sh: stacktrace/lockdep/irqflags tracing support.

Wire up all of the essentials for lockdep..

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/kernel/stacktrace.c b/arch/sh/kernel/stacktrace.c
new file mode 100644
index 0000000..0d5268a
--- /dev/null
+++ b/arch/sh/kernel/stacktrace.c
@@ -0,0 +1,43 @@
+/*
+ * arch/sh/kernel/stacktrace.c
+ *
+ * Stack trace management functions
+ *
+ *  Copyright (C) 2006  Paul Mundt
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/sched.h>
+#include <linux/stacktrace.h>
+#include <linux/thread_info.h>
+#include <asm/ptrace.h>
+
+/*
+ * Save stack-backtrace addresses into a stack_trace buffer.
+ */
+void save_stack_trace(struct stack_trace *trace, struct task_struct *task)
+{
+	unsigned long *sp;
+
+	if (!task)
+		task = current;
+	if (task == current)
+		sp = (unsigned long *)current_stack_pointer;
+	else
+		sp = (unsigned long *)task->thread.sp;
+
+	while (!kstack_end(sp)) {
+		unsigned long addr = *sp++;
+
+		if (__kernel_text_address(addr)) {
+			if (trace->skip > 0)
+				trace->skip--;
+			else
+				trace->entries[trace->nr_entries++] = addr;
+			if (trace->nr_entries >= trace->max_entries)
+				break;
+		}
+	}
+}