[ Sasha's backport helper bot ]
Hi,
✅ All tests passed successfully. No issues detected. No action required from the submitter.
The upstream commit SHA1 provided is correct: 877ace9eab7de032f954533afd5d1ecd0cf62eaf
WARNING: Author mismatch between patch and upstream commit: Backport author: Pu Lehuipulehui@huaweicloud.com Commit author: Liu Songliusong@linux.alibaba.com
Status in newer kernel trees: 6.15.y | Present (exact SHA1) 6.14.y | Present (exact SHA1) 6.12.y | Present (exact SHA1) 6.6.y | Present (exact SHA1) 6.1.y | Present (exact SHA1) 5.15.y | Not found
Note: The patch differs from the upstream commit: --- 1: 877ace9eab7de ! 1: 02dd583c7ea39 arm64: spectre: increase parameters that can be used to turn off bhb mitigation individually @@ Metadata ## Commit message ## 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%. @@ Commit message Acked-by: Catalin Marinas catalin.marinas@arm.com Link: https://lore.kernel.org/r/1661514050-22263-1-git-send-email-liusong@linux.al... Signed-off-by: Catalin Marinas catalin.marinas@arm.com + Signed-off-by: Pu Lehui pulehui@huawei.com
## Documentation/admin-guide/kernel-parameters.txt ## @@ - spectre_v2_user=off [X86] spec_store_bypass_disable=off [X86,PPC] + spectre_v2_user=off [X86] ssbd=force-off [ARM64] + nospectre_bhb [ARM64] - l1tf=off [X86] - mds=off [X86] tsx_async_abort=off [X86] + + Exceptions: @@ vulnerability. System may allow data leaks with this option.
-+ nospectre_bhb [ARM64] Disable all mitigations for Spectre-BHB (branch ++ nospectre_bhb [ARM64] Disable all mitigations for Spectre-BHB (branch + history injection) vulnerability. System may allow data leaks + with this option. + @@ Documentation/admin-guide/kernel-parameters.txt
## arch/arm64/kernel/proton-pack.c ## -@@ arch/arm64/kernel/proton-pack.c: static void this_cpu_set_vectors(enum arm64_bp_harden_el1_vectors slot) - isb(); - } +@@ arch/arm64/kernel/proton-pack.c: static void kvm_setup_bhb_slot(const char *hyp_vecs_start) { } + #endif /* CONFIG_KVM */
+ static bool spectre_bhb_fw_mitigated; +static bool __read_mostly __nospectre_bhb; +static int __init parse_spectre_bhb_param(char *str) +{ @@ arch/arm64/kernel/proton-pack.c: static void this_cpu_set_vectors(enum arm64_bp_ + return 0; +} +early_param("nospectre_bhb", parse_spectre_bhb_param); -+ + void spectre_bhb_enable_mitigation(const struct arm64_cpu_capabilities *entry) { - bp_hardening_cb_t cpu_cb; @@ arch/arm64/kernel/proton-pack.c: void spectre_bhb_enable_mitigation(const struct arm64_cpu_capabilities *entry) /* No point mitigating Spectre-BHB alone. */ } else if (!IS_ENABLED(CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY)) { ---
Results of testing on various branches:
| Branch | Patch Apply | Build Test | |---------------------------|-------------|------------| | stable/linux-5.15.y | Success | Success |