/* SPDX-License-Identifier: GPL-2.0 */ #ifndef __TOOLS_LINUX_ERR_H #define __TOOLS_LINUX_ERR_H #include <linux/compiler.h> #include <linux/types.h> #include <asm/errno.h> /* * Original kernel header comment: * * Kernel pointers have redundant information, so we can use a * scheme where we can return either an error code or a normal * pointer with the same return value. * * This should be a per-architecture thing, to allow different * error and pointer decisions. * * Userspace note: * The same principle works for userspace, because 'error' pointers * fall down to the unused hole far from user space, as described * in Documentation/x86/x86_64/mm.txt for x86_64 arch: * * 0000000000000000 - 00007fffffffffff (=47 bits) user space, different per mm hole caused by [48:63] sign extension * ffffffffffe00000 - ffffffffffffffff (=2 MB) unused hole * * It should be the same case for other architectures, because * this code is used in generic kernel code. */ #define MAX_ERRNO 4095 #define IS_ERR_VALUE(x) unlikely((x) >= (unsigned long)-MAX_ERRNO) static inline void * __must_check ERR_PTR(long error_) { return (void *) error_; } static inline long __must_check PTR_ERR(__force const void *ptr) { return (long) ptr; } static inline bool __must_check IS_ERR(__force const void *ptr) { return IS_ERR_VALUE((unsigned long)ptr); } static inline bool __must_check IS_ERR_OR_NULL(__force const void *ptr) { return unlikely(!ptr) || IS_ERR_VALUE((unsigned long)ptr); } #endif /* _LINUX_ERR_H */