4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Huaisheng Ye yehs1@lenovo.com
[ 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 dan.j.williams@intel.com 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 Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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