Re: possible deadlock in skb_queue_tail

[Cong Wang]

On Tue, Apr 3, 2018 at 4:42 AM, Kirill Tkhai <ktkhai@xxxxxxxxxxxxx> wrote:
> On 03.04.2018 14:25, Dmitry Vyukov wrote:
>> On Tue, Apr 3, 2018 at 11:50 AM, Kirill Tkhai <ktkhai@xxxxxxxxxxxxx> wrote:
>>> sk_diag_dump_icons() dumps only sockets in TCP_LISTEN state.
>>> TCP_LISTEN state may be assigned in only place in net/unix/af_unix.c:
>>> it's unix_listen(). The function is applied to stream and seqpacket
>>> socket types.
>>>
>>> It can't be stream because of the second stack, and seqpacket also can't,
>>> as I don't think it's possible for gcc to inline unix_seqpacket_sendmsg()
>>> in the way, we don't see it in the stack.
>>>
>>> So, this is looks like false positive result for me.
>>>
>>> Kirill
>>
>> Do you mean that these &(&u->lock)->rlock/1 referenced in 2 stacks are
>> always different?
>
> In these 2 particular stacks they have to be different.

So actually my patch could fix this false positive? I thought it couldn't.
https://patchwork.ozlabs.org/patch/894342/