From patchwork Sat Jun 20 03:30:00 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 11615441 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2A88960D for ; Sat, 20 Jun 2020 03:30:42 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id EB5FF2073E for ; Sat, 20 Jun 2020 03:30:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="KNzYUO4e" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EB5FF2073E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 733666B00A2; Fri, 19 Jun 2020 23:30:25 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 6E6136B00A3; Fri, 19 Jun 2020 23:30:25 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 425D76B00A5; Fri, 19 Jun 2020 23:30:25 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0035.hostedemail.com [216.40.44.35]) by kanga.kvack.org (Postfix) with ESMTP id 25D2D6B00A2 for ; Fri, 19 Jun 2020 23:30:25 -0400 (EDT) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id DA7C32DFC for ; Sat, 20 Jun 2020 03:30:24 +0000 (UTC) X-FDA: 76948162368.06.shape10_190822d26e1e Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin06.hostedemail.com (Postfix) with ESMTP id B53151003A96A for ; Sat, 20 Jun 2020 03:30:24 +0000 (UTC) X-Spam-Summary: 2,0,0,4270530b9d30cef9,d41d8cd98f00b204,keescook@chromium.org,,RULES_HIT:41:355:379:541:800:960:967:973:988:989:1260:1311:1314:1345:1437:1515:1534:1541:1711:1730:1747:1777:1792:2393:2525:2559:2566:2570:2682:2685:2693:2703:2859:2933:2937:2939:2942:2945:2947:2951:2954:3022:3352:3865:3867:3868:3870:3871:3872:3934:3936:3938:3941:3944:3947:3950:3953:3956:3959:4321:5007:6117:6119:6261:8660:8957:9025:10004:11658:13069:13148:13149:13230,0,RBL:209.85.214.193:@chromium.org:.lbl8.mailshell.net-62.2.0.100 66.100.201.201,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:22,LUA_SUMMARY:none X-HE-Tag: shape10_190822d26e1e X-Filterd-Recvd-Size: 4893 Received: from mail-pl1-f193.google.com (mail-pl1-f193.google.com [209.85.214.193]) by imf48.hostedemail.com (Postfix) with ESMTP for ; Sat, 20 Jun 2020 03:30:24 +0000 (UTC) Received: by mail-pl1-f193.google.com with SMTP id bh7so4797608plb.11 for ; Fri, 19 Jun 2020 20:30:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=LXS1lS0MPNgS4WVNAlrLifcWTqk+ZnaP0JF9yck56S4=; b=KNzYUO4ep4rSo36cd4JIipsr8ASXyCCE8oRhdqmyCQcuRLJ54mD8w7eqAHCckRiIrw zeaxkRx9uGiqPdDalv+zlc8I0e8YcRGOpFBzI5ChxOgtMC4BYU3IZf3IjdWLPyBA6Rj4 DV1OCfy3eEHniZxll4RRMXN1skYl+SLO+aH1g= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=LXS1lS0MPNgS4WVNAlrLifcWTqk+ZnaP0JF9yck56S4=; b=GaQx1lsFeM+26bZaLlS6+xpk7/YmA/MWkxaGjFVT6gs7QoRjkJXqdpRKH3UH6duxww WSZXFHHBh5G+LggvVjo3kXpEG4kUM5EjCP74J4uV5WvZmVStI4CoFPpjOLz0MKByzZmy 8nkxnJgVy4vKMYPj1QXl2Ba1h25DPdg68T09kQ/GMZNg5y2u7vx/NI56dXpkYhXoJ0I5 R2AimBAhoU8jK6PI1GI2wsYP4dmrZQBPOnmMDuGGu0HeqfimnQRPUdTjHczTys2ZPAOK GhKPoMfNBYPxJ+fuS4hiRpuQpiTOoc30tjNZtCDO08wC9f99VFY5xQ6ZMt3d0B3nP6z4 X5lg== X-Gm-Message-State: AOAM531ftyeoNfKYh/ISFY6fKE0yAvl5zL8UVy0yY0ZQISbp+wE9kzyQ ArWgxteudOdvWyLglXq6O5fN9A== X-Google-Smtp-Source: ABdhPJx80kRDNx563OHfs0qDYxTj+Nz7KdjHEYiCrGu68V9ia3oYlRYDFTGjYW28UCia8fkYF0XLCw== X-Received: by 2002:a17:90b:50d:: with SMTP id r13mr6472339pjz.94.1592623823547; Fri, 19 Jun 2020 20:30:23 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id h8sm7134891pfo.67.2020.06.19.20.30.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 19 Jun 2020 20:30:20 -0700 (PDT) From: Kees Cook To: linux-kernel@vger.kernel.org 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 Subject: [PATCH v2 09/16] clk: spear: Remove uninitialized_var() usage Date: Fri, 19 Jun 2020 20:30:00 -0700 Message-Id: <20200620033007.1444705-10-keescook@chromium.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200620033007.1444705-1-keescook@chromium.org> References: <20200620033007.1444705-1-keescook@chromium.org> MIME-Version: 1.0 X-Rspamd-Queue-Id: B53151003A96A X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam05 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: 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. [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Fixes: 7d4998f71b29 ("clk: SPEAr: Vco-pll: Fix compilation warning") Signed-off-by: Kees Cook Acked-by: Stephen Boyd --- drivers/clk/spear/clk-vco-pll.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/clk/spear/clk-vco-pll.c b/drivers/clk/spear/clk-vco-pll.c index c08dec30bfa6..fed194169666 100644 --- a/drivers/clk/spear/clk-vco-pll.c +++ b/drivers/clk/spear/clk-vco-pll.c @@ -147,7 +147,7 @@ static int clk_pll_set_rate(struct clk_hw *hw, unsigned long drate, struct clk_pll *pll = to_clk_pll(hw); struct pll_rate_tbl *rtbl = pll->vco->rtbl; unsigned long flags = 0, val; - int uninitialized_var(i); + int i = 0; clk_pll_round_rate_index(hw, drate, NULL, &i);