diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/macsec.c b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/macsec.c index 71b3a059c964..daff53ba7d09 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/macsec.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/macsec.c @@ -714,6 +714,26 @@ static int mlx5e_macsec_add_rxsc(struct macsec_context *ctx) } sc_xarray_element->rx_sc = rx_sc; + + rx_sc->md_dst = metadata_dst_alloc(0, METADATA_MACSEC, GFP_KERNEL); + if (!rx_sc->md_dst) { + err = -ENOMEM; + goto destroy_sc_xarray_elemenet; + } + + rx_sc->sci = ctx_rx_sc->sci; + rx_sc->active = ctx_rx_sc->active; + rx_sc->sc_xarray_element = sc_xarray_element; + rx_sc->md_dst->u.macsec_info.sci = rx_sc->sci; + + /* + * Publish the fully-initialised SC last: xa_alloc() makes + * sc_xarray_element->rx_sc (and rx_sc->md_dst) reachable from the RX + * datapath via xa_load(). Doing it only after md_dst is allocated and + * initialised pairs with the rcu_read_lock()/xa_load() in + * mlx5e_macsec_offload_handle_rx_skb(), so a reader can never observe + * a non-NULL md_dst with uninitialised contents. + */ err = xa_alloc(&macsec->sc_xarray, &sc_xarray_element->fs_id, sc_xarray_element, XA_LIMIT(1, MLX5_MACEC_RX_FS_ID_MAX), GFP_KERNEL); if (err) { @@ -721,27 +741,16 @@ static int mlx5e_macsec_add_rxsc(struct macsec_context *ctx) netdev_err(ctx->netdev, "MACsec offload: unable to create entry for RX SC (%d Rx SCs already allocated)\n", MLX5_MACEC_RX_FS_ID_MAX); - goto destroy_sc_xarray_elemenet; + goto destroy_md_dst; } - rx_sc->md_dst = metadata_dst_alloc(0, METADATA_MACSEC, GFP_KERNEL); - if (!rx_sc->md_dst) { - err = -ENOMEM; - goto erase_xa_alloc; - } - - rx_sc->sci = ctx_rx_sc->sci; - rx_sc->active = ctx_rx_sc->active; list_add_rcu(&rx_sc->rx_sc_list_element, rx_sc_list); - - rx_sc->sc_xarray_element = sc_xarray_element; - rx_sc->md_dst->u.macsec_info.sci = rx_sc->sci; mutex_unlock(&macsec->lock); return 0; -erase_xa_alloc: - xa_erase(&macsec->sc_xarray, sc_xarray_element->fs_id); +destroy_md_dst: + dst_release(&rx_sc->md_dst->dst); destroy_sc_xarray_elemenet: kfree(sc_xarray_element); destroy_rx_sc: @@ -829,7 +838,7 @@ static void macsec_del_rxsc_ctx(struct mlx5e_macsec *macsec, struct mlx5e_macsec */ list_del_rcu(&rx_sc->rx_sc_list_element); xa_erase(&macsec->sc_xarray, rx_sc->sc_xarray_element->fs_id); - metadata_dst_free(rx_sc->md_dst); + dst_release(&rx_sc->md_dst->dst); kfree(rx_sc->sc_xarray_element); kfree_rcu_mightsleep(rx_sc); } @@ -1695,10 +1704,10 @@ void mlx5e_macsec_offload_handle_rx_skb(struct net_device *netdev, rcu_read_lock(); sc_xarray_element = xa_load(&macsec->sc_xarray, fs_id); - rx_sc = sc_xarray_element->rx_sc; - if (rx_sc) { - dst_hold(&rx_sc->md_dst->dst); - skb_dst_set(skb, &rx_sc->md_dst->dst); + rx_sc = sc_xarray_element ? sc_xarray_element->rx_sc : NULL; + if (rx_sc && rx_sc->md_dst) { + if (dst_hold_safe(&rx_sc->md_dst->dst)) + skb_dst_set(skb, &rx_sc->md_dst->dst); } rcu_read_unlock();