From: Sean Anderson <seanga2@gmail.com>
To: Antonio Quartulli <antonio@openvpn.net>,
netdev@vger.kernel.org, Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Donald Hunter <donald.hunter@gmail.com>,
Shuah Khan <shuah@kernel.org>,
sd@queasysnail.net, ryazanov.s.a@gmail.com,
Andrew Lunn <andrew+netdev@lunn.ch>
Cc: Simon Horman <horms@kernel.org>,
linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
Xiao Liang <shaw.leon@gmail.com>,
steffen.klassert@secunet.com, antony.antony@secunet.com,
willemdebruijn.kernel@gmail.com, David Ahern <dsahern@kernel.org>,
Andrew Lunn <andrew@lunn.ch>,
Shuah Khan <skhan@linuxfoundation.org>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH net-next v19 00/26] Introducing OpenVPN Data Channel Offload
Date: Thu, 13 Feb 2025 09:26:14 -0500 [thread overview]
Message-ID: <2dc054c7-c596-b283-b26a-86c52e48efe0@gmail.com> (raw)
In-Reply-To: <20250211-b4-ovpn-v19-0-86d5daf2a47a@openvpn.net>
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
next prev parent reply other threads:[~2025-02-13 14:26 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-11 0:39 [PATCH net-next v19 00/26] Introducing OpenVPN Data Channel Offload Antonio Quartulli
2025-02-11 0:39 ` [PATCH net-next v19 01/26] net: introduce OpenVPN Data Channel Offload (ovpn) Antonio Quartulli
2025-02-11 0:39 ` [PATCH net-next v19 02/26] ovpn: add basic netlink support Antonio Quartulli
2025-02-11 0:39 ` [PATCH net-next v19 03/26] ovpn: add basic interface creation/destruction/management routines Antonio Quartulli
2025-02-11 0:39 ` [PATCH net-next v19 04/26] ovpn: keep carrier always on for MP interfaces Antonio Quartulli
2025-02-11 0:39 ` [PATCH net-next v19 05/26] ovpn: introduce the ovpn_peer object Antonio Quartulli
2025-02-11 0:39 ` [PATCH net-next v19 06/26] ovpn: introduce the ovpn_socket object Antonio Quartulli
2025-02-11 0:40 ` [PATCH net-next v19 07/26] ovpn: implement basic TX path (UDP) Antonio Quartulli
2025-02-11 0:40 ` [PATCH net-next v19 08/26] ovpn: implement basic RX " Antonio Quartulli
2025-02-11 0:40 ` [PATCH net-next v19 09/26] ovpn: implement packet processing Antonio Quartulli
2025-02-11 0:40 ` [PATCH net-next v19 10/26] ovpn: store tunnel and transport statistics Antonio Quartulli
2025-02-11 0:40 ` [PATCH net-next v19 11/26] ipv6: export inet6_stream_ops via EXPORT_SYMBOL_GPL Antonio Quartulli
2025-02-11 0:40 ` [PATCH net-next v19 12/26] ovpn: implement TCP transport Antonio Quartulli
2025-02-11 0:40 ` [PATCH net-next v19 13/26] skb: implement skb_send_sock_locked_with_flags() Antonio Quartulli
2025-02-11 0:40 ` [PATCH net-next v19 14/26] ovpn: add support for MSG_NOSIGNAL in tcp_sendmsg Antonio Quartulli
2025-02-11 0:40 ` [PATCH net-next v19 15/26] ovpn: implement multi-peer support Antonio Quartulli
2025-02-11 0:40 ` [PATCH net-next v19 16/26] ovpn: implement peer lookup logic Antonio Quartulli
2025-02-11 0:40 ` [PATCH net-next v19 17/26] ovpn: implement keepalive mechanism Antonio Quartulli
2025-02-11 0:40 ` [PATCH net-next v19 18/26] ovpn: add support for updating local UDP endpoint Antonio Quartulli
2025-02-11 0:40 ` [PATCH net-next v19 19/26] ovpn: add support for peer floating Antonio Quartulli
2025-02-11 0:40 ` [PATCH net-next v19 20/26] ovpn: implement peer add/get/dump/delete via netlink Antonio Quartulli
2025-02-11 0:40 ` [PATCH net-next v19 21/26] ovpn: implement key add/get/del/swap " Antonio Quartulli
2025-02-11 0:40 ` [PATCH net-next v19 22/26] ovpn: kill key and notify userspace in case of IV exhaustion Antonio Quartulli
2025-02-11 0:40 ` [PATCH net-next v19 23/26] ovpn: notify userspace when a peer is deleted Antonio Quartulli
2025-02-11 0:40 ` [PATCH net-next v19 24/26] ovpn: add basic ethtool support Antonio Quartulli
2025-02-11 0:40 ` [PATCH net-next v19 25/26] testing/selftests: add test tool and scripts for ovpn module Antonio Quartulli
2025-02-13 0:36 ` kernel test robot
2025-02-14 1:49 ` kernel test robot
2025-02-11 0:40 ` [PATCH net-next v19 26/26] mailmap: remove unwanted entry for Antonio Quartulli Antonio Quartulli
2025-02-12 23:34 ` [PATCH net-next v19 00/26] Introducing OpenVPN Data Channel Offload Sabrina Dubroca
2025-02-13 11:46 ` Antonio Quartulli
2025-02-13 15:46 ` Sabrina Dubroca
2025-02-13 19:40 ` Antonio Quartulli
2025-02-14 13:54 ` Antonio Quartulli
2025-02-14 14:00 ` Antonio Quartulli
2025-02-13 14:26 ` Sean Anderson [this message]
2025-02-13 19:46 ` Antonio Quartulli
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