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=-21.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 D1AFEC433B4 for ; Thu, 1 Apr 2021 18:22:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A411A6023C for ; Thu, 1 Apr 2021 18:22:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236157AbhDASWH (ORCPT ); Thu, 1 Apr 2021 14:22:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:37008 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236815AbhDASDB (ORCPT ); Thu, 1 Apr 2021 14:03:01 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B51106138C; Thu, 1 Apr 2021 16:45:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1617295557; bh=Yxoz1j6ATayqg96dpqFVU3VxNbkZPibfD69hfuZBg5Y=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Gk4Z48zC8YjsQvsFU5hsAYR1LFloXLmKpobB250U0XDVJ4p6FVPGtfyKMuJr3vr0S FF5nQesHVoiHpDuN03cve2GgeBCI+Sz6/tplX8WGoKuL6QtbkulB6D0IbfHITcyXoY EAm+vxThPoZEggCXhmHcN29ZAdHilhp35Sstrxf7sDDM0ZeiGiZxMjsz9R+A3/P14c wrYv6+R3lpNtiTAfUUnB+FVzGSL8mxMSzkdJDhE7GJZLiSfCT6mfwSAiNRUKN1IYoa kezUrwj2Gv7iMnIdvo0/k5yRymuTCRzzyQljHCXFC5KVjziTkqE5urRyR9M0SoznvD menWB9cZhHv4Q== Date: Thu, 1 Apr 2021 09:45:52 -0700 From: Nathan Chancellor To: Maciej Falkowski Cc: khilman@kernel.org, aaro.koskinen@iki.fi, tony@atomide.com, linux@armlinux.org.uk, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com Subject: Re: [PATCH] ARM: OMAP: Fix use of possibly uninitialized irq variable Message-ID: <20210401164552.n4nuwvqz5mofdblg@archlinux-ax161> References: <20210401161127.8942-1-maciej.falkowski9@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210401161127.8942-1-maciej.falkowski9@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 01, 2021 at 06:11:27PM +0200, Maciej Falkowski wrote: > The current control flow of IRQ number assignment to `irq` variable > allows a request of IRQ of unspecified value, > generating a warning under Clang compilation with omap1_defconfig on linux-next: > > arch/arm/mach-omap1/pm.c:656:11: warning: variable 'irq' is used uninitialized whenever > 'if' condition is false [-Wsometimes-uninitialized] > else if (cpu_is_omap16xx()) > ^~~~~~~~~~~~~~~~~ > ./arch/arm/mach-omap1/include/mach/soc.h:123:30: note: expanded from macro 'cpu_is_omap16xx' > ^~~~~~~~~~~~~ > arch/arm/mach-omap1/pm.c:658:18: note: uninitialized use occurs here > if (request_irq(irq, omap_wakeup_interrupt, 0, "peripheral wakeup", > ^~~ > arch/arm/mach-omap1/pm.c:656:7: note: remove the 'if' if its condition is always true > else if (cpu_is_omap16xx()) > ^~~~~~~~~~~~~~~~~~~~~~ > arch/arm/mach-omap1/pm.c:611:9: note: initialize the variable 'irq' to silence this warning > int irq; > ^ > = 0 > 1 warning generated. > > The patch provides a default value to the `irq` variable > along with a validity check. > Might be worth a fixes tag: Fixes: b75ca5217743 ("ARM: OMAP: replace setup_irq() by request_irq()") > Signed-off-by: Maciej Falkowski > Link: https://github.com/ClangBuiltLinux/linux/issues/1324 Reviewed-by: Nathan Chancellor > --- > arch/arm/mach-omap1/pm.c | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-) > > diff --git a/arch/arm/mach-omap1/pm.c b/arch/arm/mach-omap1/pm.c > index 2c1e2b32b9b3..a745d64d4699 100644 > --- a/arch/arm/mach-omap1/pm.c > +++ b/arch/arm/mach-omap1/pm.c > @@ -655,9 +655,13 @@ static int __init omap_pm_init(void) > irq = INT_7XX_WAKE_UP_REQ; > else if (cpu_is_omap16xx()) > irq = INT_1610_WAKE_UP_REQ; > - if (request_irq(irq, omap_wakeup_interrupt, 0, "peripheral wakeup", > - NULL)) > - pr_err("Failed to request irq %d (peripheral wakeup)\n", irq); > + else > + irq = -1; > + > + if (irq >= 0) { > + if (request_irq(irq, omap_wakeup_interrupt, 0, "peripheral wakeup", NULL)) > + pr_err("Failed to request irq %d (peripheral wakeup)\n", irq); > + } > > /* Program new power ramp-up time > * (0 for most boards since we don't lower voltage when in deep sleep) > -- > 2.26.3 >