task.h (4864B)
1/* SPDX-License-Identifier: GPL-2.0 */ 2#ifndef _LINUX_SCHED_TASK_H 3#define _LINUX_SCHED_TASK_H 4 5/* 6 * Interface between the scheduler and various task lifetime (fork()/exit()) 7 * functionality: 8 */ 9 10#include <linux/sched.h> 11#include <linux/uaccess.h> 12 13struct task_struct; 14struct rusage; 15union thread_union; 16struct css_set; 17 18/* All the bits taken by the old clone syscall. */ 19#define CLONE_LEGACY_FLAGS 0xffffffffULL 20 21struct kernel_clone_args { 22 u64 flags; 23 int __user *pidfd; 24 int __user *child_tid; 25 int __user *parent_tid; 26 int exit_signal; 27 unsigned long stack; 28 unsigned long stack_size; 29 unsigned long tls; 30 pid_t *set_tid; 31 /* Number of elements in *set_tid */ 32 size_t set_tid_size; 33 int cgroup; 34 int io_thread; 35 int kthread; 36 int idle; 37 int (*fn)(void *); 38 void *fn_arg; 39 struct cgroup *cgrp; 40 struct css_set *cset; 41}; 42 43/* 44 * This serializes "schedule()" and also protects 45 * the run-queue from deletions/modifications (but 46 * _adding_ to the beginning of the run-queue has 47 * a separate lock). 48 */ 49extern rwlock_t tasklist_lock; 50extern spinlock_t mmlist_lock; 51 52extern union thread_union init_thread_union; 53extern struct task_struct init_task; 54 55extern int lockdep_tasklist_lock_is_held(void); 56 57extern asmlinkage void schedule_tail(struct task_struct *prev); 58extern void init_idle(struct task_struct *idle, int cpu); 59 60extern int sched_fork(unsigned long clone_flags, struct task_struct *p); 61extern void sched_cgroup_fork(struct task_struct *p, struct kernel_clone_args *kargs); 62extern void sched_post_fork(struct task_struct *p); 63extern void sched_dead(struct task_struct *p); 64 65void __noreturn do_task_dead(void); 66void __noreturn make_task_dead(int signr); 67 68extern void proc_caches_init(void); 69 70extern void fork_init(void); 71 72extern void release_task(struct task_struct * p); 73 74extern int copy_thread(struct task_struct *, const struct kernel_clone_args *); 75 76extern void flush_thread(void); 77 78#ifdef CONFIG_HAVE_EXIT_THREAD 79extern void exit_thread(struct task_struct *tsk); 80#else 81static inline void exit_thread(struct task_struct *tsk) 82{ 83} 84#endif 85extern __noreturn void do_group_exit(int); 86 87extern void exit_files(struct task_struct *); 88extern void exit_itimers(struct signal_struct *); 89 90extern pid_t kernel_clone(struct kernel_clone_args *kargs); 91struct task_struct *create_io_thread(int (*fn)(void *), void *arg, int node); 92struct task_struct *fork_idle(int); 93struct mm_struct *copy_init_mm(void); 94extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags); 95extern pid_t user_mode_thread(int (*fn)(void *), void *arg, unsigned long flags); 96extern long kernel_wait4(pid_t, int __user *, int, struct rusage *); 97int kernel_wait(pid_t pid, int *stat); 98 99extern void free_task(struct task_struct *tsk); 100 101/* sched_exec is called by processes performing an exec */ 102#ifdef CONFIG_SMP 103extern void sched_exec(void); 104#else 105#define sched_exec() {} 106#endif 107 108static inline struct task_struct *get_task_struct(struct task_struct *t) 109{ 110 refcount_inc(&t->usage); 111 return t; 112} 113 114extern void __put_task_struct(struct task_struct *t); 115 116static inline void put_task_struct(struct task_struct *t) 117{ 118 if (refcount_dec_and_test(&t->usage)) 119 __put_task_struct(t); 120} 121 122static inline void put_task_struct_many(struct task_struct *t, int nr) 123{ 124 if (refcount_sub_and_test(nr, &t->usage)) 125 __put_task_struct(t); 126} 127 128void put_task_struct_rcu_user(struct task_struct *task); 129 130#ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT 131extern int arch_task_struct_size __read_mostly; 132#else 133# define arch_task_struct_size (sizeof(struct task_struct)) 134#endif 135 136#ifndef CONFIG_HAVE_ARCH_THREAD_STRUCT_WHITELIST 137/* 138 * If an architecture has not declared a thread_struct whitelist we 139 * must assume something there may need to be copied to userspace. 140 */ 141static inline void arch_thread_struct_whitelist(unsigned long *offset, 142 unsigned long *size) 143{ 144 *offset = 0; 145 /* Handle dynamically sized thread_struct. */ 146 *size = arch_task_struct_size - offsetof(struct task_struct, thread); 147} 148#endif 149 150#ifdef CONFIG_VMAP_STACK 151static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t) 152{ 153 return t->stack_vm_area; 154} 155#else 156static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t) 157{ 158 return NULL; 159} 160#endif 161 162/* 163 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring 164 * subscriptions and synchronises with wait4(). Also used in procfs. Also 165 * pins the final release of task.io_context. Also protects ->cpuset and 166 * ->cgroup.subsys[]. And ->vfork_done. And ->sysvshm.shm_clist. 167 * 168 * Nests both inside and outside of read_lock(&tasklist_lock). 169 * It must not be nested with write_lock_irq(&tasklist_lock), 170 * neither inside nor outside. 171 */ 172static inline void task_lock(struct task_struct *p) 173{ 174 spin_lock(&p->alloc_lock); 175} 176 177static inline void task_unlock(struct task_struct *p) 178{ 179 spin_unlock(&p->alloc_lock); 180} 181 182#endif /* _LINUX_SCHED_TASK_H */