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| author | Jessica Yu <jeyu@kernel.org> | 2018-11-05 19:53:23 +0100 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2018-11-20 12:38:26 +0100 |
| commit | c8ebf64eab743130fe404dc6679c2ff0cbc01615 (patch) | |
| tree | 5fbae96f2dbb03d1ea65fa778ba96455c3ac4eab /arch/arm64/kernel/module.c | |
| parent | arm64: mm: apply r/o permissions of VM areas to its linear alias as well (diff) | |
| download | linux-c8ebf64eab743130fe404dc6679c2ff0cbc01615.tar.xz linux-c8ebf64eab743130fe404dc6679c2ff0cbc01615.zip | |
arm64/module: use plt section indices for relocations
Instead of saving a pointer to the .plt and .init.plt sections to apply
plt-based relocations, save and use their section indices instead.
The mod->arch.{core,init}.plt pointers were problematic for livepatch
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 arm64 to pass in
their own copy of the section headers to apply_relocate_add() to apply
delayed relocations.
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/kernel/module.c')
| -rw-r--r-- | arch/arm64/kernel/module.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c index f0f27aeefb73..c2abe59c6f8f 100644 --- a/arch/arm64/kernel/module.c +++ b/arch/arm64/kernel/module.c @@ -198,7 +198,8 @@ static int reloc_insn_imm(enum aarch64_reloc_op op, __le32 *place, u64 val, return 0; } -static int reloc_insn_adrp(struct module *mod, __le32 *place, u64 val) +static int reloc_insn_adrp(struct module *mod, Elf64_Shdr *sechdrs, + __le32 *place, u64 val) { u32 insn; @@ -215,7 +216,7 @@ static int reloc_insn_adrp(struct module *mod, __le32 *place, u64 val) insn &= ~BIT(31); } else { /* out of range for ADR -> emit a veneer */ - val = module_emit_veneer_for_adrp(mod, place, val & ~0xfff); + val = module_emit_veneer_for_adrp(mod, sechdrs, place, val & ~0xfff); if (!val) return -ENOEXEC; insn = aarch64_insn_gen_branch_imm((u64)place, val, @@ -368,7 +369,7 @@ int apply_relocate_add(Elf64_Shdr *sechdrs, case R_AARCH64_ADR_PREL_PG_HI21_NC: overflow_check = false; case R_AARCH64_ADR_PREL_PG_HI21: - ovf = reloc_insn_adrp(me, loc, val); + ovf = reloc_insn_adrp(me, sechdrs, loc, val); if (ovf && ovf != -ERANGE) return ovf; break; @@ -413,7 +414,7 @@ int apply_relocate_add(Elf64_Shdr *sechdrs, if (IS_ENABLED(CONFIG_ARM64_MODULE_PLTS) && ovf == -ERANGE) { - val = module_emit_plt_entry(me, loc, &rel[i], sym); + val = module_emit_plt_entry(me, sechdrs, loc, &rel[i], sym); if (!val) return -ENOEXEC; ovf = reloc_insn_imm(RELOC_OP_PREL, loc, val, 2, |