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Merge branch 'tip/tracing/core' of git://git.kernel.org/pub/scm/linux/kernel/git...
[mirror_ubuntu-artful-kernel.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_argument(struct pt_regs *regs, void *num)
95 {
96 return regs_get_argument_nth(regs, (unsigned int)((unsigned long)num));
97 }
98
99 static __kprobes unsigned long fetch_retvalue(struct pt_regs *regs,
100 void *dummy)
101 {
102 return regs_return_value(regs);
103 }
104
105 static __kprobes unsigned long fetch_stack_address(struct pt_regs *regs,
106 void *dummy)
107 {
108 return kernel_stack_pointer(regs);
109 }
110
111 /* Memory fetching by symbol */
112 struct symbol_cache {
113 char *symbol;
114 long offset;
115 unsigned long addr;
116 };
117
118 static unsigned long update_symbol_cache(struct symbol_cache *sc)
119 {
120 sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol);
121 if (sc->addr)
122 sc->addr += sc->offset;
123 return sc->addr;
124 }
125
126 static void free_symbol_cache(struct symbol_cache *sc)
127 {
128 kfree(sc->symbol);
129 kfree(sc);
130 }
131
132 static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
133 {
134 struct symbol_cache *sc;
135
136 if (!sym || strlen(sym) == 0)
137 return NULL;
138 sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL);
139 if (!sc)
140 return NULL;
141
142 sc->symbol = kstrdup(sym, GFP_KERNEL);
143 if (!sc->symbol) {
144 kfree(sc);
145 return NULL;
146 }
147 sc->offset = offset;
148
149 update_symbol_cache(sc);
150 return sc;
151 }
152
153 static __kprobes unsigned long fetch_symbol(struct pt_regs *regs, void *data)
154 {
155 struct symbol_cache *sc = data;
156
157 if (sc->addr)
158 return fetch_memory(regs, (void *)sc->addr);
159 else
160 return 0;
161 }
162
163 /* Special indirect memory access interface */
164 struct indirect_fetch_data {
165 struct fetch_func orig;
166 long offset;
167 };
168
169 static __kprobes unsigned long fetch_indirect(struct pt_regs *regs, void *data)
170 {
171 struct indirect_fetch_data *ind = data;
172 unsigned long addr;
173
174 addr = call_fetch(&ind->orig, regs);
175 if (addr) {
176 addr += ind->offset;
177 return fetch_memory(regs, (void *)addr);
178 } else
179 return 0;
180 }
181
182 static __kprobes void free_indirect_fetch_data(struct indirect_fetch_data *data)
183 {
184 if (data->orig.func == fetch_indirect)
185 free_indirect_fetch_data(data->orig.data);
186 else if (data->orig.func == fetch_symbol)
187 free_symbol_cache(data->orig.data);
188 kfree(data);
189 }
190
191 /**
192 * Kprobe event core functions
193 */
194
195 struct probe_arg {
196 struct fetch_func fetch;
197 const char *name;
198 };
199
200 /* Flags for trace_probe */
201 #define TP_FLAG_TRACE 1
202 #define TP_FLAG_PROFILE 2
203
204 struct trace_probe {
205 struct list_head list;
206 struct kretprobe rp; /* Use rp.kp for kprobe use */
207 unsigned long nhit;
208 unsigned int flags; /* For TP_FLAG_* */
209 const char *symbol; /* symbol name */
210 struct ftrace_event_call call;
211 struct trace_event event;
212 unsigned int nr_args;
213 struct probe_arg args[];
214 };
215
216 #define SIZEOF_TRACE_PROBE(n) \
217 (offsetof(struct trace_probe, args) + \
218 (sizeof(struct probe_arg) * (n)))
219
220 static __kprobes int probe_is_return(struct trace_probe *tp)
221 {
222 return tp->rp.handler != NULL;
223 }
224
225 static __kprobes const char *probe_symbol(struct trace_probe *tp)
226 {
227 return tp->symbol ? tp->symbol : "unknown";
228 }
229
230 static int probe_arg_string(char *buf, size_t n, struct fetch_func *ff)
231 {
232 int ret = -EINVAL;
233
234 if (ff->func == fetch_argument)
235 ret = snprintf(buf, n, "$arg%lu", (unsigned long)ff->data);
236 else if (ff->func == fetch_register) {
237 const char *name;
238 name = regs_query_register_name((unsigned int)((long)ff->data));
239 ret = snprintf(buf, n, "%%%s", name);
240 } else if (ff->func == fetch_stack)
241 ret = snprintf(buf, n, "$stack%lu", (unsigned long)ff->data);
242 else if (ff->func == fetch_memory)
243 ret = snprintf(buf, n, "@0x%p", ff->data);
244 else if (ff->func == fetch_symbol) {
245 struct symbol_cache *sc = ff->data;
246 if (sc->offset)
247 ret = snprintf(buf, n, "@%s%+ld", sc->symbol,
248 sc->offset);
249 else
250 ret = snprintf(buf, n, "@%s", sc->symbol);
251 } else if (ff->func == fetch_retvalue)
252 ret = snprintf(buf, n, "$retval");
253 else if (ff->func == fetch_stack_address)
254 ret = snprintf(buf, n, "$stack");
255 else if (ff->func == fetch_indirect) {
256 struct indirect_fetch_data *id = ff->data;
257 size_t l = 0;
258 ret = snprintf(buf, n, "%+ld(", id->offset);
259 if (ret >= n)
260 goto end;
261 l += ret;
262 ret = probe_arg_string(buf + l, n - l, &id->orig);
263 if (ret < 0)
264 goto end;
265 l += ret;
266 ret = snprintf(buf + l, n - l, ")");
267 ret += l;
268 }
269 end:
270 if (ret >= n)
271 return -ENOSPC;
272 return ret;
273 }
274
275 static int register_probe_event(struct trace_probe *tp);
276 static void unregister_probe_event(struct trace_probe *tp);
277
278 static DEFINE_MUTEX(probe_lock);
279 static LIST_HEAD(probe_list);
280
281 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
282 static int kretprobe_dispatcher(struct kretprobe_instance *ri,
283 struct pt_regs *regs);
284
285 /* Check the name is good for event/group */
286 static int check_event_name(const char *name)
287 {
288 if (!isalpha(*name) && *name != '_')
289 return 0;
290 while (*++name != '\0') {
291 if (!isalpha(*name) && !isdigit(*name) && *name != '_')
292 return 0;
293 }
294 return 1;
295 }
296
297 /*
298 * Allocate new trace_probe and initialize it (including kprobes).
299 */
300 static struct trace_probe *alloc_trace_probe(const char *group,
301 const char *event,
302 void *addr,
303 const char *symbol,
304 unsigned long offs,
305 int nargs, int is_return)
306 {
307 struct trace_probe *tp;
308 int ret = -ENOMEM;
309
310 tp = kzalloc(SIZEOF_TRACE_PROBE(nargs), GFP_KERNEL);
311 if (!tp)
312 return ERR_PTR(ret);
313
314 if (symbol) {
315 tp->symbol = kstrdup(symbol, GFP_KERNEL);
316 if (!tp->symbol)
317 goto error;
318 tp->rp.kp.symbol_name = tp->symbol;
319 tp->rp.kp.offset = offs;
320 } else
321 tp->rp.kp.addr = addr;
322
323 if (is_return)
324 tp->rp.handler = kretprobe_dispatcher;
325 else
326 tp->rp.kp.pre_handler = kprobe_dispatcher;
327
328 if (!event || !check_event_name(event)) {
329 ret = -EINVAL;
330 goto error;
331 }
332
333 tp->call.name = kstrdup(event, GFP_KERNEL);
334 if (!tp->call.name)
335 goto error;
336
337 if (!group || !check_event_name(group)) {
338 ret = -EINVAL;
339 goto error;
340 }
341
342 tp->call.system = kstrdup(group, GFP_KERNEL);
343 if (!tp->call.system)
344 goto error;
345
346 INIT_LIST_HEAD(&tp->list);
347 return tp;
348 error:
349 kfree(tp->call.name);
350 kfree(tp->symbol);
351 kfree(tp);
352 return ERR_PTR(ret);
353 }
354
355 static void free_probe_arg(struct probe_arg *arg)
356 {
357 if (arg->fetch.func == fetch_symbol)
358 free_symbol_cache(arg->fetch.data);
359 else if (arg->fetch.func == fetch_indirect)
360 free_indirect_fetch_data(arg->fetch.data);
361 kfree(arg->name);
362 }
363
364 static void free_trace_probe(struct trace_probe *tp)
365 {
366 int i;
367
368 for (i = 0; i < tp->nr_args; i++)
369 free_probe_arg(&tp->args[i]);
370
371 kfree(tp->call.system);
372 kfree(tp->call.name);
373 kfree(tp->symbol);
374 kfree(tp);
375 }
376
377 static struct trace_probe *find_probe_event(const char *event,
378 const char *group)
379 {
380 struct trace_probe *tp;
381
382 list_for_each_entry(tp, &probe_list, list)
383 if (strcmp(tp->call.name, event) == 0 &&
384 strcmp(tp->call.system, group) == 0)
385 return tp;
386 return NULL;
387 }
388
389 /* Unregister a trace_probe and probe_event: call with locking probe_lock */
390 static void unregister_trace_probe(struct trace_probe *tp)
391 {
392 if (probe_is_return(tp))
393 unregister_kretprobe(&tp->rp);
394 else
395 unregister_kprobe(&tp->rp.kp);
396 list_del(&tp->list);
397 unregister_probe_event(tp);
398 }
399
400 /* Register a trace_probe and probe_event */
401 static int register_trace_probe(struct trace_probe *tp)
402 {
403 struct trace_probe *old_tp;
404 int ret;
405
406 mutex_lock(&probe_lock);
407
408 /* register as an event */
409 old_tp = find_probe_event(tp->call.name, tp->call.system);
410 if (old_tp) {
411 /* delete old event */
412 unregister_trace_probe(old_tp);
413 free_trace_probe(old_tp);
414 }
415 ret = register_probe_event(tp);
416 if (ret) {
417 pr_warning("Faild to register probe event(%d)\n", ret);
418 goto end;
419 }
420
421 tp->rp.kp.flags |= KPROBE_FLAG_DISABLED;
422 if (probe_is_return(tp))
423 ret = register_kretprobe(&tp->rp);
424 else
425 ret = register_kprobe(&tp->rp.kp);
426
427 if (ret) {
428 pr_warning("Could not insert probe(%d)\n", ret);
429 if (ret == -EILSEQ) {
430 pr_warning("Probing address(0x%p) is not an "
431 "instruction boundary.\n",
432 tp->rp.kp.addr);
433 ret = -EINVAL;
434 }
435 unregister_probe_event(tp);
436 } else
437 list_add_tail(&tp->list, &probe_list);
438 end:
439 mutex_unlock(&probe_lock);
440 return ret;
441 }
442
443 /* Split symbol and offset. */
444 static int split_symbol_offset(char *symbol, unsigned long *offset)
445 {
446 char *tmp;
447 int ret;
448
449 if (!offset)
450 return -EINVAL;
451
452 tmp = strchr(symbol, '+');
453 if (tmp) {
454 /* skip sign because strict_strtol doesn't accept '+' */
455 ret = strict_strtoul(tmp + 1, 0, offset);
456 if (ret)
457 return ret;
458 *tmp = '\0';
459 } else
460 *offset = 0;
461 return 0;
462 }
463
464 #define PARAM_MAX_ARGS 16
465 #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
466
467 static int parse_probe_vars(char *arg, struct fetch_func *ff, int is_return)
468 {
469 int ret = 0;
470 unsigned long param;
471
472 if (strcmp(arg, "retval") == 0) {
473 if (is_return) {
474 ff->func = fetch_retvalue;
475 ff->data = NULL;
476 } else
477 ret = -EINVAL;
478 } else if (strncmp(arg, "stack", 5) == 0) {
479 if (arg[5] == '\0') {
480 ff->func = fetch_stack_address;
481 ff->data = NULL;
482 } else if (isdigit(arg[5])) {
483 ret = strict_strtoul(arg + 5, 10, &param);
484 if (ret || param > PARAM_MAX_STACK)
485 ret = -EINVAL;
486 else {
487 ff->func = fetch_stack;
488 ff->data = (void *)param;
489 }
490 } else
491 ret = -EINVAL;
492 } else if (strncmp(arg, "arg", 3) == 0 && isdigit(arg[3])) {
493 ret = strict_strtoul(arg + 3, 10, &param);
494 if (ret || param > PARAM_MAX_ARGS)
495 ret = -EINVAL;
496 else {
497 ff->func = fetch_argument;
498 ff->data = (void *)param;
499 }
500 } else
501 ret = -EINVAL;
502 return ret;
503 }
504
505 /* Recursive argument parser */
506 static int __parse_probe_arg(char *arg, struct fetch_func *ff, int is_return)
507 {
508 int ret = 0;
509 unsigned long param;
510 long offset;
511 char *tmp;
512
513 switch (arg[0]) {
514 case '$':
515 ret = parse_probe_vars(arg + 1, ff, is_return);
516 break;
517 case '%': /* named register */
518 ret = regs_query_register_offset(arg + 1);
519 if (ret >= 0) {
520 ff->func = fetch_register;
521 ff->data = (void *)(unsigned long)ret;
522 ret = 0;
523 }
524 break;
525 case '@': /* memory or symbol */
526 if (isdigit(arg[1])) {
527 ret = strict_strtoul(arg + 1, 0, &param);
528 if (ret)
529 break;
530 ff->func = fetch_memory;
531 ff->data = (void *)param;
532 } else {
533 ret = split_symbol_offset(arg + 1, &offset);
534 if (ret)
535 break;
536 ff->data = alloc_symbol_cache(arg + 1, offset);
537 if (ff->data)
538 ff->func = fetch_symbol;
539 else
540 ret = -EINVAL;
541 }
542 break;
543 case '+': /* indirect memory */
544 case '-':
545 tmp = strchr(arg, '(');
546 if (!tmp) {
547 ret = -EINVAL;
548 break;
549 }
550 *tmp = '\0';
551 ret = strict_strtol(arg + 1, 0, &offset);
552 if (ret)
553 break;
554 if (arg[0] == '-')
555 offset = -offset;
556 arg = tmp + 1;
557 tmp = strrchr(arg, ')');
558 if (tmp) {
559 struct indirect_fetch_data *id;
560 *tmp = '\0';
561 id = kzalloc(sizeof(struct indirect_fetch_data),
562 GFP_KERNEL);
563 if (!id)
564 return -ENOMEM;
565 id->offset = offset;
566 ret = __parse_probe_arg(arg, &id->orig, is_return);
567 if (ret)
568 kfree(id);
569 else {
570 ff->func = fetch_indirect;
571 ff->data = (void *)id;
572 }
573 } else
574 ret = -EINVAL;
575 break;
576 default:
577 /* TODO: support custom handler */
578 ret = -EINVAL;
579 }
580 return ret;
581 }
582
583 /* String length checking wrapper */
584 static int parse_probe_arg(char *arg, struct fetch_func *ff, int is_return)
585 {
586 if (strlen(arg) > MAX_ARGSTR_LEN) {
587 pr_info("Argument is too long.: %s\n", arg);
588 return -ENOSPC;
589 }
590 return __parse_probe_arg(arg, ff, is_return);
591 }
592
593 /* Return 1 if name is reserved or already used by another argument */
594 static int conflict_field_name(const char *name,
595 struct probe_arg *args, int narg)
596 {
597 int i;
598 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
599 if (strcmp(reserved_field_names[i], name) == 0)
600 return 1;
601 for (i = 0; i < narg; i++)
602 if (strcmp(args[i].name, name) == 0)
603 return 1;
604 return 0;
605 }
606
607 static int create_trace_probe(int argc, char **argv)
608 {
609 /*
610 * Argument syntax:
611 * - Add kprobe: p[:[GRP/]EVENT] KSYM[+OFFS]|KADDR [FETCHARGS]
612 * - Add kretprobe: r[:[GRP/]EVENT] KSYM[+0] [FETCHARGS]
613 * Fetch args:
614 * $argN : fetch Nth of function argument. (N:0-)
615 * $retval : fetch return value
616 * $stack : fetch stack address
617 * $stackN : fetch Nth of stack (N:0-)
618 * @ADDR : fetch memory at ADDR (ADDR should be in kernel)
619 * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
620 * %REG : fetch register REG
621 * Indirect memory fetch:
622 * +|-offs(ARG) : fetch memory at ARG +|- offs address.
623 * Alias name of args:
624 * NAME=FETCHARG : set NAME as alias of FETCHARG.
625 */
626 struct trace_probe *tp;
627 int i, ret = 0;
628 int is_return = 0, is_delete = 0;
629 char *symbol = NULL, *event = NULL, *arg = NULL, *group = NULL;
630 unsigned long offset = 0;
631 void *addr = NULL;
632 char buf[MAX_EVENT_NAME_LEN];
633
634 /* argc must be >= 1 */
635 if (argv[0][0] == 'p')
636 is_return = 0;
637 else if (argv[0][0] == 'r')
638 is_return = 1;
639 else if (argv[0][0] == '-')
640 is_delete = 1;
641 else {
642 pr_info("Probe definition must be started with 'p', 'r' or"
643 " '-'.\n");
644 return -EINVAL;
645 }
646
647 if (argv[0][1] == ':') {
648 event = &argv[0][2];
649 if (strchr(event, '/')) {
650 group = event;
651 event = strchr(group, '/') + 1;
652 event[-1] = '\0';
653 if (strlen(group) == 0) {
654 pr_info("Group name is not specified\n");
655 return -EINVAL;
656 }
657 }
658 if (strlen(event) == 0) {
659 pr_info("Event name is not specified\n");
660 return -EINVAL;
661 }
662 }
663 if (!group)
664 group = KPROBE_EVENT_SYSTEM;
665
666 if (is_delete) {
667 if (!event) {
668 pr_info("Delete command needs an event name.\n");
669 return -EINVAL;
670 }
671 tp = find_probe_event(event, group);
672 if (!tp) {
673 pr_info("Event %s/%s doesn't exist.\n", group, event);
674 return -ENOENT;
675 }
676 /* delete an event */
677 unregister_trace_probe(tp);
678 free_trace_probe(tp);
679 return 0;
680 }
681
682 if (argc < 2) {
683 pr_info("Probe point is not specified.\n");
684 return -EINVAL;
685 }
686 if (isdigit(argv[1][0])) {
687 if (is_return) {
688 pr_info("Return probe point must be a symbol.\n");
689 return -EINVAL;
690 }
691 /* an address specified */
692 ret = strict_strtoul(&argv[1][0], 0, (unsigned long *)&addr);
693 if (ret) {
694 pr_info("Failed to parse address.\n");
695 return ret;
696 }
697 } else {
698 /* a symbol specified */
699 symbol = argv[1];
700 /* TODO: support .init module functions */
701 ret = split_symbol_offset(symbol, &offset);
702 if (ret) {
703 pr_info("Failed to parse symbol.\n");
704 return ret;
705 }
706 if (offset && is_return) {
707 pr_info("Return probe must be used without offset.\n");
708 return -EINVAL;
709 }
710 }
711 argc -= 2; argv += 2;
712
713 /* setup a probe */
714 if (!event) {
715 /* Make a new event name */
716 if (symbol)
717 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
718 is_return ? 'r' : 'p', symbol, offset);
719 else
720 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
721 is_return ? 'r' : 'p', addr);
722 event = buf;
723 }
724 tp = alloc_trace_probe(group, event, addr, symbol, offset, argc,
725 is_return);
726 if (IS_ERR(tp)) {
727 pr_info("Failed to allocate trace_probe.(%d)\n",
728 (int)PTR_ERR(tp));
729 return PTR_ERR(tp);
730 }
731
732 /* parse arguments */
733 ret = 0;
734 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
735 /* Parse argument name */
736 arg = strchr(argv[i], '=');
737 if (arg)
738 *arg++ = '\0';
739 else
740 arg = argv[i];
741
742 if (conflict_field_name(argv[i], tp->args, i)) {
743 pr_info("Argument%d name '%s' conflicts with "
744 "another field.\n", i, argv[i]);
745 ret = -EINVAL;
746 goto error;
747 }
748
749 tp->args[i].name = kstrdup(argv[i], GFP_KERNEL);
750 if (!tp->args[i].name) {
751 pr_info("Failed to allocate argument%d name '%s'.\n",
752 i, argv[i]);
753 ret = -ENOMEM;
754 goto error;
755 }
756
757 /* Parse fetch argument */
758 ret = parse_probe_arg(arg, &tp->args[i].fetch, is_return);
759 if (ret) {
760 pr_info("Parse error at argument%d. (%d)\n", i, ret);
761 kfree(tp->args[i].name);
762 goto error;
763 }
764
765 tp->nr_args++;
766 }
767
768 ret = register_trace_probe(tp);
769 if (ret)
770 goto error;
771 return 0;
772
773 error:
774 free_trace_probe(tp);
775 return ret;
776 }
777
778 static void cleanup_all_probes(void)
779 {
780 struct trace_probe *tp;
781
782 mutex_lock(&probe_lock);
783 /* TODO: Use batch unregistration */
784 while (!list_empty(&probe_list)) {
785 tp = list_entry(probe_list.next, struct trace_probe, list);
786 unregister_trace_probe(tp);
787 free_trace_probe(tp);
788 }
789 mutex_unlock(&probe_lock);
790 }
791
792
793 /* Probes listing interfaces */
794 static void *probes_seq_start(struct seq_file *m, loff_t *pos)
795 {
796 mutex_lock(&probe_lock);
797 return seq_list_start(&probe_list, *pos);
798 }
799
800 static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
801 {
802 return seq_list_next(v, &probe_list, pos);
803 }
804
805 static void probes_seq_stop(struct seq_file *m, void *v)
806 {
807 mutex_unlock(&probe_lock);
808 }
809
810 static int probes_seq_show(struct seq_file *m, void *v)
811 {
812 struct trace_probe *tp = v;
813 int i, ret;
814 char buf[MAX_ARGSTR_LEN + 1];
815
816 seq_printf(m, "%c", probe_is_return(tp) ? 'r' : 'p');
817 seq_printf(m, ":%s/%s", tp->call.system, tp->call.name);
818
819 if (!tp->symbol)
820 seq_printf(m, " 0x%p", tp->rp.kp.addr);
821 else if (tp->rp.kp.offset)
822 seq_printf(m, " %s+%u", probe_symbol(tp), tp->rp.kp.offset);
823 else
824 seq_printf(m, " %s", probe_symbol(tp));
825
826 for (i = 0; i < tp->nr_args; i++) {
827 ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i].fetch);
828 if (ret < 0) {
829 pr_warning("Argument%d decoding error(%d).\n", i, ret);
830 return ret;
831 }
832 seq_printf(m, " %s=%s", tp->args[i].name, buf);
833 }
834 seq_printf(m, "\n");
835 return 0;
836 }
837
838 static const struct seq_operations probes_seq_op = {
839 .start = probes_seq_start,
840 .next = probes_seq_next,
841 .stop = probes_seq_stop,
842 .show = probes_seq_show
843 };
844
845 static int probes_open(struct inode *inode, struct file *file)
846 {
847 if ((file->f_mode & FMODE_WRITE) &&
848 (file->f_flags & O_TRUNC))
849 cleanup_all_probes();
850
851 return seq_open(file, &probes_seq_op);
852 }
853
854 static int command_trace_probe(const char *buf)
855 {
856 char **argv;
857 int argc = 0, ret = 0;
858
859 argv = argv_split(GFP_KERNEL, buf, &argc);
860 if (!argv)
861 return -ENOMEM;
862
863 if (argc)
864 ret = create_trace_probe(argc, argv);
865
866 argv_free(argv);
867 return ret;
868 }
869
870 #define WRITE_BUFSIZE 128
871
872 static ssize_t probes_write(struct file *file, const char __user *buffer,
873 size_t count, loff_t *ppos)
874 {
875 char *kbuf, *tmp;
876 int ret;
877 size_t done;
878 size_t size;
879
880 kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
881 if (!kbuf)
882 return -ENOMEM;
883
884 ret = done = 0;
885 while (done < count) {
886 size = count - done;
887 if (size >= WRITE_BUFSIZE)
888 size = WRITE_BUFSIZE - 1;
889 if (copy_from_user(kbuf, buffer + done, size)) {
890 ret = -EFAULT;
891 goto out;
892 }
893 kbuf[size] = '\0';
894 tmp = strchr(kbuf, '\n');
895 if (tmp) {
896 *tmp = '\0';
897 size = tmp - kbuf + 1;
898 } else if (done + size < count) {
899 pr_warning("Line length is too long: "
900 "Should be less than %d.", WRITE_BUFSIZE);
901 ret = -EINVAL;
902 goto out;
903 }
904 done += size;
905 /* Remove comments */
906 tmp = strchr(kbuf, '#');
907 if (tmp)
908 *tmp = '\0';
909
910 ret = command_trace_probe(kbuf);
911 if (ret)
912 goto out;
913 }
914 ret = done;
915 out:
916 kfree(kbuf);
917 return ret;
918 }
919
920 static const struct file_operations kprobe_events_ops = {
921 .owner = THIS_MODULE,
922 .open = probes_open,
923 .read = seq_read,
924 .llseek = seq_lseek,
925 .release = seq_release,
926 .write = probes_write,
927 };
928
929 /* Probes profiling interfaces */
930 static int probes_profile_seq_show(struct seq_file *m, void *v)
931 {
932 struct trace_probe *tp = v;
933
934 seq_printf(m, " %-44s %15lu %15lu\n", tp->call.name, tp->nhit,
935 tp->rp.kp.nmissed);
936
937 return 0;
938 }
939
940 static const struct seq_operations profile_seq_op = {
941 .start = probes_seq_start,
942 .next = probes_seq_next,
943 .stop = probes_seq_stop,
944 .show = probes_profile_seq_show
945 };
946
947 static int profile_open(struct inode *inode, struct file *file)
948 {
949 return seq_open(file, &profile_seq_op);
950 }
951
952 static const struct file_operations kprobe_profile_ops = {
953 .owner = THIS_MODULE,
954 .open = profile_open,
955 .read = seq_read,
956 .llseek = seq_lseek,
957 .release = seq_release,
958 };
959
960 /* Kprobe handler */
961 static __kprobes int kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
962 {
963 struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
964 struct kprobe_trace_entry *entry;
965 struct ring_buffer_event *event;
966 struct ring_buffer *buffer;
967 int size, i, pc;
968 unsigned long irq_flags;
969 struct ftrace_event_call *call = &tp->call;
970
971 tp->nhit++;
972
973 local_save_flags(irq_flags);
974 pc = preempt_count();
975
976 size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args);
977
978 event = trace_current_buffer_lock_reserve(&buffer, call->id, size,
979 irq_flags, pc);
980 if (!event)
981 return 0;
982
983 entry = ring_buffer_event_data(event);
984 entry->nargs = tp->nr_args;
985 entry->ip = (unsigned long)kp->addr;
986 for (i = 0; i < tp->nr_args; i++)
987 entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
988
989 if (!filter_current_check_discard(buffer, call, entry, event))
990 trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
991 return 0;
992 }
993
994 /* Kretprobe handler */
995 static __kprobes int kretprobe_trace_func(struct kretprobe_instance *ri,
996 struct pt_regs *regs)
997 {
998 struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
999 struct kretprobe_trace_entry *entry;
1000 struct ring_buffer_event *event;
1001 struct ring_buffer *buffer;
1002 int size, i, pc;
1003 unsigned long irq_flags;
1004 struct ftrace_event_call *call = &tp->call;
1005
1006 local_save_flags(irq_flags);
1007 pc = preempt_count();
1008
1009 size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args);
1010
1011 event = trace_current_buffer_lock_reserve(&buffer, call->id, size,
1012 irq_flags, pc);
1013 if (!event)
1014 return 0;
1015
1016 entry = ring_buffer_event_data(event);
1017 entry->nargs = tp->nr_args;
1018 entry->func = (unsigned long)tp->rp.kp.addr;
1019 entry->ret_ip = (unsigned long)ri->ret_addr;
1020 for (i = 0; i < tp->nr_args; i++)
1021 entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
1022
1023 if (!filter_current_check_discard(buffer, call, entry, event))
1024 trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
1025
1026 return 0;
1027 }
1028
1029 /* Event entry printers */
1030 enum print_line_t
1031 print_kprobe_event(struct trace_iterator *iter, int flags)
1032 {
1033 struct kprobe_trace_entry *field;
1034 struct trace_seq *s = &iter->seq;
1035 struct trace_event *event;
1036 struct trace_probe *tp;
1037 int i;
1038
1039 field = (struct kprobe_trace_entry *)iter->ent;
1040 event = ftrace_find_event(field->ent.type);
1041 tp = container_of(event, struct trace_probe, event);
1042
1043 if (!trace_seq_printf(s, "%s: (", tp->call.name))
1044 goto partial;
1045
1046 if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
1047 goto partial;
1048
1049 if (!trace_seq_puts(s, ")"))
1050 goto partial;
1051
1052 for (i = 0; i < field->nargs; i++)
1053 if (!trace_seq_printf(s, " %s=%lx",
1054 tp->args[i].name, field->args[i]))
1055 goto partial;
1056
1057 if (!trace_seq_puts(s, "\n"))
1058 goto partial;
1059
1060 return TRACE_TYPE_HANDLED;
1061 partial:
1062 return TRACE_TYPE_PARTIAL_LINE;
1063 }
1064
1065 enum print_line_t
1066 print_kretprobe_event(struct trace_iterator *iter, int flags)
1067 {
1068 struct kretprobe_trace_entry *field;
1069 struct trace_seq *s = &iter->seq;
1070 struct trace_event *event;
1071 struct trace_probe *tp;
1072 int i;
1073
1074 field = (struct kretprobe_trace_entry *)iter->ent;
1075 event = ftrace_find_event(field->ent.type);
1076 tp = container_of(event, struct trace_probe, event);
1077
1078 if (!trace_seq_printf(s, "%s: (", tp->call.name))
1079 goto partial;
1080
1081 if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
1082 goto partial;
1083
1084 if (!trace_seq_puts(s, " <- "))
1085 goto partial;
1086
1087 if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
1088 goto partial;
1089
1090 if (!trace_seq_puts(s, ")"))
1091 goto partial;
1092
1093 for (i = 0; i < field->nargs; i++)
1094 if (!trace_seq_printf(s, " %s=%lx",
1095 tp->args[i].name, field->args[i]))
1096 goto partial;
1097
1098 if (!trace_seq_puts(s, "\n"))
1099 goto partial;
1100
1101 return TRACE_TYPE_HANDLED;
1102 partial:
1103 return TRACE_TYPE_PARTIAL_LINE;
1104 }
1105
1106 static int probe_event_enable(struct ftrace_event_call *call)
1107 {
1108 struct trace_probe *tp = (struct trace_probe *)call->data;
1109
1110 tp->flags |= TP_FLAG_TRACE;
1111 if (probe_is_return(tp))
1112 return enable_kretprobe(&tp->rp);
1113 else
1114 return enable_kprobe(&tp->rp.kp);
1115 }
1116
1117 static void probe_event_disable(struct ftrace_event_call *call)
1118 {
1119 struct trace_probe *tp = (struct trace_probe *)call->data;
1120
1121 tp->flags &= ~TP_FLAG_TRACE;
1122 if (!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE))) {
1123 if (probe_is_return(tp))
1124 disable_kretprobe(&tp->rp);
1125 else
1126 disable_kprobe(&tp->rp.kp);
1127 }
1128 }
1129
1130 static int probe_event_raw_init(struct ftrace_event_call *event_call)
1131 {
1132 INIT_LIST_HEAD(&event_call->fields);
1133
1134 return 0;
1135 }
1136
1137 #undef DEFINE_FIELD
1138 #define DEFINE_FIELD(type, item, name, is_signed) \
1139 do { \
1140 ret = trace_define_field(event_call, #type, name, \
1141 offsetof(typeof(field), item), \
1142 sizeof(field.item), is_signed, \
1143 FILTER_OTHER); \
1144 if (ret) \
1145 return ret; \
1146 } while (0)
1147
1148 static int kprobe_event_define_fields(struct ftrace_event_call *event_call)
1149 {
1150 int ret, i;
1151 struct kprobe_trace_entry field;
1152 struct trace_probe *tp = (struct trace_probe *)event_call->data;
1153
1154 DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
1155 DEFINE_FIELD(int, nargs, FIELD_STRING_NARGS, 1);
1156 /* Set argument names as fields */
1157 for (i = 0; i < tp->nr_args; i++)
1158 DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0);
1159 return 0;
1160 }
1161
1162 static int kretprobe_event_define_fields(struct ftrace_event_call *event_call)
1163 {
1164 int ret, i;
1165 struct kretprobe_trace_entry field;
1166 struct trace_probe *tp = (struct trace_probe *)event_call->data;
1167
1168 DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
1169 DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
1170 DEFINE_FIELD(int, nargs, FIELD_STRING_NARGS, 1);
1171 /* Set argument names as fields */
1172 for (i = 0; i < tp->nr_args; i++)
1173 DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0);
1174 return 0;
1175 }
1176
1177 static int __set_print_fmt(struct trace_probe *tp, char *buf, int len)
1178 {
1179 int i;
1180 int pos = 0;
1181
1182 const char *fmt, *arg;
1183
1184 if (!probe_is_return(tp)) {
1185 fmt = "(%lx)";
1186 arg = "REC->" FIELD_STRING_IP;
1187 } else {
1188 fmt = "(%lx <- %lx)";
1189 arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
1190 }
1191
1192 /* When len=0, we just calculate the needed length */
1193 #define LEN_OR_ZERO (len ? len - pos : 0)
1194
1195 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
1196
1197 for (i = 0; i < tp->nr_args; i++) {
1198 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%%lx",
1199 tp->args[i].name);
1200 }
1201
1202 pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
1203
1204 for (i = 0; i < tp->nr_args; i++) {
1205 pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
1206 tp->args[i].name);
1207 }
1208
1209 #undef LEN_OR_ZERO
1210
1211 /* return the length of print_fmt */
1212 return pos;
1213 }
1214
1215 static int set_print_fmt(struct trace_probe *tp)
1216 {
1217 int len;
1218 char *print_fmt;
1219
1220 /* First: called with 0 length to calculate the needed length */
1221 len = __set_print_fmt(tp, NULL, 0);
1222 print_fmt = kmalloc(len + 1, GFP_KERNEL);
1223 if (!print_fmt)
1224 return -ENOMEM;
1225
1226 /* Second: actually write the @print_fmt */
1227 __set_print_fmt(tp, print_fmt, len + 1);
1228 tp->call.print_fmt = print_fmt;
1229
1230 return 0;
1231 }
1232
1233 #ifdef CONFIG_EVENT_PROFILE
1234
1235 /* Kprobe profile handler */
1236 static __kprobes int kprobe_profile_func(struct kprobe *kp,
1237 struct pt_regs *regs)
1238 {
1239 struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
1240 struct ftrace_event_call *call = &tp->call;
1241 struct kprobe_trace_entry *entry;
1242 struct trace_entry *ent;
1243 int size, __size, i, pc, __cpu;
1244 unsigned long irq_flags;
1245 char *trace_buf;
1246 char *raw_data;
1247 int rctx;
1248
1249 pc = preempt_count();
1250 __size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args);
1251 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1252 size -= sizeof(u32);
1253 if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE,
1254 "profile buffer not large enough"))
1255 return 0;
1256
1257 /*
1258 * Protect the non nmi buffer
1259 * This also protects the rcu read side
1260 */
1261 local_irq_save(irq_flags);
1262
1263 rctx = perf_swevent_get_recursion_context();
1264 if (rctx < 0)
1265 goto end_recursion;
1266
1267 __cpu = smp_processor_id();
1268
1269 if (in_nmi())
1270 trace_buf = rcu_dereference(perf_trace_buf_nmi);
1271 else
1272 trace_buf = rcu_dereference(perf_trace_buf);
1273
1274 if (!trace_buf)
1275 goto end;
1276
1277 raw_data = per_cpu_ptr(trace_buf, __cpu);
1278
1279 /* Zero dead bytes from alignment to avoid buffer leak to userspace */
1280 *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
1281 entry = (struct kprobe_trace_entry *)raw_data;
1282 ent = &entry->ent;
1283
1284 tracing_generic_entry_update(ent, irq_flags, pc);
1285 ent->type = call->id;
1286 entry->nargs = tp->nr_args;
1287 entry->ip = (unsigned long)kp->addr;
1288 for (i = 0; i < tp->nr_args; i++)
1289 entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
1290 perf_tp_event(call->id, entry->ip, 1, entry, size);
1291
1292 end:
1293 perf_swevent_put_recursion_context(rctx);
1294 end_recursion:
1295 local_irq_restore(irq_flags);
1296
1297 return 0;
1298 }
1299
1300 /* Kretprobe profile handler */
1301 static __kprobes int kretprobe_profile_func(struct kretprobe_instance *ri,
1302 struct pt_regs *regs)
1303 {
1304 struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
1305 struct ftrace_event_call *call = &tp->call;
1306 struct kretprobe_trace_entry *entry;
1307 struct trace_entry *ent;
1308 int size, __size, i, pc, __cpu;
1309 unsigned long irq_flags;
1310 char *trace_buf;
1311 char *raw_data;
1312 int rctx;
1313
1314 pc = preempt_count();
1315 __size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args);
1316 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1317 size -= sizeof(u32);
1318 if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE,
1319 "profile buffer not large enough"))
1320 return 0;
1321
1322 /*
1323 * Protect the non nmi buffer
1324 * This also protects the rcu read side
1325 */
1326 local_irq_save(irq_flags);
1327
1328 rctx = perf_swevent_get_recursion_context();
1329 if (rctx < 0)
1330 goto end_recursion;
1331
1332 __cpu = smp_processor_id();
1333
1334 if (in_nmi())
1335 trace_buf = rcu_dereference(perf_trace_buf_nmi);
1336 else
1337 trace_buf = rcu_dereference(perf_trace_buf);
1338
1339 if (!trace_buf)
1340 goto end;
1341
1342 raw_data = per_cpu_ptr(trace_buf, __cpu);
1343
1344 /* Zero dead bytes from alignment to avoid buffer leak to userspace */
1345 *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
1346 entry = (struct kretprobe_trace_entry *)raw_data;
1347 ent = &entry->ent;
1348
1349 tracing_generic_entry_update(ent, irq_flags, pc);
1350 ent->type = call->id;
1351 entry->nargs = tp->nr_args;
1352 entry->func = (unsigned long)tp->rp.kp.addr;
1353 entry->ret_ip = (unsigned long)ri->ret_addr;
1354 for (i = 0; i < tp->nr_args; i++)
1355 entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
1356 perf_tp_event(call->id, entry->ret_ip, 1, entry, size);
1357
1358 end:
1359 perf_swevent_put_recursion_context(rctx);
1360 end_recursion:
1361 local_irq_restore(irq_flags);
1362
1363 return 0;
1364 }
1365
1366 static int probe_profile_enable(struct ftrace_event_call *call)
1367 {
1368 struct trace_probe *tp = (struct trace_probe *)call->data;
1369
1370 tp->flags |= TP_FLAG_PROFILE;
1371
1372 if (probe_is_return(tp))
1373 return enable_kretprobe(&tp->rp);
1374 else
1375 return enable_kprobe(&tp->rp.kp);
1376 }
1377
1378 static void probe_profile_disable(struct ftrace_event_call *call)
1379 {
1380 struct trace_probe *tp = (struct trace_probe *)call->data;
1381
1382 tp->flags &= ~TP_FLAG_PROFILE;
1383
1384 if (!(tp->flags & TP_FLAG_TRACE)) {
1385 if (probe_is_return(tp))
1386 disable_kretprobe(&tp->rp);
1387 else
1388 disable_kprobe(&tp->rp.kp);
1389 }
1390 }
1391 #endif /* CONFIG_EVENT_PROFILE */
1392
1393
1394 static __kprobes
1395 int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1396 {
1397 struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
1398
1399 if (tp->flags & TP_FLAG_TRACE)
1400 kprobe_trace_func(kp, regs);
1401 #ifdef CONFIG_EVENT_PROFILE
1402 if (tp->flags & TP_FLAG_PROFILE)
1403 kprobe_profile_func(kp, regs);
1404 #endif /* CONFIG_EVENT_PROFILE */
1405 return 0; /* We don't tweek kernel, so just return 0 */
1406 }
1407
1408 static __kprobes
1409 int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1410 {
1411 struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
1412
1413 if (tp->flags & TP_FLAG_TRACE)
1414 kretprobe_trace_func(ri, regs);
1415 #ifdef CONFIG_EVENT_PROFILE
1416 if (tp->flags & TP_FLAG_PROFILE)
1417 kretprobe_profile_func(ri, regs);
1418 #endif /* CONFIG_EVENT_PROFILE */
1419 return 0; /* We don't tweek kernel, so just return 0 */
1420 }
1421
1422 static int register_probe_event(struct trace_probe *tp)
1423 {
1424 struct ftrace_event_call *call = &tp->call;
1425 int ret;
1426
1427 /* Initialize ftrace_event_call */
1428 if (probe_is_return(tp)) {
1429 tp->event.trace = print_kretprobe_event;
1430 call->raw_init = probe_event_raw_init;
1431 call->define_fields = kretprobe_event_define_fields;
1432 } else {
1433 tp->event.trace = print_kprobe_event;
1434 call->raw_init = probe_event_raw_init;
1435 call->define_fields = kprobe_event_define_fields;
1436 }
1437 if (set_print_fmt(tp) < 0)
1438 return -ENOMEM;
1439 call->event = &tp->event;
1440 call->id = register_ftrace_event(&tp->event);
1441 if (!call->id) {
1442 kfree(call->print_fmt);
1443 return -ENODEV;
1444 }
1445 call->enabled = 0;
1446 call->regfunc = probe_event_enable;
1447 call->unregfunc = probe_event_disable;
1448
1449 #ifdef CONFIG_EVENT_PROFILE
1450 call->profile_enable = probe_profile_enable;
1451 call->profile_disable = probe_profile_disable;
1452 #endif
1453 call->data = tp;
1454 ret = trace_add_event_call(call);
1455 if (ret) {
1456 pr_info("Failed to register kprobe event: %s\n", call->name);
1457 kfree(call->print_fmt);
1458 unregister_ftrace_event(&tp->event);
1459 }
1460 return ret;
1461 }
1462
1463 static void unregister_probe_event(struct trace_probe *tp)
1464 {
1465 /* tp->event is unregistered in trace_remove_event_call() */
1466 trace_remove_event_call(&tp->call);
1467 kfree(tp->call.print_fmt);
1468 }
1469
1470 /* Make a debugfs interface for controling probe points */
1471 static __init int init_kprobe_trace(void)
1472 {
1473 struct dentry *d_tracer;
1474 struct dentry *entry;
1475
1476 d_tracer = tracing_init_dentry();
1477 if (!d_tracer)
1478 return 0;
1479
1480 entry = debugfs_create_file("kprobe_events", 0644, d_tracer,
1481 NULL, &kprobe_events_ops);
1482
1483 /* Event list interface */
1484 if (!entry)
1485 pr_warning("Could not create debugfs "
1486 "'kprobe_events' entry\n");
1487
1488 /* Profile interface */
1489 entry = debugfs_create_file("kprobe_profile", 0444, d_tracer,
1490 NULL, &kprobe_profile_ops);
1491
1492 if (!entry)
1493 pr_warning("Could not create debugfs "
1494 "'kprobe_profile' entry\n");
1495 return 0;
1496 }
1497 fs_initcall(init_kprobe_trace);
1498
1499
1500 #ifdef CONFIG_FTRACE_STARTUP_TEST
1501
1502 static int kprobe_trace_selftest_target(int a1, int a2, int a3,
1503 int a4, int a5, int a6)
1504 {
1505 return a1 + a2 + a3 + a4 + a5 + a6;
1506 }
1507
1508 static __init int kprobe_trace_self_tests_init(void)
1509 {
1510 int ret;
1511 int (*target)(int, int, int, int, int, int);
1512
1513 target = kprobe_trace_selftest_target;
1514
1515 pr_info("Testing kprobe tracing: ");
1516
1517 ret = command_trace_probe("p:testprobe kprobe_trace_selftest_target "
1518 "$arg1 $arg2 $arg3 $arg4 $stack $stack0");
1519 if (WARN_ON_ONCE(ret))
1520 pr_warning("error enabling function entry\n");
1521
1522 ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target "
1523 "$retval");
1524 if (WARN_ON_ONCE(ret))
1525 pr_warning("error enabling function return\n");
1526
1527 ret = target(1, 2, 3, 4, 5, 6);
1528
1529 cleanup_all_probes();
1530
1531 pr_cont("OK\n");
1532 return 0;
1533 }
1534
1535 late_initcall(kprobe_trace_self_tests_init);
1536
1537 #endif
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