Skip site navigation (1)Skip section navigation (2)
Date:      Tue, 30 Mar 2010 17:36:37 +0200
From:      Fabian Keil <freebsd-listen@fabiankeil.de>
To:        Andriy Gapon <avg@freebsd.org>
Cc:        Kostik Belousov <kostikbel@gmail.com>, freebsd-current@freebsd.org
Subject:   Re: newfs_msdos and DVD-RAM
Message-ID:  <20100330173637.202b4b1e@r500.local>
In-Reply-To: <4BB111D4.8060809@freebsd.org>
References:  <3a142e751003190508x6a06868ene2e8fd9ddd977f66@mail.gmail.com> <3a142e751003191021p141af009m6acf7d160c890cbb@mail.gmail.com> <20100319191133.46fe271c@r500.local> <3a142e751003191126j331e525fwb9e5573bbf6f7d58@mail.gmail.com> <4BAA30CB.1070707@icyb.net.ua> <20100328172537.501ed3d1@r500.local> <4BB0A053.9060007@freebsd.org> <20100329222920.5eef6395@r500.local> <4BB111D4.8060809@freebsd.org>

next in thread | previous in thread | raw e-mail | index | archive | help
--Sig_/v5fqwvQ_RHXzLJFnNNln84F
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: quoted-printable

Andriy Gapon <avg@freebsd.org> wrote:

> on 29/03/2010 23:29 Fabian Keil said the following:
> > Andriy Gapon <avg@freebsd.org> wrote:
> >> Thus, clearly, it is a fault of a tool that formatted the media for FA=
T.
> >> It should have picked correct values, or rejected incorrect values if
> >> those were provided as overrides via command line options.
> >=20
> > The kernel still shouldn't panic, though.
>=20
> A quick reply to this point only - yes, I completely agree.
> But remember that the panic happened only after the sources were modified=
 :)

It wasn't clear from my message, but I was mainly referring to the
division-by-zero panic mentioned at the beginning of the thread,
for which I posted a work-around in <20100319191133.46fe271c@r500.local>.

I think no backtrace has been posted yet, so here's the one
I got with mostly vanilla sources from around 2010-02-14:

Fatal trap 18: integer divide fault while in kernel mode
cpuid =3D 0; apic id =3D 00        =20
instruction pointer     =3D 0x20:0xffffffff803590b8
stack pointer           =3D 0x28:0xffffff803e845620
frame pointer           =3D 0x28:0xffffff803e845790
code segment            =3D base 0x0, limit 0xfffff, type 0x1b
                        =3D DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags        =3D interrupt enabled, resume, IOPL =3D 0
current process         =3D 2877 (mount_msdosfs)
panic: from debugger           =20
cpuid =3D 0                      =20
Uptime: 22m14s                 =20
Dumping 1992 MB (5 chunks)     =20
  chunk 0: 1MB (155 pages) ... ok
  chunk 1: 1990MB (509345 pages) 1974 [...] 6 ... ok
  chunk 2: 2MB (273 pages) ... ok
  chunk 3: 1MB (184 pages)
[...]
(kgdb) where
#0  doadump () at pcpu.h:223
#1  0xffffffff803babdf in boot (howto=3D260) at /usr/src/sys/kern/kern_shut=
down.c:416
#2  0xffffffff803bafdc in panic (fmt=3DVariable "fmt" is not available.
) at /usr/src/sys/kern/kern_shutdown.c:579
#3  0xffffffff801f4eb7 in db_panic (addr=3DVariable "addr" is not available.
) at /usr/src/sys/ddb/db_command.c:478
#4  0xffffffff801f52c1 in db_command (last_cmdp=3D0xffffffff808a07c0, cmd_t=
able=3DVariable "cmd_table" is not available.
) at /usr/src/sys/ddb/db_command.c:445
#5  0xffffffff801f5510 in db_command_loop () at /usr/src/sys/ddb/db_command=
.c:498
#6  0xffffffff801f7469 in db_trap (type=3DVariable "type" is not available.
) at /usr/src/sys/ddb/db_main.c:229
#7  0xffffffff803e9945 in kdb_trap (type=3D18, code=3D0, tf=3D0xffffff803e8=
45570) at /usr/src/sys/kern/subr_kdb.c:535
#8  0xffffffff806129fd in trap_fatal (frame=3D0xffffff803e845570, eva=3DVar=
iable "eva" is not available.
) at /usr/src/sys/amd64/amd64/trap.c:853
#9  0xffffffff80613252 in trap (frame=3D0xffffff803e845570) at /usr/src/sys=
/amd64/amd64/trap.c:647
#10 0xffffffff805fa4a3 in calltrap () at /usr/src/sys/amd64/amd64/exception=
.S:224
#11 0xffffffff803590b8 in msdosfs_mount (mp=3D0xffffff003cba25f0) at /usr/s=
rc/sys/fs/msdosfs/msdosfs_vfsops.c:610
#12 0xffffffff80436db0 in vfs_donmount (td=3DVariable "td" is not available.
) at /usr/src/sys/kern/vfs_mount.c:988
#13 0xffffffff804377b3 in nmount (td=3D0xffffff004a6d03b0, uap=3D0xffffff80=
3e845bf0) at /usr/src/sys/kern/vfs_mount.c:424
#14 0xffffffff80612e7d in syscall (frame=3D0xffffff803e845c80) at /usr/src/=
sys/amd64/amd64/trap.c:1026
#15 0xffffffff805fa781 in Xfast_syscall () at /usr/src/sys/amd64/amd64/exce=
ption.S:373
#16 0x00000008007a292c in ?? ()
Previous frame inner to this frame (corrupt stack?)

Fabian

--Sig_/v5fqwvQ_RHXzLJFnNNln84F
Content-Type: application/pgp-signature; name=signature.asc
Content-Disposition: attachment; filename=signature.asc

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.14 (FreeBSD)

iEYEARECAAYFAkuyGokACgkQBYqIVf93VJ01FQCgzTCOXx/348ZmuP86acLUZnqg
WUIAoLqMebBMHm1832bU9/j3gdU+3Cgo
=mdPO
-----END PGP SIGNATURE-----

--Sig_/v5fqwvQ_RHXzLJFnNNln84F--



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20100330173637.202b4b1e>