From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1033318Ab2I1VnR (ORCPT ); Fri, 28 Sep 2012 17:43:17 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:63188 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1032371Ab2I1UZv (ORCPT ); Fri, 28 Sep 2012 16:25:51 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, Jianguo Wu , Jiang Liu , "Luck, Tony" , Michal Hocko , Andrew Morton , Linus Torvalds Subject: [ 081/218] mm/ia64: fix a memory block size bug Date: Fri, 28 Sep 2012 13:14:58 -0700 Message-Id: <20120928201510.858307758@linuxfoundation.org> X-Mailer: git-send-email 1.7.12.1.428.g652398a In-Reply-To: <20120928201501.208384923@linuxfoundation.org> References: <20120928201501.208384923@linuxfoundation.org> User-Agent: quilt/0.60-2.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jianguo Wu commit 05cf96398e1b6502f9e191291b715c7463c9d5dd upstream. I found following definition in include/linux/memory.h, in my IA64 platform, SECTION_SIZE_BITS is equal to 32, and MIN_MEMORY_BLOCK_SIZE will be 0. #define MIN_MEMORY_BLOCK_SIZE (1 << SECTION_SIZE_BITS) Because MIN_MEMORY_BLOCK_SIZE is int type and length of 32bits, so MIN_MEMORY_BLOCK_SIZE(1 << 32) will will equal to 0. Actually when SECTION_SIZE_BITS >= 31, MIN_MEMORY_BLOCK_SIZE will be wrong. This will cause wrong system memory infomation in sysfs. I think it should be: #define MIN_MEMORY_BLOCK_SIZE (1UL << SECTION_SIZE_BITS) And "echo offline > memory0/state" will cause following call trace: kernel BUG at mm/memory_hotplug.c:885! sh[6455]: bugcheck! 0 [1] Pid: 6455, CPU 0, comm: sh psr : 0000101008526030 ifs : 8000000000000fa4 ip : [] Not tainted (3.6.0-rc1) ip is at offline_pages+0x210/0xee0 Call Trace: show_stack+0x80/0xa0 show_regs+0x640/0x920 die+0x190/0x2c0 die_if_kernel+0x50/0x80 ia64_bad_break+0x3d0/0x6e0 ia64_native_leave_kernel+0x0/0x270 offline_pages+0x210/0xee0 alloc_pages_current+0x180/0x2a0 Signed-off-by: Jianguo Wu Signed-off-by: Jiang Liu Cc: "Luck, Tony" Reviewed-by: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- include/linux/memory.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/include/linux/memory.h +++ b/include/linux/memory.h @@ -19,7 +19,7 @@ #include #include -#define MIN_MEMORY_BLOCK_SIZE (1 << SECTION_SIZE_BITS) +#define MIN_MEMORY_BLOCK_SIZE (1UL << SECTION_SIZE_BITS) struct memory_block { unsigned long start_section_nr;