[freelist] valgrindify freed blocks

Mark freed blocks as unaccessible upon free() and then as undefined
on alloc().

1 files changed, 22 insertions, 4 deletions

diff --git a/src/cairo-freelist.c b/src/cairo-freelist.c
index 3887f4b5f..e39a01e4a 100644
--- a/src/cairo-freelist.c
+++ b/src/cairo-freelist.c
@@ -24,10 +24,17 @@
 
 #include "cairo-freelist-private.h"
 
+#if HAVE_VALGRIND
+#include <memcheck.h>
+#define VG(x) x
+#else
+#define VG(x)
+#endif
+
 void
 _cairo_freelist_init (cairo_freelist_t *freelist, unsigned nodesize)
 {
-    memset (freelist, 0, sizeof(cairo_freelist_t));
+    memset (freelist, 0, sizeof (cairo_freelist_t));
     freelist->nodesize = nodesize;
 }
 
@@ -36,7 +43,11 @@ _cairo_freelist_fini (cairo_freelist_t *freelist)
 {
     cairo_freelist_node_t *node = freelist->first_free_node;
     while (node) {
-	cairo_freelist_node_t *next = node->next;
+	cairo_freelist_node_t *next;
+
+	VG (VALGRIND_MAKE_MEM_DEFINED (node, sizeof (node->next)));
+	next = node->next;
+
 	free (node);
 	node = next;
     }
@@ -46,10 +57,16 @@ void *
 _cairo_freelist_alloc (cairo_freelist_t *freelist)
 {
     if (freelist->first_free_node) {
-	cairo_freelist_node_t *node = freelist->first_free_node;
+	cairo_freelist_node_t *node;
+
+	node = freelist->first_free_node;
+	VG (VALGRIND_MAKE_MEM_DEFINED (node, sizeof (node->next)));
 	freelist->first_free_node = node->next;
-	return (void*)node;
+	VG (VALGRIND_MAKE_MEM_UNDEFINED (node, freelist->nodesize));
+
+	return node;
     }
+
     return malloc (freelist->nodesize);
 }
 
@@ -69,5 +86,6 @@ _cairo_freelist_free (cairo_freelist_t *freelist, void *voidnode)
     if (node) {
 	node->next = freelist->first_free_node;
 	freelist->first_free_node = node;
+	VG (VALGRIND_MAKE_MEM_NOACCESS (node, freelist->nodesize));
     }
 }