On Mon, Jun 1, 2020 at 5:14 AM Dave Martin <[email protected]> wrote: > Can you explain why userspace would write a changed value for x7 > but at the same time need that new to be thrown away?
The discarding behavior is the primary reason things aren't completely broken at the moment. If it read the wrong x7 value and didn't know about the Aarch64 quirk, it's often just trying to write that same wrong value back during the next stop, so if that's just ignored, that's probably fine in 99% of cases, since the value in the tracee will be undisturbed. I don't think there's a sane way to change the aarch64 NT_PRSTATUS semantics without just completely removing the x7 behavior, but of course people may be relying on that (I think somebody said upthread that strace does?) Keno
