1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * perf_hooks.c
 4 *
 5 * Copyright (C) 2016 Wang Nan <wangnan0@huawei.com>
 6 * Copyright (C) 2016 Huawei Inc.
 7 */
 8
 9#include <errno.h>
10#include <stdlib.h>
11#include <setjmp.h>
12#include <linux/err.h>
13#include <linux/kernel.h>
14#include "util/util.h"
15#include "util/debug.h"
16#include "util/perf-hooks.h"
17
18static sigjmp_buf jmpbuf;
19static const struct perf_hook_desc *current_perf_hook;
20
21void perf_hooks__invoke(const struct perf_hook_desc *desc)
22{
23	if (!(desc && desc->p_hook_func && *desc->p_hook_func))
24		return;
25
26	if (sigsetjmp(jmpbuf, 1)) {
27		pr_warning("Fatal error (SEGFAULT) in perf hook '%s'\n",
28			   desc->hook_name);
29		*(current_perf_hook->p_hook_func) = NULL;
30	} else {
31		current_perf_hook = desc;
32		(**desc->p_hook_func)(desc->hook_ctx);
33	}
34	current_perf_hook = NULL;
35}
36
37void perf_hooks__recover(void)
38{
39	if (current_perf_hook)
40		siglongjmp(jmpbuf, 1);
41}
42
43#define PERF_HOOK(name)					\
44perf_hook_func_t __perf_hook_func_##name = NULL;	\
45struct perf_hook_desc __perf_hook_desc_##name =		\
46	{.hook_name = #name,				\
47	 .p_hook_func = &__perf_hook_func_##name,	\
48	 .hook_ctx = NULL};
49#include "perf-hooks-list.h"
50#undef PERF_HOOK
51
52#define PERF_HOOK(name)		\
53	&__perf_hook_desc_##name,
54
55static struct perf_hook_desc *perf_hooks[] = {
56#include "perf-hooks-list.h"
57};
58#undef PERF_HOOK
59
60int perf_hooks__set_hook(const char *hook_name,
61			 perf_hook_func_t hook_func,
62			 void *hook_ctx)
63{
64	unsigned int i;
65
66	for (i = 0; i < ARRAY_SIZE(perf_hooks); i++) {
67		if (strcmp(hook_name, perf_hooks[i]->hook_name) != 0)
68			continue;
69
70		if (*(perf_hooks[i]->p_hook_func))
71			pr_warning("Overwrite existing hook: %s\n", hook_name);
72		*(perf_hooks[i]->p_hook_func) = hook_func;
73		perf_hooks[i]->hook_ctx = hook_ctx;
74		return 0;
75	}
76	return -ENOENT;
77}
78
79perf_hook_func_t perf_hooks__get_hook(const char *hook_name)
80{
81	unsigned int i;
82
83	for (i = 0; i < ARRAY_SIZE(perf_hooks); i++) {
84		if (strcmp(hook_name, perf_hooks[i]->hook_name) != 0)
85			continue;
86
87		return *(perf_hooks[i]->p_hook_func);
88	}
89	return ERR_PTR(-ENOENT);
90}

 
 1/*
 2 * perf_hooks.c
 3 *
 4 * Copyright (C) 2016 Wang Nan <wangnan0@huawei.com>
 5 * Copyright (C) 2016 Huawei Inc.
 6 */
 7
 8#include <errno.h>
 9#include <stdlib.h>
10#include <setjmp.h>
11#include <linux/err.h>
 
12#include "util/util.h"
13#include "util/debug.h"
14#include "util/perf-hooks.h"
15
16static sigjmp_buf jmpbuf;
17static const struct perf_hook_desc *current_perf_hook;
18
19void perf_hooks__invoke(const struct perf_hook_desc *desc)
20{
21	if (!(desc && desc->p_hook_func && *desc->p_hook_func))
22		return;
23
24	if (sigsetjmp(jmpbuf, 1)) {
25		pr_warning("Fatal error (SEGFAULT) in perf hook '%s'\n",
26			   desc->hook_name);
27		*(current_perf_hook->p_hook_func) = NULL;
28	} else {
29		current_perf_hook = desc;
30		(**desc->p_hook_func)(desc->hook_ctx);
31	}
32	current_perf_hook = NULL;
33}
34
35void perf_hooks__recover(void)
36{
37	if (current_perf_hook)
38		siglongjmp(jmpbuf, 1);
39}
40
41#define PERF_HOOK(name)					\
42perf_hook_func_t __perf_hook_func_##name = NULL;	\
43struct perf_hook_desc __perf_hook_desc_##name =		\
44	{.hook_name = #name,				\
45	 .p_hook_func = &__perf_hook_func_##name,	\
46	 .hook_ctx = NULL};
47#include "perf-hooks-list.h"
48#undef PERF_HOOK
49
50#define PERF_HOOK(name)		\
51	&__perf_hook_desc_##name,
52
53static struct perf_hook_desc *perf_hooks[] = {
54#include "perf-hooks-list.h"
55};
56#undef PERF_HOOK
57
58int perf_hooks__set_hook(const char *hook_name,
59			 perf_hook_func_t hook_func,
60			 void *hook_ctx)
61{
62	unsigned int i;
63
64	for (i = 0; i < ARRAY_SIZE(perf_hooks); i++) {
65		if (strcmp(hook_name, perf_hooks[i]->hook_name) != 0)
66			continue;
67
68		if (*(perf_hooks[i]->p_hook_func))
69			pr_warning("Overwrite existing hook: %s\n", hook_name);
70		*(perf_hooks[i]->p_hook_func) = hook_func;
71		perf_hooks[i]->hook_ctx = hook_ctx;
72		return 0;
73	}
74	return -ENOENT;
75}
76
77perf_hook_func_t perf_hooks__get_hook(const char *hook_name)
78{
79	unsigned int i;
80
81	for (i = 0; i < ARRAY_SIZE(perf_hooks); i++) {
82		if (strcmp(hook_name, perf_hooks[i]->hook_name) != 0)
83			continue;
84
85		return *(perf_hooks[i]->p_hook_func);
86	}
87	return ERR_PTR(-ENOENT);
88}