~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/kernel/trace/trace_functions.c

Version: ~ [ linux-5.11-rc3 ] ~ [ linux-5.10.7 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.89 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.167 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.215 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.251 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.251 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * ring buffer based function tracer
  3  *
  4  * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
  5  * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
  6  *
  7  * Based on code from the latency_tracer, that is:
  8  *
  9  *  Copyright (C) 2004-2006 Ingo Molnar
 10  *  Copyright (C) 2004 Nadia Yvette Chambers
 11  */
 12 #include <linux/ring_buffer.h>
 13 #include <linux/debugfs.h>
 14 #include <linux/uaccess.h>
 15 #include <linux/ftrace.h>
 16 #include <linux/fs.h>
 17 
 18 #include "trace.h"
 19 
 20 /* function tracing enabled */
 21 static int                      ftrace_function_enabled;
 22 
 23 static struct trace_array       *func_trace;
 24 
 25 static void tracing_start_function_trace(void);
 26 static void tracing_stop_function_trace(void);
 27 
 28 static int function_trace_init(struct trace_array *tr)
 29 {
 30         func_trace = tr;
 31         tr->trace_buffer.cpu = get_cpu();
 32         put_cpu();
 33 
 34         tracing_start_cmdline_record();
 35         tracing_start_function_trace();
 36         return 0;
 37 }
 38 
 39 static void function_trace_reset(struct trace_array *tr)
 40 {
 41         tracing_stop_function_trace();
 42         tracing_stop_cmdline_record();
 43 }
 44 
 45 static void function_trace_start(struct trace_array *tr)
 46 {
 47         tracing_reset_online_cpus(&tr->trace_buffer);
 48 }
 49 
 50 /* Our option */
 51 enum {
 52         TRACE_FUNC_OPT_STACK    = 0x1,
 53 };
 54 
 55 static struct tracer_flags func_flags;
 56 
 57 static void
 58 function_trace_call(unsigned long ip, unsigned long parent_ip,
 59                     struct ftrace_ops *op, struct pt_regs *pt_regs)
 60 {
 61         struct trace_array *tr = func_trace;
 62         struct trace_array_cpu *data;
 63         unsigned long flags;
 64         int bit;
 65         int cpu;
 66         int pc;
 67 
 68         if (unlikely(!ftrace_function_enabled))
 69                 return;
 70 
 71         pc = preempt_count();
 72         preempt_disable_notrace();
 73 
 74         bit = trace_test_and_set_recursion(TRACE_FTRACE_START, TRACE_FTRACE_MAX);
 75         if (bit < 0)
 76                 goto out;
 77 
 78         cpu = smp_processor_id();
 79         data = per_cpu_ptr(tr->trace_buffer.data, cpu);
 80         if (!atomic_read(&data->disabled)) {
 81                 local_save_flags(flags);
 82                 trace_function(tr, ip, parent_ip, flags, pc);
 83         }
 84         trace_clear_recursion(bit);
 85 
 86  out:
 87         preempt_enable_notrace();
 88 }
 89 
 90 static void
 91 function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
 92                           struct ftrace_ops *op, struct pt_regs *pt_regs)
 93 {
 94         struct trace_array *tr = func_trace;
 95         struct trace_array_cpu *data;
 96         unsigned long flags;
 97         long disabled;
 98         int cpu;
 99         int pc;
100 
101         if (unlikely(!ftrace_function_enabled))
102                 return;
103 
104         /*
105          * Need to use raw, since this must be called before the
106          * recursive protection is performed.
107          */
108         local_irq_save(flags);
109         cpu = raw_smp_processor_id();
110         data = per_cpu_ptr(tr->trace_buffer.data, cpu);
111         disabled = atomic_inc_return(&data->disabled);
112 
113         if (likely(disabled == 1)) {
114                 pc = preempt_count();
115                 trace_function(tr, ip, parent_ip, flags, pc);
116                 /*
117                  * skip over 5 funcs:
118                  *    __ftrace_trace_stack,
119                  *    __trace_stack,
120                  *    function_stack_trace_call
121                  *    ftrace_list_func
122                  *    ftrace_call
123                  */
124                 __trace_stack(tr, flags, 5, pc);
125         }
126 
127         atomic_dec(&data->disabled);
128         local_irq_restore(flags);
129 }
130 
131 
132 static struct ftrace_ops trace_ops __read_mostly =
133 {
134         .func = function_trace_call,
135         .flags = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE,
136 };
137 
138 static struct ftrace_ops trace_stack_ops __read_mostly =
139 {
140         .func = function_stack_trace_call,
141         .flags = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE,
142 };
143 
144 static struct tracer_opt func_opts[] = {
145 #ifdef CONFIG_STACKTRACE
146         { TRACER_OPT(func_stack_trace, TRACE_FUNC_OPT_STACK) },
147 #endif
148         { } /* Always set a last empty entry */
149 };
150 
151 static struct tracer_flags func_flags = {
152         .val = 0, /* By default: all flags disabled */
153         .opts = func_opts
154 };
155 
156 static void tracing_start_function_trace(void)
157 {
158         ftrace_function_enabled = 0;
159 
160         if (func_flags.val & TRACE_FUNC_OPT_STACK)
161                 register_ftrace_function(&trace_stack_ops);
162         else
163                 register_ftrace_function(&trace_ops);
164 
165         ftrace_function_enabled = 1;
166 }
167 
168 static void tracing_stop_function_trace(void)
169 {
170         ftrace_function_enabled = 0;
171 
172         if (func_flags.val & TRACE_FUNC_OPT_STACK)
173                 unregister_ftrace_function(&trace_stack_ops);
174         else
175                 unregister_ftrace_function(&trace_ops);
176 }
177 
178 static int func_set_flag(u32 old_flags, u32 bit, int set)
179 {
180         switch (bit) {
181         case TRACE_FUNC_OPT_STACK:
182                 /* do nothing if already set */
183                 if (!!set == !!(func_flags.val & TRACE_FUNC_OPT_STACK))
184                         break;
185 
186                 if (set) {
187                         unregister_ftrace_function(&trace_ops);
188                         register_ftrace_function(&trace_stack_ops);
189                 } else {
190                         unregister_ftrace_function(&trace_stack_ops);
191                         register_ftrace_function(&trace_ops);
192                 }
193 
194                 break;
195         default:
196                 return -EINVAL;
197         }
198 
199         return 0;
200 }
201 
202 static struct tracer function_trace __tracer_data =
203 {
204         .name           = "function",
205         .init           = function_trace_init,
206         .reset          = function_trace_reset,
207         .start          = function_trace_start,
208         .wait_pipe      = poll_wait_pipe,
209         .flags          = &func_flags,
210         .set_flag       = func_set_flag,
211 #ifdef CONFIG_FTRACE_SELFTEST
212         .selftest       = trace_selftest_startup_function,
213 #endif
214 };
215 
216 #ifdef CONFIG_DYNAMIC_FTRACE
217 static int update_count(void **data)
218 {
219         unsigned long *count = (long *)data;
220 
221         if (!*count)
222                 return 0;
223 
224         if (*count != -1)
225                 (*count)--;
226 
227         return 1;
228 }
229 
230 static void
231 ftrace_traceon_count(unsigned long ip, unsigned long parent_ip, void **data)
232 {
233         if (tracing_is_on())
234                 return;
235 
236         if (update_count(data))
237                 tracing_on();
238 }
239 
240 static void
241 ftrace_traceoff_count(unsigned long ip, unsigned long parent_ip, void **data)
242 {
243         if (!tracing_is_on())
244                 return;
245 
246         if (update_count(data))
247                 tracing_off();
248 }
249 
250 static void
251 ftrace_traceon(unsigned long ip, unsigned long parent_ip, void **data)
252 {
253         if (tracing_is_on())
254                 return;
255 
256         tracing_on();
257 }
258 
259 static void
260 ftrace_traceoff(unsigned long ip, unsigned long parent_ip, void **data)
261 {
262         if (!tracing_is_on())
263                 return;
264 
265         tracing_off();
266 }
267 
268 /*
269  * Skip 4:
270  *   ftrace_stacktrace()
271  *   function_trace_probe_call()
272  *   ftrace_ops_list_func()
273  *   ftrace_call()
274  */
275 #define STACK_SKIP 4
276 
277 static void
278 ftrace_stacktrace(unsigned long ip, unsigned long parent_ip, void **data)
279 {
280         trace_dump_stack(STACK_SKIP);
281 }
282 
283 static void
284 ftrace_stacktrace_count(unsigned long ip, unsigned long parent_ip, void **data)
285 {
286         if (!tracing_is_on())
287                 return;
288 
289         if (update_count(data))
290                 trace_dump_stack(STACK_SKIP);
291 }
292 
293 static void
294 ftrace_dump_probe(unsigned long ip, unsigned long parent_ip, void **data)
295 {
296         if (update_count(data))
297                 ftrace_dump(DUMP_ALL);
298 }
299 
300 /* Only dump the current CPU buffer. */
301 static void
302 ftrace_cpudump_probe(unsigned long ip, unsigned long parent_ip, void **data)
303 {
304         if (update_count(data))
305                 ftrace_dump(DUMP_ORIG);
306 }
307 
308 static int
309 ftrace_probe_print(const char *name, struct seq_file *m,
310                    unsigned long ip, void *data)
311 {
312         long count = (long)data;
313 
314         seq_printf(m, "%ps:%s", (void *)ip, name);
315 
316         if (count == -1)
317                 seq_printf(m, ":unlimited\n");
318         else
319                 seq_printf(m, ":count=%ld\n", count);
320 
321         return 0;
322 }
323 
324 static int
325 ftrace_traceon_print(struct seq_file *m, unsigned long ip,
326                          struct ftrace_probe_ops *ops, void *data)
327 {
328         return ftrace_probe_print("traceon", m, ip, data);
329 }
330 
331 static int
332 ftrace_traceoff_print(struct seq_file *m, unsigned long ip,
333                          struct ftrace_probe_ops *ops, void *data)
334 {
335         return ftrace_probe_print("traceoff", m, ip, data);
336 }
337 
338 static int
339 ftrace_stacktrace_print(struct seq_file *m, unsigned long ip,
340                         struct ftrace_probe_ops *ops, void *data)
341 {
342         return ftrace_probe_print("stacktrace", m, ip, data);
343 }
344 
345 static int
346 ftrace_dump_print(struct seq_file *m, unsigned long ip,
347                         struct ftrace_probe_ops *ops, void *data)
348 {
349         return ftrace_probe_print("dump", m, ip, data);
350 }
351 
352 static int
353 ftrace_cpudump_print(struct seq_file *m, unsigned long ip,
354                         struct ftrace_probe_ops *ops, void *data)
355 {
356         return ftrace_probe_print("cpudump", m, ip, data);
357 }
358 
359 static struct ftrace_probe_ops traceon_count_probe_ops = {
360         .func                   = ftrace_traceon_count,
361         .print                  = ftrace_traceon_print,
362 };
363 
364 static struct ftrace_probe_ops traceoff_count_probe_ops = {
365         .func                   = ftrace_traceoff_count,
366         .print                  = ftrace_traceoff_print,
367 };
368 
369 static struct ftrace_probe_ops stacktrace_count_probe_ops = {
370         .func                   = ftrace_stacktrace_count,
371         .print                  = ftrace_stacktrace_print,
372 };
373 
374 static struct ftrace_probe_ops dump_probe_ops = {
375         .func                   = ftrace_dump_probe,
376         .print                  = ftrace_dump_print,
377 };
378 
379 static struct ftrace_probe_ops cpudump_probe_ops = {
380         .func                   = ftrace_cpudump_probe,
381         .print                  = ftrace_cpudump_print,
382 };
383 
384 static struct ftrace_probe_ops traceon_probe_ops = {
385         .func                   = ftrace_traceon,
386         .print                  = ftrace_traceon_print,
387 };
388 
389 static struct ftrace_probe_ops traceoff_probe_ops = {
390         .func                   = ftrace_traceoff,
391         .print                  = ftrace_traceoff_print,
392 };
393 
394 static struct ftrace_probe_ops stacktrace_probe_ops = {
395         .func                   = ftrace_stacktrace,
396         .print                  = ftrace_stacktrace_print,
397 };
398 
399 static int
400 ftrace_trace_probe_callback(struct ftrace_probe_ops *ops,
401                             struct ftrace_hash *hash, char *glob,
402                             char *cmd, char *param, int enable)
403 {
404         void *count = (void *)-1;
405         char *number;
406         int ret;
407 
408         /* hash funcs only work with set_ftrace_filter */
409         if (!enable)
410                 return -EINVAL;
411 
412         if (glob[0] == '!') {
413                 unregister_ftrace_function_probe_func(glob+1, ops);
414                 return 0;
415         }
416 
417         if (!param)
418                 goto out_reg;
419 
420         number = strsep(&param, ":");
421 
422         if (!strlen(number))
423                 goto out_reg;
424 
425         /*
426          * We use the callback data field (which is a pointer)
427          * as our counter.
428          */
429         ret = kstrtoul(number, 0, (unsigned long *)&count);
430         if (ret)
431                 return ret;
432 
433  out_reg:
434         ret = register_ftrace_function_probe(glob, ops, count);
435 
436         return ret < 0 ? ret : 0;
437 }
438 
439 static int
440 ftrace_trace_onoff_callback(struct ftrace_hash *hash,
441                             char *glob, char *cmd, char *param, int enable)
442 {
443         struct ftrace_probe_ops *ops;
444 
445         /* we register both traceon and traceoff to this callback */
446         if (strcmp(cmd, "traceon") == 0)
447                 ops = param ? &traceon_count_probe_ops : &traceon_probe_ops;
448         else
449                 ops = param ? &traceoff_count_probe_ops : &traceoff_probe_ops;
450 
451         return ftrace_trace_probe_callback(ops, hash, glob, cmd,
452                                            param, enable);
453 }
454 
455 static int
456 ftrace_stacktrace_callback(struct ftrace_hash *hash,
457                            char *glob, char *cmd, char *param, int enable)
458 {
459         struct ftrace_probe_ops *ops;
460 
461         ops = param ? &stacktrace_count_probe_ops : &stacktrace_probe_ops;
462 
463         return ftrace_trace_probe_callback(ops, hash, glob, cmd,
464                                            param, enable);
465 }
466 
467 static int
468 ftrace_dump_callback(struct ftrace_hash *hash,
469                            char *glob, char *cmd, char *param, int enable)
470 {
471         struct ftrace_probe_ops *ops;
472 
473         ops = &dump_probe_ops;
474 
475         /* Only dump once. */
476         return ftrace_trace_probe_callback(ops, hash, glob, cmd,
477                                            "1", enable);
478 }
479 
480 static int
481 ftrace_cpudump_callback(struct ftrace_hash *hash,
482                            char *glob, char *cmd, char *param, int enable)
483 {
484         struct ftrace_probe_ops *ops;
485 
486         ops = &cpudump_probe_ops;
487 
488         /* Only dump once. */
489         return ftrace_trace_probe_callback(ops, hash, glob, cmd,
490                                            "1", enable);
491 }
492 
493 static struct ftrace_func_command ftrace_traceon_cmd = {
494         .name                   = "traceon",
495         .func                   = ftrace_trace_onoff_callback,
496 };
497 
498 static struct ftrace_func_command ftrace_traceoff_cmd = {
499         .name                   = "traceoff",
500         .func                   = ftrace_trace_onoff_callback,
501 };
502 
503 static struct ftrace_func_command ftrace_stacktrace_cmd = {
504         .name                   = "stacktrace",
505         .func                   = ftrace_stacktrace_callback,
506 };
507 
508 static struct ftrace_func_command ftrace_dump_cmd = {
509         .name                   = "dump",
510         .func                   = ftrace_dump_callback,
511 };
512 
513 static struct ftrace_func_command ftrace_cpudump_cmd = {
514         .name                   = "cpudump",
515         .func                   = ftrace_cpudump_callback,
516 };
517 
518 static int __init init_func_cmd_traceon(void)
519 {
520         int ret;
521 
522         ret = register_ftrace_command(&ftrace_traceoff_cmd);
523         if (ret)
524                 return ret;
525 
526         ret = register_ftrace_command(&ftrace_traceon_cmd);
527         if (ret)
528                 goto out_free_traceoff;
529 
530         ret = register_ftrace_command(&ftrace_stacktrace_cmd);
531         if (ret)
532                 goto out_free_traceon;
533 
534         ret = register_ftrace_command(&ftrace_dump_cmd);
535         if (ret)
536                 goto out_free_stacktrace;
537 
538         ret = register_ftrace_command(&ftrace_cpudump_cmd);
539         if (ret)
540                 goto out_free_dump;
541 
542         return 0;
543 
544  out_free_dump:
545         unregister_ftrace_command(&ftrace_dump_cmd);
546  out_free_stacktrace:
547         unregister_ftrace_command(&ftrace_stacktrace_cmd);
548  out_free_traceon:
549         unregister_ftrace_command(&ftrace_traceon_cmd);
550  out_free_traceoff:
551         unregister_ftrace_command(&ftrace_traceoff_cmd);
552 
553         return ret;
554 }
555 #else
556 static inline int init_func_cmd_traceon(void)
557 {
558         return 0;
559 }
560 #endif /* CONFIG_DYNAMIC_FTRACE */
561 
562 static __init int init_function_trace(void)
563 {
564         init_func_cmd_traceon();
565         return register_tracer(&function_trace);
566 }
567 core_initcall(init_function_trace);
568 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp