Re: [PATCH v10 23/40] arm64/signal: Set up and restore the GCS context for signal handlers

Dave Martin
2024-08-15T16:31:58Z

On Thu, Aug 15, 2024 at 04:29:54PM +0100, Mark Brown wrote:
> On Thu, Aug 15, 2024 at 04:11:56PM +0100, Dave Martin wrote:
> > On Thu, Aug 15, 2024 at 03:45:45PM +0100, Mark Brown wrote:
> > > On Thu, Aug 15, 2024 at 02:37:22PM +0100, Dave Martin wrote:
>
> > > > Is there a test for taking and returning from a signal on an alternate
> > > > (main) stack, when a shadow stack is in use? Sounds like something
> > > > that would be good to check if not.
>
> > > Not specifically for any of the architectures.
>
> > Can you see any reason why this shouldn't work?
>
> No, it's expected to work - I'm just not specifically aware of an
> explicit test for it. Possibly some of the userspace bringup work
> might've covered it? Any libc tests for altstack support should've
> exercised it for example.

That's true; if libc is built to use shadow stack, generic API tests
ought to cover this.

> > Maybe I'll hacking up a test if I get around to it, but don't take this
> > as a promise!
>
> Thanks for your firm commitment! :P

No problem...

Cheers
---Dave