Cleanup if allocuvm fails to alloc. Add a test.

1 files changed, 2 insertions, 1 deletions

diff --git a/vm.c b/vm.c
index 8a57ca9..95eeca8 100644
--- a/vm.c
+++ b/vm.c
@@ -195,7 +195,8 @@ allocuvm(pde_t *pgdir, char *addr, uint sz)
     if(pte == 0 || (*pte & PTE_P) == 0){
       char *mem = kalloc();
       if(mem == 0){
-        // XXX clean up?
+        cprintf("allocuvm out of memory\n");
+        deallocuvm(pgdir, addr, sz);
         return 0;
       }
       memset(mem, 0, PGSIZE);