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.
