diff --git a/arch/loongarch/mm/mmap.c b/arch/loongarch/mm/mmap.c
index a9630a81b38abbfc575ea4174af049ccd5a9a888..d3de4fd77c72495a35478fb928e93d7c13b49adb 100644
--- a/arch/loongarch/mm/mmap.c
+++ b/arch/loongarch/mm/mmap.c
@@ -8,6 +8,8 @@
 #include <linux/mm.h>
 #include <linux/mman.h>
 
+unsigned long shm_align_mask = PAGE_SIZE - 1;  /* Sane caches */
+EXPPORT_SYMBOL(shm_align_mask);
 #define SHM_ALIGN_MASK	(SHMLBA - 1)
 
 #define COLOUR_ALIGN(addr, pgoff)			\