116 lines
2.8 KiB
C
116 lines
2.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _LINUX_ERR_H
|
|
#define _LINUX_ERR_H
|
|
|
|
#include <linux/compiler.h>
|
|
#include <linux/types.h>
|
|
|
|
#include <asm/errno.h>
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
#define MAX_ERRNO 4095
|
|
|
|
#ifndef __ASSEMBLY__
|
|
|
|
/**
|
|
* IS_ERR_VALUE - Detect an error pointer.
|
|
* @x: The pointer to check.
|
|
*
|
|
* Like IS_ERR(), but does not generate a compiler warning if result is unused.
|
|
*/
|
|
#define IS_ERR_VALUE(x) unlikely((unsigned long)(void *)(x) >= (unsigned long)-MAX_ERRNO)
|
|
|
|
/**
|
|
* ERR_PTR - Create an error pointer.
|
|
* @error: A negative error code.
|
|
*
|
|
* Encodes @error into a pointer value. Users should consider the result
|
|
* opaque and not assume anything about how the error is encoded.
|
|
*
|
|
* Return: A pointer with @error encoded within its value.
|
|
*/
|
|
static inline void * __must_check ERR_PTR(long error)
|
|
{
|
|
return (void *) error;
|
|
}
|
|
|
|
/**
|
|
* PTR_ERR - Extract the error code from an error pointer.
|
|
* @ptr: An error pointer.
|
|
* Return: The error code within @ptr.
|
|
*/
|
|
static inline long __must_check PTR_ERR(__force const void *ptr)
|
|
{
|
|
return (long) ptr;
|
|
}
|
|
|
|
/**
|
|
* IS_ERR - Detect an error pointer.
|
|
* @ptr: The pointer to check.
|
|
* Return: true if @ptr is an error pointer, false otherwise.
|
|
*/
|
|
static inline bool __must_check IS_ERR(__force const void *ptr)
|
|
{
|
|
return IS_ERR_VALUE((unsigned long)ptr);
|
|
}
|
|
|
|
/**
|
|
* IS_ERR_OR_NULL - Detect an error pointer or a null pointer.
|
|
* @ptr: The pointer to check.
|
|
*
|
|
* Like IS_ERR(), but also returns true for a null pointer.
|
|
*/
|
|
static inline bool __must_check IS_ERR_OR_NULL(__force const void *ptr)
|
|
{
|
|
return unlikely(!ptr) || IS_ERR_VALUE((unsigned long)ptr);
|
|
}
|
|
|
|
/**
|
|
* ERR_CAST - Explicitly cast an error-valued pointer to another pointer type
|
|
* @ptr: The pointer to cast.
|
|
*
|
|
* Explicitly cast an error-valued pointer to another pointer type in such a
|
|
* way as to make it clear that's what's going on.
|
|
*/
|
|
static inline void * __must_check ERR_CAST(__force const void *ptr)
|
|
{
|
|
/* cast away the const */
|
|
return (void *) ptr;
|
|
}
|
|
|
|
/**
|
|
* PTR_ERR_OR_ZERO - Extract the error code from a pointer if it has one.
|
|
* @ptr: A potential error pointer.
|
|
*
|
|
* Convenience function that can be used inside a function that returns
|
|
* an error code to propagate errors received as error pointers.
|
|
* For example, ``return PTR_ERR_OR_ZERO(ptr);`` replaces:
|
|
*
|
|
* .. code-block:: c
|
|
*
|
|
* if (IS_ERR(ptr))
|
|
* return PTR_ERR(ptr);
|
|
* else
|
|
* return 0;
|
|
*
|
|
* Return: The error code within @ptr if it is an error pointer; 0 otherwise.
|
|
*/
|
|
static inline int __must_check PTR_ERR_OR_ZERO(__force const void *ptr)
|
|
{
|
|
if (IS_ERR(ptr))
|
|
return PTR_ERR(ptr);
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
#endif
|
|
|
|
#endif /* _LINUX_ERR_H */
|