On 4/2/20 8:48 PM, David Hildenbrand wrote: > Let's use asce_type where applicable. Also, simplify our sanity check for > valid table levels and convert it into a WARN_ON_ONCE(). Check if we even > have a valid gmap shadow as the very first step. > > Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> > --- > arch/s390/mm/gmap.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c > index fd32ab566f57..3c801dae7988 100644 > --- a/arch/s390/mm/gmap.c > +++ b/arch/s390/mm/gmap.c > @@ -790,17 +790,18 @@ static inline unsigned long *gmap_table_walk(struct gmap *gmap, > const int asce_type = gmap->asce & _ASCE_TYPE_MASK; > unsigned long *table; > > - if ((gmap->asce & _ASCE_TYPE_MASK) + 4 < (level * 4)) > - return NULL; > if (gmap_is_shadow(gmap) && gmap->removed) > return NULL; > > + if (WARN_ON_ONCE(level > (asce_type >> 2) + 1)) > + return NULL; > + > if (WARN_ON_ONCE(asce_type != _ASCE_TYPE_REGION1) && > gaddr & (-1UL << (31 + (asce_type >> 2) * 11))) > return NULL; > > table = gmap->table; We could also initialize this variable at the top, no? > - switch (gmap->asce & _ASCE_TYPE_MASK) { > + switch (asce_type) { > case _ASCE_TYPE_REGION1: > table += (gaddr & _REGION1_INDEX) >> _REGION1_SHIFT; > if (level == 4) >
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