[PATCH v2 12/13] asm-generic: uaccess: 1-byte access is always aligned

Arnd Bergmann
2021-05-14T10:05:22Z

From: Arnd Bergmann <arnd@arndb.de>

With the cleaned up version of asm-generic/unaligned.h,
there is a warning about the get_user/put_user helpers using
unaligned access for single-byte variables:

include/asm-generic/uaccess.h: In function ‘__get_user_fn’:
include/asm-generic/unaligned.h:13:15: warning: ‘packed’ attribute ignored for field of type ‘u8’ {aka ‘unsigned char’} [-Wattributes]
const struct { type x __packed; } *__pptr = (typeof(__pptr))(ptr); \

Change these to use a direct pointer dereference to avoid the
warnings.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
include/asm-generic/uaccess.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h
index 4973328f3c6e..7e903e450659 100644
--- a/include/asm-generic/uaccess.h
+++ b/include/asm-generic/uaccess.h
@@ -19,7 +19,7 @@ __get_user_fn(size_t size, const void __user *from, void *to)

switch (size) {
case 1:
- *(u8 *)to = get_unaligned((u8 __force *)from);
+ *(u8 *)to = *((u8 __force *)from);
return 0;
case 2:
*(u16 *)to = get_unaligned((u16 __force *)from);
@@ -45,7 +45,7 @@ __put_user_fn(size_t size, void __user *to, void *from)

switch (size) {
case 1:
- put_unaligned(*(u8 *)from, (u8 __force *)to);
+ *(*(u8 *)from, (u8 __force *)to);
return 0;
case 2:
put_unaligned(*(u16 *)from, (u16 __force *)to);
--
2.29.2