Apparently, though unproven, at 23:47 on Saturday 11 September 2010, Dale did
> >> My point was, if the sources are say in the user group, then any user
> >> can edit them? Right now, they are in the root group and owned my root
> >> which for security reasons is a good idea. That way a regular user can't
> >> edit or modify the kernel sources.
> > The group can only write if the files have the group write permission
> > set. Still in Unix 101 domain, hehe
> I know that. Why would a person want anyone BUT root to be able to
> access and change the kernel sources? Lets see if asking it this way
> makes more sense. lol
Gentoo does things different. If you read Documentation/* in the kernel
sources, you will not find there what Gentoo has.
/usr/src/linux was intended by the kernel devs to be where the system
headers are stored - what glibc uses to build. Like everything else in /usr/
this is obviously writeable for root only (usually).
The intent is that you download kernel sources to ~, build there and sudo make
Gentoo needs a kernel tree (not just headers) for all manner of stuff to build
against. These days many distros also do it this way to accommodate the needs
of getting nvidia-drivers and vm products to build their drivers etc. This
must obviously also be writeable only for root.
So, the ancient "advice" about not building as root is bullshit. It might have
been good advice once but like all advice it's time is past.
To answer your question:
"You wouldn't. Anything else is just daft."
 this itself might be ancient cruft and hopelessly out of date
alan dot mckinnon at gmail dot com