>From de6809819c06cf8c294a03ad79207b3ac9c2dca8 Mon Sep 17 00:00:00 2001
From: Hu Tao <hutao@cn.fujitsu.com>
Date: Tue, 19 Oct 2010 13:10:12 +0800
Subject: [PATCH 3/3] Use cpu sp/ip to backtrace active task

---
 defs.h        |    8 ++++++++
 global_data.c |    3 +++
 kvmdump.c     |    7 ++++++-
 qemu-load.c   |    8 ++++++--
 4 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/defs.h b/defs.h
index a26150e..f84f9d4 100755
--- a/defs.h
+++ b/defs.h
@@ -4992,4 +4992,12 @@ extern int have_full_symbols(void);
 #define XEN_HYPERVISOR_ARCH 
 #endif
 
+struct cpu_info {
+	uint64_t	esp;
+	uint64_t	eip;
+};
+
+extern struct cpu_info cpu_infos[];
+extern unsigned int n_cpu;
+
 #endif /* !GDB_COMMON */
diff --git a/global_data.c b/global_data.c
index 98a5a79..e936ca5 100755
--- a/global_data.c
+++ b/global_data.c
@@ -134,3 +134,6 @@ struct extension_table *extension_table = NULL;
 struct offset_table offset_table = { 0 };
 struct size_table size_table = { 0 };
 struct array_table array_table = { 0 };
+
+struct cpu_info cpu_infos[NR_CPUS] = {};
+unsigned int n_cpu = 0;
diff --git a/kvmdump.c b/kvmdump.c
index 1bf0d9e..4b60551 100644
--- a/kvmdump.c
+++ b/kvmdump.c
@@ -310,7 +310,12 @@ kvmdump_memory_dump(FILE *ofp)
 void 
 get_kvmdump_regs(struct bt_info *bt, ulong *pc, ulong *sp)
 {
-	machdep->get_stack_frame(bt, pc, sp);
+	if (is_task_active(bt->task)) {
+		assert(bt->tc->processor < n_cpu);
+		*sp = cpu_infos[bt->tc->processor].esp;
+		*pc = cpu_infos[bt->tc->processor].eip;
+	} else
+		machdep->get_stack_frame(bt, pc, sp);
 }
 
 ulong
diff --git a/qemu-load.c b/qemu-load.c
index 95eaf97..a7beb0b 100644
--- a/qemu-load.c
+++ b/qemu-load.c
@@ -18,6 +18,7 @@
  */
 
 #define _GNU_SOURCE
+#include "defs.h"
 #include "qemu-load.h"
 #include <stdlib.h>
 #include <string.h>
@@ -609,6 +610,11 @@ cpu_load (struct qemu_device *d, FILE *fp, int size)
 		dx86->kvm.wall_clock_msr = get_be64 (fp);
 	}
 
+	assert(d->instance_id == n_cpu);
+	cpu_infos[n_cpu].eip = dx86->eip;
+	cpu_infos[n_cpu].esp = dx86->regs[R_ESP];
+	n_cpu++;
+
 	return QEMU_FEATURE_CPU;
 }
 
@@ -924,8 +930,6 @@ fail:
  *  crash utility adaptation.
  */
 
-#include "defs.h"
-
 int
 is_qemu_vm_file(char *filename)
 {
-- 
1.7.3