Re: [PATCH] net/mac80211/mesh_plink: Convert timers to use
From: Kees Cook
Date: Thu Oct 05 2017 - 13:28:01 EST
On Wed, Oct 4, 2017 at 11:47 PM, Johannes Berg
> On Wed, 2017-10-04 at 17:49 -0700, Kees Cook wrote:
>> In preparation for unconditionally passing the struct timer_list
>> pointer to all timer callbacks, switch to using the new timer_setup()
>> and from_timer() to pass the timer pointer explicitly. This requires
>> adding a pointer back to the sta_info since container_of() can't
>> resolve the sta_info.
> The subject seems to be lacking something ... :-)
Oh wonderful, all the subjects are cut off. *sigh* I wonder which
piece of my workflow broke that...
>> This requires commit 686fef928bba ("timer: Prepare to change timer
>> callback argument type") in v4.14-rc3, but should be otherwise
> I still can't apply that because that's not in net-next right now.
Okay, I'll see if Dave brings that into net-next and resend after that.
>> static inline void mesh_plink_timer_set(struct sta_info *sta, u32
>> sta->mesh->plink_timer.expires = jiffies +
>> - sta->mesh->plink_timer.data = (unsigned long) sta;
>> - sta->mesh->plink_timer.function = mesh_plink_timer;
>> + sta->mesh->plink_sta = sta;
>> + sta->mesh->plink_timer.function =
>> sta->mesh->plink_timeout = timeout;
> Wouldn't it be better to convert this to timer_setup() now?
The problem is that plink_timer is used in several places, and it's
originally initialized in net/mac80211/sta_info.c. The call to
mesh_plink_timer_set() does an update of the function field, so it
didn't look like it could get merged with the timer_setup(), but in
looking again, it seems that this is the _only_ update to
plink_timer.function, so it could probably get collapsed into the
> That add_timer() should probably also be mod_timer() anyway?
Agreed. I'd avoided making those changes in most places, but I can do it here.
>> diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
>> index 69615016d5bf..5e5de9455e4e 100644
>> --- a/net/mac80211/sta_info.c
>> +++ b/net/mac80211/sta_info.c
>> @@ -332,7 +332,7 @@ struct sta_info *sta_info_alloc(struct
>> ieee80211_sub_if_data *sdata,
>> if (ieee80211_vif_is_mesh(&sdata->vif) &&
>> - init_timer(&sta->mesh->plink_timer);
>> + timer_setup(&sta->mesh->plink_timer, NULL,
>> sta->mesh->nonpeer_pm = NL80211_MESH_POWER_ACTIVE;
> You just have to make mesh_plink_timer() non-static, put a prototype
> into mesh.h and then you can use the proper timer_setup() here with the
> Also, the sta->mesh->plink_sta assignment should be here I'd say, no
> point rewriting it all the time.
Sounds good. I'll get it cleaned up.