[PATCH v3 2/8] elf: Add a tunable to control use of tagged memory

[H.J. Lu]

On Thu, Nov 26, 2020 at 9:14 AM Siddhesh Poyarekar <siddhesh@gotplt.org> wrote:
>
> On 11/26/20 9:49 PM, H.J. Lu wrote:
> > The ultimate goal is to have a single glibc binary which runs everywhere.
> > Glibc needs to handle static executables, dynamic executables as well as
> > dlopened shared objects.  Initially, no binaries are marked and memory
> > tag should be disabled by default.  Tunable can be used to enable memory
>
> The patchset seems to tick all those boxes.
>
> > tag manually at run-time.  We don't know if there are any issues in the current
> > patches without considering the memory tag marker support.
>
> Sure, which is why I asked the question so that we can discuss how
> memory tag marker support in the binary would impact this feature.
> Could you please elaborate on that because I still don't see it.  I can

The first few questions are

1.  Where should binary markers be checked?
2.  How should binary marker checking work together with tunables?

> see how having binaries marked to always run with tagging enabled could
> be a good way to ensure that they're always executed that way, but it's
> something that could get added on top of the current patchset and
> perhaps even backported since it doesn't affect ABI.
>
> Siddhesh



-- 
H.J.