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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Tue, 28 Feb 2023 08:48:53 +0100
Message-ID: <CAMuHMdXMWaCm7OGq7O9F5SWBxhreTppUr4K6K9FmZf1GpaAtVA@mail.gmail.com>
Subject: Re: [PATCH] m68k: mm: Move initrd phys_to_virt handling after paging_init()
To:     Finn Thain <fthain@linux-m68k.org>
Cc:     Mike Rapoport <rppt@kernel.org>, Stephen Walsh <vk3heg@vk3heg.net>,
        John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>,
        linux-m68k@lists.linux-m68k.org, linux-kernel@vger.kernel.org
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Hi Finn,

On Mon, Feb 27, 2023 at 11:46 PM Finn Thain <fthain@linux-m68k.org> wrote:
> On Mon, 27 Feb 2023, Geert Uytterhoeven wrote:
> > When booting with an initial ramdisk on platforms where physical memory
> > does not start at address zero (e.g. on Amiga):
> >
> >     initrd: 0ef0602c - 0f800000
> >     Zone ranges:
> >       DMA      [mem 0x0000000008000000-0x000000f7ffffffff]
> >       Normal   empty
> >     Movable zone start for each node
> >     Early memory node ranges
> >       node   0: [mem 0x0000000008000000-0x000000000f7fffff]
> >     Initmem setup node 0 [mem 0x0000000008000000-0x000000000f7fffff]
> >     Unable to handle kernel access at virtual address (ptrval)
> >     Oops: 00000000
> >     Modules linked in:
> >     PC: [<00201d3c>] memcmp+0x28/0x56
> >
> > As phys_to_virt() relies on m68k_memoffset and module_fixup(), it must
> > not be called before paging_init().  Hence postpone the phys_to_virt
> > handling for the initial ramdisk until after calling paging_init().
>
> Thanks for debugging this issue.

Np, you're welcome.

> > While at it, reduce #ifdef clutter by using IS_ENABLED() instead.
> >
> > Fixes: 376e3fdecb0dcae2 ("m68k: Enable memtest functionality")
>
> I apologise for the trouble caused by that patch.

Does that count as an Acked-by? ;-)

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. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds