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

[Emanuele Rocca]

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.

I now also tried moving the poisoning before the smccc_version /
smccc_conduit assignments, and the resulting kernel does *not* crash.
See [2].

[1] https://people.debian.org/~ema/w1-w17-crash.diff
[2] https://people.debian.org/~ema/w1-w17-nocrash.diff