xref: /linux/init/init_task.c (revision f79e4d5f92a129a1159c973735007d4ddc8541f3)
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
189