(gdb) bt full
#0  0xb7f65410 in __kernel_vsyscall ()
No symbol table info available.
#1  0x4f75a7d5 in raise () from /lib/tls/libc.so.6
No symbol table info available.
#2  0x4f75c149 in abort () from /lib/tls/libc.so.6
No symbol table info available.
#3  0x4f78e40a in __libc_message () from /lib/tls/libc.so.6
No symbol table info available.
#4  0x4f79551c in _int_malloc () from /lib/tls/libc.so.6
No symbol table info available.
#5  0x4f796f81 in malloc () from /lib/tls/libc.so.6
No symbol table info available.
#6  0xb7cc1b99 in iks_malloc (size=312) at utility.c:21
No locals.
#7  0xb7cc7ab4 in iks_base64_encode (buf=0xfffffff0 <Address 0xfffffff0 out of
bounds>, 
    len=0) at base64.c:69
        res = Variable "res" is not available.