[PATCH v3 1/2] rtld: Enable MTE for stack when specified in .dynamic

[Yury Khrustalev]

On Mon, Mar 16, 2026 at 11:43:03AM -0300, Adhemerval Zanella Netto wrote:
> 
> ...
>
> > We really cannot: that ABI has been ALPHA which means it's unstable and
> > is subject to change.
> 
> It is not clear to me exactly what you think we not commit wrt current 
> AArch64 Memtag ABI.

Adhemerval, if you read the document [1], you will surely see (section
3. Scope):

  As an alpha document all details in this document are subject to change.
   
I really don't know what else to add here. My understanding was that
Glibc does not add implementation for unstable ABI as a rule...

> Both gcc and clang support DT_AARCH64_MEMTAG_* for a
> while, and even Memtag ABI Extension is not fully clear about all runtime
> behavior compile support is ready and current definitions are reasonable. 

What exactly is implemented in gcc and clang with respect to stack
tagging? There is an implementation in GCC that doesn't seem to be
documented anywhere (at least I couldn't find any relevant spec).

For example, could you please point me to a place in [1] that explains
what is expected to happen in longjmp / setjmp?

We could use [1] as a vehicle to explore various options, but we should
not really use this document as the only reason to merge related changes
upstream.

[1]: https://github.com/ARM-software/abi-aa/blob/main/memtagabielf64/memtagabielf64.rst