[src/trunk]: src/sys/kern Don't allow t_linesw to be NULL.

[enami <enami%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/c824aaef99b8
branches:  trunk
changeset: 499257:c824aaef99b8
user:      enami <enami%NetBSD.org@localhost>
date:      Wed Nov 15 01:47:14 2000 +0000

description:
Don't allow t_linesw to be NULL.

diffstat:

 sys/kern/tty.c |  32 +++++++++-----------------------
 1 files changed, 9 insertions(+), 23 deletions(-)

diffs (68 lines):

diff -r 4debf4aa4d32 -r c824aaef99b8 sys/kern/tty.c
--- a/sys/kern/tty.c    Wed Nov 15 01:42:53 2000 +0000
+++ b/sys/kern/tty.c    Wed Nov 15 01:47:14 2000 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: tty.c,v 1.123 2000/11/14 22:17:49 thorpej Exp $        */
+/*     $NetBSD: tty.c,v 1.124 2000/11/15 01:47:14 enami Exp $  */
 
 /*-
  * Copyright (c) 1982, 1986, 1990, 1991, 1993
@@ -738,6 +738,7 @@
 {
        extern struct tty *constty;     /* Temporary virtual console. */
        extern int nlinesw;
+       struct linesw *lp;
        int s, error;
 
        /* If the ioctl involves modification, hang if in the background. */
@@ -934,43 +935,28 @@
        }
        case TIOCSETD: {                /* set line discipline */
                int t = *(int *)data;
-               struct linesw *lp;
-               dev_t device = tp->t_dev;
 
                if ((u_int)t >= nlinesw)
                        return (ENXIO);
                lp = linesw[t];
-               if (lp != tp->t_linesw) {
-                       s = spltty();
-                       if (tp->t_linesw) 
-                               (*tp->t_linesw->l_close)(tp, flag);
-                       error = (*lp->l_open)(device, tp);
-                       if (error) {
-                               (void)(*tp->t_linesw->l_open)(device, tp);
-                               splx(s);
-                               return (error);
-                       }
-                       tp->t_linesw = lp;
-                       splx(s);
-               }
-               break;
+               goto setldisc;
        }
        case TIOCSLINED: {              /* set line discipline */
                char *name = (char *)data;
-               struct linesw *lp;
-               dev_t device = tp->t_dev;
+               dev_t device;
 
                /* Null terminate to prevent buffer overflow */
-               data[TTLINEDNAMELEN] = 0; 
+               name[TTLINEDNAMELEN] = 0; 
                lp = ttyldisc_lookup(name);
 
-               if (!lp)
+setldisc:
+               if (lp == NULL)
                        return (ENXIO);
 
                if (lp != tp->t_linesw) {
+                       device = tp->t_dev;
                        s = spltty();
-                       if (tp->t_linesw) 
-                               (*tp->t_linesw->l_close)(tp, flag);
+                       (*tp->t_linesw->l_close)(tp, flag);
                        error = (*lp->l_open)(device, tp);
                        if (error) {
                                (void)(*tp->t_linesw->l_open)(device, tp);