v4.19.13 snapshot.
diff --git a/arch/sh/kernel/process.c b/arch/sh/kernel/process.c
new file mode 100644
index 0000000..4d1bfc8
--- /dev/null
+++ b/arch/sh/kernel/process.c
@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/mm.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/sched/signal.h>
+#include <linux/sched/task_stack.h>
+#include <linux/export.h>
+#include <linux/stackprotector.h>
+#include <asm/fpu.h>
+#include <asm/ptrace.h>
+
+struct kmem_cache *task_xstate_cachep = NULL;
+unsigned int xstate_size;
+
+#ifdef CONFIG_STACKPROTECTOR
+unsigned long __stack_chk_guard __read_mostly;
+EXPORT_SYMBOL(__stack_chk_guard);
+#endif
+
+/*
+ * this gets called so that we can store lazy state into memory and copy the
+ * current task into the new thread.
+ */
+int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
+{
+#ifdef CONFIG_SUPERH32
+ unlazy_fpu(src, task_pt_regs(src));
+#endif
+ *dst = *src;
+
+ if (src->thread.xstate) {
+ dst->thread.xstate = kmem_cache_alloc(task_xstate_cachep,
+ GFP_KERNEL);
+ if (!dst->thread.xstate)
+ return -ENOMEM;
+ memcpy(dst->thread.xstate, src->thread.xstate, xstate_size);
+ }
+
+ return 0;
+}
+
+void free_thread_xstate(struct task_struct *tsk)
+{
+ if (tsk->thread.xstate) {
+ kmem_cache_free(task_xstate_cachep, tsk->thread.xstate);
+ tsk->thread.xstate = NULL;
+ }
+}
+
+void arch_release_task_struct(struct task_struct *tsk)
+{
+ free_thread_xstate(tsk);
+}
+
+void arch_task_cache_init(void)
+{
+ if (!xstate_size)
+ return;
+
+ task_xstate_cachep = kmem_cache_create("task_xstate", xstate_size,
+ __alignof__(union thread_xstate),
+ SLAB_PANIC, NULL);
+}
+
+#ifdef CONFIG_SH_FPU_EMU
+# define HAVE_SOFTFP 1
+#else
+# define HAVE_SOFTFP 0
+#endif
+
+void init_thread_xstate(void)
+{
+ if (boot_cpu_data.flags & CPU_HAS_FPU)
+ xstate_size = sizeof(struct sh_fpu_hard_struct);
+ else if (HAVE_SOFTFP)
+ xstate_size = sizeof(struct sh_fpu_soft_struct);
+ else
+ xstate_size = 0;
+}