From 6f9c911ebe998d4b464f091140664ff556e2829c Mon Sep 17 00:00:00 2001
From: Themis Demetriades <td1223@ic.ac.uk>
Date: Mon, 4 Nov 2024 00:19:36 +0000
Subject: [PATCH] Update start_process to pad process stack before pushing argv
 elements for performance

---
 src/userprog/process.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/userprog/process.c b/src/userprog/process.c
index ffd964b..452f020 100644
--- a/src/userprog/process.c
+++ b/src/userprog/process.c
@@ -118,6 +118,10 @@ start_process (void *file_name_)
       /* TODO: Allocate an extra page for the rest of the process stack. */
     }
 
+  /* Align stack pointer to word size before pushing argv elements for
+     performance. */
+  if_.esp -= align_size * sizeof (uint8_t);
+  
   /* Push pointers to process arguments from argument linked list */
   struct list_elem *e = list_begin (&arg_list);
   struct list_elem *tail = list_tail (&arg_list);