#include <sys/time.h>

  #include <signal.h>

  #include <unistd.h>

  

  static void Handler(int ignore)

  {

   char fpubuf[108];

   __asm__ __volatile__ ("fsave %0\n" : : "m"(fpubuf));

   write(2, "*", 1);

   __asm__ __volatile__ ("frstor %0\n" : : "m"(fpubuf));

  }

  

  int main(int argc, char *argv[])

  {

   struct itimerval spec;

   signal(SIGALRM, Handler);

   spec.it_interval.tv_sec=0;

   spec.it_interval.tv_usec=100;

   spec.it_value.tv_sec=0;

   spec.it_value.tv_usec=100;

   setitimer(ITIMER_REAL, &spec, NULL);

   while(1)

    write(1, ".", 1);

  

   return 0;

  }

'Nuff said.

(Couldn't entirely follow the diagnosis. A problem with the FPU exception handler. Link.)