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efbbd9c33a
Store ISA level in the portion of the unused upper 32 bits of the hwcaps field in cache and the unused pad field in aux cache. ISA level is stored and checked only for shared objects in glibc-hwcaps subdirectories. The shared objects in the default directories aren't checked since there are no fallbacks for these shared objects. Tested on x86-64-v2, x86-64-v3 and x86-64-v4 machines with --disable-hardcoded-path-in-tests and --enable-hardcoded-path-in-tests.
61 lines
1.9 KiB
C
61 lines
1.9 KiB
C
/* Support for GNU properties in ldconfig. x86 version.
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Copyright (C) 2021 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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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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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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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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#ifndef _ELF_READ_PROP_H
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#define _ELF_READ_PROP_H
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#include <dl-cache.h>
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/* Called for each property in the NT_GNU_PROPERTY_TYPE_0 note of SEGMENT.
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Return value:
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false: Continue processing the properties.
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true : Stop processing the properties.
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*/
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static inline bool __attribute__ ((always_inline))
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read_gnu_property (unsigned int *isal_level, uint32_t type,
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uint32_t datasz, void *data)
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{
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/* Property type must be in ascending order. */
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if (type > GNU_PROPERTY_X86_ISA_1_NEEDED)
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return true;
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if (type == GNU_PROPERTY_X86_ISA_1_NEEDED)
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{
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if (datasz == 4)
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{
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/* The size of GNU_PROPERTY_X86_ISA_1_NEEDED must be 4 bytes.
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There is no point to continue if this type is ill-formed. */
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unsigned int isa_1_needed = *(unsigned int *) data;
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_Static_assert (((sizeof (isa_1_needed) * 8)
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<= (1 << DL_CACHE_HWCAP_ISA_LEVEL_COUNT)),
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"DL_CACHE_HWCAP_ISA_LEVEL_COUNT is too small");
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if (isa_1_needed != 0)
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{
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unsigned int level;
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asm ("bsr %1, %0" : "=r" (level) : "g" (isa_1_needed));
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*isal_level = level;
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}
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}
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return true;
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}
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return false;
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}
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#endif
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