xref: /openbmc/linux/init/init_task.c (revision 4eb5928d)
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 #include <linux/scs.h>
15 
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 	.exec_update_mutex = __MUTEX_INITIALIZER(init_signals.exec_update_mutex),
30 #ifdef CONFIG_POSIX_TIMERS
31 	.posix_timers = LIST_HEAD_INIT(init_signals.posix_timers),
32 	.cputimer	= {
33 		.cputime_atomic	= INIT_CPUTIME_ATOMIC,
34 	},
35 #endif
36 	INIT_CPU_TIMERS(init_signals)
37 	.pids = {
38 		[PIDTYPE_PID]	= &init_struct_pid,
39 		[PIDTYPE_TGID]	= &init_struct_pid,
40 		[PIDTYPE_PGID]	= &init_struct_pid,
41 		[PIDTYPE_SID]	= &init_struct_pid,
42 	},
43 	INIT_PREV_CPUTIME(init_signals)
44 };
45 
46 static struct sighand_struct init_sighand = {
47 	.count		= REFCOUNT_INIT(1),
48 	.action		= { { { .sa_handler = SIG_DFL, } }, },
49 	.siglock	= __SPIN_LOCK_UNLOCKED(init_sighand.siglock),
50 	.signalfd_wqh	= __WAIT_QUEUE_HEAD_INITIALIZER(init_sighand.signalfd_wqh),
51 };
52 
53 #ifdef CONFIG_SHADOW_CALL_STACK
54 unsigned long init_shadow_call_stack[SCS_SIZE / sizeof(long)]
55 		__init_task_data = {
56 	[(SCS_SIZE / sizeof(long)) - 1] = SCS_END_MAGIC
57 };
58 #endif
59 
60 /*
61  * Set up the first task table, touch at your own risk!. Base=0,
62  * limit=0x1fffff (=2MB)
63  */
64 struct task_struct init_task
65 #ifdef CONFIG_ARCH_TASK_STRUCT_ON_STACK
66 	__init_task_data
67 #endif
68 	__aligned(L1_CACHE_BYTES)
69 = {
70 #ifdef CONFIG_THREAD_INFO_IN_TASK
71 	.thread_info	= INIT_THREAD_INFO(init_task),
72 	.stack_refcount	= REFCOUNT_INIT(1),
73 #endif
74 	.state		= 0,
75 	.stack		= init_stack,
76 	.usage		= REFCOUNT_INIT(2),
77 	.flags		= PF_KTHREAD,
78 	.prio		= MAX_PRIO - 20,
79 	.static_prio	= MAX_PRIO - 20,
80 	.normal_prio	= MAX_PRIO - 20,
81 	.policy		= SCHED_NORMAL,
82 	.cpus_ptr	= &init_task.cpus_mask,
83 	.cpus_mask	= CPU_MASK_ALL,
84 	.nr_cpus_allowed= NR_CPUS,
85 	.mm		= NULL,
86 	.active_mm	= &init_mm,
87 	.restart_block	= {
88 		.fn = do_no_restart_syscall,
89 	},
90 	.se		= {
91 		.group_node 	= LIST_HEAD_INIT(init_task.se.group_node),
92 	},
93 	.rt		= {
94 		.run_list	= LIST_HEAD_INIT(init_task.rt.run_list),
95 		.time_slice	= RR_TIMESLICE,
96 	},
97 	.tasks		= LIST_HEAD_INIT(init_task.tasks),
98 #ifdef CONFIG_SMP
99 	.pushable_tasks	= PLIST_NODE_INIT(init_task.pushable_tasks, MAX_PRIO),
100 #endif
101 #ifdef CONFIG_CGROUP_SCHED
102 	.sched_task_group = &root_task_group,
103 #endif
104 	.ptraced	= LIST_HEAD_INIT(init_task.ptraced),
105 	.ptrace_entry	= LIST_HEAD_INIT(init_task.ptrace_entry),
106 	.real_parent	= &init_task,
107 	.parent		= &init_task,
108 	.children	= LIST_HEAD_INIT(init_task.children),
109 	.sibling	= LIST_HEAD_INIT(init_task.sibling),
110 	.group_leader	= &init_task,
111 	RCU_POINTER_INITIALIZER(real_cred, &init_cred),
112 	RCU_POINTER_INITIALIZER(cred, &init_cred),
113 	.comm		= INIT_TASK_COMM,
114 	.thread		= INIT_THREAD,
115 	.fs		= &init_fs,
116 	.files		= &init_files,
117 	.signal		= &init_signals,
118 	.sighand	= &init_sighand,
119 	.nsproxy	= &init_nsproxy,
120 	.pending	= {
121 		.list = LIST_HEAD_INIT(init_task.pending.list),
122 		.signal = {{0}}
123 	},
124 	.blocked	= {{0}},
125 	.alloc_lock	= __SPIN_LOCK_UNLOCKED(init_task.alloc_lock),
126 	.journal_info	= NULL,
127 	INIT_CPU_TIMERS(init_task)
128 	.pi_lock	= __RAW_SPIN_LOCK_UNLOCKED(init_task.pi_lock),
129 	.timer_slack_ns = 50000, /* 50 usec default slack */
130 	.thread_pid	= &init_struct_pid,
131 	.thread_group	= LIST_HEAD_INIT(init_task.thread_group),
132 	.thread_node	= LIST_HEAD_INIT(init_signals.thread_head),
133 #ifdef CONFIG_AUDIT
134 	.loginuid	= INVALID_UID,
135 	.sessionid	= AUDIT_SID_UNSET,
136 #endif
137 #ifdef CONFIG_PERF_EVENTS
138 	.perf_event_mutex = __MUTEX_INITIALIZER(init_task.perf_event_mutex),
139 	.perf_event_list = LIST_HEAD_INIT(init_task.perf_event_list),
140 #endif
141 #ifdef CONFIG_PREEMPT_RCU
142 	.rcu_read_lock_nesting = 0,
143 	.rcu_read_unlock_special.s = 0,
144 	.rcu_node_entry = LIST_HEAD_INIT(init_task.rcu_node_entry),
145 	.rcu_blocked_node = NULL,
146 #endif
147 #ifdef CONFIG_TASKS_RCU
148 	.rcu_tasks_holdout = false,
149 	.rcu_tasks_holdout_list = LIST_HEAD_INIT(init_task.rcu_tasks_holdout_list),
150 	.rcu_tasks_idle_cpu = -1,
151 #endif
152 #ifdef CONFIG_TASKS_TRACE_RCU
153 	.trc_reader_nesting = 0,
154 	.trc_reader_special.s = 0,
155 	.trc_holdout_list = LIST_HEAD_INIT(init_task.trc_holdout_list),
156 #endif
157 #ifdef CONFIG_CPUSETS
158 	.mems_allowed_seq = SEQCNT_SPINLOCK_ZERO(init_task.mems_allowed_seq,
159 						 &init_task.alloc_lock),
160 #endif
161 #ifdef CONFIG_RT_MUTEXES
162 	.pi_waiters	= RB_ROOT_CACHED,
163 	.pi_top_task	= NULL,
164 #endif
165 	INIT_PREV_CPUTIME(init_task)
166 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
167 	.vtime.seqcount	= SEQCNT_ZERO(init_task.vtime_seqcount),
168 	.vtime.starttime = 0,
169 	.vtime.state	= VTIME_SYS,
170 #endif
171 #ifdef CONFIG_NUMA_BALANCING
172 	.numa_preferred_nid = NUMA_NO_NODE,
173 	.numa_group	= NULL,
174 	.numa_faults	= NULL,
175 #endif
176 #ifdef CONFIG_KASAN
177 	.kasan_depth	= 1,
178 #endif
179 #ifdef CONFIG_KCSAN
180 	.kcsan_ctx = {
181 		.disable_count		= 0,
182 		.atomic_next		= 0,
183 		.atomic_nest_count	= 0,
184 		.in_flat_atomic		= false,
185 		.access_mask		= 0,
186 		.scoped_accesses	= {LIST_POISON1, NULL},
187 	},
188 #endif
189 #ifdef CONFIG_TRACE_IRQFLAGS
190 	.softirqs_enabled = 1,
191 #endif
192 #ifdef CONFIG_LOCKDEP
193 	.lockdep_depth = 0, /* no locks held yet */
194 	.curr_chain_key = INITIAL_CHAIN_KEY,
195 	.lockdep_recursion = 0,
196 #endif
197 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
198 	.ret_stack	= NULL,
199 #endif
200 #if defined(CONFIG_TRACING) && defined(CONFIG_PREEMPTION)
201 	.trace_recursion = 0,
202 #endif
203 #ifdef CONFIG_LIVEPATCH
204 	.patch_state	= KLP_UNDEFINED,
205 #endif
206 #ifdef CONFIG_SECURITY
207 	.security	= NULL,
208 #endif
209 #ifdef CONFIG_SECCOMP
210 	.seccomp	= { .filter_count = ATOMIC_INIT(0) },
211 #endif
212 };
213 EXPORT_SYMBOL(init_task);
214 
215 /*
216  * Initial thread structure. Alignment of this is handled by a special
217  * linker map entry.
218  */
219 #ifndef CONFIG_THREAD_INFO_IN_TASK
220 struct thread_info init_thread_info __init_thread_info = INIT_THREAD_INFO(init_task);
221 #endif
222