Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Content-Type: text/plain; charset="UTF-8"
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
MIME-Version: 1.0
From:   Ben Hutchings <ben@decadent.org.uk>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
CC:     akpm@linux-foundation.org,
        "Linus Torvalds" <torvalds@linux-foundation.org>,
        "James Holderness" <j4_james@hotmail.com>,
        "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>
Date:   Thu, 07 Jun 2018 15:05:21 +0100
Message-ID: <lsq.1528380321.181972819@decadent.org.uk>
Subject: [PATCH 3.16 396/410] tty: vt: fix up tabstops properly
In-Reply-To: <lsq.1528380320.647747352@decadent.org.uk>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

3.16.57-rc1 review patch.  If anyone has any objections, please let me know.

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

From: Linus Torvalds <torvalds@linux-foundation.org>

commit f1869a890cdedb92a3fab969db5d0fd982850273 upstream.

Tabs on a console with long lines do not wrap properly, so correctly
account for the line length when computing the tab placement location.

Reported-by: James Holderness <j4_james@hotmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
 drivers/tty/vt/vt.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -1705,7 +1705,7 @@ static void reset_terminal(struct vc_dat
 	default_attr(vc);
 	update_attr(vc);
 
-	vc->vc_tab_stop[0]	= 0x01010100;
+	vc->vc_tab_stop[0]	=
 	vc->vc_tab_stop[1]	=
 	vc->vc_tab_stop[2]	=
 	vc->vc_tab_stop[3]	=
@@ -1748,7 +1748,7 @@ static void do_con_trol(struct tty_struc
 		vc->vc_pos -= (vc->vc_x << 1);
 		while (vc->vc_x < vc->vc_cols - 1) {
 			vc->vc_x++;
-			if (vc->vc_tab_stop[vc->vc_x >> 5] & (1 << (vc->vc_x & 31)))
+			if (vc->vc_tab_stop[7 & (vc->vc_x >> 5)] & (1 << (vc->vc_x & 31)))
 				break;
 		}
 		vc->vc_pos += (vc->vc_x << 1);
@@ -1808,7 +1808,7 @@ static void do_con_trol(struct tty_struc
 			lf(vc);
 			return;
 		case 'H':
-			vc->vc_tab_stop[vc->vc_x >> 5] |= (1 << (vc->vc_x & 31));
+			vc->vc_tab_stop[7 & (vc->vc_x >> 5)] |= (1 << (vc->vc_x & 31));
 			return;
 		case 'Z':
 			respond_ID(tty);
@@ -2001,7 +2001,7 @@ static void do_con_trol(struct tty_struc
 			return;
 		case 'g':
 			if (!vc->vc_par[0])
-				vc->vc_tab_stop[vc->vc_x >> 5] &= ~(1 << (vc->vc_x & 31));
+				vc->vc_tab_stop[7 & (vc->vc_x >> 5)] &= ~(1 << (vc->vc_x & 31));
 			else if (vc->vc_par[0] == 3) {
 				vc->vc_tab_stop[0] =
 					vc->vc_tab_stop[1] =