Commit f792709e authored by Stanislav Fomichev's avatar Stanislav Fomichev Committed by Jakub Kicinski
Browse files

selftests: net: validate team flags propagation 



Cover three recent cases:
1. missing ops locking for the lowers during netdev_sync_lower_features
2. missing locking for dev_set_promiscuity (plus netdev_ops_assert_locked
   with a comment on why/when it's needed)
3. rcu lock during team_change_rx_flags

Verified that each one triggers when the respective fix is reverted.
Not sure about the placement, but since it all relies on teaming,
added to the teaming directory.

One ugly bit is that I add NETIF_F_LRO to netdevsim; there is no way
to trigger netdev_sync_lower_features without it.

Signed-off-by: default avatarStanislav Fomichev <stfomichev@gmail.com>
Link: https://patch.msgid.link/20250516232205.539266-1-stfomichev@gmail.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent fa919a30

drivers/net/netdevsim/netdev.c

+2 −0
Original line number Diff line number Diff line
@@ -881,11 +881,13 @@ static void nsim_setup(struct net_device *dev) 
			 NETIF_F_SG |

			 NETIF_F_FRAGLIST |

			 NETIF_F_HW_CSUM |

			 NETIF_F_LRO |

			 NETIF_F_TSO;

	dev->hw_features |= NETIF_F_HW_TC |

			    NETIF_F_SG |

			    NETIF_F_FRAGLIST |

			    NETIF_F_HW_CSUM |

			    NETIF_F_LRO |

			    NETIF_F_TSO;

	dev->max_mtu = ETH_MAX_MTU;

	dev->xdp_features = NETDEV_XDP_ACT_HW_OFFLOAD;

net/core/dev.c

+9 −1
Original line number Diff line number Diff line
@@ -9278,8 +9278,16 @@ static int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify) 


		dev_change_rx_flags(dev, IFF_PROMISC);

	}

	if (notify)

	if (notify) {

		/* The ops lock is only required to ensure consistent locking

		 * for `NETDEV_CHANGE` notifiers. This function is sometimes

		 * called without the lock, even for devices that are ops

		 * locked, such as in `dev_uc_sync_multiple` when using

		 * bonding or teaming.

		 */

		netdev_ops_assert_locked(dev);

		__dev_notify_flags(dev, old_flags, IFF_PROMISC, 0, NULL);

	}

	return 0;

}

tools/testing/selftests/drivers/net/team/Makefile

+1 −1
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0

# Makefile for net selftests



TEST_PROGS := dev_addr_lists.sh

TEST_PROGS := dev_addr_lists.sh propagation.sh



TEST_INCLUDES := \

	../bonding/lag_lib.sh \

tools/testing/selftests/drivers/net/team/config

+1 −0
Original line number Diff line number Diff line 
CONFIG_DUMMY=y

CONFIG_IPV6=y

CONFIG_MACVLAN=y

CONFIG_NETDEVSIM=m

CONFIG_NET_TEAM=y

CONFIG_NET_TEAM_MODE_LOADBALANCE=y

tools/testing/selftests/drivers/net/team/propagation.sh

0 → 100755
+80 −0
Original line number Diff line number Diff line 
#!/bin/bash

# SPDX-License-Identifier: GPL-2.0



set -e



NSIM_LRO_ID=$((256 + RANDOM % 256))

NSIM_LRO_SYS=/sys/bus/netdevsim/devices/netdevsim$NSIM_LRO_ID



NSIM_DEV_SYS_NEW=/sys/bus/netdevsim/new_device

NSIM_DEV_SYS_DEL=/sys/bus/netdevsim/del_device



cleanup()

{

	set +e

	ip link del dummyteam &>/dev/null

	ip link del team0 &>/dev/null

	echo $NSIM_LRO_ID > $NSIM_DEV_SYS_DEL

	modprobe -r netdevsim

}



# Trigger LRO propagation to the lower.

# https://lore.kernel.org/netdev/aBvOpkIoxcr9PfDg@mini-arch/

team_lro()

{

	# using netdevsim because it supports NETIF_F_LRO

	NSIM_LRO_NAME=$(find $NSIM_LRO_SYS/net -maxdepth 1 -type d ! \

		-path $NSIM_LRO_SYS/net -exec basename {} \;)



	ip link add name team0 type team

	ip link set $NSIM_LRO_NAME down

	ip link set dev $NSIM_LRO_NAME master team0

	ip link set team0 up

	ethtool -K team0 large-receive-offload off



	ip link del team0

}



# Trigger promisc propagation to the lower during IFLA_MASTER.

# https://lore.kernel.org/netdev/20250506032328.3003050-1-sdf@fomichev.me/

team_promisc()

{

	ip link add name dummyteam type dummy

	ip link add name team0 type team

	ip link set dummyteam down

	ip link set team0 promisc on

	ip link set dev dummyteam master team0

	ip link set team0 up



	ip link del team0

	ip link del dummyteam

}



# Trigger promisc propagation to the lower via netif_change_flags (aka

# ndo_change_rx_flags).

# https://lore.kernel.org/netdev/20250514220319.3505158-1-stfomichev@gmail.com/

team_change_flags()

{

	ip link add name dummyteam type dummy

	ip link add name team0 type team

	ip link set dummyteam down

	ip link set dev dummyteam master team0

	ip link set team0 up

	ip link set team0 promisc on



	# Make sure we can add more L2 addresses without any issues.

	ip link add link team0 address 00:00:00:00:00:01 team0.1 type macvlan

	ip link set team0.1 up



	ip link del team0.1

	ip link del team0

	ip link del dummyteam

}



trap cleanup EXIT

modprobe netdevsim || :

echo $NSIM_LRO_ID > $NSIM_DEV_SYS_NEW

udevadm settle

team_lro

team_promisc

team_change_flags