38 lines
1.1 KiB
C
38 lines
1.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
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#ifndef _OBJTOOL_ENDIANNESS_H
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#define _OBJTOOL_ENDIANNESS_H
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#include <linux/kernel.h>
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#include <endian.h>
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#include <objtool/elf.h>
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/*
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* Does a byte swap if target file endianness doesn't match the host, i.e. cross
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* compilation for little endian on big endian and vice versa.
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* To be used for multi-byte values conversion, which are read from / about
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* to be written to a target native endianness ELF file.
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*/
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static inline bool need_bswap(struct elf *elf)
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{
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return (__BYTE_ORDER == __LITTLE_ENDIAN) ^
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(elf->ehdr.e_ident[EI_DATA] == ELFDATA2LSB);
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}
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#define bswap_if_needed(elf, val) \
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({ \
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__typeof__(val) __ret; \
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bool __need_bswap = need_bswap(elf); \
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switch (sizeof(val)) { \
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case 8: \
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__ret = __need_bswap ? bswap_64(val) : (val); break; \
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case 4: \
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__ret = __need_bswap ? bswap_32(val) : (val); break; \
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case 2: \
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__ret = __need_bswap ? bswap_16(val) : (val); break; \
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default: \
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BUILD_BUG(); break; \
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} \
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__ret; \
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})
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#endif /* _OBJTOOL_ENDIANNESS_H */
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