Index: sys/compat/linuxkpi/common/src/linux_page.c
===================================================================
--- sys/compat/linuxkpi/common/src/linux_page.c
+++ sys/compat/linuxkpi/common/src/linux_page.c
@@ -219,9 +219,8 @@
 		return (0);
 
 	MPASS(pages != NULL);
-	va = start;
 	map = &curthread->td_proc->p_vmspace->vm_map;
-	end = start + (((size_t)nr_pages) << PAGE_SHIFT);
+	end = start + ptoa(nr_pages);
 	if (!vm_map_range_valid(map, start, end))
 		return (-EINVAL);
 	prot = write ? (VM_PROT_READ | VM_PROT_WRITE) : VM_PROT_READ;
Index: sys/dev/md/md.c
===================================================================
--- sys/dev/md/md.c
+++ sys/dev/md/md.c
@@ -1558,11 +1558,14 @@
 	case MD_NULL:
 		break;
 	case MD_SWAP:
+		KASSERT(sc->mediasize % PAGE_SIZE == 0,
+		    ("%s: invalid media size %ju",
+		    __func__, (uintmax_t)sc->mediasize));
 		if (mdr->md_mediasize <= 0 ||
 		    (mdr->md_mediasize % PAGE_SIZE) != 0)
 			return (EDOM);
-		oldpages = OFF_TO_IDX(round_page(sc->mediasize));
-		newpages = OFF_TO_IDX(round_page(mdr->md_mediasize));
+		oldpages = OFF_TO_IDX(sc->mediasize);
+		newpages = OFF_TO_IDX(mdr->md_mediasize);
 		if (newpages < oldpages) {
 			VM_OBJECT_WLOCK(sc->object);
 			vm_object_page_remove(sc->object, newpages, 0, 0);