diff options
| author | Jakub Sitnicki <jakub@cloudflare.com> | 2020-06-25 16:13:54 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-06-30 19:45:07 +0200 |
| commit | 3b7016996c4c44db5d499d98759b82fb714bb912 (patch) | |
| tree | c2b829b6dbc79ae9646900dbf55e8ea68d847ca8 /kernel/bpf/net_namespace.c | |
| parent | bpf: Enforce BPF ringbuf size to be the power of 2 (diff) | |
| download | linux-3b7016996c4c44db5d499d98759b82fb714bb912.tar.xz linux-3b7016996c4c44db5d499d98759b82fb714bb912.zip | |
flow_dissector: Pull BPF program assignment up to bpf-netns
Prepare for using bpf_prog_array to store attached programs by moving out
code that updates the attached program out of flow dissector.
Managing bpf_prog_array is more involved than updating a single bpf_prog
pointer. This will let us do it all from one place, bpf/net_namespace.c, in
the subsequent patch.
No functional change intended.
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200625141357.910330-2-jakub@cloudflare.com
Diffstat (limited to 'kernel/bpf/net_namespace.c')
| -rw-r--r-- | kernel/bpf/net_namespace.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/kernel/bpf/net_namespace.c b/kernel/bpf/net_namespace.c index 78cf061f8179..b951dab2687f 100644 --- a/kernel/bpf/net_namespace.c +++ b/kernel/bpf/net_namespace.c @@ -189,6 +189,7 @@ int netns_bpf_prog_query(const union bpf_attr *attr, int netns_bpf_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog) { enum netns_bpf_attach_type type; + struct bpf_prog *attached; struct net *net; int ret; @@ -207,12 +208,26 @@ int netns_bpf_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog) switch (type) { case NETNS_BPF_FLOW_DISSECTOR: - ret = flow_dissector_bpf_prog_attach(net, prog); + ret = flow_dissector_bpf_prog_attach_check(net, prog); break; default: ret = -EINVAL; break; } + if (ret) + goto out_unlock; + + attached = rcu_dereference_protected(net->bpf.progs[type], + lockdep_is_held(&netns_bpf_mutex)); + if (attached == prog) { + /* The same program cannot be attached twice */ + ret = -EINVAL; + goto out_unlock; + } + rcu_assign_pointer(net->bpf.progs[type], prog); + if (attached) + bpf_prog_put(attached); + out_unlock: mutex_unlock(&netns_bpf_mutex); @@ -277,7 +292,7 @@ static int netns_bpf_link_attach(struct net *net, struct bpf_link *link, switch (type) { case NETNS_BPF_FLOW_DISSECTOR: - err = flow_dissector_bpf_prog_attach(net, link->prog); + err = flow_dissector_bpf_prog_attach_check(net, link->prog); break; default: err = -EINVAL; @@ -286,6 +301,7 @@ static int netns_bpf_link_attach(struct net *net, struct bpf_link *link, if (err) goto out_unlock; + rcu_assign_pointer(net->bpf.progs[type], link->prog); net->bpf.links[type] = link; out_unlock: |