Re: [PATCH v1 1/1] ACPI: NFIT: Import GUID before use

From: Dan Williams
Date: Fri Apr 16 2021 - 12:15:50 EST


On Fri, Apr 16, 2021 at 1:58 AM Andy Shevchenko
<andy.shevchenko@xxxxxxxxx> wrote:
>
> On Fri, Apr 16, 2021 at 8:28 AM Dan Williams <dan.j.williams@xxxxxxxxx> wrote:
> >
> > On Thu, Apr 15, 2021 at 6:59 AM Andy Shevchenko
> > <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
> > >
> > > Strictly speaking the comparison between guid_t and raw buffer
> > > is not correct. Import GUID to variable of guid_t type and then
> > > compare.
> >
> > Hmm, what about something like the following instead, because it adds
> > safety. Any concerns about evaluating x twice in a macro should be
> > alleviated by the fact that ARRAY_SIZE() will fail the build if (x) is
> > not an array.
>
> ARRAY_SIZE doesn't check type.

See __must_be_array.

> I don't like hiding ugly casts like this.

See PTR_ERR, ERR_PTR, ERR_CAST.

There's nothing broken about the way the code currently stands, so I'd
rather try to find something to move the implementation forward than
sideways.