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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,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 8638CC433DF for ; Fri, 19 Jun 2020 15:57:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6350821532 for ; Fri, 19 Jun 2020 15:57:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592582239; bh=74wKcSC/1/uY7MLx3rVRs5Efvh1k7Obe/4c2cXj8RbU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=BVHV0puUUGXRefgMGIB9QXLeDuPPq40fPJrc/jl/esaPiqszSW2TBhXII0Gdue0SN 5DUgqBo+3j1y+8nZunMlLxaiyxx8ic4RQMXx3YvxCqBu2pC7w0Zez5ccy6CPB6gieJ z934FOn7DtqGdwCtb6D2XT7oBEz6iGBKGfS6vIqA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405450AbgFSP5R (ORCPT ); Fri, 19 Jun 2020 11:57:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:51560 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390560AbgFSPUZ (ORCPT ); Fri, 19 Jun 2020 11:20:25 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A135820771; Fri, 19 Jun 2020 15:20:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592580024; bh=74wKcSC/1/uY7MLx3rVRs5Efvh1k7Obe/4c2cXj8RbU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SVSS48iR8o5gteYU+s/04b+nXJasyYT61zb5RomzVMz0sETCX2UMPDoO0QG5YQmOa t5phOCq2S7wMHlsHtwvAHCcmCVO5a53vviDvGxOGP0g0x74DpFEE9zKbKnXGDNYP7w FNGt/6chFcnr5nuEp6+SkHDriFDhQ3kv8dROKT8U= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kees Cook , Aaron Brown , Jeff Kirsher , Sasha Levin Subject: [PATCH 5.7 094/376] e1000: Distribute switch variables for initialization Date: Fri, 19 Jun 2020 16:30:12 +0200 Message-Id: <20200619141714.789670361@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200619141710.350494719@linuxfoundation.org> References: <20200619141710.350494719@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kees Cook [ Upstream commit a34c7f5156654ebaf7eaace102938be7ff7036cb ] Variables declared in a switch statement before any case statements cannot be automatically initialized with compiler instrumentation (as they are not part of any execution flow). With GCC's proposed automatic stack variable initialization feature, this triggers a warning (and they don't get initialized). Clang's automatic stack variable initialization (via CONFIG_INIT_STACK_ALL=y) doesn't throw a warning, but it also doesn't initialize such variables[1]. Note that these warnings (or silent skipping) happen before the dead-store elimination optimization phase, so even when the automatic initializations are later elided in favor of direct initializations, the warnings remain. To avoid these problems, move such variables into the "case" where they're used or lift them up into the main function body. drivers/net/ethernet/intel/e1000/e1000_main.c: In function ‘e1000_xmit_frame’: drivers/net/ethernet/intel/e1000/e1000_main.c:3143:18: warning: statement will never be executed [-Wswitch-unreachable] 3143 | unsigned int pull_size; | ^~~~~~~~~ [1] https://bugs.llvm.org/show_bug.cgi?id=44916 Signed-off-by: Kees Cook Tested-by: Aaron Brown Signed-off-by: Jeff Kirsher Signed-off-by: Sasha Levin --- drivers/net/ethernet/intel/e1000/e1000_main.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c index 0d51cbc88028..05bc6e216bca 100644 --- a/drivers/net/ethernet/intel/e1000/e1000_main.c +++ b/drivers/net/ethernet/intel/e1000/e1000_main.c @@ -3136,8 +3136,9 @@ static netdev_tx_t e1000_xmit_frame(struct sk_buff *skb, hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb); if (skb->data_len && hdr_len == len) { switch (hw->mac_type) { + case e1000_82544: { unsigned int pull_size; - case e1000_82544: + /* Make sure we have room to chop off 4 bytes, * and that the end alignment will work out to * this hardware's requirements @@ -3158,6 +3159,7 @@ static netdev_tx_t e1000_xmit_frame(struct sk_buff *skb, } len = skb_headlen(skb); break; + } default: /* do nothing */ break; -- 2.25.1