gdb does not show full backtrace for deadlocked pthread program.

[Ben Greear <greearb@candelatech.com>]

Hello!

I have a program that uses pthreads and evidently has a
nifty little thread deadlock.

The interesting thing is that gdb will not show me the full
backtrace of the deadlocked threads.  Both tested system's running
a slightly modified 2.6.11 kernel.  The FC2 system is a dual-xeon with
SMP kernel.  The FC4 machine is a laptop with UP kernel.
FC2's gdb doesn't even decode frame 3, but on FC4 I get this:

[after attaching to deadlocked process]

(gdb) thread apply all bt

Thread 2 (Thread -1208132688 (LWP 9895)):
#0  0xffffe410 in ?? ()
#1  0xb7fd50e8 in ?? ()
#2  0x00000002 in ?? ()
#3  0x004b4e7e in __lll_mutex_lock_wait () from /lib/libpthread.so.0

Thread 1 (Thread -1208026656 (LWP 9892)):
#0  0xffffe410 in ?? ()
#1  0xbffff118 in ?? ()
#2  0x00000002 in ?? ()
#3  0x004b4e7e in __lll_mutex_lock_wait () from /lib/libpthread.so.0


Frames 0 and 1 appear to be in linux-gate.so, most likely whatever
kernel call allows nptl to work??

Any idea how to get a full backtrace for these threads?

Thanks,
Ben

-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com