xref: /openbmc/linux/init/init_task.c (revision 59bd9ded)
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 		.running	= false,
34 		.checking_timer = false,
35 	},
36 #endif
37 	INIT_CPU_TIMERS(init_signals)
38 	.pids = {
39 		[PIDTYPE_PID]	= &init_struct_pid,
40 		[PIDTYPE_TGID]	= &init_struct_pid,
41 		[PIDTYPE_PGID]	= &init_struct_pid,
42 		[PIDTYPE_SID]	= &init_struct_pid,
43 	},
44 	INIT_PREV_CPUTIME(init_signals)
45 };
46 
47 static struct sighand_struct init_sighand = {
48 	.count		= REFCOUNT_INIT(1),
49 	.action		= { { { .sa_handler = SIG_DFL, } }, },
50 	.siglock	= __SPIN_LOCK_UNLOCKED(init_sighand.siglock),
51 	.signalfd_wqh	= __WAIT_QUEUE_HEAD_INITIALIZER(init_sighand.signalfd_wqh),
52 };
53 
54 /*
55  * Set up the first task table, touch at your own risk!. Base=0,
56  * limit=0x1fffff (=2MB)
57  */
58 struct task_struct init_task
59 #ifdef CONFIG_ARCH_TASK_STRUCT_ON_STACK
60 	__init_task_data
61 #endif
62 = {
63 #ifdef CONFIG_THREAD_INFO_IN_TASK
64 	.thread_info	= INIT_THREAD_INFO(init_task),
65 	.stack_refcount	= REFCOUNT_INIT(1),
66 #endif
67 	.state		= 0,
68 	.stack		= init_stack,
69 	.usage		= REFCOUNT_INIT(2),
70 	.flags		= PF_KTHREAD,
71 	.prio		= MAX_PRIO - 20,
72 	.static_prio	= MAX_PRIO - 20,
73 	.normal_prio	= MAX_PRIO - 20,
74 	.policy		= SCHED_NORMAL,
75 	.cpus_allowed	= CPU_MASK_ALL,
76 	.nr_cpus_allowed= NR_CPUS,
77 	.mm		= NULL,
78 	.active_mm	= &init_mm,
79 	.restart_block	= {
80 		.fn = do_no_restart_syscall,
81 	},
82 	.se		= {
83 		.group_node 	= LIST_HEAD_INIT(init_task.se.group_node),
84 	},
85 	.rt		= {
86 		.run_list	= LIST_HEAD_INIT(init_task.rt.run_list),
87 		.time_slice	= RR_TIMESLICE,
88 	},
89 	.tasks		= LIST_HEAD_INIT(init_task.tasks),
90 #ifdef CONFIG_SMP
91 	.pushable_tasks	= PLIST_NODE_INIT(init_task.pushable_tasks, MAX_PRIO),
92 #endif
93 #ifdef CONFIG_CGROUP_SCHED
94 	.sched_task_group = &root_task_group,
95 #endif
96 	.ptraced	= LIST_HEAD_INIT(init_task.ptraced),
97 	.ptrace_entry	= LIST_HEAD_INIT(init_task.ptrace_entry),
98 	.real_parent	= &init_task,
99 	.parent		= &init_task,
100 	.children	= LIST_HEAD_INIT(init_task.children),
101 	.sibling	= LIST_HEAD_INIT(init_task.sibling),
102 	.group_leader	= &init_task,
103 	RCU_POINTER_INITIALIZER(real_cred, &init_cred),
104 	RCU_POINTER_INITIALIZER(cred, &init_cred),
105 	.comm		= INIT_TASK_COMM,
106 	.thread		= INIT_THREAD,
107 	.fs		= &init_fs,
108 	.files		= &init_files,
109 	.signal		= &init_signals,
110 	.sighand	= &init_sighand,
111 	.nsproxy	= &init_nsproxy,
112 	.pending	= {
113 		.list = LIST_HEAD_INIT(init_task.pending.list),
114 		.signal = {{0}}
115 	},
116 	.blocked	= {{0}},
117 	.alloc_lock	= __SPIN_LOCK_UNLOCKED(init_task.alloc_lock),
118 	.journal_info	= NULL,
119 	INIT_CPU_TIMERS(init_task)
120 	.pi_lock	= __RAW_SPIN_LOCK_UNLOCKED(init_task.pi_lock),
121 	.timer_slack_ns = 50000, /* 50 usec default slack */
122 	.thread_pid	= &init_struct_pid,
123 	.thread_group	= LIST_HEAD_INIT(init_task.thread_group),
124 	.thread_node	= LIST_HEAD_INIT(init_signals.thread_head),
125 #ifdef CONFIG_AUDIT
126 	.loginuid	= INVALID_UID,
127 	.sessionid	= AUDIT_SID_UNSET,
128 #endif
129 #ifdef CONFIG_PERF_EVENTS
130 	.perf_event_mutex = __MUTEX_INITIALIZER(init_task.perf_event_mutex),
131 	.perf_event_list = LIST_HEAD_INIT(init_task.perf_event_list),
132 #endif
133 #ifdef CONFIG_PREEMPT_RCU
134 	.rcu_read_lock_nesting = 0,
135 	.rcu_read_unlock_special.s = 0,
136 	.rcu_node_entry = LIST_HEAD_INIT(init_task.rcu_node_entry),
137 	.rcu_blocked_node = NULL,
138 #endif
139 #ifdef CONFIG_TASKS_RCU
140 	.rcu_tasks_holdout = false,
141 	.rcu_tasks_holdout_list = LIST_HEAD_INIT(init_task.rcu_tasks_holdout_list),
142 	.rcu_tasks_idle_cpu = -1,
143 #endif
144 #ifdef CONFIG_CPUSETS
145 	.mems_allowed_seq = SEQCNT_ZERO(init_task.mems_allowed_seq),
146 #endif
147 #ifdef CONFIG_RT_MUTEXES
148 	.pi_waiters	= RB_ROOT_CACHED,
149 	.pi_top_task	= NULL,
150 #endif
151 	INIT_PREV_CPUTIME(init_task)
152 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
153 	.vtime.seqcount	= SEQCNT_ZERO(init_task.vtime_seqcount),
154 	.vtime.starttime = 0,
155 	.vtime.state	= VTIME_SYS,
156 #endif
157 #ifdef CONFIG_NUMA_BALANCING
158 	.numa_preferred_nid = NUMA_NO_NODE,
159 	.numa_group	= NULL,
160 	.numa_faults	= NULL,
161 #endif
162 #ifdef CONFIG_KASAN
163 	.kasan_depth	= 1,
164 #endif
165 #ifdef CONFIG_TRACE_IRQFLAGS
166 	.softirqs_enabled = 1,
167 #endif
168 #ifdef CONFIG_LOCKDEP
169 	.lockdep_recursion = 0,
170 #endif
171 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
172 	.ret_stack	= NULL,
173 #endif
174 #if defined(CONFIG_TRACING) && defined(CONFIG_PREEMPT)
175 	.trace_recursion = 0,
176 #endif
177 #ifdef CONFIG_LIVEPATCH
178 	.patch_state	= KLP_UNDEFINED,
179 #endif
180 #ifdef CONFIG_SECURITY
181 	.security	= NULL,
182 #endif
183 };
184 EXPORT_SYMBOL(init_task);
185 
186 /*
187  * Initial thread structure. Alignment of this is handled by a special
188  * linker map entry.
189  */
190 #ifndef CONFIG_THREAD_INFO_IN_TASK
191 struct thread_info init_thread_info __init_thread_info = INIT_THREAD_INFO(init_task);
192 #endif
193