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1 /*
2 * Kprobes-based tracing events
3 *
4 * Created by Masami Hiramatsu <mhiramat@redhat.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20 #include <linux/module.h>
21 #include <linux/uaccess.h>
22
23 #include "trace_probe.h"
24
25 #define KPROBE_EVENT_SYSTEM "kprobes"
26
27 /**
28 * Kprobe event core functions
29 */
30 struct trace_probe {
31 struct list_head list;
32 struct kretprobe rp; /* Use rp.kp for kprobe use */
33 unsigned long nhit;
34 unsigned int flags; /* For TP_FLAG_* */
35 const char *symbol; /* symbol name */
36 struct ftrace_event_class class;
37 struct ftrace_event_call call;
38 struct ftrace_event_file * __rcu *files;
39 ssize_t size; /* trace entry size */
40 unsigned int nr_args;
41 struct probe_arg args[];
42 };
43
44 #define SIZEOF_TRACE_PROBE(n) \
45 (offsetof(struct trace_probe, args) + \
46 (sizeof(struct probe_arg) * (n)))
47
48
49 static __kprobes bool trace_probe_is_return(struct trace_probe *tp)
50 {
51 return tp->rp.handler != NULL;
52 }
53
54 static __kprobes const char *trace_probe_symbol(struct trace_probe *tp)
55 {
56 return tp->symbol ? tp->symbol : "unknown";
57 }
58
59 static __kprobes unsigned long trace_probe_offset(struct trace_probe *tp)
60 {
61 return tp->rp.kp.offset;
62 }
63
64 static __kprobes bool trace_probe_is_enabled(struct trace_probe *tp)
65 {
66 return !!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE));
67 }
68
69 static __kprobes bool trace_probe_is_registered(struct trace_probe *tp)
70 {
71 return !!(tp->flags & TP_FLAG_REGISTERED);
72 }
73
74 static __kprobes bool trace_probe_has_gone(struct trace_probe *tp)
75 {
76 return !!(kprobe_gone(&tp->rp.kp));
77 }
78
79 static __kprobes bool trace_probe_within_module(struct trace_probe *tp,
80 struct module *mod)
81 {
82 int len = strlen(mod->name);
83 const char *name = trace_probe_symbol(tp);
84 return strncmp(mod->name, name, len) == 0 && name[len] == ':';
85 }
86
87 static __kprobes bool trace_probe_is_on_module(struct trace_probe *tp)
88 {
89 return !!strchr(trace_probe_symbol(tp), ':');
90 }
91
92 static int register_probe_event(struct trace_probe *tp);
93 static void unregister_probe_event(struct trace_probe *tp);
94
95 static DEFINE_MUTEX(probe_lock);
96 static LIST_HEAD(probe_list);
97
98 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
99 static int kretprobe_dispatcher(struct kretprobe_instance *ri,
100 struct pt_regs *regs);
101
102 /*
103 * Allocate new trace_probe and initialize it (including kprobes).
104 */
105 static struct trace_probe *alloc_trace_probe(const char *group,
106 const char *event,
107 void *addr,
108 const char *symbol,
109 unsigned long offs,
110 int nargs, bool is_return)
111 {
112 struct trace_probe *tp;
113 int ret = -ENOMEM;
114
115 tp = kzalloc(SIZEOF_TRACE_PROBE(nargs), GFP_KERNEL);
116 if (!tp)
117 return ERR_PTR(ret);
118
119 if (symbol) {
120 tp->symbol = kstrdup(symbol, GFP_KERNEL);
121 if (!tp->symbol)
122 goto error;
123 tp->rp.kp.symbol_name = tp->symbol;
124 tp->rp.kp.offset = offs;
125 } else
126 tp->rp.kp.addr = addr;
127
128 if (is_return)
129 tp->rp.handler = kretprobe_dispatcher;
130 else
131 tp->rp.kp.pre_handler = kprobe_dispatcher;
132
133 if (!event || !is_good_name(event)) {
134 ret = -EINVAL;
135 goto error;
136 }
137
138 tp->call.class = &tp->class;
139 tp->call.name = kstrdup(event, GFP_KERNEL);
140 if (!tp->call.name)
141 goto error;
142
143 if (!group || !is_good_name(group)) {
144 ret = -EINVAL;
145 goto error;
146 }
147
148 tp->class.system = kstrdup(group, GFP_KERNEL);
149 if (!tp->class.system)
150 goto error;
151
152 INIT_LIST_HEAD(&tp->list);
153 return tp;
154 error:
155 kfree(tp->call.name);
156 kfree(tp->symbol);
157 kfree(tp);
158 return ERR_PTR(ret);
159 }
160
161 static void free_trace_probe(struct trace_probe *tp)
162 {
163 int i;
164
165 for (i = 0; i < tp->nr_args; i++)
166 traceprobe_free_probe_arg(&tp->args[i]);
167
168 kfree(tp->call.class->system);
169 kfree(tp->call.name);
170 kfree(tp->symbol);
171 kfree(tp);
172 }
173
174 static struct trace_probe *find_trace_probe(const char *event,
175 const char *group)
176 {
177 struct trace_probe *tp;
178
179 list_for_each_entry(tp, &probe_list, list)
180 if (strcmp(tp->call.name, event) == 0 &&
181 strcmp(tp->call.class->system, group) == 0)
182 return tp;
183 return NULL;
184 }
185
186 static int trace_probe_nr_files(struct trace_probe *tp)
187 {
188 struct ftrace_event_file **file;
189 int ret = 0;
190
191 /*
192 * Since all tp->files updater is protected by probe_enable_lock,
193 * we don't need to lock an rcu_read_lock.
194 */
195 file = rcu_dereference_raw(tp->files);
196 if (file)
197 while (*(file++))
198 ret++;
199
200 return ret;
201 }
202
203 static DEFINE_MUTEX(probe_enable_lock);
204
205 /*
206 * Enable trace_probe
207 * if the file is NULL, enable "perf" handler, or enable "trace" handler.
208 */
209 static int
210 enable_trace_probe(struct trace_probe *tp, struct ftrace_event_file *file)
211 {
212 int ret = 0;
213
214 mutex_lock(&probe_enable_lock);
215
216 if (file) {
217 struct ftrace_event_file **new, **old;
218 int n = trace_probe_nr_files(tp);
219
220 old = rcu_dereference_raw(tp->files);
221 /* 1 is for new one and 1 is for stopper */
222 new = kzalloc((n + 2) * sizeof(struct ftrace_event_file *),
223 GFP_KERNEL);
224 if (!new) {
225 ret = -ENOMEM;
226 goto out_unlock;
227 }
228 memcpy(new, old, n * sizeof(struct ftrace_event_file *));
229 new[n] = file;
230 /* The last one keeps a NULL */
231
232 rcu_assign_pointer(tp->files, new);
233 tp->flags |= TP_FLAG_TRACE;
234
235 if (old) {
236 /* Make sure the probe is done with old files */
237 synchronize_sched();
238 kfree(old);
239 }
240 } else
241 tp->flags |= TP_FLAG_PROFILE;
242
243 if (trace_probe_is_registered(tp) && !trace_probe_has_gone(tp)) {
244 if (trace_probe_is_return(tp))
245 ret = enable_kretprobe(&tp->rp);
246 else
247 ret = enable_kprobe(&tp->rp.kp);
248 }
249
250 out_unlock:
251 mutex_unlock(&probe_enable_lock);
252
253 return ret;
254 }
255
256 static int
257 trace_probe_file_index(struct trace_probe *tp, struct ftrace_event_file *file)
258 {
259 struct ftrace_event_file **files;
260 int i;
261
262 /*
263 * Since all tp->files updater is protected by probe_enable_lock,
264 * we don't need to lock an rcu_read_lock.
265 */
266 files = rcu_dereference_raw(tp->files);
267 if (files) {
268 for (i = 0; files[i]; i++)
269 if (files[i] == file)
270 return i;
271 }
272
273 return -1;
274 }
275
276 /*
277 * Disable trace_probe
278 * if the file is NULL, disable "perf" handler, or disable "trace" handler.
279 */
280 static int
281 disable_trace_probe(struct trace_probe *tp, struct ftrace_event_file *file)
282 {
283 int ret = 0;
284
285 mutex_lock(&probe_enable_lock);
286
287 if (file) {
288 struct ftrace_event_file **new, **old;
289 int n = trace_probe_nr_files(tp);
290 int i, j;
291
292 old = rcu_dereference_raw(tp->files);
293 if (n == 0 || trace_probe_file_index(tp, file) < 0) {
294 ret = -EINVAL;
295 goto out_unlock;
296 }
297
298 if (n == 1) { /* Remove the last file */
299 tp->flags &= ~TP_FLAG_TRACE;
300 new = NULL;
301 } else {
302 new = kzalloc(n * sizeof(struct ftrace_event_file *),
303 GFP_KERNEL);
304 if (!new) {
305 ret = -ENOMEM;
306 goto out_unlock;
307 }
308
309 /* This copy & check loop copies the NULL stopper too */
310 for (i = 0, j = 0; j < n && i < n + 1; i++)
311 if (old[i] != file)
312 new[j++] = old[i];
313 }
314
315 rcu_assign_pointer(tp->files, new);
316
317 /* Make sure the probe is done with old files */
318 synchronize_sched();
319 kfree(old);
320 } else
321 tp->flags &= ~TP_FLAG_PROFILE;
322
323 if (!trace_probe_is_enabled(tp) && trace_probe_is_registered(tp)) {
324 if (trace_probe_is_return(tp))
325 disable_kretprobe(&tp->rp);
326 else
327 disable_kprobe(&tp->rp.kp);
328 }
329
330 out_unlock:
331 mutex_unlock(&probe_enable_lock);
332
333 return ret;
334 }
335
336 /* Internal register function - just handle k*probes and flags */
337 static int __register_trace_probe(struct trace_probe *tp)
338 {
339 int i, ret;
340
341 if (trace_probe_is_registered(tp))
342 return -EINVAL;
343
344 for (i = 0; i < tp->nr_args; i++)
345 traceprobe_update_arg(&tp->args[i]);
346
347 /* Set/clear disabled flag according to tp->flag */
348 if (trace_probe_is_enabled(tp))
349 tp->rp.kp.flags &= ~KPROBE_FLAG_DISABLED;
350 else
351 tp->rp.kp.flags |= KPROBE_FLAG_DISABLED;
352
353 if (trace_probe_is_return(tp))
354 ret = register_kretprobe(&tp->rp);
355 else
356 ret = register_kprobe(&tp->rp.kp);
357
358 if (ret == 0)
359 tp->flags |= TP_FLAG_REGISTERED;
360 else {
361 pr_warning("Could not insert probe at %s+%lu: %d\n",
362 trace_probe_symbol(tp), trace_probe_offset(tp), ret);
363 if (ret == -ENOENT && trace_probe_is_on_module(tp)) {
364 pr_warning("This probe might be able to register after"
365 "target module is loaded. Continue.\n");
366 ret = 0;
367 } else if (ret == -EILSEQ) {
368 pr_warning("Probing address(0x%p) is not an "
369 "instruction boundary.\n",
370 tp->rp.kp.addr);
371 ret = -EINVAL;
372 }
373 }
374
375 return ret;
376 }
377
378 /* Internal unregister function - just handle k*probes and flags */
379 static void __unregister_trace_probe(struct trace_probe *tp)
380 {
381 if (trace_probe_is_registered(tp)) {
382 if (trace_probe_is_return(tp))
383 unregister_kretprobe(&tp->rp);
384 else
385 unregister_kprobe(&tp->rp.kp);
386 tp->flags &= ~TP_FLAG_REGISTERED;
387 /* Cleanup kprobe for reuse */
388 if (tp->rp.kp.symbol_name)
389 tp->rp.kp.addr = NULL;
390 }
391 }
392
393 /* Unregister a trace_probe and probe_event: call with locking probe_lock */
394 static int unregister_trace_probe(struct trace_probe *tp)
395 {
396 /* Enabled event can not be unregistered */
397 if (trace_probe_is_enabled(tp))
398 return -EBUSY;
399
400 __unregister_trace_probe(tp);
401 list_del(&tp->list);
402 unregister_probe_event(tp);
403
404 return 0;
405 }
406
407 /* Register a trace_probe and probe_event */
408 static int register_trace_probe(struct trace_probe *tp)
409 {
410 struct trace_probe *old_tp;
411 int ret;
412
413 mutex_lock(&probe_lock);
414
415 /* Delete old (same name) event if exist */
416 old_tp = find_trace_probe(tp->call.name, tp->call.class->system);
417 if (old_tp) {
418 ret = unregister_trace_probe(old_tp);
419 if (ret < 0)
420 goto end;
421 free_trace_probe(old_tp);
422 }
423
424 /* Register new event */
425 ret = register_probe_event(tp);
426 if (ret) {
427 pr_warning("Failed to register probe event(%d)\n", ret);
428 goto end;
429 }
430
431 /* Register k*probe */
432 ret = __register_trace_probe(tp);
433 if (ret < 0)
434 unregister_probe_event(tp);
435 else
436 list_add_tail(&tp->list, &probe_list);
437
438 end:
439 mutex_unlock(&probe_lock);
440 return ret;
441 }
442
443 /* Module notifier call back, checking event on the module */
444 static int trace_probe_module_callback(struct notifier_block *nb,
445 unsigned long val, void *data)
446 {
447 struct module *mod = data;
448 struct trace_probe *tp;
449 int ret;
450
451 if (val != MODULE_STATE_COMING)
452 return NOTIFY_DONE;
453
454 /* Update probes on coming module */
455 mutex_lock(&probe_lock);
456 list_for_each_entry(tp, &probe_list, list) {
457 if (trace_probe_within_module(tp, mod)) {
458 /* Don't need to check busy - this should have gone. */
459 __unregister_trace_probe(tp);
460 ret = __register_trace_probe(tp);
461 if (ret)
462 pr_warning("Failed to re-register probe %s on"
463 "%s: %d\n",
464 tp->call.name, mod->name, ret);
465 }
466 }
467 mutex_unlock(&probe_lock);
468
469 return NOTIFY_DONE;
470 }
471
472 static struct notifier_block trace_probe_module_nb = {
473 .notifier_call = trace_probe_module_callback,
474 .priority = 1 /* Invoked after kprobe module callback */
475 };
476
477 static int create_trace_probe(int argc, char **argv)
478 {
479 /*
480 * Argument syntax:
481 * - Add kprobe: p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
482 * - Add kretprobe: r[:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
483 * Fetch args:
484 * $retval : fetch return value
485 * $stack : fetch stack address
486 * $stackN : fetch Nth of stack (N:0-)
487 * @ADDR : fetch memory at ADDR (ADDR should be in kernel)
488 * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
489 * %REG : fetch register REG
490 * Dereferencing memory fetch:
491 * +|-offs(ARG) : fetch memory at ARG +|- offs address.
492 * Alias name of args:
493 * NAME=FETCHARG : set NAME as alias of FETCHARG.
494 * Type of args:
495 * FETCHARG:TYPE : use TYPE instead of unsigned long.
496 */
497 struct trace_probe *tp;
498 int i, ret = 0;
499 bool is_return = false, is_delete = false;
500 char *symbol = NULL, *event = NULL, *group = NULL;
501 char *arg;
502 unsigned long offset = 0;
503 void *addr = NULL;
504 char buf[MAX_EVENT_NAME_LEN];
505
506 /* argc must be >= 1 */
507 if (argv[0][0] == 'p')
508 is_return = false;
509 else if (argv[0][0] == 'r')
510 is_return = true;
511 else if (argv[0][0] == '-')
512 is_delete = true;
513 else {
514 pr_info("Probe definition must be started with 'p', 'r' or"
515 " '-'.\n");
516 return -EINVAL;
517 }
518
519 if (argv[0][1] == ':') {
520 event = &argv[0][2];
521 if (strchr(event, '/')) {
522 group = event;
523 event = strchr(group, '/') + 1;
524 event[-1] = '\0';
525 if (strlen(group) == 0) {
526 pr_info("Group name is not specified\n");
527 return -EINVAL;
528 }
529 }
530 if (strlen(event) == 0) {
531 pr_info("Event name is not specified\n");
532 return -EINVAL;
533 }
534 }
535 if (!group)
536 group = KPROBE_EVENT_SYSTEM;
537
538 if (is_delete) {
539 if (!event) {
540 pr_info("Delete command needs an event name.\n");
541 return -EINVAL;
542 }
543 mutex_lock(&probe_lock);
544 tp = find_trace_probe(event, group);
545 if (!tp) {
546 mutex_unlock(&probe_lock);
547 pr_info("Event %s/%s doesn't exist.\n", group, event);
548 return -ENOENT;
549 }
550 /* delete an event */
551 ret = unregister_trace_probe(tp);
552 if (ret == 0)
553 free_trace_probe(tp);
554 mutex_unlock(&probe_lock);
555 return ret;
556 }
557
558 if (argc < 2) {
559 pr_info("Probe point is not specified.\n");
560 return -EINVAL;
561 }
562 if (isdigit(argv[1][0])) {
563 if (is_return) {
564 pr_info("Return probe point must be a symbol.\n");
565 return -EINVAL;
566 }
567 /* an address specified */
568 ret = kstrtoul(&argv[1][0], 0, (unsigned long *)&addr);
569 if (ret) {
570 pr_info("Failed to parse address.\n");
571 return ret;
572 }
573 } else {
574 /* a symbol specified */
575 symbol = argv[1];
576 /* TODO: support .init module functions */
577 ret = traceprobe_split_symbol_offset(symbol, &offset);
578 if (ret) {
579 pr_info("Failed to parse symbol.\n");
580 return ret;
581 }
582 if (offset && is_return) {
583 pr_info("Return probe must be used without offset.\n");
584 return -EINVAL;
585 }
586 }
587 argc -= 2; argv += 2;
588
589 /* setup a probe */
590 if (!event) {
591 /* Make a new event name */
592 if (symbol)
593 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
594 is_return ? 'r' : 'p', symbol, offset);
595 else
596 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
597 is_return ? 'r' : 'p', addr);
598 event = buf;
599 }
600 tp = alloc_trace_probe(group, event, addr, symbol, offset, argc,
601 is_return);
602 if (IS_ERR(tp)) {
603 pr_info("Failed to allocate trace_probe.(%d)\n",
604 (int)PTR_ERR(tp));
605 return PTR_ERR(tp);
606 }
607
608 /* parse arguments */
609 ret = 0;
610 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
611 /* Increment count for freeing args in error case */
612 tp->nr_args++;
613
614 /* Parse argument name */
615 arg = strchr(argv[i], '=');
616 if (arg) {
617 *arg++ = '\0';
618 tp->args[i].name = kstrdup(argv[i], GFP_KERNEL);
619 } else {
620 arg = argv[i];
621 /* If argument name is omitted, set "argN" */
622 snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1);
623 tp->args[i].name = kstrdup(buf, GFP_KERNEL);
624 }
625
626 if (!tp->args[i].name) {
627 pr_info("Failed to allocate argument[%d] name.\n", i);
628 ret = -ENOMEM;
629 goto error;
630 }
631
632 if (!is_good_name(tp->args[i].name)) {
633 pr_info("Invalid argument[%d] name: %s\n",
634 i, tp->args[i].name);
635 ret = -EINVAL;
636 goto error;
637 }
638
639 if (traceprobe_conflict_field_name(tp->args[i].name,
640 tp->args, i)) {
641 pr_info("Argument[%d] name '%s' conflicts with "
642 "another field.\n", i, argv[i]);
643 ret = -EINVAL;
644 goto error;
645 }
646
647 /* Parse fetch argument */
648 ret = traceprobe_parse_probe_arg(arg, &tp->size, &tp->args[i],
649 is_return, true);
650 if (ret) {
651 pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
652 goto error;
653 }
654 }
655
656 ret = register_trace_probe(tp);
657 if (ret)
658 goto error;
659 return 0;
660
661 error:
662 free_trace_probe(tp);
663 return ret;
664 }
665
666 static int release_all_trace_probes(void)
667 {
668 struct trace_probe *tp;
669 int ret = 0;
670
671 mutex_lock(&probe_lock);
672 /* Ensure no probe is in use. */
673 list_for_each_entry(tp, &probe_list, list)
674 if (trace_probe_is_enabled(tp)) {
675 ret = -EBUSY;
676 goto end;
677 }
678 /* TODO: Use batch unregistration */
679 while (!list_empty(&probe_list)) {
680 tp = list_entry(probe_list.next, struct trace_probe, list);
681 unregister_trace_probe(tp);
682 free_trace_probe(tp);
683 }
684
685 end:
686 mutex_unlock(&probe_lock);
687
688 return ret;
689 }
690
691 /* Probes listing interfaces */
692 static void *probes_seq_start(struct seq_file *m, loff_t *pos)
693 {
694 mutex_lock(&probe_lock);
695 return seq_list_start(&probe_list, *pos);
696 }
697
698 static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
699 {
700 return seq_list_next(v, &probe_list, pos);
701 }
702
703 static void probes_seq_stop(struct seq_file *m, void *v)
704 {
705 mutex_unlock(&probe_lock);
706 }
707
708 static int probes_seq_show(struct seq_file *m, void *v)
709 {
710 struct trace_probe *tp = v;
711 int i;
712
713 seq_printf(m, "%c", trace_probe_is_return(tp) ? 'r' : 'p');
714 seq_printf(m, ":%s/%s", tp->call.class->system, tp->call.name);
715
716 if (!tp->symbol)
717 seq_printf(m, " 0x%p", tp->rp.kp.addr);
718 else if (tp->rp.kp.offset)
719 seq_printf(m, " %s+%u", trace_probe_symbol(tp),
720 tp->rp.kp.offset);
721 else
722 seq_printf(m, " %s", trace_probe_symbol(tp));
723
724 for (i = 0; i < tp->nr_args; i++)
725 seq_printf(m, " %s=%s", tp->args[i].name, tp->args[i].comm);
726 seq_printf(m, "\n");
727
728 return 0;
729 }
730
731 static const struct seq_operations probes_seq_op = {
732 .start = probes_seq_start,
733 .next = probes_seq_next,
734 .stop = probes_seq_stop,
735 .show = probes_seq_show
736 };
737
738 static int probes_open(struct inode *inode, struct file *file)
739 {
740 int ret;
741
742 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
743 ret = release_all_trace_probes();
744 if (ret < 0)
745 return ret;
746 }
747
748 return seq_open(file, &probes_seq_op);
749 }
750
751 static ssize_t probes_write(struct file *file, const char __user *buffer,
752 size_t count, loff_t *ppos)
753 {
754 return traceprobe_probes_write(file, buffer, count, ppos,
755 create_trace_probe);
756 }
757
758 static const struct file_operations kprobe_events_ops = {
759 .owner = THIS_MODULE,
760 .open = probes_open,
761 .read = seq_read,
762 .llseek = seq_lseek,
763 .release = seq_release,
764 .write = probes_write,
765 };
766
767 /* Probes profiling interfaces */
768 static int probes_profile_seq_show(struct seq_file *m, void *v)
769 {
770 struct trace_probe *tp = v;
771
772 seq_printf(m, " %-44s %15lu %15lu\n", tp->call.name, tp->nhit,
773 tp->rp.kp.nmissed);
774
775 return 0;
776 }
777
778 static const struct seq_operations profile_seq_op = {
779 .start = probes_seq_start,
780 .next = probes_seq_next,
781 .stop = probes_seq_stop,
782 .show = probes_profile_seq_show
783 };
784
785 static int profile_open(struct inode *inode, struct file *file)
786 {
787 return seq_open(file, &profile_seq_op);
788 }
789
790 static const struct file_operations kprobe_profile_ops = {
791 .owner = THIS_MODULE,
792 .open = profile_open,
793 .read = seq_read,
794 .llseek = seq_lseek,
795 .release = seq_release,
796 };
797
798 /* Sum up total data length for dynamic arraies (strings) */
799 static __kprobes int __get_data_size(struct trace_probe *tp,
800 struct pt_regs *regs)
801 {
802 int i, ret = 0;
803 u32 len;
804
805 for (i = 0; i < tp->nr_args; i++)
806 if (unlikely(tp->args[i].fetch_size.fn)) {
807 call_fetch(&tp->args[i].fetch_size, regs, &len);
808 ret += len;
809 }
810
811 return ret;
812 }
813
814 /* Store the value of each argument */
815 static __kprobes void store_trace_args(int ent_size, struct trace_probe *tp,
816 struct pt_regs *regs,
817 u8 *data, int maxlen)
818 {
819 int i;
820 u32 end = tp->size;
821 u32 *dl; /* Data (relative) location */
822
823 for (i = 0; i < tp->nr_args; i++) {
824 if (unlikely(tp->args[i].fetch_size.fn)) {
825 /*
826 * First, we set the relative location and
827 * maximum data length to *dl
828 */
829 dl = (u32 *)(data + tp->args[i].offset);
830 *dl = make_data_rloc(maxlen, end - tp->args[i].offset);
831 /* Then try to fetch string or dynamic array data */
832 call_fetch(&tp->args[i].fetch, regs, dl);
833 /* Reduce maximum length */
834 end += get_rloc_len(*dl);
835 maxlen -= get_rloc_len(*dl);
836 /* Trick here, convert data_rloc to data_loc */
837 *dl = convert_rloc_to_loc(*dl,
838 ent_size + tp->args[i].offset);
839 } else
840 /* Just fetching data normally */
841 call_fetch(&tp->args[i].fetch, regs,
842 data + tp->args[i].offset);
843 }
844 }
845
846 /* Kprobe handler */
847 static __kprobes void
848 __kprobe_trace_func(struct trace_probe *tp, struct pt_regs *regs,
849 struct ftrace_event_file *ftrace_file)
850 {
851 struct kprobe_trace_entry_head *entry;
852 struct ring_buffer_event *event;
853 struct ring_buffer *buffer;
854 int size, dsize, pc;
855 unsigned long irq_flags;
856 struct ftrace_event_call *call = &tp->call;
857
858 WARN_ON(call != ftrace_file->event_call);
859
860 if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
861 return;
862
863 local_save_flags(irq_flags);
864 pc = preempt_count();
865
866 dsize = __get_data_size(tp, regs);
867 size = sizeof(*entry) + tp->size + dsize;
868
869 event = trace_event_buffer_lock_reserve(&buffer, ftrace_file,
870 call->event.type,
871 size, irq_flags, pc);
872 if (!event)
873 return;
874
875 entry = ring_buffer_event_data(event);
876 entry->ip = (unsigned long)tp->rp.kp.addr;
877 store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
878
879 if (!filter_current_check_discard(buffer, call, entry, event))
880 trace_buffer_unlock_commit_regs(buffer, event,
881 irq_flags, pc, regs);
882 }
883
884 static __kprobes void
885 kprobe_trace_func(struct trace_probe *tp, struct pt_regs *regs)
886 {
887 /*
888 * Note: preempt is already disabled around the kprobe handler.
889 * However, we still need an smp_read_barrier_depends() corresponding
890 * to smp_wmb() in rcu_assign_pointer() to access the pointer.
891 */
892 struct ftrace_event_file **file = rcu_dereference_raw(tp->files);
893
894 if (unlikely(!file))
895 return;
896
897 while (*file) {
898 __kprobe_trace_func(tp, regs, *file);
899 file++;
900 }
901 }
902
903 /* Kretprobe handler */
904 static __kprobes void
905 __kretprobe_trace_func(struct trace_probe *tp, struct kretprobe_instance *ri,
906 struct pt_regs *regs,
907 struct ftrace_event_file *ftrace_file)
908 {
909 struct kretprobe_trace_entry_head *entry;
910 struct ring_buffer_event *event;
911 struct ring_buffer *buffer;
912 int size, pc, dsize;
913 unsigned long irq_flags;
914 struct ftrace_event_call *call = &tp->call;
915
916 WARN_ON(call != ftrace_file->event_call);
917
918 if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
919 return;
920
921 local_save_flags(irq_flags);
922 pc = preempt_count();
923
924 dsize = __get_data_size(tp, regs);
925 size = sizeof(*entry) + tp->size + dsize;
926
927 event = trace_event_buffer_lock_reserve(&buffer, ftrace_file,
928 call->event.type,
929 size, irq_flags, pc);
930 if (!event)
931 return;
932
933 entry = ring_buffer_event_data(event);
934 entry->func = (unsigned long)tp->rp.kp.addr;
935 entry->ret_ip = (unsigned long)ri->ret_addr;
936 store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
937
938 if (!filter_current_check_discard(buffer, call, entry, event))
939 trace_buffer_unlock_commit_regs(buffer, event,
940 irq_flags, pc, regs);
941 }
942
943 static __kprobes void
944 kretprobe_trace_func(struct trace_probe *tp, struct kretprobe_instance *ri,
945 struct pt_regs *regs)
946 {
947 /*
948 * Note: preempt is already disabled around the kprobe handler.
949 * However, we still need an smp_read_barrier_depends() corresponding
950 * to smp_wmb() in rcu_assign_pointer() to access the pointer.
951 */
952 struct ftrace_event_file **file = rcu_dereference_raw(tp->files);
953
954 if (unlikely(!file))
955 return;
956
957 while (*file) {
958 __kretprobe_trace_func(tp, ri, regs, *file);
959 file++;
960 }
961 }
962
963 /* Event entry printers */
964 static enum print_line_t
965 print_kprobe_event(struct trace_iterator *iter, int flags,
966 struct trace_event *event)
967 {
968 struct kprobe_trace_entry_head *field;
969 struct trace_seq *s = &iter->seq;
970 struct trace_probe *tp;
971 u8 *data;
972 int i;
973
974 field = (struct kprobe_trace_entry_head *)iter->ent;
975 tp = container_of(event, struct trace_probe, call.event);
976
977 if (!trace_seq_printf(s, "%s: (", tp->call.name))
978 goto partial;
979
980 if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
981 goto partial;
982
983 if (!trace_seq_puts(s, ")"))
984 goto partial;
985
986 data = (u8 *)&field[1];
987 for (i = 0; i < tp->nr_args; i++)
988 if (!tp->args[i].type->print(s, tp->args[i].name,
989 data + tp->args[i].offset, field))
990 goto partial;
991
992 if (!trace_seq_puts(s, "\n"))
993 goto partial;
994
995 return TRACE_TYPE_HANDLED;
996 partial:
997 return TRACE_TYPE_PARTIAL_LINE;
998 }
999
1000 static enum print_line_t
1001 print_kretprobe_event(struct trace_iterator *iter, int flags,
1002 struct trace_event *event)
1003 {
1004 struct kretprobe_trace_entry_head *field;
1005 struct trace_seq *s = &iter->seq;
1006 struct trace_probe *tp;
1007 u8 *data;
1008 int i;
1009
1010 field = (struct kretprobe_trace_entry_head *)iter->ent;
1011 tp = container_of(event, struct trace_probe, call.event);
1012
1013 if (!trace_seq_printf(s, "%s: (", tp->call.name))
1014 goto partial;
1015
1016 if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
1017 goto partial;
1018
1019 if (!trace_seq_puts(s, " <- "))
1020 goto partial;
1021
1022 if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
1023 goto partial;
1024
1025 if (!trace_seq_puts(s, ")"))
1026 goto partial;
1027
1028 data = (u8 *)&field[1];
1029 for (i = 0; i < tp->nr_args; i++)
1030 if (!tp->args[i].type->print(s, tp->args[i].name,
1031 data + tp->args[i].offset, field))
1032 goto partial;
1033
1034 if (!trace_seq_puts(s, "\n"))
1035 goto partial;
1036
1037 return TRACE_TYPE_HANDLED;
1038 partial:
1039 return TRACE_TYPE_PARTIAL_LINE;
1040 }
1041
1042
1043 static int kprobe_event_define_fields(struct ftrace_event_call *event_call)
1044 {
1045 int ret, i;
1046 struct kprobe_trace_entry_head field;
1047 struct trace_probe *tp = (struct trace_probe *)event_call->data;
1048
1049 DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
1050 /* Set argument names as fields */
1051 for (i = 0; i < tp->nr_args; i++) {
1052 ret = trace_define_field(event_call, tp->args[i].type->fmttype,
1053 tp->args[i].name,
1054 sizeof(field) + tp->args[i].offset,
1055 tp->args[i].type->size,
1056 tp->args[i].type->is_signed,
1057 FILTER_OTHER);
1058 if (ret)
1059 return ret;
1060 }
1061 return 0;
1062 }
1063
1064 static int kretprobe_event_define_fields(struct ftrace_event_call *event_call)
1065 {
1066 int ret, i;
1067 struct kretprobe_trace_entry_head field;
1068 struct trace_probe *tp = (struct trace_probe *)event_call->data;
1069
1070 DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
1071 DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
1072 /* Set argument names as fields */
1073 for (i = 0; i < tp->nr_args; i++) {
1074 ret = trace_define_field(event_call, tp->args[i].type->fmttype,
1075 tp->args[i].name,
1076 sizeof(field) + tp->args[i].offset,
1077 tp->args[i].type->size,
1078 tp->args[i].type->is_signed,
1079 FILTER_OTHER);
1080 if (ret)
1081 return ret;
1082 }
1083 return 0;
1084 }
1085
1086 static int __set_print_fmt(struct trace_probe *tp, char *buf, int len)
1087 {
1088 int i;
1089 int pos = 0;
1090
1091 const char *fmt, *arg;
1092
1093 if (!trace_probe_is_return(tp)) {
1094 fmt = "(%lx)";
1095 arg = "REC->" FIELD_STRING_IP;
1096 } else {
1097 fmt = "(%lx <- %lx)";
1098 arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
1099 }
1100
1101 /* When len=0, we just calculate the needed length */
1102 #define LEN_OR_ZERO (len ? len - pos : 0)
1103
1104 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
1105
1106 for (i = 0; i < tp->nr_args; i++) {
1107 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s",
1108 tp->args[i].name, tp->args[i].type->fmt);
1109 }
1110
1111 pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
1112
1113 for (i = 0; i < tp->nr_args; i++) {
1114 if (strcmp(tp->args[i].type->name, "string") == 0)
1115 pos += snprintf(buf + pos, LEN_OR_ZERO,
1116 ", __get_str(%s)",
1117 tp->args[i].name);
1118 else
1119 pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
1120 tp->args[i].name);
1121 }
1122
1123 #undef LEN_OR_ZERO
1124
1125 /* return the length of print_fmt */
1126 return pos;
1127 }
1128
1129 static int set_print_fmt(struct trace_probe *tp)
1130 {
1131 int len;
1132 char *print_fmt;
1133
1134 /* First: called with 0 length to calculate the needed length */
1135 len = __set_print_fmt(tp, NULL, 0);
1136 print_fmt = kmalloc(len + 1, GFP_KERNEL);
1137 if (!print_fmt)
1138 return -ENOMEM;
1139
1140 /* Second: actually write the @print_fmt */
1141 __set_print_fmt(tp, print_fmt, len + 1);
1142 tp->call.print_fmt = print_fmt;
1143
1144 return 0;
1145 }
1146
1147 #ifdef CONFIG_PERF_EVENTS
1148
1149 /* Kprobe profile handler */
1150 static __kprobes void
1151 kprobe_perf_func(struct trace_probe *tp, struct pt_regs *regs)
1152 {
1153 struct ftrace_event_call *call = &tp->call;
1154 struct kprobe_trace_entry_head *entry;
1155 struct hlist_head *head;
1156 int size, __size, dsize;
1157 int rctx;
1158
1159 dsize = __get_data_size(tp, regs);
1160 __size = sizeof(*entry) + tp->size + dsize;
1161 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1162 size -= sizeof(u32);
1163 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
1164 "profile buffer not large enough"))
1165 return;
1166
1167 entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
1168 if (!entry)
1169 return;
1170
1171 entry->ip = (unsigned long)tp->rp.kp.addr;
1172 memset(&entry[1], 0, dsize);
1173 store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
1174
1175 head = this_cpu_ptr(call->perf_events);
1176 perf_trace_buf_submit(entry, size, rctx,
1177 entry->ip, 1, regs, head, NULL);
1178 }
1179
1180 /* Kretprobe profile handler */
1181 static __kprobes void
1182 kretprobe_perf_func(struct trace_probe *tp, struct kretprobe_instance *ri,
1183 struct pt_regs *regs)
1184 {
1185 struct ftrace_event_call *call = &tp->call;
1186 struct kretprobe_trace_entry_head *entry;
1187 struct hlist_head *head;
1188 int size, __size, dsize;
1189 int rctx;
1190
1191 dsize = __get_data_size(tp, regs);
1192 __size = sizeof(*entry) + tp->size + dsize;
1193 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1194 size -= sizeof(u32);
1195 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
1196 "profile buffer not large enough"))
1197 return;
1198
1199 entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
1200 if (!entry)
1201 return;
1202
1203 entry->func = (unsigned long)tp->rp.kp.addr;
1204 entry->ret_ip = (unsigned long)ri->ret_addr;
1205 store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
1206
1207 head = this_cpu_ptr(call->perf_events);
1208 perf_trace_buf_submit(entry, size, rctx,
1209 entry->ret_ip, 1, regs, head, NULL);
1210 }
1211 #endif /* CONFIG_PERF_EVENTS */
1212
1213 static __kprobes
1214 int kprobe_register(struct ftrace_event_call *event,
1215 enum trace_reg type, void *data)
1216 {
1217 struct trace_probe *tp = (struct trace_probe *)event->data;
1218 struct ftrace_event_file *file = data;
1219
1220 switch (type) {
1221 case TRACE_REG_REGISTER:
1222 return enable_trace_probe(tp, file);
1223 case TRACE_REG_UNREGISTER:
1224 return disable_trace_probe(tp, file);
1225
1226 #ifdef CONFIG_PERF_EVENTS
1227 case TRACE_REG_PERF_REGISTER:
1228 return enable_trace_probe(tp, NULL);
1229 case TRACE_REG_PERF_UNREGISTER:
1230 return disable_trace_probe(tp, NULL);
1231 case TRACE_REG_PERF_OPEN:
1232 case TRACE_REG_PERF_CLOSE:
1233 case TRACE_REG_PERF_ADD:
1234 case TRACE_REG_PERF_DEL:
1235 return 0;
1236 #endif
1237 }
1238 return 0;
1239 }
1240
1241 static __kprobes
1242 int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1243 {
1244 struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
1245
1246 tp->nhit++;
1247
1248 if (tp->flags & TP_FLAG_TRACE)
1249 kprobe_trace_func(tp, regs);
1250 #ifdef CONFIG_PERF_EVENTS
1251 if (tp->flags & TP_FLAG_PROFILE)
1252 kprobe_perf_func(tp, regs);
1253 #endif
1254 return 0; /* We don't tweek kernel, so just return 0 */
1255 }
1256
1257 static __kprobes
1258 int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1259 {
1260 struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
1261
1262 tp->nhit++;
1263
1264 if (tp->flags & TP_FLAG_TRACE)
1265 kretprobe_trace_func(tp, ri, regs);
1266 #ifdef CONFIG_PERF_EVENTS
1267 if (tp->flags & TP_FLAG_PROFILE)
1268 kretprobe_perf_func(tp, ri, regs);
1269 #endif
1270 return 0; /* We don't tweek kernel, so just return 0 */
1271 }
1272
1273 static struct trace_event_functions kretprobe_funcs = {
1274 .trace = print_kretprobe_event
1275 };
1276
1277 static struct trace_event_functions kprobe_funcs = {
1278 .trace = print_kprobe_event
1279 };
1280
1281 static int register_probe_event(struct trace_probe *tp)
1282 {
1283 struct ftrace_event_call *call = &tp->call;
1284 int ret;
1285
1286 /* Initialize ftrace_event_call */
1287 INIT_LIST_HEAD(&call->class->fields);
1288 if (trace_probe_is_return(tp)) {
1289 call->event.funcs = &kretprobe_funcs;
1290 call->class->define_fields = kretprobe_event_define_fields;
1291 } else {
1292 call->event.funcs = &kprobe_funcs;
1293 call->class->define_fields = kprobe_event_define_fields;
1294 }
1295 if (set_print_fmt(tp) < 0)
1296 return -ENOMEM;
1297 ret = register_ftrace_event(&call->event);
1298 if (!ret) {
1299 kfree(call->print_fmt);
1300 return -ENODEV;
1301 }
1302 call->flags = 0;
1303 call->class->reg = kprobe_register;
1304 call->data = tp;
1305 ret = trace_add_event_call(call);
1306 if (ret) {
1307 pr_info("Failed to register kprobe event: %s\n", call->name);
1308 kfree(call->print_fmt);
1309 unregister_ftrace_event(&call->event);
1310 }
1311 return ret;
1312 }
1313
1314 static void unregister_probe_event(struct trace_probe *tp)
1315 {
1316 /* tp->event is unregistered in trace_remove_event_call() */
1317 trace_remove_event_call(&tp->call);
1318 kfree(tp->call.print_fmt);
1319 }
1320
1321 /* Make a debugfs interface for controlling probe points */
1322 static __init int init_kprobe_trace(void)
1323 {
1324 struct dentry *d_tracer;
1325 struct dentry *entry;
1326
1327 if (register_module_notifier(&trace_probe_module_nb))
1328 return -EINVAL;
1329
1330 d_tracer = tracing_init_dentry();
1331 if (!d_tracer)
1332 return 0;
1333
1334 entry = debugfs_create_file("kprobe_events", 0644, d_tracer,
1335 NULL, &kprobe_events_ops);
1336
1337 /* Event list interface */
1338 if (!entry)
1339 pr_warning("Could not create debugfs "
1340 "'kprobe_events' entry\n");
1341
1342 /* Profile interface */
1343 entry = debugfs_create_file("kprobe_profile", 0444, d_tracer,
1344 NULL, &kprobe_profile_ops);
1345
1346 if (!entry)
1347 pr_warning("Could not create debugfs "
1348 "'kprobe_profile' entry\n");
1349 return 0;
1350 }
1351 fs_initcall(init_kprobe_trace);
1352
1353
1354 #ifdef CONFIG_FTRACE_STARTUP_TEST
1355
1356 /*
1357 * The "__used" keeps gcc from removing the function symbol
1358 * from the kallsyms table.
1359 */
1360 static __used int kprobe_trace_selftest_target(int a1, int a2, int a3,
1361 int a4, int a5, int a6)
1362 {
1363 return a1 + a2 + a3 + a4 + a5 + a6;
1364 }
1365
1366 static struct ftrace_event_file *
1367 find_trace_probe_file(struct trace_probe *tp, struct trace_array *tr)
1368 {
1369 struct ftrace_event_file *file;
1370
1371 list_for_each_entry(file, &tr->events, list)
1372 if (file->event_call == &tp->call)
1373 return file;
1374
1375 return NULL;
1376 }
1377
1378 static __init int kprobe_trace_self_tests_init(void)
1379 {
1380 int ret, warn = 0;
1381 int (*target)(int, int, int, int, int, int);
1382 struct trace_probe *tp;
1383 struct ftrace_event_file *file;
1384
1385 target = kprobe_trace_selftest_target;
1386
1387 pr_info("Testing kprobe tracing: ");
1388
1389 ret = traceprobe_command("p:testprobe kprobe_trace_selftest_target "
1390 "$stack $stack0 +0($stack)",
1391 create_trace_probe);
1392 if (WARN_ON_ONCE(ret)) {
1393 pr_warn("error on probing function entry.\n");
1394 warn++;
1395 } else {
1396 /* Enable trace point */
1397 tp = find_trace_probe("testprobe", KPROBE_EVENT_SYSTEM);
1398 if (WARN_ON_ONCE(tp == NULL)) {
1399 pr_warn("error on getting new probe.\n");
1400 warn++;
1401 } else {
1402 file = find_trace_probe_file(tp, top_trace_array());
1403 if (WARN_ON_ONCE(file == NULL)) {
1404 pr_warn("error on getting probe file.\n");
1405 warn++;
1406 } else
1407 enable_trace_probe(tp, file);
1408 }
1409 }
1410
1411 ret = traceprobe_command("r:testprobe2 kprobe_trace_selftest_target "
1412 "$retval", create_trace_probe);
1413 if (WARN_ON_ONCE(ret)) {
1414 pr_warn("error on probing function return.\n");
1415 warn++;
1416 } else {
1417 /* Enable trace point */
1418 tp = find_trace_probe("testprobe2", KPROBE_EVENT_SYSTEM);
1419 if (WARN_ON_ONCE(tp == NULL)) {
1420 pr_warn("error on getting 2nd new probe.\n");
1421 warn++;
1422 } else {
1423 file = find_trace_probe_file(tp, top_trace_array());
1424 if (WARN_ON_ONCE(file == NULL)) {
1425 pr_warn("error on getting probe file.\n");
1426 warn++;
1427 } else
1428 enable_trace_probe(tp, file);
1429 }
1430 }
1431
1432 if (warn)
1433 goto end;
1434
1435 ret = target(1, 2, 3, 4, 5, 6);
1436
1437 /* Disable trace points before removing it */
1438 tp = find_trace_probe("testprobe", KPROBE_EVENT_SYSTEM);
1439 if (WARN_ON_ONCE(tp == NULL)) {
1440 pr_warn("error on getting test probe.\n");
1441 warn++;
1442 } else {
1443 file = find_trace_probe_file(tp, top_trace_array());
1444 if (WARN_ON_ONCE(file == NULL)) {
1445 pr_warn("error on getting probe file.\n");
1446 warn++;
1447 } else
1448 disable_trace_probe(tp, file);
1449 }
1450
1451 tp = find_trace_probe("testprobe2", KPROBE_EVENT_SYSTEM);
1452 if (WARN_ON_ONCE(tp == NULL)) {
1453 pr_warn("error on getting 2nd test probe.\n");
1454 warn++;
1455 } else {
1456 file = find_trace_probe_file(tp, top_trace_array());
1457 if (WARN_ON_ONCE(file == NULL)) {
1458 pr_warn("error on getting probe file.\n");
1459 warn++;
1460 } else
1461 disable_trace_probe(tp, file);
1462 }
1463
1464 ret = traceprobe_command("-:testprobe", create_trace_probe);
1465 if (WARN_ON_ONCE(ret)) {
1466 pr_warn("error on deleting a probe.\n");
1467 warn++;
1468 }
1469
1470 ret = traceprobe_command("-:testprobe2", create_trace_probe);
1471 if (WARN_ON_ONCE(ret)) {
1472 pr_warn("error on deleting a probe.\n");
1473 warn++;
1474 }
1475
1476 end:
1477 release_all_trace_probes();
1478 if (warn)
1479 pr_cont("NG: Some tests are failed. Please check them.\n");
1480 else
1481 pr_cont("OK\n");
1482 return 0;
1483 }
1484
1485 late_initcall(kprobe_trace_self_tests_init);
1486
1487 #endif
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