linux-kernel - [PATCH 2/4] mm/shmem: return -EINVAL for addr not PAGE

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Date:   Wed, 1 Jun 2022 20:44:15 +0800
From:   Chen Wandun <chenwandun@...wei.com>
To:     <hughd@...gle.com>, <akpm@...ux-foundation.org>,
        <linux-mm@...ck.org>, <linux-kernel@...r.kernel.org>
CC:     <chenwandun@...wei.com>
Subject: [PATCH 2/4] mm/shmem: return -EINVAL for addr not PAGE_SIZE aligned

If addr is not PAGE_SIZE aligned, return -EINVAL directly.
Besides, use macro offset_in_page to check addr is not
PAGE_SIZE aligned case.

Signed-off-by: Chen Wandun <chenwandun@...wei.com>
---
 mm/shmem.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/mm/shmem.c b/mm/shmem.c
index 80c361c3d82c..1136dd7da9e5 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2143,8 +2143,8 @@ unsigned long shmem_get_unmapped_area(struct file *file,
 		return addr;
 	if (IS_ERR_VALUE(addr))
 		return addr;
-	if (addr & ~PAGE_MASK)
-		return addr;
+	if (offset_in_page(addr))
+		return -EINVAL;
 	if (addr > TASK_SIZE - len)
 		return addr;
 
@@ -2197,7 +2197,7 @@ unsigned long shmem_get_unmapped_area(struct file *file,
 	inflated_addr = get_area(NULL, uaddr, inflated_len, 0, flags);
 	if (IS_ERR_VALUE(inflated_addr))
 		return addr;
-	if (inflated_addr & ~PAGE_MASK)
+	if (offset_in_page(inflated_addr))
 		return addr;
 
 	inflated_offset = inflated_addr & (HPAGE_PMD_SIZE-1);
-- 
2.25.1