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