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=-3.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS 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 BFAF4C433E1 for ; Thu, 4 Jun 2020 00:50:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9D95F20738 for ; Thu, 4 Jun 2020 00:50:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="jjo5yXOj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729347AbgFDAun (ORCPT ); Wed, 3 Jun 2020 20:50:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39474 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729323AbgFDAul (ORCPT ); Wed, 3 Jun 2020 20:50:41 -0400 Received: from mail-lj1-x244.google.com (mail-lj1-x244.google.com [IPv6:2a00:1450:4864:20::244]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 43B64C03E96D; Wed, 3 Jun 2020 17:50:40 -0700 (PDT) Received: by mail-lj1-x244.google.com with SMTP id c11so5136287ljn.2; Wed, 03 Jun 2020 17:50:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=MPLZOT/4bCsndxaWJtW6FhRuUjguIqCFp5N2dwDtYQ8=; b=jjo5yXOjBc6ExBZ0xU0p0U1vrAbDQBGzKMjBMieodOVuBzHGTF9DfthYYNAfEr4O8H rweetJbTqqdkWZQ2Mh+tJNCGkpf/fkl1rkUJQ8mQL3qjchZnqA0v3AMF1MBb2R/OeUUh DuErOylpGthQHIdGEr+3RVWllhk+DcvmzUIeBDjSdh5bWQzbscb+Y3ruNHUM8Dkq3sMo nn/nsSopZsp2D2DmmTBE1rVlfsSS3jD71ToiAPKVqzTq2U2pcrz+IKipSkRRITVVt4/Q y9VjEOyTc4mzSfqGsdsgNMIeHMEoqdZSRH5tVyANTF0vpIJUjGxVhNnyKfbEjw81HuWV wblw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=MPLZOT/4bCsndxaWJtW6FhRuUjguIqCFp5N2dwDtYQ8=; b=DjrXUPzYidLMPzRrNYY3MRYwE6HysA13H+i/iQYGe++QAbl3O0F3TeWlaBdPoNrSV2 UOTXG2uSvLAwJS1KonX2g7e2EJt88go15TGiVzxnQVjrA0VT7dtqPhsLcsy7EXq6/hNj QidZcrDEhcsBItYcTakBJvsogqfsz4RtyT+BAYH4dpY0gdOTEW4ytXPA+VPVsVrqG/uU zN0wnVp/XIydwGK9Qt8Uo4C3MXK/Qz+CigzHR32NxF073z07SpXrAxM6I5mhkPEX79Cz ih2/mNMxuDbz+wRYjm8KKcI/m5dxHj4oKdsux94wTkmj9AJBAx2BSFX14kjp7n6xoXrW vF1w== X-Gm-Message-State: AOAM532LQHV2W6GDrVYuQ/ovBK7xqJ+lxmhCHTSdq4wBA3D1EqjCJCU7 EVrWiNdgVB5CbYnb99MhzmxiysXyfYsOZ9uEbbrl0Poyl4o= X-Google-Smtp-Source: ABdhPJziTNSuHWTzq2vssLq+q8Fk3g0gJzv6ZAQGOSjz3d+G2JKB1FM3MjsolLLYpNir2cIK2vJaKIQ5Hqvq0FlOkQ0= X-Received: by 2002:a05:651c:11c7:: with SMTP id z7mr899332ljo.29.1591231838573; Wed, 03 Jun 2020 17:50:38 -0700 (PDT) MIME-Version: 1.0 References: <20200603233203.1695403-1-keescook@chromium.org> <20200603233203.1695403-11-keescook@chromium.org> In-Reply-To: <20200603233203.1695403-11-keescook@chromium.org> From: Miguel Ojeda Date: Thu, 4 Jun 2020 02:50:27 +0200 Message-ID: Subject: Re: [PATCH 10/10] compiler: Remove uninitialized_var() macro To: Kees Cook Cc: linux-kernel , Linus Torvalds , Alexander Potapenko , Joe Perches , Andy Whitcroft , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , drbd-dev@lists.linbit.com, linux-block@vger.kernel.org, b43-dev@lists.infradead.org, Network Development , linux-wireless , linux-ide@vger.kernel.org, linux-clk@vger.kernel.org, linux-spi@vger.kernel.org, Linux-MM , clang-built-linux Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Kees, On Thu, Jun 4, 2020 at 1:32 AM Kees Cook wrote: > > 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 recommended[2] by[3] Linus[4], remove the macro. > > [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: Linus Torvalds > Signed-off-by: Kees Cook > --- +1, one less trick split between `compiler*` files. Reviewed-by: Miguel Ojeda Cheers, Miguel