kern/149185: [rum] [panic] panic in rum(4) driver on 8.1-R

[Alex Kozlov]

The following reply was made to PR kern/149185; it has been noted by GNATS.

From: Alex Kozlov <spam at rm-rf.kiev.ua>
To: Juergen Lock <nox at jelal.kn-bremen.de>,
	Bernhard Schmidt <bschmidt at techwires.net>, rpaulo at freebsd.org,
	Kevin Lo <kevlo at freebsd.org>, bug-followup at freebsd.org,
	spam at rm-rf.kiev.ua
Cc:  
Subject: Re: kern/149185: [rum] [panic] panic in rum(4) driver on 8.1-R
Date: Mon, 9 Aug 2010 12:23:26 +0300

 On Sun, Aug 08, 2010 at 05:14:46PM +0200, Juergen Lock wrote:
 > On Thu, Aug 05, 2010 at 06:25:32PM +0200, Bernhard Schmidt wrote:
 > > On Thu, Aug 5, 2010 at 11:11, Alex Kozlov <spam at rm-rf.kiev.ua> wrote:
 > > > On Thu, Aug 05, 2010 at 10:05:39AM +0200, Bernhard Schmidt wrote:
 > > >> On Thu, Aug 5, 2010 at 08:52, Alex Kozlov <spam at rm-rf.kiev.ua> wrote:
 > > >> > On Wed, Aug 04, 2010 at 10:02:35PM +0200, Juergen Lock wrote:
 > > >> >>  Regarding the 8.1 if_rum(4) panics...  I got a similar one, extracted
 > > >> >> a dump and tried to gather some info for someone who knows the code:
 > > >> >>
 > > >> >>  The zero divide fault was because (apparently) rate was unitialized,
 > > >> >> as is
 > > >> >>
 > > >> >>       ((struct ieee80211_node *) m->M_dat.MH.MH_pkthdr.rcvif)->ni_vap->iv_txparms[0]
 > > >> >>
 > > >> >> i.e. struct ieee80211_txparam &vap->iv_txparms[0] in case it matters.
 > > >> > Yes, its seems that ratectl framework sometimes set ni->ni_txrate to 0
 > > >> > This can be mitigated by patch [1] or by setting ucastrate option in
 > > >> > ifconfig. Still real issue need to be solved.
 > > >>
 > > >> The real issue is that prior to an association (RUN state)
 > > >> ieee80211_ratectl_node_init() is not called, therefore iv_bss is not
 > > >> configured in any way.
 > > > ieee80211_ratectl_node_init() called from iv_newstate when switching to
 > > > IEEE80211_S_RUN state. Most drivers do the same. Is it wrong?
 > > > Some call it from iv_newassoc, but this marked /* XXX move */
 > > >
 > > >> I'll look into that if no one beats me.
 > > > Thanks.
 > > 
 > > 
 > > Please give attached patch a try, it should fix the issue for rum and
 > > all other drivers relying on the new ratectl stuff.
 > That seems to stop the panics, but the wifi still only works partially
 > (at least with hostapd), like with my original hack of a patch.  One
 That why I use ad-hoc. Yes, seems that this panic eliminated.
 
 
 --
 Adios