Program received signal SIGSEGV, Segmentation fault.
0x283cb438 in malloc_usable_size () from /lib/libc.so.7
(gdb) bt
#0 0x283cb438 in malloc_usable_size () from /lib/libc.so.7
#1 0x283cdaf3 in malloc_usable_size () from /lib/libc.so.7
#2 0x283cea5a in free () from /lib/libc.so.7
#3 0x28335e5f in kvm_getprocs () from /lib/libkvm.so.5
#4 0x0804c5b6 in proc_find_top (cpu=0x8088424, mem=0x808844c, time=0x8088474) at freebsd.c:751
#5 0x0804c994 in update_top () at freebsd.c:593
#6 0x08052f7b in run_update_callback (data=0x2888f250) at common.c:380
#7 0x2834740c in pthread_getprio () from /lib/libthr.so.3
#8 0x00000000 in ?? ()