[PATCH v4 0/4] arm64: add Armv8.3 pointer authentication enhancements

[Amit Daniel Kachhap]

These patch series adds support for Armv8.3 pointer authentication
enhanced features mandatory for Armv8.6 and optional for Armv8.3.
These features are,

 * Enhanced PAC generation algorithm (ARMv8.3-pauth2).
 * Generate fault when authenticate instruction fails (ARMV8.3-FPAC).

More details can be found here [1].

Changes since v3 [2]:
* Added a new patch "arm64: kprobe: clarify the comment of steppable hint instructions"
  as suggested in the last iteration.
* Removed the ptrauth fault handler from el0 compat handler as pointed
  by Dave.
* Mentioned the new feature name clearly as ARMV8.3-FPAC and ARMv8.3-pauth2
  as per ARMv8-A reference manual.
* Commit logs cleanup. 

Changes since v2 [3]:
* Dropped the patch "arm64: cpufeature: Fix the handler for address authentication"
* Added new matching function for address authentication as generic
  matching function has_cpuid_feature is specific for LOWER_SAFE
  features. This was suggested by Suzuki [3].
* Disabled probe of Authenticate ptrauth instructions as per Mark
  Brown's merged changes of whitelisting of hint instructions.

This series is based on kernel version v5.8-rc4.

Regards,
Amit

[1]: https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/arm-architecture-developments-armv8-6-a
[2]: https://lore.kernel.org/linux-arm-kernel/1592457029-18547-1-git-send-email-amit.kachhap@arm.com/
[3]: http://lists.infradead.org/pipermail/linux-arm-kernel/2020-April/723751.html


Amit Daniel Kachhap (4):
  arm64: ptrauth: add Armv8.3 pointer authentication enhanced features
  arm64: cpufeature: Modify address authentication cpufeature to exact
  arm64: kprobe: disable probe of fault prone ptrauth instruction
  arm64: kprobe: clarify the comment of steppable hint instructions

 arch/arm64/include/asm/esr.h           |  4 +-
 arch/arm64/include/asm/exception.h     |  1 +
 arch/arm64/include/asm/sysreg.h        | 24 +++++++----
 arch/arm64/kernel/cpufeature.c         | 56 +++++++++++++++++++++-----
 arch/arm64/kernel/entry-common.c       | 21 ++++++++++
 arch/arm64/kernel/insn.c               |  6 ---
 arch/arm64/kernel/probes/decode-insn.c |  6 ++-
 arch/arm64/kernel/traps.c              | 10 +++++
 8 files changed, 102 insertions(+), 26 deletions(-)

-- 
2.17.1