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=-14.6 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,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 72969C433E3 for ; Tue, 23 Jun 2020 18:29:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 45C9020809 for ; Tue, 23 Jun 2020 18:29:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="VRPOqKgX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387566AbgFWS3v (ORCPT ); Tue, 23 Jun 2020 14:29:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35254 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387555AbgFWS3u (ORCPT ); Tue, 23 Jun 2020 14:29:50 -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 48004C061799 for ; Tue, 23 Jun 2020 11:29:49 -0700 (PDT) Received: by mail-pj1-x1043.google.com with SMTP id i4so1938334pjd.0 for ; Tue, 23 Jun 2020 11:29:49 -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=JXkDSAr5/uPdypFT+vPhb9QM0XECCw1QogkIjza9trI=; b=VRPOqKgXBbe1omCau4oEOar/p3bhX1hnmkDK5oo6kzWoboZd6SthW3HQ/fnF48E5Ad TFy6wVC1Zt0tVzcHOtTOw47hdeOauaMgmaZ6zltDMfNdLob+S/bzF8RmsABX4aqnrS72 FqSw42FCWi78K/1FW37NBnAtRs40JSIujuQZ/C35kNhgObkKHAK+mu644bPs+DnywUvm fYYXdKXmrR/Epl78LsQPaZhh4kpgqCqvEbEKQBq3LNEoOjFO3Gb/VXUTw5HcjdoODVkn jAQBGKwdodjJ4m51Dq2h17KJmJpx4MvyUs2jS+Pi8XwYstLDwRvgem5B+kNI/TaA60cZ bdTA== 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=JXkDSAr5/uPdypFT+vPhb9QM0XECCw1QogkIjza9trI=; b=sUh1/f8ceMaB95NrxEOJYEnhspexnZdXrTQGq5svBos1IGlB85BUCfouRqVtDmZ2QA oiQ5pZeXfHDK5mrGix0citanFC5kNvHMbNDK1KOdZWcH+MZ5/gQdb5xz3MJPtHK8dyoZ i2qW03nvaE7j85wGIEhQvL6XTgPK6bNrlEpsE4l6NQSe5ve/xNfu/qpx5rV0QjWanqqz RSueP2kQISrZTNz8RLjpwUfgdNOl9biygAqBdFq/nuxOOYDosXMM2RimdoQoLerozxT3 gXcBBYPaNWuqPq4rnZZrWZQ4hy+DuyQPTDWyOjK8ziyxYBNNjo3OeA1TZ1/0Y85AAs1Q kYnQ== X-Gm-Message-State: AOAM533l0OErCmObGcIz3YxXcUxi7eROAxsoXA1yFl/PmQEeHL7eZrzW vhHlycu3g6VEQ94JVUqTd3V2PEpMPANcCV5gq+3TKQ== X-Google-Smtp-Source: ABdhPJwFYRuJg9EUbjSytVc+yfQjuDOMjwE4SVCIBy3rni20OvAXlm0XdI+2Z8txK6JARtyDXhDgAzhgcWbhIpdXKAY= X-Received: by 2002:a17:902:fe8b:: with SMTP id x11mr24842368plm.179.1592936988375; Tue, 23 Jun 2020 11:29:48 -0700 (PDT) MIME-Version: 1.0 References: <20200620033007.1444705-1-keescook@chromium.org> <20200620033007.1444705-5-keescook@chromium.org> <202006221403.EEAD37E94B@keescook> In-Reply-To: <202006221403.EEAD37E94B@keescook> From: Nick Desaulniers Date: Tue, 23 Jun 2020 11:29:38 -0700 Message-ID: Subject: Re: [PATCH v2 04/16] b43: 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 Doc Mailing List , 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: linux-ide-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ide@vger.kernel.org On Mon, Jun 22, 2020 at 2:04 PM Kees Cook wrote: > > On Mon, Jun 22, 2020 at 10:04:18AM -0700, Nick Desaulniers wrote: > > On Fri, Jun 19, 2020 at 8:30 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. > > > No later NULL deref is possible due to the early returns outside of the > > > (phy->rev >= 7 && phy->rev < 19) case, which explicitly tests for 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/ > > > > > > Fixes: 58619b14d106 ("b43: move under broadcom vendor directory") > > > Signed-off-by: Kees Cook > > > > I see three total uses of uninitialized_var() in this file, do we want > > to eliminate all of them? > > This is the only one that needed an explicit initialization -- all the > others are handled in the treewide patch. I *could* split it out here, > but I found it easier to keep the "no op" changes together in the > treewide patch. Ah, got it. Reviewed-by: Nick Desaulniers > > -Kees > > > > > > --- > > > drivers/net/wireless/broadcom/b43/phy_n.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/drivers/net/wireless/broadcom/b43/phy_n.c b/drivers/net/wireless/broadcom/b43/phy_n.c > > > index c33b4235839d..46db91846007 100644 > > > --- a/drivers/net/wireless/broadcom/b43/phy_n.c > > > +++ b/drivers/net/wireless/broadcom/b43/phy_n.c > > > @@ -4222,7 +4222,7 @@ static void b43_nphy_tx_gain_table_upload(struct b43_wldev *dev) > > > u32 rfpwr_offset; > > > u8 pga_gain, pad_gain; > > > int i; > > > - const s16 *uninitialized_var(rf_pwr_offset_table); > > > + const s16 *rf_pwr_offset_table = NULL; > > > > > > table = b43_nphy_get_tx_gain_table(dev); > > > if (!table) > > > -- > > > > -- > > Thanks, > > ~Nick Desaulniers > > -- > Kees Cook -- Thanks, ~Nick Desaulniers