Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 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> |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 11 | #include <linux/uaccess.h> |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 12 | |
| 13 | struct task_struct; |
| 14 | struct rusage; |
| 15 | union thread_union; |
| 16 | |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 17 | /* All the bits taken by the old clone syscall. */ |
| 18 | #define CLONE_LEGACY_FLAGS 0xffffffffULL |
| 19 | |
| 20 | struct kernel_clone_args { |
| 21 | u64 flags; |
| 22 | int __user *pidfd; |
| 23 | int __user *child_tid; |
| 24 | int __user *parent_tid; |
| 25 | int exit_signal; |
| 26 | unsigned long stack; |
| 27 | unsigned long stack_size; |
| 28 | unsigned long tls; |
| 29 | }; |
| 30 | |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 31 | /* |
| 32 | * This serializes "schedule()" and also protects |
| 33 | * the run-queue from deletions/modifications (but |
| 34 | * _adding_ to the beginning of the run-queue has |
| 35 | * a separate lock). |
| 36 | */ |
| 37 | extern rwlock_t tasklist_lock; |
| 38 | extern spinlock_t mmlist_lock; |
| 39 | |
| 40 | extern union thread_union init_thread_union; |
| 41 | extern struct task_struct init_task; |
| 42 | |
| 43 | #ifdef CONFIG_PROVE_RCU |
| 44 | extern int lockdep_tasklist_lock_is_held(void); |
| 45 | #endif /* #ifdef CONFIG_PROVE_RCU */ |
| 46 | |
| 47 | extern asmlinkage void schedule_tail(struct task_struct *prev); |
| 48 | extern void init_idle(struct task_struct *idle, int cpu); |
| 49 | |
| 50 | extern int sched_fork(unsigned long clone_flags, struct task_struct *p); |
| 51 | extern void sched_dead(struct task_struct *p); |
| 52 | |
| 53 | void __noreturn do_task_dead(void); |
| 54 | |
| 55 | extern void proc_caches_init(void); |
| 56 | |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 57 | extern void fork_init(void); |
| 58 | |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 59 | extern void release_task(struct task_struct * p); |
| 60 | |
| 61 | #ifdef CONFIG_HAVE_COPY_THREAD_TLS |
| 62 | extern int copy_thread_tls(unsigned long, unsigned long, unsigned long, |
| 63 | struct task_struct *, unsigned long); |
| 64 | #else |
| 65 | extern int copy_thread(unsigned long, unsigned long, unsigned long, |
| 66 | struct task_struct *); |
| 67 | |
| 68 | /* Architectures that haven't opted into copy_thread_tls get the tls argument |
| 69 | * via pt_regs, so ignore the tls argument passed via C. */ |
| 70 | static inline int copy_thread_tls( |
| 71 | unsigned long clone_flags, unsigned long sp, unsigned long arg, |
| 72 | struct task_struct *p, unsigned long tls) |
| 73 | { |
| 74 | return copy_thread(clone_flags, sp, arg, p); |
| 75 | } |
| 76 | #endif |
| 77 | extern void flush_thread(void); |
| 78 | |
| 79 | #ifdef CONFIG_HAVE_EXIT_THREAD |
| 80 | extern void exit_thread(struct task_struct *tsk); |
| 81 | #else |
| 82 | static inline void exit_thread(struct task_struct *tsk) |
| 83 | { |
| 84 | } |
| 85 | #endif |
| 86 | extern void do_group_exit(int); |
| 87 | |
| 88 | extern void exit_files(struct task_struct *); |
| 89 | extern void exit_itimers(struct signal_struct *); |
| 90 | |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 91 | extern long _do_fork(struct kernel_clone_args *kargs); |
| 92 | extern bool legacy_clone_args_valid(const struct kernel_clone_args *kargs); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 93 | extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *); |
| 94 | struct task_struct *fork_idle(int); |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 95 | struct mm_struct *copy_init_mm(void); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 96 | extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags); |
| 97 | extern long kernel_wait4(pid_t, int __user *, int, struct rusage *); |
| 98 | |
| 99 | extern void free_task(struct task_struct *tsk); |
| 100 | |
| 101 | /* sched_exec is called by processes performing an exec */ |
| 102 | #ifdef CONFIG_SMP |
| 103 | extern void sched_exec(void); |
| 104 | #else |
| 105 | #define sched_exec() {} |
| 106 | #endif |
| 107 | |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 108 | static inline struct task_struct *get_task_struct(struct task_struct *t) |
| 109 | { |
| 110 | refcount_inc(&t->usage); |
| 111 | return t; |
| 112 | } |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 113 | |
| 114 | extern void __put_task_struct(struct task_struct *t); |
| 115 | |
| 116 | static inline void put_task_struct(struct task_struct *t) |
| 117 | { |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 118 | if (refcount_dec_and_test(&t->usage)) |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 119 | __put_task_struct(t); |
| 120 | } |
| 121 | |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 122 | void put_task_struct_rcu_user(struct task_struct *task); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 123 | |
| 124 | #ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT |
| 125 | extern int arch_task_struct_size __read_mostly; |
| 126 | #else |
| 127 | # define arch_task_struct_size (sizeof(struct task_struct)) |
| 128 | #endif |
| 129 | |
| 130 | #ifndef CONFIG_HAVE_ARCH_THREAD_STRUCT_WHITELIST |
| 131 | /* |
| 132 | * If an architecture has not declared a thread_struct whitelist we |
| 133 | * must assume something there may need to be copied to userspace. |
| 134 | */ |
| 135 | static inline void arch_thread_struct_whitelist(unsigned long *offset, |
| 136 | unsigned long *size) |
| 137 | { |
| 138 | *offset = 0; |
| 139 | /* Handle dynamically sized thread_struct. */ |
| 140 | *size = arch_task_struct_size - offsetof(struct task_struct, thread); |
| 141 | } |
| 142 | #endif |
| 143 | |
| 144 | #ifdef CONFIG_VMAP_STACK |
| 145 | static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t) |
| 146 | { |
| 147 | return t->stack_vm_area; |
| 148 | } |
| 149 | #else |
| 150 | static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t) |
| 151 | { |
| 152 | return NULL; |
| 153 | } |
| 154 | #endif |
| 155 | |
| 156 | /* |
| 157 | * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring |
| 158 | * subscriptions and synchronises with wait4(). Also used in procfs. Also |
| 159 | * pins the final release of task.io_context. Also protects ->cpuset and |
| 160 | * ->cgroup.subsys[]. And ->vfork_done. |
| 161 | * |
| 162 | * Nests both inside and outside of read_lock(&tasklist_lock). |
| 163 | * It must not be nested with write_lock_irq(&tasklist_lock), |
| 164 | * neither inside nor outside. |
| 165 | */ |
| 166 | static inline void task_lock(struct task_struct *p) |
| 167 | { |
| 168 | spin_lock(&p->alloc_lock); |
| 169 | } |
| 170 | |
| 171 | static inline void task_unlock(struct task_struct *p) |
| 172 | { |
| 173 | spin_unlock(&p->alloc_lock); |
| 174 | } |
| 175 | |
| 176 | #endif /* _LINUX_SCHED_TASK_H */ |