diff mbox series

[15/16] mm: switch gup_hugepte to use try_get_compound_head

Message ID 20190601074959.14036-16-hch@lst.de (mailing list archive)
State New, archived
Headers show
Series [01/16] uaccess: add untagged_addr definition for other arches | expand

Commit Message

Christoph Hellwig June 1, 2019, 7:49 a.m. UTC 
This applies the overflow fixes from 8fde12ca79aff
("mm: prevent get_user_pages() from overflowing page refcount")
to the powerpc hugepd code and brings it back in sync with the
other GUP cases.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 mm/gup.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/mm/gup.c b/mm/gup.c
index e03c7e6b1422..6090044227f1 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -2006,7 +2006,8 @@  static int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
 		refs++;
 	} while (addr += PAGE_SIZE, addr != end);
 
-	if (!page_cache_add_speculative(head, refs)) {
+	head = try_get_compound_head(head, refs);
+	if (!head) {
 		*nr -= refs;
 		return 0;
 	}