From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f199.google.com (mail-pf0-f199.google.com [209.85.192.199]) by kanga.kvack.org (Postfix) with ESMTP id D31BD6B0271 for ; Thu, 5 Jul 2018 02:59:39 -0400 (EDT) Received: by mail-pf0-f199.google.com with SMTP id v10-v6so4271559pfm.11 for ; Wed, 04 Jul 2018 23:59:39 -0700 (PDT) Received: from mga07.intel.com (mga07.intel.com. [134.134.136.100]) by mx.google.com with ESMTPS id n8-v6si5154556pgl.101.2018.07.04.23.59.38 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 04 Jul 2018 23:59:38 -0700 (PDT) Subject: [PATCH 07/13] nvdimm/pmem-dax: check the validity of the pointer pfn From: Dan Williams Date: Wed, 04 Jul 2018 23:49:40 -0700 Message-ID: <153077338038.40830.8894996377094953603.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <153077334130.40830.2714147692560185329.stgit@dwillia2-desk3.amr.corp.intel.com> References: <153077334130.40830.2714147692560185329.stgit@dwillia2-desk3.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org Cc: Huaisheng Ye , Jan Kara , vishal.l.verma@intel.com, hch@lst.de, linux-nvdimm@lists.01.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org From: Huaisheng Ye direct_access needs to check the validity of pointer pfn for NULL assignment. If pfn equals to NULL, it doesn't need to calculate the value. Suggested-by: Dan Williams Signed-off-by: Huaisheng Ye Reviewed-by: Jan Kara Signed-off-by: Dan Williams --- tools/testing/nvdimm/pmem-dax.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/tools/testing/nvdimm/pmem-dax.c b/tools/testing/nvdimm/pmem-dax.c index b53596ad601b..d4cb5281b30e 100644 --- a/tools/testing/nvdimm/pmem-dax.c +++ b/tools/testing/nvdimm/pmem-dax.c @@ -33,7 +33,8 @@ long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff, *kaddr = pmem->virt_addr + offset; page = vmalloc_to_page(pmem->virt_addr + offset); - *pfn = page_to_pfn_t(page); + if (pfn) + *pfn = page_to_pfn_t(page); pr_debug_ratelimited("%s: pmem: %p pgoff: %#lx pfn: %#lx\n", __func__, pmem, pgoff, page_to_pfn(page)); @@ -41,7 +42,8 @@ long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff, } *kaddr = pmem->virt_addr + offset; - *pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags); + if (pfn) + *pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags); /* * If badblocks are present, limit known good range to the