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authorMark Rutland <mark.rutland@arm.com>2024-05-08 11:14:00 +0300
committerWill Deacon <will@kernel.org>2024-05-10 14:21:57 +0300
commit7187bb7d0b5c7dfa18ca82e9e5c75e13861b1d88 (patch)
tree1e7110fc3a7d2128241b578cefc63fa210f721dc /Documentation/arch/arm64
parent0ce85db6c2141b7ffb95709d76fc55a27ff3cdc1 (diff)
downloadlinux-7187bb7d0b5c7dfa18ca82e9e5c75e13861b1d88.tar.xz
arm64: errata: Add workaround for Arm errata 3194386 and 3312417
Cortex-X4 and Neoverse-V3 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. This is described in their Software Developer Errata Notice (SDEN) documents: * Cortex-X4 SDEN v8.0, erratum 3194386: https://developer.arm.com/documentation/SDEN-2432808/0800/ * Neoverse-V3 SDEN v6.0, erratum 3312417: https://developer.arm.com/documentation/SDEN-2891958/0600/ To workaround these errata, it is necessary to place a speculation barrier (SB) after MSR to the SSBS special-purpose register. This patch adds the requisite SB after writes to SSBS within the kernel, and hides the presence of SSBS from EL0 such that userspace software which cares about SSBS will manipulate this via prctl(PR_GET_SPECULATION_CTRL, ...). Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20240508081400.235362-5-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'Documentation/arch/arm64')
-rw-r--r--Documentation/arch/arm64/silicon-errata.rst4
1 files changed, 4 insertions, 0 deletions
diff --git a/Documentation/arch/arm64/silicon-errata.rst b/Documentation/arch/arm64/silicon-errata.rst
index d33e27c5ce61..eb8af8032c31 100644
--- a/Documentation/arch/arm64/silicon-errata.rst
+++ b/Documentation/arch/arm64/silicon-errata.rst
@@ -140,6 +140,8 @@ stable kernels.
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Cortex-X2 | #2224489 | ARM64_ERRATUM_2224489 |
+----------------+-----------------+-----------------+-----------------------------+
+| ARM | Cortex-X4 | #3194386 | ARM64_ERRATUM_3194386 |
++----------------+-----------------+-----------------+-----------------------------+
| ARM | Neoverse-N1 | #1188873,1418040| ARM64_ERRATUM_1418040 |
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Neoverse-N1 | #1349291 | N/A |
@@ -156,6 +158,8 @@ stable kernels.
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Neoverse-V1 | #1619801 | N/A |
+----------------+-----------------+-----------------+-----------------------------+
+| ARM | Neoverse-V3 | #3312417 | ARM64_ERRATUM_3312417 |
++----------------+-----------------+-----------------+-----------------------------+
| ARM | MMU-500 | #841119,826419 | N/A |
+----------------+-----------------+-----------------+-----------------------------+
| ARM | MMU-600 | #1076982,1209401| N/A |