ref: 562d1ccf077427d1bdcde77eeb1eaddaba2a60b2
dir: /sys/src/libc/port/strdup.c/
#include <u.h>
#include <libc.h>
char*
strdup(char *s)
{
	char *ns;
	ns = malloc(strlen(s) + 1);
	if(ns == 0)
		return 0;
	setmalloctag(ns, getcallerpc(&s));
	return strcpy(ns, s);
}