Update load_segment to load only the metadata of the pages to the SPT, w/ G

src/userprog/process.c

@@ -705,40 +705,11 @@ load_segment (struct file *file, off_t ofs, uint8_t *upage,
          and zero the final PAGE_ZERO_BYTES bytes. */
       size_t page_read_bytes = read_bytes < PGSIZE ? read_bytes : PGSIZE;
       size_t page_zero_bytes = PGSIZE - page_read_bytes;
-      
-      /* Check if virtual page already allocated */
-      struct thread *t = thread_current ();
-      uint8_t *kpage = pagedir_get_page (t->pagedir, upage);
-      
-      if (kpage == NULL){
-        
-        /* Get a new page of memory. */
-        kpage = get_usr_kpage (0, upage);
-        if (kpage == NULL){
-          return false;
-        }
-        
-        /* Add the page to the process's address space. */
-        if (!install_page (upage, kpage, writable)) 
-        {
-          free_usr_kpage (kpage);
-          return false; 
-        }     
-        
-      } else {
-        
-        /* Check if writable flag for the page should be updated */
-        if(writable && !pagedir_is_writable(t->pagedir, upage)){
-          pagedir_set_writable(t->pagedir, upage, writable); 
-        }
-        
-      }
 
-      /* Load data into the page. */
+      /* Add the page to the SPT */
-      if (file_read (file, kpage, page_read_bytes) != (int) page_read_bytes){
+      if (page_insert (file, ofs, upage, read_bytes, zero_bytes, writable,
-        return false; 
+                       PAGE_EXECUTABLE) == NULL)
-      }
+        return false;
-      memset (kpage + page_read_bytes, 0, page_zero_bytes);
 
       /* Advance. */
       read_bytes -= page_read_bytes;