From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 50D4EFA373E for ; Mon, 24 Oct 2022 09:23:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229974AbiJXJXO (ORCPT ); Mon, 24 Oct 2022 05:23:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53550 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229497AbiJXJXM (ORCPT ); Mon, 24 Oct 2022 05:23:12 -0400 Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B8DA761736 for ; Mon, 24 Oct 2022 02:23:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1666603391; x=1698139391; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=1IDCnTWE2rq8375NnRl516ZEPqpmCW5m5j0ASaRzdig=; b=LgOdVDXSiyNmERselKAW1rGPTqKwJRQ3YJWZCADnqD5tGnC1Hf5iRWWc TTSkmbjK4wl5ooLKyqSc1Re5Imp/1UTsPCCQ0V0Kq6SuglRRJVZdJhW8M u0GjKGnTd4euEjIrtT6sYA0q4b3Rw5m0ckcax23ATZB6kVuauG63BKUG+ rNfFV8r20eW1tIpoNFIz+dFf2F2/wQh80Lk5dy93kJu/aCgO+DziJwng3 zwBS1fAQRo3enMcKPd3A3Dmg2gENaIAQhE7XjpbUklZtcwrldX1wK9z+v d4NHVFh9YYgNZDdZD9VRy0E2r/laSf7vc4DUXqouT85+IxlJVg8McYI74 A==; X-IronPort-AV: E=McAfee;i="6500,9779,10509"; a="287094060" X-IronPort-AV: E=Sophos;i="5.95,207,1661842800"; d="scan'208";a="287094060" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Oct 2022 02:23:00 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10509"; a="806249867" X-IronPort-AV: E=Sophos;i="5.95,207,1661842800"; d="scan'208";a="806249867" Received: from smile.fi.intel.com ([10.237.72.54]) by orsmga005.jf.intel.com with ESMTP; 24 Oct 2022 02:22:58 -0700 Received: from andy by smile.fi.intel.com with local (Exim 4.96) (envelope-from ) id 1omtfd-001MnD-0O; Mon, 24 Oct 2022 12:22:57 +0300 Date: Mon, 24 Oct 2022 12:22:56 +0300 From: Andy Shevchenko To: Sakari Ailus Cc: Greg Kroah-Hartman , linux-kernel@vger.kernel.org, "Rafael J. Wysocki" , David Laight Subject: Re: [PATCH 1/1] linux/container_of.h: Warn about loss of constness Message-ID: References: <20221024082610.74990-1-sakari.ailus@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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