linux内核分析之进程地址空间管理

1 struct thread_info {
2     struct task_struct    *task;        /* main task structure */
3     unsigned long        flags;
4     struct exec_domain    *exec_domain;    /* execution domain */
5     int            preempt_count;    /* 0 => preemptable, <0 => BUG */
6     __u32 cpu; /* should always be 0 on m68k */
7     struct restart_block    restart_block;
8 };

  1 struct task_struct {
  2     volatile long state;    /* -1 unrunnable, 0 runnable, >0 stopped */
  3     void *stack;
  4     atomic_t usage;
  5     unsigned int flags;    /* per process flags, defined below */
  6     unsigned int ptrace;
  7 
  8     int lock_depth;        /* BKL lock depth */
  9 
 10 #ifdef CONFIG_SMP
 11 #ifdef __ARCH_WANT_UNLOCKED_CTXSW
 12     int oncpu;
 13 #endif
 14 #endif
 15     int load_weight;    /* for niceness load balancing purposes */
 16     int prio, static_prio, normal_prio;
 17     struct list_head run_list;
 18     struct prio_array *array;
 19 
 20     unsigned short ioprio;
 21 #ifdef CONFIG_BLK_DEV_IO_TRACE
 22     unsigned int btrace_seq;
 23 #endif
 24     unsigned long sleep_avg;
 25     unsigned long long timestamp, last_ran;
 26     unsigned long long sched_time; /* sched_clock time spent running */
 27     enum sleep_type sleep_type;
 28 
 29     unsigned int policy;
 30     cpumask_t cpus_allowed;
 31     unsigned int time_slice, first_time_slice;
 32 
 33 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
 34     struct sched_info sched_info;
 35 #endif
 36 
 37     struct list_head tasks;
 38     /*
 39      * ptrace_list/ptrace_children forms the list of my children
 40      * that were stolen by a ptracer.
 41      */
 42     struct list_head ptrace_children;
 43     struct list_head ptrace_list;
 44 
 45     struct mm_struct *mm, *active_mm;
 46 
 47 /* task state */
 48     struct linux_binfmt *binfmt;
 49     int exit_state;
 50     int exit_code, exit_signal;
 51     int pdeath_signal;  /*  The signal sent when the parent dies  */
 52     /* ??? */
 53     unsigned int personality;
 54     unsigned did_exec:1;
 55     pid_t pid;
 56     pid_t tgid;
 57 
 58 #ifdef CONFIG_CC_STACKPROTECTOR
 59     /* Canary value for the -fstack-protector gcc feature */
 60     unsigned long stack_canary;
 61 #endif
 62     /* 
 63      * pointers to (original) parent process, youngest child, younger sibling,
 64      * older sibling, respectively.  (p->father can be replaced with 
 65      * p->parent->pid)
 66      */
 67     struct task_struct *real_parent; /* real parent process (when being debugged) */
 68     struct task_struct *parent;    /* parent process */
 69     /*
 70      * children/sibling forms the list of my children plus the
 71      * tasks I‘m ptracing.
 72      */
 73     struct list_head children;    /* list of my children */
 74     struct list_head sibling;    /* linkage in my parent‘s children list */
 75     struct task_struct *group_leader;    /* threadgroup leader */
 76 
 77     /* PID/PID hash table linkage. */
 78     struct pid_link pids[PIDTYPE_MAX];
 79     struct list_head thread_group;
 80 
 81     struct completion *vfork_done;        /* for vfork() */
 82     int __user *set_child_tid;        /* CLONE_CHILD_SETTID */
 83     int __user *clear_child_tid;        /* CLONE_CHILD_CLEARTID */
 84 
 85     unsigned int rt_priority;
 86     cputime_t utime, stime;
 87     unsigned long nvcsw, nivcsw; /* context switch counts */
 88     struct timespec start_time;
 89 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
 90     unsigned long min_flt, maj_flt;
 91 
 92       cputime_t it_prof_expires, it_virt_expires;
 93     unsigned long long it_sched_expires;
 94     struct list_head cpu_timers[3];
 95 
 96 /* process credentials */
 97     uid_t uid,euid,suid,fsuid;
 98     gid_t gid,egid,sgid,fsgid;
 99     struct group_info *group_info;
100     kernel_cap_t   cap_effective, cap_inheritable, cap_permitted;
101     unsigned keep_capabilities:1;
102     struct user_struct *user;
103 #ifdef CONFIG_KEYS
104     struct key *request_key_auth;    /* assumed request_key authority */
105     struct key *thread_keyring;    /* keyring private to this thread */
106     unsigned char jit_keyring;    /* default keyring to attach requested keys to */
107 #endif
108     /*
109      * fpu_counter contains the number of consecutive context switches
110      * that the FPU is used. If this is over a threshold, the lazy fpu
111      * saving becomes unlazy to save the trap. This is an unsigned char
112      * so that after 256 times the counter wraps and the behavior turns
113      * lazy again; this to deal with bursty apps that only use FPU for
114      * a short time
115      */
116     unsigned char fpu_counter;
117     int oomkilladj; /* OOM kill score adjustment (bit shift). */
118     char comm[TASK_COMM_LEN]; /* executable name excluding path
119                      - access with [gs]et_task_comm (which lock
120                        it with task_lock())
121                      - initialized normally by flush_old_exec */
122 /* file system info */
123     int link_count, total_link_count;
124 #ifdef CONFIG_SYSVIPC
125 /* ipc stuff */
126     struct sysv_sem sysvsem;
127 #endif
128 /* CPU-specific state of this task */
129     struct thread_struct thread;
130 /* filesystem information */
131     struct fs_struct *fs;
132 /* open file information */
133     struct files_struct *files;
134 /* namespaces */
135     struct nsproxy *nsproxy;
136 /* signal handlers */
137     struct signal_struct *signal;
138     struct sighand_struct *sighand;
139 
140     sigset_t blocked, real_blocked;
141     sigset_t saved_sigmask;        /* To be restored with TIF_RESTORE_SIGMASK */
142     struct sigpending pending;
143 
144     unsigned long sas_ss_sp;
145     size_t sas_ss_size;
146     int (*notifier)(void *priv);
147     void *notifier_data;
148     sigset_t *notifier_mask;
149     
150     void *security;
151     struct audit_context *audit_context;
152     seccomp_t seccomp;
153 
154 /* Thread group tracking */
155        u32 parent_exec_id;
156        u32 self_exec_id;
157 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings */
158     spinlock_t alloc_lock;
159 
160     /* Protection of the PI data structures: */
161     spinlock_t pi_lock;
162 
163 #ifdef CONFIG_RT_MUTEXES
164     /* PI waiters blocked on a rt_mutex held by this task */
165     struct plist_head pi_waiters;
166     /* Deadlock detection and priority inheritance handling */
167     struct rt_mutex_waiter *pi_blocked_on;
168 #endif
169 
170 #ifdef CONFIG_DEBUG_MUTEXES
171     /* mutex deadlock detection */
172     struct mutex_waiter *blocked_on;
173 #endif
174 #ifdef CONFIG_TRACE_IRQFLAGS
175     unsigned int irq_events;
176     int hardirqs_enabled;
177     unsigned long hardirq_enable_ip;
178     unsigned int hardirq_enable_event;
179     unsigned long hardirq_disable_ip;
180     unsigned int hardirq_disable_event;
181     int softirqs_enabled;
182     unsigned long softirq_disable_ip;
183     unsigned int softirq_disable_event;
184     unsigned long softirq_enable_ip;
185     unsigned int softirq_enable_event;
186     int hardirq_context;
187     int softirq_context;
188 #endif
189 #ifdef CONFIG_LOCKDEP
190 # define MAX_LOCK_DEPTH 30UL
191     u64 curr_chain_key;
192     int lockdep_depth;
193     struct held_lock held_locks[MAX_LOCK_DEPTH];
194     unsigned int lockdep_recursion;
195 #endif
196 
197 /* journalling filesystem info */
198     void *journal_info;
199 
200 /* stacked block device info */
201     struct bio *bio_list, **bio_tail;
202 
203 /* VM state */
204     struct reclaim_state *reclaim_state;
205 
206     struct backing_dev_info *backing_dev_info;
207 
208     struct io_context *io_context;
209 
210     unsigned long ptrace_message;
211     siginfo_t *last_siginfo; /* For ptrace use.  */
212 /*
213  * current io wait handle: wait queue entry to use for io waits
214  * If this thread is processing aio, this points at the waitqueue
215  * inside the currently handled kiocb. It may be NULL (i.e. default
216  * to a stack based synchronous wait) if its doing sync IO.
217  */
218     wait_queue_t *io_wait;
219 #ifdef CONFIG_TASK_XACCT
220 /* i/o counters(bytes read/written, #syscalls */
221     u64 rchar, wchar, syscr, syscw;
222 #endif
223     struct task_io_accounting ioac;
224 #if defined(CONFIG_TASK_XACCT)
225     u64 acct_rss_mem1;    /* accumulated rss usage */
226     u64 acct_vm_mem1;    /* accumulated virtual memory usage */
227     cputime_t acct_stimexpd;/* stime since last update */
228 #endif
229 #ifdef CONFIG_NUMA
230       struct mempolicy *mempolicy;
231     short il_next;
232 #endif
233 #ifdef CONFIG_CPUSETS
234     struct cpuset *cpuset;
235     nodemask_t mems_allowed;
236     int cpuset_mems_generation;
237     int cpuset_mem_spread_rotor;
238 #endif
239     struct robust_list_head __user *robust_list;
240 #ifdef CONFIG_COMPAT
241     struct compat_robust_list_head __user *compat_robust_list;
242 #endif
243     struct list_head pi_state_list;
244     struct futex_pi_state *pi_state_cache;
245 
246     atomic_t fs_excl;    /* holding fs exclusive resources */
247     struct rcu_head rcu;
248 
249     /*
250      * cache last used pipe for splice
251      */
252     struct pipe_inode_info *splice_pipe;
253 #ifdef    CONFIG_TASK_DELAY_ACCT
254     struct task_delay_info *delays;
255 #endif
256 #ifdef CONFIG_FAULT_INJECTION
257     int make_it_fail;
258 #endif
259 };

 1 struct mm_struct {
 2     struct vm_area_struct * mmap;        /* list of VMAs */
 3     struct rb_root mm_rb;
 4     struct vm_area_struct * mmap_cache;    /* last find_vma result */
 5     unsigned long (*get_unmapped_area) (struct file *filp,
 6                 unsigned long addr, unsigned long len,
 7                 unsigned long pgoff, unsigned long flags);
 8     void (*unmap_area) (struct mm_struct *mm, unsigned long addr);
 9     unsigned long mmap_base;        /* base of mmap area */
10     unsigned long task_size;        /* size of task vm space */
11     unsigned long cached_hole_size;         /* if non-zero, the largest hole below free_area_cache */
12     unsigned long free_area_cache;        /* first hole of size cached_hole_size or larger */
13     pgd_t * pgd;
14     atomic_t mm_users;            /* How many users with user space? */
15     atomic_t mm_count;            /* How many references to "struct mm_struct" (users count as 1) */
16     int map_count;                /* number of VMAs */
17     struct rw_semaphore mmap_sem;
18     spinlock_t page_table_lock;        /* Protects page tables and some counters */
19 
20     struct list_head mmlist;        /* List of maybe swapped mm‘s.  These are globally strung    //所有mm_struct形成的链表
21                          * together off init_mm.mmlist, and are protected
22                          * by mmlist_lock
23                          */
24 
25     /* Special counters, in some configurations protected by the
26      * page_table_lock, in other configurations by being atomic.
27      */
28     mm_counter_t _file_rss;　　　　　　　　　　　　　　　　　　　　　　
29     mm_counter_t _anon_rss;　　　　　　　　　　　　　　　　　　　　　　
30 
31     unsigned long hiwater_rss;    /* High-watermark of RSS usage */
32     unsigned long hiwater_vm;    /* High-water virtual memory usage */
33 
34     unsigned long total_vm, locked_vm, shared_vm, exec_vm;
35     unsigned long stack_vm, reserved_vm, def_flags, nr_ptes;
36     unsigned long start_code, end_code, start_data, end_data;   //进程代码段、数据段的开始结束地址
37     unsigned long start_brk, brk, start_stack;                  //进程堆的首地址、堆的尾地址、进程栈的首地址
38     unsigned long arg_start, arg_end, env_start, env_end;　　   //进程命令行参数的首地址、命令行参数的尾地址、环境变量的首地址、环境变量的尾地址
39 
40     unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */
41 
42     cpumask_t cpu_vm_mask;
43 
44     /* Architecture-specific MM context */
45     mm_context_t context;
46 
47     /* Swap token stuff */
48     /*
49      * Last value of global fault stamp as seen by this process.
50      * In other words, this value gives an indication of how long
51      * it has been since this task got the token.
52      * Look at mm/thrash.c
53      */
54     unsigned int faultstamp;
55     unsigned int token_priority;
56     unsigned int last_interval;
57 
58     unsigned char dumpable:2;
59 
60     /* coredumping support */
61     int core_waiters;
62     struct completion *core_startup_done, core_done;
63 
64     /* aio bits */
65     rwlock_t        ioctx_list_lock;
66     struct kioctx        *ioctx_list;
67 };