| Message ID | 20220425151833.2603830-1-catalin.marinas@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | elf: Fix the arm64 MTE ELF segment name and value | expand |
On Mon, 25 Apr 2022 16:18:33 +0100, Catalin Marinas wrote: > Unfortunately, the name/value choice for the MTE ELF segment type > (PT_ARM_MEMTAG_MTE) was pretty poor: LOPROC+1 is already in use by > PT_AARCH64_UNWIND, as defined in the AArch64 ELF ABI > (https://github.com/ARM-software/abi-aa/blob/main/aaelf64/aaelf64.rst). > > Update the ELF segment type value to LOPROC+2 and also change the define > to PT_AARCH64_MEMTAG_MTE to match the AArch64 ELF ABI namespace. The > AArch64 ELF ABI document is updating accordingly (segment type not > previously mentioned in the document). > > [...] Applied to arm64 (for-next/fixes), thanks! [1/1] elf: Fix the arm64 MTE ELF segment name and value https://git.kernel.org/arm64/c/c35fe2a68f29 Cheers,
On Mon, Apr 25, 2022 at 04:18:33PM +0100, Catalin Marinas wrote: > Unfortunately, the name/value choice for the MTE ELF segment type > (PT_ARM_MEMTAG_MTE) was pretty poor: LOPROC+1 is already in use by > PT_AARCH64_UNWIND, as defined in the AArch64 ELF ABI > (https://github.com/ARM-software/abi-aa/blob/main/aaelf64/aaelf64.rst). > > Update the ELF segment type value to LOPROC+2 and also change the define > to PT_AARCH64_MEMTAG_MTE to match the AArch64 ELF ABI namespace. The > AArch64 ELF ABI document is updating accordingly (segment type not > previously mentioned in the document). > > Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Kees Cook <keescook@chromium.org>
diff --git a/Documentation/arm64/memory-tagging-extension.rst b/Documentation/arm64/memory-tagging-extension.rst index dd27f78d7608..dbae47bba25e 100644 --- a/Documentation/arm64/memory-tagging-extension.rst +++ b/Documentation/arm64/memory-tagging-extension.rst @@ -228,10 +228,10 @@ Core dump support ----------------- The allocation tags for user memory mapped with ``PROT_MTE`` are dumped -in the core file as additional ``PT_ARM_MEMTAG_MTE`` segments. The +in the core file as additional ``PT_AARCH64_MEMTAG_MTE`` segments. The program header for such segment is defined as: -:``p_type``: ``PT_ARM_MEMTAG_MTE`` +:``p_type``: ``PT_AARCH64_MEMTAG_MTE`` :``p_flags``: 0 :``p_offset``: segment file offset :``p_vaddr``: segment virtual address, same as the corresponding diff --git a/arch/arm64/kernel/elfcore.c b/arch/arm64/kernel/elfcore.c index 2b3f3d0544b9..98d67444a5b6 100644 --- a/arch/arm64/kernel/elfcore.c +++ b/arch/arm64/kernel/elfcore.c @@ -95,7 +95,7 @@ int elf_core_write_extra_phdrs(struct coredump_params *cprm, loff_t offset) for_each_mte_vma(current, vma) { struct elf_phdr phdr; - phdr.p_type = PT_ARM_MEMTAG_MTE; + phdr.p_type = PT_AARCH64_MEMTAG_MTE; phdr.p_offset = offset; phdr.p_vaddr = vma->vm_start; phdr.p_paddr = 0; diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h index 787c657bfae8..7ce993e6786c 100644 --- a/include/uapi/linux/elf.h +++ b/include/uapi/linux/elf.h @@ -42,7 +42,7 @@ typedef __s64 Elf64_Sxword; /* ARM MTE memory tag segment type */ -#define PT_ARM_MEMTAG_MTE (PT_LOPROC + 0x1) +#define PT_AARCH64_MEMTAG_MTE (PT_LOPROC + 0x2) /* * Extended Numbering
Unfortunately, the name/value choice for the MTE ELF segment type (PT_ARM_MEMTAG_MTE) was pretty poor: LOPROC+1 is already in use by PT_AARCH64_UNWIND, as defined in the AArch64 ELF ABI (https://github.com/ARM-software/abi-aa/blob/main/aaelf64/aaelf64.rst). Update the ELF segment type value to LOPROC+2 and also change the define to PT_AARCH64_MEMTAG_MTE to match the AArch64 ELF ABI namespace. The AArch64 ELF ABI document is updating accordingly (segment type not previously mentioned in the document). Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Fixes: 761b9b366cec ("elf: Introduce the ARM MTE ELF segment type") Cc: Will Deacon <will@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Kees Cook <keescook@chromium.org> Cc: Luis Machado <luis.machado@arm.com> Cc: Richard Earnshaw <Richard.Earnshaw@arm.com> --- Luckily, the commit being fixed here only went in for 5.18-rc1, so there is no ABI change in a mainline release. FYI, the corresponding pull request for the AArch64 ELF ABI: https://github.com/ARM-software/abi-aa/pull/148 I don't expect any further change to the segment name/value. Documentation/arm64/memory-tagging-extension.rst | 4 ++-- arch/arm64/kernel/elfcore.c | 2 +- include/uapi/linux/elf.h | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-)