bpf: offload: free prog->aux->offload when device disappears

All bpf offload operations should now be under bpf_devs_lock,
it's safe to free and clear the entire offload structure,
not only the netdev pointer.

__bpf_prog_offload_destroy() will no longer be called multiple
times.

Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Jakub Kicinski 2017-12-27 18:39:06 -08:00 committed by Daniel Borkmann
parent cae1927c0b
commit ce3b9db4db

View File

@ -70,12 +70,14 @@ int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr)
static int __bpf_offload_ndo(struct bpf_prog *prog, enum bpf_netdev_command cmd,
struct netdev_bpf *data)
{
struct net_device *netdev = prog->aux->offload->netdev;
struct bpf_dev_offload *offload = prog->aux->offload;
struct net_device *netdev;
ASSERT_RTNL();
if (!netdev)
if (!offload)
return -ENODEV;
netdev = offload->netdev;
if (!netdev->netdev_ops->ndo_bpf)
return -EOPNOTSUPP;
@ -111,7 +113,7 @@ int bpf_prog_offload_verify_insn(struct bpf_verifier_env *env,
down_read(&bpf_devs_lock);
offload = env->prog->aux->offload;
if (offload->netdev)
if (offload)
ret = offload->dev_ops->insn_hook(env, insn_idx, prev_insn_idx);
up_read(&bpf_devs_lock);
@ -123,31 +125,24 @@ static void __bpf_prog_offload_destroy(struct bpf_prog *prog)
struct bpf_dev_offload *offload = prog->aux->offload;
struct netdev_bpf data = {};
/* Caution - if netdev is destroyed before the program, this function
* will be called twice.
*/
data.offload.prog = prog;
if (offload->dev_state)
WARN_ON(__bpf_offload_ndo(prog, BPF_OFFLOAD_DESTROY, &data));
offload->dev_state = false;
list_del_init(&offload->offloads);
offload->netdev = NULL;
kfree(offload);
prog->aux->offload = NULL;
}
void bpf_prog_offload_destroy(struct bpf_prog *prog)
{
struct bpf_dev_offload *offload = prog->aux->offload;
rtnl_lock();
down_write(&bpf_devs_lock);
__bpf_prog_offload_destroy(prog);
if (prog->aux->offload)
__bpf_prog_offload_destroy(prog);
up_write(&bpf_devs_lock);
rtnl_unlock();
kfree(offload);
}
static int bpf_prog_offload_translate(struct bpf_prog *prog)