Re: [RFC PATCH 09/11] kallsyms: hide layout and expose seed

From: Baoquan He
Date: Wed Feb 26 2020 - 21:43:08 EST


On 02/06/20 at 09:51am, Kristen Carlson Accardi wrote:
> On Thu, 2020-02-06 at 04:32 -0800, Kees Cook wrote:

> > In the past, making kallsyms entirely unreadable seemed to break
> > weird
> > stuff in userspace. How about having an alternative view that just
> > contains a alphanumeric sort of the symbol names (and they will
> > continue
> > to have zeroed addresses for unprivileged users)?
> >
> > Or perhaps we wait to hear about this causing a problem, and deal
> > with
> > it then? :)
> >
>
> Yeah - I don't know what people want here. Clearly, we can't leave
> kallsyms the way it is. Removing it entirely is a pretty fast way to
> figure out how people use it though :).

Kexec-tools and makedumpfile are the users of /proc/kallsyms currently.
We use kallsyms to get page_offset_base and _stext.