From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from out02.mta.xmission.com ([166.70.13.232]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UIYzx-00011L-9d for kexec@lists.infradead.org; Thu, 21 Mar 2013 06:29:13 +0000 From: ebiederm@xmission.com (Eric W. Biederman) References: <87txo5bxk4.fsf@xmission.com> <20130321.122501.82758179.d.hatayama@jp.fujitsu.com> <8738vp75cy.fsf@xmission.com> <20130321.151428.393714972.d.hatayama@jp.fujitsu.com> Date: Wed, 20 Mar 2013 23:29:05 -0700 In-Reply-To: <20130321.151428.393714972.d.hatayama@jp.fujitsu.com> (HATAYAMA Daisuke's message of "Thu, 21 Mar 2013 15:14:28 +0900 (JST)") Message-ID: <87ip4l1d1q.fsf@xmission.com> MIME-Version: 1.0 Subject: Re: [PATCH v3 18/21] vmcore: check if vmcore objects satify mmap()'s page-size boundary requirement List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: HATAYAMA Daisuke Cc: kexec@lists.infradead.org, heiko.carstens@de.ibm.com, linux-kernel@vger.kernel.org, lisa.mitchell@hp.com, kumagai-atsushi@mxc.nes.nec.co.jp, zhangyanfei@cn.fujitsu.com, akpm@linux-foundation.org, cpw@sgi.com, vgoyal@redhat.com HATAYAMA Daisuke writes: > > Do you mean for each range represented by each PT_LOAD entry, say: > > [p_paddr, p_paddr + p_memsz] > > extend it as: > > [rounddown(p_paddr, PAGE_SIZE), roundup(p_paddr + p_memsz, PAGE_SIZE)]. > > not only objects in vmcore_list, but also updating p_paddr and p_memsz > members themselves of each PT_LOAD entry? In other words, there's no > new holes not referenced by any PT_LOAD entry since the regions > referenced by some PT_LOAD entry, themselves are extended. No. p_paddr and p_memsz as exported should remain the same. I am suggesting that we change p_offset. I am suggesting to include the data in the file as if we had changed p_paddr and p_memsz. > Then, the vmcores seen from read and mmap methods are coincide in the > direction of including both ranges > > [rounddown(p_paddr, PAGE_SIZE), p_paddr] > > and > > [p_paddr + p_memsz, roundup(p_paddr + p_memsz, PAGE_SIZE)] > > are included in both vmcores seen from read and mmap methods, although > they are originally not dump target memory, which you are not > problematic for ease of implementation. > > Is there difference here from you understanding? Preserving the actual PT_LOAD segments p_paddr and p_memsz values is important. p_offset we can change as much as we want. Which means there can be logical holes in the file between PT_LOAD segments, where we put the extra data needed to keep everything page aligned. Eric _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757312Ab3CUG3N (ORCPT ); Thu, 21 Mar 2013 02:29:13 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:44491 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755067Ab3CUG3M (ORCPT ); Thu, 21 Mar 2013 02:29:12 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: HATAYAMA Daisuke Cc: vgoyal@redhat.com, cpw@sgi.com, kumagai-atsushi@mxc.nes.nec.co.jp, lisa.mitchell@hp.com, heiko.carstens@de.ibm.com, akpm@linux-foundation.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, zhangyanfei@cn.fujitsu.com References: <87txo5bxk4.fsf@xmission.com> <20130321.122501.82758179.d.hatayama@jp.fujitsu.com> <8738vp75cy.fsf@xmission.com> <20130321.151428.393714972.d.hatayama@jp.fujitsu.com> Date: Wed, 20 Mar 2013 23:29:05 -0700 In-Reply-To: <20130321.151428.393714972.d.hatayama@jp.fujitsu.com> (HATAYAMA Daisuke's message of "Thu, 21 Mar 2013 15:14:28 +0900 (JST)") Message-ID: <87ip4l1d1q.fsf@xmission.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-AID: U2FsdGVkX18522GwLrvrtUNgkVpHHs5MAQVvqBuVA2M= X-SA-Exim-Connect-IP: 98.207.154.105 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.1 XMSubLong Long Subject * 0.0 T_TM2_M_HEADER_IN_MSG BODY: T_TM2_M_HEADER_IN_MSG * -3.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0000] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa01 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_04 7+ unique symbols in subject * 0.0 T_TooManySym_01 4+ unique symbols in subject * 0.0 T_TooManySym_03 6+ unique symbols in subject * 0.0 T_TooManySym_02 5+ unique symbols in subject X-Spam-DCC: XMission; sa01 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;HATAYAMA Daisuke X-Spam-Relay-Country: Subject: Re: [PATCH v3 18/21] vmcore: check if vmcore objects satify mmap()'s page-size boundary requirement X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Wed, 14 Nov 2012 14:26:46 -0700) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org HATAYAMA Daisuke writes: > > Do you mean for each range represented by each PT_LOAD entry, say: > > [p_paddr, p_paddr + p_memsz] > > extend it as: > > [rounddown(p_paddr, PAGE_SIZE), roundup(p_paddr + p_memsz, PAGE_SIZE)]. > > not only objects in vmcore_list, but also updating p_paddr and p_memsz > members themselves of each PT_LOAD entry? In other words, there's no > new holes not referenced by any PT_LOAD entry since the regions > referenced by some PT_LOAD entry, themselves are extended. No. p_paddr and p_memsz as exported should remain the same. I am suggesting that we change p_offset. I am suggesting to include the data in the file as if we had changed p_paddr and p_memsz. > Then, the vmcores seen from read and mmap methods are coincide in the > direction of including both ranges > > [rounddown(p_paddr, PAGE_SIZE), p_paddr] > > and > > [p_paddr + p_memsz, roundup(p_paddr + p_memsz, PAGE_SIZE)] > > are included in both vmcores seen from read and mmap methods, although > they are originally not dump target memory, which you are not > problematic for ease of implementation. > > Is there difference here from you understanding? Preserving the actual PT_LOAD segments p_paddr and p_memsz values is important. p_offset we can change as much as we want. Which means there can be logical holes in the file between PT_LOAD segments, where we put the extra data needed to keep everything page aligned. Eric