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