xref: /openbmc/linux/init/init_task.c (revision 4cff79e9)
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 
13 #include <asm/pgtable.h>
14 #include <linux/uaccess.h>
15 
16 static struct signal_struct init_signals = {
17 	.nr_threads	= 1,
18 	.thread_head	= LIST_HEAD_INIT(init_task.thread_node),
19 	.wait_chldexit	= __WAIT_QUEUE_HEAD_INITIALIZER(init_signals.wait_chldexit),
20 	.shared_pending	= {
21 		.list = LIST_HEAD_INIT(init_signals.shared_pending.list),
22 		.signal =  {{0}}
23 	},
24 	.rlim		= INIT_RLIMITS,
25 	.cred_guard_mutex = __MUTEX_INITIALIZER(init_signals.cred_guard_mutex),
26 #ifdef CONFIG_POSIX_TIMERS
27 	.posix_timers = LIST_HEAD_INIT(init_signals.posix_timers),
28 	.cputimer	= {
29 		.cputime_atomic	= INIT_CPUTIME_ATOMIC,
30 		.running	= false,
31 		.checking_timer = false,
32 	},
33 #endif
34 	INIT_CPU_TIMERS(init_signals)
35 	INIT_PREV_CPUTIME(init_signals)
36 };
37 
38 static struct sighand_struct init_sighand = {
39 	.count		= ATOMIC_INIT(1),
40 	.action		= { { { .sa_handler = SIG_DFL, } }, },
41 	.siglock	= __SPIN_LOCK_UNLOCKED(init_sighand.siglock),
42 	.signalfd_wqh	= __WAIT_QUEUE_HEAD_INITIALIZER(init_sighand.signalfd_wqh),
43 };
44 
45 /*
46  * Set up the first task table, touch at your own risk!. Base=0,
47  * limit=0x1fffff (=2MB)
48  */
49 struct task_struct init_task
50 #ifdef CONFIG_ARCH_TASK_STRUCT_ON_STACK
51 	__init_task_data
52 #endif
53 = {
54 #ifdef CONFIG_THREAD_INFO_IN_TASK
55 	.thread_info	= INIT_THREAD_INFO(init_task),
56 	.stack_refcount	= ATOMIC_INIT(1),
57 #endif
58 	.state		= 0,
59 	.stack		= init_stack,
60 	.usage		= ATOMIC_INIT(2),
61 	.flags		= PF_KTHREAD,
62 	.prio		= MAX_PRIO - 20,
63 	.static_prio	= MAX_PRIO - 20,
64 	.normal_prio	= MAX_PRIO - 20,
65 	.policy		= SCHED_NORMAL,
66 	.cpus_allowed	= CPU_MASK_ALL,
67 	.nr_cpus_allowed= NR_CPUS,
68 	.mm		= NULL,
69 	.active_mm	= &init_mm,
70 	.restart_block	= {
71 		.fn = do_no_restart_syscall,
72 	},
73 	.se		= {
74 		.group_node 	= LIST_HEAD_INIT(init_task.se.group_node),
75 	},
76 	.rt		= {
77 		.run_list	= LIST_HEAD_INIT(init_task.rt.run_list),
78 		.time_slice	= RR_TIMESLICE,
79 	},
80 	.tasks		= LIST_HEAD_INIT(init_task.tasks),
81 #ifdef CONFIG_SMP
82 	.pushable_tasks	= PLIST_NODE_INIT(init_task.pushable_tasks, MAX_PRIO),
83 #endif
84 #ifdef CONFIG_CGROUP_SCHED
85 	.sched_task_group = &root_task_group,
86 #endif
87 	.ptraced	= LIST_HEAD_INIT(init_task.ptraced),
88 	.ptrace_entry	= LIST_HEAD_INIT(init_task.ptrace_entry),
89 	.real_parent	= &init_task,
90 	.parent		= &init_task,
91 	.children	= LIST_HEAD_INIT(init_task.children),
92 	.sibling	= LIST_HEAD_INIT(init_task.sibling),
93 	.group_leader	= &init_task,
94 	RCU_POINTER_INITIALIZER(real_cred, &init_cred),
95 	RCU_POINTER_INITIALIZER(cred, &init_cred),
96 	.comm		= INIT_TASK_COMM,
97 	.thread		= INIT_THREAD,
98 	.fs		= &init_fs,
99 	.files		= &init_files,
100 	.signal		= &init_signals,
101 	.sighand	= &init_sighand,
102 	.nsproxy	= &init_nsproxy,
103 	.pending	= {
104 		.list = LIST_HEAD_INIT(init_task.pending.list),
105 		.signal = {{0}}
106 	},
107 	.blocked	= {{0}},
108 	.alloc_lock	= __SPIN_LOCK_UNLOCKED(init_task.alloc_lock),
109 	.journal_info	= NULL,
110 	INIT_CPU_TIMERS(init_task)
111 	.pi_lock	= __RAW_SPIN_LOCK_UNLOCKED(init_task.pi_lock),
112 	.timer_slack_ns = 50000, /* 50 usec default slack */
113 	.pids = {
114 		[PIDTYPE_PID]  = INIT_PID_LINK(PIDTYPE_PID),
115 		[PIDTYPE_PGID] = INIT_PID_LINK(PIDTYPE_PGID),
116 		[PIDTYPE_SID]  = INIT_PID_LINK(PIDTYPE_SID),
117 	},
118 	.thread_group	= LIST_HEAD_INIT(init_task.thread_group),
119 	.thread_node	= LIST_HEAD_INIT(init_signals.thread_head),
120 #ifdef CONFIG_AUDITSYSCALL
121 	.loginuid	= INVALID_UID,
122 	.sessionid	= (unsigned int)-1,
123 #endif
124 #ifdef CONFIG_PERF_EVENTS
125 	.perf_event_mutex = __MUTEX_INITIALIZER(init_task.perf_event_mutex),
126 	.perf_event_list = LIST_HEAD_INIT(init_task.perf_event_list),
127 #endif
128 #ifdef CONFIG_PREEMPT_RCU
129 	.rcu_read_lock_nesting = 0,
130 	.rcu_read_unlock_special.s = 0,
131 	.rcu_node_entry = LIST_HEAD_INIT(init_task.rcu_node_entry),
132 	.rcu_blocked_node = NULL,
133 #endif
134 #ifdef CONFIG_TASKS_RCU
135 	.rcu_tasks_holdout = false,
136 	.rcu_tasks_holdout_list = LIST_HEAD_INIT(init_task.rcu_tasks_holdout_list),
137 	.rcu_tasks_idle_cpu = -1,
138 #endif
139 #ifdef CONFIG_CPUSETS
140 	.mems_allowed_seq = SEQCNT_ZERO(init_task.mems_allowed_seq),
141 #endif
142 #ifdef CONFIG_RT_MUTEXES
143 	.pi_waiters	= RB_ROOT_CACHED,
144 	.pi_top_task	= NULL,
145 #endif
146 	INIT_PREV_CPUTIME(init_task)
147 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
148 	.vtime.seqcount	= SEQCNT_ZERO(init_task.vtime_seqcount),
149 	.vtime.starttime = 0,
150 	.vtime.state	= VTIME_SYS,
151 #endif
152 #ifdef CONFIG_NUMA_BALANCING
153 	.numa_preferred_nid = -1,
154 	.numa_group	= NULL,
155 	.numa_faults	= NULL,
156 #endif
157 #ifdef CONFIG_KASAN
158 	.kasan_depth	= 1,
159 #endif
160 #ifdef CONFIG_TRACE_IRQFLAGS
161 	.softirqs_enabled = 1,
162 #endif
163 #ifdef CONFIG_LOCKDEP
164 	.lockdep_recursion = 0,
165 #endif
166 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
167 	.ret_stack	= NULL,
168 #endif
169 #if defined(CONFIG_TRACING) && defined(CONFIG_PREEMPT)
170 	.trace_recursion = 0,
171 #endif
172 #ifdef CONFIG_LIVEPATCH
173 	.patch_state	= KLP_UNDEFINED,
174 #endif
175 #ifdef CONFIG_SECURITY
176 	.security	= NULL,
177 #endif
178 };
179 EXPORT_SYMBOL(init_task);
180 
181 /*
182  * Initial thread structure. Alignment of this is handled by a special
183  * linker map entry.
184  */
185 #ifndef CONFIG_THREAD_INFO_IN_TASK
186 struct thread_info init_thread_info __init_thread_info = INIT_THREAD_INFO(init_task);
187 #endif
188