Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755827Ab3EXNM6 (ORCPT ); Fri, 24 May 2013 09:12:58 -0400 Received: from mx1.redhat.com ([209.132.183.28]:22416 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752423Ab3EXNM5 (ORCPT ); Fri, 24 May 2013 09:12:57 -0400 Date: Fri, 24 May 2013 09:12:17 -0400 From: Vivek Goyal To: Andrew Morton Cc: HATAYAMA Daisuke , ebiederm@xmission.com, cpw@sgi.com, kumagai-atsushi@mxc.nes.nec.co.jp, lisa.mitchell@hp.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, zhangyanfei@cn.fujitsu.com, jingbai.ma@hp.com, linux-mm@kvack.org, riel@redhat.com, walken@google.com, hughd@google.com, kosaki.motohiro@jp.fujitsu.com Subject: Re: [PATCH v8 3/9] vmcore: treat memory chunks referenced by PT_LOAD program header entries in page-size boundary in vmcore_list Message-ID: <20130524131217.GA18218@redhat.com> References: <20130523052421.13864.83978.stgit@localhost6.localdomain6> <20130523052513.13864.85440.stgit@localhost6.localdomain6> <20130523144928.0328bb3ad7ccc1ff2da9558d@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130523144928.0328bb3ad7ccc1ff2da9558d@linux-foundation.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1386 Lines: 32 On Thu, May 23, 2013 at 02:49:28PM -0700, Andrew Morton wrote: > On Thu, 23 May 2013 14:25:13 +0900 HATAYAMA Daisuke wrote: > > > Treat memory chunks referenced by PT_LOAD program header entries in > > page-size boundary in vmcore_list. Formally, for each range [start, > > end], we set up the corresponding vmcore object in vmcore_list to > > [rounddown(start, PAGE_SIZE), roundup(end, PAGE_SIZE)]. > > > > This change affects layout of /proc/vmcore. > > Well, changing a userspace interface is generally unacceptable because > it can break existing userspace code. > > If you think the risk is acceptable then please do explain why. In > great detail! I think it should not be a problem as /proc/vmcore is useful only when one parses the elf headers and then accesses the contents of file based on the header information. This patch just introduces additional areas in /proc/vmcore file and ELF headers still point to right contents. So any tool parsing ELF headers and then accessing file contents based on that info should still be fine. AFAIK, no user space tool should be broken there. Thanks Vivek -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/