| 1 | /* Support for GNU properties in ldconfig. x86 version. |
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| 2 | Copyright (C) 2021-2022 Free Software Foundation, Inc. |
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| 3 | This file is part of the GNU C Library. |
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| 4 | |
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| 5 | The GNU C Library is free software; you can redistribute it and/or |
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| 6 | modify it under the terms of the GNU Lesser General Public |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2.1 of the License, or (at your option) any later version. |
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| 9 | |
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| 10 | The GNU C Library is distributed in the hope that it will be useful, |
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | Lesser General Public License for more details. |
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| 14 | |
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| 15 | You should have received a copy of the GNU Lesser General Public |
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| 16 | License along with the GNU C Library; if not, see |
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| 17 | <https://www.gnu.org/licenses/>. */ |
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| 18 | |
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| 19 | #ifndef _ELF_READ_PROP_H |
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| 20 | #define _ELF_READ_PROP_H |
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| 21 | |
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| 22 | #include <dl-cache.h> |
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| 23 | |
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| 24 | /* Called for each property in the NT_GNU_PROPERTY_TYPE_0 note of SEGMENT. |
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| 25 | Return value: |
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| 26 | false: Continue processing the properties. |
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| 27 | true : Stop processing the properties. |
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| 28 | */ |
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| 29 | static inline bool __attribute__ ((always_inline)) |
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| 30 | read_gnu_property (unsigned int *isal_level, uint32_t type, |
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| 31 | uint32_t datasz, void *data) |
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| 32 | { |
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| 33 | /* Property type must be in ascending order. */ |
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| 34 | if (type > GNU_PROPERTY_X86_ISA_1_NEEDED) |
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| 35 | return true; |
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| 36 | |
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| 37 | if (type == GNU_PROPERTY_X86_ISA_1_NEEDED) |
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| 38 | { |
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| 39 | if (datasz == 4) |
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| 40 | { |
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| 41 | /* The size of GNU_PROPERTY_X86_ISA_1_NEEDED must be 4 bytes. |
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| 42 | There is no point to continue if this type is ill-formed. */ |
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| 43 | unsigned int isa_1_needed = *(unsigned int *) data; |
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| 44 | _Static_assert (((sizeof (isa_1_needed) * 8) |
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| 45 | <= (1 << DL_CACHE_HWCAP_ISA_LEVEL_COUNT)), |
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| 46 | "DL_CACHE_HWCAP_ISA_LEVEL_COUNT is too small" ); |
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| 47 | if (isa_1_needed != 0) |
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| 48 | { |
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| 49 | unsigned int level; |
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| 50 | asm ("bsr %1, %0" : "=r" (level) : "g" (isa_1_needed)); |
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| 51 | *isal_level = level; |
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| 52 | } |
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| 53 | } |
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| 54 | return true; |
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| 55 | } |
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| 56 | |
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| 57 | return false; |
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| 58 | } |
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| 59 | |
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| 60 | #endif |
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| 61 | |
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