struct task_struct

struct task_struct{
#ifdef CONFIG_THREAD_INFO_IN_TASK
	/*
	 * For reasons of header soup (see current_thread_info()), this
	 * must be the first element of task_struct.
	 */
	struct thread_info		thread_info;
#endif
	/* -1 unrunnable不可运行, 0 runnable可运行, >0 stopped已经停止: */
	/* 进程状态TASK_RUNNING、TASK_INTERRUPTIBLE、TASK_UNINTERRUPTIBLE、TASK_STOPPED、TASK_TRACED */
	volatile long			state;

	/*
	 * This begins the randomizable portion of task_struct. Only
	 * scheduling-critical items should be added above here.
	 */
	randomized_struct_fields_start

	/* 进程内核栈。Linux内核通过thread_union联合体来表示进程的内核栈，其中THREAD_SIZE宏的大小为8192.通过
	alloc_thread_info函数分配它的内核栈，通过free_thread_info函数释放所分配的内核栈 */
	void				*stack;
	
	/*进程描述符的使用计数,被置为2时，表示进程描述符正在被使用而且其相应的进程处于活动状态 */
	atomic_t			usage;
	/
	/* Per task flags (PF_*), defined further below: */
	/* 进程标志。进程当前的标志状态，但不是运行状态，用于内核识别进程当前的状态，以备下一步操作PF_FORKNOEXEC、PF_SUPERPRIV、PF_DUMPCORE */
	unsigned int			flags;
	unsigned int			ptrace;

#ifdef CONFIG_SMP
	struct llist_node		wake_entry;
	/* 在SMP上帮助实现无加锁的进程切换 */
	int				on_cpu;
#ifdef CONFIG_THREAD_INFO_IN_TASK
	/* Current CPU: */
	unsigned int			cpu;
#endif
	unsigned int			wakee_flips;
	unsigned long			wakee_flip_decay_ts;
	struct task_struct		*last_wakee;

	/*
	 * recent_used_cpu is initially set as the last CPU used by a task
	 * that wakes affine another task. Waker/wakee relationships can
	 * push tasks around a CPU where each wakeup moves to the next one.
	 * Tracking a recently used CPU allows a quick search for a recently
	 * used CPU that may be idle.
	 */
	int				recent_used_cpu;
	int				wake_cpu;
#endif
	int				on_rq;

	/* 表示动态优先级，根据static_prio和交互性奖罚算出 */
	int				prio;
	/* 进程的静态优先级，在进程创建时确定，范围从-20到19，值越小，优先级越高 */
	int				static_prio;
	/* 该优先级取决于静态优先级和调度策略 */
	int				normal_prio;
	/* 用于保存实时优先级，范围是0到MAX_RT_PRIO-1(即99) */
	unsigned int			rt_priority;

	/* 调度类 */
	const struct sched_class	*sched_class;
	
	/* 普通进程的调用实体，每个进程都有其中之一的实体 */
	struct sched_entity		se;
	
	/* 实时进程的调用实体，每个进程都有其中之一的实体 */
	struct sched_rt_entity		rt;
#ifdef CONFIG_CGROUP_SCHED
	struct task_group		*sched_task_group;
#endif
	struct sched_dl_entity		dl;

#ifdef CONFIG_PREEMPT_NOTIFIERS
	/* List of struct preempt_notifier: */
	/* preempt_notifiers结构体链表 */
	struct hlist_head		preempt_notifiers;
#endif

#ifdef CONFIG_BLK_DEV_IO_TRACE
	/* blktrace是一个针对Linux内核中块设备IO层的跟踪工具   */
	unsigned int			btrace_seq;
#endif

	unsigned int			policy;
	int				nr_cpus_allowed;
	cpumask_t			cpus_allowed;

/* RCU同步原语 */
#ifdef CONFIG_PREEMPT_RCU
	int				rcu_read_lock_nesting;
	union rcu_special		rcu_read_unlock_special;
	struct list_head		rcu_node_entry;
	struct rcu_node			*rcu_blocked_node;
#endif /* #ifdef CONFIG_PREEMPT_RCU */

#ifdef CONFIG_TASKS_RCU
	unsigned long			rcu_tasks_nvcsw;
	u8				rcu_tasks_holdout;
	u8				rcu_tasks_idx;
	int				rcu_tasks_idle_cpu;
	struct list_head		rcu_tasks_holdout_list;
#endif /* #ifdef CONFIG_TASKS_RCU */

	/* 用于调度器统计进程的运行信息 */
	struct sched_info		sched_info;

	/* 用于构建进程链表 */
	struct list_head		tasks;
#ifdef CONFIG_SMP
	struct plist_node		pushable_tasks;
	struct rb_node			pushable_dl_tasks;
#endif

	/* 进程所拥有的用户空间内存描述符，内核线程无的mm为NULL */
	struct mm_struct		*mm;

	/* 指向进程运行时所使用的内存描述符，对于普通进程而言，这两个指针变量的值相同。但是内核线程kernel thread
	是没有进程地址空间的，所以内核线程的tsk->mm域是空NULL。但是内核必须知道用户空间包含了什么，因此它的active_mm
	成员被初始化为前一个运行进程的active_mm值*/
	struct mm_struct		*active_mm;

	/* Per-thread vma caching: */
	struct vmacache			vmacache;

#ifdef SPLIT_RSS_COUNTING
	struct task_rss_stat		rss_stat;
#endif
	int				exit_state;

	/* 用于设置进程的终止代号，这个值要么是_exit()或exit_group()系统调用参数(正常终止),要么是由内核提供的一个错误代号(异常终止) */
	int				exit_code;

	/* 被设置为-1时表示是某个线程组中的一员。只有当线程组的最后一个成员终止时，才会产生一个信号，以通知线程组的领头进程的父进程 */
	int				exit_signal;
	/* The signal sent when the parent dies: */
	int				pdeath_signal;
	/* JOBCTL_*, siglock protected: */
	unsigned long			jobctl;

	/* Used for emulating ABI behavior of previous Linux versions: */
	/* 用于处理不同的ABI，参见linux-man */
	unsigned int			personality;

	/* Scheduler bits, serialized by scheduler locks: */
	unsigned			sched_reset_on_fork:1;
	unsigned			sched_contributes_to_load:1;
	unsigned			sched_migrated:1;
	unsigned			sched_remote_wakeup:1;
	/* Force alignment to the next boundary: */
	unsigned			:0;

	/* Unserialized, strictly 'current' */

	/* Bit to tell LSMs we're in execve(): */
	/* 用于通知LSM是否被do_execve()函数所调用 */
	unsigned			in_execve:1;

	/* 用于判断是否进行iowait计数 */
	unsigned			in_iowait:1;
#ifndef TIF_RESTORE_SIGMASK
	unsigned			restore_sigmask:1;
#endif
#ifdef CONFIG_MEMCG
	unsigned			in_user_fault:1;
#ifdef CONFIG_MEMCG_KMEM
	unsigned			memcg_kmem_skip_account:1;
#endif
#endif
#ifdef CONFIG_COMPAT_BRK
	unsigned			brk_randomized:1;
#endif
#ifdef CONFIG_CGROUPS
	/* disallow userland-initiated cgroup migration */
	unsigned			no_cgroup_migration:1;
#endif
#ifdef CONFIG_BLK_CGROUP
	/* to be used once the psi infrastructure lands upstream. */
	unsigned			use_memdelay:1;
#endif

	unsigned long			atomic_flags; /* Flags requiring atomic access. */

	struct restart_block		restart_block;

	/* 进程标识符，相当于每一个学生的学号一样，标识符唯一标识进程 */
	pid_t				pid;
	
	/* P所在进程组的领头进程的PID */
	pid_t				tgid;

#ifdef CONFIG_STACKPROTECTOR
	/* Canary value for the -fstack-protector GCC feature: */
	/* 防止内核堆栈溢出 */
	unsigned long			stack_canary;
#endif
	/*
	 * Pointers to the (original) parent process, youngest child, younger sibling,
	 * older sibling, respectively.  (p->father can be replaced with
	 * p->real_parent->pid)
	 */

	/* Real parent process: */
	/* 指向创建了P的进程的描述符，如果P的父进程不再存在，就指向进程1(init)的描述符（因此，如果用户运行一个后台进程而且退出了shell，后台进程就会成为init的子进程 */
	struct task_struct __rcu	*real_parent;

	/* Recipient of SIGCHLD, wait4() reports: */
	/* 指向P的当前父进程（这种进程的子进程终止时，必须向父进程发信号）。它的值通常与real_parent一致，但偶尔也可以不同，例如，当另一个进程发出监控P的ptrace()系统调用请求 */
	struct task_struct __rcu	*parent;

	/*
	 * Children/sibling form the list of natural children:
	 */
	/* 链表的头部，链表中的所有元素都是P创建的子进程 */
	struct list_head		children;

	/* 指向兄弟进程链表中的下一个元素或前一个元素的指针，这些兄弟进程的父进程都是P */
	struct list_head		sibling;
	
	/* P所在进程组的领头进程的描述符指 */
	struct task_struct		*group_leader;
	/*
	 * 'ptraced' is the list of tasks this task is using ptrace() on.
	 *
	 * This includes both natural children and PTRACE_ATTACH targets.
	 * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
	 */
	/* ptrace系统调用。提供了一种父进程可以控制子进程运行并可检查和改变它的核心image。它主要用于实现断点调试。一个被
	跟踪的进程运行中，直到发生一个信号，则进程被中止，并且通知其父进程。在进程中止的状态下，进程的内存空间可以被读写。父进程还可以
	使子进程继续执行，并选择是否忽略引起中止的信号。成员ptrace被设置为0时表示不需要被跟踪 */
	struct list_head		ptraced;

	/* 指向所跟踪进程其实际父进程链表的前一个和下一个元素（用于P被跟踪的时候）*/
	struct list_head		ptrace_entry;

	/* PID/PID hash table linkage. */
	struct pid			*thread_pid;
	struct hlist_node		pid_links[PIDTYPE_MAX];

	/* 线程组中所有进程的链表 */
	struct list_head		thread_group;
	struct list_head		thread_node;

	/* 在执行do_fork()时，如果给定特别标志，则vfork_done会指向一个特殊地址 */
	struct completion		*vfork_done;

	/* CLONE_CHILD_SETTID: */
	/* 如果copy_process函数的clone_flags参数的值被置为CLONE_CHILD_SETTID或CLONE_CHILD_CLEARTID，则会把
	child_tidptr参数的值分别复制到set_child_tid和clear_child_tid成员。这些标志说明必须改变子进程用户态地址空间的
	child_tidptr所指向的变量的值*/
	int __user			*set_child_tid;

	/* CLONE_CHILD_CLEARTID: */
	int __user			*clear_child_tid;

	/* 用于记录进程在用户态下所经过的节拍数(定时器) */
	u64				utime;
	
	/* 用于记录进程在内核态下所经过的节拍数(定时器) */
	u64				stime;
	
#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
	/* 用于记录进程在用户态的运行时间，但它们以处理器的频率为刻度 */
	u64				utimescaled;

	/* 用于记录进程在内核态的运行时间，但它们以处理器的频率为刻度 */
	u64				stimescaled;
#endif

	/* 以节拍计数的虚拟机运行时间 */
	u64				gtime;

	/* 先前的运行时间 */
	struct prev_cputime		prev_cputime;
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
	struct vtime			vtime;
#endif

#ifdef CONFIG_NO_HZ_FULL
	atomic_t			tick_dep_mask;
#endif
	/* Context switch counts: */
	/* 自愿/非自愿上下文切换计数 */
	unsigned long			nvcsw;
	unsigned long			nivcsw;

	/* Monotonic time in nsecs: 进程创建时间 */
	u64				start_time;

	/* Boot based time in nsecs: 进程创建时间，还包含了进程睡眠时间 */
	u64				real_start_time;

	/* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
	/* 缺页统计 */
	unsigned long			min_flt;
	unsigned long			maj_flt;

#ifdef CONFIG_POSIX_TIMERS
	/* 用来统计进程或进程组被跟踪的处理器时间，其中的三个成员对应着cpu_timers[3]的三个链表 */
	struct task_cputime		cputime_expires;
	struct list_head		cpu_timers[3];
#endif

	/* Process credentials: */

	/* Tracer's credentials at attach: */
	const struct cred __rcu		*ptracer_cred;

	/* Objective and real subjective task credentials (COW): */
	const struct cred __rcu		*real_cred;

	/* Effective (overridable) subjective task credentials (COW): */
	const struct cred __rcu		*cred;

	/* 相应的程序名
	 * executable name, excluding path.
	 *
	 * - normally initialized setup_new_exec()
	 * - access it with [gs]et_task_comm()
	 * - lock it with task_lock()
	 */
	char				comm[TASK_COMM_LEN];

	struct nameidata		*nameidata;

#ifdef CONFIG_SYSVIPC
	struct sysv_sem			sysvsem;
	struct sysv_shm			sysvshm;
#endif
#ifdef CONFIG_DETECT_HUNG_TASK
	unsigned long			last_switch_count;
	unsigned long			last_switch_time;
#endif
	/* 用来表示进程与文件系统的联系，包括当前目录和根目录 Filesystem information: */
	struct fs_struct		*fs;

	/* 表示进程当前打开的文件 Open file information: */
	struct files_struct		*files;

	/* 命名空间 Namespaces: */
	struct nsproxy			*nsproxy;

	/* Signal handlers: */
	/* 指向进程的信号描述符的指针 */
	struct signal_struct		*signal;
	
	/* 指向进程的信号处理程序描述符的指针 */
	struct sighand_struct		*sighand;

	/* 被阻塞信号的掩码.也就是存放进程当前所屏蔽的信号 */
	sigset_t			blocked;

	/* 被阻塞信号的临时掩码(由rt_sigtimedwait()系统调用使用) */
	sigset_t			real_blocked;
	/* Restored if set_restore_sigmask() was used: */
	sigset_t			saved_sigmask;

	/* 存放私有挂起信号的数据结构 */
	struct sigpending		pending;

	/* 信号处理程序备用堆栈的地址 */
	unsigned long			sas_ss_sp;

	/* 信号处理程序备用堆栈的大小 */
	size_t				sas_ss_size;
	unsigned int			sas_ss_flags;

	struct callback_head		*task_works;

	struct audit_context		*audit_context;
#ifdef CONFIG_AUDITSYSCALL
	kuid_t				loginuid;
	unsigned int			sessionid;/*会话领头进程的PID*/
#endif
	struct seccomp			seccomp;

	/* Thread group tracking: */
	u32				parent_exec_id;
	u32				self_exec_id;

	/* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
	/* 用于保护资源分配和释放的自旋锁 */
	spinlock_t			alloc_lock;

	/* task_rq_lock函数所使用的锁 Protection of the PI data structures: */
	raw_spinlock_t			pi_lock;

	struct wake_q_node		wake_q;

/* 基于PI协议的等待互斥锁，其中PI指的是priority inheritance(优先级继承) */
#ifdef CONFIG_RT_MUTEXES
	/* PI waiters blocked on a rt_mutex held by this task: */
	struct rb_root_cached		pi_waiters;
	/* Updated under owner's pi_lock and rq lock */
	struct task_struct		*pi_top_task;
	/* Deadlock detection and priority inheritance handling: */
	struct rt_mutex_waiter		*pi_blocked_on;
#endif

#ifdef CONFIG_DEBUG_MUTEXES
	/* 死锁检测 Mutex deadlock detection: */
	struct mutex_waiter		*blocked_on;
#endif

/* 中断 */
#ifdef CONFIG_TRACE_IRQFLAGS
	unsigned int			irq_events;
	unsigned long			hardirq_enable_ip;
	unsigned long			hardirq_disable_ip;
	unsigned int			hardirq_enable_event;
	unsigned int			hardirq_disable_event;
	int				hardirqs_enabled;
	int				hardirq_context;
	unsigned long			softirq_disable_ip;
	unsigned long			softirq_enable_ip;
	unsigned int			softirq_disable_event;
	unsigned int			softirq_enable_event;
	int				softirqs_enabled;
	int				softirq_context;
#endif

#ifdef CONFIG_LOCKDEP
# define MAX_LOCK_DEPTH			48UL
	u64				curr_chain_key;
	int				lockdep_depth;
	unsigned int			lockdep_recursion;
	struct held_lock		held_locks[MAX_LOCK_DEPTH];
#endif

#ifdef CONFIG_UBSAN
	unsigned int			in_ubsan;
#endif

	/* ISF文件系统 Journalling filesystem info: */
	void				*journal_info;

	/* 块设备链表 Stacked block device info: */
	struct bio_list			*bio_list;

#ifdef CONFIG_BLOCK
	/* Stack plugging: */
	struct blk_plug			*plug;
#endif

	/* 内存回收 VM state: */
	struct reclaim_state		*reclaim_state;

	/* 存放块设备IO数据流量信息 */
	struct backing_dev_info		*backing_dev_info;

	/* IO调度器所使用的信息 */
	struct io_context		*io_context;

	/* Ptrace state: */
	unsigned long			ptrace_message;
	siginfo_t			*last_siginfo;

	struct task_io_accounting	ioac;
#ifdef CONFIG_TASK_XACCT
	/* Accumulated RSS usage: */
	u64				acct_rss_mem1;
	/* Accumulated virtual memory usage: */
	u64				acct_vm_mem1;
	/* stime + utime since last update: */
	u64				acct_timexpd;
#endif

/* CPUSET功能 */
#ifdef CONFIG_CPUSETS
	/* Protected by ->alloc_lock: */
	nodemask_t			mems_allowed;
	/* Seqence number to catch updates: */
	seqcount_t			mems_allowed_seq;
	int				cpuset_mem_spread_rotor;
	int				cpuset_slab_spread_rotor;
#endif
#ifdef CONFIG_CGROUPS
	/* Control Group info protected by css_set_lock: */
	struct css_set __rcu		*cgroups;
	/* cg_list protected by css_set_lock and tsk->alloc_lock: */
	struct list_head		cg_list;
#endif
#ifdef CONFIG_INTEL_RDT
	u32				closid;
	u32				rmid;
#endif

/* FUTEX同步机制 */
#ifdef CONFIG_FUTEX
	struct robust_list_head __user	*robust_list;
#ifdef CONFIG_COMPAT
	struct compat_robust_list_head __user *compat_robust_list;
#endif
	struct list_head		pi_state_list;
	struct futex_pi_state		*pi_state_cache;
#endif
#ifdef CONFIG_PERF_EVENTS
	struct perf_event_context	*perf_event_ctxp[perf_nr_task_contexts];
	struct mutex			perf_event_mutex;
	struct list_head		perf_event_list;
#endif
#ifdef CONFIG_DEBUG_PREEMPT
	unsigned long			preempt_disable_ip;
#endif

/* 非一致内存访问Non-Uniform Memory Access */
#ifdef CONFIG_NUMA
	/* Protected by alloc_lock: */
	struct mempolicy		*mempolicy;
	short				il_prev;
	short				pref_node_fork;
#endif

#ifdef CONFIG_NUMA_BALANCING
	int				numa_scan_seq;
	unsigned int			numa_scan_period;
	unsigned int			numa_scan_period_max;
	int				numa_preferred_nid;
	unsigned long			numa_migrate_retry;
	/* Migration stamp: */
	u64				node_stamp;
	u64				last_task_numa_placement;
	u64				last_sum_exec_runtime;
	struct callback_head		numa_work;

	struct numa_group		*numa_group;

	/*
	 * numa_faults is an array split into four regions:
	 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
	 * in this precise order.
	 *
	 * faults_memory: Exponential decaying average of faults on a per-node
	 * basis. Scheduling placement decisions are made based on these
	 * counts. The values remain static for the duration of a PTE scan.
	 * faults_cpu: Track the nodes the process was running on when a NUMA
	 * hinting fault was incurred.
	 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
	 * during the current scan window. When the scan completes, the counts
	 * in faults_memory and faults_cpu decay and these values are copied.
	 */
	unsigned long			*numa_faults;
	unsigned long			total_numa_faults;

	/*
	 * numa_faults_locality tracks if faults recorded during the last
	 * scan window were remote/local or failed to migrate. The task scan
	 * period is adapted based on the locality of the faults with different
	 * weights depending on whether they were shared or private faults
	 */
	unsigned long			numa_faults_locality[3];

	unsigned long			numa_pages_migrated;
#endif /* CONFIG_NUMA_BALANCING */

#ifdef CONFIG_RSEQ
	struct rseq __user *rseq;
	u32 rseq_len;
	u32 rseq_sig;
	/*
	 * RmW on rseq_event_mask must be performed atomically
	 * with respect to preemption.
	 */
	unsigned long rseq_event_mask;
#endif

	struct tlbflush_unmap_batch	tlb_ubc;

	/* RCU链表 */
	struct rcu_head			rcu;

	/* 管道Cache last used pipe for splice(): */
	struct pipe_inode_info		*splice_pipe;

	struct page_frag		task_frag;

#ifdef CONFIG_TASK_DELAY_ACCT
	/* 延迟计数 */
	struct task_delay_info		*delays;
#endif

#ifdef CONFIG_FAULT_INJECTION
	int				make_it_fail;
	unsigned int			fail_nth;
#endif
	/*
	 * When (nr_dirtied >= nr_dirtied_pause), it's time to call
	 * balance_dirty_pages() for a dirty throttling pause:
	 */
	int				nr_dirtied;
	int				nr_dirtied_pause;
	/* Start of a write-and-pause period: */
	unsigned long			dirty_paused_when;

#ifdef CONFIG_LATENCYTOP
	int				latency_record_count;
	struct latency_record		latency_record[LT_SAVECOUNT];
#endif
	/*
	 * Time slack values; these are used to round up poll() and
	 * select() etc timeout values. These are in nanoseconds.
	 */
	u64				timer_slack_ns;
	u64				default_timer_slack_ns;

#ifdef CONFIG_KASAN
	unsigned int			kasan_depth;
#endif

#ifdef CONFIG_FUNCTION_GRAPH_TRACER
	/* Index of current stored address in ret_stack: */
	int				curr_ret_stack;

	/* Stack of return addresses for return function tracing: */
	struct ftrace_ret_stack		*ret_stack;

	/* Timestamp for last schedule: */
	unsigned long long		ftrace_timestamp;

	/*
	 * Number of functions that haven't been traced
	 * because of depth overrun:
	 */
	atomic_t			trace_overrun;

	/* Pause tracing: */
	atomic_t			tracing_graph_pause;
#endif

#ifdef CONFIG_TRACING
	/* State flags for use by tracers: */
	unsigned long			trace;

	/* Bitmask and counter of trace recursion: */
	unsigned long			trace_recursion;
#endif /* CONFIG_TRACING */

#ifdef CONFIG_KCOV
	/* Coverage collection mode enabled for this task (0 if disabled): */
	unsigned int			kcov_mode;

	/* Size of the kcov_area: */
	unsigned int			kcov_size;

	/* Buffer for coverage collection: */
	void				*kcov_area;

	/* KCOV descriptor wired with this task or NULL: */
	struct kcov			*kcov;
#endif

#ifdef CONFIG_MEMCG
	struct mem_cgroup		*memcg_in_oom;
	gfp_t				memcg_oom_gfp_mask;
	int				memcg_oom_order;

	/* Number of pages to reclaim on returning to userland: */
	unsigned int			memcg_nr_pages_over_high;

	/* Used by memcontrol for targeted memcg charge: */
	struct mem_cgroup		*active_memcg;
#endif

#ifdef CONFIG_BLK_CGROUP
	struct request_queue		*throttle_queue;
#endif

#ifdef CONFIG_UPROBES
	struct uprobe_task		*utask;
#endif
#if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
	unsigned int			sequential_io;
	unsigned int			sequential_io_avg;
#endif
#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
	unsigned long			task_state_change;
#endif
	int				pagefault_disabled;
#ifdef CONFIG_MMU
	struct task_struct		*oom_reaper_list;
#endif
#ifdef CONFIG_VMAP_STACK
	struct vm_struct		*stack_vm_area;
#endif
#ifdef CONFIG_THREAD_INFO_IN_TASK
	/* A live task holds one reference: */
	atomic_t			stack_refcount;
#endif
#ifdef CONFIG_LIVEPATCH
	int patch_state;
#endif
#ifdef CONFIG_SECURITY
	/* Used by LSM modules for access restriction: */
	void				*security;
#endif

	/*
	 * New fields for task_struct should be added above here, so that
	 * they are included in the randomized portion of task_struct.
	 */
	randomized_struct_fields_end

	/* CPU-specific state of this task: */
	struct thread_struct		thread;

	/*
	 * WARNING: on x86, 'thread_struct' contains a variable-sized
	 * structure.  It *MUST* be at the end of 'task_struct'.
	 *
	 * Do not put anything below here!
	 */
}