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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 6C7B3C3A5A2 for ; Tue, 10 Sep 2019 09:50:25 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E970A20872 for ; Tue, 10 Sep 2019 09:50:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E970A20872 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 46SKyj2FmJzDrN9 for ; Tue, 10 Sep 2019 19:50:21 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=redhat.com (client-ip=209.132.183.28; helo=mx1.redhat.com; envelope-from=pagupta@redhat.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=redhat.com Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 46SH5R2Nc6zDqVj for ; Tue, 10 Sep 2019 17:40:56 +1000 (AEST) Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 444F910F23E6; Tue, 10 Sep 2019 07:40:54 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 33C3510018F9; Tue, 10 Sep 2019 07:40:53 +0000 (UTC) Received: from zmail21.collab.prod.int.phx2.redhat.com (zmail21.collab.prod.int.phx2.redhat.com [10.5.83.24]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id 9F7564EE50; Tue, 10 Sep 2019 07:40:53 +0000 (UTC) Date: Tue, 10 Sep 2019 03:40:52 -0400 (EDT) From: Pankaj Gupta To: "Aneesh Kumar K.V" Message-ID: <2020260189.13761278.1568101252797.JavaMail.zimbra@redhat.com> In-Reply-To: <20190910062826.10041-1-aneesh.kumar@linux.ibm.com> References: <20190910062826.10041-1-aneesh.kumar@linux.ibm.com> Subject: Re: [PATCH 1/2] libnvdimm/altmap: Track namespace boundaries in altmap MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [10.67.116.33, 10.4.195.7] Thread-Topic: libnvdimm/altmap: Track namespace boundaries in altmap Thread-Index: 0vGHbgAC4vRUi42fXCRBMq+d5EI7bA== X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.2 (mx1.redhat.com [10.5.110.66]); Tue, 10 Sep 2019 07:40:54 +0000 (UTC) X-Mailman-Approved-At: Tue, 10 Sep 2019 19:26:42 +1000 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sachin Sant , linux-nvdimm@lists.01.org, oohall@gmail.com, dan j williams , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" > > With PFN_MODE_PMEM namespace, the memmap area is allocated from the device > area. Some architectures map the memmap area with large page size. On > architectures like ppc64, 16MB page for memap mapping can map 262144 pfns. > This maps a namespace size of 16G. > > When populating memmap region with 16MB page from the device area, > make sure the allocated space is not used to map resources outside this > namespace. Such usage of device area will prevent a namespace destroy. > > Add resource end pnf in altmap and use that to check if the memmap area > allocation can map pfn outside the namespace. On ppc64 in such case we > fallback > to allocation from memory. > > This fix kernel crash reported below: > > [ 132.034989] WARNING: CPU: 13 PID: 13719 at mm/memremap.c:133 > devm_memremap_pages_release+0x2d8/0x2e0 > [ 133.464754] BUG: Unable to handle kernel data access at 0xc00c00010b204000 > [ 133.464760] Faulting instruction address: 0xc00000000007580c > [ 133.464766] Oops: Kernel access of bad area, sig: 11 [#1] > [ 133.464771] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries > ..... > [ 133.464901] NIP [c00000000007580c] vmemmap_free+0x2ac/0x3d0 > [ 133.464906] LR [c0000000000757f8] vmemmap_free+0x298/0x3d0 > [ 133.464910] Call Trace: > [ 133.464914] [c000007cbfd0f7b0] [c0000000000757f8] vmemmap_free+0x298/0x3d0 > (unreliable) > [ 133.464921] [c000007cbfd0f8d0] [c000000000370a44] > section_deactivate+0x1a4/0x240 > [ 133.464928] [c000007cbfd0f980] [c000000000386270] > __remove_pages+0x3a0/0x590 > [ 133.464935] [c000007cbfd0fa50] [c000000000074158] > arch_remove_memory+0x88/0x160 > [ 133.464942] [c000007cbfd0fae0] [c0000000003be8c0] > devm_memremap_pages_release+0x150/0x2e0 > [ 133.464949] [c000007cbfd0fb70] [c000000000738ea0] > devm_action_release+0x30/0x50 > [ 133.464955] [c000007cbfd0fb90] [c00000000073a5a4] > release_nodes+0x344/0x400 > [ 133.464961] [c000007cbfd0fc40] [c00000000073378c] > device_release_driver_internal+0x15c/0x250 > [ 133.464968] [c000007cbfd0fc80] [c00000000072fd14] unbind_store+0x104/0x110 > [ 133.464973] [c000007cbfd0fcd0] [c00000000072ee24] drv_attr_store+0x44/0x70 > [ 133.464981] [c000007cbfd0fcf0] [c0000000004a32bc] sysfs_kf_write+0x6c/0xa0 > [ 133.464987] [c000007cbfd0fd10] [c0000000004a1dfc] > kernfs_fop_write+0x17c/0x250 > [ 133.464993] [c000007cbfd0fd60] [c0000000003c348c] __vfs_write+0x3c/0x70 > [ 133.464999] [c000007cbfd0fd80] [c0000000003c75d0] vfs_write+0xd0/0x250 > > Reported-by: Sachin Sant > Signed-off-by: Aneesh Kumar K.V > --- > arch/powerpc/mm/init_64.c | 17 ++++++++++++++++- > drivers/nvdimm/pfn_devs.c | 2 ++ > include/linux/memremap.h | 1 + > 3 files changed, 19 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c > index a44f6281ca3a..4e08246acd79 100644 > --- a/arch/powerpc/mm/init_64.c > +++ b/arch/powerpc/mm/init_64.c > @@ -172,6 +172,21 @@ static __meminit void vmemmap_list_populate(unsigned > long phys, > vmemmap_list = vmem_back; > } > > +static bool altmap_cross_boundary(struct vmem_altmap *altmap, unsigned long > start, > + unsigned long page_size) > +{ > + unsigned long nr_pfn = page_size / sizeof(struct page); > + unsigned long start_pfn = page_to_pfn((struct page *)start); > + > + if ((start_pfn + nr_pfn) > altmap->end_pfn) > + return true; > + > + if (start_pfn < altmap->base_pfn) > + return true; > + > + return false; > +} > + > int __meminit vmemmap_populate(unsigned long start, unsigned long end, int > node, > struct vmem_altmap *altmap) > { > @@ -194,7 +209,7 @@ int __meminit vmemmap_populate(unsigned long start, > unsigned long end, int node, > * fail due to alignment issues when using 16MB hugepages, so > * fall back to system memory if the altmap allocation fail. > */ > - if (altmap) { > + if (altmap && !altmap_cross_boundary(altmap, start, page_size)) { > p = altmap_alloc_block_buf(page_size, altmap); > if (!p) > pr_debug("altmap block allocation failed, falling back to system > memory"); > diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c > index 3e7b11cf1aae..a616d69c8224 100644 > --- a/drivers/nvdimm/pfn_devs.c > +++ b/drivers/nvdimm/pfn_devs.c > @@ -618,9 +618,11 @@ static int __nvdimm_setup_pfn(struct nd_pfn *nd_pfn, > struct dev_pagemap *pgmap) > struct nd_namespace_common *ndns = nd_pfn->ndns; > struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev); > resource_size_t base = nsio->res.start + start_pad; > + resource_size_t end = nsio->res.end - end_trunc; > struct vmem_altmap __altmap = { > .base_pfn = init_altmap_base(base), > .reserve = init_altmap_reserve(base), > + .end_pfn = PHYS_PFN(end), > }; > > memcpy(res, &nsio->res, sizeof(*res)); > diff --git a/include/linux/memremap.h b/include/linux/memremap.h > index f8a5b2a19945..c70996fe48c8 100644 > --- a/include/linux/memremap.h > +++ b/include/linux/memremap.h > @@ -17,6 +17,7 @@ struct device; > */ > struct vmem_altmap { > const unsigned long base_pfn; > + const unsigned long end_pfn; > const unsigned long reserve; > unsigned long free; > unsigned long align; > -- > 2.21.0 This patch looks good to me. It helps to prevent namespace access across boundaries for altmap hugepage allocation. Reviewed-by: Pankaj Gupta Thanks, Pankaj > > _______________________________________________ > Linux-nvdimm mailing list > Linux-nvdimm@lists.01.org > https://lists.01.org/mailman/listinfo/linux-nvdimm >