[PATCH] x86_64 .init.setup alignment fix

We're now putting 24-byte structures into .init.setup via __setup.  But
x86_64's compiler is emitting a `.align 16' in there, so they end up on
32-byte boundaries and do_early_param()'s pointer arithmetic goes wrong.

Fix that up by forcing the compiler to align these structures to sizeof(long).

Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/linux/init.h

@@ -113,12 +113,18 @@ struct obs_kernel_param {
 	int early;
 };
 
-/* Only for really core code.  See moduleparam.h for the normal way. */
+/*
+ * Only for really core code.  See moduleparam.h for the normal way.
+ *
+ * Force the alignment so the compiler doesn't space elements of the
+ * obs_kernel_param "array" too far apart in .init.setup.
+ */
 #define __setup_param(str, unique_id, fn, early)			\
 	static char __setup_str_##unique_id[] __initdata = str;	\
 	static struct obs_kernel_param __setup_##unique_id	\
-		 __attribute_used__				\
-		 __attribute__((__section__(".init.setup")))	\
+		__attribute_used__				\
+		__attribute__((__section__(".init.setup")))	\
+		__attribute__((aligned((sizeof(long)))))	\
 		= { __setup_str_##unique_id, fn, early }
 
 #define __setup_null_param(str, unique_id)			\