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

[Will Deacon]

On Wed, Feb 05, 2025 at 11:35:18AM +0100, Emanuele Rocca wrote:
> On 2025-01-30 11:43, Will Deacon wrote:
> > On Fri, Jan 24, 2025 at 03:52:10PM +0100, Emanuele Rocca wrote:
> > > This is with kernel 6.1.123. The last known good kernel I have available right
> > > now is 6.1.119. In the 6.1.120 changelog I see the following commit which seems
> > > potentially related?
> > > 
> > >  https://lore.kernel.org/all/20241106160448.2712997-1-mark.rutland@arm.com/
> > > 
> > > That's stable commit [1].
> > 
> > I can't see anything wrong with that patch but if you have reason to
> > suspect that it's broken can you try reverting it to see if the problem
> > disappears?
> 
> Confirmed: reverting the patch fixes the issue.

I guess that's just a happy accident thanks to the clobber list changing
on the smc asm with the sve check.

Will