From 67a7f9597e187dad3dfd9732461fec2de6edbba1 Mon Sep 17 00:00:00 2001
From: MikeCAT <mikecat@users.noreply.github.com>
Date: Sat, 19 Dec 2015 23:43:56 +0900
Subject: [PATCH] add alignment check of virtual address to exec()

---
 exec.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/exec.c b/exec.c
index 8dbbdb6..e5d1816 100644
--- a/exec.c
+++ b/exec.c
@@ -46,6 +46,8 @@ exec(char *path, char **argv)
       goto bad;
     if((sz = allocuvm(pgdir, sz, ph.vaddr + ph.memsz)) == 0)
       goto bad;
+    if(ph.vaddr % PGSIZE != 0)
+      goto bad;
     if(loaduvm(pgdir, (char*)ph.vaddr, ip, ph.off, ph.filesz) < 0)
       goto bad;
   }