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			63 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			63 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* Pointer guard implementation.  Alpha version.
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|    Copyright (C) 2006-2025 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 POINTER_GUARD_H
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| #define POINTER_GUARD_H
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| 
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| /* Pointer mangling support.  Note that tls access is slow enough that
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|    we don't deoptimize things by placing the pointer check value there.  */
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| 
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| #ifdef __ASSEMBLER__
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| # if IS_IN (rtld)
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| #  define PTR_MANGLE(dst, src, tmp)                             \
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|         ldah    tmp, __pointer_chk_guard_local($29) !gprelhigh; \
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|         ldq     tmp, __pointer_chk_guard_local(tmp) !gprellow;  \
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|         xor     src, tmp, dst
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| #  define PTR_MANGLE2(dst, src, tmp)                            \
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|         xor     src, tmp, dst
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| # elif defined SHARED
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| #  define PTR_MANGLE(dst, src, tmp)             \
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|         ldq     tmp, __pointer_chk_guard;       \
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|         xor     src, tmp, dst
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| # else
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| #  define PTR_MANGLE(dst, src, tmp)             \
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|         ldq     tmp, __pointer_chk_guard_local; \
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|         xor     src, tmp, dst
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| # endif
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| # define PTR_MANGLE2(dst, src, tmp)             \
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|         xor     src, tmp, dst
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| # define PTR_DEMANGLE(dst, tmp)   PTR_MANGLE(dst, dst, tmp)
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| # define PTR_DEMANGLE2(dst, tmp)  PTR_MANGLE2(dst, dst, tmp)
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| #else
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| # include <stdint.h>
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| # if (IS_IN (rtld) \
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|       || (!defined SHARED && (IS_IN (libc) \
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|                               || IS_IN (libpthread))))
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| extern uintptr_t __pointer_chk_guard_local attribute_relro attribute_hidden;
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| #  define PTR_MANGLE(var) \
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|         (var) = (__typeof (var)) ((uintptr_t) (var) ^ __pointer_chk_guard_local)
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| # else
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| extern uintptr_t __pointer_chk_guard attribute_relro;
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| #  define PTR_MANGLE(var) \
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|         (var) = (__typeof(var)) ((uintptr_t) (var) ^ __pointer_chk_guard)
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| # endif
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| # define PTR_DEMANGLE(var)  PTR_MANGLE(var)
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| #endif /* ASSEMBLER */
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| 
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| #endif /* POINTER_GUARD_H */
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