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1 | /* SPDX-License-Identifier: GPL-2.0 */ | |
2 | #ifndef _LINUX_ERR_H | |
3 | #define _LINUX_ERR_H | |
4 | ||
5 | #include <linux/compiler.h> | |
6 | #include <linux/types.h> | |
7 | ||
8 | #include <asm/errno.h> | |
9 | ||
10 | /* | |
11 | * Kernel pointers have redundant information, so we can use a | |
12 | * scheme where we can return either an error code or a normal | |
13 | * pointer with the same return value. | |
14 | * | |
15 | * This should be a per-architecture thing, to allow different | |
16 | * error and pointer decisions. | |
17 | */ | |
18 | #define MAX_ERRNO 4095 | |
19 | ||
20 | #ifndef __ASSEMBLY__ | |
21 | ||
22 | #define IS_ERR_VALUE(x) unlikely((unsigned long)(void *)(x) >= (unsigned long)-MAX_ERRNO) | |
23 | ||
24 | static inline void * __must_check ERR_PTR(long error) | |
25 | { | |
26 | return (void *) error; | |
27 | } | |
28 | ||
29 | static inline long __must_check PTR_ERR(__force const void *ptr) | |
30 | { | |
31 | return (long) ptr; | |
32 | } | |
33 | ||
34 | static inline bool __must_check IS_ERR(__force const void *ptr) | |
35 | { | |
36 | return IS_ERR_VALUE((unsigned long)ptr); | |
37 | } | |
38 | ||
39 | static inline bool __must_check IS_ERR_OR_NULL(__force const void *ptr) | |
40 | { | |
41 | return unlikely(!ptr) || IS_ERR_VALUE((unsigned long)ptr); | |
42 | } | |
43 | ||
44 | /** | |
45 | * ERR_CAST - Explicitly cast an error-valued pointer to another pointer type | |
46 | * @ptr: The pointer to cast. | |
47 | * | |
48 | * Explicitly cast an error-valued pointer to another pointer type in such a | |
49 | * way as to make it clear that's what's going on. | |
50 | */ | |
51 | static inline void * __must_check ERR_CAST(__force const void *ptr) | |
52 | { | |
53 | /* cast away the const */ | |
54 | return (void *) ptr; | |
55 | } | |
56 | ||
57 | static inline int __must_check PTR_ERR_OR_ZERO(__force const void *ptr) | |
58 | { | |
59 | if (IS_ERR(ptr)) | |
60 | return PTR_ERR(ptr); | |
61 | else | |
62 | return 0; | |
63 | } | |
64 | ||
65 | /* Deprecated */ | |
66 | #define PTR_RET(p) PTR_ERR_OR_ZERO(p) | |
67 | ||
68 | #endif | |
69 | ||
70 | #endif /* _LINUX_ERR_H */ |