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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233/* SPDX-License-Identifier: GPL-2.0 */#ifndef _LINUX_SCHED_TASK_H#define _LINUX_SCHED_TASK_H
/* * Interface between the scheduler and various task lifetime (fork()/exit()) * functionality: */
#include <linux/rcupdate.h>#include <linux/refcount.h>#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; const char *name; int exit_signal; u32 kthread:1; u32 io_thread:1; u32 user_worker:1; u32 no_files:1; 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; int idle; int (*fn)(void *); void *fn_arg; struct cgroup *cgrp; struct css_set *cset; unsigned int kill_seq;};
/* * 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(u64 clone_flags, struct task_struct *p);extern int sched_cgroup_fork(struct task_struct *p, struct kernel_clone_args *kargs);extern void sched_cancel_fork(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);void __noreturn make_task_dead(int signr);
extern void mm_cache_init(void);extern void proc_caches_init(void);
extern void fork_init(void);
extern void release_task(struct task_struct * p);
extern int copy_thread(struct task_struct *, const struct kernel_clone_args *);
extern void flush_thread(void);
#ifdef CONFIG_HAVE_EXIT_THREADextern void exit_thread(struct task_struct *tsk);#elsestatic inline void exit_thread(struct task_struct *tsk){}#endifextern __noreturn void do_group_exit(int);
extern void exit_files(struct task_struct *);extern void exit_itimers(struct task_struct *);
extern pid_t kernel_clone(struct kernel_clone_args *kargs);struct task_struct *copy_process(struct pid *pid, int trace, int node, struct kernel_clone_args *args);struct task_struct *create_io_thread(int (*fn)(void *), void *arg, int node);struct task_struct *fork_idle(int);extern pid_t kernel_thread(int (*fn)(void *), void *arg, const char *name, unsigned long flags);extern pid_t user_mode_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);
static inline struct task_struct *get_task_struct(struct task_struct *t){ refcount_inc(&t->usage); return t;}
static inline struct task_struct *tryget_task_struct(struct task_struct *t){ return refcount_inc_not_zero(&t->usage) ? t : NULL;}
extern void __put_task_struct(struct task_struct *t);extern void __put_task_struct_rcu_cb(struct rcu_head *rhp);
static inline void put_task_struct(struct task_struct *t){ if (!refcount_dec_and_test(&t->usage)) return;
/* * Under PREEMPT_RT, we can't call __put_task_struct * in atomic context because it will indirectly * acquire sleeping locks. The same is true if the * current process has a mutex enqueued (blocked on * a PI chain). * * In !RT, it is always safe to call __put_task_struct(). * Though, in order to simplify the code, resort to the * deferred call too. * * call_rcu() will schedule __put_task_struct_rcu_cb() * to be called in process context. * * __put_task_struct() is called when * refcount_dec_and_test(&t->usage) succeeds. * * This means that it can't "conflict" with * put_task_struct_rcu_user() which abuses ->rcu the same * way; rcu_users has a reference so task->usage can't be * zero after rcu_users 1 -> 0 transition. * * delayed_free_task() also uses ->rcu, but it is only called * when it fails to fork a process. Therefore, there is no * way it can conflict with __put_task_struct(). */ call_rcu(&t->rcu, __put_task_struct_rcu_cb);}
DEFINE_FREE(put_task, struct task_struct *, if (_T) put_task_struct(_T))
static inline void put_task_struct_many(struct task_struct *t, int nr){ if (refcount_sub_and_test(nr, &t->usage)) __put_task_struct(t);}
void put_task_struct_rcu_user(struct task_struct *task);
/* Free all architecture-specific resources held by a thread. */void release_thread(struct task_struct *dead_task);
#ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCTextern int arch_task_struct_size __read_mostly;#else# define arch_task_struct_size (sizeof(struct task_struct))#endif
#ifndef CONFIG_HAVE_ARCH_THREAD_STRUCT_WHITELIST/* * 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);}#endif
#ifdef CONFIG_VMAP_STACKstatic inline struct vm_struct *task_stack_vm_area(const struct task_struct *t){ return t->stack_vm_area;}#elsestatic inline struct vm_struct *task_stack_vm_area(const struct task_struct *t){ return NULL;}#endif
/* * 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. And ->sysvshm.shm_clist. * * Nests inside 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) __acquires(&p->alloc_lock){ spin_lock(&p->alloc_lock);}
static inline void task_unlock(struct task_struct *p) __releases(&p->alloc_lock){ spin_unlock(&p->alloc_lock);}
DEFINE_LOCK_GUARD_1(task_lock, struct task_struct, task_lock(_T->lock), task_unlock(_T->lock))DECLARE_LOCK_GUARD_1_ATTRS(task_lock, __acquires(&_T->alloc_lock), __releases(&(*(struct task_struct **)_T)->alloc_lock))#define class_task_lock_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(task_lock, _T)
#endif /* _LINUX_SCHED_TASK_H */