1 files changed, 50 insertions, 0 deletions
diff --git a/arch/arm64/kernel/return_address.c b/arch/arm64/kernel/return_address.c
new file mode 100644
index 000000000..68330017d
--- /dev/null
+++ b/arch/arm64/kernel/return_address.c
@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * arch/arm64/kernel/return_address.c
+ *
+ * Copyright (C) 2013 Linaro Limited
+ * Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
+ */
+
+#include <linux/export.h>
+#include <linux/ftrace.h>
+#include <linux/kprobes.h>
+#include <linux/stacktrace.h>
+
+#include <asm/stack_pointer.h>
+
+struct return_address_data {
+	unsigned int level;
+	void *addr;
+};
+
+static bool save_return_addr(void *d, unsigned long pc)
+{
+	struct return_address_data *data = d;
+
+	if (!data->level) {
+		data->addr = (void *)pc;
+		return false;
+	} else {
+		--data->level;
+		return true;
+	}
+}
+NOKPROBE_SYMBOL(save_return_addr);
+
+void *return_address(unsigned int level)
+{
+	struct return_address_data data;
+
+	data.level = level + 2;
+	data.addr = NULL;
+
+	arch_stack_walk(save_return_addr, &data, current, NULL);
+
+	if (!data.level)
+		return data.addr;
+	else
+		return NULL;
+}
+EXPORT_SYMBOL_GPL(return_address);
+NOKPROBE_SYMBOL(return_address);