include/linux/err.h

   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 IS_ERR_VALUE(x) unlikely((x) > (unsigned long)-1000L)
  17
  18 static inline void *ERR_PTR(long error)
  19 {
  20         return (void *) error;
  21 }
  22
  23 static inline long PTR_ERR(const void *ptr)
  24 {
  25         return (long) ptr;
  26 }
  27
  28 static inline long IS_ERR(const void *ptr)
  29 {
  30         return IS_ERR_VALUE((unsigned long)ptr);
  31 }
  32
  33 #endif /* _LINUX_ERR_H */