[内核补丁] 解决2.6.29内核上加载模块出现"unknown relocation: 40"

我使用s3c2410+linux2.6.25.20+arm-linux-gcc4.3.3(使用过其它较低版本3.4.5则不会出现这个问题)加载fat.ko等fat文件系统模块时候会报错，并不是全部都报错，某些简单的如led.ko不会。

http://www.arm9home.net/read.php?tid-1708.html

从上网站中获取补丁，补丁内容如下，按照修改内核问题解决：

# Author:    Daniel Silverstone (Fri Mar 20 10:11:43 GMT 2009)
# Committer: Russell King (Sat Mar 21 11:22:33 GMT 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
#   Signed-off-by: Vincent Sanders
#   Signed-off-by: Russell King
#
#    arch/arm/include/asm/elf.h |    1 +
#    arch/arm/kernel/module.c   |    9 +++++++++
#    2 files changed, 10 insertions(+), 0 deletions(-)
diff --git a/arch/arm/include/asm/elf.h b/arch/arm/include/asm/elf.h
index a58378c..ce3b36e 100644
--- a/arch/arm/include/asm/elf.h
+++ b/arch/arm/include/asm/elf.h     //我修改的是 include/asm-arm/elf.h  文件
@@ -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.
diff --git a/arch/arm/kernel/module.c b/arch/arm/kernel/module.c
index dab48f2..9f509fd 100644
--- a/arch/arm/kernel/module.c
+++ b/arch/arm/kernel/module.c
@@ -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));