/* SPDX-License-Identifier: GPL-2.0 */

 * Interface between the scheduler and various task lifetime (fork()/exit())
 * functionality:

#include <linux/sched.h>
#include <linux/uaccess.h>

struct task_struct;
struct rusage;
union thread_union;
struct css_set;

/* All the bits taken by the old clone syscall. */
#define CLONE_LEGACY_FLAGS 0xffffffffULL

struct kernel_clone_args {
	u64 flags;
	int __user *pidfd;
	int __user *child_tid;
	int __user *parent_tid;
	int exit_signal;
	unsigned long stack;
	unsigned long stack_size;
	unsigned long tls;
	pid_t *set_tid;
	/* Number of elements in *set_tid */
	size_t set_tid_size;
	int cgroup;
	struct cgroup *cgrp;
	struct css_set *cset;

 * This serializes "schedule()" and also protects
 * the run-queue from deletions/modifications (but
 * _adding_ to the beginning of the run-queue has
 * a separate lock).
extern rwlock_t tasklist_lock;
extern spinlock_t mmlist_lock;

extern union thread_union init_thread_union;
extern struct task_struct init_task;

extern int lockdep_tasklist_lock_is_held(void);

extern asmlinkage void schedule_tail(struct task_struct *prev);
extern void init_idle(struct task_struct *idle, int cpu);

extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
extern void sched_post_fork(struct task_struct *p);
extern void sched_dead(struct task_struct *p);

void __noreturn do_task_dead(void);

extern void proc_caches_init(void);

extern void fork_init(void);

extern void release_task(struct task_struct * p);

extern int copy_thread(unsigned long, unsigned long, unsigned long,
		       struct task_struct *, unsigned long);

extern void flush_thread(void);

extern void exit_thread(struct task_struct *tsk);
static inline void exit_thread(struct task_struct *tsk)
extern void do_group_exit(int);

extern void exit_files(struct task_struct *);
extern void exit_itimers(struct signal_struct *);

extern pid_t kernel_clone(struct kernel_clone_args *kargs);
struct task_struct *fork_idle(int);
struct mm_struct *copy_init_mm(void);
extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
extern long kernel_wait4(pid_t, int __user *, int, struct rusage *);
int kernel_wait(pid_t pid, int *stat);

extern void free_task(struct task_struct *tsk);

/* sched_exec is called by processes performing an exec */
extern void sched_exec(void);
#define sched_exec()   {}

static inline struct task_struct *get_task_struct(struct task_struct *t)
	return t;

extern void __put_task_struct(struct task_struct *t);

static inline void put_task_struct(struct task_struct *t)
	if (refcount_dec_and_test(&t->usage))

static inline void put_task_struct_many(struct task_struct *t, int nr)
	if (refcount_sub_and_test(nr, &t->usage))

void put_task_struct_rcu_user(struct task_struct *task);

extern int arch_task_struct_size __read_mostly;
# define arch_task_struct_size (sizeof(struct task_struct))

 * If an architecture has not declared a thread_struct whitelist we
 * must assume something there may need to be copied to userspace.
static inline void arch_thread_struct_whitelist(unsigned long *offset,
						unsigned long *size)
	*offset = 0;
	/* Handle dynamically sized thread_struct. */
	*size = arch_task_struct_size - offsetof(struct task_struct, thread);

static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
	return t->stack_vm_area;
static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
	return NULL;

 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
 * subscriptions and synchronises with wait4().  Also used in procfs.  Also
 * pins the final release of task.io_context.  Also protects ->cpuset and
 * ->cgroup.subsys[]. And ->vfork_done.
 * Nests both inside and outside of read_lock(&tasklist_lock).
 * It must not be nested with write_lock_irq(&tasklist_lock),
 * neither inside nor outside.
static inline void task_lock(struct task_struct *p)

static inline void task_unlock(struct task_struct *p)

#endif /* _LINUX_SCHED_TASK_H */