Reworked strlen and strnlen to look at four bytes at the time. From what I understand this should be safe.

Based on info from bit twiddling hacks: http://graphics.stanford.edu/~seander/bithacks.html

src/system/libroot/posix/string/strlen.c

@@ -3,18 +3,33 @@
 ** Distributed under the terms of the NewOS License.
 */
 
-#include <sys/types.h>
 #include <string.h>
+#include <SupportDefs.h>
 
+// From Bit twiddling hacks: http://graphics.stanford.edu/~seander/bithacks.html
+#define hasZeroByte(value) (value - 0x01010101) & ~value & 0x80808080
 
 size_t
 strlen(char const *s)
 {
 	size_t i = 0;
+	uint32 *value;
 
-	while (s[i]) {
-		i += 1;
+	//Make sure we use aligned access
+	while (((uint32) s + i) & 3) {
+		if (!s[i]) return i;
+		i++;
 	}
 
+	//Check four bytes at once
+	value = (uint32 *) (s + i);
+	while (!(hasZeroByte(*value)))
+		value++;
+
+	//Find the exact length
+	i = ((char *) value) - s;
+	while (s[i])
+		i++;
+
 	return i;
 }

src/system/libroot/posix/string/strnlen.c

@@ -3,16 +3,36 @@
 ** Distributed under the terms of the NewOS License.
 */
 
-#include <sys/types.h>
 #include <string.h>
+#include <SupportDefs.h>
 
 
+// From Bit twiddling hacks: http://graphics.stanford.edu/~seander/bithacks.html
+#define hasZeroByte(value) (value - 0x01010101) & ~value & 0x80808080
+
 size_t
 strnlen(char const *s, size_t count)
 {
-	const char *sc;
+	size_t i = 0;
+	uint32 *value;
 
-	for (sc = s; count-- && *sc != '\0'; ++sc)
-		;
-	return sc - s;
+	//Make sure we use aligned access
+	while (((uint32) s + i) & 3) {
+		if (i == count || !s[i]) return i;
+		i++;
+	}
+
+
+	const uint32 * end = (uint32 *) s + count;
+	//Check four bytes at once
+	value = (uint32 *) (s + i);
+	while (value < end && !(hasZeroByte(*value)) )
+		value++;
+
+	//Find the exact length
+	i = ((char *) value) - s;
+	while (s[i] && i < count )
+		i++;
+
+	return i;
 }