Re: [PATCH v5 11/14] software node: move small properties inline when copying
From: Andy Shevchenko
Date: Wed Oct 16 2019 - 12:18:51 EST
On Wed, Oct 16, 2019 at 09:01:26AM -0700, Dmitry Torokhov wrote:
> On Wed, Oct 16, 2019 at 10:48:57AM +0300, Andy Shevchenko wrote:
> > On Tue, Oct 15, 2019 at 11:25:53AM -0700, Dmitry Torokhov wrote:
> > You store a value as union, but going to read as a member of union?
> > I'm pretty sure it breaks standard rules.
>
> No, I move the values _in place_ of the union, and the data is always
> fetched via void pointers. And copying data via char * or memcpy() is
> allowed even in C99 and C11.
>
> But I am wondering why are we actually worrying about all of this? The
> kernel is gnu89 and I think is going to stay this way because we use
> initializers with a cast in a lot of places:
>
> #define __RAW_SPIN_LOCK_UNLOCKED(lockname) \
> (raw_spinlock_t) __RAW_SPIN_LOCK_INITIALIZER(lockname)
>
> and C99 and gnu99 do not allow this. See
> https://lore.kernel.org/lkml/20141019231031.GB9319@xxxxxxxxxxxxxxxxx/
This is simple not a cast.
--
With Best Regards,
Andy Shevchenko