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