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 6A632C433E0 for ; Fri, 19 Jun 2020 16:34:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4688E21527 for ; Fri, 19 Jun 2020 16:34:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592584490; bh=ZYWXVLDRpMx6fjTzG3pCvWzbfAZaCq5fQaiK1q3eva8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=i+Y8nvr9IPgKtFhCtpRFXokbxPRS06Ck4EsR+9eva2yq+Tln7QFvO9VCTfQEcMIP/ ps0fKUGjMAXkP93QgXI376rzRjhY9hPzFwADdhrHxxS2SrSEL948UVZ0e+3YQMnH2r v3hpvqsWoPBR00KCdMmCxBRVqy9ZMxpuVPl1CXEo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389340AbgFSOuk (ORCPT ); Fri, 19 Jun 2020 10:50:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:43178 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389295AbgFSOuR (ORCPT ); Fri, 19 Jun 2020 10:50:17 -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 CCAD420776; Fri, 19 Jun 2020 14:50:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592578217; bh=ZYWXVLDRpMx6fjTzG3pCvWzbfAZaCq5fQaiK1q3eva8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BQRYiEHHu/MBEe66SrLxUNn0pqlAV8rOo8lmVlPJA1hFyIS36Vyu9KjZTwfXNd5QS 67i8U4sn/yeZXtg9tzHxuzAbhfNxG00fXLW3Qb3GR5wtDRPBlh7hRWyTb8i8yhDMfI 7IhE+EOOKrpMVQkgrsHiTQ8AE8TBIOxIgZUCQ/JM= 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 4.14 098/190] e1000: Distribute switch variables for initialization Date: Fri, 19 Jun 2020 16:32:23 +0200 Message-Id: <20200619141638.488881713@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200619141633.446429600@linuxfoundation.org> References: <20200619141633.446429600@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 3dd4aeb2706d..175681aa5260 100644 --- a/drivers/net/ethernet/intel/e1000/e1000_main.c +++ b/drivers/net/ethernet/intel/e1000/e1000_main.c @@ -3169,8 +3169,9 @@ 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 @@ -3191,6 +3192,7 @@ static netdev_tx_t e1000_xmit_frame(struct sk_buff *skb, } len = skb_headlen(skb); break; + } default: /* do nothing */ break; -- 2.25.1