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| author | Marc Zyngier <marc.zyngier@arm.com> | 2018-05-29 15:11:09 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2018-05-31 19:34:49 +0300 |
| commit | a43ae4dfe56a01f5b98ba0cb2f784b6a43bafcc6 (patch) | |
| tree | 558aed9db1b8864954a137308ea67ce398f3d5c6 /Documentation/admin-guide | |
| parent | a725e3dda1813ed306734823ac4c65ca04e38500 (diff) | |
| download | linux-a43ae4dfe56a01f5b98ba0cb2f784b6a43bafcc6.tar.xz | |
arm64: Add 'ssbd' command-line option
On a system where the firmware implements ARCH_WORKAROUND_2,
it may be useful to either permanently enable or disable the
workaround for cases where the user decides that they'd rather
not get a trap overhead, and keep the mitigation permanently
on or off instead of switching it on exception entry/exit.
In any case, default to the mitigation being enabled.
Reviewed-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'Documentation/admin-guide')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 11fc28ecdb6d..7db8868fabab 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -4047,6 +4047,23 @@ expediting. Set to zero to disable automatic expediting. + ssbd= [ARM64,HW] + Speculative Store Bypass Disable control + + On CPUs that are vulnerable to the Speculative + Store Bypass vulnerability and offer a + firmware based mitigation, this parameter + indicates how the mitigation should be used: + + force-on: Unconditionally enable mitigation for + for both kernel and userspace + force-off: Unconditionally disable mitigation for + for both kernel and userspace + kernel: Always enable mitigation in the + kernel, and offer a prctl interface + to allow userspace to register its + interest in being mitigated too. + stack_guard_gap= [MM] override the default stack gap protection. The value is in page units and it defines how many pages prior |