This is a note to let you know that I've just added the patch titled
arm64: errata: Expand speculative SSBS workaround
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arm64-errata-expand-speculative-ssbs-workaround.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 7d4d4e14c0a5bc7eb242737982d5e55063719320
Author: Mark Rutland <mark.rutland@xxxxxxx>
Date: Fri Aug 9 11:34:23 2024 +0100
arm64: errata: Expand speculative SSBS workaround
[ Upstream commit 75b3c43eab594bfbd8184ec8ee1a6b820950819a ]
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 Cortex-X4 and Neoverse-V3, in commit:
7187bb7d0b5c7dfa ("arm64: errata: Add workaround for Arm errata 3194386 and 3312417")
... as per 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/
Since then, similar errata have been published for a number of other Arm Ltd
CPUs, for which the mitigation is the same. This is described in their
respective SDEN documents:
* Cortex-A710 SDEN v19.0, errataum 3324338
https://developer.arm.com/documentation/SDEN-1775101/1900/?lang=en
* Cortex-A720 SDEN v11.0, erratum 3456091
https://developer.arm.com/documentation/SDEN-2439421/1100/?lang=en
* Cortex-X2 SDEN v19.0, erratum 3324338
https://developer.arm.com/documentation/SDEN-1775100/1900/?lang=en
* Cortex-X3 SDEN v14.0, erratum 3324335
https://developer.arm.com/documentation/SDEN-2055130/1400/?lang=en
* Cortex-X925 SDEN v8.0, erratum 3324334
https://developer.arm.com/documentation/109108/800/?lang=en
* Neoverse-N2 SDEN v17.0, erratum 3324339
https://developer.arm.com/documentation/SDEN-1982442/1700/?lang=en
* Neoverse-V2 SDEN v9.0, erratum 3324336
https://developer.arm.com/documentation/SDEN-2332927/900/?lang=en
Note that due to shared design lineage, some CPUs share the same erratum
number.
Add these to the existing mitigation under CONFIG_ARM64_ERRATUM_3194386.
As listing all of the erratum IDs in the runtime description would be
unwieldy, this is reduced to:
"SSBS not fully self-synchronizing"
... matching the description of the errata in all of the SDENs.
Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>
Cc: James Morse <james.morse@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240603111812.1514101-6-mark.rutland@xxxxxxx
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
[ Mark: fix conflicts and renames ]
Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/Documentation/arm64/silicon-errata.rst b/Documentation/arm64/silicon-errata.rst
index b2db2492bd131..542cb20bf0f79 100644
--- a/Documentation/arm64/silicon-errata.rst
+++ b/Documentation/arm64/silicon-errata.rst
@@ -88,14 +88,28 @@ stable kernels.
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Cortex-A76 | #1463225 | ARM64_ERRATUM_1463225 |
+----------------+-----------------+-----------------+-----------------------------+
+| ARM | Cortex-A710 | #3324338 | ARM64_ERRATUM_3194386 |
++----------------+-----------------+-----------------+-----------------------------+
+| ARM | Cortex-A720 | #3456091 | ARM64_ERRATUM_3194386 |
++----------------+-----------------+-----------------+-----------------------------+
+| ARM | Cortex-X2 | #3324338 | ARM64_ERRATUM_3194386 |
++----------------+-----------------+-----------------+-----------------------------+
+| ARM | Cortex-X3 | #3324335 | ARM64_ERRATUM_3194386 |
++----------------+-----------------+-----------------+-----------------------------+
| ARM | Cortex-X4 | #3194386 | ARM64_ERRATUM_3194386 |
+----------------+-----------------+-----------------+-----------------------------+
+| ARM | Cortex-X925 | #3324334 | ARM64_ERRATUM_3194386 |
++----------------+-----------------+-----------------+-----------------------------+
| ARM | Neoverse-N1 | #1188873,1418040| ARM64_ERRATUM_1418040 |
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Neoverse-N1 | #1349291 | N/A |
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Neoverse-N1 | #1542419 | ARM64_ERRATUM_1542419 |
+----------------+-----------------+-----------------+-----------------------------+
+| ARM | Neoverse-N2 | #3324339 | ARM64_ERRATUM_3194386 |
++----------------+-----------------+-----------------+-----------------------------+
+| ARM | Neoverse-V2 | #3324336 | ARM64_ERRATUM_3194386 |
++----------------+-----------------+-----------------+-----------------------------+
| ARM | Neoverse-V3 | #3312417 | ARM64_ERRATUM_3194386 |
+----------------+-----------------+-----------------+-----------------------------+
| ARM | MMU-500 | #841119,826419 | N/A |
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 1455a81ee8687..5d80f72a3459f 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -591,12 +591,19 @@ config ARM64_ERRATUM_1742098
If unsure, say Y.
config ARM64_ERRATUM_3194386
- bool "Cortex-X4/Neoverse-V3: workaround for MSR SSBS not self-synchronizing"
+ bool "Cortex-{A720,X4,X925}/Neoverse-V3: workaround for MSR SSBS not self-synchronizing"
default y
help
This option adds the workaround for the following errata:
+ * ARM Cortex-A710 erratam 3324338
+ * ARM Cortex-A720 erratum 3456091
+ * ARM Cortex-X2 erratum 3324338
+ * ARM Cortex-X3 erratum 3324335
* ARM Cortex-X4 erratum 3194386
+ * ARM Cortex-X925 erratum 3324334
+ * ARM Neoverse N2 erratum 3324339
+ * ARM Neoverse V2 erratum 3324336
* ARM Neoverse-V3 erratum 3312417
On affected cores "MSR SSBS, #0" instructions may not affect
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 5e77a7595059b..97fabbdada62e 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -843,8 +843,15 @@ static struct midr_range broken_aarch32_aes[] = {
#ifdef CONFIG_ARM64_ERRATUM_3194386
static const struct midr_range erratum_spec_ssbs_list[] = {
+ MIDR_ALL_VERSIONS(MIDR_CORTEX_A710),
+ MIDR_ALL_VERSIONS(MIDR_CORTEX_A720),
+ MIDR_ALL_VERSIONS(MIDR_CORTEX_X2),
+ MIDR_ALL_VERSIONS(MIDR_CORTEX_X3),
MIDR_ALL_VERSIONS(MIDR_CORTEX_X4),
+ MIDR_ALL_VERSIONS(MIDR_CORTEX_X925),
+ MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N2),
MIDR_ALL_VERSIONS(MIDR_NEOVERSE_V3),
+ MIDR_ALL_VERSIONS(MIDR_NEOVERSE_V2),
{}
};
#endif
@@ -1040,7 +1047,7 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
#endif
#ifdef CONFIG_ARM64_ERRATUM_3194386
{
- .desc = "ARM errata 3194386, 3312417",
+ .desc = "SSBS not fully self-synchronizing",
.capability = ARM64_WORKAROUND_SPECULATIVE_SSBS,
ERRATA_MIDR_RANGE_LIST(erratum_spec_ssbs_list),
},
