From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx127.postini.com [74.125.245.127]) by kanga.kvack.org (Postfix) with SMTP id 8C7116B0044 for ; Mon, 26 Aug 2013 17:50:01 -0400 (EDT) Date: Mon, 26 Aug 2013 14:49:59 -0700 From: Andrew Morton Subject: Re: [PATCH v2] [BUGFIX] drivers/base: fix show_mem_removable to handle missing sections Message-Id: <20130826144959.52fd24cd2833929168ee7e35@linux-foundation.org> In-Reply-To: <20130823162317.GB10988@sgi.com> References: <20130823162317.GB10988@sgi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Russ Anderson Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Greg Kroah-Hartman , "Rafael J. Wysocki" , Yinghai Lu , Yasuaki Ishimatsu On Fri, 23 Aug 2013 11:23:17 -0500 Russ Anderson wrote: > "cat /sys/devices/system/memory/memory*/removable" crashed the system. > > The problem is that show_mem_removable() is passing a > bad pfn to is_mem_section_removable(), which causes > if (!node_online(page_to_nid(page))) to blow up. > Why is it passing in a bad pfn? > > show_mem_removable() will loop sections_per_block times. > sections_per_block is 16, but mem->section_count is 8, > indicating holes in this memory block. Checking that > the memory section is present before checking to see > if the memory section is removable fixes the problem. The patch textually applies to 3.10, 3.9 and perhaps earlier. Should it be applied to earlier kernels? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org