[PATCH 1/5] libnvdimm, pmem: Allow a NULL-kaddr to ->direct_access()

Huaisheng Ye
2018-07-24T08:45:06Z

pmem_direct_access() needs to check the validity of second rank
pointer kaddr for NULL assignment. If kaddr equals to NULL, it
doesn't need to calculate the value.

Signed-off-by: Huaisheng Ye <yehs1@lenovo.com>
---
drivers/nvdimm/pmem.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 9d71492..b1d121a 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -232,7 +232,9 @@ __weak long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,
if (unlikely(is_bad_pmem(&pmem->bb, PFN_PHYS(pgoff) / 512,
PFN_PHYS(nr_pages))))
return -EIO;
- *kaddr = pmem->virt_addr + offset;
+
+ if (kaddr)
+ *kaddr = pmem->virt_addr + offset;
*pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);

/*
--
1.8.3.1