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

[Bernhard Schmidt]

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

From: Bernhard Schmidt <bschmidt at techwires.net>
To: Alex Kozlov <spam at rm-rf.kiev.ua>, bug-followup at freebsd.org
Cc: nox at freebsd.org, rpaulo at freebsd.org
Subject: Re: kern/149185: [rum] [panic] panic in rum(4) driver on 8.1-R
Date: Thu, 5 Aug 2010 11:34:35 +0200

 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:
 >> >> =A0Regarding the 8.1 if_rum(4) panics... =A0I got a similar one, extr=
 acted
 >> >> a dump and tried to gather some info for someone who knows the code:
 >> >>
 >> >> =A0The zero divide fault was because (apparently) rate was unitialize=
 d,
 >> >> as is
 >> >>
 >> >> =A0 =A0 =A0 ((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 */
 
 It is not wrong, but to late. Before RUN state and the iv_newassoc()
 call, you have to send frames for scanning and authentication, those
 need a valid rate too. I wonder if we can call node_init() in
 ieee80211_vap_setup() or something similar, that would definitely be
 early enough.
 
 >> I'll look into that if no one beats me.
 > Thanks.
 
 
 --=20
 Bernhard