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[AAELF64] Reserve dynamic tags used by memtagabielf64 and pauthabi64
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The alpha ELF extension documents define dynamic tags. To avoid
avoidable clashes with the main specification, mark the values
used as reserved.
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@smithp35
smithp35 committed Aug 16, 2023
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Showing 1 changed file with 34 additions and 9 deletions.
43 changes: 34 additions & 9 deletions aaelf64/aaelf64.rst
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Expand Up @@ -11,6 +11,7 @@

.. _AAPCS64: https://github.com/ARM-software/abi-aa/releases
.. _Addenda32: https://github.com/ARM-software/abi-aa/releases
.. _MemTagABIELF64: https://github.com/ARM-software/abi-aa/releases
.. _PAuthABIELF64: https://github.com/ARM-software/abi-aa/releases
.. _SCO-ELF: http://www.sco.com/developers/gabi/
.. _LINUX_ABI: https://github.com/hjl-tools/linux-abi/wiki
Expand Down Expand Up @@ -266,6 +267,10 @@ changes to the content of the document for that release.
| | | Linking`_, document new |
| | | PT_AARCH64_MEMTAG_MTE segment. |
+---------------+--------------------+-----------------------------------------+
| 2023Q3 | | - In `Dynamic Section`_, reserve tags |
| | | used by `PAuthABIELF64`_ and |
| | | - `MemTagABIELF64`_. |
+---------------+--------------------+-----------------------------------------+


References
Expand All @@ -284,6 +289,8 @@ This document refers to, or is referred to by, the following documents.
+------------------------------+----------------------------------------------------------------------------------------------+-------------------------------------------------------------+
| Addenda32_ | IHI 0045 | Addenda to, and Errata in, the ABI for the Arm Architecture |
+------------------------------+----------------------------------------------------------------------------------------------+-------------------------------------------------------------+
| MemTagABIELF64_ | memtagabielf64 | MemTag Extension to ELF for the Arm 64-bit Architecture |
+------------------------------+----------------------------------------------------------------------------------------------+-------------------------------------------------------------+
| PAuthABIELF64_ | pauthabielf64 | PAuth Extension to ELF for the Arm 64-bit Architecture |
+------------------------------+----------------------------------------------------------------------------------------------+-------------------------------------------------------------+
| LSB_ | http://www.linuxbase.org/ | Linux Standards Base |
Expand Down Expand Up @@ -1906,15 +1913,31 @@ AArch64 specifies the following processor-specific dynamic array tags.

.. table:: AArch64 specific dynamic array tags

+---------------------------+------------+--------+-------------------+-------------------+
| Name | Value | d\_un | Executable | Shared Object |
+===========================+============+========+===================+===================+
| DT\_AARCH64\_BTI\_PLT | 0x70000001 | d\_val | Platform specific | Platform Specific |
+---------------------------+------------+--------+-------------------+-------------------+
| DT\_AARCH64\_PAC\_PLT | 0x70000003 | d\_val | Platform specific | Platform Specific |
+---------------------------+------------+--------+-------------------+-------------------+
| DT\_AARCH64\_VARIANT\_PCS | 0x70000005 | d\_val | Platform specific | Platform Specific |
+---------------------------+------------+--------+-------------------+-------------------+
+--------------------------------+------------+--------+-------------------+-------------------+
| Name | Value | d\_un | Executable | Shared Object |
+================================+============+========+===================+===================+
| DT\_AARCH64\_BTI\_PLT | 0x70000001 | d\_val | Platform specific | Platform Specific |
+--------------------------------+------------+--------+-------------------+-------------------+
| DT\_AARCH64\_PAC\_PLT | 0x70000003 | d\_val | Platform specific | Platform Specific |
+--------------------------------+------------+--------+-------------------+-------------------+
| DT\_AARCH64\_VARIANT\_PCS | 0x70000005 | d\_val | Platform specific | Platform Specific |
+--------------------------------+------------+--------+-------------------+-------------------+
| RESERVED for `MemTagABIELF64`_ | 0x70000009 | d\_val | Platform specific | Platform Specific |
+--------------------------------+------------+--------+-------------------+-------------------+
| RESERVED for `MemTagABIELF64`_ | 0x7000000b | d\_val | Platform specific | Platform Specific |
+--------------------------------+------------+--------+-------------------+-------------------+
| RESERVED for `MemTagABIELF64`_ | 0x7000000c | d\_ptr | Platform specific | Platform Specific |
+--------------------------------+------------+--------+-------------------+-------------------+
| RESERVED for `MemTagABIELF64`_ | 0x7000000d | d\_val | Platform specific | Platform Specific |
+--------------------------------+------------+--------+-------------------+-------------------+
| RESERVED for `MemTagABIELF64`_ | 0x7000000f | d\_val | Platform specific | Platform Specific |
+--------------------------------+------------+--------+-------------------+-------------------+
| RESERVED for `PAuthABIELF64`_ | 0x70000011 | d\_val | Platform specific | Platform Specific |
+--------------------------------+------------+--------+-------------------+-------------------+
| RESERVED for `PAuthABIELF64`_ | 0x70000012 | d\_ptr | Platform specific | Platform Specific |
+--------------------------------+------------+--------+-------------------+-------------------+
| RESERVED for `PAuthABIELF64`_ | 0x70000013 | d\_val | Platform specific | Platform Specific |
+--------------------------------+------------+--------+-------------------+-------------------+

``DT_AARCH64_BTI_PLT`` indicates PLTs enabled with Branch Target Identification
mechanism.
Expand All @@ -1929,6 +1952,8 @@ Pointer Authentication.
relocations that reference symbols marked with the ``STO_AARCH64_VARIANT_PCS``
flag set in their ``st_other`` field.

See `MemTagABIELF64`_ and `PAuthABIELF64`_ for details of reserved tags.

.. raw:: pdf
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