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Commit | Line | Data |
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16444a8a ACM |
1 | /* |
2 | * Infrastructure for profiling code inserted by 'gcc -pg'. | |
3 | * | |
4 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> | |
5 | * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com> | |
6 | * | |
7 | * Originally ported from the -rt patch by: | |
8 | * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com> | |
9 | * | |
10 | * Based on code in the latency_tracer, that is: | |
11 | * | |
12 | * Copyright (C) 2004-2006 Ingo Molnar | |
13 | * Copyright (C) 2004 William Lee Irwin III | |
14 | */ | |
15 | ||
3d083395 SR |
16 | #include <linux/stop_machine.h> |
17 | #include <linux/clocksource.h> | |
18 | #include <linux/kallsyms.h> | |
5072c59f SR |
19 | #include <linux/seq_file.h> |
20 | #include <linux/debugfs.h> | |
3d083395 | 21 | #include <linux/hardirq.h> |
2d8b820b | 22 | #include <linux/kthread.h> |
5072c59f | 23 | #include <linux/uaccess.h> |
f22f9a89 | 24 | #include <linux/kprobes.h> |
2d8b820b | 25 | #include <linux/ftrace.h> |
b0fc494f | 26 | #include <linux/sysctl.h> |
5072c59f | 27 | #include <linux/ctype.h> |
3d083395 SR |
28 | #include <linux/list.h> |
29 | ||
395a59d0 AS |
30 | #include <asm/ftrace.h> |
31 | ||
3d083395 | 32 | #include "trace.h" |
16444a8a | 33 | |
6912896e SR |
34 | #define FTRACE_WARN_ON(cond) \ |
35 | do { \ | |
36 | if (WARN_ON(cond)) \ | |
37 | ftrace_kill(); \ | |
38 | } while (0) | |
39 | ||
40 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
41 | do { \ | |
42 | if (WARN_ON_ONCE(cond)) \ | |
43 | ftrace_kill(); \ | |
44 | } while (0) | |
45 | ||
4eebcc81 SR |
46 | /* ftrace_enabled is a method to turn ftrace on or off */ |
47 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 48 | static int last_ftrace_enabled; |
b0fc494f | 49 | |
df4fc315 SR |
50 | /* ftrace_pid_trace >= 0 will only trace threads with this pid */ |
51 | static int ftrace_pid_trace = -1; | |
52 | ||
60a7ecf4 SR |
53 | /* Quick disabling of function tracer. */ |
54 | int function_trace_stop; | |
55 | ||
e7d3737e FW |
56 | /* By default, current tracing type is normal tracing. */ |
57 | enum ftrace_tracing_type_t ftrace_tracing_type = FTRACE_TYPE_ENTER; | |
58 | ||
4eebcc81 SR |
59 | /* |
60 | * ftrace_disabled is set when an anomaly is discovered. | |
61 | * ftrace_disabled is much stronger than ftrace_enabled. | |
62 | */ | |
63 | static int ftrace_disabled __read_mostly; | |
64 | ||
3d083395 | 65 | static DEFINE_SPINLOCK(ftrace_lock); |
b0fc494f | 66 | static DEFINE_MUTEX(ftrace_sysctl_lock); |
df4fc315 | 67 | static DEFINE_MUTEX(ftrace_start_lock); |
b0fc494f | 68 | |
16444a8a ACM |
69 | static struct ftrace_ops ftrace_list_end __read_mostly = |
70 | { | |
71 | .func = ftrace_stub, | |
72 | }; | |
73 | ||
74 | static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; | |
75 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; | |
60a7ecf4 | 76 | ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub; |
df4fc315 | 77 | ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; |
16444a8a | 78 | |
f2252935 | 79 | static void ftrace_list_func(unsigned long ip, unsigned long parent_ip) |
16444a8a ACM |
80 | { |
81 | struct ftrace_ops *op = ftrace_list; | |
82 | ||
83 | /* in case someone actually ports this to alpha! */ | |
84 | read_barrier_depends(); | |
85 | ||
86 | while (op != &ftrace_list_end) { | |
87 | /* silly alpha */ | |
88 | read_barrier_depends(); | |
89 | op->func(ip, parent_ip); | |
90 | op = op->next; | |
91 | }; | |
92 | } | |
93 | ||
df4fc315 SR |
94 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip) |
95 | { | |
96 | if (current->pid != ftrace_pid_trace) | |
97 | return; | |
98 | ||
99 | ftrace_pid_function(ip, parent_ip); | |
100 | } | |
101 | ||
102 | static void set_ftrace_pid_function(ftrace_func_t func) | |
103 | { | |
104 | /* do not set ftrace_pid_function to itself! */ | |
105 | if (func != ftrace_pid_func) | |
106 | ftrace_pid_function = func; | |
107 | } | |
108 | ||
16444a8a | 109 | /** |
3d083395 | 110 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 111 | * |
3d083395 SR |
112 | * This NULLs the ftrace function and in essence stops |
113 | * tracing. There may be lag | |
16444a8a | 114 | */ |
3d083395 | 115 | void clear_ftrace_function(void) |
16444a8a | 116 | { |
3d083395 | 117 | ftrace_trace_function = ftrace_stub; |
60a7ecf4 | 118 | __ftrace_trace_function = ftrace_stub; |
df4fc315 | 119 | ftrace_pid_function = ftrace_stub; |
3d083395 SR |
120 | } |
121 | ||
60a7ecf4 SR |
122 | #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
123 | /* | |
124 | * For those archs that do not test ftrace_trace_stop in their | |
125 | * mcount call site, we need to do it from C. | |
126 | */ | |
127 | static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip) | |
128 | { | |
129 | if (function_trace_stop) | |
130 | return; | |
131 | ||
132 | __ftrace_trace_function(ip, parent_ip); | |
133 | } | |
134 | #endif | |
135 | ||
e309b41d | 136 | static int __register_ftrace_function(struct ftrace_ops *ops) |
3d083395 | 137 | { |
99ecdc43 | 138 | /* should not be called from interrupt context */ |
3d083395 | 139 | spin_lock(&ftrace_lock); |
16444a8a | 140 | |
16444a8a ACM |
141 | ops->next = ftrace_list; |
142 | /* | |
143 | * We are entering ops into the ftrace_list but another | |
144 | * CPU might be walking that list. We need to make sure | |
145 | * the ops->next pointer is valid before another CPU sees | |
146 | * the ops pointer included into the ftrace_list. | |
147 | */ | |
148 | smp_wmb(); | |
149 | ftrace_list = ops; | |
3d083395 | 150 | |
b0fc494f | 151 | if (ftrace_enabled) { |
df4fc315 SR |
152 | ftrace_func_t func; |
153 | ||
154 | if (ops->next == &ftrace_list_end) | |
155 | func = ops->func; | |
156 | else | |
157 | func = ftrace_list_func; | |
158 | ||
159 | if (ftrace_pid_trace >= 0) { | |
160 | set_ftrace_pid_function(func); | |
161 | func = ftrace_pid_func; | |
162 | } | |
163 | ||
b0fc494f SR |
164 | /* |
165 | * For one func, simply call it directly. | |
166 | * For more than one func, call the chain. | |
167 | */ | |
60a7ecf4 | 168 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
df4fc315 | 169 | ftrace_trace_function = func; |
60a7ecf4 | 170 | #else |
df4fc315 | 171 | __ftrace_trace_function = func; |
60a7ecf4 SR |
172 | ftrace_trace_function = ftrace_test_stop_func; |
173 | #endif | |
b0fc494f | 174 | } |
3d083395 SR |
175 | |
176 | spin_unlock(&ftrace_lock); | |
16444a8a ACM |
177 | |
178 | return 0; | |
179 | } | |
180 | ||
e309b41d | 181 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 182 | { |
16444a8a ACM |
183 | struct ftrace_ops **p; |
184 | int ret = 0; | |
185 | ||
99ecdc43 | 186 | /* should not be called from interrupt context */ |
3d083395 | 187 | spin_lock(&ftrace_lock); |
16444a8a ACM |
188 | |
189 | /* | |
3d083395 SR |
190 | * If we are removing the last function, then simply point |
191 | * to the ftrace_stub. | |
16444a8a ACM |
192 | */ |
193 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { | |
194 | ftrace_trace_function = ftrace_stub; | |
195 | ftrace_list = &ftrace_list_end; | |
196 | goto out; | |
197 | } | |
198 | ||
199 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) | |
200 | if (*p == ops) | |
201 | break; | |
202 | ||
203 | if (*p != ops) { | |
204 | ret = -1; | |
205 | goto out; | |
206 | } | |
207 | ||
208 | *p = (*p)->next; | |
209 | ||
b0fc494f SR |
210 | if (ftrace_enabled) { |
211 | /* If we only have one func left, then call that directly */ | |
df4fc315 SR |
212 | if (ftrace_list->next == &ftrace_list_end) { |
213 | ftrace_func_t func = ftrace_list->func; | |
214 | ||
215 | if (ftrace_pid_trace >= 0) { | |
216 | set_ftrace_pid_function(func); | |
217 | func = ftrace_pid_func; | |
218 | } | |
219 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
220 | ftrace_trace_function = func; | |
221 | #else | |
222 | __ftrace_trace_function = func; | |
223 | #endif | |
224 | } | |
b0fc494f | 225 | } |
16444a8a ACM |
226 | |
227 | out: | |
3d083395 SR |
228 | spin_unlock(&ftrace_lock); |
229 | ||
230 | return ret; | |
231 | } | |
232 | ||
df4fc315 SR |
233 | static void ftrace_update_pid_func(void) |
234 | { | |
235 | ftrace_func_t func; | |
236 | ||
237 | /* should not be called from interrupt context */ | |
238 | spin_lock(&ftrace_lock); | |
239 | ||
240 | if (ftrace_trace_function == ftrace_stub) | |
241 | goto out; | |
242 | ||
243 | func = ftrace_trace_function; | |
244 | ||
245 | if (ftrace_pid_trace >= 0) { | |
246 | set_ftrace_pid_function(func); | |
247 | func = ftrace_pid_func; | |
248 | } else { | |
249 | if (func != ftrace_pid_func) | |
250 | goto out; | |
251 | ||
252 | set_ftrace_pid_function(func); | |
253 | } | |
254 | ||
255 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST | |
256 | ftrace_trace_function = func; | |
257 | #else | |
258 | __ftrace_trace_function = func; | |
259 | #endif | |
260 | ||
261 | out: | |
262 | spin_unlock(&ftrace_lock); | |
263 | } | |
264 | ||
3d083395 | 265 | #ifdef CONFIG_DYNAMIC_FTRACE |
99ecdc43 | 266 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
cb7be3b2 | 267 | # error Dynamic ftrace depends on MCOUNT_RECORD |
99ecdc43 SR |
268 | #endif |
269 | ||
71c67d58 SN |
270 | /* |
271 | * Since MCOUNT_ADDR may point to mcount itself, we do not want | |
272 | * to get it confused by reading a reference in the code as we | |
273 | * are parsing on objcopy output of text. Use a variable for | |
274 | * it instead. | |
275 | */ | |
276 | static unsigned long mcount_addr = MCOUNT_ADDR; | |
277 | ||
d61f82d0 SR |
278 | enum { |
279 | FTRACE_ENABLE_CALLS = (1 << 0), | |
280 | FTRACE_DISABLE_CALLS = (1 << 1), | |
281 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), | |
282 | FTRACE_ENABLE_MCOUNT = (1 << 3), | |
283 | FTRACE_DISABLE_MCOUNT = (1 << 4), | |
284 | }; | |
285 | ||
5072c59f SR |
286 | static int ftrace_filtered; |
287 | ||
08f5ac90 | 288 | static LIST_HEAD(ftrace_new_addrs); |
3d083395 | 289 | |
41c52c0d | 290 | static DEFINE_MUTEX(ftrace_regex_lock); |
3d083395 | 291 | |
3c1720f0 SR |
292 | struct ftrace_page { |
293 | struct ftrace_page *next; | |
aa5e5cea | 294 | unsigned long index; |
3c1720f0 | 295 | struct dyn_ftrace records[]; |
aa5e5cea | 296 | }; |
3c1720f0 SR |
297 | |
298 | #define ENTRIES_PER_PAGE \ | |
299 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) | |
300 | ||
301 | /* estimate from running different kernels */ | |
302 | #define NR_TO_INIT 10000 | |
303 | ||
304 | static struct ftrace_page *ftrace_pages_start; | |
305 | static struct ftrace_page *ftrace_pages; | |
306 | ||
37ad5084 SR |
307 | static struct dyn_ftrace *ftrace_free_records; |
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; | |
353 | int i; | |
354 | ||
00fd61ae | 355 | if (ftrace_disabled || !start) |
fed1939c SR |
356 | return; |
357 | ||
99ecdc43 | 358 | /* should not be called from interrupt context */ |
fed1939c SR |
359 | spin_lock(&ftrace_lock); |
360 | ||
361 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
362 | for (i = 0; i < pg->index; i++) { | |
363 | rec = &pg->records[i]; | |
364 | ||
365 | if ((rec->ip >= s) && (rec->ip < e)) | |
366 | ftrace_free_rec(rec); | |
367 | } | |
368 | } | |
369 | spin_unlock(&ftrace_lock); | |
fed1939c SR |
370 | } |
371 | ||
e309b41d | 372 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
3c1720f0 | 373 | { |
37ad5084 SR |
374 | struct dyn_ftrace *rec; |
375 | ||
376 | /* First check for freed records */ | |
377 | if (ftrace_free_records) { | |
378 | rec = ftrace_free_records; | |
379 | ||
37ad5084 | 380 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
6912896e | 381 | FTRACE_WARN_ON_ONCE(1); |
37ad5084 SR |
382 | ftrace_free_records = NULL; |
383 | return NULL; | |
384 | } | |
385 | ||
386 | ftrace_free_records = (void *)rec->ip; | |
387 | memset(rec, 0, sizeof(*rec)); | |
388 | return rec; | |
389 | } | |
390 | ||
3c1720f0 | 391 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
08f5ac90 SR |
392 | if (!ftrace_pages->next) { |
393 | /* allocate another page */ | |
394 | ftrace_pages->next = | |
395 | (void *)get_zeroed_page(GFP_KERNEL); | |
396 | if (!ftrace_pages->next) | |
397 | return NULL; | |
398 | } | |
3c1720f0 SR |
399 | ftrace_pages = ftrace_pages->next; |
400 | } | |
401 | ||
402 | return &ftrace_pages->records[ftrace_pages->index++]; | |
403 | } | |
404 | ||
08f5ac90 | 405 | static struct dyn_ftrace * |
d61f82d0 | 406 | ftrace_record_ip(unsigned long ip) |
3d083395 | 407 | { |
08f5ac90 | 408 | struct dyn_ftrace *rec; |
3d083395 | 409 | |
f3c7ac40 | 410 | if (ftrace_disabled) |
08f5ac90 | 411 | return NULL; |
3d083395 | 412 | |
08f5ac90 SR |
413 | rec = ftrace_alloc_dyn_node(ip); |
414 | if (!rec) | |
415 | return NULL; | |
3d083395 | 416 | |
08f5ac90 | 417 | rec->ip = ip; |
3d083395 | 418 | |
08f5ac90 | 419 | list_add(&rec->list, &ftrace_new_addrs); |
3d083395 | 420 | |
08f5ac90 | 421 | return rec; |
3d083395 SR |
422 | } |
423 | ||
b17e8a37 SR |
424 | static void print_ip_ins(const char *fmt, unsigned char *p) |
425 | { | |
426 | int i; | |
427 | ||
428 | printk(KERN_CONT "%s", fmt); | |
429 | ||
430 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
431 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
432 | } | |
433 | ||
31e88909 | 434 | static void ftrace_bug(int failed, unsigned long ip) |
b17e8a37 SR |
435 | { |
436 | switch (failed) { | |
437 | case -EFAULT: | |
438 | FTRACE_WARN_ON_ONCE(1); | |
439 | pr_info("ftrace faulted on modifying "); | |
440 | print_ip_sym(ip); | |
441 | break; | |
442 | case -EINVAL: | |
443 | FTRACE_WARN_ON_ONCE(1); | |
444 | pr_info("ftrace failed to modify "); | |
445 | print_ip_sym(ip); | |
b17e8a37 | 446 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
447 | printk(KERN_CONT "\n"); |
448 | break; | |
449 | case -EPERM: | |
450 | FTRACE_WARN_ON_ONCE(1); | |
451 | pr_info("ftrace faulted on writing "); | |
452 | print_ip_sym(ip); | |
453 | break; | |
454 | default: | |
455 | FTRACE_WARN_ON_ONCE(1); | |
456 | pr_info("ftrace faulted on unknown error "); | |
457 | print_ip_sym(ip); | |
458 | } | |
459 | } | |
460 | ||
3c1720f0 | 461 | |
0eb96701 | 462 | static int |
31e88909 | 463 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) |
5072c59f | 464 | { |
41c52c0d | 465 | unsigned long ip, fl; |
e7d3737e FW |
466 | unsigned long ftrace_addr; |
467 | ||
fb52607a | 468 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e FW |
469 | if (ftrace_tracing_type == FTRACE_TYPE_ENTER) |
470 | ftrace_addr = (unsigned long)ftrace_caller; | |
471 | else | |
fb52607a | 472 | ftrace_addr = (unsigned long)ftrace_graph_caller; |
e7d3737e FW |
473 | #else |
474 | ftrace_addr = (unsigned long)ftrace_caller; | |
475 | #endif | |
5072c59f SR |
476 | |
477 | ip = rec->ip; | |
478 | ||
982c350b SR |
479 | /* |
480 | * If this record is not to be traced and | |
481 | * it is not enabled then do nothing. | |
482 | * | |
483 | * If this record is not to be traced and | |
484 | * it is enabled then disabled it. | |
485 | * | |
486 | */ | |
487 | if (rec->flags & FTRACE_FL_NOTRACE) { | |
488 | if (rec->flags & FTRACE_FL_ENABLED) | |
489 | rec->flags &= ~FTRACE_FL_ENABLED; | |
490 | else | |
491 | return 0; | |
492 | ||
493 | } else if (ftrace_filtered && enable) { | |
5072c59f | 494 | /* |
982c350b | 495 | * Filtering is on: |
5072c59f | 496 | */ |
a4500b84 | 497 | |
982c350b | 498 | fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED); |
5072c59f | 499 | |
982c350b SR |
500 | /* Record is filtered and enabled, do nothing */ |
501 | if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) | |
0eb96701 | 502 | return 0; |
5072c59f | 503 | |
982c350b SR |
504 | /* Record is not filtered and is not enabled do nothing */ |
505 | if (!fl) | |
506 | return 0; | |
507 | ||
508 | /* Record is not filtered but enabled, disable it */ | |
509 | if (fl == FTRACE_FL_ENABLED) | |
5072c59f | 510 | rec->flags &= ~FTRACE_FL_ENABLED; |
982c350b SR |
511 | else |
512 | /* Otherwise record is filtered but not enabled, enable it */ | |
5072c59f | 513 | rec->flags |= FTRACE_FL_ENABLED; |
5072c59f | 514 | } else { |
982c350b | 515 | /* Disable or not filtered */ |
5072c59f | 516 | |
41c52c0d | 517 | if (enable) { |
982c350b | 518 | /* if record is enabled, do nothing */ |
5072c59f | 519 | if (rec->flags & FTRACE_FL_ENABLED) |
0eb96701 | 520 | return 0; |
982c350b | 521 | |
5072c59f | 522 | rec->flags |= FTRACE_FL_ENABLED; |
982c350b | 523 | |
5072c59f | 524 | } else { |
982c350b SR |
525 | |
526 | /* if record is not enabled do nothing */ | |
5072c59f | 527 | if (!(rec->flags & FTRACE_FL_ENABLED)) |
0eb96701 | 528 | return 0; |
982c350b | 529 | |
5072c59f SR |
530 | rec->flags &= ~FTRACE_FL_ENABLED; |
531 | } | |
532 | } | |
533 | ||
982c350b | 534 | if (rec->flags & FTRACE_FL_ENABLED) |
e7d3737e | 535 | return ftrace_make_call(rec, ftrace_addr); |
31e88909 | 536 | else |
e7d3737e | 537 | return ftrace_make_nop(NULL, rec, ftrace_addr); |
5072c59f SR |
538 | } |
539 | ||
e309b41d | 540 | static void ftrace_replace_code(int enable) |
3c1720f0 | 541 | { |
0eb96701 | 542 | int i, failed; |
3c1720f0 SR |
543 | struct dyn_ftrace *rec; |
544 | struct ftrace_page *pg; | |
3c1720f0 | 545 | |
3c1720f0 SR |
546 | for (pg = ftrace_pages_start; pg; pg = pg->next) { |
547 | for (i = 0; i < pg->index; i++) { | |
548 | rec = &pg->records[i]; | |
549 | ||
918c1154 SR |
550 | /* |
551 | * Skip over free records and records that have | |
552 | * failed. | |
553 | */ | |
554 | if (rec->flags & FTRACE_FL_FREE || | |
555 | rec->flags & FTRACE_FL_FAILED) | |
3c1720f0 SR |
556 | continue; |
557 | ||
f22f9a89 | 558 | /* ignore updates to this record's mcount site */ |
98a05ed4 AS |
559 | if (get_kprobe((void *)rec->ip)) { |
560 | freeze_record(rec); | |
f22f9a89 | 561 | continue; |
98a05ed4 AS |
562 | } else { |
563 | unfreeze_record(rec); | |
564 | } | |
f22f9a89 | 565 | |
31e88909 | 566 | failed = __ftrace_replace_code(rec, enable); |
0eb96701 AS |
567 | if (failed && (rec->flags & FTRACE_FL_CONVERTED)) { |
568 | rec->flags |= FTRACE_FL_FAILED; | |
569 | if ((system_state == SYSTEM_BOOTING) || | |
34078a5e | 570 | !core_kernel_text(rec->ip)) { |
0eb96701 | 571 | ftrace_free_rec(rec); |
b17e8a37 | 572 | } else |
31e88909 | 573 | ftrace_bug(failed, rec->ip); |
0eb96701 | 574 | } |
3c1720f0 SR |
575 | } |
576 | } | |
577 | } | |
578 | ||
492a7ea5 | 579 | static int |
31e88909 | 580 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 SR |
581 | { |
582 | unsigned long ip; | |
593eb8a2 | 583 | int ret; |
3c1720f0 SR |
584 | |
585 | ip = rec->ip; | |
586 | ||
31e88909 | 587 | ret = ftrace_make_nop(mod, rec, mcount_addr); |
593eb8a2 | 588 | if (ret) { |
31e88909 | 589 | ftrace_bug(ret, ip); |
3c1720f0 | 590 | rec->flags |= FTRACE_FL_FAILED; |
492a7ea5 | 591 | return 0; |
37ad5084 | 592 | } |
492a7ea5 | 593 | return 1; |
3c1720f0 SR |
594 | } |
595 | ||
e309b41d | 596 | static int __ftrace_modify_code(void *data) |
3d083395 | 597 | { |
d61f82d0 SR |
598 | int *command = data; |
599 | ||
a3583244 | 600 | if (*command & FTRACE_ENABLE_CALLS) |
d61f82d0 | 601 | ftrace_replace_code(1); |
a3583244 | 602 | else if (*command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
603 | ftrace_replace_code(0); |
604 | ||
605 | if (*command & FTRACE_UPDATE_TRACE_FUNC) | |
606 | ftrace_update_ftrace_func(ftrace_trace_function); | |
607 | ||
d61f82d0 | 608 | return 0; |
3d083395 SR |
609 | } |
610 | ||
e309b41d | 611 | static void ftrace_run_update_code(int command) |
3d083395 | 612 | { |
784e2d76 | 613 | stop_machine(__ftrace_modify_code, &command, NULL); |
3d083395 SR |
614 | } |
615 | ||
d61f82d0 | 616 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 617 | static int ftrace_start_up; |
df4fc315 SR |
618 | |
619 | static void ftrace_startup_enable(int command) | |
620 | { | |
621 | if (saved_ftrace_func != ftrace_trace_function) { | |
622 | saved_ftrace_func = ftrace_trace_function; | |
623 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
624 | } | |
625 | ||
626 | if (!command || !ftrace_enabled) | |
627 | return; | |
628 | ||
629 | ftrace_run_update_code(command); | |
630 | } | |
d61f82d0 | 631 | |
e309b41d | 632 | static void ftrace_startup(void) |
3d083395 | 633 | { |
d61f82d0 SR |
634 | int command = 0; |
635 | ||
4eebcc81 SR |
636 | if (unlikely(ftrace_disabled)) |
637 | return; | |
638 | ||
cb7be3b2 | 639 | mutex_lock(&ftrace_start_lock); |
60a7ecf4 | 640 | ftrace_start_up++; |
982c350b | 641 | command |= FTRACE_ENABLE_CALLS; |
d61f82d0 | 642 | |
df4fc315 | 643 | ftrace_startup_enable(command); |
3d083395 | 644 | |
cb7be3b2 | 645 | mutex_unlock(&ftrace_start_lock); |
3d083395 SR |
646 | } |
647 | ||
e309b41d | 648 | static void ftrace_shutdown(void) |
3d083395 | 649 | { |
d61f82d0 SR |
650 | int command = 0; |
651 | ||
4eebcc81 SR |
652 | if (unlikely(ftrace_disabled)) |
653 | return; | |
654 | ||
cb7be3b2 | 655 | mutex_lock(&ftrace_start_lock); |
60a7ecf4 SR |
656 | ftrace_start_up--; |
657 | if (!ftrace_start_up) | |
d61f82d0 | 658 | command |= FTRACE_DISABLE_CALLS; |
3d083395 | 659 | |
d61f82d0 SR |
660 | if (saved_ftrace_func != ftrace_trace_function) { |
661 | saved_ftrace_func = ftrace_trace_function; | |
662 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
663 | } | |
3d083395 | 664 | |
d61f82d0 SR |
665 | if (!command || !ftrace_enabled) |
666 | goto out; | |
667 | ||
668 | ftrace_run_update_code(command); | |
3d083395 | 669 | out: |
cb7be3b2 | 670 | mutex_unlock(&ftrace_start_lock); |
3d083395 SR |
671 | } |
672 | ||
e309b41d | 673 | static void ftrace_startup_sysctl(void) |
b0fc494f | 674 | { |
d61f82d0 SR |
675 | int command = FTRACE_ENABLE_MCOUNT; |
676 | ||
4eebcc81 SR |
677 | if (unlikely(ftrace_disabled)) |
678 | return; | |
679 | ||
cb7be3b2 | 680 | mutex_lock(&ftrace_start_lock); |
d61f82d0 SR |
681 | /* Force update next time */ |
682 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
683 | /* ftrace_start_up is true if we want ftrace running */ |
684 | if (ftrace_start_up) | |
d61f82d0 SR |
685 | command |= FTRACE_ENABLE_CALLS; |
686 | ||
687 | ftrace_run_update_code(command); | |
cb7be3b2 | 688 | mutex_unlock(&ftrace_start_lock); |
b0fc494f SR |
689 | } |
690 | ||
e309b41d | 691 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 692 | { |
d61f82d0 SR |
693 | int command = FTRACE_DISABLE_MCOUNT; |
694 | ||
4eebcc81 SR |
695 | if (unlikely(ftrace_disabled)) |
696 | return; | |
697 | ||
cb7be3b2 | 698 | mutex_lock(&ftrace_start_lock); |
60a7ecf4 SR |
699 | /* ftrace_start_up is true if ftrace is running */ |
700 | if (ftrace_start_up) | |
d61f82d0 SR |
701 | command |= FTRACE_DISABLE_CALLS; |
702 | ||
703 | ftrace_run_update_code(command); | |
cb7be3b2 | 704 | mutex_unlock(&ftrace_start_lock); |
b0fc494f SR |
705 | } |
706 | ||
3d083395 SR |
707 | static cycle_t ftrace_update_time; |
708 | static unsigned long ftrace_update_cnt; | |
709 | unsigned long ftrace_update_tot_cnt; | |
710 | ||
31e88909 | 711 | static int ftrace_update_code(struct module *mod) |
3d083395 | 712 | { |
08f5ac90 | 713 | struct dyn_ftrace *p, *t; |
f22f9a89 | 714 | cycle_t start, stop; |
3d083395 | 715 | |
750ed1a4 | 716 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
717 | ftrace_update_cnt = 0; |
718 | ||
08f5ac90 | 719 | list_for_each_entry_safe(p, t, &ftrace_new_addrs, list) { |
3d083395 | 720 | |
08f5ac90 SR |
721 | /* If something went wrong, bail without enabling anything */ |
722 | if (unlikely(ftrace_disabled)) | |
723 | return -1; | |
f22f9a89 | 724 | |
08f5ac90 | 725 | list_del_init(&p->list); |
f22f9a89 | 726 | |
08f5ac90 | 727 | /* convert record (i.e, patch mcount-call with NOP) */ |
31e88909 | 728 | if (ftrace_code_disable(mod, p)) { |
08f5ac90 SR |
729 | p->flags |= FTRACE_FL_CONVERTED; |
730 | ftrace_update_cnt++; | |
731 | } else | |
732 | ftrace_free_rec(p); | |
3d083395 SR |
733 | } |
734 | ||
750ed1a4 | 735 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
736 | ftrace_update_time = stop - start; |
737 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
738 | ||
16444a8a ACM |
739 | return 0; |
740 | } | |
741 | ||
68bf21aa | 742 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
3c1720f0 SR |
743 | { |
744 | struct ftrace_page *pg; | |
745 | int cnt; | |
746 | int i; | |
3c1720f0 SR |
747 | |
748 | /* allocate a few pages */ | |
749 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); | |
750 | if (!ftrace_pages_start) | |
751 | return -1; | |
752 | ||
753 | /* | |
754 | * Allocate a few more pages. | |
755 | * | |
756 | * TODO: have some parser search vmlinux before | |
757 | * final linking to find all calls to ftrace. | |
758 | * Then we can: | |
759 | * a) know how many pages to allocate. | |
760 | * and/or | |
761 | * b) set up the table then. | |
762 | * | |
763 | * The dynamic code is still necessary for | |
764 | * modules. | |
765 | */ | |
766 | ||
767 | pg = ftrace_pages = ftrace_pages_start; | |
768 | ||
68bf21aa | 769 | cnt = num_to_init / ENTRIES_PER_PAGE; |
08f5ac90 | 770 | pr_info("ftrace: allocating %ld entries in %d pages\n", |
5821e1b7 | 771 | num_to_init, cnt + 1); |
3c1720f0 SR |
772 | |
773 | for (i = 0; i < cnt; i++) { | |
774 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); | |
775 | ||
776 | /* If we fail, we'll try later anyway */ | |
777 | if (!pg->next) | |
778 | break; | |
779 | ||
780 | pg = pg->next; | |
781 | } | |
782 | ||
783 | return 0; | |
784 | } | |
785 | ||
5072c59f SR |
786 | enum { |
787 | FTRACE_ITER_FILTER = (1 << 0), | |
788 | FTRACE_ITER_CONT = (1 << 1), | |
41c52c0d | 789 | FTRACE_ITER_NOTRACE = (1 << 2), |
eb9a7bf0 | 790 | FTRACE_ITER_FAILURES = (1 << 3), |
5072c59f SR |
791 | }; |
792 | ||
793 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ | |
794 | ||
795 | struct ftrace_iterator { | |
796 | loff_t pos; | |
797 | struct ftrace_page *pg; | |
798 | unsigned idx; | |
799 | unsigned flags; | |
800 | unsigned char buffer[FTRACE_BUFF_MAX+1]; | |
801 | unsigned buffer_idx; | |
802 | unsigned filtered; | |
803 | }; | |
804 | ||
e309b41d | 805 | static void * |
5072c59f SR |
806 | t_next(struct seq_file *m, void *v, loff_t *pos) |
807 | { | |
808 | struct ftrace_iterator *iter = m->private; | |
809 | struct dyn_ftrace *rec = NULL; | |
810 | ||
811 | (*pos)++; | |
812 | ||
99ecdc43 SR |
813 | /* should not be called from interrupt context */ |
814 | spin_lock(&ftrace_lock); | |
5072c59f SR |
815 | retry: |
816 | if (iter->idx >= iter->pg->index) { | |
817 | if (iter->pg->next) { | |
818 | iter->pg = iter->pg->next; | |
819 | iter->idx = 0; | |
820 | goto retry; | |
821 | } | |
822 | } else { | |
823 | rec = &iter->pg->records[iter->idx++]; | |
a9fdda33 SR |
824 | if ((rec->flags & FTRACE_FL_FREE) || |
825 | ||
826 | (!(iter->flags & FTRACE_ITER_FAILURES) && | |
eb9a7bf0 AS |
827 | (rec->flags & FTRACE_FL_FAILED)) || |
828 | ||
829 | ((iter->flags & FTRACE_ITER_FAILURES) && | |
a9fdda33 | 830 | !(rec->flags & FTRACE_FL_FAILED)) || |
eb9a7bf0 | 831 | |
0183fb1c SR |
832 | ((iter->flags & FTRACE_ITER_FILTER) && |
833 | !(rec->flags & FTRACE_FL_FILTER)) || | |
834 | ||
41c52c0d SR |
835 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
836 | !(rec->flags & FTRACE_FL_NOTRACE))) { | |
5072c59f SR |
837 | rec = NULL; |
838 | goto retry; | |
839 | } | |
840 | } | |
99ecdc43 | 841 | spin_unlock(&ftrace_lock); |
5072c59f SR |
842 | |
843 | iter->pos = *pos; | |
844 | ||
845 | return rec; | |
846 | } | |
847 | ||
848 | static void *t_start(struct seq_file *m, loff_t *pos) | |
849 | { | |
850 | struct ftrace_iterator *iter = m->private; | |
851 | void *p = NULL; | |
852 | loff_t l = -1; | |
853 | ||
5821e1b7 | 854 | if (*pos > iter->pos) |
855 | *pos = iter->pos; | |
856 | ||
857 | l = *pos; | |
858 | p = t_next(m, p, &l); | |
5072c59f SR |
859 | |
860 | return p; | |
861 | } | |
862 | ||
863 | static void t_stop(struct seq_file *m, void *p) | |
864 | { | |
865 | } | |
866 | ||
867 | static int t_show(struct seq_file *m, void *v) | |
868 | { | |
5821e1b7 | 869 | struct ftrace_iterator *iter = m->private; |
5072c59f SR |
870 | struct dyn_ftrace *rec = v; |
871 | char str[KSYM_SYMBOL_LEN]; | |
5821e1b7 | 872 | int ret = 0; |
5072c59f SR |
873 | |
874 | if (!rec) | |
875 | return 0; | |
876 | ||
877 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
878 | ||
5821e1b7 | 879 | ret = seq_printf(m, "%s\n", str); |
880 | if (ret < 0) { | |
881 | iter->pos--; | |
882 | iter->idx--; | |
883 | } | |
5072c59f SR |
884 | |
885 | return 0; | |
886 | } | |
887 | ||
888 | static struct seq_operations show_ftrace_seq_ops = { | |
889 | .start = t_start, | |
890 | .next = t_next, | |
891 | .stop = t_stop, | |
892 | .show = t_show, | |
893 | }; | |
894 | ||
e309b41d | 895 | static int |
5072c59f SR |
896 | ftrace_avail_open(struct inode *inode, struct file *file) |
897 | { | |
898 | struct ftrace_iterator *iter; | |
899 | int ret; | |
900 | ||
4eebcc81 SR |
901 | if (unlikely(ftrace_disabled)) |
902 | return -ENODEV; | |
903 | ||
5072c59f SR |
904 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
905 | if (!iter) | |
906 | return -ENOMEM; | |
907 | ||
908 | iter->pg = ftrace_pages_start; | |
5821e1b7 | 909 | iter->pos = 0; |
5072c59f SR |
910 | |
911 | ret = seq_open(file, &show_ftrace_seq_ops); | |
912 | if (!ret) { | |
913 | struct seq_file *m = file->private_data; | |
4bf39a94 | 914 | |
5072c59f | 915 | m->private = iter; |
4bf39a94 | 916 | } else { |
5072c59f | 917 | kfree(iter); |
4bf39a94 | 918 | } |
5072c59f SR |
919 | |
920 | return ret; | |
921 | } | |
922 | ||
923 | int ftrace_avail_release(struct inode *inode, struct file *file) | |
924 | { | |
925 | struct seq_file *m = (struct seq_file *)file->private_data; | |
926 | struct ftrace_iterator *iter = m->private; | |
927 | ||
928 | seq_release(inode, file); | |
929 | kfree(iter); | |
4bf39a94 | 930 | |
5072c59f SR |
931 | return 0; |
932 | } | |
933 | ||
eb9a7bf0 AS |
934 | static int |
935 | ftrace_failures_open(struct inode *inode, struct file *file) | |
936 | { | |
937 | int ret; | |
938 | struct seq_file *m; | |
939 | struct ftrace_iterator *iter; | |
940 | ||
941 | ret = ftrace_avail_open(inode, file); | |
942 | if (!ret) { | |
943 | m = (struct seq_file *)file->private_data; | |
944 | iter = (struct ftrace_iterator *)m->private; | |
945 | iter->flags = FTRACE_ITER_FAILURES; | |
946 | } | |
947 | ||
948 | return ret; | |
949 | } | |
950 | ||
951 | ||
41c52c0d | 952 | static void ftrace_filter_reset(int enable) |
5072c59f SR |
953 | { |
954 | struct ftrace_page *pg; | |
955 | struct dyn_ftrace *rec; | |
41c52c0d | 956 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f SR |
957 | unsigned i; |
958 | ||
99ecdc43 SR |
959 | /* should not be called from interrupt context */ |
960 | spin_lock(&ftrace_lock); | |
41c52c0d SR |
961 | if (enable) |
962 | ftrace_filtered = 0; | |
5072c59f SR |
963 | pg = ftrace_pages_start; |
964 | while (pg) { | |
965 | for (i = 0; i < pg->index; i++) { | |
966 | rec = &pg->records[i]; | |
967 | if (rec->flags & FTRACE_FL_FAILED) | |
968 | continue; | |
41c52c0d | 969 | rec->flags &= ~type; |
5072c59f SR |
970 | } |
971 | pg = pg->next; | |
972 | } | |
99ecdc43 | 973 | spin_unlock(&ftrace_lock); |
5072c59f SR |
974 | } |
975 | ||
e309b41d | 976 | static int |
41c52c0d | 977 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
978 | { |
979 | struct ftrace_iterator *iter; | |
980 | int ret = 0; | |
981 | ||
4eebcc81 SR |
982 | if (unlikely(ftrace_disabled)) |
983 | return -ENODEV; | |
984 | ||
5072c59f SR |
985 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
986 | if (!iter) | |
987 | return -ENOMEM; | |
988 | ||
41c52c0d | 989 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
990 | if ((file->f_mode & FMODE_WRITE) && |
991 | !(file->f_flags & O_APPEND)) | |
41c52c0d | 992 | ftrace_filter_reset(enable); |
5072c59f SR |
993 | |
994 | if (file->f_mode & FMODE_READ) { | |
995 | iter->pg = ftrace_pages_start; | |
5821e1b7 | 996 | iter->pos = 0; |
41c52c0d SR |
997 | iter->flags = enable ? FTRACE_ITER_FILTER : |
998 | FTRACE_ITER_NOTRACE; | |
5072c59f SR |
999 | |
1000 | ret = seq_open(file, &show_ftrace_seq_ops); | |
1001 | if (!ret) { | |
1002 | struct seq_file *m = file->private_data; | |
1003 | m->private = iter; | |
1004 | } else | |
1005 | kfree(iter); | |
1006 | } else | |
1007 | file->private_data = iter; | |
41c52c0d | 1008 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1009 | |
1010 | return ret; | |
1011 | } | |
1012 | ||
41c52c0d SR |
1013 | static int |
1014 | ftrace_filter_open(struct inode *inode, struct file *file) | |
1015 | { | |
1016 | return ftrace_regex_open(inode, file, 1); | |
1017 | } | |
1018 | ||
1019 | static int | |
1020 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
1021 | { | |
1022 | return ftrace_regex_open(inode, file, 0); | |
1023 | } | |
1024 | ||
e309b41d | 1025 | static ssize_t |
41c52c0d | 1026 | ftrace_regex_read(struct file *file, char __user *ubuf, |
5072c59f SR |
1027 | size_t cnt, loff_t *ppos) |
1028 | { | |
1029 | if (file->f_mode & FMODE_READ) | |
1030 | return seq_read(file, ubuf, cnt, ppos); | |
1031 | else | |
1032 | return -EPERM; | |
1033 | } | |
1034 | ||
e309b41d | 1035 | static loff_t |
41c52c0d | 1036 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
5072c59f SR |
1037 | { |
1038 | loff_t ret; | |
1039 | ||
1040 | if (file->f_mode & FMODE_READ) | |
1041 | ret = seq_lseek(file, offset, origin); | |
1042 | else | |
1043 | file->f_pos = ret = 1; | |
1044 | ||
1045 | return ret; | |
1046 | } | |
1047 | ||
1048 | enum { | |
1049 | MATCH_FULL, | |
1050 | MATCH_FRONT_ONLY, | |
1051 | MATCH_MIDDLE_ONLY, | |
1052 | MATCH_END_ONLY, | |
1053 | }; | |
1054 | ||
e309b41d | 1055 | static void |
41c52c0d | 1056 | ftrace_match(unsigned char *buff, int len, int enable) |
5072c59f SR |
1057 | { |
1058 | char str[KSYM_SYMBOL_LEN]; | |
1059 | char *search = NULL; | |
1060 | struct ftrace_page *pg; | |
1061 | struct dyn_ftrace *rec; | |
1062 | int type = MATCH_FULL; | |
41c52c0d | 1063 | unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
5072c59f SR |
1064 | unsigned i, match = 0, search_len = 0; |
1065 | ||
1066 | for (i = 0; i < len; i++) { | |
1067 | if (buff[i] == '*') { | |
1068 | if (!i) { | |
1069 | search = buff + i + 1; | |
1070 | type = MATCH_END_ONLY; | |
1071 | search_len = len - (i + 1); | |
1072 | } else { | |
1073 | if (type == MATCH_END_ONLY) { | |
1074 | type = MATCH_MIDDLE_ONLY; | |
1075 | } else { | |
1076 | match = i; | |
1077 | type = MATCH_FRONT_ONLY; | |
1078 | } | |
1079 | buff[i] = 0; | |
1080 | break; | |
1081 | } | |
1082 | } | |
1083 | } | |
1084 | ||
99ecdc43 SR |
1085 | /* should not be called from interrupt context */ |
1086 | spin_lock(&ftrace_lock); | |
41c52c0d SR |
1087 | if (enable) |
1088 | ftrace_filtered = 1; | |
5072c59f SR |
1089 | pg = ftrace_pages_start; |
1090 | while (pg) { | |
1091 | for (i = 0; i < pg->index; i++) { | |
1092 | int matched = 0; | |
1093 | char *ptr; | |
1094 | ||
1095 | rec = &pg->records[i]; | |
1096 | if (rec->flags & FTRACE_FL_FAILED) | |
1097 | continue; | |
1098 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
1099 | switch (type) { | |
1100 | case MATCH_FULL: | |
1101 | if (strcmp(str, buff) == 0) | |
1102 | matched = 1; | |
1103 | break; | |
1104 | case MATCH_FRONT_ONLY: | |
1105 | if (memcmp(str, buff, match) == 0) | |
1106 | matched = 1; | |
1107 | break; | |
1108 | case MATCH_MIDDLE_ONLY: | |
1109 | if (strstr(str, search)) | |
1110 | matched = 1; | |
1111 | break; | |
1112 | case MATCH_END_ONLY: | |
1113 | ptr = strstr(str, search); | |
1114 | if (ptr && (ptr[search_len] == 0)) | |
1115 | matched = 1; | |
1116 | break; | |
1117 | } | |
1118 | if (matched) | |
41c52c0d | 1119 | rec->flags |= flag; |
5072c59f SR |
1120 | } |
1121 | pg = pg->next; | |
1122 | } | |
99ecdc43 | 1123 | spin_unlock(&ftrace_lock); |
5072c59f SR |
1124 | } |
1125 | ||
e309b41d | 1126 | static ssize_t |
41c52c0d SR |
1127 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
1128 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
1129 | { |
1130 | struct ftrace_iterator *iter; | |
1131 | char ch; | |
1132 | size_t read = 0; | |
1133 | ssize_t ret; | |
1134 | ||
1135 | if (!cnt || cnt < 0) | |
1136 | return 0; | |
1137 | ||
41c52c0d | 1138 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1139 | |
1140 | if (file->f_mode & FMODE_READ) { | |
1141 | struct seq_file *m = file->private_data; | |
1142 | iter = m->private; | |
1143 | } else | |
1144 | iter = file->private_data; | |
1145 | ||
1146 | if (!*ppos) { | |
1147 | iter->flags &= ~FTRACE_ITER_CONT; | |
1148 | iter->buffer_idx = 0; | |
1149 | } | |
1150 | ||
1151 | ret = get_user(ch, ubuf++); | |
1152 | if (ret) | |
1153 | goto out; | |
1154 | read++; | |
1155 | cnt--; | |
1156 | ||
1157 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { | |
1158 | /* skip white space */ | |
1159 | while (cnt && isspace(ch)) { | |
1160 | ret = get_user(ch, ubuf++); | |
1161 | if (ret) | |
1162 | goto out; | |
1163 | read++; | |
1164 | cnt--; | |
1165 | } | |
1166 | ||
5072c59f SR |
1167 | if (isspace(ch)) { |
1168 | file->f_pos += read; | |
1169 | ret = read; | |
1170 | goto out; | |
1171 | } | |
1172 | ||
1173 | iter->buffer_idx = 0; | |
1174 | } | |
1175 | ||
1176 | while (cnt && !isspace(ch)) { | |
1177 | if (iter->buffer_idx < FTRACE_BUFF_MAX) | |
1178 | iter->buffer[iter->buffer_idx++] = ch; | |
1179 | else { | |
1180 | ret = -EINVAL; | |
1181 | goto out; | |
1182 | } | |
1183 | ret = get_user(ch, ubuf++); | |
1184 | if (ret) | |
1185 | goto out; | |
1186 | read++; | |
1187 | cnt--; | |
1188 | } | |
1189 | ||
1190 | if (isspace(ch)) { | |
1191 | iter->filtered++; | |
1192 | iter->buffer[iter->buffer_idx] = 0; | |
41c52c0d | 1193 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1194 | iter->buffer_idx = 0; |
1195 | } else | |
1196 | iter->flags |= FTRACE_ITER_CONT; | |
1197 | ||
1198 | ||
1199 | file->f_pos += read; | |
1200 | ||
1201 | ret = read; | |
1202 | out: | |
41c52c0d | 1203 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1204 | |
1205 | return ret; | |
1206 | } | |
1207 | ||
41c52c0d SR |
1208 | static ssize_t |
1209 | ftrace_filter_write(struct file *file, const char __user *ubuf, | |
1210 | size_t cnt, loff_t *ppos) | |
1211 | { | |
1212 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
1213 | } | |
1214 | ||
1215 | static ssize_t | |
1216 | ftrace_notrace_write(struct file *file, const char __user *ubuf, | |
1217 | size_t cnt, loff_t *ppos) | |
1218 | { | |
1219 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
1220 | } | |
1221 | ||
1222 | static void | |
1223 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) | |
1224 | { | |
1225 | if (unlikely(ftrace_disabled)) | |
1226 | return; | |
1227 | ||
1228 | mutex_lock(&ftrace_regex_lock); | |
1229 | if (reset) | |
1230 | ftrace_filter_reset(enable); | |
1231 | if (buf) | |
1232 | ftrace_match(buf, len, enable); | |
1233 | mutex_unlock(&ftrace_regex_lock); | |
1234 | } | |
1235 | ||
77a2b37d SR |
1236 | /** |
1237 | * ftrace_set_filter - set a function to filter on in ftrace | |
1238 | * @buf - the string that holds the function filter text. | |
1239 | * @len - the length of the string. | |
1240 | * @reset - non zero to reset all filters before applying this filter. | |
1241 | * | |
1242 | * Filters denote which functions should be enabled when tracing is enabled. | |
1243 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
1244 | */ | |
e309b41d | 1245 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 1246 | { |
41c52c0d SR |
1247 | ftrace_set_regex(buf, len, reset, 1); |
1248 | } | |
4eebcc81 | 1249 | |
41c52c0d SR |
1250 | /** |
1251 | * ftrace_set_notrace - set a function to not trace in ftrace | |
1252 | * @buf - the string that holds the function notrace text. | |
1253 | * @len - the length of the string. | |
1254 | * @reset - non zero to reset all filters before applying this filter. | |
1255 | * | |
1256 | * Notrace Filters denote which functions should not be enabled when tracing | |
1257 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
1258 | * for tracing. | |
1259 | */ | |
1260 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) | |
1261 | { | |
1262 | ftrace_set_regex(buf, len, reset, 0); | |
77a2b37d SR |
1263 | } |
1264 | ||
e309b41d | 1265 | static int |
41c52c0d | 1266 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
5072c59f SR |
1267 | { |
1268 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1269 | struct ftrace_iterator *iter; | |
1270 | ||
41c52c0d | 1271 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
1272 | if (file->f_mode & FMODE_READ) { |
1273 | iter = m->private; | |
1274 | ||
1275 | seq_release(inode, file); | |
1276 | } else | |
1277 | iter = file->private_data; | |
1278 | ||
1279 | if (iter->buffer_idx) { | |
1280 | iter->filtered++; | |
1281 | iter->buffer[iter->buffer_idx] = 0; | |
41c52c0d | 1282 | ftrace_match(iter->buffer, iter->buffer_idx, enable); |
5072c59f SR |
1283 | } |
1284 | ||
1285 | mutex_lock(&ftrace_sysctl_lock); | |
cb7be3b2 | 1286 | mutex_lock(&ftrace_start_lock); |
ee02a2e5 | 1287 | if (ftrace_start_up && ftrace_enabled) |
5072c59f | 1288 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
cb7be3b2 | 1289 | mutex_unlock(&ftrace_start_lock); |
5072c59f SR |
1290 | mutex_unlock(&ftrace_sysctl_lock); |
1291 | ||
1292 | kfree(iter); | |
41c52c0d | 1293 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
1294 | return 0; |
1295 | } | |
1296 | ||
41c52c0d SR |
1297 | static int |
1298 | ftrace_filter_release(struct inode *inode, struct file *file) | |
1299 | { | |
1300 | return ftrace_regex_release(inode, file, 1); | |
1301 | } | |
1302 | ||
1303 | static int | |
1304 | ftrace_notrace_release(struct inode *inode, struct file *file) | |
1305 | { | |
1306 | return ftrace_regex_release(inode, file, 0); | |
1307 | } | |
1308 | ||
5072c59f SR |
1309 | static struct file_operations ftrace_avail_fops = { |
1310 | .open = ftrace_avail_open, | |
1311 | .read = seq_read, | |
1312 | .llseek = seq_lseek, | |
1313 | .release = ftrace_avail_release, | |
1314 | }; | |
1315 | ||
eb9a7bf0 AS |
1316 | static struct file_operations ftrace_failures_fops = { |
1317 | .open = ftrace_failures_open, | |
1318 | .read = seq_read, | |
1319 | .llseek = seq_lseek, | |
1320 | .release = ftrace_avail_release, | |
1321 | }; | |
1322 | ||
5072c59f SR |
1323 | static struct file_operations ftrace_filter_fops = { |
1324 | .open = ftrace_filter_open, | |
41c52c0d | 1325 | .read = ftrace_regex_read, |
5072c59f | 1326 | .write = ftrace_filter_write, |
41c52c0d | 1327 | .llseek = ftrace_regex_lseek, |
5072c59f SR |
1328 | .release = ftrace_filter_release, |
1329 | }; | |
1330 | ||
41c52c0d SR |
1331 | static struct file_operations ftrace_notrace_fops = { |
1332 | .open = ftrace_notrace_open, | |
1333 | .read = ftrace_regex_read, | |
1334 | .write = ftrace_notrace_write, | |
1335 | .llseek = ftrace_regex_lseek, | |
1336 | .release = ftrace_notrace_release, | |
1337 | }; | |
1338 | ||
df4fc315 | 1339 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 1340 | { |
5072c59f SR |
1341 | struct dentry *entry; |
1342 | ||
5072c59f SR |
1343 | entry = debugfs_create_file("available_filter_functions", 0444, |
1344 | d_tracer, NULL, &ftrace_avail_fops); | |
1345 | if (!entry) | |
1346 | pr_warning("Could not create debugfs " | |
1347 | "'available_filter_functions' entry\n"); | |
1348 | ||
eb9a7bf0 AS |
1349 | entry = debugfs_create_file("failures", 0444, |
1350 | d_tracer, NULL, &ftrace_failures_fops); | |
1351 | if (!entry) | |
1352 | pr_warning("Could not create debugfs 'failures' entry\n"); | |
1353 | ||
5072c59f SR |
1354 | entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer, |
1355 | NULL, &ftrace_filter_fops); | |
1356 | if (!entry) | |
1357 | pr_warning("Could not create debugfs " | |
1358 | "'set_ftrace_filter' entry\n"); | |
41c52c0d SR |
1359 | |
1360 | entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer, | |
1361 | NULL, &ftrace_notrace_fops); | |
1362 | if (!entry) | |
1363 | pr_warning("Could not create debugfs " | |
1364 | "'set_ftrace_notrace' entry\n"); | |
ad90c0e3 | 1365 | |
5072c59f SR |
1366 | return 0; |
1367 | } | |
1368 | ||
31e88909 SR |
1369 | static int ftrace_convert_nops(struct module *mod, |
1370 | unsigned long *start, | |
68bf21aa SR |
1371 | unsigned long *end) |
1372 | { | |
1373 | unsigned long *p; | |
1374 | unsigned long addr; | |
1375 | unsigned long flags; | |
1376 | ||
08f5ac90 | 1377 | mutex_lock(&ftrace_start_lock); |
68bf21aa SR |
1378 | p = start; |
1379 | while (p < end) { | |
1380 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
1381 | /* |
1382 | * Some architecture linkers will pad between | |
1383 | * the different mcount_loc sections of different | |
1384 | * object files to satisfy alignments. | |
1385 | * Skip any NULL pointers. | |
1386 | */ | |
1387 | if (!addr) | |
1388 | continue; | |
68bf21aa | 1389 | ftrace_record_ip(addr); |
68bf21aa SR |
1390 | } |
1391 | ||
08f5ac90 | 1392 | /* disable interrupts to prevent kstop machine */ |
68bf21aa | 1393 | local_irq_save(flags); |
31e88909 | 1394 | ftrace_update_code(mod); |
68bf21aa | 1395 | local_irq_restore(flags); |
08f5ac90 | 1396 | mutex_unlock(&ftrace_start_lock); |
68bf21aa SR |
1397 | |
1398 | return 0; | |
1399 | } | |
1400 | ||
31e88909 SR |
1401 | void ftrace_init_module(struct module *mod, |
1402 | unsigned long *start, unsigned long *end) | |
90d595fe | 1403 | { |
00fd61ae | 1404 | if (ftrace_disabled || start == end) |
fed1939c | 1405 | return; |
31e88909 | 1406 | ftrace_convert_nops(mod, start, end); |
90d595fe SR |
1407 | } |
1408 | ||
68bf21aa SR |
1409 | extern unsigned long __start_mcount_loc[]; |
1410 | extern unsigned long __stop_mcount_loc[]; | |
1411 | ||
1412 | void __init ftrace_init(void) | |
1413 | { | |
1414 | unsigned long count, addr, flags; | |
1415 | int ret; | |
1416 | ||
1417 | /* Keep the ftrace pointer to the stub */ | |
1418 | addr = (unsigned long)ftrace_stub; | |
1419 | ||
1420 | local_irq_save(flags); | |
1421 | ftrace_dyn_arch_init(&addr); | |
1422 | local_irq_restore(flags); | |
1423 | ||
1424 | /* ftrace_dyn_arch_init places the return code in addr */ | |
1425 | if (addr) | |
1426 | goto failed; | |
1427 | ||
1428 | count = __stop_mcount_loc - __start_mcount_loc; | |
1429 | ||
1430 | ret = ftrace_dyn_table_alloc(count); | |
1431 | if (ret) | |
1432 | goto failed; | |
1433 | ||
1434 | last_ftrace_enabled = ftrace_enabled = 1; | |
1435 | ||
31e88909 SR |
1436 | ret = ftrace_convert_nops(NULL, |
1437 | __start_mcount_loc, | |
68bf21aa SR |
1438 | __stop_mcount_loc); |
1439 | ||
1440 | return; | |
1441 | failed: | |
1442 | ftrace_disabled = 1; | |
1443 | } | |
68bf21aa | 1444 | |
3d083395 | 1445 | #else |
0b6e4d56 FW |
1446 | |
1447 | static int __init ftrace_nodyn_init(void) | |
1448 | { | |
1449 | ftrace_enabled = 1; | |
1450 | return 0; | |
1451 | } | |
1452 | device_initcall(ftrace_nodyn_init); | |
1453 | ||
df4fc315 SR |
1454 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
1455 | static inline void ftrace_startup_enable(int command) { } | |
c7aafc54 IM |
1456 | # define ftrace_startup() do { } while (0) |
1457 | # define ftrace_shutdown() do { } while (0) | |
1458 | # define ftrace_startup_sysctl() do { } while (0) | |
1459 | # define ftrace_shutdown_sysctl() do { } while (0) | |
3d083395 SR |
1460 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
1461 | ||
df4fc315 SR |
1462 | static ssize_t |
1463 | ftrace_pid_read(struct file *file, char __user *ubuf, | |
1464 | size_t cnt, loff_t *ppos) | |
1465 | { | |
1466 | char buf[64]; | |
1467 | int r; | |
1468 | ||
1469 | if (ftrace_pid_trace >= 0) | |
1470 | r = sprintf(buf, "%u\n", ftrace_pid_trace); | |
1471 | else | |
1472 | r = sprintf(buf, "no pid\n"); | |
1473 | ||
1474 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
1475 | } | |
1476 | ||
1477 | static ssize_t | |
1478 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
1479 | size_t cnt, loff_t *ppos) | |
1480 | { | |
1481 | char buf[64]; | |
1482 | long val; | |
1483 | int ret; | |
1484 | ||
1485 | if (cnt >= sizeof(buf)) | |
1486 | return -EINVAL; | |
1487 | ||
1488 | if (copy_from_user(&buf, ubuf, cnt)) | |
1489 | return -EFAULT; | |
1490 | ||
1491 | buf[cnt] = 0; | |
1492 | ||
1493 | ret = strict_strtol(buf, 10, &val); | |
1494 | if (ret < 0) | |
1495 | return ret; | |
1496 | ||
1497 | mutex_lock(&ftrace_start_lock); | |
1498 | if (ret < 0) { | |
1499 | /* disable pid tracing */ | |
1500 | if (ftrace_pid_trace < 0) | |
1501 | goto out; | |
1502 | ftrace_pid_trace = -1; | |
1503 | ||
1504 | } else { | |
1505 | ||
1506 | if (ftrace_pid_trace == val) | |
1507 | goto out; | |
1508 | ||
1509 | ftrace_pid_trace = val; | |
1510 | } | |
1511 | ||
1512 | /* update the function call */ | |
1513 | ftrace_update_pid_func(); | |
1514 | ftrace_startup_enable(0); | |
1515 | ||
1516 | out: | |
1517 | mutex_unlock(&ftrace_start_lock); | |
1518 | ||
1519 | return cnt; | |
1520 | } | |
1521 | ||
1522 | static struct file_operations ftrace_pid_fops = { | |
1523 | .read = ftrace_pid_read, | |
1524 | .write = ftrace_pid_write, | |
1525 | }; | |
1526 | ||
1527 | static __init int ftrace_init_debugfs(void) | |
1528 | { | |
1529 | struct dentry *d_tracer; | |
1530 | struct dentry *entry; | |
1531 | ||
1532 | d_tracer = tracing_init_dentry(); | |
1533 | if (!d_tracer) | |
1534 | return 0; | |
1535 | ||
1536 | ftrace_init_dyn_debugfs(d_tracer); | |
1537 | ||
1538 | entry = debugfs_create_file("set_ftrace_pid", 0644, d_tracer, | |
1539 | NULL, &ftrace_pid_fops); | |
1540 | if (!entry) | |
1541 | pr_warning("Could not create debugfs " | |
1542 | "'set_ftrace_pid' entry\n"); | |
1543 | return 0; | |
1544 | } | |
1545 | ||
1546 | fs_initcall(ftrace_init_debugfs); | |
1547 | ||
a2bb6a3d | 1548 | /** |
81adbdc0 | 1549 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
1550 | * |
1551 | * This function should be used by panic code. It stops ftrace | |
1552 | * but in a not so nice way. If you need to simply kill ftrace | |
1553 | * from a non-atomic section, use ftrace_kill. | |
1554 | */ | |
81adbdc0 | 1555 | void ftrace_kill(void) |
a2bb6a3d SR |
1556 | { |
1557 | ftrace_disabled = 1; | |
1558 | ftrace_enabled = 0; | |
a2bb6a3d SR |
1559 | clear_ftrace_function(); |
1560 | } | |
1561 | ||
16444a8a | 1562 | /** |
3d083395 SR |
1563 | * register_ftrace_function - register a function for profiling |
1564 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 1565 | * |
3d083395 SR |
1566 | * Register a function to be called by all functions in the |
1567 | * kernel. | |
1568 | * | |
1569 | * Note: @ops->func and all the functions it calls must be labeled | |
1570 | * with "notrace", otherwise it will go into a | |
1571 | * recursive loop. | |
16444a8a | 1572 | */ |
3d083395 | 1573 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 1574 | { |
b0fc494f SR |
1575 | int ret; |
1576 | ||
4eebcc81 SR |
1577 | if (unlikely(ftrace_disabled)) |
1578 | return -1; | |
1579 | ||
b0fc494f | 1580 | mutex_lock(&ftrace_sysctl_lock); |
e7d3737e FW |
1581 | |
1582 | if (ftrace_tracing_type == FTRACE_TYPE_RETURN) { | |
1583 | ret = -EBUSY; | |
1584 | goto out; | |
1585 | } | |
1586 | ||
b0fc494f | 1587 | ret = __register_ftrace_function(ops); |
d61f82d0 | 1588 | ftrace_startup(); |
b0fc494f | 1589 | |
e7d3737e FW |
1590 | out: |
1591 | mutex_unlock(&ftrace_sysctl_lock); | |
b0fc494f | 1592 | return ret; |
3d083395 SR |
1593 | } |
1594 | ||
1595 | /** | |
1596 | * unregister_ftrace_function - unresgister a function for profiling. | |
1597 | * @ops - ops structure that holds the function to unregister | |
1598 | * | |
1599 | * Unregister a function that was added to be called by ftrace profiling. | |
1600 | */ | |
1601 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
1602 | { | |
1603 | int ret; | |
1604 | ||
b0fc494f | 1605 | mutex_lock(&ftrace_sysctl_lock); |
3d083395 | 1606 | ret = __unregister_ftrace_function(ops); |
d61f82d0 | 1607 | ftrace_shutdown(); |
b0fc494f SR |
1608 | mutex_unlock(&ftrace_sysctl_lock); |
1609 | ||
1610 | return ret; | |
1611 | } | |
1612 | ||
e309b41d | 1613 | int |
b0fc494f | 1614 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
5072c59f | 1615 | struct file *file, void __user *buffer, size_t *lenp, |
b0fc494f SR |
1616 | loff_t *ppos) |
1617 | { | |
1618 | int ret; | |
1619 | ||
4eebcc81 SR |
1620 | if (unlikely(ftrace_disabled)) |
1621 | return -ENODEV; | |
1622 | ||
b0fc494f SR |
1623 | mutex_lock(&ftrace_sysctl_lock); |
1624 | ||
5072c59f | 1625 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
b0fc494f SR |
1626 | |
1627 | if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) | |
1628 | goto out; | |
1629 | ||
1630 | last_ftrace_enabled = ftrace_enabled; | |
1631 | ||
1632 | if (ftrace_enabled) { | |
1633 | ||
1634 | ftrace_startup_sysctl(); | |
1635 | ||
1636 | /* we are starting ftrace again */ | |
1637 | if (ftrace_list != &ftrace_list_end) { | |
1638 | if (ftrace_list->next == &ftrace_list_end) | |
1639 | ftrace_trace_function = ftrace_list->func; | |
1640 | else | |
1641 | ftrace_trace_function = ftrace_list_func; | |
1642 | } | |
1643 | ||
1644 | } else { | |
1645 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
1646 | ftrace_trace_function = ftrace_stub; | |
1647 | ||
1648 | ftrace_shutdown_sysctl(); | |
1649 | } | |
1650 | ||
1651 | out: | |
1652 | mutex_unlock(&ftrace_sysctl_lock); | |
3d083395 | 1653 | return ret; |
16444a8a | 1654 | } |
f17845e5 | 1655 | |
fb52607a | 1656 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 1657 | |
287b6e68 | 1658 | static atomic_t ftrace_graph_active; |
e7d3737e | 1659 | |
287b6e68 FW |
1660 | /* The callbacks that hook a function */ |
1661 | trace_func_graph_ret_t ftrace_graph_return = | |
1662 | (trace_func_graph_ret_t)ftrace_stub; | |
1663 | trace_func_graph_ent_t ftrace_graph_entry = | |
1664 | (trace_func_graph_ent_t)ftrace_stub; | |
f201ae23 FW |
1665 | |
1666 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
1667 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
1668 | { | |
1669 | int i; | |
1670 | int ret = 0; | |
1671 | unsigned long flags; | |
1672 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
1673 | struct task_struct *g, *t; | |
1674 | ||
1675 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
1676 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
1677 | * sizeof(struct ftrace_ret_stack), | |
1678 | GFP_KERNEL); | |
1679 | if (!ret_stack_list[i]) { | |
1680 | start = 0; | |
1681 | end = i; | |
1682 | ret = -ENOMEM; | |
1683 | goto free; | |
1684 | } | |
1685 | } | |
1686 | ||
1687 | read_lock_irqsave(&tasklist_lock, flags); | |
1688 | do_each_thread(g, t) { | |
1689 | if (start == end) { | |
1690 | ret = -EAGAIN; | |
1691 | goto unlock; | |
1692 | } | |
1693 | ||
1694 | if (t->ret_stack == NULL) { | |
1695 | t->ret_stack = ret_stack_list[start++]; | |
1696 | t->curr_ret_stack = -1; | |
1697 | atomic_set(&t->trace_overrun, 0); | |
1698 | } | |
1699 | } while_each_thread(g, t); | |
1700 | ||
1701 | unlock: | |
1702 | read_unlock_irqrestore(&tasklist_lock, flags); | |
1703 | free: | |
1704 | for (i = start; i < end; i++) | |
1705 | kfree(ret_stack_list[i]); | |
1706 | return ret; | |
1707 | } | |
1708 | ||
1709 | /* Allocate a return stack for each task */ | |
fb52607a | 1710 | static int start_graph_tracing(void) |
f201ae23 FW |
1711 | { |
1712 | struct ftrace_ret_stack **ret_stack_list; | |
1713 | int ret; | |
1714 | ||
1715 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
1716 | sizeof(struct ftrace_ret_stack *), | |
1717 | GFP_KERNEL); | |
1718 | ||
1719 | if (!ret_stack_list) | |
1720 | return -ENOMEM; | |
1721 | ||
1722 | do { | |
1723 | ret = alloc_retstack_tasklist(ret_stack_list); | |
1724 | } while (ret == -EAGAIN); | |
1725 | ||
1726 | kfree(ret_stack_list); | |
1727 | return ret; | |
1728 | } | |
1729 | ||
287b6e68 FW |
1730 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
1731 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 1732 | { |
e7d3737e FW |
1733 | int ret = 0; |
1734 | ||
1735 | mutex_lock(&ftrace_sysctl_lock); | |
1736 | ||
1737 | /* | |
1738 | * Don't launch return tracing if normal function | |
1739 | * tracing is already running. | |
1740 | */ | |
1741 | if (ftrace_trace_function != ftrace_stub) { | |
1742 | ret = -EBUSY; | |
1743 | goto out; | |
1744 | } | |
287b6e68 | 1745 | atomic_inc(&ftrace_graph_active); |
fb52607a | 1746 | ret = start_graph_tracing(); |
f201ae23 | 1747 | if (ret) { |
287b6e68 | 1748 | atomic_dec(&ftrace_graph_active); |
f201ae23 FW |
1749 | goto out; |
1750 | } | |
e7d3737e | 1751 | ftrace_tracing_type = FTRACE_TYPE_RETURN; |
287b6e68 FW |
1752 | ftrace_graph_return = retfunc; |
1753 | ftrace_graph_entry = entryfunc; | |
e7d3737e FW |
1754 | ftrace_startup(); |
1755 | ||
1756 | out: | |
1757 | mutex_unlock(&ftrace_sysctl_lock); | |
1758 | return ret; | |
15e6cb36 FW |
1759 | } |
1760 | ||
fb52607a | 1761 | void unregister_ftrace_graph(void) |
15e6cb36 | 1762 | { |
e7d3737e FW |
1763 | mutex_lock(&ftrace_sysctl_lock); |
1764 | ||
287b6e68 FW |
1765 | atomic_dec(&ftrace_graph_active); |
1766 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; | |
1767 | ftrace_graph_entry = (trace_func_graph_ent_t)ftrace_stub; | |
e7d3737e FW |
1768 | ftrace_shutdown(); |
1769 | /* Restore normal tracing type */ | |
1770 | ftrace_tracing_type = FTRACE_TYPE_ENTER; | |
1771 | ||
1772 | mutex_unlock(&ftrace_sysctl_lock); | |
15e6cb36 | 1773 | } |
f201ae23 FW |
1774 | |
1775 | /* Allocate a return stack for newly created task */ | |
fb52607a | 1776 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 1777 | { |
287b6e68 | 1778 | if (atomic_read(&ftrace_graph_active)) { |
f201ae23 FW |
1779 | t->ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH |
1780 | * sizeof(struct ftrace_ret_stack), | |
1781 | GFP_KERNEL); | |
1782 | if (!t->ret_stack) | |
1783 | return; | |
1784 | t->curr_ret_stack = -1; | |
1785 | atomic_set(&t->trace_overrun, 0); | |
1786 | } else | |
1787 | t->ret_stack = NULL; | |
1788 | } | |
1789 | ||
fb52607a | 1790 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 1791 | { |
eae849ca FW |
1792 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
1793 | ||
f201ae23 | 1794 | t->ret_stack = NULL; |
eae849ca FW |
1795 | /* NULL must become visible to IRQs before we free it: */ |
1796 | barrier(); | |
1797 | ||
1798 | kfree(ret_stack); | |
f201ae23 | 1799 | } |
15e6cb36 FW |
1800 | #endif |
1801 |