From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shannon Nelson Subject: [PATCH v2] tcp: fix tcp_fastopen unaligned access complaints on sparc Date: Thu, 12 Jan 2017 14:24:58 -0800 Message-ID: <1484259898-30719-1-git-send-email-shannon.nelson@oracle.com> Cc: sparclinux@vger.kernel.org, linux-kernel@vger.kernel.org, eric.dumazet@gmail.com, rob.gardner@oracle.com, Shannon Nelson To: netdev@vger.kernel.org, davem@davemloft.net Return-path: Sender: sparclinux-owner@vger.kernel.org List-Id: netdev.vger.kernel.org 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 --- v2: Use Eric's suggestion for a union in the struct include/linux/tcp.h | 7 ++++++- net/ipv4/tcp_fastopen.c | 2 +- 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/include/linux/tcp.h b/include/linux/tcp.h index fc5848d..c93f4b3 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -62,8 +62,13 @@ static inline unsigned int tcp_optlen(const struct sk_buff *skb) /* 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]; bool exp; /* In RFC6994 experimental option format */ }; diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c index 4e777a3..f519195 100644 --- a/net/ipv4/tcp_fastopen.c +++ b/net/ipv4/tcp_fastopen.c @@ -113,7 +113,7 @@ static bool tcp_fastopen_cookie_gen(struct request_sock *req, 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; for (i = 0; i < 4; i++) -- 1.7.1