Date: Wed, 23 Sep 2015 23:15:03 +0200 From: Palle Girgensohn <girgen@gmail.com> To: Julien Charbon <jch@freebsd.org> Cc: George Neville-Neil <gnn@FreeBSD.org>, freebsd-net@freebsd.org Subject: Re: Kernel panics in tcp_twclose Message-ID: <FCA04243-C40C-4A0D-A22B-7DBCAB3DB15A@gmail.com> In-Reply-To: <5602E90A.9050504@freebsd.org> References: <26B0FF93-8AE3-4514-BDA1-B966230AAB65@FreeBSD.org> <55FC1809.3070903@freebsd.org> <20150918160605.GN67105@kib.kiev.ua> <55FFBE01.6060706@freebsd.org> <3721F099-F45D-4DCD-8AB3-84D1ABC44145@FreeBSD.org> <73856F2B-3E70-483C-9988-C84E798CEB44@FreeBSD.org> <44EBAC98-4761-4E47-8E47-5032430A1C8A@FreeBSD.org> <56019AF8.8000705@freebsd.org> <F9D29C16-502B-43A1-BE2C-D2AD30F0B9EF@FreeBSD.org> <5601CF2D.9030307@freebsd.org> <E09DF89D-AAC5-48FD-8B75-EEAB937A5C32@FreeBSD.org> <5602E90A.9050504@freebsd.org>
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> 23 sep 2015 kl. 20:01 skrev Julien Charbon <jch@freebsd.org>:
>=20
>=20
> Hi Palle, Hi George,
>=20
> On 23/09/15 16:36, Palle Girgensohn wrote:
>>> 22 sep 2015 kl. 23:59 skrev Julien Charbon <jch@freebsd.org>: On
>>> 22/09/15 22:58, Palle Girgensohn wrote:
>>>>> 22 sep 2015 kl. 20:16 skrev Julien Charbon <jch@freebsd.org>:=20
>>>>> On 22/09/15 18:49, Palle Girgensohn wrote:
>>>>>>> 22 sep 2015 kl. 18:46 skrev Palle Girgensohn=20
>>>>>>> <girgen@FreeBSD.org>:
>>>>>>>> 21 sep 2015 kl. 15:53 skrev Palle Girgensohn=20
>>>>>>>> <girgen@FreeBSD.org>:
>>>>>>>>> 21 sep 2015 kl. 10:21 skrev Julien Charbon=20
>>>>>>>>> <jch@FreeBSD.org>: On 18/09/15 18:06, Konstantin
>>>>>>>>> Belousov wrote:
>>>>>>>>>> On Fri, Sep 18, 2015 at 03:56:25PM +0200, Julien
>>>>>>>>>> Charbon wrote:
>>>>>>>>>>> [...]
>>>>>>>>> - Second, if issue is still in stable/10, compile 10.2=20
>>>>>>>>> kernel with these options:
>>>>>>>>>=20
>>>>>>>>> options DDB options DEADLKRES options=20
>>>>>>>>> INVARIANTS options INVARIANT_SUPPORT options
>>>>>>>>> WITNESS options WITNESS_SKIPSPIN
>>>>>>>>>=20
>>>>>>>>> To see where the original fault is coming from.
>>>>>>>> [...]
>>>>>>>>=20
>>>>>>>> I'll try stable/10 now. Would you suggest a "clean"=20
>>>>>>>> stable/10, or could 287621 and 287780 help?
>>>>>>>>=20
>>>>>>>> I'll add the debugging suggested options right away.
>>>>>>>>=20
>>>>>>>> Palle
>>>>>>>=20
>>>>>>> I have a new core dump from ^/stable/10 with:
>>>>>>>=20
>>>>>>> options DDB options DEADLKRES options
>>>>>>> INVARIANTS options INVARIANT_SUPPORT options WITNESS
>>>>>>> options WITNESS_SKIPSPIN
>>>>>>=20
>>>>>> # kgdb kernel /var/crash/vmcore.2 GNU gdb 6.1.1 [FreeBSD]=20
>>>>>> Copyright 2004 Free Software Foundation, Inc. GDB is free=20
>>>>>> software, covered by the GNU General Public License, and you
>>>>>> are welcome to change it and/or distribute copies of it under
>>>>>> certain conditions. Type "show copying" to see the
>>>>>> conditions. There is absolutely no warranty for GDB. Type
>>>>>> "show warranty" for details. This GDB was configured as
>>>>>> "amd64-marcel-freebsd"...
>>>>>>=20
>>>>>> Unread portion of the kernel message buffer: panic:
>>>>>> tcp_detach: INP_TIMEWAIT && INP_DROPPED && tp !=3D NULL cpuid =3D
>>>>>> 16 KDB: stack backtrace: db_trace_self_wrapper() at=20
>>>>>> db_trace_self_wrapper+0x2b/frame 0xfffffe183d9e97e0=20
>>>>>> kdb_backtrace() at kdb_backtrace+0x39/frame
>>>>>> 0xfffffe183d9e9890 vpanic() at vpanic+0x126/frame
>>>>>> 0xfffffe183d9e98d0 kassert_panic() at
>>>>>> kassert_panic+0x139/frame 0xfffffe183d9e9940
>>>>>> tcp_usr_detach() at tcp_usr_detach+0xf9/frame
>>>>>> 0xfffffe183d9e9970 sofree() at sofree+0x1f1/frame
>>>>>> 0xfffffe183d9e99a0 soclose() at soclose+0x3a0/frame
>>>>>> 0xfffffe183d9e99f0 _fdrop() at _fdrop+0x29/frame
>>>>>> 0xfffffe183d9e9a10 closef() at closef+0x1e2/frame
>>>>>> 0xfffffe183d9e9aa0 closefp() at closefp+0x9d/frame
>>>>>> 0xfffffe183d9e9ae0 amd64_syscall() at=20
>>>>>> amd64_syscall+0x25a/frame 0xfffffe183d9e9bf0 Xfast_syscall()
>>>>>> at Xfast_syscall+0xfb/frame 0xfffffe183d9e9bf0 --- syscall
>>>>>> (6, FreeBSD ELF64, sys_close), rip =3D 0x801c8d94a, rsp =3D=20
>>>>>> 0x7ffff91c8668, rbp =3D 0x7ffff91c8680 --- KDB: enter: panic=20
>>>>>> Uptime: 18h57m59s Dumping 23085 out of 98263=20
>>>>>> MB:..1%..11%..21%..31%..41%..51%..61%..71%..81%..91%
>>>>>>=20
>>>>>> Reading symbols from /boot/kernel/nullfs.ko.symbols...done.=20
>>>>>> Loaded symbols for /boot/kernel/nullfs.ko.symbols Reading
>>>>>> symbols from /boot/kernel/zfs.ko.symbols...done. Loaded
>>>>>> symbols for /boot/kernel/zfs.ko.symbols Reading symbols from
>>>>>> /boot/kernel/opensolaris.ko.symbols...done. Loaded symbols
>>>>>> for /boot/kernel/opensolaris.ko.symbols Reading symbols from
>>>>>> /boot/kernel/ng_bridge.ko.symbols...done. Loaded symbols for
>>>>>> /boot/kernel/ng_bridge.ko.symbols Reading symbols from=20
>>>>>> /boot/kernel/netgraph.ko.symbols...done. Loaded symbols for=20
>>>>>> /boot/kernel/netgraph.ko.symbols Reading symbols from=20
>>>>>> /boot/kernel/ng_eiface.ko.symbols...done. Loaded symbols for
>>>>>> /boot/kernel/ng_eiface.ko.symbols Reading symbols from=20
>>>>>> /boot/kernel/ng_ether.ko.symbols...done. Loaded symbols for=20
>>>>>> /boot/kernel/ng_ether.ko.symbols Reading symbols from=20
>>>>>> /boot/kernel/accf_data.ko.symbols...done. Loaded symbols for
>>>>>> /boot/kernel/accf_data.ko.symbols Reading symbols from=20
>>>>>> /boot/kernel/accf_http.ko.symbols...done. Loaded symbols for
>>>>>> /boot/kernel/accf_http.ko.symbols Reading symbols from=20
>>>>>> /boot/kernel/ums.ko.symbols...done. Loaded symbols for=20
>>>>>> /boot/kernel/ums.ko.symbols Reading symbols from=20
>>>>>> /boot/kernel/ng_socket.ko.symbols...done. Loaded symbols for
>>>>>> /boot/kernel/ng_socket.ko.symbols Reading symbols from=20
>>>>>> /boot/kernel/fdescfs.ko.symbols...done. Loaded symbols for=20
>>>>>> /boot/kernel/fdescfs.ko.symbols #0 doadump (textdump=3D1) at=20
>>>>>> pcpu.h:219 219 __asm("movq %%gs:%1,%0" : "=3Dr" (td) =
(kgdb) bt
>>>>>> #0 doadump (textdump=3D1) at pcpu.h:219 #1 0xffffffff8094b337
>>>>>> in kern_reboot (howto=3D260) at
>>>>>> /usr/src/sys/kern/kern_shutdown.c:451 #2 0xffffffff8094b845
>>>>>> in vpanic (fmt=3D<value optimized out>, ap=3D<value optimized
>>>>>> out>) at /usr/src/sys/kern/kern_shutdown.c:758 #3
>>>>>> 0xffffffff8094b6d9 in kassert_panic (fmt=3D<value optimized
>>>>>> out>) at /usr/src/sys/kern/kern_shutdown.c:646 #4
>>>>>> 0xffffffff80b1ee59 in tcp_usr_detach (so=3D<value optimized
>>>>>> out>) at /usr/src/sys/netinet/tcp_usrreq.c:202 #5
>>>>>> 0xffffffff809cd291 in sofree (so=3D0xfffff801dd302000) at=20
>>>>>> /usr/src/sys/kern/uipc_socket.c:747 #6 0xffffffff809cdb00 in
>>>>>> soclose (so=3D<value optimized out>) at=20
>>>>>> /usr/src/sys/kern/uipc_socket.c:849 #7 0xffffffff808fe659 in
>>>>>> _fdrop (fp=3D0xfffff802a593db40, td=3D0x0) at file.h:343 #8=20
>>>>>> 0xffffffff80901092 in closef (fp=3D0xfffff802a593db40,=20
>>>>>> td=3D0xfffff80eebc894a0) at
>>>>>> /usr/src/sys/kern/kern_descrip.c:2338 #9 0xffffffff808feb5d
>>>>>> in closefp (fdp=3D0xfffff80b20cce000, fd=3D<value optimized out>,
>>>>>> fp=3D0xfffff802a593db40, td=3D0xfffff80eebc894a0,
>>>>>> holdleaders=3D<value optimized out>) at=20
>>>>>> /usr/src/sys/kern/kern_descrip.c:1194 #10 0xffffffff80d7bc3a
>>>>>> in amd64_syscall (td=3D0xfffff80eebc894a0, traced=3D0) at=20
>>>>>> subr_syscall.c:134 #11 0xffffffff80d5f1db in Xfast_syscall ()
>>>>>> at /usr/src/sys/amd64/amd64/exception.S:396 #12
>>>>>> 0x0000000801c8d94a in ?? () Previous frame inner to this
>>>>>> frame (corrupt stack?) Current language: auto; currently
>>>>>> minimal
>>>>>=20
>>>>> Thanks for the information. As I suspected the initial error
>>>>> was elsewhere than tcp_twclose(), never got this assertion
>>>>> before:
>>>>>=20
>>>>> tcp_detach: INP_TIMEWAIT && INP_DROPPED && tp !=3D NULL
>>>>>=20
>>>>> from here:
>>>>>=20
>>>>> static void tcp_detach(struct socket *so, struct inpcb *inp) {
>>>>> struct tcpcb *tp;
>>>>>=20
>>>>> INP_INFO_WLOCK_ASSERT(&V_tcbinfo); INP_WLOCK_ASSERT(inp);
>>>>>=20
>>>>> KASSERT(so->so_pcb =3D=3D inp, ("tcp_detach: so_pcb !=3D inp"));=20=
>>>>> KASSERT(inp->inp_socket =3D=3D so, ("tcp_detach: inp_socket !=3D
>>>>> so"));
>>>>>=20
>>>>> tp =3D intotcpcb(inp);
>>>>>=20
>>>>> if (inp->inp_flags & INP_TIMEWAIT) { if (inp->inp_flags &=20
>>>>> INP_DROPPED) { KASSERT(tp =3D=3D NULL, ("tcp_detach: INP_TIMEWAIT
>>>>> && " "INP_DROPPED && tp !=3D NULL"));
>>>>>=20
>>>>> Let me check if I could find a path that could lead to this=20
>>>>> unexpected case. Unexpected because: INP_DROPPED and=20
>>>>> inp->inp_ppcb is set to NULL are set at same time here:
>>>>>=20
>>>>> void tcp_twclose(struct tcptw *tw, int reuse) { struct socket
>>>>> *so; struct inpcb *inp;
>>>>>=20
>>>>> inp =3D tw->tw_inpcb; KASSERT((inp->inp_flags & INP_TIMEWAIT),=20
>>>>> ("tcp_twclose: !timewait")); KASSERT(intotw(inp) =3D=3D tw,=20
>>>>> ("tcp_twclose: inp_ppcb !=3D tw"));=20
>>>>> INP_INFO_WLOCK_ASSERT(&V_tcbinfo); /* in_pcbfree() */=20
>>>>> INP_WLOCK_ASSERT(inp);
>>>>>=20
>>>>> tcp_tw_2msl_stop(tw, reuse); inp->inp_ppcb =3D NULL;=20
>>>>> in_pcbdrop(inp); ...
>>>>>=20
>>>>> Interesting [...]
>>=20
>> Just a quick update. Julien is pursuing this off list with a core
>> dump and we are now waiting for a new core dump with the first
>> KASSERT removed. this is on a stable/10 kernel.
>=20
> By the way Palle could you also run below Dtrace script to see where
> this tcp_close() in INP_TIMEWAIT comes from:
>=20
> $ cat tcp-close-tw.d
> fbt::tcp_close:entry
> /args[0]->t_inpcb->inp_flags & 0x01000000/
> {
> @s1[stack()] =3D count()
> }
>=20
> tick-1sec {
> printa(@s1);
> }
> $ sudo dtrace -s tcp-close-tw.d
# dtrace -s tcp-close-tw.d
dtrace: failed to compile script tcp-close-tw.d: line 2: t_inpcb is not =
a member of struct e1000_hw
>=20
on one system...
and for the other two:
# dtrace -s tcp-close-tw.d
dtrace: failed to initialize dtrace: DTrace device not available on =
system
I'm adding
options KDTRACE_HOOKS
to the kernels, I guess that will help?
Palle
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