1 files changed, 53 insertions, 0 deletions
diff --git a/arch/nds32/kernel/stacktrace.c b/arch/nds32/kernel/stacktrace.c
new file mode 100644
index 000000000..d974c0c1c
--- /dev/null
+++ b/arch/nds32/kernel/stacktrace.c
@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#include <linux/sched/debug.h>
+#include <linux/sched/task_stack.h>
+#include <linux/stacktrace.h>
+#include <linux/ftrace.h>
+
+void save_stack_trace(struct stack_trace *trace)
+{
+	save_stack_trace_tsk(current, trace);
+}
+EXPORT_SYMBOL_GPL(save_stack_trace);
+
+void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
+{
+	unsigned long *fpn;
+	int skip = trace->skip;
+	int savesched;
+	int graph_idx = 0;
+
+	if (tsk == current) {
+		__asm__ __volatile__("\tori\t%0, $fp, #0\n":"=r"(fpn));
+		savesched = 1;
+	} else {
+		fpn = (unsigned long *)thread_saved_fp(tsk);
+		savesched = 0;
+	}
+
+	while (!kstack_end(fpn) && !((unsigned long)fpn & 0x3)
+	       && (fpn >= (unsigned long *)TASK_SIZE)) {
+		unsigned long lpp, fpp;
+
+		lpp = fpn[LP_OFFSET];
+		fpp = fpn[FP_OFFSET];
+		if (!__kernel_text_address(lpp))
+			break;
+		else
+			lpp = ftrace_graph_ret_addr(tsk, &graph_idx, lpp, NULL);
+
+		if (savesched || !in_sched_functions(lpp)) {
+			if (skip) {
+				skip--;
+			} else {
+				trace->entries[trace->nr_entries++] = lpp;
+				if (trace->nr_entries >= trace->max_entries)
+					break;
+			}
+		}
+		fpn = (unsigned long *)fpp;
+	}
+}
+EXPORT_SYMBOL_GPL(save_stack_trace_tsk);