Re: [PATCH] lib: stackinit: Adjust target string to 8 bytes for m68k

[Geert Uytterhoeven]

Hi Kees,

On Tue, Feb 27, 2024 at 11:47 PM Kees Cook <keescook@xxxxxxxxxxxx> 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@xxxxxxxxxxxx>
> Closes: https://lore.kernel.org/lkml/a0d10d50-2720-4ecd-a2c6-c2c5e5aeee65@xxxxxxxxxxxx/

Do reports have an expiration date? ;-)
Reported-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Closes: https://lore.kernel.org/r/CAMuHMdX_g1tbiUL9PUQdqaegrEzCNN3GtbSvSBFYAL4TzvstFg@xxxxxxxxxxxxxx
Closes: https://lore.kernel.org/r/CAMuHMdW6N40+0gGQ+LSrN64Mo4A0-ELAm0pR3gWQ0mNanyBuUQ@xxxxxxxxxxxxxx

> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

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

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68korg

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds