1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * perf_hooks.c
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright (C) 2016 Wang Nan <wangnan0@huawei.com>
6*4882a593Smuzhiyun * Copyright (C) 2016 Huawei Inc.
7*4882a593Smuzhiyun */
8*4882a593Smuzhiyun
9*4882a593Smuzhiyun #include <errno.h>
10*4882a593Smuzhiyun #include <stdlib.h>
11*4882a593Smuzhiyun #include <string.h>
12*4882a593Smuzhiyun #include <setjmp.h>
13*4882a593Smuzhiyun #include <linux/err.h>
14*4882a593Smuzhiyun #include <linux/kernel.h>
15*4882a593Smuzhiyun #include "util/debug.h"
16*4882a593Smuzhiyun #include "util/perf-hooks.h"
17*4882a593Smuzhiyun
18*4882a593Smuzhiyun static sigjmp_buf jmpbuf;
19*4882a593Smuzhiyun static const struct perf_hook_desc *current_perf_hook;
20*4882a593Smuzhiyun
perf_hooks__invoke(const struct perf_hook_desc * desc)21*4882a593Smuzhiyun void perf_hooks__invoke(const struct perf_hook_desc *desc)
22*4882a593Smuzhiyun {
23*4882a593Smuzhiyun if (!(desc && desc->p_hook_func && *desc->p_hook_func))
24*4882a593Smuzhiyun return;
25*4882a593Smuzhiyun
26*4882a593Smuzhiyun if (sigsetjmp(jmpbuf, 1)) {
27*4882a593Smuzhiyun pr_warning("Fatal error (SEGFAULT) in perf hook '%s'\n",
28*4882a593Smuzhiyun desc->hook_name);
29*4882a593Smuzhiyun *(current_perf_hook->p_hook_func) = NULL;
30*4882a593Smuzhiyun } else {
31*4882a593Smuzhiyun current_perf_hook = desc;
32*4882a593Smuzhiyun (**desc->p_hook_func)(desc->hook_ctx);
33*4882a593Smuzhiyun }
34*4882a593Smuzhiyun current_perf_hook = NULL;
35*4882a593Smuzhiyun }
36*4882a593Smuzhiyun
perf_hooks__recover(void)37*4882a593Smuzhiyun void perf_hooks__recover(void)
38*4882a593Smuzhiyun {
39*4882a593Smuzhiyun if (current_perf_hook)
40*4882a593Smuzhiyun siglongjmp(jmpbuf, 1);
41*4882a593Smuzhiyun }
42*4882a593Smuzhiyun
43*4882a593Smuzhiyun #define PERF_HOOK(name) \
44*4882a593Smuzhiyun perf_hook_func_t __perf_hook_func_##name = NULL; \
45*4882a593Smuzhiyun struct perf_hook_desc __perf_hook_desc_##name = \
46*4882a593Smuzhiyun {.hook_name = #name, \
47*4882a593Smuzhiyun .p_hook_func = &__perf_hook_func_##name, \
48*4882a593Smuzhiyun .hook_ctx = NULL};
49*4882a593Smuzhiyun #include "perf-hooks-list.h"
50*4882a593Smuzhiyun #undef PERF_HOOK
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun #define PERF_HOOK(name) \
53*4882a593Smuzhiyun &__perf_hook_desc_##name,
54*4882a593Smuzhiyun
55*4882a593Smuzhiyun static struct perf_hook_desc *perf_hooks[] = {
56*4882a593Smuzhiyun #include "perf-hooks-list.h"
57*4882a593Smuzhiyun };
58*4882a593Smuzhiyun #undef PERF_HOOK
59*4882a593Smuzhiyun
perf_hooks__set_hook(const char * hook_name,perf_hook_func_t hook_func,void * hook_ctx)60*4882a593Smuzhiyun int perf_hooks__set_hook(const char *hook_name,
61*4882a593Smuzhiyun perf_hook_func_t hook_func,
62*4882a593Smuzhiyun void *hook_ctx)
63*4882a593Smuzhiyun {
64*4882a593Smuzhiyun unsigned int i;
65*4882a593Smuzhiyun
66*4882a593Smuzhiyun for (i = 0; i < ARRAY_SIZE(perf_hooks); i++) {
67*4882a593Smuzhiyun if (strcmp(hook_name, perf_hooks[i]->hook_name) != 0)
68*4882a593Smuzhiyun continue;
69*4882a593Smuzhiyun
70*4882a593Smuzhiyun if (*(perf_hooks[i]->p_hook_func))
71*4882a593Smuzhiyun pr_warning("Overwrite existing hook: %s\n", hook_name);
72*4882a593Smuzhiyun *(perf_hooks[i]->p_hook_func) = hook_func;
73*4882a593Smuzhiyun perf_hooks[i]->hook_ctx = hook_ctx;
74*4882a593Smuzhiyun return 0;
75*4882a593Smuzhiyun }
76*4882a593Smuzhiyun return -ENOENT;
77*4882a593Smuzhiyun }
78*4882a593Smuzhiyun
perf_hooks__get_hook(const char * hook_name)79*4882a593Smuzhiyun perf_hook_func_t perf_hooks__get_hook(const char *hook_name)
80*4882a593Smuzhiyun {
81*4882a593Smuzhiyun unsigned int i;
82*4882a593Smuzhiyun
83*4882a593Smuzhiyun for (i = 0; i < ARRAY_SIZE(perf_hooks); i++) {
84*4882a593Smuzhiyun if (strcmp(hook_name, perf_hooks[i]->hook_name) != 0)
85*4882a593Smuzhiyun continue;
86*4882a593Smuzhiyun
87*4882a593Smuzhiyun return *(perf_hooks[i]->p_hook_func);
88*4882a593Smuzhiyun }
89*4882a593Smuzhiyun return ERR_PTR(-ENOENT);
90*4882a593Smuzhiyun }
91