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=-10.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 E7AF6C433E3 for ; Mon, 13 Jul 2020 19:29:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CEFE120771 for ; Mon, 13 Jul 2020 19:29:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726617AbgGMT3E (ORCPT ); Mon, 13 Jul 2020 15:29:04 -0400 Received: from mga12.intel.com ([192.55.52.136]:33435 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726339AbgGMT3E (ORCPT ); Mon, 13 Jul 2020 15:29:04 -0400 IronPort-SDR: mrhf7rNUC2PxeAUSiRbHkUa6TJXARkYUVczThuZRGn4ISqvksSUu8os3hD30XRXalc7CPEpdZx MSUwJGITUQ5A== X-IronPort-AV: E=McAfee;i="6000,8403,9681"; a="128278626" X-IronPort-AV: E=Sophos;i="5.75,348,1589266800"; d="scan'208";a="128278626" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Jul 2020 12:29:04 -0700 IronPort-SDR: 7nnU7K24gRkjFEh2UkU1jeypUQx/rdcI1r7cJKYuqWXmY/BpvD9uFLeYYhdapQ2GcjQoBslpu0 A9E/PUCiX57A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,348,1589266800"; d="scan'208";a="485605105" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.40]) by fmsmga005.fm.intel.com with ESMTP; 13 Jul 2020 12:29:01 -0700 Received: from andy by smile with local (Exim 4.94) (envelope-from ) id 1jv48L-001eBY-Aq; Mon, 13 Jul 2020 22:29:01 +0300 Date: Mon, 13 Jul 2020 22:29:01 +0300 From: Andy Shevchenko To: Bartosz Golaszewski Cc: Jonathan Cameron , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , Michal Simek , Greg Kroah-Hartman , Guenter Roeck , linux-iio@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Bartosz Golaszewski Subject: Re: [PATCH v4 1/3] devres: provide devm_krealloc() Message-ID: <20200713192901.GD3703480@smile.fi.intel.com> References: <20200713145934.18243-1-brgl@bgdev.pl> <20200713145934.18243-2-brgl@bgdev.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200713145934.18243-2-brgl@bgdev.pl> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 13, 2020 at 04:59:32PM +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 | 67 +++++++++++++++++++ > include/linux/device.h | 2 + > 3 files changed, 70 insertions(+) > > diff --git a/Documentation/driver-api/driver-model/devres.rst b/Documentation/driver-api/driver-model/devres.rst > index eaaaafc21134f..f318a5c0033c1 100644 > --- a/Documentation/driver-api/driver-model/devres.rst > +++ b/Documentation/driver-api/driver-model/devres.rst > @@ -354,6 +354,7 @@ MEM > devm_kmalloc() > devm_kmalloc_array() > devm_kmemdup() > + devm_krealloc() > devm_kstrdup() > devm_kvasprintf() > devm_kzalloc() > diff --git a/drivers/base/devres.c b/drivers/base/devres.c > index ed615d3b9cf15..1775d35462300 100644 > --- a/drivers/base/devres.c > +++ b/drivers/base/devres.c > @@ -837,6 +837,73 @@ void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp) > } > EXPORT_SYMBOL_GPL(devm_kmalloc); > > +/** > + * devm_krealloc - Resource-managed krealloc() > + * @dev: Device to re-allocate memory for > + * @ptr: Pointer to the memory chunk to re-allocate > + * @new_size: New allocation size > + * @gfp: Allocation gfp flags > + * > + * Managed krealloc(). Resizes the memory chunk allocated with devm_kmalloc(). > + * Behaves similarly to regular krealloc(): if @ptr is NULL or ZERO_SIZE_PTR, > + * it's the equivalent of devm_kmalloc(). If new_size is zero, it returns 'it frees the previously allocated memory and returns' > + * ZERO_SIZE_PTR. This function doesn't change the order in which the release > + * callback for the re-alloc'ed devres will be called (except when falling back > + * to devm_kmalloc() 'or when freeing resources when new_size is zero' > ). The contents of the memory are preserved up to the > + * lesser of new and old sizes. > + */ > +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; > + size_t total_size; > + void *ret = NULL; > + > + 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, &total_size)) > + return NULL; > + > + spin_lock_irqsave(&dev->devres_lock, flags); > + > + old_dr = find_dr(dev, devm_kmalloc_release, devm_kmalloc_match, ptr); > + if (!old_dr) { > + spin_unlock_irqrestore(&dev->devres_lock, flags); > + WARN(1, "Memory chunk not managed or managed by a different device."); > + return NULL; > + } > + > + old_head = old_dr->node.entry; > + > + new_dr = krealloc(old_dr, total_size, gfp); > + if (!new_dr) { > + spin_unlock_irqrestore(&dev->devres_lock, flags); > + return NULL; > + } > + > + if (new_dr != old_dr) > + list_replace(&old_head, &new_dr->node.entry); > + > + ret = new_dr->data; > + spin_unlock_irqrestore(&dev->devres_lock, flags); > + return ret; > +} > +EXPORT_SYMBOL_GPL(devm_krealloc); > + > /** > * devm_kstrdup - Allocate resource managed space and > * copy an existing string into that. > diff --git a/include/linux/device.h b/include/linux/device.h > index 7322c51e9c0c7..f64f408431593 100644 > --- a/include/linux/device.h > +++ b/include/linux/device.h > @@ -206,6 +206,8 @@ int devres_release_group(struct device *dev, void *id); > > /* managed devm_k.alloc/kfree for device drivers */ > void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp) __malloc; > +void *devm_krealloc(struct device *dev, void *ptr, size_t size, > + gfp_t gfp) __must_check; Strange indentation, also you can move __must_check to the beginning of the declaration. > __printf(3, 0) char *devm_kvasprintf(struct device *dev, gfp_t gfp, > const char *fmt, va_list ap) __malloc; > __printf(3, 4) char *devm_kasprintf(struct device *dev, gfp_t gfp, > -- > 2.26.1 > -- With Best Regards, Andy Shevchenko