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path: root/kernel/trace/trace_events.c
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Diffstat (limited to 'kernel/trace/trace_events.c')
-rw-r--r--kernel/trace/trace_events.c199
1 files changed, 174 insertions, 25 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 77a5c02bd634..1d07f800a9ce 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -44,6 +44,36 @@ static void ftrace_clear_events(void)
44 } 44 }
45} 45}
46 46
47static void ftrace_event_enable_disable(struct ftrace_event_call *call,
48 int enable)
49{
50
51 switch (enable) {
52 case 0:
53 if (call->enabled) {
54 call->enabled = 0;
55 call->unregfunc();
56 }
57 if (call->raw_enabled) {
58 call->raw_enabled = 0;
59 call->raw_unreg();
60 }
61 break;
62 case 1:
63 if (!call->enabled &&
64 (call->type & TRACE_EVENT_TYPE_PRINTF)) {
65 call->enabled = 1;
66 call->regfunc();
67 }
68 if (!call->raw_enabled &&
69 (call->type & TRACE_EVENT_TYPE_RAW)) {
70 call->raw_enabled = 1;
71 call->raw_reg();
72 }
73 break;
74 }
75}
76
47static int ftrace_set_clr_event(char *buf, int set) 77static int ftrace_set_clr_event(char *buf, int set)
48{ 78{
49 struct ftrace_event_call *call = __start_ftrace_events; 79 struct ftrace_event_call *call = __start_ftrace_events;
@@ -90,19 +120,8 @@ static int ftrace_set_clr_event(char *buf, int set)
90 if (event && strcmp(event, call->name) != 0) 120 if (event && strcmp(event, call->name) != 0)
91 continue; 121 continue;
92 122
93 if (set) { 123 ftrace_event_enable_disable(call, set);
94 /* Already set? */ 124
95 if (call->enabled)
96 return 0;
97 call->enabled = 1;
98 call->regfunc();
99 } else {
100 /* Already cleared? */
101 if (!call->enabled)
102 return 0;
103 call->enabled = 0;
104 call->unregfunc();
105 }
106 ret = 0; 125 ret = 0;
107 } 126 }
108 return ret; 127 return ret;
@@ -273,7 +292,7 @@ event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
273 struct ftrace_event_call *call = filp->private_data; 292 struct ftrace_event_call *call = filp->private_data;
274 char *buf; 293 char *buf;
275 294
276 if (call->enabled) 295 if (call->enabled || call->raw_enabled)
277 buf = "1\n"; 296 buf = "1\n";
278 else 297 else
279 buf = "0\n"; 298 buf = "0\n";
@@ -304,18 +323,8 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
304 323
305 switch (val) { 324 switch (val) {
306 case 0: 325 case 0:
307 if (!call->enabled)
308 break;
309
310 call->enabled = 0;
311 call->unregfunc();
312 break;
313 case 1: 326 case 1:
314 if (call->enabled) 327 ftrace_event_enable_disable(call, val);
315 break;
316
317 call->enabled = 1;
318 call->regfunc();
319 break; 328 break;
320 329
321 default: 330 default:
@@ -327,6 +336,107 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
327 return cnt; 336 return cnt;
328} 337}
329 338
339static ssize_t
340event_type_read(struct file *filp, char __user *ubuf, size_t cnt,
341 loff_t *ppos)
342{
343 struct ftrace_event_call *call = filp->private_data;
344 char buf[16];
345 int r = 0;
346
347 if (call->type & TRACE_EVENT_TYPE_PRINTF)
348 r += sprintf(buf, "printf\n");
349
350 if (call->type & TRACE_EVENT_TYPE_RAW)
351 r += sprintf(buf+r, "raw\n");
352
353 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
354}
355
356static ssize_t
357event_type_write(struct file *filp, const char __user *ubuf, size_t cnt,
358 loff_t *ppos)
359{
360 struct ftrace_event_call *call = filp->private_data;
361 char buf[64];
362
363 /*
364 * If there's only one type, we can't change it.
365 * And currently we always have printf type, and we
366 * may or may not have raw type.
367 *
368 * This is a redundant check, the file should be read
369 * only if this is the case anyway.
370 */
371
372 if (!call->raw_init)
373 return -EPERM;
374
375 if (cnt >= sizeof(buf))
376 return -EINVAL;
377
378 if (copy_from_user(&buf, ubuf, cnt))
379 return -EFAULT;
380
381 buf[cnt] = 0;
382
383 if (!strncmp(buf, "printf", 6) &&
384 (!buf[6] || isspace(buf[6]))) {
385
386 call->type = TRACE_EVENT_TYPE_PRINTF;
387
388 /*
389 * If raw enabled, the disable it and enable
390 * printf type.
391 */
392 if (call->raw_enabled) {
393 call->raw_enabled = 0;
394 call->raw_unreg();
395
396 call->enabled = 1;
397 call->regfunc();
398 }
399
400 } else if (!strncmp(buf, "raw", 3) &&
401 (!buf[3] || isspace(buf[3]))) {
402
403 call->type = TRACE_EVENT_TYPE_RAW;
404
405 /*
406 * If printf enabled, the disable it and enable
407 * raw type.
408 */
409 if (call->enabled) {
410 call->enabled = 0;
411 call->unregfunc();
412
413 call->raw_enabled = 1;
414 call->raw_reg();
415 }
416 } else
417 return -EINVAL;
418
419 *ppos += cnt;
420
421 return cnt;
422}
423
424static ssize_t
425event_available_types_read(struct file *filp, char __user *ubuf, size_t cnt,
426 loff_t *ppos)
427{
428 struct ftrace_event_call *call = filp->private_data;
429 char buf[16];
430 int r = 0;
431
432 r += sprintf(buf, "printf\n");
433
434 if (call->raw_init)
435 r += sprintf(buf+r, "raw\n");
436
437 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
438}
439
330static const struct seq_operations show_event_seq_ops = { 440static const struct seq_operations show_event_seq_ops = {
331 .start = t_start, 441 .start = t_start,
332 .next = t_next, 442 .next = t_next,
@@ -362,6 +472,17 @@ static const struct file_operations ftrace_enable_fops = {
362 .write = event_enable_write, 472 .write = event_enable_write,
363}; 473};
364 474
475static const struct file_operations ftrace_type_fops = {
476 .open = tracing_open_generic,
477 .read = event_type_read,
478 .write = event_type_write,
479};
480
481static const struct file_operations ftrace_available_types_fops = {
482 .open = tracing_open_generic,
483 .read = event_available_types_read,
484};
485
365static struct dentry *event_trace_events_dir(void) 486static struct dentry *event_trace_events_dir(void)
366{ 487{
367 static struct dentry *d_tracer; 488 static struct dentry *d_tracer;
@@ -427,6 +548,7 @@ static int
427event_create_dir(struct ftrace_event_call *call, struct dentry *d_events) 548event_create_dir(struct ftrace_event_call *call, struct dentry *d_events)
428{ 549{
429 struct dentry *entry; 550 struct dentry *entry;
551 int ret;
430 552
431 /* 553 /*
432 * If the trace point header did not define TRACE_SYSTEM 554 * If the trace point header did not define TRACE_SYSTEM
@@ -435,6 +557,18 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events)
435 if (strcmp(call->system, "TRACE_SYSTEM") != 0) 557 if (strcmp(call->system, "TRACE_SYSTEM") != 0)
436 d_events = event_subsystem_dir(call->system, d_events); 558 d_events = event_subsystem_dir(call->system, d_events);
437 559
560 if (call->raw_init) {
561 ret = call->raw_init();
562 if (ret < 0) {
563 pr_warning("Could not initialize trace point"
564 " events/%s\n", call->name);
565 return ret;
566 }
567 }
568
569 /* default the output to printf */
570 call->type = TRACE_EVENT_TYPE_PRINTF;
571
438 call->dir = debugfs_create_dir(call->name, d_events); 572 call->dir = debugfs_create_dir(call->name, d_events);
439 if (!call->dir) { 573 if (!call->dir) {
440 pr_warning("Could not create debugfs " 574 pr_warning("Could not create debugfs "
@@ -448,6 +582,21 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events)
448 pr_warning("Could not create debugfs " 582 pr_warning("Could not create debugfs "
449 "'%s/enable' entry\n", call->name); 583 "'%s/enable' entry\n", call->name);
450 584
585 /* Only let type be writable, if we can change it */
586 entry = debugfs_create_file("type",
587 call->raw_init ? 0644 : 0444,
588 call->dir, call,
589 &ftrace_type_fops);
590 if (!entry)
591 pr_warning("Could not create debugfs "
592 "'%s/type' entry\n", call->name);
593
594 entry = debugfs_create_file("available_types", 0444, call->dir, call,
595 &ftrace_available_types_fops);
596 if (!entry)
597 pr_warning("Could not create debugfs "
598 "'%s/type' available_types\n", call->name);
599
451 return 0; 600 return 0;
452} 601}
453 602