Add an ERR_CAST() function to complement ERR_PTR and co.

Add an ERR_CAST() function to complement ERR_PTR and co. for the purposes of casting an error entyped as one pointer type to an error of another pointer type whilst making it explicit as to what is going on. This provides a replacement for the ERR_PTR(PTR_ERR(p)) construct. Signed-off-by: David Howells <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
chewitt · Feb 7, 2008 · d1bc8e9 · d1bc8e9
1 parent ae5e297
commit d1bc8e9
Showing 1 changed file with 13 additions and 0 deletions.
diff --git a/include/linux/err.h b/include/linux/err.h
@@ -34,6 +34,19 @@ static inline long IS_ERR(const void *ptr)
 	return 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 *ERR_CAST(const void *ptr)
+{
+	/* cast away the const */
+	return (void *) ptr;
+}
+
 #endif
 
 #endif /* _LINUX_ERR_H */