--- linux-2.6.15.1/include/linux/ipipe_trace.h.orig	2006-01-19 10:16:43.000000000 +0100
+++ linux-2.6.15.1/include/linux/ipipe_trace.h	2006-01-19 13:13:07.000000000 +0100
@@ -31,4 +31,7 @@ void ipipe_trace_special(unsigned char s
 int ipipe_trace_max_reset(void);
 int ipipe_trace_frozen_reset(void);
 
+void ipipe_trace_panic_freeze(void);
+void ipipe_trace_panic_dump(void);
+
 #endif	/* !__LINUX_IPIPE_H */
--- linux-2.6.15.1/kernel/ipipe/tracer.c.orig	2006-01-19 10:26:31.000000000 +0100
+++ linux-2.6.15.1/kernel/ipipe/tracer.c	2006-01-20 11:31:58.000000000 +0100
@@ -107,10 +107,17 @@ static int verbose_trace = 0;
 
 static DECLARE_MUTEX(out_mutex);
 static struct ipipe_trace_path *print_path;
+static struct ipipe_trace_path *panic_path;
 static int print_pre_trace;
 static int print_post_trace;
 
 
+static long __ipipe_signed_tsc2us(long long tsc);
+static void
+__ipipe_trace_point_type(char *buf, struct ipipe_trace_point *point);
+static void __ipipe_print_symname(struct seq_file *m, unsigned long eip);
+
+
 static notrace int __ipipe_get_free_trace_path(int old, int cpu_id)
 {
 	int new_active = old;
@@ -498,6 +505,61 @@ int ipipe_trace_frozen_reset(void)
 }
 EXPORT_SYMBOL(ipipe_trace_frozen_reset);
 
+void ipipe_trace_panic_freeze(void)
+{
+	unsigned long flags;
+	int cpu_id;
+
+	ipipe_trace_enable = 0;
+	local_irq_save_hw_notrace(flags);
+
+	cpu_id = raw_smp_processor_id();
+
+	panic_path = &trace_paths[cpu_id][active_path[cpu_id]];
+
+	local_irq_restore_hw(flags);
+}
+EXPORT_SYMBOL(ipipe_trace_panic_freeze);
+
+void ipipe_trace_panic_dump(void)
+{
+	int cnt = back_trace;
+	int start, pos;
+
+	printk("I-pipe tracer log (%d points):\n", cnt);
+
+	start = pos = WRAP_POINT_NO(panic_path->trace_pos-1);
+
+	while (cnt-- > 0) {
+		struct ipipe_trace_point *point = &panic_path->point[pos];
+		long time;
+		char buf[16];
+
+		if (!point->eip)
+			printk("-<invalid>-\n");
+		else {
+			__ipipe_trace_point_type(buf, point);
+			printk(buf);
+
+			if (point->type != IPIPE_TRACE_FN)
+				printk("0x%08lx ", point->v);
+			else
+				printk("           ");
+
+			time = __ipipe_signed_tsc2us(point->timestamp -
+				panic_path->point[start].timestamp);
+			printk(" %5ld ", time);
+
+			__ipipe_print_symname(NULL, point->eip);
+			printk(" (");
+			__ipipe_print_symname(NULL, point->parent_eip);
+			printk(")\n");
+		}
+		pos = WRAP_POINT_NO(pos - 1);
+	}
+}
+EXPORT_SYMBOL(ipipe_trace_panic_dump);
+
 
 /* --- /proc output --- */
 
@@ -510,6 +572,46 @@ static notrace int __ipipe_in_critical_t
 	          print_post_trace)));
 }
 
+static long __ipipe_signed_tsc2us(long long tsc)
+{
+        unsigned long long abs_tsc;
+        long us;
+
+	/* ipipe_tsc2us works on unsigned => handle sign separately */
+        abs_tsc = (tsc >= 0) ? tsc : -tsc;
+        us = ipipe_tsc2us(abs_tsc);
+        if (tsc < 0)
+                return -us;
+        else
+                return us;
+}
+
+static void
+__ipipe_trace_point_type(char *buf, struct ipipe_trace_point *point)
+{
+	switch (point->type) {
+		case IPIPE_TRACE_FN:
+			strcpy(buf, "fn     ");
+			break;
+
+		case IPIPE_TRACE_BEGIN:
+			strcpy(buf, "begin  ");
+			break;
+
+		case IPIPE_TRACE_END:
+			strcpy(buf, "end    ");
+			break;
+
+		case IPIPE_TRACE_FREEZE:
+			strcpy(buf, "freeze ");
+			break;
+
+		default: /* IPIPE_TRACE_SPECIAL */
+			sprintf(buf, "(0x%02x) ",
+			        point->type - IPIPE_TRACE_SPECIAL);
+	}
+}
+
 static void
 __ipipe_print_pathmark(struct seq_file *m, struct ipipe_trace_point *point)
 {
@@ -562,15 +664,26 @@ static void __ipipe_print_symname(struct
 	char *modname;
 
 	sym_name = kallsyms_lookup(eip, &size, &offset, &modname, namebuf);
-	if (sym_name) {
-		if (verbose_trace) {
-			seq_printf(m, "%s+0x%lx", sym_name, offset);
-			if (modname)
-				seq_printf(m, " [%s]", modname);
+
+	/* printing to /proc? */
+	if (m) {
+		if (sym_name) {
+			if (verbose_trace) {
+				seq_printf(m, "%s+0x%lx", sym_name, offset);
+				if (modname)
+					seq_printf(m, " [%s]", modname);
+			} else
+				seq_puts(m, sym_name);
 		} else
-			seq_puts(m, sym_name);
-	} else
-		seq_printf(m, "<%08lx>", eip);
+			seq_printf(m, "<%08lx>", eip);
+	} else {
+		/* panic dump */
+		if (sym_name) {
+			printk("%s+0x%lx", sym_name, offset);
+			if (modname)
+				printk(" [%s]", modname);
+		}
+	}
 }
 
 #if defined(CONFIG_XENO_OPT_DEBUG) || defined(CONFIG_DEBUG_PREEMPT)
@@ -690,52 +803,28 @@ static void __ipipe_prtrace_stop(struct 
 static int __ipipe_prtrace_show(struct seq_file *m, void *p)
 {
 	long time;
-	long long delta;
-	unsigned long long abs_delta;
 	struct ipipe_trace_point *point = p;
+	char buf[16];
 
 	if (!point->eip) {
 		seq_puts(m, "-<invalid>-\n");
 		return 0;
 	}
 
-	/* ipipe_tsc2us works on unsigned => handle sign separately */
-	delta = point->timestamp -
-		print_path->point[print_path->begin].timestamp;
-	abs_delta = (delta >= 0) ? delta : -delta;
-	time = ipipe_tsc2us(abs_delta);
-	if (delta < 0)
-		time = -time;
-
 	__ipipe_print_pathmark(m, point);
-	switch (point->type) {
-		case IPIPE_TRACE_FN:
-			seq_puts(m, "fn     ");
-			break;
-
-		case IPIPE_TRACE_BEGIN:
-			seq_puts(m, "begin  ");
-			break;
-
-		case IPIPE_TRACE_END:
-			seq_puts(m, "end    ");
-			break;
-
-		case IPIPE_TRACE_FREEZE:
-			seq_puts(m, "freeze ");
-			break;
-
-		default: /* IPIPE_TRACE_SPECIAL */
-			seq_printf(m, "(0x%02x) ",
-			           point->type - IPIPE_TRACE_SPECIAL);
-	}
+	__ipipe_trace_point_type(buf, point);
+	seq_puts(m, buf);
 	if (verbose_trace) {
 		if (point->type != IPIPE_TRACE_FN)
 			seq_printf(m, "0x%08lx ", point->v);
 		else
 			seq_puts(m, "           ");
 	}
+
+	time = __ipipe_signed_tsc2us(point->timestamp -
+		print_path->point[print_path->begin].timestamp);
 	seq_printf(m, "%5ld", time);
+
 	__ipipe_print_delay(m, point);
 	__ipipe_print_symname(m, point->eip);
 	seq_puts(m, " (");