Re: [PATCH v4 38/39] x86/shstk: Add ARCH_SHSTK_UNLOCK

[Kees Cook]

On Fri, Dec 02, 2022 at 04:36:05PM -0800, Rick Edgecombe wrote:
> From: Mike Rapoport <rppt@xxxxxxxxxxxxx>
> 
> Userspace loaders may lock features before a CRIU restore operation has
> the chance to set them to whatever state is required by the process
> being restored. Allow a way for CRIU to unlock features. Add it as an
> arch_prctl() like the other shadow stack operations, but restrict it being
> called by the ptrace arch_pctl() interface.
> 
> Tested-by: Pengfei Xu <pengfei.xu@xxxxxxxxx>
> Tested-by: John Allen <john.allen@xxxxxxx>
> Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

-- 
Kees Cook