Improvements and fixes in the 1.241 commit:

- Have TS_ZOMBIE ttys return POLLHUP instead of POLLERR
- Remove unneeded POLLWRNORM (old bug)
- TS_ZOMBIE ttys will set POLLIN and POLLRDNORM
- Do not call selrecord in TS_ZOMBIE ttys

PR:             kern/73821
Reviewed by:	bde
MFC after:	4 weeks

1 files changed, 9 insertions, 6 deletions

diff --git a/sys/kern/tty.c b/sys/kern/tty.c
index 0793e1f..d359f8d 100644
--- a/sys/kern/tty.c
+++ b/sys/kern/tty.c
@@ -1283,20 +1283,23 @@ ttypoll(struct cdev *dev, int events, struct thread *td)
 
 	s = spltty();
 	if (events & (POLLIN | POLLRDNORM)) {
-		if (ttnread(tp) > 0)
+		if (ISSET(tp->t_state, TS_ZOMBIE))
+			revents |= (events & (POLLIN | POLLRDNORM)) |
+			    POLLHUP;
+		else if (ttnread(tp) > 0)
 			revents |= events & (POLLIN | POLLRDNORM);
 		else
 			selrecord(td, &tp->t_rsel);
 	}
-	if (events & (POLLOUT | POLLWRNORM)) {
-		if (tp->t_outq.c_cc <= tp->t_olowat &&
+	if (events & POLLOUT) {
+		if (ISSET(tp->t_state, TS_ZOMBIE))
+			revents |= POLLHUP;
+		else if (tp->t_outq.c_cc <= tp->t_olowat &&
 		    ISSET(tp->t_state, TS_CONNECTED))
-			revents |= events & (POLLOUT | POLLWRNORM);
+			revents |= events & POLLOUT;
 		else
 			selrecord(td, &tp->t_wsel);
 	}
-	if (ISSET(tp->t_state, TS_ZOMBIE))
-		revents |= POLLERR;
 	splx(s);
 	return (revents);
 }