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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 413ADECDFBB for ; Fri, 20 Jul 2018 12:42:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 03D8D20652 for ; Fri, 20 Jul 2018 12:42:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 03D8D20652 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389633AbeGTNaN (ORCPT ); Fri, 20 Jul 2018 09:30:13 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:52194 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731571AbeGTNaM (ORCPT ); Fri, 20 Jul 2018 09:30:12 -0400 Received: from localhost (LFbn-1-12238-233.w90-92.abo.wanadoo.fr [90.92.53.233]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 079FAC8A; Fri, 20 Jul 2018 12:38:08 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Julian Wiedmann , Vasily Gorbik , "David S. Miller" Subject: [PATCH 4.17 057/101] s390/qeth: avoid using is_multicast_ether_addr_64bits on (u8 *)[6] Date: Fri, 20 Jul 2018 14:14:03 +0200 Message-Id: <20180720121425.547783082@linuxfoundation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180720121422.837870592@linuxfoundation.org> References: <20180720121422.837870592@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Vasily Gorbik [ Upstream commit 9d0a58fb9747afd27d490c02a97889a1b59f6be4 ] *ether_addr*_64bits functions have been introduced to optimize performance critical paths, which access 6-byte ethernet address as u64 value to get "nice" assembly. A harmless hack works nicely on ethernet addresses shoved into a structure or a larger buffer, until busted by Kasan on smth like plain (u8 *)[6]. qeth_l2_set_mac_address calls qeth_l2_remove_mac passing u8 old_addr[ETH_ALEN] as an argument. Adding/removing macs for an ethernet adapter is not that performance critical. Moreover is_multicast_ether_addr_64bits itself on s390 is not faster than is_multicast_ether_addr: is_multicast_ether_addr(%r2) -> %r2 llc %r2,0(%r2) risbg %r2,%r2,63,191,0 is_multicast_ether_addr_64bits(%r2) -> %r2 llgc %r2,0(%r2) risbg %r2,%r2,63,191,0 So, let's just use is_multicast_ether_addr instead of is_multicast_ether_addr_64bits. Fixes: bcacfcbc82b4 ("s390/qeth: fix MAC address update sequence") Reviewed-by: Julian Wiedmann Signed-off-by: Vasily Gorbik Signed-off-by: Julian Wiedmann Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/s390/net/qeth_l2_main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/s390/net/qeth_l2_main.c +++ b/drivers/s390/net/qeth_l2_main.c @@ -141,7 +141,7 @@ static int qeth_l2_send_setmac(struct qe static int qeth_l2_write_mac(struct qeth_card *card, u8 *mac) { - enum qeth_ipa_cmds cmd = is_multicast_ether_addr_64bits(mac) ? + enum qeth_ipa_cmds cmd = is_multicast_ether_addr(mac) ? IPA_CMD_SETGMAC : IPA_CMD_SETVMAC; int rc; @@ -158,7 +158,7 @@ static int qeth_l2_write_mac(struct qeth static int qeth_l2_remove_mac(struct qeth_card *card, u8 *mac) { - enum qeth_ipa_cmds cmd = is_multicast_ether_addr_64bits(mac) ? + enum qeth_ipa_cmds cmd = is_multicast_ether_addr(mac) ? IPA_CMD_DELGMAC : IPA_CMD_DELVMAC; int rc;