Re: [PATCH RFC] m68k: Handle __generic_copy_to_user faults more carefully

Geert Uytterhoeven
2024-04-17T06:59:19Z

Hi Michael,

On Tue, Apr 16, 2024 at 10:36 PM Michael Schmitz <schmitzmic@gmail.com> wrote:
> I have tested this fault scenario with a transfer beginning
> at a single byte at the end of a mapped page only, which IMO
> does violate m68k alignment rules. I cannot remember ever
> seeing such faults reported from conforming software before.

68020+ does support unaligned data accesses, so IMHO such transfers
are valid. For compatibility with 68000/68008/68010/68012, data is
recommended to be 2-byte aligned.
Instructions must always be aligned to 2 bytes, though.

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