Re: [RFC PATCH v2 1/3] x86: cpu/bugs: update SpectreRSB comments for AMD
From: Dave Hansen
Date: Mon Nov 11 2024 - 12:01:50 EST
On 11/11/24 08:39, Amit Shah wrote:
> From: Amit Shah <amit.shah@xxxxxxx>
>
> AMD CPUs do not fall back to the BTB when the RSB underflows for RET
> address speculation. AMD CPUs have not needed to stuff the RSB for
> underflow conditions.
>
> The RSB poisoning case is addressed by RSB filling - clean up the FIXME
> comment about it.
This amounts to "Josh was wrong" in commit 9756bba284. Before moving
forward with this, it would be great to get his ack on this to make sure
you two are on the same page.