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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 | ||
4eebcc81 SR |
56 | /* |
57 | * ftrace_disabled is set when an anomaly is discovered. | |
58 | * ftrace_disabled is much stronger than ftrace_enabled. | |
59 | */ | |
60 | static int ftrace_disabled __read_mostly; | |
61 | ||
3d083395 | 62 | static DEFINE_SPINLOCK(ftrace_lock); |
b0fc494f | 63 | static DEFINE_MUTEX(ftrace_sysctl_lock); |
df4fc315 | 64 | static DEFINE_MUTEX(ftrace_start_lock); |
b0fc494f | 65 | |
16444a8a ACM |
66 | static struct ftrace_ops ftrace_list_end __read_mostly = |
67 | { | |
68 | .func = ftrace_stub, | |
69 | }; | |
70 | ||
71 | static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; | |
72 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; | |
60a7ecf4 | 73 | ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub; |
df4fc315 | 74 | ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; |
16444a8a | 75 | |
f2252935 | 76 | static void ftrace_list_func(unsigned long ip, unsigned long parent_ip) |
16444a8a ACM |
77 | { |
78 | struct ftrace_ops *op = ftrace_list; | |
79 | ||
80 | /* in case someone actually ports this to alpha! */ | |
81 | read_barrier_depends(); | |
82 | ||
83 | while (op != &ftrace_list_end) { | |
84 | /* silly alpha */ | |
85 | read_barrier_depends(); | |
86 | op->func(ip, parent_ip); | |
87 | op = op->next; | |
88 | }; | |
89 | } | |
90 | ||
df4fc315 SR |
91 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip) |
92 | { | |
93 | if (current->pid != ftrace_pid_trace) | |
94 | return; | |
95 | ||
96 | ftrace_pid_function(ip, parent_ip); | |
97 | } | |
98 | ||
99 | static void set_ftrace_pid_function(ftrace_func_t func) | |
100 | { | |
101 | /* do not set ftrace_pid_function to itself! */ | |
102 | if (func != ftrace_pid_func) | |
103 | ftrace_pid_function = func; | |
104 | } | |
105 | ||
16444a8a | 106 | /** |
3d083395 | 107 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 108 | * |
3d083395 SR |
109 | * This NULLs the ftrace function and in essence stops |
110 | * tracing. There may be lag | |
16444a8a | 111 | */ |
3d083395 | 112 | void clear_ftrace_function(void) |
16444a8a | 113 | { |
3d083395 | 114 | ftrace_trace_function = ftrace_stub; |
60a7ecf4 | 115 | __ftrace_trace_function = ftrace_stub; |
df4fc315 | 116 | ftrace_pid_function = ftrace_stub; |
3d083395 SR |
117 | } |
118 | ||
60a7ecf4 SR |
119 | #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
120 | /* | |
121 | * For those archs that do not test ftrace_trace_stop in their | |
122 | * mcount call site, we need to do it from C. | |
123 | */ | |
124 | static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip) | |
125 | { | |
126 | if (function_trace_stop) | |
127 | return; | |
128 | ||
129 | __ftrace_trace_function(ip, parent_ip); | |
130 | } | |
131 | #endif | |
132 | ||
e309b41d | 133 | static int __register_ftrace_function(struct ftrace_ops *ops) |
3d083395 | 134 | { |
99ecdc43 | 135 | /* should not be called from interrupt context */ |
3d083395 | 136 | spin_lock(&ftrace_lock); |
16444a8a | 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 | ||
156 | if (ftrace_pid_trace >= 0) { | |
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 SR |
172 | |
173 | spin_unlock(&ftrace_lock); | |
16444a8a ACM |
174 | |
175 | return 0; | |
176 | } | |
177 | ||
e309b41d | 178 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 179 | { |
16444a8a ACM |
180 | struct ftrace_ops **p; |
181 | int ret = 0; | |
182 | ||
99ecdc43 | 183 | /* should not be called from interrupt context */ |
3d083395 | 184 | spin_lock(&ftrace_lock); |
16444a8a ACM |
185 | |
186 | /* | |
3d083395 SR |
187 | * If we are removing the last function, then simply point |
188 | * to the ftrace_stub. | |
16444a8a ACM |
189 | */ |
190 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { | |
191 | ftrace_trace_function = ftrace_stub; | |
192 | ftrace_list = &ftrace_list_end; | |
193 | goto out; | |
194 | } | |
195 | ||
196 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) | |
197 | if (*p == ops) | |
198 | break; | |
199 | ||
200 | if (*p != ops) { | |
201 | ret = -1; | |
202 | goto out; | |
203 | } | |
204 | ||
205 | *p = (*p)->next; | |
206 | ||
b0fc494f SR |
207 | if (ftrace_enabled) { |
208 | /* If we only have one func left, then call that directly */ | |
df4fc315 SR |
209 | if (ftrace_list->next == &ftrace_list_end) { |
210 | ftrace_func_t func = ftrace_list->func; | |
211 | ||
212 | if (ftrace_pid_trace >= 0) { | |
213 | set_ftrace_pid_function(func); | |
214 | func = ftrace_pid_func; | |
215 | } | |
216 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
217 | ftrace_trace_function = func; | |
218 | #else | |
219 | __ftrace_trace_function = func; | |
220 | #endif | |
221 | } | |
b0fc494f | 222 | } |
16444a8a ACM |
223 | |
224 | out: | |
3d083395 SR |
225 | spin_unlock(&ftrace_lock); |
226 | ||
227 | return ret; | |
228 | } | |
229 | ||
df4fc315 SR |
230 | static void ftrace_update_pid_func(void) |
231 | { | |
232 | ftrace_func_t func; | |
233 | ||
234 | /* should not be called from interrupt context */ | |
235 | spin_lock(&ftrace_lock); | |
236 | ||
237 | if (ftrace_trace_function == ftrace_stub) | |
238 | goto out; | |
239 | ||
240 | func = ftrace_trace_function; | |
241 | ||
242 | if (ftrace_pid_trace >= 0) { | |
243 | set_ftrace_pid_function(func); | |
244 | func = ftrace_pid_func; | |
245 | } else { | |
66eafebc LW |
246 | if (func == ftrace_pid_func) |
247 | func = ftrace_pid_function; | |
df4fc315 SR |
248 | } |
249 | ||
250 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
251 | ftrace_trace_function = func; | |
252 | #else | |
253 | __ftrace_trace_function = func; | |
254 | #endif | |
255 | ||
256 | out: | |
257 | spin_unlock(&ftrace_lock); | |
258 | } | |
259 | ||
3d083395 | 260 | #ifdef CONFIG_DYNAMIC_FTRACE |
99ecdc43 | 261 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
cb7be3b2 | 262 | # error Dynamic ftrace depends on MCOUNT_RECORD |
99ecdc43 SR |
263 | #endif |
264 | ||
71c67d58 SN |
265 | /* |
266 | * Since MCOUNT_ADDR may point to mcount itself, we do not want | |
267 | * to get it confused by reading a reference in the code as we | |
268 | * are parsing on objcopy output of text. Use a variable for | |
269 | * it instead. | |
270 | */ | |
271 | static unsigned long mcount_addr = MCOUNT_ADDR; | |
272 | ||
d61f82d0 SR |
273 | enum { |
274 | FTRACE_ENABLE_CALLS = (1 << 0), | |
275 | FTRACE_DISABLE_CALLS = (1 << 1), | |
276 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
277 | FTRACE_ENABLE_MCOUNT = (1 << 3), | |
278 | FTRACE_DISABLE_MCOUNT = (1 << 4), | |
5a45cfe1 SR |
279 | FTRACE_START_FUNC_RET = (1 << 5), |
280 | FTRACE_STOP_FUNC_RET = (1 << 6), | |
d61f82d0 SR |
281 | }; |
282 | ||
5072c59f SR |
283 | static int ftrace_filtered; |
284 | ||
08f5ac90 | 285 | static LIST_HEAD(ftrace_new_addrs); |
3d083395 | 286 | |
41c52c0d | 287 | static DEFINE_MUTEX(ftrace_regex_lock); |
3d083395 | 288 | |
3c1720f0 SR |
289 | struct ftrace_page { |
290 | struct ftrace_page *next; | |
aa5e5cea | 291 | unsigned long index; |
3c1720f0 | 292 | struct dyn_ftrace records[]; |
aa5e5cea | 293 | }; |
3c1720f0 SR |
294 | |
295 | #define ENTRIES_PER_PAGE \ | |
296 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
297 | ||
298 | /* estimate from running different kernels */ | |
299 | #define NR_TO_INIT 10000 | |
300 | ||
301 | static struct ftrace_page *ftrace_pages_start; | |
302 | static struct ftrace_page *ftrace_pages; | |
303 | ||
37ad5084 SR |
304 | static struct dyn_ftrace *ftrace_free_records; |
305 | ||
ecea656d AS |
306 | |
307 | #ifdef CONFIG_KPROBES | |
f17845e5 IM |
308 | |
309 | static int frozen_record_count; | |
310 | ||
ecea656d AS |
311 | static inline void freeze_record(struct dyn_ftrace *rec) |
312 | { | |
313 | if (!(rec->flags & FTRACE_FL_FROZEN)) { | |
314 | rec->flags |= FTRACE_FL_FROZEN; | |
315 | frozen_record_count++; | |
316 | } | |
317 | } | |
318 | ||
319 | static inline void unfreeze_record(struct dyn_ftrace *rec) | |
320 | { | |
321 | if (rec->flags & FTRACE_FL_FROZEN) { | |
322 | rec->flags &= ~FTRACE_FL_FROZEN; | |
323 | frozen_record_count--; | |
324 | } | |
325 | } | |
326 | ||
327 | static inline int record_frozen(struct dyn_ftrace *rec) | |
328 | { | |
329 | return rec->flags & FTRACE_FL_FROZEN; | |
330 | } | |
331 | #else | |
332 | # define freeze_record(rec) ({ 0; }) | |
333 | # define unfreeze_record(rec) ({ 0; }) | |
334 | # define record_frozen(rec) ({ 0; }) | |
335 | #endif /* CONFIG_KPROBES */ | |
336 | ||
e309b41d | 337 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
37ad5084 | 338 | { |
37ad5084 SR |
339 | rec->ip = (unsigned long)ftrace_free_records; |
340 | ftrace_free_records = rec; | |
341 | rec->flags |= FTRACE_FL_FREE; | |
342 | } | |
343 | ||
fed1939c SR |
344 | void ftrace_release(void *start, unsigned long size) |
345 | { | |
346 | struct dyn_ftrace *rec; | |
347 | struct ftrace_page *pg; | |
348 | unsigned long s = (unsigned long)start; | |
349 | unsigned long e = s + size; | |
350 | int i; | |
351 | ||
00fd61ae | 352 | if (ftrace_disabled || !start) |
fed1939c SR |
353 | return; |
354 | ||
99ecdc43 | 355 | /* should not be called from interrupt context */ |
fed1939c SR |
356 | spin_lock(&ftrace_lock); |
357 | ||
358 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
359 | for (i = 0; i < pg->index; i++) { | |
360 | rec = &pg->records[i]; | |
361 | ||
362 | if ((rec->ip >= s) && (rec->ip < e)) | |
363 | ftrace_free_rec(rec); | |
364 | } | |
365 | } | |
366 | spin_unlock(&ftrace_lock); | |
fed1939c SR |
367 | } |
368 | ||
e309b41d | 369 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 370 | { |
37ad5084 SR |
371 | struct dyn_ftrace *rec; |
372 | ||
373 | /* First check for freed records */ | |
374 | if (ftrace_free_records) { | |
375 | rec = ftrace_free_records; | |
376 | ||
37ad5084 | 377 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
6912896e | 378 | FTRACE_WARN_ON_ONCE(1); |
37ad5084 SR |
379 | ftrace_free_records = NULL; |
380 | return NULL; | |
381 | } | |
382 | ||
383 | ftrace_free_records = (void *)rec->ip; | |
384 | memset(rec, 0, sizeof(*rec)); | |
385 | return rec; | |
386 | } | |
387 | ||
3c1720f0 | 388 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
08f5ac90 SR |
389 | if (!ftrace_pages->next) { |
390 | /* allocate another page */ | |
391 | ftrace_pages->next = | |
392 | (void *)get_zeroed_page(GFP_KERNEL); | |
393 | if (!ftrace_pages->next) | |
394 | return NULL; | |
395 | } | |
3c1720f0 SR |
396 | ftrace_pages = ftrace_pages->next; |
397 | } | |
398 | ||
399 | return &ftrace_pages->records[ftrace_pages->index++]; | |
400 | } | |
401 | ||
08f5ac90 | 402 | static struct dyn_ftrace * |
d61f82d0 | 403 | ftrace_record_ip(unsigned long ip) |
3d083395 | 404 | { |
08f5ac90 | 405 | struct dyn_ftrace *rec; |
3d083395 | 406 | |
f3c7ac40 | 407 | if (ftrace_disabled) |
08f5ac90 | 408 | return NULL; |
3d083395 | 409 | |
08f5ac90 SR |
410 | rec = ftrace_alloc_dyn_node(ip); |
411 | if (!rec) | |
412 | return NULL; | |
3d083395 | 413 | |
08f5ac90 | 414 | rec->ip = ip; |
3d083395 | 415 | |
08f5ac90 | 416 | list_add(&rec->list, &ftrace_new_addrs); |
3d083395 | 417 | |
08f5ac90 | 418 | return rec; |
3d083395 SR |
419 | } |
420 | ||
b17e8a37 SR |
421 | static void print_ip_ins(const char *fmt, unsigned char *p) |
422 | { | |
423 | int i; | |
424 | ||
425 | printk(KERN_CONT "%s", fmt); | |
426 | ||
427 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
428 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
429 | } | |
430 | ||
31e88909 | 431 | static void ftrace_bug(int failed, unsigned long ip) |
b17e8a37 SR |
432 | { |
433 | switch (failed) { | |
434 | case -EFAULT: | |
435 | FTRACE_WARN_ON_ONCE(1); | |
436 | pr_info("ftrace faulted on modifying "); | |
437 | print_ip_sym(ip); | |
438 | break; | |
439 | case -EINVAL: | |
440 | FTRACE_WARN_ON_ONCE(1); | |
441 | pr_info("ftrace failed to modify "); | |
442 | print_ip_sym(ip); | |
b17e8a37 | 443 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
444 | printk(KERN_CONT "\n"); |
445 | break; | |
446 | case -EPERM: | |
447 | FTRACE_WARN_ON_ONCE(1); | |
448 | pr_info("ftrace faulted on writing "); | |
449 | print_ip_sym(ip); | |
450 | break; | |
451 | default: | |
452 | FTRACE_WARN_ON_ONCE(1); | |
453 | pr_info("ftrace faulted on unknown error "); | |
454 | print_ip_sym(ip); | |
455 | } | |
456 | } | |
457 | ||
3c1720f0 | 458 | |
0eb96701 | 459 | static int |
31e88909 | 460 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) |
5072c59f | 461 | { |
41c52c0d | 462 | unsigned long ip, fl; |
e7d3737e FW |
463 | unsigned long ftrace_addr; |
464 | ||
e7d3737e | 465 | ftrace_addr = (unsigned long)ftrace_caller; |
5072c59f SR |
466 | |
467 | ip = rec->ip; | |
468 | ||
982c350b SR |
469 | /* |
470 | * If this record is not to be traced and | |
471 | * it is not enabled then do nothing. | |
472 | * | |
473 | * If this record is not to be traced and | |
474 | * it is enabled then disabled it. | |
475 | * | |
476 | */ | |
477 | if (rec->flags & FTRACE_FL_NOTRACE) { | |
478 | if (rec->flags & FTRACE_FL_ENABLED) | |
479 | rec->flags &= ~FTRACE_FL_ENABLED; | |
480 | else | |
481 | return 0; | |
482 | ||
483 | } else if (ftrace_filtered && enable) { | |
5072c59f | 484 | /* |
982c350b | 485 | * Filtering is on: |
5072c59f | 486 | */ |
a4500b84 | 487 | |
982c350b | 488 | fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED); |
5072c59f | 489 | |
982c350b SR |
490 | /* Record is filtered and enabled, do nothing */ |
491 | if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) | |
0eb96701 | 492 | return 0; |
5072c59f | 493 | |
982c350b SR |
494 | /* Record is not filtered and is not enabled do nothing */ |
495 | if (!fl) | |
496 | return 0; | |
497 | ||
498 | /* Record is not filtered but enabled, disable it */ | |
499 | if (fl == FTRACE_FL_ENABLED) | |
5072c59f | 500 | rec->flags &= ~FTRACE_FL_ENABLED; |
982c350b SR |
501 | else |
502 | /* Otherwise record is filtered but not enabled, enable it */ | |
5072c59f | 503 | rec->flags |= FTRACE_FL_ENABLED; |
5072c59f | 504 | } else { |
982c350b | 505 | /* Disable or not filtered */ |
5072c59f | 506 | |
41c52c0d | 507 | if (enable) { |
982c350b | 508 | /* if record is enabled, do nothing */ |
5072c59f | 509 | if (rec->flags & FTRACE_FL_ENABLED) |
0eb96701 | 510 | return 0; |
982c350b | 511 | |
5072c59f | 512 | rec->flags |= FTRACE_FL_ENABLED; |
982c350b | 513 | |
5072c59f | 514 | } else { |
982c350b SR |
515 | |
516 | /* if record is not enabled do nothing */ | |
5072c59f | 517 | if (!(rec->flags & FTRACE_FL_ENABLED)) |
0eb96701 | 518 | return 0; |
982c350b | 519 | |
5072c59f SR |
520 | rec->flags &= ~FTRACE_FL_ENABLED; |
521 | } | |
522 | } | |
523 | ||
982c350b | 524 | if (rec->flags & FTRACE_FL_ENABLED) |
e7d3737e | 525 | return ftrace_make_call(rec, ftrace_addr); |
31e88909 | 526 | else |
e7d3737e | 527 | return ftrace_make_nop(NULL, rec, ftrace_addr); |
5072c59f SR |
528 | } |
529 | ||
e309b41d | 530 | static void ftrace_replace_code(int enable) |
3c1720f0 | 531 | { |
0eb96701 | 532 | int i, failed; |
3c1720f0 SR |
533 | struct dyn_ftrace *rec; |
534 | struct ftrace_page *pg; | |
3c1720f0 | 535 | |
3c1720f0 SR |
536 | for (pg = ftrace_pages_start; pg; pg = pg->next) { |
537 | for (i = 0; i < pg->index; i++) { | |
538 | rec = &pg->records[i]; | |
539 | ||
918c1154 SR |
540 | /* |
541 | * Skip over free records and records that have | |
542 | * failed. | |
543 | */ | |
544 | if (rec->flags & FTRACE_FL_FREE || | |
545 | rec->flags & FTRACE_FL_FAILED) | |
3c1720f0 SR |
546 | continue; |
547 | ||
f22f9a89 | 548 | /* ignore updates to this record's mcount site */ |
98a05ed4 AS |
549 | if (get_kprobe((void *)rec->ip)) { |
550 | freeze_record(rec); | |
f22f9a89 | 551 | continue; |
98a05ed4 AS |
552 | } else { |
553 | unfreeze_record(rec); | |
554 | } | |
f22f9a89 | 555 | |
31e88909 | 556 | failed = __ftrace_replace_code(rec, enable); |
0eb96701 AS |
557 | if (failed && (rec->flags & FTRACE_FL_CONVERTED)) { |
558 | rec->flags |= FTRACE_FL_FAILED; | |
559 | if ((system_state == SYSTEM_BOOTING) || | |
34078a5e | 560 | !core_kernel_text(rec->ip)) { |
0eb96701 | 561 | ftrace_free_rec(rec); |
b17e8a37 | 562 | } else |
31e88909 | 563 | ftrace_bug(failed, rec->ip); |
0eb96701 | 564 | } |
3c1720f0 SR |
565 | } |
566 | } | |
567 | } | |
568 | ||
492a7ea5 | 569 | static int |
31e88909 | 570 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 SR |
571 | { |
572 | unsigned long ip; | |
593eb8a2 | 573 | int ret; |
3c1720f0 SR |
574 | |
575 | ip = rec->ip; | |
576 | ||
31e88909 | 577 | ret = ftrace_make_nop(mod, rec, mcount_addr); |
593eb8a2 | 578 | if (ret) { |
31e88909 | 579 | ftrace_bug(ret, ip); |
3c1720f0 | 580 | rec->flags |= FTRACE_FL_FAILED; |
492a7ea5 | 581 | return 0; |
37ad5084 | 582 | } |
492a7ea5 | 583 | return 1; |
3c1720f0 SR |
584 | } |
585 | ||
e309b41d | 586 | static int __ftrace_modify_code(void *data) |
3d083395 | 587 | { |
d61f82d0 SR |
588 | int *command = data; |
589 | ||
a3583244 | 590 | if (*command & FTRACE_ENABLE_CALLS) |
d61f82d0 | 591 | ftrace_replace_code(1); |
a3583244 | 592 | else if (*command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
593 | ftrace_replace_code(0); |
594 | ||
595 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
596 | ftrace_update_ftrace_func(ftrace_trace_function); | |
597 | ||
5a45cfe1 SR |
598 | if (*command & FTRACE_START_FUNC_RET) |
599 | ftrace_enable_ftrace_graph_caller(); | |
600 | else if (*command & FTRACE_STOP_FUNC_RET) | |
601 | ftrace_disable_ftrace_graph_caller(); | |
602 | ||
d61f82d0 | 603 | return 0; |
3d083395 SR |
604 | } |
605 | ||
e309b41d | 606 | static void ftrace_run_update_code(int command) |
3d083395 | 607 | { |
784e2d76 | 608 | stop_machine(__ftrace_modify_code, &command, NULL); |
3d083395 SR |
609 | } |
610 | ||
d61f82d0 | 611 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 612 | static int ftrace_start_up; |
df4fc315 SR |
613 | |
614 | static void ftrace_startup_enable(int command) | |
615 | { | |
616 | if (saved_ftrace_func != ftrace_trace_function) { | |
617 | saved_ftrace_func = ftrace_trace_function; | |
618 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
619 | } | |
620 | ||
621 | if (!command || !ftrace_enabled) | |
622 | return; | |
623 | ||
624 | ftrace_run_update_code(command); | |
625 | } | |
d61f82d0 | 626 | |
5a45cfe1 | 627 | static void ftrace_startup(int command) |
3d083395 | 628 | { |
4eebcc81 SR |
629 | if (unlikely(ftrace_disabled)) |
630 | return; | |
631 | ||
cb7be3b2 | 632 | mutex_lock(&ftrace_start_lock); |
60a7ecf4 | 633 | ftrace_start_up++; |
982c350b | 634 | command |= FTRACE_ENABLE_CALLS; |
d61f82d0 | 635 | |
df4fc315 | 636 | ftrace_startup_enable(command); |
3d083395 | 637 | |
cb7be3b2 | 638 | mutex_unlock(&ftrace_start_lock); |
3d083395 SR |
639 | } |
640 | ||
5a45cfe1 | 641 | static void ftrace_shutdown(int command) |
3d083395 | 642 | { |
4eebcc81 SR |
643 | if (unlikely(ftrace_disabled)) |
644 | return; | |
645 | ||
cb7be3b2 | 646 | mutex_lock(&ftrace_start_lock); |
60a7ecf4 SR |
647 | ftrace_start_up--; |
648 | if (!ftrace_start_up) | |
d61f82d0 | 649 | command |= FTRACE_DISABLE_CALLS; |
3d083395 | 650 | |
d61f82d0 SR |
651 | if (saved_ftrace_func != ftrace_trace_function) { |
652 | saved_ftrace_func = ftrace_trace_function; | |
653 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
654 | } | |
3d083395 | 655 | |
d61f82d0 SR |
656 | if (!command || !ftrace_enabled) |
657 | goto out; | |
658 | ||
659 | ftrace_run_update_code(command); | |
3d083395 | 660 | out: |
cb7be3b2 | 661 | mutex_unlock(&ftrace_start_lock); |
3d083395 SR |
662 | } |
663 | ||
e309b41d | 664 | static void ftrace_startup_sysctl(void) |
b0fc494f | 665 | { |
d61f82d0 SR |
666 | int command = FTRACE_ENABLE_MCOUNT; |
667 | ||
4eebcc81 SR |
668 | if (unlikely(ftrace_disabled)) |
669 | return; | |
670 | ||
cb7be3b2 | 671 | mutex_lock(&ftrace_start_lock); |
d61f82d0 SR |
672 | /* Force update next time */ |
673 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
674 | /* ftrace_start_up is true if we want ftrace running */ |
675 | if (ftrace_start_up) | |
d61f82d0 SR |
676 | command |= FTRACE_ENABLE_CALLS; |
677 | ||
678 | ftrace_run_update_code(command); | |
cb7be3b2 | 679 | mutex_unlock(&ftrace_start_lock); |
b0fc494f SR |
680 | } |
681 | ||
e309b41d | 682 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 683 | { |
d61f82d0 SR |
684 | int command = FTRACE_DISABLE_MCOUNT; |
685 | ||
4eebcc81 SR |
686 | if (unlikely(ftrace_disabled)) |
687 | return; | |
688 | ||
cb7be3b2 | 689 | mutex_lock(&ftrace_start_lock); |
60a7ecf4 SR |
690 | /* ftrace_start_up is true if ftrace is running */ |
691 | if (ftrace_start_up) | |
d61f82d0 SR |
692 | command |= FTRACE_DISABLE_CALLS; |
693 | ||
694 | ftrace_run_update_code(command); | |
cb7be3b2 | 695 | mutex_unlock(&ftrace_start_lock); |
b0fc494f SR |
696 | } |
697 | ||
3d083395 SR |
698 | static cycle_t ftrace_update_time; |
699 | static unsigned long ftrace_update_cnt; | |
700 | unsigned long ftrace_update_tot_cnt; | |
701 | ||
31e88909 | 702 | static int ftrace_update_code(struct module *mod) |
3d083395 | 703 | { |
08f5ac90 | 704 | struct dyn_ftrace *p, *t; |
f22f9a89 | 705 | cycle_t start, stop; |
3d083395 | 706 | |
750ed1a4 | 707 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
708 | ftrace_update_cnt = 0; |
709 | ||
08f5ac90 | 710 | list_for_each_entry_safe(p, t, &ftrace_new_addrs, list) { |
3d083395 | 711 | |
08f5ac90 SR |
712 | /* If something went wrong, bail without enabling anything */ |
713 | if (unlikely(ftrace_disabled)) | |
714 | return -1; | |
f22f9a89 | 715 | |
08f5ac90 | 716 | list_del_init(&p->list); |
f22f9a89 | 717 | |
08f5ac90 | 718 | /* convert record (i.e, patch mcount-call with NOP) */ |
31e88909 | 719 | if (ftrace_code_disable(mod, p)) { |
08f5ac90 SR |
720 | p->flags |= FTRACE_FL_CONVERTED; |
721 | ftrace_update_cnt++; | |
722 | } else | |
723 | ftrace_free_rec(p); | |
3d083395 SR |
724 | } |
725 | ||
750ed1a4 | 726 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
727 | ftrace_update_time = stop - start; |
728 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
729 | ||
16444a8a ACM |
730 | return 0; |
731 | } | |
732 | ||
68bf21aa | 733 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
734 | { |
735 | struct ftrace_page *pg; | |
736 | int cnt; | |
737 | int i; | |
3c1720f0 SR |
738 | |
739 | /* allocate a few pages */ | |
740 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
741 | if (!ftrace_pages_start) | |
742 | return -1; | |
743 | ||
744 | /* | |
745 | * Allocate a few more pages. | |
746 | * | |
747 | * TODO: have some parser search vmlinux before | |
748 | * final linking to find all calls to ftrace. | |
749 | * Then we can: | |
750 | * a) know how many pages to allocate. | |
751 | * and/or | |
752 | * b) set up the table then. | |
753 | * | |
754 | * The dynamic code is still necessary for | |
755 | * modules. | |
756 | */ | |
757 | ||
758 | pg = ftrace_pages = ftrace_pages_start; | |
759 | ||
68bf21aa | 760 | cnt = num_to_init / ENTRIES_PER_PAGE; |
08f5ac90 | 761 | pr_info("ftrace: allocating %ld entries in %d pages\n", |
5821e1b7 | 762 | num_to_init, cnt + 1); |
3c1720f0 SR |
763 | |
764 | for (i = 0; i < cnt; i++) { | |
765 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
766 | ||
767 | /* If we fail, we'll try later anyway */ | |
768 | if (!pg->next) | |
769 | break; | |
770 | ||
771 | pg = pg->next; | |
772 | } | |
773 | ||
774 | return 0; | |
775 | } | |
776 | ||
5072c59f SR |
777 | enum { |
778 | FTRACE_ITER_FILTER = (1 << 0), | |
779 | FTRACE_ITER_CONT = (1 << 1), | |
41c52c0d | 780 | FTRACE_ITER_NOTRACE = (1 << 2), |
eb9a7bf0 | 781 | FTRACE_ITER_FAILURES = (1 << 3), |
5072c59f SR |
782 | }; |
783 | ||
784 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
785 | ||
786 | struct ftrace_iterator { | |
5072c59f SR |
787 | struct ftrace_page *pg; |
788 | unsigned idx; | |
789 | unsigned flags; | |
790 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
791 | unsigned buffer_idx; | |
792 | unsigned filtered; | |
793 | }; | |
794 | ||
e309b41d | 795 | static void * |
5072c59f SR |
796 | t_next(struct seq_file *m, void *v, loff_t *pos) |
797 | { | |
798 | struct ftrace_iterator *iter = m->private; | |
799 | struct dyn_ftrace *rec = NULL; | |
800 | ||
801 | (*pos)++; | |
802 | ||
99ecdc43 SR |
803 | /* should not be called from interrupt context */ |
804 | spin_lock(&ftrace_lock); | |
5072c59f SR |
805 | retry: |
806 | if (iter->idx >= iter->pg->index) { | |
807 | if (iter->pg->next) { | |
808 | iter->pg = iter->pg->next; | |
809 | iter->idx = 0; | |
810 | goto retry; | |
50cdaf08 LW |
811 | } else { |
812 | iter->idx = -1; | |
5072c59f SR |
813 | } |
814 | } else { | |
815 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
816 | if ((rec->flags & FTRACE_FL_FREE) || |
817 | ||
818 | (!(iter->flags & FTRACE_ITER_FAILURES) && | |
eb9a7bf0 AS |
819 | (rec->flags & FTRACE_FL_FAILED)) || |
820 | ||
821 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
a9fdda33 | 822 | !(rec->flags & FTRACE_FL_FAILED)) || |
eb9a7bf0 | 823 | |
0183fb1c SR |
824 | ((iter->flags & FTRACE_ITER_FILTER) && |
825 | !(rec->flags & FTRACE_FL_FILTER)) || | |
826 | ||
41c52c0d SR |
827 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
828 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
829 | rec = NULL; |
830 | goto retry; | |
831 | } | |
832 | } | |
99ecdc43 | 833 | spin_unlock(&ftrace_lock); |
5072c59f | 834 | |
5072c59f SR |
835 | return rec; |
836 | } | |
837 | ||
838 | static void *t_start(struct seq_file *m, loff_t *pos) | |
839 | { | |
840 | struct ftrace_iterator *iter = m->private; | |
841 | void *p = NULL; | |
5072c59f | 842 | |
50cdaf08 LW |
843 | if (*pos > 0) { |
844 | if (iter->idx < 0) | |
845 | return p; | |
846 | (*pos)--; | |
847 | iter->idx--; | |
848 | } | |
5821e1b7 | 849 | |
50cdaf08 | 850 | p = t_next(m, p, pos); |
5072c59f SR |
851 | |
852 | return p; | |
853 | } | |
854 | ||
855 | static void t_stop(struct seq_file *m, void *p) | |
856 | { | |
857 | } | |
858 | ||
859 | static int t_show(struct seq_file *m, void *v) | |
860 | { | |
861 | struct dyn_ftrace *rec = v; | |
862 | char str[KSYM_SYMBOL_LEN]; | |
863 | ||
864 | if (!rec) | |
865 | return 0; | |
866 | ||
867 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
868 | ||
50cdaf08 | 869 | seq_printf(m, "%s\n", str); |
5072c59f SR |
870 | |
871 | return 0; | |
872 | } | |
873 | ||
874 | static struct seq_operations show_ftrace_seq_ops = { | |
875 | .start = t_start, | |
876 | .next = t_next, | |
877 | .stop = t_stop, | |
878 | .show = t_show, | |
879 | }; | |
880 | ||
e309b41d | 881 | static int |
5072c59f SR |
882 | ftrace_avail_open(struct inode *inode, struct file *file) |
883 | { | |
884 | struct ftrace_iterator *iter; | |
885 | int ret; | |
886 | ||
4eebcc81 SR |
887 | if (unlikely(ftrace_disabled)) |
888 | return -ENODEV; | |
889 | ||
5072c59f SR |
890 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
891 | if (!iter) | |
892 | return -ENOMEM; | |
893 | ||
894 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
895 | |
896 | ret = seq_open(file, &show_ftrace_seq_ops); | |
897 | if (!ret) { | |
898 | struct seq_file *m = file->private_data; | |
4bf39a94 | 899 | |
5072c59f | 900 | m->private = iter; |
4bf39a94 | 901 | } else { |
5072c59f | 902 | kfree(iter); |
4bf39a94 | 903 | } |
5072c59f SR |
904 | |
905 | return ret; | |
906 | } | |
907 | ||
908 | int ftrace_avail_release(struct inode *inode, struct file *file) | |
909 | { | |
910 | struct seq_file *m = (struct seq_file *)file->private_data; | |
911 | struct ftrace_iterator *iter = m->private; | |
912 | ||
913 | seq_release(inode, file); | |
914 | kfree(iter); | |
4bf39a94 | 915 | |
5072c59f SR |
916 | return 0; |
917 | } | |
918 | ||
eb9a7bf0 AS |
919 | static int |
920 | ftrace_failures_open(struct inode *inode, struct file *file) | |
921 | { | |
922 | int ret; | |
923 | struct seq_file *m; | |
924 | struct ftrace_iterator *iter; | |
925 | ||
926 | ret = ftrace_avail_open(inode, file); | |
927 | if (!ret) { | |
928 | m = (struct seq_file *)file->private_data; | |
929 | iter = (struct ftrace_iterator *)m->private; | |
930 | iter->flags = FTRACE_ITER_FAILURES; | |
931 | } | |
932 | ||
933 | return ret; | |
934 | } | |
935 | ||
936 | ||
41c52c0d | 937 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
938 | { |
939 | struct ftrace_page *pg; | |
940 | struct dyn_ftrace *rec; | |
41c52c0d | 941 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f SR |
942 | unsigned i; |
943 | ||
99ecdc43 SR |
944 | /* should not be called from interrupt context */ |
945 | spin_lock(&ftrace_lock); | |
41c52c0d SR |
946 | if (enable) |
947 | ftrace_filtered = 0; | |
5072c59f SR |
948 | pg = ftrace_pages_start; |
949 | while (pg) { | |
950 | for (i = 0; i < pg->index; i++) { | |
951 | rec = &pg->records[i]; | |
952 | if (rec->flags & FTRACE_FL_FAILED) | |
953 | continue; | |
41c52c0d | 954 | rec->flags &= ~type; |
5072c59f SR |
955 | } |
956 | pg = pg->next; | |
957 | } | |
99ecdc43 | 958 | spin_unlock(&ftrace_lock); |
5072c59f SR |
959 | } |
960 | ||
e309b41d | 961 | static int |
41c52c0d | 962 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
963 | { |
964 | struct ftrace_iterator *iter; | |
965 | int ret = 0; | |
966 | ||
4eebcc81 SR |
967 | if (unlikely(ftrace_disabled)) |
968 | return -ENODEV; | |
969 | ||
5072c59f SR |
970 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
971 | if (!iter) | |
972 | return -ENOMEM; | |
973 | ||
41c52c0d | 974 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
975 | if ((file->f_mode & FMODE_WRITE) && |
976 | !(file->f_flags & O_APPEND)) | |
41c52c0d | 977 | ftrace_filter_reset(enable); |
5072c59f SR |
978 | |
979 | if (file->f_mode & FMODE_READ) { | |
980 | iter->pg = ftrace_pages_start; | |
41c52c0d SR |
981 | iter->flags = enable ? FTRACE_ITER_FILTER : |
982 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
983 | |
984 | ret = seq_open(file, &show_ftrace_seq_ops); | |
985 | if (!ret) { | |
986 | struct seq_file *m = file->private_data; | |
987 | m->private = iter; | |
988 | } else | |
989 | kfree(iter); | |
990 | } else | |
991 | file->private_data = iter; | |
41c52c0d | 992 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
993 | |
994 | return ret; | |
995 | } | |
996 | ||
41c52c0d SR |
997 | static int |
998 | ftrace_filter_open(struct inode *inode, struct file *file) | |
999 | { | |
1000 | return ftrace_regex_open(inode, file, 1); | |
1001 | } | |
1002 | ||
1003 | static int | |
1004 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
1005 | { | |
1006 | return ftrace_regex_open(inode, file, 0); | |
1007 | } | |
1008 | ||
e309b41d | 1009 | static ssize_t |
41c52c0d | 1010 | ftrace_regex_read(struct file *file, char __user *ubuf, |
5072c59f SR |
1011 | size_t cnt, loff_t *ppos) |
1012 | { | |
1013 | if (file->f_mode & FMODE_READ) | |
1014 | return seq_read(file, ubuf, cnt, ppos); | |
1015 | else | |
1016 | return -EPERM; | |
1017 | } | |
1018 | ||
e309b41d | 1019 | static loff_t |
41c52c0d | 1020 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
1021 | { |
1022 | loff_t ret; | |
1023 | ||
1024 | if (file->f_mode & FMODE_READ) | |
1025 | ret = seq_lseek(file, offset, origin); | |
1026 | else | |
1027 | file->f_pos = ret = 1; | |
1028 | ||
1029 | return ret; | |
1030 | } | |
1031 | ||
1032 | enum { | |
1033 | MATCH_FULL, | |
1034 | MATCH_FRONT_ONLY, | |
1035 | MATCH_MIDDLE_ONLY, | |
1036 | MATCH_END_ONLY, | |
1037 | }; | |
1038 | ||
e309b41d | 1039 | static void |
41c52c0d | 1040 | ftrace_match(unsigned char *buff, int len, int enable) |
5072c59f SR |
1041 | { |
1042 | char str[KSYM_SYMBOL_LEN]; | |
1043 | char *search = NULL; | |
1044 | struct ftrace_page *pg; | |
1045 | struct dyn_ftrace *rec; | |
1046 | int type = MATCH_FULL; | |
41c52c0d | 1047 | unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f SR |
1048 | unsigned i, match = 0, search_len = 0; |
1049 | ||
1050 | for (i = 0; i < len; i++) { | |
1051 | if (buff[i] == '*') { | |
1052 | if (!i) { | |
1053 | search = buff + i + 1; | |
1054 | type = MATCH_END_ONLY; | |
1055 | search_len = len - (i + 1); | |
1056 | } else { | |
1057 | if (type == MATCH_END_ONLY) { | |
1058 | type = MATCH_MIDDLE_ONLY; | |
1059 | } else { | |
1060 | match = i; | |
1061 | type = MATCH_FRONT_ONLY; | |
1062 | } | |
1063 | buff[i] = 0; | |
1064 | break; | |
1065 | } | |
1066 | } | |
1067 | } | |
1068 | ||
99ecdc43 SR |
1069 | /* should not be called from interrupt context */ |
1070 | spin_lock(&ftrace_lock); | |
41c52c0d SR |
1071 | if (enable) |
1072 | ftrace_filtered = 1; | |
5072c59f SR |
1073 | pg = ftrace_pages_start; |
1074 | while (pg) { | |
1075 | for (i = 0; i < pg->index; i++) { | |
1076 | int matched = 0; | |
1077 | char *ptr; | |
1078 | ||
1079 | rec = &pg->records[i]; | |
1080 | if (rec->flags & FTRACE_FL_FAILED) | |
1081 | continue; | |
1082 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1083 | switch (type) { | |
1084 | case MATCH_FULL: | |
1085 | if (strcmp(str, buff) == 0) | |
1086 | matched = 1; | |
1087 | break; | |
1088 | case MATCH_FRONT_ONLY: | |
1089 | if (memcmp(str, buff, match) == 0) | |
1090 | matched = 1; | |
1091 | break; | |
1092 | case MATCH_MIDDLE_ONLY: | |
1093 | if (strstr(str, search)) | |
1094 | matched = 1; | |
1095 | break; | |
1096 | case MATCH_END_ONLY: | |
1097 | ptr = strstr(str, search); | |
1098 | if (ptr && (ptr[search_len] == 0)) | |
1099 | matched = 1; | |
1100 | break; | |
1101 | } | |
1102 | if (matched) | |
41c52c0d | 1103 | rec->flags |= flag; |
5072c59f SR |
1104 | } |
1105 | pg = pg->next; | |
1106 | } | |
99ecdc43 | 1107 | spin_unlock(&ftrace_lock); |
5072c59f SR |
1108 | } |
1109 | ||
e309b41d | 1110 | static ssize_t |
41c52c0d SR |
1111 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
1112 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
1113 | { |
1114 | struct ftrace_iterator *iter; | |
1115 | char ch; | |
1116 | size_t read = 0; | |
1117 | ssize_t ret; | |
1118 | ||
1119 | if (!cnt || cnt < 0) | |
1120 | return 0; | |
1121 | ||
41c52c0d | 1122 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1123 | |
1124 | if (file->f_mode & FMODE_READ) { | |
1125 | struct seq_file *m = file->private_data; | |
1126 | iter = m->private; | |
1127 | } else | |
1128 | iter = file->private_data; | |
1129 | ||
1130 | if (!*ppos) { | |
1131 | iter->flags &= ~FTRACE_ITER_CONT; | |
1132 | iter->buffer_idx = 0; | |
1133 | } | |
1134 | ||
1135 | ret = get_user(ch, ubuf++); | |
1136 | if (ret) | |
1137 | goto out; | |
1138 | read++; | |
1139 | cnt--; | |
1140 | ||
1141 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { | |
1142 | /* skip white space */ | |
1143 | while (cnt && isspace(ch)) { | |
1144 | ret = get_user(ch, ubuf++); | |
1145 | if (ret) | |
1146 | goto out; | |
1147 | read++; | |
1148 | cnt--; | |
1149 | } | |
1150 | ||
5072c59f SR |
1151 | if (isspace(ch)) { |
1152 | file->f_pos += read; | |
1153 | ret = read; | |
1154 | goto out; | |
1155 | } | |
1156 | ||
1157 | iter->buffer_idx = 0; | |
1158 | } | |
1159 | ||
1160 | while (cnt && !isspace(ch)) { | |
1161 | if (iter->buffer_idx < FTRACE_BUFF_MAX) | |
1162 | iter->buffer[iter->buffer_idx++] = ch; | |
1163 | else { | |
1164 | ret = -EINVAL; | |
1165 | goto out; | |
1166 | } | |
1167 | ret = get_user(ch, ubuf++); | |
1168 | if (ret) | |
1169 | goto out; | |
1170 | read++; | |
1171 | cnt--; | |
1172 | } | |
1173 | ||
1174 | if (isspace(ch)) { | |
1175 | iter->filtered++; | |
1176 | iter->buffer[iter->buffer_idx] = 0; | |
41c52c0d | 1177 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1178 | iter->buffer_idx = 0; |
1179 | } else | |
1180 | iter->flags |= FTRACE_ITER_CONT; | |
1181 | ||
1182 | ||
1183 | file->f_pos += read; | |
1184 | ||
1185 | ret = read; | |
1186 | out: | |
41c52c0d | 1187 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1188 | |
1189 | return ret; | |
1190 | } | |
1191 | ||
41c52c0d SR |
1192 | static ssize_t |
1193 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
1194 | size_t cnt, loff_t *ppos) | |
1195 | { | |
1196 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
1197 | } | |
1198 | ||
1199 | static ssize_t | |
1200 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
1201 | size_t cnt, loff_t *ppos) | |
1202 | { | |
1203 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
1204 | } | |
1205 | ||
1206 | static void | |
1207 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
1208 | { | |
1209 | if (unlikely(ftrace_disabled)) | |
1210 | return; | |
1211 | ||
1212 | mutex_lock(&ftrace_regex_lock); | |
1213 | if (reset) | |
1214 | ftrace_filter_reset(enable); | |
1215 | if (buf) | |
1216 | ftrace_match(buf, len, enable); | |
1217 | mutex_unlock(&ftrace_regex_lock); | |
1218 | } | |
1219 | ||
77a2b37d SR |
1220 | /** |
1221 | * ftrace_set_filter - set a function to filter on in ftrace | |
1222 | * @buf - the string that holds the function filter text. | |
1223 | * @len - the length of the string. | |
1224 | * @reset - non zero to reset all filters before applying this filter. | |
1225 | * | |
1226 | * Filters denote which functions should be enabled when tracing is enabled. | |
1227 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
1228 | */ | |
e309b41d | 1229 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 1230 | { |
41c52c0d SR |
1231 | ftrace_set_regex(buf, len, reset, 1); |
1232 | } | |
4eebcc81 | 1233 | |
41c52c0d SR |
1234 | /** |
1235 | * ftrace_set_notrace - set a function to not trace in ftrace | |
1236 | * @buf - the string that holds the function notrace text. | |
1237 | * @len - the length of the string. | |
1238 | * @reset - non zero to reset all filters before applying this filter. | |
1239 | * | |
1240 | * Notrace Filters denote which functions should not be enabled when tracing | |
1241 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
1242 | * for tracing. | |
1243 | */ | |
1244 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
1245 | { | |
1246 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
1247 | } |
1248 | ||
e309b41d | 1249 | static int |
41c52c0d | 1250 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1251 | { |
1252 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1253 | struct ftrace_iterator *iter; | |
1254 | ||
41c52c0d | 1255 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1256 | if (file->f_mode & FMODE_READ) { |
1257 | iter = m->private; | |
1258 | ||
1259 | seq_release(inode, file); | |
1260 | } else | |
1261 | iter = file->private_data; | |
1262 | ||
1263 | if (iter->buffer_idx) { | |
1264 | iter->filtered++; | |
1265 | iter->buffer[iter->buffer_idx] = 0; | |
41c52c0d | 1266 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1267 | } |
1268 | ||
1269 | mutex_lock(&ftrace_sysctl_lock); | |
cb7be3b2 | 1270 | mutex_lock(&ftrace_start_lock); |
ee02a2e5 | 1271 | if (ftrace_start_up && ftrace_enabled) |
5072c59f | 1272 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
cb7be3b2 | 1273 | mutex_unlock(&ftrace_start_lock); |
5072c59f SR |
1274 | mutex_unlock(&ftrace_sysctl_lock); |
1275 | ||
1276 | kfree(iter); | |
41c52c0d | 1277 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1278 | return 0; |
1279 | } | |
1280 | ||
41c52c0d SR |
1281 | static int |
1282 | ftrace_filter_release(struct inode *inode, struct file *file) | |
1283 | { | |
1284 | return ftrace_regex_release(inode, file, 1); | |
1285 | } | |
1286 | ||
1287 | static int | |
1288 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
1289 | { | |
1290 | return ftrace_regex_release(inode, file, 0); | |
1291 | } | |
1292 | ||
5072c59f SR |
1293 | static struct file_operations ftrace_avail_fops = { |
1294 | .open = ftrace_avail_open, | |
1295 | .read = seq_read, | |
1296 | .llseek = seq_lseek, | |
1297 | .release = ftrace_avail_release, | |
1298 | }; | |
1299 | ||
eb9a7bf0 AS |
1300 | static struct file_operations ftrace_failures_fops = { |
1301 | .open = ftrace_failures_open, | |
1302 | .read = seq_read, | |
1303 | .llseek = seq_lseek, | |
1304 | .release = ftrace_avail_release, | |
1305 | }; | |
1306 | ||
5072c59f SR |
1307 | static struct file_operations ftrace_filter_fops = { |
1308 | .open = ftrace_filter_open, | |
41c52c0d | 1309 | .read = ftrace_regex_read, |
5072c59f | 1310 | .write = ftrace_filter_write, |
41c52c0d | 1311 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
1312 | .release = ftrace_filter_release, |
1313 | }; | |
1314 | ||
41c52c0d SR |
1315 | static struct file_operations ftrace_notrace_fops = { |
1316 | .open = ftrace_notrace_open, | |
1317 | .read = ftrace_regex_read, | |
1318 | .write = ftrace_notrace_write, | |
1319 | .llseek = ftrace_regex_lseek, | |
1320 | .release = ftrace_notrace_release, | |
1321 | }; | |
1322 | ||
ea4e2bc4 SR |
1323 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
1324 | ||
1325 | static DEFINE_MUTEX(graph_lock); | |
1326 | ||
1327 | int ftrace_graph_count; | |
1328 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; | |
1329 | ||
1330 | static void * | |
1331 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
1332 | { | |
1333 | unsigned long *array = m->private; | |
1334 | int index = *pos; | |
1335 | ||
1336 | (*pos)++; | |
1337 | ||
1338 | if (index >= ftrace_graph_count) | |
1339 | return NULL; | |
1340 | ||
1341 | return &array[index]; | |
1342 | } | |
1343 | ||
1344 | static void *g_start(struct seq_file *m, loff_t *pos) | |
1345 | { | |
1346 | void *p = NULL; | |
1347 | ||
1348 | mutex_lock(&graph_lock); | |
1349 | ||
1350 | p = g_next(m, p, pos); | |
1351 | ||
1352 | return p; | |
1353 | } | |
1354 | ||
1355 | static void g_stop(struct seq_file *m, void *p) | |
1356 | { | |
1357 | mutex_unlock(&graph_lock); | |
1358 | } | |
1359 | ||
1360 | static int g_show(struct seq_file *m, void *v) | |
1361 | { | |
1362 | unsigned long *ptr = v; | |
1363 | char str[KSYM_SYMBOL_LEN]; | |
1364 | ||
1365 | if (!ptr) | |
1366 | return 0; | |
1367 | ||
1368 | kallsyms_lookup(*ptr, NULL, NULL, NULL, str); | |
1369 | ||
1370 | seq_printf(m, "%s\n", str); | |
1371 | ||
1372 | return 0; | |
1373 | } | |
1374 | ||
1375 | static struct seq_operations ftrace_graph_seq_ops = { | |
1376 | .start = g_start, | |
1377 | .next = g_next, | |
1378 | .stop = g_stop, | |
1379 | .show = g_show, | |
1380 | }; | |
1381 | ||
1382 | static int | |
1383 | ftrace_graph_open(struct inode *inode, struct file *file) | |
1384 | { | |
1385 | int ret = 0; | |
1386 | ||
1387 | if (unlikely(ftrace_disabled)) | |
1388 | return -ENODEV; | |
1389 | ||
1390 | mutex_lock(&graph_lock); | |
1391 | if ((file->f_mode & FMODE_WRITE) && | |
1392 | !(file->f_flags & O_APPEND)) { | |
1393 | ftrace_graph_count = 0; | |
1394 | memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); | |
1395 | } | |
1396 | ||
1397 | if (file->f_mode & FMODE_READ) { | |
1398 | ret = seq_open(file, &ftrace_graph_seq_ops); | |
1399 | if (!ret) { | |
1400 | struct seq_file *m = file->private_data; | |
1401 | m->private = ftrace_graph_funcs; | |
1402 | } | |
1403 | } else | |
1404 | file->private_data = ftrace_graph_funcs; | |
1405 | mutex_unlock(&graph_lock); | |
1406 | ||
1407 | return ret; | |
1408 | } | |
1409 | ||
1410 | static ssize_t | |
1411 | ftrace_graph_read(struct file *file, char __user *ubuf, | |
1412 | size_t cnt, loff_t *ppos) | |
1413 | { | |
1414 | if (file->f_mode & FMODE_READ) | |
1415 | return seq_read(file, ubuf, cnt, ppos); | |
1416 | else | |
1417 | return -EPERM; | |
1418 | } | |
1419 | ||
1420 | static int | |
1421 | ftrace_set_func(unsigned long *array, int idx, char *buffer) | |
1422 | { | |
1423 | char str[KSYM_SYMBOL_LEN]; | |
1424 | struct dyn_ftrace *rec; | |
1425 | struct ftrace_page *pg; | |
1426 | int found = 0; | |
1427 | int i; | |
1428 | ||
1429 | if (ftrace_disabled) | |
1430 | return -ENODEV; | |
1431 | ||
1432 | /* should not be called from interrupt context */ | |
1433 | spin_lock(&ftrace_lock); | |
1434 | ||
1435 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
1436 | for (i = 0; i < pg->index; i++) { | |
1437 | rec = &pg->records[i]; | |
1438 | ||
1439 | if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE)) | |
1440 | continue; | |
1441 | ||
1442 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1443 | if (strcmp(str, buffer) == 0) { | |
1444 | found = 1; | |
1445 | array[idx] = rec->ip; | |
1446 | break; | |
1447 | } | |
1448 | } | |
1449 | } | |
1450 | spin_unlock(&ftrace_lock); | |
1451 | ||
1452 | return found ? 0 : -EINVAL; | |
1453 | } | |
1454 | ||
1455 | static ssize_t | |
1456 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
1457 | size_t cnt, loff_t *ppos) | |
1458 | { | |
1459 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
1460 | unsigned long *array; | |
1461 | size_t read = 0; | |
1462 | ssize_t ret; | |
1463 | int index = 0; | |
1464 | char ch; | |
1465 | ||
1466 | if (!cnt || cnt < 0) | |
1467 | return 0; | |
1468 | ||
1469 | mutex_lock(&graph_lock); | |
1470 | ||
1471 | if (ftrace_graph_count >= FTRACE_GRAPH_MAX_FUNCS) { | |
1472 | ret = -EBUSY; | |
1473 | goto out; | |
1474 | } | |
1475 | ||
1476 | if (file->f_mode & FMODE_READ) { | |
1477 | struct seq_file *m = file->private_data; | |
1478 | array = m->private; | |
1479 | } else | |
1480 | array = file->private_data; | |
1481 | ||
1482 | ret = get_user(ch, ubuf++); | |
1483 | if (ret) | |
1484 | goto out; | |
1485 | read++; | |
1486 | cnt--; | |
1487 | ||
1488 | /* skip white space */ | |
1489 | while (cnt && isspace(ch)) { | |
1490 | ret = get_user(ch, ubuf++); | |
1491 | if (ret) | |
1492 | goto out; | |
1493 | read++; | |
1494 | cnt--; | |
1495 | } | |
1496 | ||
1497 | if (isspace(ch)) { | |
1498 | *ppos += read; | |
1499 | ret = read; | |
1500 | goto out; | |
1501 | } | |
1502 | ||
1503 | while (cnt && !isspace(ch)) { | |
1504 | if (index < FTRACE_BUFF_MAX) | |
1505 | buffer[index++] = ch; | |
1506 | else { | |
1507 | ret = -EINVAL; | |
1508 | goto out; | |
1509 | } | |
1510 | ret = get_user(ch, ubuf++); | |
1511 | if (ret) | |
1512 | goto out; | |
1513 | read++; | |
1514 | cnt--; | |
1515 | } | |
1516 | buffer[index] = 0; | |
1517 | ||
1518 | /* we allow only one at a time */ | |
1519 | ret = ftrace_set_func(array, ftrace_graph_count, buffer); | |
1520 | if (ret) | |
1521 | goto out; | |
1522 | ||
1523 | ftrace_graph_count++; | |
1524 | ||
1525 | file->f_pos += read; | |
1526 | ||
1527 | ret = read; | |
1528 | out: | |
1529 | mutex_unlock(&graph_lock); | |
1530 | ||
1531 | return ret; | |
1532 | } | |
1533 | ||
1534 | static const struct file_operations ftrace_graph_fops = { | |
1535 | .open = ftrace_graph_open, | |
1536 | .read = ftrace_graph_read, | |
1537 | .write = ftrace_graph_write, | |
1538 | }; | |
1539 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
1540 | ||
df4fc315 | 1541 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 1542 | { |
5072c59f SR |
1543 | struct dentry *entry; |
1544 | ||
5072c59f SR |
1545 | entry = debugfs_create_file("available_filter_functions", 0444, |
1546 | d_tracer, NULL, &ftrace_avail_fops); | |
1547 | if (!entry) | |
1548 | pr_warning("Could not create debugfs " | |
1549 | "'available_filter_functions' entry\n"); | |
1550 | ||
eb9a7bf0 AS |
1551 | entry = debugfs_create_file("failures", 0444, |
1552 | d_tracer, NULL, &ftrace_failures_fops); | |
1553 | if (!entry) | |
1554 | pr_warning("Could not create debugfs 'failures' entry\n"); | |
1555 | ||
5072c59f SR |
1556 | entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer, |
1557 | NULL, &ftrace_filter_fops); | |
1558 | if (!entry) | |
1559 | pr_warning("Could not create debugfs " | |
1560 | "'set_ftrace_filter' entry\n"); | |
41c52c0d SR |
1561 | |
1562 | entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer, | |
1563 | NULL, &ftrace_notrace_fops); | |
1564 | if (!entry) | |
1565 | pr_warning("Could not create debugfs " | |
1566 | "'set_ftrace_notrace' entry\n"); | |
ad90c0e3 | 1567 | |
ea4e2bc4 SR |
1568 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
1569 | entry = debugfs_create_file("set_graph_function", 0444, d_tracer, | |
1570 | NULL, | |
1571 | &ftrace_graph_fops); | |
1572 | if (!entry) | |
1573 | pr_warning("Could not create debugfs " | |
1574 | "'set_graph_function' entry\n"); | |
1575 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
1576 | ||
5072c59f SR |
1577 | return 0; |
1578 | } | |
1579 | ||
31e88909 SR |
1580 | static int ftrace_convert_nops(struct module *mod, |
1581 | unsigned long *start, | |
68bf21aa SR |
1582 | unsigned long *end) |
1583 | { | |
1584 | unsigned long *p; | |
1585 | unsigned long addr; | |
1586 | unsigned long flags; | |
1587 | ||
08f5ac90 | 1588 | mutex_lock(&ftrace_start_lock); |
68bf21aa SR |
1589 | p = start; |
1590 | while (p < end) { | |
1591 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
1592 | /* |
1593 | * Some architecture linkers will pad between | |
1594 | * the different mcount_loc sections of different | |
1595 | * object files to satisfy alignments. | |
1596 | * Skip any NULL pointers. | |
1597 | */ | |
1598 | if (!addr) | |
1599 | continue; | |
68bf21aa | 1600 | ftrace_record_ip(addr); |
68bf21aa SR |
1601 | } |
1602 | ||
08f5ac90 | 1603 | /* disable interrupts to prevent kstop machine */ |
68bf21aa | 1604 | local_irq_save(flags); |
31e88909 | 1605 | ftrace_update_code(mod); |
68bf21aa | 1606 | local_irq_restore(flags); |
08f5ac90 | 1607 | mutex_unlock(&ftrace_start_lock); |
68bf21aa SR |
1608 | |
1609 | return 0; | |
1610 | } | |
1611 | ||
31e88909 SR |
1612 | void ftrace_init_module(struct module *mod, |
1613 | unsigned long *start, unsigned long *end) | |
90d595fe | 1614 | { |
00fd61ae | 1615 | if (ftrace_disabled || start == end) |
fed1939c | 1616 | return; |
31e88909 | 1617 | ftrace_convert_nops(mod, start, end); |
90d595fe SR |
1618 | } |
1619 | ||
68bf21aa SR |
1620 | extern unsigned long __start_mcount_loc[]; |
1621 | extern unsigned long __stop_mcount_loc[]; | |
1622 | ||
1623 | void __init ftrace_init(void) | |
1624 | { | |
1625 | unsigned long count, addr, flags; | |
1626 | int ret; | |
1627 | ||
1628 | /* Keep the ftrace pointer to the stub */ | |
1629 | addr = (unsigned long)ftrace_stub; | |
1630 | ||
1631 | local_irq_save(flags); | |
1632 | ftrace_dyn_arch_init(&addr); | |
1633 | local_irq_restore(flags); | |
1634 | ||
1635 | /* ftrace_dyn_arch_init places the return code in addr */ | |
1636 | if (addr) | |
1637 | goto failed; | |
1638 | ||
1639 | count = __stop_mcount_loc - __start_mcount_loc; | |
1640 | ||
1641 | ret = ftrace_dyn_table_alloc(count); | |
1642 | if (ret) | |
1643 | goto failed; | |
1644 | ||
1645 | last_ftrace_enabled = ftrace_enabled = 1; | |
1646 | ||
31e88909 SR |
1647 | ret = ftrace_convert_nops(NULL, |
1648 | __start_mcount_loc, | |
68bf21aa SR |
1649 | __stop_mcount_loc); |
1650 | ||
1651 | return; | |
1652 | failed: | |
1653 | ftrace_disabled = 1; | |
1654 | } | |
68bf21aa | 1655 | |
3d083395 | 1656 | #else |
0b6e4d56 FW |
1657 | |
1658 | static int __init ftrace_nodyn_init(void) | |
1659 | { | |
1660 | ftrace_enabled = 1; | |
1661 | return 0; | |
1662 | } | |
1663 | device_initcall(ftrace_nodyn_init); | |
1664 | ||
df4fc315 SR |
1665 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
1666 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 SR |
1667 | /* Keep as macros so we do not need to define the commands */ |
1668 | # define ftrace_startup(command) do { } while (0) | |
1669 | # define ftrace_shutdown(command) do { } while (0) | |
c7aafc54 IM |
1670 | # define ftrace_startup_sysctl() do { } while (0) |
1671 | # define ftrace_shutdown_sysctl() do { } while (0) | |
3d083395 SR |
1672 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
1673 | ||
df4fc315 SR |
1674 | static ssize_t |
1675 | ftrace_pid_read(struct file *file, char __user *ubuf, | |
1676 | size_t cnt, loff_t *ppos) | |
1677 | { | |
1678 | char buf[64]; | |
1679 | int r; | |
1680 | ||
1681 | if (ftrace_pid_trace >= 0) | |
1682 | r = sprintf(buf, "%u\n", ftrace_pid_trace); | |
1683 | else | |
1684 | r = sprintf(buf, "no pid\n"); | |
1685 | ||
1686 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
1687 | } | |
1688 | ||
1689 | static ssize_t | |
1690 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
1691 | size_t cnt, loff_t *ppos) | |
1692 | { | |
1693 | char buf[64]; | |
1694 | long val; | |
1695 | int ret; | |
1696 | ||
1697 | if (cnt >= sizeof(buf)) | |
1698 | return -EINVAL; | |
1699 | ||
1700 | if (copy_from_user(&buf, ubuf, cnt)) | |
1701 | return -EFAULT; | |
1702 | ||
1703 | buf[cnt] = 0; | |
1704 | ||
1705 | ret = strict_strtol(buf, 10, &val); | |
1706 | if (ret < 0) | |
1707 | return ret; | |
1708 | ||
1709 | mutex_lock(&ftrace_start_lock); | |
1710 | if (ret < 0) { | |
1711 | /* disable pid tracing */ | |
1712 | if (ftrace_pid_trace < 0) | |
1713 | goto out; | |
1714 | ftrace_pid_trace = -1; | |
1715 | ||
1716 | } else { | |
1717 | ||
1718 | if (ftrace_pid_trace == val) | |
1719 | goto out; | |
1720 | ||
1721 | ftrace_pid_trace = val; | |
1722 | } | |
1723 | ||
1724 | /* update the function call */ | |
1725 | ftrace_update_pid_func(); | |
1726 | ftrace_startup_enable(0); | |
1727 | ||
1728 | out: | |
1729 | mutex_unlock(&ftrace_start_lock); | |
1730 | ||
1731 | return cnt; | |
1732 | } | |
1733 | ||
1734 | static struct file_operations ftrace_pid_fops = { | |
1735 | .read = ftrace_pid_read, | |
1736 | .write = ftrace_pid_write, | |
1737 | }; | |
1738 | ||
1739 | static __init int ftrace_init_debugfs(void) | |
1740 | { | |
1741 | struct dentry *d_tracer; | |
1742 | struct dentry *entry; | |
1743 | ||
1744 | d_tracer = tracing_init_dentry(); | |
1745 | if (!d_tracer) | |
1746 | return 0; | |
1747 | ||
1748 | ftrace_init_dyn_debugfs(d_tracer); | |
1749 | ||
1750 | entry = debugfs_create_file("set_ftrace_pid", 0644, d_tracer, | |
1751 | NULL, &ftrace_pid_fops); | |
1752 | if (!entry) | |
1753 | pr_warning("Could not create debugfs " | |
1754 | "'set_ftrace_pid' entry\n"); | |
1755 | return 0; | |
1756 | } | |
1757 | ||
1758 | fs_initcall(ftrace_init_debugfs); | |
1759 | ||
a2bb6a3d | 1760 | /** |
81adbdc0 | 1761 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
1762 | * |
1763 | * This function should be used by panic code. It stops ftrace | |
1764 | * but in a not so nice way. If you need to simply kill ftrace | |
1765 | * from a non-atomic section, use ftrace_kill. | |
1766 | */ | |
81adbdc0 | 1767 | void ftrace_kill(void) |
a2bb6a3d SR |
1768 | { |
1769 | ftrace_disabled = 1; | |
1770 | ftrace_enabled = 0; | |
a2bb6a3d SR |
1771 | clear_ftrace_function(); |
1772 | } | |
1773 | ||
16444a8a | 1774 | /** |
3d083395 SR |
1775 | * register_ftrace_function - register a function for profiling |
1776 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 1777 | * |
3d083395 SR |
1778 | * Register a function to be called by all functions in the |
1779 | * kernel. | |
1780 | * | |
1781 | * Note: @ops->func and all the functions it calls must be labeled | |
1782 | * with "notrace", otherwise it will go into a | |
1783 | * recursive loop. | |
16444a8a | 1784 | */ |
3d083395 | 1785 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 1786 | { |
b0fc494f SR |
1787 | int ret; |
1788 | ||
4eebcc81 SR |
1789 | if (unlikely(ftrace_disabled)) |
1790 | return -1; | |
1791 | ||
b0fc494f | 1792 | mutex_lock(&ftrace_sysctl_lock); |
e7d3737e | 1793 | |
b0fc494f | 1794 | ret = __register_ftrace_function(ops); |
5a45cfe1 | 1795 | ftrace_startup(0); |
b0fc494f | 1796 | |
e7d3737e | 1797 | mutex_unlock(&ftrace_sysctl_lock); |
b0fc494f | 1798 | return ret; |
3d083395 SR |
1799 | } |
1800 | ||
1801 | /** | |
1802 | * unregister_ftrace_function - unresgister a function for profiling. | |
1803 | * @ops - ops structure that holds the function to unregister | |
1804 | * | |
1805 | * Unregister a function that was added to be called by ftrace profiling. | |
1806 | */ | |
1807 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
1808 | { | |
1809 | int ret; | |
1810 | ||
b0fc494f | 1811 | mutex_lock(&ftrace_sysctl_lock); |
3d083395 | 1812 | ret = __unregister_ftrace_function(ops); |
5a45cfe1 | 1813 | ftrace_shutdown(0); |
b0fc494f SR |
1814 | mutex_unlock(&ftrace_sysctl_lock); |
1815 | ||
1816 | return ret; | |
1817 | } | |
1818 | ||
e309b41d | 1819 | int |
b0fc494f | 1820 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
5072c59f | 1821 | struct file *file, void __user *buffer, size_t *lenp, |
b0fc494f SR |
1822 | loff_t *ppos) |
1823 | { | |
1824 | int ret; | |
1825 | ||
4eebcc81 SR |
1826 | if (unlikely(ftrace_disabled)) |
1827 | return -ENODEV; | |
1828 | ||
b0fc494f SR |
1829 | mutex_lock(&ftrace_sysctl_lock); |
1830 | ||
5072c59f | 1831 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
b0fc494f SR |
1832 | |
1833 | if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) | |
1834 | goto out; | |
1835 | ||
1836 | last_ftrace_enabled = ftrace_enabled; | |
1837 | ||
1838 | if (ftrace_enabled) { | |
1839 | ||
1840 | ftrace_startup_sysctl(); | |
1841 | ||
1842 | /* we are starting ftrace again */ | |
1843 | if (ftrace_list != &ftrace_list_end) { | |
1844 | if (ftrace_list->next == &ftrace_list_end) | |
1845 | ftrace_trace_function = ftrace_list->func; | |
1846 | else | |
1847 | ftrace_trace_function = ftrace_list_func; | |
1848 | } | |
1849 | ||
1850 | } else { | |
1851 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
1852 | ftrace_trace_function = ftrace_stub; | |
1853 | ||
1854 | ftrace_shutdown_sysctl(); | |
1855 | } | |
1856 | ||
1857 | out: | |
1858 | mutex_unlock(&ftrace_sysctl_lock); | |
3d083395 | 1859 | return ret; |
16444a8a | 1860 | } |
f17845e5 | 1861 | |
fb52607a | 1862 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 1863 | |
287b6e68 | 1864 | static atomic_t ftrace_graph_active; |
e7d3737e | 1865 | |
e49dc19c SR |
1866 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
1867 | { | |
1868 | return 0; | |
1869 | } | |
1870 | ||
287b6e68 FW |
1871 | /* The callbacks that hook a function */ |
1872 | trace_func_graph_ret_t ftrace_graph_return = | |
1873 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 1874 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
1875 | |
1876 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
1877 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
1878 | { | |
1879 | int i; | |
1880 | int ret = 0; | |
1881 | unsigned long flags; | |
1882 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
1883 | struct task_struct *g, *t; | |
1884 | ||
1885 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
1886 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
1887 | * sizeof(struct ftrace_ret_stack), | |
1888 | GFP_KERNEL); | |
1889 | if (!ret_stack_list[i]) { | |
1890 | start = 0; | |
1891 | end = i; | |
1892 | ret = -ENOMEM; | |
1893 | goto free; | |
1894 | } | |
1895 | } | |
1896 | ||
1897 | read_lock_irqsave(&tasklist_lock, flags); | |
1898 | do_each_thread(g, t) { | |
1899 | if (start == end) { | |
1900 | ret = -EAGAIN; | |
1901 | goto unlock; | |
1902 | } | |
1903 | ||
1904 | if (t->ret_stack == NULL) { | |
f201ae23 | 1905 | t->curr_ret_stack = -1; |
48d68b20 FW |
1906 | /* Make sure IRQs see the -1 first: */ |
1907 | barrier(); | |
1908 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
1909 | atomic_set(&t->trace_overrun, 0); |
1910 | } | |
1911 | } while_each_thread(g, t); | |
1912 | ||
1913 | unlock: | |
1914 | read_unlock_irqrestore(&tasklist_lock, flags); | |
1915 | free: | |
1916 | for (i = start; i < end; i++) | |
1917 | kfree(ret_stack_list[i]); | |
1918 | return ret; | |
1919 | } | |
1920 | ||
1921 | /* Allocate a return stack for each task */ | |
fb52607a | 1922 | static int start_graph_tracing(void) |
f201ae23 FW |
1923 | { |
1924 | struct ftrace_ret_stack **ret_stack_list; | |
1925 | int ret; | |
1926 | ||
1927 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
1928 | sizeof(struct ftrace_ret_stack *), | |
1929 | GFP_KERNEL); | |
1930 | ||
1931 | if (!ret_stack_list) | |
1932 | return -ENOMEM; | |
1933 | ||
1934 | do { | |
1935 | ret = alloc_retstack_tasklist(ret_stack_list); | |
1936 | } while (ret == -EAGAIN); | |
1937 | ||
1938 | kfree(ret_stack_list); | |
1939 | return ret; | |
1940 | } | |
1941 | ||
287b6e68 FW |
1942 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
1943 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 1944 | { |
e7d3737e FW |
1945 | int ret = 0; |
1946 | ||
1947 | mutex_lock(&ftrace_sysctl_lock); | |
1948 | ||
287b6e68 | 1949 | atomic_inc(&ftrace_graph_active); |
fb52607a | 1950 | ret = start_graph_tracing(); |
f201ae23 | 1951 | if (ret) { |
287b6e68 | 1952 | atomic_dec(&ftrace_graph_active); |
f201ae23 FW |
1953 | goto out; |
1954 | } | |
e53a6319 | 1955 | |
287b6e68 FW |
1956 | ftrace_graph_return = retfunc; |
1957 | ftrace_graph_entry = entryfunc; | |
e53a6319 | 1958 | |
5a45cfe1 | 1959 | ftrace_startup(FTRACE_START_FUNC_RET); |
e7d3737e FW |
1960 | |
1961 | out: | |
1962 | mutex_unlock(&ftrace_sysctl_lock); | |
1963 | return ret; | |
15e6cb36 FW |
1964 | } |
1965 | ||
fb52607a | 1966 | void unregister_ftrace_graph(void) |
15e6cb36 | 1967 | { |
e7d3737e FW |
1968 | mutex_lock(&ftrace_sysctl_lock); |
1969 | ||
287b6e68 FW |
1970 | atomic_dec(&ftrace_graph_active); |
1971 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 1972 | ftrace_graph_entry = ftrace_graph_entry_stub; |
5a45cfe1 | 1973 | ftrace_shutdown(FTRACE_STOP_FUNC_RET); |
e7d3737e FW |
1974 | |
1975 | mutex_unlock(&ftrace_sysctl_lock); | |
15e6cb36 | 1976 | } |
f201ae23 FW |
1977 | |
1978 | /* Allocate a return stack for newly created task */ | |
fb52607a | 1979 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 1980 | { |
287b6e68 | 1981 | if (atomic_read(&ftrace_graph_active)) { |
f201ae23 FW |
1982 | t->ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH |
1983 | * sizeof(struct ftrace_ret_stack), | |
1984 | GFP_KERNEL); | |
1985 | if (!t->ret_stack) | |
1986 | return; | |
1987 | t->curr_ret_stack = -1; | |
1988 | atomic_set(&t->trace_overrun, 0); | |
1989 | } else | |
1990 | t->ret_stack = NULL; | |
1991 | } | |
1992 | ||
fb52607a | 1993 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 1994 | { |
eae849ca FW |
1995 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
1996 | ||
f201ae23 | 1997 | t->ret_stack = NULL; |
eae849ca FW |
1998 | /* NULL must become visible to IRQs before we free it: */ |
1999 | barrier(); | |
2000 | ||
2001 | kfree(ret_stack); | |
f201ae23 | 2002 | } |
14a866c5 SR |
2003 | |
2004 | void ftrace_graph_stop(void) | |
2005 | { | |
2006 | ftrace_stop(); | |
2007 | } | |
15e6cb36 FW |
2008 | #endif |
2009 |