Messages in this thread Patch in this message | | | Subject | Re: [PATCH 3/5] LoongArch: Support relocation against _GLOBAL_OFFSET_TABLE_ | From | Xi Ruoyao <> | Date | Thu, 28 Jul 2022 14:41:16 +0800 |
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On Thu, 2022-07-28 at 09:02 +0800, Jinyang He wrote:
> Hi, Ruoyao, > > It is possible to create a symbol when linking, which means > maybe we can add _GLOBAL_OFFSET_TABLE_ in 'module.lds.h'. > What do you think about it?
Hi Jinyang,
I think you are right, this patch can be replaced with the following, which is much simpler.
-- >8 --
With the stack-based relocations, the assembler emits three relocations to push the PC-relative offset of a GOT entry:
R_LARCH_SOP_PUSH_PCREL _GLOBAL_OFFSET_TABLE_ R_LARCH_SOP_PUSH_GPREL foo R_LARCH_SOP_ADD
In normal relocatable ELF object files, "_GLOBAL_OFFSET_TABLE_" is undefined in the symtab and the BFD linker generates it on final link. Define it for kernel modules so we will be able to really use R_LARCH_SOP_PUSH_GPREL relocation.
Note that we need to use "HIDDEN" to make it a local symbol because each kernel module has its own GOT and the reference to it should not be resolved to the GOT in the main kernel image.
Suggested-by: Jinyang He <hejinyang@loongson.cn> Signed-off-by: Xi Ruoyao <xry111@xry111.site> --- arch/loongarch/include/asm/module.lds.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/loongarch/include/asm/module.lds.h b/arch/loongarch/include/asm/module.lds.h index 57bbd0cedd26..42b7cca0b947 100644 --- a/arch/loongarch/include/asm/module.lds.h +++ b/arch/loongarch/include/asm/module.lds.h @@ -4,5 +4,5 @@ SECTIONS { . = ALIGN(4); .plt : { BYTE(0) } .plt.idx : { BYTE(0) } - .got : { BYTE(0) } + .got : { HIDDEN(_GLOBAL_OFFSET_TABLE_ = .); BYTE(0) } } -- 2.37.0
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