init_task.c

  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
 20static 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
 52static 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
 60unsigned 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 */
 66static struct group_info init_groups = { .usage = REFCOUNT_INIT(2) };
 67
 68/*
 69 * The initial credentials for the initial task
 70 */
 71static 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 */
 96struct 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};
257EXPORT_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
264struct thread_info init_thread_info __init_thread_info = INIT_THREAD_INFO(init_task);
265#endif