4.14-stable review patch. If anyone has any objections, please let me know.
------------------ From: Huaisheng Ye <[email protected]> [ Upstream commit 45df5d3dc0c7289c1e67afe6d2ba806ad5174314 ] The mock / test version of 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 local pointer or variable that they then just throw away. Suggested-by: Dan Williams <[email protected]> Signed-off-by: Huaisheng Ye <[email protected]> Reviewed-by: Ross Zwisler <[email protected]> Signed-off-by: Dave Jiang <[email protected]> Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- tools/testing/nvdimm/pmem-dax.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) --- a/tools/testing/nvdimm/pmem-dax.c +++ b/tools/testing/nvdimm/pmem-dax.c @@ -31,17 +31,21 @@ long __pmem_direct_access(struct pmem_de if (get_nfit_res(pmem->phys_addr + offset)) { struct page *page; - *kaddr = pmem->virt_addr + offset; + if (kaddr) + *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)); return 1; } - *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
