Linux Kernel  3.7.1
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err.h
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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 
22 static inline void * __must_check ERR_PTR(long error)
23 {
24  return (void *) error;
25 }
26 
27 static inline long __must_check PTR_ERR(const void *ptr)
28 {
29  return (long) ptr;
30 }
31 
32 static inline long __must_check IS_ERR(const void *ptr)
33 {
34  return IS_ERR_VALUE((unsigned long)ptr);
35 }
36 
37 static inline long __must_check IS_ERR_OR_NULL(const void *ptr)
38 {
39  return !ptr || IS_ERR_VALUE((unsigned long)ptr);
40 }
41 
49 static inline void * __must_check ERR_CAST(const void *ptr)
50 {
51  /* cast away the const */
52  return (void *) ptr;
53 }
54 
55 static inline int __must_check PTR_RET(const void *ptr)
56 {
57  if (IS_ERR(ptr))
58  return PTR_ERR(ptr);
59  else
60  return 0;
61 }
62 
63 #endif
64 
65 #endif /* _LINUX_ERR_H */