It was pointed out to me (thanks cdub!) that list_entry is equivalent
to container_of. However, in 2.5 list_entry simply calls container_of
as it is a more descriptive name. So here is a patch to both add
container_of and make list_entry a wrapper around it.
Thanks.
Hanna
kernel.h | 11 +++++++++++
list.h | 2 +-
2 files changed, 12 insertions(+), 1 deletion(-)
-----
diff -Nru linux-2.4.20-rc1/include/linux/kernel.h
linux-container_of/include/linux/kernel.h
--- linux-2.4.20-rc1/include/linux/kernel.h Mon Nov 11 16:53:25 2002
+++ linux-container_of/include/linux/kernel.h Mon Nov 11 15:23:16 2002
@@ -174,6 +174,17 @@
extern void __out_of_line_bug(int line) ATTRIB_NORET;
#define out_of_line_bug() __out_of_line_bug(__LINE__)
+/*
+ * container_of - cast a member of a structure out to the containing
structure
+ *
+ * @ptr: the pointer to the member.
+ * @type: the type of the container struct this is embedded in.
+ * @member: the name of the member within the struct.
+ */
+#define container_of(ptr, type, member) ({ \
+ const typeof( ((type *)0)->member ) *__mptr = (ptr); \
+ (type *)( (char *)__mptr - offsetof(type,member) );})
+
#endif /* __KERNEL__ */
#define SI_LOAD_SHIFT 16
diff -Nru linux-2.4.20-rc1/include/linux/list.h
linux-container_of/include/linux/list.h
--- linux-2.4.20-rc1/include/linux/list.h Mon Nov 11 16:53:25 2002
+++ linux-container_of/include/linux/list.h Mon Nov 11 16:50:06 2002
@@ -185,7 +185,7 @@
* @member: the name of the list_struct within the struct.
*/
#define list_entry(ptr, type, member) \
- ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
+ container_of(ptr, type, member)
/**
* list_for_each - iterate over a list