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=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 667CEC32751 for ; Wed, 7 Aug 2019 10:31:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3CF012086D for ; Wed, 7 Aug 2019 10:31:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="gU7+lfF+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729191AbfHGKbr (ORCPT ); Wed, 7 Aug 2019 06:31:47 -0400 Received: from new1-smtp.messagingengine.com ([66.111.4.221]:39907 "EHLO new1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726902AbfHGKbo (ORCPT ); Wed, 7 Aug 2019 06:31:44 -0400 Received: from compute3.internal (compute3.nyi.internal [10.202.2.43]) by mailnew.nyi.internal (Postfix) with ESMTP id D5099147B; Wed, 7 Aug 2019 06:31:43 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute3.internal (MEProxy); Wed, 07 Aug 2019 06:31:43 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:date:from :in-reply-to:message-id:mime-version:references:subject:to :x-me-proxy:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s= fm3; bh=HrGyFzPmDrx1i8revLlLvQliuvEchyFbm/o2KeCOVgU=; b=gU7+lfF+ dEJ3CX3MzX2qF+WLVzDp9D/e9Ynxk4oYGK2xj6RbfPeWrCf+IJUHg9ELFwsrd9ng nZHNz9OXcK9abi9CwclpBZ1l43LV1lGcmtRQNB2WSnhn8Bz7vgTu6r5Evs8BKt19 i5L1MO9bMc5gPZg85kYofLqT2Uo5RGdnmtgR3bymb3TLj01WDQLj2WDJNLAVjClt 7zYryHpy574jX79ubNVaGOA08QyoIpIXIMhtOHovqEo/so0idfQxSUgAY1uMjyq1 Ps73MGm1wM0zKkCi1tnAb42We+T9Qujmg7TZ078zlHhHQWCti7Nr2xCkfRevw5zf 35LPIijKYb1XEw== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduvddrudduvddgvdelucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucenucfjughrpefhvffufffkofgjfhgggfestdekre dtredttdenucfhrhhomhepkfguohcuufgthhhimhhmvghluceoihguohhstghhsehiugho shgthhdrohhrgheqnecukfhppeduleefrdegjedrudeihedrvdehudenucfrrghrrghmpe hmrghilhhfrhhomhepihguohhstghhsehiughoshgthhdrohhrghenucevlhhushhtvghr ufhiiigvpedu X-ME-Proxy: Received: from splinter.mtl.com (unknown [193.47.165.251]) by mail.messagingengine.com (Postfix) with ESMTPA id 48278380090; Wed, 7 Aug 2019 06:31:41 -0400 (EDT) From: Ido Schimmel To: netdev@vger.kernel.org Cc: davem@davemloft.net, nhorman@tuxdriver.com, jiri@mellanox.com, toke@redhat.com, dsahern@gmail.com, roopa@cumulusnetworks.com, nikolay@cumulusnetworks.com, jakub.kicinski@netronome.com, andy@greyhouse.net, f.fainelli@gmail.com, andrew@lunn.ch, vivien.didelot@gmail.com, mlxsw@mellanox.com, Ido Schimmel Subject: [PATCH net-next 03/10] drop_monitor: Reset per-CPU data before starting to trace Date: Wed, 7 Aug 2019 13:30:52 +0300 Message-Id: <20190807103059.15270-4-idosch@idosch.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190807103059.15270-1-idosch@idosch.org> References: <20190807103059.15270-1-idosch@idosch.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Ido Schimmel The function reset_per_cpu_data() allocates and prepares a new skb for the summary netlink alert message ('NET_DM_CMD_ALERT'). The new skb is stored in the per-CPU 'data' variable and the old is returned. The function is invoked during module initialization and from the workqueue, before an alert is sent. This means that it is possible to receive an alert with stale data, if we stopped tracing when the hysteresis timer ('data->send_timer') was pending. Instead of invoking the function during module initialization, invoke it just before we start tracing and ensure we get a fresh skb. This also allows us to remove the calls to initialize the timer and the work item from the module initialization path, since both could have been triggered by the error paths of reset_per_cpu_data(). Signed-off-by: Ido Schimmel --- net/core/drop_monitor.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c index b266dc1660ed..1cf4988de591 100644 --- a/net/core/drop_monitor.c +++ b/net/core/drop_monitor.c @@ -252,9 +252,16 @@ static int net_dm_trace_on_set(struct netlink_ext_ack *extack) for_each_possible_cpu(cpu) { struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu); + struct sk_buff *skb; INIT_WORK(&data->dm_alert_work, send_dm_alert); timer_setup(&data->send_timer, sched_send_work, 0); + /* Allocate a new per-CPU skb for the summary alert message and + * free the old one which might contain stale data from + * previous tracing. + */ + skb = reset_per_cpu_data(data); + consume_skb(skb); } rc = register_trace_kfree_skb(trace_kfree_skb_hit, NULL); @@ -475,10 +482,7 @@ static int __init init_net_drop_monitor(void) for_each_possible_cpu(cpu) { data = &per_cpu(dm_cpu_data, cpu); - INIT_WORK(&data->dm_alert_work, send_dm_alert); - timer_setup(&data->send_timer, sched_send_work, 0); spin_lock_init(&data->lock); - reset_per_cpu_data(data); } goto out; -- 2.21.0