Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; 
  s=zapps768; d=zoho.com; 
  h=from:to:cc:subject:date:message-id:in-reply-to:references; 
  b=hK64AoQgM1uvja+b3eE4KlUiOKqK1FFMr+U6AV/H0F5C7tf+MILk2WIfy4UR1e6UHiJDEe5L3JZ3
    ABN8b/vrWqQszAnsT/Yuwl020oDGW4Iv1R/4+deF1ms/nwjsPtYF  
From:   Huaisheng Ye <yehs2007@zoho.com>
To:     linux-nvdimm@lists.01.org, dan.j.williams@intel.com
Cc:     ross.zwisler@linux.intel.com, willy@infradead.org,
        vishal.l.verma@intel.com, dave.jiang@intel.com,
        schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com,
        viro@zeniv.linux.org.uk, martin.petersen@oracle.com,
        axboe@kernel.dk, gregkh@linuxfoundation.org,
        bart.vanassche@wdc.com, jack@suse.com,
        linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, colyli@suse.de, chengnt@lenovo.com,
        Huaisheng Ye <yehs1@lenovo.com>
Subject: [PATCH v2 1/4] nvdimm/pmem: check the validity of the pointer pfn
Date:   Thu,  5 Jul 2018 00:38:20 +0800
Message-Id: <20180704163823.9980-2-yehs2007@zoho.com>
In-Reply-To: <20180704163823.9980-1-yehs2007@zoho.com>
References: <20180704163823.9980-1-yehs2007@zoho.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Huaisheng Ye <yehs1@lenovo.com>

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.

Signed-off-by: Huaisheng Ye <yehs1@lenovo.com>
Reviewed-by: Jan Kara <jack@suse.cz>
---
 drivers/nvdimm/pmem.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 9d71492..018f990 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -233,7 +233,8 @@ __weak long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,
 					PFN_PHYS(nr_pages))))
 		return -EIO;
 	*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
-- 
1.8.3.1