Re: [PATCH v4 32/39] x86: Expose thread features in /proc/$PID/status

From: Kees Cook
Date: Fri Dec 02 2022 - 21:53:10 EST


On Fri, Dec 02, 2022 at 04:35:59PM -0800, Rick Edgecombe wrote:
> Applications and loaders can have logic to decide whether to enable
> shadow stack. They usually don't report whether shadow stack has been
> enabled or not, so there is no way to verify whether an application
> actually is protected by shadow stack.
>
> Add two lines in /proc/$PID/status to report enabled and locked features.
>
> Since, this involves referring to arch specific defines in asm/prctl.h,
> implement an arch breakout to emit the feature lines.
>
> Tested-by: Pengfei Xu <pengfei.xu@xxxxxxxxx>
> Tested-by: John Allen <john.allen@xxxxxxx>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

--
Kees Cook