All other instances of gup_huge_pXd() perform the unshare check, so update
the PGD-specific function to do so as well.
While checking pgd_write() might seem unusual, this function already
performs such a check via pgd_access_permitted() so this is in line with
the existing implementation.
Suggested-by: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Lorenzo Stoakes <lstoakes@xxxxxxxxx>
---
mm/gup.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/mm/gup.c b/mm/gup.c
index ef43ffb3d1fe..78a5198e3212 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -2898,6 +2898,11 @@ static int gup_huge_pgd(pgd_t orig, pgd_t *pgdp, unsigned long addr,
return 0;
}
+ if (!pgd_write(orig) && gup_must_unshare(NULL, flags, &folio->page)) {
+ gup_put_folio(folio, refs, flags);
+ return 0;
+ }
+
*nr += refs;
folio_set_referenced(folio);
return 1;
--
2.40.1
