xref: /openbmc/linux/init/init_task.c (revision f8e17c17)
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