1
2
3
4
5
6
7
8#define pr_fmt(fmt) "trace_kprobe: " fmt
9
10#include <linux/bpf-cgroup.h>
11#include <linux/security.h>
12#include <linux/module.h>
13#include <linux/uaccess.h>
14#include <linux/rculist.h>
15#include <linux/error-injection.h>
16
17#include <asm/setup.h>
18
19#include "trace_dynevent.h"
20#include "trace_kprobe_selftest.h"
21#include "trace_probe.h"
22#include "trace_probe_tmpl.h"
23
24#define KPROBE_EVENT_SYSTEM "kprobes"
25#define KRETPROBE_MAXACTIVE_MAX 4096
26
27
28static char kprobe_boot_events_buf[COMMAND_LINE_SIZE] __initdata;
29
30static int __init set_kprobe_boot_events(char *str)
31{
32 strlcpy(kprobe_boot_events_buf, str, COMMAND_LINE_SIZE);
33 disable_tracing_selftest("running kprobe events");
34
35 return 1;
36}
37__setup("kprobe_event=", set_kprobe_boot_events);
38
39static int trace_kprobe_create(const char *raw_command);
40static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev);
41static int trace_kprobe_release(struct dyn_event *ev);
42static bool trace_kprobe_is_busy(struct dyn_event *ev);
43static bool trace_kprobe_match(const char *system, const char *event,
44 int argc, const char **argv, struct dyn_event *ev);
45
46static struct dyn_event_operations trace_kprobe_ops = {
47 .create = trace_kprobe_create,
48 .show = trace_kprobe_show,
49 .is_busy = trace_kprobe_is_busy,
50 .free = trace_kprobe_release,
51 .match = trace_kprobe_match,
52};
53
54
55
56
57struct trace_kprobe {
58 struct dyn_event devent;
59 struct kretprobe rp;
60 unsigned long __percpu *nhit;
61 const char *symbol;
62 struct trace_probe tp;
63};
64
65static bool is_trace_kprobe(struct dyn_event *ev)
66{
67 return ev->ops == &trace_kprobe_ops;
68}
69
70static struct trace_kprobe *to_trace_kprobe(struct dyn_event *ev)
71{
72 return container_of(ev, struct trace_kprobe, devent);
73}
74
75
76
77
78
79
80#define for_each_trace_kprobe(pos, dpos) \
81 for_each_dyn_event(dpos) \
82 if (is_trace_kprobe(dpos) && (pos = to_trace_kprobe(dpos)))
83
84static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk)
85{
86 return tk->rp.handler != NULL;
87}
88
89static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk)
90{
91 return tk->symbol ? tk->symbol : "unknown";
92}
93
94static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk)
95{
96 return tk->rp.kp.offset;
97}
98
99static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk)
100{
101 return kprobe_gone(&tk->rp.kp);
102}
103
104static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk,
105 struct module *mod)
106{
107 int len = strlen(module_name(mod));
108 const char *name = trace_kprobe_symbol(tk);
109
110 return strncmp(module_name(mod), name, len) == 0 && name[len] == ':';
111}
112
113static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk)
114{
115 char *p;
116 bool ret;
117
118 if (!tk->symbol)
119 return false;
120 p = strchr(tk->symbol, ':');
121 if (!p)
122 return true;
123 *p = '\0';
124 rcu_read_lock_sched();
125 ret = !!find_module(tk->symbol);
126 rcu_read_unlock_sched();
127 *p = ':';
128
129 return ret;
130}
131
132static bool trace_kprobe_is_busy(struct dyn_event *ev)
133{
134 struct trace_kprobe *tk = to_trace_kprobe(ev);
135
136 return trace_probe_is_enabled(&tk->tp);
137}
138
139static bool trace_kprobe_match_command_head(struct trace_kprobe *tk,
140 int argc, const char **argv)
141{
142 char buf[MAX_ARGSTR_LEN + 1];
143
144 if (!argc)
145 return true;
146
147 if (!tk->symbol)
148 snprintf(buf, sizeof(buf), "0x%p", tk->rp.kp.addr);
149 else if (tk->rp.kp.offset)
150 snprintf(buf, sizeof(buf), "%s+%u",
151 trace_kprobe_symbol(tk), tk->rp.kp.offset);
152 else
153 snprintf(buf, sizeof(buf), "%s", trace_kprobe_symbol(tk));
154 if (strcmp(buf, argv[0]))
155 return false;
156 argc--; argv++;
157
158 return trace_probe_match_command_args(&tk->tp, argc, argv);
159}
160
161static bool trace_kprobe_match(const char *system, const char *event,
162 int argc, const char **argv, struct dyn_event *ev)
163{
164 struct trace_kprobe *tk = to_trace_kprobe(ev);
165
166 return strcmp(trace_probe_name(&tk->tp), event) == 0 &&
167 (!system || strcmp(trace_probe_group_name(&tk->tp), system) == 0) &&
168 trace_kprobe_match_command_head(tk, argc, argv);
169}
170
171static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk)
172{
173 unsigned long nhit = 0;
174 int cpu;
175
176 for_each_possible_cpu(cpu)
177 nhit += *per_cpu_ptr(tk->nhit, cpu);
178
179 return nhit;
180}
181
182static nokprobe_inline bool trace_kprobe_is_registered(struct trace_kprobe *tk)
183{
184 return !(list_empty(&tk->rp.kp.list) &&
185 hlist_unhashed(&tk->rp.kp.hlist));
186}
187
188
189static nokprobe_inline
190unsigned long trace_kprobe_address(struct trace_kprobe *tk)
191{
192 unsigned long addr;
193
194 if (tk->symbol) {
195 addr = (unsigned long)
196 kallsyms_lookup_name(trace_kprobe_symbol(tk));
197 if (addr)
198 addr += tk->rp.kp.offset;
199 } else {
200 addr = (unsigned long)tk->rp.kp.addr;
201 }
202 return addr;
203}
204
205static nokprobe_inline struct trace_kprobe *
206trace_kprobe_primary_from_call(struct trace_event_call *call)
207{
208 struct trace_probe *tp;
209
210 tp = trace_probe_primary_from_call(call);
211 if (WARN_ON_ONCE(!tp))
212 return NULL;
213
214 return container_of(tp, struct trace_kprobe, tp);
215}
216
217bool trace_kprobe_on_func_entry(struct trace_event_call *call)
218{
219 struct trace_kprobe *tk = trace_kprobe_primary_from_call(call);
220
221 return tk ? (kprobe_on_func_entry(tk->rp.kp.addr,
222 tk->rp.kp.addr ? NULL : tk->rp.kp.symbol_name,
223 tk->rp.kp.addr ? 0 : tk->rp.kp.offset) == 0) : false;
224}
225
226bool trace_kprobe_error_injectable(struct trace_event_call *call)
227{
228 struct trace_kprobe *tk = trace_kprobe_primary_from_call(call);
229
230 return tk ? within_error_injection_list(trace_kprobe_address(tk)) :
231 false;
232}
233
234static int register_kprobe_event(struct trace_kprobe *tk);
235static int unregister_kprobe_event(struct trace_kprobe *tk);
236
237static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
238static int kretprobe_dispatcher(struct kretprobe_instance *ri,
239 struct pt_regs *regs);
240
241static void free_trace_kprobe(struct trace_kprobe *tk)
242{
243 if (tk) {
244 trace_probe_cleanup(&tk->tp);
245 kfree(tk->symbol);
246 free_percpu(tk->nhit);
247 kfree(tk);
248 }
249}
250
251
252
253
254static struct trace_kprobe *alloc_trace_kprobe(const char *group,
255 const char *event,
256 void *addr,
257 const char *symbol,
258 unsigned long offs,
259 int maxactive,
260 int nargs, bool is_return)
261{
262 struct trace_kprobe *tk;
263 int ret = -ENOMEM;
264
265 tk = kzalloc(struct_size(tk, tp.args, nargs), GFP_KERNEL);
266 if (!tk)
267 return ERR_PTR(ret);
268
269 tk->nhit = alloc_percpu(unsigned long);
270 if (!tk->nhit)
271 goto error;
272
273 if (symbol) {
274 tk->symbol = kstrdup(symbol, GFP_KERNEL);
275 if (!tk->symbol)
276 goto error;
277 tk->rp.kp.symbol_name = tk->symbol;
278 tk->rp.kp.offset = offs;
279 } else
280 tk->rp.kp.addr = addr;
281
282 if (is_return)
283 tk->rp.handler = kretprobe_dispatcher;
284 else
285 tk->rp.kp.pre_handler = kprobe_dispatcher;
286
287 tk->rp.maxactive = maxactive;
288 INIT_HLIST_NODE(&tk->rp.kp.hlist);
289 INIT_LIST_HEAD(&tk->rp.kp.list);
290
291 ret = trace_probe_init(&tk->tp, event, group, false);
292 if (ret < 0)
293 goto error;
294
295 dyn_event_init(&tk->devent, &trace_kprobe_ops);
296 return tk;
297error:
298 free_trace_kprobe(tk);
299 return ERR_PTR(ret);
300}
301
302static struct trace_kprobe *find_trace_kprobe(const char *event,
303 const char *group)
304{
305 struct dyn_event *pos;
306 struct trace_kprobe *tk;
307
308 for_each_trace_kprobe(tk, pos)
309 if (strcmp(trace_probe_name(&tk->tp), event) == 0 &&
310 strcmp(trace_probe_group_name(&tk->tp), group) == 0)
311 return tk;
312 return NULL;
313}
314
315static inline int __enable_trace_kprobe(struct trace_kprobe *tk)
316{
317 int ret = 0;
318
319 if (trace_kprobe_is_registered(tk) && !trace_kprobe_has_gone(tk)) {
320 if (trace_kprobe_is_return(tk))
321 ret = enable_kretprobe(&tk->rp);
322 else
323 ret = enable_kprobe(&tk->rp.kp);
324 }
325
326 return ret;
327}
328
329static void __disable_trace_kprobe(struct trace_probe *tp)
330{
331 struct trace_kprobe *tk;
332
333 list_for_each_entry(tk, trace_probe_probe_list(tp), tp.list) {
334 if (!trace_kprobe_is_registered(tk))
335 continue;
336 if (trace_kprobe_is_return(tk))
337 disable_kretprobe(&tk->rp);
338 else
339 disable_kprobe(&tk->rp.kp);
340 }
341}
342
343
344
345
346
347static int enable_trace_kprobe(struct trace_event_call *call,
348 struct trace_event_file *file)
349{
350 struct trace_probe *tp;
351 struct trace_kprobe *tk;
352 bool enabled;
353 int ret = 0;
354
355 tp = trace_probe_primary_from_call(call);
356 if (WARN_ON_ONCE(!tp))
357 return -ENODEV;
358 enabled = trace_probe_is_enabled(tp);
359
360
361 if (file) {
362 ret = trace_probe_add_file(tp, file);
363 if (ret)
364 return ret;
365 } else
366 trace_probe_set_flag(tp, TP_FLAG_PROFILE);
367
368 if (enabled)
369 return 0;
370
371 list_for_each_entry(tk, trace_probe_probe_list(tp), tp.list) {
372 if (trace_kprobe_has_gone(tk))
373 continue;
374 ret = __enable_trace_kprobe(tk);
375 if (ret)
376 break;
377 enabled = true;
378 }
379
380 if (ret) {
381
382 if (enabled)
383 __disable_trace_kprobe(tp);
384 if (file)
385 trace_probe_remove_file(tp, file);
386 else
387 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
388 }
389
390 return ret;
391}
392
393
394
395
396
397static int disable_trace_kprobe(struct trace_event_call *call,
398 struct trace_event_file *file)
399{
400 struct trace_probe *tp;
401
402 tp = trace_probe_primary_from_call(call);
403 if (WARN_ON_ONCE(!tp))
404 return -ENODEV;
405
406 if (file) {
407 if (!trace_probe_get_file_link(tp, file))
408 return -ENOENT;
409 if (!trace_probe_has_single_file(tp))
410 goto out;
411 trace_probe_clear_flag(tp, TP_FLAG_TRACE);
412 } else
413 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
414
415 if (!trace_probe_is_enabled(tp))
416 __disable_trace_kprobe(tp);
417
418 out:
419 if (file)
420
421
422
423
424
425
426 trace_probe_remove_file(tp, file);
427
428 return 0;
429}
430
431#if defined(CONFIG_DYNAMIC_FTRACE) && \
432 !defined(CONFIG_KPROBE_EVENTS_ON_NOTRACE)
433static bool __within_notrace_func(unsigned long addr)
434{
435 unsigned long offset, size;
436
437 if (!addr || !kallsyms_lookup_size_offset(addr, &size, &offset))
438 return false;
439
440
441 addr -= offset;
442
443
444
445
446
447 return !ftrace_location_range(addr, addr + size - 1);
448}
449
450static bool within_notrace_func(struct trace_kprobe *tk)
451{
452 unsigned long addr = trace_kprobe_address(tk);
453 char symname[KSYM_NAME_LEN], *p;
454
455 if (!__within_notrace_func(addr))
456 return false;
457
458
459 if (!lookup_symbol_name(addr, symname)) {
460 p = strchr(symname, '.');
461 if (!p)
462 return true;
463 *p = '\0';
464 addr = (unsigned long)kprobe_lookup_name(symname, 0);
465 if (addr)
466 return __within_notrace_func(addr);
467 }
468
469 return true;
470}
471#else
472#define within_notrace_func(tk) (false)
473#endif
474
475
476static int __register_trace_kprobe(struct trace_kprobe *tk)
477{
478 int i, ret;
479
480 ret = security_locked_down(LOCKDOWN_KPROBES);
481 if (ret)
482 return ret;
483
484 if (trace_kprobe_is_registered(tk))
485 return -EINVAL;
486
487 if (within_notrace_func(tk)) {
488 pr_warn("Could not probe notrace function %s\n",
489 trace_kprobe_symbol(tk));
490 return -EINVAL;
491 }
492
493 for (i = 0; i < tk->tp.nr_args; i++) {
494 ret = traceprobe_update_arg(&tk->tp.args[i]);
495 if (ret)
496 return ret;
497 }
498
499
500 if (trace_probe_is_enabled(&tk->tp))
501 tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED;
502 else
503 tk->rp.kp.flags |= KPROBE_FLAG_DISABLED;
504
505 if (trace_kprobe_is_return(tk))
506 ret = register_kretprobe(&tk->rp);
507 else
508 ret = register_kprobe(&tk->rp.kp);
509
510 return ret;
511}
512
513
514static void __unregister_trace_kprobe(struct trace_kprobe *tk)
515{
516 if (trace_kprobe_is_registered(tk)) {
517 if (trace_kprobe_is_return(tk))
518 unregister_kretprobe(&tk->rp);
519 else
520 unregister_kprobe(&tk->rp.kp);
521
522 INIT_HLIST_NODE(&tk->rp.kp.hlist);
523 INIT_LIST_HEAD(&tk->rp.kp.list);
524 if (tk->rp.kp.symbol_name)
525 tk->rp.kp.addr = NULL;
526 }
527}
528
529
530static int unregister_trace_kprobe(struct trace_kprobe *tk)
531{
532
533 if (trace_probe_has_sibling(&tk->tp))
534 goto unreg;
535
536
537 if (trace_probe_is_enabled(&tk->tp))
538 return -EBUSY;
539
540
541 if (trace_event_dyn_busy(trace_probe_event_call(&tk->tp)))
542 return -EBUSY;
543
544
545 if (unregister_kprobe_event(tk))
546 return -EBUSY;
547
548unreg:
549 __unregister_trace_kprobe(tk);
550 dyn_event_remove(&tk->devent);
551 trace_probe_unlink(&tk->tp);
552
553 return 0;
554}
555
556static bool trace_kprobe_has_same_kprobe(struct trace_kprobe *orig,
557 struct trace_kprobe *comp)
558{
559 struct trace_probe_event *tpe = orig->tp.event;
560 int i;
561
562 list_for_each_entry(orig, &tpe->probes, tp.list) {
563 if (strcmp(trace_kprobe_symbol(orig),
564 trace_kprobe_symbol(comp)) ||
565 trace_kprobe_offset(orig) != trace_kprobe_offset(comp))
566 continue;
567
568
569
570
571
572 for (i = 0; i < orig->tp.nr_args; i++) {
573 if (strcmp(orig->tp.args[i].comm,
574 comp->tp.args[i].comm))
575 break;
576 }
577
578 if (i == orig->tp.nr_args)
579 return true;
580 }
581
582 return false;
583}
584
585static int append_trace_kprobe(struct trace_kprobe *tk, struct trace_kprobe *to)
586{
587 int ret;
588
589 ret = trace_probe_compare_arg_type(&tk->tp, &to->tp);
590 if (ret) {
591
592 trace_probe_log_set_index(ret + 1);
593 trace_probe_log_err(0, DIFF_ARG_TYPE);
594 return -EEXIST;
595 }
596 if (trace_kprobe_has_same_kprobe(to, tk)) {
597 trace_probe_log_set_index(0);
598 trace_probe_log_err(0, SAME_PROBE);
599 return -EEXIST;
600 }
601
602
603 ret = trace_probe_append(&tk->tp, &to->tp);
604 if (ret)
605 return ret;
606
607
608 ret = __register_trace_kprobe(tk);
609 if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) {
610 pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
611 ret = 0;
612 }
613
614 if (ret)
615 trace_probe_unlink(&tk->tp);
616 else
617 dyn_event_add(&tk->devent, trace_probe_event_call(&tk->tp));
618
619 return ret;
620}
621
622
623static int register_trace_kprobe(struct trace_kprobe *tk)
624{
625 struct trace_kprobe *old_tk;
626 int ret;
627
628 mutex_lock(&event_mutex);
629
630 old_tk = find_trace_kprobe(trace_probe_name(&tk->tp),
631 trace_probe_group_name(&tk->tp));
632 if (old_tk) {
633 if (trace_kprobe_is_return(tk) != trace_kprobe_is_return(old_tk)) {
634 trace_probe_log_set_index(0);
635 trace_probe_log_err(0, DIFF_PROBE_TYPE);
636 ret = -EEXIST;
637 } else {
638 ret = append_trace_kprobe(tk, old_tk);
639 }
640 goto end;
641 }
642
643
644 ret = register_kprobe_event(tk);
645 if (ret) {
646 if (ret == -EEXIST) {
647 trace_probe_log_set_index(0);
648 trace_probe_log_err(0, EVENT_EXIST);
649 } else
650 pr_warn("Failed to register probe event(%d)\n", ret);
651 goto end;
652 }
653
654
655 ret = __register_trace_kprobe(tk);
656 if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) {
657 pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
658 ret = 0;
659 }
660
661 if (ret < 0)
662 unregister_kprobe_event(tk);
663 else
664 dyn_event_add(&tk->devent, trace_probe_event_call(&tk->tp));
665
666end:
667 mutex_unlock(&event_mutex);
668 return ret;
669}
670
671
672static int trace_kprobe_module_callback(struct notifier_block *nb,
673 unsigned long val, void *data)
674{
675 struct module *mod = data;
676 struct dyn_event *pos;
677 struct trace_kprobe *tk;
678 int ret;
679
680 if (val != MODULE_STATE_COMING)
681 return NOTIFY_DONE;
682
683
684 mutex_lock(&event_mutex);
685 for_each_trace_kprobe(tk, pos) {
686 if (trace_kprobe_within_module(tk, mod)) {
687
688 __unregister_trace_kprobe(tk);
689 ret = __register_trace_kprobe(tk);
690 if (ret)
691 pr_warn("Failed to re-register probe %s on %s: %d\n",
692 trace_probe_name(&tk->tp),
693 module_name(mod), ret);
694 }
695 }
696 mutex_unlock(&event_mutex);
697
698 return NOTIFY_DONE;
699}
700
701static struct notifier_block trace_kprobe_module_nb = {
702 .notifier_call = trace_kprobe_module_callback,
703 .priority = 1
704};
705
706static int __trace_kprobe_create(int argc, const char *argv[])
707{
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732 struct trace_kprobe *tk = NULL;
733 int i, len, ret = 0;
734 bool is_return = false;
735 char *symbol = NULL, *tmp = NULL;
736 const char *event = NULL, *group = KPROBE_EVENT_SYSTEM;
737 enum probe_print_type ptype;
738 int maxactive = 0;
739 long offset = 0;
740 void *addr = NULL;
741 char buf[MAX_EVENT_NAME_LEN];
742 unsigned int flags = TPARG_FL_KERNEL;
743
744 switch (argv[0][0]) {
745 case 'r':
746 is_return = true;
747 break;
748 case 'p':
749 break;
750 default:
751 return -ECANCELED;
752 }
753 if (argc < 2)
754 return -ECANCELED;
755
756 trace_probe_log_init("trace_kprobe", argc, argv);
757
758 event = strchr(&argv[0][1], ':');
759 if (event)
760 event++;
761
762 if (isdigit(argv[0][1])) {
763 if (!is_return) {
764 trace_probe_log_err(1, MAXACT_NO_KPROBE);
765 goto parse_error;
766 }
767 if (event)
768 len = event - &argv[0][1] - 1;
769 else
770 len = strlen(&argv[0][1]);
771 if (len > MAX_EVENT_NAME_LEN - 1) {
772 trace_probe_log_err(1, BAD_MAXACT);
773 goto parse_error;
774 }
775 memcpy(buf, &argv[0][1], len);
776 buf[len] = '\0';
777 ret = kstrtouint(buf, 0, &maxactive);
778 if (ret || !maxactive) {
779 trace_probe_log_err(1, BAD_MAXACT);
780 goto parse_error;
781 }
782
783
784
785 if (maxactive > KRETPROBE_MAXACTIVE_MAX) {
786 trace_probe_log_err(1, MAXACT_TOO_BIG);
787 goto parse_error;
788 }
789 }
790
791
792
793 if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) {
794 trace_probe_log_set_index(1);
795
796 if (strchr(argv[1], '/') && strchr(argv[1], ':')) {
797 ret = -ECANCELED;
798 goto error;
799 }
800
801 symbol = kstrdup(argv[1], GFP_KERNEL);
802 if (!symbol)
803 return -ENOMEM;
804
805 tmp = strchr(symbol, '%');
806 if (tmp) {
807 if (!strcmp(tmp, "%return")) {
808 *tmp = '\0';
809 is_return = true;
810 } else {
811 trace_probe_log_err(tmp - symbol, BAD_ADDR_SUFFIX);
812 goto parse_error;
813 }
814 }
815
816
817 ret = traceprobe_split_symbol_offset(symbol, &offset);
818 if (ret || offset < 0 || offset > UINT_MAX) {
819 trace_probe_log_err(0, BAD_PROBE_ADDR);
820 goto parse_error;
821 }
822 if (is_return)
823 flags |= TPARG_FL_RETURN;
824 ret = kprobe_on_func_entry(NULL, symbol, offset);
825 if (ret == 0)
826 flags |= TPARG_FL_FENTRY;
827
828 if (ret == -EINVAL && is_return) {
829 trace_probe_log_err(0, BAD_RETPROBE);
830 goto parse_error;
831 }
832 }
833
834 trace_probe_log_set_index(0);
835 if (event) {
836 ret = traceprobe_parse_event_name(&event, &group, buf,
837 event - argv[0]);
838 if (ret)
839 goto parse_error;
840 } else {
841
842 if (symbol)
843 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
844 is_return ? 'r' : 'p', symbol, offset);
845 else
846 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
847 is_return ? 'r' : 'p', addr);
848 sanitize_event_name(buf);
849 event = buf;
850 }
851
852
853 tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive,
854 argc - 2, is_return);
855 if (IS_ERR(tk)) {
856 ret = PTR_ERR(tk);
857
858 WARN_ON_ONCE(ret != -ENOMEM);
859 goto out;
860 }
861 argc -= 2; argv += 2;
862
863
864 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
865 trace_probe_log_set_index(i + 2);
866 ret = traceprobe_parse_probe_arg(&tk->tp, i, argv[i], flags);
867 if (ret)
868 goto error;
869 }
870
871 ptype = is_return ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
872 ret = traceprobe_set_print_fmt(&tk->tp, ptype);
873 if (ret < 0)
874 goto error;
875
876 ret = register_trace_kprobe(tk);
877 if (ret) {
878 trace_probe_log_set_index(1);
879 if (ret == -EILSEQ)
880 trace_probe_log_err(0, BAD_INSN_BNDRY);
881 else if (ret == -ENOENT)
882 trace_probe_log_err(0, BAD_PROBE_ADDR);
883 else if (ret != -ENOMEM && ret != -EEXIST)
884 trace_probe_log_err(0, FAIL_REG_PROBE);
885 goto error;
886 }
887
888out:
889 trace_probe_log_clear();
890 kfree(symbol);
891 return ret;
892
893parse_error:
894 ret = -EINVAL;
895error:
896 free_trace_kprobe(tk);
897 goto out;
898}
899
900static int trace_kprobe_create(const char *raw_command)
901{
902 return trace_probe_create(raw_command, __trace_kprobe_create);
903}
904
905static int create_or_delete_trace_kprobe(const char *raw_command)
906{
907 int ret;
908
909 if (raw_command[0] == '-')
910 return dyn_event_release(raw_command, &trace_kprobe_ops);
911
912 ret = trace_kprobe_create(raw_command);
913 return ret == -ECANCELED ? -EINVAL : ret;
914}
915
916static int trace_kprobe_run_command(struct dynevent_cmd *cmd)
917{
918 return create_or_delete_trace_kprobe(cmd->seq.buffer);
919}
920
921
922
923
924
925
926
927
928
929
930void kprobe_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen)
931{
932 dynevent_cmd_init(cmd, buf, maxlen, DYNEVENT_TYPE_KPROBE,
933 trace_kprobe_run_command);
934}
935EXPORT_SYMBOL_GPL(kprobe_event_cmd_init);
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960int __kprobe_event_gen_cmd_start(struct dynevent_cmd *cmd, bool kretprobe,
961 const char *name, const char *loc, ...)
962{
963 char buf[MAX_EVENT_NAME_LEN];
964 struct dynevent_arg arg;
965 va_list args;
966 int ret;
967
968 if (cmd->type != DYNEVENT_TYPE_KPROBE)
969 return -EINVAL;
970
971 if (!loc)
972 return -EINVAL;
973
974 if (kretprobe)
975 snprintf(buf, MAX_EVENT_NAME_LEN, "r:kprobes/%s", name);
976 else
977 snprintf(buf, MAX_EVENT_NAME_LEN, "p:kprobes/%s", name);
978
979 ret = dynevent_str_add(cmd, buf);
980 if (ret)
981 return ret;
982
983 dynevent_arg_init(&arg, 0);
984 arg.str = loc;
985 ret = dynevent_arg_add(cmd, &arg, NULL);
986 if (ret)
987 return ret;
988
989 va_start(args, loc);
990 for (;;) {
991 const char *field;
992
993 field = va_arg(args, const char *);
994 if (!field)
995 break;
996
997 if (++cmd->n_fields > MAX_TRACE_ARGS) {
998 ret = -EINVAL;
999 break;
1000 }
1001
1002 arg.str = field;
1003 ret = dynevent_arg_add(cmd, &arg, NULL);
1004 if (ret)
1005 break;
1006 }
1007 va_end(args);
1008
1009 return ret;
1010}
1011EXPORT_SYMBOL_GPL(__kprobe_event_gen_cmd_start);
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029int __kprobe_event_add_fields(struct dynevent_cmd *cmd, ...)
1030{
1031 struct dynevent_arg arg;
1032 va_list args;
1033 int ret = 0;
1034
1035 if (cmd->type != DYNEVENT_TYPE_KPROBE)
1036 return -EINVAL;
1037
1038 dynevent_arg_init(&arg, 0);
1039
1040 va_start(args, cmd);
1041 for (;;) {
1042 const char *field;
1043
1044 field = va_arg(args, const char *);
1045 if (!field)
1046 break;
1047
1048 if (++cmd->n_fields > MAX_TRACE_ARGS) {
1049 ret = -EINVAL;
1050 break;
1051 }
1052
1053 arg.str = field;
1054 ret = dynevent_arg_add(cmd, &arg, NULL);
1055 if (ret)
1056 break;
1057 }
1058 va_end(args);
1059
1060 return ret;
1061}
1062EXPORT_SYMBOL_GPL(__kprobe_event_add_fields);
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073int kprobe_event_delete(const char *name)
1074{
1075 char buf[MAX_EVENT_NAME_LEN];
1076
1077 snprintf(buf, MAX_EVENT_NAME_LEN, "-:%s", name);
1078
1079 return create_or_delete_trace_kprobe(buf);
1080}
1081EXPORT_SYMBOL_GPL(kprobe_event_delete);
1082
1083static int trace_kprobe_release(struct dyn_event *ev)
1084{
1085 struct trace_kprobe *tk = to_trace_kprobe(ev);
1086 int ret = unregister_trace_kprobe(tk);
1087
1088 if (!ret)
1089 free_trace_kprobe(tk);
1090 return ret;
1091}
1092
1093static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev)
1094{
1095 struct trace_kprobe *tk = to_trace_kprobe(ev);
1096 int i;
1097
1098 seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p');
1099 if (trace_kprobe_is_return(tk) && tk->rp.maxactive)
1100 seq_printf(m, "%d", tk->rp.maxactive);
1101 seq_printf(m, ":%s/%s", trace_probe_group_name(&tk->tp),
1102 trace_probe_name(&tk->tp));
1103
1104 if (!tk->symbol)
1105 seq_printf(m, " 0x%p", tk->rp.kp.addr);
1106 else if (tk->rp.kp.offset)
1107 seq_printf(m, " %s+%u", trace_kprobe_symbol(tk),
1108 tk->rp.kp.offset);
1109 else
1110 seq_printf(m, " %s", trace_kprobe_symbol(tk));
1111
1112 for (i = 0; i < tk->tp.nr_args; i++)
1113 seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm);
1114 seq_putc(m, '\n');
1115
1116 return 0;
1117}
1118
1119static int probes_seq_show(struct seq_file *m, void *v)
1120{
1121 struct dyn_event *ev = v;
1122
1123 if (!is_trace_kprobe(ev))
1124 return 0;
1125
1126 return trace_kprobe_show(m, ev);
1127}
1128
1129static const struct seq_operations probes_seq_op = {
1130 .start = dyn_event_seq_start,
1131 .next = dyn_event_seq_next,
1132 .stop = dyn_event_seq_stop,
1133 .show = probes_seq_show
1134};
1135
1136static int probes_open(struct inode *inode, struct file *file)
1137{
1138 int ret;
1139
1140 ret = security_locked_down(LOCKDOWN_TRACEFS);
1141 if (ret)
1142 return ret;
1143
1144 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
1145 ret = dyn_events_release_all(&trace_kprobe_ops);
1146 if (ret < 0)
1147 return ret;
1148 }
1149
1150 return seq_open(file, &probes_seq_op);
1151}
1152
1153static ssize_t probes_write(struct file *file, const char __user *buffer,
1154 size_t count, loff_t *ppos)
1155{
1156 return trace_parse_run_command(file, buffer, count, ppos,
1157 create_or_delete_trace_kprobe);
1158}
1159
1160static const struct file_operations kprobe_events_ops = {
1161 .owner = THIS_MODULE,
1162 .open = probes_open,
1163 .read = seq_read,
1164 .llseek = seq_lseek,
1165 .release = seq_release,
1166 .write = probes_write,
1167};
1168
1169
1170static int probes_profile_seq_show(struct seq_file *m, void *v)
1171{
1172 struct dyn_event *ev = v;
1173 struct trace_kprobe *tk;
1174 unsigned long nmissed;
1175
1176 if (!is_trace_kprobe(ev))
1177 return 0;
1178
1179 tk = to_trace_kprobe(ev);
1180 nmissed = trace_kprobe_is_return(tk) ?
1181 tk->rp.kp.nmissed + tk->rp.nmissed : tk->rp.kp.nmissed;
1182 seq_printf(m, " %-44s %15lu %15lu\n",
1183 trace_probe_name(&tk->tp),
1184 trace_kprobe_nhit(tk),
1185 nmissed);
1186
1187 return 0;
1188}
1189
1190static const struct seq_operations profile_seq_op = {
1191 .start = dyn_event_seq_start,
1192 .next = dyn_event_seq_next,
1193 .stop = dyn_event_seq_stop,
1194 .show = probes_profile_seq_show
1195};
1196
1197static int profile_open(struct inode *inode, struct file *file)
1198{
1199 int ret;
1200
1201 ret = security_locked_down(LOCKDOWN_TRACEFS);
1202 if (ret)
1203 return ret;
1204
1205 return seq_open(file, &profile_seq_op);
1206}
1207
1208static const struct file_operations kprobe_profile_ops = {
1209 .owner = THIS_MODULE,
1210 .open = profile_open,
1211 .read = seq_read,
1212 .llseek = seq_lseek,
1213 .release = seq_release,
1214};
1215
1216
1217
1218
1219static nokprobe_inline int
1220fetch_store_strlen_user(unsigned long addr)
1221{
1222 const void __user *uaddr = (__force const void __user *)addr;
1223
1224 return strnlen_user_nofault(uaddr, MAX_STRING_SIZE);
1225}
1226
1227
1228static nokprobe_inline int
1229fetch_store_strlen(unsigned long addr)
1230{
1231 int ret, len = 0;
1232 u8 c;
1233
1234#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1235 if (addr < TASK_SIZE)
1236 return fetch_store_strlen_user(addr);
1237#endif
1238
1239 do {
1240 ret = copy_from_kernel_nofault(&c, (u8 *)addr + len, 1);
1241 len++;
1242 } while (c && ret == 0 && len < MAX_STRING_SIZE);
1243
1244 return (ret < 0) ? ret : len;
1245}
1246
1247
1248
1249
1250
1251static nokprobe_inline int
1252fetch_store_string_user(unsigned long addr, void *dest, void *base)
1253{
1254 const void __user *uaddr = (__force const void __user *)addr;
1255 int maxlen = get_loc_len(*(u32 *)dest);
1256 void *__dest;
1257 long ret;
1258
1259 if (unlikely(!maxlen))
1260 return -ENOMEM;
1261
1262 __dest = get_loc_data(dest, base);
1263
1264 ret = strncpy_from_user_nofault(__dest, uaddr, maxlen);
1265 if (ret >= 0)
1266 *(u32 *)dest = make_data_loc(ret, __dest - base);
1267
1268 return ret;
1269}
1270
1271
1272
1273
1274
1275static nokprobe_inline int
1276fetch_store_string(unsigned long addr, void *dest, void *base)
1277{
1278 int maxlen = get_loc_len(*(u32 *)dest);
1279 void *__dest;
1280 long ret;
1281
1282#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1283 if ((unsigned long)addr < TASK_SIZE)
1284 return fetch_store_string_user(addr, dest, base);
1285#endif
1286
1287 if (unlikely(!maxlen))
1288 return -ENOMEM;
1289
1290 __dest = get_loc_data(dest, base);
1291
1292
1293
1294
1295
1296 ret = strncpy_from_kernel_nofault(__dest, (void *)addr, maxlen);
1297 if (ret >= 0)
1298 *(u32 *)dest = make_data_loc(ret, __dest - base);
1299
1300 return ret;
1301}
1302
1303static nokprobe_inline int
1304probe_mem_read_user(void *dest, void *src, size_t size)
1305{
1306 const void __user *uaddr = (__force const void __user *)src;
1307
1308 return copy_from_user_nofault(dest, uaddr, size);
1309}
1310
1311static nokprobe_inline int
1312probe_mem_read(void *dest, void *src, size_t size)
1313{
1314#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1315 if ((unsigned long)src < TASK_SIZE)
1316 return probe_mem_read_user(dest, src, size);
1317#endif
1318 return copy_from_kernel_nofault(dest, src, size);
1319}
1320
1321
1322static int
1323process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
1324 void *base)
1325{
1326 struct pt_regs *regs = rec;
1327 unsigned long val;
1328
1329retry:
1330
1331 switch (code->op) {
1332 case FETCH_OP_REG:
1333 val = regs_get_register(regs, code->param);
1334 break;
1335 case FETCH_OP_STACK:
1336 val = regs_get_kernel_stack_nth(regs, code->param);
1337 break;
1338 case FETCH_OP_STACKP:
1339 val = kernel_stack_pointer(regs);
1340 break;
1341 case FETCH_OP_RETVAL:
1342 val = regs_return_value(regs);
1343 break;
1344 case FETCH_OP_IMM:
1345 val = code->immediate;
1346 break;
1347 case FETCH_OP_COMM:
1348 val = (unsigned long)current->comm;
1349 break;
1350 case FETCH_OP_DATA:
1351 val = (unsigned long)code->data;
1352 break;
1353#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
1354 case FETCH_OP_ARG:
1355 val = regs_get_kernel_argument(regs, code->param);
1356 break;
1357#endif
1358 case FETCH_NOP_SYMBOL:
1359 code++;
1360 goto retry;
1361 default:
1362 return -EILSEQ;
1363 }
1364 code++;
1365
1366 return process_fetch_insn_bottom(code, val, dest, base);
1367}
1368NOKPROBE_SYMBOL(process_fetch_insn)
1369
1370
1371static nokprobe_inline void
1372__kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
1373 struct trace_event_file *trace_file)
1374{
1375 struct kprobe_trace_entry_head *entry;
1376 struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1377 struct trace_event_buffer fbuffer;
1378 int dsize;
1379
1380 WARN_ON(call != trace_file->event_call);
1381
1382 if (trace_trigger_soft_disabled(trace_file))
1383 return;
1384
1385 dsize = __get_data_size(&tk->tp, regs);
1386
1387 entry = trace_event_buffer_reserve(&fbuffer, trace_file,
1388 sizeof(*entry) + tk->tp.size + dsize);
1389 if (!entry)
1390 return;
1391
1392 fbuffer.regs = regs;
1393 entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
1394 entry->ip = (unsigned long)tk->rp.kp.addr;
1395 store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1396
1397 trace_event_buffer_commit(&fbuffer);
1398}
1399
1400static void
1401kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs)
1402{
1403 struct event_file_link *link;
1404
1405 trace_probe_for_each_link_rcu(link, &tk->tp)
1406 __kprobe_trace_func(tk, regs, link->file);
1407}
1408NOKPROBE_SYMBOL(kprobe_trace_func);
1409
1410
1411static nokprobe_inline void
1412__kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1413 struct pt_regs *regs,
1414 struct trace_event_file *trace_file)
1415{
1416 struct kretprobe_trace_entry_head *entry;
1417 struct trace_event_buffer fbuffer;
1418 struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1419 int dsize;
1420
1421 WARN_ON(call != trace_file->event_call);
1422
1423 if (trace_trigger_soft_disabled(trace_file))
1424 return;
1425
1426 dsize = __get_data_size(&tk->tp, regs);
1427
1428 entry = trace_event_buffer_reserve(&fbuffer, trace_file,
1429 sizeof(*entry) + tk->tp.size + dsize);
1430 if (!entry)
1431 return;
1432
1433 fbuffer.regs = regs;
1434 entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
1435 entry->func = (unsigned long)tk->rp.kp.addr;
1436 entry->ret_ip = get_kretprobe_retaddr(ri);
1437 store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1438
1439 trace_event_buffer_commit(&fbuffer);
1440}
1441
1442static void
1443kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1444 struct pt_regs *regs)
1445{
1446 struct event_file_link *link;
1447
1448 trace_probe_for_each_link_rcu(link, &tk->tp)
1449 __kretprobe_trace_func(tk, ri, regs, link->file);
1450}
1451NOKPROBE_SYMBOL(kretprobe_trace_func);
1452
1453
1454static enum print_line_t
1455print_kprobe_event(struct trace_iterator *iter, int flags,
1456 struct trace_event *event)
1457{
1458 struct kprobe_trace_entry_head *field;
1459 struct trace_seq *s = &iter->seq;
1460 struct trace_probe *tp;
1461
1462 field = (struct kprobe_trace_entry_head *)iter->ent;
1463 tp = trace_probe_primary_from_call(
1464 container_of(event, struct trace_event_call, event));
1465 if (WARN_ON_ONCE(!tp))
1466 goto out;
1467
1468 trace_seq_printf(s, "%s: (", trace_probe_name(tp));
1469
1470 if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
1471 goto out;
1472
1473 trace_seq_putc(s, ')');
1474
1475 if (print_probe_args(s, tp->args, tp->nr_args,
1476 (u8 *)&field[1], field) < 0)
1477 goto out;
1478
1479 trace_seq_putc(s, '\n');
1480 out:
1481 return trace_handle_return(s);
1482}
1483
1484static enum print_line_t
1485print_kretprobe_event(struct trace_iterator *iter, int flags,
1486 struct trace_event *event)
1487{
1488 struct kretprobe_trace_entry_head *field;
1489 struct trace_seq *s = &iter->seq;
1490 struct trace_probe *tp;
1491
1492 field = (struct kretprobe_trace_entry_head *)iter->ent;
1493 tp = trace_probe_primary_from_call(
1494 container_of(event, struct trace_event_call, event));
1495 if (WARN_ON_ONCE(!tp))
1496 goto out;
1497
1498 trace_seq_printf(s, "%s: (", trace_probe_name(tp));
1499
1500 if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
1501 goto out;
1502
1503 trace_seq_puts(s, " <- ");
1504
1505 if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
1506 goto out;
1507
1508 trace_seq_putc(s, ')');
1509
1510 if (print_probe_args(s, tp->args, tp->nr_args,
1511 (u8 *)&field[1], field) < 0)
1512 goto out;
1513
1514 trace_seq_putc(s, '\n');
1515
1516 out:
1517 return trace_handle_return(s);
1518}
1519
1520
1521static int kprobe_event_define_fields(struct trace_event_call *event_call)
1522{
1523 int ret;
1524 struct kprobe_trace_entry_head field;
1525 struct trace_probe *tp;
1526
1527 tp = trace_probe_primary_from_call(event_call);
1528 if (WARN_ON_ONCE(!tp))
1529 return -ENOENT;
1530
1531 DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
1532
1533 return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
1534}
1535
1536static int kretprobe_event_define_fields(struct trace_event_call *event_call)
1537{
1538 int ret;
1539 struct kretprobe_trace_entry_head field;
1540 struct trace_probe *tp;
1541
1542 tp = trace_probe_primary_from_call(event_call);
1543 if (WARN_ON_ONCE(!tp))
1544 return -ENOENT;
1545
1546 DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
1547 DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
1548
1549 return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
1550}
1551
1552#ifdef CONFIG_PERF_EVENTS
1553
1554
1555static int
1556kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
1557{
1558 struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1559 struct kprobe_trace_entry_head *entry;
1560 struct hlist_head *head;
1561 int size, __size, dsize;
1562 int rctx;
1563
1564 if (bpf_prog_array_valid(call)) {
1565 unsigned long orig_ip = instruction_pointer(regs);
1566 int ret;
1567
1568 ret = trace_call_bpf(call, regs);
1569
1570
1571
1572
1573
1574
1575 if (orig_ip != instruction_pointer(regs))
1576 return 1;
1577 if (!ret)
1578 return 0;
1579 }
1580
1581 head = this_cpu_ptr(call->perf_events);
1582 if (hlist_empty(head))
1583 return 0;
1584
1585 dsize = __get_data_size(&tk->tp, regs);
1586 __size = sizeof(*entry) + tk->tp.size + dsize;
1587 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1588 size -= sizeof(u32);
1589
1590 entry = perf_trace_buf_alloc(size, NULL, &rctx);
1591 if (!entry)
1592 return 0;
1593
1594 entry->ip = (unsigned long)tk->rp.kp.addr;
1595 memset(&entry[1], 0, dsize);
1596 store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1597 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1598 head, NULL);
1599 return 0;
1600}
1601NOKPROBE_SYMBOL(kprobe_perf_func);
1602
1603
1604static void
1605kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1606 struct pt_regs *regs)
1607{
1608 struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1609 struct kretprobe_trace_entry_head *entry;
1610 struct hlist_head *head;
1611 int size, __size, dsize;
1612 int rctx;
1613
1614 if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs))
1615 return;
1616
1617 head = this_cpu_ptr(call->perf_events);
1618 if (hlist_empty(head))
1619 return;
1620
1621 dsize = __get_data_size(&tk->tp, regs);
1622 __size = sizeof(*entry) + tk->tp.size + dsize;
1623 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1624 size -= sizeof(u32);
1625
1626 entry = perf_trace_buf_alloc(size, NULL, &rctx);
1627 if (!entry)
1628 return;
1629
1630 entry->func = (unsigned long)tk->rp.kp.addr;
1631 entry->ret_ip = get_kretprobe_retaddr(ri);
1632 store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1633 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1634 head, NULL);
1635}
1636NOKPROBE_SYMBOL(kretprobe_perf_func);
1637
1638int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type,
1639 const char **symbol, u64 *probe_offset,
1640 u64 *probe_addr, bool perf_type_tracepoint)
1641{
1642 const char *pevent = trace_event_name(event->tp_event);
1643 const char *group = event->tp_event->class->system;
1644 struct trace_kprobe *tk;
1645
1646 if (perf_type_tracepoint)
1647 tk = find_trace_kprobe(pevent, group);
1648 else
1649 tk = trace_kprobe_primary_from_call(event->tp_event);
1650 if (!tk)
1651 return -EINVAL;
1652
1653 *fd_type = trace_kprobe_is_return(tk) ? BPF_FD_TYPE_KRETPROBE
1654 : BPF_FD_TYPE_KPROBE;
1655 if (tk->symbol) {
1656 *symbol = tk->symbol;
1657 *probe_offset = tk->rp.kp.offset;
1658 *probe_addr = 0;
1659 } else {
1660 *symbol = NULL;
1661 *probe_offset = 0;
1662 *probe_addr = (unsigned long)tk->rp.kp.addr;
1663 }
1664 return 0;
1665}
1666#endif
1667
1668
1669
1670
1671
1672
1673
1674static int kprobe_register(struct trace_event_call *event,
1675 enum trace_reg type, void *data)
1676{
1677 struct trace_event_file *file = data;
1678
1679 switch (type) {
1680 case TRACE_REG_REGISTER:
1681 return enable_trace_kprobe(event, file);
1682 case TRACE_REG_UNREGISTER:
1683 return disable_trace_kprobe(event, file);
1684
1685#ifdef CONFIG_PERF_EVENTS
1686 case TRACE_REG_PERF_REGISTER:
1687 return enable_trace_kprobe(event, NULL);
1688 case TRACE_REG_PERF_UNREGISTER:
1689 return disable_trace_kprobe(event, NULL);
1690 case TRACE_REG_PERF_OPEN:
1691 case TRACE_REG_PERF_CLOSE:
1692 case TRACE_REG_PERF_ADD:
1693 case TRACE_REG_PERF_DEL:
1694 return 0;
1695#endif
1696 }
1697 return 0;
1698}
1699
1700static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1701{
1702 struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp);
1703 int ret = 0;
1704
1705 raw_cpu_inc(*tk->nhit);
1706
1707 if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE))
1708 kprobe_trace_func(tk, regs);
1709#ifdef CONFIG_PERF_EVENTS
1710 if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE))
1711 ret = kprobe_perf_func(tk, regs);
1712#endif
1713 return ret;
1714}
1715NOKPROBE_SYMBOL(kprobe_dispatcher);
1716
1717static int
1718kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1719{
1720 struct kretprobe *rp = get_kretprobe(ri);
1721 struct trace_kprobe *tk = container_of(rp, struct trace_kprobe, rp);
1722
1723 raw_cpu_inc(*tk->nhit);
1724
1725 if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE))
1726 kretprobe_trace_func(tk, ri, regs);
1727#ifdef CONFIG_PERF_EVENTS
1728 if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE))
1729 kretprobe_perf_func(tk, ri, regs);
1730#endif
1731 return 0;
1732}
1733NOKPROBE_SYMBOL(kretprobe_dispatcher);
1734
1735static struct trace_event_functions kretprobe_funcs = {
1736 .trace = print_kretprobe_event
1737};
1738
1739static struct trace_event_functions kprobe_funcs = {
1740 .trace = print_kprobe_event
1741};
1742
1743static struct trace_event_fields kretprobe_fields_array[] = {
1744 { .type = TRACE_FUNCTION_TYPE,
1745 .define_fields = kretprobe_event_define_fields },
1746 {}
1747};
1748
1749static struct trace_event_fields kprobe_fields_array[] = {
1750 { .type = TRACE_FUNCTION_TYPE,
1751 .define_fields = kprobe_event_define_fields },
1752 {}
1753};
1754
1755static inline void init_trace_event_call(struct trace_kprobe *tk)
1756{
1757 struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1758
1759 if (trace_kprobe_is_return(tk)) {
1760 call->event.funcs = &kretprobe_funcs;
1761 call->class->fields_array = kretprobe_fields_array;
1762 } else {
1763 call->event.funcs = &kprobe_funcs;
1764 call->class->fields_array = kprobe_fields_array;
1765 }
1766
1767 call->flags = TRACE_EVENT_FL_KPROBE;
1768 call->class->reg = kprobe_register;
1769}
1770
1771static int register_kprobe_event(struct trace_kprobe *tk)
1772{
1773 init_trace_event_call(tk);
1774
1775 return trace_probe_register_event_call(&tk->tp);
1776}
1777
1778static int unregister_kprobe_event(struct trace_kprobe *tk)
1779{
1780 return trace_probe_unregister_event_call(&tk->tp);
1781}
1782
1783#ifdef CONFIG_PERF_EVENTS
1784
1785struct trace_event_call *
1786create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
1787 bool is_return)
1788{
1789 enum probe_print_type ptype;
1790 struct trace_kprobe *tk;
1791 int ret;
1792 char *event;
1793
1794
1795
1796
1797
1798
1799 event = func ? func : "DUMMY_EVENT";
1800
1801 tk = alloc_trace_kprobe(KPROBE_EVENT_SYSTEM, event, (void *)addr, func,
1802 offs, 0 , 0 ,
1803 is_return);
1804
1805 if (IS_ERR(tk)) {
1806 pr_info("Failed to allocate trace_probe.(%d)\n",
1807 (int)PTR_ERR(tk));
1808 return ERR_CAST(tk);
1809 }
1810
1811 init_trace_event_call(tk);
1812
1813 ptype = trace_kprobe_is_return(tk) ?
1814 PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
1815 if (traceprobe_set_print_fmt(&tk->tp, ptype) < 0) {
1816 ret = -ENOMEM;
1817 goto error;
1818 }
1819
1820 ret = __register_trace_kprobe(tk);
1821 if (ret < 0)
1822 goto error;
1823
1824 return trace_probe_event_call(&tk->tp);
1825error:
1826 free_trace_kprobe(tk);
1827 return ERR_PTR(ret);
1828}
1829
1830void destroy_local_trace_kprobe(struct trace_event_call *event_call)
1831{
1832 struct trace_kprobe *tk;
1833
1834 tk = trace_kprobe_primary_from_call(event_call);
1835 if (unlikely(!tk))
1836 return;
1837
1838 if (trace_probe_is_enabled(&tk->tp)) {
1839 WARN_ON(1);
1840 return;
1841 }
1842
1843 __unregister_trace_kprobe(tk);
1844
1845 free_trace_kprobe(tk);
1846}
1847#endif
1848
1849static __init void enable_boot_kprobe_events(void)
1850{
1851 struct trace_array *tr = top_trace_array();
1852 struct trace_event_file *file;
1853 struct trace_kprobe *tk;
1854 struct dyn_event *pos;
1855
1856 mutex_lock(&event_mutex);
1857 for_each_trace_kprobe(tk, pos) {
1858 list_for_each_entry(file, &tr->events, list)
1859 if (file->event_call == trace_probe_event_call(&tk->tp))
1860 trace_event_enable_disable(file, 1, 0);
1861 }
1862 mutex_unlock(&event_mutex);
1863}
1864
1865static __init void setup_boot_kprobe_events(void)
1866{
1867 char *p, *cmd = kprobe_boot_events_buf;
1868 int ret;
1869
1870 strreplace(kprobe_boot_events_buf, ',', ' ');
1871
1872 while (cmd && *cmd != '\0') {
1873 p = strchr(cmd, ';');
1874 if (p)
1875 *p++ = '\0';
1876
1877 ret = create_or_delete_trace_kprobe(cmd);
1878 if (ret)
1879 pr_warn("Failed to add event(%d): %s\n", ret, cmd);
1880
1881 cmd = p;
1882 }
1883
1884 enable_boot_kprobe_events();
1885}
1886
1887
1888
1889
1890
1891static __init int init_kprobe_trace_early(void)
1892{
1893 int ret;
1894
1895 ret = dyn_event_register(&trace_kprobe_ops);
1896 if (ret)
1897 return ret;
1898
1899 if (register_module_notifier(&trace_kprobe_module_nb))
1900 return -EINVAL;
1901
1902 return 0;
1903}
1904core_initcall(init_kprobe_trace_early);
1905
1906
1907static __init int init_kprobe_trace(void)
1908{
1909 int ret;
1910 struct dentry *entry;
1911
1912 ret = tracing_init_dentry();
1913 if (ret)
1914 return 0;
1915
1916 entry = tracefs_create_file("kprobe_events", TRACE_MODE_WRITE,
1917 NULL, NULL, &kprobe_events_ops);
1918
1919
1920 if (!entry)
1921 pr_warn("Could not create tracefs 'kprobe_events' entry\n");
1922
1923
1924 entry = tracefs_create_file("kprobe_profile", TRACE_MODE_READ,
1925 NULL, NULL, &kprobe_profile_ops);
1926
1927 if (!entry)
1928 pr_warn("Could not create tracefs 'kprobe_profile' entry\n");
1929
1930 setup_boot_kprobe_events();
1931
1932 return 0;
1933}
1934fs_initcall(init_kprobe_trace);
1935
1936
1937#ifdef CONFIG_FTRACE_STARTUP_TEST
1938static __init struct trace_event_file *
1939find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr)
1940{
1941 struct trace_event_file *file;
1942
1943 list_for_each_entry(file, &tr->events, list)
1944 if (file->event_call == trace_probe_event_call(&tk->tp))
1945 return file;
1946
1947 return NULL;
1948}
1949
1950
1951
1952
1953
1954static __init int kprobe_trace_self_tests_init(void)
1955{
1956 int ret, warn = 0;
1957 int (*target)(int, int, int, int, int, int);
1958 struct trace_kprobe *tk;
1959 struct trace_event_file *file;
1960
1961 if (tracing_is_disabled())
1962 return -ENODEV;
1963
1964 if (tracing_selftest_disabled)
1965 return 0;
1966
1967 target = kprobe_trace_selftest_target;
1968
1969 pr_info("Testing kprobe tracing: ");
1970
1971 ret = create_or_delete_trace_kprobe("p:testprobe kprobe_trace_selftest_target $stack $stack0 +0($stack)");
1972 if (WARN_ON_ONCE(ret)) {
1973 pr_warn("error on probing function entry.\n");
1974 warn++;
1975 } else {
1976
1977 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
1978 if (WARN_ON_ONCE(tk == NULL)) {
1979 pr_warn("error on getting new probe.\n");
1980 warn++;
1981 } else {
1982 file = find_trace_probe_file(tk, top_trace_array());
1983 if (WARN_ON_ONCE(file == NULL)) {
1984 pr_warn("error on getting probe file.\n");
1985 warn++;
1986 } else
1987 enable_trace_kprobe(
1988 trace_probe_event_call(&tk->tp), file);
1989 }
1990 }
1991
1992 ret = create_or_delete_trace_kprobe("r:testprobe2 kprobe_trace_selftest_target $retval");
1993 if (WARN_ON_ONCE(ret)) {
1994 pr_warn("error on probing function return.\n");
1995 warn++;
1996 } else {
1997
1998 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
1999 if (WARN_ON_ONCE(tk == NULL)) {
2000 pr_warn("error on getting 2nd new probe.\n");
2001 warn++;
2002 } else {
2003 file = find_trace_probe_file(tk, top_trace_array());
2004 if (WARN_ON_ONCE(file == NULL)) {
2005 pr_warn("error on getting probe file.\n");
2006 warn++;
2007 } else
2008 enable_trace_kprobe(
2009 trace_probe_event_call(&tk->tp), file);
2010 }
2011 }
2012
2013 if (warn)
2014 goto end;
2015
2016 ret = target(1, 2, 3, 4, 5, 6);
2017
2018
2019
2020
2021
2022
2023 if (ret != 21)
2024 warn++;
2025
2026
2027 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
2028 if (WARN_ON_ONCE(tk == NULL)) {
2029 pr_warn("error on getting test probe.\n");
2030 warn++;
2031 } else {
2032 if (trace_kprobe_nhit(tk) != 1) {
2033 pr_warn("incorrect number of testprobe hits\n");
2034 warn++;
2035 }
2036
2037 file = find_trace_probe_file(tk, top_trace_array());
2038 if (WARN_ON_ONCE(file == NULL)) {
2039 pr_warn("error on getting probe file.\n");
2040 warn++;
2041 } else
2042 disable_trace_kprobe(
2043 trace_probe_event_call(&tk->tp), file);
2044 }
2045
2046 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
2047 if (WARN_ON_ONCE(tk == NULL)) {
2048 pr_warn("error on getting 2nd test probe.\n");
2049 warn++;
2050 } else {
2051 if (trace_kprobe_nhit(tk) != 1) {
2052 pr_warn("incorrect number of testprobe2 hits\n");
2053 warn++;
2054 }
2055
2056 file = find_trace_probe_file(tk, top_trace_array());
2057 if (WARN_ON_ONCE(file == NULL)) {
2058 pr_warn("error on getting probe file.\n");
2059 warn++;
2060 } else
2061 disable_trace_kprobe(
2062 trace_probe_event_call(&tk->tp), file);
2063 }
2064
2065 ret = create_or_delete_trace_kprobe("-:testprobe");
2066 if (WARN_ON_ONCE(ret)) {
2067 pr_warn("error on deleting a probe.\n");
2068 warn++;
2069 }
2070
2071 ret = create_or_delete_trace_kprobe("-:testprobe2");
2072 if (WARN_ON_ONCE(ret)) {
2073 pr_warn("error on deleting a probe.\n");
2074 warn++;
2075 }
2076
2077end:
2078 ret = dyn_events_release_all(&trace_kprobe_ops);
2079 if (WARN_ON_ONCE(ret)) {
2080 pr_warn("error on cleaning up probes.\n");
2081 warn++;
2082 }
2083
2084
2085
2086
2087 wait_for_kprobe_optimizer();
2088 if (warn)
2089 pr_cont("NG: Some tests are failed. Please check them.\n");
2090 else
2091 pr_cont("OK\n");
2092 return 0;
2093}
2094
2095late_initcall(kprobe_trace_self_tests_init);
2096
2097#endif
2098