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 <string.h> |
12 | #include <setjmp.h> |
13 | #include <linux/err.h> |
14 | #include <linux/kernel.h> |
15 | #include "util/debug.h" |
16 | #include "util/perf-hooks.h" |
17 | |
18 | static sigjmp_buf jmpbuf; |
19 | static const struct perf_hook_desc *current_perf_hook; |
20 | |
21 | void 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 | |
37 | void perf_hooks__recover(void) |
38 | { |
39 | if (current_perf_hook) |
40 | siglongjmp(jmpbuf, 1); |
41 | } |
42 | |
43 | #define PERF_HOOK(name) \ |
44 | perf_hook_func_t __perf_hook_func_##name = NULL; \ |
45 | struct 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 | |
55 | static struct perf_hook_desc *perf_hooks[] = { |
56 | #include "perf-hooks-list.h" |
57 | }; |
58 | #undef PERF_HOOK |
59 | |
60 | int 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 | |
79 | perf_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(error: -ENOENT); |
90 | } |
91 | |