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tracing: Remove duplicate id information in event structure
[deliverable/linux.git] / kernel / trace / trace_kprobe.c
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 #include <linux/kprobes.h>
23 #include <linux/seq_file.h>
24 #include <linux/slab.h>
25 #include <linux/smp.h>
26 #include <linux/debugfs.h>
27 #include <linux/types.h>
28 #include <linux/string.h>
29 #include <linux/ctype.h>
30 #include <linux/ptrace.h>
31 #include <linux/perf_event.h>
32
33 #include "trace.h"
34 #include "trace_output.h"
35
36 #define MAX_TRACE_ARGS 128
37 #define MAX_ARGSTR_LEN 63
38 #define MAX_EVENT_NAME_LEN 64
39 #define KPROBE_EVENT_SYSTEM "kprobes"
40
41 /* Reserved field names */
42 #define FIELD_STRING_IP "__probe_ip"
43 #define FIELD_STRING_NARGS "__probe_nargs"
44 #define FIELD_STRING_RETIP "__probe_ret_ip"
45 #define FIELD_STRING_FUNC "__probe_func"
46
47 const char *reserved_field_names[] = {
48 "common_type",
49 "common_flags",
50 "common_preempt_count",
51 "common_pid",
52 "common_tgid",
53 "common_lock_depth",
54 FIELD_STRING_IP,
55 FIELD_STRING_NARGS,
56 FIELD_STRING_RETIP,
57 FIELD_STRING_FUNC,
58 };
59
60 struct fetch_func {
61 unsigned long (*func)(struct pt_regs *, void *);
62 void *data;
63 };
64
65 static __kprobes unsigned long call_fetch(struct fetch_func *f,
66 struct pt_regs *regs)
67 {
68 return f->func(regs, f->data);
69 }
70
71 /* fetch handlers */
72 static __kprobes unsigned long fetch_register(struct pt_regs *regs,
73 void *offset)
74 {
75 return regs_get_register(regs, (unsigned int)((unsigned long)offset));
76 }
77
78 static __kprobes unsigned long fetch_stack(struct pt_regs *regs,
79 void *num)
80 {
81 return regs_get_kernel_stack_nth(regs,
82 (unsigned int)((unsigned long)num));
83 }
84
85 static __kprobes unsigned long fetch_memory(struct pt_regs *regs, void *addr)
86 {
87 unsigned long retval;
88
89 if (probe_kernel_address(addr, retval))
90 return 0;
91 return retval;
92 }
93
94 static __kprobes unsigned long fetch_retvalue(struct pt_regs *regs,
95 void *dummy)
96 {
97 return regs_return_value(regs);
98 }
99
100 static __kprobes unsigned long fetch_stack_address(struct pt_regs *regs,
101 void *dummy)
102 {
103 return kernel_stack_pointer(regs);
104 }
105
106 /* Memory fetching by symbol */
107 struct symbol_cache {
108 char *symbol;
109 long offset;
110 unsigned long addr;
111 };
112
113 static unsigned long update_symbol_cache(struct symbol_cache *sc)
114 {
115 sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol);
116 if (sc->addr)
117 sc->addr += sc->offset;
118 return sc->addr;
119 }
120
121 static void free_symbol_cache(struct symbol_cache *sc)
122 {
123 kfree(sc->symbol);
124 kfree(sc);
125 }
126
127 static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
128 {
129 struct symbol_cache *sc;
130
131 if (!sym || strlen(sym) == 0)
132 return NULL;
133 sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL);
134 if (!sc)
135 return NULL;
136
137 sc->symbol = kstrdup(sym, GFP_KERNEL);
138 if (!sc->symbol) {
139 kfree(sc);
140 return NULL;
141 }
142 sc->offset = offset;
143
144 update_symbol_cache(sc);
145 return sc;
146 }
147
148 static __kprobes unsigned long fetch_symbol(struct pt_regs *regs, void *data)
149 {
150 struct symbol_cache *sc = data;
151
152 if (sc->addr)
153 return fetch_memory(regs, (void *)sc->addr);
154 else
155 return 0;
156 }
157
158 /* Special indirect memory access interface */
159 struct indirect_fetch_data {
160 struct fetch_func orig;
161 long offset;
162 };
163
164 static __kprobes unsigned long fetch_indirect(struct pt_regs *regs, void *data)
165 {
166 struct indirect_fetch_data *ind = data;
167 unsigned long addr;
168
169 addr = call_fetch(&ind->orig, regs);
170 if (addr) {
171 addr += ind->offset;
172 return fetch_memory(regs, (void *)addr);
173 } else
174 return 0;
175 }
176
177 static __kprobes void free_indirect_fetch_data(struct indirect_fetch_data *data)
178 {
179 if (data->orig.func == fetch_indirect)
180 free_indirect_fetch_data(data->orig.data);
181 else if (data->orig.func == fetch_symbol)
182 free_symbol_cache(data->orig.data);
183 kfree(data);
184 }
185
186 /**
187 * Kprobe event core functions
188 */
189
190 struct probe_arg {
191 struct fetch_func fetch;
192 const char *name;
193 };
194
195 /* Flags for trace_probe */
196 #define TP_FLAG_TRACE 1
197 #define TP_FLAG_PROFILE 2
198
199 struct trace_probe {
200 struct list_head list;
201 struct kretprobe rp; /* Use rp.kp for kprobe use */
202 unsigned long nhit;
203 unsigned int flags; /* For TP_FLAG_* */
204 const char *symbol; /* symbol name */
205 struct ftrace_event_class class;
206 struct ftrace_event_call call;
207 unsigned int nr_args;
208 struct probe_arg args[];
209 };
210
211 #define SIZEOF_TRACE_PROBE(n) \
212 (offsetof(struct trace_probe, args) + \
213 (sizeof(struct probe_arg) * (n)))
214
215 static __kprobes int probe_is_return(struct trace_probe *tp)
216 {
217 return tp->rp.handler != NULL;
218 }
219
220 static __kprobes const char *probe_symbol(struct trace_probe *tp)
221 {
222 return tp->symbol ? tp->symbol : "unknown";
223 }
224
225 static int probe_arg_string(char *buf, size_t n, struct fetch_func *ff)
226 {
227 int ret = -EINVAL;
228
229 if (ff->func == fetch_register) {
230 const char *name;
231 name = regs_query_register_name((unsigned int)((long)ff->data));
232 ret = snprintf(buf, n, "%%%s", name);
233 } else if (ff->func == fetch_stack)
234 ret = snprintf(buf, n, "$stack%lu", (unsigned long)ff->data);
235 else if (ff->func == fetch_memory)
236 ret = snprintf(buf, n, "@0x%p", ff->data);
237 else if (ff->func == fetch_symbol) {
238 struct symbol_cache *sc = ff->data;
239 if (sc->offset)
240 ret = snprintf(buf, n, "@%s%+ld", sc->symbol,
241 sc->offset);
242 else
243 ret = snprintf(buf, n, "@%s", sc->symbol);
244 } else if (ff->func == fetch_retvalue)
245 ret = snprintf(buf, n, "$retval");
246 else if (ff->func == fetch_stack_address)
247 ret = snprintf(buf, n, "$stack");
248 else if (ff->func == fetch_indirect) {
249 struct indirect_fetch_data *id = ff->data;
250 size_t l = 0;
251 ret = snprintf(buf, n, "%+ld(", id->offset);
252 if (ret >= n)
253 goto end;
254 l += ret;
255 ret = probe_arg_string(buf + l, n - l, &id->orig);
256 if (ret < 0)
257 goto end;
258 l += ret;
259 ret = snprintf(buf + l, n - l, ")");
260 ret += l;
261 }
262 end:
263 if (ret >= n)
264 return -ENOSPC;
265 return ret;
266 }
267
268 static int register_probe_event(struct trace_probe *tp);
269 static void unregister_probe_event(struct trace_probe *tp);
270
271 static DEFINE_MUTEX(probe_lock);
272 static LIST_HEAD(probe_list);
273
274 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
275 static int kretprobe_dispatcher(struct kretprobe_instance *ri,
276 struct pt_regs *regs);
277
278 /* Check the name is good for event/group */
279 static int check_event_name(const char *name)
280 {
281 if (!isalpha(*name) && *name != '_')
282 return 0;
283 while (*++name != '\0') {
284 if (!isalpha(*name) && !isdigit(*name) && *name != '_')
285 return 0;
286 }
287 return 1;
288 }
289
290 /*
291 * Allocate new trace_probe and initialize it (including kprobes).
292 */
293 static struct trace_probe *alloc_trace_probe(const char *group,
294 const char *event,
295 void *addr,
296 const char *symbol,
297 unsigned long offs,
298 int nargs, int is_return)
299 {
300 struct trace_probe *tp;
301 int ret = -ENOMEM;
302
303 tp = kzalloc(SIZEOF_TRACE_PROBE(nargs), GFP_KERNEL);
304 if (!tp)
305 return ERR_PTR(ret);
306
307 if (symbol) {
308 tp->symbol = kstrdup(symbol, GFP_KERNEL);
309 if (!tp->symbol)
310 goto error;
311 tp->rp.kp.symbol_name = tp->symbol;
312 tp->rp.kp.offset = offs;
313 } else
314 tp->rp.kp.addr = addr;
315
316 if (is_return)
317 tp->rp.handler = kretprobe_dispatcher;
318 else
319 tp->rp.kp.pre_handler = kprobe_dispatcher;
320
321 if (!event || !check_event_name(event)) {
322 ret = -EINVAL;
323 goto error;
324 }
325
326 tp->call.class = &tp->class;
327 tp->call.name = kstrdup(event, GFP_KERNEL);
328 if (!tp->call.name)
329 goto error;
330
331 if (!group || !check_event_name(group)) {
332 ret = -EINVAL;
333 goto error;
334 }
335
336 tp->class.system = kstrdup(group, GFP_KERNEL);
337 if (!tp->class.system)
338 goto error;
339
340 INIT_LIST_HEAD(&tp->list);
341 return tp;
342 error:
343 kfree(tp->call.name);
344 kfree(tp->symbol);
345 kfree(tp);
346 return ERR_PTR(ret);
347 }
348
349 static void free_probe_arg(struct probe_arg *arg)
350 {
351 if (arg->fetch.func == fetch_symbol)
352 free_symbol_cache(arg->fetch.data);
353 else if (arg->fetch.func == fetch_indirect)
354 free_indirect_fetch_data(arg->fetch.data);
355 kfree(arg->name);
356 }
357
358 static void free_trace_probe(struct trace_probe *tp)
359 {
360 int i;
361
362 for (i = 0; i < tp->nr_args; i++)
363 free_probe_arg(&tp->args[i]);
364
365 kfree(tp->call.class->system);
366 kfree(tp->call.name);
367 kfree(tp->symbol);
368 kfree(tp);
369 }
370
371 static struct trace_probe *find_probe_event(const char *event,
372 const char *group)
373 {
374 struct trace_probe *tp;
375
376 list_for_each_entry(tp, &probe_list, list)
377 if (strcmp(tp->call.name, event) == 0 &&
378 strcmp(tp->call.class->system, group) == 0)
379 return tp;
380 return NULL;
381 }
382
383 /* Unregister a trace_probe and probe_event: call with locking probe_lock */
384 static void unregister_trace_probe(struct trace_probe *tp)
385 {
386 if (probe_is_return(tp))
387 unregister_kretprobe(&tp->rp);
388 else
389 unregister_kprobe(&tp->rp.kp);
390 list_del(&tp->list);
391 unregister_probe_event(tp);
392 }
393
394 /* Register a trace_probe and probe_event */
395 static int register_trace_probe(struct trace_probe *tp)
396 {
397 struct trace_probe *old_tp;
398 int ret;
399
400 mutex_lock(&probe_lock);
401
402 /* register as an event */
403 old_tp = find_probe_event(tp->call.name, tp->call.class->system);
404 if (old_tp) {
405 /* delete old event */
406 unregister_trace_probe(old_tp);
407 free_trace_probe(old_tp);
408 }
409 ret = register_probe_event(tp);
410 if (ret) {
411 pr_warning("Faild to register probe event(%d)\n", ret);
412 goto end;
413 }
414
415 tp->rp.kp.flags |= KPROBE_FLAG_DISABLED;
416 if (probe_is_return(tp))
417 ret = register_kretprobe(&tp->rp);
418 else
419 ret = register_kprobe(&tp->rp.kp);
420
421 if (ret) {
422 pr_warning("Could not insert probe(%d)\n", ret);
423 if (ret == -EILSEQ) {
424 pr_warning("Probing address(0x%p) is not an "
425 "instruction boundary.\n",
426 tp->rp.kp.addr);
427 ret = -EINVAL;
428 }
429 unregister_probe_event(tp);
430 } else
431 list_add_tail(&tp->list, &probe_list);
432 end:
433 mutex_unlock(&probe_lock);
434 return ret;
435 }
436
437 /* Split symbol and offset. */
438 static int split_symbol_offset(char *symbol, unsigned long *offset)
439 {
440 char *tmp;
441 int ret;
442
443 if (!offset)
444 return -EINVAL;
445
446 tmp = strchr(symbol, '+');
447 if (tmp) {
448 /* skip sign because strict_strtol doesn't accept '+' */
449 ret = strict_strtoul(tmp + 1, 0, offset);
450 if (ret)
451 return ret;
452 *tmp = '\0';
453 } else
454 *offset = 0;
455 return 0;
456 }
457
458 #define PARAM_MAX_ARGS 16
459 #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
460
461 static int parse_probe_vars(char *arg, struct fetch_func *ff, int is_return)
462 {
463 int ret = 0;
464 unsigned long param;
465
466 if (strcmp(arg, "retval") == 0) {
467 if (is_return) {
468 ff->func = fetch_retvalue;
469 ff->data = NULL;
470 } else
471 ret = -EINVAL;
472 } else if (strncmp(arg, "stack", 5) == 0) {
473 if (arg[5] == '\0') {
474 ff->func = fetch_stack_address;
475 ff->data = NULL;
476 } else if (isdigit(arg[5])) {
477 ret = strict_strtoul(arg + 5, 10, &param);
478 if (ret || param > PARAM_MAX_STACK)
479 ret = -EINVAL;
480 else {
481 ff->func = fetch_stack;
482 ff->data = (void *)param;
483 }
484 } else
485 ret = -EINVAL;
486 } else
487 ret = -EINVAL;
488 return ret;
489 }
490
491 /* Recursive argument parser */
492 static int __parse_probe_arg(char *arg, struct fetch_func *ff, int is_return)
493 {
494 int ret = 0;
495 unsigned long param;
496 long offset;
497 char *tmp;
498
499 switch (arg[0]) {
500 case '$':
501 ret = parse_probe_vars(arg + 1, ff, is_return);
502 break;
503 case '%': /* named register */
504 ret = regs_query_register_offset(arg + 1);
505 if (ret >= 0) {
506 ff->func = fetch_register;
507 ff->data = (void *)(unsigned long)ret;
508 ret = 0;
509 }
510 break;
511 case '@': /* memory or symbol */
512 if (isdigit(arg[1])) {
513 ret = strict_strtoul(arg + 1, 0, &param);
514 if (ret)
515 break;
516 ff->func = fetch_memory;
517 ff->data = (void *)param;
518 } else {
519 ret = split_symbol_offset(arg + 1, &offset);
520 if (ret)
521 break;
522 ff->data = alloc_symbol_cache(arg + 1, offset);
523 if (ff->data)
524 ff->func = fetch_symbol;
525 else
526 ret = -EINVAL;
527 }
528 break;
529 case '+': /* indirect memory */
530 case '-':
531 tmp = strchr(arg, '(');
532 if (!tmp) {
533 ret = -EINVAL;
534 break;
535 }
536 *tmp = '\0';
537 ret = strict_strtol(arg + 1, 0, &offset);
538 if (ret)
539 break;
540 if (arg[0] == '-')
541 offset = -offset;
542 arg = tmp + 1;
543 tmp = strrchr(arg, ')');
544 if (tmp) {
545 struct indirect_fetch_data *id;
546 *tmp = '\0';
547 id = kzalloc(sizeof(struct indirect_fetch_data),
548 GFP_KERNEL);
549 if (!id)
550 return -ENOMEM;
551 id->offset = offset;
552 ret = __parse_probe_arg(arg, &id->orig, is_return);
553 if (ret)
554 kfree(id);
555 else {
556 ff->func = fetch_indirect;
557 ff->data = (void *)id;
558 }
559 } else
560 ret = -EINVAL;
561 break;
562 default:
563 /* TODO: support custom handler */
564 ret = -EINVAL;
565 }
566 return ret;
567 }
568
569 /* String length checking wrapper */
570 static int parse_probe_arg(char *arg, struct fetch_func *ff, int is_return)
571 {
572 if (strlen(arg) > MAX_ARGSTR_LEN) {
573 pr_info("Argument is too long.: %s\n", arg);
574 return -ENOSPC;
575 }
576 return __parse_probe_arg(arg, ff, is_return);
577 }
578
579 /* Return 1 if name is reserved or already used by another argument */
580 static int conflict_field_name(const char *name,
581 struct probe_arg *args, int narg)
582 {
583 int i;
584 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
585 if (strcmp(reserved_field_names[i], name) == 0)
586 return 1;
587 for (i = 0; i < narg; i++)
588 if (strcmp(args[i].name, name) == 0)
589 return 1;
590 return 0;
591 }
592
593 static int create_trace_probe(int argc, char **argv)
594 {
595 /*
596 * Argument syntax:
597 * - Add kprobe: p[:[GRP/]EVENT] KSYM[+OFFS]|KADDR [FETCHARGS]
598 * - Add kretprobe: r[:[GRP/]EVENT] KSYM[+0] [FETCHARGS]
599 * Fetch args:
600 * $retval : fetch return value
601 * $stack : fetch stack address
602 * $stackN : fetch Nth of stack (N:0-)
603 * @ADDR : fetch memory at ADDR (ADDR should be in kernel)
604 * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
605 * %REG : fetch register REG
606 * Indirect memory fetch:
607 * +|-offs(ARG) : fetch memory at ARG +|- offs address.
608 * Alias name of args:
609 * NAME=FETCHARG : set NAME as alias of FETCHARG.
610 */
611 struct trace_probe *tp;
612 int i, ret = 0;
613 int is_return = 0, is_delete = 0;
614 char *symbol = NULL, *event = NULL, *arg = NULL, *group = NULL;
615 unsigned long offset = 0;
616 void *addr = NULL;
617 char buf[MAX_EVENT_NAME_LEN];
618
619 /* argc must be >= 1 */
620 if (argv[0][0] == 'p')
621 is_return = 0;
622 else if (argv[0][0] == 'r')
623 is_return = 1;
624 else if (argv[0][0] == '-')
625 is_delete = 1;
626 else {
627 pr_info("Probe definition must be started with 'p', 'r' or"
628 " '-'.\n");
629 return -EINVAL;
630 }
631
632 if (argv[0][1] == ':') {
633 event = &argv[0][2];
634 if (strchr(event, '/')) {
635 group = event;
636 event = strchr(group, '/') + 1;
637 event[-1] = '\0';
638 if (strlen(group) == 0) {
639 pr_info("Group name is not specified\n");
640 return -EINVAL;
641 }
642 }
643 if (strlen(event) == 0) {
644 pr_info("Event name is not specified\n");
645 return -EINVAL;
646 }
647 }
648 if (!group)
649 group = KPROBE_EVENT_SYSTEM;
650
651 if (is_delete) {
652 if (!event) {
653 pr_info("Delete command needs an event name.\n");
654 return -EINVAL;
655 }
656 tp = find_probe_event(event, group);
657 if (!tp) {
658 pr_info("Event %s/%s doesn't exist.\n", group, event);
659 return -ENOENT;
660 }
661 /* delete an event */
662 unregister_trace_probe(tp);
663 free_trace_probe(tp);
664 return 0;
665 }
666
667 if (argc < 2) {
668 pr_info("Probe point is not specified.\n");
669 return -EINVAL;
670 }
671 if (isdigit(argv[1][0])) {
672 if (is_return) {
673 pr_info("Return probe point must be a symbol.\n");
674 return -EINVAL;
675 }
676 /* an address specified */
677 ret = strict_strtoul(&argv[1][0], 0, (unsigned long *)&addr);
678 if (ret) {
679 pr_info("Failed to parse address.\n");
680 return ret;
681 }
682 } else {
683 /* a symbol specified */
684 symbol = argv[1];
685 /* TODO: support .init module functions */
686 ret = split_symbol_offset(symbol, &offset);
687 if (ret) {
688 pr_info("Failed to parse symbol.\n");
689 return ret;
690 }
691 if (offset && is_return) {
692 pr_info("Return probe must be used without offset.\n");
693 return -EINVAL;
694 }
695 }
696 argc -= 2; argv += 2;
697
698 /* setup a probe */
699 if (!event) {
700 /* Make a new event name */
701 if (symbol)
702 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
703 is_return ? 'r' : 'p', symbol, offset);
704 else
705 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
706 is_return ? 'r' : 'p', addr);
707 event = buf;
708 }
709 tp = alloc_trace_probe(group, event, addr, symbol, offset, argc,
710 is_return);
711 if (IS_ERR(tp)) {
712 pr_info("Failed to allocate trace_probe.(%d)\n",
713 (int)PTR_ERR(tp));
714 return PTR_ERR(tp);
715 }
716
717 /* parse arguments */
718 ret = 0;
719 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
720 /* Parse argument name */
721 arg = strchr(argv[i], '=');
722 if (arg)
723 *arg++ = '\0';
724 else
725 arg = argv[i];
726
727 if (conflict_field_name(argv[i], tp->args, i)) {
728 pr_info("Argument%d name '%s' conflicts with "
729 "another field.\n", i, argv[i]);
730 ret = -EINVAL;
731 goto error;
732 }
733
734 tp->args[i].name = kstrdup(argv[i], GFP_KERNEL);
735 if (!tp->args[i].name) {
736 pr_info("Failed to allocate argument%d name '%s'.\n",
737 i, argv[i]);
738 ret = -ENOMEM;
739 goto error;
740 }
741
742 /* Parse fetch argument */
743 ret = parse_probe_arg(arg, &tp->args[i].fetch, is_return);
744 if (ret) {
745 pr_info("Parse error at argument%d. (%d)\n", i, ret);
746 kfree(tp->args[i].name);
747 goto error;
748 }
749
750 tp->nr_args++;
751 }
752
753 ret = register_trace_probe(tp);
754 if (ret)
755 goto error;
756 return 0;
757
758 error:
759 free_trace_probe(tp);
760 return ret;
761 }
762
763 static void cleanup_all_probes(void)
764 {
765 struct trace_probe *tp;
766
767 mutex_lock(&probe_lock);
768 /* TODO: Use batch unregistration */
769 while (!list_empty(&probe_list)) {
770 tp = list_entry(probe_list.next, struct trace_probe, list);
771 unregister_trace_probe(tp);
772 free_trace_probe(tp);
773 }
774 mutex_unlock(&probe_lock);
775 }
776
777
778 /* Probes listing interfaces */
779 static void *probes_seq_start(struct seq_file *m, loff_t *pos)
780 {
781 mutex_lock(&probe_lock);
782 return seq_list_start(&probe_list, *pos);
783 }
784
785 static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
786 {
787 return seq_list_next(v, &probe_list, pos);
788 }
789
790 static void probes_seq_stop(struct seq_file *m, void *v)
791 {
792 mutex_unlock(&probe_lock);
793 }
794
795 static int probes_seq_show(struct seq_file *m, void *v)
796 {
797 struct trace_probe *tp = v;
798 int i, ret;
799 char buf[MAX_ARGSTR_LEN + 1];
800
801 seq_printf(m, "%c", probe_is_return(tp) ? 'r' : 'p');
802 seq_printf(m, ":%s/%s", tp->call.class->system, tp->call.name);
803
804 if (!tp->symbol)
805 seq_printf(m, " 0x%p", tp->rp.kp.addr);
806 else if (tp->rp.kp.offset)
807 seq_printf(m, " %s+%u", probe_symbol(tp), tp->rp.kp.offset);
808 else
809 seq_printf(m, " %s", probe_symbol(tp));
810
811 for (i = 0; i < tp->nr_args; i++) {
812 ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i].fetch);
813 if (ret < 0) {
814 pr_warning("Argument%d decoding error(%d).\n", i, ret);
815 return ret;
816 }
817 seq_printf(m, " %s=%s", tp->args[i].name, buf);
818 }
819 seq_printf(m, "\n");
820 return 0;
821 }
822
823 static const struct seq_operations probes_seq_op = {
824 .start = probes_seq_start,
825 .next = probes_seq_next,
826 .stop = probes_seq_stop,
827 .show = probes_seq_show
828 };
829
830 static int probes_open(struct inode *inode, struct file *file)
831 {
832 if ((file->f_mode & FMODE_WRITE) &&
833 (file->f_flags & O_TRUNC))
834 cleanup_all_probes();
835
836 return seq_open(file, &probes_seq_op);
837 }
838
839 static int command_trace_probe(const char *buf)
840 {
841 char **argv;
842 int argc = 0, ret = 0;
843
844 argv = argv_split(GFP_KERNEL, buf, &argc);
845 if (!argv)
846 return -ENOMEM;
847
848 if (argc)
849 ret = create_trace_probe(argc, argv);
850
851 argv_free(argv);
852 return ret;
853 }
854
855 #define WRITE_BUFSIZE 128
856
857 static ssize_t probes_write(struct file *file, const char __user *buffer,
858 size_t count, loff_t *ppos)
859 {
860 char *kbuf, *tmp;
861 int ret;
862 size_t done;
863 size_t size;
864
865 kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
866 if (!kbuf)
867 return -ENOMEM;
868
869 ret = done = 0;
870 while (done < count) {
871 size = count - done;
872 if (size >= WRITE_BUFSIZE)
873 size = WRITE_BUFSIZE - 1;
874 if (copy_from_user(kbuf, buffer + done, size)) {
875 ret = -EFAULT;
876 goto out;
877 }
878 kbuf[size] = '\0';
879 tmp = strchr(kbuf, '\n');
880 if (tmp) {
881 *tmp = '\0';
882 size = tmp - kbuf + 1;
883 } else if (done + size < count) {
884 pr_warning("Line length is too long: "
885 "Should be less than %d.", WRITE_BUFSIZE);
886 ret = -EINVAL;
887 goto out;
888 }
889 done += size;
890 /* Remove comments */
891 tmp = strchr(kbuf, '#');
892 if (tmp)
893 *tmp = '\0';
894
895 ret = command_trace_probe(kbuf);
896 if (ret)
897 goto out;
898 }
899 ret = done;
900 out:
901 kfree(kbuf);
902 return ret;
903 }
904
905 static const struct file_operations kprobe_events_ops = {
906 .owner = THIS_MODULE,
907 .open = probes_open,
908 .read = seq_read,
909 .llseek = seq_lseek,
910 .release = seq_release,
911 .write = probes_write,
912 };
913
914 /* Probes profiling interfaces */
915 static int probes_profile_seq_show(struct seq_file *m, void *v)
916 {
917 struct trace_probe *tp = v;
918
919 seq_printf(m, " %-44s %15lu %15lu\n", tp->call.name, tp->nhit,
920 tp->rp.kp.nmissed);
921
922 return 0;
923 }
924
925 static const struct seq_operations profile_seq_op = {
926 .start = probes_seq_start,
927 .next = probes_seq_next,
928 .stop = probes_seq_stop,
929 .show = probes_profile_seq_show
930 };
931
932 static int profile_open(struct inode *inode, struct file *file)
933 {
934 return seq_open(file, &profile_seq_op);
935 }
936
937 static const struct file_operations kprobe_profile_ops = {
938 .owner = THIS_MODULE,
939 .open = profile_open,
940 .read = seq_read,
941 .llseek = seq_lseek,
942 .release = seq_release,
943 };
944
945 /* Kprobe handler */
946 static __kprobes void kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
947 {
948 struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
949 struct kprobe_trace_entry *entry;
950 struct ring_buffer_event *event;
951 struct ring_buffer *buffer;
952 int size, i, pc;
953 unsigned long irq_flags;
954 struct ftrace_event_call *call = &tp->call;
955
956 tp->nhit++;
957
958 local_save_flags(irq_flags);
959 pc = preempt_count();
960
961 size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args);
962
963 event = trace_current_buffer_lock_reserve(&buffer, call->event.type,
964 size, irq_flags, pc);
965 if (!event)
966 return;
967
968 entry = ring_buffer_event_data(event);
969 entry->nargs = tp->nr_args;
970 entry->ip = (unsigned long)kp->addr;
971 for (i = 0; i < tp->nr_args; i++)
972 entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
973
974 if (!filter_current_check_discard(buffer, call, entry, event))
975 trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
976 }
977
978 /* Kretprobe handler */
979 static __kprobes void kretprobe_trace_func(struct kretprobe_instance *ri,
980 struct pt_regs *regs)
981 {
982 struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
983 struct kretprobe_trace_entry *entry;
984 struct ring_buffer_event *event;
985 struct ring_buffer *buffer;
986 int size, i, pc;
987 unsigned long irq_flags;
988 struct ftrace_event_call *call = &tp->call;
989
990 local_save_flags(irq_flags);
991 pc = preempt_count();
992
993 size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args);
994
995 event = trace_current_buffer_lock_reserve(&buffer, call->event.type,
996 size, irq_flags, pc);
997 if (!event)
998 return;
999
1000 entry = ring_buffer_event_data(event);
1001 entry->nargs = tp->nr_args;
1002 entry->func = (unsigned long)tp->rp.kp.addr;
1003 entry->ret_ip = (unsigned long)ri->ret_addr;
1004 for (i = 0; i < tp->nr_args; i++)
1005 entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
1006
1007 if (!filter_current_check_discard(buffer, call, entry, event))
1008 trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
1009 }
1010
1011 /* Event entry printers */
1012 enum print_line_t
1013 print_kprobe_event(struct trace_iterator *iter, int flags,
1014 struct trace_event *event)
1015 {
1016 struct kprobe_trace_entry *field;
1017 struct trace_seq *s = &iter->seq;
1018 struct trace_probe *tp;
1019 int i;
1020
1021 field = (struct kprobe_trace_entry *)iter->ent;
1022 tp = container_of(event, struct trace_probe, call.event);
1023
1024 if (!trace_seq_printf(s, "%s: (", tp->call.name))
1025 goto partial;
1026
1027 if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
1028 goto partial;
1029
1030 if (!trace_seq_puts(s, ")"))
1031 goto partial;
1032
1033 for (i = 0; i < field->nargs; i++)
1034 if (!trace_seq_printf(s, " %s=%lx",
1035 tp->args[i].name, field->args[i]))
1036 goto partial;
1037
1038 if (!trace_seq_puts(s, "\n"))
1039 goto partial;
1040
1041 return TRACE_TYPE_HANDLED;
1042 partial:
1043 return TRACE_TYPE_PARTIAL_LINE;
1044 }
1045
1046 enum print_line_t
1047 print_kretprobe_event(struct trace_iterator *iter, int flags,
1048 struct trace_event *event)
1049 {
1050 struct kretprobe_trace_entry *field;
1051 struct trace_seq *s = &iter->seq;
1052 struct trace_probe *tp;
1053 int i;
1054
1055 field = (struct kretprobe_trace_entry *)iter->ent;
1056 tp = container_of(event, struct trace_probe, call.event);
1057
1058 if (!trace_seq_printf(s, "%s: (", tp->call.name))
1059 goto partial;
1060
1061 if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
1062 goto partial;
1063
1064 if (!trace_seq_puts(s, " <- "))
1065 goto partial;
1066
1067 if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
1068 goto partial;
1069
1070 if (!trace_seq_puts(s, ")"))
1071 goto partial;
1072
1073 for (i = 0; i < field->nargs; i++)
1074 if (!trace_seq_printf(s, " %s=%lx",
1075 tp->args[i].name, field->args[i]))
1076 goto partial;
1077
1078 if (!trace_seq_puts(s, "\n"))
1079 goto partial;
1080
1081 return TRACE_TYPE_HANDLED;
1082 partial:
1083 return TRACE_TYPE_PARTIAL_LINE;
1084 }
1085
1086 static int probe_event_enable(struct ftrace_event_call *call)
1087 {
1088 struct trace_probe *tp = (struct trace_probe *)call->data;
1089
1090 tp->flags |= TP_FLAG_TRACE;
1091 if (probe_is_return(tp))
1092 return enable_kretprobe(&tp->rp);
1093 else
1094 return enable_kprobe(&tp->rp.kp);
1095 }
1096
1097 static void probe_event_disable(struct ftrace_event_call *call)
1098 {
1099 struct trace_probe *tp = (struct trace_probe *)call->data;
1100
1101 tp->flags &= ~TP_FLAG_TRACE;
1102 if (!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE))) {
1103 if (probe_is_return(tp))
1104 disable_kretprobe(&tp->rp);
1105 else
1106 disable_kprobe(&tp->rp.kp);
1107 }
1108 }
1109
1110 static int probe_event_raw_init(struct ftrace_event_call *event_call)
1111 {
1112 return 0;
1113 }
1114
1115 #undef DEFINE_FIELD
1116 #define DEFINE_FIELD(type, item, name, is_signed) \
1117 do { \
1118 ret = trace_define_field(event_call, #type, name, \
1119 offsetof(typeof(field), item), \
1120 sizeof(field.item), is_signed, \
1121 FILTER_OTHER); \
1122 if (ret) \
1123 return ret; \
1124 } while (0)
1125
1126 static int kprobe_event_define_fields(struct ftrace_event_call *event_call)
1127 {
1128 int ret, i;
1129 struct kprobe_trace_entry field;
1130 struct trace_probe *tp = (struct trace_probe *)event_call->data;
1131
1132 DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
1133 DEFINE_FIELD(int, nargs, FIELD_STRING_NARGS, 1);
1134 /* Set argument names as fields */
1135 for (i = 0; i < tp->nr_args; i++)
1136 DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0);
1137 return 0;
1138 }
1139
1140 static int kretprobe_event_define_fields(struct ftrace_event_call *event_call)
1141 {
1142 int ret, i;
1143 struct kretprobe_trace_entry field;
1144 struct trace_probe *tp = (struct trace_probe *)event_call->data;
1145
1146 DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
1147 DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
1148 DEFINE_FIELD(int, nargs, FIELD_STRING_NARGS, 1);
1149 /* Set argument names as fields */
1150 for (i = 0; i < tp->nr_args; i++)
1151 DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0);
1152 return 0;
1153 }
1154
1155 static int __set_print_fmt(struct trace_probe *tp, char *buf, int len)
1156 {
1157 int i;
1158 int pos = 0;
1159
1160 const char *fmt, *arg;
1161
1162 if (!probe_is_return(tp)) {
1163 fmt = "(%lx)";
1164 arg = "REC->" FIELD_STRING_IP;
1165 } else {
1166 fmt = "(%lx <- %lx)";
1167 arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
1168 }
1169
1170 /* When len=0, we just calculate the needed length */
1171 #define LEN_OR_ZERO (len ? len - pos : 0)
1172
1173 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
1174
1175 for (i = 0; i < tp->nr_args; i++) {
1176 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%%lx",
1177 tp->args[i].name);
1178 }
1179
1180 pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
1181
1182 for (i = 0; i < tp->nr_args; i++) {
1183 pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
1184 tp->args[i].name);
1185 }
1186
1187 #undef LEN_OR_ZERO
1188
1189 /* return the length of print_fmt */
1190 return pos;
1191 }
1192
1193 static int set_print_fmt(struct trace_probe *tp)
1194 {
1195 int len;
1196 char *print_fmt;
1197
1198 /* First: called with 0 length to calculate the needed length */
1199 len = __set_print_fmt(tp, NULL, 0);
1200 print_fmt = kmalloc(len + 1, GFP_KERNEL);
1201 if (!print_fmt)
1202 return -ENOMEM;
1203
1204 /* Second: actually write the @print_fmt */
1205 __set_print_fmt(tp, print_fmt, len + 1);
1206 tp->call.print_fmt = print_fmt;
1207
1208 return 0;
1209 }
1210
1211 #ifdef CONFIG_PERF_EVENTS
1212
1213 /* Kprobe profile handler */
1214 static __kprobes void kprobe_perf_func(struct kprobe *kp,
1215 struct pt_regs *regs)
1216 {
1217 struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
1218 struct ftrace_event_call *call = &tp->call;
1219 struct kprobe_trace_entry *entry;
1220 int size, __size, i;
1221 unsigned long irq_flags;
1222 int rctx;
1223
1224 __size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args);
1225 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1226 size -= sizeof(u32);
1227 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
1228 "profile buffer not large enough"))
1229 return;
1230
1231 entry = perf_trace_buf_prepare(size, call->event.type,
1232 &rctx, &irq_flags);
1233 if (!entry)
1234 return;
1235
1236 entry->nargs = tp->nr_args;
1237 entry->ip = (unsigned long)kp->addr;
1238 for (i = 0; i < tp->nr_args; i++)
1239 entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
1240
1241 perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, irq_flags, regs);
1242 }
1243
1244 /* Kretprobe profile handler */
1245 static __kprobes void kretprobe_perf_func(struct kretprobe_instance *ri,
1246 struct pt_regs *regs)
1247 {
1248 struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
1249 struct ftrace_event_call *call = &tp->call;
1250 struct kretprobe_trace_entry *entry;
1251 int size, __size, i;
1252 unsigned long irq_flags;
1253 int rctx;
1254
1255 __size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args);
1256 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1257 size -= sizeof(u32);
1258 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
1259 "profile buffer not large enough"))
1260 return;
1261
1262 entry = perf_trace_buf_prepare(size, call->event.type,
1263 &rctx, &irq_flags);
1264 if (!entry)
1265 return;
1266
1267 entry->nargs = tp->nr_args;
1268 entry->func = (unsigned long)tp->rp.kp.addr;
1269 entry->ret_ip = (unsigned long)ri->ret_addr;
1270 for (i = 0; i < tp->nr_args; i++)
1271 entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
1272
1273 perf_trace_buf_submit(entry, size, rctx, entry->ret_ip, 1,
1274 irq_flags, regs);
1275 }
1276
1277 static int probe_perf_enable(struct ftrace_event_call *call)
1278 {
1279 struct trace_probe *tp = (struct trace_probe *)call->data;
1280
1281 tp->flags |= TP_FLAG_PROFILE;
1282
1283 if (probe_is_return(tp))
1284 return enable_kretprobe(&tp->rp);
1285 else
1286 return enable_kprobe(&tp->rp.kp);
1287 }
1288
1289 static void probe_perf_disable(struct ftrace_event_call *call)
1290 {
1291 struct trace_probe *tp = (struct trace_probe *)call->data;
1292
1293 tp->flags &= ~TP_FLAG_PROFILE;
1294
1295 if (!(tp->flags & TP_FLAG_TRACE)) {
1296 if (probe_is_return(tp))
1297 disable_kretprobe(&tp->rp);
1298 else
1299 disable_kprobe(&tp->rp.kp);
1300 }
1301 }
1302 #endif /* CONFIG_PERF_EVENTS */
1303
1304 static __kprobes
1305 int kprobe_register(struct ftrace_event_call *event, enum trace_reg type)
1306 {
1307 switch (type) {
1308 case TRACE_REG_REGISTER:
1309 return probe_event_enable(event);
1310 case TRACE_REG_UNREGISTER:
1311 probe_event_disable(event);
1312 return 0;
1313
1314 #ifdef CONFIG_PERF_EVENTS
1315 case TRACE_REG_PERF_REGISTER:
1316 return probe_perf_enable(event);
1317 case TRACE_REG_PERF_UNREGISTER:
1318 probe_perf_disable(event);
1319 return 0;
1320 #endif
1321 }
1322 return 0;
1323 }
1324
1325 static __kprobes
1326 int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1327 {
1328 struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
1329
1330 if (tp->flags & TP_FLAG_TRACE)
1331 kprobe_trace_func(kp, regs);
1332 #ifdef CONFIG_PERF_EVENTS
1333 if (tp->flags & TP_FLAG_PROFILE)
1334 kprobe_perf_func(kp, regs);
1335 #endif
1336 return 0; /* We don't tweek kernel, so just return 0 */
1337 }
1338
1339 static __kprobes
1340 int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1341 {
1342 struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
1343
1344 if (tp->flags & TP_FLAG_TRACE)
1345 kretprobe_trace_func(ri, regs);
1346 #ifdef CONFIG_PERF_EVENTS
1347 if (tp->flags & TP_FLAG_PROFILE)
1348 kretprobe_perf_func(ri, regs);
1349 #endif
1350 return 0; /* We don't tweek kernel, so just return 0 */
1351 }
1352
1353 static struct trace_event_functions kretprobe_funcs = {
1354 .trace = print_kretprobe_event
1355 };
1356
1357 static struct trace_event_functions kprobe_funcs = {
1358 .trace = print_kprobe_event
1359 };
1360
1361 static int register_probe_event(struct trace_probe *tp)
1362 {
1363 struct ftrace_event_call *call = &tp->call;
1364 int ret;
1365
1366 /* Initialize ftrace_event_call */
1367 if (probe_is_return(tp)) {
1368 INIT_LIST_HEAD(&call->class->fields);
1369 call->event.funcs = &kretprobe_funcs;
1370 call->class->raw_init = probe_event_raw_init;
1371 call->class->define_fields = kretprobe_event_define_fields;
1372 } else {
1373 INIT_LIST_HEAD(&call->class->fields);
1374 call->event.funcs = &kprobe_funcs;
1375 call->class->raw_init = probe_event_raw_init;
1376 call->class->define_fields = kprobe_event_define_fields;
1377 }
1378 if (set_print_fmt(tp) < 0)
1379 return -ENOMEM;
1380 ret = register_ftrace_event(&call->event);
1381 if (!ret) {
1382 kfree(call->print_fmt);
1383 return -ENODEV;
1384 }
1385 call->enabled = 0;
1386 call->class->reg = kprobe_register;
1387 call->data = tp;
1388 ret = trace_add_event_call(call);
1389 if (ret) {
1390 pr_info("Failed to register kprobe event: %s\n", call->name);
1391 kfree(call->print_fmt);
1392 unregister_ftrace_event(&call->event);
1393 }
1394 return ret;
1395 }
1396
1397 static void unregister_probe_event(struct trace_probe *tp)
1398 {
1399 /* tp->event is unregistered in trace_remove_event_call() */
1400 trace_remove_event_call(&tp->call);
1401 kfree(tp->call.print_fmt);
1402 }
1403
1404 /* Make a debugfs interface for controling probe points */
1405 static __init int init_kprobe_trace(void)
1406 {
1407 struct dentry *d_tracer;
1408 struct dentry *entry;
1409
1410 d_tracer = tracing_init_dentry();
1411 if (!d_tracer)
1412 return 0;
1413
1414 entry = debugfs_create_file("kprobe_events", 0644, d_tracer,
1415 NULL, &kprobe_events_ops);
1416
1417 /* Event list interface */
1418 if (!entry)
1419 pr_warning("Could not create debugfs "
1420 "'kprobe_events' entry\n");
1421
1422 /* Profile interface */
1423 entry = debugfs_create_file("kprobe_profile", 0444, d_tracer,
1424 NULL, &kprobe_profile_ops);
1425
1426 if (!entry)
1427 pr_warning("Could not create debugfs "
1428 "'kprobe_profile' entry\n");
1429 return 0;
1430 }
1431 fs_initcall(init_kprobe_trace);
1432
1433
1434 #ifdef CONFIG_FTRACE_STARTUP_TEST
1435
1436 static int kprobe_trace_selftest_target(int a1, int a2, int a3,
1437 int a4, int a5, int a6)
1438 {
1439 return a1 + a2 + a3 + a4 + a5 + a6;
1440 }
1441
1442 static __init int kprobe_trace_self_tests_init(void)
1443 {
1444 int ret, warn = 0;
1445 int (*target)(int, int, int, int, int, int);
1446 struct trace_probe *tp;
1447
1448 target = kprobe_trace_selftest_target;
1449
1450 pr_info("Testing kprobe tracing: ");
1451
1452 ret = command_trace_probe("p:testprobe kprobe_trace_selftest_target "
1453 "$stack $stack0 +0($stack)");
1454 if (WARN_ON_ONCE(ret)) {
1455 pr_warning("error on probing function entry.\n");
1456 warn++;
1457 } else {
1458 /* Enable trace point */
1459 tp = find_probe_event("testprobe", KPROBE_EVENT_SYSTEM);
1460 if (WARN_ON_ONCE(tp == NULL)) {
1461 pr_warning("error on getting new probe.\n");
1462 warn++;
1463 } else
1464 probe_event_enable(&tp->call);
1465 }
1466
1467 ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target "
1468 "$retval");
1469 if (WARN_ON_ONCE(ret)) {
1470 pr_warning("error on probing function return.\n");
1471 warn++;
1472 } else {
1473 /* Enable trace point */
1474 tp = find_probe_event("testprobe2", KPROBE_EVENT_SYSTEM);
1475 if (WARN_ON_ONCE(tp == NULL)) {
1476 pr_warning("error on getting new probe.\n");
1477 warn++;
1478 } else
1479 probe_event_enable(&tp->call);
1480 }
1481
1482 if (warn)
1483 goto end;
1484
1485 ret = target(1, 2, 3, 4, 5, 6);
1486
1487 ret = command_trace_probe("-:testprobe");
1488 if (WARN_ON_ONCE(ret)) {
1489 pr_warning("error on deleting a probe.\n");
1490 warn++;
1491 }
1492
1493 ret = command_trace_probe("-:testprobe2");
1494 if (WARN_ON_ONCE(ret)) {
1495 pr_warning("error on deleting a probe.\n");
1496 warn++;
1497 }
1498
1499 end:
1500 cleanup_all_probes();
1501 if (warn)
1502 pr_cont("NG: Some tests are failed. Please check them.\n");
1503 else
1504 pr_cont("OK\n");
1505 return 0;
1506 }
1507
1508 late_initcall(kprobe_trace_self_tests_init);
1509
1510 #endif
Linux kernel - Deliverables
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