Re: kernel/workqueue.c:4434:61: sparse: expression using sizeof bool

From: Tejun Heo
Date: Thu Apr 04 2013 - 11:44:00 EST


Hey,

On Thu, Apr 04, 2013 at 09:42:09AM +0800, Fengguang Wu wrote:
> > > 4433 /* copy worker description */
> > > > 4434 probe_kernel_read(&desc_valid, &worker->desc_valid, sizeof(desc_valid));
> > > 4435 if (desc_valid)
> >
> > I don't know what to make of this warning. Yes, it's probing a bool
> > variable and of course using sizeof(bool) to do that. Why does sparse
> > complain about this?
>
> I guess sparse warns on sizeof(bool) because it is compiler defined.
> It may be 1, 4, or even 8 depending on the gcc version and platform.

Yeah, it's copying out a bool so as long as that's the actual size,
it's okay. I mean, it's not like sizeof(long) is constant across
platforms. I'm gonna ignore it but still curious what the warning is
good for.

Thanks.

--
tejun
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