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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 nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk)
77 {
78 unsigned long nhit = 0;
79 int cpu;
80
81 for_each_possible_cpu(cpu)
82 nhit += *per_cpu_ptr(tk->nhit, cpu);
83
84 return nhit;
85 }
86
87 static int register_kprobe_event(struct trace_kprobe *tk);
88 static int unregister_kprobe_event(struct trace_kprobe *tk);
89
90 static DEFINE_MUTEX(probe_lock);
91 static LIST_HEAD(probe_list);
92
93 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
94 static int kretprobe_dispatcher(struct kretprobe_instance *ri,
95 struct pt_regs *regs);
96
97 /* Memory fetching by symbol */
98 struct symbol_cache {
99 char *symbol;
100 long offset;
101 unsigned long addr;
102 };
103
104 unsigned long update_symbol_cache(struct symbol_cache *sc)
105 {
106 sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol);
107
108 if (sc->addr)
109 sc->addr += sc->offset;
110
111 return sc->addr;
112 }
113
114 void free_symbol_cache(struct symbol_cache *sc)
115 {
116 kfree(sc->symbol);
117 kfree(sc);
118 }
119
120 struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
121 {
122 struct symbol_cache *sc;
123
124 if (!sym || strlen(sym) == 0)
125 return NULL;
126
127 sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL);
128 if (!sc)
129 return NULL;
130
131 sc->symbol = kstrdup(sym, GFP_KERNEL);
132 if (!sc->symbol) {
133 kfree(sc);
134 return NULL;
135 }
136 sc->offset = offset;
137 update_symbol_cache(sc);
138
139 return sc;
140 }
141
142 /*
143 * Kprobes-specific fetch functions
144 */
145 #define DEFINE_FETCH_stack(type) \
146 static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \
147 void *offset, void *dest) \
148 { \
149 *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \
150 (unsigned int)((unsigned long)offset)); \
151 } \
152 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(stack, type));
153
154 DEFINE_BASIC_FETCH_FUNCS(stack)
155 /* No string on the stack entry */
156 #define fetch_stack_string NULL
157 #define fetch_stack_string_size NULL
158
159 #define DEFINE_FETCH_memory(type) \
160 static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \
161 void *addr, void *dest) \
162 { \
163 type retval; \
164 if (probe_kernel_address(addr, retval)) \
165 *(type *)dest = 0; \
166 else \
167 *(type *)dest = retval; \
168 } \
169 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, type));
170
171 DEFINE_BASIC_FETCH_FUNCS(memory)
172 /*
173 * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
174 * length and relative data location.
175 */
176 static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
177 void *addr, void *dest)
178 {
179 int maxlen = get_rloc_len(*(u32 *)dest);
180 u8 *dst = get_rloc_data(dest);
181 long ret;
182
183 if (!maxlen)
184 return;
185
186 /*
187 * Try to get string again, since the string can be changed while
188 * probing.
189 */
190 ret = strncpy_from_unsafe(dst, addr, maxlen);
191
192 if (ret < 0) { /* Failed to fetch string */
193 dst[0] = '\0';
194 *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest));
195 } else {
196 *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest));
197 }
198 }
199 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string));
200
201 /* Return the length of string -- including null terminal byte */
202 static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
203 void *addr, void *dest)
204 {
205 mm_segment_t old_fs;
206 int ret, len = 0;
207 u8 c;
208
209 old_fs = get_fs();
210 set_fs(KERNEL_DS);
211 pagefault_disable();
212
213 do {
214 ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1);
215 len++;
216 } while (c && ret == 0 && len < MAX_STRING_SIZE);
217
218 pagefault_enable();
219 set_fs(old_fs);
220
221 if (ret < 0) /* Failed to check the length */
222 *(u32 *)dest = 0;
223 else
224 *(u32 *)dest = len;
225 }
226 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string_size));
227
228 #define DEFINE_FETCH_symbol(type) \
229 void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs, void *data, void *dest)\
230 { \
231 struct symbol_cache *sc = data; \
232 if (sc->addr) \
233 fetch_memory_##type(regs, (void *)sc->addr, dest); \
234 else \
235 *(type *)dest = 0; \
236 } \
237 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(symbol, type));
238
239 DEFINE_BASIC_FETCH_FUNCS(symbol)
240 DEFINE_FETCH_symbol(string)
241 DEFINE_FETCH_symbol(string_size)
242
243 /* kprobes don't support file_offset fetch methods */
244 #define fetch_file_offset_u8 NULL
245 #define fetch_file_offset_u16 NULL
246 #define fetch_file_offset_u32 NULL
247 #define fetch_file_offset_u64 NULL
248 #define fetch_file_offset_string NULL
249 #define fetch_file_offset_string_size NULL
250
251 /* Fetch type information table */
252 static const struct fetch_type kprobes_fetch_type_table[] = {
253 /* Special types */
254 [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
255 sizeof(u32), 1, "__data_loc char[]"),
256 [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
257 string_size, sizeof(u32), 0, "u32"),
258 /* Basic types */
259 ASSIGN_FETCH_TYPE(u8, u8, 0),
260 ASSIGN_FETCH_TYPE(u16, u16, 0),
261 ASSIGN_FETCH_TYPE(u32, u32, 0),
262 ASSIGN_FETCH_TYPE(u64, u64, 0),
263 ASSIGN_FETCH_TYPE(s8, u8, 1),
264 ASSIGN_FETCH_TYPE(s16, u16, 1),
265 ASSIGN_FETCH_TYPE(s32, u32, 1),
266 ASSIGN_FETCH_TYPE(s64, u64, 1),
267 ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0),
268 ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
269 ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
270 ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
271
272 ASSIGN_FETCH_TYPE_END
273 };
274
275 /*
276 * Allocate new trace_probe and initialize it (including kprobes).
277 */
278 static struct trace_kprobe *alloc_trace_kprobe(const char *group,
279 const char *event,
280 void *addr,
281 const char *symbol,
282 unsigned long offs,
283 int nargs, bool is_return)
284 {
285 struct trace_kprobe *tk;
286 int ret = -ENOMEM;
287
288 tk = kzalloc(SIZEOF_TRACE_KPROBE(nargs), GFP_KERNEL);
289 if (!tk)
290 return ERR_PTR(ret);
291
292 tk->nhit = alloc_percpu(unsigned long);
293 if (!tk->nhit)
294 goto error;
295
296 if (symbol) {
297 tk->symbol = kstrdup(symbol, GFP_KERNEL);
298 if (!tk->symbol)
299 goto error;
300 tk->rp.kp.symbol_name = tk->symbol;
301 tk->rp.kp.offset = offs;
302 } else
303 tk->rp.kp.addr = addr;
304
305 if (is_return)
306 tk->rp.handler = kretprobe_dispatcher;
307 else
308 tk->rp.kp.pre_handler = kprobe_dispatcher;
309
310 if (!event || !is_good_name(event)) {
311 ret = -EINVAL;
312 goto error;
313 }
314
315 tk->tp.call.class = &tk->tp.class;
316 tk->tp.call.name = kstrdup(event, GFP_KERNEL);
317 if (!tk->tp.call.name)
318 goto error;
319
320 if (!group || !is_good_name(group)) {
321 ret = -EINVAL;
322 goto error;
323 }
324
325 tk->tp.class.system = kstrdup(group, GFP_KERNEL);
326 if (!tk->tp.class.system)
327 goto error;
328
329 INIT_LIST_HEAD(&tk->list);
330 INIT_LIST_HEAD(&tk->tp.files);
331 return tk;
332 error:
333 kfree(tk->tp.call.name);
334 kfree(tk->symbol);
335 free_percpu(tk->nhit);
336 kfree(tk);
337 return ERR_PTR(ret);
338 }
339
340 static void free_trace_kprobe(struct trace_kprobe *tk)
341 {
342 int i;
343
344 for (i = 0; i < tk->tp.nr_args; i++)
345 traceprobe_free_probe_arg(&tk->tp.args[i]);
346
347 kfree(tk->tp.call.class->system);
348 kfree(tk->tp.call.name);
349 kfree(tk->symbol);
350 free_percpu(tk->nhit);
351 kfree(tk);
352 }
353
354 static struct trace_kprobe *find_trace_kprobe(const char *event,
355 const char *group)
356 {
357 struct trace_kprobe *tk;
358
359 list_for_each_entry(tk, &probe_list, list)
360 if (strcmp(trace_event_name(&tk->tp.call), event) == 0 &&
361 strcmp(tk->tp.call.class->system, group) == 0)
362 return tk;
363 return NULL;
364 }
365
366 /*
367 * Enable trace_probe
368 * if the file is NULL, enable "perf" handler, or enable "trace" handler.
369 */
370 static int
371 enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file)
372 {
373 int ret = 0;
374
375 if (file) {
376 struct event_file_link *link;
377
378 link = kmalloc(sizeof(*link), GFP_KERNEL);
379 if (!link) {
380 ret = -ENOMEM;
381 goto out;
382 }
383
384 link->file = file;
385 list_add_tail_rcu(&link->list, &tk->tp.files);
386
387 tk->tp.flags |= TP_FLAG_TRACE;
388 } else
389 tk->tp.flags |= TP_FLAG_PROFILE;
390
391 if (trace_probe_is_registered(&tk->tp) && !trace_kprobe_has_gone(tk)) {
392 if (trace_kprobe_is_return(tk))
393 ret = enable_kretprobe(&tk->rp);
394 else
395 ret = enable_kprobe(&tk->rp.kp);
396 }
397 out:
398 return ret;
399 }
400
401 /*
402 * Disable trace_probe
403 * if the file is NULL, disable "perf" handler, or disable "trace" handler.
404 */
405 static int
406 disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file)
407 {
408 struct event_file_link *link = NULL;
409 int wait = 0;
410 int ret = 0;
411
412 if (file) {
413 link = find_event_file_link(&tk->tp, file);
414 if (!link) {
415 ret = -EINVAL;
416 goto out;
417 }
418
419 list_del_rcu(&link->list);
420 wait = 1;
421 if (!list_empty(&tk->tp.files))
422 goto out;
423
424 tk->tp.flags &= ~TP_FLAG_TRACE;
425 } else
426 tk->tp.flags &= ~TP_FLAG_PROFILE;
427
428 if (!trace_probe_is_enabled(&tk->tp) && trace_probe_is_registered(&tk->tp)) {
429 if (trace_kprobe_is_return(tk))
430 disable_kretprobe(&tk->rp);
431 else
432 disable_kprobe(&tk->rp.kp);
433 wait = 1;
434 }
435 out:
436 if (wait) {
437 /*
438 * Synchronize with kprobe_trace_func/kretprobe_trace_func
439 * to ensure disabled (all running handlers are finished).
440 * This is not only for kfree(), but also the caller,
441 * trace_remove_event_call() supposes it for releasing
442 * event_call related objects, which will be accessed in
443 * the kprobe_trace_func/kretprobe_trace_func.
444 */
445 synchronize_sched();
446 kfree(link); /* Ignored if link == NULL */
447 }
448
449 return ret;
450 }
451
452 /* Internal register function - just handle k*probes and flags */
453 static int __register_trace_kprobe(struct trace_kprobe *tk)
454 {
455 int i, ret;
456
457 if (trace_probe_is_registered(&tk->tp))
458 return -EINVAL;
459
460 for (i = 0; i < tk->tp.nr_args; i++)
461 traceprobe_update_arg(&tk->tp.args[i]);
462
463 /* Set/clear disabled flag according to tp->flag */
464 if (trace_probe_is_enabled(&tk->tp))
465 tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED;
466 else
467 tk->rp.kp.flags |= KPROBE_FLAG_DISABLED;
468
469 if (trace_kprobe_is_return(tk))
470 ret = register_kretprobe(&tk->rp);
471 else
472 ret = register_kprobe(&tk->rp.kp);
473
474 if (ret == 0)
475 tk->tp.flags |= TP_FLAG_REGISTERED;
476 else {
477 pr_warn("Could not insert probe at %s+%lu: %d\n",
478 trace_kprobe_symbol(tk), trace_kprobe_offset(tk), ret);
479 if (ret == -ENOENT && trace_kprobe_is_on_module(tk)) {
480 pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
481 ret = 0;
482 } else if (ret == -EILSEQ) {
483 pr_warn("Probing address(0x%p) is not an instruction boundary.\n",
484 tk->rp.kp.addr);
485 ret = -EINVAL;
486 }
487 }
488
489 return ret;
490 }
491
492 /* Internal unregister function - just handle k*probes and flags */
493 static void __unregister_trace_kprobe(struct trace_kprobe *tk)
494 {
495 if (trace_probe_is_registered(&tk->tp)) {
496 if (trace_kprobe_is_return(tk))
497 unregister_kretprobe(&tk->rp);
498 else
499 unregister_kprobe(&tk->rp.kp);
500 tk->tp.flags &= ~TP_FLAG_REGISTERED;
501 /* Cleanup kprobe for reuse */
502 if (tk->rp.kp.symbol_name)
503 tk->rp.kp.addr = NULL;
504 }
505 }
506
507 /* Unregister a trace_probe and probe_event: call with locking probe_lock */
508 static int unregister_trace_kprobe(struct trace_kprobe *tk)
509 {
510 /* Enabled event can not be unregistered */
511 if (trace_probe_is_enabled(&tk->tp))
512 return -EBUSY;
513
514 /* Will fail if probe is being used by ftrace or perf */
515 if (unregister_kprobe_event(tk))
516 return -EBUSY;
517
518 __unregister_trace_kprobe(tk);
519 list_del(&tk->list);
520
521 return 0;
522 }
523
524 /* Register a trace_probe and probe_event */
525 static int register_trace_kprobe(struct trace_kprobe *tk)
526 {
527 struct trace_kprobe *old_tk;
528 int ret;
529
530 mutex_lock(&probe_lock);
531
532 /* Delete old (same name) event if exist */
533 old_tk = find_trace_kprobe(trace_event_name(&tk->tp.call),
534 tk->tp.call.class->system);
535 if (old_tk) {
536 ret = unregister_trace_kprobe(old_tk);
537 if (ret < 0)
538 goto end;
539 free_trace_kprobe(old_tk);
540 }
541
542 /* Register new event */
543 ret = register_kprobe_event(tk);
544 if (ret) {
545 pr_warn("Failed to register probe event(%d)\n", ret);
546 goto end;
547 }
548
549 /* Register k*probe */
550 ret = __register_trace_kprobe(tk);
551 if (ret < 0)
552 unregister_kprobe_event(tk);
553 else
554 list_add_tail(&tk->list, &probe_list);
555
556 end:
557 mutex_unlock(&probe_lock);
558 return ret;
559 }
560
561 /* Module notifier call back, checking event on the module */
562 static int trace_kprobe_module_callback(struct notifier_block *nb,
563 unsigned long val, void *data)
564 {
565 struct module *mod = data;
566 struct trace_kprobe *tk;
567 int ret;
568
569 if (val != MODULE_STATE_COMING)
570 return NOTIFY_DONE;
571
572 /* Update probes on coming module */
573 mutex_lock(&probe_lock);
574 list_for_each_entry(tk, &probe_list, list) {
575 if (trace_kprobe_within_module(tk, mod)) {
576 /* Don't need to check busy - this should have gone. */
577 __unregister_trace_kprobe(tk);
578 ret = __register_trace_kprobe(tk);
579 if (ret)
580 pr_warn("Failed to re-register probe %s on %s: %d\n",
581 trace_event_name(&tk->tp.call),
582 mod->name, ret);
583 }
584 }
585 mutex_unlock(&probe_lock);
586
587 return NOTIFY_DONE;
588 }
589
590 static struct notifier_block trace_kprobe_module_nb = {
591 .notifier_call = trace_kprobe_module_callback,
592 .priority = 1 /* Invoked after kprobe module callback */
593 };
594
595 static int create_trace_kprobe(int argc, char **argv)
596 {
597 /*
598 * Argument syntax:
599 * - Add kprobe: p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
600 * - Add kretprobe: r[:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
601 * Fetch args:
602 * $retval : fetch return value
603 * $stack : fetch stack address
604 * $stackN : fetch Nth of stack (N:0-)
605 * $comm : fetch current task comm
606 * @ADDR : fetch memory at ADDR (ADDR should be in kernel)
607 * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
608 * %REG : fetch register REG
609 * Dereferencing memory fetch:
610 * +|-offs(ARG) : fetch memory at ARG +|- offs address.
611 * Alias name of args:
612 * NAME=FETCHARG : set NAME as alias of FETCHARG.
613 * Type of args:
614 * FETCHARG:TYPE : use TYPE instead of unsigned long.
615 */
616 struct trace_kprobe *tk;
617 int i, ret = 0;
618 bool is_return = false, is_delete = false;
619 char *symbol = NULL, *event = NULL, *group = NULL;
620 char *arg;
621 unsigned long offset = 0;
622 void *addr = NULL;
623 char buf[MAX_EVENT_NAME_LEN];
624
625 /* argc must be >= 1 */
626 if (argv[0][0] == 'p')
627 is_return = false;
628 else if (argv[0][0] == 'r')
629 is_return = true;
630 else if (argv[0][0] == '-')
631 is_delete = true;
632 else {
633 pr_info("Probe definition must be started with 'p', 'r' or"
634 " '-'.\n");
635 return -EINVAL;
636 }
637
638 if (argv[0][1] == ':') {
639 event = &argv[0][2];
640 if (strchr(event, '/')) {
641 group = event;
642 event = strchr(group, '/') + 1;
643 event[-1] = '\0';
644 if (strlen(group) == 0) {
645 pr_info("Group name is not specified\n");
646 return -EINVAL;
647 }
648 }
649 if (strlen(event) == 0) {
650 pr_info("Event name is not specified\n");
651 return -EINVAL;
652 }
653 }
654 if (!group)
655 group = KPROBE_EVENT_SYSTEM;
656
657 if (is_delete) {
658 if (!event) {
659 pr_info("Delete command needs an event name.\n");
660 return -EINVAL;
661 }
662 mutex_lock(&probe_lock);
663 tk = find_trace_kprobe(event, group);
664 if (!tk) {
665 mutex_unlock(&probe_lock);
666 pr_info("Event %s/%s doesn't exist.\n", group, event);
667 return -ENOENT;
668 }
669 /* delete an event */
670 ret = unregister_trace_kprobe(tk);
671 if (ret == 0)
672 free_trace_kprobe(tk);
673 mutex_unlock(&probe_lock);
674 return ret;
675 }
676
677 if (argc < 2) {
678 pr_info("Probe point is not specified.\n");
679 return -EINVAL;
680 }
681 if (isdigit(argv[1][0])) {
682 if (is_return) {
683 pr_info("Return probe point must be a symbol.\n");
684 return -EINVAL;
685 }
686 /* an address specified */
687 ret = kstrtoul(&argv[1][0], 0, (unsigned long *)&addr);
688 if (ret) {
689 pr_info("Failed to parse address.\n");
690 return ret;
691 }
692 } else {
693 /* a symbol specified */
694 symbol = argv[1];
695 /* TODO: support .init module functions */
696 ret = traceprobe_split_symbol_offset(symbol, &offset);
697 if (ret) {
698 pr_info("Failed to parse symbol.\n");
699 return ret;
700 }
701 if (offset && is_return) {
702 pr_info("Return probe must be used without offset.\n");
703 return -EINVAL;
704 }
705 }
706 argc -= 2; argv += 2;
707
708 /* setup a probe */
709 if (!event) {
710 /* Make a new event name */
711 if (symbol)
712 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
713 is_return ? 'r' : 'p', symbol, offset);
714 else
715 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
716 is_return ? 'r' : 'p', addr);
717 event = buf;
718 }
719 tk = alloc_trace_kprobe(group, event, addr, symbol, offset, argc,
720 is_return);
721 if (IS_ERR(tk)) {
722 pr_info("Failed to allocate trace_probe.(%d)\n",
723 (int)PTR_ERR(tk));
724 return PTR_ERR(tk);
725 }
726
727 /* parse arguments */
728 ret = 0;
729 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
730 struct probe_arg *parg = &tk->tp.args[i];
731
732 /* Increment count for freeing args in error case */
733 tk->tp.nr_args++;
734
735 /* Parse argument name */
736 arg = strchr(argv[i], '=');
737 if (arg) {
738 *arg++ = '\0';
739 parg->name = kstrdup(argv[i], GFP_KERNEL);
740 } else {
741 arg = argv[i];
742 /* If argument name is omitted, set "argN" */
743 snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1);
744 parg->name = kstrdup(buf, GFP_KERNEL);
745 }
746
747 if (!parg->name) {
748 pr_info("Failed to allocate argument[%d] name.\n", i);
749 ret = -ENOMEM;
750 goto error;
751 }
752
753 if (!is_good_name(parg->name)) {
754 pr_info("Invalid argument[%d] name: %s\n",
755 i, parg->name);
756 ret = -EINVAL;
757 goto error;
758 }
759
760 if (traceprobe_conflict_field_name(parg->name,
761 tk->tp.args, i)) {
762 pr_info("Argument[%d] name '%s' conflicts with "
763 "another field.\n", i, argv[i]);
764 ret = -EINVAL;
765 goto error;
766 }
767
768 /* Parse fetch argument */
769 ret = traceprobe_parse_probe_arg(arg, &tk->tp.size, parg,
770 is_return, true,
771 kprobes_fetch_type_table);
772 if (ret) {
773 pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
774 goto error;
775 }
776 }
777
778 ret = register_trace_kprobe(tk);
779 if (ret)
780 goto error;
781 return 0;
782
783 error:
784 free_trace_kprobe(tk);
785 return ret;
786 }
787
788 static int release_all_trace_kprobes(void)
789 {
790 struct trace_kprobe *tk;
791 int ret = 0;
792
793 mutex_lock(&probe_lock);
794 /* Ensure no probe is in use. */
795 list_for_each_entry(tk, &probe_list, list)
796 if (trace_probe_is_enabled(&tk->tp)) {
797 ret = -EBUSY;
798 goto end;
799 }
800 /* TODO: Use batch unregistration */
801 while (!list_empty(&probe_list)) {
802 tk = list_entry(probe_list.next, struct trace_kprobe, list);
803 ret = unregister_trace_kprobe(tk);
804 if (ret)
805 goto end;
806 free_trace_kprobe(tk);
807 }
808
809 end:
810 mutex_unlock(&probe_lock);
811
812 return ret;
813 }
814
815 /* Probes listing interfaces */
816 static void *probes_seq_start(struct seq_file *m, loff_t *pos)
817 {
818 mutex_lock(&probe_lock);
819 return seq_list_start(&probe_list, *pos);
820 }
821
822 static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
823 {
824 return seq_list_next(v, &probe_list, pos);
825 }
826
827 static void probes_seq_stop(struct seq_file *m, void *v)
828 {
829 mutex_unlock(&probe_lock);
830 }
831
832 static int probes_seq_show(struct seq_file *m, void *v)
833 {
834 struct trace_kprobe *tk = v;
835 int i;
836
837 seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p');
838 seq_printf(m, ":%s/%s", tk->tp.call.class->system,
839 trace_event_name(&tk->tp.call));
840
841 if (!tk->symbol)
842 seq_printf(m, " 0x%p", tk->rp.kp.addr);
843 else if (tk->rp.kp.offset)
844 seq_printf(m, " %s+%u", trace_kprobe_symbol(tk),
845 tk->rp.kp.offset);
846 else
847 seq_printf(m, " %s", trace_kprobe_symbol(tk));
848
849 for (i = 0; i < tk->tp.nr_args; i++)
850 seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm);
851 seq_putc(m, '\n');
852
853 return 0;
854 }
855
856 static const struct seq_operations probes_seq_op = {
857 .start = probes_seq_start,
858 .next = probes_seq_next,
859 .stop = probes_seq_stop,
860 .show = probes_seq_show
861 };
862
863 static int probes_open(struct inode *inode, struct file *file)
864 {
865 int ret;
866
867 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
868 ret = release_all_trace_kprobes();
869 if (ret < 0)
870 return ret;
871 }
872
873 return seq_open(file, &probes_seq_op);
874 }
875
876 static ssize_t probes_write(struct file *file, const char __user *buffer,
877 size_t count, loff_t *ppos)
878 {
879 return traceprobe_probes_write(file, buffer, count, ppos,
880 create_trace_kprobe);
881 }
882
883 static const struct file_operations kprobe_events_ops = {
884 .owner = THIS_MODULE,
885 .open = probes_open,
886 .read = seq_read,
887 .llseek = seq_lseek,
888 .release = seq_release,
889 .write = probes_write,
890 };
891
892 /* Probes profiling interfaces */
893 static int probes_profile_seq_show(struct seq_file *m, void *v)
894 {
895 struct trace_kprobe *tk = v;
896
897 seq_printf(m, " %-44s %15lu %15lu\n",
898 trace_event_name(&tk->tp.call),
899 trace_kprobe_nhit(tk),
900 tk->rp.kp.nmissed);
901
902 return 0;
903 }
904
905 static const struct seq_operations profile_seq_op = {
906 .start = probes_seq_start,
907 .next = probes_seq_next,
908 .stop = probes_seq_stop,
909 .show = probes_profile_seq_show
910 };
911
912 static int profile_open(struct inode *inode, struct file *file)
913 {
914 return seq_open(file, &profile_seq_op);
915 }
916
917 static const struct file_operations kprobe_profile_ops = {
918 .owner = THIS_MODULE,
919 .open = profile_open,
920 .read = seq_read,
921 .llseek = seq_lseek,
922 .release = seq_release,
923 };
924
925 /* Kprobe handler */
926 static nokprobe_inline void
927 __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
928 struct trace_event_file *trace_file)
929 {
930 struct kprobe_trace_entry_head *entry;
931 struct ring_buffer_event *event;
932 struct ring_buffer *buffer;
933 int size, dsize, pc;
934 unsigned long irq_flags;
935 struct trace_event_call *call = &tk->tp.call;
936
937 WARN_ON(call != trace_file->event_call);
938
939 if (trace_trigger_soft_disabled(trace_file))
940 return;
941
942 local_save_flags(irq_flags);
943 pc = preempt_count();
944
945 dsize = __get_data_size(&tk->tp, regs);
946 size = sizeof(*entry) + tk->tp.size + dsize;
947
948 event = trace_event_buffer_lock_reserve(&buffer, trace_file,
949 call->event.type,
950 size, irq_flags, pc);
951 if (!event)
952 return;
953
954 entry = ring_buffer_event_data(event);
955 entry->ip = (unsigned long)tk->rp.kp.addr;
956 store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
957
958 event_trigger_unlock_commit_regs(trace_file, buffer, event,
959 entry, irq_flags, pc, regs);
960 }
961
962 static void
963 kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs)
964 {
965 struct event_file_link *link;
966
967 list_for_each_entry_rcu(link, &tk->tp.files, list)
968 __kprobe_trace_func(tk, regs, link->file);
969 }
970 NOKPROBE_SYMBOL(kprobe_trace_func);
971
972 /* Kretprobe handler */
973 static nokprobe_inline void
974 __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
975 struct pt_regs *regs,
976 struct trace_event_file *trace_file)
977 {
978 struct kretprobe_trace_entry_head *entry;
979 struct ring_buffer_event *event;
980 struct ring_buffer *buffer;
981 int size, pc, dsize;
982 unsigned long irq_flags;
983 struct trace_event_call *call = &tk->tp.call;
984
985 WARN_ON(call != trace_file->event_call);
986
987 if (trace_trigger_soft_disabled(trace_file))
988 return;
989
990 local_save_flags(irq_flags);
991 pc = preempt_count();
992
993 dsize = __get_data_size(&tk->tp, regs);
994 size = sizeof(*entry) + tk->tp.size + dsize;
995
996 event = trace_event_buffer_lock_reserve(&buffer, trace_file,
997 call->event.type,
998 size, irq_flags, pc);
999 if (!event)
1000 return;
1001
1002 entry = ring_buffer_event_data(event);
1003 entry->func = (unsigned long)tk->rp.kp.addr;
1004 entry->ret_ip = (unsigned long)ri->ret_addr;
1005 store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
1006
1007 event_trigger_unlock_commit_regs(trace_file, buffer, event,
1008 entry, irq_flags, pc, regs);
1009 }
1010
1011 static void
1012 kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1013 struct pt_regs *regs)
1014 {
1015 struct event_file_link *link;
1016
1017 list_for_each_entry_rcu(link, &tk->tp.files, list)
1018 __kretprobe_trace_func(tk, ri, regs, link->file);
1019 }
1020 NOKPROBE_SYMBOL(kretprobe_trace_func);
1021
1022 /* Event entry printers */
1023 static enum print_line_t
1024 print_kprobe_event(struct trace_iterator *iter, int flags,
1025 struct trace_event *event)
1026 {
1027 struct kprobe_trace_entry_head *field;
1028 struct trace_seq *s = &iter->seq;
1029 struct trace_probe *tp;
1030 u8 *data;
1031 int i;
1032
1033 field = (struct kprobe_trace_entry_head *)iter->ent;
1034 tp = container_of(event, struct trace_probe, call.event);
1035
1036 trace_seq_printf(s, "%s: (", trace_event_name(&tp->call));
1037
1038 if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
1039 goto out;
1040
1041 trace_seq_putc(s, ')');
1042
1043 data = (u8 *)&field[1];
1044 for (i = 0; i < tp->nr_args; i++)
1045 if (!tp->args[i].type->print(s, tp->args[i].name,
1046 data + tp->args[i].offset, field))
1047 goto out;
1048
1049 trace_seq_putc(s, '\n');
1050 out:
1051 return trace_handle_return(s);
1052 }
1053
1054 static enum print_line_t
1055 print_kretprobe_event(struct trace_iterator *iter, int flags,
1056 struct trace_event *event)
1057 {
1058 struct kretprobe_trace_entry_head *field;
1059 struct trace_seq *s = &iter->seq;
1060 struct trace_probe *tp;
1061 u8 *data;
1062 int i;
1063
1064 field = (struct kretprobe_trace_entry_head *)iter->ent;
1065 tp = container_of(event, struct trace_probe, call.event);
1066
1067 trace_seq_printf(s, "%s: (", trace_event_name(&tp->call));
1068
1069 if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
1070 goto out;
1071
1072 trace_seq_puts(s, " <- ");
1073
1074 if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
1075 goto out;
1076
1077 trace_seq_putc(s, ')');
1078
1079 data = (u8 *)&field[1];
1080 for (i = 0; i < tp->nr_args; i++)
1081 if (!tp->args[i].type->print(s, tp->args[i].name,
1082 data + tp->args[i].offset, field))
1083 goto out;
1084
1085 trace_seq_putc(s, '\n');
1086
1087 out:
1088 return trace_handle_return(s);
1089 }
1090
1091
1092 static int kprobe_event_define_fields(struct trace_event_call *event_call)
1093 {
1094 int ret, i;
1095 struct kprobe_trace_entry_head field;
1096 struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data;
1097
1098 DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
1099 /* Set argument names as fields */
1100 for (i = 0; i < tk->tp.nr_args; i++) {
1101 struct probe_arg *parg = &tk->tp.args[i];
1102
1103 ret = trace_define_field(event_call, parg->type->fmttype,
1104 parg->name,
1105 sizeof(field) + parg->offset,
1106 parg->type->size,
1107 parg->type->is_signed,
1108 FILTER_OTHER);
1109 if (ret)
1110 return ret;
1111 }
1112 return 0;
1113 }
1114
1115 static int kretprobe_event_define_fields(struct trace_event_call *event_call)
1116 {
1117 int ret, i;
1118 struct kretprobe_trace_entry_head field;
1119 struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data;
1120
1121 DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
1122 DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
1123 /* Set argument names as fields */
1124 for (i = 0; i < tk->tp.nr_args; i++) {
1125 struct probe_arg *parg = &tk->tp.args[i];
1126
1127 ret = trace_define_field(event_call, parg->type->fmttype,
1128 parg->name,
1129 sizeof(field) + parg->offset,
1130 parg->type->size,
1131 parg->type->is_signed,
1132 FILTER_OTHER);
1133 if (ret)
1134 return ret;
1135 }
1136 return 0;
1137 }
1138
1139 #ifdef CONFIG_PERF_EVENTS
1140
1141 /* Kprobe profile handler */
1142 static void
1143 kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
1144 {
1145 struct trace_event_call *call = &tk->tp.call;
1146 struct bpf_prog *prog = call->prog;
1147 struct kprobe_trace_entry_head *entry;
1148 struct hlist_head *head;
1149 int size, __size, dsize;
1150 int rctx;
1151
1152 if (prog && !trace_call_bpf(prog, regs))
1153 return;
1154
1155 head = this_cpu_ptr(call->perf_events);
1156 if (hlist_empty(head))
1157 return;
1158
1159 dsize = __get_data_size(&tk->tp, regs);
1160 __size = sizeof(*entry) + tk->tp.size + dsize;
1161 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1162 size -= sizeof(u32);
1163
1164 entry = perf_trace_buf_alloc(size, NULL, &rctx);
1165 if (!entry)
1166 return;
1167
1168 entry->ip = (unsigned long)tk->rp.kp.addr;
1169 memset(&entry[1], 0, dsize);
1170 store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
1171 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1172 head, NULL);
1173 }
1174 NOKPROBE_SYMBOL(kprobe_perf_func);
1175
1176 /* Kretprobe profile handler */
1177 static void
1178 kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1179 struct pt_regs *regs)
1180 {
1181 struct trace_event_call *call = &tk->tp.call;
1182 struct bpf_prog *prog = call->prog;
1183 struct kretprobe_trace_entry_head *entry;
1184 struct hlist_head *head;
1185 int size, __size, dsize;
1186 int rctx;
1187
1188 if (prog && !trace_call_bpf(prog, regs))
1189 return;
1190
1191 head = this_cpu_ptr(call->perf_events);
1192 if (hlist_empty(head))
1193 return;
1194
1195 dsize = __get_data_size(&tk->tp, regs);
1196 __size = sizeof(*entry) + tk->tp.size + dsize;
1197 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1198 size -= sizeof(u32);
1199
1200 entry = perf_trace_buf_alloc(size, NULL, &rctx);
1201 if (!entry)
1202 return;
1203
1204 entry->func = (unsigned long)tk->rp.kp.addr;
1205 entry->ret_ip = (unsigned long)ri->ret_addr;
1206 store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
1207 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1208 head, NULL);
1209 }
1210 NOKPROBE_SYMBOL(kretprobe_perf_func);
1211 #endif /* CONFIG_PERF_EVENTS */
1212
1213 /*
1214 * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex.
1215 *
1216 * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe
1217 * lockless, but we can't race with this __init function.
1218 */
1219 static int kprobe_register(struct trace_event_call *event,
1220 enum trace_reg type, void *data)
1221 {
1222 struct trace_kprobe *tk = (struct trace_kprobe *)event->data;
1223 struct trace_event_file *file = data;
1224
1225 switch (type) {
1226 case TRACE_REG_REGISTER:
1227 return enable_trace_kprobe(tk, file);
1228 case TRACE_REG_UNREGISTER:
1229 return disable_trace_kprobe(tk, file);
1230
1231 #ifdef CONFIG_PERF_EVENTS
1232 case TRACE_REG_PERF_REGISTER:
1233 return enable_trace_kprobe(tk, NULL);
1234 case TRACE_REG_PERF_UNREGISTER:
1235 return disable_trace_kprobe(tk, NULL);
1236 case TRACE_REG_PERF_OPEN:
1237 case TRACE_REG_PERF_CLOSE:
1238 case TRACE_REG_PERF_ADD:
1239 case TRACE_REG_PERF_DEL:
1240 return 0;
1241 #endif
1242 }
1243 return 0;
1244 }
1245
1246 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1247 {
1248 struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp);
1249
1250 raw_cpu_inc(*tk->nhit);
1251
1252 if (tk->tp.flags & TP_FLAG_TRACE)
1253 kprobe_trace_func(tk, regs);
1254 #ifdef CONFIG_PERF_EVENTS
1255 if (tk->tp.flags & TP_FLAG_PROFILE)
1256 kprobe_perf_func(tk, regs);
1257 #endif
1258 return 0; /* We don't tweek kernel, so just return 0 */
1259 }
1260 NOKPROBE_SYMBOL(kprobe_dispatcher);
1261
1262 static int
1263 kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1264 {
1265 struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp);
1266
1267 raw_cpu_inc(*tk->nhit);
1268
1269 if (tk->tp.flags & TP_FLAG_TRACE)
1270 kretprobe_trace_func(tk, ri, regs);
1271 #ifdef CONFIG_PERF_EVENTS
1272 if (tk->tp.flags & TP_FLAG_PROFILE)
1273 kretprobe_perf_func(tk, ri, regs);
1274 #endif
1275 return 0; /* We don't tweek kernel, so just return 0 */
1276 }
1277 NOKPROBE_SYMBOL(kretprobe_dispatcher);
1278
1279 static struct trace_event_functions kretprobe_funcs = {
1280 .trace = print_kretprobe_event
1281 };
1282
1283 static struct trace_event_functions kprobe_funcs = {
1284 .trace = print_kprobe_event
1285 };
1286
1287 static int register_kprobe_event(struct trace_kprobe *tk)
1288 {
1289 struct trace_event_call *call = &tk->tp.call;
1290 int ret;
1291
1292 /* Initialize trace_event_call */
1293 INIT_LIST_HEAD(&call->class->fields);
1294 if (trace_kprobe_is_return(tk)) {
1295 call->event.funcs = &kretprobe_funcs;
1296 call->class->define_fields = kretprobe_event_define_fields;
1297 } else {
1298 call->event.funcs = &kprobe_funcs;
1299 call->class->define_fields = kprobe_event_define_fields;
1300 }
1301 if (set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0)
1302 return -ENOMEM;
1303 ret = register_trace_event(&call->event);
1304 if (!ret) {
1305 kfree(call->print_fmt);
1306 return -ENODEV;
1307 }
1308 call->flags = TRACE_EVENT_FL_KPROBE;
1309 call->class->reg = kprobe_register;
1310 call->data = tk;
1311 ret = trace_add_event_call(call);
1312 if (ret) {
1313 pr_info("Failed to register kprobe event: %s\n",
1314 trace_event_name(call));
1315 kfree(call->print_fmt);
1316 unregister_trace_event(&call->event);
1317 }
1318 return ret;
1319 }
1320
1321 static int unregister_kprobe_event(struct trace_kprobe *tk)
1322 {
1323 int ret;
1324
1325 /* tp->event is unregistered in trace_remove_event_call() */
1326 ret = trace_remove_event_call(&tk->tp.call);
1327 if (!ret)
1328 kfree(tk->tp.call.print_fmt);
1329 return ret;
1330 }
1331
1332 /* Make a tracefs interface for controlling probe points */
1333 static __init int init_kprobe_trace(void)
1334 {
1335 struct dentry *d_tracer;
1336 struct dentry *entry;
1337
1338 if (register_module_notifier(&trace_kprobe_module_nb))
1339 return -EINVAL;
1340
1341 d_tracer = tracing_init_dentry();
1342 if (IS_ERR(d_tracer))
1343 return 0;
1344
1345 entry = tracefs_create_file("kprobe_events", 0644, d_tracer,
1346 NULL, &kprobe_events_ops);
1347
1348 /* Event list interface */
1349 if (!entry)
1350 pr_warn("Could not create tracefs 'kprobe_events' entry\n");
1351
1352 /* Profile interface */
1353 entry = tracefs_create_file("kprobe_profile", 0444, d_tracer,
1354 NULL, &kprobe_profile_ops);
1355
1356 if (!entry)
1357 pr_warn("Could not create tracefs 'kprobe_profile' entry\n");
1358 return 0;
1359 }
1360 fs_initcall(init_kprobe_trace);
1361
1362
1363 #ifdef CONFIG_FTRACE_STARTUP_TEST
1364 /*
1365 * The "__used" keeps gcc from removing the function symbol
1366 * from the kallsyms table. 'noinline' makes sure that there
1367 * isn't an inlined version used by the test method below
1368 */
1369 static __used __init noinline int
1370 kprobe_trace_selftest_target(int a1, int a2, int a3, int a4, int a5, int a6)
1371 {
1372 return a1 + a2 + a3 + a4 + a5 + a6;
1373 }
1374
1375 static struct __init trace_event_file *
1376 find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr)
1377 {
1378 struct trace_event_file *file;
1379
1380 list_for_each_entry(file, &tr->events, list)
1381 if (file->event_call == &tk->tp.call)
1382 return file;
1383
1384 return NULL;
1385 }
1386
1387 /*
1388 * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this
1389 * stage, we can do this lockless.
1390 */
1391 static __init int kprobe_trace_self_tests_init(void)
1392 {
1393 int ret, warn = 0;
1394 int (*target)(int, int, int, int, int, int);
1395 struct trace_kprobe *tk;
1396 struct trace_event_file *file;
1397
1398 if (tracing_is_disabled())
1399 return -ENODEV;
1400
1401 target = kprobe_trace_selftest_target;
1402
1403 pr_info("Testing kprobe tracing: ");
1404
1405 ret = traceprobe_command("p:testprobe kprobe_trace_selftest_target "
1406 "$stack $stack0 +0($stack)",
1407 create_trace_kprobe);
1408 if (WARN_ON_ONCE(ret)) {
1409 pr_warn("error on probing function entry.\n");
1410 warn++;
1411 } else {
1412 /* Enable trace point */
1413 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
1414 if (WARN_ON_ONCE(tk == NULL)) {
1415 pr_warn("error on getting new probe.\n");
1416 warn++;
1417 } else {
1418 file = find_trace_probe_file(tk, top_trace_array());
1419 if (WARN_ON_ONCE(file == NULL)) {
1420 pr_warn("error on getting probe file.\n");
1421 warn++;
1422 } else
1423 enable_trace_kprobe(tk, file);
1424 }
1425 }
1426
1427 ret = traceprobe_command("r:testprobe2 kprobe_trace_selftest_target "
1428 "$retval", create_trace_kprobe);
1429 if (WARN_ON_ONCE(ret)) {
1430 pr_warn("error on probing function return.\n");
1431 warn++;
1432 } else {
1433 /* Enable trace point */
1434 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
1435 if (WARN_ON_ONCE(tk == NULL)) {
1436 pr_warn("error on getting 2nd new probe.\n");
1437 warn++;
1438 } else {
1439 file = find_trace_probe_file(tk, top_trace_array());
1440 if (WARN_ON_ONCE(file == NULL)) {
1441 pr_warn("error on getting probe file.\n");
1442 warn++;
1443 } else
1444 enable_trace_kprobe(tk, file);
1445 }
1446 }
1447
1448 if (warn)
1449 goto end;
1450
1451 ret = target(1, 2, 3, 4, 5, 6);
1452
1453 /*
1454 * Not expecting an error here, the check is only to prevent the
1455 * optimizer from removing the call to target() as otherwise there
1456 * are no side-effects and the call is never performed.
1457 */
1458 if (ret != 21)
1459 warn++;
1460
1461 /* Disable trace points before removing it */
1462 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
1463 if (WARN_ON_ONCE(tk == NULL)) {
1464 pr_warn("error on getting test probe.\n");
1465 warn++;
1466 } else {
1467 if (trace_kprobe_nhit(tk) != 1) {
1468 pr_warn("incorrect number of testprobe hits\n");
1469 warn++;
1470 }
1471
1472 file = find_trace_probe_file(tk, top_trace_array());
1473 if (WARN_ON_ONCE(file == NULL)) {
1474 pr_warn("error on getting probe file.\n");
1475 warn++;
1476 } else
1477 disable_trace_kprobe(tk, file);
1478 }
1479
1480 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
1481 if (WARN_ON_ONCE(tk == NULL)) {
1482 pr_warn("error on getting 2nd test probe.\n");
1483 warn++;
1484 } else {
1485 if (trace_kprobe_nhit(tk) != 1) {
1486 pr_warn("incorrect number of testprobe2 hits\n");
1487 warn++;
1488 }
1489
1490 file = find_trace_probe_file(tk, top_trace_array());
1491 if (WARN_ON_ONCE(file == NULL)) {
1492 pr_warn("error on getting probe file.\n");
1493 warn++;
1494 } else
1495 disable_trace_kprobe(tk, file);
1496 }
1497
1498 ret = traceprobe_command("-:testprobe", create_trace_kprobe);
1499 if (WARN_ON_ONCE(ret)) {
1500 pr_warn("error on deleting a probe.\n");
1501 warn++;
1502 }
1503
1504 ret = traceprobe_command("-:testprobe2", create_trace_kprobe);
1505 if (WARN_ON_ONCE(ret)) {
1506 pr_warn("error on deleting a probe.\n");
1507 warn++;
1508 }
1509
1510 end:
1511 release_all_trace_kprobes();
1512 if (warn)
1513 pr_cont("NG: Some tests are failed. Please check them.\n");
1514 else
1515 pr_cont("OK\n");
1516 return 0;
1517 }
1518
1519 late_initcall(kprobe_trace_self_tests_init);
1520
1521 #endif
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