[ Upstream commit 081eb7932c2b244f63317a982c5e3990e2c7fbdd ]
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") * 145502cac7ea70b5 ("arm64: errata: Expand speculative SSBS workaround (again)")
Since then, a (hopefully final) batch of updates have been published, with two more affected CPUs. For the affected CPUs the existing mitigation is sufficient, as described in their respective Software Developer Errata Notice (SDEN) documents:
* Cortex-A715 (MP148) SDEN v15.0, erratum 3456084 https://developer.arm.com/documentation/SDEN-2148827/1500/
* Neoverse-N3 (MP195) SDEN v5.0, erratum 3456111 https://developer.arm.com/documentation/SDEN-3050973/0500/
Enable the existing mitigation by adding the relevant MIDRs to erratum_spec_ssbs_list, and update silicon-errata.rst and the Kconfig text accordingly.
Signed-off-by: Mark Rutland mark.rutland@arm.com Cc: James Morse james.morse@arm.com Cc: Will Deacon will@kernel.org Link: https://lore.kernel.org/r/20240930111705.3352047-3-mark.rutland@arm.com Signed-off-by: Catalin Marinas catalin.marinas@arm.com [ Mark: fix conflict in silicon-errata.rst, handle move ] Signed-off-by: Mark Rutland mark.rutland@arm.com --- Documentation/arm64/silicon-errata.rst | 4 ++++ arch/arm64/Kconfig | 2 ++ arch/arm64/kernel/cpu_errata.c | 2 ++ 3 files changed, 8 insertions(+)
diff --git a/Documentation/arm64/silicon-errata.rst b/Documentation/arm64/silicon-errata.rst index 00755541a9c50..17da972099760 100644 --- a/Documentation/arm64/silicon-errata.rst +++ b/Documentation/arm64/silicon-errata.rst @@ -98,6 +98,8 @@ stable kernels. +----------------+-----------------+-----------------+-----------------------------+ | ARM | Cortex-A710 | #3324338 | ARM64_ERRATUM_3194386 | +----------------+-----------------+-----------------+-----------------------------+ +| ARM | Cortex-A715 | #3456084 | ARM64_ERRATUM_3194386 | ++----------------+-----------------+-----------------+-----------------------------+ | ARM | Cortex-A720 | #3456091 | ARM64_ERRATUM_3194386 | +----------------+-----------------+-----------------+-----------------------------+ | ARM | Cortex-A725 | #3456106 | ARM64_ERRATUM_3194386 | @@ -124,6 +126,8 @@ stable kernels. +----------------+-----------------+-----------------+-----------------------------+ | ARM | Neoverse-N2 | #3324339 | ARM64_ERRATUM_3194386 | +----------------+-----------------+-----------------+-----------------------------+ +| ARM | Neoverse-N3 | #3456111 | ARM64_ERRATUM_3194386 | ++----------------+-----------------+-----------------+-----------------------------+ | ARM | Neoverse-V1 | #3324341 | ARM64_ERRATUM_3194386 | +----------------+-----------------+-----------------+-----------------------------+ | ARM | Neoverse-V2 | #3324336 | ARM64_ERRATUM_3194386 | diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 562558e0915cb..82eba7ffa1d58 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -602,6 +602,7 @@ config ARM64_ERRATUM_3194386 * ARM Cortex-A78C erratum 3324346 * ARM Cortex-A78C erratum 3324347 * ARM Cortex-A710 erratam 3324338 + * ARM Cortex-A715 errartum 3456084 * ARM Cortex-A720 erratum 3456091 * ARM Cortex-A725 erratum 3456106 * ARM Cortex-X1 erratum 3324344 @@ -612,6 +613,7 @@ config ARM64_ERRATUM_3194386 * ARM Cortex-X925 erratum 3324334 * ARM Neoverse-N1 erratum 3324349 * ARM Neoverse N2 erratum 3324339 + * ARM Neoverse-N3 erratum 3456111 * ARM Neoverse-V1 erratum 3324341 * ARM Neoverse V2 erratum 3324336 * ARM Neoverse-V3 erratum 3312417 diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 20c8d39b71cd6..1e1dfe59a469e 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -848,6 +848,7 @@ static const struct midr_range erratum_spec_ssbs_list[] = { MIDR_ALL_VERSIONS(MIDR_CORTEX_A78), MIDR_ALL_VERSIONS(MIDR_CORTEX_A78C), MIDR_ALL_VERSIONS(MIDR_CORTEX_A710), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A715), MIDR_ALL_VERSIONS(MIDR_CORTEX_A720), MIDR_ALL_VERSIONS(MIDR_CORTEX_A725), MIDR_ALL_VERSIONS(MIDR_CORTEX_X1), @@ -858,6 +859,7 @@ static const struct midr_range erratum_spec_ssbs_list[] = { MIDR_ALL_VERSIONS(MIDR_CORTEX_X925), MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N1), MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N2), + MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N3), MIDR_ALL_VERSIONS(MIDR_NEOVERSE_V1), MIDR_ALL_VERSIONS(MIDR_NEOVERSE_V2), MIDR_ALL_VERSIONS(MIDR_NEOVERSE_V3),