libc {
  GLIBC_PRIVATE {
    __vdso_get_tbfreq;
    __vdso_clock_gettime;
    __vdso_clock_getres;
    __vdso_getcpu;
    __vdso_time;
  }
}
libm {
  GLIBC_2.19 {
  }
}
libpthread {
  GLIBC_2.6 {
    __libpthread_version_placeholder;
  }
}