On Tue, Dec 21, 2004 at 10:15:54AM -0800, Marc Singer wrote:
> On Mon, Dec 20, 2004 at 02:52:50AM +0100, Goswin von Brederlow wrote:
> > Marc Singer <[EMAIL PROTECTED]> writes:
> >
> > > On running mdadm --assemble /dev/md0
> > >
> > > mdadm[4247]: segfault at 000000000000002c rip 000000000804b19e rsp
> > > 00000000ffffdb80 error 4
> > > mdadm[4253]: segfault at 000000000000002c rip 000000000804b19e rsp
> > > 00000000ffffdb80 error 4
> >
> > That doesn't mean much. Unaligned access gets reported as such as
> > well for example.
> >
> > Could you paste a gdb stack backtrace preverably after rebuilding
> > mdadm with debug info?
>
> I've had a look at the mdadm side of this problem. It looks like it
> is crashing because there is no configuration file. From mdadm.c
>
> break;
> case ASSEMBLE:
> if (devs_found == 1 && ident.uuid_set == 0 &&
> ident.super_minor == UnSet && !scan ) {
> /* Only a device has been given, so get details from config
> file */
> mddev_ident_t array_ident = conf_get_ident(configfile,
> devlist->devname);
> mdfd = open_mddev(devlist->devname, array_ident->autof);
>
> The conf_get_ident() is returning 0 which is then dereferenced by the
> open_mddev() call and segfault'ing. configfile is NULL because none
> was given. AFAICT, configfile never defaults. And even if it did,
> there is no config file on my machine.
>
> I haven't yet looked into the code within the initrd to see what it
> does. It is possible that the only way that my setup can work is if
> the md driver is compiled in.
>
> Still, I wonder about the ioctl errors that I see with fdisk.
I took a breif look at initrd and for reference have included
how it handles mdadm below. I think that the important bit
is that it passes not only the md device but its component
devices to mdadm -A (--assemble). It seems to me that as your
invocation does not do that, it is going into a code path
in mdadm that has a bug in it and thus segfaults. In a nutshell,
I don't think it is a kernel problem.
--
Horms
getraid_mdadm() {
mdadm=$(mdadm -D "$device") || {
echo "$PROG: mdadm -D $device failed" >&2
exit 1
}
eval "$(
echo "$mdadm" | awk '
$1 == "Raid" && $2 == "Level" { print "echo " $4; next }
$1 == "Number" && $2 == "Major" { start = 1; next }
$1 == "UUID" { print "uuid=" $3; start = 0; next }
!start { next }
$2 == 0 && $3 == 0 { next }
{ devices = devices " " $NF }
END { print "devices='\''" devices "'\''" }
'
)"
printf '%s\n' $devices > getroot
echo mdadm -A /devfs/md/$minor -R -u $uuid $devices \
> md$minor-script
echo /sbin/mdadm >&6
}
