Re: [RFC] add mount options to sysfs

[Vasiliy Kulikov <segoon@openwall.com>]

On Fri, May 20, 2011 at 06:30 -0700, Greg KH wrote:
> > > > Here https://lkml.org/lkml/2011/2/25/300 you, not aware of usefull
> > > > applications of world-writable debugfs file, agreeded to statically
> > > > restrict permissions of all files.  I suggest more flexible and
> > > > configurable in runtime solution.  It doesn't break anything - default
> > > > behaviour doesn't differ from current one.  What has changed in your
> > > > mind since 2/25?
> > > 
> > > That's debugfs, not sysfs, which we are talking about here, right?
> > 
> > Correct.  So, if I understood you, you are OK with adding mount options
> > for debugfs, but not sysfs, right?  What is the difference between them
> > in sense of permissions?
> 
> debugfs is "there are no rules", so changing the permissions on it
> shouldn't break anything as no userspace tools "should" rely on it.  Now
> that really isn't true (see the perf stuff), but overall it is, so I
> don't worry about changing things there as much as sysfs, which has
> hundreds of tools relying on it.

What would break if the default behaviour is not changed?

Thanks,

-- 
Vasiliy Kulikov
http://www.openwall.com - bringing security into open computing environments