[PATCH] powerpc: Set the correct kernel taint on machine check errors.

[Daniel Axtens]

On Wed, 2015-06-24 at 15:00 +1000, Michael Ellerman wrote:
> On Mon, 2015-06-15 at 13:25 +1000, Daniel Axtens wrote:
> > This means the 'M' flag will work properly when the kernel prints a backtrace.
> > 
> > Signed-off-by: Daniel Axtens <dja at axtens.net>
> > ---
> >  arch/powerpc/kernel/traps.c | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
> > index 6530f1b..37de90f 100644
> > --- a/arch/powerpc/kernel/traps.c
> > +++ b/arch/powerpc/kernel/traps.c
> > @@ -297,6 +297,8 @@ long machine_check_early(struct pt_regs *regs)
> >  
> >  	__this_cpu_inc(irq_stat.mce_exceptions);
> >  
> > +	add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
> 
> I'm not sure about the lockdep bit.
> 
> I guess it's safer to just declare it fubar.
> 
I'm also not sure; I was matching x86 behaviour.

> Does this fix a bug, or just nice to have?
> 
If you consider having the taint bits set incorrectly to be a bug, then
it fixes a bug. Otherwise, it's just nice debug info to have: when we
get a traceback with M set that isn't obviously related to a MCE we are
forewarned.

> cheers
> 
> 

-- 
Regards,
Daniel
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