On Fri, Mar 17, 2023 at 1:42 PM Miguel Ojeda
<miguel.ojeda.sandonis@xxxxxxxxx> wrote:
>
> It is comparing against just the `.code` in the `m5mols_default_ffmt`
> table, i.e. the `MEDIA_BUS_FMT_VYUY8_2X8` (8199 = 0x2007) and
> `MEDIA_BUS_FMT_JPEG_1X8` (16385 = 0x4001), see
Yeah, I see what it's doing.
But:
> If the condition had `++type` instead, it would not be a problem,
> because the loop stops before we go into the out of bounds access thus
> no UB.
Yeah, but clang really should have generated a proper third iteration,
which calls that "out of bounds" case, and then returns, instead fo
falling off the end.
I do think that on the kernel side, the fix is to just change
} while (type++ != SIZE_DEFAULT_FFMT);
to
} while (++type != SIZE_DEFAULT_FFMT);
but I would *really* like clang to be fixed to not silently generate
code that does insane things and would be basically impossible to
debug if it ever triggers.
We would have spent a *lot* of time wondering how the heck we Oopsed
in m5mols_get_frame_desc().
Linus
