diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 845c5b430cdd6446f4b20806a01a9452f9ecd3b7..d9d845077b8be13b0e352d0646eb374af3a5bdba 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -281,16 +281,22 @@ static long pmem_dax_direct_access(struct dax_device *dax_dev,
 	return __pmem_direct_access(pmem, pgoff, nr_pages, kaddr, pfn);
 }
 
+/*
+ * Use the 'no check' versions of copy_from_iter_flushcache() and
+ * copy_to_iter_mcsafe() to bypass HARDENED_USERCOPY overhead. Bounds
+ * checking, both file offset and device offset, is handled by
+ * dax_iomap_actor()
+ */
 static size_t pmem_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
 		void *addr, size_t bytes, struct iov_iter *i)
 {
-	return copy_from_iter_flushcache(addr, bytes, i);
+	return _copy_from_iter_flushcache(addr, bytes, i);
 }
 
 static size_t pmem_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff,
 		void *addr, size_t bytes, struct iov_iter *i)
 {
-	return copy_to_iter_mcsafe(addr, bytes, i);
+	return _copy_to_iter_mcsafe(addr, bytes, i);
 }
 
 static const struct dax_operations pmem_dax_ops = {