--- a/src/impl/vm_impl.cbc	Thu Jan 23 21:24:30 2020 +0900
+++ b/src/impl/vm_impl.cbc	Fri Jan 24 14:45:38 2020 +0900
@@ -26,6 +26,8 @@
     vm_impl->sz  = 0;
     vm_impl->loaduvm_ptesize_check = C_loaduvm_ptesize_checkvm_impl;
     vm_impl->loaduvm_loop = C_loaduvm_loopvm_impl;
+    vm_impl->allocuvm_check_newsz = C_allocuvm_check_newszvm_impl;
+    vm_impl->allocuvm_loop = C_allocuvm_loopvm_impl;
     vm->init_vmm = C_init_vmmvm_impl;
     vm->kpt_freerange = C_kpt_freerangevm_impl;
     vm->kpt_alloc = C_kpt_allocvm_impl;
@@ -84,7 +86,7 @@
 }
 
 typedef struct proc proc;
-__code switchuvmvm_impl(struct vm_impl* vm ,struct proc* p, __code next(...)) { //:skip
+__code switchuvmvm_impl(struct vm_impl* vm , struct proc* p, __code next(...)) { //:skip
 
     goto next(...);
 }
@@ -106,7 +108,7 @@
 
 __code allocuvmvm_impl(struct vm_impl* vm, pde_t* pgdir, uint oldsz, uint newsz, __code next(...)) {
 
-    goto next(...);
+    goto allocuvm_check_newszvm_impl(vm, pgdir, oldsz, newsz, next(...));
 }
 
 __code clearpteuvm_impl(struct vm_impl* vm, pde_t* pgdir, char* uva,  __code next(...)) {

--- a/src/impl/vm_impl.h	Thu Jan 23 21:24:30 2020 +0900
+++ b/src/impl/vm_impl.h	Fri Jan 24 14:45:38 2020 +0900
@@ -9,10 +9,16 @@
     uint offset;
     uint pa;
     uint n;
+    uint oldsz;
+    uint newsz;
+    uint a;
+    int ret;
 
     __code kpt_alloc_check_impl(Type* vm_impl, __code next(...));
     __code loaduvm_ptesize_check(Type* vm_impl, __code next(...));
     __code loaduvm_loop(Type* vm_impl, uint i, pte_t* pte, uint sz, __code next(...));
+    __code allocuvm_check_newsz(Type* vm_impl, pde_t* pgdir, uint oldsz, uint newsz, __code next(...));
+    __code allocuvm_loop(Type* vm_impl, pde_t* pgdir, uint oldsz, uint newsz, uint a, __code next(...));
     __code next(...);
  
 

--- a/src/impl/vm_impl_private.cbc	Thu Jan 23 21:24:30 2020 +0900
+++ b/src/impl/vm_impl_private.cbc	Fri Jan 24 14:45:38 2020 +0900
@@ -131,3 +131,27 @@
     memset(r, 0, PT_SZ);
     goto next((char*)r);
 }
+
+__code allocuvm_check_newszvm_impl(struct vm_impl* vm_impl, pde_t* pgdir, uint oldsz, uint newsz, __code next(int ret, ...)){
+    if (newsz >= UADDR_SZ) {
+       goto next(0, ...);
+    }
+
+    if (newsz < oldsz) {
+       ret = newsz;
+       goto next(ret);
+    }
+
+    uint a = align_up(oldsz, PTE_SZ);
+
+    goto allocuvm_loopvm_impl(vm_impl, pgdir, oldsz, newsz, a, next(...));
+}
+
+__code allocuvm_loopvm_impl(struct vm_impl* vm_impl, pde_t* pgdir, uint oldsz, uint newsz, uint a, __code next(...)) {
+
+    if (a < newsz) {
+        goto allocuvm_loopvm_impl(vm_impl, pgdir, oldsz, newsz, a + PTE_SZ, next(...)); 
+    }
+    
+    goto next(newsz);
+}