[patch v3 34/36] Hexagon: Add basic stacktrace functionality for Hexagon architecture.

Richard Kuo
2011-09-09T01:09:21Z

[-- Attachment #1: stacktrace.diff --]
[-- Type: text/plain, Size: 2475 bytes --]

Signed-off-by: Richard Kuo <rkuo@codeaurora.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>

---
arch/hexagon/kernel/stacktrace.c | 66 +++++++++++++++++++++++++++++++++++++++
1 file changed, 66 insertions(+)

Index: linux-hexagon-kernel/arch/hexagon/kernel/stacktrace.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-hexagon-kernel/arch/hexagon/kernel/stacktrace.c 2011-09-07 13:00:31.140647106 -0500
@@ -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);