On a pretty current machine (15th of september) the command pfstat -f /var/db/pfstat.db seems to hang. I've stopped all cron jobs regarding pfstat.
I'm not that familiar with ktrace and kdump, but this it the three last lines: 30126 pfstat CALL mmap(0,0x5000,0x3<PROT_READ|PROT_WRITE>,0x1002<MAP_PRIVATE|MAP_ANON>,-1,0) 30126 pfstat RET mmap 4168834117632/0x3caa1e07000 30126 pfstat CALL pread(3,0x3caa1e07030,0x4000,0x4000) 30126 pfstat RET pread 16384/0x4000 30126 pfstat CALL open(0x7f7ffffd57b2,0x10222<O_RDWR|O_EXLOCK|O_CREAT|O_CLOEXEC>,0600<S_IRUSR|S_IWUSR>) no more output if given...