On Wed, Aug 21, 2024 at 03:54:49PM +0000, Edgecombe, Rick P wrote:

On Wed, 2024-08-21 at 13:45 +0100, Mark Brown wrote:

quoted

It's entirely possible it just leaked.  My own attempts to dig through
the archives haven't turned up anything on the subjecti either, it seems
to have been there from the get go and just gone in without comment.
Equally it could just be that people felt that this was a more tasteful
way of specifying stacks, or that some future use was envisioned.

Ok, well I'm suspicious, but won't object over it. The rest seems settled from
my side. I may try to attract some other x86 attention to that CMPXCHG helper,
but otherwise.

OK, I'll post what I've got (with the current ABI) today, incorporating
your x86 fixes and the tighter validation and we can see what people
think.  Perhaps Christian remembers what's going on there?

quoted

quoted

Sorry for that. I looked through all the old threads expecting to find
discussion, but couldn't find an answer. Is clone3 support a dependency for
arm
shadow stacks?

quoted

Catalin didn't want to merge the arm64 support without clone3(), and
there's code dependencies as a result.  I could unpick it and reverse
the ordering so long as the arm64 maintainers are OK with that since the
overlap is in the implementation of copy_thread() and some of the
dependency patches.

Actually in an off-list discussion today Catalin indicated that he's
fine with relaxing that a little so I'm in the process of picking the
dependency apart.