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From:   Weikang shi <swkhack@gmail.com>
To:     linux-mm@kvack.org
Cc:     linux-kernel@vger.kernel.org, swkhack <swkhack@gmail.com>
Subject: [PATCH] mm: Change count_mm_mlocked_page_nr return type
Date:   Mon, 22 Apr 2019 18:38:36 +0800
Message-Id: <20190422103836.48566-1-swkhack@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: swkhack <swkhack@gmail.com>

In 64-bit machine,the value of "vma->vm_end - vma->vm_start"
maybe negative in 32bit int and the "count >> PAGE_SHIFT"'s rusult
will be wrong.So change the local variable and return
value to unsigned long will fix the problem.

Signed-off-by: swkhack <swkhack@gmail.com>
---
 mm/mlock.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/mlock.c b/mm/mlock.c
index 080f3b364..d614163f5 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -636,11 +636,11 @@ static int apply_vma_lock_flags(unsigned long start, size_t len,
  * is also counted.
  * Return value: previously mlocked page counts
  */
-static int count_mm_mlocked_page_nr(struct mm_struct *mm,
+static unsigned long count_mm_mlocked_page_nr(struct mm_struct *mm,
 		unsigned long start, size_t len)
 {
 	struct vm_area_struct *vma;
-	int count = 0;
+	unsigned long count = 0;
 
 	if (mm == NULL)
 		mm = current->mm;
-- 
2.17.1