Let me repeat I know nothing about shadow stacks, only tried to
read Documentation/arch/x86/shstk.rst few minutes ago ;)

On 05/13, Jiri Olsa wrote:

1) current uretprobe which are not working at the moment and we change
   the top value of shadow stack with shstk_push_frame
2) optimized uretprobe which needs to push new frame on shadow stack
   with shstk_update_last_frame

I think we should do 1) and have current uretprobe working with shadow
stack, which is broken at the moment

Agreed,

I'm ok with not using optimized uretprobe when shadow stack is detected
as enabled and we go with current uretprobe in that case

But how can we detect it? Again, suppose userspace does

	enable_shstk()
	{
		prctl(ARCH_SHSTK_SHSTK);
	}

what if enable_shstk() is ret-probed ?

Oleg.