[PATCH 0/2] arm64: fix+cleanup for ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD

From: Mark Rutland <mark.rutland@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: catalin.marinas@arm.com, james.morse@arm.com,
	mark.rutland@arm.com, robh@kernel.org, stable@vger.kernel.org,
	will@kernel.org
Subject: [PATCH 0/2] arm64: fix+cleanup for ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
Date: Tue, 16 Jan 2024 11:02:19 +0000	[thread overview]
Message-ID: <20240116110221.420467-1-mark.rutland@arm.com> (raw)

Hi,

While testing an unrelated patch on the arm64 for-next/core branch, I
spotted an issue in the ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
workaround. The first patch fixes that issue, and the second patch
cleans up the remaining logic.

The issue has existed since the workaround was introduced in commit:

  471470bc7052d28c ("arm64: errata: Add Cortex-A520 speculative unprivileged load workaround")

As that logic has recently been reworked in the arm64 for-next/core
branch, these patches are based atop that rework, specifically atop
commit:

  546b7cde9b1dd360 ("arm64: Rename ARM64_WORKAROUND_2966298")

As the patches alter the KPTI exception return logic, I've given this
testing with KPTI forced on, forced off, and disabled at build time,
which all appear to be fine. I don't have any hardware requiring the
ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD workaround, but as the
resulting logic for this is very simple I do not expect any issues with
that part of the logic.

Mark.

Mark Rutland (2):
  arm64: entry: fix ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
  arm64: entry: simplify kernel_exit logic

 arch/arm64/kernel/entry.S | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

-- 
2.30.2

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel