Re: [PATCH v11 25/25] x86/cet/shstk: Add arch_prctl functions for shadow stack

Andy Lutomirski
2020-08-25T00:36:20Z

On Mon, Aug 24, 2020 at 5:30 PM Yu-cheng Yu <yu-cheng.yu@intel.com> wrote:

> arch_prctl(ARCH_X86_CET_MMAP_SHSTK, u64 *args)
> Allocate a new shadow stack.
>
> The parameter 'args' is a pointer to a user buffer.
>
> *args = desired size
> *(args + 1) = MAP_32BIT or MAP_POPULATE
>
> On returning, *args is the allocated shadow stack address.

This is hideous. Would this be better as a new syscall?

--Andy