init/init_task.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/init_task.h>
   3 #include <linux/export.h>
   4 #include <linux/mqueue.h>
   5 #include <linux/sched.h>
   6 #include <linux/sched/sysctl.h>
   7 #include <linux/sched/rt.h>
   8 #include <linux/sched/task.h>
   9 #include <linux/init.h>
  10 #include <linux/fs.h>
  11 #include <linux/mm.h>
  12 #include <linux/audit.h>
  13 #include <linux/numa.h>
  14
  15 #include <asm/pgtable.h>
  16 #include <linux/uaccess.h>
  17
  18 static struct signal_struct init_signals = {
  19         .nr_threads     = 1,
  20         .thread_head    = LIST_HEAD_INIT(init_task.thread_node),
  21         .wait_chldexit  = __WAIT_QUEUE_HEAD_INITIALIZER(init_signals.wait_chldexit),
  22         .shared_pending = {
  23                 .list = LIST_HEAD_INIT(init_signals.shared_pending.list),
  24                 .signal =  {{0}}
  25         },
  26         .multiprocess   = HLIST_HEAD_INIT,
  27         .rlim           = INIT_RLIMITS,
  28         .cred_guard_mutex = __MUTEX_INITIALIZER(init_signals.cred_guard_mutex),
  29 #ifdef CONFIG_POSIX_TIMERS
  30         .posix_timers = LIST_HEAD_INIT(init_signals.posix_timers),
  31         .cputimer       = {
  32                 .cputime_atomic = INIT_CPUTIME_ATOMIC,
  33                 .running        = false,
  34                 .checking_timer = false,
  35         },
  36 #endif
  37         INIT_CPU_TIMERS(init_signals)
  38         .pids = {
  39                 [PIDTYPE_PID]   = &init_struct_pid,
  40                 [PIDTYPE_TGID]  = &init_struct_pid,
  41                 [PIDTYPE_PGID]  = &init_struct_pid,
  42                 [PIDTYPE_SID]   = &init_struct_pid,
  43         },
  44         INIT_PREV_CPUTIME(init_signals)
  45 };
  46
  47 static struct sighand_struct init_sighand = {
  48         .count          = REFCOUNT_INIT(1),
  49         .action         = { { { .sa_handler = SIG_DFL, } }, },
  50         .siglock        = __SPIN_LOCK_UNLOCKED(init_sighand.siglock),
  51         .signalfd_wqh   = __WAIT_QUEUE_HEAD_INITIALIZER(init_sighand.signalfd_wqh),
  52 };
  53
  54 /*
  55  * Set up the first task table, touch at your own risk!. Base=0,
  56  * limit=0x1fffff (=2MB)
  57  */
  58 struct task_struct init_task
  59 #ifdef CONFIG_ARCH_TASK_STRUCT_ON_STACK
  60         __init_task_data
  61 #endif
  62 = {
  63 #ifdef CONFIG_THREAD_INFO_IN_TASK
  64         .thread_info    = INIT_THREAD_INFO(init_task),
  65         .stack_refcount = REFCOUNT_INIT(1),
  66 #endif
  67         .state          = 0,
  68         .stack          = init_stack,
  69         .usage          = REFCOUNT_INIT(2),
  70         .flags          = PF_KTHREAD,
  71         .prio           = MAX_PRIO - 20,
  72         .static_prio    = MAX_PRIO - 20,
  73         .normal_prio    = MAX_PRIO - 20,
  74         .policy         = SCHED_NORMAL,
  75         .cpus_allowed   = CPU_MASK_ALL,
  76         .nr_cpus_allowed= NR_CPUS,
  77         .mm             = NULL,
  78         .active_mm      = &init_mm,
  79         .restart_block  = {
  80                 .fn = do_no_restart_syscall,
  81         },
  82         .se             = {
  83                 .group_node     = LIST_HEAD_INIT(init_task.se.group_node),
  84         },
  85         .rt             = {
  86                 .run_list       = LIST_HEAD_INIT(init_task.rt.run_list),
  87                 .time_slice     = RR_TIMESLICE,
  88         },
  89         .tasks          = LIST_HEAD_INIT(init_task.tasks),
  90 #ifdef CONFIG_SMP
  91         .pushable_tasks = PLIST_NODE_INIT(init_task.pushable_tasks, MAX_PRIO),
  92 #endif
  93 #ifdef CONFIG_CGROUP_SCHED
  94         .sched_task_group = &root_task_group,
  95 #endif
  96         .ptraced        = LIST_HEAD_INIT(init_task.ptraced),
  97         .ptrace_entry   = LIST_HEAD_INIT(init_task.ptrace_entry),
  98         .real_parent    = &init_task,
  99         .parent         = &init_task,
 100         .children       = LIST_HEAD_INIT(init_task.children),
 101         .sibling        = LIST_HEAD_INIT(init_task.sibling),
 102         .group_leader   = &init_task,
 103         RCU_POINTER_INITIALIZER(real_cred, &init_cred),
 104         RCU_POINTER_INITIALIZER(cred, &init_cred),
 105         .comm           = INIT_TASK_COMM,
 106         .thread         = INIT_THREAD,
 107         .fs             = &init_fs,
 108         .files          = &init_files,
 109         .signal         = &init_signals,
 110         .sighand        = &init_sighand,
 111         .nsproxy        = &init_nsproxy,
 112         .pending        = {
 113                 .list = LIST_HEAD_INIT(init_task.pending.list),
 114                 .signal = {{0}}
 115         },
 116         .blocked        = {{0}},
 117         .alloc_lock     = __SPIN_LOCK_UNLOCKED(init_task.alloc_lock),
 118         .journal_info   = NULL,
 119         INIT_CPU_TIMERS(init_task)
 120         .pi_lock        = __RAW_SPIN_LOCK_UNLOCKED(init_task.pi_lock),
 121         .timer_slack_ns = 50000, /* 50 usec default slack */
 122         .thread_pid     = &init_struct_pid,
 123         .thread_group   = LIST_HEAD_INIT(init_task.thread_group),
 124         .thread_node    = LIST_HEAD_INIT(init_signals.thread_head),
 125 #ifdef CONFIG_AUDIT
 126         .loginuid       = INVALID_UID,
 127         .sessionid      = AUDIT_SID_UNSET,
 128 #endif
 129 #ifdef CONFIG_PERF_EVENTS
 130         .perf_event_mutex = __MUTEX_INITIALIZER(init_task.perf_event_mutex),
 131         .perf_event_list = LIST_HEAD_INIT(init_task.perf_event_list),
 132 #endif
 133 #ifdef CONFIG_PREEMPT_RCU
 134         .rcu_read_lock_nesting = 0,
 135         .rcu_read_unlock_special.s = 0,
 136         .rcu_node_entry = LIST_HEAD_INIT(init_task.rcu_node_entry),
 137         .rcu_blocked_node = NULL,
 138 #endif
 139 #ifdef CONFIG_TASKS_RCU
 140         .rcu_tasks_holdout = false,
 141         .rcu_tasks_holdout_list = LIST_HEAD_INIT(init_task.rcu_tasks_holdout_list),
 142         .rcu_tasks_idle_cpu = -1,
 143 #endif
 144 #ifdef CONFIG_CPUSETS
 145         .mems_allowed_seq = SEQCNT_ZERO(init_task.mems_allowed_seq),
 146 #endif
 147 #ifdef CONFIG_RT_MUTEXES
 148         .pi_waiters     = RB_ROOT_CACHED,
 149         .pi_top_task    = NULL,
 150 #endif
 151         INIT_PREV_CPUTIME(init_task)
 152 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
 153         .vtime.seqcount = SEQCNT_ZERO(init_task.vtime_seqcount),
 154         .vtime.starttime = 0,
 155         .vtime.state    = VTIME_SYS,
 156 #endif
 157 #ifdef CONFIG_NUMA_BALANCING
 158         .numa_preferred_nid = NUMA_NO_NODE,
 159         .numa_group     = NULL,
 160         .numa_faults    = NULL,
 161 #endif
 162 #ifdef CONFIG_KASAN
 163         .kasan_depth    = 1,
 164 #endif
 165 #ifdef CONFIG_TRACE_IRQFLAGS
 166         .softirqs_enabled = 1,
 167 #endif
 168 #ifdef CONFIG_LOCKDEP
 169         .lockdep_recursion = 0,
 170 #endif
 171 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 172         .ret_stack      = NULL,
 173 #endif
 174 #if defined(CONFIG_TRACING) && defined(CONFIG_PREEMPT)
 175         .trace_recursion = 0,
 176 #endif
 177 #ifdef CONFIG_LIVEPATCH
 178         .patch_state    = KLP_UNDEFINED,
 179 #endif
 180 #ifdef CONFIG_SECURITY
 181         .security       = NULL,
 182 #endif
 183 };
 184 EXPORT_SYMBOL(init_task);
 185
 186 /*
 187  * Initial thread structure. Alignment of this is handled by a special
 188  * linker map entry.
 189  */
 190 #ifndef CONFIG_THREAD_INFO_IN_TASK
 191 struct thread_info init_thread_info __init_thread_info = INIT_THREAD_INFO(init_task);
 192 #endif