diff --git a/arch/arm/arm/src/los_arch_mmu.c b/arch/arm/arm/src/los_arch_mmu.c
index 39ef435f..edb22e47 100644
--- a/arch/arm/arm/src/los_arch_mmu.c
+++ b/arch/arm/arm/src/los_arch_mmu.c
@@ -892,9 +892,9 @@ STATIC VOID OsSetKSectionAttr(UINTPTR virtAddr, BOOL uncached)
     length = sizeof(mmuKernelMappings) / sizeof(LosArchMmuInitMapping);
     for (i = 0; i < length; i++) {
         kernelMap = &mmuKernelMappings[i];
-	if (uncached) {
-	    flags |= VM_MAP_REGION_FLAG_UNCACHED;
-	}
+        if (uncached) {
+            kernelMap->flags |= VM_MAP_REGION_FLAG_UNCACHED;
+        }
         status = LOS_ArchMmuMap(&kSpace->archMmu, kernelMap->virt, kernelMap->phys,
                                  kernelMap->size >> MMU_DESCRIPTOR_L2_SMALL_SHIFT, kernelMap->flags);
         if (status != (kernelMap->size >> MMU_DESCRIPTOR_L2_SMALL_SHIFT)) {
diff --git a/kernel/base/vm/los_vm_map.c b/kernel/base/vm/los_vm_map.c
index 3f4010c9..95242796 100644
--- a/kernel/base/vm/los_vm_map.c
+++ b/kernel/base/vm/los_vm_map.c
@@ -238,34 +238,6 @@ STATIC BOOL OsVmSpaceParamCheck(LosVmSpace *vmSpace)
     return TRUE;
 }
 
-LosVmMapRegion *OsShareRegionClone(LosVmMapRegion *oldRegion)
-{
-    /* no need to create vm object */
-    LosVmMapRegion *newRegion = LOS_MemAlloc(m_aucSysMem0, sizeof(LosVmMapRegion));
-    if (newRegion == NULL) {
-        VM_ERR("malloc new region struct failed.");
-        return NULL;
-    }
-
-    /* todo: */
-    *newRegion = *oldRegion;
-    return newRegion;
-}
-
-LosVmMapRegion *OsPrivateRegionClone(LosVmMapRegion *oldRegion)
-{
-    /* need to create vm object */
-    LosVmMapRegion *newRegion = LOS_MemAlloc(m_aucSysMem0, sizeof(LosVmMapRegion));
-    if (newRegion == NULL) {
-        VM_ERR("malloc new region struct failed.");
-        return NULL;
-    }
-
-    /* todo: */
-    *newRegion = *oldRegion;
-    return newRegion;
-}
-
 STATUS_T LOS_VmSpaceClone(LosVmSpace *oldVmSpace, LosVmSpace *newVmSpace)
 {
     LosVmMapRegion *oldRegion = NULL;
@@ -840,11 +812,6 @@ STATUS_T OsIsRegionCanExpand(LosVmSpace *space, LosVmMapRegion *region, size_t s
         return LOS_NOK;
     }
 
-    /* if next node is head, then we can expand */
-    if (OsIsVmRegionEmpty(space) == TRUE) {
-        return LOS_OK;
-    }
-
     nextRegion = (LosVmMapRegion *)LOS_RbSuccessorNode(&space->regionRbTree, &region->rbNode);
     /* if the gap is larger than size, then we can expand */
     if ((nextRegion != NULL) && ((nextRegion->range.base - region->range.base) >= size)) {