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Re: udev device naming policy concerns



Miles Bader <miles@lsi.nec.co.jp> writes:

> Goswin von Brederlow <brederlo@informatik.uni-tuebingen.de> writes:
> > So I'm all for sticking with maintaining devfs names.
> 
> And I'm all against it.  (Whee!)

Thats makes 1:1. Lets get more people to get a quorum.

> > The only thing obsolete in devfs is the suposedly race codition
> > riddled code. The nameing scheme is way better and more orderly than
> > the obsolete flat /dev structure.
> 
> Well, it's nice that you've expressed your opinion, but if debian's dev
> naming scheme is to be changed, then it should be done as the result of
> a concensus to make that change, not because a particular maintainer
> happened to like it better.

Currently using udev is your choice. And its the maintainers choice
how to package it up. As seen with for example ifupdown, if the
maintainer is not willing to change a package your out of luck.

It should be done by forming a concensus and the maintainer following
that but saddly enough thats not what happens in Debian. Luckily the
udev maintainer is open for suggestions and discussions.

> Using udev does remove the most annoying thing about the traditional
> naming scheme on a typical workstation, the enormous gobs of unused
> names; here's my /dev for instance, which seems quite reasonable to me:
> 
>    MAKEDEV@  fd@   hdc       mice    pts/      tty   tty6     xconsole|
>    agpgart   fd0   initctl|  mouse0  random    tty0  tty7     zero
>    apm_bios  full  kmem      null    shm/      tty1  tty8
>    console   hda   kmsg      port    sndstat@  tty2  tty9
>    core@     hda1  log=      ppp     stderr@   tty3  ttyS0
>    event0    hda2  loop0     psaux   stdin@    tty4  ttyS1
>    event1    hda3  mem       ptmx    stdout@   tty5  urandom

Hmm, I'm missing a few things but that is probably your kernel config:

No /dev/rtc? You realy have no realtime clock support?

How does loop0 come about? Is that in use or did you limit the number
of loop devices in the kernel to 1?

No ramdisk support?

> created with this /etc/udev/udev.rules file (and all other .rules files
> in /etc/udev deleted):
> 
>    KERNEL="ttyS[2-9]"
>    KERNEL="tty[1-9][0-9]"
>    #default: KERNEL="*", NAME="%k"

Which leaves the problem of varying device nodes for hardware.

This can be a security issue: The cleaning lady pulled the plug on an
external drive, the system reboots and suddenly the zipdrive is
mounted as /usr giving instant root access trough a
/usr/bin/root-shell setuid.

Or cause data loss: The harddisk with /tmp doesn't spin up on reboot
and the next one, where /home is, is used instead. Enjoy tmp being
cleaned.

Or is just anoying because you can't see what device is which drive
unless you have the early boot messages still around.

MfG
        Goswin



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