xref: /openbmc/linux/init/init_task.c (revision d23015c1)
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 
15 #include <asm/pgtable.h>
16 #include <linux/uaccess.h>
17 
18 static 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 #ifdef CONFIG_POSIX_TIMERS
30 	.posix_timers = LIST_HEAD_INIT(init_signals.posix_timers),
31 	.cputimer	= {
32 		.cputime_atomic	= INIT_CPUTIME_ATOMIC,
33 	},
34 #endif
35 	INIT_CPU_TIMERS(init_signals)
36 	.pids = {
37 		[PIDTYPE_PID]	= &init_struct_pid,
38 		[PIDTYPE_TGID]	= &init_struct_pid,
39 		[PIDTYPE_PGID]	= &init_struct_pid,
40 		[PIDTYPE_SID]	= &init_struct_pid,
41 	},
42 	INIT_PREV_CPUTIME(init_signals)
43 };
44 
45 static struct sighand_struct init_sighand = {
46 	.count		= REFCOUNT_INIT(1),
47 	.action		= { { { .sa_handler = SIG_DFL, } }, },
48 	.siglock	= __SPIN_LOCK_UNLOCKED(init_sighand.siglock),
49 	.signalfd_wqh	= __WAIT_QUEUE_HEAD_INITIALIZER(init_sighand.signalfd_wqh),
50 };
51 
52 /*
53  * Set up the first task table, touch at your own risk!. Base=0,
54  * limit=0x1fffff (=2MB)
55  */
56 struct task_struct init_task
57 #ifdef CONFIG_ARCH_TASK_STRUCT_ON_STACK
58 	__init_task_data
59 #endif
60 = {
61 #ifdef CONFIG_THREAD_INFO_IN_TASK
62 	.thread_info	= INIT_THREAD_INFO(init_task),
63 	.stack_refcount	= REFCOUNT_INIT(1),
64 #endif
65 	.state		= 0,
66 	.stack		= init_stack,
67 	.usage		= REFCOUNT_INIT(2),
68 	.flags		= PF_KTHREAD,
69 	.prio		= MAX_PRIO - 20,
70 	.static_prio	= MAX_PRIO - 20,
71 	.normal_prio	= MAX_PRIO - 20,
72 	.policy		= SCHED_NORMAL,
73 	.cpus_ptr	= &init_task.cpus_mask,
74 	.cpus_mask	= CPU_MASK_ALL,
75 	.nr_cpus_allowed= NR_CPUS,
76 	.mm		= NULL,
77 	.active_mm	= &init_mm,
78 	.restart_block	= {
79 		.fn = do_no_restart_syscall,
80 	},
81 	.se		= {
82 		.group_node 	= LIST_HEAD_INIT(init_task.se.group_node),
83 	},
84 	.rt		= {
85 		.run_list	= LIST_HEAD_INIT(init_task.rt.run_list),
86 		.time_slice	= RR_TIMESLICE,
87 	},
88 	.tasks		= LIST_HEAD_INIT(init_task.tasks),
89 #ifdef CONFIG_SMP
90 	.pushable_tasks	= PLIST_NODE_INIT(init_task.pushable_tasks, MAX_PRIO),
91 #endif
92 #ifdef CONFIG_CGROUP_SCHED
93 	.sched_task_group = &root_task_group,
94 #endif
95 	.ptraced	= LIST_HEAD_INIT(init_task.ptraced),
96 	.ptrace_entry	= LIST_HEAD_INIT(init_task.ptrace_entry),
97 	.real_parent	= &init_task,
98 	.parent		= &init_task,
99 	.children	= LIST_HEAD_INIT(init_task.children),
100 	.sibling	= LIST_HEAD_INIT(init_task.sibling),
101 	.group_leader	= &init_task,
102 	RCU_POINTER_INITIALIZER(real_cred, &init_cred),
103 	RCU_POINTER_INITIALIZER(cred, &init_cred),
104 	.comm		= INIT_TASK_COMM,
105 	.thread		= INIT_THREAD,
106 	.fs		= &init_fs,
107 	.files		= &init_files,
108 	.signal		= &init_signals,
109 	.sighand	= &init_sighand,
110 	.nsproxy	= &init_nsproxy,
111 	.pending	= {
112 		.list = LIST_HEAD_INIT(init_task.pending.list),
113 		.signal = {{0}}
114 	},
115 	.blocked	= {{0}},
116 	.alloc_lock	= __SPIN_LOCK_UNLOCKED(init_task.alloc_lock),
117 	.journal_info	= NULL,
118 	INIT_CPU_TIMERS(init_task)
119 	.pi_lock	= __RAW_SPIN_LOCK_UNLOCKED(init_task.pi_lock),
120 	.timer_slack_ns = 50000, /* 50 usec default slack */
121 	.thread_pid	= &init_struct_pid,
122 	.thread_group	= LIST_HEAD_INIT(init_task.thread_group),
123 	.thread_node	= LIST_HEAD_INIT(init_signals.thread_head),
124 #ifdef CONFIG_AUDIT
125 	.loginuid	= INVALID_UID,
126 	.sessionid	= AUDIT_SID_UNSET,
127 #endif
128 #ifdef CONFIG_PERF_EVENTS
129 	.perf_event_mutex = __MUTEX_INITIALIZER(init_task.perf_event_mutex),
130 	.perf_event_list = LIST_HEAD_INIT(init_task.perf_event_list),
131 #endif
132 #ifdef CONFIG_PREEMPT_RCU
133 	.rcu_read_lock_nesting = 0,
134 	.rcu_read_unlock_special.s = 0,
135 	.rcu_node_entry = LIST_HEAD_INIT(init_task.rcu_node_entry),
136 	.rcu_blocked_node = NULL,
137 #endif
138 #ifdef CONFIG_TASKS_RCU
139 	.rcu_tasks_holdout = false,
140 	.rcu_tasks_holdout_list = LIST_HEAD_INIT(init_task.rcu_tasks_holdout_list),
141 	.rcu_tasks_idle_cpu = -1,
142 #endif
143 #ifdef CONFIG_CPUSETS
144 	.mems_allowed_seq = SEQCNT_ZERO(init_task.mems_allowed_seq),
145 #endif
146 #ifdef CONFIG_RT_MUTEXES
147 	.pi_waiters	= RB_ROOT_CACHED,
148 	.pi_top_task	= NULL,
149 #endif
150 	INIT_PREV_CPUTIME(init_task)
151 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
152 	.vtime.seqcount	= SEQCNT_ZERO(init_task.vtime_seqcount),
153 	.vtime.starttime = 0,
154 	.vtime.state	= VTIME_SYS,
155 #endif
156 #ifdef CONFIG_NUMA_BALANCING
157 	.numa_preferred_nid = NUMA_NO_NODE,
158 	.numa_group	= NULL,
159 	.numa_faults	= NULL,
160 #endif
161 #ifdef CONFIG_KASAN
162 	.kasan_depth	= 1,
163 #endif
164 #ifdef CONFIG_TRACE_IRQFLAGS
165 	.softirqs_enabled = 1,
166 #endif
167 #ifdef CONFIG_LOCKDEP
168 	.lockdep_depth = 0, /* no locks held yet */
169 	.curr_chain_key = INITIAL_CHAIN_KEY,
170 	.lockdep_recursion = 0,
171 #endif
172 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
173 	.ret_stack	= NULL,
174 #endif
175 #if defined(CONFIG_TRACING) && defined(CONFIG_PREEMPTION)
176 	.trace_recursion = 0,
177 #endif
178 #ifdef CONFIG_LIVEPATCH
179 	.patch_state	= KLP_UNDEFINED,
180 #endif
181 #ifdef CONFIG_SECURITY
182 	.security	= NULL,
183 #endif
184 };
185 EXPORT_SYMBOL(init_task);
186 
187 /*
188  * Initial thread structure. Alignment of this is handled by a special
189  * linker map entry.
190  */
191 #ifndef CONFIG_THREAD_INFO_IN_TASK
192 struct thread_info init_thread_info __init_thread_info = INIT_THREAD_INFO(init_task);
193 #endif
194