Re: [gentoo-user] Kernel 3.7.9: Lots of devices are root root rw-------.

[Alan Mackenzie <acm@muc.de>]

On Sun, Feb 24, 2013 at 10:44:19AM +0200, Alan McKinnon wrote:
> On 23/02/2013 19:18, Alan Mackenzie wrote:
> > Hi, Gentoo!

> > Just built the new kernel 3.7.9 last night, and it's one of these
> > "nothing works" situations.

Sorry, I was exaggerating here.  I can work normally as long as I don't
try to use a peripheral, such as printer, audio, or scanner.  My network
connection is working OK.

> > It seems the problems are with the device files, whose ownership is set
> > to "root root" (rather than, e.g., "root audio") and whose permissions
> > are set to crw------- (rather than the expected crw-rw----).

> > I'm still running udev-171-r10.  This might well make a difference.

> > Needless to say, everything works under kernel 3.6.11.  It would be nice
> > if there were some mistake in my kernel config.

> > Could somebody help me get this fixed, please.


> udev sets ownership and permissions on devices nodes, not the kernel.

> I'd guess your udev setup is incompatible with 3.7.* so let's start with
> the usual:

> What is your kernel config for the various TMPFS settings in the kernel?
> (grep TMPFS in .config)

CONFIG_DEVTMPFS=y
CONFIG_DEVTMPFS_MOUNT=y
CONFIG_TMPFS=y
CONFIG_TMPFS_POSIX_ACL=y
CONFIG_TMPFS_XATTR=y

> What mount options apply to /dev?

On my (working) 3.6.11:
devtmpfs on /dev type devtmpfs (rw,relatime,size=1988792k,nr_inodes=497198,mode=755)

On my (non-working) 3.7.9:
devtmpfs on /dev type devtmpfs (rw,relatime,size=1988680k,nr_inodes=497170,mode=755)

> Contents of /etc/fstab?

(Leading comments have been removed.)

#/dev/BOOT              /boot           ext2            noauto,noatime  1 2
/dev/md6                /               ext3            noatime         0 1
/dev/sda2               none            swap            sw              0 0
/dev/sdb2               none            swap            sw              0 0

#/dev/mapper/vg-usr     /usr            ext3            noatime         1 2
/dev/mapper/vg-usrportage       /usr/portage    ext2            noatime         1 2
/dev/mapper/vg-usrportagedistfiles /usr/portage/distfiles ext2  noatime         1 2
/dev/mapper/vg-usrsrc   /usr/src        ext3            noatime         1 2

/dev/mapper/vg-home     /home           ext3            noatime         1 2
/dev/mapper/vg-opt      /opt            ext3            noatime         1 2

/dev/mapper/vg-var      /var            ext3            noatime         1 2
/dev/mapper/vg-varspoolmail     /var/spool/mail ext3            noatime         1 2
/dev/mapper/vg-varspoolnews     /var/spool/news reiserfs        noatime         1 2
/dev/mapper/vg-vardbpkg         /var/db/pkg     ext3            noatime         1 2

/dev/mapper/vg-iso      /iso            ext2            noatime         1 2
/dev/mapper/vg-old      /old            ext2            noatime         1 2
/dev/mapper/vg-vg--backup       /backup         ext2            noatime         1 2

/dev/cdrom              /mnt/cdrom      auto            noauto,ro       0 0
/dev/fd0                /mnt/floppy     auto            noauto          0 0

# glibc 2.2 and above expects tmpfs to be mounted at /dev/shm for
# POSIX shared memory (shm_open, shm_unlink).
# (tmpfs is a dynamically expandable/shrinkable ramdisk, and will
#  use almost no memory if not populated with files)
shm                     /dev/shm        tmpfs           nodev,nosuid,noexec     0 0


> USE flags that apply to udev?

[ebuild   R    ] sys-fs/udev-171-r10
    USE="gudev hwdb introspection keymap rule_generator
    -action_modeswitch -build -debug -edd (-extras) -floppy (-selinux) {-test}"

> -- 
> Alan McKinnon
> alan.mckinnon@gmail.com

-- 
Alan Mackenzie (Nuremberg, Germany).