linux-kernel - Re: [PATCH v7 33/41] x86/shstk: Introduce map_shadow

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Message-ID: <20230310200519.GDZAuNf+bvYjGtazqv@fat_crate.local>
Date:   Fri, 10 Mar 2023 21:05:19 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     "Edgecombe, Rick P" <rick.p.edgecombe@...el.com>
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Subject: Re: [PATCH v7 33/41] x86/shstk: Introduce map_shadow_stack syscall

On Fri, Mar 10, 2023 at 05:12:40PM +0000, Edgecombe, Rick P wrote:
> > Can we use distinct negative retvals in each case so that it is clear
> > to
> > userspace where it fails, *if* it fails?
> 
> Good idea, I think maybe ERANGE.

For those two, right?

        /* If there isn't space for a token */
        if (set_tok && size < 8)
                return -EINVAL;

        if (addr && addr <= 0xFFFFFFFF)
                return -EINVAL;

They are kinda range-checking of sorts. A wider range but still
similar... 

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette