From: Lorenzo Stoakes <lstoakes@gmail.com>
To: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@redhat.com>,
Lorenzo Stoakes <lstoakes@gmail.com>
Subject: [PATCH] mm/gup: add missing gup_must_unshare() check to gup_huge_pgd()
Date: Sat, 6 May 2023 15:05:25 +0100 [thread overview]
Message-ID: <cb971ac8dd315df97058ea69442ecc007b9a364a.1683381545.git.lstoakes@gmail.com> (raw)
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@redhat.com>
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
---
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
next reply other threads:[~2023-05-06 14:05 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-06 14:05 Lorenzo Stoakes [this message]
2023-05-08 0:30 ` [PATCH] mm/gup: add missing gup_must_unshare() check to gup_huge_pgd() Andrew Morton
2023-05-08 0:45 ` David Hildenbrand
2023-05-08 1:00 ` Andrew Morton
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