Merge tag 'kvm-s390-next-6.4-2' of https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

For 6.4

1 files changed, 11 insertions, 21 deletions

diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index 9f18a4af9c13..cb2ee06df286 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -192,21 +192,10 @@ static int expected_page_refs(struct page *page)
 	return res;
 }
 
-static int make_secure_pte(pte_t *ptep, unsigned long addr,
-			   struct page *exp_page, struct uv_cb_header *uvcb)
+static int make_page_secure(struct page *page, struct uv_cb_header *uvcb)
 {
-	pte_t entry = READ_ONCE(*ptep);
-	struct page *page;
 	int expected, cc = 0;
 
-	if (!pte_present(entry))
-		return -ENXIO;
-	if (pte_val(entry) & _PAGE_INVALID)
-		return -ENXIO;
-
-	page = pte_page(entry);
-	if (page != exp_page)
-		return -ENXIO;
 	if (PageWriteback(page))
 		return -EAGAIN;
 	expected = expected_page_refs(page);
@@ -304,17 +293,18 @@ again:
 		goto out;
 
 	rc = -ENXIO;
-	page = follow_page(vma, uaddr, FOLL_WRITE);
-	if (IS_ERR_OR_NULL(page))
-		goto out;
-
-	lock_page(page);
 	ptep = get_locked_pte(gmap->mm, uaddr, &ptelock);
-	if (should_export_before_import(uvcb, gmap->mm))
-		uv_convert_from_secure(page_to_phys(page));
-	rc = make_secure_pte(ptep, uaddr, page, uvcb);
+	if (pte_present(*ptep) && !(pte_val(*ptep) & _PAGE_INVALID) && pte_write(*ptep)) {
+		page = pte_page(*ptep);
+		rc = -EAGAIN;
+		if (trylock_page(page)) {
+			if (should_export_before_import(uvcb, gmap->mm))
+				uv_convert_from_secure(page_to_phys(page));
+			rc = make_page_secure(page, uvcb);
+			unlock_page(page);
+		}
+	}
 	pte_unmap_unlock(ptep, ptelock);
-	unlock_page(page);
 out:
 	mmap_read_unlock(gmap->mm);