X-Git-Url: https://git.ozlabs.org/?a=blobdiff_plain;f=ccan%2Fmem%2Fmem.c;h=13027a2a7b0fec1b18ae386f9704d84aed41c5f1;hb=870b63169c782ef0cc52687397e5b9a7125a61b0;hp=5eb15070ed3c3f9f5bf8d2dd8b0d0f060ffa1766;hpb=6e5c2f3f55d4e537ccc69703cc41a4295afcd170;p=ccan

diff --git a/ccan/mem/mem.c b/ccan/mem/mem.c
index 5eb15070..13027a2a 100644
--- a/ccan/mem/mem.c
+++ b/ccan/mem/mem.c
@@ -107,3 +107,22 @@ bool memeqzero(const void *data, size_t length)
 	/* Now we know that's zero, memcmp with self. */
 	return memcmp(data, p, length) == 0;
 }
+
+void memtaint(void *data, size_t len)
+{
+	/* Using 16 bytes is a bit quicker than 4 */
+	const unsigned tainter[]
+		= { 0xdeadbeef, 0xdeadbeef, 0xdeadbeef, 0xdeadbeef };
+	char *p = data;
+
+	while (len >= sizeof(tainter)) {
+		memcpy(p, tainter, sizeof(tainter));
+		p += sizeof(tainter);
+		len -= sizeof(tainter);
+	}
+	memcpy(p, tainter, len);
+
+#if HAVE_VALGRIND_MEMCHECK_H
+	VALGRIND_MAKE_MEM_UNDEFINED(data, len);
+#endif
+}