From patchwork Fri Jun 15 20:33:39 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Jiang X-Patchwork-Id: 10467615 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id BB00360384 for ; Fri, 15 Jun 2018 20:33:42 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AAEB428A21 for ; Fri, 15 Jun 2018 20:33:42 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9F97D28C90; Fri, 15 Jun 2018 20:33:42 +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=-2.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 381CC28A21 for ; Fri, 15 Jun 2018 20:33:42 +0000 (UTC) Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id EC2CF210D5137; Fri, 15 Jun 2018 13:33:41 -0700 (PDT) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=134.134.136.20; helo=mga02.intel.com; envelope-from=dave.jiang@intel.com; receiver=linux-nvdimm@lists.01.org Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id E2C64210C2D65 for ; Fri, 15 Jun 2018 13:33:40 -0700 (PDT) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 15 Jun 2018 13:33:40 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,228,1526367600"; d="scan'208";a="208462145" Received: from djiang5-desk3.ch.intel.com ([143.182.136.93]) by orsmga004.jf.intel.com with ESMTP; 15 Jun 2018 13:33:39 -0700 Subject: [PATCH v2] mm: disallow mapping that conflict for devm_memremap_pages() From: Dave Jiang To: akpm@linux-foundation.org Date: Fri, 15 Jun 2018 13:33:39 -0700 Message-ID: <152909478401.50143.312364396244072931.stgit@djiang5-desk3.ch.intel.com> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-mm@kvack.org, linux-nvdimm@lists.01.org Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" X-Virus-Scanned: ClamAV using ClamSMTP When pmem namespaces created are smaller than section size, this can cause issue during removal and gpf was observed: [ 249.613597] general protection fault: 0000 1 SMP PTI [ 249.725203] CPU: 36 PID: 3941 Comm: ndctl Tainted: G W 4.14.28-1.el7uek.x86_64 #2 [ 249.745495] task: ffff88acda150000 task.stack: ffffc900233a4000 [ 249.752107] RIP: 0010:__put_page+0x56/0x79 [ 249.844675] Call Trace: [ 249.847410] devm_memremap_pages_release+0x155/0x23a [ 249.852953] release_nodes+0x21e/0x260 [ 249.857138] devres_release_all+0x3c/0x48 [ 249.861606] device_release_driver_internal+0x15c/0x207 [ 249.867439] device_release_driver+0x12/0x14 [ 249.872204] unbind_store+0xba/0xd8 [ 249.876098] drv_attr_store+0x27/0x31 [ 249.880186] sysfs_kf_write+0x3f/0x46 [ 249.884266] kernfs_fop_write+0x10f/0x18b [ 249.888734] __vfs_write+0x3a/0x16d [ 249.892628] ? selinux_file_permission+0xe5/0x116 [ 249.897881] ? security_file_permission+0x41/0xbb [ 249.903133] vfs_write+0xb2/0x1a1 [ 249.906835] ? syscall_trace_enter+0x1ce/0x2b8 [ 249.911795] SyS_write+0x55/0xb9 [ 249.915397] do_syscall_64+0x79/0x1ae [ 249.919485] entry_SYSCALL_64_after_hwframe+0x3d/0x0 Add code to check whether we have mapping already in the same section and prevent additional mapping from created if that is the case. Signed-off-by: Dave Jiang --- v2: Change dev_warn() to dev_WARN() to provide helpful backtrace. (Robert E) kernel/memremap.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/kernel/memremap.c b/kernel/memremap.c index 5857267a4af5..a734b1747466 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -176,10 +176,27 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) unsigned long pfn, pgoff, order; pgprot_t pgprot = PAGE_KERNEL; int error, nid, is_ram; + struct dev_pagemap *conflict_pgmap; align_start = res->start & ~(SECTION_SIZE - 1); align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE) - align_start; + align_end = align_start + align_size - 1; + + conflict_pgmap = get_dev_pagemap(PHYS_PFN(align_start), NULL); + if (conflict_pgmap) { + dev_WARN(dev, "Conflicting mapping in same section\n"); + put_dev_pagemap(conflict_pgmap); + return ERR_PTR(-ENOMEM); + } + + conflict_pgmap = get_dev_pagemap(PHYS_PFN(align_end), NULL); + if (conflict_pgmap) { + dev_WARN(dev, "Conflicting mapping in same section\n"); + put_dev_pagemap(conflict_pgmap); + return ERR_PTR(-ENOMEM); + } + is_ram = region_intersects(align_start, align_size, IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE); @@ -199,7 +216,6 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) mutex_lock(&pgmap_lock); error = 0; - align_end = align_start + align_size - 1; foreach_order_pgoff(res, order, pgoff) { error = __radix_tree_insert(&pgmap_radix,