Message-ID: <87y4ckg1fp.wl%kuninori.morimoto.gx@renesas.com>
From: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
To: Andrzej Hajda <a.hajda@samsung.com>
CC: Liam Girdwood <lgirdwood@gmail.com>, Mark Brown <broonie@kernel.org>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com>,
        "moderated list:SOUND - SOC LAYER / DYNAMIC AUDIO POWER MANAGEM..." 
	<alsa-devel@alsa-project.org>,
        "open list" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] ASoC: rsnd: fix usrcnt decrementing bug
In-Reply-To: <1450867041-729-4-git-send-email-a.hajda@samsung.com>
References: <1450867041-729-1-git-send-email-a.hajda@samsung.com>
	<1450867041-729-4-git-send-email-a.hajda@samsung.com>
User-Agent: Wanderlust/2.15.9 Emacs/24.3 Mule/6.0
MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue")
Content-Type: text/plain; charset="US-ASCII"
Date: Thu, 24 Dec 2015 00:04:00 +0000
SpamDiagnosticOutput: 1:23
SpamDiagnosticMetadata: NSPM
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 24 Dec 2015 00:04:00.2372 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-Transport-CrossTenantHeadersStamped: HKXPR06MB1016
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
Content-Length: 1441
Lines: 57


Hi Andrzej

> Field usrcnt is unsigned so it cannot be lesser than zero.
> 
> The problem has been detected using proposed semantic patch
> scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci [1].
> 
> [1]: http://permalink.gmane.org/gmane.linux.kernel/2038576
> 
> Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
> ---

Thank you for your patch. good catch !
I noticed current error case is not good for ssi.c
Can you agree below ?

---------
diff --git a/sound/soc/sh/rcar/ssi.c b/sound/soc/sh/rcar/ssi.c
index 7db05fd..e519e30 100644
--- a/sound/soc/sh/rcar/ssi.c
+++ b/sound/soc/sh/rcar/ssi.c
@@ -403,6 +403,12 @@ static int rsnd_ssi_quit(struct rsnd_mod *mod,
 	struct rsnd_ssi *ssi = rsnd_mod_to_ssi(mod);
 	struct device *dev = rsnd_priv_to_dev(priv);
 
+	if (!ssi->usrcnt) {
+		dev_err(dev, "%s[%d] usrcnt error\n",
+			rsnd_mod_name(mod), rsnd_mod_id(mod));
+		return -EIO;
+	}
+
 	if (rsnd_ssi_is_parent(mod, io))
 		goto rsnd_ssi_quit_end;
 
@@ -422,10 +428,6 @@ rsnd_ssi_quit_end:
 
 	ssi->usrcnt--;
 
-	if (ssi->usrcnt < 0)
-		dev_err(dev, "%s[%d] usrcnt error\n",
-			rsnd_mod_name(mod), rsnd_mod_id(mod));
-
 	return 0;
 }
 
---------


Best regards
---
Kuninori Morimoto
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/