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 EFD30C05027 for ; Tue, 14 Feb 2023 15:25:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230337AbjBNPZ5 (ORCPT ); Tue, 14 Feb 2023 10:25:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45426 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229506AbjBNPZ4 (ORCPT ); Tue, 14 Feb 2023 10:25:56 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CD6BB2A143; Tue, 14 Feb 2023 07:25:54 -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 8E7ACB81BFA; Tue, 14 Feb 2023 15:25:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CE26CC433EF; Tue, 14 Feb 2023 15:25:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1676388352; bh=S672kuM2oKkdizJFtUPdFijqnxwsifpqRIps1yp91iA=; h=From:To:Cc:Subject:Date:From; b=PHh5CRZ99XD1TaFZ1paqrurf/zq/FH7vYrIiq7aCOtOKbEZpaebqUKELEfOBBtaoY Yz/l+RRRaujZhwCH7D9zIYv5Fs8L4bzd6TYuuNIRw/c3jYwn3Lvaztpo/KjHan52ZH MQTRkwCglfeZwvAENIAMGnMvEgUzYO5MLPSBPQaP7pm9pEuilZrJl2a6X1zW17nPA/ unJyFzPjE8BEVYhrq9LkCuCWAXSktDTqn1DDjZj3Em1XQBUCZ5n8gpONP1WXOqAbh0 teS4WER/vNmOnGDU42z2SOc2ujCzKkiKJwwk62HS3Qf3x8lCMjSxbeIWihKaK1qNTo 1ws56mDxoyINA== From: Arnd Bergmann To: Jesse Brandeburg , Tony Nguyen , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Martyna Szapar-Mudlaw Cc: Arnd Bergmann , Alexander Lobakin , Marcin Szycik , Michal Swiatkowski , Amritha Nambiar , Wojciech Drewek , Lu Wei , intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] [v2] ethernet: ice: avoid gcc-9 integer overflow warning Date: Tue, 14 Feb 2023 16:25:36 +0100 Message-Id: <20230214152548.826703-1-arnd@kernel.org> X-Mailer: git-send-email 2.39.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Arnd Bergmann With older compilers like gcc-9, the calculation of the vlan priority field causes a false-positive warning from the byteswap: In file included from drivers/net/ethernet/intel/ice/ice_tc_lib.c:4: drivers/net/ethernet/intel/ice/ice_tc_lib.c: In function 'ice_parse_cls_flower': include/uapi/linux/swab.h:15:15: error: integer overflow in expression '(int)(short unsigned int)((int)match.key->..vlan_priority << 13) & 57344 & 255' of type 'int' results in '0' [-Werror=overflow] 15 | (((__u16)(x) & (__u16)0x00ffU) << 8) | \ | ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ include/uapi/linux/swab.h:106:2: note: in expansion of macro '___constant_swab16' 106 | ___constant_swab16(x) : \ | ^~~~~~~~~~~~~~~~~~ include/uapi/linux/byteorder/little_endian.h:42:43: note: in expansion of macro '__swab16' 42 | #define __cpu_to_be16(x) ((__force __be16)__swab16((x))) | ^~~~~~~~ include/linux/byteorder/generic.h:96:21: note: in expansion of macro '__cpu_to_be16' 96 | #define cpu_to_be16 __cpu_to_be16 | ^~~~~~~~~~~~~ drivers/net/ethernet/intel/ice/ice_tc_lib.c:1458:5: note: in expansion of macro 'cpu_to_be16' 1458 | cpu_to_be16((match.key->vlan_priority << | ^~~~~~~~~~~ After a change to be16_encode_bits(), the code becomes more readable to both people and compilers, which avoids the warning. Fixes: 34800178b302 ("ice: Add support for VLAN priority filters in switchdev") Suggested-by: Alexander Lobakin Signed-off-by: Arnd Bergmann --- v2: use be16_encode_bits() instead of a temporary variable. --- drivers/net/ethernet/intel/ice/ice_tc_lib.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/intel/ice/ice_tc_lib.c b/drivers/net/ethernet/intel/ice/ice_tc_lib.c index 6b48cbc049c6..76f29a5bf8d7 100644 --- a/drivers/net/ethernet/intel/ice/ice_tc_lib.c +++ b/drivers/net/ethernet/intel/ice/ice_tc_lib.c @@ -1455,8 +1455,8 @@ ice_parse_cls_flower(struct net_device *filter_dev, struct ice_vsi *vsi, if (match.mask->vlan_priority) { fltr->flags |= ICE_TC_FLWR_FIELD_VLAN_PRIO; headers->vlan_hdr.vlan_prio = - cpu_to_be16((match.key->vlan_priority << - VLAN_PRIO_SHIFT) & VLAN_PRIO_MASK); + be16_encode_bits(match.key->vlan_priority, + VLAN_PRIO_MASK); } if (match.mask->vlan_tpid) @@ -1489,8 +1489,8 @@ ice_parse_cls_flower(struct net_device *filter_dev, struct ice_vsi *vsi, if (match.mask->vlan_priority) { fltr->flags |= ICE_TC_FLWR_FIELD_CVLAN_PRIO; headers->cvlan_hdr.vlan_prio = - cpu_to_be16((match.key->vlan_priority << - VLAN_PRIO_SHIFT) & VLAN_PRIO_MASK); + be16_encode_bits(match.key->vlan_priority, + VLAN_PRIO_MASK); } } -- 2.39.1