Re: [PATCH v2] powerpc/32s: Fix random crashes by adding isync() after locking/unlocking KUEP
From: Michael Ellerman
Date: Fri Aug 27 2021 - 09:26:44 EST
On Wed, 18 Aug 2021 06:49:29 +0000 (UTC), Christophe Leroy wrote:
> Commit b5efec00b671 ("powerpc/32s: Move KUEP locking/unlocking in C")
> removed the 'isync' instruction after adding/removing NX bit in user
> segments. The reasoning behind this change was that when setting the
> NX bit we don't mind it taking effect with delay as the kernel never
> executes text from userspace, and when clearing the NX bit this is
> to return to userspace and then the 'rfi' should synchronise the
> context.
>
> [...]
Applied to powerpc/fixes.
[1/1] powerpc/32s: Fix random crashes by adding isync() after locking/unlocking KUEP
https://git.kernel.org/powerpc/c/ef486bf448a057a6e2d50e40ae879f7add6585da
cheers