From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (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 B4AE4212741F2 for ; Thu, 6 Jun 2019 14:46:44 -0700 (PDT) Date: Thu, 6 Jun 2019 14:46:43 -0700 From: Andrew Morton Subject: Re: [PATCH v9 11/12] libnvdimm/pfn: Fix fsdax-mode namespace info-block zero-fields Message-Id: <20190606144643.4f3363db9499ebbf8f76e62e@linux-foundation.org> In-Reply-To: <155977193862.2443951.10284714500308539570.stgit@dwillia2-desk3.amr.corp.intel.com> References: <155977186863.2443951.9036044808311959913.stgit@dwillia2-desk3.amr.corp.intel.com> <155977193862.2443951.10284714500308539570.stgit@dwillia2-desk3.amr.corp.intel.com> Mime-Version: 1.0 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: Dan Williams Cc: mhocko@suse.com, linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux-mm@kvack.org, osalvador@suse.de List-ID: On Wed, 05 Jun 2019 14:58:58 -0700 Dan Williams wrote: > At namespace creation time there is the potential for the "expected to > be zero" fields of a 'pfn' info-block to be filled with indeterminate > data. While the kernel buffer is zeroed on allocation it is immediately > overwritten by nd_pfn_validate() filling it with the current contents of > the on-media info-block location. For fields like, 'flags' and the > 'padding' it potentially means that future implementations can not rely > on those fields being zero. > > In preparation to stop using the 'start_pad' and 'end_trunc' fields for > section alignment, arrange for fields that are not explicitly > initialized to be guaranteed zero. Bump the minor version to indicate it > is safe to assume the 'padding' and 'flags' are zero. Otherwise, this > corruption is expected to benign since all other critical fields are > explicitly initialized. > > Fixes: 32ab0a3f5170 ("libnvdimm, pmem: 'struct page' for pmem") > Cc: > Signed-off-by: Dan Williams The cc:stable in [11/12] seems odd. Is this independent of the other patches? If so, shouldn't it be a standalone thing which can be prioritized? _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm