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

From: Dan Williams
Date: Fri Apr 16 2021 - 14:04:51 EST


On Fri, Apr 16, 2021 at 10:34 AM Andy Shevchenko
<andy.shevchenko@xxxxxxxxx> wrote:
>
> On Fri, Apr 16, 2021 at 09:15:34AM -0700, Dan Williams wrote:
> > 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.
>
> It's special, i.e. error pointer case. We don't handle such here.
>
> > 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.
>
> Submit a patch then. I rest my case b/c I consider that ugly castings worse
> than additional API call, although it's not ideal.

It sounds like you'll NAK that patch, and I'm not too enthusiastic
about these proposed changes either because I disagree that the code
is incorrect. Is there another compromise?