Re: [PATCH v5 06/30] arm64: context switch POR_EL0 register

[Catalin Marinas <catalin.marinas@arm.com>]

On Wed, Sep 04, 2024 at 11:22:54AM +0100, Will Deacon wrote:
> On Tue, Sep 03, 2024 at 03:54:13PM +0100, Joey Gouly wrote:
> > commit 3141fb86bee8d48ae47cab1594dad54f974a8899
> > Author: Joey Gouly <joey.gouly@arm.com>
> > Date:   Tue Sep 3 15:47:26 2024 +0100
> > 
> >     fixup! arm64: context switch POR_EL0 register
> > 
> > diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
> > index a3a61ecdb165..c224b0955f1a 100644
> > --- a/arch/arm64/kernel/process.c
> > +++ b/arch/arm64/kernel/process.c
> > @@ -515,11 +515,8 @@ static void permission_overlay_switch(struct task_struct *next)
> >                 return;
> > 
> >         current->thread.por_el0 = read_sysreg_s(SYS_POR_EL0);
> > -       if (current->thread.por_el0 != next->thread.por_el0) {
> > +       if (current->thread.por_el0 != next->thread.por_el0)
> >                 write_sysreg_s(next->thread.por_el0, SYS_POR_EL0);
> > -               /* ISB required for kernel uaccess routines when chaning POR_EL0 */
> > -               isb();
> > -       }
> >  }
> 
> What about the one in flush_poe()? I'm inclined to drop that as well.

Yes, that's a similar thing.

-- 
Catalin