(gdb) bt full
#0  0xb7e31f89 in free () from /lib/libc.so.6
No symbol table info available.
#1  0xb7b0187f in __sip_destroy (p=0x81a4738, lockowner=1) at chan_sip.c:2097
        cur = (struct sip_pvt *) 0x81a3210
        prev = (struct sip_pvt *) 0x0
        cp = (struct sip_pkt *) 0xb7b34e7e
#2  0xb7b02541 in sip_destroy (p=0x81a4738) at chan_sip.c:2270
No locals.
#3  0xb7afe14b in __sip_autodestruct (data=0x81a4738) at chan_sip.c:1332
        p = (struct sip_pvt *) 0x81a4738
#4  0x0805706e in ast_sched_runq (con=0x8142348) at sched.c:374
        current = (struct sched *) 0x81647a8
        tv = {tv_sec = 1137941835, tv_usec = 622709}
        x = 0
        res = -1092617248
#5  0xb7b2c3e4 in do_monitor (data=0x0) at chan_sip.c:11362
        res = 0
        sip = (struct sip_pvt *) 0x0
        peer = (struct sip_peer *) 0x0
        t = 1137941835
        fastrestart = 0
        lastpeernum = -1
        curpeernum = 8
        reloading = 0
#6  0xb7f9673e in pthread_start_thread () from /lib/libpthread.so.0
No symbol table info available.
#7  0xb7e8a08a in clone () from /lib/libc.so.6
No symbol table info available.
(gdb)