The following reply was made to PR kern/29787; it has been noted by GNATS.

From: Arto Selonen <arto@selonen.org>
To: gnats-bugs@NetBSD.org
Cc: 
Subject: Re: kern/29787 (me too on fxp(4))
Date: Tue, 26 Apr 2005 19:18:34 +0300 (EEST)

 Hi!
 
 I also experienced this panic today (some 30 hours after upgrading from
 2.99.16 to 3.99.3). My sources are from ~20050421, if that makes any 
 difference. The box has two fxp(4) interfaces, and acts as a 
 gateway/firewall with transparent web proxy (squid), plus DNS/NTP/etc.
 
 Here is what I have from the crash dump:
 
 # gdb netbsd.9
 (gdb) target kcore netbsd.9.core
 panic: m_copydata: m == 0, len %d
 #0  0x3fec0000 in ?? ()
 (gdb) bt
 #0  0x3fec0000 in ?? ()
 #1  0xc02a7447 in cpu_reboot ()
 #2  0xc01f59c1 in db_reboot_cmd ()
 #3  0xc01f5507 in db_command ()
 #4  0xc01f521a in db_command_loop ()
 #5  0xc01f82ec in db_trap ()
 #6  0xc02a4c7a in kdb_trap ()
 #7  0xc02af5c4 in trap ()
 #8  0xc0102e35 in calltrap ()
 #9  0xc0230efd in panic ()
 #10 0xc02446e9 in m_copydata ()
 #11 0xc011f92d in tcp_build_datapkt ()
 #12 0xc011eccd in tcp_output ()
 #13 0xc012014e in tcp_sack_newack ()
 #14 0xc011ac32 in tcp_input ()
 #15 0xc01144fc in ip_input ()
 #16 0xc0113f12 in ipintr ()
 #17 0xc0102b11 in Xsoftnet ()
 
 and here is that panic message:
 
 # dmesg -M netbsd.9.core | grep panic
 panic: m_copydata: m == 0, len 1
 
 I'm disabling SACK now...
 
 
 Hope this helps,
  		Artsi
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