From patchwork Thu Nov 3 17:01:28 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nathan Chancellor X-Patchwork-Id: 15027 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:6687:0:0:0:0:0 with SMTP id l7csp655491wru; Thu, 3 Nov 2022 10:07:34 -0700 (PDT) X-Google-Smtp-Source: AMsMyM6ATuGZygctIueiAPR7rzZ6n6vlJB9nICOBYV35hAkleRxgWNKn3kl2Z9BFALTa3li+DagX X-Received: by 2002:a17:907:2cd7:b0:7ad:ef1e:3b72 with SMTP id hg23-20020a1709072cd700b007adef1e3b72mr14715100ejc.449.1667495254362; Thu, 03 Nov 2022 10:07:34 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1667495254; cv=none; d=google.com; s=arc-20160816; b=g7XCq2Xt3rqUYpCQC24ECHjcwULlK1s5uzHUV2itYA6jgD3WsyWmSYQcxdM2gWsJ8X kcYgdGipIAIUsHaXMKfEbZFqQXbfG3gjbnd0MsKNGIpUZu4hlYmWNLJudkfVDvXO1Kyz b6/GOOO6SGBLkrdUGc/hIzBPU7/YJVKXox2oeU36APDABok2HvyLTzrMEFknAimruKe8 g/XnYy5fwGG0PId7nyXLBn0cUDcdQmlzMSe/eFZxlvU5AX7IcriENWrUNPEjkBek9Dm7 YqMULCTz9MLKM807kfwAr/Ak9V40Ljxiz4KEG4jnNZ6LxS99YrAlUJcps8xXdeY8bh/B 5idQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :message-id:date:subject:cc:to:from:dkim-signature; bh=REKp97/yy21NEKUHZQzhZhHnf6Yidizs9H23Acb3yag=; b=uL4xeMeYLa7pcumUjVLQBHKXvjqW7QYwhgR36BVXj4NoP9I1F55a3ECX/KU9+LQYba YswMWUNzVsH8l1E4APirYcU+vqy/pIJuf48AOrsWFEa06NB+SYKBJ7nC278Z89SNc8lf BlWbQr3FbLYAx2UXVFJMZZFhshDta2HDBxnlPnc1SI+OGS1MjwDMAj89aS+Eboi4adA5 7DYmngRmO/8MWNBgY6Qb5uA9T44eDipmKnEgrN3cm8l8ThTNUr5alfwsqvZ1+PswB8pV BYzwKBRcrNlcc1yDmBGfnkCcwq/GLDCJ8pKDJmz0ZxmnT+SLW6rVxEhozRMCyQeK1dou VoDA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=SUvqFdxc; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id w15-20020a05640234cf00b004618ed2dfe2si2335815edc.6.2022.11.03.10.07.10; Thu, 03 Nov 2022 10:07:34 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=SUvqFdxc; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231971AbiKCRC2 (ORCPT + 99 others); Thu, 3 Nov 2022 13:02:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57742 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231849AbiKCRBx (ORCPT ); Thu, 3 Nov 2022 13:01:53 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D51CB396; Thu, 3 Nov 2022 10:01:52 -0700 (PDT) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 719A161F87; Thu, 3 Nov 2022 17:01:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D78D1C433D7; Thu, 3 Nov 2022 17:01:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1667494911; bh=Ayl0uMDQLjbJW7HCHCKMEYKRRMbofKS7PhzsOSwmDk0=; h=From:To:Cc:Subject:Date:From; b=SUvqFdxcftHNWUAWw3dMM1PZETx6pz6Tfjvf4PVSCtSdHo7FLBnENF9vCdx+5kQgJ gZBfl7sOEfZA9dpToAGOJ9GepoHcDJ8H7SJowBqOR08qOl12zVXLRg8fbpoG7Fy/XX ZBchd/NuvSFoFISyB7zdE2yxxw2oiXgPDHIovpT5ZfAArsNfM4lOHiwD+LY/pD+noV TtkcoDqEvhUft8VDoHVdPxlv23EHKGEICdRSFI5PJSFVIR48hGo5/SjadQFubD+32I b01hoNn7eSmALD9CgzHvOGaVlIql8gdPgJMREvLB9lQvs44IV987nfcM4LTmPVVHEj INkM9jDEZn7Gw== From: Nathan Chancellor To: Alexandra Winter , Wenjia Zhang Cc: Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , linux-s390@vger.kernel.org, netdev@vger.kernel.org, Nick Desaulniers , Tom Rix , Kees Cook , Sami Tolvanen , llvm@lists.linux.dev, linux-kernel@vger.kernel.org, patches@lists.linux.dev, Nathan Chancellor Subject: [PATCH v2 1/3] s390/ctcm: Fix return type of ctc{mp,}m_tx() Date: Thu, 3 Nov 2022 10:01:28 -0700 Message-Id: <20221103170130.1727408-1-nathan@kernel.org> X-Mailer: git-send-email 2.38.1 MIME-Version: 1.0 X-Spam-Status: No, score=-8.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1748495503574671757?= X-GMAIL-MSGID: =?utf-8?q?1748495503574671757?= 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/ctcm_main.c:1064:21: 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 = ctcm_tx, ^~~~~~~ drivers/s390/net/ctcm_main.c:1072:21: 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 = ctcmpc_tx, ^~~~~~~~~ ->ndo_start_xmit() in 'struct net_device_ops' expects a return type of 'netdev_tx_t', not 'int'. Adjust the return type of ctc{mp,}m_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 --- v2: - Pick up tags from Alexandra and Kees. - Remove comment block above ctcm_tx() (Alexandra). v1: https://lore.kernel.org/20221102163252.49175-1-nathan@kernel.org/ --- drivers/s390/net/ctcm_main.c | 11 ++--------- 1 file changed, 2 insertions(+), 9 deletions(-) base-commit: 9abf2313adc1ca1b6180c508c25f22f9395cc780 diff --git a/drivers/s390/net/ctcm_main.c b/drivers/s390/net/ctcm_main.c index 37b551bd43bf..bdfab9ea0046 100644 --- a/drivers/s390/net/ctcm_main.c +++ b/drivers/s390/net/ctcm_main.c @@ -825,16 +825,9 @@ static int ctcmpc_transmit_skb(struct channel *ch, struct sk_buff *skb) /* * Start transmission of a packet. * Called from generic network device layer. - * - * skb Pointer to buffer containing the packet. - * dev Pointer to interface struct. - * - * returns 0 if packet consumed, !0 if packet rejected. - * Note: If we return !0, then the packet is free'd by - * the generic network layer. */ /* first merge version - leaving both functions separated */ -static int ctcm_tx(struct sk_buff *skb, struct net_device *dev) +static netdev_tx_t ctcm_tx(struct sk_buff *skb, struct net_device *dev) { struct ctcm_priv *priv = dev->ml_priv; @@ -877,7 +870,7 @@ static int ctcm_tx(struct sk_buff *skb, struct net_device *dev) } /* unmerged MPC variant of ctcm_tx */ -static int ctcmpc_tx(struct sk_buff *skb, struct net_device *dev) +static netdev_tx_t ctcmpc_tx(struct sk_buff *skb, struct net_device *dev) { int len = 0; struct ctcm_priv *priv = dev->ml_priv; From patchwork Thu Nov 3 17:01:29 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nathan Chancellor X-Patchwork-Id: 15024 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:6687:0:0:0:0:0 with SMTP id l7csp655366wru; Thu, 3 Nov 2022 10:07:17 -0700 (PDT) X-Google-Smtp-Source: AMsMyM7cDRcZkGMs+9Y9WJHfsKpJdaUt0qrYvubZsLEA2ZA+1S8U/bWokHXlK3WZ7U6FZOc/BI97 X-Received: by 2002:a17:90b:118:b0:215:4338:d05e with SMTP id p24-20020a17090b011800b002154338d05emr8483294pjz.88.1667495237309; Thu, 03 Nov 2022 10:07:17 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1667495237; cv=none; d=google.com; s=arc-20160816; b=qWnOgbxR0Qhg5jtDo0Nm6xFL3qBV1iaz29TvnhQgFvGG4NsCqFnYZq/hS5uqUwk8Ve klONYwkQVeXw9mxMH6yHotwDV37d8hVnzkWOF+nsgCWAsnExGnCYPmYH1RNCBnvuJr9K zpPGBhl2KdPfCkJHTBCjbHdemnXGylqB9YUXjK2Tuunl9bcxKmOzrIqboyNw2hqeqYWi 0hcqlAgJWCZ429eclwCQ+mW5eBOpDqUq2VM3ifxQL87WU/R0Q9iskWHCfIU0V4ec0g1a u0f4TzpVQyd/zegsU1O5mFs+amGKHQ5IE6jCvfnYf/7odrrdYF4BFQ9WiV/Gz8zCmg93 ey9w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=c//glqDc3s34i71VuZZMRGtGsXCHRcUqPee+sNTAjS0=; b=pCM8d/q3WjUZzI0Ezp0SyuAKCH2P+WI+sBSbliW+FmVMUwOGH+zA58PgURvGCXwrd0 pIlukYhWK901i9oQSSp7xNf+HAWU8Ta2G4j1vSTHln1ab/FITkdYEtKRXYkgczsAyiKT Rg/lZPdMuiNVZCSn8WF9IS79V/8f8TUbVAaecNJoGLJ2ivqPSLGlXOhFbiDJypIrl3l5 SLcTwCwe1vclc8aWo19K+tTSxoP2F5XwvLFipmzHVDJpP9Rp0bE3vPGawQA/bVS+WzoZ HZ+5UA8VfnPmFxPS9x65p+qrpZAeG2Re4QYc8Tpkvaa9ns4dRb4C4yh9tR8DmH+4Toee NW3g== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=IvELajK6; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id m13-20020a170902f64d00b00176c9015627si1342900plg.94.2022.11.03.10.07.02; Thu, 03 Nov 2022 10:07:17 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=IvELajK6; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231899AbiKCRCZ (ORCPT + 99 others); Thu, 3 Nov 2022 13:02:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57804 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231941AbiKCRBz (ORCPT ); Thu, 3 Nov 2022 13:01:55 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9FF571143; Thu, 3 Nov 2022 10:01:54 -0700 (PDT) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 3D27F61F87; Thu, 3 Nov 2022 17:01:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B2C85C433B5; Thu, 3 Nov 2022 17:01:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1667494913; bh=f6y6m1EnUKwUsyjzfNr41VDZUX99wh7+ivnefKR1ZII=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IvELajK622CDtEFS3+Ndom/QAcrk2LdjDsIKm24NObJTK2STWaEF4arbw04pLNHCI YoG29onc7BA/p6VUkguQljzIoQ6N3IppFAGDiFFro5n8rICMp0V619jM6mjpHJONlr H/K4uGzHzHh+uyJ7dusvQBwQEofJaWE1qVWEGXzc3aAWHfASCXjPapjURUL6JyH1Pv xe9Ai/oWFSeNaDl3YdbeQiPRcdBW8qRWztLuBGGKMo2vV9FX0uf1z/1WkJW+cRgwBc +IKFm/7vzni39ewblgUJWogi4H0rO0edEFA+aIOQoRoXy0zx32gon1dapt8/7/9bSA JC/AvS7uXIC8w== From: Nathan Chancellor To: Alexandra Winter , Wenjia Zhang Cc: Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , linux-s390@vger.kernel.org, netdev@vger.kernel.org, Nick Desaulniers , Tom Rix , Kees Cook , Sami Tolvanen , llvm@lists.linux.dev, linux-kernel@vger.kernel.org, patches@lists.linux.dev, Nathan Chancellor Subject: [PATCH v2 2/3] s390/netiucv: Fix return type of netiucv_tx() Date: Thu, 3 Nov 2022 10:01:29 -0700 Message-Id: <20221103170130.1727408-2-nathan@kernel.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221103170130.1727408-1-nathan@kernel.org> References: <20221103170130.1727408-1-nathan@kernel.org> MIME-Version: 1.0 X-Spam-Status: No, score=-8.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1748495486099284542?= X-GMAIL-MSGID: =?utf-8?q?1748495486099284542?= 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 --- v2: - Pick up tags from Alexandra and Kees. - Remove comment block above netiucv_tx() (Alexandra). v1: https://lore.kernel.org/20221102163252.49175-2-nathan@kernel.org/ --- 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 65aa0a96c21d..66076cada8ae 100644 --- a/drivers/s390/net/netiucv.c +++ b/drivers/s390/net/netiucv.c @@ -1248,15 +1248,8 @@ static int netiucv_close(struct net_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; From patchwork Thu Nov 3 17:01:30 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nathan Chancellor X-Patchwork-Id: 15025 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:6687:0:0:0:0:0 with SMTP id l7csp655444wru; Thu, 3 Nov 2022 10:07:29 -0700 (PDT) X-Google-Smtp-Source: AMsMyM6qLZaHpsm3SpcVG/PDs2KUC1op8ktNri98z/n3KU1h1INhp8+/9nHoORzkkpFW/HpyUf+M X-Received: by 2002:a17:907:760e:b0:7ad:e4c9:dc79 with SMTP id jx14-20020a170907760e00b007ade4c9dc79mr17617826ejc.308.1667495249638; Thu, 03 Nov 2022 10:07:29 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1667495249; cv=none; d=google.com; s=arc-20160816; b=O0NpH1WbJcRLmlYcmEt4q2Dk6sPiAen7P9m2UxOkshlPwXq2SQOI/Kl9A4ru0aKNSA 47Cjtz0pcKAIcCicKVpbmbmu6+KC3Eoc+bCqTj90l/xttQxkM5rmVY1dBUxrBOXgw1sD qAMhl4pN/te8U9rzkOEY1OWj2oMxUjfNNVy0e/N6h/fEZkr1qUAjQiQvLW4OhXsuB44w 0KyScHV/J634jRHKr8u2cBrQfKGChB6elcNwDnnMAH6Ym1UuzkvOQoVaJ9vR87o8QOK1 YMz9qyNTSwZYewN9zmxyEkLOy37ug6qO91pRsmRsbE+YuWeSG9abpxrK4wcmK56DVy7T JKtA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=JwZlEmgR4X4A9cjjdyhcJgXVCV16WnI1s6+Oby2Ojdw=; b=OamtENBJpBmAfCEDdvQvRPF7ZzTxe9x2GciI4qgKPPQB1tXYXat8fhKp1GYAzjCnrd loqO6PiXwpYiFCOQEOvxHwSY5h4Akuo7aVG40m8P8CdVU59MDjTKWNbTWGzIKtapM6Kq 6XEKsVIzPaJREATTfElnGiTi33Y0V6PG5oaGbWgM4IXSnsiSaOJRsMGGjVlbbDq9xFJ3 4H5DQKzsBHxoCAk5yc+UCC420PYXgnd0pcOIjAhmnPi2mLXe8ZNAm9isSJf2ThqWghur yB7tBRqtDxZth1EhMSv5EHzUMYNKsA8gI4jzKZBIAmBUC/9Ks4vlMvIDXcvq8qYQEAOp jPVQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=XMDIuoDV; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id v18-20020a1709064e9200b00779a3220c5asi1312266eju.343.2022.11.03.10.07.04; Thu, 03 Nov 2022 10:07:29 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=XMDIuoDV; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231807AbiKCRCW (ORCPT + 99 others); Thu, 3 Nov 2022 13:02:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57826 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231956AbiKCRB6 (ORCPT ); Thu, 3 Nov 2022 13:01:58 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB9C9396; Thu, 3 Nov 2022 10:01:57 -0700 (PDT) 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 A5CE1B82962; Thu, 3 Nov 2022 17:01:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 54C8DC433D7; Thu, 3 Nov 2022 17:01:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1667494915; bh=D6/fRtPSM2LL/1pNEu7S9mDvRcvLO6bXEXGfxKCxLfk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XMDIuoDVdszuwgtpet7Zhut7+sLQ3lCO+sIwchaG0nneXIBaKXTtNveI6/Ed4b2Pt dcsH02Dfwofx3dgr6jxvcTPCCZjiS7qJGFcBa7gdRajTjVyL1dpFbLZqrqjKUgA8Vk qnPsDUOxD1tl1JsrA73L4wCeH/fVZVPpecXhCXR8j0RNb2dwlfpsL288P3+FHFWIgw wN4rACbk21wqlBUqmyJI/4GKab1pyUhx8u3zGw3NlgUOQVRuqiaaPoHyTuVA8x87KD nkQt1apI4lSBd0jku12nocowT0xOsKZy5cYO560fkLb6ttyU/3iIHOcyGOjn1zjhxU efVmAj/18PjJg== From: Nathan Chancellor To: Alexandra Winter , Wenjia Zhang Cc: Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , linux-s390@vger.kernel.org, netdev@vger.kernel.org, Nick Desaulniers , Tom Rix , Kees Cook , Sami Tolvanen , llvm@lists.linux.dev, linux-kernel@vger.kernel.org, patches@lists.linux.dev, Nathan Chancellor Subject: [PATCH v2 3/3] s390/lcs: Fix return type of lcs_start_xmit() Date: Thu, 3 Nov 2022 10:01:30 -0700 Message-Id: <20221103170130.1727408-3-nathan@kernel.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221103170130.1727408-1-nathan@kernel.org> References: <20221103170130.1727408-1-nathan@kernel.org> MIME-Version: 1.0 X-Spam-Status: No, score=-8.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1748495498826971773?= X-GMAIL-MSGID: =?utf-8?q?1748495498826971773?= 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/lcs.c:2090:21: 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 = lcs_start_xmit, ^~~~~~~~~~~~~~ drivers/s390/net/lcs.c:2097:21: 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 = lcs_start_xmit, ^~~~~~~~~~~~~~ ->ndo_start_xmit() in 'struct net_device_ops' expects a return type of 'netdev_tx_t', not 'int'. Adjust the return type of lcs_start_xmit() to match the prototype's to resolve the warning and potential CFI failure, should s390 select ARCH_SUPPORTS_CFI_CLANG in the future. Link: https://github.com/ClangBuiltLinux/linux/issues/1750 Reviewed-by: Alexandra Winter Reviewed-by: Kees Cook Signed-off-by: Nathan Chancellor --- v2: - Pick up tags from Alexandra and Kees. - Adjust indentation of modified lines, as they can fit within the line limit (Alexandra). v1: https://lore.kernel.org/20221102163252.49175-3-nathan@kernel.org/ --- drivers/s390/net/lcs.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/drivers/s390/net/lcs.c b/drivers/s390/net/lcs.c index 84c8981317b4..38f312664ce7 100644 --- a/drivers/s390/net/lcs.c +++ b/drivers/s390/net/lcs.c @@ -1519,9 +1519,8 @@ lcs_txbuffer_cb(struct lcs_channel *channel, struct lcs_buffer *buffer) /* * Packet transmit function called by network stack */ -static int -__lcs_start_xmit(struct lcs_card *card, struct sk_buff *skb, - struct net_device *dev) +static netdev_tx_t __lcs_start_xmit(struct lcs_card *card, struct sk_buff *skb, + struct net_device *dev) { struct lcs_header *header; int rc = NETDEV_TX_OK; @@ -1582,8 +1581,7 @@ __lcs_start_xmit(struct lcs_card *card, struct sk_buff *skb, return rc; } -static int -lcs_start_xmit(struct sk_buff *skb, struct net_device *dev) +static netdev_tx_t lcs_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct lcs_card *card; int rc;