diff options
| -rw-r--r-- | include/linux/types.h | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/include/linux/types.h b/include/linux/types.h index 01a082f56ef..357dbc19606 100644 --- a/include/linux/types.h +++ b/include/linux/types.h @@ -121,7 +121,15 @@ typedef __u64 u_int64_t; typedef __s64 int64_t; #endif -/* this is a special 64bit data type that is 8-byte aligned */ +/* + * aligned_u64 should be used in defining kernel<->userspace ABIs to avoid + * common 32/64-bit compat problems. + * 64-bit values align to 4-byte boundaries on x86_32 (and possibly other + * architectures) and to 8-byte boundaries on 64-bit architetures. The new + * aligned_64 type enforces 8-byte alignment so that structs containing + * aligned_64 values have the same alignment on 32-bit and 64-bit architectures. + * No conversions are necessary between 32-bit user-space and a 64-bit kernel. + */ #define aligned_u64 __u64 __attribute__((aligned(8))) #define aligned_be64 __be64 __attribute__((aligned(8))) #define aligned_le64 __le64 __attribute__((aligned(8))) @@ -178,6 +186,11 @@ typedef __u64 __bitwise __be64; typedef __u16 __bitwise __sum16; typedef __u32 __bitwise __wsum; +/* this is a special 64bit data type that is 8-byte aligned */ +#define __aligned_u64 __u64 __attribute__((aligned(8))) +#define __aligned_be64 __be64 __attribute__((aligned(8))) +#define __aligned_le64 __le64 __attribute__((aligned(8))) + #ifdef __KERNEL__ typedef unsigned __bitwise__ gfp_t; typedef unsigned __bitwise__ fmode_t; |