Date: Fri, 31 Oct 2014 19:01:54 +0100 (CET) From: elof2@sentor.se To: freebsd-net <freebsd-net@freebsd.org> Cc: John-Mark Gurney <jmg@funkthat.com> Subject: Re: Unable to kill a non-zombie process with -9 Message-ID: <alpine.BSF.2.00.1410311859220.32996@farmermaggot.shire.sentor.se> In-Reply-To: <alpine.BSF.2.00.1410151135410.33062@farmermaggot.shire.sentor.se> References: <alpine.BSF.2.00.1410081310340.39263@farmermaggot.shire.sentor.se> <20141009222926.GC1852@funkthat.com> <alpine.BSF.2.00.1410151135410.33062@farmermaggot.shire.sentor.se>
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No one have any thoughts about this? Its happening sporadically on several FreeBSD 10 machines of mine, while all of the FreeBSD 9-machines work just fine. If the problem isn't fixed, people won't be able to upgrade to and run snort on FreeBSD 10. log: > I'm starting snort (as root). > > <<<lots of startup logs for pid 22646>>> > Oct 15 08:46:59 snort[22646]: Initializing daemon mode > Oct 15 08:46:59 snort[22648]: Daemon initialized, signaled parent pid: 22646 > Oct 15 08:46:59 snort[22648]: Reload thread starting... > Oct 15 08:46:59 snort[22648]: Reload thread started, thread 0x8146e8800 (22648) > End of log. > > Error! Nothing more happens with the snort process! > Normally it should continue and log the following lines as well: > > > snort[nnn]: Decoding Ethernet > snort[nnn]: Checking PID path... > snort[nnn]: PID path stat checked out ok, PID path set to /var/run/ > snort[nnn]: Writing PID "7627" to file "/var/run//snort_mon0.pid" > snort[nnn]: Chroot directory = /usr/foobar/log > snort[nnn]: Set gid to 100 > snort[nnn]: Set uid to 100 > snort[nnn]: > snort[nnn]: --== Initialization Complete ==-- > snort[nnn]: Commencing packet processing (pid=nnn) > > > > > > When looking at this half-started snort process with 'ps', it looks like > this: > > ps faxulwwj 22648 > USER PID %CPU %MEM VSZ RSS TT STAT STARTED TIME COMMAND UID PPID CPU PRI NI MWCHAN PGID SID JOBC > root 22648 51.8 1.1 488552 179344 - Rs 8:46AM 53:06.52 /usr/local/bin/s 0 1 0 88 0 - 22648 22648 0 > > > The process is still owned by root, so just as the missing log lines are > saying, it has not yet performed any change of uid/gid. > > > > > So there seem to be two questions. > > Q1) > What happens between "Reload thread started, thread 0x8146e8800 (22648)" and > "Decoding Ethernet"? > Apparently something goes wrong here on FreeBSD 10.0. > (this problem does not always occur, sometimes snort start just fine) > > Q2) > When the process has frozen in this half-started state, it can't be killed > even with a -9. Why? > > > > > John-Mark asked me for some debugging info. Here it is: > > I now run 'kill 22648' on the above semi-started process: > > USER PID %CPU %MEM VSZ RSS TT STAT STARTED TIME COMMAND UID > PPID CPU PRI NI MWCHAN PGID SID JOBC > old root 22648 51.8 1.1 488552 179344 - Rs 8:46AM 53:06.52 > /usr/local/bin/s 0 1 0 88 0 - 22648 22648 0 > new root 22648 52.3 1.1 488552 179344 - Rs 8:46AM 53:36.48 > /usr/local/bin/s 0 1 0 52 0 - 22648 22648 0 > > No change. > > > > kill -9 22648 > > USER PID %CPU %MEM VSZ RSS TT STAT STARTED TIME COMMAND UID > PPID CPU PRI NI MWCHAN PGID SID JOBC > old root 22648 51.8 1.1 488552 179344 - Rs 8:46AM 53:06.52 > /usr/local/bin/s 0 1 0 88 0 - 22648 22648 0 > new root 22648 37.7 1.1 488552 179344 - Ts 8:46AM 53:50.87 > /usr/local/bin/s 0 1 0 52 0 - 22648 22648 0 > > Less CPU-usage and STAT changed to "Ts". > > > > > kill -CONT 22648 > > USER PID %CPU %MEM VSZ RSS TT STAT STARTED TIME COMMAND UID > PPID CPU PRI NI MWCHAN PGID SID JOBC > old root 22648 51.8 1.1 488552 179344 - Rs 8:46AM 53:06.52 > /usr/local/bin/s 0 1 0 88 0 - 22648 22648 0 > new root 22648 0.0 1.1 488552 179344 - Ts 8:46AM 53:50.88 > /usr/local/bin/s 0 1 0 52 0 - 22648 22648 0 > > No change except cpu is down to 0. > > > I now start 'kgdb' > info threads > I found two threads for snort, doing a bt for both of them: > 372 Thread 100602 (PID=22648: snort) sched_switch (td=0xfffff802c061f490, > newtd=<value optimized out>, flags=<value optimized out>) at > /usr/src/sys/kern/sched_ule.c:1962 > 371 Thread 100598 (PID=22648: snort) sched_switch (td=0xfffff80221857000, > newtd=<value optimized out>, flags=<value optimized out>) at > /usr/src/sys/kern/sched_ule.c:1962 > thread 372 > [Switching to thread 372 (Thread 100602)]#0 sched_switch > (td=0xfffff802c061f490, newtd=<value optimized out>, flags=<value optimized > out>) at /usr/src/sys/kern/sched_ule.c:1962 > 1962 in /usr/src/sys/kern/sched_ule.c > bt > #0 sched_switch (td=0xfffff802c061f490, newtd=<value optimized out>, > flags=<value optimized out>) at /usr/src/sys/kern/sched_ule.c:1962 > #1 0xffffffff808b8c1e in mi_switch (flags=266, newtd=0x0) at > /usr/src/sys/kern/kern_synch.c:494 > #2 0xffffffff808c04b0 in thread_suspend_switch (td=0xfffff802c061f490) at > /usr/src/sys/kern/kern_thread.c:883 > #3 0xffffffff808c0276 in thread_single (mode=1) at > /usr/src/sys/kern/kern_thread.c:713 > #4 0xffffffff8087c1bb in exit1 (td=0xfffff802c061f490, rv=9) at > /usr/src/sys/kern/kern_exit.c:180 > #5 0xffffffff808b2faf in sigexit (td=<value optimized out>, sig=<value > optimized out>) at /usr/src/sys/kern/kern_sig.c:2935 > #6 0xffffffff808b3669 in postsig (sig=<value optimized out>) at > /usr/src/sys/kern/kern_sig.c:2822 > #7 0xffffffff808f6f57 in ast (framep=<value optimized out>) at > /usr/src/sys/kern/subr_trap.c:271 > #8 0xffffffff80c75870 in Xfast_syscall () at > /usr/src/sys/amd64/amd64/exception.S:416 > #9 0x0000000801d6f19a in ?? () > Previous frame inner to this frame (corrupt stack?) > > > thread 371 > [Switching to thread 371 (Thread 100598)]#0 sched_switch > (td=0xfffff80221857000, newtd=<value optimized out>, flags=<value optimized > out>) at /usr/src/sys/kern/sched_ule.c:1962 > 1962 in /usr/src/sys/kern/sched_ule.c > bt > #0 sched_switch (td=0xfffff80221857000, newtd=<value optimized out>, > flags=<value optimized out>) at /usr/src/sys/kern/sched_ule.c:1962 > #1 0xffffffff808b8c1e in mi_switch (flags=260, newtd=0x0) at > /usr/src/sys/kern/kern_synch.c:494 > #2 0xffffffff808f2e3a in sleepq_wait (wchan=0x0, pri=0) at > /usr/src/sys/kern/subr_sleepqueue.c:620 > #3 0xffffffff80864aad in _cv_wait (cvp=0xffffffff8147a500, > lock=0xffffffff8147a480) at /usr/src/sys/kern/kern_condvar.c:139 > #4 0xffffffff808fb05f in vmem_xalloc (vm=0xffffffff8147a480, size0=<value > optimized out>, align=<value optimized out>, phase=0, nocross=<value > optimized out>, minaddr=0, maxaddr=18446735286768857088, flags=8194, > addrp=<value optimized out>) at /usr/src/sys/kern/subr_vmem.c:1196 > #5 0xffffffff808fae6b in vmem_alloc (vm=0x0, size=0, flags=<value optimized > out>, addrp=0xfffffe0466e1d6e8) at /usr/src/sys/kern/subr_vmem.c:1082 > #6 0xffffffff80b0fa58 in kmem_malloc (vmem=0xffffffff8147a480, > size=2139729920, flags=2) at /usr/src/sys/vm/vm_kern.c:314 > #7 0xffffffff80b08dfb in uma_large_malloc (size=<value optimized out>, > wait=2) at /usr/src/sys/vm/uma_core.c:1006 > #8 0xffffffff80898cf3 in malloc (size=2139729920, mtp=0xffffffff813a0450, > flags=0) at /usr/src/sys/kern/kern_malloc.c:520 > #9 0xffffffff8096307b in bpf_buffer_ioctl_sblen (d=0xfffff80159ea9000, > i=<value optimized out>) at /usr/src/sys/net/bpf_buffer.c:183 > #10 0xffffffff80960a3c in bpfioctl (dev=0x0, cmd=<value optimized out>, > addr=0xfffff801fbd06b40 "", flags=0, td=0xfffff80221857000) at > /usr/src/sys/net/bpf.c:408 > #11 0xffffffff807ac1df in devfs_ioctl_f (fp=0xfffff8002b3d9d20, > com=3221504614, data=0xfffff801fbd06b40, cred=<value optimized out>, > td=0xfffff80221857000) at /usr/src/sys/fs/devfs/devfs_vnops.c:757 > #12 0xffffffff808fdfae in kern_ioctl (td=0xfffff80221857000, fd=<value > optimized out>, com=0) at file.h:319 > #13 0xffffffff808fdd2f in sys_ioctl (td=0xfffff80221857000, > uap=0xfffffe0466e1da40) at /usr/src/sys/kern/sys_generic.c:702 > #14 0xffffffff80c8f117 in amd64_syscall (td=0xfffff80221857000, traced=0) at > subr_syscall.c:134 > #15 0xffffffff80c7580b in Xfast_syscall () at > /usr/src/sys/amd64/amd64/exception.S:391 > #16 0x0000000801d8f08a in ?? () > Previous frame inner to this frame (corrupt stack?) > > > Let me know if I can debug this any further. > > /Elof > > > > On Thu, 9 Oct 2014, John-Mark Gurney wrote: > >> elof2@sentor.se wrote this message on Wed, Oct 08, 2014 at 13:30 +0200: >>> >>> I guess this is a bug report for FreeBSD 10.0. >>> >>> >>> >>> Sometimes I can't kill my snort process on FreeBSD 10.0. >>> It won't die, even with kill -9. >>> >>> I'm not talking about a zombie process. Snort is a process that should >>> die normally. >>> I've run snort on over 100 nodes since FreeBSD v6.x and I've never seen >>> this behavior until now in FreeBSD 10.0. >>> >>> >>> Example: >>> >>> #ps faxuw >>> USER PID %CPU %MEM VSZ RSS TT STAT STARTED TIME >>> COMMAND >>> root 49222 53.4 2.2 492648 183012 - Rs 11:46AM 7:05.59 >>> /usr/local/bin/snort -q -D -c snort.conf >>> root 47937 0.0 2.2 488552 182864 - Ts 10:56AM 29:35.98 >>> /usr/local/bin/snort -q -D -c snort.conf >> >> What is the MWCHAN? add l to the ps command... >> >>> The pid 47937 has been killed (repeatedly) with -9. >>> Its status is "Ts" meaning it is Stopped. >> >> have you tried to kill -CONT <pid> to resume it? >> >>> But it won't actually die and disappear. The only way to get rid of it >>> seem to be to reboot the machine. :-( >>> >>> (pid 49222 is the new process that was started after 47937 was killed) >>> >>> >>> The problem doesn't happen all the time and I haven't found any patterns >>> as to when it does. :-( >>> If I restart snort once every day, it fails to die approximately 2-4 times >>> per month. >>> Even though the problem doesn't happen on every kill, it is a definately a >>> recurring event. >> >> Can you run kgdb on the machine? (yes, it works on a live machine), use >> info threads to find the thread id, and then use thread <threadid> to >> switch to it, and run bt to get a back trace... >> >>> I began to see it on a heavily loaded 10GE sensor, so I thought it could >>> have something to do with the ix driver, or the heavy load. >>> But now another FreeBSD 10.0-sensor had the exact same problem, and this >>> sensor don't have any 10GE NICs. In fact, this sensor has been running >>> just fine with both FreeBSD 9.1 and 9.3 for the past years. Snort has >>> always terminated correctly! After I reinstalled this machine with FreeBSD >>> 10.0 last friday, snort has then terminated correctly every day until >>> today, when it failed with the above pid 47937. (this sensor use the 'em' >>> driver, not 'ixgbe') >>> >>> I'm running snort with the same configuration, settings, version, daq, >>> libs, etc on 10.0 as I do on 9.3. >>> None of the 9.3 sensors have this problem, so it has to be something new >>> in FreeBSD 10.0. >> >> -- >> John-Mark Gurney Voice: +1 415 225 5579 >> >> "All that I will do, has been done, All that I have, has not." >> > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org" >
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