On Fri, 2013-06-28 at 14:05 +0200, Daniel Borkmann wrote:

+static noinline_for_stack
+char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
+			 struct printf_spec spec, const char *fmt)
+{
+	bool have_p = (fmt[2] && fmt[2] == 'p');

	bool have_p = fmt[2] == 'p';

you don't need the first "fmt[2] &&"
but I can imagine a case where the other flow/scope types
could be specified generically and the 'p' may not be in
array index 2

I think you should probably do the same while loop like
the ip6_addr_string_sa block.