Re: [AppArmor 39/45] AppArmor: Profile loading and manipulation,pathname matching

From: Greg KH
Date: Sat Jun 16 2007 - 00:24:50 EST


On Fri, Jun 15, 2007 at 09:21:57PM -0400, James Morris wrote:
> On Fri, 15 Jun 2007, Greg KH wrote:
>
> > Oh great, then things like source code control systems would have no
> > problems with new files being created under them, or renaming whole
> > trees.
>
> It depends -- I think we may be talking about different things.
>
> If you're using inotify to watch for new files and kick something in
> userspace to relabel them, it could take a while to relabel a lot of
> files, although there are likely some gains to be had from parallel
> relabeling which we've not explored.
>
> What I was saying is that you can use traditional SELinux labeling policy
> underneath that to ensure that there is always a safe label on each file
> before it is relabeled from userspace.

Ok, yes, I think we are in violent agreement here :)

> > So, so much for the "it's going to be too slow re-labeling everything"
> > issue, as it's not even required for almost all situations :)
>
> You could probably get an idea of the cost by running something like:
>
> $ time find /usr/src/linux | xargs setfattr -n user.foo -v bar
>
> On my system, it takes about 1.2 seconds to label a fully checked out
> kernel source tree with ~23,000 files in this manner, on a stock standard
> ext3 filesystem with a SATA drive.

Yeah, that should be very reasonable. I'll wait to see Crispin's code
to work off of and see if I can get it to approach that kind of speed.

thanks,

greg k-h
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