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From:   Cong Wang <xiyou.wangcong@gmail.com>
Date:   Sun, 1 Oct 2023 11:32:28 -0700
Message-ID: <CAM_iQpUbDR1S6hY6gPhjXrnWCQHGjQZ6JcB27zbauzdBhP76RA@mail.gmail.com>
Subject: Re: [PATCH] net/sched: use spin_lock_bh() on &gact->tcf_lock
To:     Chengfeng Ye <dg573847474@gmail.com>
Cc:     jhs@mojatatu.com, jiri@resnulli.us, davem@davemloft.net,
        edumazet@google.com, kuba@kernel.org, pabeni@redhat.com,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
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On Tue, Sep 26, 2023 at 11:27=E2=80=AFAM Chengfeng Ye <dg573847474@gmail.co=
m> wrote:
>
> I find tcf_gate_act() acquires &gact->tcf_lock without disable
> bh explicitly, as gact->tcf_lock is acquired inside timer under
> softirq context, if tcf_gate_act() is not called with bh disable
> by default or under softirq context(which I am not sure as I cannot
> find corresponding documentation), then it could be the following
> deadlocks.

Did you find this during code review or did you see a real
lockdep splat? If the latter, please include the full lockdep log.

Thanks.