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[0/3] arm64: errata: Expand speculative SSBS workaround (again)

Message ID 20240801101803.1982459-1-mark.rutland@arm.com (mailing list archive)
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Series arm64: errata: Expand speculative SSBS workaround (again) | expand

Message

Mark Rutland Aug. 1, 2024, 10:18 a.m. UTC
Hi,

A number of Arm Ltd CPUs suffer from errata whereby an MSR to the SSBS
special-purpose register does not affect subsequent speculative
instructions, permitting speculative store bypassing for a window of
time.

We worked around this for a number of CPUs in commits:

* 7187bb7d0b5c7dfa ("arm64: errata: Add workaround for Arm errata 3194386 and 3312417")
* 75b3c43eab594bfb ("arm64: errata: Expand speculative SSBS workaround")

Since then, similar errata have been published for a number of other Arm
Ltd CPUs, for which the same mitigation is sufficient. These patches expand the
existing workaround to cover those CPUs.

Mark.

Mark Rutland (3):
  arm64: cputype: Add Cortex-X1C definitions
  arm64: cputype: Add Cortex-A725 definitions
  arm64: errata: Expand speculative SSBS workaround (again)

 Documentation/arch/arm64/silicon-errata.rst | 18 +++++++++++++++++
 arch/arm64/Kconfig                          | 22 +++++++++++++++------
 arch/arm64/include/asm/cputype.h            |  4 ++++
 arch/arm64/kernel/cpu_errata.c              | 11 ++++++++++-
 4 files changed, 48 insertions(+), 7 deletions(-)

Comments

Catalin Marinas Aug. 1, 2024, 5:14 p.m. UTC | #1
On Thu, 01 Aug 2024 11:18:00 +0100, Mark Rutland wrote:
> A number of Arm Ltd CPUs suffer from errata whereby an MSR to the SSBS
> special-purpose register does not affect subsequent speculative
> instructions, permitting speculative store bypassing for a window of
> time.
> 
> We worked around this for a number of CPUs in commits:
> 
> [...]

Applied to arm64 (for-next/fixes), thanks!

[1/3] arm64: cputype: Add Cortex-X1C definitions
      https://git.kernel.org/arm64/c/58d245e03c32
[2/3] arm64: cputype: Add Cortex-A725 definitions
      https://git.kernel.org/arm64/c/9ef54a384526
[3/3] arm64: errata: Expand speculative SSBS workaround (again)
      https://git.kernel.org/arm64/c/adeec61a4723