From: Hui Su <sh_def@163.com>
Date: Tue, 15 Dec 2020 03:11:55 +0000 (-0800)
Subject: mm/hugetlb.c: just use put_page_testzero() instead of page_count()
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=e5dfacebe4a47fc9e4dd25246ed3599d60122e38;p=linux.git

mm/hugetlb.c: just use put_page_testzero() instead of page_count()

We test the page reference count is zero or not here, it can be a bug here
if page refercence count is not zero.  So we can just use
put_page_testzero() instead of page_count().

Link: https://lkml.kernel.org/r/20201007170949.GA6416@rlk
Signed-off-by: Hui Su <sh_def@163.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 4b809cc7a3fda..987d4b57ab0d7 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2014,8 +2014,7 @@ retry:
 		 * This page is now managed by the hugetlb allocator and has
 		 * no users -- drop the buddy allocator's reference.
 		 */
-		put_page_testzero(page);
-		VM_BUG_ON_PAGE(page_count(page), page);
+		VM_BUG_ON_PAGE(!put_page_testzero(page), page);
 		enqueue_huge_page(h, page);
 	}
 free: