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From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: Wed, 28 Feb 2024 08:58:03 +0100
Message-ID: <CAMuHMdVMsbVPmcztWCDaorLSvwtLfWz-QVuA=vLFfX_iTdARcA@mail.gmail.com>
Subject: Re: [PATCH] lib: stackinit: Adjust target string to 8 bytes for m68k
To: Kees Cook <keescook@chromium.org>
Cc: Guenter Roeck <linux@roeck-us.net>, linux-kernel@vger.kernel.org, 
	linux-hardening@vger.kernel.org
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Hi Kees,

On Tue, Feb 27, 2024 at 11:47=E2=80=AFPM Kees Cook <keescook@chromium.org> =
wrote:
> For reasons I cannot understand, m68k moves the start of the stack frame
> for consecutive calls to the same function if the function's test
> variable is larger than 8 bytes. This was only happening for the char
> array test (obviously), so adjust the length of the string for m68k
> only. I want the array size to be longer than "unsigned long" for every
> given architecture, so the other remain unchanged.
>
> Additionally adjust the error message to be a bit more clear about
> what's happened, and move the KUNIT check outside of the consecutive
> calls to minimize what happens between them.

Thanks for your patch!

> Reported-by: Guenter Roeck <linux@roeck-us.net>
> Closes: https://lore.kernel.org/lkml/a0d10d50-2720-4ecd-a2c6-c2c5e5aeee65=
@roeck-us.net/

Do reports have an expiration date? ;-)
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Closes: https://lore.kernel.org/r/CAMuHMdX_g1tbiUL9PUQdqaegrEzCNN3GtbSvSBFY=
AL4TzvstFg@mail.gmail.com
Closes: https://lore.kernel.org/r/CAMuHMdW6N40+0gGQ+LSrN64Mo4A0-ELAm0pR3gWQ=
0mNanyBuUQ@mail.gmail.com

> Signed-off-by: Kees Cook <keescook@chromium.org>

Finally all parts of this test are passing on m68k, great!
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>

Gr{oetje,eeting}s,

                        Geert

--=20
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k=
org

In personal conversations with technical people, I call myself a hacker. Bu=
t
when I'm talking to journalists I just say "programmer" or something like t=
hat.
                                -- Linus Torvalds