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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 93930C48BD3 for ; Thu, 27 Jun 2019 00:48:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5C43D20665 for ; Thu, 27 Jun 2019 00:48:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1561596485; bh=pf3TY0qhiBRSgL4uXDgcr/l4Y53BKYcGEPOf2PFRwlE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=otRponKHBKx86gH7qminVfTt3cuQIr3T8cURQ5znQM2wQmjg7p8AKzq6Vj/AH0olq /Jmx4E58tW12vNunGU3WLEVMQS/Yihcovmz6Ixxm1kcFrQCUMLenNh+9VwJvLoLTYR Cwk6PhjscOLkSkafjBoKVA5vT5gKmDdtAxCwsIyw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728882AbfF0Aij (ORCPT ); Wed, 26 Jun 2019 20:38:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:42910 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727078AbfF0Aih (ORCPT ); Wed, 26 Jun 2019 20:38:37 -0400 Received: from sasha-vm.mshome.net (unknown [107.242.116.147]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 865CC217F9; Thu, 27 Jun 2019 00:38:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1561595916; bh=pf3TY0qhiBRSgL4uXDgcr/l4Y53BKYcGEPOf2PFRwlE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GYCu65WGmmIADgoddOX2rVgEYgKbh5qZXL7lheJ4REsARGzghxodD6aCpkTNHP9/n wEHSd7g/wCTsP/p7wH/CV0NY8mGG43GE9ATkpLygrgiK1+q5jcnxV3+UpBjSiCWASV jY9yRRl8nRUVJtpeA7q6tih1KEKyE3QPCLpG3eEY= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Toshiaki Makita , David Ahern , Daniel Borkmann , Sasha Levin , netdev@vger.kernel.org, xdp-newbies@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 44/60] bpf, devmap: Add missing RCU read lock on flush Date: Wed, 26 Jun 2019 20:35:59 -0400 Message-Id: <20190627003616.20767-44-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190627003616.20767-1-sashal@kernel.org> References: <20190627003616.20767-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Toshiaki Makita [ Upstream commit 86723c8640633bee4b4588d3c7784ee7a0032f65 ] .ndo_xdp_xmit() assumes it is called under RCU. For example virtio_net uses RCU to detect it has setup the resources for tx. The assumption accidentally broke when introducing bulk queue in devmap. Fixes: 5d053f9da431 ("bpf: devmap prepare xdp frames for bulking") Reported-by: David Ahern Signed-off-by: Toshiaki Makita Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin --- kernel/bpf/devmap.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c index 357d456d57b9..fc500ca464d0 100644 --- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -282,6 +282,7 @@ void __dev_map_flush(struct bpf_map *map) unsigned long *bitmap = this_cpu_ptr(dtab->flush_needed); u32 bit; + rcu_read_lock(); for_each_set_bit(bit, bitmap, map->max_entries) { struct bpf_dtab_netdev *dev = READ_ONCE(dtab->netdev_map[bit]); struct xdp_bulk_queue *bq; @@ -297,6 +298,7 @@ void __dev_map_flush(struct bpf_map *map) __clear_bit(bit, bitmap); } + rcu_read_unlock(); } /* rcu_read_lock (from syscall and BPF contexts) ensures that if a delete and/or @@ -389,6 +391,7 @@ static void dev_map_flush_old(struct bpf_dtab_netdev *dev) int cpu; + rcu_read_lock(); for_each_online_cpu(cpu) { bitmap = per_cpu_ptr(dev->dtab->flush_needed, cpu); __clear_bit(dev->bit, bitmap); @@ -396,6 +399,7 @@ static void dev_map_flush_old(struct bpf_dtab_netdev *dev) bq = per_cpu_ptr(dev->bulkq, cpu); bq_xmit_all(dev, bq, XDP_XMIT_FLUSH, false); } + rcu_read_unlock(); } } -- 2.20.1