Re: [PATCH v3 2.6.39-rc1-tip 12/26] 12: uprobes: slot allocationfor uprobes

From: Peter Zijlstra
Date: Tue Apr 19 2011 - 05:03:51 EST


On Tue, 2011-04-19 at 11:56 +0530, Srikar Dronamraju wrote:
> > > + /*
> > > + * Find the end of the top mapping and skip a page.
> > > + * If there is no space for PAGE_SIZE above
> > > + * that, mmap will ignore our address hint.
> > > + *
> > > + * We allocate a "fake" unlinked shmem file because
> > > + * anonymous memory might not be granted execute
> > > + * permission when the selinux security hooks have
> > > + * their way.
> > > + */
> >
> > That just annoys me, so we're working around some stupid sekurity crap,
> > executable anonymous maps are perfectly fine, also what do JITs do?
>
> Yes, we are working around selinux security hooks, but do we have a
> choice.

Of course you have a choice, mark selinux broken and let them sort
it ;-)

Anyway, it looks like install_special_mapping() the thing I think you
ought to use (and I'm sure I said that before) also wobbles around
selinux by using security_file_mmap() even though its very clearly not a
file mmap (hint: vm_file == NULL).


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/