From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Wed, 5 Aug 2015 17:04:01 -0300
Subject: Initial import

---
 arch/powerpc/kernel/stacktrace.c | 63 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)
 create mode 100644 arch/powerpc/kernel/stacktrace.c

(limited to 'arch/powerpc/kernel/stacktrace.c')

diff --git a/arch/powerpc/kernel/stacktrace.c b/arch/powerpc/kernel/stacktrace.c
new file mode 100644
index 000000000..ea43a347a
--- /dev/null
+++ b/arch/powerpc/kernel/stacktrace.c
@@ -0,0 +1,63 @@
+/*
+ * Stack trace utility
+ *
+ * Copyright 2008 Christoph Hellwig, IBM Corp.
+ *
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/export.h>
+#include <linux/sched.h>
+#include <linux/stacktrace.h>
+#include <asm/ptrace.h>
+#include <asm/processor.h>
+
+/*
+ * Save stack-backtrace addresses into a stack_trace buffer.
+ */
+static void save_context_stack(struct stack_trace *trace, unsigned long sp,
+			struct task_struct *tsk, int savesched)
+{
+	for (;;) {
+		unsigned long *stack = (unsigned long *) sp;
+		unsigned long newsp, ip;
+
+		if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD))
+			return;
+
+		newsp = stack[0];
+		ip = stack[STACK_FRAME_LR_SAVE];
+
+		if (savesched || !in_sched_functions(ip)) {
+			if (!trace->skip)
+				trace->entries[trace->nr_entries++] = ip;
+			else
+				trace->skip--;
+		}
+
+		if (trace->nr_entries >= trace->max_entries)
+			return;
+
+		sp = newsp;
+	}
+}
+
+void save_stack_trace(struct stack_trace *trace)
+{
+	unsigned long sp;
+
+	sp = current_stack_pointer();
+
+	save_context_stack(trace, sp, current, 1);
+}
+EXPORT_SYMBOL_GPL(save_stack_trace);
+
+void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
+{
+	save_context_stack(trace, tsk->thread.ksp, tsk, 0);
+}
+EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
-- 
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