From patchwork Thu Jan 10 21:09:34 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Khalid Aziz X-Patchwork-Id: 10756881 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9F8DC159A for ; Thu, 10 Jan 2019 21:10:32 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8CED929B8A for ; Thu, 10 Jan 2019 21:10:32 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8073B29BB4; Thu, 10 Jan 2019 21:10:32 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EF31B29B97 for ; Thu, 10 Jan 2019 21:10:31 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 793068E0005; Thu, 10 Jan 2019 16:10:30 -0500 (EST) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 71DF98E0001; Thu, 10 Jan 2019 16:10:30 -0500 (EST) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5BFDF8E0005; Thu, 10 Jan 2019 16:10:30 -0500 (EST) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from mail-pf1-f197.google.com (mail-pf1-f197.google.com [209.85.210.197]) by kanga.kvack.org (Postfix) with ESMTP id 1AB008E0001 for ; Thu, 10 Jan 2019 16:10:30 -0500 (EST) Received: by mail-pf1-f197.google.com with SMTP id i3so8674959pfj.4 for ; Thu, 10 Jan 2019 13:10:30 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:dkim-signature:from:to:cc:subject:date :message-id:in-reply-to:references:in-reply-to:references; bh=rxloVUR5hTpog4EkfpKEBfCxP1GI1EsadkVaOQCjD2o=; b=QJ+gB/oARHPBU136xbUyP+YArMY/xuBNHVq2ZpoLJ/g6Rlj3zy/rHgWIAnlOl9g8uf PIm6nBnxKwv5VwyY+54n9wH8CO1fYDtnrXX3pPIAZwXgACb6vfsbnp98q0/cMHO0MRfw RWAdf8FIfcTeaImIH9ufNRXHUlVzjXUN5aqotyfLqL3xLE92q9XGuZWtJS3UiY487pz6 zt+x+vX2d5NherCPlercePRN/EElnN4E2hJ/W8ugZuPr1MT0pp4PuZruKXQmz0qUBTfb Zz76MNhLltagE80tG/0ljFLPcK33InOofweQ+F4lChnEQm1yvd9LhycpAP+EDdyEcARa +lVw== X-Gm-Message-State: AJcUuke7h6Fo1KocBZEdNGP+Vgc9F2Bz1TBE7iW0DGy65ZtOXNWmng9n deFfqeXMXQZfmJ9mST2XdtTO7lhw6xQyTuaawKTUb5hExm7ZNpWTqr0kqsyuifRphj0R8CdgEb+ 2tJ07gUQn5th5LCMYd0LXjKW30byNfMDiw876lWy+LE6zSCRl09UW1gZmuRNkqxMKvw== X-Received: by 2002:a62:5658:: with SMTP id k85mr11652874pfb.231.1547154629753; Thu, 10 Jan 2019 13:10:29 -0800 (PST) X-Google-Smtp-Source: ALg8bN5JDS8Blg7AON5Mht9uKRTjBubsOM9wnNkAo2Zw+L2DzcfEUMO8k0FvTbFx5fpfbu+FyMUY X-Received: by 2002:a62:5658:: with SMTP id k85mr11652833pfb.231.1547154628946; Thu, 10 Jan 2019 13:10:28 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1547154628; cv=none; d=google.com; s=arc-20160816; b=X1g1sSWhI8pHtUN+uGx1Z91LHIBJaPx0E3jnpfcIZM2itXpvAvAGLCLzH1wSBOJuR5 m8yMXMKST8MAT2CkaX8aHHmJrZaGcUoY+yMqimwjZamz3WhmNbFQx0QxPHLpfF4mIUcW /kHo6rIhZ2osJbuml9/zrlnVMYOZKm2AO+w8wngDa2NNY/acT3ZlZ95GUPibO9gVeqxS Yx/X1WDCQo6MunWe8LZfkSjttc0VhMFAnJ9p2AcbsY9QBNDypeNRE5Zl20u1C9TnRq5f IEu8vTRzO0rlpH4FPDtyuLzA8f4W+QPh+LN70F2dPYb3Jjwv65n6Y0rzT6R4k4wcxzkW Gdmg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=references:in-reply-to:references:in-reply-to:message-id:date :subject:cc:to:from:dkim-signature; bh=rxloVUR5hTpog4EkfpKEBfCxP1GI1EsadkVaOQCjD2o=; b=P2nNzkK+bToeXZOYq1sjnVN7YOsqK1fvdJNNovvNr1cs2r5fMYa3VaDWjTC9GKGenL dhmG3vecyM7HHFDHyxmLooG98PTeDHq/Io7jBuhV0xlmDrjwY//rLfwA5OLnVytkbbvt 51wEmfJ8LY3URA8ftugGJbWj+lzrMeEjptcB1umXqfMRkL0uc7IOlrOvhvFHceZMfa2B 9aBVGehaXkXDVNmHFFZ1vfnAfge9L0h5b686TcI8IV6UCNgXFs9yd3Xf7uTNkbjR3Uj8 tinsOIdRg/pxkgD1Ub7wYVnDVZe7WyfFQWpwNFgtttcgyHiVrdmKNAgZY/VDg99lLxB9 SUGQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2018-07-02 header.b=1CYkyUJc; spf=pass (google.com: domain of khalid.aziz@oracle.com designates 156.151.31.85 as permitted sender) smtp.mailfrom=khalid.aziz@oracle.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=oracle.com Received: from userp2120.oracle.com (userp2120.oracle.com. [156.151.31.85]) by mx.google.com with ESMTPS id o127si18490753pfo.251.2019.01.10.13.10.28 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 10 Jan 2019 13:10:28 -0800 (PST) Received-SPF: pass (google.com: domain of khalid.aziz@oracle.com designates 156.151.31.85 as permitted sender) client-ip=156.151.31.85; Authentication-Results: mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2018-07-02 header.b=1CYkyUJc; spf=pass (google.com: domain of khalid.aziz@oracle.com designates 156.151.31.85 as permitted sender) smtp.mailfrom=khalid.aziz@oracle.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=oracle.com Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.22/8.16.0.22) with SMTP id x0AL8uEQ192919; Thu, 10 Jan 2019 21:10:18 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : in-reply-to : references; s=corp-2018-07-02; bh=rxloVUR5hTpog4EkfpKEBfCxP1GI1EsadkVaOQCjD2o=; b=1CYkyUJc4Qs2o0butOq1ThTUw0aGOHhtGvgscR/9iH/yWacmRM01oZvKfD4Gt31YBLEM ce9ixyvlKWNm/xwoNnMIWXjHRhkJlHhKG7fBtz1G2ss13MtAzB1P+0ZMGeWdtgi4T0dq dIcMgf+jX0Jelv8dbvcLwmQz2WNq6a2d+1eNlp91l4a45r45cp5GH4GY4pnQpLkQv2wb VcVhVfb4sHJ3GpJ9krKLY7oSD+xhZEwYCYbOWVMEhq0EL+RRT4bkWE+i9wcDPueGbJ7B P7HJ8t2860x1dpq4pYilUvGWzzNx1DUnQxLD7dk3BC/9AkpMY9iRoAeGOYUL8Cme3mQO kA== Received: from userv0021.oracle.com (userv0021.oracle.com [156.151.31.71]) by userp2120.oracle.com with ESMTP id 2ptn7r9f34-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 10 Jan 2019 21:10:17 +0000 Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userv0021.oracle.com (8.14.4/8.14.4) with ESMTP id x0ALAHxT008490 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 10 Jan 2019 21:10:17 GMT Received: from abhmp0009.oracle.com (abhmp0009.oracle.com [141.146.116.15]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x0ALAGV0022904; Thu, 10 Jan 2019 21:10:16 GMT Received: from concerto.internal (/24.9.64.241) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 10 Jan 2019 13:10:15 -0800 From: Khalid Aziz To: juergh@gmail.com, tycho@tycho.ws, jsteckli@amazon.de, ak@linux.intel.com, torvalds@linux-foundation.org, liran.alon@oracle.com, keescook@google.com, konrad.wilk@oracle.com Cc: Tycho Andersen , deepa.srinivasan@oracle.com, chris.hyser@oracle.com, tyhicks@canonical.com, dwmw@amazon.co.uk, andrew.cooper3@citrix.com, jcm@redhat.com, boris.ostrovsky@oracle.com, kanth.ghatraju@oracle.com, joao.m.martins@oracle.com, jmattson@google.com, pradeep.vincent@oracle.com, john.haxby@oracle.com, tglx@linutronix.de, kirill.shutemov@linux.intel.com, hch@lst.de, steven.sistare@oracle.com, kernel-hardening@lists.openwall.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, x86@kernel.org, Khalid Aziz Subject: [RFC PATCH v7 02/16] x86: always set IF before oopsing from page fault Date: Thu, 10 Jan 2019 14:09:34 -0700 Message-Id: <46b0f1a61dabf6440d461c063a32573b96f3a5ce.1547153058.git.khalid.aziz@oracle.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: References: In-Reply-To: References: X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9132 signatures=668680 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=953 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1901100164 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: X-Virus-Scanned: ClamAV using ClamSMTP From: Tycho Andersen Oopsing might kill the task, via rewind_stack_do_exit() at the bottom, and that might sleep: Aug 23 19:30:27 xpfo kernel: [ 38.302714] BUG: sleeping function called from invalid context at ./include/linux/percpu-rwsem.h:33 Aug 23 19:30:27 xpfo kernel: [ 38.303837] in_atomic(): 0, irqs_disabled(): 1, pid: 1970, name: lkdtm_xpfo_test Aug 23 19:30:27 xpfo kernel: [ 38.304758] CPU: 3 PID: 1970 Comm: lkdtm_xpfo_test Tainted: G D 4.13.0-rc5+ #228 Aug 23 19:30:27 xpfo kernel: [ 38.305813] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.1-1ubuntu1 04/01/2014 Aug 23 19:30:27 xpfo kernel: [ 38.306926] Call Trace: Aug 23 19:30:27 xpfo kernel: [ 38.307243] dump_stack+0x63/0x8b Aug 23 19:30:27 xpfo kernel: [ 38.307665] ___might_sleep+0xec/0x110 Aug 23 19:30:27 xpfo kernel: [ 38.308139] __might_sleep+0x45/0x80 Aug 23 19:30:27 xpfo kernel: [ 38.308593] exit_signals+0x21/0x1c0 Aug 23 19:30:27 xpfo kernel: [ 38.309046] ? blocking_notifier_call_chain+0x11/0x20 Aug 23 19:30:27 xpfo kernel: [ 38.309677] do_exit+0x98/0xbf0 Aug 23 19:30:27 xpfo kernel: [ 38.310078] ? smp_reader+0x27/0x40 [lkdtm] Aug 23 19:30:27 xpfo kernel: [ 38.310604] ? kthread+0x10f/0x150 Aug 23 19:30:27 xpfo kernel: [ 38.311045] ? read_user_with_flags+0x60/0x60 [lkdtm] Aug 23 19:30:27 xpfo kernel: [ 38.311680] rewind_stack_do_exit+0x17/0x20 To be safe, let's just always enable irqs. The particular case I'm hitting is: Aug 23 19:30:27 xpfo kernel: [ 38.278615] __bad_area_nosemaphore+0x1a9/0x1d0 Aug 23 19:30:27 xpfo kernel: [ 38.278617] bad_area_nosemaphore+0xf/0x20 Aug 23 19:30:27 xpfo kernel: [ 38.278618] __do_page_fault+0xd1/0x540 Aug 23 19:30:27 xpfo kernel: [ 38.278620] ? irq_work_queue+0x9b/0xb0 Aug 23 19:30:27 xpfo kernel: [ 38.278623] ? wake_up_klogd+0x36/0x40 Aug 23 19:30:27 xpfo kernel: [ 38.278624] trace_do_page_fault+0x3c/0xf0 Aug 23 19:30:27 xpfo kernel: [ 38.278625] do_async_page_fault+0x14/0x60 Aug 23 19:30:27 xpfo kernel: [ 38.278627] async_page_fault+0x28/0x30 When a fault is in kernel space which has been triggered by XPFO. Signed-off-by: Tycho Andersen CC: x86@kernel.org Signed-off-by: Khalid Aziz --- arch/x86/mm/fault.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 71d4b9d4d43f..ba51652fbd33 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -748,6 +748,12 @@ no_context(struct pt_regs *regs, unsigned long error_code, /* Executive summary in case the body of the oops scrolled away */ printk(KERN_DEFAULT "CR2: %016lx\n", address); + /* + * We're about to oops, which might kill the task. Make sure we're + * allowed to sleep. + */ + flags |= X86_EFLAGS_IF; + oops_end(flags, regs, sig); }