Merging upstream version 4.19.282.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 11 insertions, 5 deletions

diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c
index 7be064758..a40739ea3 100644
--- a/arch/s390/mm/maccess.c
+++ b/arch/s390/mm/maccess.c
@@ -58,13 +58,19 @@ static notrace long s390_kernel_write_odd(void *dst, const void *src, size_t siz
  */
 void notrace s390_kernel_write(void *dst, const void *src, size_t size)
 {
+	unsigned long flags;
 	long copied;
 
-	while (size) {
-		copied = s390_kernel_write_odd(dst, src, size);
-		dst += copied;
-		src += copied;
-		size -= copied;
+	flags = arch_local_save_flags();
+	if (!(flags & PSW_MASK_DAT)) {
+		memcpy(dst, src, size);
+	} else {
+		while (size) {
+			copied = s390_kernel_write_odd(dst, src, size);
+			dst += copied;
+			src += copied;
+			size -= copied;
+		}
 	}
 }