bpf: introduce BPF_PROG_QUERY command
introduce BPF_PROG_QUERY command to retrieve a set of either
attached programs to given cgroup or a set of effective programs
that will execute for events within a cgroup
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
for cgroup bits
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 6b49e19..eba966c 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -1412,6 +1412,44 @@ void bpf_prog_array_free(struct bpf_prog_array __rcu *progs)
kfree_rcu(progs, rcu);
}
+int bpf_prog_array_length(struct bpf_prog_array __rcu *progs)
+{
+ struct bpf_prog **prog;
+ u32 cnt = 0;
+
+ rcu_read_lock();
+ prog = rcu_dereference(progs)->progs;
+ for (; *prog; prog++)
+ cnt++;
+ rcu_read_unlock();
+ return cnt;
+}
+
+int bpf_prog_array_copy_to_user(struct bpf_prog_array __rcu *progs,
+ __u32 __user *prog_ids, u32 cnt)
+{
+ struct bpf_prog **prog;
+ u32 i = 0, id;
+
+ rcu_read_lock();
+ prog = rcu_dereference(progs)->progs;
+ for (; *prog; prog++) {
+ id = (*prog)->aux->id;
+ if (copy_to_user(prog_ids + i, &id, sizeof(id))) {
+ rcu_read_unlock();
+ return -EFAULT;
+ }
+ if (++i == cnt) {
+ prog++;
+ break;
+ }
+ }
+ rcu_read_unlock();
+ if (*prog)
+ return -ENOSPC;
+ return 0;
+}
+
static void bpf_prog_free_deferred(struct work_struct *work)
{
struct bpf_prog_aux *aux;