linux-kernel - [PATCH AUTOSEL 4.19 089/172] tty: n

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20200618012218.607130-89-sashal@kernel.org>
Date:   Wed, 17 Jun 2020 21:20:55 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Gregory CLEMENT <gregory.clement@...tlin.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH AUTOSEL 4.19 089/172] tty: n_gsm: Fix SOF skipping

From: Gregory CLEMENT <gregory.clement@...tlin.com>

[ Upstream commit 84d6f81c1fb58b56eba81ff0a36cf31946064b40 ]

For at least some modems like the TELIT LE910, skipping SOF makes
transfers blocking indefinitely after a short amount of data
transferred.

Given the small improvement provided by skipping the SOF (just one
byte on about 100 bytes), it seems better to completely remove this
"feature" than make it optional.

Fixes: e1eaea46bb40 ("tty: n_gsm line discipline")
Signed-off-by: Gregory CLEMENT <gregory.clement@...tlin.com>
Link: https://lore.kernel.org/r/20200512115323.1447922-3-gregory.clement@bootlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/tty/n_gsm.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 86b7e20ffd7f..8d8229dd2796 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -669,7 +669,6 @@ static void gsm_data_kick(struct gsm_mux *gsm)
 {
 	struct gsm_msg *msg, *nmsg;
 	int len;
-	int skip_sof = 0;
 
 	list_for_each_entry_safe(msg, nmsg, &gsm->tx_list, list) {
 		if (gsm->constipated && msg->addr)
@@ -691,15 +690,10 @@ static void gsm_data_kick(struct gsm_mux *gsm)
 			print_hex_dump_bytes("gsm_data_kick: ",
 					     DUMP_PREFIX_OFFSET,
 					     gsm->txframe, len);
-
-		if (gsm->output(gsm, gsm->txframe + skip_sof,
-						len - skip_sof) < 0)
+		if (gsm->output(gsm, gsm->txframe, len) < 0)
 			break;
 		/* FIXME: Can eliminate one SOF in many more cases */
 		gsm->tx_bytes -= msg->len;
-		/* For a burst of frames skip the extra SOF within the
-		   burst */
-		skip_sof = 1;
 
 		list_del(&msg->list);
 		kfree(msg);
-- 
2.25.1