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-rw-r--r--kernel/trace/trace_kprobe.c1542
1 files changed, 1542 insertions, 0 deletions
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
new file mode 100644
index 000000000000..b52d397e57eb
--- /dev/null
+++ b/kernel/trace/trace_kprobe.c
@@ -0,0 +1,1542 @@
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
47const 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
60struct fetch_func {
61 unsigned long (*func)(struct pt_regs *, void *);
62 void *data;
63};
64
65static __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 */
72static __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
78static __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
85static __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
94static __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
99static __kprobes unsigned long fetch_retvalue(struct pt_regs *regs,
100 void *dummy)
101{
102 return regs_return_value(regs);
103}
104
105static __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 */
112struct symbol_cache {
113 char *symbol;
114 long offset;
115 unsigned long addr;
116};
117
118static 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
126static void free_symbol_cache(struct symbol_cache *sc)
127{
128 kfree(sc->symbol);
129 kfree(sc);
130}
131
132static 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
153static __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 */
164struct indirect_fetch_data {
165 struct fetch_func orig;
166 long offset;
167};
168
169static __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
182static __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
195struct 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
204struct 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
220static __kprobes int probe_is_return(struct trace_probe *tp)
221{
222 return tp->rp.handler != NULL;
223}
224
225static __kprobes const char *probe_symbol(struct trace_probe *tp)
226{
227 return tp->symbol ? tp->symbol : "unknown";
228}
229
230static 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 }
269end:
270 if (ret >= n)
271 return -ENOSPC;
272 return ret;
273}
274
275static int register_probe_event(struct trace_probe *tp);
276static void unregister_probe_event(struct trace_probe *tp);
277
278static DEFINE_MUTEX(probe_lock);
279static LIST_HEAD(probe_list);
280
281static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
282static int kretprobe_dispatcher(struct kretprobe_instance *ri,
283 struct pt_regs *regs);
284
285/*
286 * Allocate new trace_probe and initialize it (including kprobes).
287 */
288static struct trace_probe *alloc_trace_probe(const char *group,
289 const char *event,
290 void *addr,
291 const char *symbol,
292 unsigned long offs,
293 int nargs, int is_return)
294{
295 struct trace_probe *tp;
296
297 tp = kzalloc(SIZEOF_TRACE_PROBE(nargs), GFP_KERNEL);
298 if (!tp)
299 return ERR_PTR(-ENOMEM);
300
301 if (symbol) {
302 tp->symbol = kstrdup(symbol, GFP_KERNEL);
303 if (!tp->symbol)
304 goto error;
305 tp->rp.kp.symbol_name = tp->symbol;
306 tp->rp.kp.offset = offs;
307 } else
308 tp->rp.kp.addr = addr;
309
310 if (is_return)
311 tp->rp.handler = kretprobe_dispatcher;
312 else
313 tp->rp.kp.pre_handler = kprobe_dispatcher;
314
315 if (!event)
316 goto error;
317 tp->call.name = kstrdup(event, GFP_KERNEL);
318 if (!tp->call.name)
319 goto error;
320
321 if (!group)
322 goto error;
323 tp->call.system = kstrdup(group, GFP_KERNEL);
324 if (!tp->call.system)
325 goto error;
326
327 INIT_LIST_HEAD(&tp->list);
328 return tp;
329error:
330 kfree(tp->call.name);
331 kfree(tp->symbol);
332 kfree(tp);
333 return ERR_PTR(-ENOMEM);
334}
335
336static void free_probe_arg(struct probe_arg *arg)
337{
338 if (arg->fetch.func == fetch_symbol)
339 free_symbol_cache(arg->fetch.data);
340 else if (arg->fetch.func == fetch_indirect)
341 free_indirect_fetch_data(arg->fetch.data);
342 kfree(arg->name);
343}
344
345static void free_trace_probe(struct trace_probe *tp)
346{
347 int i;
348
349 for (i = 0; i < tp->nr_args; i++)
350 free_probe_arg(&tp->args[i]);
351
352 kfree(tp->call.system);
353 kfree(tp->call.name);
354 kfree(tp->symbol);
355 kfree(tp);
356}
357
358static struct trace_probe *find_probe_event(const char *event,
359 const char *group)
360{
361 struct trace_probe *tp;
362
363 list_for_each_entry(tp, &probe_list, list)
364 if (strcmp(tp->call.name, event) == 0 &&
365 strcmp(tp->call.system, group) == 0)
366 return tp;
367 return NULL;
368}
369
370/* Unregister a trace_probe and probe_event: call with locking probe_lock */
371static void unregister_trace_probe(struct trace_probe *tp)
372{
373 if (probe_is_return(tp))
374 unregister_kretprobe(&tp->rp);
375 else
376 unregister_kprobe(&tp->rp.kp);
377 list_del(&tp->list);
378 unregister_probe_event(tp);
379}
380
381/* Register a trace_probe and probe_event */
382static int register_trace_probe(struct trace_probe *tp)
383{
384 struct trace_probe *old_tp;
385 int ret;
386
387 mutex_lock(&probe_lock);
388
389 /* register as an event */
390 old_tp = find_probe_event(tp->call.name, tp->call.system);
391 if (old_tp) {
392 /* delete old event */
393 unregister_trace_probe(old_tp);
394 free_trace_probe(old_tp);
395 }
396 ret = register_probe_event(tp);
397 if (ret) {
398 pr_warning("Faild to register probe event(%d)\n", ret);
399 goto end;
400 }
401
402 tp->rp.kp.flags |= KPROBE_FLAG_DISABLED;
403 if (probe_is_return(tp))
404 ret = register_kretprobe(&tp->rp);
405 else
406 ret = register_kprobe(&tp->rp.kp);
407
408 if (ret) {
409 pr_warning("Could not insert probe(%d)\n", ret);
410 if (ret == -EILSEQ) {
411 pr_warning("Probing address(0x%p) is not an "
412 "instruction boundary.\n",
413 tp->rp.kp.addr);
414 ret = -EINVAL;
415 }
416 unregister_probe_event(tp);
417 } else
418 list_add_tail(&tp->list, &probe_list);
419end:
420 mutex_unlock(&probe_lock);
421 return ret;
422}
423
424/* Split symbol and offset. */
425static int split_symbol_offset(char *symbol, unsigned long *offset)
426{
427 char *tmp;
428 int ret;
429
430 if (!offset)
431 return -EINVAL;
432
433 tmp = strchr(symbol, '+');
434 if (tmp) {
435 /* skip sign because strict_strtol doesn't accept '+' */
436 ret = strict_strtoul(tmp + 1, 0, offset);
437 if (ret)
438 return ret;
439 *tmp = '\0';
440 } else
441 *offset = 0;
442 return 0;
443}
444
445#define PARAM_MAX_ARGS 16
446#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
447
448static int parse_probe_vars(char *arg, struct fetch_func *ff, int is_return)
449{
450 int ret = 0;
451 unsigned long param;
452
453 if (strcmp(arg, "retval") == 0) {
454 if (is_return) {
455 ff->func = fetch_retvalue;
456 ff->data = NULL;
457 } else
458 ret = -EINVAL;
459 } else if (strncmp(arg, "stack", 5) == 0) {
460 if (arg[5] == '\0') {
461 ff->func = fetch_stack_address;
462 ff->data = NULL;
463 } else if (isdigit(arg[5])) {
464 ret = strict_strtoul(arg + 5, 10, &param);
465 if (ret || param > PARAM_MAX_STACK)
466 ret = -EINVAL;
467 else {
468 ff->func = fetch_stack;
469 ff->data = (void *)param;
470 }
471 } else
472 ret = -EINVAL;
473 } else if (strncmp(arg, "arg", 3) == 0 && isdigit(arg[3])) {
474 ret = strict_strtoul(arg + 3, 10, &param);
475 if (ret || param > PARAM_MAX_ARGS)
476 ret = -EINVAL;
477 else {
478 ff->func = fetch_argument;
479 ff->data = (void *)param;
480 }
481 } else
482 ret = -EINVAL;
483 return ret;
484}
485
486/* Recursive argument parser */
487static int __parse_probe_arg(char *arg, struct fetch_func *ff, int is_return)
488{
489 int ret = 0;
490 unsigned long param;
491 long offset;
492 char *tmp;
493
494 switch (arg[0]) {
495 case '$':
496 ret = parse_probe_vars(arg + 1, ff, is_return);
497 break;
498 case '%': /* named register */
499 ret = regs_query_register_offset(arg + 1);
500 if (ret >= 0) {
501 ff->func = fetch_register;
502 ff->data = (void *)(unsigned long)ret;
503 ret = 0;
504 }
505 break;
506 case '@': /* memory or symbol */
507 if (isdigit(arg[1])) {
508 ret = strict_strtoul(arg + 1, 0, &param);
509 if (ret)
510 break;
511 ff->func = fetch_memory;
512 ff->data = (void *)param;
513 } else {
514 ret = split_symbol_offset(arg + 1, &offset);
515 if (ret)
516 break;
517 ff->data = alloc_symbol_cache(arg + 1, offset);
518 if (ff->data)
519 ff->func = fetch_symbol;
520 else
521 ret = -EINVAL;
522 }
523 break;
524 case '+': /* indirect memory */
525 case '-':
526 tmp = strchr(arg, '(');
527 if (!tmp) {
528 ret = -EINVAL;
529 break;
530 }
531 *tmp = '\0';
532 ret = strict_strtol(arg + 1, 0, &offset);
533 if (ret)
534 break;
535 if (arg[0] == '-')
536 offset = -offset;
537 arg = tmp + 1;
538 tmp = strrchr(arg, ')');
539 if (tmp) {
540 struct indirect_fetch_data *id;
541 *tmp = '\0';
542 id = kzalloc(sizeof(struct indirect_fetch_data),
543 GFP_KERNEL);
544 if (!id)
545 return -ENOMEM;
546 id->offset = offset;
547 ret = __parse_probe_arg(arg, &id->orig, is_return);
548 if (ret)
549 kfree(id);
550 else {
551 ff->func = fetch_indirect;
552 ff->data = (void *)id;
553 }
554 } else
555 ret = -EINVAL;
556 break;
557 default:
558 /* TODO: support custom handler */
559 ret = -EINVAL;
560 }
561 return ret;
562}
563
564/* String length checking wrapper */
565static int parse_probe_arg(char *arg, struct fetch_func *ff, int is_return)
566{
567 if (strlen(arg) > MAX_ARGSTR_LEN) {
568 pr_info("Argument is too long.: %s\n", arg);
569 return -ENOSPC;
570 }
571 return __parse_probe_arg(arg, ff, is_return);
572}
573
574/* Return 1 if name is reserved or already used by another argument */
575static int conflict_field_name(const char *name,
576 struct probe_arg *args, int narg)
577{
578 int i;
579 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
580 if (strcmp(reserved_field_names[i], name) == 0)
581 return 1;
582 for (i = 0; i < narg; i++)
583 if (strcmp(args[i].name, name) == 0)
584 return 1;
585 return 0;
586}
587
588static int create_trace_probe(int argc, char **argv)
589{
590 /*
591 * Argument syntax:
592 * - Add kprobe: p[:[GRP/]EVENT] KSYM[+OFFS]|KADDR [FETCHARGS]
593 * - Add kretprobe: r[:[GRP/]EVENT] KSYM[+0] [FETCHARGS]
594 * Fetch args:
595 * $argN : fetch Nth of function argument. (N:0-)
596 * $retval : fetch return value
597 * $stack : fetch stack address
598 * $stackN : fetch Nth of stack (N:0-)
599 * @ADDR : fetch memory at ADDR (ADDR should be in kernel)
600 * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
601 * %REG : fetch register REG
602 * Indirect memory fetch:
603 * +|-offs(ARG) : fetch memory at ARG +|- offs address.
604 * Alias name of args:
605 * NAME=FETCHARG : set NAME as alias of FETCHARG.
606 */
607 struct trace_probe *tp;
608 int i, ret = 0;
609 int is_return = 0, is_delete = 0;
610 char *symbol = NULL, *event = NULL, *arg = NULL, *group = NULL;
611 unsigned long offset = 0;
612 void *addr = NULL;
613 char buf[MAX_EVENT_NAME_LEN];
614
615 /* argc must be >= 1 */
616 if (argv[0][0] == 'p')
617 is_return = 0;
618 else if (argv[0][0] == 'r')
619 is_return = 1;
620 else if (argv[0][0] == '-')
621 is_delete = 1;
622 else {
623 pr_info("Probe definition must be started with 'p', 'r' or"
624 " '-'.\n");
625 return -EINVAL;
626 }
627
628 if (argv[0][1] == ':') {
629 event = &argv[0][2];
630 if (strchr(event, '/')) {
631 group = event;
632 event = strchr(group, '/') + 1;
633 event[-1] = '\0';
634 if (strlen(group) == 0) {
635 pr_info("Group name is not specifiled\n");
636 return -EINVAL;
637 }
638 }
639 if (strlen(event) == 0) {
640 pr_info("Event name is not specifiled\n");
641 return -EINVAL;
642 }
643 }
644 if (!group)
645 group = KPROBE_EVENT_SYSTEM;
646
647 if (is_delete) {
648 if (!event) {
649 pr_info("Delete command needs an event name.\n");
650 return -EINVAL;
651 }
652 tp = find_probe_event(event, group);
653 if (!tp) {
654 pr_info("Event %s/%s doesn't exist.\n", group, event);
655 return -ENOENT;
656 }
657 /* delete an event */
658 unregister_trace_probe(tp);
659 free_trace_probe(tp);
660 return 0;
661 }
662
663 if (argc < 2) {
664 pr_info("Probe point is not specified.\n");
665 return -EINVAL;
666 }
667 if (isdigit(argv[1][0])) {
668 if (is_return) {
669 pr_info("Return probe point must be a symbol.\n");
670 return -EINVAL;
671 }
672 /* an address specified */
673 ret = strict_strtoul(&argv[0][2], 0, (unsigned long *)&addr);
674 if (ret) {
675 pr_info("Failed to parse address.\n");
676 return ret;
677 }
678 } else {
679 /* a symbol specified */
680 symbol = argv[1];
681 /* TODO: support .init module functions */
682 ret = split_symbol_offset(symbol, &offset);
683 if (ret) {
684 pr_info("Failed to parse symbol.\n");
685 return ret;
686 }
687 if (offset && is_return) {
688 pr_info("Return probe must be used without offset.\n");
689 return -EINVAL;
690 }
691 }
692 argc -= 2; argv += 2;
693
694 /* setup a probe */
695 if (!event) {
696 /* Make a new event name */
697 if (symbol)
698 snprintf(buf, MAX_EVENT_NAME_LEN, "%c@%s%+ld",
699 is_return ? 'r' : 'p', symbol, offset);
700 else
701 snprintf(buf, MAX_EVENT_NAME_LEN, "%c@0x%p",
702 is_return ? 'r' : 'p', addr);
703 event = buf;
704 }
705 tp = alloc_trace_probe(group, event, addr, symbol, offset, argc,
706 is_return);
707 if (IS_ERR(tp)) {
708 pr_info("Failed to allocate trace_probe.(%d)\n",
709 (int)PTR_ERR(tp));
710 return PTR_ERR(tp);
711 }
712
713 /* parse arguments */
714 ret = 0;
715 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
716 /* Parse argument name */
717 arg = strchr(argv[i], '=');
718 if (arg)
719 *arg++ = '\0';
720 else
721 arg = argv[i];
722
723 if (conflict_field_name(argv[i], tp->args, i)) {
724 pr_info("Argument%d name '%s' conflicts with "
725 "another field.\n", i, argv[i]);
726 ret = -EINVAL;
727 goto error;
728 }
729
730 tp->args[i].name = kstrdup(argv[i], GFP_KERNEL);
731 if (!tp->args[i].name) {
732 pr_info("Failed to allocate argument%d name '%s'.\n",
733 i, argv[i]);
734 ret = -ENOMEM;
735 goto error;
736 }
737
738 /* Parse fetch argument */
739 ret = parse_probe_arg(arg, &tp->args[i].fetch, is_return);
740 if (ret) {
741 pr_info("Parse error at argument%d. (%d)\n", i, ret);
742 kfree(tp->args[i].name);
743 goto error;
744 }
745
746 tp->nr_args++;
747 }
748
749 ret = register_trace_probe(tp);
750 if (ret)
751 goto error;
752 return 0;
753
754error:
755 free_trace_probe(tp);
756 return ret;
757}
758
759static void cleanup_all_probes(void)
760{
761 struct trace_probe *tp;
762
763 mutex_lock(&probe_lock);
764 /* TODO: Use batch unregistration */
765 while (!list_empty(&probe_list)) {
766 tp = list_entry(probe_list.next, struct trace_probe, list);
767 unregister_trace_probe(tp);
768 free_trace_probe(tp);
769 }
770 mutex_unlock(&probe_lock);
771}
772
773
774/* Probes listing interfaces */
775static void *probes_seq_start(struct seq_file *m, loff_t *pos)
776{
777 mutex_lock(&probe_lock);
778 return seq_list_start(&probe_list, *pos);
779}
780
781static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
782{
783 return seq_list_next(v, &probe_list, pos);
784}
785
786static void probes_seq_stop(struct seq_file *m, void *v)
787{
788 mutex_unlock(&probe_lock);
789}
790
791static int probes_seq_show(struct seq_file *m, void *v)
792{
793 struct trace_probe *tp = v;
794 int i, ret;
795 char buf[MAX_ARGSTR_LEN + 1];
796
797 seq_printf(m, "%c", probe_is_return(tp) ? 'r' : 'p');
798 seq_printf(m, ":%s/%s", tp->call.system, tp->call.name);
799
800 if (!tp->symbol)
801 seq_printf(m, " 0x%p", tp->rp.kp.addr);
802 else if (tp->rp.kp.offset)
803 seq_printf(m, " %s+%u", probe_symbol(tp), tp->rp.kp.offset);
804 else
805 seq_printf(m, " %s", probe_symbol(tp));
806
807 for (i = 0; i < tp->nr_args; i++) {
808 ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i].fetch);
809 if (ret < 0) {
810 pr_warning("Argument%d decoding error(%d).\n", i, ret);
811 return ret;
812 }
813 seq_printf(m, " %s=%s", tp->args[i].name, buf);
814 }
815 seq_printf(m, "\n");
816 return 0;
817}
818
819static const struct seq_operations probes_seq_op = {
820 .start = probes_seq_start,
821 .next = probes_seq_next,
822 .stop = probes_seq_stop,
823 .show = probes_seq_show
824};
825
826static int probes_open(struct inode *inode, struct file *file)
827{
828 if ((file->f_mode & FMODE_WRITE) &&
829 (file->f_flags & O_TRUNC))
830 cleanup_all_probes();
831
832 return seq_open(file, &probes_seq_op);
833}
834
835static int command_trace_probe(const char *buf)
836{
837 char **argv;
838 int argc = 0, ret = 0;
839
840 argv = argv_split(GFP_KERNEL, buf, &argc);
841 if (!argv)
842 return -ENOMEM;
843
844 if (argc)
845 ret = create_trace_probe(argc, argv);
846
847 argv_free(argv);
848 return ret;
849}
850
851#define WRITE_BUFSIZE 128
852
853static ssize_t probes_write(struct file *file, const char __user *buffer,
854 size_t count, loff_t *ppos)
855{
856 char *kbuf, *tmp;
857 int ret;
858 size_t done;
859 size_t size;
860
861 kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
862 if (!kbuf)
863 return -ENOMEM;
864
865 ret = done = 0;
866 while (done < count) {
867 size = count - done;
868 if (size >= WRITE_BUFSIZE)
869 size = WRITE_BUFSIZE - 1;
870 if (copy_from_user(kbuf, buffer + done, size)) {
871 ret = -EFAULT;
872 goto out;
873 }
874 kbuf[size] = '\0';
875 tmp = strchr(kbuf, '\n');
876 if (tmp) {
877 *tmp = '\0';
878 size = tmp - kbuf + 1;
879 } else if (done + size < count) {
880 pr_warning("Line length is too long: "
881 "Should be less than %d.", WRITE_BUFSIZE);
882 ret = -EINVAL;
883 goto out;
884 }
885 done += size;
886 /* Remove comments */
887 tmp = strchr(kbuf, '#');
888 if (tmp)
889 *tmp = '\0';
890
891 ret = command_trace_probe(kbuf);
892 if (ret)
893 goto out;
894 }
895 ret = done;
896out:
897 kfree(kbuf);
898 return ret;
899}
900
901static const struct file_operations kprobe_events_ops = {
902 .owner = THIS_MODULE,
903 .open = probes_open,
904 .read = seq_read,
905 .llseek = seq_lseek,
906 .release = seq_release,
907 .write = probes_write,
908};
909
910/* Probes profiling interfaces */
911static int probes_profile_seq_show(struct seq_file *m, void *v)
912{
913 struct trace_probe *tp = v;
914
915 seq_printf(m, " %-44s %15lu %15lu\n", tp->call.name, tp->nhit,
916 tp->rp.kp.nmissed);
917
918 return 0;
919}
920
921static const struct seq_operations profile_seq_op = {
922 .start = probes_seq_start,
923 .next = probes_seq_next,
924 .stop = probes_seq_stop,
925 .show = probes_profile_seq_show
926};
927
928static int profile_open(struct inode *inode, struct file *file)
929{
930 return seq_open(file, &profile_seq_op);
931}
932
933static const struct file_operations kprobe_profile_ops = {
934 .owner = THIS_MODULE,
935 .open = profile_open,
936 .read = seq_read,
937 .llseek = seq_lseek,
938 .release = seq_release,
939};
940
941/* Kprobe handler */
942static __kprobes int kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
943{
944 struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
945 struct kprobe_trace_entry *entry;
946 struct ring_buffer_event *event;
947 struct ring_buffer *buffer;
948 int size, i, pc;
949 unsigned long irq_flags;
950 struct ftrace_event_call *call = &tp->call;
951
952 tp->nhit++;
953
954 local_save_flags(irq_flags);
955 pc = preempt_count();
956
957 size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args);
958
959 event = trace_current_buffer_lock_reserve(&buffer, call->id, size,
960 irq_flags, pc);
961 if (!event)
962 return 0;
963
964 entry = ring_buffer_event_data(event);
965 entry->nargs = tp->nr_args;
966 entry->ip = (unsigned long)kp->addr;
967 for (i = 0; i < tp->nr_args; i++)
968 entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
969
970 if (!filter_current_check_discard(buffer, call, entry, event))
971 trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
972 return 0;
973}
974
975/* Kretprobe handler */
976static __kprobes int kretprobe_trace_func(struct kretprobe_instance *ri,
977 struct pt_regs *regs)
978{
979 struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
980 struct kretprobe_trace_entry *entry;
981 struct ring_buffer_event *event;
982 struct ring_buffer *buffer;
983 int size, i, pc;
984 unsigned long irq_flags;
985 struct ftrace_event_call *call = &tp->call;
986
987 local_save_flags(irq_flags);
988 pc = preempt_count();
989
990 size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args);
991
992 event = trace_current_buffer_lock_reserve(&buffer, call->id, size,
993 irq_flags, pc);
994 if (!event)
995 return 0;
996
997 entry = ring_buffer_event_data(event);
998 entry->nargs = tp->nr_args;
999 entry->func = (unsigned long)tp->rp.kp.addr;
1000 entry->ret_ip = (unsigned long)ri->ret_addr;
1001 for (i = 0; i < tp->nr_args; i++)
1002 entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
1003
1004 if (!filter_current_check_discard(buffer, call, entry, event))
1005 trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
1006
1007 return 0;
1008}
1009
1010/* Event entry printers */
1011enum print_line_t
1012print_kprobe_event(struct trace_iterator *iter, int flags)
1013{
1014 struct kprobe_trace_entry *field;
1015 struct trace_seq *s = &iter->seq;
1016 struct trace_event *event;
1017 struct trace_probe *tp;
1018 int i;
1019
1020 field = (struct kprobe_trace_entry *)iter->ent;
1021 event = ftrace_find_event(field->ent.type);
1022 tp = container_of(event, struct trace_probe, 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;
1042partial:
1043 return TRACE_TYPE_PARTIAL_LINE;
1044}
1045
1046enum print_line_t
1047print_kretprobe_event(struct trace_iterator *iter, int flags)
1048{
1049 struct kretprobe_trace_entry *field;
1050 struct trace_seq *s = &iter->seq;
1051 struct trace_event *event;
1052 struct trace_probe *tp;
1053 int i;
1054
1055 field = (struct kretprobe_trace_entry *)iter->ent;
1056 event = ftrace_find_event(field->ent.type);
1057 tp = container_of(event, struct trace_probe, event);
1058
1059 if (!trace_seq_printf(s, "%s: (", tp->call.name))
1060 goto partial;
1061
1062 if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
1063 goto partial;
1064
1065 if (!trace_seq_puts(s, " <- "))
1066 goto partial;
1067
1068 if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
1069 goto partial;
1070
1071 if (!trace_seq_puts(s, ")"))
1072 goto partial;
1073
1074 for (i = 0; i < field->nargs; i++)
1075 if (!trace_seq_printf(s, " %s=%lx",
1076 tp->args[i].name, field->args[i]))
1077 goto partial;
1078
1079 if (!trace_seq_puts(s, "\n"))
1080 goto partial;
1081
1082 return TRACE_TYPE_HANDLED;
1083partial:
1084 return TRACE_TYPE_PARTIAL_LINE;
1085}
1086
1087static int probe_event_enable(struct ftrace_event_call *call)
1088{
1089 struct trace_probe *tp = (struct trace_probe *)call->data;
1090
1091 tp->flags |= TP_FLAG_TRACE;
1092 if (probe_is_return(tp))
1093 return enable_kretprobe(&tp->rp);
1094 else
1095 return enable_kprobe(&tp->rp.kp);
1096}
1097
1098static void probe_event_disable(struct ftrace_event_call *call)
1099{
1100 struct trace_probe *tp = (struct trace_probe *)call->data;
1101
1102 tp->flags &= ~TP_FLAG_TRACE;
1103 if (!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE))) {
1104 if (probe_is_return(tp))
1105 disable_kretprobe(&tp->rp);
1106 else
1107 disable_kprobe(&tp->rp.kp);
1108 }
1109}
1110
1111static int probe_event_raw_init(struct ftrace_event_call *event_call)
1112{
1113 INIT_LIST_HEAD(&event_call->fields);
1114
1115 return 0;
1116}
1117
1118#undef DEFINE_FIELD
1119#define DEFINE_FIELD(type, item, name, is_signed) \
1120 do { \
1121 ret = trace_define_field(event_call, #type, name, \
1122 offsetof(typeof(field), item), \
1123 sizeof(field.item), is_signed, \
1124 FILTER_OTHER); \
1125 if (ret) \
1126 return ret; \
1127 } while (0)
1128
1129static int kprobe_event_define_fields(struct ftrace_event_call *event_call)
1130{
1131 int ret, i;
1132 struct kprobe_trace_entry field;
1133 struct trace_probe *tp = (struct trace_probe *)event_call->data;
1134
1135 ret = trace_define_common_fields(event_call);
1136 if (ret)
1137 return ret;
1138
1139 DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
1140 DEFINE_FIELD(int, nargs, FIELD_STRING_NARGS, 1);
1141 /* Set argument names as fields */
1142 for (i = 0; i < tp->nr_args; i++)
1143 DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0);
1144 return 0;
1145}
1146
1147static int kretprobe_event_define_fields(struct ftrace_event_call *event_call)
1148{
1149 int ret, i;
1150 struct kretprobe_trace_entry field;
1151 struct trace_probe *tp = (struct trace_probe *)event_call->data;
1152
1153 ret = trace_define_common_fields(event_call);
1154 if (ret)
1155 return ret;
1156
1157 DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
1158 DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
1159 DEFINE_FIELD(int, nargs, FIELD_STRING_NARGS, 1);
1160 /* Set argument names as fields */
1161 for (i = 0; i < tp->nr_args; i++)
1162 DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0);
1163 return 0;
1164}
1165
1166static int __probe_event_show_format(struct trace_seq *s,
1167 struct trace_probe *tp, const char *fmt,
1168 const char *arg)
1169{
1170 int i;
1171
1172 /* Show format */
1173 if (!trace_seq_printf(s, "\nprint fmt: \"%s", fmt))
1174 return 0;
1175
1176 for (i = 0; i < tp->nr_args; i++)
1177 if (!trace_seq_printf(s, " %s=%%lx", tp->args[i].name))
1178 return 0;
1179
1180 if (!trace_seq_printf(s, "\", %s", arg))
1181 return 0;
1182
1183 for (i = 0; i < tp->nr_args; i++)
1184 if (!trace_seq_printf(s, ", REC->%s", tp->args[i].name))
1185 return 0;
1186
1187 return trace_seq_puts(s, "\n");
1188}
1189
1190#undef SHOW_FIELD
1191#define SHOW_FIELD(type, item, name) \
1192 do { \
1193 ret = trace_seq_printf(s, "\tfield: " #type " %s;\t" \
1194 "offset:%u;\tsize:%u;\n", name, \
1195 (unsigned int)offsetof(typeof(field), item),\
1196 (unsigned int)sizeof(type)); \
1197 if (!ret) \
1198 return 0; \
1199 } while (0)
1200
1201static int kprobe_event_show_format(struct ftrace_event_call *call,
1202 struct trace_seq *s)
1203{
1204 struct kprobe_trace_entry field __attribute__((unused));
1205 int ret, i;
1206 struct trace_probe *tp = (struct trace_probe *)call->data;
1207
1208 SHOW_FIELD(unsigned long, ip, FIELD_STRING_IP);
1209 SHOW_FIELD(int, nargs, FIELD_STRING_NARGS);
1210
1211 /* Show fields */
1212 for (i = 0; i < tp->nr_args; i++)
1213 SHOW_FIELD(unsigned long, args[i], tp->args[i].name);
1214 trace_seq_puts(s, "\n");
1215
1216 return __probe_event_show_format(s, tp, "(%lx)",
1217 "REC->" FIELD_STRING_IP);
1218}
1219
1220static int kretprobe_event_show_format(struct ftrace_event_call *call,
1221 struct trace_seq *s)
1222{
1223 struct kretprobe_trace_entry field __attribute__((unused));
1224 int ret, i;
1225 struct trace_probe *tp = (struct trace_probe *)call->data;
1226
1227 SHOW_FIELD(unsigned long, func, FIELD_STRING_FUNC);
1228 SHOW_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP);
1229 SHOW_FIELD(int, nargs, FIELD_STRING_NARGS);
1230
1231 /* Show fields */
1232 for (i = 0; i < tp->nr_args; i++)
1233 SHOW_FIELD(unsigned long, args[i], tp->args[i].name);
1234 trace_seq_puts(s, "\n");
1235
1236 return __probe_event_show_format(s, tp, "(%lx <- %lx)",
1237 "REC->" FIELD_STRING_FUNC
1238 ", REC->" FIELD_STRING_RETIP);
1239}
1240
1241#ifdef CONFIG_EVENT_PROFILE
1242
1243/* Kprobe profile handler */
1244static __kprobes int kprobe_profile_func(struct kprobe *kp,
1245 struct pt_regs *regs)
1246{
1247 struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
1248 struct ftrace_event_call *call = &tp->call;
1249 struct kprobe_trace_entry *entry;
1250 struct trace_entry *ent;
1251 int size, __size, i, pc, __cpu;
1252 unsigned long irq_flags;
1253 char *trace_buf;
1254 char *raw_data;
1255 int rctx;
1256
1257 pc = preempt_count();
1258 __size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args);
1259 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1260 size -= sizeof(u32);
1261 if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE,
1262 "profile buffer not large enough"))
1263 return 0;
1264
1265 /*
1266 * Protect the non nmi buffer
1267 * This also protects the rcu read side
1268 */
1269 local_irq_save(irq_flags);
1270
1271 rctx = perf_swevent_get_recursion_context();
1272 if (rctx < 0)
1273 goto end_recursion;
1274
1275 __cpu = smp_processor_id();
1276
1277 if (in_nmi())
1278 trace_buf = rcu_dereference(perf_trace_buf_nmi);
1279 else
1280 trace_buf = rcu_dereference(perf_trace_buf);
1281
1282 if (!trace_buf)
1283 goto end;
1284
1285 raw_data = per_cpu_ptr(trace_buf, __cpu);
1286
1287 /* Zero dead bytes from alignment to avoid buffer leak to userspace */
1288 *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
1289 entry = (struct kprobe_trace_entry *)raw_data;
1290 ent = &entry->ent;
1291
1292 tracing_generic_entry_update(ent, irq_flags, pc);
1293 ent->type = call->id;
1294 entry->nargs = tp->nr_args;
1295 entry->ip = (unsigned long)kp->addr;
1296 for (i = 0; i < tp->nr_args; i++)
1297 entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
1298 perf_tp_event(call->id, entry->ip, 1, entry, size);
1299
1300end:
1301 perf_swevent_put_recursion_context(rctx);
1302end_recursion:
1303 local_irq_restore(irq_flags);
1304
1305 return 0;
1306}
1307
1308/* Kretprobe profile handler */
1309static __kprobes int kretprobe_profile_func(struct kretprobe_instance *ri,
1310 struct pt_regs *regs)
1311{
1312 struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
1313 struct ftrace_event_call *call = &tp->call;
1314 struct kretprobe_trace_entry *entry;
1315 struct trace_entry *ent;
1316 int size, __size, i, pc, __cpu;
1317 unsigned long irq_flags;
1318 char *trace_buf;
1319 char *raw_data;
1320 int rctx;
1321
1322 pc = preempt_count();
1323 __size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args);
1324 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1325 size -= sizeof(u32);
1326 if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE,
1327 "profile buffer not large enough"))
1328 return 0;
1329
1330 /*
1331 * Protect the non nmi buffer
1332 * This also protects the rcu read side
1333 */
1334 local_irq_save(irq_flags);
1335
1336 rctx = perf_swevent_get_recursion_context();
1337 if (rctx < 0)
1338 goto end_recursion;
1339
1340 __cpu = smp_processor_id();
1341
1342 if (in_nmi())
1343 trace_buf = rcu_dereference(perf_trace_buf_nmi);
1344 else
1345 trace_buf = rcu_dereference(perf_trace_buf);
1346
1347 if (!trace_buf)
1348 goto end;
1349
1350 raw_data = per_cpu_ptr(trace_buf, __cpu);
1351
1352 /* Zero dead bytes from alignment to avoid buffer leak to userspace */
1353 *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
1354 entry = (struct kretprobe_trace_entry *)raw_data;
1355 ent = &entry->ent;
1356
1357 tracing_generic_entry_update(ent, irq_flags, pc);
1358 ent->type = call->id;
1359 entry->nargs = tp->nr_args;
1360 entry->func = (unsigned long)tp->rp.kp.addr;
1361 entry->ret_ip = (unsigned long)ri->ret_addr;
1362 for (i = 0; i < tp->nr_args; i++)
1363 entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
1364 perf_tp_event(call->id, entry->ret_ip, 1, entry, size);
1365
1366end:
1367 perf_swevent_put_recursion_context(rctx);
1368end_recursion:
1369 local_irq_restore(irq_flags);
1370
1371 return 0;
1372}
1373
1374static int probe_profile_enable(struct ftrace_event_call *call)
1375{
1376 struct trace_probe *tp = (struct trace_probe *)call->data;
1377
1378 tp->flags |= TP_FLAG_PROFILE;
1379
1380 if (probe_is_return(tp))
1381 return enable_kretprobe(&tp->rp);
1382 else
1383 return enable_kprobe(&tp->rp.kp);
1384}
1385
1386static void probe_profile_disable(struct ftrace_event_call *call)
1387{
1388 struct trace_probe *tp = (struct trace_probe *)call->data;
1389
1390 tp->flags &= ~TP_FLAG_PROFILE;
1391
1392 if (!(tp->flags & TP_FLAG_TRACE)) {
1393 if (probe_is_return(tp))
1394 disable_kretprobe(&tp->rp);
1395 else
1396 disable_kprobe(&tp->rp.kp);
1397 }
1398}
1399#endif /* CONFIG_EVENT_PROFILE */
1400
1401
1402static __kprobes
1403int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1404{
1405 struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
1406
1407 if (tp->flags & TP_FLAG_TRACE)
1408 kprobe_trace_func(kp, regs);
1409#ifdef CONFIG_EVENT_PROFILE
1410 if (tp->flags & TP_FLAG_PROFILE)
1411 kprobe_profile_func(kp, regs);
1412#endif /* CONFIG_EVENT_PROFILE */
1413 return 0; /* We don't tweek kernel, so just return 0 */
1414}
1415
1416static __kprobes
1417int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1418{
1419 struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
1420
1421 if (tp->flags & TP_FLAG_TRACE)
1422 kretprobe_trace_func(ri, regs);
1423#ifdef CONFIG_EVENT_PROFILE
1424 if (tp->flags & TP_FLAG_PROFILE)
1425 kretprobe_profile_func(ri, regs);
1426#endif /* CONFIG_EVENT_PROFILE */
1427 return 0; /* We don't tweek kernel, so just return 0 */
1428}
1429
1430static int register_probe_event(struct trace_probe *tp)
1431{
1432 struct ftrace_event_call *call = &tp->call;
1433 int ret;
1434
1435 /* Initialize ftrace_event_call */
1436 if (probe_is_return(tp)) {
1437 tp->event.trace = print_kretprobe_event;
1438 call->raw_init = probe_event_raw_init;
1439 call->show_format = kretprobe_event_show_format;
1440 call->define_fields = kretprobe_event_define_fields;
1441 } else {
1442 tp->event.trace = print_kprobe_event;
1443 call->raw_init = probe_event_raw_init;
1444 call->show_format = kprobe_event_show_format;
1445 call->define_fields = kprobe_event_define_fields;
1446 }
1447 call->event = &tp->event;
1448 call->id = register_ftrace_event(&tp->event);
1449 if (!call->id)
1450 return -ENODEV;
1451 call->enabled = 0;
1452 call->regfunc = probe_event_enable;
1453 call->unregfunc = probe_event_disable;
1454
1455#ifdef CONFIG_EVENT_PROFILE
1456 atomic_set(&call->profile_count, -1);
1457 call->profile_enable = probe_profile_enable;
1458 call->profile_disable = probe_profile_disable;
1459#endif
1460 call->data = tp;
1461 ret = trace_add_event_call(call);
1462 if (ret) {
1463 pr_info("Failed to register kprobe event: %s\n", call->name);
1464 unregister_ftrace_event(&tp->event);
1465 }
1466 return ret;
1467}
1468
1469static void unregister_probe_event(struct trace_probe *tp)
1470{
1471 /* tp->event is unregistered in trace_remove_event_call() */
1472 trace_remove_event_call(&tp->call);
1473}
1474
1475/* Make a debugfs interface for controling probe points */
1476static __init int init_kprobe_trace(void)
1477{
1478 struct dentry *d_tracer;
1479 struct dentry *entry;
1480
1481 d_tracer = tracing_init_dentry();
1482 if (!d_tracer)
1483 return 0;
1484
1485 entry = debugfs_create_file("kprobe_events", 0644, d_tracer,
1486 NULL, &kprobe_events_ops);
1487
1488 /* Event list interface */
1489 if (!entry)
1490 pr_warning("Could not create debugfs "
1491 "'kprobe_events' entry\n");
1492
1493 /* Profile interface */
1494 entry = debugfs_create_file("kprobe_profile", 0444, d_tracer,
1495 NULL, &kprobe_profile_ops);
1496
1497 if (!entry)
1498 pr_warning("Could not create debugfs "
1499 "'kprobe_profile' entry\n");
1500 return 0;
1501}
1502fs_initcall(init_kprobe_trace);
1503
1504
1505#ifdef CONFIG_FTRACE_STARTUP_TEST
1506
1507static int kprobe_trace_selftest_target(int a1, int a2, int a3,
1508 int a4, int a5, int a6)
1509{
1510 return a1 + a2 + a3 + a4 + a5 + a6;
1511}
1512
1513static __init int kprobe_trace_self_tests_init(void)
1514{
1515 int ret;
1516 int (*target)(int, int, int, int, int, int);
1517
1518 target = kprobe_trace_selftest_target;
1519
1520 pr_info("Testing kprobe tracing: ");
1521
1522 ret = command_trace_probe("p:testprobe kprobe_trace_selftest_target "
1523 "$arg1 $arg2 $arg3 $arg4 $stack $stack0");
1524 if (WARN_ON_ONCE(ret))
1525 pr_warning("error enabling function entry\n");
1526
1527 ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target "
1528 "$retval");
1529 if (WARN_ON_ONCE(ret))
1530 pr_warning("error enabling function return\n");
1531
1532 ret = target(1, 2, 3, 4, 5, 6);
1533
1534 cleanup_all_probes();
1535
1536 pr_cont("OK\n");
1537 return 0;
1538}
1539
1540late_initcall(kprobe_trace_self_tests_init);
1541
1542#endif
generated by cgit v1.2.2 (git 2.25.0) at 2025-05-29 10:52:12 -0400