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