34 Thread 0x41d4c950 (LWP 22247)  0x00007ff080205336 in poll () from /lib/libc.so.6
  33 Thread 0x40a2d950 (LWP 22266)  0x00007ff080205336 in poll () from /lib/libc.so.6
  32 Thread 0x40a69950 (LWP 22267)  0x00007ff0801df241 in nanosleep () from /lib/libc.so.6
  31 Thread 0x41d88950 (LWP 22268)  0x00007ff0802072f2 in select () from /lib/libc.so.6
  30 Thread 0x41dc4950 (LWP 22269)  0x00007ff0802072f2 in select () from /lib/libc.so.6
  29 Thread 0x41e00950 (LWP 22270)  0x00007ff0802072f2 in select () from /lib/libc.so.6
  28 Thread 0x40ec0950 (LWP 22295)  0x00007ff0802072f2 in select () from /lib/libc.so.6
  27 Thread 0x40efc950 (LWP 22296)  0x00007ff0802072f2 in select () from /lib/libc.so.6
  26 Thread 0x40d59950 (LWP 22297)  0x00007ff0801df241 in nanosleep () from /lib/libc.so.6
  25 Thread 0x40d95950 (LWP 22298)  0x00007ff080b6f38b in accept () from /lib/libpthread.so.0
  24 Thread 0x40dd1950 (LWP 22299)  0x00007ff080205336 in poll () from /lib/libc.so.6
  23 Thread 0x41b66950 (LWP 22300)  0x00007ff080b6c889 in pthread_cond_wait@@GLIBC_2.3.2 ()
   from /lib/libpthread.so.0
  22 Thread 0x40278950 (LWP 22301)  0x00007ff0802072f2 in select () from /lib/libc.so.6
  21 Thread 0x407cf950 (LWP 22302)  0x00007ff080205336 in poll () from /lib/libc.so.6
  20 Thread 0x416fe950 (LWP 22303)  0x00007ff080205336 in poll () from /lib/libc.so.6
  19 Thread 0x41e3c950 (LWP 22304)  0x00007ff080205336 in poll () from /lib/libc.so.6
  18 Thread 0x41e78950 (LWP 22305)  0x00007ff0801df241 in nanosleep () from /lib/libc.so.6
  17 Thread 0x412d6950 (LWP 22306)  0x00007ff080b6c889 in pthread_cond_wait@@GLIBC_2.3.2 ()
   from /lib/libpthread.so.0
  16 Thread 0x41312950 (LWP 22307)  0x00007ff080b6c889 in pthread_cond_wait@@GLIBC_2.3.2 ()
   from /lib/libpthread.so.0
  15 Thread 0x4134e950 (LWP 22308)  0x00007ff080b6c889 in pthread_cond_wait@@GLIBC_2.3.2 ()
   from /lib/libpthread.so.0
  14 Thread 0x4138a950 (LWP 22309)  0x00007ff080b6c889 in pthread_cond_wait@@GLIBC_2.3.2 ()
   from /lib/libpthread.so.0
  13 Thread 0x413c6950 (LWP 22310)  0x00007ff080b6c889 in pthread_cond_wait@@GLIBC_2.3.2 ()
   from /lib/libpthread.so.0
  12 Thread 0x41402950 (LWP 22311)  0x00007ff080b6c889 in pthread_cond_wait@@GLIBC_2.3.2 ()
   from /lib/libpthread.so.0
  11 Thread 0x4143e950 (LWP 22312)  0x00007ff080b6c889 in pthread_cond_wait@@GLIBC_2.3.2 ()
   from /lib/libpthread.so.0
  10 Thread 0x4147a950 (LWP 22313)  0x00007ff080b6c889 in pthread_cond_wait@@GLIBC_2.3.2 ()
   from /lib/libpthread.so.0
  9 Thread 0x414b6950 (LWP 22314)  0x00007ff080b6c889 in pthread_cond_wait@@GLIBC_2.3.2 ()
   from /lib/libpthread.so.0
  8 Thread 0x414f2950 (LWP 22315)  0x00007ff080b6c889 in pthread_cond_wait@@GLIBC_2.3.2 ()
   from /lib/libpthread.so.0
  7 Thread 0x4152e950 (LWP 22316)  0x00007ff080b6cb0d in pthread_cond_timedwait@@GLIBC_2.3.2 ()
   from /lib/libpthread.so.0
  6 Thread 0x4156a950 (LWP 22317)  0x00007ff080205336 in poll () from /lib/libc.so.6
  5 Thread 0x410ac950 (LWP 22318)  0x00007ff080b6ed04 in __lll_lock_wait () from /lib/libpthread.so.0
  4 Thread 0x403da950 (LWP 22319)  0x00007ff080205336 in poll () from /lib/libc.so.6
  3 Thread 0x40530950 (LWP 22321)  0x00007ff080205336 in poll () from /lib/libc.so.6
  2 Thread 0x4119e950 (LWP 22345)  0x00007ff080b6ed04 in __lll_lock_wait () from /lib/libpthread.so.0
  1 Thread 0x7ff08108a6e0 (LWP 22245)  0x00007ff080205336 in poll () from /lib/libc.so.6

Thread 34 (Thread 0x41d4c950 (LWP 22247)):
#0  0x00007ff080205336 in poll () from /lib/libc.so.6
#1  0x000000000042b2ab in listener (unused=0x0) at asterisk.c:995
#2  0x00000000004c89a7 in dummy_start (data=0x16e33a0) at utils.c:895
#3  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#4  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#5  0x0000000000000000 in ?? ()

Thread 33 (Thread 0x40a2d950 (LWP 22266)):
#0  0x00007ff080205336 in poll () from /lib/libc.so.6
#1  0x000000000047f2c9 in accept_thread (ignore=0x0) at manager.c:2496
#2  0x00000000004c89a7 in dummy_start (data=0x16e6130) at utils.c:895
#3  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#4  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#5  0x0000000000000000 in ?? ()

Thread 32 (Thread 0x40a69950 (LWP 22267)):
#0  0x00007ff0801df241 in nanosleep () from /lib/libc.so.6
#1  0x00007ff080207ad4 in usleep () from /lib/libc.so.6
#2  0x000000000044123c in channel_find_locked (prev=0x0, name=0x40a68ee0 "Zap/1-", namelen=6, 
    context=0x0, exten=0x0, uniqueid=0x0) at channel.c:1106
#3  0x00000000004412ef in ast_get_channel_by_name_prefix_locked (name=0x40a68ee0 "Zap/1-", namelen=6)
    at channel.c:1127
#4  0x0000000000459d39 in ast_parse_device_state (device=0x16f0468 "Zap/1") at devicestate.c:118
#5  0x0000000000459f4c in ast_device_state (device=0x16f0468 "Zap/1") at devicestate.c:170
#6  0x000000000045a49a in do_state_change (device=0x16f0468 "Zap/1", cid_num=0x16f03c8 "", 
    cid_name=0x16f0418 "") at devicestate.c:287
#7  0x000000000045aaac in do_devstate_changes (data=0x0) at devicestate.c:383
#8  0x00000000004c89a7 in dummy_start (data=0x16e6040) at utils.c:895
#9  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#10 0x00007ff08020d5bd in clone () from /lib/libc.so.6
#11 0x0000000000000000 in ?? ()

Thread 31 (Thread 0x41d88950 (LWP 22268)):
#0  0x00007ff0802072f2 in select () from /lib/libc.so.6
#1  0x00007ff07f2f9ed4 in ?? () from /usr/lib/asterisk/modules/res_features.so
#2  0x00007ff07f2f9e94 in ?? () from /usr/lib/asterisk/modules/res_features.so
#3  0x00000000004c89a7 in dummy_start (data=0x16ee530) at utils.c:895
#4  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#5  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 30 (Thread 0x41dc4950 (LWP 22269)):
#0  0x00007ff0802072f2 in select () from /lib/libc.so.6
#1  0x00007ff07f2f9ed4 in ?? () from /usr/lib/asterisk/modules/res_features.so
#2  0x00007ff07f2fb6b3 in ?? () from /usr/lib/asterisk/modules/res_features.so
#3  0x00000000004c89a7 in dummy_start (data=0x16f1820) at utils.c:895
#4  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#5  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 29 (Thread 0x41e00950 (LWP 22270)):
#0  0x00007ff0802072f2 in select () from /lib/libc.so.6
#1  0x00007ff07f2f9ed4 in ?? () from /usr/lib/asterisk/modules/res_features.so
#2  0x00007ff07f2fda0d in ?? () from /usr/lib/asterisk/modules/res_features.so
#3  0x00000000004c89a7 in dummy_start (data=0x16f1c70) at utils.c:895
#4  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#5  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 28 (Thread 0x40ec0950 (LWP 22295)):
#0  0x00007ff0802072f2 in select () from /lib/libc.so.6
#1  0x00007ff077fef35c in ast_select (nfds=11, rfds=0x40ebefa0, wfds=0x40ebef20, efds=0x0, tvp=0x0)
    at /home/kmshanah/debs/asterisk/asterisk-1.4.21.2~dfsg/include/asterisk/channel.h:1374
#2  0x00007ff077fef11f in sound_thread (arg=0x172a080) at chan_oss.c:628
#3  0x00000000004c89a7 in dummy_start (data=0x1729cc0) at utils.c:895
#4  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#5  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 27 (Thread 0x40efc950 (LWP 22296)):
#0  0x00007ff0802072f2 in select () from /lib/libc.so.6
#1  0x00007ff077fef35c in ast_select (nfds=13, rfds=0x40efafa0, wfds=0x40efaf20, efds=0x0, tvp=0x0)
    at /home/kmshanah/debs/asterisk/asterisk-1.4.21.2~dfsg/include/asterisk/channel.h:1374
#2  0x00007ff077fef11f in sound_thread (arg=0x172a790) at chan_oss.c:628
#3  0x00000000004c89a7 in dummy_start (data=0x1729e70) at utils.c:895
#4  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#5  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 26 (Thread 0x40d59950 (LWP 22297)):
#0  0x00007ff0801df241 in nanosleep () from /lib/libc.so.6
#1  0x00007ff0801df064 in sleep () from /lib/libc.so.6
#2  0x00007ff075bba388 in scan_thread (unused=0x0) at pbx_spool.c:458
#3  0x00000000004c89a7 in dummy_start (data=0x1734010) at utils.c:895
#4  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#5  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 25 (Thread 0x40d95950 (LWP 22298)):
#0  0x00007ff080b6f38b in accept () from /lib/libpthread.so.0
#1  0x00007ff0757acd91 in accept_thread (ignore=0x0) at chan_skinny.c:4582
#2  0x00000000004c89a7 in dummy_start (data=0x1734ea0) at utils.c:895
#3  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#4  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#5  0x0000000000000000 in ?? ()

Thread 24 (Thread 0x40dd1950 (LWP 22299)):
#0  0x00007ff080205336 in poll () from /lib/libc.so.6
#1  0x0000000000470769 in ast_io_wait (ioc=0x1734e70, howlong=1000) at io.c:266
#2  0x00007ff0757acf77 in do_monitor (data=0x0) at chan_skinny.c:4629
#3  0x00000000004c89a7 in dummy_start (data=0x1734ec0) at utils.c:895
#4  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#5  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 23 (Thread 0x41b66950 (LWP 22300)):
#0  0x00007ff080b6c889 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00007ff074d7ea86 in ast_cond_wait (cond=0x7ff074f93bf8, t=0x7ff074f93bd0)
    at /home/kmshanah/debs/asterisk/asterisk-1.4.21.2~dfsg/include/asterisk/lock.h:787
#2  0x00007ff074d7e95d in device_state_thread (data=0x0) at app_queue.c:697
#3  0x00000000004c89a7 in dummy_start (data=0x173d3f0) at utils.c:895
#4  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#5  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 22 (Thread 0x40278950 (LWP 22301)):
#0  0x00007ff0802072f2 in select () from /lib/libc.so.6
#1  0x00007ff06e9cce16 in ast_select (nfds=0, rfds=0x40277fb0, wfds=0x0, efds=0x40277f30, tvp=0x0)
    at /home/kmshanah/debs/asterisk/asterisk-1.4.21.2~dfsg/include/asterisk/channel.h:1374
#2  0x00007ff06e9ccc2f in do_monitor (data=0x0) at chan_phone.c:1061
#3  0x00000000004c89a7 in dummy_start (data=0x7ff0700083f0) at utils.c:895
#4  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#5  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 21 (Thread 0x407cf950 (LWP 22302)):
#0  0x00007ff080205336 in poll () from /lib/libc.so.6
#1  0x0000000000470769 in ast_io_wait (ioc=0x7ff07000bc10, howlong=1000) at io.c:266
#2  0x00007ff06d98ff3b in do_monitor (data=0x0) at chan_sip.c:15775
#3  0x00000000004c89a7 in dummy_start (data=0x7ff070010ce0) at utils.c:895
#4  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#5  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 20 (Thread 0x416fe950 (LWP 22303)):
#0  0x00007ff080205336 in poll () from /lib/libc.so.6
#1  0x0000000000470769 in ast_io_wait (ioc=0x7ff070010d40, howlong=1000) at io.c:266
#2  0x00007ff06cd0b2d7 in do_monitor (data=0x0) at chan_mgcp.c:3514
#3  0x00000000004c89a7 in dummy_start (data=0x7ff070010df0) at utils.c:895
#4  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#5  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 19 (Thread 0x41e3c950 (LWP 22304)):
#0  0x00007ff080205336 in poll () from /lib/libc.so.6
#1  0x0000000000470769 in ast_io_wait (ioc=0x7ff07000fae0, howlong=1000) at io.c:266
#2  0x00007ff06bed1b23 in network_thread (ignore=0x0) at pbx_dundi.c:2139
#3  0x00000000004c89a7 in dummy_start (data=0x7ff070010df0) at utils.c:895
#4  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#5  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 18 (Thread 0x41e78950 (LWP 22305)):
#0  0x00007ff0801df241 in nanosleep () from /lib/libc.so.6
#1  0x00007ff0801df064 in sleep () from /lib/libc.so.6
#2  0x00007ff06bed1c9c in process_precache (ign=0x0) at pbx_dundi.c:2182
#3  0x00000000004c89a7 in dummy_start (data=0x7ff070013d00) at utils.c:895
#4  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#5  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 17 (Thread 0x412d6950 (LWP 22306)):
#0  0x00007ff080b6c889 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00007ff062d27440 in ast_cond_wait (cond=0x7ff0700b8fa8, t=0x7ff0700b8f80)
    at /home/kmshanah/debs/asterisk/asterisk-1.4.21.2~dfsg/include/asterisk/lock.h:787
#2  0x00007ff062d2705d in iax2_process_thread (data=0x7ff0700b7ec0) at chan_iax2.c:8588
#3  0x00000000004c89a7 in dummy_start (data=0x7ff0700b66e0) at utils.c:895
#4  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#5  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 16 (Thread 0x41312950 (LWP 22307)):
#0  0x00007ff080b6c889 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00007ff062d27440 in ast_cond_wait (cond=0x7ff0700ba0f8, t=0x7ff0700ba0d0)
    at /home/kmshanah/debs/asterisk/asterisk-1.4.21.2~dfsg/include/asterisk/lock.h:787
#2  0x00007ff062d2705d in iax2_process_thread (data=0x7ff0700b9010) at chan_iax2.c:8588
#3  0x00000000004c89a7 in dummy_start (data=0x7ff0700b7920) at utils.c:895
#4  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#5  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 15 (Thread 0x4134e950 (LWP 22308)):
#0  0x00007ff080b6c889 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00007ff062d27440 in ast_cond_wait (cond=0x7ff0700bb248, t=0x7ff0700bb220)
    at /home/kmshanah/debs/asterisk/asterisk-1.4.21.2~dfsg/include/asterisk/lock.h:787
#2  0x00007ff062d2705d in iax2_process_thread (data=0x7ff0700ba160) at chan_iax2.c:8588
#3  0x00000000004c89a7 in dummy_start (data=0x7ff0700b66e0) at utils.c:895
#4  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#5  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 14 (Thread 0x4138a950 (LWP 22309)):
#0  0x00007ff080b6c889 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00007ff062d27440 in ast_cond_wait (cond=0x7ff0700bc398, t=0x7ff0700bc370)
    at /home/kmshanah/debs/asterisk/asterisk-1.4.21.2~dfsg/include/asterisk/lock.h:787
#2  0x00007ff062d2705d in iax2_process_thread (data=0x7ff0700bb2b0) at chan_iax2.c:8588
#3  0x00000000004c89a7 in dummy_start (data=0x7ff0700b7a80) at utils.c:895
#4  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#5  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 13 (Thread 0x413c6950 (LWP 22310)):
#0  0x00007ff080b6c889 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00007ff062d27440 in ast_cond_wait (cond=0x7ff0700bd4e8, t=0x7ff0700bd4c0)
    at /home/kmshanah/debs/asterisk/asterisk-1.4.21.2~dfsg/include/asterisk/lock.h:787
#2  0x00007ff062d2705d in iax2_process_thread (data=0x7ff0700bc400) at chan_iax2.c:8588
#3  0x00000000004c89a7 in dummy_start (data=0x7ff0700b7920) at utils.c:895
#4  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#5  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 12 (Thread 0x41402950 (LWP 22311)):
#0  0x00007ff080b6c889 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00007ff062d27440 in ast_cond_wait (cond=0x7ff0700be638, t=0x7ff0700be610)
    at /home/kmshanah/debs/asterisk/asterisk-1.4.21.2~dfsg/include/asterisk/lock.h:787
#2  0x00007ff062d2705d in iax2_process_thread (data=0x7ff0700bd550) at chan_iax2.c:8588
#3  0x00000000004c89a7 in dummy_start (data=0x7ff0700b75e0) at utils.c:895
#4  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#5  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 11 (Thread 0x4143e950 (LWP 22312)):
#0  0x00007ff080b6c889 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00007ff062d27440 in ast_cond_wait (cond=0x7ff0700bf788, t=0x7ff0700bf760)
    at /home/kmshanah/debs/asterisk/asterisk-1.4.21.2~dfsg/include/asterisk/lock.h:787
#2  0x00007ff062d2705d in iax2_process_thread (data=0x7ff0700be6a0) at chan_iax2.c:8588
#3  0x00000000004c89a7 in dummy_start (data=0x7ff0700b75e0) at utils.c:895
#4  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#5  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 10 (Thread 0x4147a950 (LWP 22313)):
#0  0x00007ff080b6c889 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00007ff062d27440 in ast_cond_wait (cond=0x7ff0700c08d8, t=0x7ff0700c08b0)
    at /home/kmshanah/debs/asterisk/asterisk-1.4.21.2~dfsg/include/asterisk/lock.h:787
#2  0x00007ff062d2705d in iax2_process_thread (data=0x7ff0700bf7f0) at chan_iax2.c:8588
#3  0x00000000004c89a7 in dummy_start (data=0x7ff0700b7a80) at utils.c:895
#4  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#5  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 9 (Thread 0x414b6950 (LWP 22314)):
#0  0x00007ff080b6c889 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00007ff062d27440 in ast_cond_wait (cond=0x7ff0700c1a28, t=0x7ff0700c1a00)
    at /home/kmshanah/debs/asterisk/asterisk-1.4.21.2~dfsg/include/asterisk/lock.h:787
#2  0x00007ff062d2705d in iax2_process_thread (data=0x7ff0700c0940) at chan_iax2.c:8588
#3  0x00000000004c89a7 in dummy_start (data=0x7ff0700b75e0) at utils.c:895
#4  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#5  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 8 (Thread 0x414f2950 (LWP 22315)):
#0  0x00007ff080b6c889 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00007ff062d27440 in ast_cond_wait (cond=0x7ff0700c2ca8, t=0x7ff0700c2c80)
    at /home/kmshanah/debs/asterisk/asterisk-1.4.21.2~dfsg/include/asterisk/lock.h:787
#2  0x00007ff062d2705d in iax2_process_thread (data=0x7ff0700c1bc0) at chan_iax2.c:8588
#3  0x00000000004c89a7 in dummy_start (data=0x7ff0700b7a80) at utils.c:895
#4  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#5  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 7 (Thread 0x4152e950 (LWP 22316)):
#0  0x00007ff080b6cb0d in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00007ff062d27421 in ast_cond_timedwait (cond=0x7ff062f45c60, t=0x7ff062f43040, abstime=0x4152e020)
    at /home/kmshanah/debs/asterisk/asterisk-1.4.21.2~dfsg/include/asterisk/lock.h:792
#2  0x00007ff062d29016 in sched_thread (ignore=0x0) at chan_iax2.c:9042
#3  0x00000000004c89a7 in dummy_start (data=0x7ff0700b75e0) at utils.c:895
#4  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#5  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 6 (Thread 0x4156a950 (LWP 22317)):
#0  0x00007ff080205336 in poll () from /lib/libc.so.6
#1  0x0000000000470769 in ast_io_wait (ioc=0x7ff0700b41c0, howlong=-1) at io.c:266
#2  0x00007ff062d2934f in network_thread (ignore=0x0) at chan_iax2.c:9111
#3  0x00000000004c89a7 in dummy_start (data=0x7ff0700b7a80) at utils.c:895
#4  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#5  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 5 (Thread 0x410ac950 (LWP 22318)):
#0  0x00007ff080b6ed04 in __lll_lock_wait () from /lib/libpthread.so.0
#1  0x00007ff080b6a933 in _L_lock_261 () from /lib/libpthread.so.0
#2  0x00007ff080b6a2f8 in pthread_mutex_lock () from /lib/libpthread.so.0
#3  0x000000000048346a in ast_mutex_lock (pmutex=0x17872b8)
    at /home/kmshanah/debs/asterisk/asterisk-1.4.21.2~dfsg/include/asterisk/lock.h:755
#4  0x0000000000490dd8 in pbx_builtin_setvar_helper (chan=0x17871f0, 
    name=0x7ff062628ac2 "PRI_NETWORK_CID", value=0x410abab0 "883251325") at pbx.c:5882
#5  0x00007ff062614dd8 in pri_dchannel (vpri=0x7ff062831080) at chan_zap.c:9607
#6  0x00000000004c89a7 in dummy_start (data=0x7ff0700b75e0) at utils.c:895
#7  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#8  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#9  0x0000000000000000 in ?? ()

Thread 4 (Thread 0x403da950 (LWP 22319)):
#0  0x00007ff080205336 in poll () from /lib/libc.so.6
#1  0x00007ff06260a725 in do_monitor (data=0x0) at chan_zap.c:7068
#2  0x00000000004c89a7 in dummy_start (data=0x7ff0700b75e0) at utils.c:895
#3  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#4  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#5  0x0000000000000000 in ?? ()

Thread 3 (Thread 0x40530950 (LWP 22321)):
#0  0x00007ff080205336 in poll () from /lib/libc.so.6
#1  0x000000000042b0ce in netconsole (vconsole=0x753a00) at asterisk.c:944
#2  0x00000000004c89a7 in dummy_start (data=0x16e4d00) at utils.c:895
#3  0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#4  0x00007ff08020d5bd in clone () from /lib/libc.so.6
#5  0x0000000000000000 in ?? ()

Thread 2 (Thread 0x4119e950 (LWP 22345)):
#0  0x00007ff080b6ed04 in __lll_lock_wait () from /lib/libpthread.so.0
#1  0x00007ff080b6a933 in _L_lock_261 () from /lib/libpthread.so.0
#2  0x00007ff080b6a2f8 in pthread_mutex_lock () from /lib/libpthread.so.0
#3  0x00007ff0625f114d in ast_mutex_lock (pmutex=0x7ff0700c7380)
    at /home/kmshanah/debs/asterisk/asterisk-1.4.21.2~dfsg/include/asterisk/lock.h:755
#4  0x00007ff0625f82e0 in zt_answer (ast=0x17871f0) at chan_zap.c:2882
#5  0x0000000000442614 in ast_answer (chan=0x17871f0) at channel.c:1545
#6  0x00007ff06cf2a04a in vm_exec (chan=0x17871f0, data=0x4119ba00) at app_voicemail.c:7033
#7  0x00000000004833d4 in pbx_exec (c=0x17871f0, app=0x7ff07000eca0, data=0x4119ba00) at pbx.c:537
#8  0x0000000000486a06 in pbx_extension_helper (c=0x17871f0, con=0x0, context=0x1787440 "incoming", 
    exten=0x1787490 "82457100", priority=3, label=0x0, callerid=0x16fcfd0 "883251325", action=E_SPAWN)
    at pbx.c:1862
#9  0x0000000000487c50 in ast_spawn_extension (c=0x17871f0, context=0x1787440 "incoming", 
    exten=0x1787490 "82457100", priority=3, callerid=0x16fcfd0 "883251325") at pbx.c:2317
#10 0x00000000004881d5 in __ast_pbx_run (c=0x17871f0) at pbx.c:2419
#11 0x0000000000489060 in pbx_thread (data=0x17871f0) at pbx.c:2636
#12 0x00000000004c89a7 in dummy_start (data=0x16fcc80) at utils.c:895
#13 0x00007ff080b68017 in start_thread () from /lib/libpthread.so.0
#14 0x00007ff08020d5bd in clone () from /lib/libc.so.6
#15 0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7ff08108a6e0 (LWP 22245)):
#0  0x00007ff080205336 in poll () from /lib/libc.so.6
#1  0x000000000042f8e3 in monitor_sig_flags (unused=0x0) at asterisk.c:2597
#2  0x0000000000431636 in main (argc=5, argv=0x7fff8919be88) at asterisk.c:3135
#0  0x00007ff080205336 in poll () from /lib/libc.so.6

--

Looking at thread 5, we are calling pbx_builtin_setvar_helper() from pri_dchannel() at chan_zap.c:9607.
Going up to line 9593, we take this lock:  ast_mutex_lock(&pri->pvts[chanpos]->lock);
Let's jump into gdb again:

(gdb) thread 5
[Switching to thread 5 (Thread 0x410ac950 (LWP 22318))]#0  0x00007ff080b6ed04 in __lll_lock_wait ()
   from /lib/libpthread.so.0
(gdb) print &pri_dchannel::pri->pvts[pri_dchannel::chanpos]->lock
$2 = (ast_mutex_t *) 0x7ff0700c7380

Note the address of this lock. It is the same lock being taken on line 3 of the backtrace on thread 2.
Moving back up that call path, we have come down via ast_answer() -> zt_answer() -> ast_mutex_lock().
Now, the first thing that ast_answer does is take the channel lock at channel.c:1530.

(gdb) thread 2
[Switching to thread 2 (Thread 0x4119e950 (LWP 22345))]#0  0x00007ff080b6ed04 in __lll_lock_wait ()
   from /lib/libpthread.so.0
(gdb) print &ast_answer::chan->lock
$5 = (ast_mutex_t *) 0x17872b8

Same lock that pbx_builtin_setvar_helper() is waiting for in thread 5.

AB <-> BA deadlock.