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 974B5223304; Thu, 12 Dec 2024 16:02:46 +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=1734019366; cv=none; b=SZ4TLIFERYZ+NMIO51qvBfQ1M4oqQ0ifEuRYNtuAT/HjXfzQuWtHsy6PtDX8EAZAYCUzMgIvDqrmQTHf8v+/2aoaGlZ9ZGYnf2QKhr2LuzhuUITeCQQ+2aucM2M0XHGdrpGJtYp963iGC491h7kT0me21oXBazEnUq8hpmAdka4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734019366; c=relaxed/simple; bh=gwiHL1rfY7c4BwzMvix21ktgeTl5SAQp6XitKxJYNZA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NtWPH/GiB8N/k5VznsR+CcDFiSQ0dVFDP1lkpNmbLEntLNxPlq62TeoYhe6FqCE1F24C6xGRoHEFicvVSID5F7QF1V4CMixAtpwAGMVnVA04WUrcjQeHQwFk+k3fpnLLORAyWp6noMw7kanrq4sjsvSjWj+Q6GWmX+4seomNaok= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=jrIYqUAf; 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="jrIYqUAf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 152ADC4CECE; Thu, 12 Dec 2024 16:02:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1734019366; bh=gwiHL1rfY7c4BwzMvix21ktgeTl5SAQp6XitKxJYNZA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jrIYqUAfWBTxm6YAWIVXCC2emGnaow/EjioIVrIRDOdV7fPCepcQlBDRQaavMgRNt bmNJORgBScMUggTCqB7DQD8JsTC6LrdE2vUhGLsI5qLkrGOHULA9Zeq59JlJmrTXEH 1Z0iQaprkPIi5RAG+rwixba2C3S5Y4LnBsliR+Hk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , Guillaume Nault , Kuniyuki Iwashima , Willem de Bruijn , Paolo Abeni , Sasha Levin Subject: [PATCH 6.1 187/772] sock_diag: allow concurrent operation in sock_diag_rcv_msg() Date: Thu, 12 Dec 2024 15:52:12 +0100 Message-ID: <20241212144357.670858894@linuxfoundation.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20241212144349.797589255@linuxfoundation.org> References: <20241212144349.797589255@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 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 86e8921df05c6e9423ab74ab8d41022775d8b83a ] TCPDIAG_GETSOCK and DCCPDIAG_GETSOCK diag are serialized on sock_diag_table_mutex. This is to make sure inet_diag module is not unloaded while diag was ongoing. It is time to get rid of this mutex and use RCU protection, allowing full parallelism. Signed-off-by: Eric Dumazet Reviewed-by: Guillaume Nault Reviewed-by: Kuniyuki Iwashima Reviewed-by: Willem de Bruijn Signed-off-by: Paolo Abeni Stable-dep-of: eb02688c5c45 ("ipv6: release nexthop on device removal") Signed-off-by: Sasha Levin --- include/linux/sock_diag.h | 9 ++++++-- net/core/sock_diag.c | 43 +++++++++++++++++++++++---------------- net/ipv4/inet_diag.c | 9 ++++++-- 3 files changed, 40 insertions(+), 21 deletions(-) diff --git a/include/linux/sock_diag.h b/include/linux/sock_diag.h index 7c07754d711b9..110978dc9af1b 100644 --- a/include/linux/sock_diag.h +++ b/include/linux/sock_diag.h @@ -23,8 +23,13 @@ struct sock_diag_handler { int sock_diag_register(const struct sock_diag_handler *h); void sock_diag_unregister(const struct sock_diag_handler *h); -void sock_diag_register_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh)); -void sock_diag_unregister_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh)); +struct sock_diag_inet_compat { + struct module *owner; + int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh); +}; + +void sock_diag_register_inet_compat(const struct sock_diag_inet_compat *ptr); +void sock_diag_unregister_inet_compat(const struct sock_diag_inet_compat *ptr); u64 __sock_gen_cookie(struct sock *sk); diff --git a/net/core/sock_diag.c b/net/core/sock_diag.c index 73b2e36032b3e..d36beb9a9a928 100644 --- a/net/core/sock_diag.c +++ b/net/core/sock_diag.c @@ -17,8 +17,9 @@ #include static const struct sock_diag_handler __rcu *sock_diag_handlers[AF_MAX]; -static int (*inet_rcv_compat)(struct sk_buff *skb, struct nlmsghdr *nlh); -static DEFINE_MUTEX(sock_diag_table_mutex); + +static struct sock_diag_inet_compat __rcu *inet_rcv_compat; + static struct workqueue_struct *broadcast_wq; DEFINE_COOKIE(sock_cookie); @@ -181,19 +182,20 @@ void sock_diag_broadcast_destroy(struct sock *sk) queue_work(broadcast_wq, &bsk->work); } -void sock_diag_register_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh)) +void sock_diag_register_inet_compat(const struct sock_diag_inet_compat *ptr) { - mutex_lock(&sock_diag_table_mutex); - inet_rcv_compat = fn; - mutex_unlock(&sock_diag_table_mutex); + xchg((__force const struct sock_diag_inet_compat **)&inet_rcv_compat, + ptr); } EXPORT_SYMBOL_GPL(sock_diag_register_inet_compat); -void sock_diag_unregister_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh)) +void sock_diag_unregister_inet_compat(const struct sock_diag_inet_compat *ptr) { - mutex_lock(&sock_diag_table_mutex); - inet_rcv_compat = NULL; - mutex_unlock(&sock_diag_table_mutex); + const struct sock_diag_inet_compat *old; + + old = xchg((__force const struct sock_diag_inet_compat **)&inet_rcv_compat, + NULL); + WARN_ON_ONCE(old != ptr); } EXPORT_SYMBOL_GPL(sock_diag_unregister_inet_compat); @@ -256,20 +258,27 @@ static int __sock_diag_cmd(struct sk_buff *skb, struct nlmsghdr *nlh) static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, struct netlink_ext_ack *extack) { + const struct sock_diag_inet_compat *ptr; int ret; switch (nlh->nlmsg_type) { case TCPDIAG_GETSOCK: case DCCPDIAG_GETSOCK: - if (inet_rcv_compat == NULL) + + if (!rcu_access_pointer(inet_rcv_compat)) sock_load_diag_module(AF_INET, 0); - mutex_lock(&sock_diag_table_mutex); - if (inet_rcv_compat != NULL) - ret = inet_rcv_compat(skb, nlh); - else - ret = -EOPNOTSUPP; - mutex_unlock(&sock_diag_table_mutex); + rcu_read_lock(); + ptr = rcu_dereference(inet_rcv_compat); + if (ptr && !try_module_get(ptr->owner)) + ptr = NULL; + rcu_read_unlock(); + + ret = -EOPNOTSUPP; + if (ptr) { + ret = ptr->fn(skb, nlh); + module_put(ptr->owner); + } return ret; case SOCK_DIAG_BY_FAMILY: diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c index a3d0e18885f59..2bd5d0ed7a6fc 100644 --- a/net/ipv4/inet_diag.c +++ b/net/ipv4/inet_diag.c @@ -1445,6 +1445,11 @@ void inet_diag_unregister(const struct inet_diag_handler *h) } EXPORT_SYMBOL_GPL(inet_diag_unregister); +static const struct sock_diag_inet_compat inet_diag_compat = { + .owner = THIS_MODULE, + .fn = inet_diag_rcv_msg_compat, +}; + static int __init inet_diag_init(void) { const int inet_diag_table_size = (IPPROTO_MAX * @@ -1463,7 +1468,7 @@ static int __init inet_diag_init(void) if (err) goto out_free_inet; - sock_diag_register_inet_compat(inet_diag_rcv_msg_compat); + sock_diag_register_inet_compat(&inet_diag_compat); out: return err; @@ -1478,7 +1483,7 @@ static void __exit inet_diag_exit(void) { sock_diag_unregister(&inet6_diag_handler); sock_diag_unregister(&inet_diag_handler); - sock_diag_unregister_inet_compat(inet_diag_rcv_msg_compat); + sock_diag_unregister_inet_compat(&inet_diag_compat); kfree(inet_diag_table); } -- 2.43.0