1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Kprobes-based tracing events
4 *
5 * Created by Masami Hiramatsu <mhiramat@redhat.com>
6 *
7 */
8#define pr_fmt(fmt) "trace_kprobe: " fmt
9
10#include <linux/bpf-cgroup.h>
11#include <linux/cleanup.h>
12#include <linux/security.h>
13#include <linux/module.h>
14#include <linux/uaccess.h>
15#include <linux/rculist.h>
16#include <linux/error-injection.h>
17
18#include <asm/setup.h> /* for COMMAND_LINE_SIZE */
19
20#include "trace_dynevent.h"
21#include "trace_kprobe_selftest.h"
22#include "trace_probe.h"
23#include "trace_probe_tmpl.h"
24#include "trace_probe_kernel.h"
25
26#define KPROBE_EVENT_SYSTEM "kprobes"
27#define KRETPROBE_MAXACTIVE_MAX 4096
28
29/* Kprobe early definition from command line */
30static char kprobe_boot_events_buf[COMMAND_LINE_SIZE] __initdata;
31
32static int __init set_kprobe_boot_events(char *str)
33{
34 strscpy(kprobe_boot_events_buf, str, COMMAND_LINE_SIZE);
35 disable_tracing_selftest(reason: "running kprobe events");
36
37 return 1;
38}
39__setup("kprobe_event=", set_kprobe_boot_events);
40
41static int trace_kprobe_create(const char *raw_command);
42static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev);
43static int trace_kprobe_release(struct dyn_event *ev);
44static bool trace_kprobe_is_busy(struct dyn_event *ev);
45static bool trace_kprobe_match(const char *system, const char *event,
46 int argc, const char **argv, struct dyn_event *ev);
47
48static struct dyn_event_operations trace_kprobe_ops = {
49 .create = trace_kprobe_create,
50 .show = trace_kprobe_show,
51 .is_busy = trace_kprobe_is_busy,
52 .free = trace_kprobe_release,
53 .match = trace_kprobe_match,
54};
55
56/*
57 * Kprobe event core functions
58 */
59struct trace_kprobe {
60 struct dyn_event devent;
61 struct kretprobe rp; /* Use rp.kp for kprobe use */
62 unsigned long __percpu *nhit;
63 const char *symbol; /* symbol name */
64 struct trace_probe tp;
65};
66
67static bool is_trace_kprobe(struct dyn_event *ev)
68{
69 return ev->ops == &trace_kprobe_ops;
70}
71
72static struct trace_kprobe *to_trace_kprobe(struct dyn_event *ev)
73{
74 return container_of(ev, struct trace_kprobe, devent);
75}
76
77/**
78 * for_each_trace_kprobe - iterate over the trace_kprobe list
79 * @pos: the struct trace_kprobe * for each entry
80 * @dpos: the struct dyn_event * to use as a loop cursor
81 */
82#define for_each_trace_kprobe(pos, dpos) \
83 for_each_dyn_event(dpos) \
84 if (is_trace_kprobe(dpos) && (pos = to_trace_kprobe(dpos)))
85
86static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk)
87{
88 return tk->rp.handler != NULL;
89}
90
91static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk)
92{
93 return tk->symbol ? tk->symbol : "unknown";
94}
95
96static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk)
97{
98 return tk->rp.kp.offset;
99}
100
101static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk)
102{
103 return kprobe_gone(p: &tk->rp.kp);
104}
105
106static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk,
107 struct module *mod)
108{
109 int len = strlen(module_name(mod));
110 const char *name = trace_kprobe_symbol(tk);
111
112 return strncmp(module_name(mod), name, len) == 0 && name[len] == ':';
113}
114
115#ifdef CONFIG_MODULES
116static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk)
117{
118 char *p;
119 bool ret;
120
121 if (!tk->symbol)
122 return false;
123 p = strchr(tk->symbol, ':');
124 if (!p)
125 return true;
126 *p = '\0';
127 scoped_guard(rcu)
128 ret = !!find_module(name: tk->symbol);
129 *p = ':';
130
131 return ret;
132}
133#else
134static inline bool trace_kprobe_module_exist(struct trace_kprobe *tk)
135{
136 return false;
137}
138#endif
139
140static bool trace_kprobe_is_busy(struct dyn_event *ev)
141{
142 struct trace_kprobe *tk = to_trace_kprobe(ev);
143
144 return trace_probe_is_enabled(tp: &tk->tp);
145}
146
147static bool trace_kprobe_match_command_head(struct trace_kprobe *tk,
148 int argc, const char **argv)
149{
150 char buf[MAX_ARGSTR_LEN + 1];
151
152 if (!argc)
153 return true;
154
155 if (!tk->symbol)
156 snprintf(buf, size: sizeof(buf), fmt: "0x%p", tk->rp.kp.addr);
157 else if (tk->rp.kp.offset)
158 snprintf(buf, size: sizeof(buf), fmt: "%s+%u",
159 trace_kprobe_symbol(tk), tk->rp.kp.offset);
160 else
161 snprintf(buf, size: sizeof(buf), fmt: "%s", trace_kprobe_symbol(tk));
162 if (strcmp(buf, argv[0]))
163 return false;
164 argc--; argv++;
165
166 return trace_probe_match_command_args(tp: &tk->tp, argc, argv);
167}
168
169static bool trace_kprobe_match(const char *system, const char *event,
170 int argc, const char **argv, struct dyn_event *ev)
171{
172 struct trace_kprobe *tk = to_trace_kprobe(ev);
173
174 return (event[0] == '\0' ||
175 strcmp(trace_probe_name(tp: &tk->tp), event) == 0) &&
176 (!system || strcmp(trace_probe_group_name(tp: &tk->tp), system) == 0) &&
177 trace_kprobe_match_command_head(tk, argc, argv);
178}
179
180static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk)
181{
182 unsigned long nhit = 0;
183 int cpu;
184
185 for_each_possible_cpu(cpu)
186 nhit += *per_cpu_ptr(tk->nhit, cpu);
187
188 return nhit;
189}
190
191static nokprobe_inline bool trace_kprobe_is_registered(struct trace_kprobe *tk)
192{
193 return !(list_empty(head: &tk->rp.kp.list) &&
194 hlist_unhashed(h: &tk->rp.kp.hlist));
195}
196
197/* Return 0 if it fails to find the symbol address */
198static nokprobe_inline
199unsigned long trace_kprobe_address(struct trace_kprobe *tk)
200{
201 unsigned long addr;
202
203 if (tk->symbol) {
204 addr = (unsigned long)
205 kallsyms_lookup_name(name: trace_kprobe_symbol(tk));
206 if (addr)
207 addr += tk->rp.kp.offset;
208 } else {
209 addr = (unsigned long)tk->rp.kp.addr;
210 }
211 return addr;
212}
213
214static nokprobe_inline struct trace_kprobe *
215trace_kprobe_primary_from_call(struct trace_event_call *call)
216{
217 struct trace_probe *tp;
218
219 tp = trace_probe_primary_from_call(call);
220 if (WARN_ON_ONCE(!tp))
221 return NULL;
222
223 return container_of(tp, struct trace_kprobe, tp);
224}
225
226bool trace_kprobe_on_func_entry(struct trace_event_call *call)
227{
228 struct trace_kprobe *tk = trace_kprobe_primary_from_call(call);
229
230 return tk ? (kprobe_on_func_entry(addr: tk->rp.kp.addr,
231 sym: tk->rp.kp.addr ? NULL : tk->rp.kp.symbol_name,
232 offset: tk->rp.kp.addr ? 0 : tk->rp.kp.offset) == 0) : false;
233}
234
235bool trace_kprobe_error_injectable(struct trace_event_call *call)
236{
237 struct trace_kprobe *tk = trace_kprobe_primary_from_call(call);
238
239 return tk ? within_error_injection_list(addr: trace_kprobe_address(tk)) :
240 false;
241}
242
243static int register_kprobe_event(struct trace_kprobe *tk);
244static int unregister_kprobe_event(struct trace_kprobe *tk);
245
246static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
247static int kretprobe_dispatcher(struct kretprobe_instance *ri,
248 struct pt_regs *regs);
249
250static void free_trace_kprobe(struct trace_kprobe *tk)
251{
252 if (tk) {
253 trace_probe_cleanup(tp: &tk->tp);
254 kfree(objp: tk->symbol);
255 free_percpu(pdata: tk->nhit);
256 kfree(objp: tk);
257 }
258}
259
260DEFINE_FREE(free_trace_kprobe, struct trace_kprobe *,
261 if (!IS_ERR_OR_NULL(_T)) free_trace_kprobe(_T))
262
263/*
264 * Allocate new trace_probe and initialize it (including kprobes).
265 */
266static struct trace_kprobe *alloc_trace_kprobe(const char *group,
267 const char *event,
268 void *addr,
269 const char *symbol,
270 unsigned long offs,
271 int maxactive,
272 int nargs, bool is_return)
273{
274 struct trace_kprobe *tk __free(free_trace_kprobe) = NULL;
275 int ret = -ENOMEM;
276
277 tk = kzalloc(struct_size(tk, tp.args, nargs), GFP_KERNEL);
278 if (!tk)
279 return ERR_PTR(error: ret);
280
281 tk->nhit = alloc_percpu(unsigned long);
282 if (!tk->nhit)
283 return ERR_PTR(error: ret);
284
285 if (symbol) {
286 tk->symbol = kstrdup(s: symbol, GFP_KERNEL);
287 if (!tk->symbol)
288 return ERR_PTR(error: ret);
289 tk->rp.kp.symbol_name = tk->symbol;
290 tk->rp.kp.offset = offs;
291 } else
292 tk->rp.kp.addr = addr;
293
294 if (is_return)
295 tk->rp.handler = kretprobe_dispatcher;
296 else
297 tk->rp.kp.pre_handler = kprobe_dispatcher;
298
299 tk->rp.maxactive = maxactive;
300 INIT_HLIST_NODE(h: &tk->rp.kp.hlist);
301 INIT_LIST_HEAD(list: &tk->rp.kp.list);
302
303 ret = trace_probe_init(tp: &tk->tp, event, group, alloc_filter: false, nargs);
304 if (ret < 0)
305 return ERR_PTR(error: ret);
306
307 dyn_event_init(ev: &tk->devent, ops: &trace_kprobe_ops);
308 return_ptr(tk);
309}
310
311static struct trace_kprobe *find_trace_kprobe(const char *event,
312 const char *group)
313{
314 struct dyn_event *pos;
315 struct trace_kprobe *tk;
316
317 for_each_trace_kprobe(tk, pos)
318 if (strcmp(trace_probe_name(tp: &tk->tp), event) == 0 &&
319 strcmp(trace_probe_group_name(tp: &tk->tp), group) == 0)
320 return tk;
321 return NULL;
322}
323
324static inline int __enable_trace_kprobe(struct trace_kprobe *tk)
325{
326 int ret = 0;
327
328 if (trace_kprobe_is_registered(tk) && !trace_kprobe_has_gone(tk)) {
329 if (trace_kprobe_is_return(tk))
330 ret = enable_kretprobe(rp: &tk->rp);
331 else
332 ret = enable_kprobe(kp: &tk->rp.kp);
333 }
334
335 return ret;
336}
337
338static void __disable_trace_kprobe(struct trace_probe *tp)
339{
340 struct trace_kprobe *tk;
341
342 list_for_each_entry(tk, trace_probe_probe_list(tp), tp.list) {
343 if (!trace_kprobe_is_registered(tk))
344 continue;
345 if (trace_kprobe_is_return(tk))
346 disable_kretprobe(rp: &tk->rp);
347 else
348 disable_kprobe(kp: &tk->rp.kp);
349 }
350}
351
352/*
353 * Enable trace_probe
354 * if the file is NULL, enable "perf" handler, or enable "trace" handler.
355 */
356static int enable_trace_kprobe(struct trace_event_call *call,
357 struct trace_event_file *file)
358{
359 struct trace_probe *tp;
360 struct trace_kprobe *tk;
361 bool enabled;
362 int ret = 0;
363
364 tp = trace_probe_primary_from_call(call);
365 if (WARN_ON_ONCE(!tp))
366 return -ENODEV;
367 enabled = trace_probe_is_enabled(tp);
368
369 /* This also changes "enabled" state */
370 if (file) {
371 ret = trace_probe_add_file(tp, file);
372 if (ret)
373 return ret;
374 } else
375 trace_probe_set_flag(tp, TP_FLAG_PROFILE);
376
377 if (enabled)
378 return 0;
379
380 list_for_each_entry(tk, trace_probe_probe_list(tp), tp.list) {
381 if (trace_kprobe_has_gone(tk))
382 continue;
383 ret = __enable_trace_kprobe(tk);
384 if (ret)
385 break;
386 enabled = true;
387 }
388
389 if (ret) {
390 /* Failed to enable one of them. Roll back all */
391 if (enabled)
392 __disable_trace_kprobe(tp);
393 if (file)
394 trace_probe_remove_file(tp, file);
395 else
396 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
397 }
398
399 return ret;
400}
401
402/*
403 * Disable trace_probe
404 * if the file is NULL, disable "perf" handler, or disable "trace" handler.
405 */
406static int disable_trace_kprobe(struct trace_event_call *call,
407 struct trace_event_file *file)
408{
409 struct trace_probe *tp;
410
411 tp = trace_probe_primary_from_call(call);
412 if (WARN_ON_ONCE(!tp))
413 return -ENODEV;
414
415 if (file) {
416 if (!trace_probe_get_file_link(tp, file))
417 return -ENOENT;
418 if (!trace_probe_has_single_file(tp))
419 goto out;
420 trace_probe_clear_flag(tp, TP_FLAG_TRACE);
421 } else
422 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
423
424 if (!trace_probe_is_enabled(tp))
425 __disable_trace_kprobe(tp);
426
427 out:
428 if (file)
429 /*
430 * Synchronization is done in below function. For perf event,
431 * file == NULL and perf_trace_event_unreg() calls
432 * tracepoint_synchronize_unregister() to ensure synchronize
433 * event. We don't need to care about it.
434 */
435 trace_probe_remove_file(tp, file);
436
437 return 0;
438}
439
440#if defined(CONFIG_DYNAMIC_FTRACE) && \
441 !defined(CONFIG_KPROBE_EVENTS_ON_NOTRACE)
442static bool __within_notrace_func(unsigned long addr)
443{
444 unsigned long offset, size;
445
446 if (!addr || !kallsyms_lookup_size_offset(addr, &size, &offset))
447 return false;
448
449 /* Get the entry address of the target function */
450 addr -= offset;
451
452 /*
453 * Since ftrace_location_range() does inclusive range check, we need
454 * to subtract 1 byte from the end address.
455 */
456 return !ftrace_location_range(addr, addr + size - 1);
457}
458
459static bool within_notrace_func(struct trace_kprobe *tk)
460{
461 unsigned long addr = trace_kprobe_address(tk);
462 char symname[KSYM_NAME_LEN], *p;
463
464 if (!__within_notrace_func(addr))
465 return false;
466
467 /* Check if the address is on a suffixed-symbol */
468 if (!lookup_symbol_name(addr, symname)) {
469 p = strchr(symname, '.');
470 if (!p)
471 return true;
472 *p = '\0';
473 addr = (unsigned long)kprobe_lookup_name(symname, 0);
474 if (addr)
475 return __within_notrace_func(addr);
476 }
477
478 return true;
479}
480#else
481#define within_notrace_func(tk) (false)
482#endif
483
484/* Internal register function - just handle k*probes and flags */
485static int __register_trace_kprobe(struct trace_kprobe *tk)
486{
487 int i, ret;
488
489 ret = security_locked_down(what: LOCKDOWN_KPROBES);
490 if (ret)
491 return ret;
492
493 if (trace_kprobe_is_registered(tk))
494 return -EINVAL;
495
496 if (within_notrace_func(tk)) {
497 pr_warn("Could not probe notrace function %ps\n",
498 (void *)trace_kprobe_address(tk));
499 return -EINVAL;
500 }
501
502 for (i = 0; i < tk->tp.nr_args; i++) {
503 ret = traceprobe_update_arg(arg: &tk->tp.args[i]);
504 if (ret)
505 return ret;
506 }
507
508 /* Set/clear disabled flag according to tp->flag */
509 if (trace_probe_is_enabled(tp: &tk->tp))
510 tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED;
511 else
512 tk->rp.kp.flags |= KPROBE_FLAG_DISABLED;
513
514 if (trace_kprobe_is_return(tk))
515 ret = register_kretprobe(rp: &tk->rp);
516 else
517 ret = register_kprobe(p: &tk->rp.kp);
518
519 return ret;
520}
521
522/* Internal unregister function - just handle k*probes and flags */
523static void __unregister_trace_kprobe(struct trace_kprobe *tk)
524{
525 if (trace_kprobe_is_registered(tk)) {
526 if (trace_kprobe_is_return(tk))
527 unregister_kretprobe(rp: &tk->rp);
528 else
529 unregister_kprobe(p: &tk->rp.kp);
530 /* Cleanup kprobe for reuse and mark it unregistered */
531 INIT_HLIST_NODE(h: &tk->rp.kp.hlist);
532 INIT_LIST_HEAD(list: &tk->rp.kp.list);
533 if (tk->rp.kp.symbol_name)
534 tk->rp.kp.addr = NULL;
535 }
536}
537
538/* Unregister a trace_probe and probe_event */
539static int unregister_trace_kprobe(struct trace_kprobe *tk)
540{
541 /* If other probes are on the event, just unregister kprobe */
542 if (trace_probe_has_sibling(tp: &tk->tp))
543 goto unreg;
544
545 /* Enabled event can not be unregistered */
546 if (trace_probe_is_enabled(tp: &tk->tp))
547 return -EBUSY;
548
549 /* If there's a reference to the dynamic event */
550 if (trace_event_dyn_busy(call: trace_probe_event_call(tp: &tk->tp)))
551 return -EBUSY;
552
553 /* Will fail if probe is being used by ftrace or perf */
554 if (unregister_kprobe_event(tk))
555 return -EBUSY;
556
557unreg:
558 __unregister_trace_kprobe(tk);
559 dyn_event_remove(ev: &tk->devent);
560 trace_probe_unlink(tp: &tk->tp);
561
562 return 0;
563}
564
565static bool trace_kprobe_has_same_kprobe(struct trace_kprobe *orig,
566 struct trace_kprobe *comp)
567{
568 struct trace_probe_event *tpe = orig->tp.event;
569 int i;
570
571 list_for_each_entry(orig, &tpe->probes, tp.list) {
572 if (strcmp(trace_kprobe_symbol(tk: orig),
573 trace_kprobe_symbol(tk: comp)) ||
574 trace_kprobe_offset(tk: orig) != trace_kprobe_offset(tk: comp))
575 continue;
576
577 /*
578 * trace_probe_compare_arg_type() ensured that nr_args and
579 * each argument name and type are same. Let's compare comm.
580 */
581 for (i = 0; i < orig->tp.nr_args; i++) {
582 if (strcmp(orig->tp.args[i].comm,
583 comp->tp.args[i].comm))
584 break;
585 }
586
587 if (i == orig->tp.nr_args)
588 return true;
589 }
590
591 return false;
592}
593
594static int append_trace_kprobe(struct trace_kprobe *tk, struct trace_kprobe *to)
595{
596 int ret;
597
598 ret = trace_probe_compare_arg_type(a: &tk->tp, b: &to->tp);
599 if (ret) {
600 /* Note that argument starts index = 2 */
601 trace_probe_log_set_index(index: ret + 1);
602 trace_probe_log_err(0, DIFF_ARG_TYPE);
603 return -EEXIST;
604 }
605 if (trace_kprobe_has_same_kprobe(orig: to, comp: tk)) {
606 trace_probe_log_set_index(index: 0);
607 trace_probe_log_err(0, SAME_PROBE);
608 return -EEXIST;
609 }
610
611 /* Append to existing event */
612 ret = trace_probe_append(tp: &tk->tp, to: &to->tp);
613 if (ret)
614 return ret;
615
616 /* Register k*probe */
617 ret = __register_trace_kprobe(tk);
618 if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) {
619 pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
620 ret = 0;
621 }
622
623 if (ret)
624 trace_probe_unlink(tp: &tk->tp);
625 else
626 dyn_event_add(ev: &tk->devent, call: trace_probe_event_call(tp: &tk->tp));
627
628 return ret;
629}
630
631/* Register a trace_probe and probe_event */
632static int register_trace_kprobe(struct trace_kprobe *tk)
633{
634 struct trace_kprobe *old_tk;
635 int ret;
636
637 guard(mutex)(T: &event_mutex);
638
639 old_tk = find_trace_kprobe(event: trace_probe_name(tp: &tk->tp),
640 group: trace_probe_group_name(tp: &tk->tp));
641 if (old_tk) {
642 if (trace_kprobe_is_return(tk) != trace_kprobe_is_return(tk: old_tk)) {
643 trace_probe_log_set_index(index: 0);
644 trace_probe_log_err(0, DIFF_PROBE_TYPE);
645 return -EEXIST;
646 }
647 return append_trace_kprobe(tk, to: old_tk);
648 }
649
650 /* Register new event */
651 ret = register_kprobe_event(tk);
652 if (ret) {
653 if (ret == -EEXIST) {
654 trace_probe_log_set_index(index: 0);
655 trace_probe_log_err(0, EVENT_EXIST);
656 } else
657 pr_warn("Failed to register probe event(%d)\n", ret);
658 return ret;
659 }
660
661 /* Register k*probe */
662 ret = __register_trace_kprobe(tk);
663 if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) {
664 pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
665 ret = 0;
666 }
667
668 if (ret < 0)
669 unregister_kprobe_event(tk);
670 else
671 dyn_event_add(ev: &tk->devent, call: trace_probe_event_call(tp: &tk->tp));
672
673 return ret;
674}
675
676#ifdef CONFIG_MODULES
677static int validate_module_probe_symbol(const char *modname, const char *symbol);
678
679static int register_module_trace_kprobe(struct module *mod, struct trace_kprobe *tk)
680{
681 const char *p;
682 int ret = 0;
683
684 p = strchr(trace_kprobe_symbol(tk), ':');
685 if (p)
686 ret = validate_module_probe_symbol(module_name(mod), symbol: p + 1);
687 if (!ret)
688 ret = __register_trace_kprobe(tk);
689 return ret;
690}
691
692/* Module notifier call back, checking event on the module */
693static int trace_kprobe_module_callback(struct notifier_block *nb,
694 unsigned long val, void *data)
695{
696 struct module *mod = data;
697 struct dyn_event *pos;
698 struct trace_kprobe *tk;
699 int ret;
700
701 if (val != MODULE_STATE_COMING)
702 return NOTIFY_DONE;
703
704 /* Update probes on coming module */
705 guard(mutex)(T: &event_mutex);
706 for_each_trace_kprobe(tk, pos) {
707 if (trace_kprobe_within_module(tk, mod)) {
708 /* Don't need to check busy - this should have gone. */
709 __unregister_trace_kprobe(tk);
710 ret = register_module_trace_kprobe(mod, tk);
711 if (ret)
712 pr_warn("Failed to re-register probe %s on %s: %d\n",
713 trace_probe_name(&tk->tp),
714 module_name(mod), ret);
715 }
716 }
717
718 return NOTIFY_DONE;
719}
720
721static struct notifier_block trace_kprobe_module_nb = {
722 .notifier_call = trace_kprobe_module_callback,
723 .priority = 2 /* Invoked after kprobe and jump_label module callback */
724};
725static int trace_kprobe_register_module_notifier(void)
726{
727 return register_module_notifier(nb: &trace_kprobe_module_nb);
728}
729#else
730static int trace_kprobe_register_module_notifier(void)
731{
732 return 0;
733}
734#endif /* CONFIG_MODULES */
735
736static int count_symbols(void *data, unsigned long unused)
737{
738 unsigned int *count = data;
739
740 (*count)++;
741
742 return 0;
743}
744
745struct sym_count_ctx {
746 unsigned int count;
747 const char *name;
748};
749
750static int count_mod_symbols(void *data, const char *name, unsigned long unused)
751{
752 struct sym_count_ctx *ctx = data;
753
754 if (strcmp(name, ctx->name) == 0)
755 ctx->count++;
756
757 return 0;
758}
759
760static unsigned int number_of_same_symbols(const char *mod, const char *func_name)
761{
762 struct sym_count_ctx ctx = { .count = 0, .name = func_name };
763
764 if (!mod)
765 kallsyms_on_each_match_symbol(fn: count_symbols, name: func_name, data: &ctx.count);
766
767 module_kallsyms_on_each_symbol(modname: mod, fn: count_mod_symbols, data: &ctx);
768
769 return ctx.count;
770}
771
772static int validate_module_probe_symbol(const char *modname, const char *symbol)
773{
774 unsigned int count = number_of_same_symbols(mod: modname, func_name: symbol);
775
776 if (count > 1) {
777 /*
778 * Users should use ADDR to remove the ambiguity of
779 * using KSYM only.
780 */
781 return -EADDRNOTAVAIL;
782 } else if (count == 0) {
783 /*
784 * We can return ENOENT earlier than when register the
785 * kprobe.
786 */
787 return -ENOENT;
788 }
789 return 0;
790}
791
792#ifdef CONFIG_MODULES
793/* Return NULL if the module is not loaded or under unloading. */
794static struct module *try_module_get_by_name(const char *name)
795{
796 struct module *mod;
797
798 guard(rcu)();
799 mod = find_module(name);
800 if (mod && !try_module_get(module: mod))
801 mod = NULL;
802 return mod;
803}
804#else
805#define try_module_get_by_name(name) (NULL)
806#endif
807
808static int validate_probe_symbol(char *symbol)
809{
810 struct module *mod = NULL;
811 char *modname = NULL, *p;
812 int ret = 0;
813
814 p = strchr(symbol, ':');
815 if (p) {
816 modname = symbol;
817 symbol = p + 1;
818 *p = '\0';
819 mod = try_module_get_by_name(name: modname);
820 if (!mod)
821 goto out;
822 }
823
824 ret = validate_module_probe_symbol(modname, symbol);
825out:
826 if (p)
827 *p = ':';
828 if (mod)
829 module_put(module: mod);
830 return ret;
831}
832
833static int trace_kprobe_entry_handler(struct kretprobe_instance *ri,
834 struct pt_regs *regs);
835
836static int trace_kprobe_create_internal(int argc, const char *argv[],
837 struct traceprobe_parse_context *ctx)
838{
839 /*
840 * Argument syntax:
841 * - Add kprobe:
842 * p[:[GRP/][EVENT]] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
843 * - Add kretprobe:
844 * r[MAXACTIVE][:[GRP/][EVENT]] [MOD:]KSYM[+0] [FETCHARGS]
845 * Or
846 * p[:[GRP/][EVENT]] [MOD:]KSYM[+0]%return [FETCHARGS]
847 *
848 * Fetch args:
849 * $retval : fetch return value
850 * $stack : fetch stack address
851 * $stackN : fetch Nth of stack (N:0-)
852 * $comm : fetch current task comm
853 * @ADDR : fetch memory at ADDR (ADDR should be in kernel)
854 * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
855 * %REG : fetch register REG
856 * Dereferencing memory fetch:
857 * +|-offs(ARG) : fetch memory at ARG +|- offs address.
858 * Alias name of args:
859 * NAME=FETCHARG : set NAME as alias of FETCHARG.
860 * Type of args:
861 * FETCHARG:TYPE : use TYPE instead of unsigned long.
862 */
863 struct trace_kprobe *tk __free(free_trace_kprobe) = NULL;
864 int i, len, new_argc = 0, ret = 0;
865 bool is_return = false;
866 char *symbol __free(kfree) = NULL;
867 char *tmp = NULL;
868 const char **new_argv __free(kfree) = NULL;
869 const char *event = NULL, *group = KPROBE_EVENT_SYSTEM;
870 enum probe_print_type ptype;
871 int maxactive = 0;
872 long offset = 0;
873 void *addr = NULL;
874 char buf[MAX_EVENT_NAME_LEN];
875 char gbuf[MAX_EVENT_NAME_LEN];
876 char abuf[MAX_BTF_ARGS_LEN];
877 char *dbuf __free(kfree) = NULL;
878
879 switch (argv[0][0]) {
880 case 'r':
881 is_return = true;
882 break;
883 case 'p':
884 break;
885 default:
886 return -ECANCELED;
887 }
888 if (argc < 2)
889 return -ECANCELED;
890
891 event = strchr(&argv[0][1], ':');
892 if (event)
893 event++;
894
895 if (isdigit(c: argv[0][1])) {
896 if (!is_return) {
897 trace_probe_log_err(1, BAD_MAXACT_TYPE);
898 return -EINVAL;
899 }
900 if (event)
901 len = event - &argv[0][1] - 1;
902 else
903 len = strlen(&argv[0][1]);
904 if (len > MAX_EVENT_NAME_LEN - 1) {
905 trace_probe_log_err(1, BAD_MAXACT);
906 return -EINVAL;
907 }
908 memcpy(buf, &argv[0][1], len);
909 buf[len] = '\0';
910 ret = kstrtouint(s: buf, base: 0, res: &maxactive);
911 if (ret || !maxactive) {
912 trace_probe_log_err(1, BAD_MAXACT);
913 return -EINVAL;
914 }
915 /* kretprobes instances are iterated over via a list. The
916 * maximum should stay reasonable.
917 */
918 if (maxactive > KRETPROBE_MAXACTIVE_MAX) {
919 trace_probe_log_err(1, MAXACT_TOO_BIG);
920 return -EINVAL;
921 }
922 }
923
924 /* try to parse an address. if that fails, try to read the
925 * input as a symbol. */
926 if (kstrtoul(s: argv[1], base: 0, res: (unsigned long *)&addr)) {
927 trace_probe_log_set_index(index: 1);
928 /* Check whether uprobe event specified */
929 if (strchr(argv[1], '/') && strchr(argv[1], ':'))
930 return -ECANCELED;
931
932 /* a symbol specified */
933 symbol = kstrdup(s: argv[1], GFP_KERNEL);
934 if (!symbol)
935 return -ENOMEM;
936
937 tmp = strchr(symbol, '%');
938 if (tmp) {
939 if (!strcmp(tmp, "%return")) {
940 *tmp = '\0';
941 is_return = true;
942 } else {
943 trace_probe_log_err(tmp - symbol, BAD_ADDR_SUFFIX);
944 return -EINVAL;
945 }
946 }
947
948 /* TODO: support .init module functions */
949 ret = traceprobe_split_symbol_offset(symbol, offset: &offset);
950 if (ret || offset < 0 || offset > UINT_MAX) {
951 trace_probe_log_err(0, BAD_PROBE_ADDR);
952 return -EINVAL;
953 }
954 ret = validate_probe_symbol(symbol);
955 if (ret) {
956 if (ret == -EADDRNOTAVAIL)
957 trace_probe_log_err(0, NON_UNIQ_SYMBOL);
958 else
959 trace_probe_log_err(0, BAD_PROBE_ADDR);
960 return -EINVAL;
961 }
962 if (is_return)
963 ctx->flags |= TPARG_FL_RETURN;
964 ret = kprobe_on_func_entry(NULL, sym: symbol, offset);
965 if (ret == 0 && !is_return)
966 ctx->flags |= TPARG_FL_FENTRY;
967 /* Defer the ENOENT case until register kprobe */
968 if (ret == -EINVAL && is_return) {
969 trace_probe_log_err(0, BAD_RETPROBE);
970 return -EINVAL;
971 }
972 }
973
974 trace_probe_log_set_index(index: 0);
975 if (event) {
976 ret = traceprobe_parse_event_name(pevent: &event, pgroup: &group, buf: gbuf,
977 offset: event - argv[0]);
978 if (ret)
979 return ret;
980 }
981
982 if (!event) {
983 /* Make a new event name */
984 if (symbol)
985 snprintf(buf, MAX_EVENT_NAME_LEN, fmt: "%c_%s_%ld",
986 is_return ? 'r' : 'p', symbol, offset);
987 else
988 snprintf(buf, MAX_EVENT_NAME_LEN, fmt: "%c_0x%p",
989 is_return ? 'r' : 'p', addr);
990 sanitize_event_name(name: buf);
991 event = buf;
992 }
993
994 argc -= 2; argv += 2;
995 ctx->funcname = symbol;
996 new_argv = traceprobe_expand_meta_args(argc, argv, new_argc: &new_argc,
997 buf: abuf, MAX_BTF_ARGS_LEN, ctx);
998 if (IS_ERR(ptr: new_argv)) {
999 ret = PTR_ERR(ptr: new_argv);
1000 new_argv = NULL;
1001 return ret;
1002 }
1003 if (new_argv) {
1004 argc = new_argc;
1005 argv = new_argv;
1006 }
1007 if (argc > MAX_TRACE_ARGS) {
1008 trace_probe_log_set_index(index: 2);
1009 trace_probe_log_err(0, TOO_MANY_ARGS);
1010 return -E2BIG;
1011 }
1012
1013 ret = traceprobe_expand_dentry_args(argc, argv, buf: &dbuf);
1014 if (ret)
1015 return ret;
1016
1017 /* setup a probe */
1018 tk = alloc_trace_kprobe(group, event, addr, symbol, offs: offset, maxactive,
1019 nargs: argc, is_return);
1020 if (IS_ERR(ptr: tk)) {
1021 ret = PTR_ERR(ptr: tk);
1022 /* This must return -ENOMEM, else there is a bug */
1023 WARN_ON_ONCE(ret != -ENOMEM);
1024 return ret; /* We know tk is not allocated */
1025 }
1026
1027 /* parse arguments */
1028 for (i = 0; i < argc; i++) {
1029 trace_probe_log_set_index(index: i + 2);
1030 ctx->offset = 0;
1031 ret = traceprobe_parse_probe_arg(tp: &tk->tp, i, argv: argv[i], ctx);
1032 if (ret)
1033 return ret; /* This can be -ENOMEM */
1034 }
1035 /* entry handler for kretprobe */
1036 if (is_return && tk->tp.entry_arg) {
1037 tk->rp.entry_handler = trace_kprobe_entry_handler;
1038 tk->rp.data_size = traceprobe_get_entry_data_size(tp: &tk->tp);
1039 }
1040
1041 ptype = is_return ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
1042 ret = traceprobe_set_print_fmt(tp: &tk->tp, ptype);
1043 if (ret < 0)
1044 return ret;
1045
1046 ret = register_trace_kprobe(tk);
1047 if (ret) {
1048 trace_probe_log_set_index(index: 1);
1049 if (ret == -EILSEQ)
1050 trace_probe_log_err(0, BAD_INSN_BNDRY);
1051 else if (ret == -ENOENT)
1052 trace_probe_log_err(0, BAD_PROBE_ADDR);
1053 else if (ret != -ENOMEM && ret != -EEXIST)
1054 trace_probe_log_err(0, FAIL_REG_PROBE);
1055 return ret;
1056 }
1057 /*
1058 * Here, 'tk' has been registered to the list successfully,
1059 * so we don't need to free it.
1060 */
1061 tk = NULL;
1062
1063 return 0;
1064}
1065
1066static int trace_kprobe_create_cb(int argc, const char *argv[])
1067{
1068 struct traceprobe_parse_context ctx = { .flags = TPARG_FL_KERNEL };
1069 int ret;
1070
1071 trace_probe_log_init(subsystem: "trace_kprobe", argc, argv);
1072
1073 ret = trace_kprobe_create_internal(argc, argv, ctx: &ctx);
1074
1075 traceprobe_finish_parse(ctx: &ctx);
1076 trace_probe_log_clear();
1077 return ret;
1078}
1079
1080static int trace_kprobe_create(const char *raw_command)
1081{
1082 return trace_probe_create(raw_command, createfn: trace_kprobe_create_cb);
1083}
1084
1085static int create_or_delete_trace_kprobe(const char *raw_command)
1086{
1087 int ret;
1088
1089 if (raw_command[0] == '-')
1090 return dyn_event_release(raw_command, type: &trace_kprobe_ops);
1091
1092 ret = dyn_event_create(raw_command, type: &trace_kprobe_ops);
1093 return ret == -ECANCELED ? -EINVAL : ret;
1094}
1095
1096static int trace_kprobe_run_command(struct dynevent_cmd *cmd)
1097{
1098 return create_or_delete_trace_kprobe(raw_command: cmd->seq.buffer);
1099}
1100
1101/**
1102 * kprobe_event_cmd_init - Initialize a kprobe event command object
1103 * @cmd: A pointer to the dynevent_cmd struct representing the new event
1104 * @buf: A pointer to the buffer used to build the command
1105 * @maxlen: The length of the buffer passed in @buf
1106 *
1107 * Initialize a synthetic event command object. Use this before
1108 * calling any of the other kprobe_event functions.
1109 */
1110void kprobe_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen)
1111{
1112 dynevent_cmd_init(cmd, buf, maxlen, type: DYNEVENT_TYPE_KPROBE,
1113 run_command: trace_kprobe_run_command);
1114}
1115EXPORT_SYMBOL_GPL(kprobe_event_cmd_init);
1116
1117/**
1118 * __kprobe_event_gen_cmd_start - Generate a kprobe event command from arg list
1119 * @cmd: A pointer to the dynevent_cmd struct representing the new event
1120 * @kretprobe: Is this a return probe?
1121 * @name: The name of the kprobe event
1122 * @loc: The location of the kprobe event
1123 * @...: Variable number of arg (pairs), one pair for each field
1124 *
1125 * NOTE: Users normally won't want to call this function directly, but
1126 * rather use the kprobe_event_gen_cmd_start() wrapper, which automatically
1127 * adds a NULL to the end of the arg list. If this function is used
1128 * directly, make sure the last arg in the variable arg list is NULL.
1129 *
1130 * Generate a kprobe event command to be executed by
1131 * kprobe_event_gen_cmd_end(). This function can be used to generate the
1132 * complete command or only the first part of it; in the latter case,
1133 * kprobe_event_add_fields() can be used to add more fields following this.
1134 *
1135 * Unlikely the synth_event_gen_cmd_start(), @loc must be specified. This
1136 * returns -EINVAL if @loc == NULL.
1137 *
1138 * Return: 0 if successful, error otherwise.
1139 */
1140int __kprobe_event_gen_cmd_start(struct dynevent_cmd *cmd, bool kretprobe,
1141 const char *name, const char *loc, ...)
1142{
1143 char buf[MAX_EVENT_NAME_LEN];
1144 struct dynevent_arg arg;
1145 va_list args;
1146 int ret;
1147
1148 if (cmd->type != DYNEVENT_TYPE_KPROBE)
1149 return -EINVAL;
1150
1151 if (!loc)
1152 return -EINVAL;
1153
1154 if (kretprobe)
1155 snprintf(buf, MAX_EVENT_NAME_LEN, fmt: "r:kprobes/%s", name);
1156 else
1157 snprintf(buf, MAX_EVENT_NAME_LEN, fmt: "p:kprobes/%s", name);
1158
1159 ret = dynevent_str_add(cmd, str: buf);
1160 if (ret)
1161 return ret;
1162
1163 dynevent_arg_init(arg: &arg, separator: 0);
1164 arg.str = loc;
1165 ret = dynevent_arg_add(cmd, arg: &arg, NULL);
1166 if (ret)
1167 return ret;
1168
1169 va_start(args, loc);
1170 for (;;) {
1171 const char *field;
1172
1173 field = va_arg(args, const char *);
1174 if (!field)
1175 break;
1176
1177 if (++cmd->n_fields > MAX_TRACE_ARGS) {
1178 ret = -EINVAL;
1179 break;
1180 }
1181
1182 arg.str = field;
1183 ret = dynevent_arg_add(cmd, arg: &arg, NULL);
1184 if (ret)
1185 break;
1186 }
1187 va_end(args);
1188
1189 return ret;
1190}
1191EXPORT_SYMBOL_GPL(__kprobe_event_gen_cmd_start);
1192
1193/**
1194 * __kprobe_event_add_fields - Add probe fields to a kprobe command from arg list
1195 * @cmd: A pointer to the dynevent_cmd struct representing the new event
1196 * @...: Variable number of arg (pairs), one pair for each field
1197 *
1198 * NOTE: Users normally won't want to call this function directly, but
1199 * rather use the kprobe_event_add_fields() wrapper, which
1200 * automatically adds a NULL to the end of the arg list. If this
1201 * function is used directly, make sure the last arg in the variable
1202 * arg list is NULL.
1203 *
1204 * Add probe fields to an existing kprobe command using a variable
1205 * list of args. Fields are added in the same order they're listed.
1206 *
1207 * Return: 0 if successful, error otherwise.
1208 */
1209int __kprobe_event_add_fields(struct dynevent_cmd *cmd, ...)
1210{
1211 struct dynevent_arg arg;
1212 va_list args;
1213 int ret = 0;
1214
1215 if (cmd->type != DYNEVENT_TYPE_KPROBE)
1216 return -EINVAL;
1217
1218 dynevent_arg_init(arg: &arg, separator: 0);
1219
1220 va_start(args, cmd);
1221 for (;;) {
1222 const char *field;
1223
1224 field = va_arg(args, const char *);
1225 if (!field)
1226 break;
1227
1228 if (++cmd->n_fields > MAX_TRACE_ARGS) {
1229 ret = -EINVAL;
1230 break;
1231 }
1232
1233 arg.str = field;
1234 ret = dynevent_arg_add(cmd, arg: &arg, NULL);
1235 if (ret)
1236 break;
1237 }
1238 va_end(args);
1239
1240 return ret;
1241}
1242EXPORT_SYMBOL_GPL(__kprobe_event_add_fields);
1243
1244/**
1245 * kprobe_event_delete - Delete a kprobe event
1246 * @name: The name of the kprobe event to delete
1247 *
1248 * Delete a kprobe event with the give @name from kernel code rather
1249 * than directly from the command line.
1250 *
1251 * Return: 0 if successful, error otherwise.
1252 */
1253int kprobe_event_delete(const char *name)
1254{
1255 char buf[MAX_EVENT_NAME_LEN];
1256
1257 snprintf(buf, MAX_EVENT_NAME_LEN, fmt: "-:%s", name);
1258
1259 return create_or_delete_trace_kprobe(raw_command: buf);
1260}
1261EXPORT_SYMBOL_GPL(kprobe_event_delete);
1262
1263static int trace_kprobe_release(struct dyn_event *ev)
1264{
1265 struct trace_kprobe *tk = to_trace_kprobe(ev);
1266 int ret = unregister_trace_kprobe(tk);
1267
1268 if (!ret)
1269 free_trace_kprobe(tk);
1270 return ret;
1271}
1272
1273static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev)
1274{
1275 struct trace_kprobe *tk = to_trace_kprobe(ev);
1276 int i;
1277
1278 seq_putc(m, c: trace_kprobe_is_return(tk) ? 'r' : 'p');
1279 if (trace_kprobe_is_return(tk) && tk->rp.maxactive)
1280 seq_printf(m, fmt: "%d", tk->rp.maxactive);
1281 seq_printf(m, fmt: ":%s/%s", trace_probe_group_name(tp: &tk->tp),
1282 trace_probe_name(tp: &tk->tp));
1283
1284 if (!tk->symbol)
1285 seq_printf(m, fmt: " 0x%p", tk->rp.kp.addr);
1286 else if (tk->rp.kp.offset)
1287 seq_printf(m, fmt: " %s+%u", trace_kprobe_symbol(tk),
1288 tk->rp.kp.offset);
1289 else
1290 seq_printf(m, fmt: " %s", trace_kprobe_symbol(tk));
1291
1292 for (i = 0; i < tk->tp.nr_args; i++)
1293 seq_printf(m, fmt: " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm);
1294 seq_putc(m, c: '\n');
1295
1296 return 0;
1297}
1298
1299static int probes_seq_show(struct seq_file *m, void *v)
1300{
1301 struct dyn_event *ev = v;
1302
1303 if (!is_trace_kprobe(ev))
1304 return 0;
1305
1306 return trace_kprobe_show(m, ev);
1307}
1308
1309static const struct seq_operations probes_seq_op = {
1310 .start = dyn_event_seq_start,
1311 .next = dyn_event_seq_next,
1312 .stop = dyn_event_seq_stop,
1313 .show = probes_seq_show
1314};
1315
1316static int probes_open(struct inode *inode, struct file *file)
1317{
1318 int ret;
1319
1320 ret = security_locked_down(what: LOCKDOWN_TRACEFS);
1321 if (ret)
1322 return ret;
1323
1324 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
1325 ret = dyn_events_release_all(type: &trace_kprobe_ops);
1326 if (ret < 0)
1327 return ret;
1328 }
1329
1330 return seq_open(file, &probes_seq_op);
1331}
1332
1333static ssize_t probes_write(struct file *file, const char __user *buffer,
1334 size_t count, loff_t *ppos)
1335{
1336 return trace_parse_run_command(file, buffer, count, ppos,
1337 createfn: create_or_delete_trace_kprobe);
1338}
1339
1340static const struct file_operations kprobe_events_ops = {
1341 .owner = THIS_MODULE,
1342 .open = probes_open,
1343 .read = seq_read,
1344 .llseek = seq_lseek,
1345 .release = seq_release,
1346 .write = probes_write,
1347};
1348
1349static unsigned long trace_kprobe_missed(struct trace_kprobe *tk)
1350{
1351 return trace_kprobe_is_return(tk) ?
1352 tk->rp.kp.nmissed + tk->rp.nmissed : tk->rp.kp.nmissed;
1353}
1354
1355/* Probes profiling interfaces */
1356static int probes_profile_seq_show(struct seq_file *m, void *v)
1357{
1358 struct dyn_event *ev = v;
1359 struct trace_kprobe *tk;
1360 unsigned long nmissed;
1361
1362 if (!is_trace_kprobe(ev))
1363 return 0;
1364
1365 tk = to_trace_kprobe(ev);
1366 nmissed = trace_kprobe_missed(tk);
1367 seq_printf(m, fmt: " %-44s %15lu %15lu\n",
1368 trace_probe_name(tp: &tk->tp),
1369 trace_kprobe_nhit(tk),
1370 nmissed);
1371
1372 return 0;
1373}
1374
1375static const struct seq_operations profile_seq_op = {
1376 .start = dyn_event_seq_start,
1377 .next = dyn_event_seq_next,
1378 .stop = dyn_event_seq_stop,
1379 .show = probes_profile_seq_show
1380};
1381
1382static int profile_open(struct inode *inode, struct file *file)
1383{
1384 int ret;
1385
1386 ret = security_locked_down(what: LOCKDOWN_TRACEFS);
1387 if (ret)
1388 return ret;
1389
1390 return seq_open(file, &profile_seq_op);
1391}
1392
1393static const struct file_operations kprobe_profile_ops = {
1394 .owner = THIS_MODULE,
1395 .open = profile_open,
1396 .read = seq_read,
1397 .llseek = seq_lseek,
1398 .release = seq_release,
1399};
1400
1401/* Note that we don't verify it, since the code does not come from user space */
1402static int
1403process_fetch_insn(struct fetch_insn *code, void *rec, void *edata,
1404 void *dest, void *base)
1405{
1406 struct pt_regs *regs = rec;
1407 unsigned long val;
1408 int ret;
1409
1410retry:
1411 /* 1st stage: get value from context */
1412 switch (code->op) {
1413 case FETCH_OP_REG:
1414 val = regs_get_register(regs, offset: code->param);
1415 break;
1416 case FETCH_OP_STACK:
1417 val = regs_get_kernel_stack_nth(regs, n: code->param);
1418 break;
1419 case FETCH_OP_STACKP:
1420 val = kernel_stack_pointer(regs);
1421 break;
1422 case FETCH_OP_RETVAL:
1423 val = regs_return_value(regs);
1424 break;
1425#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
1426 case FETCH_OP_ARG:
1427 val = regs_get_kernel_argument(regs, n: code->param);
1428 break;
1429 case FETCH_OP_EDATA:
1430 val = *(unsigned long *)((unsigned long)edata + code->offset);
1431 break;
1432#endif
1433 case FETCH_NOP_SYMBOL: /* Ignore a place holder */
1434 code++;
1435 goto retry;
1436 default:
1437 ret = process_common_fetch_insn(code, val: &val);
1438 if (ret < 0)
1439 return ret;
1440 }
1441 code++;
1442
1443 return process_fetch_insn_bottom(code, val, dest, base);
1444}
1445NOKPROBE_SYMBOL(process_fetch_insn)
1446
1447/* Kprobe handler */
1448static nokprobe_inline void
1449__kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
1450 struct trace_event_file *trace_file)
1451{
1452 struct kprobe_trace_entry_head *entry;
1453 struct trace_event_call *call = trace_probe_event_call(tp: &tk->tp);
1454 struct trace_event_buffer fbuffer;
1455 int dsize;
1456
1457 WARN_ON(call != trace_file->event_call);
1458
1459 if (trace_trigger_soft_disabled(file: trace_file))
1460 return;
1461
1462 dsize = __get_data_size(tp: &tk->tp, regs, NULL);
1463
1464 entry = trace_event_buffer_reserve(fbuffer: &fbuffer, trace_file,
1465 len: sizeof(*entry) + tk->tp.size + dsize);
1466 if (!entry)
1467 return;
1468
1469 fbuffer.regs = regs;
1470 entry->ip = (unsigned long)tk->rp.kp.addr;
1471 store_trace_args(data: &entry[1], tp: &tk->tp, rec: regs, NULL, header_size: sizeof(*entry), maxlen: dsize);
1472
1473 trace_event_buffer_commit(fbuffer: &fbuffer);
1474}
1475
1476static void
1477kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs)
1478{
1479 struct event_file_link *link;
1480
1481 trace_probe_for_each_link_rcu(link, &tk->tp)
1482 __kprobe_trace_func(tk, regs, trace_file: link->file);
1483}
1484NOKPROBE_SYMBOL(kprobe_trace_func);
1485
1486/* Kretprobe handler */
1487
1488static int trace_kprobe_entry_handler(struct kretprobe_instance *ri,
1489 struct pt_regs *regs)
1490{
1491 struct kretprobe *rp = get_kretprobe(ri);
1492 struct trace_kprobe *tk;
1493
1494 /*
1495 * There is a small chance that get_kretprobe(ri) returns NULL when
1496 * the kretprobe is unregister on another CPU between kretprobe's
1497 * trampoline_handler and this function.
1498 */
1499 if (unlikely(!rp))
1500 return -ENOENT;
1501
1502 tk = container_of(rp, struct trace_kprobe, rp);
1503
1504 /* store argument values into ri->data as entry data */
1505 if (tk->tp.entry_arg)
1506 store_trace_entry_data(edata: ri->data, tp: &tk->tp, regs);
1507
1508 return 0;
1509}
1510
1511
1512static nokprobe_inline void
1513__kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1514 struct pt_regs *regs,
1515 struct trace_event_file *trace_file)
1516{
1517 struct kretprobe_trace_entry_head *entry;
1518 struct trace_event_buffer fbuffer;
1519 struct trace_event_call *call = trace_probe_event_call(tp: &tk->tp);
1520 int dsize;
1521
1522 WARN_ON(call != trace_file->event_call);
1523
1524 if (trace_trigger_soft_disabled(file: trace_file))
1525 return;
1526
1527 dsize = __get_data_size(tp: &tk->tp, regs, edata: ri->data);
1528
1529 entry = trace_event_buffer_reserve(fbuffer: &fbuffer, trace_file,
1530 len: sizeof(*entry) + tk->tp.size + dsize);
1531 if (!entry)
1532 return;
1533
1534 fbuffer.regs = regs;
1535 entry->func = (unsigned long)tk->rp.kp.addr;
1536 entry->ret_ip = get_kretprobe_retaddr(ri);
1537 store_trace_args(data: &entry[1], tp: &tk->tp, rec: regs, edata: ri->data, header_size: sizeof(*entry), maxlen: dsize);
1538
1539 trace_event_buffer_commit(fbuffer: &fbuffer);
1540}
1541
1542static void
1543kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1544 struct pt_regs *regs)
1545{
1546 struct event_file_link *link;
1547
1548 trace_probe_for_each_link_rcu(link, &tk->tp)
1549 __kretprobe_trace_func(tk, ri, regs, trace_file: link->file);
1550}
1551NOKPROBE_SYMBOL(kretprobe_trace_func);
1552
1553/* Event entry printers */
1554static enum print_line_t
1555print_kprobe_event(struct trace_iterator *iter, int flags,
1556 struct trace_event *event)
1557{
1558 struct kprobe_trace_entry_head *field;
1559 struct trace_seq *s = &iter->seq;
1560 struct trace_probe *tp;
1561
1562 field = (struct kprobe_trace_entry_head *)iter->ent;
1563 tp = trace_probe_primary_from_call(
1564 container_of(event, struct trace_event_call, event));
1565 if (WARN_ON_ONCE(!tp))
1566 goto out;
1567
1568 trace_seq_printf(s, fmt: "%s: (", trace_probe_name(tp));
1569
1570 if (!seq_print_ip_sym(s, ip: field->ip, sym_flags: flags | TRACE_ITER_SYM_OFFSET))
1571 goto out;
1572
1573 trace_seq_putc(s, c: ')');
1574
1575 if (trace_probe_print_args(s, args: tp->args, nr_args: tp->nr_args,
1576 data: (u8 *)&field[1], field) < 0)
1577 goto out;
1578
1579 trace_seq_putc(s, c: '\n');
1580 out:
1581 return trace_handle_return(s);
1582}
1583
1584static enum print_line_t
1585print_kretprobe_event(struct trace_iterator *iter, int flags,
1586 struct trace_event *event)
1587{
1588 struct kretprobe_trace_entry_head *field;
1589 struct trace_seq *s = &iter->seq;
1590 struct trace_probe *tp;
1591
1592 field = (struct kretprobe_trace_entry_head *)iter->ent;
1593 tp = trace_probe_primary_from_call(
1594 container_of(event, struct trace_event_call, event));
1595 if (WARN_ON_ONCE(!tp))
1596 goto out;
1597
1598 trace_seq_printf(s, fmt: "%s: (", trace_probe_name(tp));
1599
1600 if (!seq_print_ip_sym(s, ip: field->ret_ip, sym_flags: flags | TRACE_ITER_SYM_OFFSET))
1601 goto out;
1602
1603 trace_seq_puts(s, str: " <- ");
1604
1605 if (!seq_print_ip_sym(s, ip: field->func, sym_flags: flags & ~TRACE_ITER_SYM_OFFSET))
1606 goto out;
1607
1608 trace_seq_putc(s, c: ')');
1609
1610 if (trace_probe_print_args(s, args: tp->args, nr_args: tp->nr_args,
1611 data: (u8 *)&field[1], field) < 0)
1612 goto out;
1613
1614 trace_seq_putc(s, c: '\n');
1615
1616 out:
1617 return trace_handle_return(s);
1618}
1619
1620
1621static int kprobe_event_define_fields(struct trace_event_call *event_call)
1622{
1623 int ret;
1624 struct kprobe_trace_entry_head field;
1625 struct trace_probe *tp;
1626
1627 tp = trace_probe_primary_from_call(call: event_call);
1628 if (WARN_ON_ONCE(!tp))
1629 return -ENOENT;
1630
1631 DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
1632
1633 return traceprobe_define_arg_fields(event_call, offset: sizeof(field), tp);
1634}
1635
1636static int kretprobe_event_define_fields(struct trace_event_call *event_call)
1637{
1638 int ret;
1639 struct kretprobe_trace_entry_head field;
1640 struct trace_probe *tp;
1641
1642 tp = trace_probe_primary_from_call(call: event_call);
1643 if (WARN_ON_ONCE(!tp))
1644 return -ENOENT;
1645
1646 DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
1647 DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
1648
1649 return traceprobe_define_arg_fields(event_call, offset: sizeof(field), tp);
1650}
1651
1652#ifdef CONFIG_PERF_EVENTS
1653
1654/* Kprobe profile handler */
1655static int
1656kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
1657{
1658 struct trace_event_call *call = trace_probe_event_call(tp: &tk->tp);
1659 struct kprobe_trace_entry_head *entry;
1660 struct hlist_head *head;
1661 int size, __size, dsize;
1662 int rctx;
1663
1664 if (bpf_prog_array_valid(call)) {
1665 unsigned long orig_ip = instruction_pointer(regs);
1666 int ret;
1667
1668 ret = trace_call_bpf(call, ctx: regs);
1669
1670 /*
1671 * We need to check and see if we modified the pc of the
1672 * pt_regs, and if so return 1 so that we don't do the
1673 * single stepping.
1674 */
1675 if (orig_ip != instruction_pointer(regs))
1676 return 1;
1677 if (!ret)
1678 return 0;
1679 }
1680
1681 head = this_cpu_ptr(call->perf_events);
1682 if (hlist_empty(h: head))
1683 return 0;
1684
1685 dsize = __get_data_size(tp: &tk->tp, regs, NULL);
1686 __size = sizeof(*entry) + tk->tp.size + dsize;
1687 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1688 size -= sizeof(u32);
1689
1690 entry = perf_trace_buf_alloc(size, NULL, rctxp: &rctx);
1691 if (!entry)
1692 return 0;
1693
1694 entry->ip = (unsigned long)tk->rp.kp.addr;
1695 memset(&entry[1], 0, dsize);
1696 store_trace_args(data: &entry[1], tp: &tk->tp, rec: regs, NULL, header_size: sizeof(*entry), maxlen: dsize);
1697 perf_trace_buf_submit(raw_data: entry, size, rctx, type: call->event.type, count: 1, regs,
1698 head, NULL);
1699 return 0;
1700}
1701NOKPROBE_SYMBOL(kprobe_perf_func);
1702
1703/* Kretprobe profile handler */
1704static void
1705kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1706 struct pt_regs *regs)
1707{
1708 struct trace_event_call *call = trace_probe_event_call(tp: &tk->tp);
1709 struct kretprobe_trace_entry_head *entry;
1710 struct hlist_head *head;
1711 int size, __size, dsize;
1712 int rctx;
1713
1714 if (bpf_prog_array_valid(call) && !trace_call_bpf(call, ctx: regs))
1715 return;
1716
1717 head = this_cpu_ptr(call->perf_events);
1718 if (hlist_empty(h: head))
1719 return;
1720
1721 dsize = __get_data_size(tp: &tk->tp, regs, edata: ri->data);
1722 __size = sizeof(*entry) + tk->tp.size + dsize;
1723 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1724 size -= sizeof(u32);
1725
1726 entry = perf_trace_buf_alloc(size, NULL, rctxp: &rctx);
1727 if (!entry)
1728 return;
1729
1730 entry->func = (unsigned long)tk->rp.kp.addr;
1731 entry->ret_ip = get_kretprobe_retaddr(ri);
1732 store_trace_args(data: &entry[1], tp: &tk->tp, rec: regs, edata: ri->data, header_size: sizeof(*entry), maxlen: dsize);
1733 perf_trace_buf_submit(raw_data: entry, size, rctx, type: call->event.type, count: 1, regs,
1734 head, NULL);
1735}
1736NOKPROBE_SYMBOL(kretprobe_perf_func);
1737
1738int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type,
1739 const char **symbol, u64 *probe_offset,
1740 u64 *probe_addr, unsigned long *missed,
1741 bool perf_type_tracepoint)
1742{
1743 const char *pevent = trace_event_name(call: event->tp_event);
1744 const char *group = event->tp_event->class->system;
1745 struct trace_kprobe *tk;
1746
1747 if (perf_type_tracepoint)
1748 tk = find_trace_kprobe(event: pevent, group);
1749 else
1750 tk = trace_kprobe_primary_from_call(call: event->tp_event);
1751 if (!tk)
1752 return -EINVAL;
1753
1754 *fd_type = trace_kprobe_is_return(tk) ? BPF_FD_TYPE_KRETPROBE
1755 : BPF_FD_TYPE_KPROBE;
1756 *probe_offset = tk->rp.kp.offset;
1757 *probe_addr = kallsyms_show_value(current_cred()) ?
1758 (unsigned long)tk->rp.kp.addr : 0;
1759 *symbol = tk->symbol;
1760 if (missed)
1761 *missed = trace_kprobe_missed(tk);
1762 return 0;
1763}
1764#endif /* CONFIG_PERF_EVENTS */
1765
1766/*
1767 * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex.
1768 *
1769 * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe
1770 * lockless, but we can't race with this __init function.
1771 */
1772static int kprobe_register(struct trace_event_call *event,
1773 enum trace_reg type, void *data)
1774{
1775 struct trace_event_file *file = data;
1776
1777 switch (type) {
1778 case TRACE_REG_REGISTER:
1779 return enable_trace_kprobe(call: event, file);
1780 case TRACE_REG_UNREGISTER:
1781 return disable_trace_kprobe(call: event, file);
1782
1783#ifdef CONFIG_PERF_EVENTS
1784 case TRACE_REG_PERF_REGISTER:
1785 return enable_trace_kprobe(call: event, NULL);
1786 case TRACE_REG_PERF_UNREGISTER:
1787 return disable_trace_kprobe(call: event, NULL);
1788 case TRACE_REG_PERF_OPEN:
1789 case TRACE_REG_PERF_CLOSE:
1790 case TRACE_REG_PERF_ADD:
1791 case TRACE_REG_PERF_DEL:
1792 return 0;
1793#endif
1794 }
1795 return 0;
1796}
1797
1798static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1799{
1800 struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp);
1801 int ret = 0;
1802
1803 raw_cpu_inc(*tk->nhit);
1804
1805 if (trace_probe_test_flag(tp: &tk->tp, TP_FLAG_TRACE))
1806 kprobe_trace_func(tk, regs);
1807#ifdef CONFIG_PERF_EVENTS
1808 if (trace_probe_test_flag(tp: &tk->tp, TP_FLAG_PROFILE))
1809 ret = kprobe_perf_func(tk, regs);
1810#endif
1811 return ret;
1812}
1813NOKPROBE_SYMBOL(kprobe_dispatcher);
1814
1815static int
1816kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1817{
1818 struct kretprobe *rp = get_kretprobe(ri);
1819 struct trace_kprobe *tk;
1820
1821 /*
1822 * There is a small chance that get_kretprobe(ri) returns NULL when
1823 * the kretprobe is unregister on another CPU between kretprobe's
1824 * trampoline_handler and this function.
1825 */
1826 if (unlikely(!rp))
1827 return 0;
1828
1829 tk = container_of(rp, struct trace_kprobe, rp);
1830 raw_cpu_inc(*tk->nhit);
1831
1832 if (trace_probe_test_flag(tp: &tk->tp, TP_FLAG_TRACE))
1833 kretprobe_trace_func(tk, ri, regs);
1834#ifdef CONFIG_PERF_EVENTS
1835 if (trace_probe_test_flag(tp: &tk->tp, TP_FLAG_PROFILE))
1836 kretprobe_perf_func(tk, ri, regs);
1837#endif
1838 return 0; /* We don't tweak kernel, so just return 0 */
1839}
1840NOKPROBE_SYMBOL(kretprobe_dispatcher);
1841
1842static struct trace_event_functions kretprobe_funcs = {
1843 .trace = print_kretprobe_event
1844};
1845
1846static struct trace_event_functions kprobe_funcs = {
1847 .trace = print_kprobe_event
1848};
1849
1850static struct trace_event_fields kretprobe_fields_array[] = {
1851 { .type = TRACE_FUNCTION_TYPE,
1852 .define_fields = kretprobe_event_define_fields },
1853 {}
1854};
1855
1856static struct trace_event_fields kprobe_fields_array[] = {
1857 { .type = TRACE_FUNCTION_TYPE,
1858 .define_fields = kprobe_event_define_fields },
1859 {}
1860};
1861
1862static inline void init_trace_event_call(struct trace_kprobe *tk)
1863{
1864 struct trace_event_call *call = trace_probe_event_call(tp: &tk->tp);
1865
1866 if (trace_kprobe_is_return(tk)) {
1867 call->event.funcs = &kretprobe_funcs;
1868 call->class->fields_array = kretprobe_fields_array;
1869 } else {
1870 call->event.funcs = &kprobe_funcs;
1871 call->class->fields_array = kprobe_fields_array;
1872 }
1873
1874 call->flags = TRACE_EVENT_FL_KPROBE;
1875 call->class->reg = kprobe_register;
1876}
1877
1878static int register_kprobe_event(struct trace_kprobe *tk)
1879{
1880 init_trace_event_call(tk);
1881
1882 return trace_probe_register_event_call(tp: &tk->tp);
1883}
1884
1885static int unregister_kprobe_event(struct trace_kprobe *tk)
1886{
1887 return trace_probe_unregister_event_call(tp: &tk->tp);
1888}
1889
1890#ifdef CONFIG_PERF_EVENTS
1891
1892/* create a trace_kprobe, but don't add it to global lists */
1893struct trace_event_call *
1894create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
1895 bool is_return)
1896{
1897 enum probe_print_type ptype;
1898 struct trace_kprobe *tk __free(free_trace_kprobe) = NULL;
1899 int ret;
1900 char *event;
1901
1902 if (func) {
1903 ret = validate_probe_symbol(symbol: func);
1904 if (ret)
1905 return ERR_PTR(error: ret);
1906 }
1907
1908 /*
1909 * local trace_kprobes are not added to dyn_event, so they are never
1910 * searched in find_trace_kprobe(). Therefore, there is no concern of
1911 * duplicated name here.
1912 */
1913 event = func ? func : "DUMMY_EVENT";
1914
1915 tk = alloc_trace_kprobe(KPROBE_EVENT_SYSTEM, event, addr: (void *)addr, symbol: func,
1916 offs, maxactive: 0 /* maxactive */, nargs: 0 /* nargs */,
1917 is_return);
1918
1919 if (IS_ERR(ptr: tk)) {
1920 pr_info("Failed to allocate trace_probe.(%d)\n",
1921 (int)PTR_ERR(tk));
1922 return ERR_CAST(ptr: tk);
1923 }
1924
1925 init_trace_event_call(tk);
1926
1927 ptype = trace_kprobe_is_return(tk) ?
1928 PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
1929 if (traceprobe_set_print_fmt(tp: &tk->tp, ptype) < 0)
1930 return ERR_PTR(error: -ENOMEM);
1931
1932 ret = __register_trace_kprobe(tk);
1933 if (ret < 0)
1934 return ERR_PTR(error: ret);
1935
1936 return trace_probe_event_call(tp: &(no_free_ptr(tk)->tp));
1937}
1938
1939void destroy_local_trace_kprobe(struct trace_event_call *event_call)
1940{
1941 struct trace_kprobe *tk;
1942
1943 tk = trace_kprobe_primary_from_call(call: event_call);
1944 if (unlikely(!tk))
1945 return;
1946
1947 if (trace_probe_is_enabled(tp: &tk->tp)) {
1948 WARN_ON(1);
1949 return;
1950 }
1951
1952 __unregister_trace_kprobe(tk);
1953
1954 free_trace_kprobe(tk);
1955}
1956#endif /* CONFIG_PERF_EVENTS */
1957
1958static __init void enable_boot_kprobe_events(void)
1959{
1960 struct trace_array *tr = top_trace_array();
1961 struct trace_event_file *file;
1962 struct trace_kprobe *tk;
1963 struct dyn_event *pos;
1964
1965 guard(mutex)(T: &event_mutex);
1966 for_each_trace_kprobe(tk, pos) {
1967 list_for_each_entry(file, &tr->events, list)
1968 if (file->event_call == trace_probe_event_call(tp: &tk->tp))
1969 trace_event_enable_disable(file, enable: 1, soft_disable: 0);
1970 }
1971}
1972
1973static __init void setup_boot_kprobe_events(void)
1974{
1975 char *p, *cmd = kprobe_boot_events_buf;
1976 int ret;
1977
1978 strreplace(str: kprobe_boot_events_buf, old: ',', new: ' ');
1979
1980 while (cmd && *cmd != '\0') {
1981 p = strchr(cmd, ';');
1982 if (p)
1983 *p++ = '\0';
1984
1985 ret = create_or_delete_trace_kprobe(raw_command: cmd);
1986 if (ret)
1987 pr_warn("Failed to add event(%d): %s\n", ret, cmd);
1988
1989 cmd = p;
1990 }
1991
1992 enable_boot_kprobe_events();
1993}
1994
1995/*
1996 * Register dynevent at core_initcall. This allows kernel to setup kprobe
1997 * events in postcore_initcall without tracefs.
1998 */
1999static __init int init_kprobe_trace_early(void)
2000{
2001 int ret;
2002
2003 ret = dyn_event_register(ops: &trace_kprobe_ops);
2004 if (ret)
2005 return ret;
2006
2007 if (trace_kprobe_register_module_notifier())
2008 return -EINVAL;
2009
2010 return 0;
2011}
2012core_initcall(init_kprobe_trace_early);
2013
2014/* Make a tracefs interface for controlling probe points */
2015static __init int init_kprobe_trace(void)
2016{
2017 int ret;
2018
2019 ret = tracing_init_dentry();
2020 if (ret)
2021 return 0;
2022
2023 /* Event list interface */
2024 trace_create_file(name: "kprobe_events", TRACE_MODE_WRITE,
2025 NULL, NULL, fops: &kprobe_events_ops);
2026
2027 /* Profile interface */
2028 trace_create_file(name: "kprobe_profile", TRACE_MODE_READ,
2029 NULL, NULL, fops: &kprobe_profile_ops);
2030
2031 setup_boot_kprobe_events();
2032
2033 return 0;
2034}
2035fs_initcall(init_kprobe_trace);
2036
2037
2038#ifdef CONFIG_FTRACE_STARTUP_TEST
2039static __init struct trace_event_file *
2040find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr)
2041{
2042 struct trace_event_file *file;
2043
2044 list_for_each_entry(file, &tr->events, list)
2045 if (file->event_call == trace_probe_event_call(tp: &tk->tp))
2046 return file;
2047
2048 return NULL;
2049}
2050
2051/*
2052 * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this
2053 * stage, we can do this lockless.
2054 */
2055static __init int kprobe_trace_self_tests_init(void)
2056{
2057 int ret, warn = 0;
2058 int (*target)(int, int, int, int, int, int);
2059 struct trace_kprobe *tk;
2060 struct trace_event_file *file;
2061
2062 if (tracing_is_disabled())
2063 return -ENODEV;
2064
2065 if (tracing_selftest_disabled)
2066 return 0;
2067
2068 target = kprobe_trace_selftest_target;
2069
2070 pr_info("Testing kprobe tracing: ");
2071
2072 ret = create_or_delete_trace_kprobe(raw_command: "p:testprobe kprobe_trace_selftest_target $stack $stack0 +0($stack)");
2073 if (WARN_ONCE(ret, "error on probing function entry.")) {
2074 warn++;
2075 } else {
2076 /* Enable trace point */
2077 tk = find_trace_kprobe(event: "testprobe", KPROBE_EVENT_SYSTEM);
2078 if (WARN_ONCE(tk == NULL, "error on probing function entry.")) {
2079 warn++;
2080 } else {
2081 file = find_trace_probe_file(tk, tr: top_trace_array());
2082 if (WARN_ONCE(file == NULL, "error on getting probe file.")) {
2083 warn++;
2084 } else
2085 enable_trace_kprobe(
2086 call: trace_probe_event_call(tp: &tk->tp), file);
2087 }
2088 }
2089
2090 ret = create_or_delete_trace_kprobe(raw_command: "r:testprobe2 kprobe_trace_selftest_target $retval");
2091 if (WARN_ONCE(ret, "error on probing function return.")) {
2092 warn++;
2093 } else {
2094 /* Enable trace point */
2095 tk = find_trace_kprobe(event: "testprobe2", KPROBE_EVENT_SYSTEM);
2096 if (WARN_ONCE(tk == NULL, "error on getting 2nd new probe.")) {
2097 warn++;
2098 } else {
2099 file = find_trace_probe_file(tk, tr: top_trace_array());
2100 if (WARN_ONCE(file == NULL, "error on getting probe file.")) {
2101 warn++;
2102 } else
2103 enable_trace_kprobe(
2104 call: trace_probe_event_call(tp: &tk->tp), file);
2105 }
2106 }
2107
2108 if (warn)
2109 goto end;
2110
2111 ret = target(1, 2, 3, 4, 5, 6);
2112
2113 /*
2114 * Not expecting an error here, the check is only to prevent the
2115 * optimizer from removing the call to target() as otherwise there
2116 * are no side-effects and the call is never performed.
2117 */
2118 if (ret != 21)
2119 warn++;
2120
2121 /* Disable trace points before removing it */
2122 tk = find_trace_kprobe(event: "testprobe", KPROBE_EVENT_SYSTEM);
2123 if (WARN_ONCE(tk == NULL, "error on getting test probe.")) {
2124 warn++;
2125 } else {
2126 if (WARN_ONCE(trace_kprobe_nhit(tk) != 1,
2127 "incorrect number of testprobe hits."))
2128 warn++;
2129
2130 file = find_trace_probe_file(tk, tr: top_trace_array());
2131 if (WARN_ONCE(file == NULL, "error on getting probe file.")) {
2132 warn++;
2133 } else
2134 disable_trace_kprobe(
2135 call: trace_probe_event_call(tp: &tk->tp), file);
2136 }
2137
2138 tk = find_trace_kprobe(event: "testprobe2", KPROBE_EVENT_SYSTEM);
2139 if (WARN_ONCE(tk == NULL, "error on getting 2nd test probe.")) {
2140 warn++;
2141 } else {
2142 if (WARN_ONCE(trace_kprobe_nhit(tk) != 1,
2143 "incorrect number of testprobe2 hits."))
2144 warn++;
2145
2146 file = find_trace_probe_file(tk, tr: top_trace_array());
2147 if (WARN_ONCE(file == NULL, "error on getting probe file.")) {
2148 warn++;
2149 } else
2150 disable_trace_kprobe(
2151 call: trace_probe_event_call(tp: &tk->tp), file);
2152 }
2153
2154 ret = create_or_delete_trace_kprobe(raw_command: "-:testprobe");
2155 if (WARN_ONCE(ret, "error on deleting a probe."))
2156 warn++;
2157
2158 ret = create_or_delete_trace_kprobe(raw_command: "-:testprobe2");
2159 if (WARN_ONCE(ret, "error on deleting a probe."))
2160 warn++;
2161
2162
2163end:
2164 /*
2165 * Wait for the optimizer work to finish. Otherwise it might fiddle
2166 * with probes in already freed __init text.
2167 */
2168 wait_for_kprobe_optimizer();
2169 if (warn)
2170 pr_cont("NG: Some tests are failed. Please check them.\n");
2171 else
2172 pr_cont("OK\n");
2173 return 0;
2174}
2175
2176late_initcall(kprobe_trace_self_tests_init);
2177
2178#endif
2179

source code of linux/kernel/trace/trace_kprobe.c