tree fd5f02656e9975bd5cfe5a2288d4ae034030cf6a
parent 4c4f0c2bf3415a5fe7512d17d841bc1f8020b2cb
parent 22b70e6f2da0a4c8b1421b00cfc3016bc9d4d9d4
author Linus Torvalds <torvalds@linux-foundation.org> 1632507137 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1632507137 -0700
mergetag object 22b70e6f2da0a4c8b1421b00cfc3016bc9d4d9d4
 type commit
 tag arm64-fixes
 tagger Catalin Marinas <catalin.marinas@arm.com> 1632504068 +0100
 
 arm64 fixes:
 
 - It turns out that the optimised string routines merged in 5.14 are not
   safe with in-kernel MTE (KASAN_HW_TAGS) because of reading beyond the
   end of a string (strcmp, strncmp). Such reading may go across a 16
   byte tag granule and cause a tag check fault. When KASAN_HW_TAGS is
   enabled, use the generic strcmp/strncmp C implementation.
 
 - An errata workaround for ThunderX relied on the CPU capabilities being
   enabled in a specific order. This disappeared with the automatic
   generation of the cpucaps.h file (sorted alphabetically). Fix it by
   checking the current CPU only rather than the system-wide capability.
 
 - Add system_supports_mte() checks on the kernel entry/exit path and
   thread switching to avoid unnecessary barriers and function calls on
   systems where MTE is not supported.
 
 - kselftests: skip arm64 tests if the required features are missing.
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Catalin Marinas:

 - It turns out that the optimised string routines merged in 5.14 are
   not safe with in-kernel MTE (KASAN_HW_TAGS) because of reading beyond
   the end of a string (strcmp, strncmp). Such reading may go across a
   16 byte tag granule and cause a tag check fault. When KASAN_HW_TAGS
   is enabled, use the generic strcmp/strncmp C implementation.

 - An errata workaround for ThunderX relied on the CPU capabilities
   being enabled in a specific order. This disappeared with the
   automatic generation of the cpucaps.h file (sorted alphabetically).
   Fix it by checking the current CPU only rather than the system-wide
   capability.

 - Add system_supports_mte() checks on the kernel entry/exit path and
   thread switching to avoid unnecessary barriers and function calls on
   systems where MTE is not supported.

 - kselftests: skip arm64 tests if the required features are missing.

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: Restore forced disabling of KPTI on ThunderX
  kselftest/arm64: signal: Skip tests if required features are missing
  arm64: Mitigate MTE issues with str{n}cmp()
  arm64: add MTE supported check to thread switching and syscall entry/exit