Hi Antonio,
On 2/10/25 19:39, Antonio Quartulli wrote:
NOTE: TCP tests are still showing the following warning while running
iperf.
I have analysed the report several times, but it definitely looks like
a false positive to me, so nothing to worry about.
Basically the lockdep engine gets confused thinking that we are
acquiring the lock twice on the same sock, but actually:
1) the kernel is first locking the 'iperf' (user) TCP socket;
2) ovpn is later locking the underlying TCP trasport socket.
So there is NO risk of deadlock (and indeed nothing hangs), but I
couldn't find a way to make the warning go away.
I think you can use a "nested" lock to avoid this. See e.g. commit
86a41ea9fd79 ("l2tp: fix lockdep splat") for an example.
--Sean
[1] https://www.kernel.org/doc/html/latest/locking/lockdep-design.html#exception-nested-data-dependencies-leading-to-nested-locking
