Re: [PATCH v1 03/27] powerpc/mm: don't BUG() in slice_mask_for_size()

[Christophe Leroy]

Le 11/04/2019 Ã 07:41, Aneesh Kumar K.V a ÃcritÂ:
> Christophe Leroy <christophe.leroy@xxxxxx> writes:
>
> > When no mask is found for the page size, WARN() and return NULL
> > instead of BUG()ing.
> >
> > Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
> > ---
> >   arch/powerpc/mm/slice.c | 6 ++++--
> >   1 file changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/powerpc/mm/slice.c b/arch/powerpc/mm/slice.c
> > index aec91dbcdc0b..011d470ea340 100644
> > --- a/arch/powerpc/mm/slice.c
> > +++ b/arch/powerpc/mm/slice.c
> > @@ -165,7 +165,8 @@ static struct slice_mask *slice_mask_for_size(struct mm_struct *mm, int psize)
> >   	if (psize == MMU_PAGE_16G)
> >   		return &mm->context.mask_16g;
> >   #endif
> > -	BUG();
> > +	WARN_ON(true);
> > +	return NULL;
> >   }
>
>
> Same here. There are not catching runtime errors. We should never find
> that true. This is to catch mistakes during development changes. Switch
> to VM_BUG_ON?

Ok, I'll switch to VM_BUG_ON()

Christophe

> >   #elif defined(CONFIG_PPC_8xx)
> >   static struct slice_mask *slice_mask_for_size(struct mm_struct *mm, int psize)
> > @@ -178,7 +179,8 @@ static struct slice_mask *slice_mask_for_size(struct mm_struct *mm, int psize)
> >   	if (psize == MMU_PAGE_8M)
> >   		return &mm->context.mask_8m;
> >   #endif
> > -	BUG();
> > +	WARN_ON(true);
> > +	return NULL;
> >   }
> >   #else
> >   #error "Must define the slice masks for page sizes supported by the platform"
> > --
> > 2.13.3