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