From 0646c28b417b7fe307c9da72ca1c508e43b57dc0 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Mon, 14 Nov 2022 23:27:47 +0530 Subject: objtool: Use target file endianness instead of a compiled constant Some architectures like powerpc support both endianness, it's therefore not possible to fix the endianness via arch/endianness.h because there is no easy way to get the target endianness at build time. Use the endianness recorded in the file objtool is working on. Tested-by: Naveen N. Rao Reviewed-by: Naveen N. Rao Acked-by: Josh Poimboeuf Acked-by: Peter Zijlstra (Intel) Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20221114175754.1131267-10-sv@linux.ibm.com --- tools/objtool/include/objtool/endianness.h | 32 +++++++++++++++--------------- 1 file changed, 16 insertions(+), 16 deletions(-) (limited to 'tools/objtool/include') diff --git a/tools/objtool/include/objtool/endianness.h b/tools/objtool/include/objtool/endianness.h index 10241341eff3..4d2aa9b0fe2f 100644 --- a/tools/objtool/include/objtool/endianness.h +++ b/tools/objtool/include/objtool/endianness.h @@ -2,33 +2,33 @@ #ifndef _OBJTOOL_ENDIANNESS_H #define _OBJTOOL_ENDIANNESS_H -#include #include #include - -#ifndef __TARGET_BYTE_ORDER -#error undefined arch __TARGET_BYTE_ORDER -#endif - -#if __BYTE_ORDER != __TARGET_BYTE_ORDER -#define __NEED_BSWAP 1 -#else -#define __NEED_BSWAP 0 -#endif +#include /* - * Does a byte swap if target endianness doesn't match the host, i.e. cross + * Does a byte swap if target file endianness doesn't match the host, i.e. cross * compilation for little endian on big endian and vice versa. * To be used for multi-byte values conversion, which are read from / about * to be written to a target native endianness ELF file. */ -#define bswap_if_needed(val) \ +static inline bool need_bswap(struct elf *elf) +{ + return (__BYTE_ORDER == __LITTLE_ENDIAN) ^ + (elf->ehdr.e_ident[EI_DATA] == ELFDATA2LSB); +} + +#define bswap_if_needed(elf, val) \ ({ \ __typeof__(val) __ret; \ + bool __need_bswap = need_bswap(elf); \ switch (sizeof(val)) { \ - case 8: __ret = __NEED_BSWAP ? bswap_64(val) : (val); break; \ - case 4: __ret = __NEED_BSWAP ? bswap_32(val) : (val); break; \ - case 2: __ret = __NEED_BSWAP ? bswap_16(val) : (val); break; \ + case 8: \ + __ret = __need_bswap ? bswap_64(val) : (val); break; \ + case 4: \ + __ret = __need_bswap ? bswap_32(val) : (val); break; \ + case 2: \ + __ret = __need_bswap ? bswap_16(val) : (val); break; \ default: \ BUILD_BUG(); break; \ } \ -- cgit v1.2.3