Commit c6a2cd1d authored Oct 31, 2023 by Hongchen Zhang

LoongArch: Add support for 32_PCREL relocation type

LoongArch inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8C3BV

------------------------------------------

When build and update kernel with the latest upstream binutils and
loongson3_defconfig, module loader fails with:

  kmod: zsmalloc: Unsupport relocation type 99, please add its support.
  kmod: fuse: Unsupport relocation type 99, please add its support.
  kmod: ipmi_msghandler: Unsupport relocation type 99, please add its support.
  kmod: ipmi_msghandler: Unsupport relocation type 99, please add its support.
  kmod: pstore: Unsupport relocation type 99, please add its support.
  kmod: drm_display_helper: Unsupport relocation type 99, please add its support.
  kmod: drm_display_helper: Unsupport relocation type 99, please add its support.
  kmod: drm_display_helper: Unsupport relocation type 99, please add its support.
  kmod: fuse: Unsupport relocation type 99, please add its support.
  kmod: fat: Unsupport relocation type 99, please add its support.

This is because the latest upstream binutils replaces a pair of ADD32
and SUB32 with 32_PCREL, so add support for 32_PCREL relocation type.

Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=ecb802d02eeb


Cc: <stable@vger.kernel.org>
Co-developed-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Hongchen Zhang <zhanghongchen@loongson.cn>

parent ba31387b

arch/loongarch/kernel/module.c

+10 −0

Original line number	Diff line number	Diff line
		@@ -372,6 +372,15 @@ static int apply_r_larch_got_pc(struct module mod, u32 location, Elf_Addr v,
		return apply_r_larch_pcala(mod, location, got, rela_stack, rela_stack_top, type);
		}

		static int apply_r_larch_32_pcrel(struct module mod, u32 location, Elf_Addr v,
		s64 rela_stack, size_t rela_stack_top, unsigned int type)
		{
		ptrdiff_t offset = (void )v - (void )location;

		(u32 )location = offset;
		return 0;
		}

		/*
		* reloc_handlers_rela() - Apply a particular relocation to a module
		* @mod: the module to apply the reloc to
		@@ -404,6 +413,7 @@ static reloc_rela_handler reloc_rela_handlers[] = {
		[R_LARCH_B26] = apply_r_larch_b26,
		[R_LARCH_PCALA_HI20...R_LARCH_PCALA64_HI12] = apply_r_larch_pcala,
		[R_LARCH_GOT_PC_HI20...R_LARCH_GOT_PC_LO12] = apply_r_larch_got_pc,
		[R_LARCH_32_PCREL] = apply_r_larch_32_pcrel,
		};

		int apply_relocate_add(Elf_Shdr sechdrs, const char strtab,