On Tue, Jun 10, 2014 at 8:25 PM, Kees Cook [off-list ref] wrote:

This adds the new "seccomp" syscall with both an "operation" and "flags"
parameter for future expansion. The third argument is a pointer value,
used with the SECCOMP_SET_MODE_FILTER operation. Currently, flags must
be 0. This is functionally equivalent to prctl(PR_SET_SECCOMP, ...).

Question for the linux-abi people:

What's the preferred way to do this these days?  This syscall is a
general purpose "adjust the seccomp state" thing.  The alternative
would be a specific new syscall to add a filter with a flags argument.

--Andy