[PATCH] Add epoll compat_ code to fs/compat.c

IA64 and ARM-OABI are currently using their own version of epoll compat_
code.

An architecture needs epoll_event translation if alignof(u64) in 32 bit
mode is different from alignof(u64) in 64 bit mode.  If an architecture
needs epoll_event translation, it must define struct compat_epoll_event in
asm/compat.h and set CONFIG_HAVE_COMPAT_EPOLL_EVENT and use
compat_sys_epoll_ctl and compat_sys_epoll_wait.

All 64 bit architecture should use compat_sys_epoll_pwait.

[sfr: restructure and move to fs/compat.c, remove MIPS version
of compat_sys_epoll_pwait, use __put_user_unaligned]

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/compat.h b/include/linux/compat.h
index 80b17f4..ccd863d 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -234,5 +234,24 @@
 		compat_ulong_t maxnode, const compat_ulong_t __user *old_nodes,
 		const compat_ulong_t __user *new_nodes);
 
+/*
+ * epoll (fs/eventpoll.c) compat bits follow ...
+ */
+#ifndef CONFIG_HAS_COMPAT_EPOLL_EVENT
+struct epoll_event;
+#define compat_epoll_event	epoll_event
+#else
+asmlinkage long compat_sys_epoll_ctl(int epfd, int op, int fd,
+			struct compat_epoll_event __user *event);
+asmlinkage long compat_sys_epoll_wait(int epfd,
+			struct compat_epoll_event __user *events,
+			int maxevents, int timeout);
+#endif
+asmlinkage long compat_sys_epoll_pwait(int epfd,
+			struct compat_epoll_event __user *events,
+			int maxevents, int timeout,
+			const compat_sigset_t __user *sigmask,
+			compat_size_t sigsetsize);
+
 #endif /* CONFIG_COMPAT */
 #endif /* _LINUX_COMPAT_H */