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From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: Tue, 27 Feb 2024 08:41:46 +0100
Message-ID: <CAMuHMdVYjw9CEBUzxuJ-10wudK_mvJZgqP3gR4kuv-FDYBZ-Aw@mail.gmail.com>
Subject: Re: Linux 6.8-rc6
To: Guenter Roeck <linux@roeck-us.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>, 
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, Kees Cook <keescook@chromium.org>, 
	linux-m68k <linux-m68k@lists.linux-m68k.org>
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Hi G=C3=BCnter,

CC Kees

On Mon, Feb 26, 2024 at 6:52=E2=80=AFPM Guenter Roeck <linux@roeck-us.net> =
wrote:
> stackinit
> ---------
>
> Seen with m68k:q800 emulation.
>
>     # test_char_array_zero: ASSERTION FAILED at lib/stackinit_kunit.c:333
>     Expected stackinit_range_contains(fill_start, fill_size, target_start=
, target_size) to be true, but is false
> stack fill missed target!? (fill 16 wide, target offset by -12)
>
>     # test_char_array_none: ASSERTION FAILED at lib/stackinit_kunit.c:343
>     Expected stackinit_range_contains(fill_start, fill_size, target_start=
, target_size) to be true, but is false
> stack fill missed target!? (fill 16 wide, target offset by -12)
>
> Report:
> https://lore.kernel.org/lkml/a0d10d50-2720-4ecd-a2c6-c2c5e5aeee65@roeck-u=
s.net/

I don't think these have ever succeeded before, see
https://lore.kernel.org/all/CAMuHMdX_g1tbiUL9PUQdqaegrEzCNN3GtbSvSBFYAL4Tzv=
stFg@mail.gmail.com

> I suspect this may be caused by the test assuming that stack growth is
> downward, but I don't really understand the test well enough to be sure.
> I'll disable this set of tests for m68k going forward, so I am not going
> to report the problem again in the future.

On m68k, the stack does grow downward.
AFAIK only parisc has a stack that grows upward.

Gr{oetje,eeting}s,

                        Geert

--
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