blob: a5fbec864f2b8cbae38255f7c630332ffd7d8f8a [file] [log] [blame]
--- a/include/linux/types.h 2010-08-04 10:45:59.000000000 -0700
+++ b/include/linux/types.h 2014-06-06 15:11:42.439540137 -0700
@@ -33,6 +33,17 @@
typedef __u16 __bitwise __sum16;
typedef __u32 __bitwise __wsum;
+/*
+ * 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 architectures. 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)))
+
#endif /* __ASSEMBLY__ */
#endif /* _LINUX_TYPES_H */