strncpy case fails in kernel space.

test_strncpy (void)
{
  ...        

  (void) strcpy (one, "abcdefgh");
  (void) strncpy (one, "xyz", 5);               /* Copy includes padding. */
  equal (one, "xyz", 7);
  equal (one+4, "", 8);
  equal (one+5, "fgh", 9);

  (void) strcpy (one, "abc");
  (void) strncpy (one, "xyz", 0);               /* Zero-length copy. */
  equal (one, "abc", 10);

  (void) strncpy (one, "", 2);          /* Zero-length source. */
  equal (one, "", 11);
  equal (one+1, "", 12);
  equal (one+2, "c", 13);

 ...
}

root:/proc/sys/kernel> insmod /lib/modules/string_test.ko
strncpy flunked test 8
strncpy flunked test 12