From patchwork Thu May 25 20:52:06 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Pfaff X-Patchwork-Id: 767115 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3wYhKJ38Tpz9s8N for ; Fri, 26 May 2017 06:52:20 +1000 (AEST) Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id AD642B93; Thu, 25 May 2017 20:52:17 +0000 (UTC) X-Original-To: dev@openvswitch.org Delivered-To: ovs-dev@mail.linuxfoundation.org Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 290293EE for ; Thu, 25 May 2017 20:52:16 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from relay5-d.mail.gandi.net (relay5-d.mail.gandi.net [217.70.183.197]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id D90B915C for ; Thu, 25 May 2017 20:52:14 +0000 (UTC) Received: from mfilter5-d.gandi.net (mfilter5-d.gandi.net [217.70.178.132]) by relay5-d.mail.gandi.net (Postfix) with ESMTP id A421541C080; Thu, 25 May 2017 22:52:13 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at mfilter5-d.gandi.net Received: from relay5-d.mail.gandi.net ([IPv6:::ffff:217.70.183.197]) by mfilter5-d.gandi.net (mfilter5-d.gandi.net [::ffff:10.0.15.180]) (amavisd-new, port 10024) with ESMTP id 9WJTHFoodsXb; Thu, 25 May 2017 22:52:11 +0200 (CEST) X-Originating-IP: 208.91.2.3 Received: from sigabrt.benpfaff.org (unknown [208.91.2.3]) (Authenticated sender: blp@ovn.org) by relay5-d.mail.gandi.net (Postfix) with ESMTPSA id 67E8D41C07D; Thu, 25 May 2017 22:52:10 +0200 (CEST) From: Ben Pfaff To: dev@openvswitch.org Date: Thu, 25 May 2017 13:52:06 -0700 Message-Id: <20170525205206.1700-1-blp@ovn.org> X-Mailer: git-send-email 2.10.2 X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Cc: Ben Pfaff Subject: [ovs-dev] [PATCH] packets: Remove unnecessary "packed" annotations. X-BeenThere: ovs-dev@openvswitch.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: ovs-dev-bounces@openvswitch.org Errors-To: ovs-dev-bounces@openvswitch.org I know of two reasons to mark a structure as "packed". The first is because the structure must match some defined interface and therefore compiler-inserted padding between or after members would cause its layout to diverge from that interface. This is not a problem in a structure that follows the general alignment rules that are seen in ABIs for all the architectures that OVS cares about: basically, that a struct member needs to be aligned on a boundary that is a multiple of the member's size. The second reason is because instances of the struct tend to be at misaligned addresses. struct eth_header and struct vlan_eth_header are normally aligned on 16-bit boundaries (at least), and they contain only 16-bit members, so there's no need to pack them. This commit removes the packed annotation. This commit also removes the packed annotation from struct llc_header. Since that struct only contains 8-bit members, I don't know of any benefit to packing it, period. This commit also removes a few more packed annotations that are much less important. When these packed annotations were removed, it caused a few warnings related to casts from 'uint8_t *' to more strictly aligned pointer types, related to struct ovs_action_push_tnl. That's because that struct had a trailing member used to store packet headers, that was declared as a uint8_t[]. Before, when this was cast to 'struct eth_header *', there was no change in alignment since eth_header was packed; now that eth_header is not packed, the compiler considers it suspicious. This commit avoids that problem by changing the member from uint8_t[] to uint32_t[], which assures the compiler that it is properly aligned. CC: Joe Stringer Signed-off-by: Ben Pfaff Acked-by: Joe Stringer --- datapath/linux/compat/include/linux/openvswitch.h | 2 +- lib/packets.h | 9 +++------ lib/stp.c | 8 +++----- ofproto/bundles.h | 4 ++-- 4 files changed, 9 insertions(+), 14 deletions(-) diff --git a/datapath/linux/compat/include/linux/openvswitch.h b/datapath/linux/compat/include/linux/openvswitch.h index d22102e224a7..55ec6c13fbd2 100644 --- a/datapath/linux/compat/include/linux/openvswitch.h +++ b/datapath/linux/compat/include/linux/openvswitch.h @@ -715,7 +715,7 @@ struct ovs_action_push_tnl { uint32_t out_port; uint32_t header_len; uint32_t tnl_type; /* For logging. */ - uint8_t header[TNL_PUSH_HEADER_SIZE]; + uint32_t header[TNL_PUSH_HEADER_SIZE / 4]; }; #endif diff --git a/lib/packets.h b/lib/packets.h index 7dbf6dd0b415..65ab8e8b5699 100644 --- a/lib/packets.h +++ b/lib/packets.h @@ -395,12 +395,11 @@ static inline bool eth_type_vlan(ovs_be16 eth_type) #define ETH_TOTAL_MIN (ETH_HEADER_LEN + ETH_PAYLOAD_MIN) #define ETH_TOTAL_MAX (ETH_HEADER_LEN + ETH_PAYLOAD_MAX) #define ETH_VLAN_TOTAL_MAX (ETH_HEADER_LEN + VLAN_HEADER_LEN + ETH_PAYLOAD_MAX) -OVS_PACKED( struct eth_header { struct eth_addr eth_dst; struct eth_addr eth_src; ovs_be16 eth_type; -}); +}; BUILD_ASSERT_DECL(ETH_HEADER_LEN == sizeof(struct eth_header)); void push_eth(struct dp_packet *packet, const struct eth_addr *dst, @@ -412,12 +411,11 @@ void pop_eth(struct dp_packet *packet); #define LLC_CNTL_SNAP 3 #define LLC_HEADER_LEN 3 -OVS_PACKED( struct llc_header { uint8_t llc_dsap; uint8_t llc_ssap; uint8_t llc_cntl; -}); +}; BUILD_ASSERT_DECL(LLC_HEADER_LEN == sizeof(struct llc_header)); /* LLC field values used for STP frames. */ @@ -484,14 +482,13 @@ struct vlan_header { BUILD_ASSERT_DECL(VLAN_HEADER_LEN == sizeof(struct vlan_header)); #define VLAN_ETH_HEADER_LEN (ETH_HEADER_LEN + VLAN_HEADER_LEN) -OVS_PACKED( struct vlan_eth_header { struct eth_addr veth_dst; struct eth_addr veth_src; ovs_be16 veth_type; /* Always htons(ETH_TYPE_VLAN). */ ovs_be16 veth_tci; /* Lowest 12 bits are VLAN ID. */ ovs_be16 veth_next_type; -}); +}; BUILD_ASSERT_DECL(VLAN_ETH_HEADER_LEN == sizeof(struct vlan_eth_header)); /* MPLS related definitions */ diff --git a/lib/stp.c b/lib/stp.c index 952d3ce434c3..d83d42521498 100644 --- a/lib/stp.c +++ b/lib/stp.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2016 Nicira, Inc. + * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2016, 2017 Nicira, Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. @@ -45,12 +45,11 @@ static struct vlog_rate_limit stp_rl = VLOG_RATE_LIMIT_INIT(60, 60); #define STP_TYPE_CONFIG 0x00 #define STP_TYPE_TCN 0x80 -OVS_PACKED( struct stp_bpdu_header { ovs_be16 protocol_id; /* STP_PROTOCOL_ID. */ uint8_t protocol_version; /* STP_PROTOCOL_VERSION. */ uint8_t bpdu_type; /* One of STP_TYPE_*. */ -}); +}; BUILD_ASSERT_DECL(sizeof(struct stp_bpdu_header) == 4); enum stp_config_bpdu_flags { @@ -73,10 +72,9 @@ struct stp_config_bpdu { }); BUILD_ASSERT_DECL(sizeof(struct stp_config_bpdu) == 35); -OVS_PACKED( struct stp_tcn_bpdu { struct stp_bpdu_header header; /* Type STP_TYPE_TCN. */ -}); +}; BUILD_ASSERT_DECL(sizeof(struct stp_tcn_bpdu) == 4); struct stp_timer { diff --git a/ofproto/bundles.h b/ofproto/bundles.h index dd64700aa348..b63681708d3b 100644 --- a/ofproto/bundles.h +++ b/ofproto/bundles.h @@ -1,7 +1,7 @@ /* * Copyright (c) 2013, 2014 Alexandru Copot , with support from IXIA. * Copyright (c) 2013, 2014 Daniel Baluta - * Copyright (c) 2014, 2015, 2016 Nicira, Inc. + * Copyright (c) 2014, 2015, 2016, 2017 Nicira, Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. @@ -49,7 +49,7 @@ struct ofp_bundle_entry { }; }; -enum OVS_PACKED_ENUM bundle_state { +enum bundle_state { BS_OPEN, BS_CLOSED };