Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
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linux
1#ifndef _LINUX_ERR_H
2#define _LINUX_ERR_H
3
4#include <linux/compiler.h>
5
6#include <asm/errno.h>
7
8/*
9 * Kernel pointers have redundant information, so we can use a
10 * scheme where we can return either an error code or a dentry
11 * pointer with the same return value.
12 *
13 * This should be a per-architecture thing, to allow different
14 * error and pointer decisions.
15 */
16#define MAX_ERRNO 4095
17
18#ifndef __ASSEMBLY__
19
20#define IS_ERR_VALUE(x) unlikely((x) >= (unsigned long)-MAX_ERRNO)
21
22static inline void *ERR_PTR(long error)
23{
24 return (void *) error;
25}
26
27static inline long PTR_ERR(const void *ptr)
28{
29 return (long) ptr;
30}
31
32static inline long IS_ERR(const void *ptr)
33{
34 return IS_ERR_VALUE((unsigned long)ptr);
35}
36
37/**
38 * ERR_CAST - Explicitly cast an error-valued pointer to another pointer type
39 * @ptr: The pointer to cast.
40 *
41 * Explicitly cast an error-valued pointer to another pointer type in such a
42 * way as to make it clear that's what's going on.
43 */
44static inline void *ERR_CAST(const void *ptr)
45{
46 /* cast away the const */
47 return (void *) ptr;
48}
49
50#endif
51
52#endif /* _LINUX_ERR_H */