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=-8.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 3132EC3A59E for ; Mon, 2 Sep 2019 22:37:08 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id F2DAB20828 for ; Mon, 2 Sep 2019 22:37:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="KSCzGPZ4" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F2DAB20828 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=C2m71fIHkK3pZIMyvBAFAECbkT4bWsVWOG7BlXE86fk=; b=KSCzGPZ4jSzbBl MHs64xY1tB5pQMGYS0YQH43usCABvDgTd7PIRAlMsXKBvh5KWXtq8Crb3faGhlDL1twpRxbM/55sT xtfhtg12mPern8wzqeDs6VHbLXON8o8KMC2wI70+C5PoPYJcDSv6JjK+qna2rcCul3S4+SHEDhMwb xFZ5FMK+/PxeGtYff3/1AtFSMG+qy/CAyYU+YMr7Zhi7LRVtbFV2Jrqg9MO62YjNn6O2PiUAZ9S5s b5Y/BR+ViwO/8nhAoFeCXNksB2vAcUFjqrUGGr4CkC75RF+9TVTDItlXLap+bodbVXjyjm8A8Ukld PNINabqihSHkiU79fpiw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i4uwY-0005Hf-6A; Mon, 02 Sep 2019 22:37:02 +0000 Received: from relay8-d.mail.gandi.net ([217.70.183.201]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1i4uwV-0005Gt-Ao for linux-arm-kernel@lists.infradead.org; Mon, 02 Sep 2019 22:37:01 +0000 X-Originating-IP: 90.65.161.137 Received: from localhost (lfbn-1-1545-137.w90-65.abo.wanadoo.fr [90.65.161.137]) (Authenticated sender: alexandre.belloni@bootlin.com) by relay8-d.mail.gandi.net (Postfix) with ESMTPSA id A57DF1BF207; Mon, 2 Sep 2019 22:36:50 +0000 (UTC) Date: Tue, 3 Sep 2019 00:36:50 +0200 From: Alexandre Belloni To: Yizhuo Subject: Re: [PATCH] clocksource: atmel-st: Variable sr in at91rm9200_timer_interrupt() could be uninitialized Message-ID: <20190902223650.GJ21922@piout.net> References: <20190902222946.20548-1-yzhai003@ucr.edu> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190902222946.20548-1-yzhai003@ucr.edu> User-Agent: Mutt/1.12.1 (2019-06-15) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190902_153659_524926_6DF81819 X-CRM114-Status: GOOD ( 16.04 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: csong@cs.ucr.edu, Daniel Lezcano , zhiyunq@cs.ucr.edu, linux-kernel@vger.kernel.org, Ludovic Desroches , Thomas Gleixner , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 02/09/2019 15:29:46-0700, Yizhuo wrote: > Inside function at91rm9200_timer_interrupt(), variable sr could > be uninitialized if regmap_read() fails. However, sr is used Could you elaborate on how this could fail? > to decide the control flow later in the if statement, which is > potentially unsafe. We could check the return value of > regmap_read() and print an error here. > > Signed-off-by: Yizhuo > --- > drivers/clocksource/timer-atmel-st.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/clocksource/timer-atmel-st.c b/drivers/clocksource/timer-atmel-st.c > index ab0aabfae5f0..061a3f27847e 100644 > --- a/drivers/clocksource/timer-atmel-st.c > +++ b/drivers/clocksource/timer-atmel-st.c > @@ -48,8 +48,14 @@ static inline unsigned long read_CRTR(void) > static irqreturn_t at91rm9200_timer_interrupt(int irq, void *dev_id) > { > u32 sr; > + int ret; > + > + ret = regmap_read(regmap_st, AT91_ST_SR, &sr); > + if (ret) { > + pr_err("Fail to read AT91_ST_SR.\n"); > + return ret; > + } > > - regmap_read(regmap_st, AT91_ST_SR, &sr); > sr &= irqmask; > > /* > -- > 2.17.1 > -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel