 is Linux-kernel specific)
   • poll

As well as any calls needed for memory allocation to work.  Note
however, that GnuTLS depends on libc for the system calls, and there is
no guarantee that libc will call the expected system call.  For that it
is recommended to test your program in all the targeted platforms when
filters like seccomp are in place.

An example with a seccomp filter from GnuTLS' test suite is at:
<https://gitlab.com/gnutls/gnutls/blob/master/tests/seccomp.c>.

