From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8D961C43387 for ; Thu, 20 Dec 2018 13:46:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 66F4F21852 for ; Thu, 20 Dec 2018 13:46:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733236AbeLTNq6 (ORCPT ); Thu, 20 Dec 2018 08:46:58 -0500 Received: from smtp.gentoo.org ([140.211.166.183]:49116 "EHLO smtp.gentoo.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733117AbeLTNq5 (ORCPT ); Thu, 20 Dec 2018 08:46:57 -0500 Received: from [IPv6:2001:a62:180a:4401:23b6:57c7:ac31:7c25] (unknown [IPv6:2001:a62:180a:4401:23b6:57c7:ac31:7c25]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: zzam) by smtp.gentoo.org (Postfix) with ESMTPSA id E2285335C6F; Thu, 20 Dec 2018 13:46:55 +0000 (UTC) Subject: Re: [PATCH] media: si2165: fix a missing check of return value To: Kangjie Lu Cc: pakki001@umn.edu, Mauro Carvalho Chehab , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org References: <20181220081209.40807-1-kjlu@umn.edu> From: Matthias Schwarzott Message-ID: <40956844-c18d-31d2-1f2c-e164dfe82ecf@gentoo.org> Date: Thu, 20 Dec 2018 14:46:52 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.3.3 MIME-Version: 1.0 In-Reply-To: <20181220081209.40807-1-kjlu@umn.edu> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 20.12.18 um 09:12 schrieb Kangjie Lu: > si2165_readreg8() may fail. Looking into si2165_readreg8(), we will find > that "val_tmp" will be an uninitialized value when regmap_read() fails. > "val_tmp" is then assigned to "val". So if si2165_readreg8() fails, > "val" will be a random value. Further use will lead to undefined > behaviors. The fix checks if si2165_readreg8() fails, and if so, returns > "-EINVAL". > Good catch. I reviewed it. See below. > Signed-off-by: Kangjie Lu > --- > drivers/media/dvb-frontends/si2165.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/drivers/media/dvb-frontends/si2165.c b/drivers/media/dvb-frontends/si2165.c > index feacd8da421d..c134f312fa5b 100644 > --- a/drivers/media/dvb-frontends/si2165.c > +++ b/drivers/media/dvb-frontends/si2165.c > @@ -275,18 +275,20 @@ static u32 si2165_get_fe_clk(struct si2165_state *state) > > static int si2165_wait_init_done(struct si2165_state *state) > { > - int ret = -EINVAL; > + int ret; > u8 val = 0; > int i; > > for (i = 0; i < 3; ++i) { > - si2165_readreg8(state, REG_INIT_DONE, &val); > + ret = si2165_readreg8(state, REG_INIT_DONE, &val); > + if (ret < 0) > + return -EINVAL; This code should return "ret" instead of "-EINVAL". > if (val == 0x01) > return 0; > usleep_range(1000, 50000); > } > dev_err(&state->client->dev, "init_done was not set\n"); > - return ret; > + return -EINVAL; Here I am not sure if -ETIMEDOUT would be a better return code. > } > > static int si2165_upload_firmware_block(struct si2165_state *state, >