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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 55CABC433EF for ; Sun, 8 Sep 2019 08:31:53 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id F102A20863 for ; Sun, 8 Sep 2019 08:31:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F102A20863 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 270216B0005; Sun, 8 Sep 2019 04:31:52 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 220316B0006; Sun, 8 Sep 2019 04:31:52 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1371C6B0007; Sun, 8 Sep 2019 04:31:52 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0028.hostedemail.com [216.40.44.28]) by kanga.kvack.org (Postfix) with ESMTP id E73DA6B0005 for ; Sun, 8 Sep 2019 04:31:51 -0400 (EDT) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with SMTP id 82847824CA3A for ; Sun, 8 Sep 2019 08:31:51 +0000 (UTC) X-FDA: 75911085222.25.join40_4a41f78aba84b X-HE-Tag: join40_4a41f78aba84b X-Filterd-Recvd-Size: 2624 Received: from huawei.com (szxga05-in.huawei.com [45.249.212.191]) by imf36.hostedemail.com (Postfix) with ESMTP for ; Sun, 8 Sep 2019 08:31:50 +0000 (UTC) Received: from DGGEMS402-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 73A7687D29BFBA0A6B45; Sun, 8 Sep 2019 16:31:42 +0800 (CST) Received: from [127.0.0.1] (10.177.29.68) by DGGEMS402-HUB.china.huawei.com (10.3.19.202) with Microsoft SMTP Server id 14.3.439.0; Sun, 8 Sep 2019 16:31:34 +0800 Message-ID: <5D74BC65.4070309@huawei.com> Date: Sun, 8 Sep 2019 16:31:33 +0800 From: zhong jiang User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: CC: Vinayak Menon , Linux-MM , "Wangkefeng (Kevin)" , , zhongjiang Subject: Speculative page faults Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.29.68] X-CFilter-Loop: Reflected 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: Hi, Laurent, Vinayak I have got the following crash on 4.14 kernel with speculative page faults enabled. Unfortunately, The issue disappears when trying disabling SPF. The call trace is as follows. Unable to handle kernel NULL pointer dereference at virtual address 00000000 user pgtable: 4k pages, 39-bit VAs, pgd = ffffffc177337000 [0000000000000000] *pgd=0000000177346003, *pud=0000000177346003, *pmd=0000000000000000 Internal error: Oops: 96000046 [#1] PREEMPT SMP CPU: 0 PID: 3184 Comm: Signal Catcher VIP: 00 Tainted: G O 4.14.116 #1 PC is at __rb_erase_color+0x54/0x260 LR is at anon_vma_interval_tree_remove+0x2ac/0x2c0 Call trace: [] __rb_erase_color+0x54/0x260 [] anon_vma_interval_tree_remove+0x2ac/0x2c0 [] unlink_anon_vmas+0x84/0x170 [] free_pgtables+0x9c/0x100 [] exit_mmap+0xb0/0x1d8 [] mmput+0x3c/0xe0 [ffffff800822ed00>] do_exit+0x2f0/0x954 [] do_group_exit+0x88/0x9c [] get_signal+0x360/0x56c [] do_notify_resume+0x150/0x5e4 Exception stack(0xffffffc1eac07ec0 to 0xffffffc1eac08000) It seems to rb_node is empty accidentally under anon_vma rwsem when the process is exiting. I have no idea whether any race existence or not to result in the issue. Let me know if you have hit the issue or any suggestions. Thanks, zhong jiang