Re: [PATCH v1 01/27] powerpc/mm: Don't BUG() in hugepd_page()

[Christophe Leroy]

Le 11/04/2019 Ã 07:39, Aneesh Kumar K.V a ÃcritÂ:
> Christophe Leroy <christophe.leroy@xxxxxx> writes:
>
> > Don't BUG(), just warn and return NULL.
> > If the NULL value is not handled, it will get catched anyway.
> >
> > Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
> > ---
> >   arch/powerpc/include/asm/hugetlb.h | 6 ++++--
> >   1 file changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/powerpc/include/asm/hugetlb.h b/arch/powerpc/include/asm/hugetlb.h
> > index 8d40565ad0c3..48c29686c78e 100644
> > --- a/arch/powerpc/include/asm/hugetlb.h
> > +++ b/arch/powerpc/include/asm/hugetlb.h
> > @@ -14,7 +14,8 @@
> >    */
> >   static inline pte_t *hugepd_page(hugepd_t hpd)
> >   {
> > -	BUG_ON(!hugepd_ok(hpd));
> > +	if (WARN_ON(!hugepd_ok(hpd)))
> > +		return NULL;
>
> We should not find that true. That BUG_ON was there to catch errors
> when changing pte formats. May be switch that VM_BUG_ON()?

Ok, I'll switch to VM_BUG_ON()

Christophe

> >   	/*
> >   	 * We have only four bits to encode, MMU page size
> >   	 */
> > @@ -42,7 +43,8 @@ static inline void flush_hugetlb_page(struct vm_area_struct *vma,
> >   
> >   static inline pte_t *hugepd_page(hugepd_t hpd)
> >   {
> > -	BUG_ON(!hugepd_ok(hpd));
> > +	if (WARN_ON(!hugepd_ok(hpd)))
> > +		return NULL;
> >   #ifdef CONFIG_PPC_8xx
> >   	return (pte_t *)__va(hpd_val(hpd) & ~HUGEPD_SHIFT_MASK);
> >   #else
> > --
> > 2.13.3