From mboxrd@z Thu Jan 1 00:00:00 1970 From: wcohen@redhat.com (William Cohen) Date: Tue, 29 Oct 2013 12:52:09 -0400 Subject: [PATCH] Make the 32-bit ARM get_user() and put_user() work for 16-bit quantities Message-ID: <1383065529-20001-1-git-send-email-wcohen@redhat.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org The 32-bit ARM does not have instructions to perform 16-bit loads or stores. The __get_user_asm_half and __put_user_asm_half macros sythesize those operations. However, in most cases the pointers passed into these macros are pointers to 16-bit types and the pointer arithmetic will end up pointing at the next 16-bit quantity rather than the second half (byte) of the 16-bit quantity. The macros need to explicitly typecast the pointers as pointers to 8-bit quantities to make the pointer arithmetic work out properly. Signed-off-by: William Cohen --- arch/arm/include/asm/uaccess.h | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h index 7e1f760..c2d9439 100644 --- a/arch/arm/include/asm/uaccess.h +++ b/arch/arm/include/asm/uaccess.h @@ -277,16 +277,16 @@ do { \ #define __get_user_asm_half(x,__gu_addr,err) \ ({ \ unsigned long __b1, __b2; \ - __get_user_asm_byte(__b1, __gu_addr, err); \ - __get_user_asm_byte(__b2, __gu_addr + 1, err); \ + __get_user_asm_byte(__b1, (u8 *)(__gu_addr), err); \ + __get_user_asm_byte(__b2, ((u8 *)(__gu_addr)) + 1, err);\ (x) = __b1 | (__b2 << 8); \ }) #else #define __get_user_asm_half(x,__gu_addr,err) \ ({ \ unsigned long __b1, __b2; \ - __get_user_asm_byte(__b1, __gu_addr, err); \ - __get_user_asm_byte(__b2, __gu_addr + 1, err); \ + __get_user_asm_byte(__b1, (u8 *)(__gu_addr), err); \ + __get_user_asm_byte(__b2, ((u8 *)(__gu_addr)) + 1, err);\ (x) = (__b1 << 8) | __b2; \ }) #endif @@ -358,15 +358,15 @@ do { \ #define __put_user_asm_half(x,__pu_addr,err) \ ({ \ unsigned long __temp = (unsigned long)(x); \ - __put_user_asm_byte(__temp, __pu_addr, err); \ - __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \ + __put_user_asm_byte(__temp, (u8 *)(__pu_addr), err); \ + __put_user_asm_byte(__temp >> 8, ((u8 *)(__pu_addr)) + 1, err);\ }) #else #define __put_user_asm_half(x,__pu_addr,err) \ ({ \ unsigned long __temp = (unsigned long)(x); \ - __put_user_asm_byte(__temp >> 8, __pu_addr, err); \ - __put_user_asm_byte(__temp, __pu_addr + 1, err); \ + __put_user_asm_byte(__temp >> 8, (u8 *)(__pu_addr), err);\ + __put_user_asm_byte(__temp, ((u8 *)(__pu_addr)) + 1, err);\ }) #endif -- 1.8.3.1