On Mon, Feb 01, 2021 at 07:11:12PM -0500, Keno Fischer wrote:

Hi Andrei,

quoted

This series introduces the PTRACE_O_ARM64_RAW_REGS option. If it is set,
PTRACE_GETREGSET returns values of all registers, and PTRACE_SETREGSET
allows to change any of them.

thanks for picking this up. I meant to work on this, but unfortunately ran out
of time to be able to push it through, so I'm glad you're working on
it, since it
does absolutely need to get fixed. Besides this issue, the other problem we
ran into when trying to port our ptracer to aarch64 is that orig_x0 is not
accessible through the ptrace interface on aarch64, which can cause tricky
behavior around restarts.

Could you describe the problem in more details? I wonder whether we have
the same thing in CRIU...

We managed to work around that in the end,
but it's painful. If we're fixing the kernel here anyway, I'm wondering if
we might want to address that as well while we're at it.

Sure let think how to do this properly.

In this case, I think the ptrace option isn't a good choise. I don't
think that it is a good idea to change the layout of regset depending on
options...

Thanks,
Andrei

Keno