Re: [PATCH 5.15 6/9] arm64: spectre: increase parameters that can be used to turn off bhb mitigation individually

[Sasha Levin <sashal@kernel.org>]

[ 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 Lehui<pulehui@huaweicloud.com>
Commit author: Liu Song<liusong@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)

Note: The patch differs from the upstream commit:
---
1:  877ace9eab7de ! 1:  8c7e23e93b2d7 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.alibaba.com
         Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
    +    Signed-off-by: Pu Lehui <pulehui@huawei.com>
     
      ## Documentation/admin-guide/kernel-parameters.txt ##
     @@
    + 					       spectre_bhi=off [X86]
      					       spectre_v2_user=off [X86]
    - 					       spec_store_bypass_disable=off [X86,PPC]
      					       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.
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.1.y        |  Success    |  Success   |