RELENG_7 crash

Mike Tancsa mike at
Tue Apr 21 15:20:09 UTC 2009

At 11:11 AM 4/21/2009, John Baldwin wrote:

>Can you do 'frame 7' followed by 'l', 'p ifp', and 'p ifp->if_snd'?


kgdb) bt
#0  doadump () at pcpu.h:196
#1  0xc05964d7 in boot (howto=260) at /usr/src/sys/kern/kern_shutdown.c:418
#2  0xc05967a9 in panic (fmt=Variable "fmt" is not available.
) at /usr/src/sys/kern/kern_shutdown.c:574
#3  0xc07f64ac in trap_fatal (frame=0xe766ea6c, eva=104) at 
#4  0xc07f6730 in trap_pfault (frame=0xe766ea6c, usermode=0, eva=104) 
at /usr/src/sys/i386/i386/trap.c:852
#5  0xc07f70dc in trap (frame=0xe766ea6c) at /usr/src/sys/i386/i386/trap.c:530
#6  0xc07db7eb in calltrap () at /usr/src/sys/i386/i386/exception.s:159
#7  0xc0637146 in sysctl_ifdata (oidp=0xc08816a0, arg1=0xe766ec24, 
arg2=2, req=0xe766eba4) at /usr/src/sys/net/if_mib.c:127
#8  0xc059fd77 in sysctl_root (oidp=Variable "oidp" is not available.
) at /usr/src/sys/kern/kern_sysctl.c:1413
#9  0xc059ff14 in userland_sysctl (td=0xc5374460, name=0xe766ec14, 
namelen=6, old=0x0, oldlenp=0xbfbf8478, inkernel=0, new=0x0,
     newlen=0, retval=0xe766ec10, flags=0) at 
#10 0xc05a0064 in __sysctl (td=0xc5374460, uap=0xe766ecfc) at 
#11 0xc07f6a85 in syscall (frame=0xe766ed38) at 
#12 0xc07db850 in Xint0x80_syscall () at /usr/src/sys/i386/i386/exception.s:255
#13 0x00000033 in ?? ()
Previous frame inner to this frame (corrupt stack?)
(kgdb) frame 7
#7  0xc0637146 in sysctl_ifdata (oidp=0xc08816a0, arg1=0xe766ec24, 
arg2=2, req=0xe766eba4) at /usr/src/sys/net/if_mib.c:127
127                     ifp->if_snd.ifq_drops = ifmd.ifmd_snd_drops;
(kgdb) l
122                     DONTCOPY(baudrate);
123     #undef DONTCOPY
124     #define COPY(fld) ifp->if_##fld = ifmd.ifmd_##fld
125                     COPY(data);
126                     ifp->if_snd.ifq_maxlen = ifmd.ifmd_snd_maxlen;
127                     ifp->if_snd.ifq_drops = ifmd.ifmd_snd_drops;
128     #undef COPY
129                     break;
131             case IFDATA_LINKSPECIFIC:
(kgdb) p ifp
$1 = (struct ifnet *) 0x0
(kgdb) p ifp->if_snd
Cannot access memory at address 0xf4

Is it possible I am running into some of the interface lock fixes 
rwatson has been working on ?  This box has a lot of ng interfaces 
which come and go. Perhaps snmp asking about an interface that just 
went away caused the panic ? I disabled bsnmp since the reboot and 
the box has been up for 10hrs so far.


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