Date: Thu, 27 Nov 2003 11:50:27 -0800 From: Sam Leffler <sam@errno.com> To: "Bjoern A. Zeeb" <bzeeb-lists@lists.zabbadoz.net>, Yuriy Tsibizov <Yuriy.Tsibizov@gfk.ru> Cc: freebsd-current@freebsd.org Subject: Re: recent current panic Message-ID: <200311271150.27841.sam@errno.com> In-Reply-To: <Pine.BSF.4.53.0311271431590.52886@e0-0.zab2.int.zabbadoz.net> References: <20031127110256.H711@free.home.local> <Pine.BSF.4.53.0311271431590.52886@e0-0.zab2.int.zabbadoz.net>
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On Thursday 27 November 2003 06:38 am, Bjoern A. Zeeb wrote: > On Thu, 27 Nov 2003, Yuriy Tsibizov wrote: > > Hi, > > > >i got a panic on recent -CURRENT: > > > > > ># tcpdump -i lo0 port 23 & > > >[1] 507 > > >listening on lo0 > > > > > ># telnet localhost > > >Trying ::1... > > > > > >Wed Nov 26 14:51:23 MSK 2003 > > >Debugger+0x55: xchgl %ebx,in_Debugger.0 > > > > [....] > > > > It looks very similar to > > http://www.freebsd.org/cgi/query-pr.cgi?pr=59576. You can revert to > > version 1.28 of net/bpf.h if you need tcpdump on lo, tun, ic, plip, disc > > or gif interface right now. > > just to note: I ran tcpdump on tunN (which was a pppoe interface) w/o > problems two days ago (with a recent world) while debugging and > testing other net related things. As was noted earlier, the issue is the addition of M_ASSERTVALID to the BPF_MTAP macro. This fails in numerous cases because existing practice was to allocate a "fake mbuf" on the stack for passing local data in to bpf. If this mbuf is not zero'd (or at least m_flags) then the assertion may trip. It's arguable what the correct solution is for these problems but you should be able to safely remove the assert until we can make a sweep over the drivers as the existing code has been around for a while (not to imply this makes it right :)). Sam
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