fa9ee9c4b9
PTR_RET() can be used if you have an error-pointer and are only interested in the eventual error value, but not the pointer. Yields the usual 0 for no error, -ESOMETHING otherwise. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
66 lines
1.3 KiB
C
66 lines
1.3 KiB
C
#ifndef _LINUX_ERR_H
|
|
#define _LINUX_ERR_H
|
|
|
|
#include <linux/compiler.h>
|
|
|
|
#include <asm/errno.h>
|
|
|
|
/*
|
|
* Kernel pointers have redundant information, so we can use a
|
|
* scheme where we can return either an error code or a dentry
|
|
* pointer with the same return value.
|
|
*
|
|
* This should be a per-architecture thing, to allow different
|
|
* error and pointer decisions.
|
|
*/
|
|
#define MAX_ERRNO 4095
|
|
|
|
#ifndef __ASSEMBLY__
|
|
|
|
#define IS_ERR_VALUE(x) unlikely((x) >= (unsigned long)-MAX_ERRNO)
|
|
|
|
static inline void * __must_check ERR_PTR(long error)
|
|
{
|
|
return (void *) error;
|
|
}
|
|
|
|
static inline long __must_check PTR_ERR(const void *ptr)
|
|
{
|
|
return (long) ptr;
|
|
}
|
|
|
|
static inline long __must_check IS_ERR(const void *ptr)
|
|
{
|
|
return IS_ERR_VALUE((unsigned long)ptr);
|
|
}
|
|
|
|
static inline long __must_check IS_ERR_OR_NULL(const void *ptr)
|
|
{
|
|
return !ptr || IS_ERR_VALUE((unsigned long)ptr);
|
|
}
|
|
|
|
/**
|
|
* ERR_CAST - Explicitly cast an error-valued pointer to another pointer type
|
|
* @ptr: The pointer to cast.
|
|
*
|
|
* Explicitly cast an error-valued pointer to another pointer type in such a
|
|
* way as to make it clear that's what's going on.
|
|
*/
|
|
static inline void * __must_check ERR_CAST(const void *ptr)
|
|
{
|
|
/* cast away the const */
|
|
return (void *) ptr;
|
|
}
|
|
|
|
static inline int __must_check PTR_RET(const void *ptr)
|
|
{
|
|
if (IS_ERR(ptr))
|
|
return PTR_ERR(ptr);
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
#endif
|
|
|
|
#endif /* _LINUX_ERR_H */
|