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 16 static sigjmp_buf jmpbuf; 17 static const struct perf_hook_desc *current_perf_hook; 18 19 void 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 35 void perf_hooks__recover(void) 36 { 37 if (current_perf_hook) 38 siglongjmp(jmpbuf, 1); 39 } 40 41 #define PERF_HOOK(name) \ 42 perf_hook_func_t __perf_hook_func_##name = NULL; \ 43 struct 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 53 static struct perf_hook_desc *perf_hooks[] = { 54 #include "perf-hooks-list.h" 55 }; 56 #undef PERF_HOOK 57 58 int 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 77 perf_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 } 89