From patchwork Thu Oct 15 00:42:09 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 11838343 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AEDF661C for ; Thu, 15 Oct 2020 01:00:44 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 7D7DF22257 for ; Thu, 15 Oct 2020 01:00:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7D7DF22257 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 8DFD66B0062; Wed, 14 Oct 2020 21:00:43 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 890316B0068; Wed, 14 Oct 2020 21:00:43 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 757196B006E; Wed, 14 Oct 2020 21:00:43 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0178.hostedemail.com [216.40.44.178]) by kanga.kvack.org (Postfix) with ESMTP id 497F16B0062 for ; Wed, 14 Oct 2020 21:00:43 -0400 (EDT) Received: from smtpin13.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id DCA54180AD815 for ; Thu, 15 Oct 2020 01:00:42 +0000 (UTC) X-FDA: 77372354724.13.toy82_620f34327210 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin13.hostedemail.com (Postfix) with ESMTP id BC1A918140B67 for ; Thu, 15 Oct 2020 01:00:42 +0000 (UTC) X-Spam-Summary: 1,0,0,,d41d8cd98f00b204,dan.j.williams@intel.com,,RULES_HIT:30054:30064:30070,0,RBL:192.55.52.115:@intel.com:.lbl8.mailshell.net-62.18.0.100 64.95.201.95;04yriaw4i76cfcwu9maytb8th3pdoypnqnzq61jgd3ts3c9sxtc5udrft5wqtn9.znp3w1an7eb65wbraiy7px3u4sjqm64o1c6jzkgtcauhi86m5djgo8mu6iisi35.y-lbl8.mailshell.net-223.238.255.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:ft,MSBL:0,DNSBL:none,Custom_rules:0:0:0,LFtime:25,LUA_SUMMARY:none X-HE-Tag: toy82_620f34327210 X-Filterd-Recvd-Size: 6805 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by imf20.hostedemail.com (Postfix) with ESMTP for ; Thu, 15 Oct 2020 01:00:41 +0000 (UTC) IronPort-SDR: 1tsSZ4aIuvT/wcvWowBUMBRRIfaxVNf9odawvhCfGULMjDQm3Eg/2mFNFDKpZ7PTlSw5Zg1J/W euATr16aC5Zg== X-IronPort-AV: E=McAfee;i="6000,8403,9774"; a="165445321" X-IronPort-AV: E=Sophos;i="5.77,376,1596524400"; d="scan'208";a="165445321" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Oct 2020 18:00:39 -0700 IronPort-SDR: +GanhSOzVZlWa2eF4YEC17nMwSUu/4Nio4x/byPlczB6DLh+lElcwDVvtvX2fqdpq8R32Ouhil KS5M8ZHJU1+g== X-IronPort-AV: E=Sophos;i="5.77,376,1596524400"; d="scan'208";a="464089569" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.25]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Oct 2020 18:00:38 -0700 Subject: [PATCH 1/2] device-dax/kmem: Fix resource release From: Dan Williams To: linux-kernel@vger.kernel.org Cc: David Hildenbrand , Vishal Verma , Dave Hansen , Pavel Tatashin , Brice Goglin , Dave Jiang , Ira Weiny , Jia He , Joao Martins , Jonathan Cameron , akpm@linux-foundation.org, linux-nvdimm@lists.01.org, linux-mm@kvack.org Date: Wed, 14 Oct 2020 17:42:09 -0700 Message-ID: <160272252925.3136502.17220638073995895400.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <160272252400.3136502.13635752844548960833.stgit@dwillia2-desk3.amr.corp.intel.com> References: <160272252400.3136502.13635752844548960833.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.18-3-g996c MIME-Version: 1.0 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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. Reported-by: David Hildenbrand Fixes: 0513bd5bb114 ("device-dax/kmem: replace release_resource() with release_mem_region()") 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: Dan Williams Reviewed-by: David Hildenbrand --- drivers/dax/kmem.c | 48 ++++++++++++++++++++++++++++++++++-------------- 1 file changed, 34 insertions(+), 14 deletions(-) diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c index 6c933f2b604e..af04b6d1d263 100644 --- a/drivers/dax/kmem.c +++ b/drivers/dax/kmem.c @@ -35,11 +35,17 @@ static int dax_kmem_range(struct dev_dax *dev_dax, int i, struct range *r) 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_dax *dev_dax) 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_dax *dev_dax) } /* 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_dax *dev_dax) */ 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_dax *dev_dax) 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 dev_dax *dev_dax) { 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 dev_dax *dev_dax) 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 dev_dax *dev_dax) } if (success >= dev_dax->nr_range) { - kfree(res_name); + kfree(data->res_name); + kfree(data); dev_set_drvdata(dev, NULL); }