[PATCH v7 0/6] arm64: add Armv8.3 pointer authentication enhancements

Amit Daniel Kachhap amit.kachhap at arm.com
Wed Sep 9 10:07:53 EDT 2020

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 v6 [2]:
* Clubbed Ptrauth combined branch instructions as suggested by Will.

Changes since v5 [3]:
* Few Comments modified as suggested by Dave and Suzuki.
* Added Reviewed-by's.

Changes since v4 [4]:
* New patch "arm64: kprobe: add checks for ARMv8.3-PAuth combined instructions".
  This fixes uprobe crash with ARMv8.3-PAuth combined instructions.
* New patch "arm64: traps: Allow force_signal_inject to pass esr error code".
  This is preparatory patch for ARMV8.3-FPAC fault exception handling.
* Removed caching of bootcpu address authentication cpufeature levels in
  static variables. This was suggested by Dave and Suzuki.
* Use existing force_signal_inject function to invoke ptrauth fault
  signal as suggested by Dave.
* Commit log changes.

Changes since v3 [5]:
* 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 [6]:
* 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 v5.9-rc3.


[1]: https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/arm-architecture-developments-armv8-6-a
[2]: http://lists.infradead.org/pipermail/linux-arm-kernel/2020-September/598163.html 
[3]: https://lore.kernel.org/linux-arm-kernel/1597734671-23407-1-git-send-email-amit.kachhap@arm.com/
[4]: http://lists.infradead.org/pipermail/linux-arm-kernel/2020-July/584393.html
[5]: https://lore.kernel.org/linux-arm-kernel/1592457029-18547-1-git-send-email-amit.kachhap@arm.com/
[6]: http://lists.infradead.org/pipermail/linux-arm-kernel/2020-April/723751.html

Amit Daniel Kachhap (6):
  arm64: kprobe: add checks for ARMv8.3-PAuth combined instructions
  arm64: traps: Allow force_signal_inject to pass esr error code
  arm64: ptrauth: Introduce Armv8.3 pointer aut hentication enhancements
  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/insn.h          |  4 +++
 arch/arm64/include/asm/sysreg.h        | 24 +++++++++-----
 arch/arm64/include/asm/traps.h         |  2 +-
 arch/arm64/kernel/cpufeature.c         | 46 +++++++++++++++++++++-----
 arch/arm64/kernel/entry-common.c       | 21 ++++++++++++
 arch/arm64/kernel/fpsimd.c             |  4 +--
 arch/arm64/kernel/insn.c               | 11 +++---
 arch/arm64/kernel/probes/decode-insn.c |  9 +++--
 arch/arm64/kernel/traps.c              | 26 +++++++++++----
 11 files changed, 114 insertions(+), 38 deletions(-)


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