Re: [PATCH 5/5] arm64: mte: Document the core dump file format
From: Luis Machado <hidden>
Date: 2022-01-03 17:29:39
On 12/8/21 9:19 AM, Catalin Marinas wrote:
quoted hunk ↗ jump to hunk
Add the program header definition and data layout for the PT_ARM_MEMTAG_MTE segments. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> --- .../arm64/memory-tagging-extension.rst | 22 +++++++++++++++++++ 1 file changed, 22 insertions(+)diff --git a/Documentation/arm64/memory-tagging-extension.rst b/Documentation/arm64/memory-tagging-extension.rst index 7b99c8f428eb..34c7eb47f61e 100644 --- a/Documentation/arm64/memory-tagging-extension.rst +++ b/Documentation/arm64/memory-tagging-extension.rst@@ -213,6 +213,28 @@ address ABI control and MTE configuration of a process as per the Documentation/arm64/tagged-address-abi.rst and above. The corresponding ``regset`` is 1 element of 8 bytes (``sizeof(long))``). +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 +program header for such segment is defined as: + +:``p_type``: ``PT_ARM_MEMTAG_MTE`` +:``p_flags``: 0 +:``p_offset``: segment file offset +:``p_vaddr``: segment virtual address, same as the corresponding + ``PT_LOAD`` segment +:``p_paddr``: 0 +:``p_filesz``: segment size in file, calculated as ``p_mem_sz / 16 / 2``
For the sake of making things extra clear, I'd describe what the constants (16 and 2) mean.
+:``p_memsz``: segment size in memory, same as the corresponding + ``PT_LOAD`` segment +:``p_align``: 0 + +The tags are stored in the core file at ``p_offset`` as two 4-bit tags +in a byte. With the tag granule of 16 bytes, a 4K page requires 128 +bytes in the core file. + Example of correct usage ========================
Otherwise looks good to me. Acked-by: Luis Machado <redacted> _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel