Commit 4731f8b6 authored Mar 20, 2009 by Daniel Silverstone Committed by Russell King Mar 21, 2009

[ARM] 5428/1: Module relocation update for R_ARM_V4BX



It would seem when building kernel modules with modern binutils
(required by modern GCC) for ARM v4T targets (specifically observed
with the Samsung 24xx SoC which is an 920T) R_ARM_V4BX relocations
are emitted for function epilogues.

This manifests at module load time with an "unknown relocation: 40"
error message.

The following patch adds the R_ARM_V4BX relocation to the ARM kernel
module loader. The relocation operation is taken from that within the
binutils bfd library.

Signed-off-by: Simtec Linux Team <linux@simtec.co.uk>
Signed-off-by: Vincent Sanders <vince@simtec.co.uk>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

parent 65c24491

arch/arm/include/asm/elf.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -50,6 +50,7 @@ typedef struct user_fp elf_fpregset_t;
		#define R_ARM_ABS32 2
		#define R_ARM_CALL 28
		#define R_ARM_JUMP24 29
		#define R_ARM_V4BX 40

		/*
		* These are used to set parameters in the core dumps.

arch/arm/kernel/module.c

+9 −0

Original line number	Diff line number	Diff line
		@@ -132,6 +132,15 @@ apply_relocate(Elf32_Shdr sechdrs, const char strtab, unsigned int symindex,
		(u32 )loc \|= offset & 0x00ffffff;
		break;

		case R_ARM_V4BX:
		/* Preserve Rm and the condition code. Alter
		* other bits to re-code instruction as
		* MOV PC,Rm.
		*/
		(u32 )loc &= 0xf000000f;
		(u32 )loc \|= 0x01a0f000;
		break;

		default:
		printk(KERN_ERR "%s: unknown relocation: %u\n",
		module->name, ELF32_R_TYPE(rel->r_info));

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