binfmt_misc trouble with kernel 2.6.7

binfmt_misc trouble with kernel 2.6.7

[Anand Buddhdev]

Hi,

A few days ago I upgraded to fedora kernel 2.6.7-1.494.2.2. Before that, 
I had kernels in which binfmt_misc was compiled as a module. The wine 
init script modprobe'd the module and then registered /usr/bin/wine as a 
handler for windows executables. However, in the new 2.6.7 kernel, 
binfmt_misc is compiled into the kernel, so the modprobe in the wine 
init script fails. I can fix that, but main problem I am having is that 
now, the permissions on the /proc/sys/fs/binfmt_misc directory are 0555:

dr-xr-xr-x  2 root root 0 Aug 13 19:04 /proc/sys/fs/binfmt_misc

I cannot create a file called register under /proc/sys/fs/binfmt_misc.

I created a Fedora bugzilla entry for this but I was told that this is a 
problem in the kernel upstream. Is this indeed a known problem, and is 
there a fix?

Re: binfmt_misc trouble with kernel 2.6.7

[Alan Cox]

On Gwe, 2004-08-13 at 18:06, Anand Buddhdev wrote:
> I created a Fedora bugzilla entry for this but I was told that this is a 
> problem in the kernel upstream. Is this indeed a known problem, and is 
> there a fix?

Its not a kernel problem but a configuration one. The Fedora Core setup
relies on binfmt_misc being a module in order to automount the
binfmt_misc file system. 

Re: binfmt_misc trouble with kernel 2.6.7

[Anand Buddhdev]

Alan Cox wrote:

> On Gwe, 2004-08-13 at 18:06, Anand Buddhdev wrote:
> 
>>I created a Fedora bugzilla entry for this but I was told that this is a 
>>problem in the kernel upstream. Is this indeed a known problem, and is 
>>there a fix?
> 
> Its not a kernel problem but a configuration one. The Fedora Core setup
> relies on binfmt_misc being a module in order to automount the
> binfmt_misc file system. 

You're right. It's not a kernel bug at all. Up until fedora kernel 
2.6.6, binfmt_misc was compiled as a module, and was loaded only when 
the wine script was run. When they changed it to compiled-in in kernel 
2.6.7, they should have provided a script as part of the upgrade 
process. I've suggested that via bugzilla. Don't know if they will 
implement it.

Re: [solved] binfmt_misc trouble with kernel 2.6.7

[Anand Buddhdev]

Anand Buddhdev wrote:

> Hi,
> 
> A few days ago I upgraded to fedora kernel 2.6.7-1.494.2.2. Before that, 
> I had kernels in which binfmt_misc was compiled as a module. The wine 
> init script modprobe'd the module and then registered /usr/bin/wine as a 
> handler for windows executables. However, in the new 2.6.7 kernel, 
> binfmt_misc is compiled into the kernel, so the modprobe in the wine 
> init script fails. I can fix that, but main problem I am having is that 
> now, the permissions on the /proc/sys/fs/binfmt_misc directory are 0555:
> 
> dr-xr-xr-x  2 root root 0 Aug 13 19:04 /proc/sys/fs/binfmt_misc
> 
> I cannot create a file called register under /proc/sys/fs/binfmt_misc.
> 
> I created a Fedora bugzilla entry for this but I was told that this is a 
> problem in the kernel upstream. Is this indeed a known problem, and is 
> there a fix?

Geoffrey Leach from the Fedora list provided a hint to the solution. 
There's no bug. I just have to add:

none  /proc/sys/fs/binfmt_misc  binfmt_misc  defaults  0 0

to my /etc/fstab, and then the /proc/sys/fs/binfmt_misc directory 
becomes writable, with a register and a status file in it. Sorry to have 
bothered you all.

Re: [solved] binfmt_misc trouble with kernel 2.6.7

[Lee Revell]

On Fri, 2004-08-13 at 18:34, Anand Buddhdev wrote:
> Anand Buddhdev wrote:
> Geoffrey Leach from the Fedora list provided a hint to the solution. 
> There's no bug. I just have to add:
> 
> none  /proc/sys/fs/binfmt_misc  binfmt_misc  defaults  0 0
> 
> to my /etc/fstab, and then the /proc/sys/fs/binfmt_misc directory 
> becomes writable, with a register and a status file in it. Sorry to have 
> bothered you all.

That is certainly a Fedora bug if they update a kernel package that
requires userland configs to be updated and then don't update those
configs.  This seems to be a common pattern with Fedora, the kernel
packages change way faster than the userland tools and they are fast and
loose about not updating userland.  To be perfectly honest I switched to
Debian partially for this reason.

Do they really claim this is not a bug?

Lee

Re: [solved] binfmt_misc trouble with kernel 2.6.7

[Alan Cox]

On Gwe, 2004-08-13 at 23:52, Lee Revell wrote:
> That is certainly a Fedora bug if they update a kernel package that
> requires userland configs to be updated and then don't update those
> configs. 

We've always not had an automount for that line. If there was an
automount it would keep loading that module for every user and 99.99999%
of the users don't care about or use binfmt_misc.

That's a decision that goes back to RH8 or so when binfmt_misc first
acquired its own file system.

Alan