.
Thread 3 (LWP 2533):
#0  0xb779b416 in __kernel_vsyscall ()
No symbol table info available.
#1  0xb6e87e4b in poll () at ../sysdeps/unix/syscall-template.S:81
No locals.
#2  0xb6fcc21b in ?? ()
No symbol table info available.
#3  0xb9711468 in ?? ()
No symbol table info available.
Backtrace stopped: previous frame inner to this frame (corrupt stack?)
.
Thread 2 (LWP 2532):
#0  0xb779b416 in __kernel_vsyscall ()
No symbol table info available.
#1  0xb6e87e4b in poll () at ../sysdeps/unix/syscall-template.S:81
No locals.
#2  0xb6fcc21b in ?? ()
No symbol table info available.
#3  0xb56023d0 in ?? ()
No symbol table info available.
Backtrace stopped: previous frame inner to this frame (corrupt stack?)
.
Thread 1 (LWP 2531):
#0  0xb779b416 in __kernel_vsyscall ()
No symbol table info available.
#1  0xb6dd8786 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
        resultvar = <optimized out>
        resultvar = <optimized out>
        pid = -1225433088
        selftid = 2531
#2  0xb6ddbbd3 in __GI_abort () at abort.c:89
        save_stage = 2
        act = {__sigaction_handler = {sa_handler = 0x7364765b, sa_sigaction = 0x7364765b}, sa_mask = {__val = {1644846447, 1664694071, 758132784, 1647785826, 808464483, 2016244256, 808460400, 808464432, 807415856, 825244216, 876032288, 540161336, 538976288, 1651076143, 942893359, 1768697142, 762869102, 796225127, 841835628, 775434542, 1644851059, 1667381047, 758132784, 1647785826, 808464484, 757953056, 808460400, 812003632, 807415856, 825244216, 0, 0}}, sa_flags = -1227088708, sa_restorer = 0xb6f56000}
        sigs = {__val = {32, 0 <repeats 31 times>}}
#3  0xb6e138d8 in __libc_message (do_abort=do_abort@entry=2, fmt=fmt@entry=0xb6f11330 "*** Error in `%s': %s: 0x%s ***\n") at ../sysdeps/posix/libc_fatal.c:175
        ap = <optimized out>
        fd = 2
        on_2 = <optimized out>
        list = <optimized out>
        nlist = <optimized out>
        cp = <optimized out>
        written = <optimized out>
#4  0xb6e1de2a in malloc_printerr (action=<optimized out>, str=0xb6f0ce0f "free(): invalid pointer", ptr=0xa5673008) at malloc.c:4924
        buf = "a5673008"
        cp = <optimized out>
#5  0xb6e1ea6c in _int_free (av=0xb6f56420 <main_arena>, p=0xa5673000, have_lock=0) at malloc.c:3780
        size = <optimized out>
        fb = <optimized out>
        nextchunk = <optimized out>
        nextsize = <optimized out>
        nextinuse = <optimized out>
        prevsize = <optimized out>
        bck = <optimized out>
        fwd = <optimized out>
        errstr = <optimized out>
        locked = <optimized out>
        __func__ = "_int_free"
#6  0xb6fc2d40 in ?? ()
No symbol table info available.
#7  0x00000000 in ?? ()
No symbol table info available.