From aba1f12c1495179ad7a3c39acb1fcfd5603c275a Mon Sep 17 00:00:00 2001
From: "kfraser@dhcp93.uk.xensource.com" <kfraser@dhcp93.uk.xensource.com>
Date: Mon, 19 Jun 2006 13:06:10 +0100
Subject: [PATCH] [XEN] New function dump_execution_state() displays current
 register and stack state of local CPU. Use this to extend the 'd' debug key
 to be more useful. Signed-off-by: Keir Fraser <keir@xensource.com>

---
 xen/arch/x86/traps.c            | 15 +++++++++++++++
 xen/common/keyhandler.c         | 20 +++++++++++++++++++-
 xen/include/asm-x86/processor.h |  5 +++++
 3 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index 199ad50b72..6d442ed4ca 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -487,6 +487,21 @@ asmlinkage int do_invalid_op(struct cpu_user_regs *regs)
 
     if ( unlikely(!guest_mode(regs)) )
     {
+        char sig[5];
+        /* Signature (ud2; .ascii "dbg") indicates dump state and continue. */
+        if ( (__copy_from_user(sig, (char *)regs->eip, sizeof(sig)) == 0) &&
+             (memcmp(sig, "\xf\xb""dbg", sizeof(sig)) == 0) )
+        {
+            show_execution_state(regs);
+            regs->eip += sizeof(sig);
+            return EXCRET_fault_fixed;
+        }
+        printk("%02x %02x %02x %02x %02x\n",
+               (unsigned char)sig[0],
+               (unsigned char)sig[1],
+               (unsigned char)sig[2],
+               (unsigned char)sig[3],
+               (unsigned char)sig[4]);
         DEBUGGER_trap_fatal(TRAP_invalid_op, regs);
         show_execution_state(regs);
         panic("CPU%d FATAL TRAP: vector = %d (invalid opcode)\n",
diff --git a/xen/common/keyhandler.c b/xen/common/keyhandler.c
index aea0f1a787..3f286e3ae6 100644
--- a/xen/common/keyhandler.c
+++ b/xen/common/keyhandler.c
@@ -87,10 +87,28 @@ static void show_handlers(unsigned char key)
                    key_table[i].desc);
 }
 
+static void __dump_execstate(void *unused)
+{
+    dump_execution_state();
+}
+
 static void dump_registers(unsigned char key, struct cpu_user_regs *regs)
 {
+    unsigned int cpu;
+
     printk("'%c' pressed -> dumping registers\n", key); 
-    show_execution_state(regs); 
+
+    /* Get local execution state out immediately, in case we get stuck. */
+    printk("\n*** Dumping CPU%d state: ***\n", smp_processor_id());
+    show_execution_state(regs);
+
+    for_each_online_cpu ( cpu )
+    {
+        if ( cpu == smp_processor_id() )
+            continue;
+        printk("\n*** Dumping CPU%d state: ***\n", cpu);
+        on_selected_cpus(cpumask_of_cpu(cpu), __dump_execstate, NULL, 1, 1);
+    }
 }
 
 static void halt_machine(unsigned char key, struct cpu_user_regs *regs)
diff --git a/xen/include/asm-x86/processor.h b/xen/include/asm-x86/processor.h
index 75d0772fef..c6b3247763 100644
--- a/xen/include/asm-x86/processor.h
+++ b/xen/include/asm-x86/processor.h
@@ -535,6 +535,11 @@ void show_execution_state(struct cpu_user_regs *regs);
 void show_page_walk(unsigned long addr);
 asmlinkage void fatal_trap(int trapnr, struct cpu_user_regs *regs);
 
+/* Dumps current register and stack state. */
+#define dump_execution_state()                                              \
+    /* NB. Needs interrupts enabled else we end up in fatal_trap(). */      \
+    __asm__ __volatile__ ( "pushf ; sti ; ud2 ; .ascii \"dbg\" ; popf" )
+
 extern void mtrr_ap_init(void);
 extern void mtrr_bp_init(void);
 
-- 
2.30.2