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From: espo@bpa.UUCP (Bob Esposito)
Newsgroups: net.unix-wizards
Subject: SystemV fix for tty.c
Message-ID: <295@bpa.UUCP>
Date: Sun, 2-Feb-86 12:36:27 EST
Article-I.D.: bpa.295
Posted: Sun Feb  2 12:36:27 1986
Date-Received: Wed, 5-Feb-86 00:49:50 EST
Distribution: net.unix
Organization: Wayne, Pennsylvania
Lines: 44


	Here's my fix for the protection violation trap on a VAX
	in tty.c



	Bob Esposito ... bpa!espo


***** tty.c

/*
 * common ioctl tty code
 */
ttiocom(tp, cmd, arg, mode)
register struct tty *tp;
{
	register flag;
	struct termio cb;
	struct sgttyb tb;
+	extern nulldev();

	switch(cmd) {


                 ------------------------------------------

	case TCSETA:
		if (copyin(arg, &cb, sizeof cb)) {
			u.u_error = EFAULT;
			break;
		}
		if (tp->t_line != cb.c_line) {
			if (cb.c_line < 0 || cb.c_line >= linecnt) {
				u.u_error = EINVAL;
				break;
			}
+			if (linesw[cb.c_line].l_ioctl == nulldev) {
+				u.u_error = EINVAL;
+				break;
+			}

			(*linesw[tp->t_line].l_ioctl)(tp, LDCLOSE, 0, mode);
		}