/* 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 */
|
