[PATCH v2 2/3] mm/shmem: return error code directly for invalid addr

From: Chen Wandun
Date: Sat Jun 04 2022 - 23:47:29 EST


Return error code directly for addr is not PAGE_SIZE aligned or
beyond TASK_SIZE, no need to check these cases in caller.

Signed-off-by: Chen Wandun <chenwandun@xxxxxxxxxx>
---
mm/shmem.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/mm/shmem.c b/mm/shmem.c
index 17f8297ece29..5e61692f2d8e 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2142,10 +2142,10 @@ 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;
+ return -ENOMEM;

if (shmem_huge == SHMEM_HUGE_DENY)
return addr;
@@ -2196,7 +2196,7 @@ 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