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=-4.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 A2C84C433E3 for ; Mon, 22 Jun 2020 09:03:52 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5E51F20738 for ; Mon, 22 Jun 2020 09:03:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="Xh/zfNmL" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5E51F20738 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 05DC16B0007; Mon, 22 Jun 2020 05:03:52 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 00ECA6B0008; Mon, 22 Jun 2020 05:03:51 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E8E1E6B000A; Mon, 22 Jun 2020 05:03:51 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0173.hostedemail.com [216.40.44.173]) by kanga.kvack.org (Postfix) with ESMTP id DD12F6B0007 for ; Mon, 22 Jun 2020 05:03:51 -0400 (EDT) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id ABEEC181ACC80 for ; Mon, 22 Jun 2020 09:03:51 +0000 (UTC) X-FDA: 76956260262.12.fly67_5a12c0f26e31 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin12.hostedemail.com (Postfix) with ESMTP id 774CA1801124E for ; Mon, 22 Jun 2020 09:03:51 +0000 (UTC) X-HE-Tag: fly67_5a12c0f26e31 X-Filterd-Recvd-Size: 3194 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf40.hostedemail.com (Postfix) with ESMTP for ; Mon, 22 Jun 2020 09:03:51 +0000 (UTC) Received: from kernel.org (unknown [104.132.0.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3708D20716; Mon, 22 Jun 2020 09:03:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592816630; bh=uHzWPbIY/41z+WQ/nEUcOLsdKXZ7Qrprx0s9J3nM1WI=; h=In-Reply-To:References:Subject:From:Cc:To:Date:From; b=Xh/zfNmL3ERN7ZAuWqJeou0LUUvk4MxvRvqg/wo1SCR+kIFKaY9IoS91eJwSGmLxN 41gDTQtH3HmNO1ivPmHrDiY28L/xmHDYW6B2Zu88FibzNrSxqjvk4opMhmkVX7J1zb BUvEkLF+J6WNitfbDSFytorOw4J66B/N2vbM1fp8= Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable In-Reply-To: <20200620033007.1444705-10-keescook@chromium.org> References: <20200620033007.1444705-1-keescook@chromium.org> <20200620033007.1444705-10-keescook@chromium.org> Subject: Re: [PATCH v2 09/16] clk: spear: Remove uninitialized_var() usage From: Stephen Boyd Cc: Kees Cook , Linus Torvalds , Miguel Ojeda , Alexander Potapenko , Joe Perches , Andy Whitcroft , x86@kernel.org, drbd-dev@lists.linbit.com, linux-block@vger.kernel.org, b43-dev@lists.infradead.org, netdev@vger.kernel.org, linux-doc@vger.kernel.org, linux-wireless@vger.kernel.org, linux-ide@vger.kernel.org, linux-clk@vger.kernel.org, linux-spi@vger.kernel.org, linux-mm@kvack.org, clang-built-linux@googlegroups.com To: Kees Cook , linux-kernel@vger.kernel.org Date: Mon, 22 Jun 2020 02:03:49 -0700 Message-ID: <159281662960.62212.15318119299039755482@swboyd.mtv.corp.google.com> User-Agent: alot/0.9 X-Rspamd-Queue-Id: 774CA1801124E X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam04 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Quoting Kees Cook (2020-06-19 20:30:00) > Using uninitialized_var() is dangerous as it papers over real bugs[1] > (or can in the future), and suppresses unrelated compiler warnings (e.g. > "unused variable"). If the compiler thinks it is uninitialized, either > simply initialize the variable or make compiler changes. As a precursor > to removing[2] this[3] macro[4], initialize "i" to zero. The compiler > warning was not a false positive, since clk_pll_set_rate()'s call to > clk_pll_round_rate_index() will always fail (since "prate" is NULL), so > "i" was never being initialized. >=20 > [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.co= m/ > [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=3D1TGqCR5vQkCzWJ0QxK6Cern= OU6eedsudAixw@mail.gmail.com/ > [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz= 9knmPuXhOeg@mail.gmail.com/ > [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=3DyVJu65TpLg= N_ybYNv0VEOKA@mail.gmail.com/ >=20 > Fixes: 7d4998f71b29 ("clk: SPEAr: Vco-pll: Fix compilation warning") > Signed-off-by: Kees Cook > --- Acked-by: Stephen Boyd