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| author | Youling Tang <tangyouling@loongson.cn> | 2022-12-10 22:39:48 +0800 |
|---|---|---|
| committer | Huacai Chen <chenhuacai@loongson.cn> | 2022-12-14 08:36:11 +0800 |
| commit | 3d36f4298ba91fbdec6bc56aa7bb0663cba6ab0c (patch) | |
| tree | 18b04c43e9acae25114c33a45814ae1233a09955 /scripts/mod | |
| parent | 508f28c67171e276356650f407dd87d42b6913ef (diff) | |
| download | linux-3d36f4298ba91fbdec6bc56aa7bb0663cba6ab0c.tar.bz2 | |
LoongArch: Switch to relative exception tables
Similar to other architectures such as arm64, x86, riscv and so on, use
offsets relative to the exception table entry values rather than their
absolute addresses for both the exception location and the fixup.
However, LoongArch label difference because it will actually produce two
relocations, a pair of R_LARCH_ADD32 and R_LARCH_SUB32. Take simple code
below for example:
$ cat test_ex_table.S
.section .text
1:
nop
.section __ex_table,"a"
.balign 4
.long (1b - .)
.previous
$ loongarch64-unknown-linux-gnu-gcc -c test_ex_table.S
$ loongarch64-unknown-linux-gnu-readelf -Wr test_ex_table.o
Relocation section '.rela__ex_table' at offset 0x100 contains 2 entries:
Offset Info Type Symbol's Value Symbol's Name + Addend
0000000000000000 0000000600000032 R_LARCH_ADD32 0000000000000000 .L1^B1 + 0
0000000000000000 0000000500000037 R_LARCH_SUB32 0000000000000000 L0^A + 0
The modpost will complain the R_LARCH_SUB32 relocation, so we need to
patch modpost.c to skip this relocation for .rela__ex_table section.
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Diffstat (limited to 'scripts/mod')
| -rw-r--r-- | scripts/mod/modpost.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 2c80da0220c3..9321c0a05ffd 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -1523,6 +1523,14 @@ static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) #define R_RISCV_SUB32 39 #endif +#ifndef EM_LOONGARCH +#define EM_LOONGARCH 258 +#endif + +#ifndef R_LARCH_SUB32 +#define R_LARCH_SUB32 55 +#endif + static void section_rela(const char *modname, struct elf_info *elf, Elf_Shdr *sechdr) { @@ -1564,6 +1572,11 @@ static void section_rela(const char *modname, struct elf_info *elf, ELF_R_TYPE(r.r_info) == R_RISCV_SUB32) continue; break; + case EM_LOONGARCH: + if (!strcmp("__ex_table", fromsec) && + ELF_R_TYPE(r.r_info) == R_LARCH_SUB32) + continue; + break; } sym = elf->symtab_start + r_sym; /* Skip special sections */ |