Re: [PATCH v1] m68k: save extra registers on sys_exit and sys_exit_group syscall entry

Michael Schmitz
2021-06-13T20:07:28Z

Linus,

On 14/06/21 7:59 am, Linus Torvalds wrote:
> On Sat, Jun 12, 2021 at 4:38 PM Michael Schmitz <schmitzmic@gmail.com> wrote:
>> do_exit() calls prace_stop() which may require access to all saved
>> registers. We only save those registers not preserved by C code
>> currently.
>>
>> Provide a special syscall entry for exit and exit_group syscalls
>> similar to that used by clone and clone3, which have the same
>> requirements.
> ACK, this looks correct to me.
>
> It might be a good idea to generate a test-case for this - some
> "ptrace child, catch exit of it, show registers" kind of thing - just
> to show what the effects of the bug was (and to show it's fixed). But
> maybe it's not worth the effort.

I'd love that, too. My test rig doesn't allow dumping of registers by
strace, but someone else may have that capacity.

Cheers,

Michael

>
> Linus