gistfile1.h

static void
create_sigstack()
{
  stack_t ss;
  ss.ss_size = SIGSTKSZ;
  ss.ss_sp = malloc(ss.ss_size);
  ss.ss_flags = 0;
  if (sigaltstack(&ss, NULL) < 0) {
    free(ss.ss_sp);
    fprintf(stderr, "Couldn't create signal stack! Error %d: %s\n", errno, strerror(errno));
    exit(1);
  }
}