On Wed, 29 Oct 2025 11:00:14 +0100 David Hildenbrand <[email protected]> wrote:
> On 28.10.25 14:01, Claudio Imbrenda wrote: > > For hugetlbs, gmap puds have the present bit set. For normal puds > > (which point to ptes), the bit is not set. This is in contrast to the > > normal userspace puds, which always have the bit set for present pmds. > > > > This causes issues when ___pte_offset_map() is modified to only check > > for the present bit. > > > > The solution to the problem is simply to always set the present bit for > > present gmap pmds. > > > > Signed-off-by: Claudio Imbrenda <[email protected]> > > Link: > > https://lore.kernel.org/lkml/[email protected]/ > > Tested-by: Christian Borntraeger <[email protected]> > > Acked-by: Christian Borntraeger <[email protected]> > > --- > > arch/s390/mm/gmap.c | 5 +++-- > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c > > index 8ff6bba107e8..22c448b32340 100644 > > --- a/arch/s390/mm/gmap.c > > +++ b/arch/s390/mm/gmap.c > > @@ -599,8 +599,9 @@ int __gmap_link(struct gmap *gmap, unsigned long gaddr, > > unsigned long vmaddr) > > | _SEGMENT_ENTRY_GMAP_UC > > | _SEGMENT_ENTRY; > > } else > > - *table = pmd_val(*pmd) & > > - _SEGMENT_ENTRY_HARDWARE_BITS; > > I'd add a comment here like > > /* Make sure that pmd_present() will work on these entries. */ the whole file is going away very soon anyway > > > + *table = (pmd_val(*pmd) & > > + _SEGMENT_ENTRY_HARDWARE_BITS) > > + | _SEGMENT_ENTRY; > > } > > } else if (*table & _SEGMENT_ENTRY_PROTECT && > > !(pmd_val(*pmd) & _SEGMENT_ENTRY_PROTECT)) { > > Reviewed-by: David Hildenbrand <[email protected]> >
