On Wed, Jun 26, 2019 at 09:45:02PM -0700, Andy Lutomirski wrote:
> The vsyscall=native feature is gone -- remove the docs.
>
> Fixes: 076ca272a14c ("x86/vsyscall/64: Drop "native" vsyscalls")
> Cc: stable@xxxxxxxxxxxxxxx
> Cc: Kees Cook <keescook@xxxxxxxxxxxx>
> Cc: Borislav Petkov <bp@xxxxxxxxx>
> Cc: Kernel Hardening <kernel-hardening@xxxxxxxxxxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>
-Kees
> ---
> Documentation/admin-guide/kernel-parameters.txt | 6 ------
> 1 file changed, 6 deletions(-)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 138f6664b2e2..0082d1e56999 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -5102,12 +5102,6 @@
> emulate [default] Vsyscalls turn into traps and are
> emulated reasonably safely.
>
> - native Vsyscalls are native syscall instructions.
> - This is a little bit faster than trapping
> - and makes a few dynamic recompilers work
> - better than they would in emulation mode.
> - It also makes exploits much easier to write.
> -
> none Vsyscalls don't work at all. This makes
> them quite hard to use for exploits but
> might break your system.
> --
> 2.21.0
>
--
Kees Cook
