Re: [PATCH v2 1/8] x86/vsyscall: Remove the vsyscall=native documentation

[Kees Cook]

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