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 X-Spam-Level: X-Spam-Status: No, score=-8.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 45885C04AB4 for ; Tue, 14 May 2019 19:12:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 16E642086A for ; Tue, 14 May 2019 19:12:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557861168; bh=Dx8fO3TTAFVbhjdjmVSXfGcWo/4xM9XJT2npi4xsxtc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=rDLRpHdEnReibuqiyn9NSXi/7d6FaOo0zFWG/TffTl5U20e4MEC6/BBg9oQ7sLqvI UwWyD1osRCQE2c2IjaFMAUQTNY8jW2IHnyc+F9KB42xTXRisqg3LYyxo7n7pKL//c9 9a5iqg7t2BfL0YEE47GsC9bl6WcOLkQdwd01WXMU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726325AbfENTMq (ORCPT ); Tue, 14 May 2019 15:12:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:38182 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726036AbfENTMq (ORCPT ); Tue, 14 May 2019 15:12:46 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8AFDD20675; Tue, 14 May 2019 19:12:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557861166; bh=Dx8fO3TTAFVbhjdjmVSXfGcWo/4xM9XJT2npi4xsxtc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=toauLP82s6SvK8V1KkHf5COFmXqXrCdzvWsSIFzpnOMz7HsK8pGBWSn2riYujnQm3 UI2pj0XEpWNT5f3qUGUCkuemRm2ajtG8i/wdw9VqAHsfrUmDKzFPIQ/O90P7kZZGPL U0nCodj8lpkzjPsBWsi9XCyThfy2fiK8twsrFumQ= Date: Tue, 14 May 2019 21:12:43 +0200 From: Greg Kroah-Hartman To: Dan Williams Cc: akpm@linux-foundation.org, Logan Gunthorpe , Bjorn Helgaas , Christoph Hellwig , "Rafael J. Wysocki" , Ira Weiny , linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-mm@kvack.org Subject: Re: [PATCH v2 1/6] drivers/base/devres: Introduce devm_release_action() Message-ID: <20190514191243.GA17226@kroah.com> References: <155727335978.292046.12068191395005445711.stgit@dwillia2-desk3.amr.corp.intel.com> <155727336530.292046.2926860263201336366.stgit@dwillia2-desk3.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <155727336530.292046.2926860263201336366.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: Mutt/1.11.4 (2019-03-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 07, 2019 at 04:56:05PM -0700, Dan Williams wrote: > The devm_add_action() facility allows a resource allocation routine to > add custom devm semantics. One such user is devm_memremap_pages(). > > There is now a need to manually trigger devm_memremap_pages_release(). > Introduce devm_release_action() so the release action can be triggered > via a new devm_memunmap_pages() api in a follow-on change. > > Cc: Logan Gunthorpe > Cc: Bjorn Helgaas > Cc: Christoph Hellwig > Cc: Greg Kroah-Hartman > Cc: "Rafael J. Wysocki" > Reviewed-by: Ira Weiny > Signed-off-by: Dan Williams > --- > drivers/base/devres.c | 24 +++++++++++++++++++++++- > include/linux/device.h | 1 + > 2 files changed, 24 insertions(+), 1 deletion(-) > > diff --git a/drivers/base/devres.c b/drivers/base/devres.c > index e038e2b3b7ea..0bbb328bd17f 100644 > --- a/drivers/base/devres.c > +++ b/drivers/base/devres.c > @@ -755,10 +755,32 @@ void devm_remove_action(struct device *dev, void (*action)(void *), void *data) > > WARN_ON(devres_destroy(dev, devm_action_release, devm_action_match, > &devres)); > - > } > EXPORT_SYMBOL_GPL(devm_remove_action); > > +/** > + * devm_release_action() - release previously added custom action > + * @dev: Device that owns the action > + * @action: Function implementing the action > + * @data: Pointer to data passed to @action implementation > + * > + * Releases and removes instance of @action previously added by > + * devm_add_action(). Both action and data should match one of the > + * existing entries. > + */ > +void devm_release_action(struct device *dev, void (*action)(void *), void *data) > +{ > + struct action_devres devres = { > + .data = data, > + .action = action, > + }; > + > + WARN_ON(devres_release(dev, devm_action_release, devm_action_match, > + &devres)); What does WARN_ON help here? are we going to start getting syzbot reports of this happening? How can this fail? thanks, greg k-h