Re: [PATCH v6 28/41] x86: Introduce userspace API for shadow stack

[Borislav Petkov]

On Sat, Feb 18, 2023 at 01:14:20PM -0800, Rick Edgecombe wrote:
> diff --git a/arch/x86/include/uapi/asm/prctl.h b/arch/x86/include/uapi/asm/prctl.h
> index 500b96e71f18..b2b3b7200b2d 100644
> --- a/arch/x86/include/uapi/asm/prctl.h
> +++ b/arch/x86/include/uapi/asm/prctl.h
> @@ -20,4 +20,10 @@
>  #define ARCH_MAP_VDSO_32		0x2002
>  #define ARCH_MAP_VDSO_64		0x2003
>  
> +/* Don't use 0x3001-0x3004 because of old glibcs */

So where is this all new interface to userspace programs documented? Do
we have an agreement with all the involved parties that this is how
we're going to support shadow stacks and that this is what userspace
should do?

I'd like to avoid one more fiasco with glibc etc here...

Thx.

-- 
Regards/Gruss,
    Boris.

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