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| author | Huacai Chen <chenhuacai@loongson.cn> | 2022-12-10 17:40:15 +0300 |
|---|---|---|
| committer | Huacai Chen <chenhuacai@loongson.cn> | 2022-12-14 03:41:53 +0300 |
| commit | 9151dde40356880bb445f719f5ebbb1319054d5f (patch) | |
| tree | 3283144662ff8a91ac742c3085b6d6ecf16697c0 /arch/loongarch/include | |
| parent | 09f33601bf940f955c10a6e75a1c1b7bcadee5e2 (diff) | |
| download | linux-9151dde40356880bb445f719f5ebbb1319054d5f.tar.xz | |
LoongArch: module: Use got/plt section indices for relocations
Instead of saving a pointer to the .got, .plt and .plt_idx sections to
apply {got,plt}-based relocations, save and use their section indices
instead.
The mod->arch.{core,init}.{got,plt} pointers were problematic for live-
patch because they pointed within temporary section headers (provided by
the module loader via info->sechdrs) that would be freed after module
load. Since livepatch modules may need to apply relocations post-module-
load (for example, to patch a module that is loaded later), using section
indices to offset into the section headers (instead of accessing them
through a saved pointer) allows livepatch modules on LoongArch to pass
in their own copy of the section headers to apply_relocate_add() to
apply delayed relocations.
The method used is same as commit c8ebf64eab743 ("arm64/module: use plt
section indices for relocations").
Signed-off-by: Hongchen Zhang <zhanghongchen@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Diffstat (limited to 'arch/loongarch/include')
| -rw-r--r-- | arch/loongarch/include/asm/module.h | 22 |
1 files changed, 12 insertions, 10 deletions
diff --git a/arch/loongarch/include/asm/module.h b/arch/loongarch/include/asm/module.h index b29b19a46f42..60dc62a1146e 100644 --- a/arch/loongarch/include/asm/module.h +++ b/arch/loongarch/include/asm/module.h @@ -11,7 +11,7 @@ #define RELA_STACK_DEPTH 16 struct mod_section { - Elf_Shdr *shdr; + int shndx; int num_entries; int max_entries; }; @@ -37,8 +37,8 @@ struct plt_idx_entry { Elf_Addr symbol_addr; }; -Elf_Addr module_emit_got_entry(struct module *mod, Elf_Addr val); -Elf_Addr module_emit_plt_entry(struct module *mod, Elf_Addr val); +Elf_Addr module_emit_got_entry(struct module *mod, Elf_Shdr *sechdrs, Elf_Addr val); +Elf_Addr module_emit_plt_entry(struct module *mod, Elf_Shdr *sechdrs, Elf_Addr val); static inline struct got_entry emit_got_entry(Elf_Addr val) { @@ -62,10 +62,10 @@ static inline struct plt_idx_entry emit_plt_idx_entry(unsigned long val) return (struct plt_idx_entry) { val }; } -static inline int get_plt_idx(unsigned long val, const struct mod_section *sec) +static inline int get_plt_idx(unsigned long val, Elf_Shdr *sechdrs, const struct mod_section *sec) { int i; - struct plt_idx_entry *plt_idx = (struct plt_idx_entry *)sec->shdr->sh_addr; + struct plt_idx_entry *plt_idx = (struct plt_idx_entry *)sechdrs[sec->shndx].sh_addr; for (i = 0; i < sec->num_entries; i++) { if (plt_idx[i].symbol_addr == val) @@ -76,11 +76,12 @@ static inline int get_plt_idx(unsigned long val, const struct mod_section *sec) } static inline struct plt_entry *get_plt_entry(unsigned long val, - const struct mod_section *sec_plt, - const struct mod_section *sec_plt_idx) + Elf_Shdr *sechdrs, + const struct mod_section *sec_plt, + const struct mod_section *sec_plt_idx) { - int plt_idx = get_plt_idx(val, sec_plt_idx); - struct plt_entry *plt = (struct plt_entry *)sec_plt->shdr->sh_addr; + int plt_idx = get_plt_idx(val, sechdrs, sec_plt_idx); + struct plt_entry *plt = (struct plt_entry *)sechdrs[sec_plt->shndx].sh_addr; if (plt_idx < 0) return NULL; @@ -89,10 +90,11 @@ static inline struct plt_entry *get_plt_entry(unsigned long val, } static inline struct got_entry *get_got_entry(Elf_Addr val, + Elf_Shdr *sechdrs, const struct mod_section *sec) { - struct got_entry *got = (struct got_entry *)sec->shdr->sh_addr; int i; + struct got_entry *got = (struct got_entry *)sechdrs[sec->shndx].sh_addr; for (i = 0; i < sec->num_entries; i++) if (got[i].symbol_addr == val) |