#0  0xb76ea424 in __kernel_vsyscall ()
#1  0xb7395827 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
#2  0xb7398c53 in __GI_abort () at abort.c:89
#3  0xb73d0993 in __libc_message (do_abort=do_abort@entry=1,     fmt=fmt@entry=0xb74cda5c "*** Error in `%s': %s: 0x%s ***n")
at ../sysdeps/posix/libc_fatal.c:175
#4  0xb73dae7a in malloc_printerr (action=<optimized out>,     str=0xb74cdc20 "double free or corruption (fasttop)", ptr=0x87e2760)
at malloc.c:4996
#5  0xb73dbaed in _int_free (av=0xb7512420 <main_arena>, p=<optimized  out>, have_lock=0) at malloc.c:3840