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