2023-11-19 16:24:47

by Haiyang Zhang

[permalink] [raw]
Subject: [PATCH net,v5, 2/3] hv_netvsc: Fix race of register_netdevice_notifier and VF register

If VF NIC is registered earlier, NETDEV_REGISTER event is replayed,
but NETDEV_POST_INIT is not.

Move register_netdevice_notifier() earlier, so the call back
function is set before probing.

Cc: [email protected]
Fixes: e04e7a7bbd4b ("hv_netvsc: Fix a deadlock by getting rtnl lock earlier in netvsc_probe()")
Reported-by: Dexuan Cui <[email protected]>
Signed-off-by: Haiyang Zhang <[email protected]>
Reviewed-by: Wojciech Drewek <[email protected]>
Reviewed-by: Dexuan Cui <[email protected]>

---
v5:
Use a more idiomatic form for the error path, suggested by Simon Horman.
v3:
Divide it into two patches, suggested by Jakub Kicinski.
v2:
Fix rtnl_unlock() in error handling as found by Wojciech Drewek.
---
drivers/net/hyperv/netvsc_drv.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 5e528a76f5f5..b7dfd51f09e6 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -2793,12 +2793,17 @@ static int __init netvsc_drv_init(void)
}
netvsc_ring_bytes = ring_size * PAGE_SIZE;

+ register_netdevice_notifier(&netvsc_netdev_notifier);
+
ret = vmbus_driver_register(&netvsc_drv);
if (ret)
- return ret;
+ goto err_vmbus_reg;

- register_netdevice_notifier(&netvsc_netdev_notifier);
return 0;
+
+err_vmbus_reg:
+ unregister_netdevice_notifier(&netvsc_netdev_notifier);
+ return ret;
}

MODULE_LICENSE("GPL");
--
2.34.1