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/sched/ext.h>
  10 #include <linux/init.h>
  11 #include <linux/fs.h>
  12 #include <linux/mm.h>
  13 #include <linux/audit.h>
  14 #include <linux/numa.h>
  15 #include <linux/scs.h>
  16 #include <linux/plist.h>
  17
  18 #include <linux/uaccess.h>
  19
  20 static struct signal_struct init_signals = {
  21         .nr_threads     = 1,
  22         .thread_head    = LIST_HEAD_INIT(init_task.thread_node),
  23         .wait_chldexit  = __WAIT_QUEUE_HEAD_INITIALIZER(init_signals.wait_chldexit),
  24         .shared_pending = {
  25                 .list = LIST_HEAD_INIT(init_signals.shared_pending.list),
  26                 .signal =  {{0}}
  27         },
  28         .multiprocess   = HLIST_HEAD_INIT,
  29         .rlim           = INIT_RLIMITS,
  30         .cred_guard_mutex = __MUTEX_INITIALIZER(init_signals.cred_guard_mutex),
  31         .exec_update_lock = __RWSEM_INITIALIZER(init_signals.exec_update_lock),
  32 #ifdef CONFIG_POSIX_TIMERS
  33         .posix_timers   = HLIST_HEAD_INIT,
  34         .cputimer       = {
  35                 .cputime_atomic = INIT_CPUTIME_ATOMIC,
  36         },
  37 #endif
  38         INIT_CPU_TIMERS(init_signals)
  39         .pids = {
  40                 [PIDTYPE_PID]   = &init_struct_pid,
  41                 [PIDTYPE_TGID]  = &init_struct_pid,
  42                 [PIDTYPE_PGID]  = &init_struct_pid,
  43                 [PIDTYPE_SID]   = &init_struct_pid,
  44         },
  45         INIT_PREV_CPUTIME(init_signals)
  46 };
  47
  48 static struct sighand_struct init_sighand = {
  49         .count          = REFCOUNT_INIT(1),
  50         .action         = { { { .sa_handler = SIG_DFL, } }, },
  51         .siglock        = __SPIN_LOCK_UNLOCKED(init_sighand.siglock),
  52         .signalfd_wqh   = __WAIT_QUEUE_HEAD_INITIALIZER(init_sighand.signalfd_wqh),
  53 };
  54
  55 #ifdef CONFIG_SHADOW_CALL_STACK
  56 unsigned long init_shadow_call_stack[SCS_SIZE / sizeof(long)] = {
  57         [(SCS_SIZE / sizeof(long)) - 1] = SCS_END_MAGIC
  58 };
  59 #endif
  60
  61 /*
  62  * Set up the first task table, touch at your own risk!. Base=0,
  63  * limit=0x1fffff (=2MB)
  64  */
  65 struct task_struct init_task __aligned(L1_CACHE_BYTES) = {
  66 #ifdef CONFIG_THREAD_INFO_IN_TASK
  67         .thread_info    = INIT_THREAD_INFO(init_task),
  68         .stack_refcount = REFCOUNT_INIT(1),
  69 #endif
  70         .__state        = 0,
  71         .stack          = init_stack,
  72         .usage          = REFCOUNT_INIT(2),
  73         .flags          = PF_KTHREAD,
  74         .prio           = MAX_PRIO - 20,
  75         .static_prio    = MAX_PRIO - 20,
  76         .normal_prio    = MAX_PRIO - 20,
  77         .policy         = SCHED_NORMAL,
  78         .cpus_ptr       = &init_task.cpus_mask,
  79         .user_cpus_ptr  = NULL,
  80         .cpus_mask      = CPU_MASK_ALL,
  81         .max_allowed_capacity   = SCHED_CAPACITY_SCALE,
  82         .nr_cpus_allowed= NR_CPUS,
  83         .mm             = NULL,
  84         .active_mm      = &init_mm,
  85         .faults_disabled_mapping = NULL,
  86         .restart_block  = {
  87                 .fn = do_no_restart_syscall,
  88         },
  89         .se             = {
  90                 .group_node     = LIST_HEAD_INIT(init_task.se.group_node),
  91         },
  92         .rt             = {
  93                 .run_list       = LIST_HEAD_INIT(init_task.rt.run_list),
  94                 .time_slice     = RR_TIMESLICE,
  95         },
  96         .tasks          = LIST_HEAD_INIT(init_task.tasks),
  97 #ifdef CONFIG_SMP
  98         .pushable_tasks = PLIST_NODE_INIT(init_task.pushable_tasks, MAX_PRIO),
  99 #endif
 100 #ifdef CONFIG_CGROUP_SCHED
 101         .sched_task_group = &root_task_group,
 102 #endif
 103 #ifdef CONFIG_SCHED_CLASS_EXT
 104         .scx            = {
 105                 .dsq_list.node  = LIST_HEAD_INIT(init_task.scx.dsq_list.node),
 106                 .sticky_cpu     = -1,
 107                 .holding_cpu    = -1,
 108                 .runnable_node  = LIST_HEAD_INIT(init_task.scx.runnable_node),
 109                 .runnable_at    = INITIAL_JIFFIES,
 110                 .ddsp_dsq_id    = SCX_DSQ_INVALID,
 111                 .slice          = SCX_SLICE_DFL,
 112         },
 113 #endif
 114         .ptraced        = LIST_HEAD_INIT(init_task.ptraced),
 115         .ptrace_entry   = LIST_HEAD_INIT(init_task.ptrace_entry),
 116         .real_parent    = &init_task,
 117         .parent         = &init_task,
 118         .children       = LIST_HEAD_INIT(init_task.children),
 119         .sibling        = LIST_HEAD_INIT(init_task.sibling),
 120         .group_leader   = &init_task,
 121         RCU_POINTER_INITIALIZER(real_cred, &init_cred),
 122         RCU_POINTER_INITIALIZER(cred, &init_cred),
 123         .comm           = INIT_TASK_COMM,
 124         .thread         = INIT_THREAD,
 125         .fs             = &init_fs,
 126         .files          = &init_files,
 127 #ifdef CONFIG_IO_URING
 128         .io_uring       = NULL,
 129 #endif
 130         .signal         = &init_signals,
 131         .sighand        = &init_sighand,
 132         .nsproxy        = &init_nsproxy,
 133         .pending        = {
 134                 .list = LIST_HEAD_INIT(init_task.pending.list),
 135                 .signal = {{0}}
 136         },
 137         .blocked        = {{0}},
 138         .alloc_lock     = __SPIN_LOCK_UNLOCKED(init_task.alloc_lock),
 139         .journal_info   = NULL,
 140         INIT_CPU_TIMERS(init_task)
 141         .pi_lock        = __RAW_SPIN_LOCK_UNLOCKED(init_task.pi_lock),
 142         .timer_slack_ns = 50000, /* 50 usec default slack */
 143         .thread_pid     = &init_struct_pid,
 144         .thread_node    = LIST_HEAD_INIT(init_signals.thread_head),
 145 #ifdef CONFIG_AUDIT
 146         .loginuid       = INVALID_UID,
 147         .sessionid      = AUDIT_SID_UNSET,
 148 #endif
 149 #ifdef CONFIG_PERF_EVENTS
 150         .perf_event_mutex = __MUTEX_INITIALIZER(init_task.perf_event_mutex),
 151         .perf_event_list = LIST_HEAD_INIT(init_task.perf_event_list),
 152 #endif
 153 #ifdef CONFIG_PREEMPT_RCU
 154         .rcu_read_lock_nesting = 0,
 155         .rcu_read_unlock_special.s = 0,
 156         .rcu_node_entry = LIST_HEAD_INIT(init_task.rcu_node_entry),
 157         .rcu_blocked_node = NULL,
 158 #endif
 159 #ifdef CONFIG_TASKS_RCU
 160         .rcu_tasks_holdout = false,
 161         .rcu_tasks_holdout_list = LIST_HEAD_INIT(init_task.rcu_tasks_holdout_list),
 162         .rcu_tasks_idle_cpu = -1,
 163         .rcu_tasks_exit_list = LIST_HEAD_INIT(init_task.rcu_tasks_exit_list),
 164 #endif
 165 #ifdef CONFIG_TASKS_TRACE_RCU
 166         .trc_reader_nesting = 0,
 167         .trc_reader_special.s = 0,
 168         .trc_holdout_list = LIST_HEAD_INIT(init_task.trc_holdout_list),
 169         .trc_blkd_node = LIST_HEAD_INIT(init_task.trc_blkd_node),
 170 #endif
 171 #ifdef CONFIG_CPUSETS
 172         .mems_allowed_seq = SEQCNT_SPINLOCK_ZERO(init_task.mems_allowed_seq,
 173                                                  &init_task.alloc_lock),
 174 #endif
 175 #ifdef CONFIG_RT_MUTEXES
 176         .pi_waiters     = RB_ROOT_CACHED,
 177         .pi_top_task    = NULL,
 178 #endif
 179         INIT_PREV_CPUTIME(init_task)
 180 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
 181         .vtime.seqcount = SEQCNT_ZERO(init_task.vtime_seqcount),
 182         .vtime.starttime = 0,
 183         .vtime.state    = VTIME_SYS,
 184 #endif
 185 #ifdef CONFIG_NUMA_BALANCING
 186         .numa_preferred_nid = NUMA_NO_NODE,
 187         .numa_group     = NULL,
 188         .numa_faults    = NULL,
 189 #endif
 190 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
 191         .kasan_depth    = 1,
 192 #endif
 193 #ifdef CONFIG_KCSAN
 194         .kcsan_ctx = {
 195                 .scoped_accesses        = {LIST_POISON1, NULL},
 196         },
 197 #endif
 198 #ifdef CONFIG_TRACE_IRQFLAGS
 199         .softirqs_enabled = 1,
 200 #endif
 201 #ifdef CONFIG_LOCKDEP
 202         .lockdep_depth = 0, /* no locks held yet */
 203         .curr_chain_key = INITIAL_CHAIN_KEY,
 204         .lockdep_recursion = 0,
 205 #endif
 206 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 207         .ret_stack              = NULL,
 208         .tracing_graph_pause    = ATOMIC_INIT(0),
 209 #endif
 210 #if defined(CONFIG_TRACING) && defined(CONFIG_PREEMPTION)
 211         .trace_recursion = 0,
 212 #endif
 213 #ifdef CONFIG_LIVEPATCH
 214         .patch_state    = KLP_TRANSITION_IDLE,
 215 #endif
 216 #ifdef CONFIG_SECURITY
 217         .security       = NULL,
 218 #endif
 219 #ifdef CONFIG_SECCOMP_FILTER
 220         .seccomp        = { .filter_count = ATOMIC_INIT(0) },
 221 #endif
 222 };
 223 EXPORT_SYMBOL(init_task);
 224
 225 /*
 226  * Initial thread structure. Alignment of this is handled by a special
 227  * linker map entry.
 228  */
 229 #ifndef CONFIG_THREAD_INFO_IN_TASK
 230 struct thread_info init_thread_info __init_thread_info = INIT_THREAD_INFO(init_task);
 231 #endif