Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936818AbdCJMQB (ORCPT ); Fri, 10 Mar 2017 07:16:01 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:45146 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936812AbdCJMP6 (ORCPT ); Fri, 10 Mar 2017 07:15:58 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Shannon Nelson" , "Eric Dumazet" , "Eric Dumazet" , "David S. Miller" Date: Fri, 10 Mar 2017 11:46:23 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 349/370] tcp: fix tcp_fastopen unaligned access complaints on sparc In-Reply-To: X-SA-Exim-Connect-IP: 82.70.136.246 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2040 Lines: 60 3.16.42-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Shannon Nelson [ Upstream commit 003c941057eaa868ca6fedd29a274c863167230d ] Fix up a data alignment issue on sparc by swapping the order of the cookie byte array field with the length field in struct tcp_fastopen_cookie, and making it a proper union to clean up the typecasting. This addresses log complaints like these: log_unaligned: 113 callbacks suppressed Kernel unaligned access at TPC[976490] tcp_try_fastopen+0x2d0/0x360 Kernel unaligned access at TPC[9764ac] tcp_try_fastopen+0x2ec/0x360 Kernel unaligned access at TPC[9764c8] tcp_try_fastopen+0x308/0x360 Kernel unaligned access at TPC[9764e4] tcp_try_fastopen+0x324/0x360 Kernel unaligned access at TPC[976490] tcp_try_fastopen+0x2d0/0x360 Cc: Eric Dumazet Signed-off-by: Shannon Nelson Acked-by: Eric Dumazet Signed-off-by: David S. Miller [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- include/linux/tcp.h | 7 ++++++- net/ipv4/tcp_fastopen.c | 2 +- 2 files changed, 7 insertions(+), 2 deletions(-) --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -57,8 +57,13 @@ static inline unsigned int tcp_optlen(co /* TCP Fast Open Cookie as stored in memory */ struct tcp_fastopen_cookie { + union { + u8 val[TCP_FASTOPEN_COOKIE_MAX]; +#if IS_ENABLED(CONFIG_IPV6) + struct in6_addr addr; +#endif + }; s8 len; - u8 val[TCP_FASTOPEN_COOKIE_MAX]; }; /* This defines a selective acknowledgement block. */ --- a/net/ipv4/tcp_fastopen.c +++ b/net/ipv4/tcp_fastopen.c @@ -112,7 +112,7 @@ static bool tcp_fastopen_cookie_gen(stru struct tcp_fastopen_cookie tmp; if (__tcp_fastopen_cookie_gen(&ip6h->saddr, &tmp)) { - struct in6_addr *buf = (struct in6_addr *) tmp.val; + struct in6_addr *buf = &tmp.addr; int i = 4; for (i = 0; i < 4; i++)