91 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			91 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0
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| /*
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|  * perf_hooks.c
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|  *
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|  * Copyright (C) 2016 Wang Nan <wangnan0@huawei.com>
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|  * Copyright (C) 2016 Huawei Inc.
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|  */
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| 
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| #include <errno.h>
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| #include <stdlib.h>
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| #include <string.h>
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| #include <setjmp.h>
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| #include <linux/err.h>
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| #include <linux/kernel.h>
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| #include "util/debug.h"
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| #include "util/perf-hooks.h"
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| 
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| static sigjmp_buf jmpbuf;
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| static const struct perf_hook_desc *current_perf_hook;
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| 
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| void perf_hooks__invoke(const struct perf_hook_desc *desc)
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| {
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| 	if (!(desc && desc->p_hook_func && *desc->p_hook_func))
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| 		return;
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| 
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| 	if (sigsetjmp(jmpbuf, 1)) {
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| 		pr_warning("Fatal error (SEGFAULT) in perf hook '%s'\n",
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| 			   desc->hook_name);
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| 		*(current_perf_hook->p_hook_func) = NULL;
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| 	} else {
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| 		current_perf_hook = desc;
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| 		(**desc->p_hook_func)(desc->hook_ctx);
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| 	}
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| 	current_perf_hook = NULL;
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| }
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| 
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| void perf_hooks__recover(void)
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| {
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| 	if (current_perf_hook)
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| 		siglongjmp(jmpbuf, 1);
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| }
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| 
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| #define PERF_HOOK(name)					\
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| perf_hook_func_t __perf_hook_func_##name = NULL;	\
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| struct perf_hook_desc __perf_hook_desc_##name =		\
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| 	{.hook_name = #name,				\
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| 	 .p_hook_func = &__perf_hook_func_##name,	\
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| 	 .hook_ctx = NULL};
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| #include "perf-hooks-list.h"
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| #undef PERF_HOOK
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| 
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| #define PERF_HOOK(name)		\
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| 	&__perf_hook_desc_##name,
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| 
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| static struct perf_hook_desc *perf_hooks[] = {
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| #include "perf-hooks-list.h"
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| };
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| #undef PERF_HOOK
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| 
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| int perf_hooks__set_hook(const char *hook_name,
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| 			 perf_hook_func_t hook_func,
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| 			 void *hook_ctx)
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| {
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| 	unsigned int i;
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| 
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| 	for (i = 0; i < ARRAY_SIZE(perf_hooks); i++) {
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| 		if (strcmp(hook_name, perf_hooks[i]->hook_name) != 0)
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| 			continue;
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| 
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| 		if (*(perf_hooks[i]->p_hook_func))
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| 			pr_warning("Overwrite existing hook: %s\n", hook_name);
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| 		*(perf_hooks[i]->p_hook_func) = hook_func;
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| 		perf_hooks[i]->hook_ctx = hook_ctx;
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| 		return 0;
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| 	}
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| 	return -ENOENT;
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| }
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| 
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| perf_hook_func_t perf_hooks__get_hook(const char *hook_name)
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| {
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| 	unsigned int i;
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| 
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| 	for (i = 0; i < ARRAY_SIZE(perf_hooks); i++) {
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| 		if (strcmp(hook_name, perf_hooks[i]->hook_name) != 0)
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| 			continue;
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| 
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| 		return *(perf_hooks[i]->p_hook_func);
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| 	}
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| 	return ERR_PTR(-ENOENT);
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| }
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