From mboxrd@z Thu Jan 1 00:00:00 1970 From: ard.biesheuvel@linaro.org (Ard Biesheuvel) Date: Sat, 31 Jan 2015 19:49:16 +0000 Subject: [PATCH resend 1/4] ARM: handle interworking and out-of-range relocations separately In-Reply-To: <1422733759-27236-1-git-send-email-ard.biesheuvel@linaro.org> References: <1422733759-27236-1-git-send-email-ard.biesheuvel@linaro.org> Message-ID: <1422733759-27236-2-git-send-email-ard.biesheuvel@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Currently, interworking calls on module boundaries are not supported, and are handled by the same error handling code path as non-interworking calls whose targets are simply out of range. Before modifying the handling of those out-of-range jump and call relocations in a subsequent patch, move the handling of interworking restrictions out of it. Acked-by: Nicolas Pitre Signed-off-by: Ard Biesheuvel --- arch/arm/kernel/module.c | 38 ++++++++++++++++++++++++-------------- 1 file changed, 24 insertions(+), 14 deletions(-) diff --git a/arch/arm/kernel/module.c b/arch/arm/kernel/module.c index 6a4dffefd357..16804df4857c 100644 --- a/arch/arm/kernel/module.c +++ b/arch/arm/kernel/module.c @@ -98,14 +98,19 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex, case R_ARM_PC24: case R_ARM_CALL: case R_ARM_JUMP24: + if (sym->st_value & 3) { + pr_err("%s: section %u reloc %u sym '%s': unsupported interworking call (ARM -> Thumb)\n", + module->name, relindex, i, symname); + return -ENOEXEC; + } + offset = __mem_to_opcode_arm(*(u32 *)loc); offset = (offset & 0x00ffffff) << 2; if (offset & 0x02000000) offset -= 0x04000000; offset += sym->st_value - loc; - if (offset & 3 || - offset <= (s32)0xfe000000 || + if (offset <= (s32)0xfe000000 || offset >= (s32)0x02000000) { pr_err("%s: section %u reloc %u sym '%s': relocation %u out of range (%#lx -> %#x)\n", module->name, relindex, i, symname, @@ -155,6 +160,22 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex, #ifdef CONFIG_THUMB2_KERNEL case R_ARM_THM_CALL: case R_ARM_THM_JUMP24: + /* + * For function symbols, only Thumb addresses are + * allowed (no interworking). + * + * For non-function symbols, the destination + * has no specific ARM/Thumb disposition, so + * the branch is resolved under the assumption + * that interworking is not required. + */ + if (ELF32_ST_TYPE(sym->st_info) == STT_FUNC && + !(sym->st_value & 1)) { + pr_err("%s: section %u reloc %u sym '%s': unsupported interworking call (Thumb -> ARM)\n", + module->name, relindex, i, symname); + return -ENOEXEC; + } + upper = __mem_to_opcode_thumb16(*(u16 *)loc); lower = __mem_to_opcode_thumb16(*(u16 *)(loc + 2)); @@ -182,18 +203,7 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex, offset -= 0x02000000; offset += sym->st_value - loc; - /* - * For function symbols, only Thumb addresses are - * allowed (no interworking). - * - * For non-function symbols, the destination - * has no specific ARM/Thumb disposition, so - * the branch is resolved under the assumption - * that interworking is not required. - */ - if ((ELF32_ST_TYPE(sym->st_info) == STT_FUNC && - !(offset & 1)) || - offset <= (s32)0xff000000 || + if (offset <= (s32)0xff000000 || offset >= (s32)0x01000000) { pr_err("%s: section %u reloc %u sym '%s': relocation %u out of range (%#lx -> %#x)\n", module->name, relindex, i, symname, -- 1.8.3.2