netdev - Re: [PATCH] net/mac80211/mesh_plink: Convert timers to use

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Message-ID: <1507186052.2387.11.camel@sipsolutions.net>
Date:   Thu, 05 Oct 2017 08:47:32 +0200
From:   Johannes Berg <johannes@...solutions.net>
To:     Kees Cook <keescook@...omium.org>, linux-kernel@...r.kernel.org
Cc:     "David S. Miller" <davem@...emloft.net>,
        linux-wireless@...r.kernel.org, netdev@...r.kernel.org,
        Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [PATCH] net/mac80211/mesh_plink: Convert timers to use

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 ... :-)

> This requires commit 686fef928bba ("timer: Prepare to change timer
> callback argument type") in v4.14-rc3, but should be otherwise
> stand-alone.

I still can't apply that because that's not in net-next right now.

>  static inline void mesh_plink_timer_set(struct sta_info *sta, u32
> timeout)
>  {
>  	sta->mesh->plink_timer.expires = jiffies +
> msecs_to_jiffies(timeout);
> -	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 =
> (TIMER_FUNC_TYPE)mesh_plink_timer;
>  	sta->mesh->plink_timeout = timeout;
>  	add_timer(&sta->mesh->plink_timer);

Wouldn't it be better to convert this to timer_setup() now?

That add_timer() should probably also be mod_timer() anyway?

> 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,
>  		spin_lock_init(&sta->mesh->plink_lock);
>  		if (ieee80211_vif_is_mesh(&sdata->vif) &&
>  		    !sdata->u.mesh.user_mpm)
> -			init_timer(&sta->mesh->plink_timer);
> +			timer_setup(&sta->mesh->plink_timer, NULL,
> 0);
>  		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
function?

Also, the sta->mesh->plink_sta assignment should be here I'd say, no
point rewriting it all the time.

I guess you were shooting for minimal, and I suppose we can do the
cleanups later too ...

johannes