Re: [PATCH v2 2/2] arm64: Implement branch predictor hardening for Falkor

From: Will Deacon
Date: Tue Jan 09 2018 - 05:04:34 EST


On Mon, Jan 08, 2018 at 03:31:08PM -0600, Shanker Donthineni wrote:
> Falkor is susceptible to branch predictor aliasing and can
> theoretically be attacked by malicious code. This patch
> implements a mitigation for these attacks, preventing any
> malicious entries from affecting other victim contexts.
>
> Signed-off-by: Shanker Donthineni <shankerd@xxxxxxxxxxxxxx>
> ---
> Changes since v1:
> Corrected typo to fix the compilation errors if HARDEN_BRANCH_PREDICTOR=n
>
> This patch requires FALKOR MIDR which is available in upstream v4.15-rc7
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/arch/arm64?h=v4.15-rc7&id=c622cc013cece073722592cff1ac6643a33b1622 ans also
> attached this v2 patch series.

Please resend this as a fixup on top of for-next/core. It might make the
most sense to queue that at -rc1, after the MIDR change has already landed
in mainline.

Will