From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from cantor2.suse.de ([195.135.220.15] helo=mx2.suse.de) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XopR4-0000Ok-O5 for kexec@lists.infradead.org; Thu, 13 Nov 2014 08:07:23 +0000 Date: Thu, 13 Nov 2014 09:06:57 +0100 From: Petr Tesarik Subject: Re: [PATCH] kdump, x86: report actual value of phys_base in VMCOREINFO Message-ID: <20141113090657.2578f087@hananiah.suse.cz> In-Reply-To: <20141113.091709.520211949477822929.d.hatayama@jp.fujitsu.com> References: <20141112.154042.59640143160036130.d.hatayama@jp.fujitsu.com> <20141112221205.GB5265@redhat.com> <20141113.091709.520211949477822929.d.hatayama@jp.fujitsu.com> MIME-Version: 1.0 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, linux-kernel@vger.kernel.org, anderson@redhat.com, ebiederm@xmission.com, kumagai-atsushi@mxc.nes.nec.co.jp, vgoyal@redhat.com On Thu, 13 Nov 2014 09:17:09 +0900 (JST) HATAYAMA Daisuke wrote: > From: Vivek Goyal > Subject: Re: [PATCH] kdump, x86: report actual value of phys_base in VMCOREINFO > Date: Wed, 12 Nov 2014 17:12:05 -0500 > > > On Wed, Nov 12, 2014 at 03:40:42PM +0900, HATAYAMA Daisuke wrote: > >> Currently, VMCOREINFO note information reports the virtual address of > >> phys_base that is assigned to symbol phys_base. But this doesn't make > >> sense because to refer to value of the phys_base, it's necessary to > >> get the value of phys_base itself we are now about to refer to. > >> > > > > Hi Hatayama, > > > > /proc/vmcore ELF headers have virtual address information and using > > that you should be able to read actual value of phys_base. gdb deals > > with virtual addresses all the time and can read value of any symbol > > using those headers. > > > > So I am not sure what's the need for exporting actual value of > > phys_base. > > > > Sorry, my logic in the patch description was wrong. For /proc/vmcore, > there's enough information for makedumpdile to get phys_base. It's > correct. The problem here is that other crash dump mechanisms that run > outside Linux kernel independently don't have information to get > phys_base. Yes, but these mechanisms won't be able to read VMCOREINFO either, will they? Petr T _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec