From 46a590cde0bd17cc983e40e74c195311cc8ba555 Mon Sep 17 00:00:00 2001 From: Huaisheng Ye Date: Mon, 30 Jul 2018 15:15:43 +0800 Subject: 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 Reviewed-by: Ross Zwisler Signed-off-by: Dave Jiang --- drivers/nvdimm/pmem.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'drivers/nvdimm') diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 68940356cad3..f3096564acb2 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -227,8 +227,11 @@ __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; - *pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags); + + if (kaddr) + *kaddr = pmem->virt_addr + offset; + if (pfn) + *pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags); /* * If badblocks are present, limit known good range to the -- cgit v1.2.3-59-g8ed1b