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/util.h" 16 #include "util/debug.h" 17 #include "util/perf-hooks.h" 18 19 static sigjmp_buf jmpbuf; 20 static const struct perf_hook_desc *current_perf_hook; 21 22 void perf_hooks__invoke(const struct perf_hook_desc *desc) 23 { 24 if (!(desc && desc->p_hook_func && *desc->p_hook_func)) 25 return; 26 27 if (sigsetjmp(jmpbuf, 1)) { 28 pr_warning("Fatal error (SEGFAULT) in perf hook '%s'\n", 29 desc->hook_name); 30 *(current_perf_hook->p_hook_func) = NULL; 31 } else { 32 current_perf_hook = desc; 33 (**desc->p_hook_func)(desc->hook_ctx); 34 } 35 current_perf_hook = NULL; 36 } 37 38 void perf_hooks__recover(void) 39 { 40 if (current_perf_hook) 41 siglongjmp(jmpbuf, 1); 42 } 43 44 #define PERF_HOOK(name) \ 45 perf_hook_func_t __perf_hook_func_##name = NULL; \ 46 struct perf_hook_desc __perf_hook_desc_##name = \ 47 {.hook_name = #name, \ 48 .p_hook_func = &__perf_hook_func_##name, \ 49 .hook_ctx = NULL}; 50 #include "perf-hooks-list.h" 51 #undef PERF_HOOK 52 53 #define PERF_HOOK(name) \ 54 &__perf_hook_desc_##name, 55 56 static struct perf_hook_desc *perf_hooks[] = { 57 #include "perf-hooks-list.h" 58 }; 59 #undef PERF_HOOK 60 61 int perf_hooks__set_hook(const char *hook_name, 62 perf_hook_func_t hook_func, 63 void *hook_ctx) 64 { 65 unsigned int i; 66 67 for (i = 0; i < ARRAY_SIZE(perf_hooks); i++) { 68 if (strcmp(hook_name, perf_hooks[i]->hook_name) != 0) 69 continue; 70 71 if (*(perf_hooks[i]->p_hook_func)) 72 pr_warning("Overwrite existing hook: %s\n", hook_name); 73 *(perf_hooks[i]->p_hook_func) = hook_func; 74 perf_hooks[i]->hook_ctx = hook_ctx; 75 return 0; 76 } 77 return -ENOENT; 78 } 79 80 perf_hook_func_t perf_hooks__get_hook(const char *hook_name) 81 { 82 unsigned int i; 83 84 for (i = 0; i < ARRAY_SIZE(perf_hooks); i++) { 85 if (strcmp(hook_name, perf_hooks[i]->hook_name) != 0) 86 continue; 87 88 return *(perf_hooks[i]->p_hook_func); 89 } 90 return ERR_PTR(-ENOENT); 91 } 92