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=-6.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 AB49DC433DF for ; Fri, 16 Oct 2020 02:41:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5A17620E65 for ; Fri, 16 Oct 2020 02:41:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602816064; bh=OSEcPJLMtx8G3SsM6bFzw/qICIC1Jh2yMWhAeui6SSg=; h=Date:From:To:Subject:In-Reply-To:Reply-To:List-ID:From; b=tH3O3leUcoH4oiU78pHv/gNNA3wHv4isW+3b9k5PWcNvbMWK2Jt+gDcPrNnH3406K VnnHWsDcXzewKQ1FrFlC7MnSN/R4bvatjRMSa/FrXLpK9C8j8yczFAa9wnn27irzmK lsf/0S7Noe5Z9vzjJAzgLpP2guLx2pmdwsgHLeOg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404279AbgJPClD (ORCPT ); Thu, 15 Oct 2020 22:41:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:56502 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404278AbgJPClD (ORCPT ); Thu, 15 Oct 2020 22:41:03 -0400 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (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 49D2020878; Fri, 16 Oct 2020 02:41:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602816061; bh=OSEcPJLMtx8G3SsM6bFzw/qICIC1Jh2yMWhAeui6SSg=; h=Date:From:To:Subject:In-Reply-To:From; b=Kb+0FXckKYAXEet8lpciyiZOaa9TwfidG+gLTfHpl+FSw1LnMif++2Mcj82uK8mqN PDa0if/cA//vnpiTbnDQy/482WYOBZMNwMKmJQfB6ryuScpY+Fhs85RS2RFtrct3Xi Pfq0oE9SCXcI9zBm9owd52b3kLaMmP4rrOYob4JI= Date: Thu, 15 Oct 2020 19:40:59 -0700 From: Andrew Morton To: akpm@linux-foundation.org, Brice.Goglin@inria.fr, dan.j.williams@intel.com, dave.hansen@linux.intel.com, dave.jiang@intel.com, david@redhat.com, ira.weiny@intel.com, joao.m.martins@oracle.com, Jonathan.Cameron@huawei.com, justin.he@arm.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, pasha.tatashin@soleen.com, torvalds@linux-foundation.org, vishal.l.verma@intel.com Subject: [patch 001/156] device-dax/kmem: fix resource release Message-ID: <20201016024059.Ycwm4GmQ8%akpm@linux-foundation.org> In-Reply-To: <20201015192732.f448da14e9854c7cb7299956@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Dan Williams Subject: device-dax/kmem: fix resource release The conversion to request_mem_region() is broken because it assumes that the range is marked busy prior to release. However, due to the way that the kmem driver manipulates the IORESOURCE_BUSY flag (clears it to let {add,remove}_memory() handle busy) it requires a manual release_resource() to perform cleanup. Given that the actual 'struct resource *' needs to be recalled, not just the range, add that tracking to the kmem driver-data. Link: https://lkml.kernel.org/r/160272252925.3136502.17220638073995895400.stgit@dwillia2-desk3.amr.corp.intel.com Fixes: 0513bd5bb114 ("device-dax/kmem: replace release_resource() with release_mem_region()") Signed-off-by: Dan Williams Reported-by: David Hildenbrand Reviewed-by: David Hildenbrand Cc: Vishal Verma Cc: Dave Hansen Cc: Pavel Tatashin Cc: Brice Goglin Cc: Dave Jiang Cc: Ira Weiny Cc: Jia He Cc: Joao Martins Cc: Jonathan Cameron Signed-off-by: Andrew Morton --- drivers/dax/kmem.c | 48 ++++++++++++++++++++++++++++++------------- 1 file changed, 34 insertions(+), 14 deletions(-) --- a/drivers/dax/kmem.c~device-dax-kmem-fix-resource-release +++ a/drivers/dax/kmem.c @@ -35,11 +35,17 @@ static int dax_kmem_range(struct dev_dax return 0; } +struct dax_kmem_data { + const char *res_name; + struct resource *res[]; +}; + static int dev_dax_kmem_probe(struct dev_dax *dev_dax) { struct device *dev = &dev_dax->dev; + struct dax_kmem_data *data; + int rc = -ENOMEM; int i, mapped = 0; - char *res_name; int numa_node; /* @@ -55,14 +61,17 @@ static int dev_dax_kmem_probe(struct dev return -EINVAL; } - res_name = kstrdup(dev_name(dev), GFP_KERNEL); - if (!res_name) + data = kzalloc(sizeof(*data) + sizeof(struct resource *) * dev_dax->nr_range, GFP_KERNEL); + if (!data) return -ENOMEM; + data->res_name = kstrdup(dev_name(dev), GFP_KERNEL); + if (!data->res_name) + goto err_res_name; + for (i = 0; i < dev_dax->nr_range; i++) { struct resource *res; struct range range; - int rc; rc = dax_kmem_range(dev_dax, i, &range); if (rc) { @@ -72,7 +81,7 @@ static int dev_dax_kmem_probe(struct dev } /* Region is permanently reserved if hotremove fails. */ - res = request_mem_region(range.start, range_len(&range), res_name); + res = request_mem_region(range.start, range_len(&range), data->res_name); if (!res) { dev_warn(dev, "mapping%d: %#llx-%#llx could not reserve region\n", i, range.start, range.end); @@ -82,9 +91,10 @@ static int dev_dax_kmem_probe(struct dev */ if (mapped) continue; - kfree(res_name); - return -EBUSY; + rc = -EBUSY; + goto err_request_mem; } + data->res[i] = res; /* * Set flags appropriate for System RAM. Leave ..._BUSY clear @@ -104,18 +114,25 @@ static int dev_dax_kmem_probe(struct dev if (rc) { dev_warn(dev, "mapping%d: %#llx-%#llx memory add failed\n", i, range.start, range.end); - release_mem_region(range.start, range_len(&range)); + release_resource(res); + kfree(res); + data->res[i] = NULL; if (mapped) continue; - kfree(res_name); - return rc; + goto err_request_mem; } mapped++; } - dev_set_drvdata(dev, res_name); + dev_set_drvdata(dev, data); return 0; + +err_request_mem: + kfree(data->res_name); +err_res_name: + kfree(data); + return rc; } #ifdef CONFIG_MEMORY_HOTREMOVE @@ -123,7 +140,7 @@ static int dev_dax_kmem_remove(struct de { int i, success = 0; struct device *dev = &dev_dax->dev; - const char *res_name = dev_get_drvdata(dev); + struct dax_kmem_data *data = dev_get_drvdata(dev); /* * We have one shot for removing memory, if some memory blocks were not @@ -142,7 +159,9 @@ static int dev_dax_kmem_remove(struct de rc = remove_memory(dev_dax->target_node, range.start, range_len(&range)); if (rc == 0) { - release_mem_region(range.start, range_len(&range)); + release_resource(data->res[i]); + kfree(data->res[i]); + data->res[i] = NULL; success++; continue; } @@ -153,7 +172,8 @@ static int dev_dax_kmem_remove(struct de } if (success >= dev_dax->nr_range) { - kfree(res_name); + kfree(data->res_name); + kfree(data); dev_set_drvdata(dev, NULL); } _