-LRN: Portable memory poisoning:

  Uses GNU extension function as a non-W32 equivalent of msize()
(there are subtle differences, but they are of no consequence). Also
swaps the poison bits depending on endianness (i'm tired of seeing
0xdf0adba everywhere instead of 0xbaadf00d).

diff --git a/src/util/common_allocation.c b/src/util/common_allocation.c
index c86185685ddbf74aeb5b76ada7f0c4abd4d30fca..a385450b944abd2e353fa253fa8e275c499c0f63 100644 (file)
--- a/src/util/common_allocation.c
+++ b/src/util/common_allocation.c
@@ -182,6 +182,24 @@ GNUNET_xrealloc_ (void *ptr, size_t n, const char *filename, int linenumber)
 }
 
 
+# if __BYTE_ORDER == __LITTLE_ENDIAN
+#define BAADFOOD_STR "\x0D\xF0\xAD\xBA"
+#endif
+# if __BYTE_ORDER == __BIG_ENDIAN
+#define BAADFOOD_STR "\xBA\xAD\xF0\x0D"
+#endif
+
+#if WINDOWS
+#define MSIZE(p) _msize (p)
+#endif
+#if LINUX
+/* FIXME: manpage claims that this function is a GNU extension,
+ * but googling shows that it is available on many platforms via
+ * inclusion of various headers. For now let's make it Linux-only.
+ */
+#define MSIZE(p) malloc_usable_size (p)
+#endif
+
 /**
  * Free memory. Merely a wrapper for the case that we
  * want to keep track of allocations.
@@ -198,12 +216,12 @@ GNUNET_xfree_ (void *ptr, const char *filename, int linenumber)
   ptr = &((size_t *) ptr)[-1];
   mem_used -= *((size_t *) ptr);
 #endif
-#if WINDOWS
+#if defined(MSIZE)
 #if ENABLE_POISONING
   {
     size_t i;
-    char baadfood[4] = "\xBA\xAD\xF0\x0D";
-    size_t s = _msize (ptr);
+    char baadfood[5] = BAADFOOD_STR;
+    size_t s = MSIZE (ptr);
     for (i = 0; i < s; i++)
       ((char *) ptr)[i] = baadfood[i % 4];
   }