v4.19.13 snapshot.
diff --git a/arch/arm/include/asm/stacktrace.h b/arch/arm/include/asm/stacktrace.h
new file mode 100644
index 0000000..2d76a2e
--- /dev/null
+++ b/arch/arm/include/asm/stacktrace.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_STACKTRACE_H
+#define __ASM_STACKTRACE_H
+
+#include <asm/ptrace.h>
+
+struct stackframe {
+ /*
+ * FP member should hold R7 when CONFIG_THUMB2_KERNEL is enabled
+ * and R11 otherwise.
+ */
+ unsigned long fp;
+ unsigned long sp;
+ unsigned long lr;
+ unsigned long pc;
+};
+
+static __always_inline
+void arm_get_current_stackframe(struct pt_regs *regs, struct stackframe *frame)
+{
+ frame->fp = frame_pointer(regs);
+ frame->sp = regs->ARM_sp;
+ frame->lr = regs->ARM_lr;
+ frame->pc = regs->ARM_pc;
+}
+
+extern int unwind_frame(struct stackframe *frame);
+extern void walk_stackframe(struct stackframe *frame,
+ int (*fn)(struct stackframe *, void *), void *data);
+
+#endif /* __ASM_STACKTRACE_H */