Linux加载ko出现unknown relocation: 38 的解决办法

Kernel module build with GCOV profiling fails to load with the
following error:

$ insmod test_module.ko
test_module: unknown relocation: 38
insmod: can't insert 'test_module.ko': invalid module format

This happens because constructor pointers in the .init_array section
have not supported R_ARM_TARGET1 relocation type.

Documentation (ELF for the ARM Architecture) says:
"The relocation must be processed either in the same way as R_ARM_REL32 or
as R_ARM_ABS32: a virtual platform must specify which method is used."

Since kernel expects to see absolute addresses in .init_array R_ARM_TARGET1
relocation type should be treated the same way as R_ARM_ABS32.

Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
---
arch/arm/include/asm/elf.h | 1 +
arch/arm/kernel/module.c   | 1 +
2 files changed, 2 insertions(+)
diff --git a/arch/arm/include/asm/elf.h b/arch/arm/include/asm/elf.h
index f4b46d3..afb9caf 100644
--- a/arch/arm/include/asm/elf.h
+++ b/arch/arm/include/asm/elf.h
@@ -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_TARGET1		38
#define R_ARM_V4BX		40
#define R_ARM_PREL31		42
#define R_ARM_MOVW_ABS_NC	43
diff --git a/arch/arm/kernel/module.c b/arch/arm/kernel/module.c
index 45e4781..6a4dffe 100644
--- a/arch/arm/kernel/module.c
+++ b/arch/arm/kernel/module.c
@@ -91,6 +91,7 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex,
break;

case R_ARM_ABS32:
+		case R_ARM_TARGET1:
*(u32 *)loc += sym->st_value;
break;

--
1.8.5.5