Re: [RFC PATCH] x86/split_lock: Disable SLD if an unaware (out-of-tree) module enables VMX

Andy Lutomirski
2020-04-06T22:54:39Z

On Mon, Apr 6, 2020 at 10:11 AM Christoph Hellwig <hch@infradead.org> wrote:
>
> On Mon, Apr 06, 2020 at 06:01:57PM +0200, Peter Zijlstra wrote:
> > Please feel free to use my pgprot_nx() and apply liberally on any
> > exported function.
> >
> > But crucially, I don't think any of the still exported functions allows
> > getting memory in the text range, and if you want to run code outside of
> > the text range, things become _much_ harder. That said, modules
> > shouldn't be able to create executable code, full-stop (IMO).
>
> This is what i've got for now:
>
> http://git.infradead.org/users/hch/misc.git/shortlog/refs/heads/sanitize-vmalloc-api

You have:

mm: remove __get_vm_area

Switch the two remaining callers to use __get_vm_area instead.

The second line contains a typo :)

Otherwise this looks pretty good.