From nobody Tue Apr 7 14:55:51 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D4456ECAAD5 for ; Mon, 29 Aug 2022 13:27:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230161AbiH2N1S (ORCPT ); Mon, 29 Aug 2022 09:27:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34056 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229707AbiH2N0t (ORCPT ); Mon, 29 Aug 2022 09:26:49 -0400 Received: from mail.ispras.ru (mail.ispras.ru [83.149.199.84]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AF29E4A816 for ; Mon, 29 Aug 2022 06:25:18 -0700 (PDT) Received: from localhost.localdomain (unknown [95.31.169.23]) by mail.ispras.ru (Postfix) with ESMTPSA id 84E1040737B8; Mon, 29 Aug 2022 13:17:22 +0000 (UTC) From: Fedor Pchelkin To: Greg Kroah-Hartman Cc: Fedor Pchelkin , Jiri Slaby , linux-kernel@vger.kernel.org, Alexey Khoroshilov , ldv-project@linuxtesting.org, Hillf Danton Subject: [PATCH v4 1/2] tty: n_gsm: replace kicktimer with delayed_work Date: Mon, 29 Aug 2022 16:16:39 +0300 Message-Id: <20220829131640.69254-2-pchelkin@ispras.ru> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220829131640.69254-1-pchelkin@ispras.ru> References: <20220829131640.69254-1-pchelkin@ispras.ru> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" A kick_timer timer_list is replaced with kick_timeout delayed_work to be able to synchronize with mutexes as a prerequisite for the introduction of tx_mutex. Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Fixes: c568f7086c6e ("tty: n_gsm: fix missing timer to handle stalled links= ") Suggested-by: Hillf Danton Signed-off-by: Fedor Pchelkin Signed-off-by: Alexey Khoroshilov Reviewed-by: Jiri Slaby --- v1->v2: sorry, now adapted patch from 5.10 to upstream v2->v3: replaced a kick_timer with a delayed_work v3->v4: separated kick_timer and tx_mutex into different patches drivers/tty/n_gsm.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index caa5c14ed57f..c4164c85ffd4 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -256,7 +256,7 @@ struct gsm_mux { struct list_head tx_data_list; /* Pending data packets */ =20 /* Control messages */ - struct timer_list kick_timer; /* Kick TX queuing on timeout */ + struct delayed_work kick_timeout; /* Kick TX queuing on timeout */ struct timer_list t2_timer; /* Retransmit timer for commands */ int cretries; /* Command retry counter */ struct gsm_control *pending_cmd;/* Our current pending command */ @@ -1009,7 +1009,7 @@ static void __gsm_data_queue(struct gsm_dlci *dlci, s= truct gsm_msg *msg) gsm->tx_bytes +=3D msg->len; =20 gsmld_write_trigger(gsm); - mod_timer(&gsm->kick_timer, jiffies + 10 * gsm->t1 * HZ / 100); + schedule_delayed_work(&gsm->kick_timeout, 10 * gsm->t1 * HZ / 100); } =20 /** @@ -1984,16 +1984,16 @@ static void gsm_dlci_command(struct gsm_dlci *dlci,= const u8 *data, int len) } =20 /** - * gsm_kick_timer - transmit if possible - * @t: timer contained in our gsm object + * gsm_kick_timeout - transmit if possible + * @work: work contained in our gsm object * * Transmit data from DLCIs if the queue is empty. We can't rely on * a tty wakeup except when we filled the pipe so we need to fire off * new data ourselves in other cases. */ -static void gsm_kick_timer(struct timer_list *t) +static void gsm_kick_timeout(struct work_struct *work) { - struct gsm_mux *gsm =3D from_timer(gsm, t, kick_timer); + struct gsm_mux *gsm =3D container_of(work, struct gsm_mux, kick_timeout.w= ork); unsigned long flags; int sent =3D 0; =20 @@ -2458,7 +2458,7 @@ static void gsm_cleanup_mux(struct gsm_mux *gsm, bool= disc) } =20 /* Finish outstanding timers, making sure they are done */ - del_timer_sync(&gsm->kick_timer); + cancel_delayed_work_sync(&gsm->kick_timeout); del_timer_sync(&gsm->t2_timer); =20 /* Finish writing to ldisc */ @@ -2501,7 +2501,7 @@ static int gsm_activate_mux(struct gsm_mux *gsm) if (dlci =3D=3D NULL) return -ENOMEM; =20 - timer_setup(&gsm->kick_timer, gsm_kick_timer, 0); + INIT_DELAYED_WORK(&gsm->kick_timeout, gsm_kick_timeout); timer_setup(&gsm->t2_timer, gsm_control_retransmit, 0); INIT_WORK(&gsm->tx_work, gsmld_write_task); init_waitqueue_head(&gsm->event); @@ -2946,7 +2946,7 @@ static int gsmld_open(struct tty_struct *tty) =20 gsmld_attach_gsm(tty, gsm); =20 - timer_setup(&gsm->kick_timer, gsm_kick_timer, 0); + INIT_DELAYED_WORK(&gsm->kick_timeout, gsm_kick_timeout); timer_setup(&gsm->t2_timer, gsm_control_retransmit, 0); INIT_WORK(&gsm->tx_work, gsmld_write_task); =20 --=20 2.25.1