Commit b6c5f945 authored by David Wei's avatar David Wei Committed by Jens Axboe
Browse files

io_uring/zcrx: call netdev_queue_get_dma_dev() under instance lock 



netdev ops must be called under instance lock or rtnl_lock, but
io_register_zcrx_ifq() isn't doing this for netdev_queue_get_dma_dev().
Fix this by taking the instance lock using netdev_get_by_index_lock().

Extended the instance lock section to include attaching a memory
provider. Could not move io_zcrx_create_area() outside, since the dmabuf
codepath IORING_ZCRX_AREA_DMABUF requires ifq->dev.

Fixes: 59b8b32a ("io_uring/zcrx: add support for custom DMA devices")
Signed-off-by: default avatarDavid Wei <dw@davidwei.uk>
Reviewed-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Reviewed-by: default avatarJakub Kicinski <kuba@kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent c07a491c

io_uring/zcrx.c

+10 −6
Original line number Diff line number Diff line
@@ -620,29 +620,30 @@ int io_register_zcrx_ifq(struct io_ring_ctx *ctx, 
	if (ret)

		goto err;



	ifq->netdev = netdev_get_by_index(current->nsproxy->net_ns, reg.if_idx,

					  &ifq->netdev_tracker, GFP_KERNEL);

	ifq->netdev = netdev_get_by_index_lock(current->nsproxy->net_ns, reg.if_idx);

	if (!ifq->netdev) {

		ret = -ENODEV;

		goto err;

	}

	netdev_hold(ifq->netdev, &ifq->netdev_tracker, GFP_KERNEL);



	ifq->dev = netdev_queue_get_dma_dev(ifq->netdev, reg.if_rxq);

	if (!ifq->dev) {

		ret = -EOPNOTSUPP;

		goto err;

		goto netdev_put_unlock;

	}

	get_device(ifq->dev);



	ret = io_zcrx_create_area(ifq, &area);

	if (ret)

		goto err;

		goto netdev_put_unlock;



	mp_param.mp_ops = &io_uring_pp_zc_ops;

	mp_param.mp_priv = ifq;

	ret = net_mp_open_rxq(ifq->netdev, reg.if_rxq, &mp_param);

	ret = __net_mp_open_rxq(ifq->netdev, reg.if_rxq, &mp_param, NULL);

	if (ret)

		goto err;

		goto netdev_put_unlock;

	netdev_unlock(ifq->netdev);

	ifq->if_rxq = reg.if_rxq;



	reg.zcrx_id = id;
@@ -661,6 +662,9 @@ int io_register_zcrx_ifq(struct io_ring_ctx *ctx, 
		goto err;

	}

	return 0;

netdev_put_unlock:

	netdev_put(ifq->netdev, &ifq->netdev_tracker);

	netdev_unlock(ifq->netdev);

err:

	scoped_guard(mutex, &ctx->mmap_lock)

		xa_erase(&ctx->zcrx_ctxs, id);