(2014/11/13 17:06), Petr Tesarik wrote: > On Thu, 13 Nov 2014 09:17:09 +0900 (JST) > HATAYAMA Daisuke <d.hatayama at jp.fujitsu.com> wrote: > >> From: Vivek Goyal <vgoyal at redhat.com> >> 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? > I don't intend such sophisticated function only by VMCOREINFO. Search vmcore for VMCOREINFO using strings + grep before opening it by crash. I intend that only here. -- Thanks. HATAYAMA, Daisuke
