The FEAT_MTE_TAGGED_FAR feature provides support for
reporting all non-address bits during a synchronous MTE tag check fault.

This patchset extends the reporting tag to include
not only the memory tag (logical tag) but also the address tag via
si_addr when FEAT_MTE_TAGGED_FAR feature is supported.

Patch Sequences
================

Patch #1 adds cpufeature FEAT_MTE_TAGGED_FAR

Patch #2 adds MTE_FAR hwcaps and export address tag when it supports

Patch #3 adds mtefar hwcap test

Patch #4 to #7 prepares to add mtefar testcase

Patch #8 refactor check_mmap_option using general testcase pattern

Patch #9 adds mtefar test cases corresponding to
each testcase of check_mmap_options

Patch History
================
v7 to v8:
  - rewording some comment word.
  - https://lore.kernel.org/all/20250611135818.31070-1-yeoreum.yun@arm.com/

v6 to v7:
  - fix some error on testcase.
  - https://lore.kernel.org/all/20250611094107.928457-1-yeoreum.yun@arm.com/

v5 to v6:
  - split Patch #4.
  - refactor check_mmap_option using general testcase pattern
  - https://lore.kernel.org/linux-arm-kernel/20250610150144.2523945-1-yeoreum.yun@arm.com/

v4 to v5:
  - rebased on v6.16-rc1
  - https://lore.kernel.org/linux-arm-kernel/20250507095757.1663684-1-yeoreum.yun@arm.com/

v3 to v4:
  - fix hwcap string for FEAT_MTE_TAGGED_FAR
  - split cpufeature and hwcap modification and merge hwcap's
    modification with exporting address tag patch
  - add mtefar testcase on check_mmap_options
  - https://lore.kernel.org/all/20250410074721.947380-1-yeoreum.yun@arm.com/

v2 to v3:
  - Rebase to 6.15-rc1
  - https://lore.kernel.org/all/20250403172758.67106-1-yeoreum.yun@arm.com/

v1 to v2:
  - add hwcap test for MTE_FAR feature.
  - add MTE_FAR doc into elf_hwcap.rst
  - https://lore.kernel.org/all/20250403142707.26397-1-yeoreum.yun@arm.com/

Yeoreum Yun (9):
  arm64/cpufeature: add FEAT_MTE_TAGGED_FAR feature
  arm64: report address tag when FEAT_MTE_TAGGED_FAR is supported
  tools/kselftest: add MTE_FAR hwcap test
  kselftest/arm64/mte: register mte signal handler with
    SA_EXPOSE_TAGBITS
  kselftest/arm64/mte: check MTE_FAR feature is supported
  kselftest/arm64/mte: add address tag related macro and function
  kselftest/arm64/mte: add verification for address tag in signal
    handler
  kselftest/arm64/mte: refactor check_mmap_option test
  kselftest/arm64/mte: add mtefar tests on check_mmap_options

 Documentation/arch/arm64/elf_hwcaps.rst       |   3 +
 Documentation/arch/arm64/tagged-pointers.rst  |  11 +-
 arch/arm64/include/asm/hwcap.h                |   1 +
 arch/arm64/include/uapi/asm/hwcap.h           |   1 +
 arch/arm64/kernel/cpufeature.c                |   9 +
 arch/arm64/kernel/cpuinfo.c                   |   1 +
 arch/arm64/mm/fault.c                         |   7 +-
 arch/arm64/tools/cpucaps                      |   1 +
 tools/testing/selftests/arm64/abi/hwcap.c     |   6 +
 .../selftests/arm64/mte/check_buffer_fill.c   |   2 +-
 .../selftests/arm64/mte/check_child_memory.c  |   4 +-
 .../arm64/mte/check_hugetlb_options.c         |   4 +-
 .../selftests/arm64/mte/check_ksm_options.c   |   4 +-
 .../selftests/arm64/mte/check_mmap_options.c  | 551 +++++++++++++++---
 .../arm64/mte/check_tags_inclusion.c          |   2 +-
 .../selftests/arm64/mte/check_user_mem.c      |   2 +-
 .../selftests/arm64/mte/mte_common_util.c     |  70 ++-
 .../selftests/arm64/mte/mte_common_util.h     |   6 +-
 tools/testing/selftests/arm64/mte/mte_def.h   |   8 +
 19 files changed, 593 insertions(+), 100 deletions(-)

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