On Mon, 15 Jun 2026 21:56:17 +0530, Mukesh Kumar Chaurasiya (IBM) wrote:

During a syscall restart, block KUAP so that pending interrupts can be
replayed. The original KUAP state is not restored before returning to
userspace, causing subsequent userspace accesses to fault and eventually
trigger bad_access_pkey(), crashing the kernel.

The original KUAP register values are already saved in
arch_enter_from_user_mode(). Restore them on the syscall restart exit
path before returning to userspace.

[...]

Applied to powerpc/next.

[1/1] powerpc: Restore KUAP registers on syscall restart exit
      https://git.kernel.org/powerpc/c/4e1187e12de40b5301977b2476d21b569358dafb

cheers