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			59 lines
		
	
	
		
			1.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			59 lines
		
	
	
		
			1.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* ELF symbol resolve functions for VDSO objects.
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|    Copyright (C) 2005-2025 Free Software Foundation, Inc.
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|    This file is part of the GNU C Library.
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| 
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|    The GNU C Library is free software; you can redistribute it and/or
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|    modify it under the terms of the GNU Lesser General Public
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|    License as published by the Free Software Foundation; either
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|    version 2.1 of the License, or (at your option) any later version.
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| 
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|    The GNU C Library is distributed in the hope that it will be useful,
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|    but WITHOUT ANY WARRANTY; without even the implied warranty of
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|    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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|    Lesser General Public License for more details.
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| 
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|    You should have received a copy of the GNU Lesser General Public
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|    License along with the GNU C Library; if not, see
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|    <https://www.gnu.org/licenses/>.  */
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| 
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| #ifndef _DL_VDSO_H
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| #define _DL_VDSO_H	1
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| 
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| #include <ldsodefs.h>
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| #include <dl-hash.h>
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| 
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| /* If the architecture support vDSO it should define which is the expected
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|    kernel version and hash value through both VDSO_NAME and VDSO_HASH
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|    (usually defined at architecture sysdep.h).  */
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| 
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| #ifndef VDSO_NAME
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| # define VDSO_NAME "LINUX_0.0"
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| #endif
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| #ifndef VDSO_HASH
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| # define VDSO_HASH 0
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| #endif
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| 
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| /* Functions for resolving symbols in the VDSO link map.  */
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| static inline void *
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| dl_vdso_vsym (const char *name)
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| {
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|   struct link_map *map = GLRO (dl_sysinfo_map);
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|   if (map == NULL)
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|     return NULL;
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| 
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|   /* Use a WEAK REF so we don't error out if the symbol is not found.  */
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|   ElfW (Sym) wsym = { 0 };
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|   wsym.st_info = (unsigned char) ELFW (ST_INFO (STB_WEAK, STT_NOTYPE));
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| 
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|   const struct r_found_version rfv = { VDSO_NAME, VDSO_HASH, 1, NULL };
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| 
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|   /* Search the scope of the vdso map.  */
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|   const ElfW (Sym) *ref = &wsym;
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|   lookup_t result = GLRO (dl_lookup_symbol_x) (name, map, &ref,
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| 					       map->l_local_scope,
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| 					       &rfv, 0, 0, NULL);
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|   return ref != NULL ? DL_SYMBOL_ADDRESS (result, ref) : NULL;
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| }
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| 
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| #endif /* dl-vdso.h */
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