linux/init/init_task.c
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   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
  16static 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
  38static 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 */
  49struct 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};
 179EXPORT_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
 186struct thread_info init_thread_info __init_thread_info = INIT_THREAD_INFO(init_task);
 187#endif
 188