v4.19.13 snapshot.
diff --git a/arch/sh/kernel/dumpstack.c b/arch/sh/kernel/dumpstack.c
new file mode 100644
index 0000000..b564b1e
--- /dev/null
+++ b/arch/sh/kernel/dumpstack.c
@@ -0,0 +1,162 @@
+/*
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
+ * Copyright (C) 2009 Matt Fleming
+ * Copyright (C) 2002 - 2012 Paul Mundt
+ *
+ * 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.
+ */
+#include <linux/kallsyms.h>
+#include <linux/ftrace.h>
+#include <linux/debug_locks.h>
+#include <linux/sched/debug.h>
+#include <linux/sched/task_stack.h>
+#include <linux/kdebug.h>
+#include <linux/export.h>
+#include <linux/uaccess.h>
+#include <asm/unwinder.h>
+#include <asm/stacktrace.h>
+
+void dump_mem(const char *str, unsigned long bottom, unsigned long top)
+{
+ unsigned long p;
+ int i;
+
+ printk("%s(0x%08lx to 0x%08lx)\n", str, bottom, top);
+
+ for (p = bottom & ~31; p < top; ) {
+ printk("%04lx: ", p & 0xffff);
+
+ for (i = 0; i < 8; i++, p += 4) {
+ unsigned int val;
+
+ if (p < bottom || p >= top)
+ printk(" ");
+ else {
+ if (__get_user(val, (unsigned int __user *)p)) {
+ printk("\n");
+ return;
+ }
+ printk("%08x ", val);
+ }
+ }
+ printk("\n");
+ }
+}
+
+void printk_address(unsigned long address, int reliable)
+{
+ printk(" [<%p>] %s%pS\n", (void *) address,
+ reliable ? "" : "? ", (void *) address);
+}
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+static void
+print_ftrace_graph_addr(unsigned long addr, void *data,
+ const struct stacktrace_ops *ops,
+ struct thread_info *tinfo, int *graph)
+{
+ struct task_struct *task = tinfo->task;
+ unsigned long ret_addr;
+ int index = task->curr_ret_stack;
+
+ if (addr != (unsigned long)return_to_handler)
+ return;
+
+ if (!task->ret_stack || index < *graph)
+ return;
+
+ index -= *graph;
+ ret_addr = task->ret_stack[index].ret;
+
+ ops->address(data, ret_addr, 1);
+
+ (*graph)++;
+}
+#else
+static inline void
+print_ftrace_graph_addr(unsigned long addr, void *data,
+ const struct stacktrace_ops *ops,
+ struct thread_info *tinfo, int *graph)
+{ }
+#endif
+
+void
+stack_reader_dump(struct task_struct *task, struct pt_regs *regs,
+ unsigned long *sp, const struct stacktrace_ops *ops,
+ void *data)
+{
+ struct thread_info *context;
+ int graph = 0;
+
+ context = (struct thread_info *)
+ ((unsigned long)sp & (~(THREAD_SIZE - 1)));
+
+ while (!kstack_end(sp)) {
+ unsigned long addr = *sp++;
+
+ if (__kernel_text_address(addr)) {
+ ops->address(data, addr, 1);
+
+ print_ftrace_graph_addr(addr, data, ops,
+ context, &graph);
+ }
+ }
+}
+
+static int print_trace_stack(void *data, char *name)
+{
+ printk("%s <%s> ", (char *)data, name);
+ return 0;
+}
+
+/*
+ * Print one address/symbol entries per line.
+ */
+static void print_trace_address(void *data, unsigned long addr, int reliable)
+{
+ printk("%s", (char *)data);
+ printk_address(addr, reliable);
+}
+
+static const struct stacktrace_ops print_trace_ops = {
+ .stack = print_trace_stack,
+ .address = print_trace_address,
+};
+
+void show_trace(struct task_struct *tsk, unsigned long *sp,
+ struct pt_regs *regs)
+{
+ if (regs && user_mode(regs))
+ return;
+
+ printk("\nCall trace:\n");
+
+ unwind_stack(tsk, regs, sp, &print_trace_ops, "");
+
+ printk("\n");
+
+ if (!tsk)
+ tsk = current;
+
+ debug_show_held_locks(tsk);
+}
+
+void show_stack(struct task_struct *tsk, unsigned long *sp)
+{
+ unsigned long stack;
+
+ if (!tsk)
+ tsk = current;
+ if (tsk == current)
+ sp = (unsigned long *)current_stack_pointer;
+ else
+ sp = (unsigned long *)tsk->thread.sp;
+
+ stack = (unsigned long)sp;
+ dump_mem("Stack: ", stack, THREAD_SIZE +
+ (unsigned long)task_stack_page(tsk));
+ show_trace(tsk, sp, NULL);
+}