From patchwork Tue Jun 11 22:29:02 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuniyuki Iwashima X-Patchwork-Id: 13694256 X-Patchwork-Delegate: kuba@kernel.org Received: from smtp-fw-9106.amazon.com (smtp-fw-9106.amazon.com [207.171.188.206]) (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 1D4EB15278E for ; Tue, 11 Jun 2024 22:32:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=207.171.188.206 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718145164; cv=none; b=cyzNd6eW5nnEAvRzPkMQ5DillXn6rcv8dbIe1/9QlIVMpc6RUFVdarjVVFw2O95Y0OY3Cou2poPSrv8FvysisKWz0vDolKS2ctbch3hQUUmjkRaPM8FOOsV3airFI2MHKDmuEMmpDZQQ33VNGDNTLhWsFIvyGp4QfvT2170mOPI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718145164; c=relaxed/simple; bh=udUm2LC/qzSMBDJthhkDdtTFLieys9e3ldn61HccRI4=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Pjvj8n6HVzw4sAbc4hzg0DYrQRTqA9NcsNkCwPKaFVQC9Q8T+Wj7IzgWZWCwdnEVMgEornJZurqLDrUMBctdvmvZkj+mJvCe2FlDAwZsiHb4yX+FfNbUX9on9JF5SfyQRiGGtSPC7Gims0uRq0UFUG2vTjJDeMSd+LM54A6RKKQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com; spf=pass smtp.mailfrom=amazon.co.jp; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b=hrz3OIWD; arc=none smtp.client-ip=207.171.188.206 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=amazon.co.jp Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="hrz3OIWD" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1718145164; x=1749681164; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=anwahdqBQK9r3jBx/O3HLI0cjKUMgXh8B6HzkENYRQM=; b=hrz3OIWDCjhDIeUnrxbN5yKLVVCHeNMisO+Z9478tOjvbePZNKdohZlS e+cvakdMEtYTwFBISyhA7zGV1FYtyiivQxuoBs9bGWfq85T/RzC3xx+sB xC6NdCvAY34uAB2YDXChtLTRXMshu8WppM+KA8bqqLYnRyMPkGXFE798c c=; X-IronPort-AV: E=Sophos;i="6.08,231,1712620800"; d="scan'208";a="732261512" Received: from pdx4-co-svc-p1-lb2-vlan2.amazon.com (HELO smtpout.prod.us-west-2.prod.farcaster.email.amazon.dev) ([10.25.36.210]) by smtp-border-fw-9106.sea19.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jun 2024 22:32:37 +0000 Received: from EX19MTAUWA001.ant.amazon.com [10.0.7.35:64026] by smtpin.naws.us-west-2.prod.farcaster.email.amazon.dev [10.0.6.196:2525] with esmtp (Farcaster) id c6cd5124-1a9c-4b8e-b1e7-aaffd60bdf59; Tue, 11 Jun 2024 22:32:36 +0000 (UTC) X-Farcaster-Flow-ID: c6cd5124-1a9c-4b8e-b1e7-aaffd60bdf59 Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX19MTAUWA001.ant.amazon.com (10.250.64.217) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.34; Tue, 11 Jun 2024 22:32:32 +0000 Received: from 88665a182662.ant.amazon.com.com (10.187.171.17) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.34; Tue, 11 Jun 2024 22:32:29 +0000 From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni CC: Kent Overstreet , Kuniyuki Iwashima , Kuniyuki Iwashima , Subject: [PATCH v2 net-next 08/11] af_unix: Define locking order for U_RECVQ_LOCK_EMBRYO in unix_collect_skb(). Date: Tue, 11 Jun 2024 15:29:02 -0700 Message-ID: <20240611222905.34695-9-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20240611222905.34695-1-kuniyu@amazon.com> References: <20240611222905.34695-1-kuniyu@amazon.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: EX19D032UWA002.ant.amazon.com (10.13.139.81) To EX19D004ANA001.ant.amazon.com (10.37.240.138) X-Patchwork-Delegate: kuba@kernel.org While GC is cleaning up cyclic references by SCM_RIGHTS, unix_collect_skb() collects skb in the socket's recvq. If the socket is TCP_LISTEN, we need to collect skb in the embryo's queue. Then, both the listener's recvq lock and the embroy's one are held. The locking is always done in the listener -> embryo order. Let's define it as unix_recvq_lock_cmp_fn() instead of using spin_lock_nested(). Signed-off-by: Kuniyuki Iwashima --- net/unix/af_unix.c | 17 +++++++++++++++++ net/unix/garbage.c | 8 +------- 2 files changed, 18 insertions(+), 7 deletions(-) diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 8d03c5ef61df..8959ee8753d1 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -170,6 +170,21 @@ static int unix_state_lock_cmp_fn(const struct lockdep_map *_a, /* unix_state_double_lock(): ascending address order. */ return cmp_ptr(a, b); } + +static int unix_recvq_lock_cmp_fn(const struct lockdep_map *_a, + const struct lockdep_map *_b) +{ + const struct sock *a, *b; + + a = container_of(_a, struct sock, sk_receive_queue.lock.dep_map); + b = container_of(_b, struct sock, sk_receive_queue.lock.dep_map); + + /* unix_collect_skb(): listener -> embryo order. */ + if (a->sk_state == TCP_LISTEN && unix_sk(b)->listener == a) + return -1; + + return 0; +} #endif static unsigned int unix_unbound_hash(struct sock *sk) @@ -1017,6 +1032,8 @@ static struct sock *unix_create1(struct net *net, struct socket *sock, int kern, sk->sk_write_space = unix_write_space; sk->sk_max_ack_backlog = READ_ONCE(net->unx.sysctl_max_dgram_qlen); sk->sk_destruct = unix_sock_destructor; + lock_set_cmp_fn(&sk->sk_receive_queue.lock, unix_recvq_lock_cmp_fn, NULL); + u = unix_sk(sk); u->listener = NULL; u->vertex = NULL; diff --git a/net/unix/garbage.c b/net/unix/garbage.c index dfe94a90ece4..eb8aa5171a68 100644 --- a/net/unix/garbage.c +++ b/net/unix/garbage.c @@ -337,11 +337,6 @@ static bool unix_vertex_dead(struct unix_vertex *vertex) return true; } -enum unix_recv_queue_lock_class { - U_RECVQ_LOCK_NORMAL, - U_RECVQ_LOCK_EMBRYO, -}; - static void unix_collect_queue(struct unix_sock *u, struct sk_buff_head *hitlist) { skb_queue_splice_init(&u->sk.sk_receive_queue, hitlist); @@ -375,8 +370,7 @@ static void unix_collect_skb(struct list_head *scc, struct sk_buff_head *hitlist skb_queue_walk(queue, skb) { struct sk_buff_head *embryo_queue = &skb->sk->sk_receive_queue; - /* listener -> embryo order, the inversion never happens. */ - spin_lock_nested(&embryo_queue->lock, U_RECVQ_LOCK_EMBRYO); + spin_lock(&embryo_queue->lock); unix_collect_queue(unix_sk(skb->sk), hitlist); spin_unlock(&embryo_queue->lock); }