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tracing/kprobe: Update kprobe tracing self test for new syntax
[linux-2.6/btrfs-unstable.git] / kernel / trace / trace_kprobe.c
blobd6266cad69531faa245cc72d477aa7053d5469b6
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_call call;
206 struct trace_event event;
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.name = kstrdup(event, GFP_KERNEL);
327 if (!tp->call.name)
328 goto error;
329
330 if (!group || !check_event_name(group)) {
331 ret = -EINVAL;
332 goto error;
333 }
334
335 tp->call.system = kstrdup(group, GFP_KERNEL);
336 if (!tp->call.system)
337 goto error;
338
339 INIT_LIST_HEAD(&tp->list);
340 return tp;
341 error:
342 kfree(tp->call.name);
343 kfree(tp->symbol);
344 kfree(tp);
345 return ERR_PTR(ret);
346 }
347
348 static void free_probe_arg(struct probe_arg *arg)
349 {
350 if (arg->fetch.func == fetch_symbol)
351 free_symbol_cache(arg->fetch.data);
352 else if (arg->fetch.func == fetch_indirect)
353 free_indirect_fetch_data(arg->fetch.data);
354 kfree(arg->name);
355 }
356
357 static void free_trace_probe(struct trace_probe *tp)
358 {
359 int i;
360
361 for (i = 0; i < tp->nr_args; i++)
362 free_probe_arg(&tp->args[i]);
363
364 kfree(tp->call.system);
365 kfree(tp->call.name);
366 kfree(tp->symbol);
367 kfree(tp);
368 }
369
370 static struct trace_probe *find_probe_event(const char *event,
371 const char *group)
372 {
373 struct trace_probe *tp;
374
375 list_for_each_entry(tp, &probe_list, list)
376 if (strcmp(tp->call.name, event) == 0 &&
377 strcmp(tp->call.system, group) == 0)
378 return tp;
379 return NULL;
380 }
381
382 /* Unregister a trace_probe and probe_event: call with locking probe_lock */
383 static void unregister_trace_probe(struct trace_probe *tp)
384 {
385 if (probe_is_return(tp))
386 unregister_kretprobe(&tp->rp);
387 else
388 unregister_kprobe(&tp->rp.kp);
389 list_del(&tp->list);
390 unregister_probe_event(tp);
391 }
392
393 /* Register a trace_probe and probe_event */
394 static int register_trace_probe(struct trace_probe *tp)
395 {
396 struct trace_probe *old_tp;
397 int ret;
398
399 mutex_lock(&probe_lock);
400
401 /* register as an event */
402 old_tp = find_probe_event(tp->call.name, tp->call.system);
403 if (old_tp) {
404 /* delete old event */
405 unregister_trace_probe(old_tp);
406 free_trace_probe(old_tp);
407 }
408 ret = register_probe_event(tp);
409 if (ret) {
410 pr_warning("Faild to register probe event(%d)\n", ret);
411 goto end;
412 }
413
414 tp->rp.kp.flags |= KPROBE_FLAG_DISABLED;
415 if (probe_is_return(tp))
416 ret = register_kretprobe(&tp->rp);
417 else
418 ret = register_kprobe(&tp->rp.kp);
419
420 if (ret) {
421 pr_warning("Could not insert probe(%d)\n", ret);
422 if (ret == -EILSEQ) {
423 pr_warning("Probing address(0x%p) is not an "
424 "instruction boundary.\n",
425 tp->rp.kp.addr);
426 ret = -EINVAL;
427 }
428 unregister_probe_event(tp);
429 } else
430 list_add_tail(&tp->list, &probe_list);
431 end:
432 mutex_unlock(&probe_lock);
433 return ret;
434 }
435
436 /* Split symbol and offset. */
437 static int split_symbol_offset(char *symbol, unsigned long *offset)
438 {
439 char *tmp;
440 int ret;
441
442 if (!offset)
443 return -EINVAL;
444
445 tmp = strchr(symbol, '+');
446 if (tmp) {
447 /* skip sign because strict_strtol doesn't accept '+' */
448 ret = strict_strtoul(tmp + 1, 0, offset);
449 if (ret)
450 return ret;
451 *tmp = '\0';
452 } else
453 *offset = 0;
454 return 0;
455 }
456
457 #define PARAM_MAX_ARGS 16
458 #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
459
460 static int parse_probe_vars(char *arg, struct fetch_func *ff, int is_return)
461 {
462 int ret = 0;
463 unsigned long param;
464
465 if (strcmp(arg, "retval") == 0) {
466 if (is_return) {
467 ff->func = fetch_retvalue;
468 ff->data = NULL;
469 } else
470 ret = -EINVAL;
471 } else if (strncmp(arg, "stack", 5) == 0) {
472 if (arg[5] == '\0') {
473 ff->func = fetch_stack_address;
474 ff->data = NULL;
475 } else if (isdigit(arg[5])) {
476 ret = strict_strtoul(arg + 5, 10, &param);
477 if (ret || param > PARAM_MAX_STACK)
478 ret = -EINVAL;
479 else {
480 ff->func = fetch_stack;
481 ff->data = (void *)param;
482 }
483 } else
484 ret = -EINVAL;
485 } else
486 ret = -EINVAL;
487 return ret;
488 }
489
490 /* Recursive argument parser */
491 static int __parse_probe_arg(char *arg, struct fetch_func *ff, int is_return)
492 {
493 int ret = 0;
494 unsigned long param;
495 long offset;
496 char *tmp;
497
498 switch (arg[0]) {
499 case '$':
500 ret = parse_probe_vars(arg + 1, ff, is_return);
501 break;
502 case '%': /* named register */
503 ret = regs_query_register_offset(arg + 1);
504 if (ret >= 0) {
505 ff->func = fetch_register;
506 ff->data = (void *)(unsigned long)ret;
507 ret = 0;
508 }
509 break;
510 case '@': /* memory or symbol */
511 if (isdigit(arg[1])) {
512 ret = strict_strtoul(arg + 1, 0, &param);
513 if (ret)
514 break;
515 ff->func = fetch_memory;
516 ff->data = (void *)param;
517 } else {
518 ret = split_symbol_offset(arg + 1, &offset);
519 if (ret)
520 break;
521 ff->data = alloc_symbol_cache(arg + 1, offset);
522 if (ff->data)
523 ff->func = fetch_symbol;
524 else
525 ret = -EINVAL;
526 }
527 break;
528 case '+': /* indirect memory */
529 case '-':
530 tmp = strchr(arg, '(');
531 if (!tmp) {
532 ret = -EINVAL;
533 break;
534 }
535 *tmp = '\0';
536 ret = strict_strtol(arg + 1, 0, &offset);
537 if (ret)
538 break;
539 if (arg[0] == '-')
540 offset = -offset;
541 arg = tmp + 1;
542 tmp = strrchr(arg, ')');
543 if (tmp) {
544 struct indirect_fetch_data *id;
545 *tmp = '\0';
546 id = kzalloc(sizeof(struct indirect_fetch_data),
547 GFP_KERNEL);
548 if (!id)
549 return -ENOMEM;
550 id->offset = offset;
551 ret = __parse_probe_arg(arg, &id->orig, is_return);
552 if (ret)
553 kfree(id);
554 else {
555 ff->func = fetch_indirect;
556 ff->data = (void *)id;
557 }
558 } else
559 ret = -EINVAL;
560 break;
561 default:
562 /* TODO: support custom handler */
563 ret = -EINVAL;
564 }
565 return ret;
566 }
567
568 /* String length checking wrapper */
569 static int parse_probe_arg(char *arg, struct fetch_func *ff, int is_return)
570 {
571 if (strlen(arg) > MAX_ARGSTR_LEN) {
572 pr_info("Argument is too long.: %s\n", arg);
573 return -ENOSPC;
574 }
575 return __parse_probe_arg(arg, ff, is_return);
576 }
577
578 /* Return 1 if name is reserved or already used by another argument */
579 static int conflict_field_name(const char *name,
580 struct probe_arg *args, int narg)
581 {
582 int i;
583 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
584 if (strcmp(reserved_field_names[i], name) == 0)
585 return 1;
586 for (i = 0; i < narg; i++)
587 if (strcmp(args[i].name, name) == 0)
588 return 1;
589 return 0;
590 }
591
592 static int create_trace_probe(int argc, char **argv)
593 {
594 /*
595 * Argument syntax:
596 * - Add kprobe: p[:[GRP/]EVENT] KSYM[+OFFS]|KADDR [FETCHARGS]
597 * - Add kretprobe: r[:[GRP/]EVENT] KSYM[+0] [FETCHARGS]
598 * Fetch args:
599 * $retval : fetch return value
600 * $stack : fetch stack address
601 * $stackN : fetch Nth of stack (N:0-)
602 * @ADDR : fetch memory at ADDR (ADDR should be in kernel)
603 * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
604 * %REG : fetch register REG
605 * Indirect memory fetch:
606 * +|-offs(ARG) : fetch memory at ARG +|- offs address.
607 * Alias name of args:
608 * NAME=FETCHARG : set NAME as alias of FETCHARG.
609 */
610 struct trace_probe *tp;
611 int i, ret = 0;
612 int is_return = 0, is_delete = 0;
613 char *symbol = NULL, *event = NULL, *arg = NULL, *group = NULL;
614 unsigned long offset = 0;
615 void *addr = NULL;
616 char buf[MAX_EVENT_NAME_LEN];
617
618 /* argc must be >= 1 */
619 if (argv[0][0] == 'p')
620 is_return = 0;
621 else if (argv[0][0] == 'r')
622 is_return = 1;
623 else if (argv[0][0] == '-')
624 is_delete = 1;
625 else {
626 pr_info("Probe definition must be started with 'p', 'r' or"
627 " '-'.\n");
628 return -EINVAL;
629 }
630
631 if (argv[0][1] == ':') {
632 event = &argv[0][2];
633 if (strchr(event, '/')) {
634 group = event;
635 event = strchr(group, '/') + 1;
636 event[-1] = '\0';
637 if (strlen(group) == 0) {
638 pr_info("Group name is not specifiled\n");
639 return -EINVAL;
640 }
641 }
642 if (strlen(event) == 0) {
643 pr_info("Event name is not specifiled\n");
644 return -EINVAL;
645 }
646 }
647 if (!group)
648 group = KPROBE_EVENT_SYSTEM;
649
650 if (is_delete) {
651 if (!event) {
652 pr_info("Delete command needs an event name.\n");
653 return -EINVAL;
654 }
655 tp = find_probe_event(event, group);
656 if (!tp) {
657 pr_info("Event %s/%s doesn't exist.\n", group, event);
658 return -ENOENT;
659 }
660 /* delete an event */
661 unregister_trace_probe(tp);
662 free_trace_probe(tp);
663 return 0;
664 }
665
666 if (argc < 2) {
667 pr_info("Probe point is not specified.\n");
668 return -EINVAL;
669 }
670 if (isdigit(argv[1][0])) {
671 if (is_return) {
672 pr_info("Return probe point must be a symbol.\n");
673 return -EINVAL;
674 }
675 /* an address specified */
676 ret = strict_strtoul(&argv[0][2], 0, (unsigned long *)&addr);
677 if (ret) {
678 pr_info("Failed to parse address.\n");
679 return ret;
680 }
681 } else {
682 /* a symbol specified */
683 symbol = argv[1];
684 /* TODO: support .init module functions */
685 ret = split_symbol_offset(symbol, &offset);
686 if (ret) {
687 pr_info("Failed to parse symbol.\n");
688 return ret;
689 }
690 if (offset && is_return) {
691 pr_info("Return probe must be used without offset.\n");
692 return -EINVAL;
693 }
694 }
695 argc -= 2; argv += 2;
696
697 /* setup a probe */
698 if (!event) {
699 /* Make a new event name */
700 if (symbol)
701 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
702 is_return ? 'r' : 'p', symbol, offset);
703 else
704 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
705 is_return ? 'r' : 'p', addr);
706 event = buf;
707 }
708 tp = alloc_trace_probe(group, event, addr, symbol, offset, argc,
709 is_return);
710 if (IS_ERR(tp)) {
711 pr_info("Failed to allocate trace_probe.(%d)\n",
712 (int)PTR_ERR(tp));
713 return PTR_ERR(tp);
714 }
715
716 /* parse arguments */
717 ret = 0;
718 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
719 /* Parse argument name */
720 arg = strchr(argv[i], '=');
721 if (arg)
722 *arg++ = '\0';
723 else
724 arg = argv[i];
725
726 if (conflict_field_name(argv[i], tp->args, i)) {
727 pr_info("Argument%d name '%s' conflicts with "
728 "another field.\n", i, argv[i]);
729 ret = -EINVAL;
730 goto error;
731 }
732
733 tp->args[i].name = kstrdup(argv[i], GFP_KERNEL);
734 if (!tp->args[i].name) {
735 pr_info("Failed to allocate argument%d name '%s'.\n",
736 i, argv[i]);
737 ret = -ENOMEM;
738 goto error;
739 }
740
741 /* Parse fetch argument */
742 ret = parse_probe_arg(arg, &tp->args[i].fetch, is_return);
743 if (ret) {
744 pr_info("Parse error at argument%d. (%d)\n", i, ret);
745 kfree(tp->args[i].name);
746 goto error;
747 }
748
749 tp->nr_args++;
750 }
751
752 ret = register_trace_probe(tp);
753 if (ret)
754 goto error;
755 return 0;
756
757 error:
758 free_trace_probe(tp);
759 return ret;
760 }
761
762 static void cleanup_all_probes(void)
763 {
764 struct trace_probe *tp;
765
766 mutex_lock(&probe_lock);
767 /* TODO: Use batch unregistration */
768 while (!list_empty(&probe_list)) {
769 tp = list_entry(probe_list.next, struct trace_probe, list);
770 unregister_trace_probe(tp);
771 free_trace_probe(tp);
772 }
773 mutex_unlock(&probe_lock);
774 }
775
776
777 /* Probes listing interfaces */
778 static void *probes_seq_start(struct seq_file *m, loff_t *pos)
779 {
780 mutex_lock(&probe_lock);
781 return seq_list_start(&probe_list, *pos);
782 }
783
784 static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
785 {
786 return seq_list_next(v, &probe_list, pos);
787 }
788
789 static void probes_seq_stop(struct seq_file *m, void *v)
790 {
791 mutex_unlock(&probe_lock);
792 }
793
794 static int probes_seq_show(struct seq_file *m, void *v)
795 {
796 struct trace_probe *tp = v;
797 int i, ret;
798 char buf[MAX_ARGSTR_LEN + 1];
799
800 seq_printf(m, "%c", probe_is_return(tp) ? 'r' : 'p');
801 seq_printf(m, ":%s/%s", tp->call.system, tp->call.name);
802
803 if (!tp->symbol)
804 seq_printf(m, " 0x%p", tp->rp.kp.addr);
805 else if (tp->rp.kp.offset)
806 seq_printf(m, " %s+%u", probe_symbol(tp), tp->rp.kp.offset);
807 else
808 seq_printf(m, " %s", probe_symbol(tp));
809
810 for (i = 0; i < tp->nr_args; i++) {
811 ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i].fetch);
812 if (ret < 0) {
813 pr_warning("Argument%d decoding error(%d).\n", i, ret);
814 return ret;
815 }
816 seq_printf(m, " %s=%s", tp->args[i].name, buf);
817 }
818 seq_printf(m, "\n");
819 return 0;
820 }
821
822 static const struct seq_operations probes_seq_op = {
823 .start = probes_seq_start,
824 .next = probes_seq_next,
825 .stop = probes_seq_stop,
826 .show = probes_seq_show
827 };
828
829 static int probes_open(struct inode *inode, struct file *file)
830 {
831 if ((file->f_mode & FMODE_WRITE) &&
832 (file->f_flags & O_TRUNC))
833 cleanup_all_probes();
834
835 return seq_open(file, &probes_seq_op);
836 }
837
838 static int command_trace_probe(const char *buf)
839 {
840 char **argv;
841 int argc = 0, ret = 0;
842
843 argv = argv_split(GFP_KERNEL, buf, &argc);
844 if (!argv)
845 return -ENOMEM;
846
847 if (argc)
848 ret = create_trace_probe(argc, argv);
849
850 argv_free(argv);
851 return ret;
852 }
853
854 #define WRITE_BUFSIZE 128
855
856 static ssize_t probes_write(struct file *file, const char __user *buffer,
857 size_t count, loff_t *ppos)
858 {
859 char *kbuf, *tmp;
860 int ret;
861 size_t done;
862 size_t size;
863
864 kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
865 if (!kbuf)
866 return -ENOMEM;
867
868 ret = done = 0;
869 while (done < count) {
870 size = count - done;
871 if (size >= WRITE_BUFSIZE)
872 size = WRITE_BUFSIZE - 1;
873 if (copy_from_user(kbuf, buffer + done, size)) {
874 ret = -EFAULT;
875 goto out;
876 }
877 kbuf[size] = '\0';
878 tmp = strchr(kbuf, '\n');
879 if (tmp) {
880 *tmp = '\0';
881 size = tmp - kbuf + 1;
882 } else if (done + size < count) {
883 pr_warning("Line length is too long: "
884 "Should be less than %d.", WRITE_BUFSIZE);
885 ret = -EINVAL;
886 goto out;
887 }
888 done += size;
889 /* Remove comments */
890 tmp = strchr(kbuf, '#');
891 if (tmp)
892 *tmp = '\0';
893
894 ret = command_trace_probe(kbuf);
895 if (ret)
896 goto out;
897 }
898 ret = done;
899 out:
900 kfree(kbuf);
901 return ret;
902 }
903
904 static const struct file_operations kprobe_events_ops = {
905 .owner = THIS_MODULE,
906 .open = probes_open,
907 .read = seq_read,
908 .llseek = seq_lseek,
909 .release = seq_release,
910 .write = probes_write,
911 };
912
913 /* Probes profiling interfaces */
914 static int probes_profile_seq_show(struct seq_file *m, void *v)
915 {
916 struct trace_probe *tp = v;
917
918 seq_printf(m, " %-44s %15lu %15lu\n", tp->call.name, tp->nhit,
919 tp->rp.kp.nmissed);
920
921 return 0;
922 }
923
924 static const struct seq_operations profile_seq_op = {
925 .start = probes_seq_start,
926 .next = probes_seq_next,
927 .stop = probes_seq_stop,
928 .show = probes_profile_seq_show
929 };
930
931 static int profile_open(struct inode *inode, struct file *file)
932 {
933 return seq_open(file, &profile_seq_op);
934 }
935
936 static const struct file_operations kprobe_profile_ops = {
937 .owner = THIS_MODULE,
938 .open = profile_open,
939 .read = seq_read,
940 .llseek = seq_lseek,
941 .release = seq_release,
942 };
943
944 /* Kprobe handler */
945 static __kprobes int kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
946 {
947 struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
948 struct kprobe_trace_entry *entry;
949 struct ring_buffer_event *event;
950 struct ring_buffer *buffer;
951 int size, i, pc;
952 unsigned long irq_flags;
953 struct ftrace_event_call *call = &tp->call;
954
955 tp->nhit++;
956
957 local_save_flags(irq_flags);
958 pc = preempt_count();
959
960 size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args);
961
962 event = trace_current_buffer_lock_reserve(&buffer, call->id, size,
963 irq_flags, pc);
964 if (!event)
965 return 0;
966
967 entry = ring_buffer_event_data(event);
968 entry->nargs = tp->nr_args;
969 entry->ip = (unsigned long)kp->addr;
970 for (i = 0; i < tp->nr_args; i++)
971 entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
972
973 if (!filter_current_check_discard(buffer, call, entry, event))
974 trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
975 return 0;
976 }
977
978 /* Kretprobe handler */
979 static __kprobes int 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->id, size,
996 irq_flags, pc);
997 if (!event)
998 return 0;
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 return 0;
1011 }
1012
1013 /* Event entry printers */
1014 enum print_line_t
1015 print_kprobe_event(struct trace_iterator *iter, int flags)
1016 {
1017 struct kprobe_trace_entry *field;
1018 struct trace_seq *s = &iter->seq;
1019 struct trace_event *event;
1020 struct trace_probe *tp;
1021 int i;
1022
1023 field = (struct kprobe_trace_entry *)iter->ent;
1024 event = ftrace_find_event(field->ent.type);
1025 tp = container_of(event, struct trace_probe, event);
1026
1027 if (!trace_seq_printf(s, "%s: (", tp->call.name))
1028 goto partial;
1029
1030 if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
1031 goto partial;
1032
1033 if (!trace_seq_puts(s, ")"))
1034 goto partial;
1035
1036 for (i = 0; i < field->nargs; i++)
1037 if (!trace_seq_printf(s, " %s=%lx",
1038 tp->args[i].name, field->args[i]))
1039 goto partial;
1040
1041 if (!trace_seq_puts(s, "\n"))
1042 goto partial;
1043
1044 return TRACE_TYPE_HANDLED;
1045 partial:
1046 return TRACE_TYPE_PARTIAL_LINE;
1047 }
1048
1049 enum print_line_t
1050 print_kretprobe_event(struct trace_iterator *iter, int flags)
1051 {
1052 struct kretprobe_trace_entry *field;
1053 struct trace_seq *s = &iter->seq;
1054 struct trace_event *event;
1055 struct trace_probe *tp;
1056 int i;
1057
1058 field = (struct kretprobe_trace_entry *)iter->ent;
1059 event = ftrace_find_event(field->ent.type);
1060 tp = container_of(event, struct trace_probe, event);
1061
1062 if (!trace_seq_printf(s, "%s: (", tp->call.name))
1063 goto partial;
1064
1065 if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
1066 goto partial;
1067
1068 if (!trace_seq_puts(s, " <- "))
1069 goto partial;
1070
1071 if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
1072 goto partial;
1073
1074 if (!trace_seq_puts(s, ")"))
1075 goto partial;
1076
1077 for (i = 0; i < field->nargs; i++)
1078 if (!trace_seq_printf(s, " %s=%lx",
1079 tp->args[i].name, field->args[i]))
1080 goto partial;
1081
1082 if (!trace_seq_puts(s, "\n"))
1083 goto partial;
1084
1085 return TRACE_TYPE_HANDLED;
1086 partial:
1087 return TRACE_TYPE_PARTIAL_LINE;
1088 }
1089
1090 static int probe_event_enable(struct ftrace_event_call *call)
1091 {
1092 struct trace_probe *tp = (struct trace_probe *)call->data;
1093
1094 tp->flags |= TP_FLAG_TRACE;
1095 if (probe_is_return(tp))
1096 return enable_kretprobe(&tp->rp);
1097 else
1098 return enable_kprobe(&tp->rp.kp);
1099 }
1100
1101 static void probe_event_disable(struct ftrace_event_call *call)
1102 {
1103 struct trace_probe *tp = (struct trace_probe *)call->data;
1104
1105 tp->flags &= ~TP_FLAG_TRACE;
1106 if (!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE))) {
1107 if (probe_is_return(tp))
1108 disable_kretprobe(&tp->rp);
1109 else
1110 disable_kprobe(&tp->rp.kp);
1111 }
1112 }
1113
1114 static int probe_event_raw_init(struct ftrace_event_call *event_call)
1115 {
1116 INIT_LIST_HEAD(&event_call->fields);
1117
1118 return 0;
1119 }
1120
1121 #undef DEFINE_FIELD
1122 #define DEFINE_FIELD(type, item, name, is_signed) \
1123 do { \
1124 ret = trace_define_field(event_call, #type, name, \
1125 offsetof(typeof(field), item), \
1126 sizeof(field.item), is_signed, \
1127 FILTER_OTHER); \
1128 if (ret) \
1129 return ret; \
1130 } while (0)
1131
1132 static int kprobe_event_define_fields(struct ftrace_event_call *event_call)
1133 {
1134 int ret, i;
1135 struct kprobe_trace_entry field;
1136 struct trace_probe *tp = (struct trace_probe *)event_call->data;
1137
1138 DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
1139 DEFINE_FIELD(int, nargs, FIELD_STRING_NARGS, 1);
1140 /* Set argument names as fields */
1141 for (i = 0; i < tp->nr_args; i++)
1142 DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0);
1143 return 0;
1144 }
1145
1146 static int kretprobe_event_define_fields(struct ftrace_event_call *event_call)
1147 {
1148 int ret, i;
1149 struct kretprobe_trace_entry field;
1150 struct trace_probe *tp = (struct trace_probe *)event_call->data;
1151
1152 DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
1153 DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
1154 DEFINE_FIELD(int, nargs, FIELD_STRING_NARGS, 1);
1155 /* Set argument names as fields */
1156 for (i = 0; i < tp->nr_args; i++)
1157 DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0);
1158 return 0;
1159 }
1160
1161 static int __probe_event_show_format(struct trace_seq *s,
1162 struct trace_probe *tp, const char *fmt,
1163 const char *arg)
1164 {
1165 int i;
1166
1167 /* Show format */
1168 if (!trace_seq_printf(s, "\nprint fmt: \"%s", fmt))
1169 return 0;
1170
1171 for (i = 0; i < tp->nr_args; i++)
1172 if (!trace_seq_printf(s, " %s=%%lx", tp->args[i].name))
1173 return 0;
1174
1175 if (!trace_seq_printf(s, "\", %s", arg))
1176 return 0;
1177
1178 for (i = 0; i < tp->nr_args; i++)
1179 if (!trace_seq_printf(s, ", REC->%s", tp->args[i].name))
1180 return 0;
1181
1182 return trace_seq_puts(s, "\n");
1183 }
1184
1185 #undef SHOW_FIELD
1186 #define SHOW_FIELD(type, item, name) \
1187 do { \
1188 ret = trace_seq_printf(s, "\tfield:" #type " %s;\t" \
1189 "offset:%u;\tsize:%u;\tsigned:%d;\n", name,\
1190 (unsigned int)offsetof(typeof(field), item),\
1191 (unsigned int)sizeof(type), \
1192 is_signed_type(type)); \
1193 if (!ret) \
1194 return 0; \
1195 } while (0)
1196
1197 static int kprobe_event_show_format(struct ftrace_event_call *call,
1198 struct trace_seq *s)
1199 {
1200 struct kprobe_trace_entry field __attribute__((unused));
1201 int ret, i;
1202 struct trace_probe *tp = (struct trace_probe *)call->data;
1203
1204 SHOW_FIELD(unsigned long, ip, FIELD_STRING_IP);
1205 SHOW_FIELD(int, nargs, FIELD_STRING_NARGS);
1206
1207 /* Show fields */
1208 for (i = 0; i < tp->nr_args; i++)
1209 SHOW_FIELD(unsigned long, args[i], tp->args[i].name);
1210 trace_seq_puts(s, "\n");
1211
1212 return __probe_event_show_format(s, tp, "(%lx)",
1213 "REC->" FIELD_STRING_IP);
1214 }
1215
1216 static int kretprobe_event_show_format(struct ftrace_event_call *call,
1217 struct trace_seq *s)
1218 {
1219 struct kretprobe_trace_entry field __attribute__((unused));
1220 int ret, i;
1221 struct trace_probe *tp = (struct trace_probe *)call->data;
1222
1223 SHOW_FIELD(unsigned long, func, FIELD_STRING_FUNC);
1224 SHOW_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP);
1225 SHOW_FIELD(int, nargs, FIELD_STRING_NARGS);
1226
1227 /* Show fields */
1228 for (i = 0; i < tp->nr_args; i++)
1229 SHOW_FIELD(unsigned long, args[i], tp->args[i].name);
1230 trace_seq_puts(s, "\n");
1231
1232 return __probe_event_show_format(s, tp, "(%lx <- %lx)",
1233 "REC->" FIELD_STRING_FUNC
1234 ", REC->" FIELD_STRING_RETIP);
1235 }
1236
1237 #ifdef CONFIG_PERF_EVENTS
1238
1239 /* Kprobe profile handler */
1240 static __kprobes int kprobe_profile_func(struct kprobe *kp,
1241 struct pt_regs *regs)
1242 {
1243 struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
1244 struct ftrace_event_call *call = &tp->call;
1245 struct kprobe_trace_entry *entry;
1246 struct trace_entry *ent;
1247 int size, __size, i, pc, __cpu;
1248 unsigned long irq_flags;
1249 char *trace_buf;
1250 char *raw_data;
1251 int rctx;
1252
1253 pc = preempt_count();
1254 __size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args);
1255 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1256 size -= sizeof(u32);
1257 if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE,
1258 "profile buffer not large enough"))
1259 return 0;
1260
1261 /*
1262 * Protect the non nmi buffer
1263 * This also protects the rcu read side
1264 */
1265 local_irq_save(irq_flags);
1266
1267 rctx = perf_swevent_get_recursion_context();
1268 if (rctx < 0)
1269 goto end_recursion;
1270
1271 __cpu = smp_processor_id();
1272
1273 if (in_nmi())
1274 trace_buf = rcu_dereference(perf_trace_buf_nmi);
1275 else
1276 trace_buf = rcu_dereference(perf_trace_buf);
1277
1278 if (!trace_buf)
1279 goto end;
1280
1281 raw_data = per_cpu_ptr(trace_buf, __cpu);
1282
1283 /* Zero dead bytes from alignment to avoid buffer leak to userspace */
1284 *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
1285 entry = (struct kprobe_trace_entry *)raw_data;
1286 ent = &entry->ent;
1287
1288 tracing_generic_entry_update(ent, irq_flags, pc);
1289 ent->type = call->id;
1290 entry->nargs = tp->nr_args;
1291 entry->ip = (unsigned long)kp->addr;
1292 for (i = 0; i < tp->nr_args; i++)
1293 entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
1294 perf_tp_event(call->id, entry->ip, 1, entry, size);
1295
1296 end:
1297 perf_swevent_put_recursion_context(rctx);
1298 end_recursion:
1299 local_irq_restore(irq_flags);
1300
1301 return 0;
1302 }
1303
1304 /* Kretprobe profile handler */
1305 static __kprobes int kretprobe_profile_func(struct kretprobe_instance *ri,
1306 struct pt_regs *regs)
1307 {
1308 struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
1309 struct ftrace_event_call *call = &tp->call;
1310 struct kretprobe_trace_entry *entry;
1311 struct trace_entry *ent;
1312 int size, __size, i, pc, __cpu;
1313 unsigned long irq_flags;
1314 char *trace_buf;
1315 char *raw_data;
1316 int rctx;
1317
1318 pc = preempt_count();
1319 __size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args);
1320 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1321 size -= sizeof(u32);
1322 if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE,
1323 "profile buffer not large enough"))
1324 return 0;
1325
1326 /*
1327 * Protect the non nmi buffer
1328 * This also protects the rcu read side
1329 */
1330 local_irq_save(irq_flags);
1331
1332 rctx = perf_swevent_get_recursion_context();
1333 if (rctx < 0)
1334 goto end_recursion;
1335
1336 __cpu = smp_processor_id();
1337
1338 if (in_nmi())
1339 trace_buf = rcu_dereference(perf_trace_buf_nmi);
1340 else
1341 trace_buf = rcu_dereference(perf_trace_buf);
1342
1343 if (!trace_buf)
1344 goto end;
1345
1346 raw_data = per_cpu_ptr(trace_buf, __cpu);
1347
1348 /* Zero dead bytes from alignment to avoid buffer leak to userspace */
1349 *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
1350 entry = (struct kretprobe_trace_entry *)raw_data;
1351 ent = &entry->ent;
1352
1353 tracing_generic_entry_update(ent, irq_flags, pc);
1354 ent->type = call->id;
1355 entry->nargs = tp->nr_args;
1356 entry->func = (unsigned long)tp->rp.kp.addr;
1357 entry->ret_ip = (unsigned long)ri->ret_addr;
1358 for (i = 0; i < tp->nr_args; i++)
1359 entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
1360 perf_tp_event(call->id, entry->ret_ip, 1, entry, size);
1361
1362 end:
1363 perf_swevent_put_recursion_context(rctx);
1364 end_recursion:
1365 local_irq_restore(irq_flags);
1366
1367 return 0;
1368 }
1369
1370 static int probe_profile_enable(struct ftrace_event_call *call)
1371 {
1372 struct trace_probe *tp = (struct trace_probe *)call->data;
1373
1374 tp->flags |= TP_FLAG_PROFILE;
1375
1376 if (probe_is_return(tp))
1377 return enable_kretprobe(&tp->rp);
1378 else
1379 return enable_kprobe(&tp->rp.kp);
1380 }
1381
1382 static void probe_profile_disable(struct ftrace_event_call *call)
1383 {
1384 struct trace_probe *tp = (struct trace_probe *)call->data;
1385
1386 tp->flags &= ~TP_FLAG_PROFILE;
1387
1388 if (!(tp->flags & TP_FLAG_TRACE)) {
1389 if (probe_is_return(tp))
1390 disable_kretprobe(&tp->rp);
1391 else
1392 disable_kprobe(&tp->rp.kp);
1393 }
1394 }
1395 #endif /* CONFIG_PERF_EVENTS */
1396
1397
1398 static __kprobes
1399 int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1400 {
1401 struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
1402
1403 if (tp->flags & TP_FLAG_TRACE)
1404 kprobe_trace_func(kp, regs);
1405 #ifdef CONFIG_PERF_EVENTS
1406 if (tp->flags & TP_FLAG_PROFILE)
1407 kprobe_profile_func(kp, regs);
1408 #endif
1409 return 0; /* We don't tweek kernel, so just return 0 */
1410 }
1411
1412 static __kprobes
1413 int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1414 {
1415 struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
1416
1417 if (tp->flags & TP_FLAG_TRACE)
1418 kretprobe_trace_func(ri, regs);
1419 #ifdef CONFIG_PERF_EVENTS
1420 if (tp->flags & TP_FLAG_PROFILE)
1421 kretprobe_profile_func(ri, regs);
1422 #endif
1423 return 0; /* We don't tweek kernel, so just return 0 */
1424 }
1425
1426 static int register_probe_event(struct trace_probe *tp)
1427 {
1428 struct ftrace_event_call *call = &tp->call;
1429 int ret;
1430
1431 /* Initialize ftrace_event_call */
1432 if (probe_is_return(tp)) {
1433 tp->event.trace = print_kretprobe_event;
1434 call->raw_init = probe_event_raw_init;
1435 call->show_format = kretprobe_event_show_format;
1436 call->define_fields = kretprobe_event_define_fields;
1437 } else {
1438 tp->event.trace = print_kprobe_event;
1439 call->raw_init = probe_event_raw_init;
1440 call->show_format = kprobe_event_show_format;
1441 call->define_fields = kprobe_event_define_fields;
1442 }
1443 call->event = &tp->event;
1444 call->id = register_ftrace_event(&tp->event);
1445 if (!call->id)
1446 return -ENODEV;
1447 call->enabled = 0;
1448 call->regfunc = probe_event_enable;
1449 call->unregfunc = probe_event_disable;
1450
1451 #ifdef CONFIG_PERF_EVENTS
1452 call->profile_enable = probe_profile_enable;
1453 call->profile_disable = probe_profile_disable;
1454 #endif
1455 call->data = tp;
1456 ret = trace_add_event_call(call);
1457 if (ret) {
1458 pr_info("Failed to register kprobe event: %s\n", call->name);
1459 unregister_ftrace_event(&tp->event);
1460 }
1461 return ret;
1462 }
1463
1464 static void unregister_probe_event(struct trace_probe *tp)
1465 {
1466 /* tp->event is unregistered in trace_remove_event_call() */
1467 trace_remove_event_call(&tp->call);
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, warn = 0;
1511 int (*target)(int, int, int, int, int, int);
1512 struct trace_probe *tp;
1513
1514 target = kprobe_trace_selftest_target;
1515
1516 pr_info("Testing kprobe tracing: ");
1517
1518 ret = command_trace_probe("p:testprobe kprobe_trace_selftest_target "
1519 "$stack $stack0 +0($stack)");
1520 if (WARN_ON_ONCE(ret)) {
1521 pr_warning("error on probing function entry.\n");
1522 warn++;
1523 } else {
1524 /* Enable trace point */
1525 tp = find_probe_event("testprobe", KPROBE_EVENT_SYSTEM);
1526 if (WARN_ON_ONCE(tp == NULL)) {
1527 pr_warning("error on getting new probe.\n");
1528 warn++;
1529 } else
1530 probe_event_enable(&tp->call);
1531 }
1532
1533 ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target "
1534 "$retval");
1535 if (WARN_ON_ONCE(ret)) {
1536 pr_warning("error on probing function return.\n");
1537 warn++;
1538 } else {
1539 /* Enable trace point */
1540 tp = find_probe_event("testprobe2", KPROBE_EVENT_SYSTEM);
1541 if (WARN_ON_ONCE(tp == NULL)) {
1542 pr_warning("error on getting new probe.\n");
1543 warn++;
1544 } else
1545 probe_event_enable(&tp->call);
1546 }
1547
1548 if (warn)
1549 goto end;
1550
1551 ret = target(1, 2, 3, 4, 5, 6);
1552
1553 ret = command_trace_probe("-:testprobe");
1554 if (WARN_ON_ONCE(ret)) {
1555 pr_warning("error on deleting a probe.\n");
1556 warn++;
1557 }
1558
1559 ret = command_trace_probe("-:testprobe2");
1560 if (WARN_ON_ONCE(ret)) {
1561 pr_warning("error on deleting a probe.\n");
1562 warn++;
1563 }
1564
1565 end:
1566 cleanup_all_probes();
1567 if (warn)
1568 pr_cont("NG: Some tests are failed. Please check them.\n");
1569 else
1570 pr_cont("OK\n");
1571 return 0;
1572 }
1573
1574 late_initcall(kprobe_trace_self_tests_init);
1575
1576 #endif
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