unify {de,}mangle_poll(), get rid of kernel-side POLL...

except, again, POLLFREE and POLL_BUSY_LOOP.

With this, we finally get to the promised end result:

 - POLL{IN,OUT,...} are plain integers and *not* in __poll_t, so any
   stray instances of ->poll() still using those will be caught by
   sparse.

 - eventpoll.c and select.c warning-free wrt __poll_t

 - no more kernel-side definitions of POLL... - userland ones are
   visible through the entire kernel (and used pretty much only for
   mangle/demangle)

 - same behavior as after the first series (i.e. sparc et.al. epoll(2)
   working correctly).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 24 insertions, 0 deletions

diff --git a/include/linux/poll.h b/include/linux/poll.h
index d23104b32931..f45ebd017eaa 100644
--- a/include/linux/poll.h
+++ b/include/linux/poll.h
@@ -108,4 +108,28 @@ extern int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,
 extern int poll_select_set_timeout(struct timespec64 *to, time64_t sec,
 				   long nsec);
 
+#define __MAP(v, from, to) \
+	(from < to ? (v & from) * (to/from) : (v & from) / (from/to))
+
+static inline __u16 mangle_poll(__poll_t val)
+{
+	__u16 v = (__force __u16)val;
+#define M(X) __MAP(v, (__force __u16)EPOLL##X, POLL##X)
+	return M(IN) | M(OUT) | M(PRI) | M(ERR) | M(NVAL) |
+		M(RDNORM) | M(RDBAND) | M(WRNORM) | M(WRBAND) |
+		M(HUP) | M(RDHUP) | M(MSG);
+#undef M
+}
+
+static inline __poll_t demangle_poll(u16 val)
+{
+#define M(X) (__force __poll_t)__MAP(val, POLL##X, (__force __u16)EPOLL##X)
+	return M(IN) | M(OUT) | M(PRI) | M(ERR) | M(NVAL) |
+		M(RDNORM) | M(RDBAND) | M(WRNORM) | M(WRBAND) |
+		M(HUP) | M(RDHUP) | M(MSG);
+#undef M
+}
+#undef __MAP
+
+
 #endif /* _LINUX_POLL_H */