X-Git-Url: https://git.ozlabs.org/?a=blobdiff_plain;f=ccan%2Fmem%2Fmem.c;h=13027a2a7b0fec1b18ae386f9704d84aed41c5f1;hb=ee77e470b467cf85dc533cee8c08e08bd4c9be06;hp=af41f9e011edbc6738667c3fc89d9d043b1dbcf6;hpb=b967dac8c71a2313c39910ef8ca0e1644fe178c0;p=ccan

diff --git a/ccan/mem/mem.c b/ccan/mem/mem.c
index af41f9e0..13027a2a 100644
--- a/ccan/mem/mem.c
+++ b/ccan/mem/mem.c
@@ -92,13 +92,37 @@ void memswap(void *a, void *b, size_t n)
 bool memeqzero(const void *data, size_t length)
 {
 	const unsigned char *p = data;
-	static unsigned long zeroes[16];
+	size_t len;
 
-	while (length > sizeof(zeroes)) {
-		if (memcmp(zeroes, p, sizeof(zeroes)))
+	/* Check first 16 bytes manually */
+	for (len = 0; len < 16; len++) {
+		if (!length)
+			return true;
+		if (*p)
 			return false;
-		p += sizeof(zeroes);
-		length -= sizeof(zeroes);
+		p++;
+		length--;
 	}
-	return memcmp(zeroes, p, length) == 0;
+
+	/* 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
 }