Support stack probing for arm64 (aarch64)

[tmandry]

Background: #43241

This issue is to track implementation of stack probing on arm64. Most of the work necessary is in in LLVM, but this is a convenient place to track progress and final support in the Rust compiler.

Implementation: @cuviper has suggested using LLVM's inline-asm support for stack probing: #43241 (comment). It does not yet support arm64.

External trackers:

• https://projects.linaro.org/browse/LLVM-618

[pietroalbini]

@rustbot ping arm

[rustbot]

Hey ARM Group! This bug has been identified as a good "ARM candidate".
In case it's useful, here are some instructions for tackling these sorts of
bugs. Maybe take a look?
Thanks! <3

cc @JamieCunliffe @joaopaulocarreiro @raw-bin @Stammark @vigoux

[tmandry]

Hi @raw-bin, what's the status of this? As I recall this work was planned to land as part of LLVM 12, but I haven't seen updates on the Linaro tracker yet.

[raw-bin]

Hi Tyler. I believe there has been progress but let me get the definitive and circle back ASAP. Cheers, Robin

…

On Sat, Feb 13, 2021 at 2:24 AM Tyler Mandry ***@***.***> wrote: Hi @raw-bin <https://github.com/raw-bin>, what's the status of this? As I recall this work was planned to land as part of LLVM 12, but I haven't seen updates on the Linaro tracker yet. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#77071 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAFMKYURA7T2IXM4NP5ZNGTS6XPEXANCNFSM4RWDXQ2Q> .

[raw-bin]

Hi @tmandry, folks.

Apologies for the delay.

There has been good progress.

Please note the following patches that have been posted by Linaro for review:

https://reviews.llvm.org/D96004
https://reviews.llvm.org/D96005
https://reviews.llvm.org/D96006
https://reviews.llvm.org/D96007

At present Linaro is blocking on review.

If possible, please do chime in.

I will provide further updates as needed.

Cheers

[tmandry]

Great, thanks for the update! Let me ask around to see if I can help get those patches reviewed.

[joshtriplett]

What's the current state of this? What needs to happen to get working stack probes on aarch64?