diff options
| author | Daniel Borkmann <daniel@iogearbox.net> | 2016-11-09 22:02:34 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-11-12 23:31:57 -0500 |
| commit | c540594f864bb4645573c2c0a304919fabb3d7ea (patch) | |
| tree | bbc81f35747fb25416c9015d23fc7071d54feb11 /drivers/net | |
| parent | b602e491a518439abd98a25ccded85e1347b9a14 (diff) | |
| download | lwn-c540594f864bb4645573c2c0a304919fabb3d7ea.tar.gz lwn-c540594f864bb4645573c2c0a304919fabb3d7ea.zip | |
bpf, mlx4: fix prog refcount in mlx4_en_try_alloc_resources error path
Commit 67f8b1dcb9ee ("net/mlx4_en: Refactor the XDP forwarding rings
scheme") added a bug in that the prog's reference count is not dropped
in the error path when mlx4_en_try_alloc_resources() is failing from
mlx4_xdp_set().
We previously took bpf_prog_add(prog, priv->rx_ring_num - 1), that we
need to release again. Earlier in the call path, dev_change_xdp_fd()
itself holds a reference to the prog as well (hence the '- 1' in the
bpf_prog_add()), so a simple atomic_sub() is safe to use here. When
an error is propagated, then bpf_prog_put() is called eventually from
dev_change_xdp_fd()
Fixes: 67f8b1dcb9ee ("net/mlx4_en: Refactor the XDP forwarding rings scheme")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/ethernet/mellanox/mlx4/en_netdev.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c index 0f6225c042be..9bf7320107b0 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c @@ -2747,8 +2747,11 @@ static int mlx4_xdp_set(struct net_device *dev, struct bpf_prog *prog) } err = mlx4_en_try_alloc_resources(priv, tmp, &new_prof); - if (err) + if (err) { + if (prog) + bpf_prog_sub(prog, priv->rx_ring_num - 1); goto unlock_out; + } if (priv->port_up) { port_up = 1; |