[PATCH 2/4] mm/shmem: return -EINVAL for addr not PAGE_SIZE aligned

From: Chen Wandun
Date: Wed Jun 01 2022 - 08:23:41 EST


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@xxxxxxxxxx>
---
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