From: Ben Pfaff <blp@cs.stanford.edu>
Date: Mon, 25 Oct 2004 23:39:46 +0000 (+0000)
Subject: Add some more correctness assertions to free().
X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e49798d967361536af9339202a3306fe1347d93f;p=pintos-anon

Add some more correctness assertions to free().
(I did some basic testing on this.)
---

diff --git a/src/threads/malloc.c b/src/threads/malloc.c
index 487e938..2077354 100644
--- a/src/threads/malloc.c
+++ b/src/threads/malloc.c
@@ -228,8 +228,16 @@ static struct arena *
 block_to_arena (struct block *b)
 {
   struct arena *a = pg_round_down (b);
+
+  /* Check that the arena is valid. */
   ASSERT (a != NULL);
   ASSERT (a->magic == ARENA_MAGIC);
+
+  /* Check that the block is properly aligned for the arena. */
+  ASSERT (a->desc == NULL
+          || (pg_ofs (b) - sizeof *a) % a->desc->block_size == 0);
+  ASSERT (a->desc != NULL || pg_ofs (b) == sizeof *a);
+
   return a;
 }