Date: Mon, 23 May 2005 14:27:52 -0400 From: "Robin P. Blanchard" <robin.blanchard@gactr.uga.edu> To: "Doug White" <dwhite@gumbysoft.com> Cc: stable@freebsd.org Subject: RE: RELENG_5 panic Message-ID: <9B5C1FCAFB35084787C21EFFFA78DD9EF136A6@EBE1.gc.nat>
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> Oh another of these wonderful races... can you go to that=20
> frame and "print ts"? If its NULL then someone has ripped=20
> out the ts out from under us since it was checked for NULL in=20
> the previous line!
Maybe this is a more useful kgdb session (I'm hoping)
# kgdb kernel.debug /usr/local/var/adm/crash/vmcore.44=20
[GDB will not be able to debug user-mode threads: =
/usr/lib/libthread_db.so:
Undefined symbol "ps_pglobal_lookup"]
GNU gdb 6.1.1 [FreeBSD]
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you =
are
welcome to change it and/or distribute copies of it under certain =
conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for =
details.
This GDB was configured as "i386-marcel-freebsd".
#0 doadump () at pcpu.h:160
160 __asm __volatile("movl %%fs:0,%0" : "=3Dr" (td));
(kgdb) l *0xc0504808
0xc0504808 is in turnstile_wait =
(/usr/src/sys/kern/subr_turnstile.c:245).
240 /*
241 * Pick up the lock that td is blocked on.
242 */
243 ts =3D td->td_blocked;
244 MPASS(ts !=3D NULL);
245 tc =3D TC_LOOKUP(ts->ts_lockobj);
246 mtx_lock_spin(&tc->tc_lock);
247
248 /*
249 * This thread may not be blocked on this =
turnstile
anymore
(kgdb) bt=20
#0 doadump () at pcpu.h:160
#1 0xc04dd58c in boot (howto=3D260) at =
/usr/src/sys/kern/kern_shutdown.c:410
#2 0xc04ddccd in panic (fmt=3D0xc066e594 "%s") at
/usr/src/sys/kern/kern_shutdown.c:566
#3 0xc0641e92 in trap_fatal (frame=3D0xc7ac0bc8, eva=3D36) at
/usr/src/sys/i386/i386/trap.c:817
#4 0xc0642535 in trap (frame=3D
{tf_fs =3D 24, tf_es =3D -1066598384, tf_ds =3D -1066532848, =
tf_edi =3D
-1053916800, tf_esi =3D -1049515008, tf_ebp =3D -945025988, tf_isp =3D =
-945026060,
tf_ebx =3D -1053916800, tf_edx =3D -1053937024, tf_ecx =3D 56, tf_eax =
=3D 0,
tf_trapno =3D 12, tf_err =3D 0, tf_eip =3D -1068480504, tf_cs =3D 8, =
tf_eflags =3D
65683, tf_esp =3D -1053914880, tf_ss =3D 582}) at
/usr/src/sys/i386/i386/trap.c:255
#5 0xc062da3a in calltrap () at /usr/src/sys/i386/i386/exception.s:140
#6 0x00000018 in ?? ()
#7 0xc06d0010 in ipq ()
#8 0xc06e0010 in sc_buffer.3 ()
#9 0xc12e8180 in ?? ()
#10 0xc171ac00 in ?? ()
#11 0xc7ac0c3c in ?? ()
#12 0xc7ac0bf4 in ?? ()
#13 0xc12e8180 in ?? ()
#14 0xc12e3280 in ?? ()
#15 0x00000038 in ?? ()
#16 0x00000000 in ?? ()
#17 0x0000000c in ?? ()
#18 0x00000000 in ?? ()
#19 0xc0504808 in turnstile_wait (ts=3D0xc12e3280, lock=3D0xc06d022c,
owner=3D0xc171ac00)
at /usr/src/sys/kern/subr_turnstile.c:243
#20 0xc04d2b7f in _mtx_lock_sleep (m=3D0xc06d022c, td=3D0xc12e8180, =
opts=3D0,
file=3D0x0, line=3D0)
at /usr/src/sys/kern/kern_mutex.c:552
#21 0xc058a592 in tcp_isn_tick (xtp=3D0x0) at
/usr/src/sys/netinet/tcp_subr.c:1380
#22 0xc04ed069 in softclock (dummy=3D0x0) at
/usr/src/sys/kern/kern_timeout.c:279
#23 0xc04c460a in ithread_loop (arg=3D0xc12fd500) at
/usr/src/sys/kern/kern_intr.c:547
#24 0xc04c32c2 in fork_exit (callout=3D0xc04c4550 <ithread_loop>, =
arg=3D0x0,
frame=3D0x0)
at /usr/src/sys/kern/kern_fork.c:791
#25 0xc062da9c in fork_trampoline () at
/usr/src/sys/i386/i386/exception.s:209
(kgdb) frame 19
#19 0xc0504808 in turnstile_wait (ts=3D0xc12e3280, lock=3D0xc06d022c,
owner=3D0xc171ac00)
at /usr/src/sys/kern/subr_turnstile.c:243
243 ts =3D td->td_blocked;
(kgdb) list
238 ts->ts_lockobj->lo_name));
239
240 /*
241 * Pick up the lock that td is blocked on.
242 */
243 ts =3D td->td_blocked;
244 MPASS(ts !=3D NULL);
245 tc =3D TC_LOOKUP(ts->ts_lockobj);
246 mtx_lock_spin(&tc->tc_lock);
247
(kgdb) print ts
$1 =3D (struct turnstile *) 0xc12e3280
(kgdb) up
#20 0xc04d2b7f in _mtx_lock_sleep (m=3D0xc06d022c, td=3D0xc12e8180, =
opts=3D0,
file=3D0x0, line=3D0)
at /usr/src/sys/kern/kern_mutex.c:552
552 turnstile_wait(ts, &m->mtx_object, =
mtx_owner(m));
(kgdb) list
547 #endif
548
549 /*
550 * Block on the turnstile.
551 */
552 turnstile_wait(ts, &m->mtx_object, =
mtx_owner(m));
553 }
554
555 #ifdef KTR
556 if (cont_logged) {
(kgdb) print ts
$2 =3D (struct turnstile *) 0x0
(kgdb)=20
---------------------------------------
Robin P. Blanchard
Systems Integration Specialist
Georgia Center for Continuing Education
fon: 706.542.2404 < > fax: 706.542.6546
---------------------------------------
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