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