#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_CC_STACKPROTECTORunsigned 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 | SLAB_NOTRACK, 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;}