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authorLiu Song <liusong@linux.alibaba.com>2025-06-07 15:25:18 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2025-06-27 11:04:23 +0100
commitd38941ee87aa1e5848515f14cd61fa0e057ba512 (patch)
tree8622a9dcbd7fac6f319d39b3c0b4076512ca4b4a /Documentation
parent86ca67653d1a48ee41a9d4a7cd33dfd700dabd90 (diff)
arm64: spectre: increase parameters that can be used to turn off bhb mitigation individually
[ Upstream commit 877ace9eab7de032f954533afd5d1ecd0cf62eaf ] In our environment, it was found that the mitigation BHB has a great impact on the benchmark performance. For example, in the lmbench test, the "process fork && exit" test performance drops by 20%. So it is necessary to have the ability to turn off the mitigation individually through cmdline, thus avoiding having to compile the kernel by adjusting the config. Signed-off-by: Liu Song <liusong@linux.alibaba.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/1661514050-22263-1-git-send-email-liusong@linux.alibaba.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Pu Lehui <pulehui@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt5
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 88110e74b3f7..1eff15169983 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2954,6 +2954,7 @@
spec_store_bypass_disable=off [X86,PPC]
spectre_v2_user=off [X86]
ssbd=force-off [ARM64]
+ nospectre_bhb [ARM64]
tsx_async_abort=off [X86]
Exceptions:
@@ -3367,6 +3368,10 @@
vulnerability. System may allow data leaks with this
option.
+ nospectre_bhb [ARM64] Disable all mitigations for Spectre-BHB (branch
+ history injection) vulnerability. System may allow data leaks
+ with this option.
+
nospec_store_bypass_disable
[HW] Disable all mitigations for the Speculative Store Bypass vulnerability