Line data    Source code

       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          36 :         return (void *) error;
      27             : }
      28             : 
      29             : static inline long __must_check PTR_ERR(__force const void *ptr)
      30             : {
      31          29 :         return (long) ptr;
      32             : }
      33             : 
      34             : static inline bool __must_check IS_ERR(__force const void *ptr)
      35             : {
      36       31165 :         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         305 :         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           1 :         if (IS_ERR(ptr))
      60           0 :                 return PTR_ERR(ptr);
      61             :         else
      62             :                 return 0;
      63             : }
      64             : 
      65             : #endif
      66             : 
      67             : #endif /* _LINUX_ERR_H */