From: Nathaniel Wesley Filardo <nwf@cs.jhu.edu>
Date: Wed, 11 Nov 2015 04:38:27 +0000 (-0500)
Subject: umalloc: poison frees
X-Git-Url: https://hydra-www.ietfng.org/gitweb/?a=commitdiff_plain;h=53a55eacddac88ffa3e14125d8f3491147291fdc;p=xv6-public

umalloc: poison frees
---

diff --git a/umalloc.c b/umalloc.c
index a7e7d2c..ee339d5 100644
--- a/umalloc.c
+++ b/umalloc.c
@@ -30,6 +30,7 @@ free(void *ap)
   for(p = freep; !(bp > p && bp < p->s.ptr); p = p->s.ptr)
     if(p >= p->s.ptr && (bp > p || bp < p->s.ptr))
       break;
+  memset(ap, 0xDE, bp->s.size);
   if(bp + bp->s.size == p->s.ptr){
     bp->s.size += p->s.ptr->s.size;
     bp->s.ptr = p->s.ptr->s.ptr;