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

From: Jann Horn
Date: Thu Feb 06 2020 - 14:28:15 EST


On Thu, Feb 6, 2020 at 6:51 PM Kristen Carlson Accardi
<kristen@xxxxxxxxxxxxxxx> 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 :).

FYI, a pretty decent way to see how people are using an API is
codesearch.debian.net, which searches through the source code of all
the packages debian ships:

https://codesearch.debian.net/search?q=%2Fproc%2Fkallsyms&literal=1