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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 BF07AC2BB85 for ; Sat, 11 Apr 2020 12:19:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 95A5720787 for ; Sat, 11 Apr 2020 12:19:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586607555; bh=FZXFlRXzKlaa2+RbF7IY7IsWEhyI/PtTcq1Hj+DqqiE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=FYt+ha6BnW0UTQaQwzBQLI/Nmmnj0rqwKvMvttpTKhs7gYC3sw3rEv2BucLEupJag 7GymWNuLydSB8VzrOwT2BVPO3u1UhhB9/rT6uNdsWGIJbRihnlXC50EFBu6WdpHYb3 f9Md16XvBpo9+bGs7+CmWsQ+VwFqu6tossQcR+r8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727876AbgDKMTN (ORCPT ); Sat, 11 Apr 2020 08:19:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:54480 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728742AbgDKMTL (ORCPT ); Sat, 11 Apr 2020 08:19:11 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EA63A20644; Sat, 11 Apr 2020 12:19:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586607551; bh=FZXFlRXzKlaa2+RbF7IY7IsWEhyI/PtTcq1Hj+DqqiE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JZWUCXl6QUv7z7dk7fzG9TtaorJJnYcGrwegTOxUDuA9iWA2XUztJ6bM4uBhLu1C+ 0IK33nqIMrlC2Cz46nUoB0mfI54OBoipVb5o9PjEeCdVoqBbB76h2yyJ3h79EaCw+i GGhT/NKuj6q7mRUXGa4EbdW/WBynT2R3VQMjI5rM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jason Gunthorpe Subject: [PATCH 5.5 24/44] RDMA/cma: Teach lockdep about the order of rtnl and lock Date: Sat, 11 Apr 2020 14:09:44 +0200 Message-Id: <20200411115459.203079812@linuxfoundation.org> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200411115456.934174282@linuxfoundation.org> References: <20200411115456.934174282@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jason Gunthorpe commit 32ac9e4399b12d3e54d312a0e0e30ed5cd19bd4e upstream. This lock ordering only happens when bonding is enabled and a certain bonding related event fires. However, since it can happen this is a global restriction on lock ordering. Teach lockdep about the order directly and unconditionally so bugs here are found quickly. See https://syzkaller.appspot.com/bug?extid=55de90ab5f44172b0c90 Link: https://lore.kernel.org/r/20200227203651.GA27185@ziepe.ca Signed-off-by: Jason Gunthorpe Signed-off-by: Greg Kroah-Hartman --- drivers/infiniband/core/cma.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) --- a/drivers/infiniband/core/cma.c +++ b/drivers/infiniband/core/cma.c @@ -4746,6 +4746,19 @@ static int __init cma_init(void) { int ret; + /* + * There is a rare lock ordering dependency in cma_netdev_callback() + * that only happens when bonding is enabled. Teach lockdep that rtnl + * must never be nested under lock so it can find these without having + * to test with bonding. + */ + if (IS_ENABLED(CONFIG_LOCKDEP)) { + rtnl_lock(); + mutex_lock(&lock); + mutex_unlock(&lock); + rtnl_unlock(); + } + cma_wq = alloc_ordered_workqueue("rdma_cm", WQ_MEM_RECLAIM); if (!cma_wq) return -ENOMEM;