v4.19.13 snapshot.
diff --git a/arch/parisc/kernel/stacktrace.c b/arch/parisc/kernel/stacktrace.c
new file mode 100644
index 0000000..ec5835e
--- /dev/null
+++ b/arch/parisc/kernel/stacktrace.c
@@ -0,0 +1,50 @@
+/*
+ * Stack trace management functions
+ *
+ * Copyright (C) 2009 Helge Deller <deller@gmx.de>
+ * based on arch/x86/kernel/stacktrace.c by Ingo Molnar <mingo@redhat.com>
+ * and parisc unwind functions by Randolph Chung <tausq@debian.org>
+ *
+ * TODO: Userspace stacktrace (CONFIG_USER_STACKTRACE_SUPPORT)
+ */
+#include <linux/module.h>
+#include <linux/stacktrace.h>
+
+#include <asm/unwind.h>
+
+static void dump_trace(struct task_struct *task, struct stack_trace *trace)
+{
+ struct unwind_frame_info info;
+
+ unwind_frame_init_task(&info, task, NULL);
+
+ /* unwind stack and save entries in stack_trace struct */
+ trace->nr_entries = 0;
+ while (trace->nr_entries < trace->max_entries) {
+ if (unwind_once(&info) < 0 || info.ip == 0)
+ break;
+
+ if (__kernel_text_address(info.ip))
+ trace->entries[trace->nr_entries++] = info.ip;
+ }
+}
+
+
+/*
+ * Save stack-backtrace addresses into a stack_trace buffer.
+ */
+void save_stack_trace(struct stack_trace *trace)
+{
+ dump_trace(current, trace);
+ if (trace->nr_entries < trace->max_entries)
+ trace->entries[trace->nr_entries++] = ULONG_MAX;
+}
+EXPORT_SYMBOL_GPL(save_stack_trace);
+
+void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
+{
+ dump_trace(tsk, trace);
+ if (trace->nr_entries < trace->max_entries)
+ trace->entries[trace->nr_entries++] = ULONG_MAX;
+}
+EXPORT_SYMBOL_GPL(save_stack_trace_tsk);