From patchwork Fri Oct 9 19:50:33 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ira Weiny X-Patchwork-Id: 11828147 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0A9B114D5 for ; Fri, 9 Oct 2020 19:55:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EE63C22C9F for ; Fri, 9 Oct 2020 19:55:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391342AbgJITys (ORCPT ); Fri, 9 Oct 2020 15:54:48 -0400 Received: from mga12.intel.com ([192.55.52.136]:29419 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391275AbgJITyL (ORCPT ); Fri, 9 Oct 2020 15:54:11 -0400 IronPort-SDR: q1PZMJUmKFKlQ0BClGvwyzOjNwzGSo5B944T29UwXjVfp2YopDniYa7pTU6UFtwNvsti9h6T08 dfV2TT7Nz02w== X-IronPort-AV: E=McAfee;i="6000,8403,9769"; a="144851137" X-IronPort-AV: E=Sophos;i="5.77,355,1596524400"; d="scan'208";a="144851137" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Oct 2020 12:54:10 -0700 IronPort-SDR: LoljxrxdEbdUiebRGt6guGtjo6SPfpWGHMJuLgTgYB7BeDU8CJtiGau7DzbQyZ+Y5gpHVnCtT5 urTwCEpflSRg== X-IronPort-AV: E=Sophos;i="5.77,355,1596524400"; d="scan'208";a="343972696" Received: from iweiny-desk2.sc.intel.com (HELO localhost) ([10.3.52.147]) by fmsmga004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Oct 2020 12:54:09 -0700 From: ira.weiny@intel.com To: Andrew Morton , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Andy Lutomirski , Peter Zijlstra Cc: Ira Weiny , x86@kernel.org, Dave Hansen , Dan Williams , Fenghua Yu , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, kexec@lists.infradead.org, linux-bcache@vger.kernel.org, linux-mtd@lists.infradead.org, devel@driverdev.osuosl.org, linux-efi@vger.kernel.org, linux-mmc@vger.kernel.org, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, linux-nfs@vger.kernel.org, ceph-devel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-aio@kvack.org, io-uring@vger.kernel.org, linux-erofs@lists.ozlabs.org, linux-um@lists.infradead.org, linux-ntfs-dev@lists.sourceforge.net, reiserfs-devel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-nilfs@vger.kernel.org, cluster-devel@redhat.com, ecryptfs@vger.kernel.org, linux-cifs@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-afs@lists.infradead.org, linux-rdma@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, drbd-dev@lists.linbit.com, linux-block@vger.kernel.org, xen-devel@lists.xenproject.org, linux-cachefs@redhat.com, samba-technical@lists.samba.org, intel-wired-lan@lists.osuosl.org Subject: [PATCH RFC PKS/PMEM 58/58] [dax|pmem]: Enable stray access protection Date: Fri, 9 Oct 2020 12:50:33 -0700 Message-Id: <20201009195033.3208459-59-ira.weiny@intel.com> X-Mailer: git-send-email 2.28.0.rc0.12.gb6a658bd00c9 In-Reply-To: <20201009195033.3208459-1-ira.weiny@intel.com> References: <20201009195033.3208459-1-ira.weiny@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Ira Weiny Protecting against stray writes is particularly important for PMEM because, unlike writes to anonymous memory, writes to PMEM persists across a reboot. Thus data corruption could result in permanent loss of data. While stray writes are more serious than reads, protection is also enabled for reads. This helps to detect bugs in code which would incorrectly access device memory and prevents a more serious machine checks should those bug reads from a poison page. Enable stray access protection by setting the flag in pgmap which requests it. There is no option presented to the user. If Zone Device Access Protection not be supported this flag will have no affect. Signed-off-by: Ira Weiny --- drivers/dax/device.c | 2 ++ drivers/nvdimm/pmem.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/drivers/dax/device.c b/drivers/dax/device.c index 1e89513f3c59..e6fb35b4f0fb 100644 --- a/drivers/dax/device.c +++ b/drivers/dax/device.c @@ -430,6 +430,8 @@ int dev_dax_probe(struct device *dev) } dev_dax->pgmap.type = MEMORY_DEVICE_GENERIC; + dev_dax->pgmap.flags |= PGMAP_PROT_ENABLED; + addr = devm_memremap_pages(dev, &dev_dax->pgmap); if (IS_ERR(addr)) return PTR_ERR(addr); diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index e4dc1ae990fc..9fcd8338e23f 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -426,6 +426,8 @@ static int pmem_attach_disk(struct device *dev, return -EBUSY; } + pmem->pgmap.flags |= PGMAP_PROT_ENABLED; + q = blk_alloc_queue(dev_to_node(dev)); if (!q) return -ENOMEM;