init_task
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init_task是kernel的第一个进程，0号进程，当kernel初始化完成后，它便化身为idle进程出现在我们的面前。
一init_thread_union
unionthread_union init_thread_union __init_task_data =
{ INIT_THREAD_INFO(init_task) };
#define INIT_THREAD_INFO(tsk) \
{ \
.task = &tsk, \\ 进程描述符init_task \
.exec_domain = &default_exec_domain,\\ Linux执行域 \
.flags = 0, \
.preempt_count =INIT_PREEMPT_COUNT, \
.addr_limit = KERNEL_DS,// 内核地址空间0-0xFFFFFFFF \
.restart_block = {//重新启动系统调用相关 \
.fn =do_no_restart_syscall, \
}, \
}
structthread_info { // 定义在kernel/arch/ar,64/include/asm/thread_info.h中
unsigned long flags; /* low level flags */
mm_segment_t addr_limit; /* address limit */
struct task_struct *task; /* main task structure */ // 进程描述符
struct exec_domain *exec_domain; /* execution domain */ //
执行域描述符
struct restart_block restart_block;
int preempt_count; /* 0 => preemptable, <0 => bug */
int cpu; /* cpu */
};
structexec_domain default_exec_domain = { // Linux执行域
.name ="Linux", /* name */
.handler = default_handler, /*lcall7 causes a seg fault. */
.pers_low = 0, /* PER_LINUX personality. */
.pers_high = 0, /* PER_LINUX personality. */
.signal_map = ident_map, /*Identity map signals. */
.signal_invmap = ident_map, /* - both ways. */
};
#define INIT_PREEMPT_COUNT (1 +PREEMPT_ACTIVE) // 定义在include/linux/sched.h中
#define PREEMPT_ACTIVE 0x40000000 // 定义在arch/arm64/include/asm/thread_info.h中
将preempt_count赋值为0x40000001是为了在scheduler还没初始化前暂时禁掉进程抢占
#define KERNEL_DS (-1UL) // 内核地址空间0-0xFFFFFFFF
二init_task
2.1 INIT_TASK(tsk)
structtask_struct init_task = INIT_TASK(init_task);
#define INIT_TASK(tsk) \
{ \
.state = 0, // 进程状态，0表示可运行状态，说明正在运行或正准备运行 \
.stack =&init_thread_info, //thread_info \
.usage =ATOMIC_INIT(2), //有2个进程正在使用该结构 \
.flags = PF_KTHREAD, //kernel进程 \
.prio = MAX_PRIO-20, // 优先级 \
.static_prio = MAX_PRIO-20, \
.normal_prio = MAX_PRIO-20, \
.policy = SCHED_NORMAL, // 采用SCHED_NORMAL调度策略 \
.cpus_allowed = CPU_MASK_ALL, // cpu亲和性 \
.nr_cpus_allowed= NR_CPUS, // 该进程可以在全部cpu上运行 \
.mm = NULL, \
.active_mm = &init_mm, // 见3.2 \
.se = { // 调度实体 \
.group_node =LIST_HEAD_INIT(tsk.se.group_node), \
}, \
.rt = { // 实时任务调度实体 \
.run_list =LIST_HEAD_INIT(tsk.rt.run_list), \
.time_slice =RR_TIMESLICE, \
}, \
.tasks =LIST_HEAD_INIT(tsk.tasks), // 任务队列 \
INIT_PUSHABLE_TASKS(tsk) // .pushable_tasks =PLIST_NODE_INIT(tsk.pushable_tasks, MAX_PRIO), \
INIT_CGROUP_SCHED(tsk) // .sched_task_group =&root_task_group, // 而root_task_group在sched_init中初始化 \
.ptraced =LIST_HEAD_INIT(tsk.ptraced), \
.ptrace_entry =LIST_HEAD_INIT(tsk.ptrace_entry), \
.real_parent = &tsk, // init_task进程的父进程是他自己 \
.parent = &tsk,//init_task进程的父进程是他自己 \
.children = LIST_HEAD_INIT(tsk.children),// 初始化子进程链表 \
.sibling = LIST_HEAD_INIT(tsk.sibling),// 初始化兄弟进程链表 \
.group_leader = &tsk, // init_task的线程链表指向它自己 \
RCU_POINTER_INITIALIZER(real_cred, &init_cred), //.p = (typeof(*v) __force __rcu *)(v) \
RCU_POINTER_INITIALIZER(cred, &init_cred), // rcu指针指向init_cred//init_cred见3.3 \
.comm = INIT_TASK_COMM, //#define INIT_TASK_COMM "swapper" // 进程名字为swapper \
.thread = INIT_THREAD, //#define INIT_THREAD { } \
.fs = &init_fs,// 见3.4 \
.files = &init_files,//见3.5 \
.signal =&init_signals, // 见3.6 \
.sighand = &init_sighand, // 见3.7 \
.nsproxy = &init_nsproxy, // 见3.8 \
.pending = { // 等待处理的signal列表 \
.list =LIST_HEAD_INIT(tsk.pending.list), \
.signal = {{0}}}, \
.blocked = {{0}}, // 被阻塞的信号集 \
.alloc_lock =__SPIN_LOCK_UNLOCKED(tsk.alloc_lock), // 自旋锁 \
.journal_info = NULL, \
.cpu_timers =INIT_CPU_TIMERS(tsk.cpu_timers), // cpu定时器 \
.pi_lock =__RAW_SPIN_LOCK_UNLOCKED(tsk.pi_lock), \
.timer_slack_ns = 50000, /* 50 usec default slack */// 设置select()和poll()的超时时间为50ms \
.pids = { // 见3.9 \
[PIDTYPE_PID] =INIT_PID_LINK(PIDTYPE_PID), \\ 进程pid \
[PIDTYPE_PGID] =INIT_PID_LINK(PIDTYPE_PGID), \\ 线程组领头线程pid \
[PIDTYPE_SID] =INIT_PID_LINK(PIDTYPE_SID), \
}, \
.thread_group =LIST_HEAD_INIT(tsk.thread_group), // init_task的线程链表 \
.thread_node =LIST_HEAD_INIT(init_signals.thread_head), \
INIT_IDS // loginuid, sessionid \
INIT_PERF_EVENTS(tsk) \\ Performance Event是一个的性能诊断工具 \
INIT_TRACE_IRQFLAGS \\ softirqs_enabled \
INIT_LOCKDEP \\ Linux死锁检测模块 \
INIT_FTRACE_GRAPH \\ ftrace跟踪器 \
INIT_TRACE_RECURSION \
INIT_TASK_RCU_PREEMPT(tsk) // RCU同步原语 \
INIT_TASK_RCU_TASKS(tsk) \
INIT_CPUSET_SEQ(tsk) \
INIT_RT_MUTEXES(tsk) \\ 基于PI协议的等待互斥锁，priorityinheritance（优先级继承） \
INIT_VTIME(tsk) \
INIT_KASAN(tsk) \\ Kasan 是 Kernel Address Sanitizer 的缩写,它是一个动态检测内存错误的工具,主要功能是检查内存越界访问和使用已释放的内存等问题。 \
}
#define init_thread_info (init_thread_union.thread_info)
#define init_stack (init_thread_union.stack)
三 init_task相关结构体
本节仅仅是摘录，并没有对结构体内容进行解释说明
3.1 task_struct
structtask_struct { // 定义在kernel/include/linux/sched.h
volatile long state; /* -1 unrunnable, 0runnable, >0 stopped */
void *stack;
atomic_t usage;
unsigned int flags; /* per process flags,defined below */
unsigned int ptrace;
#ifdefCONFIG_SMP
struct llist_node wake_entry;
int on_cpu;
struct task_struct *last_wakee;
unsigned long wakee_flips;
unsigned long wakee_flip_decay_ts;
int wake_cpu;
#endif
int on_rq;
int prio, static_prio, normal_prio;
unsigned int rt_priority;
const struct sched_class *sched_class;
struct sched_entity se;
struct sched_rt_entity rt;
#ifdefCONFIG_SCHED_HMP
struct ravg ravg;
/*
* 'init_load_pct' represents the initial taskload assigned to children
* of this task
*/
u32 init_load_pct;
u64 last_wake_ts;
u64 last_switch_out_ts;
#ifdefCONFIG_SCHED_QHMP
u64 run_start;
#endif
struct related_thread_group *grp;
struct list_head grp_list;
#endif
#ifdefCONFIG_CGROUP_SCHED
struct task_group *sched_task_group;
#endif
struct sched_dl_entity dl;
#ifdefCONFIG_PREEMPT_NOTIFIERS
/* list of struct preempt_notifier: */
struct hlist_head preempt_notifiers;
#endif
#ifdefCONFIG_BLK_DEV_IO_TRACE
unsigned int btrace_seq;
#endif
unsigned int policy;
int nr_cpus_allowed;
cpumask_t cpus_allowed;
#ifdefCONFIG_PREEMPT_RCU
int rcu_read_lock_nesting;
union rcu_special rcu_read_unlock_special;
struct list_head rcu_node_entry;
#endif/* #ifdef CONFIG_PREEMPT_RCU */
#ifdefCONFIG_TREE_PREEMPT_RCU
struct rcu_node *rcu_blocked_node;
#endif/* #ifdef CONFIG_TREE_PREEMPT_RCU */
#ifdefCONFIG_TASKS_RCU
unsigned long rcu_tasks_nvcsw;
bool rcu_tasks_holdout;
struct list_head rcu_tasks_holdout_list;
int rcu_tasks_idle_cpu;
#endif/* #ifdef CONFIG_TASKS_RCU */
#ifdefined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
struct sched_info sched_info;
#endif
struct list_head tasks;
#ifdefCONFIG_SMP
struct plist_node pushable_tasks;
struct rb_node pushable_dl_tasks;
#endif
struct mm_struct *mm, *active_mm;
#ifdefCONFIG_COMPAT_BRK
unsigned brk_randomized:1;
#endif
/* per-thread vma caching */
u32 vmacache_seqnum;
struct vm_area_struct *vmacache[VMACACHE_SIZE];
#ifdefined(SPLIT_RSS_COUNTING)
struct task_rss_stat rss_stat;
#endif
/* taskstate */
int exit_state;
int exit_code, exit_signal;
int pdeath_signal; /* The signal sent whenthe parent dies */
unsigned int jobctl; /* JOBCTL_*, siglockprotected */
/* Used for emulating ABI behavior of previous Linuxversions */
unsigned int personality;
unsigned in_execve:1; /* Tell the LSMsthat the process is doing an
*execve */
unsigned in_iowait:1;
/* Revert to default priority/policy when forking */
unsigned sched_reset_on_fork:1;
unsigned sched_contributes_to_load:1;
unsigned long atomic_flags; /* Flags needing atomicaccess. */
pid_t pid;
pid_t tgid;
#ifdefCONFIG_CC_STACKPROTECTOR
/* Canary value for the -fstack-protector gcc feature*/
unsigned long stack_canary;
#endif
/*
* pointers to (original) parent process,youngest child, younger sibling,
* older sibling, respectively. (p->father can be replaced with
* p->real_parent->pid)
*/
struct task_struct __rcu *real_parent; /* real parentprocess */
struct task_struct __rcu *parent; /* recipient ofSIGCHLD, wait4() reports */
/*
* children/sibling forms the list of my naturalchildren
*/
struct list_head children; /* list of mychildren */
struct list_head sibling; /* linkage inmy parent's children list */
struct task_struct *group_leader; /*threadgroup leader */
/*
* ptraced is the list of tasks this task isusing ptrace on.
* This includes both natural children andPTRACE_ATTACH targets.
* p->ptrace_entry is p's link on thep->parent->ptraced list.
*/
struct list_head ptraced;
struct list_head ptrace_entry;
/* PID/PID hash table linkage. */
struct pid_link pids[PIDTYPE_MAX];
struct list_head thread_group;
struct list_head thread_node;
struct completion *vfork_done; /* for vfork() */
int __user *set_child_tid; /* CLONE_CHILD_SETTID */
int __user *clear_child_tid; /* CLONE_CHILD_CLEARTID */
cputime_t utime, stime, utimescaled, stimescaled;
cputime_t gtime;
unsigned long long cpu_power;
#ifndefCONFIG_VIRT_CPU_ACCOUNTING_NATIVE
struct cputime prev_cputime;
#endif
#ifdefCONFIG_VIRT_CPU_ACCOUNTING_GEN
seqlock_t vtime_seqlock;
unsigned long long vtime_snap;
enum {
VTIME_SLEEPING = 0,
VTIME_USER,
VTIME_SYS,
} vtime_snap_whence;
#endif
unsigned long nvcsw, nivcsw; /* context switch counts*/
u64 start_time; /*monotonic time in nsec */
u64 real_start_time; /* boot based timein nsec */
/* mmfault and swap info: this can arguably be seen as either mm-specific orthread-specific */
unsigned long min_flt, maj_flt;
struct task_cputime cputime_expires;
struct list_head cpu_timers[3];
/*process credentials */
const struct cred __rcu *real_cred; /* objective andreal subjective task
* credentials (COW) */
const struct cred __rcu *cred; /*effective (overridable) subjective task
* credentials (COW) */
char comm[TASK_COMM_LEN]; /* executable name excludingpath
- access with [gs]et_task_comm (which lock
it with task_lock())
- initialized normally by setup_new_exec */
/* filesystem info */
int link_count, total_link_count;
#ifdefCONFIG_SYSVIPC
/* ipcstuff */
struct sysv_sem sysvsem;
struct sysv_shm sysvshm;
#endif
#ifdefCONFIG_DETECT_HUNG_TASK
/* hungtask detection */
unsigned long last_switch_count;
#endif
/*CPU-specific state of this task */
struct thread_struct thread;
/*filesystem information */
struct fs_struct *fs;
/* openfile information */
struct files_struct *files;
/*namespaces */
struct nsproxy *nsproxy;
/*signal handlers */
struct signal_struct *signal;
struct sighand_struct *sighand;
sigset_t blocked, real_blocked;
sigset_t saved_sigmask; /* restored ifset_restore_sigmask() was used */
struct sigpending pending;
unsigned long sas_ss_sp;
size_t sas_ss_size;
int (*notifier)(void *priv);
void *notifier_data;
sigset_t *notifier_mask;
struct callback_head *task_works;
struct audit_context *audit_context;
#ifdefCONFIG_AUDITSYSCALL
kuid_t loginuid;
unsigned int sessionid;
#endif
struct seccomp seccomp;
/*Thread group tracking */
u32 parent_exec_id;
u32 self_exec_id;
/*Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
* mempolicy */
spinlock_t alloc_lock;
/* Protection of the PI data structures: */
raw_spinlock_t pi_lock;
#ifdefCONFIG_RT_MUTEXES
/* PI waiters blocked on a rt_mutex held by this task*/
struct rb_root pi_waiters;
struct rb_node *pi_waiters_leftmost;
/* Deadlock detection and priority inheritancehandling */
struct rt_mutex_waiter *pi_blocked_on;
#endif
#ifdefCONFIG_DEBUG_MUTEXES
/* mutex deadlock detection */
struct mutex_waiter *blocked_on;
#endif
#ifdefCONFIG_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
#ifdefCONFIG_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];
gfp_t lockdep_reclaim_gfp;
#endif
/*journalling filesystem info */
void *journal_info;
/*stacked block device info */
struct bio_list *bio_list;
#ifdefCONFIG_BLOCK
/*stack plugging */
struct blk_plug *plug;
#endif
/* VMstate */
struct reclaim_state *reclaim_state;
struct backing_dev_info *backing_dev_info;
struct io_context *io_context;
unsigned long ptrace_message;
siginfo_t *last_siginfo; /* For ptrace use. */
struct task_io_accounting ioac;
#ifdefined(CONFIG_TASK_XACCT)
u64 acct_rss_mem1; /* accumulated rssusage */
u64 acct_vm_mem1; /* accumulated virtualmemory usage */
cputime_t acct_timexpd; /* stime + utimesince last update */
#endif
#ifdefCONFIG_CPUSETS
nodemask_t mems_allowed; /* Protected byalloc_lock */
seqcount_t mems_allowed_seq; /* Seqenceno to catch updates */
int cpuset_mem_spread_rotor;
int cpuset_slab_spread_rotor;
#endif
#ifdefCONFIG_CGROUPS
/* Control Group info protected by css_set_lock */
struct css_set __rcu *cgroups;
/* cg_list protected by css_set_lock andtsk->alloc_lock */
struct list_head cg_list;
#endif
#ifdefCONFIG_FUTEX
struct robust_list_head __user *robust_list;
#ifdefCONFIG_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
#ifdefCONFIG_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
#ifdefCONFIG_DEBUG_PREEMPT
unsigned long preempt_disable_ip;
#endif
#ifdefCONFIG_NUMA
struct mempolicy *mempolicy; /* Protectedby alloc_lock */
short il_next;
short pref_node_fork;
#endif
#ifdefCONFIG_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;
u64 node_stamp; /* migration stamp */
u64 last_task_numa_placement;
u64 last_sum_exec_runtime;
struct callback_head numa_work;
struct list_head numa_entry;
struct numa_group *numa_group;
/*
* Exponential decaying average of faults on aper-node basis.
* Scheduling placement decisions are made basedon the these counts.
* The values remain static for the duration of aPTE scan
*/
unsigned long *numa_faults_memory;
unsigned long total_numa_faults;
/*
* numa_faults_buffer records faults per nodeduring the current
* scan window. When the scan completes, thecounts in
* numa_faults_memory decay and these values arecopied.
*/
unsigned long *numa_faults_buffer_memory;
/*
* Track the nodes the process was running onwhen a NUMA hinting
* fault was incurred.
*/
unsigned long *numa_faults_cpu;
unsigned long *numa_faults_buffer_cpu;
/*
* numa_faults_locality tracks if faults recordedduring the last
* scan window were remote/local. The task scanperiod is adapted
* based on the locality of the faults withdifferent weights
* depending on whether they were shared orprivate faults
*/
unsigned long numa_faults_locality[2];
unsigned long numa_pages_migrated;
#endif/* CONFIG_NUMA_BALANCING */
struct rcu_head rcu;
/*
* cache last used pipe for splice
*/
struct pipe_inode_info *splice_pipe;
struct page_frag task_frag;
#ifdef CONFIG_TASK_DELAY_ACCT
struct task_delay_info *delays;
#endif
#ifdefCONFIG_FAULT_INJECTION
int make_it_fail;
#endif
/*
* when (nr_dirtied >= nr_dirtied_pause), it'stime to call
* balance_dirty_pages() for some dirtythrottling pause
*/
int nr_dirtied;
int nr_dirtied_pause;
unsigned long dirty_paused_when; /* start of awrite-and-pause period */
#ifdefCONFIG_LATENCYTOP
int latency_record_count;
struct latency_record latency_record[LT_SAVECOUNT];
#endif
/*
* time slack values; these are used to round uppoll() and
* select() etc timeout values. These are innanoseconds.
*/
unsigned long timer_slack_ns;
unsigned long default_timer_slack_ns;
#ifdefCONFIG_KASAN
unsigned int kasan_depth;
#endif
#ifdefCONFIG_FUNCTION_GRAPH_TRACER
/* Index of current stored address in ret_stack */
int curr_ret_stack;
/* Stack of return addresses for return functiontracing */
struct ftrace_ret_stack *ret_stack;
/* time stamp 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 for the tracing */
atomic_t tracing_graph_pause;
#endif
#ifdefCONFIG_TRACING
/* state flags for use by tracers */
unsigned long trace;
/* bitmask and counter of trace recursion */
unsigned long trace_recursion;
#endif/* CONFIG_TRACING */
#ifdefCONFIG_MEMCG /* memcg uses this to do batch job */
unsigned int memcg_kmem_skip_account;
struct memcg_oom_info {
struct mem_cgroup *memcg;
gfp_t gfp_mask;
int order;
unsigned int may_oom:1;
} memcg_oom;
#endif
#ifdefCONFIG_UPROBES
struct uprobe_task *utask;
#endif
#ifdefined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
unsigned int sequential_io;
unsigned int sequential_io_avg;
#endif
};
3.2init_mm
内存描述符
structmm_struct init_mm = {
.mm_rb = RB_ROOT,
.pgd = swapper_pg_dir,
.mm_users = ATOMIC_INIT(2),
.mm_count = ATOMIC_INIT(1),
.mmap_sem =__RWSEM_INITIALIZER(init_mm.mmap_sem),
.page_table_lock = __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock),
.mmlist =LIST_HEAD_INIT(init_mm.mmlist),
INIT_MM_CONTEXT(init_mm)
};
structmm_struct {
struct vm_area_struct *mmap; /* list of VMAs */
struct rb_root mm_rb;
u32 vmacache_seqnum; /* per-thread vmacache */
#ifdefCONFIG_MMU
unsigned long (*get_unmapped_area) (struct file *filp,
unsignedlong addr, unsigned long len,
unsignedlong pgoff, unsigned long flags);
#endif
unsigned long mmap_base; /*base of mmap area */
unsigned long mmap_legacy_base; /* base of mmap area in bottom-up allocations */
unsigned long task_size; /*size of task vm space */
unsigned long highest_vm_end; /* highest vma end address */
pgd_t * pgd;
atomic_t mm_users; /* How many users with user space? */
atomic_t mm_count; /* How many references to "struct mm_struct" (users count as1) */
atomic_long_t nr_ptes; /* Page table pages */
int map_count; /* number of VMAs */
spinlock_t page_table_lock; /* Protects page tables and some counters */
struct rw_semaphore mmap_sem;
struct list_head mmlist; /*List of maybe swapped mm's. These are globally strung
* together off init_mm.mmlist, and are protected
* by mmlist_lock
*/
unsigned long hiwater_rss; /*High-watermark of RSS usage */
unsigned long hiwater_vm; /* High-watervirtual memory usage */
unsigned long total_vm; /*Total pages mapped */
unsigned long locked_vm; /* Pages thathave PG_mlocked set */
unsigned long pinned_vm; /* Refcountpermanently increased */
unsigned long shared_vm; /* Shared pages(files) */
unsigned long exec_vm; /*VM_EXEC & ~VM_WRITE */
unsigned long stack_vm; /*VM_GROWSUP/DOWN */
unsigned long def_flags;
unsigned long start_code, end_code, start_data,end_data;
unsigned long start_brk, brk, start_stack;
unsigned long arg_start, arg_end, env_start, env_end;
unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for/proc/PID/auxv */
/*
* Special counters, in some configurationsprotected by the
* page_table_lock, in other configurations bybeing atomic.
*/
struct mm_rss_stat rss_stat;
struct linux_binfmt *binfmt;
cpumask_var_t cpu_vm_mask_var;
/* Architecture-specific MM context */
mm_context_t context;
unsigned long flags; /* Must use atomic bitops toaccess the bits */
struct core_state *core_state; /* coredumping support*/
#ifdefCONFIG_AIO
spinlock_t ioctx_lock;
struct kioctx_table __rcu *ioctx_table;
#endif
#ifdefCONFIG_MEMCG
/*
* "owner" points to a task that isregarded as the canonical
* user/owner of this mm. All of the followingmust be true in
* order for it to be changed:
*
* current == mm->owner
* current->mm != mm
* new_owner->mm == mm
* new_owner->alloc_lock is held
*/
struct task_struct __rcu *owner;
#endif
/* store ref to file /proc/
struct file *exe_file;
#ifdefCONFIG_MMU_NOTIFIER
struct mmu_notifier_mm *mmu_notifier_mm;
#endif
#ifdefined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
pgtable_t pmd_huge_pte; /* protected bypage_table_lock */
#endif
#ifdefCONFIG_CPUMASK_OFFSTACK
struct cpumask cpumask_allocation;
#endif
#ifdefCONFIG_NUMA_BALANCING
/*
* numa_next_scan is the next time that the PTEswill be marked
* pte_numa. NUMA hinting faults will gatherstatistics and migrate
* pages to new nodes if necessary.
*/
unsigned long numa_next_scan;
/* Restart point for scanning and setting pte_numa */
unsigned long numa_scan_offset;
/* numa_scan_seq prevents two threads setting pte_numa*/
int numa_scan_seq;
#endif
#ifdefined(CONFIG_NUMA_BALANCING) || defined(CONFIG_COMPACTION)
/*
* An operation with batched TLB flushing isgoing on. Anything that
* can move process memory needs to flush the TLBwhen moving a
* PROT_NONE or PROT_NUMA mapped page.
*/
bool tlb_flush_pending;
#endif
struct uprobes_state uprobes_state;
#ifdefCONFIG_MSM_APP_SETTINGS
int app_setting;
#endif
};
.3.3init_cred
structcred init_cred = {
.usage =ATOMIC_INIT(4),
#ifdefCONFIG_DEBUG_CREDENTIALS
.subscribers =ATOMIC_INIT(2),
.magic = CRED_MAGIC,
#endif
.uid =GLOBAL_ROOT_UID,
.gid =GLOBAL_ROOT_GID,
.suid =GLOBAL_ROOT_UID,
.sgid =GLOBAL_ROOT_GID,
.euid =GLOBAL_ROOT_UID,
.egid =GLOBAL_ROOT_GID,
.fsuid =GLOBAL_ROOT_UID,
.fsgid =GLOBAL_ROOT_GID,
.securebits = SECUREBITS_DEFAULT,
.cap_inheritable = CAP_EMPTY_SET,
.cap_permitted = CAP_FULL_SET,
.cap_effective = CAP_FULL_SET,
.cap_bset = CAP_FULL_SET,
.user =INIT_USER,
.user_ns =&init_user_ns,
.group_info = &init_groups,
};
3.4init_fs
structfs_struct init_fs = {
.users = 1,
.lock =__SPIN_LOCK_UNLOCKED(init_fs.lock),
.seq =SEQCNT_ZERO(init_fs.seq),
.umask = 0022,
};
3.5init_files
structfiles_struct init_files = {
.count = ATOMIC_INIT(1),
.fdt =&init_files.fdtab,
.fdtab = {
.max_fds = NR_OPEN_DEFAULT,
.fd =&init_files.fd_array[0],
.close_on_exec =init_files.close_on_exec_init,
.open_fds =init_files.open_fds_init,
},
.file_lock =__SPIN_LOCK_UNLOCKED(init_files.file_lock),
};
3.6init_signals
staticstruct signal_struct init_signals = INIT_SIGNALS(init_signals);
#define INIT_SIGNALS(sig) { \
.nr_threads = 1, \
.thread_head =LIST_HEAD_INIT(init_task.thread_node), \
.wait_chldexit =__WAIT_QUEUE_HEAD_INITIALIZER(sig.wait_chldexit),\
.shared_pending = { \
.list =LIST_HEAD_INIT(sig.shared_pending.list), \
.signal = {{0}}}, \
.posix_timers =LIST_HEAD_INIT(sig.posix_timers), \
.cpu_timers =INIT_CPU_TIMERS(sig.cpu_timers), \
.rlim = INIT_RLIMITS, \
.cputimer = { \
.cputime = INIT_CPUTIME, \
.running = 0, \
.lock =__RAW_SPIN_LOCK_UNLOCKED(sig.cputimer.lock), \
}, \
.cred_guard_mutex = \
__MUTEX_INITIALIZER(sig.cred_guard_mutex), \
INIT_GROUP_RWSEM(sig) \
}
3.7init_sighand
staticstruct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
#define INIT_SIGHAND(sighand) { \
.count =ATOMIC_INIT(1), \
.action = { { { .sa_handler= SIG_DFL, } }, }, \
.siglock =__SPIN_LOCK_UNLOCKED(sighand.siglock), \
.signalfd_wqh =__WAIT_QUEUE_HEAD_INITIALIZER(sighand.signalfd_wqh), \
}
3.8init_nsproxy
structnsproxy init_nsproxy = {
.count =ATOMIC_INIT(1),
.uts_ns =&init_uts_ns, // UTS命名空间包含了运行内核的名称、版本、底层体系结构类型等信息
#ifdefined(CONFIG_POSIX_MQUEUE) || defined(CONFIG_SYSVIPC) // 进程间通信IPC命名空间
.ipc_ns =&init_ipc_ns,
#endif
.mnt_ns =NULL, // 挂载命名空间
.pid_ns_for_children = &init_pid_ns,// PID命名空间
#ifdefCONFIG_NET
.net_ns =&init_net, // 网络命名空间
#endif
};
structuts_namespace init_uts_ns = {
.kref = {
.refcount = ATOMIC_INIT(2),
},
.name = {
.sysname = UTS_SYSNAME,
.nodename = UTS_NODENAME,
.release = UTS_RELEASE,
.version = UTS_VERSION,
.machine = UTS_MACHINE,
.domainname =UTS_DOMAINNAME,
},
.user_ns = &init_user_ns,
.proc_inum = PROC_UTS_INIT_INO,
};
structipc_namespace init_ipc_ns = {
.count = ATOMIC_INIT(1),
.user_ns = &init_user_ns,
.proc_inum = PROC_IPC_INIT_INO,
};
structpid_namespace init_pid_ns = {
.kref = {
.refcount =ATOMIC_INIT(2),
},
.pidmap = {
[ 0 ... PIDMAP_ENTRIES-1] = {ATOMIC_INIT(BITS_PER_PAGE), NULL }
},
.last_pid = 0,
.nr_hashed = PIDNS_HASH_ADDING,
.level = 0,
.child_reaper = &init_task,
.user_ns = &init_user_ns,
.proc_inum = PROC_PID_INIT_INO,
};
structnet init_net = {
.dev_base_head =LIST_HEAD_INIT(init_net.dev_base_head),
};
3.9INIT_PID_LINK
#define INIT_PID_LINK(type) \
{ \
.node = { \
.next = NULL, \
.pprev = NULL, \
}, \
.pid = &init_struct_pid, \
}
structpid init_struct_pid = INIT_STRUCT_PID;
#define INIT_STRUCT_PID { \
.count =ATOMIC_INIT(1), \
.tasks = { \
{ .first = NULL }, \
{ .first = NULL }, \
{ .first = NULL }, \
}, \
.level = 0, \
.numbers = { { \
.nr =0, \
.ns =&init_pid_ns, \
.pid_chain = { .next =NULL, .pprev = NULL }, \
}, } \
}
structpid_namespace init_pid_ns = {
.kref = {
.refcount =ATOMIC_INIT(2),
},
.pidmap = {
[ 0 ... PIDMAP_ENTRIES-1] = {ATOMIC_INIT(BITS_PER_PAGE), NULL }
},
.last_pid = 0,
.nr_hashed = PIDNS_HASH_ADDING,
.level = 0,
.child_reaper = &init_task,
.user_ns = &init_user_ns,
.proc_inum = PROC_PID_INIT_INO,
};
源文档 <http://blog.csdn.net/xichangbao/article/details/52859472>