Provide helper macros for fields which represent pointers in kernel-userspace ABI. This facilitates handling of 32-bit user-space by 64-bit kernels by defining those fields as 32-bit 0-padding and 32-bit integer on 32-bit architectures, which allows the kernel to treat those as 64-bit integers. The order of padding and 32-bit integer depends on the endianness.
Signed-off-by: Mathieu Desnoyers <[email protected]> CC: "Paul E. McKenney" <[email protected]> CC: Peter Zijlstra <[email protected]> CC: Paul Turner <[email protected]> CC: Thomas Gleixner <[email protected]> CC: Andrew Hunter <[email protected]> CC: Andy Lutomirski <[email protected]> CC: Andi Kleen <[email protected]> CC: Dave Watson <[email protected]> CC: Chris Lameter <[email protected]> CC: Ingo Molnar <[email protected]> CC: "H. Peter Anvin" <[email protected]> CC: Ben Maurer <[email protected]> CC: Steven Rostedt <[email protected]> CC: Josh Triplett <[email protected]> CC: Linus Torvalds <[email protected]> CC: Andrew Morton <[email protected]> CC: Russell King <[email protected]> CC: Catalin Marinas <[email protected]> CC: Will Deacon <[email protected]> CC: Michael Kerrisk <[email protected]> CC: Boqun Feng <[email protected]> CC: [email protected] --- Changes since v1: - Public uapi headers use __u32 and __u64 rather than uint32_t and uint64_t. --- include/uapi/linux/types_32_64.h | 50 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 include/uapi/linux/types_32_64.h diff --git a/include/uapi/linux/types_32_64.h b/include/uapi/linux/types_32_64.h new file mode 100644 index 000000000000..0a87ace34a57 --- /dev/null +++ b/include/uapi/linux/types_32_64.h @@ -0,0 +1,50 @@ +/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */ +#ifndef _UAPI_LINUX_TYPES_32_64_H +#define _UAPI_LINUX_TYPES_32_64_H + +/* + * linux/types_32_64.h + * + * Integer type declaration for pointers across 32-bit and 64-bit systems. + * + * Copyright (c) 2015-2018 Mathieu Desnoyers <[email protected]> + */ + +#ifdef __KERNEL__ +# include <linux/types.h> +#else +# include <stdint.h> +#endif + +#include <asm/byteorder.h> + +#ifdef __BYTE_ORDER +# if (__BYTE_ORDER == __BIG_ENDIAN) +# define LINUX_BYTE_ORDER_BIG_ENDIAN +# else +# define LINUX_BYTE_ORDER_LITTLE_ENDIAN +# endif +#else +# ifdef __BIG_ENDIAN +# define LINUX_BYTE_ORDER_BIG_ENDIAN +# else +# define LINUX_BYTE_ORDER_LITTLE_ENDIAN +# endif +#endif + +#ifdef __LP64__ +# define LINUX_FIELD_u32_u64(field) __u64 field +# define LINUX_FIELD_u32_u64_INIT_ONSTACK(field, v) field = (intptr_t)v +#else +# ifdef LINUX_BYTE_ORDER_BIG_ENDIAN +# define LINUX_FIELD_u32_u64(field) __u32 field ## _padding, field +# define LINUX_FIELD_u32_u64_INIT_ONSTACK(field, v) \ + field ## _padding = 0, field = (intptr_t)v +# else +# define LINUX_FIELD_u32_u64(field) __u32 field, field ## _padding +# define LINUX_FIELD_u32_u64_INIT_ONSTACK(field, v) \ + field = (intptr_t)v, field ## _padding = 0 +# endif +#endif + +#endif /* _UAPI_LINUX_TYPES_32_64_H */ -- 2.11.0
