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=-7.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 18614C433E0 for ; Thu, 2 Jul 2020 12:42:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E07BC2088E for ; Thu, 2 Jul 2020 12:42:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593693775; bh=5Id979Qu+TbMvFs3bdzAkBCYv828DS3FPkCk09ao5tA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=mib1AkxPc6UVeR8MlJfX8fucj/of7ckc8mHqjqkmawCWtntrhadPc8th01oOIxKUX DW9QzPZMOP5W48Iudt3GfHQwpb6wTZfeF87suDK7vJnaG9Rl8hXsuceybnf8X0b7RR Fmu0kXbdV41i6Di2uKQiT1zBOmrUmcyaArUKUDbM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728966AbgGBMmz (ORCPT ); Thu, 2 Jul 2020 08:42:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:48304 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728808AbgGBMmz (ORCPT ); Thu, 2 Jul 2020 08:42:55 -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 08AA820885; Thu, 2 Jul 2020 12:42:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593693774; bh=5Id979Qu+TbMvFs3bdzAkBCYv828DS3FPkCk09ao5tA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=NnEiOIpme/oFl0LG5LH6yJgz74OeVj3OGC7bfMvt0oxzcNXw+2nUkp3q2zvGrrPGq UsSwLsIAvHHV+/6JJLtgHnigNwQNASJFS46tZVN8u14zfgkXkyxA9J5vACUSl8en8a NkSQAtlPXwcKyiBMDvyEfJKL+vgGQz13nystJm24= Date: Thu, 2 Jul 2020 14:42:58 +0200 From: Greg Kroah-Hartman To: Bartosz Golaszewski Cc: Jonathan Corbet , "Rafael J . Wysocki" , Guenter Roeck , Jean Delvare , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hwmon@vger.kernel.org, Bartosz Golaszewski Subject: Re: [PATCH v2 5/6] devres: provide devm_krealloc() Message-ID: <20200702124258.GA1882489@kroah.com> References: <20200629065008.27620-1-brgl@bgdev.pl> <20200629065008.27620-6-brgl@bgdev.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200629065008.27620-6-brgl@bgdev.pl> Sender: linux-hwmon-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org On Mon, Jun 29, 2020 at 08:50:07AM +0200, Bartosz Golaszewski wrote: > From: Bartosz Golaszewski > > Implement the managed variant of krealloc(). This function works with > all memory allocated by devm_kmalloc() (or devres functions using it > implicitly like devm_kmemdup(), devm_kstrdup() etc.). > > Managed realloc'ed chunks can be manually released with devm_kfree(). > > Signed-off-by: Bartosz Golaszewski > --- > .../driver-api/driver-model/devres.rst | 1 + > drivers/base/devres.c | 50 +++++++++++++++++++ > include/linux/device.h | 2 + > 3 files changed, 53 insertions(+) > > diff --git a/Documentation/driver-api/driver-model/devres.rst b/Documentation/driver-api/driver-model/devres.rst > index e0b58c392e4f..0a2572c3813c 100644 > --- a/Documentation/driver-api/driver-model/devres.rst > +++ b/Documentation/driver-api/driver-model/devres.rst > @@ -352,6 +352,7 @@ MEM > devm_kfree() > devm_kmalloc() > devm_kmalloc_array() > + devm_krealloc() > devm_kmemdup() > devm_kstrdup() > devm_kvasprintf() > diff --git a/drivers/base/devres.c b/drivers/base/devres.c > index ed615d3b9cf1..4b8870ef6a3f 100644 > --- a/drivers/base/devres.c > +++ b/drivers/base/devres.c > @@ -837,6 +837,56 @@ void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp) > } > EXPORT_SYMBOL_GPL(devm_kmalloc); > > +void *devm_krealloc(struct device *dev, void *ptr, size_t new_size, gfp_t gfp) > +{ > + struct devres *old_dr, *new_dr; > + struct list_head old_head; > + unsigned long flags; > + void *ret = NULL; > + size_t tot_size; > + > + if (unlikely(!new_size)) { > + devm_kfree(dev, ptr); > + return ZERO_SIZE_PTR; > + } > + > + if (unlikely(ZERO_OR_NULL_PTR(ptr))) > + return devm_kmalloc(dev, new_size, gfp); > + > + if (WARN_ON(is_kernel_rodata((unsigned long)ptr))) > + /* > + * We cannot reliably realloc a const string returned by > + * devm_kstrdup_const(). > + */ > + return NULL; > + > + if (!check_dr_size(new_size, &tot_size)) > + return NULL; > + > + spin_lock_irqsave(&dev->devres_lock, flags); > + > + old_dr = find_dr(dev, devm_kmalloc_release, devm_kmalloc_match, ptr); > + if (WARN_ON(!old_dr)) > + /* Memory chunk not managed or managed by a different device. */ > + goto out; > + > + old_head = old_dr->node.entry; > + > + new_dr = krealloc(old_dr, tot_size, gfp); > + if (!new_dr) > + goto out; > + > + if (new_dr != old_dr) > + list_replace(&old_head, &new_dr->node.entry); > + > + ret = new_dr->data; > + > +out: > + spin_unlock_irqrestore(&dev->devres_lock, flags); > + return ret; > +} > +EXPORT_SYMBOL_GPL(devm_krealloc); That's a lot of logic that does not seem to match up with the krealloc() logic in mm/slab_common.c, are you sure we need to do all of that? Who wants this? thanks, greg k-h