60 lines
1.3 KiB
C
60 lines
1.3 KiB
C
#ifndef _LINUX_ERR_H
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#define _LINUX_ERR_H
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#include <linux/compiler.h>
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#include <linux/compat.h>
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#include <linux/errno.h>
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/*
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* Kernel pointers have redundant information, so we can use a
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* scheme where we can return either an error code or a dentry
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* pointer with the same return value.
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*
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* This should be a per-architecture thing, to allow different
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* error and pointer decisions.
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*/
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#define MAX_ERRNO 4095
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#ifndef __ASSEMBLY__
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#define IS_ERR_VALUE(x) unlikely((x) >= (unsigned long)-MAX_ERRNO)
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static inline void *ERR_PTR(long error)
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{
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return (void *)(CONFIG_ERR_PTR_OFFSET + error);
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}
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static inline long PTR_ERR(const void *ptr)
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{
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return ((long)ptr - CONFIG_ERR_PTR_OFFSET);
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}
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static inline long IS_ERR(const void *ptr)
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{
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return IS_ERR_VALUE((unsigned long)PTR_ERR(ptr));
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}
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static inline bool IS_ERR_OR_NULL(const void *ptr)
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{
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return !ptr || IS_ERR_VALUE((unsigned long)PTR_ERR(ptr));
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}
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/**
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* ERR_CAST - Explicitly cast an error-valued pointer to another pointer type
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* @ptr: The pointer to cast.
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*
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* Explicitly cast an error-valued pointer to another pointer type in such a
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* way as to make it clear that's what's going on.
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*/
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static inline void * __must_check ERR_CAST(__force const void *ptr)
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{
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/* cast away the const */
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return (void *) ptr;
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}
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#endif
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#endif /* _LINUX_ERR_H */
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