diff --git a/mm/mmap.c b/mm/mmap.c
index 339cf5c..e7a5a68 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1030,6 +1030,10 @@
 	} else {
 		switch (flags & MAP_TYPE) {
 		case MAP_SHARED:
+			/*
+			 * Ignore pgoff.
+			 */
+			pgoff = 0;
 			vm_flags |= VM_SHARED | VM_MAYSHARE;
 			break;
 		case MAP_PRIVATE: