From patchwork Tue Jun 6 15:00:43 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Takashi Iwai X-Patchwork-Id: 9769059 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 7F1F86035D for ; Tue, 6 Jun 2017 15:01:55 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 72C4228502 for ; Tue, 6 Jun 2017 15:01:55 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 66FE828576; Tue, 6 Jun 2017 15:01:55 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9AA5D2850D for ; Tue, 6 Jun 2017 15:01:54 +0000 (UTC) Received: from alsa0.perex.cz (localhost [127.0.0.1]) by alsa0.perex.cz (Postfix) with ESMTP id 46094266F54; Tue, 6 Jun 2017 17:01:05 +0200 (CEST) X-Original-To: alsa-devel@alsa-project.org Delivered-To: alsa-devel@alsa-project.org Received: by alsa0.perex.cz (Postfix, from userid 1000) id 5A876266F5B; Tue, 6 Jun 2017 17:01:02 +0200 (CEST) Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) by alsa0.perex.cz (Postfix) with ESMTP id 083C4266F11 for ; Tue, 6 Jun 2017 17:00:50 +0200 (CEST) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 6A62EAC03; Tue, 6 Jun 2017 15:00:50 +0000 (UTC) From: Takashi Iwai To: alsa-devel@alsa-project.org Date: Tue, 6 Jun 2017 17:00:43 +0200 Message-Id: <20170606150043.10525-5-tiwai@suse.de> X-Mailer: git-send-email 2.13.0 In-Reply-To: <20170606150043.10525-1-tiwai@suse.de> References: <20170606150043.10525-1-tiwai@suse.de> Cc: Kostya Serebryany , Alexander Potapenko , Dmitriy Vyukov , Andrey Konovalov Subject: [alsa-devel] [PATCH 4/4] ALSA: timer: Wrap with spinlock for queue access X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org X-Virus-Scanned: ClamAV using ClamSMTP For accessing the snd_timer_user queue indices, we take tu->qlock. But it's forgotten in a couple of places. The one in snd_timer_user_params() should be safe without the spinlock as the timer is already stopped. But it's better for consistency. The one in poll is just a read-out, so it's not inevitably needed, but it'd be good to make the result consistent, too. Tested-by: Alexander Potapenko Signed-off-by: Takashi Iwai --- sound/core/timer.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/sound/core/timer.c b/sound/core/timer.c index 96cffb1be57f..148290ace756 100644 --- a/sound/core/timer.c +++ b/sound/core/timer.c @@ -1755,6 +1755,7 @@ static int snd_timer_user_params(struct file *file, if (err < 0) goto _end; } + spin_lock_irq(&tu->qlock); tu->qhead = tu->qtail = tu->qused = 0; if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) { if (tu->tread) { @@ -1775,6 +1776,7 @@ static int snd_timer_user_params(struct file *file, } tu->filter = params.filter; tu->ticks = params.ticks; + spin_unlock_irq(&tu->qlock); err = 0; _end: if (copy_to_user(_params, ¶ms, sizeof(params))) @@ -2022,10 +2024,12 @@ static unsigned int snd_timer_user_poll(struct file *file, poll_table * wait) poll_wait(file, &tu->qchange_sleep, wait); mask = 0; + spin_lock_irq(&tu->qlock); if (tu->qused) mask |= POLLIN | POLLRDNORM; if (tu->disconnected) mask |= POLLERR; + spin_unlock_irq(&tu->qlock); return mask; }