Re: CVS commit: src/sys/netinet6

[Ryota Ozaki <ozaki-r%netbsd.org@localhost>]

On Wed, Dec 27, 2017 at 10:36 AM, Taylor R Campbell
<campbell+netbsd-source-changes-d%mumble.net@localhost> wrote:
>> Date: Wed, 27 Dec 2017 10:31:25 +0900
>> From: Ryota Ozaki <ozaki-r%netbsd.org@localhost>
>>
>> On Wed, Dec 27, 2017 at 10:27 AM, Taylor R Campbell
>> <campbell+netbsd-source-changes-d%mumble.net@localhost> wrote:
>> > Can you add this to the collection?
>> >
>> > #ifdef NET_MPSAFE
>> > #define SOFTNET_INTERLOCK_IF_NET_MPSAFE (&softnet_lock)
>> > #else
>> > #define SOFTNET_INTERLOCK_IF_MPSAFE     NULL
>> > #endif
>>
>> Oh I meant if not NET_MPSAFE, nd6_dad_stoptimer can be called with or without
>> softnet_lock. So the macro doesn't work.
>
> So push it into the callers: nd6_dad_stop, nd6_dad_duplicated?  That's
> why I mentioned...
>
>> >> > Can you just pass the interlock -- softnet_lock or NULL, depending on
>> >> > NET_MPSAFE -- as an argument to nd6_dad_stoptimer?  It looks like it
>> >> > will trickle up into the call stack a little bit, but not all that
>> >> > far, unless .dom_if_link_state_change and .dom_if_down ever hold
>> >> > softnet lock.
>
> ...the .dom_if_link_state_change and .dom_if_down callbacks, which
> where as far as I looked back in the call graph.

There are other paths. nd6_dad_stop is called from in6_purgeaddr,
in6_if_link_down and nd6_ioctl. nd6_dad_duplicated is called nd6_dad_timer,
nd6_dad_ns_input and nd6_dad_na_input.

  ozaki-r