Re: reproducible crash when building sysutils/net-snmp

["Steven M. Bellovin" <smb%cs.columbia.edu@localhost>]

On Fri, 11 Jan 2008 02:53:00 +0000
"Steven M. Bellovin" <smb%cs.columbia.edu@localhost> wrote:

> I'm trying to rebuild sysutils/net-snmp on a T61 running
> amd64-current.  The disk is FFS; I'm not using softdep.  Every time I
> try the build, the system hangs or panics.  This last time, I turned
> off cpu1; it didn't help.  The kernel is from last night.  Here's the
> backtrace from the dump:
> 
> #0  0xffffffff80503105 in cpu_reboot (howto=256, bootstr=<value
> optimized out>) at /usr/src/sys/arch/amd64/amd64/machdep.c:666
> 666                     dumpsys();
> (gdb) bt
> #0  0xffffffff80503105 in cpu_reboot (howto=256, bootstr=<value
> optimized out>) at /usr/src/sys/arch/amd64/amd64/machdep.c:666
> #1  0xffffffff80463178 in panic (
>     fmt=0xffffffff80961f05 <Address 0xffffffff80961f05 out of bounds>)
>     at /usr/src/sys/kern/subr_prf.c:230
> #2  0xffffffff80504e94 in trap (frame=0xffff80004f3428b0)
>     at /usr/src/sys/arch/amd64/amd64/trap.c:264
> #3  0xffffffff80100f02 in calltrap ()
> #4  0x0000000000001000 in ?? ()
> Previous frame inner to this frame (corrupt stack?)
> 
> I was able to rebuilt most of my other packages without any trouble;
> however, the system also crashed while I was deleting all of my
> packages prior to doing the rebuild.
> 
I narrowed down the problem to a particular portion of the autoconfig
script.  Here are the last few lines (with 'set -x' added) before it
crashes:

+ echo configure:38037: checking for correct flags to ps
+ echo -n checking for correct flags to ps... 
checking for correct flags to ps... + sync
+ test  = set
+ sync
+ grep -E  (ps) *$
+ + awk/bin/ps {print $NF} -e

As best I can tell, here's the actual code in that area:

echo $ECHO_N "checking for correct flags to ps... $ECHO_C" >&6
if test "${ac_cv_ps_flags+set}" = set; then
  echo $ECHO_N "(cached) $ECHO_C" >&6
else
  if test "`($PSPROG -e 2>&1) | $EGREP ' (ps) *$' | awk '{print $NF}'`"
= "ps" ; then
  ac_cv_ps_flags="-e"

However, I can execute that exact pipeline by hand without any problem.



                --Steve Bellovin, http://www.cs.columbia.edu/~smb