From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3240973722; Mon, 29 Jan 2024 17:15:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706548538; cv=none; b=gp6dcCgMC4w8VGHE6YMN9fO8xf2xiCu9WqJGTprFx5dezZFU5ZkQK7/4zHurBkv6RE2hyjJqQjBOpLWj6iCpWu/Aa3YFTKZXHRlcOuDBvBSHGOjK+xu0ySsp/lKhMjAepB3JvnSRBlyjXlgvIZubA7SggO2Z553bLCvY53W/HaE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706548538; c=relaxed/simple; bh=2TQk6OswGj1XiKG0KEQcGnPvMY1CiJXiPLYL/RG+gU4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=V+uzcHqDt/MBo1GfyP4wp8Pk3klyrtowSfj7vcxhw6JjUffehbPAoTgPYiGhRtrVZx71YNH9NdHY2E956NbSJ2YoGvRVY7Ll+k5uDVbo5Ggnt+HHG713PCfEuKNXbsi5oLv1h9V00OtZMLXtY8NUsVOl+qwSFYNtV22o3OMDg+A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=cU/8DEqE; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="cU/8DEqE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EF2CBC433C7; Mon, 29 Jan 2024 17:15:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1706548538; bh=2TQk6OswGj1XiKG0KEQcGnPvMY1CiJXiPLYL/RG+gU4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cU/8DEqEfIe8lPpguJflOwHMpacwqlzHDvdPHy4o1PXTXFjWA9M5hh+DZ67q8JMXE FPKaVuM/N7sWNFqamaxiyGxErGUbgcBCaOA+0ZRq3rq0YIRm4+KQNju2oDbdFU+dz6 mwsvBUtPtCmNMdLCDSoBbAQrOIURc1RvCB/GsHns= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , Paolo Abeni , Willem de Bruijn , Kuniyuki Iwashima , "David S. Miller" , Sasha Levin Subject: [PATCH 6.6 177/331] udp: fix busy polling Date: Mon, 29 Jan 2024 09:04:01 -0800 Message-ID: <20240129170020.087034986@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240129170014.969142961@linuxfoundation.org> References: <20240129170014.969142961@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit a54d51fb2dfb846aedf3751af501e9688db447f5 ] Generic sk_busy_loop_end() only looks at sk->sk_receive_queue for presence of packets. Problem is that for UDP sockets after blamed commit, some packets could be present in another queue: udp_sk(sk)->reader_queue In some cases, a busy poller could spin until timeout expiration, even if some packets are available in udp_sk(sk)->reader_queue. v3: - make sk_busy_loop_end() nicer (Willem) v2: - add a READ_ONCE(sk->sk_family) in sk_is_inet() to avoid KCSAN splats. - add a sk_is_inet() check in sk_is_udp() (Willem feedback) - add a sk_is_inet() check in sk_is_tcp(). Fixes: 2276f58ac589 ("udp: use a separate rx queue for packet reception") Signed-off-by: Eric Dumazet Reviewed-by: Paolo Abeni Reviewed-by: Willem de Bruijn Reviewed-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- include/linux/skmsg.h | 6 ------ include/net/inet_sock.h | 5 ----- include/net/sock.h | 18 +++++++++++++++++- net/core/sock.c | 11 +++++++++-- 4 files changed, 26 insertions(+), 14 deletions(-) diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h index c953b8c0d2f4..bd4418377bac 100644 --- a/include/linux/skmsg.h +++ b/include/linux/skmsg.h @@ -500,12 +500,6 @@ static inline bool sk_psock_strp_enabled(struct sk_psock *psock) return !!psock->saved_data_ready; } -static inline bool sk_is_udp(const struct sock *sk) -{ - return sk->sk_type == SOCK_DGRAM && - sk->sk_protocol == IPPROTO_UDP; -} - #if IS_ENABLED(CONFIG_NET_SOCK_MSG) #define BPF_F_STRPARSER (1UL << 1) diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h index 2de0e4d4a027..2790ba58ffe5 100644 --- a/include/net/inet_sock.h +++ b/include/net/inet_sock.h @@ -301,11 +301,6 @@ static inline unsigned long inet_cmsg_flags(const struct inet_sock *inet) #define inet_assign_bit(nr, sk, val) \ assign_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags, val) -static inline bool sk_is_inet(struct sock *sk) -{ - return sk->sk_family == AF_INET || sk->sk_family == AF_INET6; -} - /** * sk_to_full_sk - Access to a full socket * @sk: pointer to a socket diff --git a/include/net/sock.h b/include/net/sock.h index 70a771d96467..e70c903b04f3 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -2793,9 +2793,25 @@ static inline void skb_setup_tx_timestamp(struct sk_buff *skb, __u16 tsflags) &skb_shinfo(skb)->tskey); } +static inline bool sk_is_inet(const struct sock *sk) +{ + int family = READ_ONCE(sk->sk_family); + + return family == AF_INET || family == AF_INET6; +} + static inline bool sk_is_tcp(const struct sock *sk) { - return sk->sk_type == SOCK_STREAM && sk->sk_protocol == IPPROTO_TCP; + return sk_is_inet(sk) && + sk->sk_type == SOCK_STREAM && + sk->sk_protocol == IPPROTO_TCP; +} + +static inline bool sk_is_udp(const struct sock *sk) +{ + return sk_is_inet(sk) && + sk->sk_type == SOCK_DGRAM && + sk->sk_protocol == IPPROTO_UDP; } static inline bool sk_is_stream_unix(const struct sock *sk) diff --git a/net/core/sock.c b/net/core/sock.c index 5cd21e699f2d..383e30fe79f4 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -107,6 +107,7 @@ #include #include #include +#include #include #include #include @@ -4136,8 +4137,14 @@ bool sk_busy_loop_end(void *p, unsigned long start_time) { struct sock *sk = p; - return !skb_queue_empty_lockless(&sk->sk_receive_queue) || - sk_busy_loop_timeout(sk, start_time); + if (!skb_queue_empty_lockless(&sk->sk_receive_queue)) + return true; + + if (sk_is_udp(sk) && + !skb_queue_empty_lockless(&udp_sk(sk)->reader_queue)) + return true; + + return sk_busy_loop_timeout(sk, start_time); } EXPORT_SYMBOL(sk_busy_loop_end); #endif /* CONFIG_NET_RX_BUSY_POLL */ -- 2.43.0