1/* SPDX-License-Identifier: GPL-2.0-or-later */ 2#ifndef _OBJTOOL_ENDIANNESS_H 3#define _OBJTOOL_ENDIANNESS_H 4 5#include <linux/kernel.h> 6#include <endian.h> 7#include <objtool/elf.h> 8 9/* 10 * Does a byte swap if target file endianness doesn't match the host, i.e. cross 11 * compilation for little endian on big endian and vice versa. 12 * To be used for multi-byte values conversion, which are read from / about 13 * to be written to a target native endianness ELF file. 14 */ 15static inline bool need_bswap(struct elf *elf) 16{ 17 return (__BYTE_ORDER == __LITTLE_ENDIAN) ^ 18 (elf->ehdr.e_ident[EI_DATA] == ELFDATA2LSB); 19} 20 21#define bswap_if_needed(elf, val) \ 22({ \ 23 __typeof__(val) __ret; \ 24 bool __need_bswap = need_bswap(elf); \ 25 switch (sizeof(val)) { \ 26 case 8: \ 27 __ret = __need_bswap ? bswap_64(val) : (val); break; \ 28 case 4: \ 29 __ret = __need_bswap ? bswap_32(val) : (val); break; \ 30 case 2: \ 31 __ret = __need_bswap ? bswap_16(val) : (val); break; \ 32 default: \ 33 BUILD_BUG(); break; \ 34 } \ 35 __ret; \ 36}) 37 38#endif /* _OBJTOOL_ENDIANNESS_H */ 39