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 | ||
df4fc315 | 221 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 222 | return; |
df4fc315 SR |
223 | |
224 | func = ftrace_trace_function; | |
225 | ||
978f3a45 | 226 | if (ftrace_pid_trace) { |
df4fc315 SR |
227 | set_ftrace_pid_function(func); |
228 | func = ftrace_pid_func; | |
229 | } else { | |
66eafebc LW |
230 | if (func == ftrace_pid_func) |
231 | func = ftrace_pid_function; | |
df4fc315 SR |
232 | } |
233 | ||
234 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
235 | ftrace_trace_function = func; | |
236 | #else | |
237 | __ftrace_trace_function = func; | |
238 | #endif | |
df4fc315 SR |
239 | } |
240 | ||
73d3fd96 IM |
241 | /* set when tracing only a pid */ |
242 | struct pid *ftrace_pid_trace; | |
243 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; | |
244 | ||
3d083395 | 245 | #ifdef CONFIG_DYNAMIC_FTRACE |
73d3fd96 | 246 | |
99ecdc43 | 247 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
cb7be3b2 | 248 | # error Dynamic ftrace depends on MCOUNT_RECORD |
99ecdc43 SR |
249 | #endif |
250 | ||
8fc0c701 SR |
251 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; |
252 | ||
b6887d79 | 253 | struct ftrace_func_probe { |
8fc0c701 | 254 | struct hlist_node node; |
b6887d79 | 255 | struct ftrace_probe_ops *ops; |
8fc0c701 SR |
256 | unsigned long flags; |
257 | unsigned long ip; | |
258 | void *data; | |
259 | struct rcu_head rcu; | |
260 | }; | |
261 | ||
262 | ||
d61f82d0 SR |
263 | enum { |
264 | FTRACE_ENABLE_CALLS = (1 << 0), | |
265 | FTRACE_DISABLE_CALLS = (1 << 1), | |
266 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
267 | FTRACE_ENABLE_MCOUNT = (1 << 3), | |
268 | FTRACE_DISABLE_MCOUNT = (1 << 4), | |
5a45cfe1 SR |
269 | FTRACE_START_FUNC_RET = (1 << 5), |
270 | FTRACE_STOP_FUNC_RET = (1 << 6), | |
d61f82d0 SR |
271 | }; |
272 | ||
5072c59f SR |
273 | static int ftrace_filtered; |
274 | ||
08f5ac90 | 275 | static LIST_HEAD(ftrace_new_addrs); |
3d083395 | 276 | |
41c52c0d | 277 | static DEFINE_MUTEX(ftrace_regex_lock); |
3d083395 | 278 | |
3c1720f0 SR |
279 | struct ftrace_page { |
280 | struct ftrace_page *next; | |
431aa3fb | 281 | int index; |
3c1720f0 | 282 | struct dyn_ftrace records[]; |
aa5e5cea | 283 | }; |
3c1720f0 SR |
284 | |
285 | #define ENTRIES_PER_PAGE \ | |
286 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
287 | ||
288 | /* estimate from running different kernels */ | |
289 | #define NR_TO_INIT 10000 | |
290 | ||
291 | static struct ftrace_page *ftrace_pages_start; | |
292 | static struct ftrace_page *ftrace_pages; | |
293 | ||
37ad5084 SR |
294 | static struct dyn_ftrace *ftrace_free_records; |
295 | ||
265c831c SR |
296 | /* |
297 | * This is a double for. Do not use 'break' to break out of the loop, | |
298 | * you must use a goto. | |
299 | */ | |
300 | #define do_for_each_ftrace_rec(pg, rec) \ | |
301 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
302 | int _____i; \ | |
303 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
304 | rec = &pg->records[_____i]; | |
305 | ||
306 | #define while_for_each_ftrace_rec() \ | |
307 | } \ | |
308 | } | |
ecea656d AS |
309 | |
310 | #ifdef CONFIG_KPROBES | |
f17845e5 IM |
311 | |
312 | static int frozen_record_count; | |
313 | ||
ecea656d AS |
314 | static inline void freeze_record(struct dyn_ftrace *rec) |
315 | { | |
316 | if (!(rec->flags & FTRACE_FL_FROZEN)) { | |
317 | rec->flags |= FTRACE_FL_FROZEN; | |
318 | frozen_record_count++; | |
319 | } | |
320 | } | |
321 | ||
322 | static inline void unfreeze_record(struct dyn_ftrace *rec) | |
323 | { | |
324 | if (rec->flags & FTRACE_FL_FROZEN) { | |
325 | rec->flags &= ~FTRACE_FL_FROZEN; | |
326 | frozen_record_count--; | |
327 | } | |
328 | } | |
329 | ||
330 | static inline int record_frozen(struct dyn_ftrace *rec) | |
331 | { | |
332 | return rec->flags & FTRACE_FL_FROZEN; | |
333 | } | |
334 | #else | |
335 | # define freeze_record(rec) ({ 0; }) | |
336 | # define unfreeze_record(rec) ({ 0; }) | |
337 | # define record_frozen(rec) ({ 0; }) | |
338 | #endif /* CONFIG_KPROBES */ | |
339 | ||
e309b41d | 340 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
37ad5084 | 341 | { |
37ad5084 SR |
342 | rec->ip = (unsigned long)ftrace_free_records; |
343 | ftrace_free_records = rec; | |
344 | rec->flags |= FTRACE_FL_FREE; | |
345 | } | |
346 | ||
fed1939c SR |
347 | void ftrace_release(void *start, unsigned long size) |
348 | { | |
349 | struct dyn_ftrace *rec; | |
350 | struct ftrace_page *pg; | |
351 | unsigned long s = (unsigned long)start; | |
352 | unsigned long e = s + size; | |
fed1939c | 353 | |
00fd61ae | 354 | if (ftrace_disabled || !start) |
fed1939c SR |
355 | return; |
356 | ||
52baf119 | 357 | mutex_lock(&ftrace_lock); |
265c831c | 358 | do_for_each_ftrace_rec(pg, rec) { |
b00f0b6d Z |
359 | if ((rec->ip >= s) && (rec->ip < e) && |
360 | !(rec->flags & FTRACE_FL_FREE)) | |
265c831c SR |
361 | ftrace_free_rec(rec); |
362 | } while_for_each_ftrace_rec(); | |
52baf119 | 363 | mutex_unlock(&ftrace_lock); |
fed1939c SR |
364 | } |
365 | ||
e309b41d | 366 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 367 | { |
37ad5084 SR |
368 | struct dyn_ftrace *rec; |
369 | ||
370 | /* First check for freed records */ | |
371 | if (ftrace_free_records) { | |
372 | rec = ftrace_free_records; | |
373 | ||
37ad5084 | 374 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
6912896e | 375 | FTRACE_WARN_ON_ONCE(1); |
37ad5084 SR |
376 | ftrace_free_records = NULL; |
377 | return NULL; | |
378 | } | |
379 | ||
380 | ftrace_free_records = (void *)rec->ip; | |
381 | memset(rec, 0, sizeof(*rec)); | |
382 | return rec; | |
383 | } | |
384 | ||
3c1720f0 | 385 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
08f5ac90 SR |
386 | if (!ftrace_pages->next) { |
387 | /* allocate another page */ | |
388 | ftrace_pages->next = | |
389 | (void *)get_zeroed_page(GFP_KERNEL); | |
390 | if (!ftrace_pages->next) | |
391 | return NULL; | |
392 | } | |
3c1720f0 SR |
393 | ftrace_pages = ftrace_pages->next; |
394 | } | |
395 | ||
396 | return &ftrace_pages->records[ftrace_pages->index++]; | |
397 | } | |
398 | ||
08f5ac90 | 399 | static struct dyn_ftrace * |
d61f82d0 | 400 | ftrace_record_ip(unsigned long ip) |
3d083395 | 401 | { |
08f5ac90 | 402 | struct dyn_ftrace *rec; |
3d083395 | 403 | |
f3c7ac40 | 404 | if (ftrace_disabled) |
08f5ac90 | 405 | return NULL; |
3d083395 | 406 | |
08f5ac90 SR |
407 | rec = ftrace_alloc_dyn_node(ip); |
408 | if (!rec) | |
409 | return NULL; | |
3d083395 | 410 | |
08f5ac90 | 411 | rec->ip = ip; |
3d083395 | 412 | |
08f5ac90 | 413 | list_add(&rec->list, &ftrace_new_addrs); |
3d083395 | 414 | |
08f5ac90 | 415 | return rec; |
3d083395 SR |
416 | } |
417 | ||
b17e8a37 SR |
418 | static void print_ip_ins(const char *fmt, unsigned char *p) |
419 | { | |
420 | int i; | |
421 | ||
422 | printk(KERN_CONT "%s", fmt); | |
423 | ||
424 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
425 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
426 | } | |
427 | ||
31e88909 | 428 | static void ftrace_bug(int failed, unsigned long ip) |
b17e8a37 SR |
429 | { |
430 | switch (failed) { | |
431 | case -EFAULT: | |
432 | FTRACE_WARN_ON_ONCE(1); | |
433 | pr_info("ftrace faulted on modifying "); | |
434 | print_ip_sym(ip); | |
435 | break; | |
436 | case -EINVAL: | |
437 | FTRACE_WARN_ON_ONCE(1); | |
438 | pr_info("ftrace failed to modify "); | |
439 | print_ip_sym(ip); | |
b17e8a37 | 440 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
441 | printk(KERN_CONT "\n"); |
442 | break; | |
443 | case -EPERM: | |
444 | FTRACE_WARN_ON_ONCE(1); | |
445 | pr_info("ftrace faulted on writing "); | |
446 | print_ip_sym(ip); | |
447 | break; | |
448 | default: | |
449 | FTRACE_WARN_ON_ONCE(1); | |
450 | pr_info("ftrace faulted on unknown error "); | |
451 | print_ip_sym(ip); | |
452 | } | |
453 | } | |
454 | ||
3c1720f0 | 455 | |
0eb96701 | 456 | static int |
31e88909 | 457 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) |
5072c59f | 458 | { |
e7d3737e | 459 | unsigned long ftrace_addr; |
6a24a244 | 460 | unsigned long ip, fl; |
e7d3737e | 461 | |
f0001207 | 462 | ftrace_addr = (unsigned long)FTRACE_ADDR; |
5072c59f SR |
463 | |
464 | ip = rec->ip; | |
465 | ||
982c350b SR |
466 | /* |
467 | * If this record is not to be traced and | |
468 | * it is not enabled then do nothing. | |
469 | * | |
470 | * If this record is not to be traced and | |
57794a9d | 471 | * it is enabled then disable it. |
982c350b SR |
472 | * |
473 | */ | |
474 | if (rec->flags & FTRACE_FL_NOTRACE) { | |
475 | if (rec->flags & FTRACE_FL_ENABLED) | |
476 | rec->flags &= ~FTRACE_FL_ENABLED; | |
477 | else | |
478 | return 0; | |
479 | ||
480 | } else if (ftrace_filtered && enable) { | |
5072c59f | 481 | /* |
982c350b | 482 | * Filtering is on: |
5072c59f | 483 | */ |
a4500b84 | 484 | |
982c350b | 485 | fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED); |
5072c59f | 486 | |
982c350b SR |
487 | /* Record is filtered and enabled, do nothing */ |
488 | if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) | |
0eb96701 | 489 | return 0; |
5072c59f | 490 | |
57794a9d | 491 | /* Record is not filtered or enabled, do nothing */ |
982c350b SR |
492 | if (!fl) |
493 | return 0; | |
494 | ||
495 | /* Record is not filtered but enabled, disable it */ | |
496 | if (fl == FTRACE_FL_ENABLED) | |
5072c59f | 497 | rec->flags &= ~FTRACE_FL_ENABLED; |
982c350b SR |
498 | else |
499 | /* Otherwise record is filtered but not enabled, enable it */ | |
5072c59f | 500 | rec->flags |= FTRACE_FL_ENABLED; |
5072c59f | 501 | } else { |
982c350b | 502 | /* Disable or not filtered */ |
5072c59f | 503 | |
41c52c0d | 504 | if (enable) { |
982c350b | 505 | /* if record is enabled, do nothing */ |
5072c59f | 506 | if (rec->flags & FTRACE_FL_ENABLED) |
0eb96701 | 507 | return 0; |
982c350b | 508 | |
5072c59f | 509 | rec->flags |= FTRACE_FL_ENABLED; |
982c350b | 510 | |
5072c59f | 511 | } else { |
982c350b | 512 | |
57794a9d | 513 | /* if record is not enabled, do nothing */ |
5072c59f | 514 | if (!(rec->flags & FTRACE_FL_ENABLED)) |
0eb96701 | 515 | return 0; |
982c350b | 516 | |
5072c59f SR |
517 | rec->flags &= ~FTRACE_FL_ENABLED; |
518 | } | |
519 | } | |
520 | ||
982c350b | 521 | if (rec->flags & FTRACE_FL_ENABLED) |
e7d3737e | 522 | return ftrace_make_call(rec, ftrace_addr); |
31e88909 | 523 | else |
e7d3737e | 524 | return ftrace_make_nop(NULL, rec, ftrace_addr); |
5072c59f SR |
525 | } |
526 | ||
e309b41d | 527 | static void ftrace_replace_code(int enable) |
3c1720f0 | 528 | { |
3c1720f0 SR |
529 | struct dyn_ftrace *rec; |
530 | struct ftrace_page *pg; | |
6a24a244 | 531 | int failed; |
3c1720f0 | 532 | |
265c831c SR |
533 | do_for_each_ftrace_rec(pg, rec) { |
534 | /* | |
fa9d13cf Z |
535 | * Skip over free records, records that have |
536 | * failed and not converted. | |
265c831c SR |
537 | */ |
538 | if (rec->flags & FTRACE_FL_FREE || | |
fa9d13cf Z |
539 | rec->flags & FTRACE_FL_FAILED || |
540 | rec->flags & FTRACE_FL_CONVERTED) | |
265c831c SR |
541 | continue; |
542 | ||
543 | /* ignore updates to this record's mcount site */ | |
544 | if (get_kprobe((void *)rec->ip)) { | |
545 | freeze_record(rec); | |
546 | continue; | |
547 | } else { | |
548 | unfreeze_record(rec); | |
549 | } | |
f22f9a89 | 550 | |
265c831c | 551 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 552 | if (failed) { |
265c831c SR |
553 | rec->flags |= FTRACE_FL_FAILED; |
554 | if ((system_state == SYSTEM_BOOTING) || | |
555 | !core_kernel_text(rec->ip)) { | |
556 | ftrace_free_rec(rec); | |
4377245a | 557 | } else { |
265c831c | 558 | ftrace_bug(failed, rec->ip); |
4377245a SR |
559 | /* Stop processing */ |
560 | return; | |
561 | } | |
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 | ||
000ab691 SR |
583 | /* |
584 | * archs can override this function if they must do something | |
585 | * before the modifying code is performed. | |
586 | */ | |
587 | int __weak ftrace_arch_code_modify_prepare(void) | |
588 | { | |
589 | return 0; | |
590 | } | |
591 | ||
592 | /* | |
593 | * archs can override this function if they must do something | |
594 | * after the modifying code is performed. | |
595 | */ | |
596 | int __weak ftrace_arch_code_modify_post_process(void) | |
597 | { | |
598 | return 0; | |
599 | } | |
600 | ||
e309b41d | 601 | static int __ftrace_modify_code(void *data) |
3d083395 | 602 | { |
d61f82d0 SR |
603 | int *command = data; |
604 | ||
a3583244 | 605 | if (*command & FTRACE_ENABLE_CALLS) |
d61f82d0 | 606 | ftrace_replace_code(1); |
a3583244 | 607 | else if (*command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
608 | ftrace_replace_code(0); |
609 | ||
610 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
611 | ftrace_update_ftrace_func(ftrace_trace_function); | |
612 | ||
5a45cfe1 SR |
613 | if (*command & FTRACE_START_FUNC_RET) |
614 | ftrace_enable_ftrace_graph_caller(); | |
615 | else if (*command & FTRACE_STOP_FUNC_RET) | |
616 | ftrace_disable_ftrace_graph_caller(); | |
617 | ||
d61f82d0 | 618 | return 0; |
3d083395 SR |
619 | } |
620 | ||
e309b41d | 621 | static void ftrace_run_update_code(int command) |
3d083395 | 622 | { |
000ab691 SR |
623 | int ret; |
624 | ||
625 | ret = ftrace_arch_code_modify_prepare(); | |
626 | FTRACE_WARN_ON(ret); | |
627 | if (ret) | |
628 | return; | |
629 | ||
784e2d76 | 630 | stop_machine(__ftrace_modify_code, &command, NULL); |
000ab691 SR |
631 | |
632 | ret = ftrace_arch_code_modify_post_process(); | |
633 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
634 | } |
635 | ||
d61f82d0 | 636 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 637 | static int ftrace_start_up; |
df4fc315 SR |
638 | |
639 | static void ftrace_startup_enable(int command) | |
640 | { | |
641 | if (saved_ftrace_func != ftrace_trace_function) { | |
642 | saved_ftrace_func = ftrace_trace_function; | |
643 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
644 | } | |
645 | ||
646 | if (!command || !ftrace_enabled) | |
647 | return; | |
648 | ||
649 | ftrace_run_update_code(command); | |
650 | } | |
d61f82d0 | 651 | |
5a45cfe1 | 652 | static void ftrace_startup(int command) |
3d083395 | 653 | { |
4eebcc81 SR |
654 | if (unlikely(ftrace_disabled)) |
655 | return; | |
656 | ||
60a7ecf4 | 657 | ftrace_start_up++; |
982c350b | 658 | command |= FTRACE_ENABLE_CALLS; |
d61f82d0 | 659 | |
df4fc315 | 660 | ftrace_startup_enable(command); |
3d083395 SR |
661 | } |
662 | ||
5a45cfe1 | 663 | static void ftrace_shutdown(int command) |
3d083395 | 664 | { |
4eebcc81 SR |
665 | if (unlikely(ftrace_disabled)) |
666 | return; | |
667 | ||
60a7ecf4 SR |
668 | ftrace_start_up--; |
669 | if (!ftrace_start_up) | |
d61f82d0 | 670 | command |= FTRACE_DISABLE_CALLS; |
3d083395 | 671 | |
d61f82d0 SR |
672 | if (saved_ftrace_func != ftrace_trace_function) { |
673 | saved_ftrace_func = ftrace_trace_function; | |
674 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
675 | } | |
3d083395 | 676 | |
d61f82d0 | 677 | if (!command || !ftrace_enabled) |
e6ea44e9 | 678 | return; |
d61f82d0 SR |
679 | |
680 | ftrace_run_update_code(command); | |
3d083395 SR |
681 | } |
682 | ||
e309b41d | 683 | static void ftrace_startup_sysctl(void) |
b0fc494f | 684 | { |
d61f82d0 SR |
685 | int command = FTRACE_ENABLE_MCOUNT; |
686 | ||
4eebcc81 SR |
687 | if (unlikely(ftrace_disabled)) |
688 | return; | |
689 | ||
d61f82d0 SR |
690 | /* Force update next time */ |
691 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
692 | /* ftrace_start_up is true if we want ftrace running */ |
693 | if (ftrace_start_up) | |
d61f82d0 SR |
694 | command |= FTRACE_ENABLE_CALLS; |
695 | ||
696 | ftrace_run_update_code(command); | |
b0fc494f SR |
697 | } |
698 | ||
e309b41d | 699 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 700 | { |
d61f82d0 SR |
701 | int command = FTRACE_DISABLE_MCOUNT; |
702 | ||
4eebcc81 SR |
703 | if (unlikely(ftrace_disabled)) |
704 | return; | |
705 | ||
60a7ecf4 SR |
706 | /* ftrace_start_up is true if ftrace is running */ |
707 | if (ftrace_start_up) | |
d61f82d0 SR |
708 | command |= FTRACE_DISABLE_CALLS; |
709 | ||
710 | ftrace_run_update_code(command); | |
b0fc494f SR |
711 | } |
712 | ||
3d083395 SR |
713 | static cycle_t ftrace_update_time; |
714 | static unsigned long ftrace_update_cnt; | |
715 | unsigned long ftrace_update_tot_cnt; | |
716 | ||
31e88909 | 717 | static int ftrace_update_code(struct module *mod) |
3d083395 | 718 | { |
08f5ac90 | 719 | struct dyn_ftrace *p, *t; |
f22f9a89 | 720 | cycle_t start, stop; |
3d083395 | 721 | |
750ed1a4 | 722 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
723 | ftrace_update_cnt = 0; |
724 | ||
08f5ac90 | 725 | list_for_each_entry_safe(p, t, &ftrace_new_addrs, list) { |
3d083395 | 726 | |
08f5ac90 SR |
727 | /* If something went wrong, bail without enabling anything */ |
728 | if (unlikely(ftrace_disabled)) | |
729 | return -1; | |
f22f9a89 | 730 | |
08f5ac90 | 731 | list_del_init(&p->list); |
f22f9a89 | 732 | |
08f5ac90 | 733 | /* convert record (i.e, patch mcount-call with NOP) */ |
31e88909 | 734 | if (ftrace_code_disable(mod, p)) { |
08f5ac90 SR |
735 | p->flags |= FTRACE_FL_CONVERTED; |
736 | ftrace_update_cnt++; | |
737 | } else | |
738 | ftrace_free_rec(p); | |
3d083395 SR |
739 | } |
740 | ||
750ed1a4 | 741 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
742 | ftrace_update_time = stop - start; |
743 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
744 | ||
16444a8a ACM |
745 | return 0; |
746 | } | |
747 | ||
68bf21aa | 748 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
749 | { |
750 | struct ftrace_page *pg; | |
751 | int cnt; | |
752 | int i; | |
3c1720f0 SR |
753 | |
754 | /* allocate a few pages */ | |
755 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
756 | if (!ftrace_pages_start) | |
757 | return -1; | |
758 | ||
759 | /* | |
760 | * Allocate a few more pages. | |
761 | * | |
762 | * TODO: have some parser search vmlinux before | |
763 | * final linking to find all calls to ftrace. | |
764 | * Then we can: | |
765 | * a) know how many pages to allocate. | |
766 | * and/or | |
767 | * b) set up the table then. | |
768 | * | |
769 | * The dynamic code is still necessary for | |
770 | * modules. | |
771 | */ | |
772 | ||
773 | pg = ftrace_pages = ftrace_pages_start; | |
774 | ||
68bf21aa | 775 | cnt = num_to_init / ENTRIES_PER_PAGE; |
08f5ac90 | 776 | pr_info("ftrace: allocating %ld entries in %d pages\n", |
5821e1b7 | 777 | num_to_init, cnt + 1); |
3c1720f0 SR |
778 | |
779 | for (i = 0; i < cnt; i++) { | |
780 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
781 | ||
782 | /* If we fail, we'll try later anyway */ | |
783 | if (!pg->next) | |
784 | break; | |
785 | ||
786 | pg = pg->next; | |
787 | } | |
788 | ||
789 | return 0; | |
790 | } | |
791 | ||
5072c59f SR |
792 | enum { |
793 | FTRACE_ITER_FILTER = (1 << 0), | |
794 | FTRACE_ITER_CONT = (1 << 1), | |
41c52c0d | 795 | FTRACE_ITER_NOTRACE = (1 << 2), |
eb9a7bf0 | 796 | FTRACE_ITER_FAILURES = (1 << 3), |
0c75a3ed | 797 | FTRACE_ITER_PRINTALL = (1 << 4), |
8fc0c701 | 798 | FTRACE_ITER_HASH = (1 << 5), |
5072c59f SR |
799 | }; |
800 | ||
801 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
802 | ||
803 | struct ftrace_iterator { | |
5072c59f | 804 | struct ftrace_page *pg; |
8fc0c701 | 805 | int hidx; |
431aa3fb | 806 | int idx; |
5072c59f SR |
807 | unsigned flags; |
808 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
809 | unsigned buffer_idx; | |
810 | unsigned filtered; | |
811 | }; | |
812 | ||
8fc0c701 SR |
813 | static void * |
814 | t_hash_next(struct seq_file *m, void *v, loff_t *pos) | |
815 | { | |
816 | struct ftrace_iterator *iter = m->private; | |
817 | struct hlist_node *hnd = v; | |
818 | struct hlist_head *hhd; | |
819 | ||
820 | WARN_ON(!(iter->flags & FTRACE_ITER_HASH)); | |
821 | ||
822 | (*pos)++; | |
823 | ||
824 | retry: | |
825 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
826 | return NULL; | |
827 | ||
828 | hhd = &ftrace_func_hash[iter->hidx]; | |
829 | ||
830 | if (hlist_empty(hhd)) { | |
831 | iter->hidx++; | |
832 | hnd = NULL; | |
833 | goto retry; | |
834 | } | |
835 | ||
836 | if (!hnd) | |
837 | hnd = hhd->first; | |
838 | else { | |
839 | hnd = hnd->next; | |
840 | if (!hnd) { | |
841 | iter->hidx++; | |
842 | goto retry; | |
843 | } | |
844 | } | |
845 | ||
846 | return hnd; | |
847 | } | |
848 | ||
849 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
850 | { | |
851 | struct ftrace_iterator *iter = m->private; | |
852 | void *p = NULL; | |
853 | ||
854 | iter->flags |= FTRACE_ITER_HASH; | |
855 | ||
856 | return t_hash_next(m, p, pos); | |
857 | } | |
858 | ||
859 | static int t_hash_show(struct seq_file *m, void *v) | |
860 | { | |
b6887d79 | 861 | struct ftrace_func_probe *rec; |
8fc0c701 SR |
862 | struct hlist_node *hnd = v; |
863 | char str[KSYM_SYMBOL_LEN]; | |
864 | ||
b6887d79 | 865 | rec = hlist_entry(hnd, struct ftrace_func_probe, node); |
8fc0c701 | 866 | |
809dcf29 SR |
867 | if (rec->ops->print) |
868 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
869 | ||
8fc0c701 SR |
870 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
871 | seq_printf(m, "%s:", str); | |
872 | ||
873 | kallsyms_lookup((unsigned long)rec->ops->func, NULL, NULL, NULL, str); | |
874 | seq_printf(m, "%s", str); | |
875 | ||
876 | if (rec->data) | |
877 | seq_printf(m, ":%p", rec->data); | |
878 | seq_putc(m, '\n'); | |
879 | ||
880 | return 0; | |
881 | } | |
882 | ||
e309b41d | 883 | static void * |
5072c59f SR |
884 | t_next(struct seq_file *m, void *v, loff_t *pos) |
885 | { | |
886 | struct ftrace_iterator *iter = m->private; | |
887 | struct dyn_ftrace *rec = NULL; | |
888 | ||
8fc0c701 SR |
889 | if (iter->flags & FTRACE_ITER_HASH) |
890 | return t_hash_next(m, v, pos); | |
891 | ||
5072c59f SR |
892 | (*pos)++; |
893 | ||
0c75a3ed SR |
894 | if (iter->flags & FTRACE_ITER_PRINTALL) |
895 | return NULL; | |
896 | ||
5072c59f SR |
897 | retry: |
898 | if (iter->idx >= iter->pg->index) { | |
899 | if (iter->pg->next) { | |
900 | iter->pg = iter->pg->next; | |
901 | iter->idx = 0; | |
902 | goto retry; | |
50cdaf08 LW |
903 | } else { |
904 | iter->idx = -1; | |
5072c59f SR |
905 | } |
906 | } else { | |
907 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
908 | if ((rec->flags & FTRACE_FL_FREE) || |
909 | ||
910 | (!(iter->flags & FTRACE_ITER_FAILURES) && | |
eb9a7bf0 AS |
911 | (rec->flags & FTRACE_FL_FAILED)) || |
912 | ||
913 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
a9fdda33 | 914 | !(rec->flags & FTRACE_FL_FAILED)) || |
eb9a7bf0 | 915 | |
0183fb1c SR |
916 | ((iter->flags & FTRACE_ITER_FILTER) && |
917 | !(rec->flags & FTRACE_FL_FILTER)) || | |
918 | ||
41c52c0d SR |
919 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
920 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
921 | rec = NULL; |
922 | goto retry; | |
923 | } | |
924 | } | |
925 | ||
5072c59f SR |
926 | return rec; |
927 | } | |
928 | ||
929 | static void *t_start(struct seq_file *m, loff_t *pos) | |
930 | { | |
931 | struct ftrace_iterator *iter = m->private; | |
932 | void *p = NULL; | |
5072c59f | 933 | |
8fc0c701 | 934 | mutex_lock(&ftrace_lock); |
0c75a3ed SR |
935 | /* |
936 | * For set_ftrace_filter reading, if we have the filter | |
937 | * off, we can short cut and just print out that all | |
938 | * functions are enabled. | |
939 | */ | |
940 | if (iter->flags & FTRACE_ITER_FILTER && !ftrace_filtered) { | |
941 | if (*pos > 0) | |
8fc0c701 | 942 | return t_hash_start(m, pos); |
0c75a3ed SR |
943 | iter->flags |= FTRACE_ITER_PRINTALL; |
944 | (*pos)++; | |
945 | return iter; | |
946 | } | |
947 | ||
8fc0c701 SR |
948 | if (iter->flags & FTRACE_ITER_HASH) |
949 | return t_hash_start(m, pos); | |
950 | ||
50cdaf08 LW |
951 | if (*pos > 0) { |
952 | if (iter->idx < 0) | |
953 | return p; | |
954 | (*pos)--; | |
955 | iter->idx--; | |
956 | } | |
5821e1b7 | 957 | |
50cdaf08 | 958 | p = t_next(m, p, pos); |
5072c59f | 959 | |
8fc0c701 SR |
960 | if (!p) |
961 | return t_hash_start(m, pos); | |
962 | ||
5072c59f SR |
963 | return p; |
964 | } | |
965 | ||
966 | static void t_stop(struct seq_file *m, void *p) | |
967 | { | |
8fc0c701 | 968 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
969 | } |
970 | ||
971 | static int t_show(struct seq_file *m, void *v) | |
972 | { | |
0c75a3ed | 973 | struct ftrace_iterator *iter = m->private; |
5072c59f SR |
974 | struct dyn_ftrace *rec = v; |
975 | char str[KSYM_SYMBOL_LEN]; | |
976 | ||
8fc0c701 SR |
977 | if (iter->flags & FTRACE_ITER_HASH) |
978 | return t_hash_show(m, v); | |
979 | ||
0c75a3ed SR |
980 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
981 | seq_printf(m, "#### all functions enabled ####\n"); | |
982 | return 0; | |
983 | } | |
984 | ||
5072c59f SR |
985 | if (!rec) |
986 | return 0; | |
987 | ||
988 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
989 | ||
50cdaf08 | 990 | seq_printf(m, "%s\n", str); |
5072c59f SR |
991 | |
992 | return 0; | |
993 | } | |
994 | ||
995 | static struct seq_operations show_ftrace_seq_ops = { | |
996 | .start = t_start, | |
997 | .next = t_next, | |
998 | .stop = t_stop, | |
999 | .show = t_show, | |
1000 | }; | |
1001 | ||
e309b41d | 1002 | static int |
5072c59f SR |
1003 | ftrace_avail_open(struct inode *inode, struct file *file) |
1004 | { | |
1005 | struct ftrace_iterator *iter; | |
1006 | int ret; | |
1007 | ||
4eebcc81 SR |
1008 | if (unlikely(ftrace_disabled)) |
1009 | return -ENODEV; | |
1010 | ||
5072c59f SR |
1011 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1012 | if (!iter) | |
1013 | return -ENOMEM; | |
1014 | ||
1015 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
1016 | |
1017 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1018 | if (!ret) { | |
1019 | struct seq_file *m = file->private_data; | |
4bf39a94 | 1020 | |
5072c59f | 1021 | m->private = iter; |
4bf39a94 | 1022 | } else { |
5072c59f | 1023 | kfree(iter); |
4bf39a94 | 1024 | } |
5072c59f SR |
1025 | |
1026 | return ret; | |
1027 | } | |
1028 | ||
1029 | int ftrace_avail_release(struct inode *inode, struct file *file) | |
1030 | { | |
1031 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1032 | struct ftrace_iterator *iter = m->private; | |
1033 | ||
1034 | seq_release(inode, file); | |
1035 | kfree(iter); | |
4bf39a94 | 1036 | |
5072c59f SR |
1037 | return 0; |
1038 | } | |
1039 | ||
eb9a7bf0 AS |
1040 | static int |
1041 | ftrace_failures_open(struct inode *inode, struct file *file) | |
1042 | { | |
1043 | int ret; | |
1044 | struct seq_file *m; | |
1045 | struct ftrace_iterator *iter; | |
1046 | ||
1047 | ret = ftrace_avail_open(inode, file); | |
1048 | if (!ret) { | |
1049 | m = (struct seq_file *)file->private_data; | |
1050 | iter = (struct ftrace_iterator *)m->private; | |
1051 | iter->flags = FTRACE_ITER_FAILURES; | |
1052 | } | |
1053 | ||
1054 | return ret; | |
1055 | } | |
1056 | ||
1057 | ||
41c52c0d | 1058 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
1059 | { |
1060 | struct ftrace_page *pg; | |
1061 | struct dyn_ftrace *rec; | |
41c52c0d | 1062 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f | 1063 | |
52baf119 | 1064 | mutex_lock(&ftrace_lock); |
41c52c0d SR |
1065 | if (enable) |
1066 | ftrace_filtered = 0; | |
265c831c SR |
1067 | do_for_each_ftrace_rec(pg, rec) { |
1068 | if (rec->flags & FTRACE_FL_FAILED) | |
1069 | continue; | |
1070 | rec->flags &= ~type; | |
1071 | } while_for_each_ftrace_rec(); | |
52baf119 | 1072 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1073 | } |
1074 | ||
e309b41d | 1075 | static int |
41c52c0d | 1076 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1077 | { |
1078 | struct ftrace_iterator *iter; | |
1079 | int ret = 0; | |
1080 | ||
4eebcc81 SR |
1081 | if (unlikely(ftrace_disabled)) |
1082 | return -ENODEV; | |
1083 | ||
5072c59f SR |
1084 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1085 | if (!iter) | |
1086 | return -ENOMEM; | |
1087 | ||
41c52c0d | 1088 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1089 | if ((file->f_mode & FMODE_WRITE) && |
1090 | !(file->f_flags & O_APPEND)) | |
41c52c0d | 1091 | ftrace_filter_reset(enable); |
5072c59f SR |
1092 | |
1093 | if (file->f_mode & FMODE_READ) { | |
1094 | iter->pg = ftrace_pages_start; | |
41c52c0d SR |
1095 | iter->flags = enable ? FTRACE_ITER_FILTER : |
1096 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
1097 | |
1098 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1099 | if (!ret) { | |
1100 | struct seq_file *m = file->private_data; | |
1101 | m->private = iter; | |
1102 | } else | |
1103 | kfree(iter); | |
1104 | } else | |
1105 | file->private_data = iter; | |
41c52c0d | 1106 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1107 | |
1108 | return ret; | |
1109 | } | |
1110 | ||
41c52c0d SR |
1111 | static int |
1112 | ftrace_filter_open(struct inode *inode, struct file *file) | |
1113 | { | |
1114 | return ftrace_regex_open(inode, file, 1); | |
1115 | } | |
1116 | ||
1117 | static int | |
1118 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
1119 | { | |
1120 | return ftrace_regex_open(inode, file, 0); | |
1121 | } | |
1122 | ||
e309b41d | 1123 | static loff_t |
41c52c0d | 1124 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
1125 | { |
1126 | loff_t ret; | |
1127 | ||
1128 | if (file->f_mode & FMODE_READ) | |
1129 | ret = seq_lseek(file, offset, origin); | |
1130 | else | |
1131 | file->f_pos = ret = 1; | |
1132 | ||
1133 | return ret; | |
1134 | } | |
1135 | ||
1136 | enum { | |
1137 | MATCH_FULL, | |
1138 | MATCH_FRONT_ONLY, | |
1139 | MATCH_MIDDLE_ONLY, | |
1140 | MATCH_END_ONLY, | |
1141 | }; | |
1142 | ||
9f4801e3 SR |
1143 | /* |
1144 | * (static function - no need for kernel doc) | |
1145 | * | |
1146 | * Pass in a buffer containing a glob and this function will | |
1147 | * set search to point to the search part of the buffer and | |
1148 | * return the type of search it is (see enum above). | |
1149 | * This does modify buff. | |
1150 | * | |
1151 | * Returns enum type. | |
1152 | * search returns the pointer to use for comparison. | |
1153 | * not returns 1 if buff started with a '!' | |
1154 | * 0 otherwise. | |
1155 | */ | |
1156 | static int | |
64e7c440 | 1157 | ftrace_setup_glob(char *buff, int len, char **search, int *not) |
5072c59f | 1158 | { |
5072c59f | 1159 | int type = MATCH_FULL; |
9f4801e3 | 1160 | int i; |
ea3a6d6d SR |
1161 | |
1162 | if (buff[0] == '!') { | |
9f4801e3 | 1163 | *not = 1; |
ea3a6d6d SR |
1164 | buff++; |
1165 | len--; | |
9f4801e3 SR |
1166 | } else |
1167 | *not = 0; | |
1168 | ||
1169 | *search = buff; | |
5072c59f SR |
1170 | |
1171 | for (i = 0; i < len; i++) { | |
1172 | if (buff[i] == '*') { | |
1173 | if (!i) { | |
9f4801e3 | 1174 | *search = buff + 1; |
5072c59f | 1175 | type = MATCH_END_ONLY; |
5072c59f | 1176 | } else { |
9f4801e3 | 1177 | if (type == MATCH_END_ONLY) |
5072c59f | 1178 | type = MATCH_MIDDLE_ONLY; |
9f4801e3 | 1179 | else |
5072c59f | 1180 | type = MATCH_FRONT_ONLY; |
5072c59f SR |
1181 | buff[i] = 0; |
1182 | break; | |
1183 | } | |
1184 | } | |
1185 | } | |
1186 | ||
9f4801e3 SR |
1187 | return type; |
1188 | } | |
1189 | ||
64e7c440 | 1190 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 1191 | { |
9f4801e3 SR |
1192 | int matched = 0; |
1193 | char *ptr; | |
1194 | ||
9f4801e3 SR |
1195 | switch (type) { |
1196 | case MATCH_FULL: | |
1197 | if (strcmp(str, regex) == 0) | |
1198 | matched = 1; | |
1199 | break; | |
1200 | case MATCH_FRONT_ONLY: | |
1201 | if (strncmp(str, regex, len) == 0) | |
1202 | matched = 1; | |
1203 | break; | |
1204 | case MATCH_MIDDLE_ONLY: | |
1205 | if (strstr(str, regex)) | |
1206 | matched = 1; | |
1207 | break; | |
1208 | case MATCH_END_ONLY: | |
1209 | ptr = strstr(str, regex); | |
1210 | if (ptr && (ptr[len] == 0)) | |
1211 | matched = 1; | |
1212 | break; | |
1213 | } | |
1214 | ||
1215 | return matched; | |
1216 | } | |
1217 | ||
64e7c440 SR |
1218 | static int |
1219 | ftrace_match_record(struct dyn_ftrace *rec, char *regex, int len, int type) | |
1220 | { | |
1221 | char str[KSYM_SYMBOL_LEN]; | |
1222 | ||
1223 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1224 | return ftrace_match(str, regex, len, type); | |
1225 | } | |
1226 | ||
9f4801e3 SR |
1227 | static void ftrace_match_records(char *buff, int len, int enable) |
1228 | { | |
6a24a244 | 1229 | unsigned int search_len; |
9f4801e3 SR |
1230 | struct ftrace_page *pg; |
1231 | struct dyn_ftrace *rec; | |
6a24a244 SR |
1232 | unsigned long flag; |
1233 | char *search; | |
9f4801e3 | 1234 | int type; |
9f4801e3 SR |
1235 | int not; |
1236 | ||
6a24a244 | 1237 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
9f4801e3 SR |
1238 | type = ftrace_setup_glob(buff, len, &search, ¬); |
1239 | ||
1240 | search_len = strlen(search); | |
1241 | ||
52baf119 | 1242 | mutex_lock(&ftrace_lock); |
265c831c | 1243 | do_for_each_ftrace_rec(pg, rec) { |
265c831c SR |
1244 | |
1245 | if (rec->flags & FTRACE_FL_FAILED) | |
1246 | continue; | |
9f4801e3 SR |
1247 | |
1248 | if (ftrace_match_record(rec, search, search_len, type)) { | |
265c831c SR |
1249 | if (not) |
1250 | rec->flags &= ~flag; | |
1251 | else | |
1252 | rec->flags |= flag; | |
1253 | } | |
e68746a2 SR |
1254 | /* |
1255 | * Only enable filtering if we have a function that | |
1256 | * is filtered on. | |
1257 | */ | |
1258 | if (enable && (rec->flags & FTRACE_FL_FILTER)) | |
1259 | ftrace_filtered = 1; | |
265c831c | 1260 | } while_for_each_ftrace_rec(); |
52baf119 | 1261 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1262 | } |
1263 | ||
64e7c440 SR |
1264 | static int |
1265 | ftrace_match_module_record(struct dyn_ftrace *rec, char *mod, | |
1266 | char *regex, int len, int type) | |
1267 | { | |
1268 | char str[KSYM_SYMBOL_LEN]; | |
1269 | char *modname; | |
1270 | ||
1271 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
1272 | ||
1273 | if (!modname || strcmp(modname, mod)) | |
1274 | return 0; | |
1275 | ||
1276 | /* blank search means to match all funcs in the mod */ | |
1277 | if (len) | |
1278 | return ftrace_match(str, regex, len, type); | |
1279 | else | |
1280 | return 1; | |
1281 | } | |
1282 | ||
1283 | static void ftrace_match_module_records(char *buff, char *mod, int enable) | |
1284 | { | |
6a24a244 | 1285 | unsigned search_len = 0; |
64e7c440 SR |
1286 | struct ftrace_page *pg; |
1287 | struct dyn_ftrace *rec; | |
1288 | int type = MATCH_FULL; | |
6a24a244 SR |
1289 | char *search = buff; |
1290 | unsigned long flag; | |
64e7c440 SR |
1291 | int not = 0; |
1292 | ||
6a24a244 SR |
1293 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
1294 | ||
64e7c440 SR |
1295 | /* blank or '*' mean the same */ |
1296 | if (strcmp(buff, "*") == 0) | |
1297 | buff[0] = 0; | |
1298 | ||
1299 | /* handle the case of 'dont filter this module' */ | |
1300 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
1301 | buff[0] = 0; | |
1302 | not = 1; | |
1303 | } | |
1304 | ||
1305 | if (strlen(buff)) { | |
1306 | type = ftrace_setup_glob(buff, strlen(buff), &search, ¬); | |
1307 | search_len = strlen(search); | |
1308 | } | |
1309 | ||
52baf119 | 1310 | mutex_lock(&ftrace_lock); |
64e7c440 SR |
1311 | do_for_each_ftrace_rec(pg, rec) { |
1312 | ||
1313 | if (rec->flags & FTRACE_FL_FAILED) | |
1314 | continue; | |
1315 | ||
1316 | if (ftrace_match_module_record(rec, mod, | |
1317 | search, search_len, type)) { | |
1318 | if (not) | |
1319 | rec->flags &= ~flag; | |
1320 | else | |
1321 | rec->flags |= flag; | |
1322 | } | |
e68746a2 SR |
1323 | if (enable && (rec->flags & FTRACE_FL_FILTER)) |
1324 | ftrace_filtered = 1; | |
64e7c440 SR |
1325 | |
1326 | } while_for_each_ftrace_rec(); | |
52baf119 | 1327 | mutex_unlock(&ftrace_lock); |
64e7c440 SR |
1328 | } |
1329 | ||
f6180773 SR |
1330 | /* |
1331 | * We register the module command as a template to show others how | |
1332 | * to register the a command as well. | |
1333 | */ | |
1334 | ||
1335 | static int | |
1336 | ftrace_mod_callback(char *func, char *cmd, char *param, int enable) | |
1337 | { | |
1338 | char *mod; | |
1339 | ||
1340 | /* | |
1341 | * cmd == 'mod' because we only registered this func | |
1342 | * for the 'mod' ftrace_func_command. | |
1343 | * But if you register one func with multiple commands, | |
1344 | * you can tell which command was used by the cmd | |
1345 | * parameter. | |
1346 | */ | |
1347 | ||
1348 | /* we must have a module name */ | |
1349 | if (!param) | |
1350 | return -EINVAL; | |
1351 | ||
1352 | mod = strsep(¶m, ":"); | |
1353 | if (!strlen(mod)) | |
1354 | return -EINVAL; | |
1355 | ||
1356 | ftrace_match_module_records(func, mod, enable); | |
1357 | return 0; | |
1358 | } | |
1359 | ||
1360 | static struct ftrace_func_command ftrace_mod_cmd = { | |
1361 | .name = "mod", | |
1362 | .func = ftrace_mod_callback, | |
1363 | }; | |
1364 | ||
1365 | static int __init ftrace_mod_cmd_init(void) | |
1366 | { | |
1367 | return register_ftrace_command(&ftrace_mod_cmd); | |
1368 | } | |
1369 | device_initcall(ftrace_mod_cmd_init); | |
1370 | ||
59df055f | 1371 | static void |
b6887d79 | 1372 | function_trace_probe_call(unsigned long ip, unsigned long parent_ip) |
59df055f | 1373 | { |
b6887d79 | 1374 | struct ftrace_func_probe *entry; |
59df055f SR |
1375 | struct hlist_head *hhd; |
1376 | struct hlist_node *n; | |
1377 | unsigned long key; | |
1378 | int resched; | |
1379 | ||
1380 | key = hash_long(ip, FTRACE_HASH_BITS); | |
1381 | ||
1382 | hhd = &ftrace_func_hash[key]; | |
1383 | ||
1384 | if (hlist_empty(hhd)) | |
1385 | return; | |
1386 | ||
1387 | /* | |
1388 | * Disable preemption for these calls to prevent a RCU grace | |
1389 | * period. This syncs the hash iteration and freeing of items | |
1390 | * on the hash. rcu_read_lock is too dangerous here. | |
1391 | */ | |
1392 | resched = ftrace_preempt_disable(); | |
1393 | hlist_for_each_entry_rcu(entry, n, hhd, node) { | |
1394 | if (entry->ip == ip) | |
1395 | entry->ops->func(ip, parent_ip, &entry->data); | |
1396 | } | |
1397 | ftrace_preempt_enable(resched); | |
1398 | } | |
1399 | ||
b6887d79 | 1400 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 1401 | { |
b6887d79 | 1402 | .func = function_trace_probe_call, |
59df055f SR |
1403 | }; |
1404 | ||
b6887d79 | 1405 | static int ftrace_probe_registered; |
59df055f | 1406 | |
b6887d79 | 1407 | static void __enable_ftrace_function_probe(void) |
59df055f SR |
1408 | { |
1409 | int i; | |
1410 | ||
b6887d79 | 1411 | if (ftrace_probe_registered) |
59df055f SR |
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 | break; | |
1418 | } | |
1419 | /* Nothing registered? */ | |
1420 | if (i == FTRACE_FUNC_HASHSIZE) | |
1421 | return; | |
1422 | ||
b6887d79 | 1423 | __register_ftrace_function(&trace_probe_ops); |
59df055f | 1424 | ftrace_startup(0); |
b6887d79 | 1425 | ftrace_probe_registered = 1; |
59df055f SR |
1426 | } |
1427 | ||
b6887d79 | 1428 | static void __disable_ftrace_function_probe(void) |
59df055f SR |
1429 | { |
1430 | int i; | |
1431 | ||
b6887d79 | 1432 | if (!ftrace_probe_registered) |
59df055f SR |
1433 | return; |
1434 | ||
1435 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1436 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1437 | if (hhd->first) | |
1438 | return; | |
1439 | } | |
1440 | ||
1441 | /* no more funcs left */ | |
b6887d79 | 1442 | __unregister_ftrace_function(&trace_probe_ops); |
59df055f | 1443 | ftrace_shutdown(0); |
b6887d79 | 1444 | ftrace_probe_registered = 0; |
59df055f SR |
1445 | } |
1446 | ||
1447 | ||
1448 | static void ftrace_free_entry_rcu(struct rcu_head *rhp) | |
1449 | { | |
b6887d79 SR |
1450 | struct ftrace_func_probe *entry = |
1451 | container_of(rhp, struct ftrace_func_probe, rcu); | |
59df055f SR |
1452 | |
1453 | if (entry->ops->free) | |
1454 | entry->ops->free(&entry->data); | |
1455 | kfree(entry); | |
1456 | } | |
1457 | ||
1458 | ||
1459 | int | |
b6887d79 | 1460 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
1461 | void *data) |
1462 | { | |
b6887d79 | 1463 | struct ftrace_func_probe *entry; |
59df055f SR |
1464 | struct ftrace_page *pg; |
1465 | struct dyn_ftrace *rec; | |
59df055f | 1466 | int type, len, not; |
6a24a244 | 1467 | unsigned long key; |
59df055f SR |
1468 | int count = 0; |
1469 | char *search; | |
1470 | ||
1471 | type = ftrace_setup_glob(glob, strlen(glob), &search, ¬); | |
1472 | len = strlen(search); | |
1473 | ||
b6887d79 | 1474 | /* we do not support '!' for function probes */ |
59df055f SR |
1475 | if (WARN_ON(not)) |
1476 | return -EINVAL; | |
1477 | ||
1478 | mutex_lock(&ftrace_lock); | |
1479 | do_for_each_ftrace_rec(pg, rec) { | |
1480 | ||
1481 | if (rec->flags & FTRACE_FL_FAILED) | |
1482 | continue; | |
1483 | ||
1484 | if (!ftrace_match_record(rec, search, len, type)) | |
1485 | continue; | |
1486 | ||
1487 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1488 | if (!entry) { | |
b6887d79 | 1489 | /* If we did not process any, then return error */ |
59df055f SR |
1490 | if (!count) |
1491 | count = -ENOMEM; | |
1492 | goto out_unlock; | |
1493 | } | |
1494 | ||
1495 | count++; | |
1496 | ||
1497 | entry->data = data; | |
1498 | ||
1499 | /* | |
1500 | * The caller might want to do something special | |
1501 | * for each function we find. We call the callback | |
1502 | * to give the caller an opportunity to do so. | |
1503 | */ | |
1504 | if (ops->callback) { | |
1505 | if (ops->callback(rec->ip, &entry->data) < 0) { | |
1506 | /* caller does not like this func */ | |
1507 | kfree(entry); | |
1508 | continue; | |
1509 | } | |
1510 | } | |
1511 | ||
1512 | entry->ops = ops; | |
1513 | entry->ip = rec->ip; | |
1514 | ||
1515 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
1516 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
1517 | ||
1518 | } while_for_each_ftrace_rec(); | |
b6887d79 | 1519 | __enable_ftrace_function_probe(); |
59df055f SR |
1520 | |
1521 | out_unlock: | |
1522 | mutex_unlock(&ftrace_lock); | |
1523 | ||
1524 | return count; | |
1525 | } | |
1526 | ||
1527 | enum { | |
b6887d79 SR |
1528 | PROBE_TEST_FUNC = 1, |
1529 | PROBE_TEST_DATA = 2 | |
59df055f SR |
1530 | }; |
1531 | ||
1532 | static void | |
b6887d79 | 1533 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
1534 | void *data, int flags) |
1535 | { | |
b6887d79 | 1536 | struct ftrace_func_probe *entry; |
59df055f SR |
1537 | struct hlist_node *n, *tmp; |
1538 | char str[KSYM_SYMBOL_LEN]; | |
1539 | int type = MATCH_FULL; | |
1540 | int i, len = 0; | |
1541 | char *search; | |
1542 | ||
1543 | if (glob && (strcmp(glob, "*") || !strlen(glob))) | |
1544 | glob = NULL; | |
1545 | else { | |
1546 | int not; | |
1547 | ||
1548 | type = ftrace_setup_glob(glob, strlen(glob), &search, ¬); | |
1549 | len = strlen(search); | |
1550 | ||
b6887d79 | 1551 | /* we do not support '!' for function probes */ |
59df055f SR |
1552 | if (WARN_ON(not)) |
1553 | return; | |
1554 | } | |
1555 | ||
1556 | mutex_lock(&ftrace_lock); | |
1557 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
1558 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
1559 | ||
1560 | hlist_for_each_entry_safe(entry, n, tmp, hhd, node) { | |
1561 | ||
1562 | /* break up if statements for readability */ | |
b6887d79 | 1563 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
1564 | continue; |
1565 | ||
b6887d79 | 1566 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
1567 | continue; |
1568 | ||
1569 | /* do this last, since it is the most expensive */ | |
1570 | if (glob) { | |
1571 | kallsyms_lookup(entry->ip, NULL, NULL, | |
1572 | NULL, str); | |
1573 | if (!ftrace_match(str, glob, len, type)) | |
1574 | continue; | |
1575 | } | |
1576 | ||
1577 | hlist_del(&entry->node); | |
1578 | call_rcu(&entry->rcu, ftrace_free_entry_rcu); | |
1579 | } | |
1580 | } | |
b6887d79 | 1581 | __disable_ftrace_function_probe(); |
59df055f SR |
1582 | mutex_unlock(&ftrace_lock); |
1583 | } | |
1584 | ||
1585 | void | |
b6887d79 | 1586 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
1587 | void *data) |
1588 | { | |
b6887d79 SR |
1589 | __unregister_ftrace_function_probe(glob, ops, data, |
1590 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
1591 | } |
1592 | ||
1593 | void | |
b6887d79 | 1594 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 1595 | { |
b6887d79 | 1596 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
1597 | } |
1598 | ||
b6887d79 | 1599 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 1600 | { |
b6887d79 | 1601 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
1602 | } |
1603 | ||
f6180773 SR |
1604 | static LIST_HEAD(ftrace_commands); |
1605 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
1606 | ||
1607 | int register_ftrace_command(struct ftrace_func_command *cmd) | |
1608 | { | |
1609 | struct ftrace_func_command *p; | |
1610 | int ret = 0; | |
1611 | ||
1612 | mutex_lock(&ftrace_cmd_mutex); | |
1613 | list_for_each_entry(p, &ftrace_commands, list) { | |
1614 | if (strcmp(cmd->name, p->name) == 0) { | |
1615 | ret = -EBUSY; | |
1616 | goto out_unlock; | |
1617 | } | |
1618 | } | |
1619 | list_add(&cmd->list, &ftrace_commands); | |
1620 | out_unlock: | |
1621 | mutex_unlock(&ftrace_cmd_mutex); | |
1622 | ||
1623 | return ret; | |
1624 | } | |
1625 | ||
1626 | int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
1627 | { | |
1628 | struct ftrace_func_command *p, *n; | |
1629 | int ret = -ENODEV; | |
1630 | ||
1631 | mutex_lock(&ftrace_cmd_mutex); | |
1632 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
1633 | if (strcmp(cmd->name, p->name) == 0) { | |
1634 | ret = 0; | |
1635 | list_del_init(&p->list); | |
1636 | goto out_unlock; | |
1637 | } | |
1638 | } | |
1639 | out_unlock: | |
1640 | mutex_unlock(&ftrace_cmd_mutex); | |
1641 | ||
1642 | return ret; | |
1643 | } | |
1644 | ||
64e7c440 SR |
1645 | static int ftrace_process_regex(char *buff, int len, int enable) |
1646 | { | |
f6180773 | 1647 | char *func, *command, *next = buff; |
6a24a244 | 1648 | struct ftrace_func_command *p; |
f6180773 | 1649 | int ret = -EINVAL; |
64e7c440 SR |
1650 | |
1651 | func = strsep(&next, ":"); | |
1652 | ||
1653 | if (!next) { | |
1654 | ftrace_match_records(func, len, enable); | |
1655 | return 0; | |
1656 | } | |
1657 | ||
f6180773 | 1658 | /* command found */ |
64e7c440 SR |
1659 | |
1660 | command = strsep(&next, ":"); | |
1661 | ||
f6180773 SR |
1662 | mutex_lock(&ftrace_cmd_mutex); |
1663 | list_for_each_entry(p, &ftrace_commands, list) { | |
1664 | if (strcmp(p->name, command) == 0) { | |
1665 | ret = p->func(func, command, next, enable); | |
1666 | goto out_unlock; | |
1667 | } | |
64e7c440 | 1668 | } |
f6180773 SR |
1669 | out_unlock: |
1670 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 1671 | |
f6180773 | 1672 | return ret; |
64e7c440 SR |
1673 | } |
1674 | ||
e309b41d | 1675 | static ssize_t |
41c52c0d SR |
1676 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
1677 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
1678 | { |
1679 | struct ftrace_iterator *iter; | |
1680 | char ch; | |
1681 | size_t read = 0; | |
1682 | ssize_t ret; | |
1683 | ||
1684 | if (!cnt || cnt < 0) | |
1685 | return 0; | |
1686 | ||
41c52c0d | 1687 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1688 | |
1689 | if (file->f_mode & FMODE_READ) { | |
1690 | struct seq_file *m = file->private_data; | |
1691 | iter = m->private; | |
1692 | } else | |
1693 | iter = file->private_data; | |
1694 | ||
1695 | if (!*ppos) { | |
1696 | iter->flags &= ~FTRACE_ITER_CONT; | |
1697 | iter->buffer_idx = 0; | |
1698 | } | |
1699 | ||
1700 | ret = get_user(ch, ubuf++); | |
1701 | if (ret) | |
1702 | goto out; | |
1703 | read++; | |
1704 | cnt--; | |
1705 | ||
1706 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { | |
1707 | /* skip white space */ | |
1708 | while (cnt && isspace(ch)) { | |
1709 | ret = get_user(ch, ubuf++); | |
1710 | if (ret) | |
1711 | goto out; | |
1712 | read++; | |
1713 | cnt--; | |
1714 | } | |
1715 | ||
5072c59f SR |
1716 | if (isspace(ch)) { |
1717 | file->f_pos += read; | |
1718 | ret = read; | |
1719 | goto out; | |
1720 | } | |
1721 | ||
1722 | iter->buffer_idx = 0; | |
1723 | } | |
1724 | ||
1725 | while (cnt && !isspace(ch)) { | |
1726 | if (iter->buffer_idx < FTRACE_BUFF_MAX) | |
1727 | iter->buffer[iter->buffer_idx++] = ch; | |
1728 | else { | |
1729 | ret = -EINVAL; | |
1730 | goto out; | |
1731 | } | |
1732 | ret = get_user(ch, ubuf++); | |
1733 | if (ret) | |
1734 | goto out; | |
1735 | read++; | |
1736 | cnt--; | |
1737 | } | |
1738 | ||
1739 | if (isspace(ch)) { | |
1740 | iter->filtered++; | |
1741 | iter->buffer[iter->buffer_idx] = 0; | |
64e7c440 SR |
1742 | ret = ftrace_process_regex(iter->buffer, |
1743 | iter->buffer_idx, enable); | |
1744 | if (ret) | |
1745 | goto out; | |
5072c59f SR |
1746 | iter->buffer_idx = 0; |
1747 | } else | |
1748 | iter->flags |= FTRACE_ITER_CONT; | |
1749 | ||
1750 | ||
1751 | file->f_pos += read; | |
1752 | ||
1753 | ret = read; | |
1754 | out: | |
41c52c0d | 1755 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1756 | |
1757 | return ret; | |
1758 | } | |
1759 | ||
41c52c0d SR |
1760 | static ssize_t |
1761 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
1762 | size_t cnt, loff_t *ppos) | |
1763 | { | |
1764 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
1765 | } | |
1766 | ||
1767 | static ssize_t | |
1768 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
1769 | size_t cnt, loff_t *ppos) | |
1770 | { | |
1771 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
1772 | } | |
1773 | ||
1774 | static void | |
1775 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
1776 | { | |
1777 | if (unlikely(ftrace_disabled)) | |
1778 | return; | |
1779 | ||
1780 | mutex_lock(&ftrace_regex_lock); | |
1781 | if (reset) | |
1782 | ftrace_filter_reset(enable); | |
1783 | if (buf) | |
7f24b31b | 1784 | ftrace_match_records(buf, len, enable); |
41c52c0d SR |
1785 | mutex_unlock(&ftrace_regex_lock); |
1786 | } | |
1787 | ||
77a2b37d SR |
1788 | /** |
1789 | * ftrace_set_filter - set a function to filter on in ftrace | |
1790 | * @buf - the string that holds the function filter text. | |
1791 | * @len - the length of the string. | |
1792 | * @reset - non zero to reset all filters before applying this filter. | |
1793 | * | |
1794 | * Filters denote which functions should be enabled when tracing is enabled. | |
1795 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
1796 | */ | |
e309b41d | 1797 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 1798 | { |
41c52c0d SR |
1799 | ftrace_set_regex(buf, len, reset, 1); |
1800 | } | |
4eebcc81 | 1801 | |
41c52c0d SR |
1802 | /** |
1803 | * ftrace_set_notrace - set a function to not trace in ftrace | |
1804 | * @buf - the string that holds the function notrace text. | |
1805 | * @len - the length of the string. | |
1806 | * @reset - non zero to reset all filters before applying this filter. | |
1807 | * | |
1808 | * Notrace Filters denote which functions should not be enabled when tracing | |
1809 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
1810 | * for tracing. | |
1811 | */ | |
1812 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
1813 | { | |
1814 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
1815 | } |
1816 | ||
e309b41d | 1817 | static int |
41c52c0d | 1818 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1819 | { |
1820 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1821 | struct ftrace_iterator *iter; | |
1822 | ||
41c52c0d | 1823 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1824 | if (file->f_mode & FMODE_READ) { |
1825 | iter = m->private; | |
1826 | ||
1827 | seq_release(inode, file); | |
1828 | } else | |
1829 | iter = file->private_data; | |
1830 | ||
1831 | if (iter->buffer_idx) { | |
1832 | iter->filtered++; | |
1833 | iter->buffer[iter->buffer_idx] = 0; | |
7f24b31b | 1834 | ftrace_match_records(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1835 | } |
1836 | ||
e6ea44e9 | 1837 | mutex_lock(&ftrace_lock); |
ee02a2e5 | 1838 | if (ftrace_start_up && ftrace_enabled) |
5072c59f | 1839 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
e6ea44e9 | 1840 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
1841 | |
1842 | kfree(iter); | |
41c52c0d | 1843 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1844 | return 0; |
1845 | } | |
1846 | ||
41c52c0d SR |
1847 | static int |
1848 | ftrace_filter_release(struct inode *inode, struct file *file) | |
1849 | { | |
1850 | return ftrace_regex_release(inode, file, 1); | |
1851 | } | |
1852 | ||
1853 | static int | |
1854 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
1855 | { | |
1856 | return ftrace_regex_release(inode, file, 0); | |
1857 | } | |
1858 | ||
5e2336a0 | 1859 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
1860 | .open = ftrace_avail_open, |
1861 | .read = seq_read, | |
1862 | .llseek = seq_lseek, | |
1863 | .release = ftrace_avail_release, | |
1864 | }; | |
1865 | ||
5e2336a0 | 1866 | static const struct file_operations ftrace_failures_fops = { |
eb9a7bf0 AS |
1867 | .open = ftrace_failures_open, |
1868 | .read = seq_read, | |
1869 | .llseek = seq_lseek, | |
1870 | .release = ftrace_avail_release, | |
1871 | }; | |
1872 | ||
5e2336a0 | 1873 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 1874 | .open = ftrace_filter_open, |
850a80cf | 1875 | .read = seq_read, |
5072c59f | 1876 | .write = ftrace_filter_write, |
41c52c0d | 1877 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
1878 | .release = ftrace_filter_release, |
1879 | }; | |
1880 | ||
5e2336a0 | 1881 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 1882 | .open = ftrace_notrace_open, |
850a80cf | 1883 | .read = seq_read, |
41c52c0d SR |
1884 | .write = ftrace_notrace_write, |
1885 | .llseek = ftrace_regex_lseek, | |
1886 | .release = ftrace_notrace_release, | |
1887 | }; | |
1888 | ||
ea4e2bc4 SR |
1889 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
1890 | ||
1891 | static DEFINE_MUTEX(graph_lock); | |
1892 | ||
1893 | int ftrace_graph_count; | |
1894 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; | |
1895 | ||
1896 | static void * | |
1897 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
1898 | { | |
1899 | unsigned long *array = m->private; | |
1900 | int index = *pos; | |
1901 | ||
1902 | (*pos)++; | |
1903 | ||
1904 | if (index >= ftrace_graph_count) | |
1905 | return NULL; | |
1906 | ||
1907 | return &array[index]; | |
1908 | } | |
1909 | ||
1910 | static void *g_start(struct seq_file *m, loff_t *pos) | |
1911 | { | |
1912 | void *p = NULL; | |
1913 | ||
1914 | mutex_lock(&graph_lock); | |
1915 | ||
f9349a8f FW |
1916 | /* Nothing, tell g_show to print all functions are enabled */ |
1917 | if (!ftrace_graph_count && !*pos) | |
1918 | return (void *)1; | |
1919 | ||
ea4e2bc4 SR |
1920 | p = g_next(m, p, pos); |
1921 | ||
1922 | return p; | |
1923 | } | |
1924 | ||
1925 | static void g_stop(struct seq_file *m, void *p) | |
1926 | { | |
1927 | mutex_unlock(&graph_lock); | |
1928 | } | |
1929 | ||
1930 | static int g_show(struct seq_file *m, void *v) | |
1931 | { | |
1932 | unsigned long *ptr = v; | |
1933 | char str[KSYM_SYMBOL_LEN]; | |
1934 | ||
1935 | if (!ptr) | |
1936 | return 0; | |
1937 | ||
f9349a8f FW |
1938 | if (ptr == (unsigned long *)1) { |
1939 | seq_printf(m, "#### all functions enabled ####\n"); | |
1940 | return 0; | |
1941 | } | |
1942 | ||
ea4e2bc4 SR |
1943 | kallsyms_lookup(*ptr, NULL, NULL, NULL, str); |
1944 | ||
1945 | seq_printf(m, "%s\n", str); | |
1946 | ||
1947 | return 0; | |
1948 | } | |
1949 | ||
1950 | static struct seq_operations ftrace_graph_seq_ops = { | |
1951 | .start = g_start, | |
1952 | .next = g_next, | |
1953 | .stop = g_stop, | |
1954 | .show = g_show, | |
1955 | }; | |
1956 | ||
1957 | static int | |
1958 | ftrace_graph_open(struct inode *inode, struct file *file) | |
1959 | { | |
1960 | int ret = 0; | |
1961 | ||
1962 | if (unlikely(ftrace_disabled)) | |
1963 | return -ENODEV; | |
1964 | ||
1965 | mutex_lock(&graph_lock); | |
1966 | if ((file->f_mode & FMODE_WRITE) && | |
1967 | !(file->f_flags & O_APPEND)) { | |
1968 | ftrace_graph_count = 0; | |
1969 | memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); | |
1970 | } | |
1971 | ||
1972 | if (file->f_mode & FMODE_READ) { | |
1973 | ret = seq_open(file, &ftrace_graph_seq_ops); | |
1974 | if (!ret) { | |
1975 | struct seq_file *m = file->private_data; | |
1976 | m->private = ftrace_graph_funcs; | |
1977 | } | |
1978 | } else | |
1979 | file->private_data = ftrace_graph_funcs; | |
1980 | mutex_unlock(&graph_lock); | |
1981 | ||
1982 | return ret; | |
1983 | } | |
1984 | ||
ea4e2bc4 | 1985 | static int |
f9349a8f | 1986 | ftrace_set_func(unsigned long *array, int *idx, char *buffer) |
ea4e2bc4 | 1987 | { |
ea4e2bc4 SR |
1988 | struct dyn_ftrace *rec; |
1989 | struct ftrace_page *pg; | |
f9349a8f | 1990 | int search_len; |
ea4e2bc4 | 1991 | int found = 0; |
f9349a8f FW |
1992 | int type, not; |
1993 | char *search; | |
1994 | bool exists; | |
1995 | int i; | |
ea4e2bc4 SR |
1996 | |
1997 | if (ftrace_disabled) | |
1998 | return -ENODEV; | |
1999 | ||
f9349a8f FW |
2000 | /* decode regex */ |
2001 | type = ftrace_setup_glob(buffer, strlen(buffer), &search, ¬); | |
2002 | if (not) | |
2003 | return -EINVAL; | |
2004 | ||
2005 | search_len = strlen(search); | |
2006 | ||
52baf119 | 2007 | mutex_lock(&ftrace_lock); |
265c831c SR |
2008 | do_for_each_ftrace_rec(pg, rec) { |
2009 | ||
f9349a8f FW |
2010 | if (*idx >= FTRACE_GRAPH_MAX_FUNCS) |
2011 | break; | |
2012 | ||
265c831c SR |
2013 | if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE)) |
2014 | continue; | |
2015 | ||
f9349a8f FW |
2016 | if (ftrace_match_record(rec, search, search_len, type)) { |
2017 | /* ensure it is not already in the array */ | |
2018 | exists = false; | |
2019 | for (i = 0; i < *idx; i++) | |
2020 | if (array[i] == rec->ip) { | |
2021 | exists = true; | |
265c831c SR |
2022 | break; |
2023 | } | |
f9349a8f FW |
2024 | if (!exists) { |
2025 | array[(*idx)++] = rec->ip; | |
2026 | found = 1; | |
2027 | } | |
ea4e2bc4 | 2028 | } |
265c831c | 2029 | } while_for_each_ftrace_rec(); |
f9349a8f | 2030 | |
52baf119 | 2031 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 SR |
2032 | |
2033 | return found ? 0 : -EINVAL; | |
2034 | } | |
2035 | ||
2036 | static ssize_t | |
2037 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
2038 | size_t cnt, loff_t *ppos) | |
2039 | { | |
2040 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
2041 | unsigned long *array; | |
2042 | size_t read = 0; | |
2043 | ssize_t ret; | |
2044 | int index = 0; | |
2045 | char ch; | |
2046 | ||
2047 | if (!cnt || cnt < 0) | |
2048 | return 0; | |
2049 | ||
2050 | mutex_lock(&graph_lock); | |
2051 | ||
2052 | if (ftrace_graph_count >= FTRACE_GRAPH_MAX_FUNCS) { | |
2053 | ret = -EBUSY; | |
2054 | goto out; | |
2055 | } | |
2056 | ||
2057 | if (file->f_mode & FMODE_READ) { | |
2058 | struct seq_file *m = file->private_data; | |
2059 | array = m->private; | |
2060 | } else | |
2061 | array = file->private_data; | |
2062 | ||
2063 | ret = get_user(ch, ubuf++); | |
2064 | if (ret) | |
2065 | goto out; | |
2066 | read++; | |
2067 | cnt--; | |
2068 | ||
2069 | /* skip white space */ | |
2070 | while (cnt && isspace(ch)) { | |
2071 | ret = get_user(ch, ubuf++); | |
2072 | if (ret) | |
2073 | goto out; | |
2074 | read++; | |
2075 | cnt--; | |
2076 | } | |
2077 | ||
2078 | if (isspace(ch)) { | |
2079 | *ppos += read; | |
2080 | ret = read; | |
2081 | goto out; | |
2082 | } | |
2083 | ||
2084 | while (cnt && !isspace(ch)) { | |
2085 | if (index < FTRACE_BUFF_MAX) | |
2086 | buffer[index++] = ch; | |
2087 | else { | |
2088 | ret = -EINVAL; | |
2089 | goto out; | |
2090 | } | |
2091 | ret = get_user(ch, ubuf++); | |
2092 | if (ret) | |
2093 | goto out; | |
2094 | read++; | |
2095 | cnt--; | |
2096 | } | |
2097 | buffer[index] = 0; | |
2098 | ||
f9349a8f FW |
2099 | /* we allow only one expression at a time */ |
2100 | ret = ftrace_set_func(array, &ftrace_graph_count, buffer); | |
ea4e2bc4 SR |
2101 | if (ret) |
2102 | goto out; | |
2103 | ||
ea4e2bc4 SR |
2104 | file->f_pos += read; |
2105 | ||
2106 | ret = read; | |
2107 | out: | |
2108 | mutex_unlock(&graph_lock); | |
2109 | ||
2110 | return ret; | |
2111 | } | |
2112 | ||
2113 | static const struct file_operations ftrace_graph_fops = { | |
2114 | .open = ftrace_graph_open, | |
850a80cf | 2115 | .read = seq_read, |
ea4e2bc4 SR |
2116 | .write = ftrace_graph_write, |
2117 | }; | |
2118 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2119 | ||
df4fc315 | 2120 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 2121 | { |
5072c59f SR |
2122 | struct dentry *entry; |
2123 | ||
5072c59f SR |
2124 | entry = debugfs_create_file("available_filter_functions", 0444, |
2125 | d_tracer, NULL, &ftrace_avail_fops); | |
2126 | if (!entry) | |
2127 | pr_warning("Could not create debugfs " | |
2128 | "'available_filter_functions' entry\n"); | |
2129 | ||
eb9a7bf0 AS |
2130 | entry = debugfs_create_file("failures", 0444, |
2131 | d_tracer, NULL, &ftrace_failures_fops); | |
2132 | if (!entry) | |
2133 | pr_warning("Could not create debugfs 'failures' entry\n"); | |
2134 | ||
5072c59f SR |
2135 | entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer, |
2136 | NULL, &ftrace_filter_fops); | |
2137 | if (!entry) | |
2138 | pr_warning("Could not create debugfs " | |
2139 | "'set_ftrace_filter' entry\n"); | |
41c52c0d SR |
2140 | |
2141 | entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer, | |
2142 | NULL, &ftrace_notrace_fops); | |
2143 | if (!entry) | |
2144 | pr_warning("Could not create debugfs " | |
2145 | "'set_ftrace_notrace' entry\n"); | |
ad90c0e3 | 2146 | |
ea4e2bc4 SR |
2147 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
2148 | entry = debugfs_create_file("set_graph_function", 0444, d_tracer, | |
2149 | NULL, | |
2150 | &ftrace_graph_fops); | |
2151 | if (!entry) | |
2152 | pr_warning("Could not create debugfs " | |
2153 | "'set_graph_function' entry\n"); | |
2154 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2155 | ||
5072c59f SR |
2156 | return 0; |
2157 | } | |
2158 | ||
31e88909 SR |
2159 | static int ftrace_convert_nops(struct module *mod, |
2160 | unsigned long *start, | |
68bf21aa SR |
2161 | unsigned long *end) |
2162 | { | |
2163 | unsigned long *p; | |
2164 | unsigned long addr; | |
2165 | unsigned long flags; | |
2166 | ||
e6ea44e9 | 2167 | mutex_lock(&ftrace_lock); |
68bf21aa SR |
2168 | p = start; |
2169 | while (p < end) { | |
2170 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
2171 | /* |
2172 | * Some architecture linkers will pad between | |
2173 | * the different mcount_loc sections of different | |
2174 | * object files to satisfy alignments. | |
2175 | * Skip any NULL pointers. | |
2176 | */ | |
2177 | if (!addr) | |
2178 | continue; | |
68bf21aa | 2179 | ftrace_record_ip(addr); |
68bf21aa SR |
2180 | } |
2181 | ||
08f5ac90 | 2182 | /* disable interrupts to prevent kstop machine */ |
68bf21aa | 2183 | local_irq_save(flags); |
31e88909 | 2184 | ftrace_update_code(mod); |
68bf21aa | 2185 | local_irq_restore(flags); |
e6ea44e9 | 2186 | mutex_unlock(&ftrace_lock); |
68bf21aa SR |
2187 | |
2188 | return 0; | |
2189 | } | |
2190 | ||
31e88909 SR |
2191 | void ftrace_init_module(struct module *mod, |
2192 | unsigned long *start, unsigned long *end) | |
90d595fe | 2193 | { |
00fd61ae | 2194 | if (ftrace_disabled || start == end) |
fed1939c | 2195 | return; |
31e88909 | 2196 | ftrace_convert_nops(mod, start, end); |
90d595fe SR |
2197 | } |
2198 | ||
68bf21aa SR |
2199 | extern unsigned long __start_mcount_loc[]; |
2200 | extern unsigned long __stop_mcount_loc[]; | |
2201 | ||
2202 | void __init ftrace_init(void) | |
2203 | { | |
2204 | unsigned long count, addr, flags; | |
2205 | int ret; | |
2206 | ||
2207 | /* Keep the ftrace pointer to the stub */ | |
2208 | addr = (unsigned long)ftrace_stub; | |
2209 | ||
2210 | local_irq_save(flags); | |
2211 | ftrace_dyn_arch_init(&addr); | |
2212 | local_irq_restore(flags); | |
2213 | ||
2214 | /* ftrace_dyn_arch_init places the return code in addr */ | |
2215 | if (addr) | |
2216 | goto failed; | |
2217 | ||
2218 | count = __stop_mcount_loc - __start_mcount_loc; | |
2219 | ||
2220 | ret = ftrace_dyn_table_alloc(count); | |
2221 | if (ret) | |
2222 | goto failed; | |
2223 | ||
2224 | last_ftrace_enabled = ftrace_enabled = 1; | |
2225 | ||
31e88909 SR |
2226 | ret = ftrace_convert_nops(NULL, |
2227 | __start_mcount_loc, | |
68bf21aa SR |
2228 | __stop_mcount_loc); |
2229 | ||
2230 | return; | |
2231 | failed: | |
2232 | ftrace_disabled = 1; | |
2233 | } | |
68bf21aa | 2234 | |
3d083395 | 2235 | #else |
0b6e4d56 FW |
2236 | |
2237 | static int __init ftrace_nodyn_init(void) | |
2238 | { | |
2239 | ftrace_enabled = 1; | |
2240 | return 0; | |
2241 | } | |
2242 | device_initcall(ftrace_nodyn_init); | |
2243 | ||
df4fc315 SR |
2244 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
2245 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 SR |
2246 | /* Keep as macros so we do not need to define the commands */ |
2247 | # define ftrace_startup(command) do { } while (0) | |
2248 | # define ftrace_shutdown(command) do { } while (0) | |
c7aafc54 IM |
2249 | # define ftrace_startup_sysctl() do { } while (0) |
2250 | # define ftrace_shutdown_sysctl() do { } while (0) | |
3d083395 SR |
2251 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
2252 | ||
df4fc315 SR |
2253 | static ssize_t |
2254 | ftrace_pid_read(struct file *file, char __user *ubuf, | |
2255 | size_t cnt, loff_t *ppos) | |
2256 | { | |
2257 | char buf[64]; | |
2258 | int r; | |
2259 | ||
e32d8956 SR |
2260 | if (ftrace_pid_trace == ftrace_swapper_pid) |
2261 | r = sprintf(buf, "swapper tasks\n"); | |
2262 | else if (ftrace_pid_trace) | |
978f3a45 | 2263 | r = sprintf(buf, "%u\n", pid_nr(ftrace_pid_trace)); |
df4fc315 SR |
2264 | else |
2265 | r = sprintf(buf, "no pid\n"); | |
2266 | ||
2267 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
2268 | } | |
2269 | ||
e32d8956 | 2270 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
2271 | { |
2272 | struct task_struct *p; | |
e32d8956 | 2273 | int cpu; |
978f3a45 | 2274 | |
e32d8956 SR |
2275 | get_online_cpus(); |
2276 | for_each_online_cpu(cpu) { | |
2277 | p = idle_task(cpu); | |
978f3a45 | 2278 | clear_tsk_trace_trace(p); |
e32d8956 SR |
2279 | } |
2280 | put_online_cpus(); | |
2281 | } | |
978f3a45 | 2282 | |
e32d8956 SR |
2283 | static void set_ftrace_swapper(void) |
2284 | { | |
2285 | struct task_struct *p; | |
2286 | int cpu; | |
2287 | ||
2288 | get_online_cpus(); | |
2289 | for_each_online_cpu(cpu) { | |
2290 | p = idle_task(cpu); | |
2291 | set_tsk_trace_trace(p); | |
2292 | } | |
2293 | put_online_cpus(); | |
978f3a45 SR |
2294 | } |
2295 | ||
e32d8956 SR |
2296 | static void clear_ftrace_pid(struct pid *pid) |
2297 | { | |
2298 | struct task_struct *p; | |
2299 | ||
229c4ef8 | 2300 | rcu_read_lock(); |
e32d8956 SR |
2301 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2302 | clear_tsk_trace_trace(p); | |
2303 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
2304 | rcu_read_unlock(); |
2305 | ||
e32d8956 SR |
2306 | put_pid(pid); |
2307 | } | |
2308 | ||
2309 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
2310 | { |
2311 | struct task_struct *p; | |
2312 | ||
229c4ef8 | 2313 | rcu_read_lock(); |
978f3a45 SR |
2314 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
2315 | set_tsk_trace_trace(p); | |
2316 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 2317 | rcu_read_unlock(); |
978f3a45 SR |
2318 | } |
2319 | ||
e32d8956 SR |
2320 | static void clear_ftrace_pid_task(struct pid **pid) |
2321 | { | |
2322 | if (*pid == ftrace_swapper_pid) | |
2323 | clear_ftrace_swapper(); | |
2324 | else | |
2325 | clear_ftrace_pid(*pid); | |
2326 | ||
2327 | *pid = NULL; | |
2328 | } | |
2329 | ||
2330 | static void set_ftrace_pid_task(struct pid *pid) | |
2331 | { | |
2332 | if (pid == ftrace_swapper_pid) | |
2333 | set_ftrace_swapper(); | |
2334 | else | |
2335 | set_ftrace_pid(pid); | |
2336 | } | |
2337 | ||
df4fc315 SR |
2338 | static ssize_t |
2339 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
2340 | size_t cnt, loff_t *ppos) | |
2341 | { | |
978f3a45 | 2342 | struct pid *pid; |
df4fc315 SR |
2343 | char buf[64]; |
2344 | long val; | |
2345 | int ret; | |
2346 | ||
2347 | if (cnt >= sizeof(buf)) | |
2348 | return -EINVAL; | |
2349 | ||
2350 | if (copy_from_user(&buf, ubuf, cnt)) | |
2351 | return -EFAULT; | |
2352 | ||
2353 | buf[cnt] = 0; | |
2354 | ||
2355 | ret = strict_strtol(buf, 10, &val); | |
2356 | if (ret < 0) | |
2357 | return ret; | |
2358 | ||
e6ea44e9 | 2359 | mutex_lock(&ftrace_lock); |
978f3a45 | 2360 | if (val < 0) { |
df4fc315 | 2361 | /* disable pid tracing */ |
978f3a45 | 2362 | if (!ftrace_pid_trace) |
df4fc315 | 2363 | goto out; |
978f3a45 SR |
2364 | |
2365 | clear_ftrace_pid_task(&ftrace_pid_trace); | |
df4fc315 SR |
2366 | |
2367 | } else { | |
e32d8956 SR |
2368 | /* swapper task is special */ |
2369 | if (!val) { | |
2370 | pid = ftrace_swapper_pid; | |
2371 | if (pid == ftrace_pid_trace) | |
2372 | goto out; | |
2373 | } else { | |
2374 | pid = find_get_pid(val); | |
df4fc315 | 2375 | |
e32d8956 SR |
2376 | if (pid == ftrace_pid_trace) { |
2377 | put_pid(pid); | |
2378 | goto out; | |
2379 | } | |
0ef8cde5 | 2380 | } |
0ef8cde5 | 2381 | |
978f3a45 SR |
2382 | if (ftrace_pid_trace) |
2383 | clear_ftrace_pid_task(&ftrace_pid_trace); | |
2384 | ||
2385 | if (!pid) | |
2386 | goto out; | |
2387 | ||
2388 | ftrace_pid_trace = pid; | |
2389 | ||
2390 | set_ftrace_pid_task(ftrace_pid_trace); | |
df4fc315 SR |
2391 | } |
2392 | ||
2393 | /* update the function call */ | |
2394 | ftrace_update_pid_func(); | |
2395 | ftrace_startup_enable(0); | |
2396 | ||
2397 | out: | |
e6ea44e9 | 2398 | mutex_unlock(&ftrace_lock); |
df4fc315 SR |
2399 | |
2400 | return cnt; | |
2401 | } | |
2402 | ||
5e2336a0 | 2403 | static const struct file_operations ftrace_pid_fops = { |
df4fc315 SR |
2404 | .read = ftrace_pid_read, |
2405 | .write = ftrace_pid_write, | |
2406 | }; | |
2407 | ||
2408 | static __init int ftrace_init_debugfs(void) | |
2409 | { | |
2410 | struct dentry *d_tracer; | |
2411 | struct dentry *entry; | |
2412 | ||
2413 | d_tracer = tracing_init_dentry(); | |
2414 | if (!d_tracer) | |
2415 | return 0; | |
2416 | ||
2417 | ftrace_init_dyn_debugfs(d_tracer); | |
2418 | ||
2419 | entry = debugfs_create_file("set_ftrace_pid", 0644, d_tracer, | |
2420 | NULL, &ftrace_pid_fops); | |
2421 | if (!entry) | |
2422 | pr_warning("Could not create debugfs " | |
2423 | "'set_ftrace_pid' entry\n"); | |
2424 | return 0; | |
2425 | } | |
df4fc315 SR |
2426 | fs_initcall(ftrace_init_debugfs); |
2427 | ||
a2bb6a3d | 2428 | /** |
81adbdc0 | 2429 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
2430 | * |
2431 | * This function should be used by panic code. It stops ftrace | |
2432 | * but in a not so nice way. If you need to simply kill ftrace | |
2433 | * from a non-atomic section, use ftrace_kill. | |
2434 | */ | |
81adbdc0 | 2435 | void ftrace_kill(void) |
a2bb6a3d SR |
2436 | { |
2437 | ftrace_disabled = 1; | |
2438 | ftrace_enabled = 0; | |
a2bb6a3d SR |
2439 | clear_ftrace_function(); |
2440 | } | |
2441 | ||
16444a8a | 2442 | /** |
3d083395 SR |
2443 | * register_ftrace_function - register a function for profiling |
2444 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 2445 | * |
3d083395 SR |
2446 | * Register a function to be called by all functions in the |
2447 | * kernel. | |
2448 | * | |
2449 | * Note: @ops->func and all the functions it calls must be labeled | |
2450 | * with "notrace", otherwise it will go into a | |
2451 | * recursive loop. | |
16444a8a | 2452 | */ |
3d083395 | 2453 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 2454 | { |
b0fc494f SR |
2455 | int ret; |
2456 | ||
4eebcc81 SR |
2457 | if (unlikely(ftrace_disabled)) |
2458 | return -1; | |
2459 | ||
e6ea44e9 | 2460 | mutex_lock(&ftrace_lock); |
e7d3737e | 2461 | |
b0fc494f | 2462 | ret = __register_ftrace_function(ops); |
5a45cfe1 | 2463 | ftrace_startup(0); |
b0fc494f | 2464 | |
e6ea44e9 | 2465 | mutex_unlock(&ftrace_lock); |
b0fc494f | 2466 | return ret; |
3d083395 SR |
2467 | } |
2468 | ||
2469 | /** | |
32632920 | 2470 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
2471 | * @ops - ops structure that holds the function to unregister |
2472 | * | |
2473 | * Unregister a function that was added to be called by ftrace profiling. | |
2474 | */ | |
2475 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
2476 | { | |
2477 | int ret; | |
2478 | ||
e6ea44e9 | 2479 | mutex_lock(&ftrace_lock); |
3d083395 | 2480 | ret = __unregister_ftrace_function(ops); |
5a45cfe1 | 2481 | ftrace_shutdown(0); |
e6ea44e9 | 2482 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
2483 | |
2484 | return ret; | |
2485 | } | |
2486 | ||
e309b41d | 2487 | int |
b0fc494f | 2488 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
5072c59f | 2489 | struct file *file, void __user *buffer, size_t *lenp, |
b0fc494f SR |
2490 | loff_t *ppos) |
2491 | { | |
2492 | int ret; | |
2493 | ||
4eebcc81 SR |
2494 | if (unlikely(ftrace_disabled)) |
2495 | return -ENODEV; | |
2496 | ||
e6ea44e9 | 2497 | mutex_lock(&ftrace_lock); |
b0fc494f | 2498 | |
5072c59f | 2499 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
b0fc494f SR |
2500 | |
2501 | if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) | |
2502 | goto out; | |
2503 | ||
2504 | last_ftrace_enabled = ftrace_enabled; | |
2505 | ||
2506 | if (ftrace_enabled) { | |
2507 | ||
2508 | ftrace_startup_sysctl(); | |
2509 | ||
2510 | /* we are starting ftrace again */ | |
2511 | if (ftrace_list != &ftrace_list_end) { | |
2512 | if (ftrace_list->next == &ftrace_list_end) | |
2513 | ftrace_trace_function = ftrace_list->func; | |
2514 | else | |
2515 | ftrace_trace_function = ftrace_list_func; | |
2516 | } | |
2517 | ||
2518 | } else { | |
2519 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
2520 | ftrace_trace_function = ftrace_stub; | |
2521 | ||
2522 | ftrace_shutdown_sysctl(); | |
2523 | } | |
2524 | ||
2525 | out: | |
e6ea44e9 | 2526 | mutex_unlock(&ftrace_lock); |
3d083395 | 2527 | return ret; |
16444a8a | 2528 | } |
f17845e5 | 2529 | |
fb52607a | 2530 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 2531 | |
287b6e68 | 2532 | static atomic_t ftrace_graph_active; |
4a2b8dda | 2533 | static struct notifier_block ftrace_suspend_notifier; |
e7d3737e | 2534 | |
e49dc19c SR |
2535 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
2536 | { | |
2537 | return 0; | |
2538 | } | |
2539 | ||
287b6e68 FW |
2540 | /* The callbacks that hook a function */ |
2541 | trace_func_graph_ret_t ftrace_graph_return = | |
2542 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 2543 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
2544 | |
2545 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
2546 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
2547 | { | |
2548 | int i; | |
2549 | int ret = 0; | |
2550 | unsigned long flags; | |
2551 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
2552 | struct task_struct *g, *t; | |
2553 | ||
2554 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
2555 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
2556 | * sizeof(struct ftrace_ret_stack), | |
2557 | GFP_KERNEL); | |
2558 | if (!ret_stack_list[i]) { | |
2559 | start = 0; | |
2560 | end = i; | |
2561 | ret = -ENOMEM; | |
2562 | goto free; | |
2563 | } | |
2564 | } | |
2565 | ||
2566 | read_lock_irqsave(&tasklist_lock, flags); | |
2567 | do_each_thread(g, t) { | |
2568 | if (start == end) { | |
2569 | ret = -EAGAIN; | |
2570 | goto unlock; | |
2571 | } | |
2572 | ||
2573 | if (t->ret_stack == NULL) { | |
f201ae23 | 2574 | t->curr_ret_stack = -1; |
48d68b20 FW |
2575 | /* Make sure IRQs see the -1 first: */ |
2576 | barrier(); | |
2577 | t->ret_stack = ret_stack_list[start++]; | |
380c4b14 | 2578 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 FW |
2579 | atomic_set(&t->trace_overrun, 0); |
2580 | } | |
2581 | } while_each_thread(g, t); | |
2582 | ||
2583 | unlock: | |
2584 | read_unlock_irqrestore(&tasklist_lock, flags); | |
2585 | free: | |
2586 | for (i = start; i < end; i++) | |
2587 | kfree(ret_stack_list[i]); | |
2588 | return ret; | |
2589 | } | |
2590 | ||
2591 | /* Allocate a return stack for each task */ | |
fb52607a | 2592 | static int start_graph_tracing(void) |
f201ae23 FW |
2593 | { |
2594 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 2595 | int ret, cpu; |
f201ae23 FW |
2596 | |
2597 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
2598 | sizeof(struct ftrace_ret_stack *), | |
2599 | GFP_KERNEL); | |
2600 | ||
2601 | if (!ret_stack_list) | |
2602 | return -ENOMEM; | |
2603 | ||
5b058bcd FW |
2604 | /* The cpu_boot init_task->ret_stack will never be freed */ |
2605 | for_each_online_cpu(cpu) | |
2606 | ftrace_graph_init_task(idle_task(cpu)); | |
2607 | ||
f201ae23 FW |
2608 | do { |
2609 | ret = alloc_retstack_tasklist(ret_stack_list); | |
2610 | } while (ret == -EAGAIN); | |
2611 | ||
2612 | kfree(ret_stack_list); | |
2613 | return ret; | |
2614 | } | |
2615 | ||
4a2b8dda FW |
2616 | /* |
2617 | * Hibernation protection. | |
2618 | * The state of the current task is too much unstable during | |
2619 | * suspend/restore to disk. We want to protect against that. | |
2620 | */ | |
2621 | static int | |
2622 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
2623 | void *unused) | |
2624 | { | |
2625 | switch (state) { | |
2626 | case PM_HIBERNATION_PREPARE: | |
2627 | pause_graph_tracing(); | |
2628 | break; | |
2629 | ||
2630 | case PM_POST_HIBERNATION: | |
2631 | unpause_graph_tracing(); | |
2632 | break; | |
2633 | } | |
2634 | return NOTIFY_DONE; | |
2635 | } | |
2636 | ||
287b6e68 FW |
2637 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
2638 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 2639 | { |
e7d3737e FW |
2640 | int ret = 0; |
2641 | ||
e6ea44e9 | 2642 | mutex_lock(&ftrace_lock); |
e7d3737e | 2643 | |
4a2b8dda FW |
2644 | ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; |
2645 | register_pm_notifier(&ftrace_suspend_notifier); | |
2646 | ||
287b6e68 | 2647 | atomic_inc(&ftrace_graph_active); |
fb52607a | 2648 | ret = start_graph_tracing(); |
f201ae23 | 2649 | if (ret) { |
287b6e68 | 2650 | atomic_dec(&ftrace_graph_active); |
f201ae23 FW |
2651 | goto out; |
2652 | } | |
e53a6319 | 2653 | |
287b6e68 FW |
2654 | ftrace_graph_return = retfunc; |
2655 | ftrace_graph_entry = entryfunc; | |
e53a6319 | 2656 | |
5a45cfe1 | 2657 | ftrace_startup(FTRACE_START_FUNC_RET); |
e7d3737e FW |
2658 | |
2659 | out: | |
e6ea44e9 | 2660 | mutex_unlock(&ftrace_lock); |
e7d3737e | 2661 | return ret; |
15e6cb36 FW |
2662 | } |
2663 | ||
fb52607a | 2664 | void unregister_ftrace_graph(void) |
15e6cb36 | 2665 | { |
e6ea44e9 | 2666 | mutex_lock(&ftrace_lock); |
e7d3737e | 2667 | |
287b6e68 FW |
2668 | atomic_dec(&ftrace_graph_active); |
2669 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 2670 | ftrace_graph_entry = ftrace_graph_entry_stub; |
5a45cfe1 | 2671 | ftrace_shutdown(FTRACE_STOP_FUNC_RET); |
4a2b8dda | 2672 | unregister_pm_notifier(&ftrace_suspend_notifier); |
e7d3737e | 2673 | |
e6ea44e9 | 2674 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 2675 | } |
f201ae23 FW |
2676 | |
2677 | /* Allocate a return stack for newly created task */ | |
fb52607a | 2678 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 2679 | { |
287b6e68 | 2680 | if (atomic_read(&ftrace_graph_active)) { |
f201ae23 FW |
2681 | t->ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH |
2682 | * sizeof(struct ftrace_ret_stack), | |
2683 | GFP_KERNEL); | |
2684 | if (!t->ret_stack) | |
2685 | return; | |
2686 | t->curr_ret_stack = -1; | |
380c4b14 | 2687 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 FW |
2688 | atomic_set(&t->trace_overrun, 0); |
2689 | } else | |
2690 | t->ret_stack = NULL; | |
2691 | } | |
2692 | ||
fb52607a | 2693 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 2694 | { |
eae849ca FW |
2695 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
2696 | ||
f201ae23 | 2697 | t->ret_stack = NULL; |
eae849ca FW |
2698 | /* NULL must become visible to IRQs before we free it: */ |
2699 | barrier(); | |
2700 | ||
2701 | kfree(ret_stack); | |
f201ae23 | 2702 | } |
14a866c5 SR |
2703 | |
2704 | void ftrace_graph_stop(void) | |
2705 | { | |
2706 | ftrace_stop(); | |
2707 | } | |
15e6cb36 FW |
2708 | #endif |
2709 |