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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 98451C10F1E for ; Sun, 18 Dec 2022 17:07:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232011AbiLRRH5 (ORCPT ); Sun, 18 Dec 2022 12:07:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59206 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233386AbiLRRGJ (ORCPT ); Sun, 18 Dec 2022 12:06:09 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B402D13CD3; Sun, 18 Dec 2022 08:22:25 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 603ABB80B43; Sun, 18 Dec 2022 16:22:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AAD7FC433F0; Sun, 18 Dec 2022 16:22:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1671380543; bh=MXHyYopZ4S2ODtjoIFP4OUghp3esDJ8iLRzh3BEjY30=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fl1LQHoXJ6tM+Bca/x5ihCjbdoNBP1UmGrEnK3BTbTNqQU6HlNANnOxUR7gzQOBLy v381yFo8ULLZa4vcYGIAAhw6THuHUXAX3sShpMlPh+KgG4cNdaEgsBNsz1eouH9OUX PdhM5xW/oIPMAlUZIjVX8UX6tPn1iaqnox161nAIZ16AJAAKQCcyXoxN+P9SaYkO8e fBtM482VMpA8AuLKR7IJISeDT3uGAVeNC/69JROjDzGOuDPDmrW3vczUmNLCLBUNHK lup5XcMjyT2/gK8YyMyBcpNKhMF5S8bnUEnPw1/yrXQe31x2CH5sOOSGBE5GkKanj+ +tgJ1au3HTqww== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Nathan Chancellor , Alexandra Winter , Kees Cook , "David S . Miller" , Sasha Levin , wenjia@linux.ibm.com, hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com, ndesaulniers@google.com, linux-s390@vger.kernel.org, netdev@vger.kernel.org, llvm@lists.linux.dev Subject: [PATCH AUTOSEL 4.14 11/23] s390/netiucv: Fix return type of netiucv_tx() Date: Sun, 18 Dec 2022 11:21:37 -0500 Message-Id: <20221218162149.935047-11-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221218162149.935047-1-sashal@kernel.org> References: <20221218162149.935047-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Nathan Chancellor [ Upstream commit 88d86d18d7cf7e9137c95f9d212bb9fff8a1b4be ] With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG), indirect call targets are validated against the expected function pointer prototype to make sure the call target is valid to help mitigate ROP attacks. If they are not identical, there is a failure at run time, which manifests as either a kernel panic or thread getting killed. A proposed warning in clang aims to catch these at compile time, which reveals: drivers/s390/net/netiucv.c:1854:21: error: incompatible function pointer types initializing 'netdev_tx_t (*)(struct sk_buff *, struct net_device *)' (aka 'enum netdev_tx (*)(struct sk_buff *, struct net_device *)') with an expression of type 'int (struct sk_buff *, struct net_device *)' [-Werror,-Wincompatible-function-pointer-types-strict] .ndo_start_xmit = netiucv_tx, ^~~~~~~~~~ ->ndo_start_xmit() in 'struct net_device_ops' expects a return type of 'netdev_tx_t', not 'int'. Adjust the return type of netiucv_tx() to match the prototype's to resolve the warning and potential CFI failure, should s390 select ARCH_SUPPORTS_CFI_CLANG in the future. Additionally, while in the area, remove a comment block that is no longer relevant. Link: https://github.com/ClangBuiltLinux/linux/issues/1750 Reviewed-by: Alexandra Winter Reviewed-by: Kees Cook Signed-off-by: Nathan Chancellor Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/s390/net/netiucv.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) diff --git a/drivers/s390/net/netiucv.c b/drivers/s390/net/netiucv.c index b9c7c1e61da2..b6d123c60742 100644 --- a/drivers/s390/net/netiucv.c +++ b/drivers/s390/net/netiucv.c @@ -1358,15 +1358,8 @@ static int netiucv_pm_restore_thaw(struct device *dev) /** * Start transmission of a packet. * Called from generic network device layer. - * - * @param skb Pointer to buffer containing the packet. - * @param dev Pointer to interface struct. - * - * @return 0 if packet consumed, !0 if packet rejected. - * Note: If we return !0, then the packet is free'd by - * the generic network layer. */ -static int netiucv_tx(struct sk_buff *skb, struct net_device *dev) +static netdev_tx_t netiucv_tx(struct sk_buff *skb, struct net_device *dev) { struct netiucv_priv *privptr = netdev_priv(dev); int rc; -- 2.35.1