Commit 46a590cd authored Jul 30, 2018 by Huaisheng Ye Committed by Dave Jiang Jul 30, 2018

libnvdimm, pmem: kaddr and pfn can be NULL to ->direct_access()



pmem_direct_access() needs to check the validity of pointers kaddr
and pfn for NULL assignment. If anyone equals to NULL, it doesn't need
to calculate the value.

If pointer equals to NULL, that is to say callers may have no need for
kaddr or pfn, so this patch is prepared for allowing them to pass in
NULL instead of having to pass in a pointer or local variable that
they then just throw away.

Signed-off-by: Huaisheng Ye <yehs1@lenovo.com>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

parent cc3d3458

drivers/nvdimm/pmem.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -227,7 +227,10 @@ __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;

		if (kaddr)
		*kaddr = pmem->virt_addr + offset;
		if (pfn)
		*pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);

		/*

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