bpf: Add seccomp program type

This patchset introduces seccomp program type which can be
used to attach to the existing seccomp framework.

The motivation is to enable sharing of seccomp filter through
bpf prog fd and bpffs. With this in place, we can eliminate
a hot path of JITing cBPF program (seccomp filter) where we apply
the same seccomp filter to thousands of micro VMs on a bare metal
instance.

This also allows us to write seccomp filter in an intuitive way,
see selftests for reference.

Hengqi Chen (6):
  bpf: Introduce BPF_PROG_TYPE_SECCOMP
  bpf: Add test_run support for seccomp program type
  seccomp: Refactor filter copy/create for reuse
  seccomp: Support attaching BPF_PROG_TYPE_SECCOMP progs
  selftests/bpf: Add seccomp verifier tests
  selftests/bpf: Test BPF_PROG_TYPE_SECCOMP

 include/linux/bpf.h                           |   3 +
 include/linux/bpf_types.h                     |   4 +
 include/linux/seccomp.h                       |   3 +-
 include/uapi/linux/bpf.h                      |   1 +
 include/uapi/linux/seccomp.h                  |   2 +
 kernel/seccomp.c                              | 142 ++++++++++++++--
 net/bpf/test_run.c                            |  27 +++
 tools/include/uapi/linux/bpf.h                |   1 +
 tools/include/uapi/linux/seccomp.h            |   2 +
 tools/lib/bpf/libbpf.c                        |   2 +
 tools/lib/bpf/libbpf_probes.c                 |   1 +
 .../selftests/bpf/prog_tests/seccomp.c        |  40 +++++
 .../selftests/bpf/prog_tests/verifier.c       |   2 +
 .../selftests/bpf/progs/test_seccomp.c        |  24 +++
 .../selftests/bpf/progs/verifier_seccomp.c    | 154 ++++++++++++++++++
 15 files changed, 390 insertions(+), 18 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/seccomp.c
 create mode 100644 tools/testing/selftests/bpf/progs/test_seccomp.c
 create mode 100644 tools/testing/selftests/bpf/progs/verifier_seccomp.c

-- 
2.34.1