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Merge tag 'rtc-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux
[deliverable/linux.git] / kernel / trace / trace_kprobe.c
1 /*
2 * Kprobes-based tracing events
3 *
4 * Created by Masami Hiramatsu <mhiramat@redhat.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20 #include <linux/module.h>
21 #include <linux/uaccess.h>
22
23 #include "trace_probe.h"
24
25 #define KPROBE_EVENT_SYSTEM "kprobes"
26
27 /**
28 * Kprobe event core functions
29 */
30 struct trace_kprobe {
31 struct list_head list;
32 struct kretprobe rp; /* Use rp.kp for kprobe use */
33 unsigned long __percpu *nhit;
34 const char *symbol; /* symbol name */
35 struct trace_probe tp;
36 };
37
38 #define SIZEOF_TRACE_KPROBE(n) \
39 (offsetof(struct trace_kprobe, tp.args) + \
40 (sizeof(struct probe_arg) * (n)))
41
42
43 static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk)
44 {
45 return tk->rp.handler != NULL;
46 }
47
48 static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk)
49 {
50 return tk->symbol ? tk->symbol : "unknown";
51 }
52
53 static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk)
54 {
55 return tk->rp.kp.offset;
56 }
57
58 static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk)
59 {
60 return !!(kprobe_gone(&tk->rp.kp));
61 }
62
63 static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk,
64 struct module *mod)
65 {
66 int len = strlen(mod->name);
67 const char *name = trace_kprobe_symbol(tk);
68 return strncmp(mod->name, name, len) == 0 && name[len] == ':';
69 }
70
71 static nokprobe_inline bool trace_kprobe_is_on_module(struct trace_kprobe *tk)
72 {
73 return !!strchr(trace_kprobe_symbol(tk), ':');
74 }
75
76 static int register_kprobe_event(struct trace_kprobe *tk);
77 static int unregister_kprobe_event(struct trace_kprobe *tk);
78
79 static DEFINE_MUTEX(probe_lock);
80 static LIST_HEAD(probe_list);
81
82 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
83 static int kretprobe_dispatcher(struct kretprobe_instance *ri,
84 struct pt_regs *regs);
85
86 /* Memory fetching by symbol */
87 struct symbol_cache {
88 char *symbol;
89 long offset;
90 unsigned long addr;
91 };
92
93 unsigned long update_symbol_cache(struct symbol_cache *sc)
94 {
95 sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol);
96
97 if (sc->addr)
98 sc->addr += sc->offset;
99
100 return sc->addr;
101 }
102
103 void free_symbol_cache(struct symbol_cache *sc)
104 {
105 kfree(sc->symbol);
106 kfree(sc);
107 }
108
109 struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
110 {
111 struct symbol_cache *sc;
112
113 if (!sym || strlen(sym) == 0)
114 return NULL;
115
116 sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL);
117 if (!sc)
118 return NULL;
119
120 sc->symbol = kstrdup(sym, GFP_KERNEL);
121 if (!sc->symbol) {
122 kfree(sc);
123 return NULL;
124 }
125 sc->offset = offset;
126 update_symbol_cache(sc);
127
128 return sc;
129 }
130
131 /*
132 * Kprobes-specific fetch functions
133 */
134 #define DEFINE_FETCH_stack(type) \
135 static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \
136 void *offset, void *dest) \
137 { \
138 *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \
139 (unsigned int)((unsigned long)offset)); \
140 } \
141 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(stack, type));
142
143 DEFINE_BASIC_FETCH_FUNCS(stack)
144 /* No string on the stack entry */
145 #define fetch_stack_string NULL
146 #define fetch_stack_string_size NULL
147
148 #define DEFINE_FETCH_memory(type) \
149 static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \
150 void *addr, void *dest) \
151 { \
152 type retval; \
153 if (probe_kernel_address(addr, retval)) \
154 *(type *)dest = 0; \
155 else \
156 *(type *)dest = retval; \
157 } \
158 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, type));
159
160 DEFINE_BASIC_FETCH_FUNCS(memory)
161 /*
162 * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
163 * length and relative data location.
164 */
165 static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
166 void *addr, void *dest)
167 {
168 int maxlen = get_rloc_len(*(u32 *)dest);
169 u8 *dst = get_rloc_data(dest);
170 long ret;
171
172 if (!maxlen)
173 return;
174
175 /*
176 * Try to get string again, since the string can be changed while
177 * probing.
178 */
179 ret = strncpy_from_unsafe(dst, addr, maxlen);
180
181 if (ret < 0) { /* Failed to fetch string */
182 dst[0] = '\0';
183 *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest));
184 } else {
185 *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest));
186 }
187 }
188 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string));
189
190 /* Return the length of string -- including null terminal byte */
191 static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
192 void *addr, void *dest)
193 {
194 mm_segment_t old_fs;
195 int ret, len = 0;
196 u8 c;
197
198 old_fs = get_fs();
199 set_fs(KERNEL_DS);
200 pagefault_disable();
201
202 do {
203 ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1);
204 len++;
205 } while (c && ret == 0 && len < MAX_STRING_SIZE);
206
207 pagefault_enable();
208 set_fs(old_fs);
209
210 if (ret < 0) /* Failed to check the length */
211 *(u32 *)dest = 0;
212 else
213 *(u32 *)dest = len;
214 }
215 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string_size));
216
217 #define DEFINE_FETCH_symbol(type) \
218 void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs, void *data, void *dest)\
219 { \
220 struct symbol_cache *sc = data; \
221 if (sc->addr) \
222 fetch_memory_##type(regs, (void *)sc->addr, dest); \
223 else \
224 *(type *)dest = 0; \
225 } \
226 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(symbol, type));
227
228 DEFINE_BASIC_FETCH_FUNCS(symbol)
229 DEFINE_FETCH_symbol(string)
230 DEFINE_FETCH_symbol(string_size)
231
232 /* kprobes don't support file_offset fetch methods */
233 #define fetch_file_offset_u8 NULL
234 #define fetch_file_offset_u16 NULL
235 #define fetch_file_offset_u32 NULL
236 #define fetch_file_offset_u64 NULL
237 #define fetch_file_offset_string NULL
238 #define fetch_file_offset_string_size NULL
239
240 /* Fetch type information table */
241 static const struct fetch_type kprobes_fetch_type_table[] = {
242 /* Special types */
243 [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
244 sizeof(u32), 1, "__data_loc char[]"),
245 [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
246 string_size, sizeof(u32), 0, "u32"),
247 /* Basic types */
248 ASSIGN_FETCH_TYPE(u8, u8, 0),
249 ASSIGN_FETCH_TYPE(u16, u16, 0),
250 ASSIGN_FETCH_TYPE(u32, u32, 0),
251 ASSIGN_FETCH_TYPE(u64, u64, 0),
252 ASSIGN_FETCH_TYPE(s8, u8, 1),
253 ASSIGN_FETCH_TYPE(s16, u16, 1),
254 ASSIGN_FETCH_TYPE(s32, u32, 1),
255 ASSIGN_FETCH_TYPE(s64, u64, 1),
256
257 ASSIGN_FETCH_TYPE_END
258 };
259
260 /*
261 * Allocate new trace_probe and initialize it (including kprobes).
262 */
263 static struct trace_kprobe *alloc_trace_kprobe(const char *group,
264 const char *event,
265 void *addr,
266 const char *symbol,
267 unsigned long offs,
268 int nargs, bool is_return)
269 {
270 struct trace_kprobe *tk;
271 int ret = -ENOMEM;
272
273 tk = kzalloc(SIZEOF_TRACE_KPROBE(nargs), GFP_KERNEL);
274 if (!tk)
275 return ERR_PTR(ret);
276
277 tk->nhit = alloc_percpu(unsigned long);
278 if (!tk->nhit)
279 goto error;
280
281 if (symbol) {
282 tk->symbol = kstrdup(symbol, GFP_KERNEL);
283 if (!tk->symbol)
284 goto error;
285 tk->rp.kp.symbol_name = tk->symbol;
286 tk->rp.kp.offset = offs;
287 } else
288 tk->rp.kp.addr = addr;
289
290 if (is_return)
291 tk->rp.handler = kretprobe_dispatcher;
292 else
293 tk->rp.kp.pre_handler = kprobe_dispatcher;
294
295 if (!event || !is_good_name(event)) {
296 ret = -EINVAL;
297 goto error;
298 }
299
300 tk->tp.call.class = &tk->tp.class;
301 tk->tp.call.name = kstrdup(event, GFP_KERNEL);
302 if (!tk->tp.call.name)
303 goto error;
304
305 if (!group || !is_good_name(group)) {
306 ret = -EINVAL;
307 goto error;
308 }
309
310 tk->tp.class.system = kstrdup(group, GFP_KERNEL);
311 if (!tk->tp.class.system)
312 goto error;
313
314 INIT_LIST_HEAD(&tk->list);
315 INIT_LIST_HEAD(&tk->tp.files);
316 return tk;
317 error:
318 kfree(tk->tp.call.name);
319 kfree(tk->symbol);
320 free_percpu(tk->nhit);
321 kfree(tk);
322 return ERR_PTR(ret);
323 }
324
325 static void free_trace_kprobe(struct trace_kprobe *tk)
326 {
327 int i;
328
329 for (i = 0; i < tk->tp.nr_args; i++)
330 traceprobe_free_probe_arg(&tk->tp.args[i]);
331
332 kfree(tk->tp.call.class->system);
333 kfree(tk->tp.call.name);
334 kfree(tk->symbol);
335 free_percpu(tk->nhit);
336 kfree(tk);
337 }
338
339 static struct trace_kprobe *find_trace_kprobe(const char *event,
340 const char *group)
341 {
342 struct trace_kprobe *tk;
343
344 list_for_each_entry(tk, &probe_list, list)
345 if (strcmp(trace_event_name(&tk->tp.call), event) == 0 &&
346 strcmp(tk->tp.call.class->system, group) == 0)
347 return tk;
348 return NULL;
349 }
350
351 /*
352 * Enable trace_probe
353 * if the file is NULL, enable "perf" handler, or enable "trace" handler.
354 */
355 static int
356 enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file)
357 {
358 int ret = 0;
359
360 if (file) {
361 struct event_file_link *link;
362
363 link = kmalloc(sizeof(*link), GFP_KERNEL);
364 if (!link) {
365 ret = -ENOMEM;
366 goto out;
367 }
368
369 link->file = file;
370 list_add_tail_rcu(&link->list, &tk->tp.files);
371
372 tk->tp.flags |= TP_FLAG_TRACE;
373 } else
374 tk->tp.flags |= TP_FLAG_PROFILE;
375
376 if (trace_probe_is_registered(&tk->tp) && !trace_kprobe_has_gone(tk)) {
377 if (trace_kprobe_is_return(tk))
378 ret = enable_kretprobe(&tk->rp);
379 else
380 ret = enable_kprobe(&tk->rp.kp);
381 }
382 out:
383 return ret;
384 }
385
386 /*
387 * Disable trace_probe
388 * if the file is NULL, disable "perf" handler, or disable "trace" handler.
389 */
390 static int
391 disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file)
392 {
393 struct event_file_link *link = NULL;
394 int wait = 0;
395 int ret = 0;
396
397 if (file) {
398 link = find_event_file_link(&tk->tp, file);
399 if (!link) {
400 ret = -EINVAL;
401 goto out;
402 }
403
404 list_del_rcu(&link->list);
405 wait = 1;
406 if (!list_empty(&tk->tp.files))
407 goto out;
408
409 tk->tp.flags &= ~TP_FLAG_TRACE;
410 } else
411 tk->tp.flags &= ~TP_FLAG_PROFILE;
412
413 if (!trace_probe_is_enabled(&tk->tp) && trace_probe_is_registered(&tk->tp)) {
414 if (trace_kprobe_is_return(tk))
415 disable_kretprobe(&tk->rp);
416 else
417 disable_kprobe(&tk->rp.kp);
418 wait = 1;
419 }
420 out:
421 if (wait) {
422 /*
423 * Synchronize with kprobe_trace_func/kretprobe_trace_func
424 * to ensure disabled (all running handlers are finished).
425 * This is not only for kfree(), but also the caller,
426 * trace_remove_event_call() supposes it for releasing
427 * event_call related objects, which will be accessed in
428 * the kprobe_trace_func/kretprobe_trace_func.
429 */
430 synchronize_sched();
431 kfree(link); /* Ignored if link == NULL */
432 }
433
434 return ret;
435 }
436
437 /* Internal register function - just handle k*probes and flags */
438 static int __register_trace_kprobe(struct trace_kprobe *tk)
439 {
440 int i, ret;
441
442 if (trace_probe_is_registered(&tk->tp))
443 return -EINVAL;
444
445 for (i = 0; i < tk->tp.nr_args; i++)
446 traceprobe_update_arg(&tk->tp.args[i]);
447
448 /* Set/clear disabled flag according to tp->flag */
449 if (trace_probe_is_enabled(&tk->tp))
450 tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED;
451 else
452 tk->rp.kp.flags |= KPROBE_FLAG_DISABLED;
453
454 if (trace_kprobe_is_return(tk))
455 ret = register_kretprobe(&tk->rp);
456 else
457 ret = register_kprobe(&tk->rp.kp);
458
459 if (ret == 0)
460 tk->tp.flags |= TP_FLAG_REGISTERED;
461 else {
462 pr_warning("Could not insert probe at %s+%lu: %d\n",
463 trace_kprobe_symbol(tk), trace_kprobe_offset(tk), ret);
464 if (ret == -ENOENT && trace_kprobe_is_on_module(tk)) {
465 pr_warning("This probe might be able to register after"
466 "target module is loaded. Continue.\n");
467 ret = 0;
468 } else if (ret == -EILSEQ) {
469 pr_warning("Probing address(0x%p) is not an "
470 "instruction boundary.\n",
471 tk->rp.kp.addr);
472 ret = -EINVAL;
473 }
474 }
475
476 return ret;
477 }
478
479 /* Internal unregister function - just handle k*probes and flags */
480 static void __unregister_trace_kprobe(struct trace_kprobe *tk)
481 {
482 if (trace_probe_is_registered(&tk->tp)) {
483 if (trace_kprobe_is_return(tk))
484 unregister_kretprobe(&tk->rp);
485 else
486 unregister_kprobe(&tk->rp.kp);
487 tk->tp.flags &= ~TP_FLAG_REGISTERED;
488 /* Cleanup kprobe for reuse */
489 if (tk->rp.kp.symbol_name)
490 tk->rp.kp.addr = NULL;
491 }
492 }
493
494 /* Unregister a trace_probe and probe_event: call with locking probe_lock */
495 static int unregister_trace_kprobe(struct trace_kprobe *tk)
496 {
497 /* Enabled event can not be unregistered */
498 if (trace_probe_is_enabled(&tk->tp))
499 return -EBUSY;
500
501 /* Will fail if probe is being used by ftrace or perf */
502 if (unregister_kprobe_event(tk))
503 return -EBUSY;
504
505 __unregister_trace_kprobe(tk);
506 list_del(&tk->list);
507
508 return 0;
509 }
510
511 /* Register a trace_probe and probe_event */
512 static int register_trace_kprobe(struct trace_kprobe *tk)
513 {
514 struct trace_kprobe *old_tk;
515 int ret;
516
517 mutex_lock(&probe_lock);
518
519 /* Delete old (same name) event if exist */
520 old_tk = find_trace_kprobe(trace_event_name(&tk->tp.call),
521 tk->tp.call.class->system);
522 if (old_tk) {
523 ret = unregister_trace_kprobe(old_tk);
524 if (ret < 0)
525 goto end;
526 free_trace_kprobe(old_tk);
527 }
528
529 /* Register new event */
530 ret = register_kprobe_event(tk);
531 if (ret) {
532 pr_warning("Failed to register probe event(%d)\n", ret);
533 goto end;
534 }
535
536 /* Register k*probe */
537 ret = __register_trace_kprobe(tk);
538 if (ret < 0)
539 unregister_kprobe_event(tk);
540 else
541 list_add_tail(&tk->list, &probe_list);
542
543 end:
544 mutex_unlock(&probe_lock);
545 return ret;
546 }
547
548 /* Module notifier call back, checking event on the module */
549 static int trace_kprobe_module_callback(struct notifier_block *nb,
550 unsigned long val, void *data)
551 {
552 struct module *mod = data;
553 struct trace_kprobe *tk;
554 int ret;
555
556 if (val != MODULE_STATE_COMING)
557 return NOTIFY_DONE;
558
559 /* Update probes on coming module */
560 mutex_lock(&probe_lock);
561 list_for_each_entry(tk, &probe_list, list) {
562 if (trace_kprobe_within_module(tk, mod)) {
563 /* Don't need to check busy - this should have gone. */
564 __unregister_trace_kprobe(tk);
565 ret = __register_trace_kprobe(tk);
566 if (ret)
567 pr_warning("Failed to re-register probe %s on"
568 "%s: %d\n",
569 trace_event_name(&tk->tp.call),
570 mod->name, ret);
571 }
572 }
573 mutex_unlock(&probe_lock);
574
575 return NOTIFY_DONE;
576 }
577
578 static struct notifier_block trace_kprobe_module_nb = {
579 .notifier_call = trace_kprobe_module_callback,
580 .priority = 1 /* Invoked after kprobe module callback */
581 };
582
583 static int create_trace_kprobe(int argc, char **argv)
584 {
585 /*
586 * Argument syntax:
587 * - Add kprobe: p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
588 * - Add kretprobe: r[:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
589 * Fetch args:
590 * $retval : fetch return value
591 * $stack : fetch stack address
592 * $stackN : fetch Nth of stack (N:0-)
593 * @ADDR : fetch memory at ADDR (ADDR should be in kernel)
594 * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
595 * %REG : fetch register REG
596 * Dereferencing memory fetch:
597 * +|-offs(ARG) : fetch memory at ARG +|- offs address.
598 * Alias name of args:
599 * NAME=FETCHARG : set NAME as alias of FETCHARG.
600 * Type of args:
601 * FETCHARG:TYPE : use TYPE instead of unsigned long.
602 */
603 struct trace_kprobe *tk;
604 int i, ret = 0;
605 bool is_return = false, is_delete = false;
606 char *symbol = NULL, *event = NULL, *group = NULL;
607 char *arg;
608 unsigned long offset = 0;
609 void *addr = NULL;
610 char buf[MAX_EVENT_NAME_LEN];
611
612 /* argc must be >= 1 */
613 if (argv[0][0] == 'p')
614 is_return = false;
615 else if (argv[0][0] == 'r')
616 is_return = true;
617 else if (argv[0][0] == '-')
618 is_delete = true;
619 else {
620 pr_info("Probe definition must be started with 'p', 'r' or"
621 " '-'.\n");
622 return -EINVAL;
623 }
624
625 if (argv[0][1] == ':') {
626 event = &argv[0][2];
627 if (strchr(event, '/')) {
628 group = event;
629 event = strchr(group, '/') + 1;
630 event[-1] = '\0';
631 if (strlen(group) == 0) {
632 pr_info("Group name is not specified\n");
633 return -EINVAL;
634 }
635 }
636 if (strlen(event) == 0) {
637 pr_info("Event name is not specified\n");
638 return -EINVAL;
639 }
640 }
641 if (!group)
642 group = KPROBE_EVENT_SYSTEM;
643
644 if (is_delete) {
645 if (!event) {
646 pr_info("Delete command needs an event name.\n");
647 return -EINVAL;
648 }
649 mutex_lock(&probe_lock);
650 tk = find_trace_kprobe(event, group);
651 if (!tk) {
652 mutex_unlock(&probe_lock);
653 pr_info("Event %s/%s doesn't exist.\n", group, event);
654 return -ENOENT;
655 }
656 /* delete an event */
657 ret = unregister_trace_kprobe(tk);
658 if (ret == 0)
659 free_trace_kprobe(tk);
660 mutex_unlock(&probe_lock);
661 return ret;
662 }
663
664 if (argc < 2) {
665 pr_info("Probe point is not specified.\n");
666 return -EINVAL;
667 }
668 if (isdigit(argv[1][0])) {
669 if (is_return) {
670 pr_info("Return probe point must be a symbol.\n");
671 return -EINVAL;
672 }
673 /* an address specified */
674 ret = kstrtoul(&argv[1][0], 0, (unsigned long *)&addr);
675 if (ret) {
676 pr_info("Failed to parse address.\n");
677 return ret;
678 }
679 } else {
680 /* a symbol specified */
681 symbol = argv[1];
682 /* TODO: support .init module functions */
683 ret = traceprobe_split_symbol_offset(symbol, &offset);
684 if (ret) {
685 pr_info("Failed to parse symbol.\n");
686 return ret;
687 }
688 if (offset && is_return) {
689 pr_info("Return probe must be used without offset.\n");
690 return -EINVAL;
691 }
692 }
693 argc -= 2; argv += 2;
694
695 /* setup a probe */
696 if (!event) {
697 /* Make a new event name */
698 if (symbol)
699 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
700 is_return ? 'r' : 'p', symbol, offset);
701 else
702 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
703 is_return ? 'r' : 'p', addr);
704 event = buf;
705 }
706 tk = alloc_trace_kprobe(group, event, addr, symbol, offset, argc,
707 is_return);
708 if (IS_ERR(tk)) {
709 pr_info("Failed to allocate trace_probe.(%d)\n",
710 (int)PTR_ERR(tk));
711 return PTR_ERR(tk);
712 }
713
714 /* parse arguments */
715 ret = 0;
716 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
717 struct probe_arg *parg = &tk->tp.args[i];
718
719 /* Increment count for freeing args in error case */
720 tk->tp.nr_args++;
721
722 /* Parse argument name */
723 arg = strchr(argv[i], '=');
724 if (arg) {
725 *arg++ = '\0';
726 parg->name = kstrdup(argv[i], GFP_KERNEL);
727 } else {
728 arg = argv[i];
729 /* If argument name is omitted, set "argN" */
730 snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1);
731 parg->name = kstrdup(buf, GFP_KERNEL);
732 }
733
734 if (!parg->name) {
735 pr_info("Failed to allocate argument[%d] name.\n", i);
736 ret = -ENOMEM;
737 goto error;
738 }
739
740 if (!is_good_name(parg->name)) {
741 pr_info("Invalid argument[%d] name: %s\n",
742 i, parg->name);
743 ret = -EINVAL;
744 goto error;
745 }
746
747 if (traceprobe_conflict_field_name(parg->name,
748 tk->tp.args, i)) {
749 pr_info("Argument[%d] name '%s' conflicts with "
750 "another field.\n", i, argv[i]);
751 ret = -EINVAL;
752 goto error;
753 }
754
755 /* Parse fetch argument */
756 ret = traceprobe_parse_probe_arg(arg, &tk->tp.size, parg,
757 is_return, true,
758 kprobes_fetch_type_table);
759 if (ret) {
760 pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
761 goto error;
762 }
763 }
764
765 ret = register_trace_kprobe(tk);
766 if (ret)
767 goto error;
768 return 0;
769
770 error:
771 free_trace_kprobe(tk);
772 return ret;
773 }
774
775 static int release_all_trace_kprobes(void)
776 {
777 struct trace_kprobe *tk;
778 int ret = 0;
779
780 mutex_lock(&probe_lock);
781 /* Ensure no probe is in use. */
782 list_for_each_entry(tk, &probe_list, list)
783 if (trace_probe_is_enabled(&tk->tp)) {
784 ret = -EBUSY;
785 goto end;
786 }
787 /* TODO: Use batch unregistration */
788 while (!list_empty(&probe_list)) {
789 tk = list_entry(probe_list.next, struct trace_kprobe, list);
790 ret = unregister_trace_kprobe(tk);
791 if (ret)
792 goto end;
793 free_trace_kprobe(tk);
794 }
795
796 end:
797 mutex_unlock(&probe_lock);
798
799 return ret;
800 }
801
802 /* Probes listing interfaces */
803 static void *probes_seq_start(struct seq_file *m, loff_t *pos)
804 {
805 mutex_lock(&probe_lock);
806 return seq_list_start(&probe_list, *pos);
807 }
808
809 static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
810 {
811 return seq_list_next(v, &probe_list, pos);
812 }
813
814 static void probes_seq_stop(struct seq_file *m, void *v)
815 {
816 mutex_unlock(&probe_lock);
817 }
818
819 static int probes_seq_show(struct seq_file *m, void *v)
820 {
821 struct trace_kprobe *tk = v;
822 int i;
823
824 seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p');
825 seq_printf(m, ":%s/%s", tk->tp.call.class->system,
826 trace_event_name(&tk->tp.call));
827
828 if (!tk->symbol)
829 seq_printf(m, " 0x%p", tk->rp.kp.addr);
830 else if (tk->rp.kp.offset)
831 seq_printf(m, " %s+%u", trace_kprobe_symbol(tk),
832 tk->rp.kp.offset);
833 else
834 seq_printf(m, " %s", trace_kprobe_symbol(tk));
835
836 for (i = 0; i < tk->tp.nr_args; i++)
837 seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm);
838 seq_putc(m, '\n');
839
840 return 0;
841 }
842
843 static const struct seq_operations probes_seq_op = {
844 .start = probes_seq_start,
845 .next = probes_seq_next,
846 .stop = probes_seq_stop,
847 .show = probes_seq_show
848 };
849
850 static int probes_open(struct inode *inode, struct file *file)
851 {
852 int ret;
853
854 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
855 ret = release_all_trace_kprobes();
856 if (ret < 0)
857 return ret;
858 }
859
860 return seq_open(file, &probes_seq_op);
861 }
862
863 static ssize_t probes_write(struct file *file, const char __user *buffer,
864 size_t count, loff_t *ppos)
865 {
866 return traceprobe_probes_write(file, buffer, count, ppos,
867 create_trace_kprobe);
868 }
869
870 static const struct file_operations kprobe_events_ops = {
871 .owner = THIS_MODULE,
872 .open = probes_open,
873 .read = seq_read,
874 .llseek = seq_lseek,
875 .release = seq_release,
876 .write = probes_write,
877 };
878
879 /* Probes profiling interfaces */
880 static int probes_profile_seq_show(struct seq_file *m, void *v)
881 {
882 struct trace_kprobe *tk = v;
883 unsigned long nhit = 0;
884 int cpu;
885
886 for_each_possible_cpu(cpu)
887 nhit += *per_cpu_ptr(tk->nhit, cpu);
888
889 seq_printf(m, " %-44s %15lu %15lu\n",
890 trace_event_name(&tk->tp.call), nhit,
891 tk->rp.kp.nmissed);
892
893 return 0;
894 }
895
896 static const struct seq_operations profile_seq_op = {
897 .start = probes_seq_start,
898 .next = probes_seq_next,
899 .stop = probes_seq_stop,
900 .show = probes_profile_seq_show
901 };
902
903 static int profile_open(struct inode *inode, struct file *file)
904 {
905 return seq_open(file, &profile_seq_op);
906 }
907
908 static const struct file_operations kprobe_profile_ops = {
909 .owner = THIS_MODULE,
910 .open = profile_open,
911 .read = seq_read,
912 .llseek = seq_lseek,
913 .release = seq_release,
914 };
915
916 /* Kprobe handler */
917 static nokprobe_inline void
918 __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
919 struct trace_event_file *trace_file)
920 {
921 struct kprobe_trace_entry_head *entry;
922 struct ring_buffer_event *event;
923 struct ring_buffer *buffer;
924 int size, dsize, pc;
925 unsigned long irq_flags;
926 struct trace_event_call *call = &tk->tp.call;
927
928 WARN_ON(call != trace_file->event_call);
929
930 if (trace_trigger_soft_disabled(trace_file))
931 return;
932
933 local_save_flags(irq_flags);
934 pc = preempt_count();
935
936 dsize = __get_data_size(&tk->tp, regs);
937 size = sizeof(*entry) + tk->tp.size + dsize;
938
939 event = trace_event_buffer_lock_reserve(&buffer, trace_file,
940 call->event.type,
941 size, irq_flags, pc);
942 if (!event)
943 return;
944
945 entry = ring_buffer_event_data(event);
946 entry->ip = (unsigned long)tk->rp.kp.addr;
947 store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
948
949 event_trigger_unlock_commit_regs(trace_file, buffer, event,
950 entry, irq_flags, pc, regs);
951 }
952
953 static void
954 kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs)
955 {
956 struct event_file_link *link;
957
958 list_for_each_entry_rcu(link, &tk->tp.files, list)
959 __kprobe_trace_func(tk, regs, link->file);
960 }
961 NOKPROBE_SYMBOL(kprobe_trace_func);
962
963 /* Kretprobe handler */
964 static nokprobe_inline void
965 __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
966 struct pt_regs *regs,
967 struct trace_event_file *trace_file)
968 {
969 struct kretprobe_trace_entry_head *entry;
970 struct ring_buffer_event *event;
971 struct ring_buffer *buffer;
972 int size, pc, dsize;
973 unsigned long irq_flags;
974 struct trace_event_call *call = &tk->tp.call;
975
976 WARN_ON(call != trace_file->event_call);
977
978 if (trace_trigger_soft_disabled(trace_file))
979 return;
980
981 local_save_flags(irq_flags);
982 pc = preempt_count();
983
984 dsize = __get_data_size(&tk->tp, regs);
985 size = sizeof(*entry) + tk->tp.size + dsize;
986
987 event = trace_event_buffer_lock_reserve(&buffer, trace_file,
988 call->event.type,
989 size, irq_flags, pc);
990 if (!event)
991 return;
992
993 entry = ring_buffer_event_data(event);
994 entry->func = (unsigned long)tk->rp.kp.addr;
995 entry->ret_ip = (unsigned long)ri->ret_addr;
996 store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
997
998 event_trigger_unlock_commit_regs(trace_file, buffer, event,
999 entry, irq_flags, pc, regs);
1000 }
1001
1002 static void
1003 kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1004 struct pt_regs *regs)
1005 {
1006 struct event_file_link *link;
1007
1008 list_for_each_entry_rcu(link, &tk->tp.files, list)
1009 __kretprobe_trace_func(tk, ri, regs, link->file);
1010 }
1011 NOKPROBE_SYMBOL(kretprobe_trace_func);
1012
1013 /* Event entry printers */
1014 static enum print_line_t
1015 print_kprobe_event(struct trace_iterator *iter, int flags,
1016 struct trace_event *event)
1017 {
1018 struct kprobe_trace_entry_head *field;
1019 struct trace_seq *s = &iter->seq;
1020 struct trace_probe *tp;
1021 u8 *data;
1022 int i;
1023
1024 field = (struct kprobe_trace_entry_head *)iter->ent;
1025 tp = container_of(event, struct trace_probe, call.event);
1026
1027 trace_seq_printf(s, "%s: (", trace_event_name(&tp->call));
1028
1029 if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
1030 goto out;
1031
1032 trace_seq_putc(s, ')');
1033
1034 data = (u8 *)&field[1];
1035 for (i = 0; i < tp->nr_args; i++)
1036 if (!tp->args[i].type->print(s, tp->args[i].name,
1037 data + tp->args[i].offset, field))
1038 goto out;
1039
1040 trace_seq_putc(s, '\n');
1041 out:
1042 return trace_handle_return(s);
1043 }
1044
1045 static enum print_line_t
1046 print_kretprobe_event(struct trace_iterator *iter, int flags,
1047 struct trace_event *event)
1048 {
1049 struct kretprobe_trace_entry_head *field;
1050 struct trace_seq *s = &iter->seq;
1051 struct trace_probe *tp;
1052 u8 *data;
1053 int i;
1054
1055 field = (struct kretprobe_trace_entry_head *)iter->ent;
1056 tp = container_of(event, struct trace_probe, call.event);
1057
1058 trace_seq_printf(s, "%s: (", trace_event_name(&tp->call));
1059
1060 if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
1061 goto out;
1062
1063 trace_seq_puts(s, " <- ");
1064
1065 if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
1066 goto out;
1067
1068 trace_seq_putc(s, ')');
1069
1070 data = (u8 *)&field[1];
1071 for (i = 0; i < tp->nr_args; i++)
1072 if (!tp->args[i].type->print(s, tp->args[i].name,
1073 data + tp->args[i].offset, field))
1074 goto out;
1075
1076 trace_seq_putc(s, '\n');
1077
1078 out:
1079 return trace_handle_return(s);
1080 }
1081
1082
1083 static int kprobe_event_define_fields(struct trace_event_call *event_call)
1084 {
1085 int ret, i;
1086 struct kprobe_trace_entry_head field;
1087 struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data;
1088
1089 DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
1090 /* Set argument names as fields */
1091 for (i = 0; i < tk->tp.nr_args; i++) {
1092 struct probe_arg *parg = &tk->tp.args[i];
1093
1094 ret = trace_define_field(event_call, parg->type->fmttype,
1095 parg->name,
1096 sizeof(field) + parg->offset,
1097 parg->type->size,
1098 parg->type->is_signed,
1099 FILTER_OTHER);
1100 if (ret)
1101 return ret;
1102 }
1103 return 0;
1104 }
1105
1106 static int kretprobe_event_define_fields(struct trace_event_call *event_call)
1107 {
1108 int ret, i;
1109 struct kretprobe_trace_entry_head field;
1110 struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data;
1111
1112 DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
1113 DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
1114 /* Set argument names as fields */
1115 for (i = 0; i < tk->tp.nr_args; i++) {
1116 struct probe_arg *parg = &tk->tp.args[i];
1117
1118 ret = trace_define_field(event_call, parg->type->fmttype,
1119 parg->name,
1120 sizeof(field) + parg->offset,
1121 parg->type->size,
1122 parg->type->is_signed,
1123 FILTER_OTHER);
1124 if (ret)
1125 return ret;
1126 }
1127 return 0;
1128 }
1129
1130 #ifdef CONFIG_PERF_EVENTS
1131
1132 /* Kprobe profile handler */
1133 static void
1134 kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
1135 {
1136 struct trace_event_call *call = &tk->tp.call;
1137 struct bpf_prog *prog = call->prog;
1138 struct kprobe_trace_entry_head *entry;
1139 struct hlist_head *head;
1140 int size, __size, dsize;
1141 int rctx;
1142
1143 if (prog && !trace_call_bpf(prog, regs))
1144 return;
1145
1146 head = this_cpu_ptr(call->perf_events);
1147 if (hlist_empty(head))
1148 return;
1149
1150 dsize = __get_data_size(&tk->tp, regs);
1151 __size = sizeof(*entry) + tk->tp.size + dsize;
1152 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1153 size -= sizeof(u32);
1154
1155 entry = perf_trace_buf_prepare(size, call->event.type, NULL, &rctx);
1156 if (!entry)
1157 return;
1158
1159 entry->ip = (unsigned long)tk->rp.kp.addr;
1160 memset(&entry[1], 0, dsize);
1161 store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
1162 perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL);
1163 }
1164 NOKPROBE_SYMBOL(kprobe_perf_func);
1165
1166 /* Kretprobe profile handler */
1167 static void
1168 kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1169 struct pt_regs *regs)
1170 {
1171 struct trace_event_call *call = &tk->tp.call;
1172 struct bpf_prog *prog = call->prog;
1173 struct kretprobe_trace_entry_head *entry;
1174 struct hlist_head *head;
1175 int size, __size, dsize;
1176 int rctx;
1177
1178 if (prog && !trace_call_bpf(prog, regs))
1179 return;
1180
1181 head = this_cpu_ptr(call->perf_events);
1182 if (hlist_empty(head))
1183 return;
1184
1185 dsize = __get_data_size(&tk->tp, regs);
1186 __size = sizeof(*entry) + tk->tp.size + dsize;
1187 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1188 size -= sizeof(u32);
1189
1190 entry = perf_trace_buf_prepare(size, call->event.type, NULL, &rctx);
1191 if (!entry)
1192 return;
1193
1194 entry->func = (unsigned long)tk->rp.kp.addr;
1195 entry->ret_ip = (unsigned long)ri->ret_addr;
1196 store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
1197 perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL);
1198 }
1199 NOKPROBE_SYMBOL(kretprobe_perf_func);
1200 #endif /* CONFIG_PERF_EVENTS */
1201
1202 /*
1203 * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex.
1204 *
1205 * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe
1206 * lockless, but we can't race with this __init function.
1207 */
1208 static int kprobe_register(struct trace_event_call *event,
1209 enum trace_reg type, void *data)
1210 {
1211 struct trace_kprobe *tk = (struct trace_kprobe *)event->data;
1212 struct trace_event_file *file = data;
1213
1214 switch (type) {
1215 case TRACE_REG_REGISTER:
1216 return enable_trace_kprobe(tk, file);
1217 case TRACE_REG_UNREGISTER:
1218 return disable_trace_kprobe(tk, file);
1219
1220 #ifdef CONFIG_PERF_EVENTS
1221 case TRACE_REG_PERF_REGISTER:
1222 return enable_trace_kprobe(tk, NULL);
1223 case TRACE_REG_PERF_UNREGISTER:
1224 return disable_trace_kprobe(tk, NULL);
1225 case TRACE_REG_PERF_OPEN:
1226 case TRACE_REG_PERF_CLOSE:
1227 case TRACE_REG_PERF_ADD:
1228 case TRACE_REG_PERF_DEL:
1229 return 0;
1230 #endif
1231 }
1232 return 0;
1233 }
1234
1235 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1236 {
1237 struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp);
1238
1239 raw_cpu_inc(*tk->nhit);
1240
1241 if (tk->tp.flags & TP_FLAG_TRACE)
1242 kprobe_trace_func(tk, regs);
1243 #ifdef CONFIG_PERF_EVENTS
1244 if (tk->tp.flags & TP_FLAG_PROFILE)
1245 kprobe_perf_func(tk, regs);
1246 #endif
1247 return 0; /* We don't tweek kernel, so just return 0 */
1248 }
1249 NOKPROBE_SYMBOL(kprobe_dispatcher);
1250
1251 static int
1252 kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1253 {
1254 struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp);
1255
1256 raw_cpu_inc(*tk->nhit);
1257
1258 if (tk->tp.flags & TP_FLAG_TRACE)
1259 kretprobe_trace_func(tk, ri, regs);
1260 #ifdef CONFIG_PERF_EVENTS
1261 if (tk->tp.flags & TP_FLAG_PROFILE)
1262 kretprobe_perf_func(tk, ri, regs);
1263 #endif
1264 return 0; /* We don't tweek kernel, so just return 0 */
1265 }
1266 NOKPROBE_SYMBOL(kretprobe_dispatcher);
1267
1268 static struct trace_event_functions kretprobe_funcs = {
1269 .trace = print_kretprobe_event
1270 };
1271
1272 static struct trace_event_functions kprobe_funcs = {
1273 .trace = print_kprobe_event
1274 };
1275
1276 static int register_kprobe_event(struct trace_kprobe *tk)
1277 {
1278 struct trace_event_call *call = &tk->tp.call;
1279 int ret;
1280
1281 /* Initialize trace_event_call */
1282 INIT_LIST_HEAD(&call->class->fields);
1283 if (trace_kprobe_is_return(tk)) {
1284 call->event.funcs = &kretprobe_funcs;
1285 call->class->define_fields = kretprobe_event_define_fields;
1286 } else {
1287 call->event.funcs = &kprobe_funcs;
1288 call->class->define_fields = kprobe_event_define_fields;
1289 }
1290 if (set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0)
1291 return -ENOMEM;
1292 ret = register_trace_event(&call->event);
1293 if (!ret) {
1294 kfree(call->print_fmt);
1295 return -ENODEV;
1296 }
1297 call->flags = TRACE_EVENT_FL_KPROBE;
1298 call->class->reg = kprobe_register;
1299 call->data = tk;
1300 ret = trace_add_event_call(call);
1301 if (ret) {
1302 pr_info("Failed to register kprobe event: %s\n",
1303 trace_event_name(call));
1304 kfree(call->print_fmt);
1305 unregister_trace_event(&call->event);
1306 }
1307 return ret;
1308 }
1309
1310 static int unregister_kprobe_event(struct trace_kprobe *tk)
1311 {
1312 int ret;
1313
1314 /* tp->event is unregistered in trace_remove_event_call() */
1315 ret = trace_remove_event_call(&tk->tp.call);
1316 if (!ret)
1317 kfree(tk->tp.call.print_fmt);
1318 return ret;
1319 }
1320
1321 /* Make a tracefs interface for controlling probe points */
1322 static __init int init_kprobe_trace(void)
1323 {
1324 struct dentry *d_tracer;
1325 struct dentry *entry;
1326
1327 if (register_module_notifier(&trace_kprobe_module_nb))
1328 return -EINVAL;
1329
1330 d_tracer = tracing_init_dentry();
1331 if (IS_ERR(d_tracer))
1332 return 0;
1333
1334 entry = tracefs_create_file("kprobe_events", 0644, d_tracer,
1335 NULL, &kprobe_events_ops);
1336
1337 /* Event list interface */
1338 if (!entry)
1339 pr_warning("Could not create tracefs "
1340 "'kprobe_events' entry\n");
1341
1342 /* Profile interface */
1343 entry = tracefs_create_file("kprobe_profile", 0444, d_tracer,
1344 NULL, &kprobe_profile_ops);
1345
1346 if (!entry)
1347 pr_warning("Could not create tracefs "
1348 "'kprobe_profile' entry\n");
1349 return 0;
1350 }
1351 fs_initcall(init_kprobe_trace);
1352
1353
1354 #ifdef CONFIG_FTRACE_STARTUP_TEST
1355
1356 /*
1357 * The "__used" keeps gcc from removing the function symbol
1358 * from the kallsyms table.
1359 */
1360 static __used int kprobe_trace_selftest_target(int a1, int a2, int a3,
1361 int a4, int a5, int a6)
1362 {
1363 return a1 + a2 + a3 + a4 + a5 + a6;
1364 }
1365
1366 static struct trace_event_file *
1367 find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr)
1368 {
1369 struct trace_event_file *file;
1370
1371 list_for_each_entry(file, &tr->events, list)
1372 if (file->event_call == &tk->tp.call)
1373 return file;
1374
1375 return NULL;
1376 }
1377
1378 /*
1379 * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this
1380 * stage, we can do this lockless.
1381 */
1382 static __init int kprobe_trace_self_tests_init(void)
1383 {
1384 int ret, warn = 0;
1385 int (*target)(int, int, int, int, int, int);
1386 struct trace_kprobe *tk;
1387 struct trace_event_file *file;
1388
1389 if (tracing_is_disabled())
1390 return -ENODEV;
1391
1392 target = kprobe_trace_selftest_target;
1393
1394 pr_info("Testing kprobe tracing: ");
1395
1396 ret = traceprobe_command("p:testprobe kprobe_trace_selftest_target "
1397 "$stack $stack0 +0($stack)",
1398 create_trace_kprobe);
1399 if (WARN_ON_ONCE(ret)) {
1400 pr_warn("error on probing function entry.\n");
1401 warn++;
1402 } else {
1403 /* Enable trace point */
1404 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
1405 if (WARN_ON_ONCE(tk == NULL)) {
1406 pr_warn("error on getting new probe.\n");
1407 warn++;
1408 } else {
1409 file = find_trace_probe_file(tk, top_trace_array());
1410 if (WARN_ON_ONCE(file == NULL)) {
1411 pr_warn("error on getting probe file.\n");
1412 warn++;
1413 } else
1414 enable_trace_kprobe(tk, file);
1415 }
1416 }
1417
1418 ret = traceprobe_command("r:testprobe2 kprobe_trace_selftest_target "
1419 "$retval", create_trace_kprobe);
1420 if (WARN_ON_ONCE(ret)) {
1421 pr_warn("error on probing function return.\n");
1422 warn++;
1423 } else {
1424 /* Enable trace point */
1425 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
1426 if (WARN_ON_ONCE(tk == NULL)) {
1427 pr_warn("error on getting 2nd new probe.\n");
1428 warn++;
1429 } else {
1430 file = find_trace_probe_file(tk, top_trace_array());
1431 if (WARN_ON_ONCE(file == NULL)) {
1432 pr_warn("error on getting probe file.\n");
1433 warn++;
1434 } else
1435 enable_trace_kprobe(tk, file);
1436 }
1437 }
1438
1439 if (warn)
1440 goto end;
1441
1442 ret = target(1, 2, 3, 4, 5, 6);
1443
1444 /* Disable trace points before removing it */
1445 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
1446 if (WARN_ON_ONCE(tk == NULL)) {
1447 pr_warn("error on getting test probe.\n");
1448 warn++;
1449 } else {
1450 file = find_trace_probe_file(tk, top_trace_array());
1451 if (WARN_ON_ONCE(file == NULL)) {
1452 pr_warn("error on getting probe file.\n");
1453 warn++;
1454 } else
1455 disable_trace_kprobe(tk, file);
1456 }
1457
1458 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
1459 if (WARN_ON_ONCE(tk == NULL)) {
1460 pr_warn("error on getting 2nd test probe.\n");
1461 warn++;
1462 } else {
1463 file = find_trace_probe_file(tk, top_trace_array());
1464 if (WARN_ON_ONCE(file == NULL)) {
1465 pr_warn("error on getting probe file.\n");
1466 warn++;
1467 } else
1468 disable_trace_kprobe(tk, file);
1469 }
1470
1471 ret = traceprobe_command("-:testprobe", create_trace_kprobe);
1472 if (WARN_ON_ONCE(ret)) {
1473 pr_warn("error on deleting a probe.\n");
1474 warn++;
1475 }
1476
1477 ret = traceprobe_command("-:testprobe2", create_trace_kprobe);
1478 if (WARN_ON_ONCE(ret)) {
1479 pr_warn("error on deleting a probe.\n");
1480 warn++;
1481 }
1482
1483 end:
1484 release_all_trace_kprobes();
1485 if (warn)
1486 pr_cont("NG: Some tests are failed. Please check them.\n");
1487 else
1488 pr_cont("OK\n");
1489 return 0;
1490 }
1491
1492 late_initcall(kprobe_trace_self_tests_init);
1493
1494 #endif
Linux kernel - Deliverables
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