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1// SPDX-License-Identifier: GPL-2.02/*3 * perf_hooks.c4 *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 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_HOOK51 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_HOOK59 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}91