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=-2.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, T_DKIMWL_WL_HIGH,UNPARSEABLE_RELAY,URIBL_BLOCKED,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 356DEC67790 for ; Fri, 27 Jul 2018 21:17:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CB62920671 for ; Fri, 27 Jul 2018 21:17:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="VOXbXRQW" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CB62920671 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=oracle.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389842AbeG0Wli (ORCPT ); Fri, 27 Jul 2018 18:41:38 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:60920 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389659AbeG0Wli (ORCPT ); Fri, 27 Jul 2018 18:41:38 -0400 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 w6RLEju1016148; Fri, 27 Jul 2018 21:17:35 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id; s=corp-2018-07-02; bh=FeD56HSiwh1LVtS9tlX8UGgNfpreoW2uJ2w9Dzh34Pk=; b=VOXbXRQWfQnzsnqg85FKWMIB0Rm8WTIljg9YNjXm9cE5IsCenlgiFuDFmLeMxri5OB5L gUQXJviuiQ09ShAG1QsP2cddAvHO7Qn5IK3CDrg+lBQmFjISMQ6I2FrFIHhNmavSMu1D jD5JSi//n81ittidsz3khZAV1219DACNh5QutR+XlCPtZ7nutMsCZmVGeYnoF7Sn1T9x 8vcd0lIDmATSzEs7lvAkhvDLZROuUV9DV5XRl2pJXZyAmG1/uBzRW60Ul56CKFzxg58h yD7kERQuevGyp4qjJA/SHbk7uL9QRyV5IvNghW2v3jGkT+7fv3oITbKM6r4mAjdbRu0N 1w== Received: from aserv0022.oracle.com (aserv0022.oracle.com [141.146.126.234]) by userp2120.oracle.com with ESMTP id 2kbwfq8n7k-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 27 Jul 2018 21:17:34 +0000 Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by aserv0022.oracle.com (8.14.4/8.14.4) with ESMTP id w6RLHXG1021808 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 27 Jul 2018 21:17:34 GMT Received: from abhmp0018.oracle.com (abhmp0018.oracle.com [141.146.116.24]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id w6RLHWvd010961; Fri, 27 Jul 2018 21:17:32 GMT Received: from brm-x4600-03.us.oracle.com (/10.80.150.114) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 27 Jul 2018 14:17:32 -0700 From: Jane Chu To: akpm@linux-foundation.org Cc: dan.j.williams@intel.com, mhocko@suse.com, jack@suse.cz, jglisse@redhat.com, mike.kravetz@oracle.com, dave@stgolabs.net, linux-mm@kvack.org, linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org, jane.chu@oracle.com Subject: [PATCH] ipc/shm.c add ->pagesize function to shm_vm_ops Date: Fri, 27 Jul 2018 15:17:27 -0600 Message-Id: <20180727211727.5020-1-jane.chu@oracle.com> X-Mailer: git-send-email 2.15.GIT X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8967 signatures=668706 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=1 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1806210000 definitions=main-1807270215 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit 05ea88608d4e13 (mm, hugetlbfs: introduce ->pagesize() to vm_operations_struct) adds a new ->pagesize() function to hugetlb_vm_ops, intended to cover all hugetlbfs backed files. With System V shared memory model, if "huge page" is specified, the "shared memory" is backed by hugetlbfs files, but the mappings initiated via shmget/shmat have their original vm_ops overwritten with shm_vm_ops, so we need to add a ->pagesize function to shm_vm_ops. Otherwise, vma_kernel_pagesize() returns PAGE_SIZE given a hugetlbfs backed vma, result in below BUG: fs/hugetlbfs/inode.c 443 if (unlikely(page_mapped(page))) { 444 BUG_ON(truncate_op); [ 242.268342] hugetlbfs: oracle (4592): Using mlock ulimits for SHM_HUGETLB is deprecated [ 282.653208] ------------[ cut here ]------------ [ 282.708447] kernel BUG at fs/hugetlbfs/inode.c:444! [ 282.818957] Modules linked in: nfsv3 rpcsec_gss_krb5 nfsv4 ... [ 284.025873] CPU: 35 PID: 5583 Comm: oracle_5583_sbt Not tainted 4.14.35-1829.el7uek.x86_64 #2 [ 284.246609] task: ffff9bf0507aaf80 task.stack: ffffa9e625628000 [ 284.317455] RIP: 0010:remove_inode_hugepages+0x3db/0x3e2 .... [ 285.292389] Call Trace: [ 285.321630] hugetlbfs_evict_inode+0x1e/0x3e [ 285.372707] evict+0xdb/0x1af [ 285.408185] iput+0x1a2/0x1f7 [ 285.443661] dentry_unlink_inode+0xc6/0xf0 [ 285.492661] __dentry_kill+0xd8/0x18d [ 285.536459] dput+0x1b5/0x1ed [ 285.571939] __fput+0x18b/0x216 [ 285.609495] ____fput+0xe/0x10 [ 285.646030] task_work_run+0x90/0xa7 [ 285.688788] exit_to_usermode_loop+0xdd/0x116 [ 285.740905] do_syscall_64+0x187/0x1ae [ 285.785740] entry_SYSCALL_64_after_hwframe+0x150/0x0 Suggested-by: Mike Kravetz Signed-off-by: Jane Chu --- include/linux/mm.h | 7 +++++++ ipc/shm.c | 12 ++++++++++++ 2 files changed, 19 insertions(+) diff --git a/include/linux/mm.h b/include/linux/mm.h index a0fbb9ffe380..0c759379f2d9 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -387,6 +387,13 @@ enum page_entry_size { * These are the virtual MM functions - opening of an area, closing and * unmapping it (needed to keep files on disk up-to-date etc), pointer * to the functions called when a no-page or a wp-page exception occurs. + * + * Note, when a new function is introduced to vm_operations_struct and + * added to hugetlb_vm_ops, please consider adding the function to + * shm_vm_ops. This is because under System V memory model, though + * mappings created via shmget/shmat with "huge page" specified are + * backed by hugetlbfs files, their original vm_ops are overwritten with + * shm_vm_ops. */ struct vm_operations_struct { void (*open)(struct vm_area_struct * area); diff --git a/ipc/shm.c b/ipc/shm.c index 051a3e1fb8df..fefa00d310fb 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -427,6 +427,17 @@ static int shm_split(struct vm_area_struct *vma, unsigned long addr) return 0; } +static unsigned long shm_pagesize(struct vm_area_struct *vma) +{ + struct file *file = vma->vm_file; + struct shm_file_data *sfd = shm_file_data(file); + + if (sfd->vm_ops->pagesize) + return sfd->vm_ops->pagesize(vma); + + return PAGE_SIZE; +} + #ifdef CONFIG_NUMA static int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new) { @@ -554,6 +565,7 @@ static const struct vm_operations_struct shm_vm_ops = { .close = shm_close, /* callback for when the vm-area is released */ .fault = shm_fault, .split = shm_split, + .pagesize = shm_pagesize, #if defined(CONFIG_NUMA) .set_policy = shm_set_policy, .get_policy = shm_get_policy, -- 2.15.GIT