[PATCH v2] arm64: spectre: Prevent lockdep splat on v4 mitigation enable path

[Will Deacon]

On Thu, 18 Feb 2021 14:03:46 +0000, Will Deacon wrote:
> The Spectre-v4 workaround is re-configured when resuming from suspend,
> as the firmware may have re-enabled the mitigation despite the user
> previously asking for it to be disabled.
> 
> Enabling or disabling the workaround can result in an undefined
> instruction exception on CPUs which implement PSTATE.SSBS but only allow
> it to be configured by adjusting the SPSR on exception return. We handle
> this by installing an 'undef hook' which effectively emulates the access.
> 
> [...]

Applied to arm64 (for-next/fixes), thanks!

[1/1] arm64: spectre: Prevent lockdep splat on v4 mitigation enable path
      https://git.kernel.org/arm64/c/a2c42bbabbe2

Cheers,
-- 
Will

https://fixes.arm64.dev
https://next.arm64.dev
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