xref: /linux/init/init_task.c (revision 7fc2cd2e4b398c57c9cf961cfea05eadbf34c05c)
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/sched/ext.h>
10 #include <linux/init.h>
11 #include <linux/fs.h>
12 #include <linux/mm.h>
13 #include <linux/audit.h>
14 #include <linux/numa.h>
15 #include <linux/scs.h>
16 #include <linux/plist.h>
17 
18 #include <linux/uaccess.h>
19 
20 static struct signal_struct init_signals = {
21 	.nr_threads	= 1,
22 	.thread_head	= LIST_HEAD_INIT(init_task.thread_node),
23 	.wait_chldexit	= __WAIT_QUEUE_HEAD_INITIALIZER(init_signals.wait_chldexit),
24 	.shared_pending	= {
25 		.list = LIST_HEAD_INIT(init_signals.shared_pending.list),
26 		.signal =  {{0}}
27 	},
28 	.multiprocess	= HLIST_HEAD_INIT,
29 	.rlim		= INIT_RLIMITS,
30 #ifdef CONFIG_CGROUPS
31 	.cgroup_threadgroup_rwsem	= __RWSEM_INITIALIZER(init_signals.cgroup_threadgroup_rwsem),
32 #endif
33 	.cred_guard_mutex = __MUTEX_INITIALIZER(init_signals.cred_guard_mutex),
34 	.exec_update_lock = __RWSEM_INITIALIZER(init_signals.exec_update_lock),
35 #ifdef CONFIG_POSIX_TIMERS
36 	.posix_timers		= HLIST_HEAD_INIT,
37 	.ignored_posix_timers	= HLIST_HEAD_INIT,
38 	.cputimer		= {
39 		.cputime_atomic	= INIT_CPUTIME_ATOMIC,
40 	},
41 #endif
42 	INIT_CPU_TIMERS(init_signals)
43 	.pids = {
44 		[PIDTYPE_PID]	= &init_struct_pid,
45 		[PIDTYPE_TGID]	= &init_struct_pid,
46 		[PIDTYPE_PGID]	= &init_struct_pid,
47 		[PIDTYPE_SID]	= &init_struct_pid,
48 	},
49 	INIT_PREV_CPUTIME(init_signals)
50 };
51 
52 static struct sighand_struct init_sighand = {
53 	.count		= REFCOUNT_INIT(1),
54 	.action		= { { { .sa_handler = SIG_DFL, } }, },
55 	.siglock	= __SPIN_LOCK_UNLOCKED(init_sighand.siglock),
56 	.signalfd_wqh	= __WAIT_QUEUE_HEAD_INITIALIZER(init_sighand.signalfd_wqh),
57 };
58 
59 #ifdef CONFIG_SHADOW_CALL_STACK
60 unsigned long init_shadow_call_stack[SCS_SIZE / sizeof(long)] = {
61 	[(SCS_SIZE / sizeof(long)) - 1] = SCS_END_MAGIC
62 };
63 #endif
64 
65 /* init to 2 - one for init_task, one to ensure it is never freed */
66 static struct group_info init_groups = { .usage = REFCOUNT_INIT(2) };
67 
68 /*
69  * The initial credentials for the initial task
70  */
71 static struct cred init_cred = {
72 	.usage			= ATOMIC_INIT(4),
73 	.uid			= GLOBAL_ROOT_UID,
74 	.gid			= GLOBAL_ROOT_GID,
75 	.suid			= GLOBAL_ROOT_UID,
76 	.sgid			= GLOBAL_ROOT_GID,
77 	.euid			= GLOBAL_ROOT_UID,
78 	.egid			= GLOBAL_ROOT_GID,
79 	.fsuid			= GLOBAL_ROOT_UID,
80 	.fsgid			= GLOBAL_ROOT_GID,
81 	.securebits		= SECUREBITS_DEFAULT,
82 	.cap_inheritable	= CAP_EMPTY_SET,
83 	.cap_permitted		= CAP_FULL_SET,
84 	.cap_effective		= CAP_FULL_SET,
85 	.cap_bset		= CAP_FULL_SET,
86 	.user			= INIT_USER,
87 	.user_ns		= &init_user_ns,
88 	.group_info		= &init_groups,
89 	.ucounts		= &init_ucounts,
90 };
91 
92 /*
93  * Set up the first task table, touch at your own risk!. Base=0,
94  * limit=0x1fffff (=2MB)
95  */
96 struct task_struct init_task __aligned(L1_CACHE_BYTES) = {
97 #ifdef CONFIG_THREAD_INFO_IN_TASK
98 	.thread_info	= INIT_THREAD_INFO(init_task),
99 	.stack_refcount	= REFCOUNT_INIT(1),
100 #endif
101 	.__state	= 0,
102 	.stack		= init_stack,
103 	.usage		= REFCOUNT_INIT(2),
104 	.flags		= PF_KTHREAD,
105 	.prio		= MAX_PRIO - 20,
106 	.static_prio	= MAX_PRIO - 20,
107 	.normal_prio	= MAX_PRIO - 20,
108 	.policy		= SCHED_NORMAL,
109 	.cpus_ptr	= &init_task.cpus_mask,
110 	.user_cpus_ptr	= NULL,
111 	.cpus_mask	= CPU_MASK_ALL,
112 	.max_allowed_capacity	= SCHED_CAPACITY_SCALE,
113 	.nr_cpus_allowed= NR_CPUS,
114 	.mm		= NULL,
115 	.active_mm	= &init_mm,
116 	.faults_disabled_mapping = NULL,
117 	.restart_block	= {
118 		.fn = do_no_restart_syscall,
119 	},
120 	.se		= {
121 		.group_node 	= LIST_HEAD_INIT(init_task.se.group_node),
122 	},
123 	.rt		= {
124 		.run_list	= LIST_HEAD_INIT(init_task.rt.run_list),
125 		.time_slice	= RR_TIMESLICE,
126 	},
127 	.tasks		= LIST_HEAD_INIT(init_task.tasks),
128 #ifdef CONFIG_SMP
129 	.pushable_tasks	= PLIST_NODE_INIT(init_task.pushable_tasks, MAX_PRIO),
130 #endif
131 #ifdef CONFIG_CGROUP_SCHED
132 	.sched_task_group = &root_task_group,
133 #endif
134 #ifdef CONFIG_SCHED_CLASS_EXT
135 	.scx		= {
136 		.dsq_list.node	= LIST_HEAD_INIT(init_task.scx.dsq_list.node),
137 		.sticky_cpu	= -1,
138 		.holding_cpu	= -1,
139 		.runnable_node	= LIST_HEAD_INIT(init_task.scx.runnable_node),
140 		.runnable_at	= INITIAL_JIFFIES,
141 		.ddsp_dsq_id	= SCX_DSQ_INVALID,
142 		.slice		= SCX_SLICE_DFL,
143 	},
144 #endif
145 	.ptraced	= LIST_HEAD_INIT(init_task.ptraced),
146 	.ptrace_entry	= LIST_HEAD_INIT(init_task.ptrace_entry),
147 	.real_parent	= &init_task,
148 	.parent		= &init_task,
149 	.children	= LIST_HEAD_INIT(init_task.children),
150 	.sibling	= LIST_HEAD_INIT(init_task.sibling),
151 	.group_leader	= &init_task,
152 	RCU_POINTER_INITIALIZER(real_cred, &init_cred),
153 	RCU_POINTER_INITIALIZER(cred, &init_cred),
154 	.comm		= INIT_TASK_COMM,
155 	.thread		= INIT_THREAD,
156 	.fs		= &init_fs,
157 	.files		= &init_files,
158 #ifdef CONFIG_IO_URING
159 	.io_uring	= NULL,
160 #endif
161 	.signal		= &init_signals,
162 	.sighand	= &init_sighand,
163 	.nsproxy	= &init_nsproxy,
164 	.pending	= {
165 		.list = LIST_HEAD_INIT(init_task.pending.list),
166 		.signal = {{0}}
167 	},
168 	.blocked	= {{0}},
169 	.alloc_lock	= __SPIN_LOCK_UNLOCKED(init_task.alloc_lock),
170 	.journal_info	= NULL,
171 	INIT_CPU_TIMERS(init_task)
172 	.pi_lock	= __RAW_SPIN_LOCK_UNLOCKED(init_task.pi_lock),
173 	.timer_slack_ns = 50000, /* 50 usec default slack */
174 	.thread_pid	= &init_struct_pid,
175 	.thread_node	= LIST_HEAD_INIT(init_signals.thread_head),
176 #ifdef CONFIG_AUDIT
177 	.loginuid	= INVALID_UID,
178 	.sessionid	= AUDIT_SID_UNSET,
179 #endif
180 #ifdef CONFIG_PERF_EVENTS
181 	.perf_event_mutex = __MUTEX_INITIALIZER(init_task.perf_event_mutex),
182 	.perf_event_list = LIST_HEAD_INIT(init_task.perf_event_list),
183 #endif
184 #ifdef CONFIG_PREEMPT_RCU
185 	.rcu_read_lock_nesting = 0,
186 	.rcu_read_unlock_special.s = 0,
187 	.rcu_node_entry = LIST_HEAD_INIT(init_task.rcu_node_entry),
188 	.rcu_blocked_node = NULL,
189 #endif
190 #ifdef CONFIG_TASKS_RCU
191 	.rcu_tasks_holdout = false,
192 	.rcu_tasks_holdout_list = LIST_HEAD_INIT(init_task.rcu_tasks_holdout_list),
193 	.rcu_tasks_idle_cpu = -1,
194 	.rcu_tasks_exit_list = LIST_HEAD_INIT(init_task.rcu_tasks_exit_list),
195 #endif
196 #ifdef CONFIG_TASKS_TRACE_RCU
197 	.trc_reader_nesting = 0,
198 	.trc_reader_special.s = 0,
199 	.trc_holdout_list = LIST_HEAD_INIT(init_task.trc_holdout_list),
200 	.trc_blkd_node = LIST_HEAD_INIT(init_task.trc_blkd_node),
201 #endif
202 #ifdef CONFIG_CPUSETS
203 	.mems_allowed_seq = SEQCNT_SPINLOCK_ZERO(init_task.mems_allowed_seq,
204 						 &init_task.alloc_lock),
205 #endif
206 #ifdef CONFIG_RT_MUTEXES
207 	.pi_waiters	= RB_ROOT_CACHED,
208 	.pi_top_task	= NULL,
209 #endif
210 	INIT_PREV_CPUTIME(init_task)
211 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
212 	.vtime.seqcount	= SEQCNT_ZERO(init_task.vtime_seqcount),
213 	.vtime.starttime = 0,
214 	.vtime.state	= VTIME_SYS,
215 #endif
216 #ifdef CONFIG_NUMA_BALANCING
217 	.numa_preferred_nid = NUMA_NO_NODE,
218 	.numa_group	= NULL,
219 	.numa_faults	= NULL,
220 #endif
221 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
222 	.kasan_depth	= 1,
223 #endif
224 #ifdef CONFIG_KCSAN
225 	.kcsan_ctx = {
226 		.scoped_accesses	= {LIST_POISON1, NULL},
227 	},
228 #endif
229 #ifdef CONFIG_TRACE_IRQFLAGS
230 	.softirqs_enabled = 1,
231 #endif
232 #ifdef CONFIG_LOCKDEP
233 	.lockdep_depth = 0, /* no locks held yet */
234 	.curr_chain_key = INITIAL_CHAIN_KEY,
235 	.lockdep_recursion = 0,
236 #endif
237 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
238 	.ret_stack		= NULL,
239 	.tracing_graph_pause	= ATOMIC_INIT(0),
240 #endif
241 #if defined(CONFIG_TRACING) && defined(CONFIG_PREEMPTION)
242 	.trace_recursion = 0,
243 #endif
244 #ifdef CONFIG_LIVEPATCH
245 	.patch_state	= KLP_TRANSITION_IDLE,
246 #endif
247 #ifdef CONFIG_SECURITY
248 	.security	= NULL,
249 #endif
250 #ifdef CONFIG_SECCOMP_FILTER
251 	.seccomp	= { .filter_count = ATOMIC_INIT(0) },
252 #endif
253 #ifdef CONFIG_SCHED_MM_CID
254 	.mm_cid		= { .cid = MM_CID_UNSET, },
255 #endif
256 };
257 EXPORT_SYMBOL(init_task);
258 
259 /*
260  * Initial thread structure. Alignment of this is handled by a special
261  * linker map entry.
262  */
263 #ifndef CONFIG_THREAD_INFO_IN_TASK
264 struct thread_info init_thread_info __init_thread_info = INIT_THREAD_INFO(init_task);
265 #endif
266