[v2,2/4] nvdimm/pmem-dax: check the validity of the pointer pfn

Commit Message

Huaisheng Ye July 4, 2018, 4:38 p.m. UTC

From: Huaisheng Ye <[e-mail]>

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 <[e-mail]>
Signed-off-by: Huaisheng Ye <[e-mail]>
Reviewed-by: Jan Kara <[e-mail]>
---
 tools/testing/nvdimm/pmem-dax.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

Patch

diff --git a/tools/testing/nvdimm/pmem-dax.c b/tools/testing/nvdimm/pmem-dax.c
index b53596a..d4cb528 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