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