Re: [BUG] ARM64 regression: NULL pointer dereference in arm_smccc_version_init+0x90/0x1ac

Will Deacon
2025-03-13T22:10:34Z

On Thu, Feb 06, 2025 at 05:57:41PM +0100, Emanuele Rocca wrote:
> On 2025-02-06 01:11, Will Deacon wrote:
> > In your screenshot, x6 looks like it's retained its poison value, but
> > that was the register being corrupted in the initial report. Maybe you
> > could share the diff you made?
>
> Sure, please see [1]. A kernel built with that patch crashes and all
> registers retain their poison values.

Okey doke, at least it sounds like the firmware isn't taking advantage
of the broken spec, then.

In any case, I think the right way forward here is to use the
out-of-line 1.2 helpers whenever we can (the spectre mitigations can
stay as they are).

Will