Refactor: abstract new page allocation to one general function and make helper functions static

src/vm/stackgrowth.c

@@ -7,9 +7,28 @@
 
 #define MAX_STACK_ACCESS_DIST 32
 
-/* Validates a given address for being <=32 bytes away from the stack pointer or
-   above the stack */
-bool needs_new_page (void *addr, void *esp)
+static bool needs_new_page (const void *addr, const void *esp);
+static bool grow_stack (const void *addr);
+
+bool
+try_alloc_new_page (const void *ptr, const void *esp)
+{
+  if (needs_new_page (ptr, esp))
+  {
+    if (!grow_stack (ptr))
+      return 0;
+    else
+      return 1;
+  }
+  else
+    return 0;
+}
+
+/* Validates a given address for being a stack query and not a generic erroneous
+   address
+ */
+static bool
+needs_new_page (const void *addr, const void *esp)
 {
     return (is_user_vaddr (addr) &&
             (uint32_t*)addr >= ((uint32_t*)esp - MAX_STACK_ACCESS_DIST) &&
@@ -18,7 +37,8 @@ bool needs_new_page (void *addr, void *esp)
 }
 
 /* Extends the stack by the necessary number of pages */
-bool grow_stack (void *addr)
+static bool
+grow_stack (const void *addr)
 {
   struct thread *t = thread_current ();
   void *last_page = pg_round_down (addr);
@@ -35,6 +55,4 @@ bool grow_stack (void *addr)
     return false;
   }
   return true;
-
-
 }