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Date:   Mon, 24 Oct 2022 12:22:56 +0300
From:   Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To:     Sakari Ailus <sakari.ailus@linux.intel.com>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-kernel@vger.kernel.org,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        David Laight <David.Laight@aculab.com>
Subject: Re: [PATCH 1/1] linux/container_of.h: Warn about loss of constness
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On Mon, Oct 24, 2022 at 09:11:53AM +0000, Sakari Ailus wrote:
> On Mon, Oct 24, 2022 at 10:45:25AM +0200, Greg Kroah-Hartman wrote:
> > On Mon, Oct 24, 2022 at 10:43:52AM +0200, Greg Kroah-Hartman wrote:

...

> > Wait, no one uses this macro, so why not just remove it entirely?
> 
> Good question. It appears to be a (relatively) common pattern to look up
> something and the return its containing object if the lookup was
> successful. Doing a quick
> 
> 	$ git grep 'container_of.*:' drivers include
> 
> reveals more than 20 instances of the pattern. There are probably more
> those that use if for testing for NULL. I guess people don't know about
> this macro, apart from the developers of the staging driver it was added
> for (commit 05e6557b8ed833546ee2b66ce6b58fecf09f439e).

Maybe we can provide an example to keep this macro in the kernel, meaning
convert one of the drivers / subsystem to actually use it?

-- 
With Best Regards,
Andy Shevchenko