Am 27.10.25 um 17:47 schrieb Claudio Imbrenda:
On Mon, 20 Oct 2025 10:41:28 +0200
David Hildenbrand <[email protected]> wrote:
On 20.10.25 09:00, Christian Borntraeger wrote:
Am 17.10.25 um 23:56 schrieb Balbir Singh:
In the meanwhile, does this fix/workaround work?
diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
index 0c847cdf4fd3..31c1754d5bd4 100644
--- a/mm/pgtable-generic.c
+++ b/mm/pgtable-generic.c
@@ -290,7 +290,7 @@ pte_t *___pte_offset_map(pmd_t *pmd, unsigned long addr,
pmd_t *pmdvalp)
if (pmdvalp)
*pmdvalp = pmdval;
- if (unlikely(pmd_none(pmdval) || !pmd_present(pmdval)))
+ if (unlikely(pmd_none(pmdval) ||
is_pmd_non_present_folio_entry(pmdval)))
goto nomap;
if (unlikely(pmd_trans_huge(pmdval)))
goto nomap;
Yes, this seems to work.
Right, but that's not what we will want here. We'll have to adjust s390x
gmap code (which is getting redesigned either way) to only take the page
lock.
In the end, we'll want here later a single
if (!pmd_present(pmdval))
goto nomap;
this seems to do the trick:
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;
+ *table = (pmd_val(*pmd) &
+ _SEGMENT_ENTRY_HARDWARE_BITS)
+ | _SEGMENT_ENTRY;
}
} else if (*table & _SEGMENT_ENTRY_PROTECT &&
!(pmd_val(*pmd) & _SEGMENT_ENTRY_PROTECT)) {
Tested-by: Christian Borntraeger <[email protected]>
Acked-by: Christian Borntraeger <[email protected]>
can you send a proper patch? I guess we should add it to Andrews mm true to
keep it close to the patch that uncovered the issue.
s390 maintainers cced.
