Re: [dpdk-dev] [RFC V2] ethdev: fix issue that dev close in PMD calls twice

[Huisong Li <lihuisong@huawei.com>]

Hi, all

This patch can enhance the security of device uninstallation to 
eliminate dependency on user usage methods.

Can you check this patch?


在 2021/8/3 10:30, Huisong Li 写道:
> Ethernet devices in DPDK can be released by rte_eth_dev_close() and
> rte_dev_remove(). These APIs both call xxx_dev_close() in PMD layer
> to uninstall hardware. However, the two APIs do not have explicit
> invocation restrictions. In other words, at the ethdev layer, it is
> possible to call rte_eth_dev_close() before calling rte_dev_remove()
> or rte_eal_hotplug_remove(). In such a bad scenario, the primary
> process may be fine, but it may cause that xxx_dev_close() in the PMD
> layer will be called twice in the secondary process. So this patch
> fixes it.
>
> Fixes: 99a2dd955fba ("lib: remove librte_ prefix from directory names")
>
> Signed-off-by: Huisong Li <lihuisong@huawei.com>
> ---
>   v2: fix commit description
> ---
>   lib/ethdev/ethdev_pci.h | 13 +++++++++++++
>   1 file changed, 13 insertions(+)
>
> diff --git a/lib/ethdev/ethdev_pci.h b/lib/ethdev/ethdev_pci.h
> index 8edca82..429c4c7 100644
> --- a/lib/ethdev/ethdev_pci.h
> +++ b/lib/ethdev/ethdev_pci.h
> @@ -151,6 +151,19 @@ rte_eth_dev_pci_generic_remove(struct rte_pci_device *pci_dev,
>   	if (!eth_dev)
>   		return 0;
>   
> +	/*
> +	 * The eth_dev->data->name doesn't be cleared by the secondary process,
> +	 * so above "eth_dev" isn't NULL after rte_eth_dev_close() called.
> +	 * Namely, whether "eth_dev" is NULL cannot be used to determine whether
> +	 * an ethdev port has been released.
> +	 * For both primary process and secondary process, eth_dev->state is
> +	 * RTE_ETH_DEV_UNUSED, which means the ethdev port has been released.
> +	 */
> +	if (eth_dev->state == RTE_ETH_DEV_UNUSED) {
> +		RTE_ETHDEV_LOG(INFO, "The ethdev port has been released.");
> +		return 0;
> +	}
> +
>   	if (dev_uninit) {
>   		ret = dev_uninit(eth_dev);
>   		if (ret)