From patchwork Sat Jun 20 03:30:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 215293 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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 5A5D9C433EA for ; Sat, 20 Jun 2020 03:31:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2B88523159 for ; Sat, 20 Jun 2020 03:31:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="nLZb9q5M" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733040AbgFTDbH (ORCPT ); Fri, 19 Jun 2020 23:31:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58226 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733033AbgFTDaz (ORCPT ); Fri, 19 Jun 2020 23:30:55 -0400 Received: from mail-pj1-x1043.google.com (mail-pj1-x1043.google.com [IPv6:2607:f8b0:4864:20::1043]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 36FAAC0619EB for ; Fri, 19 Jun 2020 20:30:25 -0700 (PDT) Received: by mail-pj1-x1043.google.com with SMTP id u8so4990212pje.4 for ; Fri, 19 Jun 2020 20:30:25 -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=TsJU39le/9mzUUvkg/vEQ1ejtljvEC7MElEcoRxU/hs=; b=nLZb9q5MNXSO30mRLC8p+Z6tp7SeKI4c8mbyilFhnvlC39t+V3j0iQJ4vfU5EbJ/Ge yJs0yUXWykR2+lKlShzU2CG/atXeM++8u60h/nbziIo1McpvPT8URV5HcgXBrobq0ydJ LtCik9CXYKbYzZN1wG1+1XbNp5/sueNlWfLSk= 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=TsJU39le/9mzUUvkg/vEQ1ejtljvEC7MElEcoRxU/hs=; b=FukHms7AeQXaB2HQAe5/jji6u8Mnc3jLqkO7cw5C26/ZIce5yP4234qvhRcBuG1ORa DEbjdFwpMMt1ihEIb6DACIyRIfqtdxE6in19yoIZzZMDT3dLrdlsrhq/0mZJNJkO6+At D6LdnqOoyX/vkkVRoHv/XYRqLUJwLEWItCZbqb2/yZktJW7G4bpZP2mv+wdS+UdxbecX uL/DFZMcrrSsmV00H0sABedVvTnAmYDV67hs455y57eyxiQqZJWvkKV0HsSh9LPa79sa BfDuRCOcKF9dUykj7Wb8YpoK2qePI8CpX8uVkKqed2YQXQtQqrFy9Q2yheFNs8PUH+pd zl4A== X-Gm-Message-State: AOAM5317Mr5a2M3CV84JJDUrj0OPEkGfClzcdUwTmotCfGcw+mkNNdxc vJ+Wa+UgWnMyzGX6qdMdBr6R9g== X-Google-Smtp-Source: ABdhPJx/5DcfB27JAL/c3SFwGw95qhIKfr9dnkeTlJXy/0XzMHLMuVPklbRvet5f9iLDNbeJ3PiIXQ== X-Received: by 2002:a17:902:8f83:: with SMTP id z3mr10333002plo.203.1592623824777; Fri, 19 Jun 2020 20:30:24 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id ev20sm6238855pjb.8.2020.06.19.20.30.19 (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 , Nathan Chancellor , 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 10/16] KVM: PPC: Book3S PR: Remove uninitialized_var() usage Date: Fri, 19 Jun 2020 20:30:01 -0700 Message-Id: <20200620033007.1444705-11-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 Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org 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], just remove this variable since it was actually unused: arch/powerpc/kvm/book3s_pr.c:1832:16: warning: unused variable 'vrsave' [-Wunused-variable] unsigned long vrsave; ^ [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/ Suggested-by: Nathan Chancellor Fixes: f05ed4d56e9c ("KVM: PPC: Split out code from book3s.c into book3s_pr.c") Signed-off-by: Kees Cook --- arch/powerpc/kvm/book3s_pr.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c index ef54f917bdaf..ed12dfbf9bb5 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -1828,9 +1828,6 @@ static int kvmppc_vcpu_run_pr(struct kvm_vcpu *vcpu) { struct kvm_run *run = vcpu->run; int ret; -#ifdef CONFIG_ALTIVEC - unsigned long uninitialized_var(vrsave); -#endif /* Check if we can run the vcpu at all */ if (!vcpu->arch.sane) {