Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Fri, 2 Dec 2022 14:01:31 +0200
From:   Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     Sakari Ailus <sakari.ailus@linux.intel.com>,
        linux-kernel@vger.kernel.org, Jason Gunthorpe <jgg@ziepe.ca>,
        Matthew Wilcox <willy@infradead.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>
Subject: Re: [PATCH 1/4] container_of: add container_of_const() that
 preserves const-ness of the pointer
Message-ID: <Y4npGz+qwqv3xtBi@smile.fi.intel.com>
References: <20221201193057.1195255-1-gregkh@linuxfoundation.org>
 <Y4k3DrPW1eG9WB7r@paasikivi.fi.intel.com>
 <Y4nXY05iM034z6Gi@kroah.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <Y4nXY05iM034z6Gi@kroah.com>
Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo
Precedence: bulk

On Fri, Dec 02, 2022 at 11:45:55AM +0100, Greg Kroah-Hartman wrote:
> On Thu, Dec 01, 2022 at 11:21:50PM +0000, Sakari Ailus wrote:
> > On Thu, Dec 01, 2022 at 08:30:54PM +0100, Greg Kroah-Hartman wrote:
> > > container_of does not preserve the const-ness of a pointer that is
> > > passed into it, which can cause C code that passes in a const pointer to
> > > get a pointer back that is not const and then scribble all over the data
> > > in it.  To prevent this, container_of_const() will preserve the const
> > > status of the pointer passed into it using the newly available _Generic()
> > > method.
> > 
> > "_const" in the name suggests that the macro would always take a const
> > argument.
> 
> I mean it here to be "this will preserve const" as yes, it can take a
> const.  Or not.
> 
> > Could this be called e.g. container_of_safe() (for type-safe, but
> > full type_safe would be a bit long)?
> 
> const is an attribute of type safety, container_of is also type-safe
> as-is, it's just the const portion here that is the difference between
> the two.

container_of_const_safe() :-)

> Naming is hard :(

True.

-- 
With Best Regards,
Andy Shevchenko