From patchwork Mon Aug 3 05:02:51 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 11697183 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 ACF7D13B1 for ; Mon, 3 Aug 2020 05:19:12 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 94DD6206D7 for ; Mon, 3 Aug 2020 05:19:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 94DD6206D7 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvdimm-bounces@lists.01.org Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 1DE8D12A6D4C7; Sun, 2 Aug 2020 22:19:13 -0700 (PDT) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=192.55.52.120; helo=mga04.intel.com; envelope-from=dan.j.williams@intel.com; receiver= Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 5719412A6D4C0 for ; Sun, 2 Aug 2020 22:19:11 -0700 (PDT) IronPort-SDR: PX/KUZFkw4WVsuXZCKkLhIHNOTEVnSg5ZEBvo8YUFumDocATaR6qwXik4/tj53i/av4/TSW9k1 xLQE4KQYMjWQ== X-IronPort-AV: E=McAfee;i="6000,8403,9701"; a="149487646" X-IronPort-AV: E=Sophos;i="5.75,429,1589266800"; d="scan'208";a="149487646" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Aug 2020 22:19:10 -0700 IronPort-SDR: 8ZbSyWkuiQpaoznBPn1FxKc+srq2l6P5lOudvhAUNkNIJsl+a3nncXA0wCho+X3KpHCpnstaPs RdjCl47Fzn1A== X-IronPort-AV: E=Sophos;i="5.75,429,1589266800"; d="scan'208";a="314537621" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.16]) by fmsmga004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Aug 2020 22:19:10 -0700 Subject: [PATCH v4 05/23] resource: Report parent to walk_iomem_res_desc() callback From: Dan Williams To: akpm@linux-foundation.org Date: Sun, 02 Aug 2020 22:02:51 -0700 Message-ID: <159643097166.4062302.11875688887228572793.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <159643094279.4062302.17779410714418721328.stgit@dwillia2-desk3.amr.corp.intel.com> References: <159643094279.4062302.17779410714418721328.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.18-3-g996c MIME-Version: 1.0 Message-ID-Hash: O26AWWGMOHY4FOA3BFFWK6FWQKN23EGS X-Message-ID-Hash: O26AWWGMOHY4FOA3BFFWK6FWQKN23EGS X-MailFrom: dan.j.williams@intel.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; suspicious-header CC: Jason Gunthorpe , Dave Hansen , Tom Lendacky , peterz@infradead.org, ard.biesheuvel@linaro.org, linux-mm@kvack.org, linux-nvdimm@lists.01.org, joao.m.martins@oracle.com, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, dri-devel@lists.freedesktop.org X-Mailman-Version: 3.1.1 Precedence: list List-Id: "Linux-nvdimm developer list." Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: In support of detecting whether a resource might have been been claimed, report the parent to the walk_iomem_res_desc() callback. For example, the ACPI HMAT parser publishes "hmem" platform devices per target range. However, if the HMAT is disabled / missing a fallback driver can attach devices to the raw memory ranges as a fallback if it sees unclaimed / orphan "Soft Reserved" resources in the resource tree. Otherwise, find_next_iomem_res() returns a resource with garbage data from the stack allocation in __walk_iomem_res_desc() for the res->parent field. There are currently no users that expect ->child and ->sibling to be valid, and the resource_lock would be needed to traverse them. Use a compound literal to implicitly zero initialize the fields that are not being returned in addition to setting ->parent. Cc: Jason Gunthorpe Cc: Dave Hansen Cc: Wei Yang Cc: Tom Lendacky Signed-off-by: Dan Williams --- kernel/resource.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/kernel/resource.c b/kernel/resource.c index 841737bbda9e..f1175ce93a1d 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -382,10 +382,13 @@ static int find_next_iomem_res(resource_size_t start, resource_size_t end, if (p) { /* copy data */ - res->start = max(start, p->start); - res->end = min(end, p->end); - res->flags = p->flags; - res->desc = p->desc; + *res = (struct resource) { + .start = max(start, p->start), + .end = min(end, p->end), + .flags = p->flags, + .desc = p->desc, + .parent = p->parent, + }; } read_unlock(&resource_lock);