From 6871ed8f8682b635bbd7a844488ec05883e89172 Mon Sep 17 00:00:00 2001
From: deraadt <deraadt@openbsd.org>
Date: Thu, 2 Dec 2021 15:13:49 +0000
Subject: [PATCH] firstc() and nextc() use an int of global static storage. 
 Make this a pointer to a local variable to allow concurrent use if that ever
 needs to happen in the future. ok mpi kettenis

---
 sys/kern/tty.c      | 16 +++++++++-------
 sys/kern/tty_subr.c | 18 ++++++++----------
 sys/sys/tty.h       |  6 +++---
 3 files changed, 20 insertions(+), 20 deletions(-)

diff --git a/sys/kern/tty.c b/sys/kern/tty.c
index eaaa4b2a6e4..9dfe18756ed 100644
--- a/sys/kern/tty.c
+++ b/sys/kern/tty.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tty.c,v 1.170 2021/10/24 00:02:25 jsg Exp $	*/
+/*	$OpenBSD: tty.c,v 1.171 2021/12/02 15:13:49 deraadt Exp $	*/
 /*	$NetBSD: tty.c,v 1.68.4.2 1996/06/06 16:04:52 thorpej Exp $	*/
 
 /*-
@@ -1901,7 +1901,7 @@ ttyrub(int c, struct tty *tp)
 {
 	u_char *cp;
 	int savecol;
-	int tabc, s;
+	int tabc, s, cc;
 
 	if (!ISSET(tp->t_lflag, ECHO) || ISSET(tp->t_lflag, EXTPROC))
 		return 0;
@@ -1937,8 +1937,8 @@ ttyrub(int c, struct tty *tp)
 				SET(tp->t_state, TS_CNTTB);
 				SET(tp->t_lflag, FLUSHO);
 				tp->t_column = tp->t_rocol;
-				for (cp = firstc(&tp->t_rawq, &tabc); cp;
-				    cp = nextc(&tp->t_rawq, cp, &tabc))
+				for (cp = firstc(&tp->t_rawq, &tabc, &cc); cp;
+				    cp = nextc(&tp->t_rawq, cp, &tabc, &cc))
 					ttyecho(tabc, tp);
 				CLR(tp->t_lflag, FLUSHO);
 				CLR(tp->t_state, TS_CNTTB);
@@ -1995,7 +1995,7 @@ int
 ttyretype(struct tty *tp)
 {
 	u_char *cp;
-	int s, c;
+	int s, c, cc;
 
 	/* Echo the reprint character. */
 	if (tp->t_cc[VREPRINT] != _POSIX_VDISABLE)
@@ -2004,9 +2004,11 @@ ttyretype(struct tty *tp)
 	(void)ttyoutput('\n', tp);
 
 	s = spltty();
-	for (cp = firstc(&tp->t_canq, &c); cp; cp = nextc(&tp->t_canq, cp, &c))
+	for (cp = firstc(&tp->t_canq, &c, &cc); cp;
+	    cp = nextc(&tp->t_canq, cp, &c, &cc))
 		ttyecho(c, tp);
-	for (cp = firstc(&tp->t_rawq, &c); cp; cp = nextc(&tp->t_rawq, cp, &c))
+	for (cp = firstc(&tp->t_rawq, &c, &cc); cp;
+	    cp = nextc(&tp->t_rawq, cp, &c, &cc))
 		ttyecho(c, tp);
 	CLR(tp->t_state, TS_ERASE);
 	splx(s);
diff --git a/sys/kern/tty_subr.c b/sys/kern/tty_subr.c
index c8bca080ddb..c680d2466a4 100644
--- a/sys/kern/tty_subr.c
+++ b/sys/kern/tty_subr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tty_subr.c,v 1.34 2021/12/01 17:04:26 deraadt Exp $	*/
+/*	$OpenBSD: tty_subr.c,v 1.35 2021/12/02 15:13:49 deraadt Exp $	*/
 /*	$NetBSD: tty_subr.c,v 1.13 1996/02/09 19:00:43 christos Exp $	*/
 
 /*
@@ -346,8 +346,6 @@ out:
 	return count;
 }
 
-static int cc;
-
 /*
  * Given a non-NULL pointer into the clist return the pointer
  * to the next character in the list or return NULL if no more chars.
@@ -357,18 +355,18 @@ static int cc;
  * masked.
  */
 u_char *
-nextc(struct clist *clp, u_char *cp, int *c)
+nextc(struct clist *clp, u_char *cp, int *c, int *ccp)
 {
 
 	if (clp->c_cf == cp) {
 		/*
 		 * First time initialization.
 		 */
-		cc = clp->c_cc;
+		*ccp = clp->c_cc;
 	}
-	if (cc == 0 || cp == NULL)
+	if (*ccp == 0 || cp == NULL)
 		return NULL;
-	if (--cc == 0)
+	if (--(*ccp) == 0)
 		return NULL;
 	if (++cp == clp->c_ce)
 		cp = clp->c_cs;
@@ -391,12 +389,12 @@ nextc(struct clist *clp, u_char *cp, int *c)
  * *c is set to the NEXT character
  */
 u_char *
-firstc(struct clist *clp, int *c)
+firstc(struct clist *clp, int *c, int *ccp)
 {
 	u_char *cp;
 
-	cc = clp->c_cc;
-	if (cc == 0)
+	*ccp = clp->c_cc;
+	if (*ccp == 0)
 		return NULL;
 	cp = clp->c_cf;
 	*c = *cp & 0xff;
diff --git a/sys/sys/tty.h b/sys/sys/tty.h
index cce15817321..b31aeec35d9 100644
--- a/sys/sys/tty.h
+++ b/sys/sys/tty.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tty.h,v 1.39 2020/07/14 14:33:06 deraadt Exp $	*/
+/*	$OpenBSD: tty.h,v 1.40 2021/12/02 15:13:49 deraadt Exp $	*/
 /*	$NetBSD: tty.h,v 1.30.4.1 1996/06/02 09:08:13 mrg Exp $	*/
 
 /*-
@@ -260,7 +260,8 @@ void	 clist_init(void);
 int	 getc(struct clist *q);
 void	 ndflush(struct clist *q, int cc);
 int	 ndqb(struct clist *q, int flag);
-u_char	*nextc(struct clist *q, u_char *cp, int *c);
+u_char	*firstc(struct clist *clp, int *c, int *cc);
+u_char	*nextc(struct clist *q, u_char *cp, int *c, int *cc);
 int	 putc(int c, struct clist *q);
 int	 q_to_b(struct clist *q, u_char *cp, int cc);
 int	 unputc(struct clist *q);
@@ -300,7 +301,6 @@ void	 ttytstamp(struct tty *tp, int octs, int ncts, int odcd, int ndcd);
 void	tty_init(void);
 struct tty *ttymalloc(int);
 void	 ttyfree(struct tty *);
-u_char	*firstc(struct clist *clp, int *c);
 
 int	cttyopen(dev_t, int, int, struct proc *);
 int	cttyread(dev_t, struct uio *, int);
-- 
2.20.1