Linus,

On 14/06/21 7:59 am, Linus Torvalds wrote:

On Sat, Jun 12, 2021 at 4:38 PM Michael Schmitz [off-list ref] wrote:

quoted

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