/* SPDX-License-Identifier: GPL-2.0 */#ifndef _LINUX_SCHED_TASK_STACK_H#define _LINUX_SCHED_TASK_STACK_H /* * task->stack (kernel stack) handling interfaces: */ #include <linux/sched.h>#include <linux/magic.h>#include <linux/refcount.h>#include <linux/kasan.h> #ifdef CONFIG_THREAD_INFO_IN_TASK /* * When accessing the stack of a non-current task that might exit, use * try_get_task_stack() instead.  task_stack_page will return a pointer * that could get freed out from under you. */static __always_inline void *task_stack_page(const struct task_struct *task){	return task->stack;} #define setup_thread_stack(new,old)	do { } while(0) static __always_inline unsigned long *end_of_stack(const struct task_struct *task){#ifdef CONFIG_STACK_GROWSUP	return (unsigned long *)((unsigned long)task->stack + THREAD_SIZE) - 1;#else	return task->stack;#endif} #else #define task_stack_page(task)	((void *)(task)->stack) static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org){	*task_thread_info(p) = *task_thread_info(org);	task_thread_info(p)->task = p;} /* * Return the address of the last usable long on the stack. * * When the stack grows down, this is just above the thread * info struct. Going any lower will corrupt the threadinfo. * * When the stack grows up, this is the highest address. * Beyond that position, we corrupt data on the next page. */static inline unsigned long *end_of_stack(struct task_struct *p){#ifdef CONFIG_STACK_GROWSUP	return (unsigned long *)((unsigned long)task_thread_info(p) + THREAD_SIZE) - 1;#else	return (unsigned long *)(task_thread_info(p) + 1);#endif} #endif #ifdef CONFIG_THREAD_INFO_IN_TASKstatic inline void *try_get_task_stack(struct task_struct *tsk){	return refcount_inc_not_zero(&tsk->stack_refcount) ?		task_stack_page(tsk) : NULL;} extern void put_task_stack(struct task_struct *tsk);#elsestatic inline void *try_get_task_stack(struct task_struct *tsk){	return task_stack_page(tsk);} static inline void put_task_stack(struct task_struct *tsk) {}#endif void exit_task_stack_account(struct task_struct *tsk); #define task_stack_end_corrupted(task) \		(*(end_of_stack(task)) != STACK_END_MAGIC) static inline int object_is_on_stack(const void *obj){	void *stack = task_stack_page(current); 	obj = kasan_reset_tag(obj);	return (obj >= stack) && (obj < (stack + THREAD_SIZE));} extern void thread_stack_cache_init(void); #ifdef CONFIG_DEBUG_STACK_USAGEunsigned long stack_not_used(struct task_struct *p);#elsestatic inline unsigned long stack_not_used(struct task_struct *p){	return 0;}#endifextern void set_task_stack_end_magic(struct task_struct *tsk); #ifndef __HAVE_ARCH_KSTACK_ENDstatic inline int kstack_end(void *addr){	/* Reliable end of stack detection:	 * Some APM bios versions misalign the stack	 */	return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));}#endif #endif /* _LINUX_SCHED_TASK_STACK_H */