bpf, sock_map: Move cancel_work_sync() out of sock lock
[ Upstream commit 8bbabb3f ] Stanislav reported a lockdep warning, which is caused by the cancel_work_sync() called inside sock_map_close(), as analyzed below by Jakub: psock->work.func = sk_psock_backlog() ACQUIRE psock->work_mutex sk_psock_handle_skb() skb_send_sock() __skb_send_sock() sendpage_unlocked() kernel_sendpage() sock->ops->sendpage = inet_sendpage() sk->sk_prot->sendpage = tcp_sendpage() ACQUIRE sk->sk_lock tcp_sendpage_locked() RELEASE sk->sk_lock RELEASE psock->work_mutex sock_map_close() ACQUIRE sk->sk_lock sk_psock_stop() sk_psock_clear_state(psock, SK_PSOCK_TX_ENABLED) cancel_work_sync() __cancel_work_timer() __flush_work() // wait for psock->work to finish RELEASE sk->sk_lock We can move the cancel_work_sync() out of the sock lock protection, but still before saved_close() was called. Fixes: 799aa7f9 ("skmsg: Avoid lock_sock() in sk_psock_backlog()") Reported-by:Stanislav Fomichev <sdf@google.com> Signed-off-by:
Cong Wang <cong.wang@bytedance.com> Signed-off-by:
Daniel Borkmann <daniel@iogearbox.net> Tested-by:
Jakub Sitnicki <jakub@cloudflare.com> Acked-by:
John Fastabend <john.fastabend@gmail.com> Acked-by:
Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/bpf/20221102043417.279409-1-xiyou.wangcong@gmail.com Signed-off-by:
Sasha Levin <sashal@kernel.org>
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32b5dd03
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