| Message ID | 20211208121941.494956-6-catalin.marinas@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: mte: add core dump support | expand |
On 12/8/21 9:19 AM, Catalin Marinas wrote: > 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 <luis.machado@linaro.org>
Hi Luis, On Mon, Jan 03, 2022 at 02:27:54PM -0300, Luis Machado wrote: > On 12/8/21 9:19 AM, Catalin Marinas wrote: > > 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. I'll rewrite this as: "``p_mem_sz / 32`` (two 4-bit tags cover 32 bytes of memory)". I find the "16 / 2" more confusing. > Acked-by: Luis Machado <luis.machado@linaro.org> Thanks for the acks.
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`` +:``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 ========================
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(+)