[PATCH v2] rtld: Enable MTE for stack when specified in .dynamic

[Yury Khrustalev]

On Wed, Feb 25, 2026 at 05:29:42PM +0000, Cupertino Miranda wrote:
> Hi Yury,
> 
> Can you please detail some more what are you working on.

We look at heap allocations so it will touch the part that implements
memory tagging in malloc. Ideally, we'd like to have some uniformity in
configuration of Glibc's use of memory tags. E.g. there is a tunable
that is supposed to control malloc use of memory tags (glibc.mem.tagging)
and you use dynamic array tags in binaries which seem like a good option
but we probably need to use only one mechanism. I'll take a closer look
at your patches tomorrow.

> Please notice that my changes in GLibc in respect to MTE are in sync with
> the work from Claudiu (in cc as well), which is already upstreamed to GCC.

You and Claudiu seem to have followed the mem tag ABI [1] which
probably requires some kernel work that hasn't been done yet to
properly allow Glibc to deal with stack protection, though I need
to check this further.

> 
> https://gcc.gnu.org/pipermail/gcc-patches/2025-November/699675.html
> 
> Looking forward to your reply.

I found two patch series so far [2] and [3]. Are those the latest
versions? Any other patches that I missed? These are pretty old,
do you plan to rebased and send newer versions any time soon? I can
review [2] and [3] otherwise.

I'm not sure how this never came up during any of the patch
review calls... Please do CC someone from Arm when you change
code specific to an Arm target.

---

[1]: https://github.com/ARM-software/abi-aa/blob/main/memtagabielf64/memtagabielf64.rst
[2]: https://patchwork.sourceware.org/project/glibc/list/?series=51446
[3]: https://patchwork.sourceware.org/project/glibc/list/?series=45014

Thanks,
Yury