From: Muuhh IKEDA <mikeda@redhat.com>
Date: Wed, 2 Apr 2008 11:26:00 -0400
Subject: [x86_64] add phys_base to vmcoreinfo
Message-id: 47F3A588.1070307@redhat.com
O-Subject: [RHEL5.2 PATCH] Add phys_base to vmcoreinfo
Bugzilla: 439304

Hi all,

Bugzilla: 439304
https://bugzilla.redhat.com/show_bug.cgi?id=439304

Description
------------
>From RHEL5.2, "makedumpfile", which is a filter to reduce the size of
dumpfile, reads ELF note section of /proc/vmcore for virtual/physical
address translation instead of kernel-debug-info as in RHEL5.1.
The makedumpfile recognizes the kernel is relocatable if a symbol
"phys_base" exists in ELF note section of /proc/vmcore.  If not,
makedupfile recognizes the kernel as a non-relocatable one.
RHEL5.2 kernel doesn't have "phys_base" in /proc/vmcore despite it is
relocatalbe.  As a result of it, makedumpfile fails and dumpfile can't
be created properly.
This patch adds "phys_base" to /proc/vmcore to solve the problem.

RHEL Version Found
------------------
5.2

Test Status
-----------
Dump file was properly created with patch applied bare-metal kernel on
x86_64.
The test environment is:
- RHEL5.2-Server-20080326.0
- kernel.x86_64-2.6.18-87.el5
- kexec-tools.x86_64-1.102pre-16.el5

Now asking NEC folks to confirm no regression led by this patch in Xen
environment.

Upstream Status
----------------
Posted at:
http://lists.infradead.org/pipermail/kexec/2008-March/001514.html

* The posted patch doesn't include #ifndef CONFIG_XEN
  because upstream kernel isn't capable for x86_64 + Xen.

--
Munehiro "Muuhh" IKEDA
  On-site engineer from NEC in Westford
    mikeda@redhat.com

Acked-by: Dave Anderson <anderson@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Neil Horman <nhorman@redhat.com>

diff --git a/arch/x86_64/kernel/machine_kexec.c b/arch/x86_64/kernel/machine_kexec.c
index efb6a0a..7eb9457 100644
--- a/arch/x86_64/kernel/machine_kexec.c
+++ b/arch/x86_64/kernel/machine_kexec.c
@@ -240,6 +240,9 @@ void machine_kexec_cleanup(struct kimage *image)
 
 void arch_crash_save_vmcoreinfo(void)
 {
+#ifndef CONFIG_XEN
+	SYMBOL(phys_base);
+#endif
 #ifdef CONFIG_ARCH_DISCONTIGMEM_ENABLE
 	SYMBOL(node_data);
 	LENGTH(node_data, MAX_NUMNODES);