Cover all state checks and updates with spltty() in filt_ttyread().

diff --git a/sys/kern/tty.c b/sys/kern/tty.c
index 9dfe187..37e9ab5 100644 (file)
--- a/sys/kern/tty.c
+++ b/sys/kern/tty.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: tty.c,v 1.171 2021/12/02 15:13:49 deraadt Exp $       */
+/*     $OpenBSD: tty.c,v 1.172 2021/12/14 15:32:20 visa Exp $  */
 /*     $NetBSD: tty.c,v 1.68.4.2 1996/06/06 16:04:52 thorpej Exp $     */
 
 /*-
@@ -1154,18 +1154,19 @@ int
 filt_ttyread(struct knote *kn, long hint)
 {
        struct tty *tp = kn->kn_hook;
-       int s;
+       int active, s;
 
        s = spltty();
        kn->kn_data = ttnread(tp);
-       splx(s);
+       active = (kn->kn_data > 0);
        if (!ISSET(tp->t_cflag, CLOCAL) && !ISSET(tp->t_state, TS_CARR_ON)) {
                kn->kn_flags |= EV_EOF;
                if (kn->kn_flags & __EV_POLL)
                        kn->kn_flags |= __EV_HUP;
-               return (1);
+               active = 1;
        }
-       return (kn->kn_data > 0);
+       splx(s);
+       return (active);
 }
 
 void