1
2
3
4
5
6
7
8#define pr_fmt(fmt) "trace_kprobe: " fmt
9
10#include <linux/module.h>
11#include <linux/uaccess.h>
12#include <linux/rculist.h>
13#include <linux/error-injection.h>
14
15#include "trace_kprobe_selftest.h"
16#include "trace_probe.h"
17
18#define KPROBE_EVENT_SYSTEM "kprobes"
19#define KRETPROBE_MAXACTIVE_MAX 4096
20
21
22
23
24struct trace_kprobe {
25 struct list_head list;
26 struct kretprobe rp;
27 unsigned long __percpu *nhit;
28 const char *symbol;
29 struct trace_probe tp;
30};
31
32#define SIZEOF_TRACE_KPROBE(n) \
33 (offsetof(struct trace_kprobe, tp.args) + \
34 (sizeof(struct probe_arg) * (n)))
35
36static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk)
37{
38 return tk->rp.handler != NULL;
39}
40
41static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk)
42{
43 return tk->symbol ? tk->symbol : "unknown";
44}
45
46static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk)
47{
48 return tk->rp.kp.offset;
49}
50
51static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk)
52{
53 return !!(kprobe_gone(&tk->rp.kp));
54}
55
56static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk,
57 struct module *mod)
58{
59 int len = strlen(mod->name);
60 const char *name = trace_kprobe_symbol(tk);
61 return strncmp(mod->name, name, len) == 0 && name[len] == ':';
62}
63
64static nokprobe_inline bool trace_kprobe_is_on_module(struct trace_kprobe *tk)
65{
66 return !!strchr(trace_kprobe_symbol(tk), ':');
67}
68
69static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk)
70{
71 unsigned long nhit = 0;
72 int cpu;
73
74 for_each_possible_cpu(cpu)
75 nhit += *per_cpu_ptr(tk->nhit, cpu);
76
77 return nhit;
78}
79
80
81static nokprobe_inline
82unsigned long trace_kprobe_address(struct trace_kprobe *tk)
83{
84 unsigned long addr;
85
86 if (tk->symbol) {
87 addr = (unsigned long)
88 kallsyms_lookup_name(trace_kprobe_symbol(tk));
89 if (addr)
90 addr += tk->rp.kp.offset;
91 } else {
92 addr = (unsigned long)tk->rp.kp.addr;
93 }
94 return addr;
95}
96
97bool trace_kprobe_on_func_entry(struct trace_event_call *call)
98{
99 struct trace_kprobe *tk = (struct trace_kprobe *)call->data;
100
101 return kprobe_on_func_entry(tk->rp.kp.addr,
102 tk->rp.kp.addr ? NULL : tk->rp.kp.symbol_name,
103 tk->rp.kp.addr ? 0 : tk->rp.kp.offset);
104}
105
106bool trace_kprobe_error_injectable(struct trace_event_call *call)
107{
108 struct trace_kprobe *tk = (struct trace_kprobe *)call->data;
109
110 return within_error_injection_list(trace_kprobe_address(tk));
111}
112
113static int register_kprobe_event(struct trace_kprobe *tk);
114static int unregister_kprobe_event(struct trace_kprobe *tk);
115
116static DEFINE_MUTEX(probe_lock);
117static LIST_HEAD(probe_list);
118
119static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
120static int kretprobe_dispatcher(struct kretprobe_instance *ri,
121 struct pt_regs *regs);
122
123
124struct symbol_cache {
125 char *symbol;
126 long offset;
127 unsigned long addr;
128};
129
130unsigned long update_symbol_cache(struct symbol_cache *sc)
131{
132 sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol);
133
134 if (sc->addr)
135 sc->addr += sc->offset;
136
137 return sc->addr;
138}
139
140void free_symbol_cache(struct symbol_cache *sc)
141{
142 kfree(sc->symbol);
143 kfree(sc);
144}
145
146struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
147{
148 struct symbol_cache *sc;
149
150 if (!sym || strlen(sym) == 0)
151 return NULL;
152
153 sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL);
154 if (!sc)
155 return NULL;
156
157 sc->symbol = kstrdup(sym, GFP_KERNEL);
158 if (!sc->symbol) {
159 kfree(sc);
160 return NULL;
161 }
162 sc->offset = offset;
163 update_symbol_cache(sc);
164
165 return sc;
166}
167
168
169
170
171#define DEFINE_FETCH_stack(type) \
172static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \
173 void *offset, void *dest) \
174{ \
175 *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \
176 (unsigned int)((unsigned long)offset)); \
177} \
178NOKPROBE_SYMBOL(FETCH_FUNC_NAME(stack, type));
179
180DEFINE_BASIC_FETCH_FUNCS(stack)
181
182#define fetch_stack_string NULL
183#define fetch_stack_string_size NULL
184
185#define DEFINE_FETCH_memory(type) \
186static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \
187 void *addr, void *dest) \
188{ \
189 type retval; \
190 if (probe_kernel_address(addr, retval)) \
191 *(type *)dest = 0; \
192 else \
193 *(type *)dest = retval; \
194} \
195NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, type));
196
197DEFINE_BASIC_FETCH_FUNCS(memory)
198
199
200
201
202static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
203 void *addr, void *dest)
204{
205 int maxlen = get_rloc_len(*(u32 *)dest);
206 u8 *dst = get_rloc_data(dest);
207 long ret;
208
209 if (!maxlen)
210 return;
211
212
213
214
215
216 ret = strncpy_from_unsafe(dst, addr, maxlen);
217
218 if (ret < 0) {
219 dst[0] = '\0';
220 *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest));
221 } else {
222 *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest));
223 }
224}
225NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string));
226
227
228static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
229 void *addr, void *dest)
230{
231 mm_segment_t old_fs;
232 int ret, len = 0;
233 u8 c;
234
235 old_fs = get_fs();
236 set_fs(KERNEL_DS);
237 pagefault_disable();
238
239 do {
240 ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1);
241 len++;
242 } while (c && ret == 0 && len < MAX_STRING_SIZE);
243
244 pagefault_enable();
245 set_fs(old_fs);
246
247 if (ret < 0)
248 *(u32 *)dest = 0;
249 else
250 *(u32 *)dest = len;
251}
252NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string_size));
253
254#define DEFINE_FETCH_symbol(type) \
255void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs, void *data, void *dest)\
256{ \
257 struct symbol_cache *sc = data; \
258 if (sc->addr) \
259 fetch_memory_##type(regs, (void *)sc->addr, dest); \
260 else \
261 *(type *)dest = 0; \
262} \
263NOKPROBE_SYMBOL(FETCH_FUNC_NAME(symbol, type));
264
265DEFINE_BASIC_FETCH_FUNCS(symbol)
266DEFINE_FETCH_symbol(string)
267DEFINE_FETCH_symbol(string_size)
268
269
270#define fetch_file_offset_u8 NULL
271#define fetch_file_offset_u16 NULL
272#define fetch_file_offset_u32 NULL
273#define fetch_file_offset_u64 NULL
274#define fetch_file_offset_string NULL
275#define fetch_file_offset_string_size NULL
276
277
278static const struct fetch_type kprobes_fetch_type_table[] = {
279
280 [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
281 sizeof(u32), 1, "__data_loc char[]"),
282 [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
283 string_size, sizeof(u32), 0, "u32"),
284
285 ASSIGN_FETCH_TYPE(u8, u8, 0),
286 ASSIGN_FETCH_TYPE(u16, u16, 0),
287 ASSIGN_FETCH_TYPE(u32, u32, 0),
288 ASSIGN_FETCH_TYPE(u64, u64, 0),
289 ASSIGN_FETCH_TYPE(s8, u8, 1),
290 ASSIGN_FETCH_TYPE(s16, u16, 1),
291 ASSIGN_FETCH_TYPE(s32, u32, 1),
292 ASSIGN_FETCH_TYPE(s64, u64, 1),
293 ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0),
294 ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
295 ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
296 ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
297
298 ASSIGN_FETCH_TYPE_END
299};
300
301
302
303
304static struct trace_kprobe *alloc_trace_kprobe(const char *group,
305 const char *event,
306 void *addr,
307 const char *symbol,
308 unsigned long offs,
309 int maxactive,
310 int nargs, bool is_return)
311{
312 struct trace_kprobe *tk;
313 int ret = -ENOMEM;
314
315 tk = kzalloc(SIZEOF_TRACE_KPROBE(nargs), GFP_KERNEL);
316 if (!tk)
317 return ERR_PTR(ret);
318
319 tk->nhit = alloc_percpu(unsigned long);
320 if (!tk->nhit)
321 goto error;
322
323 if (symbol) {
324 tk->symbol = kstrdup(symbol, GFP_KERNEL);
325 if (!tk->symbol)
326 goto error;
327 tk->rp.kp.symbol_name = tk->symbol;
328 tk->rp.kp.offset = offs;
329 } else
330 tk->rp.kp.addr = addr;
331
332 if (is_return)
333 tk->rp.handler = kretprobe_dispatcher;
334 else
335 tk->rp.kp.pre_handler = kprobe_dispatcher;
336
337 tk->rp.maxactive = maxactive;
338
339 if (!event || !is_good_name(event)) {
340 ret = -EINVAL;
341 goto error;
342 }
343
344 tk->tp.call.class = &tk->tp.class;
345 tk->tp.call.name = kstrdup(event, GFP_KERNEL);
346 if (!tk->tp.call.name)
347 goto error;
348
349 if (!group || !is_good_name(group)) {
350 ret = -EINVAL;
351 goto error;
352 }
353
354 tk->tp.class.system = kstrdup(group, GFP_KERNEL);
355 if (!tk->tp.class.system)
356 goto error;
357
358 INIT_LIST_HEAD(&tk->list);
359 INIT_LIST_HEAD(&tk->tp.files);
360 return tk;
361error:
362 kfree(tk->tp.call.name);
363 kfree(tk->symbol);
364 free_percpu(tk->nhit);
365 kfree(tk);
366 return ERR_PTR(ret);
367}
368
369static void free_trace_kprobe(struct trace_kprobe *tk)
370{
371 int i;
372
373 for (i = 0; i < tk->tp.nr_args; i++)
374 traceprobe_free_probe_arg(&tk->tp.args[i]);
375
376 kfree(tk->tp.call.class->system);
377 kfree(tk->tp.call.name);
378 kfree(tk->symbol);
379 free_percpu(tk->nhit);
380 kfree(tk);
381}
382
383static struct trace_kprobe *find_trace_kprobe(const char *event,
384 const char *group)
385{
386 struct trace_kprobe *tk;
387
388 list_for_each_entry(tk, &probe_list, list)
389 if (strcmp(trace_event_name(&tk->tp.call), event) == 0 &&
390 strcmp(tk->tp.call.class->system, group) == 0)
391 return tk;
392 return NULL;
393}
394
395static inline int __enable_trace_kprobe(struct trace_kprobe *tk)
396{
397 int ret = 0;
398
399 if (trace_probe_is_registered(&tk->tp) && !trace_kprobe_has_gone(tk)) {
400 if (trace_kprobe_is_return(tk))
401 ret = enable_kretprobe(&tk->rp);
402 else
403 ret = enable_kprobe(&tk->rp.kp);
404 }
405
406 return ret;
407}
408
409
410
411
412
413static int
414enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file)
415{
416 struct event_file_link *link;
417 int ret = 0;
418
419 if (file) {
420 link = kmalloc(sizeof(*link), GFP_KERNEL);
421 if (!link) {
422 ret = -ENOMEM;
423 goto out;
424 }
425
426 link->file = file;
427 list_add_tail_rcu(&link->list, &tk->tp.files);
428
429 tk->tp.flags |= TP_FLAG_TRACE;
430 ret = __enable_trace_kprobe(tk);
431 if (ret) {
432 list_del_rcu(&link->list);
433 kfree(link);
434 tk->tp.flags &= ~TP_FLAG_TRACE;
435 }
436
437 } else {
438 tk->tp.flags |= TP_FLAG_PROFILE;
439 ret = __enable_trace_kprobe(tk);
440 if (ret)
441 tk->tp.flags &= ~TP_FLAG_PROFILE;
442 }
443 out:
444 return ret;
445}
446
447
448
449
450
451static int
452disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file)
453{
454 struct event_file_link *link = NULL;
455 int wait = 0;
456 int ret = 0;
457
458 if (file) {
459 link = find_event_file_link(&tk->tp, file);
460 if (!link) {
461 ret = -EINVAL;
462 goto out;
463 }
464
465 list_del_rcu(&link->list);
466 wait = 1;
467 if (!list_empty(&tk->tp.files))
468 goto out;
469
470 tk->tp.flags &= ~TP_FLAG_TRACE;
471 } else
472 tk->tp.flags &= ~TP_FLAG_PROFILE;
473
474 if (!trace_probe_is_enabled(&tk->tp) && trace_probe_is_registered(&tk->tp)) {
475 if (trace_kprobe_is_return(tk))
476 disable_kretprobe(&tk->rp);
477 else
478 disable_kprobe(&tk->rp.kp);
479 wait = 1;
480 }
481
482
483
484
485
486
487 if (list_empty(&tk->list))
488 wait = 0;
489 out:
490 if (wait) {
491
492
493
494
495
496
497
498
499 synchronize_sched();
500 kfree(link);
501 }
502
503 return ret;
504}
505
506#if defined(CONFIG_KPROBES_ON_FTRACE) && \
507 !defined(CONFIG_KPROBE_EVENTS_ON_NOTRACE)
508static bool within_notrace_func(struct trace_kprobe *tk)
509{
510 unsigned long offset, size, addr;
511
512 addr = trace_kprobe_address(tk);
513 if (!addr || !kallsyms_lookup_size_offset(addr, &size, &offset))
514 return false;
515
516
517 addr -= offset;
518
519
520
521
522
523 return !ftrace_location_range(addr, addr + size - 1);
524}
525#else
526#define within_notrace_func(tk) (false)
527#endif
528
529
530static int __register_trace_kprobe(struct trace_kprobe *tk)
531{
532 int i, ret;
533
534 if (trace_probe_is_registered(&tk->tp))
535 return -EINVAL;
536
537 if (within_notrace_func(tk)) {
538 pr_warn("Could not probe notrace function %s\n",
539 trace_kprobe_symbol(tk));
540 return -EINVAL;
541 }
542
543 for (i = 0; i < tk->tp.nr_args; i++)
544 traceprobe_update_arg(&tk->tp.args[i]);
545
546
547 if (trace_probe_is_enabled(&tk->tp))
548 tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED;
549 else
550 tk->rp.kp.flags |= KPROBE_FLAG_DISABLED;
551
552 if (trace_kprobe_is_return(tk))
553 ret = register_kretprobe(&tk->rp);
554 else
555 ret = register_kprobe(&tk->rp.kp);
556
557 if (ret == 0)
558 tk->tp.flags |= TP_FLAG_REGISTERED;
559 else {
560 if (ret == -ENOENT && trace_kprobe_is_on_module(tk)) {
561 pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
562 ret = 0;
563 } else if (ret == -EILSEQ) {
564 pr_warn("Probing address(0x%p) is not an instruction boundary.\n",
565 tk->rp.kp.addr);
566 ret = -EINVAL;
567 }
568 }
569
570 return ret;
571}
572
573
574static void __unregister_trace_kprobe(struct trace_kprobe *tk)
575{
576 if (trace_probe_is_registered(&tk->tp)) {
577 if (trace_kprobe_is_return(tk))
578 unregister_kretprobe(&tk->rp);
579 else
580 unregister_kprobe(&tk->rp.kp);
581 tk->tp.flags &= ~TP_FLAG_REGISTERED;
582
583 if (tk->rp.kp.symbol_name)
584 tk->rp.kp.addr = NULL;
585 }
586}
587
588
589static int unregister_trace_kprobe(struct trace_kprobe *tk)
590{
591
592 if (trace_probe_is_enabled(&tk->tp))
593 return -EBUSY;
594
595
596 if (unregister_kprobe_event(tk))
597 return -EBUSY;
598
599 __unregister_trace_kprobe(tk);
600 list_del(&tk->list);
601
602 return 0;
603}
604
605
606static int register_trace_kprobe(struct trace_kprobe *tk)
607{
608 struct trace_kprobe *old_tk;
609 int ret;
610
611 mutex_lock(&probe_lock);
612
613
614 old_tk = find_trace_kprobe(trace_event_name(&tk->tp.call),
615 tk->tp.call.class->system);
616 if (old_tk) {
617 ret = unregister_trace_kprobe(old_tk);
618 if (ret < 0)
619 goto end;
620 free_trace_kprobe(old_tk);
621 }
622
623
624 ret = register_kprobe_event(tk);
625 if (ret) {
626 pr_warn("Failed to register probe event(%d)\n", ret);
627 goto end;
628 }
629
630
631 ret = __register_trace_kprobe(tk);
632 if (ret < 0)
633 unregister_kprobe_event(tk);
634 else
635 list_add_tail(&tk->list, &probe_list);
636
637end:
638 mutex_unlock(&probe_lock);
639 return ret;
640}
641
642
643static int trace_kprobe_module_callback(struct notifier_block *nb,
644 unsigned long val, void *data)
645{
646 struct module *mod = data;
647 struct trace_kprobe *tk;
648 int ret;
649
650 if (val != MODULE_STATE_COMING)
651 return NOTIFY_DONE;
652
653
654 mutex_lock(&probe_lock);
655 list_for_each_entry(tk, &probe_list, list) {
656 if (trace_kprobe_within_module(tk, mod)) {
657
658 __unregister_trace_kprobe(tk);
659 ret = __register_trace_kprobe(tk);
660 if (ret)
661 pr_warn("Failed to re-register probe %s on %s: %d\n",
662 trace_event_name(&tk->tp.call),
663 mod->name, ret);
664 }
665 }
666 mutex_unlock(&probe_lock);
667
668 return NOTIFY_DONE;
669}
670
671static struct notifier_block trace_kprobe_module_nb = {
672 .notifier_call = trace_kprobe_module_callback,
673 .priority = 1
674};
675
676
677static inline void sanitize_event_name(char *name)
678{
679 while (*name++ != '\0')
680 if (*name == ':' || *name == '.')
681 *name = '_';
682}
683
684static int create_trace_kprobe(int argc, char **argv)
685{
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707 struct trace_kprobe *tk;
708 int i, ret = 0;
709 bool is_return = false, is_delete = false;
710 char *symbol = NULL, *event = NULL, *group = NULL;
711 int maxactive = 0;
712 char *arg;
713 long offset = 0;
714 void *addr = NULL;
715 char buf[MAX_EVENT_NAME_LEN];
716
717
718 if (argv[0][0] == 'p')
719 is_return = false;
720 else if (argv[0][0] == 'r')
721 is_return = true;
722 else if (argv[0][0] == '-')
723 is_delete = true;
724 else {
725 pr_info("Probe definition must be started with 'p', 'r' or"
726 " '-'.\n");
727 return -EINVAL;
728 }
729
730 event = strchr(&argv[0][1], ':');
731 if (event) {
732 event[0] = '\0';
733 event++;
734 }
735 if (is_return && isdigit(argv[0][1])) {
736 ret = kstrtouint(&argv[0][1], 0, &maxactive);
737 if (ret) {
738 pr_info("Failed to parse maxactive.\n");
739 return ret;
740 }
741
742
743
744 if (maxactive > KRETPROBE_MAXACTIVE_MAX) {
745 pr_info("Maxactive is too big (%d > %d).\n",
746 maxactive, KRETPROBE_MAXACTIVE_MAX);
747 return -E2BIG;
748 }
749 }
750
751 if (event) {
752 if (strchr(event, '/')) {
753 group = event;
754 event = strchr(group, '/') + 1;
755 event[-1] = '\0';
756 if (strlen(group) == 0) {
757 pr_info("Group name is not specified\n");
758 return -EINVAL;
759 }
760 }
761 if (strlen(event) == 0) {
762 pr_info("Event name is not specified\n");
763 return -EINVAL;
764 }
765 }
766 if (!group)
767 group = KPROBE_EVENT_SYSTEM;
768
769 if (is_delete) {
770 if (!event) {
771 pr_info("Delete command needs an event name.\n");
772 return -EINVAL;
773 }
774 mutex_lock(&probe_lock);
775 tk = find_trace_kprobe(event, group);
776 if (!tk) {
777 mutex_unlock(&probe_lock);
778 pr_info("Event %s/%s doesn't exist.\n", group, event);
779 return -ENOENT;
780 }
781
782 ret = unregister_trace_kprobe(tk);
783 if (ret == 0)
784 free_trace_kprobe(tk);
785 mutex_unlock(&probe_lock);
786 return ret;
787 }
788
789 if (argc < 2) {
790 pr_info("Probe point is not specified.\n");
791 return -EINVAL;
792 }
793
794
795
796 if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) {
797
798 symbol = argv[1];
799
800 ret = traceprobe_split_symbol_offset(symbol, &offset);
801 if (ret || offset < 0 || offset > UINT_MAX) {
802 pr_info("Failed to parse either an address or a symbol.\n");
803 return ret;
804 }
805 if (offset && is_return &&
806 !kprobe_on_func_entry(NULL, symbol, offset)) {
807 pr_info("Given offset is not valid for return probe.\n");
808 return -EINVAL;
809 }
810 }
811 argc -= 2; argv += 2;
812
813
814 if (!event) {
815
816 if (symbol)
817 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
818 is_return ? 'r' : 'p', symbol, offset);
819 else
820 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
821 is_return ? 'r' : 'p', addr);
822 sanitize_event_name(buf);
823 event = buf;
824 }
825 tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive,
826 argc, is_return);
827 if (IS_ERR(tk)) {
828 pr_info("Failed to allocate trace_probe.(%d)\n",
829 (int)PTR_ERR(tk));
830 return PTR_ERR(tk);
831 }
832
833
834 ret = 0;
835 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
836 struct probe_arg *parg = &tk->tp.args[i];
837
838
839 tk->tp.nr_args++;
840
841
842 arg = strchr(argv[i], '=');
843 if (arg) {
844 *arg++ = '\0';
845 parg->name = kstrdup(argv[i], GFP_KERNEL);
846 } else {
847 arg = argv[i];
848
849 snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1);
850 parg->name = kstrdup(buf, GFP_KERNEL);
851 }
852
853 if (!parg->name) {
854 pr_info("Failed to allocate argument[%d] name.\n", i);
855 ret = -ENOMEM;
856 goto error;
857 }
858
859 if (!is_good_name(parg->name)) {
860 pr_info("Invalid argument[%d] name: %s\n",
861 i, parg->name);
862 ret = -EINVAL;
863 goto error;
864 }
865
866 if (traceprobe_conflict_field_name(parg->name,
867 tk->tp.args, i)) {
868 pr_info("Argument[%d] name '%s' conflicts with "
869 "another field.\n", i, argv[i]);
870 ret = -EINVAL;
871 goto error;
872 }
873
874
875 ret = traceprobe_parse_probe_arg(arg, &tk->tp.size, parg,
876 is_return, true,
877 kprobes_fetch_type_table);
878 if (ret) {
879 pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
880 goto error;
881 }
882 }
883
884 ret = register_trace_kprobe(tk);
885 if (ret)
886 goto error;
887 return 0;
888
889error:
890 free_trace_kprobe(tk);
891 return ret;
892}
893
894static int release_all_trace_kprobes(void)
895{
896 struct trace_kprobe *tk;
897 int ret = 0;
898
899 mutex_lock(&probe_lock);
900
901 list_for_each_entry(tk, &probe_list, list)
902 if (trace_probe_is_enabled(&tk->tp)) {
903 ret = -EBUSY;
904 goto end;
905 }
906
907 while (!list_empty(&probe_list)) {
908 tk = list_entry(probe_list.next, struct trace_kprobe, list);
909 ret = unregister_trace_kprobe(tk);
910 if (ret)
911 goto end;
912 free_trace_kprobe(tk);
913 }
914
915end:
916 mutex_unlock(&probe_lock);
917
918 return ret;
919}
920
921
922static void *probes_seq_start(struct seq_file *m, loff_t *pos)
923{
924 mutex_lock(&probe_lock);
925 return seq_list_start(&probe_list, *pos);
926}
927
928static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
929{
930 return seq_list_next(v, &probe_list, pos);
931}
932
933static void probes_seq_stop(struct seq_file *m, void *v)
934{
935 mutex_unlock(&probe_lock);
936}
937
938static int probes_seq_show(struct seq_file *m, void *v)
939{
940 struct trace_kprobe *tk = v;
941 int i;
942
943 seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p');
944 seq_printf(m, ":%s/%s", tk->tp.call.class->system,
945 trace_event_name(&tk->tp.call));
946
947 if (!tk->symbol)
948 seq_printf(m, " 0x%p", tk->rp.kp.addr);
949 else if (tk->rp.kp.offset)
950 seq_printf(m, " %s+%u", trace_kprobe_symbol(tk),
951 tk->rp.kp.offset);
952 else
953 seq_printf(m, " %s", trace_kprobe_symbol(tk));
954
955 for (i = 0; i < tk->tp.nr_args; i++)
956 seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm);
957 seq_putc(m, '\n');
958
959 return 0;
960}
961
962static const struct seq_operations probes_seq_op = {
963 .start = probes_seq_start,
964 .next = probes_seq_next,
965 .stop = probes_seq_stop,
966 .show = probes_seq_show
967};
968
969static int probes_open(struct inode *inode, struct file *file)
970{
971 int ret;
972
973 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
974 ret = release_all_trace_kprobes();
975 if (ret < 0)
976 return ret;
977 }
978
979 return seq_open(file, &probes_seq_op);
980}
981
982static ssize_t probes_write(struct file *file, const char __user *buffer,
983 size_t count, loff_t *ppos)
984{
985 return trace_parse_run_command(file, buffer, count, ppos,
986 create_trace_kprobe);
987}
988
989static const struct file_operations kprobe_events_ops = {
990 .owner = THIS_MODULE,
991 .open = probes_open,
992 .read = seq_read,
993 .llseek = seq_lseek,
994 .release = seq_release,
995 .write = probes_write,
996};
997
998
999static int probes_profile_seq_show(struct seq_file *m, void *v)
1000{
1001 struct trace_kprobe *tk = v;
1002
1003 seq_printf(m, " %-44s %15lu %15lu\n",
1004 trace_event_name(&tk->tp.call),
1005 trace_kprobe_nhit(tk),
1006 tk->rp.kp.nmissed);
1007
1008 return 0;
1009}
1010
1011static const struct seq_operations profile_seq_op = {
1012 .start = probes_seq_start,
1013 .next = probes_seq_next,
1014 .stop = probes_seq_stop,
1015 .show = probes_profile_seq_show
1016};
1017
1018static int profile_open(struct inode *inode, struct file *file)
1019{
1020 return seq_open(file, &profile_seq_op);
1021}
1022
1023static const struct file_operations kprobe_profile_ops = {
1024 .owner = THIS_MODULE,
1025 .open = profile_open,
1026 .read = seq_read,
1027 .llseek = seq_lseek,
1028 .release = seq_release,
1029};
1030
1031
1032static nokprobe_inline void
1033__kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
1034 struct trace_event_file *trace_file)
1035{
1036 struct kprobe_trace_entry_head *entry;
1037 struct ring_buffer_event *event;
1038 struct ring_buffer *buffer;
1039 int size, dsize, pc;
1040 unsigned long irq_flags;
1041 struct trace_event_call *call = &tk->tp.call;
1042
1043 WARN_ON(call != trace_file->event_call);
1044
1045 if (trace_trigger_soft_disabled(trace_file))
1046 return;
1047
1048 local_save_flags(irq_flags);
1049 pc = preempt_count();
1050
1051 dsize = __get_data_size(&tk->tp, regs);
1052 size = sizeof(*entry) + tk->tp.size + dsize;
1053
1054 event = trace_event_buffer_lock_reserve(&buffer, trace_file,
1055 call->event.type,
1056 size, irq_flags, pc);
1057 if (!event)
1058 return;
1059
1060 entry = ring_buffer_event_data(event);
1061 entry->ip = (unsigned long)tk->rp.kp.addr;
1062 store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
1063
1064 event_trigger_unlock_commit_regs(trace_file, buffer, event,
1065 entry, irq_flags, pc, regs);
1066}
1067
1068static void
1069kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs)
1070{
1071 struct event_file_link *link;
1072
1073 list_for_each_entry_rcu(link, &tk->tp.files, list)
1074 __kprobe_trace_func(tk, regs, link->file);
1075}
1076NOKPROBE_SYMBOL(kprobe_trace_func);
1077
1078
1079static nokprobe_inline void
1080__kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1081 struct pt_regs *regs,
1082 struct trace_event_file *trace_file)
1083{
1084 struct kretprobe_trace_entry_head *entry;
1085 struct ring_buffer_event *event;
1086 struct ring_buffer *buffer;
1087 int size, pc, dsize;
1088 unsigned long irq_flags;
1089 struct trace_event_call *call = &tk->tp.call;
1090
1091 WARN_ON(call != trace_file->event_call);
1092
1093 if (trace_trigger_soft_disabled(trace_file))
1094 return;
1095
1096 local_save_flags(irq_flags);
1097 pc = preempt_count();
1098
1099 dsize = __get_data_size(&tk->tp, regs);
1100 size = sizeof(*entry) + tk->tp.size + dsize;
1101
1102 event = trace_event_buffer_lock_reserve(&buffer, trace_file,
1103 call->event.type,
1104 size, irq_flags, pc);
1105 if (!event)
1106 return;
1107
1108 entry = ring_buffer_event_data(event);
1109 entry->func = (unsigned long)tk->rp.kp.addr;
1110 entry->ret_ip = (unsigned long)ri->ret_addr;
1111 store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
1112
1113 event_trigger_unlock_commit_regs(trace_file, buffer, event,
1114 entry, irq_flags, pc, regs);
1115}
1116
1117static void
1118kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1119 struct pt_regs *regs)
1120{
1121 struct event_file_link *link;
1122
1123 list_for_each_entry_rcu(link, &tk->tp.files, list)
1124 __kretprobe_trace_func(tk, ri, regs, link->file);
1125}
1126NOKPROBE_SYMBOL(kretprobe_trace_func);
1127
1128
1129static enum print_line_t
1130print_kprobe_event(struct trace_iterator *iter, int flags,
1131 struct trace_event *event)
1132{
1133 struct kprobe_trace_entry_head *field;
1134 struct trace_seq *s = &iter->seq;
1135 struct trace_probe *tp;
1136 u8 *data;
1137 int i;
1138
1139 field = (struct kprobe_trace_entry_head *)iter->ent;
1140 tp = container_of(event, struct trace_probe, call.event);
1141
1142 trace_seq_printf(s, "%s: (", trace_event_name(&tp->call));
1143
1144 if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
1145 goto out;
1146
1147 trace_seq_putc(s, ')');
1148
1149 data = (u8 *)&field[1];
1150 for (i = 0; i < tp->nr_args; i++)
1151 if (!tp->args[i].type->print(s, tp->args[i].name,
1152 data + tp->args[i].offset, field))
1153 goto out;
1154
1155 trace_seq_putc(s, '\n');
1156 out:
1157 return trace_handle_return(s);
1158}
1159
1160static enum print_line_t
1161print_kretprobe_event(struct trace_iterator *iter, int flags,
1162 struct trace_event *event)
1163{
1164 struct kretprobe_trace_entry_head *field;
1165 struct trace_seq *s = &iter->seq;
1166 struct trace_probe *tp;
1167 u8 *data;
1168 int i;
1169
1170 field = (struct kretprobe_trace_entry_head *)iter->ent;
1171 tp = container_of(event, struct trace_probe, call.event);
1172
1173 trace_seq_printf(s, "%s: (", trace_event_name(&tp->call));
1174
1175 if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
1176 goto out;
1177
1178 trace_seq_puts(s, " <- ");
1179
1180 if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
1181 goto out;
1182
1183 trace_seq_putc(s, ')');
1184
1185 data = (u8 *)&field[1];
1186 for (i = 0; i < tp->nr_args; i++)
1187 if (!tp->args[i].type->print(s, tp->args[i].name,
1188 data + tp->args[i].offset, field))
1189 goto out;
1190
1191 trace_seq_putc(s, '\n');
1192
1193 out:
1194 return trace_handle_return(s);
1195}
1196
1197
1198static int kprobe_event_define_fields(struct trace_event_call *event_call)
1199{
1200 int ret, i;
1201 struct kprobe_trace_entry_head field;
1202 struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data;
1203
1204 DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
1205
1206 for (i = 0; i < tk->tp.nr_args; i++) {
1207 struct probe_arg *parg = &tk->tp.args[i];
1208
1209 ret = trace_define_field(event_call, parg->type->fmttype,
1210 parg->name,
1211 sizeof(field) + parg->offset,
1212 parg->type->size,
1213 parg->type->is_signed,
1214 FILTER_OTHER);
1215 if (ret)
1216 return ret;
1217 }
1218 return 0;
1219}
1220
1221static int kretprobe_event_define_fields(struct trace_event_call *event_call)
1222{
1223 int ret, i;
1224 struct kretprobe_trace_entry_head field;
1225 struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data;
1226
1227 DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
1228 DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
1229
1230 for (i = 0; i < tk->tp.nr_args; i++) {
1231 struct probe_arg *parg = &tk->tp.args[i];
1232
1233 ret = trace_define_field(event_call, parg->type->fmttype,
1234 parg->name,
1235 sizeof(field) + parg->offset,
1236 parg->type->size,
1237 parg->type->is_signed,
1238 FILTER_OTHER);
1239 if (ret)
1240 return ret;
1241 }
1242 return 0;
1243}
1244
1245#ifdef CONFIG_PERF_EVENTS
1246
1247
1248static int
1249kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
1250{
1251 struct trace_event_call *call = &tk->tp.call;
1252 struct kprobe_trace_entry_head *entry;
1253 struct hlist_head *head;
1254 int size, __size, dsize;
1255 int rctx;
1256
1257 if (bpf_prog_array_valid(call)) {
1258 unsigned long orig_ip = instruction_pointer(regs);
1259 int ret;
1260
1261 ret = trace_call_bpf(call, regs);
1262
1263
1264
1265
1266
1267
1268 if (orig_ip != instruction_pointer(regs))
1269 return 1;
1270 if (!ret)
1271 return 0;
1272 }
1273
1274 head = this_cpu_ptr(call->perf_events);
1275 if (hlist_empty(head))
1276 return 0;
1277
1278 dsize = __get_data_size(&tk->tp, regs);
1279 __size = sizeof(*entry) + tk->tp.size + dsize;
1280 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1281 size -= sizeof(u32);
1282
1283 entry = perf_trace_buf_alloc(size, NULL, &rctx);
1284 if (!entry)
1285 return 0;
1286
1287 entry->ip = (unsigned long)tk->rp.kp.addr;
1288 memset(&entry[1], 0, dsize);
1289 store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
1290 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1291 head, NULL);
1292 return 0;
1293}
1294NOKPROBE_SYMBOL(kprobe_perf_func);
1295
1296
1297static void
1298kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1299 struct pt_regs *regs)
1300{
1301 struct trace_event_call *call = &tk->tp.call;
1302 struct kretprobe_trace_entry_head *entry;
1303 struct hlist_head *head;
1304 int size, __size, dsize;
1305 int rctx;
1306
1307 if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs))
1308 return;
1309
1310 head = this_cpu_ptr(call->perf_events);
1311 if (hlist_empty(head))
1312 return;
1313
1314 dsize = __get_data_size(&tk->tp, regs);
1315 __size = sizeof(*entry) + tk->tp.size + dsize;
1316 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1317 size -= sizeof(u32);
1318
1319 entry = perf_trace_buf_alloc(size, NULL, &rctx);
1320 if (!entry)
1321 return;
1322
1323 entry->func = (unsigned long)tk->rp.kp.addr;
1324 entry->ret_ip = (unsigned long)ri->ret_addr;
1325 store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
1326 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1327 head, NULL);
1328}
1329NOKPROBE_SYMBOL(kretprobe_perf_func);
1330
1331int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type,
1332 const char **symbol, u64 *probe_offset,
1333 u64 *probe_addr, bool perf_type_tracepoint)
1334{
1335 const char *pevent = trace_event_name(event->tp_event);
1336 const char *group = event->tp_event->class->system;
1337 struct trace_kprobe *tk;
1338
1339 if (perf_type_tracepoint)
1340 tk = find_trace_kprobe(pevent, group);
1341 else
1342 tk = event->tp_event->data;
1343 if (!tk)
1344 return -EINVAL;
1345
1346 *fd_type = trace_kprobe_is_return(tk) ? BPF_FD_TYPE_KRETPROBE
1347 : BPF_FD_TYPE_KPROBE;
1348 if (tk->symbol) {
1349 *symbol = tk->symbol;
1350 *probe_offset = tk->rp.kp.offset;
1351 *probe_addr = 0;
1352 } else {
1353 *symbol = NULL;
1354 *probe_offset = 0;
1355 *probe_addr = (unsigned long)tk->rp.kp.addr;
1356 }
1357 return 0;
1358}
1359#endif
1360
1361
1362
1363
1364
1365
1366
1367static int kprobe_register(struct trace_event_call *event,
1368 enum trace_reg type, void *data)
1369{
1370 struct trace_kprobe *tk = (struct trace_kprobe *)event->data;
1371 struct trace_event_file *file = data;
1372
1373 switch (type) {
1374 case TRACE_REG_REGISTER:
1375 return enable_trace_kprobe(tk, file);
1376 case TRACE_REG_UNREGISTER:
1377 return disable_trace_kprobe(tk, file);
1378
1379#ifdef CONFIG_PERF_EVENTS
1380 case TRACE_REG_PERF_REGISTER:
1381 return enable_trace_kprobe(tk, NULL);
1382 case TRACE_REG_PERF_UNREGISTER:
1383 return disable_trace_kprobe(tk, NULL);
1384 case TRACE_REG_PERF_OPEN:
1385 case TRACE_REG_PERF_CLOSE:
1386 case TRACE_REG_PERF_ADD:
1387 case TRACE_REG_PERF_DEL:
1388 return 0;
1389#endif
1390 }
1391 return 0;
1392}
1393
1394static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1395{
1396 struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp);
1397 int ret = 0;
1398
1399 raw_cpu_inc(*tk->nhit);
1400
1401 if (tk->tp.flags & TP_FLAG_TRACE)
1402 kprobe_trace_func(tk, regs);
1403#ifdef CONFIG_PERF_EVENTS
1404 if (tk->tp.flags & TP_FLAG_PROFILE)
1405 ret = kprobe_perf_func(tk, regs);
1406#endif
1407 return ret;
1408}
1409NOKPROBE_SYMBOL(kprobe_dispatcher);
1410
1411static int
1412kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1413{
1414 struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp);
1415
1416 raw_cpu_inc(*tk->nhit);
1417
1418 if (tk->tp.flags & TP_FLAG_TRACE)
1419 kretprobe_trace_func(tk, ri, regs);
1420#ifdef CONFIG_PERF_EVENTS
1421 if (tk->tp.flags & TP_FLAG_PROFILE)
1422 kretprobe_perf_func(tk, ri, regs);
1423#endif
1424 return 0;
1425}
1426NOKPROBE_SYMBOL(kretprobe_dispatcher);
1427
1428static struct trace_event_functions kretprobe_funcs = {
1429 .trace = print_kretprobe_event
1430};
1431
1432static struct trace_event_functions kprobe_funcs = {
1433 .trace = print_kprobe_event
1434};
1435
1436static inline void init_trace_event_call(struct trace_kprobe *tk,
1437 struct trace_event_call *call)
1438{
1439 INIT_LIST_HEAD(&call->class->fields);
1440 if (trace_kprobe_is_return(tk)) {
1441 call->event.funcs = &kretprobe_funcs;
1442 call->class->define_fields = kretprobe_event_define_fields;
1443 } else {
1444 call->event.funcs = &kprobe_funcs;
1445 call->class->define_fields = kprobe_event_define_fields;
1446 }
1447
1448 call->flags = TRACE_EVENT_FL_KPROBE;
1449 call->class->reg = kprobe_register;
1450 call->data = tk;
1451}
1452
1453static int register_kprobe_event(struct trace_kprobe *tk)
1454{
1455 struct trace_event_call *call = &tk->tp.call;
1456 int ret = 0;
1457
1458 init_trace_event_call(tk, call);
1459
1460 if (set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0)
1461 return -ENOMEM;
1462 ret = register_trace_event(&call->event);
1463 if (!ret) {
1464 kfree(call->print_fmt);
1465 return -ENODEV;
1466 }
1467 ret = trace_add_event_call(call);
1468 if (ret) {
1469 pr_info("Failed to register kprobe event: %s\n",
1470 trace_event_name(call));
1471 kfree(call->print_fmt);
1472 unregister_trace_event(&call->event);
1473 }
1474 return ret;
1475}
1476
1477static int unregister_kprobe_event(struct trace_kprobe *tk)
1478{
1479 int ret;
1480
1481
1482 ret = trace_remove_event_call(&tk->tp.call);
1483 if (!ret)
1484 kfree(tk->tp.call.print_fmt);
1485 return ret;
1486}
1487
1488#ifdef CONFIG_PERF_EVENTS
1489
1490struct trace_event_call *
1491create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
1492 bool is_return)
1493{
1494 struct trace_kprobe *tk;
1495 int ret;
1496 char *event;
1497
1498
1499
1500
1501
1502
1503 event = func ? func : "DUMMY_EVENT";
1504
1505 tk = alloc_trace_kprobe(KPROBE_EVENT_SYSTEM, event, (void *)addr, func,
1506 offs, 0 , 0 ,
1507 is_return);
1508
1509 if (IS_ERR(tk)) {
1510 pr_info("Failed to allocate trace_probe.(%d)\n",
1511 (int)PTR_ERR(tk));
1512 return ERR_CAST(tk);
1513 }
1514
1515 init_trace_event_call(tk, &tk->tp.call);
1516
1517 if (set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) {
1518 ret = -ENOMEM;
1519 goto error;
1520 }
1521
1522 ret = __register_trace_kprobe(tk);
1523 if (ret < 0) {
1524 kfree(tk->tp.call.print_fmt);
1525 goto error;
1526 }
1527
1528 return &tk->tp.call;
1529error:
1530 free_trace_kprobe(tk);
1531 return ERR_PTR(ret);
1532}
1533
1534void destroy_local_trace_kprobe(struct trace_event_call *event_call)
1535{
1536 struct trace_kprobe *tk;
1537
1538 tk = container_of(event_call, struct trace_kprobe, tp.call);
1539
1540 if (trace_probe_is_enabled(&tk->tp)) {
1541 WARN_ON(1);
1542 return;
1543 }
1544
1545 __unregister_trace_kprobe(tk);
1546
1547 kfree(tk->tp.call.print_fmt);
1548 free_trace_kprobe(tk);
1549}
1550#endif
1551
1552
1553static __init int init_kprobe_trace(void)
1554{
1555 struct dentry *d_tracer;
1556 struct dentry *entry;
1557
1558 if (register_module_notifier(&trace_kprobe_module_nb))
1559 return -EINVAL;
1560
1561 d_tracer = tracing_init_dentry();
1562 if (IS_ERR(d_tracer))
1563 return 0;
1564
1565 entry = tracefs_create_file("kprobe_events", 0644, d_tracer,
1566 NULL, &kprobe_events_ops);
1567
1568
1569 if (!entry)
1570 pr_warn("Could not create tracefs 'kprobe_events' entry\n");
1571
1572
1573 entry = tracefs_create_file("kprobe_profile", 0444, d_tracer,
1574 NULL, &kprobe_profile_ops);
1575
1576 if (!entry)
1577 pr_warn("Could not create tracefs 'kprobe_profile' entry\n");
1578 return 0;
1579}
1580fs_initcall(init_kprobe_trace);
1581
1582
1583#ifdef CONFIG_FTRACE_STARTUP_TEST
1584static __init struct trace_event_file *
1585find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr)
1586{
1587 struct trace_event_file *file;
1588
1589 list_for_each_entry(file, &tr->events, list)
1590 if (file->event_call == &tk->tp.call)
1591 return file;
1592
1593 return NULL;
1594}
1595
1596
1597
1598
1599
1600static __init int kprobe_trace_self_tests_init(void)
1601{
1602 int ret, warn = 0;
1603 int (*target)(int, int, int, int, int, int);
1604 struct trace_kprobe *tk;
1605 struct trace_event_file *file;
1606
1607 if (tracing_is_disabled())
1608 return -ENODEV;
1609
1610 target = kprobe_trace_selftest_target;
1611
1612 pr_info("Testing kprobe tracing: ");
1613
1614 ret = trace_run_command("p:testprobe kprobe_trace_selftest_target "
1615 "$stack $stack0 +0($stack)",
1616 create_trace_kprobe);
1617 if (WARN_ON_ONCE(ret)) {
1618 pr_warn("error on probing function entry.\n");
1619 warn++;
1620 } else {
1621
1622 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
1623 if (WARN_ON_ONCE(tk == NULL)) {
1624 pr_warn("error on getting new probe.\n");
1625 warn++;
1626 } else {
1627 file = find_trace_probe_file(tk, top_trace_array());
1628 if (WARN_ON_ONCE(file == NULL)) {
1629 pr_warn("error on getting probe file.\n");
1630 warn++;
1631 } else
1632 enable_trace_kprobe(tk, file);
1633 }
1634 }
1635
1636 ret = trace_run_command("r:testprobe2 kprobe_trace_selftest_target "
1637 "$retval", create_trace_kprobe);
1638 if (WARN_ON_ONCE(ret)) {
1639 pr_warn("error on probing function return.\n");
1640 warn++;
1641 } else {
1642
1643 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
1644 if (WARN_ON_ONCE(tk == NULL)) {
1645 pr_warn("error on getting 2nd new probe.\n");
1646 warn++;
1647 } else {
1648 file = find_trace_probe_file(tk, top_trace_array());
1649 if (WARN_ON_ONCE(file == NULL)) {
1650 pr_warn("error on getting probe file.\n");
1651 warn++;
1652 } else
1653 enable_trace_kprobe(tk, file);
1654 }
1655 }
1656
1657 if (warn)
1658 goto end;
1659
1660 ret = target(1, 2, 3, 4, 5, 6);
1661
1662
1663
1664
1665
1666
1667 if (ret != 21)
1668 warn++;
1669
1670
1671 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
1672 if (WARN_ON_ONCE(tk == NULL)) {
1673 pr_warn("error on getting test probe.\n");
1674 warn++;
1675 } else {
1676 if (trace_kprobe_nhit(tk) != 1) {
1677 pr_warn("incorrect number of testprobe hits\n");
1678 warn++;
1679 }
1680
1681 file = find_trace_probe_file(tk, top_trace_array());
1682 if (WARN_ON_ONCE(file == NULL)) {
1683 pr_warn("error on getting probe file.\n");
1684 warn++;
1685 } else
1686 disable_trace_kprobe(tk, file);
1687 }
1688
1689 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
1690 if (WARN_ON_ONCE(tk == NULL)) {
1691 pr_warn("error on getting 2nd test probe.\n");
1692 warn++;
1693 } else {
1694 if (trace_kprobe_nhit(tk) != 1) {
1695 pr_warn("incorrect number of testprobe2 hits\n");
1696 warn++;
1697 }
1698
1699 file = find_trace_probe_file(tk, top_trace_array());
1700 if (WARN_ON_ONCE(file == NULL)) {
1701 pr_warn("error on getting probe file.\n");
1702 warn++;
1703 } else
1704 disable_trace_kprobe(tk, file);
1705 }
1706
1707 ret = trace_run_command("-:testprobe", create_trace_kprobe);
1708 if (WARN_ON_ONCE(ret)) {
1709 pr_warn("error on deleting a probe.\n");
1710 warn++;
1711 }
1712
1713 ret = trace_run_command("-:testprobe2", create_trace_kprobe);
1714 if (WARN_ON_ONCE(ret)) {
1715 pr_warn("error on deleting a probe.\n");
1716 warn++;
1717 }
1718
1719end:
1720 release_all_trace_kprobes();
1721
1722
1723
1724
1725 wait_for_kprobe_optimizer();
1726 if (warn)
1727 pr_cont("NG: Some tests are failed. Please check them.\n");
1728 else
1729 pr_cont("OK\n");
1730 return 0;
1731}
1732
1733late_initcall(kprobe_trace_self_tests_init);
1734
1735#endif
1736
