From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wen Congyang Subject: [PATCH 4/8] donot allow to eject the memory device if it is being used Date: Tue, 26 Jun 2012 17:20:44 +0800 Message-ID: <4FE97EEC.6060008@cn.fujitsu.com> References: <4FE97DD5.6030205@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from cn.fujitsu.com ([222.73.24.84]:50505 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753473Ab2FZJQT (ORCPT ); Tue, 26 Jun 2012 05:16:19 -0400 In-Reply-To: <4FE97DD5.6030205@cn.fujitsu.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: lenb@kernel.org, linux-acpi@vger.kernel.org, "linux-kernel@vger.kernel.org" Cc: Yasuaki ISIMATU 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 | 34 +++++++++++++++++++++++++++------- 1 files changed, 27 insertions(+), 7 deletions(-) diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c index a325bb9..2e5d5ab 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 { @@ -251,9 +252,19 @@ 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; num_enabled++; } if (!num_enabled) { @@ -317,11 +328,20 @@ 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); } -- 1.7.1