[RFC nf-next v5 0/2] netfilter: bpf: support prog update

["D. Wythe" <alibuda@linux.alibaba.com>]

From: "D. Wythe" <alibuda@linux.alibaba.com>

This patches attempt to implements updating of progs within
bpf netfilter link, allowing user update their ebpf netfilter
prog in hot update manner.

Besides, a corresponding test case has been added to verify
whether the update works.
--
v1:
1. remove unnecessary context, access the prog directly via rcu.
2. remove synchronize_rcu(), dealloc the nf_link via kfree_rcu.
3. check the dead flag during the update.
--
v1->v2:
1. remove unnecessary nf_prog, accessing nf_link->link.prog in direct.
--
v2->v3:
1. access nf_link->link.prog via rcu_dereference_raw to avoid warning.
--
v3->v4:
1. remove mutex for link update, as it is unnecessary and can be replaced
by atomic operations.
--
v4->v5:
1. fix error retval check on cmpxhcg

D. Wythe (2):
  netfilter: bpf: support prog update
  selftests/bpf: Add netfilter link prog update test

 net/netfilter/nf_bpf_link.c                        | 50 ++++++++-----
 .../bpf/prog_tests/netfilter_link_update_prog.c    | 83 ++++++++++++++++++++++
 .../bpf/progs/test_netfilter_link_update_prog.c    | 24 +++++++
 3 files changed, 141 insertions(+), 16 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/netfilter_link_update_prog.c
 create mode 100644 tools/testing/selftests/bpf/progs/test_netfilter_link_update_prog.c

-- 
1.8.3.1