diff options
| author | Jakub Sitnicki <jakub@cloudflare.com> | 2020-05-31 10:28:35 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-06-01 15:21:02 -0700 |
| commit | 171526f6fee84de0c39e2b7aa7e666ba0bbfd173 (patch) | |
| tree | 1ac0a09641c79cee0e5800c3557ba5c63320b91b /net/core | |
| parent | febeb6dff7beafcaf89521f6c8ff7b0adac08d54 (diff) | |
| download | linux-171526f6fee84de0c39e2b7aa7e666ba0bbfd173.tar.bz2 | |
flow_dissector: Pull locking up from prog attach callback
Split out the part of attach callback that happens with attach/detach lock
acquired. This structures the prog attach callback in a way that opens up
doors for moving the locking out of flow_dissector and into generic
callbacks for attaching/detaching progs to netns in subsequent patches.
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20200531082846.2117903-2-jakub@cloudflare.com
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/flow_dissector.c | 40 |
1 files changed, 20 insertions, 20 deletions
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index 0aeb33572feb..b64a44a083fd 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -109,15 +109,10 @@ int skb_flow_dissector_prog_query(const union bpf_attr *attr, return 0; } -int skb_flow_dissector_bpf_prog_attach(const union bpf_attr *attr, - struct bpf_prog *prog) +static int flow_dissector_bpf_prog_attach(struct net *net, + struct bpf_prog *prog) { struct bpf_prog *attached; - struct net *net; - int ret = 0; - - net = current->nsproxy->net_ns; - mutex_lock(&flow_dissector_mutex); if (net == &init_net) { /* BPF flow dissector in the root namespace overrides @@ -130,33 +125,38 @@ int skb_flow_dissector_bpf_prog_attach(const union bpf_attr *attr, for_each_net(ns) { if (ns == &init_net) continue; - if (rcu_access_pointer(ns->flow_dissector_prog)) { - ret = -EEXIST; - goto out; - } + if (rcu_access_pointer(ns->flow_dissector_prog)) + return -EEXIST; } } else { /* Make sure root flow dissector is not attached * when attaching to the non-root namespace. */ - if (rcu_access_pointer(init_net.flow_dissector_prog)) { - ret = -EEXIST; - goto out; - } + if (rcu_access_pointer(init_net.flow_dissector_prog)) + return -EEXIST; } attached = rcu_dereference_protected(net->flow_dissector_prog, lockdep_is_held(&flow_dissector_mutex)); - if (attached == prog) { + if (attached == prog) /* The same program cannot be attached twice */ - ret = -EINVAL; - goto out; - } + return -EINVAL; + rcu_assign_pointer(net->flow_dissector_prog, prog); if (attached) bpf_prog_put(attached); -out: + return 0; +} + +int skb_flow_dissector_bpf_prog_attach(const union bpf_attr *attr, + struct bpf_prog *prog) +{ + int ret; + + mutex_lock(&flow_dissector_mutex); + ret = flow_dissector_bpf_prog_attach(current->nsproxy->net_ns, prog); mutex_unlock(&flow_dissector_mutex); + return ret; } |