| Message ID | 1416833706-27043-1-git-send-email-ard.biesheuvel@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Mon, 24 Nov 2014, Ard Biesheuvel wrote: > 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. > > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Nicolas Pitre <nico@linaro.org> > --- > 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 > >
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,
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. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- arch/arm/kernel/module.c | 38 ++++++++++++++++++++++++-------------- 1 file changed, 24 insertions(+), 14 deletions(-)