From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7C9E7C47082 for ; Tue, 8 Jun 2021 19:22:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 65C4861182 for ; Tue, 8 Jun 2021 19:22:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234074AbhFHTXy (ORCPT ); Tue, 8 Jun 2021 15:23:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:58766 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236904AbhFHTLn (ORCPT ); Tue, 8 Jun 2021 15:11:43 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 22DAF61461; Tue, 8 Jun 2021 18:49:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1623178149; bh=Xd8sKBW52rGJ+PBUBAVrXHiFQyeJpduTKPcd2uOIiJs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pAJOU7iSjknaCjlqvXIUxBUQ3XWY5xiPnaRzLIwG6+HPsNcYbDmvrYHKogJq4iggB sDQC/kTahG01i5EVHF79Tso+Fxd4HquB0AezoP9tjWRbyXQHgy+NBEkBq72wcQXBnx tV1mY77tgyL9KZz7W74CuqsLW7P0fwF7UPdxcnoQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Jason A. Donenfeld" , "David S. Miller" Subject: [PATCH 5.12 096/161] wireguard: use synchronize_net rather than synchronize_rcu Date: Tue, 8 Jun 2021 20:27:06 +0200 Message-Id: <20210608175948.698136203@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210608175945.476074951@linuxfoundation.org> References: <20210608175945.476074951@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jason A. Donenfeld commit 24b70eeeb4f46c09487f8155239ebfb1f875774a upstream. Many of the synchronization points are sometimes called under the rtnl lock, which means we should use synchronize_net rather than synchronize_rcu. Under the hood, this expands to using the expedited flavor of function in the event that rtnl is held, in order to not stall other concurrent changes. This fixes some very, very long delays when removing multiple peers at once, which would cause some operations to take several minutes. Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Cc: stable@vger.kernel.org Signed-off-by: Jason A. Donenfeld Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/wireguard/peer.c | 6 +++--- drivers/net/wireguard/socket.c | 2 +- 2 files changed, 4 insertions(+), 4 deletions(-) --- a/drivers/net/wireguard/peer.c +++ b/drivers/net/wireguard/peer.c @@ -89,7 +89,7 @@ static void peer_make_dead(struct wg_pee /* Mark as dead, so that we don't allow jumping contexts after. */ WRITE_ONCE(peer->is_dead, true); - /* The caller must now synchronize_rcu() for this to take effect. */ + /* The caller must now synchronize_net() for this to take effect. */ } static void peer_remove_after_dead(struct wg_peer *peer) @@ -161,7 +161,7 @@ void wg_peer_remove(struct wg_peer *peer lockdep_assert_held(&peer->device->device_update_lock); peer_make_dead(peer); - synchronize_rcu(); + synchronize_net(); peer_remove_after_dead(peer); } @@ -179,7 +179,7 @@ void wg_peer_remove_all(struct wg_device peer_make_dead(peer); list_add_tail(&peer->peer_list, &dead_peers); } - synchronize_rcu(); + synchronize_net(); list_for_each_entry_safe(peer, temp, &dead_peers, peer_list) peer_remove_after_dead(peer); } --- a/drivers/net/wireguard/socket.c +++ b/drivers/net/wireguard/socket.c @@ -430,7 +430,7 @@ void wg_socket_reinit(struct wg_device * if (new4) wg->incoming_port = ntohs(inet_sk(new4)->inet_sport); mutex_unlock(&wg->socket_update_lock); - synchronize_rcu(); + synchronize_net(); sock_free(old4); sock_free(old6); }