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=-14.4 required=3.0 tests=DKIMWL_WL_MED,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_IN_DEF_DKIM_WL 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 59357C433DF for ; Thu, 4 Jun 2020 19:56:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 39D8E2075B for ; Thu, 4 Jun 2020 19:56:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="qPGYj+Fa" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728657AbgFDT4Z (ORCPT ); Thu, 4 Jun 2020 15:56:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47646 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728025AbgFDT4Y (ORCPT ); Thu, 4 Jun 2020 15:56:24 -0400 Received: from mail-pg1-x541.google.com (mail-pg1-x541.google.com [IPv6:2607:f8b0:4864:20::541]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 71335C08C5C2 for ; Thu, 4 Jun 2020 12:56:24 -0700 (PDT) Received: by mail-pg1-x541.google.com with SMTP id u5so3999462pgn.5 for ; Thu, 04 Jun 2020 12:56:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=JchjGYZl0wqUOrU5YQvGeZV5DROtdtYOgYQQhEiIskY=; b=qPGYj+Fa3kUn8rqUio1Dqo/wmmdxLTwJv3dkdlE3ClgOnCxbEa6OJED06WKQ9xZ/S5 drxLk5d97vcv5eQ6d4d6pUs5J9MwW0FbQj4r4wLXcZG5wYgEinukAsqpd6SbNEpGTiIL ybbjkH30SzUTY9QY0bM3t5oBYgf/gdFtcqSjGZ4Vd93wXluzmD0tkk2N1s4+IczoK5T8 73LFTDcT2N2adp5wR2Mlu3UFct0QurWe1qbINXwuT+3G9C5se3K/oYDgtwvOmb8nMB81 9/qgL3YapcLXLfnBA8fVq9DtyGqYOQK0MGNYMtExoxZdmGcyOrFvw2budA/p7MR7MkMh dTFw== 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=JchjGYZl0wqUOrU5YQvGeZV5DROtdtYOgYQQhEiIskY=; b=aL8Y+4hHFRqG3jnOYUjNC4u/xjz/NjdmARzuYVss/GyIH6H6QHSQAce7ToZzRdUEUX 475A5xb66JU7/STk+A4kIEKdXVEDc5XBsuz5dqbXyryN2VA6JaEnhB+yR44TqCqKt/82 5/SuD+F51qxo6yqs236I/KLKWv3i88pAy2ni3vLxS88UkdqA3dA1o1TRN01op4Yon8x7 LjE/wCC0dhVPqsKFv1CZkEM11UHpq920onjzXzgt9HXdf6YBXUMJ07vnDC9HD88SnftX KyR0ynh0AVC2jxVS3/mGuOGkRmBKOuOBnWa6j1EN2prVtInlkxldShA2Fkk8kmrAFNOL w2Ug== X-Gm-Message-State: AOAM530YPPLHaapuXZLSPhvuuGwPC7Afsb7FdDvOAM9l4amxN63KPac5 1b611BDgQd1CGLvmNAthriRD7C+JpNzWriMCvJmiKA== X-Google-Smtp-Source: ABdhPJy7InXrusPAFFTJ9/oFSaSF0Eic2jn49VfP7aR0w5k1vGP4KYsGIQVm0HirYrhRu0SFvISfn3kdwUp620gXyHY= X-Received: by 2002:a63:f00d:: with SMTP id k13mr6167247pgh.263.1591300583418; Thu, 04 Jun 2020 12:56:23 -0700 (PDT) MIME-Version: 1.0 References: <20200603233203.1695403-1-keescook@chromium.org> <20200603233203.1695403-3-keescook@chromium.org> In-Reply-To: <20200603233203.1695403-3-keescook@chromium.org> From: Nick Desaulniers Date: Thu, 4 Jun 2020 12:56:11 -0700 Message-ID: Subject: Re: [PATCH 02/10] drbd: Remove uninitialized_var() usage To: Kees Cook Cc: LKML , Linus Torvalds , Miguel Ojeda , 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 Memory Management List , clang-built-linux Content-Type: text/plain; charset="UTF-8" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, Jun 3, 2020 at 4:32 PM 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 a precursor > to removing[2] this[3] macro[4], just initialize this variable to NULL. > > [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/ > > Signed-off-by: Kees Cook Reviewed-by: Nick Desaulniers Fixes: a29728463b25 ("drbd: Backport the "events2" command") > --- > drivers/block/drbd/drbd_state.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/block/drbd/drbd_state.c b/drivers/block/drbd/drbd_state.c > index eeaa3b49b264..0067d328f0b5 100644 > --- a/drivers/block/drbd/drbd_state.c > +++ b/drivers/block/drbd/drbd_state.c > @@ -1604,7 +1604,7 @@ static void broadcast_state_change(struct drbd_state_change *state_change) > unsigned int n_device, n_connection, n_peer_device, n_peer_devices; > void (*last_func)(struct sk_buff *, unsigned int, void *, > enum drbd_notification_type) = NULL; > - void *uninitialized_var(last_arg); > + void *last_arg = NULL; > > #define HAS_CHANGED(state) ((state)[OLD] != (state)[NEW]) > #define FINAL_STATE_CHANGE(type) \ > -- > 2.25.1 > > -- > You received this message because you are subscribed to the Google Groups "Clang Built Linux" group. > To unsubscribe from this group and stop receiving emails from it, send an email to clang-built-linux+unsubscribe@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/clang-built-linux/20200603233203.1695403-3-keescook%40chromium.org. -- Thanks, ~Nick Desaulniers