Re: Kubuntu's udev broken with 2.6.18-rc2-mm1

Andrew James Wade
2006-07-28T14:33:21Z

On Thursday 27 July 2006 16:12, Greg KH wrote:
> On Thu, Jul 27, 2006 at 12:56:55PM -0700, Andrew Morton wrote:
> > On Fri, 28 Jul 2006 15:46:08 -0400
> > Andrew James Wade <andrew.j.wade@gmail.com> wrote:
> >
> > > Hello,
> > >
> > > Some change between -rc1-mm2 and -rc2-mm1 broke Kubuntu's udev
> > > (079-0ubuntu34). In particular /dev/mem went missing, and /dev/null had
> > > bogus permissions (crw-------). I've kludged around the problem by
> > > populating /lib/udev/devices from a good /dev, but I'm assuming the
> > > breakage was unintentional.
> > >
> >
> > /dev/null damage is due to a combination of vdso-hash-style-fix.patch and
> > doing the kernel build as root (don't do that).
> >
> > I don't know what happened to /dev/mem.
>
> Me either. Look in /sys/class/mem/ Is it full of symlinks or real
> directories?

Symlinks.

> If symlinks, your version of udev should be able to handle it properly,
> but might have a bug somehow.
>
> Try running udevmonitor and echo a "1" to /sys/class/mem/mem/uevent and
> see if udev creates the device properly or not.

udevmonitor prints the received event from the kernel [UEVENT]
and the event which udev sends out after rule processing [UDEV]

UEVENT[1154093169.330045] add@/devices/mem
UDEV [1154093169.331914] add@/devices/mem

The device node was not created.

udev.log for 2.6.18-rc1-mm2 (which does work) has these lines:

UEVENT[1154105360.092631] add@/class/mem/mem
ACTION=add
DEVPATH=/class/mem/mem
SUBSYSTEM=mem
SEQNUM=589
MAJOR=1
MINOR=1

...

UDEV [1154105363.575086] add@/class/mem/mem
UDEV_LOG=3
ACTION=add
DEVPATH=/class/mem/mem
SUBSYSTEM=mem
SEQNUM=589
MAJOR=1
MINOR=1
UDEVD_EVENT=1
DEVNAME=/dev/mem

The Changelog for udev v081 has:
"prepare moving of /sys/class devices to /sys/devices"
Is this related?

Thanks,
Andrew Wade