From patchwork Wed Jul 11 07:49:26 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wen Congyang X-Patchwork-Id: 1180801 Return-Path: X-Original-To: patchwork-linux-acpi@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id 1DB6BDF25A for ; Wed, 11 Jul 2012 07:45:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756353Ab2GKHpE (ORCPT ); Wed, 11 Jul 2012 03:45:04 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:23895 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752719Ab2GKHpD (ORCPT ); Wed, 11 Jul 2012 03:45:03 -0400 X-IronPort-AV: E=Sophos;i="4.77,566,1336320000"; d="scan'208";a="5371827" Received: from unknown (HELO tang.cn.fujitsu.com) ([10.167.250.3]) by song.cn.fujitsu.com with ESMTP; 11 Jul 2012 15:44:03 +0800 Received: from fnstmail02.fnst.cn.fujitsu.com (tang.cn.fujitsu.com [127.0.0.1]) by tang.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id q6B7il2f020969; Wed, 11 Jul 2012 15:44:51 +0800 Received: from [10.167.225.226] ([10.167.225.226]) by fnstmail02.fnst.cn.fujitsu.com (Lotus Domino Release 8.5.3) with ESMTP id 2012071115444187-643565 ; Wed, 11 Jul 2012 15:44:41 +0800 Message-ID: <4FFD3006.3020502@cn.fujitsu.com> Date: Wed, 11 Jul 2012 15:49:26 +0800 From: Wen Congyang User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100413 Fedora/3.0.4-2.fc13 Thunderbird/3.0.4 MIME-Version: 1.0 To: lenb@kernel.org, linux-acpi@vger.kernel.org, "linux-kernel@vger.kernel.org" CC: Yasuaki ISIMATU , David Rientjes , Andrew Morton , Konrad Rzeszutek Wilk Subject: [PATCH 4/7 v2] don't allow to eject the memory device if it is being used References: <4FFD2F1E.10006@cn.fujitsu.com> In-Reply-To: <4FFD2F1E.10006@cn.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/07/11 15:44:41, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/07/11 15:44:47, Serialize complete at 2012/07/11 15:44:47 Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org We eject the memory device even if it is in use. It is very dangerous, and it will cause the kernel panicked. Signed-off-by: Wen Congyang --- drivers/acpi/acpi_memhotplug.c | 38 +++++++++++++++++++++++++++++++------- 1 files changed, 31 insertions(+), 7 deletions(-) diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c index 1f6196a..1597348 100644 --- a/drivers/acpi/acpi_memhotplug.c +++ b/drivers/acpi/acpi_memhotplug.c @@ -78,6 +78,7 @@ struct acpi_memory_info { unsigned short caching; /* memory cache attribute */ unsigned short write_protect; /* memory read/write attribute */ unsigned int enabled:1; + unsigned int failed:1; }; struct acpi_memory_device { @@ -257,9 +258,23 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device) node = memory_add_physaddr_to_nid(info->start_addr); result = add_memory(node, info->start_addr, info->length); - if (result) + + /* + * If the memory block has been used by the kernel, add_memory() + * returns -EEXIST. If add_memory() returns the other error, it + * means that this memory block is not used by the kernel. + */ + if (result && result != -EEXIST) { + info->failed = 1; continue; - info->enabled = 1; + } + + if (!result) + info->enabled = 1; + /* + * Add num_enable even if add_memory() returns -EEXIST, so the + * device is bound to this driver. + */ num_enabled++; } if (!num_enabled) { @@ -323,11 +338,20 @@ static int acpi_memory_disable_device(struct acpi_memory_device *mem_device) * Note: Assume that this function returns zero on success */ list_for_each_entry_safe(info, n, &mem_device->res_list, list) { - if (info->enabled) { - result = remove_memory(info->start_addr, info->length); - if (result) - return result; - } + if (info->failed) + /* The kernel does not use this memory block */ + continue; + + if (!info->enabled) + /* + * The kernel uses this memory block, but it may be not + * managed by us. + */ + return -EBUSY; + + result = remove_memory(info->start_addr, info->length); + if (result) + return result; list_del(&info->list); kfree(info); }