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io_uring/zcrx: call netdev_queue_get_dma_dev() under instance lock

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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: 59b8b32ac8 ("io_uring/zcrx: add support for custom DMA devices")
Signed-off-by: David Wei <dw@davidwei.uk>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
David Wei
2025-10-31 19:24:49 -07:00
committed by Jens Axboe
parent c07a491c1b
commit b6c5f9454e
1 changed files with 10 additions and 6 deletions
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16
io_uring/zcrx.c
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@@ -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);