v4.19.13 snapshot.
diff --git a/arch/xtensa/include/asm/stacktrace.h b/arch/xtensa/include/asm/stacktrace.h
new file mode 100644
index 0000000..fe06e8e
--- /dev/null
+++ b/arch/xtensa/include/asm/stacktrace.h
@@ -0,0 +1,44 @@
+/*
+ * arch/xtensa/include/asm/stacktrace.h
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2001 - 2013 Tensilica Inc.
+ */
+#ifndef _XTENSA_STACKTRACE_H
+#define _XTENSA_STACKTRACE_H
+
+#include <linux/sched.h>
+
+struct stackframe {
+ unsigned long pc;
+ unsigned long sp;
+};
+
+static __always_inline unsigned long *stack_pointer(struct task_struct *task)
+{
+ unsigned long *sp;
+
+ if (!task || task == current)
+ __asm__ __volatile__ ("mov %0, a1\n" : "=a"(sp));
+ else
+ sp = (unsigned long *)task->thread.sp;
+
+ return sp;
+}
+
+void walk_stackframe(unsigned long *sp,
+ int (*fn)(struct stackframe *frame, void *data),
+ void *data);
+
+void xtensa_backtrace_kernel(struct pt_regs *regs, unsigned int depth,
+ int (*kfn)(struct stackframe *frame, void *data),
+ int (*ufn)(struct stackframe *frame, void *data),
+ void *data);
+void xtensa_backtrace_user(struct pt_regs *regs, unsigned int depth,
+ int (*ufn)(struct stackframe *frame, void *data),
+ void *data);
+
+#endif /* _XTENSA_STACKTRACE_H */