define the commands */ |
1453 | # define ftrace_startup(command) do { } while (0) | |
1454 | # define ftrace_shutdown(command) do { } while (0) | |
c7aafc54 IM |
1455 | # define ftrace_startup_sysctl() do { } while (0) |
1456 | # define ftrace_shutdown_sysctl() do { } while (0) | |
3d083395 SR |
1457 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
1458 | ||
df4fc315 SR |
1459 | static ssize_t |
1460 | ftrace_pid_read(struct file *file, char __user *ubuf, | |
1461 | size_t cnt, loff_t *ppos) | |
1462 | { | |
1463 | char buf[64]; | |
1464 | int r; | |
1465 | ||
1466 | if (ftrace_pid_trace >= 0) | |
1467 | r = sprintf(buf, "%u\n", ftrace_pid_trace); | |
1468 | else | |
1469 | r = sprintf(buf, "no pid\n"); | |
1470 | ||
1471 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
1472 | } | |
1473 | ||
1474 | static ssize_t | |
1475 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
1476 | size_t cnt, loff_t *ppos) | |
1477 | { | |
1478 | char buf[64]; | |
1479 | long val; | |
1480 | int ret; | |
1481 | ||
1482 | if (cnt >= sizeof(buf)) | |
1483 | return -EINVAL; | |
1484 | ||
1485 | if (copy_from_user(&buf, ubuf, cnt)) | |
1486 | return -EFAULT; | |
1487 | ||
1488 | buf[cnt] = 0; | |
1489 | ||
1490 | ret = strict_strtol(buf, 10, &val); | |
1491 | if (ret < 0) | |
1492 | return ret; | |
1493 | ||
1494 | mutex_lock(&ftrace_start_lock); | |
1495 | if (ret < 0) { | |
1496 | /* disable pid tracing */ | |
1497 | if (ftrace_pid_trace < 0) | |
1498 | goto out; | |
1499 | ftrace_pid_trace = -1; | |
1500 | ||
1501 | } else { | |
1502 | ||
1503 | if (ftrace_pid_trace == val) | |
1504 | goto out; | |
1505 | ||
1506 | ftrace_pid_trace = val; | |
1507 | } | |
1508 | ||
1509 | /* update the function call */ | |
1510 | ftrace_update_pid_func(); | |
1511 | ftrace_startup_enable(0); | |
1512 | ||
1513 | out: | |
1514 | mutex_unlock(&ftrace_start_lock); | |
1515 | ||
1516 | return cnt; | |
1517 | } | |
1518 | ||
1519 | static struct file_operations ftrace_pid_fops = { | |
1520 | .read = ftrace_pid_read, | |
1521 | .write = ftrace_pid_write, | |
1522 | }; | |
1523 | ||
1524 | static __init int ftrace_init_debugfs(void) | |
1525 | { | |
1526 | struct dentry *d_tracer; | |
1527 | struct dentry *entry; | |
1528 | ||
1529 | d_tracer = tracing_init_dentry(); | |
1530 | if (!d_tracer) | |
1531 | return 0; | |
1532 | ||
1533 | ftrace_init_dyn_debugfs(d_tracer); | |
1534 | ||
1535 | entry = debugfs_create_file("set_ftrace_pid", 0644, d_tracer, | |
1536 | NULL, &ftrace_pid_fops); | |
1537 | if (!entry) | |
1538 | pr_warning("Could not create debugfs " | |
1539 | "'set_ftrace_pid' entry\n"); | |
1540 | return 0; | |
1541 | } | |
1542 | ||
1543 | fs_initcall(ftrace_init_debugfs); | |
1544 | ||
a2bb6a3d | 1545 | /** |
81adbdc0 | 1546 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
1547 | * |
1548 | * This function should be used by panic code. It stops ftrace | |
1549 | * but in a not so nice way. If you need to simply kill ftrace | |
1550 | * from a non-atomic section, use ftrace_kill. | |
1551 | */ | |
81adbdc0 | 1552 | void ftrace_kill(void) |
a2bb6a3d SR |
1553 | { |
1554 | ftrace_disabled = 1; | |
1555 | ftrace_enabled = 0; | |
a2bb6a3d SR |
1556 | clear_ftrace_function(); |
1557 | } | |
1558 | ||
16444a8a | 1559 | /** |
3d083395 SR |
1560 | * register_ftrace_function - register a function for profiling |
1561 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 1562 | * |
3d083395 SR |
1563 | * Register a function to be called by all functions in the |
1564 | * kernel. | |
1565 | * | |
1566 | * Note: @ops->func and all the functions it calls must be labeled | |
1567 | * with "notrace", otherwise it will go into a | |
1568 | * recursive loop. | |
16444a8a | 1569 | */ |
3d083395 | 1570 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 1571 | { |
b0fc494f SR |
1572 | int ret; |
1573 | ||
4eebcc81 SR |
1574 | if (unlikely(ftrace_disabled)) |
1575 | return -1; | |
1576 | ||
b0fc494f | 1577 | mutex_lock(&ftrace_sysctl_lock); |
e7d3737e FW |
1578 | |
1579 | if (ftrace_tracing_type == FTRACE_TYPE_RETURN) { | |
1580 | ret = -EBUSY; | |
1581 | goto out; | |
1582 | } | |
1583 | ||
b0fc494f | 1584 | ret = __register_ftrace_function(ops); |
5a45cfe1 | 1585 | ftrace_startup(0); |
b0fc494f | 1586 | |
e7d3737e FW |
1587 | out: |
1588 | mutex_unlock(&ftrace_sysctl_lock); | |
b0fc494f | 1589 | return ret; |
3d083395 SR |
1590 | } |
1591 | ||
1592 | /** | |
1593 | * unregister_ftrace_function - unresgister a function for profiling. | |
1594 | * @ops - ops structure that holds the function to unregister | |
1595 | * | |
1596 | * Unregister a function that was added to be called by ftrace profiling. | |
1597 | */ | |
1598 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
1599 | { | |
1600 | int ret; | |
1601 | ||
b0fc494f | 1602 | mutex_lock(&ftrace_sysctl_lock); |
3d083395 | 1603 | ret = __unregister_ftrace_function(ops); |
5a45cfe1 | 1604 | ftrace_shutdown(0); |
b0fc494f SR |
1605 | mutex_unlock(&ftrace_sysctl_lock); |
1606 | ||
1607 | return ret; | |
1608 | } | |
1609 | ||
e309b41d | 1610 | int |
b0fc494f | 1611 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
5072c59f | 1612 | struct file *file, void __user *buffer, size_t *lenp, |
b0fc494f SR |
1613 | loff_t *ppos) |
1614 | { | |
1615 | int ret; | |
1616 | ||
4eebcc81 SR |
1617 | if (unlikely(ftrace_disabled)) |
1618 | return -ENODEV; | |
1619 | ||
b0fc494f SR |
1620 | mutex_lock(&ftrace_sysctl_lock); |
1621 | ||
5072c59f | 1622 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
b0fc494f SR |
1623 | |
1624 | if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) | |
1625 | goto out; | |
1626 | ||
1627 | last_ftrace_enabled = ftrace_enabled; | |
1628 | ||
1629 | if (ftrace_enabled) { | |
1630 | ||
1631 | ftrace_startup_sysctl(); | |
1632 | ||
1633 | /* we are starting ftrace again */ | |
1634 | if (ftrace_list != &ftrace_list_end) { | |
1635 | if (ftrace_list->next == &ftrace_list_end) | |
1636 | ftrace_trace_function = ftrace_list->func; | |
1637 | else | |
1638 | ftrace_trace_function = ftrace_list_func; | |
1639 | } | |
1640 | ||
1641 | } else { | |
1642 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
1643 | ftrace_trace_function = ftrace_stub; | |
1644 | ||
1645 | ftrace_shutdown_sysctl(); | |
1646 | } | |
1647 | ||
1648 | out: | |
1649 | mutex_unlock(&ftrace_sysctl_lock); | |
3d083395 | 1650 | return ret; |
16444a8a | 1651 | } |
f17845e5 | 1652 | |
fb52607a | 1653 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 1654 | |
287b6e68 | 1655 | static atomic_t ftrace_graph_active; |
e7d3737e | 1656 | |
287b6e68 FW |
1657 | /* The callbacks that hook a function */ |
1658 | trace_func_graph_ret_t ftrace_graph_return = | |
1659 | (trace_func_graph_ret_t)ftrace_stub; | |
1660 | trace_func_graph_ent_t ftrace_graph_entry = | |
1661 | (trace_func_graph_ent_t)ftrace_stub; | |
f201ae23 FW |
1662 | |
1663 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
1664 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
1665 | { | |
1666 | int i; | |
1667 | int ret = 0; | |
1668 | unsigned long flags; | |
1669 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
1670 | struct task_struct *g, *t; | |
1671 | ||
1672 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
1673 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
1674 | * sizeof(struct ftrace_ret_stack), | |
1675 | GFP_KERNEL); | |
1676 | if (!ret_stack_list[i]) { | |
1677 | start = 0; | |
1678 | end = i; | |
1679 | ret = -ENOMEM; | |
1680 | goto free; | |
1681 | } | |
1682 | } | |
1683 | ||
1684 | read_lock_irqsave(&tasklist_lock, flags); | |
1685 | do_each_thread(g, t) { | |
1686 | if (start == end) { | |
1687 | ret = -EAGAIN; | |
1688 | goto unlock; | |
1689 | } | |
1690 | ||
1691 | if (t->ret_stack == NULL) { | |
1692 | t->ret_stack = ret_stack_list[start++]; | |
1693 | t->curr_ret_stack = -1; | |
1694 | atomic_set(&t->trace_overrun, 0); | |
1695 | } | |
1696 | } while_each_thread(g, t); | |
1697 | ||
1698 | unlock: | |
1699 | read_unlock_irqrestore(&tasklist_lock, flags); | |
1700 | free: | |
1701 | for (i = start; i < end; i++) | |
1702 | kfree(ret_stack_list[i]); | |
1703 | return ret; | |
1704 | } | |
1705 | ||
1706 | /* Allocate a return stack for each task */ | |
fb52607a | 1707 | static int start_graph_tracing(void) |
f201ae23 FW |
1708 | { |
1709 | struct ftrace_ret_stack **ret_stack_list; | |
1710 | int ret; | |
1711 | ||
1712 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
1713 | sizeof(struct ftrace_ret_stack *), | |
1714 | GFP_KERNEL); | |
1715 | ||
1716 | if (!ret_stack_list) | |
1717 | return -ENOMEM; | |
1718 | ||
1719 | do { | |
1720 | ret = alloc_retstack_tasklist(ret_stack_list); | |
1721 | } while (ret == -EAGAIN); | |
1722 | ||
1723 | kfree(ret_stack_list); | |
1724 | return ret; | |
1725 | } | |
1726 | ||
287b6e68 FW |
1727 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
1728 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 1729 | { |
e7d3737e FW |
1730 | int ret = 0; |
1731 | ||
1732 | mutex_lock(&ftrace_sysctl_lock); | |
1733 | ||
1734 | /* | |
1735 | * Don't launch return tracing if normal function | |
1736 | * tracing is already running. | |
1737 | */ | |
1738 | if (ftrace_trace_function != ftrace_stub) { | |
1739 | ret = -EBUSY; | |
1740 | goto out; | |
1741 | } | |
287b6e68 | 1742 | atomic_inc(&ftrace_graph_active); |
fb52607a | 1743 | ret = start_graph_tracing(); |
f201ae23 | 1744 | if (ret) { |
287b6e68 | 1745 | atomic_dec(&ftrace_graph_active); |
f201ae23 FW |
1746 | goto out; |
1747 | } | |
e7d3737e | 1748 | ftrace_tracing_type = FTRACE_TYPE_RETURN; |
287b6e68 FW |
1749 | ftrace_graph_return = retfunc; |
1750 | ftrace_graph_entry = entryfunc; | |
5a45cfe1 | 1751 | ftrace_startup(FTRACE_START_FUNC_RET); |
e7d3737e FW |
1752 | |
1753 | out: | |
1754 | mutex_unlock(&ftrace_sysctl_lock); | |
1755 | return ret; | |
15e6cb36 FW |
1756 | } |
1757 | ||
fb52607a | 1758 | void unregister_ftrace_graph(void) |
15e6cb36 | 1759 | { |
e7d3737e FW |
1760 | mutex_lock(&ftrace_sysctl_lock); |
1761 | ||
287b6e68 FW |
1762 | atomic_dec(&ftrace_graph_active); |
1763 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; | |
1764 | ftrace_graph_entry = (trace_func_graph_ent_t)ftrace_stub; | |
5a45cfe1 | 1765 | ftrace_shutdown(FTRACE_STOP_FUNC_RET); |
e7d3737e FW |
1766 | /* Restore normal tracing type */ |
1767 | ftrace_tracing_type = FTRACE_TYPE_ENTER; | |
1768 | ||
1769 | mutex_unlock(&ftrace_sysctl_lock); | |
15e6cb36 | 1770 | } |
f201ae23 FW |
1771 | |
1772 | /* Allocate a return stack for newly created task */ | |
fb52607a | 1773 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 1774 | { |
287b6e68 | 1775 | if (atomic_read(&ftrace_graph_active)) { |
f201ae23 FW |
1776 | t->ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH |
1777 | * sizeof(struct ftrace_ret_stack), | |
1778 | GFP_KERNEL); | |
1779 | if (!t->ret_stack) | |
1780 | return; | |
1781 | t->curr_ret_stack = -1; | |
1782 | atomic_set(&t->trace_overrun, 0); | |
1783 | } else | |
1784 | t->ret_stack = NULL; | |
1785 | } | |
1786 | ||
fb52607a | 1787 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 1788 | { |
eae849ca FW |
1789 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
1790 | ||
f201ae23 | 1791 | t->ret_stack = NULL; |
eae849ca FW |
1792 | /* NULL must become visible to IRQs before we free it: */ |
1793 | barrier(); | |
1794 | ||
1795 | kfree(ret_stack); | |
f201ae23 | 1796 | } |
15e6cb36 FW |
1797 | #endif |
1798 |