[PATCH 1/3] nvdimm/pmem: check the validity of the pointer pfn

From: Huaisheng Ye
Date: Wed Jul 04 2018 - 02:42:08 EST


From: Huaisheng Ye <yehs1@xxxxxxxxxx>

Some functions within fs/dax don't need to get gfn from direct_access.
Assigning NULL to gfn of dax_direct_access is more intuitive and simple
than offering a useless local variable.

So direct_access needs to check validity of the pointer pfn For NULL
assignment.

Signed-off-by: Huaisheng Ye <yehs1@xxxxxxxxxx>
---
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