UML - fix epoll

UML/x86_64 needs the same packing of struct epoll_event as x86_64.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

include/linux/eventpoll.h

@@ -31,12 +31,19 @@
 /* 
  * On x86-64 make the 64bit structure have the same alignment as the
  * 32bit structure. This makes 32bit emulation easier.
+ *
+ * UML/x86_64 needs the same packing as x86_64 - UML + UML_X86 +
+ * 64_BIT adds up to UML/x86_64.
  */
 #ifdef __x86_64__
 #define EPOLL_PACKED __attribute__((packed))
 #else
+#if defined(CONFIG_UML) && defined(CONFIG_UML_X86) && defined(CONFIG_64BIT)
+#define EPOLL_PACKED __attribute__((packed))
+#else
 #define EPOLL_PACKED
 #endif
+#endif
 
 struct epoll_event {
 	__u32 events;