From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Kees Cook <keescook@chromium.org>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>,
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
Date: Mon, 24 Oct 2022 12:00:16 +0300 [thread overview]
Message-ID: <Y1ZUIEYcjQZMdSfp@smile.fi.intel.com> (raw)
In-Reply-To: <Y1ZQpcdK4sdy+5QZ@kroah.com>
+ Kees
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:
> > On Mon, Oct 24, 2022 at 11:26:10AM +0300, Sakari Ailus wrote:
> > > container_of() casts the original type to another which leads to the loss
> > > of the const qualifier if it is not specified in the caller-provided type.
> > > This easily leads to container_of() returning a non-const pointer to a
> > > const struct which the C compiler does not warn about.
...
> > > * @type: the type of the container struct this is embedded in.
> > > * @member: the name of the member within the struct.
> > > *
> > > + * WARNING: as container_of() casts the given struct to another, also the
>
> Wrong function name here.
>
> > > + * possible const qualifier of @ptr is lost unless it is also specified in
> > > + * @type. This is not a problem if the containing object is not const. Use with
> > > + * care.
> >
> > Same comments here.
>
> Wait, no one uses this macro, so why not just remove it entirely?
Kees, do you know why and what for we have container_of_safe()?
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2022-10-24 9:00 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-24 8:26 [PATCH 1/1] linux/container_of.h: Warn about loss of constness Sakari Ailus
2022-10-24 8:43 ` Greg Kroah-Hartman
2022-10-24 8:45 ` Greg Kroah-Hartman
2022-10-24 9:00 ` Andy Shevchenko [this message]
2022-10-24 17:39 ` Kees Cook
2022-10-24 17:51 ` Rafael J. Wysocki
2022-10-24 21:24 ` David Laight
2022-10-25 7:47 ` Greg Kroah-Hartman
2022-10-24 9:11 ` Sakari Ailus
2022-10-24 9:22 ` Andy Shevchenko
2022-10-24 9:34 ` David Laight
2022-10-24 9:37 ` 'Andy Shevchenko'
2022-10-24 9:46 ` David Laight
2022-10-24 10:01 ` Greg Kroah-Hartman
2022-10-24 10:05 ` David Laight
2022-10-24 9:48 ` Greg Kroah-Hartman
2022-10-24 10:07 ` Sakari Ailus
2022-10-24 8:59 ` David Laight
2022-10-24 10:11 ` Sakari Ailus
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