Re: [PATCH] powerpc/traps: fix recoverability of machine check handling on book3s/32

[Christophe Leroy]

Hello,

Le 11/09/2020 à 11:15, Michal Suchánek a écrit :
> Hello,
>
> does this logic apply to "Unrecoverable System Reset" as well?

I don't know, I don't think I have any way the generate a System Reset 
on my board to check it.

Christophe

> Thanks
>
> Michal
>
> On Tue, Jan 22, 2019 at 02:11:24PM +0000, Christophe Leroy wrote:
> > Looks like book3s/32 doesn't set RI on machine check, so
> > checking RI before calling die() will always be fatal
> > allthought this is not an issue in most cases.
> >
> > Fixes: b96672dd840f ("powerpc: Machine check interrupt is a non-maskable interrupt")
> > Fixes: daf00ae71dad ("powerpc/traps: restore recoverability of machine_check interrupts")
> > Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
> > Cc: stable@xxxxxxxxxxxxxxx
> > ---
> >   arch/powerpc/kernel/traps.c | 8 ++++----
> >   1 file changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
> > index 64936b60d521..c740f8bfccc9 100644
> > --- a/arch/powerpc/kernel/traps.c
> > +++ b/arch/powerpc/kernel/traps.c
> > @@ -763,15 +763,15 @@ void machine_check_exception(struct pt_regs *regs)
> >   	if (check_io_access(regs))
> >   		goto bail;
> >   
> > -	/* Must die if the interrupt is not recoverable */
> > -	if (!(regs->msr & MSR_RI))
> > -		nmi_panic(regs, "Unrecoverable Machine check");
> > -
> >   	if (!nested)
> >   		nmi_exit();
> >   
> >   	die("Machine check", regs, SIGBUS);
> >   
> > +	/* Must die if the interrupt is not recoverable */
> > +	if (!(regs->msr & MSR_RI))
> > +		nmi_panic(regs, "Unrecoverable Machine check");
> > +
> >   	return;
> >   
> >   bail:
> > --
> > 2.13.3