On 3/14/25 12:13 PM, Toke Høiland-Jørgensen wrote:
> Wang Liang <wangliang74@xxxxxxxxxx> writes:
>
>> Following operations can trigger a warning[1]:
>>
>> ip netns add ns1
>> ip netns exec ns1 ip link add bond0 type bond mode balance-rr
>> ip netns exec ns1 ip link set dev bond0 xdp obj af_xdp_kern.o sec xdp
>> ip netns exec ns1 ip link set bond0 type bond mode broadcast
>> ip netns del ns1
>>
>> When delete the namespace, dev_xdp_uninstall() is called to remove xdp
>> program on bond dev, and bond_xdp_set() will check the bond mode. If bond
>> mode is changed after attaching xdp program, the warning may occur.
>>
>> Some bond modes (broadcast, etc.) do not support native xdp. Set bond mode
>> with xdp program attached is not good. Add check for xdp program when set
>> bond mode.
>>
>> [1]
>> ------------[ cut here ]------------
>> WARNING: CPU: 0 PID: 11 at net/core/dev.c:9912 unregister_netdevice_many_notify+0x8d9/0x930
>> Modules linked in:
>> CPU: 0 UID: 0 PID: 11 Comm: kworker/u4:0 Not tainted 6.14.0-rc4 #107
>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014
>> Workqueue: netns cleanup_net
>> RIP: 0010:unregister_netdevice_many_notify+0x8d9/0x930
>> Code: 00 00 48 c7 c6 6f e3 a2 82 48 c7 c7 d0 b3 96 82 e8 9c 10 3e ...
>> RSP: 0018:ffffc90000063d80 EFLAGS: 00000282
>> RAX: 00000000ffffffa1 RBX: ffff888004959000 RCX: 00000000ffffdfff
>> RDX: 0000000000000000 RSI: 00000000ffffffea RDI: ffffc90000063b48
>> RBP: ffffc90000063e28 R08: ffffffff82d39b28 R09: 0000000000009ffb
>> R10: 0000000000000175 R11: ffffffff82d09b40 R12: ffff8880049598e8
>> R13: 0000000000000001 R14: dead000000000100 R15: ffffc90000045000
>> FS: 0000000000000000(0000) GS:ffff888007a00000(0000) knlGS:0000000000000000
>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> CR2: 000000000d406b60 CR3: 000000000483e000 CR4: 00000000000006f0
>> Call Trace:
>> <TASK>
>> ? __warn+0x83/0x130
>> ? unregister_netdevice_many_notify+0x8d9/0x930
>> ? report_bug+0x18e/0x1a0
>> ? handle_bug+0x54/0x90
>> ? exc_invalid_op+0x18/0x70
>> ? asm_exc_invalid_op+0x1a/0x20
>> ? unregister_netdevice_many_notify+0x8d9/0x930
>> ? bond_net_exit_batch_rtnl+0x5c/0x90
>> cleanup_net+0x237/0x3d0
>> process_one_work+0x163/0x390
>> worker_thread+0x293/0x3b0
>> ? __pfx_worker_thread+0x10/0x10
>> kthread+0xec/0x1e0
>> ? __pfx_kthread+0x10/0x10
>> ? __pfx_kthread+0x10/0x10
>> ret_from_fork+0x2f/0x50
>> ? __pfx_kthread+0x10/0x10
>> ret_from_fork_asm+0x1a/0x30
>> </TASK>
>> ---[ end trace 0000000000000000 ]---
>>
>> Fixes: 9e2ee5c7e7c3 ("net, bonding: Add XDP support to the bonding driver")
>> Signed-off-by: Wang Liang <wangliang74@xxxxxxxxxx>
>> ---
>> drivers/net/bonding/bond_options.c | 3 +++
>> 1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/net/bonding/bond_options.c b/drivers/net/bonding/bond_options.c
>> index 327b6ecdc77e..127181866829 100644
>> --- a/drivers/net/bonding/bond_options.c
>> +++ b/drivers/net/bonding/bond_options.c
>> @@ -868,6 +868,9 @@ static bool bond_set_xfrm_features(struct bonding *bond)
>> static int bond_option_mode_set(struct bonding *bond,
>> const struct bond_opt_value *newval)
>> {
>> + if (bond->xdp_prog)
>> + return -EOPNOTSUPP;
>> +
>
> Should we allow changing as long as the new mode also supports XDP?
>
> -Toke
>
>
+1
I think we should allow it, the best way probably is to add a new
BOND_VALFLAG_XDP_UNSUPP (for example) as a bond option flag and to set
it in bond_options.c for each mode that doesn't support XDP, then you
can do the check in a generic way (for any option) in
bond_opt_check_deps. Any bond option that can't be changed with XDP prog
should have that flag set.
Cheers,
Nik
