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From:   "Eelco Chaudron" <echaudro@redhat.com>
To:     xiangxia.m.yue@gmail.com
Cc:     davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com,
        pshelar@ovn.org, syzkaller-bugs@googlegroups.com,
        dev@openvswitch.org, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org
Subject: Re: [PATCH] net: openvswitch: silence suspicious RCU usage warning
Date:   Wed, 05 Aug 2020 21:21:13 +0200
Message-ID: <323728A6-9ED5-4588-92D5-3F6799357D0A@redhat.com>
In-Reply-To: <20200805071911.64101-1-xiangxia.m.yue@gmail.com>
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On 5 Aug 2020, at 9:19, xiangxia.m.yue@gmail.com wrote:

> From: Tonghao Zhang <xiangxia.m.yue@gmail.com>
>
> ovs_flow_tbl_destroy always is called from RCU callback
> or error path. It is no need to check if rcu_read_lock
> or lockdep_ovsl_is_held was held.
>
> ovs_dp_cmd_fill_info always is called with ovs_mutex,
> So use the rcu_dereference_ovsl instead of rcu_dereference
> in ovs_flow_tbl_masks_cache_size.
>
> Fixes: 9bf24f594c6a ("net: openvswitch: make masks cache size 
> configurable")
> Cc: Eelco Chaudron <echaudro@redhat.com>
> Reported-by: syzbot+c0eb9e7cdde04e4eb4be@syzkaller.appspotmail.com
> Reported-by: syzbot+f612c02823acb02ff9bc@syzkaller.appspotmail.com
> Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>

Thanks for fixing this, I was (am) on PTO so did not notice it earlier!

Cheers,

Eelco