Current File : //usr/src/kernels/3.10.0-1160.88.1.el7.centos.plus.x86_64/include/linux/err.h
#ifndef _LINUX_ERR_H
#define _LINUX_ERR_H
#include <linux/compiler.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 dentry
* 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__
#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(const void *ptr)
{
return (long) ptr;
}
static inline long __must_check IS_ERR(const void *ptr)
{
return IS_ERR_VALUE((unsigned long)ptr);
}
static inline long __must_check IS_ERR_OR_NULL(const void *ptr)
{
return !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(const void *ptr)
{
/* cast away the const */
return (void *) ptr;
}
static inline int __must_check PTR_ERR_OR_ZERO(const void *ptr)
{
if (IS_ERR(ptr))
return PTR_ERR(ptr);
else
return 0;
}
/* Deprecated */
#define PTR_RET(p) PTR_ERR_OR_ZERO(p)
#endif
#endif /* _LINUX_ERR_H */
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