From e890d01729e9b4c28f88d2a156d17c78970bcb9b Mon Sep 17 00:00:00 2001
From: Richard Kuo <rkuo@codeaurora.org>
Date: Mon, 31 Oct 2011 18:56:19 -0500
Subject: [PATCH] --- yaml --- r: 272263 b: refs/heads/master c:
 74d04d6ffd39274457eafa15022ab717e40cbc63 h: refs/heads/master i:   272261:
 4c2311f9e44ca5009f76cac639f2850148dbfe54   272259:
 a34898a0eaa8e879031f739786f1e94697910fd0   272255:
 3d87adae544a81e89b1a1b67f307caf5d302d7e0 v: v3

---
 [refs]                                 |  2 +-
 trunk/arch/hexagon/kernel/stacktrace.c | 66 ++++++++++++++++++++++++++
 2 files changed, 67 insertions(+), 1 deletion(-)
 create mode 100644 trunk/arch/hexagon/kernel/stacktrace.c

diff --git a/[refs] b/[refs]
index f4dcf8f02122..d8bdc6a29f4b 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: e95bf452a9e22bd1c9ae23fea041989e0603c39d
+refs/heads/master: 74d04d6ffd39274457eafa15022ab717e40cbc63
diff --git a/trunk/arch/hexagon/kernel/stacktrace.c b/trunk/arch/hexagon/kernel/stacktrace.c
new file mode 100644
index 000000000000..11c597b2ac59
--- /dev/null
+++ b/trunk/arch/hexagon/kernel/stacktrace.c
@@ -0,0 +1,66 @@
+/*
+ * Stacktrace support for Hexagon
+ *
+ * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#include <linux/sched.h>
+#include <linux/stacktrace.h>
+#include <linux/thread_info.h>
+#include <linux/module.h>
+
+register unsigned long current_frame_pointer asm("r30");
+
+struct stackframe {
+	unsigned long fp;
+	unsigned long rets;
+};
+
+/*
+ * Save stack-backtrace addresses into a stack_trace buffer.
+ */
+void save_stack_trace(struct stack_trace *trace)
+{
+	unsigned long low, high;
+	unsigned long fp;
+	struct stackframe *frame;
+	int skip = trace->skip;
+
+	low = (unsigned long)task_stack_page(current);
+	high = low + THREAD_SIZE;
+	fp = current_frame_pointer;
+
+	while (fp >= low && fp <= (high - sizeof(*frame))) {
+		frame = (struct stackframe *)fp;
+
+		if (skip) {
+			skip--;
+		} else {
+			trace->entries[trace->nr_entries++] = frame->rets;
+			if (trace->nr_entries >= trace->max_entries)
+				break;
+		}
+
+		/*
+		 * The next frame must be at a higher address than the
+		 * current frame.
+		 */
+		low = fp + sizeof(*frame);
+		fp = frame->fp;
+	}
+}
+EXPORT_SYMBOL_GPL(save_stack_trace);